Statistical Analysis of Helicopter Pilot Performance during Instrument Flight Across Repeated Flights.

DTIC Science & Technology

1983-09-15

there is obvious dif- ficulty in intepreting these results. In the absence of degradation in system performance, it would be difficult to argue that...standard deviation during instru- 2 .441 ment take-off 3 -.218 4 .596 5 .831 6 -.916 0 44 0~i FILMED 3-85 DTIC

Global positioning system measurements for crustal deformation: Precision and accuracy

USGS Publications Warehouse

Prescott, W.H.; Davis, J.L.; Svarc, J.L.

1989-01-01

Analysis of 27 repeated observations of Global Positioning System (GPS) position-difference vectors, up to 11 kilometers in length, indicates that the standard deviation of the measurements is 4 millimeters for the north component, 6 millimeters for the east component, and 10 to 20 millimeters for the vertical component. The uncertainty grows slowly with increasing vector length. At 225 kilometers, the standard deviation of the measurement is 6, 11, and 40 millimeters for the north, east, and up components, respectively. Measurements with GPS and Geodolite, an electromagnetic distance-measuring system, over distances of 10 to 40 kilometers agree within 0.2 part per million. Measurements with GPS and very long baseline interferometry of the 225-kilometer vector agree within 0.05 part per million.

Cruise Summary of WHP P6, A10, I3 and I4 Revisits in 2003

NASA Astrophysics Data System (ADS)

Kawano, T.; Uchida, H.; Schneider, W.; Kumamoto, Y.; Nishina, A.; Aoyama, M.; Murata, A.; Sasaki, K.; Yoshikawa, Y.; Watanabe, S.; Fukasawa, M.

2004-12-01

Japan Agency for Marin-Earth Science and Technology (JAMSTEC) conducted a research cruise to round in the southern hemisphere by R/V Mirai. In this presentation, we introduce an outline of the cruise and data quality obtained during the cruise. The cruise started on Aug. 3, 2003 in Brisbane, Australia and sailed eastward until it reached Fremantle, Australia on Feb. 19, 2004. It contained six legs and legs 1, 2, 4 and 5 were revisits of WOCE Hydrographic Program (WHP) sections P6W, P6E, A10 and I3/I4, respectively. The sections consisted of about 500 hydrographic stations in total. On each station, CTD profiles and up to 36 water samples by 12L Niskin-X bottles were taken from the surface to within 10 m of the bottom. Water samples were analyzed at every station for salinity, dissolved oxygen (DO), and nutrients and at alternate stations for concentration of freons, dissolved inorganic carbon (CT), total alkalinity (AT), pH, and so on. Approximately 17,000 samples were obtained for salinity. The standard seawater was measured repeatedly to estimate the uncertainty caused by the setting and stability of the salinometer. The standard deviation of 699 repeated runs of standard seawater was 0.0002 in salinity. Replicate samples, which are a pair of samples drawn from the same Niskin bottle to different sample bottles, were taken to evaluate the overall uncertainty. The standard deviation of absolute differences of 2,769 replicates was also 0.0002 in salinity. For DO, about 13,400 samples were obtained. The analysis was made by a photometric titration technique. The reproducibility estimated from the absolute standard deviation of 1,625 replicates was about 0.09 umol/kg. CTD temperature was calibrated against a deep ocean standards thermometer (SBE35) which was attached to the CTD using a polynomial expression Tcal = T - (a +b*P + c*t), where Tcal is calibrated temperature, T is CTD temperature, P is CTD pressure and t is time. Calibration coefficients, a, b and c, were determined for each station by minimizing the sum of absolute deviation from SBE35 temperature below 2,000dbar. CTD salinity and DO were fitted to values obtained by sampled water analysis using similar polynomials. These corrections yielded deviations of about 0.0002 K in temperature, 0.0003 in salinity and 0.6 umol/kg in DO. Nutrients analyses were accomplished on 16,000 samples using the reference material of nutrients in seawater (RMNS). To establish the traceability and to get higher quality data, 500 bottles of RMNS from the same lot and 150 sets of RMNSs were used. The precisions of phosphate, nitrate and silicate measurements were 0.18 %, 0.17 % and 0.16 % in terms of median of those at 493 stations, respectively. The nutrients concentrations could be expressed with uncertainties explicitly because of the repeated runs of RMNSs. All the analyses for the CO{2}-system parameters in water columns were finished onboard. Analytical precisions of CT, AT and pH were estimated to be \\sim1.0 umol/kg, \\sim2.0 umol/kg, and \\sim7*10-4 pH unit, respectively. Approximately 6,300 samples were obtained for CFC-11 and CFC-12. The concentrations were determined with an electron capture detector - gas chromatograph (ECD-GC) attached the purge and trapping system. The reproducibility estimated from the absolute standard deviation of 365 replicates was less than 1% with respect to the surface concentrations.

Design and preliminary assessment of Vanderbilt hand exoskeleton.

PubMed

Gasser, Benjamin W; Bennett, Daniel A; Durrough, Christina M; Goldfarb, Michael

2017-07-01

This paper presents the design of a hand exoskeleton intended to enable or facilitate bimanual activities of daily living (ADLs) for individuals with chronic upper extremity hemiparesis resulting from stroke. The paper describes design of the battery-powered, self-contained exoskeleton and presents the results of initial testing with a single subject with hemiparesis from stroke. Specifically, an experiment was conducted requiring the subject to repeatedly remove the lid from a water bottle both with and without the hand exoskeleton. The relative times required to remove the lid from the bottles was considerably lower when using the exoskeleton. Specifically, the average amount of time required to grasp the bottle with the paretic hand without the exoskeleton was 25.9 s, with a standard deviation of 33.5 s, while the corresponding average amount of time required to grasp the bottle with the exoskeleton was 5.1 s, with a standard deviation of 1.9 s. Thus, the task time involving the paretic hand was reduced by a factor of five, while the standard deviation was reduced by a factor of 16.

Suitability of open-field autorefractors as pupillometers and instrument design effects.

PubMed

Otero, Carles; Aldaba, Mikel; Ferrer, Oriol; Gascón, Andrea; Ondategui-Parra, Juan C; Pujol, Jaume

2017-01-01

To determine the agreement and repeatability of the pupil measurement obtained with VIP-200 (Neuroptics), PowerRef II (Plusoptix), WAM-5500 (Grand Seiko) and study the effects of instrument design on pupillometry. Forty patients were measured twice in low, mid and high mesopic. Repeatability was analyzed with the within-subject standard deviation (Sw) and paired t -tests. Agreement was studied with Bland-Altman plots and repeated measures ANOVA. Instrument design analysis consisted on measuring pupil size with PowerRef II simulating monocular and binocular conditions as well as with proximity cues and without proximity cues. The mean difference (±standard deviation) between test-retest for low, mid and high mesopic conditions were, respectively: -0.09 (±0.16), -0.05 (±0.18) and -0.08 (±0.23) mm for Neuroptics, -0.05 (±0.17), -0.12 (±0.23) and -0.17 (±0.34) mm for WAM-5500, -0.04 (±0.27), -0.13 (±0.37) and -0.11 (±0.28) mm for PowerRef II. Regarding agreement with Neuroptics, the mean difference for low, mid and high mesopic conditions were, respectively: -0.48 (±0.35), -0.83 (±0.52) and -0.38 (±0.56) mm for WAM-5500, -0.28 (±0.56), -0.70 (±0.55) and -0.61 (±0.54) mm for PowerRef II. The mean difference of binocular minus monocular pupil measurements was: -0.83 (±0.87) mm; and with proximity cues minus without proximity cues was: -0.30 (±0.77) mm. All the instruments show similar repeat-ability. In all illumination conditions, agreement of Neuroptics with WAM-5500 and PowerRef II is not good enough, which can be partially induced due to their open field design.

30 CFR 7.86 - Test equipment and specifications.

Code of Federal Regulations, 2013 CFR

2013-07-01

...). (v) Be sampled at the same time by a pair of filters in series (one primary and one backup filter) so... feet (0.5 meters) or 3 times the diameter of the exhaust pipe, whichever is the larger, from the.... (ii) The repeatability, defined as 2.5 times the standard deviation of 10 repetitive responses to a...

30 CFR 7.86 - Test equipment and specifications.

Code of Federal Regulations, 2011 CFR

2011-07-01

...). (v) Be sampled at the same time by a pair of filters in series (one primary and one backup filter) so... feet (0.5 meters) or 3 times the diameter of the exhaust pipe, whichever is the larger, from the.... (ii) The repeatability, defined as 2.5 times the standard deviation of 10 repetitive responses to a...

30 CFR 7.86 - Test equipment and specifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

...). (v) Be sampled at the same time by a pair of filters in series (one primary and one backup filter) so... feet (0.5 meters) or 3 times the diameter of the exhaust pipe, whichever is the larger, from the.... (ii) The repeatability, defined as 2.5 times the standard deviation of 10 repetitive responses to a...

Single-Station Sigma for the Iranian Strong Motion Stations

NASA Astrophysics Data System (ADS)

Zafarani, H.; Soghrat, M. R.

2017-11-01

In development of ground motion prediction equations (GMPEs), the residuals are assumed to have a log-normal distribution with a zero mean and a standard deviation, designated as sigma. Sigma has significant effect on evaluation of seismic hazard for designing important infrastructures such as nuclear power plants and dams. Both aleatory and epistemic uncertainties are involved in the sigma parameter. However, ground-motion observations over long time periods are not available at specific sites and the GMPEs have been derived using observed data from multiple sites for a small number of well-recorded earthquakes. Therefore, sigma is dominantly related to the statistics of the spatial variability of ground motion instead of temporal variability at a single point (ergodic assumption). The main purpose of this study is to reduce the variability of the residuals so as to handle it as epistemic uncertainty. In this regard, it is tried to partially apply the non-ergodic assumption by removing repeatable site effects from total variability of six GMPEs driven from the local, Europe-Middle East and worldwide data. For this purpose, we used 1837 acceleration time histories from 374 shallow earthquakes with moment magnitudes ranging from M w 4.0 to 7.3 recorded at 370 stations with at least two recordings per station. According to estimated single-station sigma for the Iranian strong motion stations, the ratio of event-corrected single-station standard deviation ( Φ ss) to within-event standard deviation ( Φ) is about 0.75. In other words, removing the ergodic assumption on site response resulted in 25% reduction of the within-event standard deviation that reduced the total standard deviation by about 15%.

Dosimetry audits and intercomparisons in radiotherapy: A Malaysian profile

NASA Astrophysics Data System (ADS)

M. Noor, Noramaliza; Nisbet, A.; Hussein, M.; Chu S, Sarene; Kadni, T.; Abdullah, N.; Bradley, D. A.

2017-11-01

Quality audits and intercomparisons are important in ensuring control of processes in any system of endeavour. Present interest is in control of dosimetry in teletherapy, there being a need to assess the extent to which there is consistent radiation dose delivery to the patient. In this study we review significant factors that impact upon radiotherapy dosimetry, focusing upon the example situation of radiotherapy delivery in Malaysia, examining existing literature in support of such efforts. A number of recommendations are made to provide for increased quality assurance and control. In addition to this study, the first level of intercomparison audit i.e. measuring beam output under reference conditions at eight selected Malaysian radiotherapy centres is checked; use being made of 9 μm core diameter Ge-doped silica fibres (Ge-9 μm). The results of Malaysian Secondary Standard Dosimetry Laboratory (SSDL) participation in the IAEA/WHO TLD postal dose audit services during the period between 2011 and 2015 will also been discussed. In conclusion, following review of the development of dosimetry audits and the conduct of one such exercise in Malaysia, it is apparent that regular periodic radiotherapy audits and intercomparison programmes should be strongly supported and implemented worldwide. The programmes to-date demonstrate these to be a good indicator of errors and of consistency between centres. A total of ei+ght beams have been checked in eight Malaysian radiotherapy centres. One out of the eight beams checked produced an unacceptable deviation; this was found to be due to unfamiliarity with the irradiation procedures. Prior to a repeat measurement, the mean ratio of measured to quoted dose was found to be 0.99 with standard deviation of 3%. Subsequent to the repeat measurement, the mean distribution was 1.00, and the standard deviation was 1.3%.

Effect Sizes for Growth-Modeling Analysis for Controlled Clinical Trials in the Same Metric as for Classical Analysis

PubMed Central

Feingold, Alan

2009-01-01

The use of growth-modeling analysis (GMA)--including Hierarchical Linear Models, Latent Growth Models, and General Estimating Equations--to evaluate interventions in psychology, psychiatry, and prevention science has grown rapidly over the last decade. However, an effect size associated with the difference between the trajectories of the intervention and control groups that captures the treatment effect is rarely reported. This article first reviews two classes of formulas for effect sizes associated with classical repeated-measures designs that use the standard deviation of either change scores or raw scores for the denominator. It then broadens the scope to subsume GMA, and demonstrates that the independent groups, within-subjects, pretest-posttest control-group, and GMA designs all estimate the same effect size when the standard deviation of raw scores is uniformly used. Finally, it is shown that the correct effect size for treatment efficacy in GMA--the difference between the estimated means of the two groups at end of study (determined from the coefficient for the slope difference and length of study) divided by the baseline standard deviation--is not reported in clinical trials. PMID:19271847

Analysis of in-flight acoustic data for a twin-engined turboprop airplane

NASA Technical Reports Server (NTRS)

Wilby, J. F.; Wilby, E. G.

1988-01-01

Acoustic measurements were made on the exterior and interior of a general aviation turboprop airplane during four flight tests. The test conditions were carefully controlled and repeated for each flight in order to determine data variability. For the first three flights the cabin was untreated and for the fourth flight the fuselage was treated with glass fiber batts. On the exterior, measured propeller harmonic sound pressure levels showed typical standard deviations of +1.4 dB, -2.3 dB, and turbulent boundary layer pressure levels, +1.2 dB, -1.6. Propeller harmonic levels in the cabin showed greater variability, with typical standard deviations of +2.0 dB, -4.2 dB. When interior sound pressure levels from different flights with different cabin treatments were used to evaluate insertion loss, the standard deviations were typically plus or minus 6.5 dB. This is due in part to the variability of the sound pressure level measurements, but probably is also influenced by changes in the model characteristics of the cabin. Recommendations are made for the planning and performance of future flight tests to measure interior noise of propeller-driven aircraft, either high-speed advanced turboprop or general aviation propellers.

Determination of total monomeric anthocyanin pigment content of fruit juices, beverages, natural colorants, and wines by the pH differential method: collaborative study.

PubMed

Lee, Jungmin; Durst, Robert W; Wrolstad, Ronald E

2005-01-01

This collaborative study was conducted to determine the total monomeric anthocyanin concentration by the pH differential method, which is a rapid and simple spectrophotometric method based on the anthocyanin structural transformation that occurs with a change in pH (colored at pH 1.0 and colorless at pH 4.5). Eleven collaborators representing commercial laboratories, academic institutions, and government laboratories participated. Seven Youden pair materials representing fruit juices, beverages, natural colorants, and wines were tested. The repeatability relative standard deviation (RSDr) varied from 1.06 to 4.16%. The reproducibility relative standard deviation (RSDR) ranged from 2.69 to 10.12%. The HorRat values were < or = 1.33 for all materials. The Study Director recommends that the method be adopted Official First Action.

Mentors Offering Maternal Support (M.O.M.S.)

DTIC Science & Technology

2011-08-02

at Sessions 1, 5, and 8. Table 1. Pretest - posttest , randomized, controlled, repeated measured design Experimental Intervention Sessions...theoretical mediators of self-esteem and emotional support (0.6 standard deviation change from pretest to posttest ) with reduction of effect to 0.4...always brought back to the designated topic . In order to have statistically significant results for the outcome variables the study sessions must

SU-E-T-135: Investigation of Commercial-Grade Flatbed Scanners and a Medical- Grade Scanner for Radiochromic EBT Film Dosimetry.

PubMed

Syh, J; Patel, B; Syh, J; Wu, H; Rosen, L; Durci, M; Katz, S; Sibata, C

2012-06-01

To evaluate the characteristics of commercial-grade flatbed scanners and medical-grade scanners for radiochromic EBT film dosimetry. Performance aspects of a Vidar Dosimetry Pro Advantage (Red), Epson 750 Pro, Microtek ArtixScan 1800f, and Microtek ScanMaker 8700 scanner for EBT2 Gafchromic film were evaluated in the categories of repeatability, maximum distinguishable optical density (OD) differentiation, OD variance, and dose curve characteristics. OD step film by Stouffer Industries containing 31 steps ranging from 0.05 to 3.62 OD was used. EBT films were irradiated with dose ranging from 20 to 600 cGy in 6×6 cm 2 field sizes and analyzed 24 hours later using RIT113 and Tomotherapy Film Analyzer software. Scans were performed in transmissive mode, landscape orientation, 16-bit image. The mean and standard deviation Analog to Digital (A/D) scanner value was measured by selecting a 3×3 mm 2 uniform area in the central region of each OD step from a total of 20 scans performed over several weeks. Repeatability was determined from the variance of OD step 0.38. Maximum distinguishable OD was defined as the last OD step whose range of A/D values does not overlap with its neighboring step. Repeatability uncertainty ranged from 0.1% for Vidar to 4% for Epson. Average standard deviation of OD steps ranged from 0.21% for Vidar to 6.4% for ArtixScan 1800f. Maximum distinguishable optical density ranged from 3.38 for Vidar to 1.32 for ScanMaker 8700. A/D range of each OD step corresponds to a dose range. Dose ranges of OD steps varied from 1% for Vidar to 20% for ScanMaker 8700. The Vidar exhibited a dose curve that utilized a broader range of OD values than the other scanners. Vidar exhibited higher maximum distinguishable OD, smaller variance in repeatability, smaller A/D value deviation per OD step, and a shallower dose curve with respect to OD. © 2012 American Association of Physicists in Medicine.

Liquid chromatographic determination of histamine in fish, sauerkraut, and wine: interlaboratory study.

PubMed

Beljaars, P R; Van Dijk, R; Jonker, K M; Schout, L J

1998-01-01

An interlaboratory study of the liquid chromatographic (LC) determination of histamine in fish, sauerkraut, and wine was conducted. Diminuted and homogenized samples were suspended in water followed by clarification of extracts with perchloric acid, filtration, and dilution with water. After LC separation on a reversed-phase C18 column with phosphate buffer (pH 3.0)--acetonitrile (875 + 125, v/v) as mobile phase, histamine was measured fluorometrically (excitation, 340 nm; emission, 455 nm) in samples and standards after postcolumn derivatization with o-phthaldialdehyde (OPA). Fourteen samples (including 6 blind duplicates and 1 split level) containing histamine at about 10-400 mg/kg or mg/L were analyzed singly according to the proposed procedure by 11 laboratories. Results from one participant were excluded from statistical analysis. For all samples analyzed, repeatability relative standard deviations varied from 2.1 to 5.6%, and reproducibility relative standard deviations ranged from 2.2 to 7.1%. Averaged recoveries of histamine for this concentration range varied from 94 to 100%.

Event-specific qualitative and quantitative detection of five genetically modified rice events using a single standard reference molecule.

PubMed

Kim, Jae-Hwan; Park, Saet-Byul; Roh, Hyo-Jeong; Shin, Min-Ki; Moon, Gui-Im; Hong, Jin-Hwan; Kim, Hae-Yeong

2017-07-01

One novel standard reference plasmid, namely pUC-RICE5, was constructed as a positive control and calibrator for event-specific qualitative and quantitative detection of genetically modified (GM) rice (Bt63, Kemingdao1, Kefeng6, Kefeng8, and LLRice62). pUC-RICE5 contained fragments of a rice-specific endogenous reference gene (sucrose phosphate synthase) as well as the five GM rice events. An existing qualitative PCR assay approach was modified using pUC-RICE5 to create a quantitative method with limits of detection correlating to approximately 1-10 copies of rice haploid genomes. In this quantitative PCR assay, the square regression coefficients ranged from 0.993 to 1.000. The standard deviation and relative standard deviation values for repeatability ranged from 0.02 to 0.22 and 0.10% to 0.67%, respectively. The Ministry of Food and Drug Safety (Korea) validated the method and the results suggest it could be used routinely to identify five GM rice events. Copyright © 2017 Elsevier Ltd. All rights reserved.

What Children Recall about a Repeated Event When One Instance Is Different from the Others

ERIC Educational Resources Information Center

Connolly, Deborah A.; Gordon, Heidi M.; Woiwod, Dayna M.; Price, Heather L.

2016-01-01

This research examined whether a memorable and unexpected change (deviation details) presented during 1 instance of a repeated event facilitated children's memory for that instance and whether a repeated event facilitated children's memory for deviation details. In Experiments 1 and 2, 8-year-olds (N = 167) watched 1 or 4 live magic shows.…

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

Bamberger, Judith A.; Piepel, Gregory F.; Enderlin, Carl W.

Understanding how uncertainty manifests itself in complex experiments is important for developing the testing protocol and interpreting the experimental results. This paper describes experimental and measurement uncertainties, and how they can depend on the order of performing experimental tests. Experiments with pulse-jet mixers in tanks at three scales were conducted to characterize the performance of transient-developing periodic flows in Newtonian slurries. Other test parameters included the simulant, solids concentration, and nozzle exit velocity. Critical suspension velocity and cloud height were the metrics used to characterize Newtonian slurry flow associated with mobilization and mixing. During testing, near-replicate and near-repeat tests weremore » conducted. The experimental results were used to quantify the combined experimental and measurement uncertainties using standard deviations and percent relative standard deviations (%RSD) The uncertainties in critical suspension velocity and cloud height tend to increase with the values of these responses. Hence, the %RSD values are the more appropriate summary measure of near-replicate testing and measurement uncertainty.« less

Suppression of Systematic Errors of Electronic Distance Meters for Measurement of Short Distances

PubMed Central

Braun, Jaroslav; Štroner, Martin; Urban, Rudolf; Dvořáček, Filip

2015-01-01

In modern industrial geodesy, high demands are placed on the final accuracy, with expectations currently falling below 1 mm. The measurement methodology and surveying instruments used have to be adjusted to meet these stringent requirements, especially the total stations as the most often used instruments. A standard deviation of the measured distance is the accuracy parameter, commonly between 1 and 2 mm. This parameter is often discussed in conjunction with the determination of the real accuracy of measurements at very short distances (5–50 m) because it is generally known that this accuracy cannot be increased by simply repeating the measurement because a considerable part of the error is systematic. This article describes the detailed testing of electronic distance meters to determine the absolute size of their systematic errors, their stability over time, their repeatability and the real accuracy of their distance measurement. Twenty instruments (total stations) have been tested, and more than 60,000 distances in total were measured to determine the accuracy and precision parameters of the distance meters. Based on the experiments’ results, calibration procedures were designed, including a special correction function for each instrument, whose usage reduces the standard deviation of the measurement of distance by at least 50%. PMID:26258777

A certified urea reference material (NMIJ CRM 6006-a) as a reliable calibrant for the elemental analyses of amino acids and food samples.

PubMed

Itoh, Nobuyasu; Yamazaki, Taichi; Sato, Ayako; Numata, Masahiko; Takatsu, Akiko

2014-01-01

We examined the reliability of a certified reference material (CRM) for urea (NMIJ CRM 6006-a) as a calibrant for N, C, and H in elemental analyzers. Only the N content for this CRM is provided as an indicative value. To estimate the C and H contents of the urea CRM, we took into account the purity of the urea and the presence of other identified impurities. When we examined the use of various masses of the calibrant (0.2 to 2 mg), we unexpectedly observed low signal intensities for small masses of H and N, but these plateaued at about 2 mg. We therefore analyzed four amino acid CRMs and four food CRMs on a 2-mg scale with the urea CRM as the calibrant. For the amino acid CRMs, the differences in the analytical and theoretical contents (≤0.0026 kg/kg) were acceptable with good repeatability (≤0.0013 kg/kg in standard deviation; n = 4). For food CRMs, comparable repeatabilities to those obtained with amino acid CRMs (≤0.0025 kg/kg in standard deviation; n = 4) were obtained. The urea CRM can therefore be used as a reliable calibrant for C, H, and N in an elemental analyzer.

Suppression of Systematic Errors of Electronic Distance Meters for Measurement of Short Distances.

PubMed

Braun, Jaroslav; Štroner, Martin; Urban, Rudolf; Dvoček, Filip

2015-08-06

In modern industrial geodesy, high demands are placed on the final accuracy, with expectations currently falling below 1 mm. The measurement methodology and surveying instruments used have to be adjusted to meet these stringent requirements, especially the total stations as the most often used instruments. A standard deviation of the measured distance is the accuracy parameter, commonly between 1 and 2 mm. This parameter is often discussed in conjunction with the determination of the real accuracy of measurements at very short distances (5-50 m) because it is generally known that this accuracy cannot be increased by simply repeating the measurement because a considerable part of the error is systematic. This article describes the detailed testing of electronic distance meters to determine the absolute size of their systematic errors, their stability over time, their repeatability and the real accuracy of their distance measurement. Twenty instruments (total stations) have been tested, and more than 60,000 distances in total were measured to determine the accuracy and precision parameters of the distance meters. Based on the experiments' results, calibration procedures were designed, including a special correction function for each instrument, whose usage reduces the standard deviation of the measurement of distance by at least 50%.

Apparent diffusion coefficient is highly reproducible on preclinical imaging systems: Evidence from a seven-center multivendor study.

PubMed

Doblas, Sabrina; Almeida, Gilberto S; Blé, François-Xavier; Garteiser, Philippe; Hoff, Benjamin A; McIntyre, Dominick J O; Wachsmuth, Lydia; Chenevert, Thomas L; Faber, Cornelius; Griffiths, John R; Jacobs, Andreas H; Morris, David M; O'Connor, James P B; Robinson, Simon P; Van Beers, Bernard E; Waterton, John C

2015-12-01

To evaluate between-site agreement of apparent diffusion coefficient (ADC) measurements in preclinical magnetic resonance imaging (MRI) systems. A miniaturized thermally stable ice-water phantom was devised. ADC (mean and interquartile range) was measured over several days, on 4.7T, 7T, and 9.4T Bruker, Agilent, and Magnex small-animal MRI systems using a common protocol across seven sites. Day-to-day repeatability was expressed as percent variation of mean ADC between acquisitions. Cross-site reproducibility was expressed as 1.96 × standard deviation of percent deviation of ADC values. ADC measurements were equivalent across all seven sites with a cross-site ADC reproducibility of 6.3%. Mean day-to-day repeatability of ADC measurements was 2.3%, and no site was identified as presenting different measurements than others (analysis of variance [ANOVA] P = 0.02, post-hoc test n.s.). Between-slice ADC variability was negligible and similar between sites (P = 0.15). Mean within-region-of-interest ADC variability was 5.5%, with one site presenting a significantly greater variation than the others (P = 0.0013). Absolute ADC values in preclinical studies are comparable between sites and equipment, provided standardized protocols are employed. © 2015 Wiley Periodicals, Inc.

Remote auditing of radiotherapy facilities using optically stimulated luminescence dosimeters

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

Lye, Jessica, E-mail: jessica.lye@arpansa.gov.au; Dunn, Leon; Kenny, John

Purpose: On 1 July 2012, the Australian Clinical Dosimetry Service (ACDS) released its Optically Stimulated Luminescent Dosimeter (OSLD) Level I audit, replacing the previous TLD based audit. The aim of this work is to present the results from this new service and the complete uncertainty analysis on which the audit tolerances are based. Methods: The audit release was preceded by a rigorous evaluation of the InLight® nanoDot OSLD system from Landauer (Landauer, Inc., Glenwood, IL). Energy dependence, signal fading from multiple irradiations, batch variation, reader variation, and dose response factors were identified and quantified for each individual OSLD. The detectorsmore » are mailed to the facility in small PMMA blocks, based on the design of the existing Radiological Physics Centre audit. Modeling and measurement were used to determine a factor that could convert the dose measured in the PMMA block, to dose in water for the facility's reference conditions. This factor is dependent on the beam spectrum. The TPR{sub 20,10} was used as the beam quality index to determine the specific block factor for a beam being audited. The audit tolerance was defined using a rigorous uncertainty calculation. The audit outcome is then determined using a scientifically based two tiered action level approach. Audit outcomes within two standard deviations were defined as Pass (Optimal Level), within three standard deviations as Pass (Action Level), and outside of three standard deviations the outcome is Fail (Out of Tolerance). Results: To-date the ACDS has audited 108 photon beams with TLD and 162 photon beams with OSLD. The TLD audit results had an average deviation from ACDS of 0.0% and a standard deviation of 1.8%. The OSLD audit results had an average deviation of −0.2% and a standard deviation of 1.4%. The relative combined standard uncertainty was calculated to be 1.3% (1σ). Pass (Optimal Level) was reduced to ≤2.6% (2σ), and Fail (Out of Tolerance) was reduced to >3.9% (3σ) for the new OSLD audit. Previously with the TLD audit the Pass (Optimal Level) and Fail (Out of Tolerance) were set at ≤4.0% (2σ) and >6.0% (3σ). Conclusions: The calculated standard uncertainty of 1.3% at one standard deviation is consistent with the measured standard deviation of 1.4% from the audits and confirming the suitability of the uncertainty budget derived audit tolerances. The OSLD audit shows greater accuracy than the previous TLD audit, justifying the reduction in audit tolerances. In the TLD audit, all outcomes were Pass (Optimal Level) suggesting that the tolerances were too conservative. In the OSLD audit 94% of the audits have resulted in Pass (Optimal level) and 6% of the audits have resulted in Pass (Action Level). All Pass (Action level) results have been resolved with a repeat OSLD audit, or an on-site ion chamber measurement.« less

Repeatability of testing a small broadband sensor in the Albuquerque Seismological Laboratory Underground Vault

USGS Publications Warehouse

Ringler, Adam; Holland, Austin; Wilson, David

2017-01-01

Variability in seismic instrumentation performance plays a fundamental role in our ability to carry out experiments in observational seismology. Many such experiments rely on the assumed performance of various seismic sensors as well as on methods to isolate the sensors from nonseismic noise sources. We look at the repeatability of estimating the self‐noise, midband sensitivity, and the relative orientation by comparing three collocated Nanometrics Trillium Compact sensors. To estimate the repeatability, we conduct a total of 15 trials in which one sensor is repeatedly reinstalled, alongside two undisturbed sensors. We find that we are able to estimate the midband sensitivity with an error of no greater than 0.04% with a 99th percentile confidence, assuming a standard normal distribution. We also find that we are able to estimate mean sensor self‐noise to within ±5.6  dB with a 99th percentile confidence in the 30–100‐s‐period band. Finally, we find our relative orientation errors have a mean difference in orientation of 0.0171° from the reference, but our trials have a standard deviation of 0.78°.

Corsica: A Multi-Mission Absolute Calibration Site

NASA Astrophysics Data System (ADS)

Bonnefond, P.; Exertier, P.; Laurain, O.; Guinle, T.; Femenias, P.

2013-09-01

In collaboration with the CNES and NASA oceanographic projects (TOPEX/Poseidon and Jason), the OCA (Observatoire de la Côte d'Azur) developed a verification site in Corsica since 1996, operational since 1998. CALibration/VALidation embraces a wide variety of activities, ranging from the interpretation of information from internal-calibration modes of the sensors to validation of the fully corrected estimates of the reflector heights using in situ data. Now, Corsica is, like the Harvest platform (NASA side) [14], an operating calibration site able to support a continuous monitoring with a high level of accuracy: a 'point calibration' which yields instantaneous bias estimates with a 10-day repeatability of 30 mm (standard deviation) and mean errors of 4 mm (standard error). For a 35-day repeatability (ERS, Envisat), due to a smaller time series, the standard error is about the double ( 7 mm).In this paper, we will present updated results of the absolute Sea Surface Height (SSH) biases for TOPEX/Poseidon (T/P), Jason-1, Jason-2, ERS-2 and Envisat.

Standard random number generation for MBASIC

NASA Technical Reports Server (NTRS)

Tausworthe, R. C.

1976-01-01

A machine-independent algorithm is presented and analyzed for generating pseudorandom numbers suitable for the standard MBASIC system. The algorithm used is the polynomial congruential or linear recurrence modulo 2 method. Numbers, formed as nonoverlapping adjacent 28-bit words taken from the bit stream produced by the formula a sub m + 532 = a sub m + 37 + a sub m (modulo 2), do not repeat within the projected age of the solar system, show no ensemble correlation, exhibit uniform distribution of adjacent numbers up to 19 dimensions, and do not deviate from random runs-up and runs-down behavior.

Optimisation of a sample preparation procedure for the screening of fungal infection and assessment of deoxynivalenol content in maize using mid-infrared attenuated total reflection spectroscopy.

PubMed

Kos, Gregor; Lohninger, Hans; Mizaikoff, Boris; Krska, Rudolf

2007-07-01

A sample preparation procedure for the determination of deoxynivalenol (DON) using attenuated total reflection mid-infrared spectroscopy is presented. Repeatable spectra were obtained from samples featuring a narrow particle size distribution. Samples were ground with a centrifugal mill and analysed with an analytical sieve shaker. Particle sizes of <100, 100-250, 250-500, 500-710 and 710-1000 microm were obtained. Repeatability, classification and quantification abilities for DON were compared with non-sieved samples. The 100-250 microm fraction showed the best repeatability. The relative standard deviation of spectral measurements improved from 20 to 4.4% and 100% of sieved samples were correctly classified compared with 79% of non-sieved samples. The DON level in analysed fractions was a good estimate of overall toxin content.

Multielement trace determination in SiC powders: assessment of interlaboratory comparisons aimed at the validation and standardization of analytical procedures with direct solid sampling based on ETV ICP OES and DC arc OES.

PubMed

Matschat, Ralf; Hassler, Jürgen; Traub, Heike; Dette, Angelika

2005-12-01

The members of the committee NMP 264 "Chemical analysis of non-oxidic raw and basic materials" of the German Standards Institute (DIN) have organized two interlaboratory comparisons for multielement determination of trace elements in silicon carbide (SiC) powders via direct solid sampling methods. One of the interlaboratory comparisons was based on the application of inductively coupled plasma optical emission spectrometry with electrothermal vaporization (ETV ICP OES), and the other on the application of optical emission spectrometry with direct current arc (DC arc OES). The interlaboratory comparisons were organized and performed in the framework of the development of two standards related to "the determination of mass fractions of metallic impurities in powders and grain sizes of ceramic raw and basic materials" by both methods. SiC powders were used as typical examples of this category of material. The aim of the interlaboratory comparisons was to determine the repeatability and reproducibility of both analytical methods to be standardized. This was an important contribution to the practical applicability of both draft standards. Eight laboratories participated in the interlaboratory comparison with ETV ICP OES and nine in the interlaboratory comparison with DC arc OES. Ten analytes were investigated by ETV ICP OES and eleven by DC arc OES. Six different SiC powders were used for the calibration. The mass fractions of their relevant trace elements were determined after wet chemical digestion. All participants followed the analytical requirements described in the draft standards. In the calculation process, three of the calibration materials were used successively as analytical samples. This was managed in the following manner: the material that had just been used as the analytical sample was excluded from the calibration, so the five other materials were used to establish the calibration plot. The results from the interlaboratory comparisons were summarized and used to determine the repeatability and the reproducibility (expressed as standard deviations) of both methods. The calculation was carried out according to the related standard. The results are specified and discussed in this paper, as are the optimized analytical conditions determined and used by the authors of this paper. For both methods, the repeatability relative standard deviations were <25%, usually ~10%, and the reproducibility relative standard deviations were <35%, usually ~15%. These results were regarded as satifactory for both methods intended for rapid analysis of materials for which decomposition is difficult and time-consuming. Also described are some results from an interlaboratory comparison used to certify one of the materials that had been previously used for validation in both interlaboratory comparisons. Thirty laboratories (from eight countries) participated in this interlaboratory comparison for certification. As examples, accepted results are shown from laboratories that used ETV ICP OES or DC arc OES and had performed calibrations by using solutions or oxides, respectively. The certified mass fractions of the certified reference materials were also compared with the mass fractions determined in the interlaboratory comparisons performed within the framework of method standardization. Good agreement was found for most of the analytes.

Repeatability of Cryogenic Multilayer Insulation

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-01-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4 whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 16. Based on detailed statistical analysis, the data has been shown to be statistically significant.

Repeatability of Cryogenic Multilayer Insulation

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-01-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

Repeatability of Cryogenic Multilayer Insulation

NASA Astrophysics Data System (ADS)

Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

2017-12-01

Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

The Effective Mutation Rate at Y Chromosome Short Tandem Repeats, with Application to Human Population-Divergence Time

PubMed Central

Zhivotovsky, Lev A.; Underhill, Peter A.; Cinnioğlu, Cengiz; Kayser, Manfred; Morar, Bharti; Kivisild, Toomas; Scozzari, Rosaria; Cruciani, Fulvio; Destro-Bisol, Giovanni; Spedini, Gabriella; Chambers, Geoffrey K.; Herrera, Rene J.; Yong, Kiau Kiun; Gresham, David; Tournev, Ivailo; Feldman, Marcus W.; Kalaydjieva, Luba

2004-01-01

We estimate an effective mutation rate at an average Y chromosome short-tandem repeat locus as 6.9×10-4 per 25 years, with a standard deviation across loci of 5.7×10-4, using data on microsatellite variation within Y chromosome haplogroups defined by unique-event polymorphisms in populations with documented short-term histories, as well as comparative data on worldwide populations at both the Y chromosome and various autosomal loci. This value is used to estimate the times of the African Bantu expansion, the divergence of Polynesian populations (the Maoris, Cook Islanders, and Samoans), and the origin of Gypsy populations from Bulgaria. PMID:14691732

A Correlation Study between Two Color-Measuring Spectrophotometers

DTIC Science & Technology

1991-01-01

a color difference pair) were_ measured for short- and long-term repeataoility. Each instrument was found to show a repeatability of 0.12 CIELAB color...for the Green Fabric Samples on the ACS II: Standard Deviation of Tristimulus 26 Values (X,Y,Z) 5. CIELAB Color Differences for Tan Color Difference...value on the ACS I is considerably higher. The largest AE ( CIELAB color difference between the two means) observed was 0.5 CIELAB units. The two-sample

Single isotope evaluation of pulmonary capillary protein leak (ARDS model) using computerized gamma scintigraphy

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

Tatum, J.L.; Strash, A.M.; Sugerman, H.J.

Using a canine oleic acid model, a computerized gamma scintigraphic technique was evaluated to determine 1) ability to detect pulmonary capillary protein leak in a model temporally consistent with clinical adult respiratory distress syndrome (ARDS), 2) the possibility of providing a quantitative index of leak, and 3) the feasibility of closely spaced repeat evaluations. Study animals received oleic acid (controls, n . 10; 0.05 ml/kg, n . 10; 0.10 ml/kg, n . 12; 0.15 ml/kg, n . 6) 3 hours prior to a tracer dose of technetium-99m (/sup 99/mTc) HSA. One animal in each dose group also received two repeatmore » tracer injections spaced a minimum of 45 minutes apart. Digital images were obtained with a conventional gamma camera interfaced to a dedicated medical computer. Lung: heart ratio versus time curves were generated, and a slope index was calculated for each curve. Slope index values for all doses were significantly greater than control values (P(t) less than 0.0001). Each incremental dose increase was also significantly greater than the previous dose level. Oleic acid dose versus slope index fitted a linear regression model with r . 0.94. Repeat dosing produced index values with standard deviations less than the group sample standard deviations. We feel this technique may have application in the clinical study of pulmonary permeability edema.« less

Thermal Infrared Spectrometer for Earth Science Remote Sensing Applications—Instrument Modifications and Measurement Procedures

PubMed Central

Hecker, Christoph; Hook, Simon; van der Meijde, Mark; Bakker, Wim; van der Werff, Harald; Wilbrink, Henk; van Ruitenbeek, Frank; de Smeth, Boudewijn; van der Meer, Freek

2011-01-01

In this article we describe a new instrumental setup at the University of Twente Faculty ITC with an optimized processing chain to measure absolute directional-hemispherical reflectance values of typical earth science samples in the 2.5 to 16 μm range. A Bruker Vertex 70 FTIR spectrometer was chosen as the base instrument. It was modified with an external integrating sphere with a 30 mm sampling port to allow measuring large, inhomogeneous samples and quantitatively compare the laboratory results to airborne and spaceborne remote sensing data. During the processing to directional-hemispherical reflectance values, a background radiation subtraction is performed, removing the effect of radiance not reflected from the sample itself on the detector. This provides more accurate reflectance values for low-reflecting samples. Repeat measurements taken over a 20 month period on a quartz sand standard show that the repeatability of the system is very high, with a standard deviation ranging between 0.001 and 0.006 reflectance units depending on wavelength. This high level of repeatability is achieved even after replacing optical components, re-aligning mirrors and placement of sample port reducers. Absolute reflectance values of measurements taken by the instrument here presented compare very favorably to measurements of other leading laboratories taken on identical sample standards. PMID:22346683

Thermal infrared spectrometer for Earth science remote sensing applications-instrument modifications and measurement procedures.

PubMed

Hecker, Christoph; Hook, Simon; van der Meijde, Mark; Bakker, Wim; van der Werff, Harald; Wilbrink, Henk; van Ruitenbeek, Frank; de Smeth, Boudewijn; van der Meer, Freek

2011-01-01

In this article we describe a new instrumental setup at the University of Twente Faculty ITC with an optimized processing chain to measure absolute directional-hemispherical reflectance values of typical earth science samples in the 2.5 to 16 μm range. A Bruker Vertex 70 FTIR spectrometer was chosen as the base instrument. It was modified with an external integrating sphere with a 30 mm sampling port to allow measuring large, inhomogeneous samples and quantitatively compare the laboratory results to airborne and spaceborne remote sensing data. During the processing to directional-hemispherical reflectance values, a background radiation subtraction is performed, removing the effect of radiance not reflected from the sample itself on the detector. This provides more accurate reflectance values for low-reflecting samples. Repeat measurements taken over a 20 month period on a quartz sand standard show that the repeatability of the system is very high, with a standard deviation ranging between 0.001 and 0.006 reflectance units depending on wavelength. This high level of repeatability is achieved even after replacing optical components, re-aligning mirrors and placement of sample port reducers. Absolute reflectance values of measurements taken by the instrument here presented compare very favorably to measurements of other leading laboratories taken on identical sample standards.

Uncertainty in Vs30-based site response

USGS Publications Warehouse

Thompson, Eric M.; Wald, David J.

2016-01-01

Methods that account for site response range in complexity from simple linear categorical adjustment factors to sophisticated nonlinear constitutive models. Seismic‐hazard analysis usually relies on ground‐motion prediction equations (GMPEs); within this framework site response is modeled statistically with simplified site parameters that include the time‐averaged shear‐wave velocity to 30 m (VS30) and basin depth parameters. Because VS30 is not known in most locations, it must be interpolated or inferred through secondary information such as geology or topography. In this article, we analyze a subset of stations for which VS30 has been measured to address effects of VS30 proxies on the uncertainty in the ground motions as modeled by GMPEs. The stations we analyze also include multiple recordings, which allow us to compute the repeatable site effects (or empirical amplification factors [EAFs]) from the ground motions. Although all methods exhibit similar bias, the proxy methods only reduce the ground‐motion standard deviations at long periods when compared to GMPEs without a site term, whereas measured VS30 values reduce the standard deviations at all periods. The standard deviation of the ground motions are much lower when the EAFs are used, indicating that future refinements of the site term in GMPEs have the potential to substantially reduce the overall uncertainty in the prediction of ground motions by GMPEs.

Comparison of emotional and non-emotional word repetitions in patients with aphasia

PubMed Central

Bakhtiyari, Jalal; Khatoonabadi, Seyyed Ahmad Reza; Dadgar, Hooshang; Bakhtiari, Behrooz Mahmoodi; Khosravizadeh, Parvaneh; Shaygannejad, Vahid

2015-01-01

Background: Aphasia is a language disorder caused by left hemisphere damage. For treatment of aphasia, in some of therapeutic approaches, the right hemisphere (RH) abilities, such as, emotional perception, is used for stimulation of the language process in the left hemisphere. The aim of this study is to investigate emotional word repetition in aphasia after a stroke, in Persian language patients. Materials and Methods: Fifteen aphasic patients (eleven male and four female) between 45 and 65 (58/4 ± 7/8) years of age, participated in this cross-sectional study. A list of 20 emotional words and a list of 20 neutral words as stimuli were prepared and the patients were asked to repeat each word after five seconds; if a patient needed to repeat a word again, it was repeated for him/her again, and the total score for each subject was calculated. The paired t-test was used to test group mean differences and the significant level was 0.05. Results: The mean and standard deviation for emotional word repetitions were 6.93 ± 1.72 and for non-emotional word repetition was 7.10 ± 2.23, and the P value = 0.892, thus, no significant difference between emotional and non-emotional word repetitions was noticed. The mean and standard deviation for the positive emotional word repetitions were 3.53 ± 3.29 and for negative word repetitions were 3.40 ± 3.56, (P = 0.751), with no significant difference between positive and negative emotional word repetitions. Conclusion: Despite the main hypothesis that the right hemisphere is involved in the processing of emotions, it can be stated that both hemispheres are involved in the processing of emotional words, albeit in a different and probably complementary manner. PMID:26436078

Repeatability Assessment by ISO 11843-7 in Quantitative HPLC for Herbal Medicines.

PubMed

Chen, Liangmian; Kotani, Akira; Hakamata, Hideki; Tsutsumi, Risa; Hayashi, Yuzuru; Wang, Zhimin; Kusu, Fumiyo

2015-01-01

We have proposed an assessment methods to estimate the measurement relative standard deviation (RSD) of chromatographic peaks in quantitative HPLC for herbal medicines by the methodology of ISO 11843 Part 7 (ISO 11843-7:2012), which provides detection limits stochastically. In quantitative HPLC with UV detection (HPLC-UV) of Scutellaria Radix for the determination of baicalin, the measurement RSD of baicalin by ISO 11843-7:2012 stochastically was within a 95% confidence interval of the statistically obtained RSD by repetitive measurements (n = 6). Thus, our findings show that it is applicable for estimating of the repeatability of HPLC-UV for determining baicalin without repeated measurements. In addition, the allowable limit of the "System repeatability" in "Liquid Chromatography" regulated in a pharmacopoeia can be obtained by the present assessment method. Moreover, the present assessment method was also successfully applied to estimate the measurement RSDs of quantitative three-channel liquid chromatography with electrochemical detection (LC-3ECD) of Chrysanthemi Flos for determining caffeoylquinic acids and flavonoids. By the present repeatability assessment method, reliable measurement RSD was obtained stochastically, and the experimental time was remarkably reduced.

Intraobserver reliability of contact pachymetry in children.

PubMed

Weise, Katherine K; Kaminski, Brett; Melia, Michele; Repka, Michael X; Bradfield, Yasmin S; Davitt, Bradley V; Johnson, David A; Kraker, Raymond T; Manny, Ruth E; Matta, Noelle S; Schloff, Susan

2013-04-01

Central corneal thickness (CCT) is an important measurement in the treatment and management of pediatric glaucoma and potentially of refractive error, but data regarding reliability of CCT measurement in children are limited. The purpose of this study was to evaluate the reliability of CCT measurement with the use of handheld contact pachymetry in children. We conducted a multicenter intraobserver test-retest reliability study of more than 3,400 healthy eyes in children aged from newborn to 17 years by using a handheld contact pachymeter (Pachmate DGH55; DGH Technology Inc, Exton, PA) in 2 clinical settings--with the use of topical anesthesia in the office and with the patient under general anesthesia in a surgical facility. The overall standard error of measurement, including only measurements with standard deviation ≤5 μm, was 8 μm; the corresponding coefficient of repeatability, or limits within which 95% of test-retest differences fell, was ±22.3 μm. However, standard error of measurement increased as CCT increased, from 6.8 μm for CCT less than 525 μm, to 12.9 μm for CCT 625 μm and greater. The standard error of measurement including measurements with standard deviation >5 μm was 10.5 μm. Age, sex, race/ethnicity group, and examination setting did not influence the magnitude of test-retest differences. CCT measurement reliability in children via the Pachmate DGH55 handheld contact pachymeter is similar to that reported for adults. Because thicker CCT measurements are less reliable than thinner measurements, a second measure may be helpful when the first exceeds 575 μm. Reliability is also improved by disregarding measurements with instrument-reported standard deviations >5 μm. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

Microbial ranking of porous packaging materials (exposure chamber method), ASTM method: collaborative study.

PubMed

Placencia, A M; Peeler, J T

1999-01-01

A collaborative study involving 11 laboratories was conducted to measure the microbial barrier effectiveness of porous medical packaging. Two randomly cut samples from each of 6 commercially available porous materials and one positive and one negative control were tested by one operator in each of 11 laboratories. Microbial barrier effectiveness was measured in terms of logarithm reduction value (LRV), which reflects the log10 microbial penetration of the material being tested. The logarithm of the final concentration is subtracted from that of the initial concentration to obtain the LRV. Thus the higher the LRV, the better the barrier. Repeatability standard deviations ranged from 6.42 to 16.40; reproducibility standard deviations ranged from 15.50 to 22.70. Materials B(53), C(50), D(CT), and E(45MF) differ significantly from the positive control. The microbial ranking of porous packaging materials (exposure chamber method), ASTM method, has been adopted First Action by AOAC INTERNATIONAL.

Determination of patulin in apple juice by liquid chromatography: collaborative study.

PubMed

Brause, A R; Trucksess, M W; Thomas, F S; Page, S W

1996-01-01

An AOAC International-International Union of Pure and Applied Chemistry-International Fruit Juice Union (AOAC-IUPAC-IFJU) collaborative study was conducted to evaluate a liquid chromatographic (LC) procedure for determination of patulin in apple juice. Patulin is a mold metabolite found naturally in rotting apples. Patulin is extracted with ethyl acetate, treated with sodium carbonate solution, and determined by reversed-phase LC with UV detection at 254 or 276 nm. Water, water-tetrahydrofuran, or water-acetonitrile was used as mobile phase. Levels determined in spiked test samples were 20, 50, 100, and 200 micrograms/L. A test sample naturally contaminated at 31 micrograms/L was also included. Twenty-two collaborators in 10 countries analyzed 12 test samples of apple juice. Recoveries averaged 96%, with a range of 91-108%. Repeatability relative standard deviations (RSDr) ranged from 10.9 to 53.8%. The reproducibility relative standard deviation (RSDR) ranged from 15.1 to 68.8%. The LC method for determination of patulin in apple juice has been adopted first action by AOAC INTERNATIONAL.

Estimating River Surface Elevation From ArcticDEM

NASA Astrophysics Data System (ADS)

Dai, Chunli; Durand, Michael; Howat, Ian M.; Altenau, Elizabeth H.; Pavelsky, Tamlin M.

2018-04-01

ArcticDEM is a collection of 2-m resolution, repeat digital surface models created from stereoscopic satellite imagery. To demonstrate the potential of ArcticDEM for measuring river stages and discharges, we estimate river surface heights along a reach of Tanana River near Fairbanks, Alaska, by the precise detection of river shorelines and mapping of shorelines to land surface elevation. The river height profiles over a 15-km reach agree with in situ measurements to a standard deviation less than 30 cm. The time series of ArcticDEM-derived river heights agree with the U.S. Geological Survey gage measurements with a standard deviation of 32 cm. Using the rating curve for that gage, we obtain discharges with a validation accuracy (root-mean-square error) of 234 m3/s (23% of the mean discharge). Our results demonstrate that ArcticDEM can accurately measure spatial and temporal variations of river surfaces, providing a new and powerful data set for hydrologic analysis.

Characterizing the Performance of the Wheel Electrostatic Spectrometer

NASA Technical Reports Server (NTRS)

Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Calle, C. I.; Clements, J. S.

2013-01-01

Insulators need to be discharged after each wheel revolution. Sensor responses repeatable within one standard deviation in the noise of the signal. Insulators may not need to be cleaned after each revolution. Parent Technology- Mars Environmental Compatibility Assessment/Electrometer Electrostatic sensors with dissimilar cover insulators Protruding insulators tribocharge against regolith simulant Developed for use on the scoop for the 2001 Mars Odyssey lander Wheel Electrostatic Spectrometer Embedded electrostatic sensors in prototype Martian rover wheel If successful, this technology will enable constant electrostatic testing on Mars Air ionizing fan used to neutralize the surface charge on cover insulators . WES rolled on JSClA lunar simulant Control experiment -Static elimination not conducted between trials -Capacitor discharged after each experiment Charge neutralization experiment -Static elimination conducted between trials -Capacitor discharged after each experiment. Air ionizing fan used on insulators after each wheel revolution Capacitor discharged after each trial Care was taken to roll WES with same speed/pressure Error bars represent one standard deviation in the noise of e ach sensor

Insights from analysis for harmful and potentially harmful constituents (HPHCs) in tobacco products.

PubMed

Oldham, Michael J; DeSoi, Darren J; Rimmer, Lonnie T; Wagner, Karl A; Morton, Michael J

2014-10-01

A total of 20 commercial cigarette and 16 commercial smokeless tobacco products were assayed for 96 compounds listed as harmful and potentially harmful constituents (HPHCs) by the US Food and Drug Administration. For each product, a single lot was used for all testing. Both International Organization for Standardization and Health Canada smoking regimens were used for cigarette testing. For those HPHCs detected, measured levels were consistent with levels reported in the literature, however substantial assay variability (measured as average relative standard deviation) was found for most results. Using an abbreviated list of HPHCs, statistically significant differences for most of these HPHCs occurred when results were obtained 4-6months apart (i.e., temporal variability). The assay variability and temporal variability demonstrate the need for standardized analytical methods with defined repeatability and reproducibility for each HPHC using certified reference standards. Temporal variability also means that simple conventional comparisons, such as two-sample t-tests, are inappropriate for comparing products tested at different points in time from the same laboratory or from different laboratories. Until capable laboratories use standardized assays with established repeatability, reproducibility, and certified reference standards, the resulting HPHC data will be unreliable for product comparisons or other decision making in regulatory science. Copyright © 2014 Elsevier Inc. All rights reserved.

THE DIFFUSION LENGTH OF THERMAL NEUTRONS IN PORTLAND CONCRETE

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

Dugdale, R.A.; Healy, E.

1957-10-01

A measurement of the diffusion length of thermal neutrons in Portland concrete, originally raade by Salmon two years previously, has been repeated. An apparent decrease from 7.04 cm to 6.61 cm has oocurred. This change, which is only four times the standard deviation of the result, could be due to a small increase in water content. In assessing the amount required, a discrepancy between calculated and measured diffusion length was found. Possible explanations of the discrepancy are discussed. (auth)

Six-month Longitudinal Comparison of a Portable Tablet Perimeter With the Humphrey Field Analyzer.

PubMed

Prea, Selwyn Marc; Kong, Yu Xiang George; Mehta, Aditi; He, Mingguang; Crowston, Jonathan G; Gupta, Vinay; Martin, Keith R; Vingrys, Algis J

2018-06-01

To establish the medium-term repeatability of the iPad perimetry app Melbourne Rapid Fields (MRF) compared to Humphrey Field Analyzer (HFA) 24-2 SITA-standard and SITA-fast programs. Multicenter longitudinal observational clinical study. Sixty patients (stable glaucoma/ocular hypertension/glaucoma suspects) were recruited into a 6-month longitudinal clinical study with visits planned at baseline and at 2, 4, and 6 months. At each visit patients undertook visual field assessment using the MRF perimetry application and either HFA SITA-fast (n = 21) or SITA-standard (n = 39). The primary outcome measure was the association and repeatability of mean deviation (MD) for the MRF and HFA tests. Secondary measures were the point-wise threshold and repeatability for each test, as well as test time. MRF was similar to SITA-fast in speed and significantly faster than SITA-standard (MRF 4.6 ± 0.1 minutes vs SITA-fast 4.3 ± 0.2 minutes vs SITA-standard 6.2 ± 0.1 minutes, P < .001). Intraclass correlation coefficients (ICC) between MRF and SITA-fast for MD at the 4 visits ranged from 0.71 to 0.88. ICC values between MRF and SITA-standard for MD ranged from 0.81 to 0.90. Repeatability of MRF MD outcomes was excellent, with ICC for baseline and the 6-month visit being 0.98 (95% confidence interval: 0.96-0.99). In comparison, ICC at 6-month retest for SITA-fast was 0.95 and SITA-standard 0.93. Fewer points changed with the MRF, although for those that did, the MRF gave greater point-wise variability than did the SITA tests. MRF correlated strongly with HFA across 4 visits over a 6-month period, and has good test-retest reliability. MRF is suitable for monitoring visual fields in settings where conventional perimetry is not readily accessible. Copyright © 2018 Elsevier Inc. All rights reserved.

Evaluation of a new tear osmometer for repeatability and accuracy, using 0.5-microL (500-Nanoliter) samples.

PubMed

Yildiz, Elvin H; Fan, Vincent C; Banday, Hina; Ramanathan, Lakshmi V; Bitra, Ratna K; Garry, Eileen; Asbell, Penny A

2009-07-01

To evaluate the repeatability and accuracy of a new tear osmometer that measures the osmolality of 0.5-microL (500-nanoliter) samples. Four standardized solutions were tested with 0.5-microL (500-nanoliter) samples for repeatability of measurements and comparability to standardized technique. Two known standard salt solutions (290 mOsm/kg H2O, 304 mOsm/kg H2O), a normal artificial tear matrix sample (306 mOsm/kg H2O), and an abnormal artificial tear matrix sample (336 mOsm/kg H2O) were repeatedly tested (n = 20 each) for osmolality with use of the Advanced Instruments Model 3100 Tear Osmometer (0.5-microL [500-nanoliter] sample size) and the FDA-approved Advanced Instruments Model 3D2 Clinical Osmometer (250-microL sample size). Four standard solutions were used, with osmolality values of 290, 304, 306, and 336 mOsm/kg H2O. The respective precision data, including the mean and standard deviation, were: 291.8 +/- 4.4, 305.6 +/- 2.4, 305.1 +/- 2.3, and 336.4 +/- 2.2 mOsm/kg H2O. The percent recoveries for the 290 mOsm/kg H2O standard solution, the 304 mOsm/kg H2O reference solution, the normal value-assigned 306 mOsm/kg H2O sample, and the abnormal value-assigned 336 mOsm/kg H2O sample were 100.3, 100.2, 99.8, and 100.3 mOsm/kg H2O, respectively. The repeatability data are in accordance with data obtained on clinical osmometers with use of larger sample sizes. All 4 samples tested on the tear osmometer have osmolality values that correlate well to the clinical instrument method. The tear osmometer is a suitable instrument for testing the osmolality of microliter-sized samples, such as tears, and therefore may be useful in diagnosing, monitoring, and classifying tear abnormalities such as the severity of dry eye disease.

Simultaneous Determination of Total Vitamins B1, B2, B3, and B6 in Infant Formula and Related Nutritionals by Enzymatic Digestion and LC-MS/MS: Single-Laboratory Validation, First Action 2015.14.

PubMed

Salvati, Louis M; McClure, Sean C; Reddy, Todime M; Cellar, Nicholas A

2016-05-01

This method provides simultaneous determination of total vitamins B1, B2, B3, and B6 in infant formula and related nutritionals (adult and infant). The method was given First Action for vitamins B1, B2, and B6, but not B3, during the AOAC Annual Meeting in September 2015. The method uses acid phosphatase to dephosphorylate the phosphorylated vitamin forms. It then measures thiamine (vitamin B1); riboflavin (vitamin B2); nicotinamide and nicotinic acid (vitamin B3); and pyridoxine, pyridoxal, and pyridoxamine (vitamin B6) from digested sample extract by liquid chromatography-tandem mass spectrometry. A single-laboratory validation was performed on 14 matrixes provided by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) to demonstrate method effectiveness. The method met requirements of the AOAC SPIFAN Standard Method Performance Requirement for each of the three vitamins, including average over-spike recovery of 99.6 ± 3.5%, average repeatability of 1.5 ± 0.8% relative standard deviation, and average intermediate precision of 3.9 ± 1.3% relative standard deviation.

Accuracy of Digital Impressions and Fitness of Single Crowns Based on Digital Impressions

PubMed Central

Yang, Xin; Lv, Pin; Liu, Yihong; Si, Wenjie; Feng, Hailan

2015-01-01

In this study, the accuracy (precision and trueness) of digital impressions and the fitness of single crowns manufactured based on digital impressions were evaluated. #14-17 epoxy resin dentitions were made, while full-crown preparations of extracted natural teeth were embedded at #16. (1) To assess precision, deviations among repeated scan models made by intraoral scanner TRIOS and MHT and model scanner D700 and inEos were calculated through best-fit algorithm and three-dimensional (3D) comparison. Root mean square (RMS) and color-coded difference images were offered. (2) To assess trueness, micro computed tomography (micro-CT) was used to get the reference model (REF). Deviations between REF and repeated scan models (from (1)) were calculated. (3) To assess fitness, single crowns were manufactured based on TRIOS, MHT, D700 and inEos scan models. The adhesive gaps were evaluated under stereomicroscope after cross-sectioned. Digital impressions showed lower precision and better trueness. Except for MHT, the means of RMS for precision were lower than 10 μm. Digital impressions showed better internal fitness. Fitness of single crowns based on digital impressions was up to clinical standard. Digital impressions could be an alternative method for single crowns manufacturing. PMID:28793417

Simultaneous quantitative determination of 11 sesquiterpene lactones in Jerusalem artichoke (Helianthus tuberosus L.) leaves by ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Yuan, Xiaoyan; Yang, Qianxu

2017-04-01

A method of ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was developed for the simultaneous quantification of 11 sesquiterpene lactones in 11 Jerusalem artichoke leaf samples harvested in a number of areas at different periods. The optimal chromatographic conditions were achieved on a ZORBAX Eclipse Plus C 18 column (3.0 × 150 mm, 1.8 μm) with linear gradient elution of methanol and water in 8 min. Quantitative analysis was carried out under selective ion monitoring mode. All of the sesquiterpene lactones showed good linearity (R 2 ≥ 0.9949), repeatability (relative standard deviations < 4.66%), and intra- and interday precisions (relative standard deviations < 4.52%) with an accuracy of 95.24-104.84%. The recoveries measured at three concentration levels varied from 95.07 to 104.87% with relative standard deviations less than 4.9%. The limit of detection and limit of quantitation for this method were 0.89-5.05 and 1.12-44.33 ng/mL, respectively. The results showed that the contents of sesquiterpene lactones varied significantly in the Jerusalem artichoke leaf samples from different areas. Among them, the content of sesquiterpene lactones in the sample collected from Dalian, Liaoning province was the highest and the early flowering period was considered to be the optimal harvest time. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Internal Quality Control Practices in Coagulation Laboratories: recommendations based on a patterns-of-practice survey.

PubMed

McFarlane, A; Aslan, B; Raby, A; Moffat, K A; Selby, R; Padmore, R

2015-12-01

Internal quality control (IQC) procedures are crucial for ensuring accurate patient test results. The IQMH Centre for Proficiency Testing conducted a web-based survey to gather information on the current IQC practices in coagulation testing. A questionnaire was distributed to 174 Ontario laboratories licensed to perform prothrombin time (PT) and activated partial thromboplastin time (APTT). All laboratories reported using two levels of commercial QC (CQC); 12% incorporate pooled patient plasma into their IQC program; >68% run CQC at the beginning of each shift; 56% following maintenance, with reagent changes, during a shift, or with every repeat sample; 6% only run CQC at the beginning of the day and 25% when the instruments have been idle for a defined period of time. IQC run frequency was determined by manufacturer recommendations (71%) but also influenced by the stability of test (27%), clinical impact of an incorrect test result (25%), and sample's batch number (10%). IQC was monitored using preset limits based on standard deviation (66%), precision goals (46%), or allowable performance limits (36%). 95% use multirules. Failure actions include repeating the IQC (90%) and reporting patient results; if repeat passes, 42% perform repeat analysis of all patient samples from last acceptable IQC. Variability exists in coagulation IQC practices among Ontario clinical laboratories. The recommendations presented here would be useful in encouraging standardized IQC practices. © 2015 John Wiley & Sons Ltd.

Preclinical Toxicological Evaluation of IDM01: The Botanical Composition of 4-Hydroxyisoleucine- and Trigonelline-based Standardized Fenugreek Seed Extract.

PubMed

Deshpande, Pallavi O; Mohan, Vishwaraman; Thakurdesai, Prasad Arvind

2017-01-01

To evaluate acute oral toxicity (AOT), subchronic (90-day repeated dose) toxicity, mutagenicity, and genotoxicity potential of IDM01, the botanical composition of 4-hydroxyisoleucine- and trigonelline-based standardized fenugreek ( Trigonella foenum-graecum L) seed extract in laboratory rats. The AOT and subchronic (90-day repeated dose) toxicity were evaluated using Sprague-Dawley rats as per the Organisation for Economic Co-operation and Development (OECD) guidelines No. 423 and No. 408, respectively. During the subchronic study, the effects on body weight, food and water consumption, organ weights with hematology, clinical biochemistry, and histology were studied. The mutagenicity and genotoxicity of IDM01 were evaluated by reverse mutation assay (Ames test, OECD guideline No. 471) and chromosome aberration test (OECD guideline No. 473), respectively. The IDM01 did not show mortality or treatment-related adverse signs during acute (limit dose of 2000 mg/kg) and subchronic (90-day repeated dose of 250, 500, and 1000 mg/kg with 28 days of recovery period) administration. The IDM01 showed oral median lethal dose (LD50) >2000 mg/kg during AOT study. The no-observed adverse effect level (NOAEL) of IDM01 was 500 mg/kg. IDM01 did not show mutagenicity up to a concentration of 5000 μg/plate during Ames test and did not induce structural chromosomal aberrations up to 50 mg/culture. IDM01 was found safe during preclinical acute and subchronic (90-day repeated dose) toxicity in rats without mutagenicity or genotoxicity. Acute oral toxicity, subchronic (90-day) oral toxicity, mutagenicity and genotoxicity of IDM01 (4-hydroxyisoleucine- and trigonelline-based standardized fenugreek seed extract) was evaluated.The median lethal dose, LD50, of IDM01 was more than 2000 mg/kg of body weight in rats.No observed adverse effect level (NOAEL) of IDM01 was 500 mg/kg of body weight in rats.IDM01 was found safe during acute and subchronic oral toxicity studies in rats without mutagenicity or genotoxicity potetial. Abbreviations Used: 2-AA: 2-aminoanthracene; 2-AF: 2-aminofluorene; 4 NQNO: 4-nitroquinolene-N-oxide; 4HI: 4-hydroxyisoleucine; ANOVA: Analysis of variance; AOT: Acute oral toxicity; DM: Diabetes mellitus; IDM01: The Botanical composition of 4-hydroxyisoleucine- and trigonelline-based standardized fenugreek seed extract; LD50: Median lethal dose; MMS: Methyl methanesulfonate; NAD: No abnormality detected; OECD: Organisation for Economic Co-operation and Development; SD: Standard deviation; UV: Ultraviolet; VC: Vehicle control. 2-AA: 2-aminoanthracene; 2-AF: 2-aminofluorene; 4 NQNO: 4-nitroquinolene-N-oxide; 4HI: 4-hydroxyisoleucine; ANOVA: Analysis of variance; AOT: Acute oral toxicity; DM: Diabetes mellitus; IDM01: The Botanical composition of 4-hydroxyisoleucine- and trigonelline-based standardized fenugreek seed extract; LD50: Median lethal dose; MMS: Methyl methanesulfonate; NAD: No abnormality detected; OECD: Organisation for Economic Co-operation and Development; SD: Standard deviation; UV: Ultraviolet; VC: Vehicle control.

Preclinical Toxicological Evaluation of IDM01: The Botanical Composition of 4-Hydroxyisoleucine- and Trigonelline-based Standardized Fenugreek Seed Extract

PubMed Central

Deshpande, Pallavi O.; Mohan, Vishwaraman; Thakurdesai, Prasad Arvind

2017-01-01

Objective: To evaluate acute oral toxicity (AOT), subchronic (90-day repeated dose) toxicity, mutagenicity, and genotoxicity potential of IDM01, the botanical composition of 4-hydroxyisoleucine- and trigonelline-based standardized fenugreek (Trigonella foenum-graecum L) seed extract in laboratory rats. Materials and Methods: The AOT and subchronic (90-day repeated dose) toxicity were evaluated using Sprague-Dawley rats as per the Organisation for Economic Co-operation and Development (OECD) guidelines No. 423 and No. 408, respectively. During the subchronic study, the effects on body weight, food and water consumption, organ weights with hematology, clinical biochemistry, and histology were studied. The mutagenicity and genotoxicity of IDM01 were evaluated by reverse mutation assay (Ames test, OECD guideline No. 471) and chromosome aberration test (OECD guideline No. 473), respectively. Results: The IDM01 did not show mortality or treatment-related adverse signs during acute (limit dose of 2000 mg/kg) and subchronic (90-day repeated dose of 250, 500, and 1000 mg/kg with 28 days of recovery period) administration. The IDM01 showed oral median lethal dose (LD50) >2000 mg/kg during AOT study. The no-observed adverse effect level (NOAEL) of IDM01 was 500 mg/kg. IDM01 did not show mutagenicity up to a concentration of 5000 μg/plate during Ames test and did not induce structural chromosomal aberrations up to 50 mg/culture. Conclusions: IDM01 was found safe during preclinical acute and subchronic (90-day repeated dose) toxicity in rats without mutagenicity or genotoxicity. SUMMARY Acute oral toxicity, subchronic (90-day) oral toxicity, mutagenicity and genotoxicity of IDM01 (4-hydroxyisoleucine- and trigonelline-based standardized fenugreek seed extract) was evaluated.The median lethal dose, LD50, of IDM01 was more than 2000 mg/kg of body weight in rats.No observed adverse effect level (NOAEL) of IDM01 was 500 mg/kg of body weight in rats.IDM01 was found safe during acute and subchronic oral toxicity studies in rats without mutagenicity or genotoxicity potetial. Abbreviations Used: 2-AA: 2-aminoanthracene; 2-AF: 2-aminofluorene; 4 NQNO: 4-nitroquinolene-N-oxide; 4HI: 4-hydroxyisoleucine; ANOVA: Analysis of variance; AOT: Acute oral toxicity; DM: Diabetes mellitus; IDM01: The Botanical composition of 4-hydroxyisoleucine- and trigonelline-based standardized fenugreek seed extract; LD50: Median lethal dose; MMS: Methyl methanesulfonate; NAD: No abnormality detected; OECD: Organisation for Economic Co-operation and Development; SD: Standard deviation; UV: Ultraviolet; VC: Vehicle control. 2-AA: 2-aminoanthracene; 2-AF: 2-aminofluorene; 4 NQNO: 4-nitroquinolene-N-oxide; 4HI: 4-hydroxyisoleucine; ANOVA: Analysis of variance; AOT: Acute oral toxicity; DM: Diabetes mellitus; IDM01: The Botanical composition of 4-hydroxyisoleucine- and trigonelline-based standardized fenugreek seed extract; LD50: Median lethal dose; MMS: Methyl methanesulfonate; NAD: No abnormality detected; OECD: Organisation for Economic Co-operation and Development; SD: Standard deviation; UV: Ultraviolet; VC: Vehicle control PMID:28539737

Resistance Training Increases the Variability of Strength Test Scores

DTIC Science & Technology

2009-06-08

standard deviations for pretest and posttest strength measurements. This information was recorded for every strength test used in a total of 377 samples...significant if the posttest standard deviation consistently was larger than the pretest standard deviation. This condition could be satisfied even if...the difference in the standard deviations was small. For example, the posttest standard deviation might be 1% larger than the pretest standard

[Determination of total, soluble and insoluble dietary fiber in foods by enzymatic-gravimetric method].

PubMed

Yang, X; Yang, Y; Zhou, R; Bian, L

2001-11-01

For studying the contents of dietary fiber in general foods and functional foods, a enzymatic-gravimetric method recommended by AOAC was established in our laboratory. The method for the determination of total, soluble and insoluble dietary fiber in foods and functional foods could be used for many other kind of foods. The relative standard deviations (RSD) of reproducibility between-run and within-run were 2.04%-7.85%, 3.42%-55.23% respectively. The repeatability of the methods was good, and the methods are suitable for many foods.

Estimate of standard deviation for a log-transformed variable using arithmetic means and standard deviations.

PubMed

Quan, Hui; Zhang, Ji

2003-09-15

Analyses of study variables are frequently based on log transformations. To calculate the power for detecting the between-treatment difference in the log scale, we need an estimate of the standard deviation of the log-transformed variable. However, in many situations a literature search only provides the arithmetic means and the corresponding standard deviations. Without individual log-transformed data to directly calculate the sample standard deviation, we need alternative methods to estimate it. This paper presents methods for estimating and constructing confidence intervals for the standard deviation of a log-transformed variable given the mean and standard deviation of the untransformed variable. It also presents methods for estimating the standard deviation of change from baseline in the log scale given the means and standard deviations of the untransformed baseline value, on-treatment value and change from baseline. Simulations and examples are provided to assess the performance of these estimates. Copyright 2003 John Wiley & Sons, Ltd.

Non-Contact Determination of Antisymmetric Plate Wave Velocity in Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1996-01-01

A 13 mJ NdYAG 1064 nm, 4 ns, laser pulse was employed to produce ultrasonic plate waves in 20 percent porous SiC/SiC composite tensile specimens of three different architectures. An air coupled 0.5 MHz transducer was used to detect and collect the waveforms which contained first antisymmetric plate wave pulses for determining the shear wave velocity (VS). These results were compared to VS values determined on the same specimens with 0.5 MHz ultrasonic transducers with contact coupling. Averages of four noncontact determinations on each of 18 specimens were compared to averages of four contact values. The noncontact VS's fall in the same range as the contact. The standard deviations for the noncontact VS's averaged 2.8 percent. The standard deviations for the contact measurements averaged 2.3 percent, indicating similar reproducibility. Repeated laser pulsing at the same location always lead to deterioration of the ulu-"nic signal. The signal would recover in about 24 hr in air however, indicating that no permanent damage was produced.

Long-term reproducibility of relative sensitivity factors obtained with CAMECA Wf

NASA Astrophysics Data System (ADS)

Gui, D.; Xing, Z. X.; Huang, Y. H.; Mo, Z. Q.; Hua, Y. N.; Zhao, S. P.; Cha, L. Z.

2008-12-01

As the wafer size continues to increase and the feature size of the integrated circuits (IC) continues to shrink, process control of IC manufacturing becomes ever more important to reduce the cost of failures caused by the drift of processes or equipments. Characterization tools with high precision and reproducibility are required to capture any abnormality of the process. Although Secondary ion mass spectrometry (SIMS) has been widely used in dopant profile control, it was reported that magnetic sector SIMS, compared to quadrupole SIMS, has lower short-term repeatability and long-term reproducibility due to the high extraction field applied between sample and extraction lens. In this paper, we demonstrate that CAMECA Wf can deliver high long-term reproducibility because of its high-level automation and improved design of immersion lens. The relative standard deviation (R.S.D.) of the relative sensitivity factors (RSF) of three typical elements, i.e., boron (B), phosphorous (P) and nitrogen (N), over 3 years are 3.7%, 5.5% and 4.1%, respectively. The high reproducibility results have a practical implication that deviation can be estimated without testing the standards.

Determination of sulfur in kerosene by combustion and molecular absorption spectrometry in the gas phase

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

Ruschak, M.L.; Syty, A.

1982-08-01

A technique of nonflame molecular adsorption in the gas phase developed for the determination of sulfite trapped in tetrachloromercurate, is described herein for application to the determination of total sulfur in kerosene. The burner head is removed from the atomic absorption spectrometer and replaced with a flow-through absorption cell. A special reaction vessel is used to evolve SO/sub 2/ from the sulfite in a precise and convenient manner. The transient absorbance caused by the SO/sub 2/, as it is carried through the absorption cell, is measured. Both spiked and unspiked samples of kerosene were analyzed, and the reproducibility of themore » repeated runs is evidenced by a relative standard deviation from the mean of 5% for the unspiked kerosene and 4% for the spiked kerosene. If the detection level is defined as that concentration of S which gives a % S twice the standard deviation from the mean yields, the detection limit for the present method is 0.002% S by weight in kerosene.« less

A simplified and accurate detection of the genetically modified wheat MON71800 with one calibrator plasmid.

PubMed

Kim, Jae-Hwan; Park, Saet-Byul; Roh, Hyo-Jeong; Park, Sunghoon; Shin, Min-Ki; Moon, Gui Im; Hong, Jin-Hwan; Kim, Hae-Yeong

2015-06-01

With the increasing number of genetically modified (GM) events, unauthorized GMO releases into the food market have increased dramatically, and many countries have developed detection tools for them. This study described the qualitative and quantitative detection methods of unauthorized the GM wheat MON71800 with a reference plasmid (pGEM-M71800). The wheat acetyl-CoA carboxylase (acc) gene was used as the endogenous gene. The plasmid pGEM-M71800, which contains both the acc gene and the event-specific target MON71800, was constructed as a positive control for the qualitative and quantitative analyses. The limit of detection in the qualitative PCR assay was approximately 10 copies. In the quantitative PCR assay, the standard deviation and relative standard deviation repeatability values ranged from 0.06 to 0.25 and from 0.23% to 1.12%, respectively. This study supplies a powerful and very simple but accurate detection strategy for unauthorized GM wheat MON71800 that utilizes a single calibrator plasmid. Copyright © 2014 Elsevier Ltd. All rights reserved.

Accuracy of a method based on atomic absorption spectrometry to determine inorganic arsenic in food: Outcome of the collaborative trial IMEP-41.

PubMed

Fiamegkos, I; Cordeiro, F; Robouch, P; Vélez, D; Devesa, V; Raber, G; Sloth, J J; Rasmussen, R R; Llorente-Mirandes, T; Lopez-Sanchez, J F; Rubio, R; Cubadda, F; D'Amato, M; Feldmann, J; Raab, A; Emteborg, H; de la Calle, M B

2016-12-15

A collaborative trial was conducted to determine the performance characteristics of an analytical method for the quantification of inorganic arsenic (iAs) in food. The method is based on (i) solubilisation of the protein matrix with concentrated hydrochloric acid to denature proteins and allow the release of all arsenic species into solution, and (ii) subsequent extraction of the inorganic arsenic present in the acid medium using chloroform followed by back-extraction to acidic medium. The final detection and quantification is done by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). The seven test items used in this exercise were reference materials covering a broad range of matrices: mussels, cabbage, seaweed (hijiki), fish protein, rice, wheat, mushrooms, with concentrations ranging from 0.074 to 7.55mgkg(-1). The relative standard deviation for repeatability (RSDr) ranged from 4.1 to 10.3%, while the relative standard deviation for reproducibility (RSDR) ranged from 6.1 to 22.8%. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Measurement of resistant starch by enzymatic digestion in starch and selected plant materials: collaborative study.

PubMed

McCleary, Barry V; McNally, Marian; Rossiter, Patricia

2002-01-01

Interlaboratory performance statistics was determined for a method developed to measure the resistant starch (RS) content of selected plant food products and a range of commercial starch samples. Food materials examined contained RS (cooked kidney beans, green banana, and corn flakes) and commercial starches, most of which naturally contain, or were processed to yield, elevated RS levels. The method evaluated was optimized to yield RS values in agreement with those reported for in vivo studies. Thirty-seven laboratories tested 8 pairs of blind duplicate starch or plant material samples with RS values between 0.6 (regular maize starch) and 64% (fresh weight basis). For matrixes excluding regular maize starch, repeatability relative standard deviation (RSDr) values ranged from 1.97 to 4.2%, and reproducibility relative standard deviation (RSDR) values ranged from 4.58 to 10.9%. The range of applicability of the test is 2-64% RS. The method is not suitable for products with <1% RS (e.g., regular maize starch; 0.6% RS). For such products, RSDr and RSDR values are unacceptably high.

Mixture models reveal multiple positional bias types in RNA-Seq data and lead to accurate transcript concentration estimates.

PubMed

Tuerk, Andreas; Wiktorin, Gregor; Güler, Serhat

2017-05-01

Accuracy of transcript quantification with RNA-Seq is negatively affected by positional fragment bias. This article introduces Mix2 (rd. "mixquare"), a transcript quantification method which uses a mixture of probability distributions to model and thereby neutralize the effects of positional fragment bias. The parameters of Mix2 are trained by Expectation Maximization resulting in simultaneous transcript abundance and bias estimates. We compare Mix2 to Cufflinks, RSEM, eXpress and PennSeq; state-of-the-art quantification methods implementing some form of bias correction. On four synthetic biases we show that the accuracy of Mix2 overall exceeds the accuracy of the other methods and that its bias estimates converge to the correct solution. We further evaluate Mix2 on real RNA-Seq data from the Microarray and Sequencing Quality Control (MAQC, SEQC) Consortia. On MAQC data, Mix2 achieves improved correlation to qPCR measurements with a relative increase in R2 between 4% and 50%. Mix2 also yields repeatable concentration estimates across technical replicates with a relative increase in R2 between 8% and 47% and reduced standard deviation across the full concentration range. We further observe more accurate detection of differential expression with a relative increase in true positives between 74% and 378% for 5% false positives. In addition, Mix2 reveals 5 dominant biases in MAQC data deviating from the common assumption of a uniform fragment distribution. On SEQC data, Mix2 yields higher consistency between measured and predicted concentration ratios. A relative error of 20% or less is obtained for 51% of transcripts by Mix2, 40% of transcripts by Cufflinks and RSEM and 30% by eXpress. Titration order consistency is correct for 47% of transcripts for Mix2, 41% for Cufflinks and RSEM and 34% for eXpress. We, further, observe improved repeatability across laboratory sites with a relative increase in R2 between 8% and 44% and reduced standard deviation.

Variability and repeatability analysis of plantar pressure during gait in older people.

PubMed

Franco, Pedro S; Silva, Caio Borella P da; Rocha, Emmanuel S da; Carpes, Felipe P

2015-01-01

Repeatability and variability of the plantar pressure during walking are important components in the clinical assessment of the elderly. However, there is a lack of information on the uniformity of plantar pressure patterns in the elderly. To analyze the repeatability and variability in plantar pressure considering mean, peak and asymmetries during aged gait. Plantar pressure was monitored in four different days for ten elderly subjects (5 female), with mean±standard-deviation age of 73±6 years, walking barefoot at preferred speed. Data were compared between steps for each day and between different days. Mean and peak plantar pressure values were similar between the different days of evaluation. Asymmetry indexes were similar between the different days evaluated. Plantar pressure presented a consistent pattern in the elderly. However, the asymmetry indexes observed suggest that the elderly are exposed to repetitive asymmetric loading during locomotion. Such result requires further investigation, especially concerning the role of these asymmetries for development of articular injuries. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Special electronic distance meter calibration for precise engineering surveying industrial applications

NASA Astrophysics Data System (ADS)

Braun, Jaroslav; Štroner, Martin; Urban, Rudolf

2015-05-01

All surveying instruments and their measurements suffer from some errors. To refine the measurement results, it is necessary to use procedures restricting influence of the instrument errors on the measured values or to implement numerical corrections. In precise engineering surveying industrial applications the accuracy of the distances usually realized on relatively short distance is a key parameter limiting the resulting accuracy of the determined values (coordinates, etc.). To determine the size of systematic and random errors of the measured distances were made test with the idea of the suppression of the random error by the averaging of the repeating measurement, and reducing systematic errors influence of by identifying their absolute size on the absolute baseline realized in geodetic laboratory at the Faculty of Civil Engineering CTU in Prague. The 16 concrete pillars with forced centerings were set up and the absolute distances between the points were determined with a standard deviation of 0.02 millimetre using a Leica Absolute Tracker AT401. For any distance measured by the calibrated instruments (up to the length of the testing baseline, i.e. 38.6 m) can now be determined the size of error correction of the distance meter in two ways: Firstly by the interpolation on the raw data, or secondly using correction function derived by previous FFT transformation usage. The quality of this calibration and correction procedure was tested on three instruments (Trimble S6 HP, Topcon GPT-7501, Trimble M3) experimentally using Leica Absolute Tracker AT401. By the correction procedure was the standard deviation of the measured distances reduced significantly to less than 0.6 mm. In case of Topcon GPT-7501 is the nominal standard deviation 2 mm, achieved (without corrections) 2.8 mm and after corrections 0.55 mm; in case of Trimble M3 is nominal standard deviation 3 mm, achieved (without corrections) 1.1 mm and after corrections 0.58 mm; and finally in case of Trimble S6 is nominal standard deviation 1 mm, achieved (without corrections) 1.2 mm and after corrections 0.51 mm. Proposed procedure of the calibration and correction is in our opinion very suitable for increasing of the accuracy of the electronic distance measurement and allows the use of the common surveying instrument to achieve uncommonly high precision.

Standard error of measurement of 5 health utility indexes across the range of health for use in estimating reliability and responsiveness.

PubMed

Palta, Mari; Chen, Han-Yang; Kaplan, Robert M; Feeny, David; Cherepanov, Dasha; Fryback, Dennis G

2011-01-01

Standard errors of measurement (SEMs) of health-related quality of life (HRQoL) indexes are not well characterized. SEM is needed to estimate responsiveness statistics, and is a component of reliability. To estimate the SEM of 5 HRQoL indexes. The National Health Measurement Study (NHMS) was a population-based survey. The Clinical Outcomes and Measurement of Health Study (COMHS) provided repeated measures. A total of 3844 randomly selected adults from the noninstitutionalized population aged 35 to 89 y in the contiguous United States and 265 cataract patients. The SF6-36v2™, QWB-SA, EQ-5D, HUI2, and HUI3 were included. An item-response theory approach captured joint variation in indexes into a composite construct of health (theta). The authors estimated 1) the test-retest standard deviation (SEM-TR) from COMHS, 2) the structural standard deviation (SEM-S) around theta from NHMS, and 3) reliability coefficients. SEM-TR was 0.068 (SF-6D), 0.087 (QWB-SA), 0.093 (EQ-5D), 0.100 (HUI2), and 0.134 (HUI3), whereas SEM-S was 0.071, 0.094, 0.084, 0.074, and 0.117, respectively. These yield reliability coefficients 0.66 (COMHS) and 0.71 (NHMS) for SF-6D, 0.59 and 0.64 for QWB-SA, 0.61 and 0.70 for EQ-5D, 0.64 and 0.80 for HUI2, and 0.75 and 0.77 for HUI3, respectively. The SEM varied across levels of health, especially for HUI2, HUI3, and EQ-5D, and was influenced by ceiling effects. Limitations. Repeated measures were 5 mo apart, and estimated theta contained measurement error. The 2 types of SEM are similar and substantial for all the indexes and vary across health.

7 CFR 400.204 - Notification of deviation from standards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Notification of deviation from standards. 400.204... Contract-Standards for Approval § 400.204 Notification of deviation from standards. A Contractor shall advise the Corporation immediately if the Contractor deviates from the requirements of these standards...

[Study on the reproducibility of ACTH concentrations in plasma of horses with and without equine Cushing syndrome].

PubMed

Gehlen, Heidrun; Bradaric, Zrinkja

2013-01-01

The evaluation of plasma ACTH and the dexamethasone suppression test are considered the methods of choice to evaluate the course of therapy of pituitary pars intermedia dysfunction (PPID). Sampling protocols as well as vacutainers for analysis differ between the laboratories. To evaluate the reproducability of plasma ACTH measurement between four different laboratories (A, B, C, D) in Germany as well as within the laboratories themselves, ten horses with previously diagnosed PPID and four healthy horses were sampled and analyzed. Each laboratory received two differently labeled samples of each horse which had been drawn at the same time (blinded samples). Sampling was performed in the morning at the same time. The sampling vacutainers (with and without addition of coagulation and proteinase inhibitors) and postage of the samples was performed according to laboratory standards. In one laboratory the influence of the time of centrifugation (immediately after taking blood versus after one hour) was determined. The samples were processed and analyzed according to laboratory protocols. Determination of ACTH levels was performed using chemiluminescence immunoassay. In total 132 blood samples were analyzed. The results of doubled blood samples of the same horse showed a standard deviation ranging from +/- 6 to +/- 27 pg/ml within the laboratories (Ø 19,29 pg/ml). The standard deviation of the repeatability of the variation coefficient was 13,48%. Blood samples of the same horse resulted in ACTH levels of 121 pg/ml in the first probe and in < 5 pg/ml in the second probe. Standard deviation of measured ACTH values between the laboratories was +/- 26,4 pg/ml (Ø 27,44 pg/ml). The standard deviation of the reproducibility of the variation coefficient was 18,36%. In a 20 year old gelding the lowest ACTH value was 60.9 pg/ml whereas the highest measured value was 108 pg/ml. Immediate centrifugation of blood samples resulted in significantly higher ACTH values at an average of 11.6 pg/ml. The additional use of proteinase inhibitors (aprotinine) showed no influence on ACTH levels in this study.

Healing and/or breaking? The mental health implications of repeated economic insecurity.

PubMed

Watson, Barry; Osberg, Lars

2017-09-01

Current literature confirms the negative consequences of contemporaneous economic insecurity for mental health, but ignores possible implications of repeated insecurity. This paper asks how much a person's history of economic insecurity matters for psychological distress by contrasting the implications of two models. Consistent with the health capital literature, the Healing model suggests psychological distress is a stock variable affected by shocks from life events, with past events having less impact than more recent shocks. Alternatively, the Breaking Point model considers that high levels of distress represent a distinct shift in life state, which occurs if the accumulation of past life stresses exceeds some critical value. Using five cycles of Canadian National Population Health Survey data (2000-2009), we model the impact of past economic insecurity shocks on current psychological distress in a way that can distinguish between these hypotheses. In our sample of 1775 males and 1883 females aged 25 to 64, we find a robust healing effect for one-time economic insecurity shocks. For males, only a recent one-time occurrence of economic insecurity is predictive of higher current psychological distress (0.19 standard deviations). Moreover, working age adults tend to recover from past accumulated experiences of economic insecurity if they were recently economically secure. However, consistent with the Breaking Point hypothesis, males experiencing three or four cycles of recent insecurity are estimated to have a level of current psychological distress that is 0.26-0.29 standard deviations higher than those who were employed and job secure throughout the same time period. We also find, consistent with other literature, distinct gender differences - for working age females, all economic insecurity variables are statistically insignificant at conventional levels. Our results suggest that although Canadians are resilient to one-time insecurity shocks, males most vulnerable to repeated bouts suffer from elevated levels of psychological distress. Copyright © 2017 Elsevier Ltd. All rights reserved.

The validity and reliability of the StationMaster: a device to improve the accuracy of station assessment in labour.

PubMed

Awan, Noveen; Rhoades, Anthony; Weeks, Andrew D

2009-07-01

To compare the accuracy of digital assessment and the StationMaster (SM) in the assessment of fetal head station. The SM is a simple modification of the amniotomy hook which works by relocating the point of reference for station assessment from the ischial spines to the posterior fourchette. It is first adjusted to the woman's pelvic size, and then inserted into the vagina until it touches the fetal head. The station is then read off at the posterior fourchette in cm. An in vitro study of test validity and reliability was conducted at Liverpool Women's Hospital, Liverpool, UK. An apparatus was constructed in which a model fetal head could be accurately positioned within a mannequin's pelvis. Twenty midwives and 20 doctors (in current labour ward practice) gave their consent to take part. First, the head was placed in 5 random stations (-2 to +7 cm) and the participant asked to record their digital assessment for each. The participant was then taught to use the SM and the experiment repeated with 5 new stations. The complete experiment was repeated at least 2 weeks later using the same stations but in reverse order. The true values were compared with both the digital and SM assessments using mean differences with 95% limits of agreement. The repeatability of the two methods was assessed in the same way. Overall, the SM was more accurate than digital examination. The mean error (S.D.) ranged from 0.1 (1.2) to 2.6 (1.6) for the StationMaster and 0.3 (1.3) to 4.3 (1.1) for digital examination. Inaccuracies increased as the head descended through the pelvis. When assessed digitally, the true value fell outside one standard deviation for stations of more than +1cm. In contrast, with the SM the true value remained inside one standard deviation for all stations up to +5. In vitro the SM improves the accuracy of intrapartum station assessment.

The Standard Deviation of Launch Vehicle Environments

NASA Technical Reports Server (NTRS)

Yunis, Isam

2005-01-01

Statistical analysis is used in the development of the launch vehicle environments of acoustics, vibrations, and shock. The standard deviation of these environments is critical to accurate statistical extrema. However, often very little data exists to define the standard deviation and it is better to use a typical standard deviation than one derived from a few measurements. This paper uses Space Shuttle and expendable launch vehicle flight data to define a typical standard deviation for acoustics and vibrations. The results suggest that 3dB is a conservative and reasonable standard deviation for the source environment and the payload environment.

Characterizing the Perfonnance of the Wheel Electrostatic Spectrometer

NASA Technical Reports Server (NTRS)

Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Clements, J. S.; Calle, C. I.

2013-01-01

A Wheel Electrostatic Spectrometer has been developed as a surveying tool to be incorporated into a planetary rover design. Electrostatic sensors with various protruding cover insulators are embedded into a prototype rover wheel. When these insulators come into contact with a surface, a charge develops on the cover insulator through tribocharging. A charge spectrum is created by analyzing the accumulated charge on each of the dissimilar cover insulators. We eventually intend to prove charge spectra can be used o determine differences in planetary regolith properties. We tested the effects of residual surface charge on the cover insulators and discovered a need to discharge the sensor cover insulators after each revolution. We proved the repeatability of the measurements for this sensor package and found that the sensor repeatability lies within one standard deviation of the noise in the signal.

Comparison of three-dimensional multi-segmental foot models used in clinical gait laboratories.

PubMed

Nicholson, Kristen; Church, Chris; Takata, Colton; Niiler, Tim; Chen, Brian Po-Jung; Lennon, Nancy; Sees, Julie P; Henley, John; Miller, Freeman

2018-05-16

Many skin-mounted three-dimensional multi-segmented foot models are currently in use for gait analysis. Evidence regarding the repeatability of models, including between trial and between assessors, is mixed, and there are no between model comparisons of kinematic results. This study explores differences in kinematics and repeatability between five three-dimensional multi-segmented foot models. The five models include duPont, Heidelberg, Oxford Child, Leardini, and Utah. Hind foot, forefoot, and hallux angles were calculated with each model for ten individuals. Two physical therapists applied markers three times to each individual to assess within and between therapist variability. Standard deviations were used to evaluate marker placement variability. Locally weighted regression smoothing with alpha-adjusted serial T tests analysis was used to assess kinematic similarities. All five models had similar variability, however, the Leardini model showed high standard deviations in plantarflexion/dorsiflexion angles. P-value curves for the gait cycle were used to assess kinematic similarities. The duPont and Oxford models had the most similar kinematics. All models demonstrated similar marker placement variability. Lower variability was noted in the sagittal and coronal planes compared to rotation in the transverse plane, suggesting a higher minimal detectable change when clinically considering rotation and a need for additional research. Between the five models, the duPont and Oxford shared the most kinematic similarities. While patterns of movement were very similar between all models, offsets were often present and need to be considered when evaluating published data. Copyright © 2018 Elsevier B.V. All rights reserved.

Polymeric ionic liquid based on magnetic materials fabricated through layer-by-layer assembly as adsorbents for extraction of pesticides.

PubMed

He, Lijun; Cui, Wenhang; Wang, Yali; Zhao, Wenjie; Xiang, Guoqiang; Jiang, Xiuming; Mao, Pu; He, Juan; Zhang, Shusheng

2017-11-03

In this study, layer-by-layer assembly of polyelectrolyte multilayer films on magnetic silica provided a convenient and controllable way to prepare polymeric ionic liquid-based magnetic adsorbents. The resulting particles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and magnetic measurements. The data showed that the magnetic particles had more homogeneous spherical shapes with higher saturation magnetization when compared to those obtained by free radical polymerization method. This facilitated the convenient collection of magnetic particles, with higher extraction repeatability. The extraction performance of the multilayer polymeric ionic liquid-based adsorbents was evaluated by magnetic solid-phase extraction of four pesticides including quinalphos, fenthion, phoxim, and chlorpropham. The data suggested that the extraction efficiency depended on the number of layers in the film. The parameters affecting the extraction efficiency were optimized, and good linearity ranging from 2 to 250μgL -1 was obtained with correlation coefficients of 0.9994-0.9998. Moreover, the proposed method presented low limit of detection (0.5μgL -1 , S/N=3) and limit of quantification (1.5μgL -1 , S/N=10), and good repeatability expressed by the relative standard deviation (2.0%-4.6%, n=5). The extraction recoveries of four pesticides were found to range from 58.9% to 85.8%. The reliability of the proposed method was demonstrated by analyzing environmental water samples, and the results revealed satisfactory spiked recovery, relative standard deviation, and selectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

Site-specific 13C content by quantitative isotopic 13C nuclear magnetic resonance spectrometry: a pilot inter-laboratory study.

PubMed

Chaintreau, Alain; Fieber, Wolfgang; Sommer, Horst; Gilbert, Alexis; Yamada, Keita; Yoshida, Naohiro; Pagelot, Alain; Moskau, Detlef; Moreno, Aitor; Schleucher, Jürgen; Reniero, Fabiano; Holland, Margaret; Guillou, Claude; Silvestre, Virginie; Akoka, Serge; Remaud, Gérald S

2013-07-25

Isotopic (13)C NMR spectrometry, which is able to measure intra-molecular (13)C composition, is of emerging demand because of the new information provided by the (13)C site-specific content of a given molecule. A systematic evaluation of instrumental behaviour is of importance to envisage isotopic (13)C NMR as a routine tool. This paper describes the first collaborative study of intra-molecular (13)C composition by NMR. The main goals of the ring test were to establish intra- and inter-variability of the spectrometer response. Eight instruments with different configuration were retained for the exercise on the basis of a qualification test. Reproducibility at the natural abundance of isotopic (13)C NMR was then assessed on vanillin from three different origins associated with specific δ (13)Ci profiles. The standard deviation was, on average, between 0.9 and 1.2‰ for intra-variability. The highest standard deviation for inter-variability was 2.1‰. This is significantly higher than the internal precision but could be considered good in respect of a first ring test on a new analytical method. The standard deviation of δ (13)Ci in vanillin was not homogeneous over the eight carbons, with no trend either for the carbon position or for the configuration of the spectrometer. However, since the repeatability for each instrument was satisfactory, correction factors for each carbon in vanillin could be calculated to harmonize the results. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of measurement deviations for the patient-specific quality assurance using intensity-modulated spot-scanning particle beams

NASA Astrophysics Data System (ADS)

Li, Yongqiang; Hsi, Wen C.

2017-04-01

To analyze measurement deviations of patient-specific quality assurance (QA) using intensity-modulated spot-scanning particle beams, a commercial radiation dosimeter using 24 pinpoint ionization chambers was utilized. Before the clinical trial, validations of the radiation dosimeter and treatment planning system were conducted. During the clinical trial 165 measurements were performed on 36 enrolled patients. Two or three fields of particle beam were used for each patient. Measurements were typically performed with the dosimeter placed at special regions of dose distribution along depth and lateral profiles. In order to investigate the dosimeter accuracy, repeated measurements with uniform dose irradiations were also carried out. A two-step approach was proposed to analyze 24 sampling points over a 3D treatment volume. The mean value and the standard deviation of each measurement did not exceed 5% for all measurements performed on patients with various diseases. According to the defined intervention thresholds of mean deviation and the distance-to-agreement concept with a Gamma index analysis using criteria of 3.0% and 2 mm, a decision could be made regarding whether the dose distribution was acceptable for the patient. Based measurement results, deviation analysis was carried out. In this study, the dosimeter was used for dose verification and provided a safety guard to assure precise dose delivery of highly modulated particle therapy. Patient-specific QA will be investigated in future clinical operations.

Sulfuric acid/hydrogen peroxide digestion and colorimetric a collaborative study.

PubMed

Christians, D K; Aspelund, T G; Brayton, S V; Roberts, L L

1991-01-01

Seven laboratories participated in a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested in sulfuric acid and hydrogen peroxide; digestion is complete in approximately 10 min. Phosphorus is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (SR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

Simultaneous characterization and quantification of 17 main compounds in Rabdosia rubescens by high performance liquid chromatography.

PubMed

Guo, Sen; Cui, Xueqin; Jiang, Mi; Bai, Lu; Tian, Xiao; Guo, Tiantian; Liu, Qingchao; Zhang, Li; Ho, Chi-Tang; Bai, Naisheng

2017-04-01

Rabdosia rubescens is a healthy herbal tea and well-known Chinese medicinal herb. To evaluate the quality of R. rubescens from China, a high performance liquid chromatography method with dual-wavelength detection was developed and validated. The method was successfully applied for the simultaneous characterization and quantification of 17 main constituents from four different cultivation regions in China. Under optimal conditions, analysis was performed on a Luna C-18 column and gradient elution with a solvent system of acetonitrile and 0.5% (v/v) acetic acid-water at a flow rate of 1.0 mL/min and wavelength of 220 nm and 280 nm. All standard calibration curves exhibited good linearity (r 2  > 0.9992) within the test ranges. The precision was evaluated by intraday and interday tests, which revealed relative standard deviation values within the ranges of 0.57-2.35% and 0.52-3.40%, respectively. The recoveries were in the range of 96.37-101.66%. The relative standard deviation values for stability and repeatability were < 5%. The contents of some compounds were low and varied with different cultivars. The proposed method could serve as a prerequisite for quality control of R. rubescens materials and products. Copyright © 2016. Published by Elsevier B.V.

Applicability of the DPPH assay for evaluating the antioxidant capacity of food additives - inter-laboratory evaluation study -.

PubMed

Shimamura, Tomoko; Sumikura, Yoshihiro; Yamazaki, Takeshi; Tada, Atsuko; Kashiwagi, Takehiro; Ishikawa, Hiroya; Matsui, Toshiro; Sugimoto, Naoki; Akiyama, Hiroshi; Ukeda, Hiroyuki

2014-01-01

An inter-laboratory evaluation study was conducted in order to evaluate the antioxidant capacity of food additives by using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Four antioxidants used as existing food additives (i.e., tea extract, grape seed extract, enju extract, and d-α-tocopherol) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) were used as analytical samples, and 14 laboratories participated in this study. The repeatability relative standard deviation (RSD(r)) of the IC50 of Trolox, four antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) were 1.8-2.2%, 2.2-2.9%, and 2.1-2.5%, respectively. Thus, the proposed DPPH assay showed good performance within the same laboratory. The reproducibility relative standard deviation (RSD(R)) of IC50 of Trolox, four antioxidants, and TEAC were 4.0-7.9%, 6.0-11%, and 3.7-9.3%, respectively. The RSD(R)/RSD(r) values of TEAC were lower than, or nearly equal to, those of IC50 of the four antioxidants, suggesting that the use of TEAC was effective for reducing the variance among the laboratories. These results showed that the proposed DPPH assay could be used as a standard method to evaluate the antioxidant capacity of food additives.

Determination of volatile bases in seafood using the ammonia ion selective electrode: collaborative study.

PubMed

Ellis, P C; Pivarnik, L F; Thiam, M; Ellis, P C; Pivarnik, L F; Thiam, M

2000-01-01

Nine collaborating laboratories tested a combination of 23 seafood samples for volatile bases using an ammonia ion selective electrode. Results were reported as mg NH3/100 g fish, but the method reflected levels of both ammonia and trimethylamine, which permeated the ammonia membrane. The 23 samples were broken down into 8 blind duplicate pairs, 2 Youden matched pairs, and 3 single samples covering fresh to spoiled product ranging from 8 to 82 mg NH3/100 g. Seven species were evaluated: Atlantic cod, squid, Atlantic halibut, gray sole, monkfish, dogfish, and Atlantic mackerel. The ammonia electrode assay was performed on an aqueous homogenate consisting of 95 mL distilled water and 5.0 g sample tissue. Alkaline ion strength adjusting solution (2 mL) was added to the homogenate to liberate ammonia that was sensed by the ion specific electrode and measured on a precalibrated portable meter. Repeatability standard deviations (RSDr) ranged from 4.2 to 17%; reproducibility standard deviations (RSDR) ranged from 8.8 to 21%. A standard ammonium chloride solution was provided to all laboratories to spike 3 different samples at 10 mg NH3/100 g. Recoveries of added ammonia as ammonium chloride for fresh, borderline, and spoiled samples were 88.6, 107, and 128%, respectively.

Quantifying gait deviations in individuals with rheumatoid arthritis using the Gait Deviation Index.

PubMed

Esbjörnsson, A-C; Rozumalski, A; Iversen, M D; Schwartz, M H; Wretenberg, P; Broström, E W

2014-01-01

In this study we evaluated the usability of the Gait Deviation Index (GDI), an index that summarizes the amount of deviation in movement from a standard norm, in adults with rheumatoid arthritis (RA). The aims of the study were to evaluate the ability of the GDI to identify gait deviations, assess inter-trial repeatability, and examine the relationship between the GDI and walking speed, physical disability, and pain. Sixty-three adults with RA and 59 adults with typical gait patterns were included in this retrospective case-control study. Following a three-dimensional gait analysis (3DGA), representative gait cycles were selected and GDI scores calculated. To evaluate the effect of walking speed, GDI scores were calculated using both a free-speed and a speed-matched reference set. Physical disability was assessed using the Health Assessment Questionnaire (HAQ) and subjects rated their pain during walking. Adults with RA had significantly increased gait deviations compared to healthy individuals, as shown by lower GDI scores [87.9 (SD = 8.7) vs. 99.4 (SD = 8.3), p < 0.001]. This difference was also seen when adjusting for walking speed [91.7 (SD = 9.0) vs. 99.9 (SD = 8.6), p < 0.001]. It was estimated that a change of ≥ 5 GDI units was required to account for natural variation in gait. There was no evident relationship between GDI and low/high RA-related physical disability and pain. The GDI seems to useful for identifying and summarizing gait deviations in individuals with RA. Thus, we consider that the GDI provides an overall measure of gait deviation that may reflect lower extremity pathology and may help clinicians to understand the impact of RA on gait dynamics.

Error-compensation model for simultaneous measurement of five degrees of freedom motion errors of a rotary axis

NASA Astrophysics Data System (ADS)

Bao, Chuanchen; Li, Jiakun; Feng, Qibo; Zhang, Bin

2018-07-01

This paper introduces an error-compensation model for our measurement method to measure five motion errors of a rotary axis based on fibre laser collimation. The error-compensation model is established in a matrix form using the homogeneous coordinate transformation theory. The influences of the installation errors, error crosstalk, and manufacturing errors are analysed. The model is verified by both ZEMAX simulation and measurement experiments. The repeatability values of the radial and axial motion errors are significantly suppressed by more than 50% after compensation. The repeatability experiments of five degrees of freedom motion errors and the comparison experiments of two degrees of freedom motion errors of an indexing table were performed by our measuring device and a standard instrument. The results show that the repeatability values of the angular positioning error ε z and tilt motion error around the Y axis ε y are 1.2″ and 4.4″, and the comparison deviations of the two motion errors are 4.0″ and 4.4″, respectively. The repeatability values of the radial and axial motion errors, δ y and δ z , are 1.3 and 0.6 µm, respectively. The repeatability value of the tilt motion error around the X axis ε x is 3.8″.

7 CFR 400.174 - Notification of deviation from financial standards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Notification of deviation from financial standards... Agreement-Standards for Approval; Regulations for the 1997 and Subsequent Reinsurance Years § 400.174 Notification of deviation from financial standards. An insurer must immediately advise FCIC if it deviates from...

Degrees of Freedom for Allan Deviation Estimates of Multiple Clocks

DTIC Science & Technology

2016-04-01

Allan deviation . Allan deviation will be represented by σ and standard deviation will be represented by δ. In practice, when the Allan deviation of a...the Allan deviation of standard noise types. Once the number of degrees of freedom is known, an approximate confidence interval can be assigned by...measurement errors from paired difference data. We extend this approach by using the Allan deviation to estimate the error in a frequency standard

Assessing Diversity of DNA Structure-Related Sequence Features in Prokaryotic Genomes

PubMed Central

Huang, Yongjie; Mrázek, Jan

2014-01-01

Prokaryotic genomes are diverse in terms of their nucleotide and oligonucleotide composition as well as presence of various sequence features that can affect physical properties of the DNA molecule. We present a survey of local sequence patterns which have a potential to promote non-canonical DNA conformations (i.e. different from standard B-DNA double helix) and interpret the results in terms of relationships with organisms' habitats, phylogenetic classifications, and other characteristics. Our present work differs from earlier similar surveys not only by investigating a wider range of sequence patterns in a large number of genomes but also by using a more realistic null model to assess significant deviations. Our results show that simple sequence repeats and Z-DNA-promoting patterns are generally suppressed in prokaryotic genomes, whereas palindromes and inverted repeats are over-represented. Representation of patterns that promote Z-DNA and intrinsic DNA curvature increases with increasing optimal growth temperature (OGT), and decreases with increasing oxygen requirement. Additionally, representations of close direct repeats, palindromes and inverted repeats exhibit clear negative trends with increasing OGT. The observed relationships with environmental characteristics, particularly OGT, suggest possible evolutionary scenarios of structural adaptation of DNA to particular environmental niches. PMID:24408877

Micromachined piconewton force sensor for biophysics investigations

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

Koch, Steven J.; Thayer, Gayle E.; Corwin, Alex D.

2006-10-23

We describe a micromachined force sensor that is able to measure forces as small as 1 pN in both air and water. First, we measured the force field produced by an electromagnet on individual 2.8 {mu}m magnetic beads glued to the sensor. By repeating with 11 different beads, we measured a 9% standard deviation in saturation magnetization. We next demonstrated that the sensor was fully functional when immersed in physiological buffer. These results show that the force sensors can be useful for magnetic force calibration and also for measurement of biophysical forces on chip.

1 CFR 21.14 - Deviations from standard organization of the Code of Federal Regulations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 1 General Provisions 1 2010-01-01 2010-01-01 false Deviations from standard organization of the... CODIFICATION General Numbering § 21.14 Deviations from standard organization of the Code of Federal Regulations. (a) Any deviation from standard Code of Federal Regulations designations must be approved in advance...

Comparison of 30-2 Standard and Fast programs of Swedish Interactive Threshold Algorithm of Humphrey Field Analyzer for perimetry in patients with intracranial tumors.

PubMed

Singh, Manav Deep; Jain, Kanika

2017-11-01

To find out whether 30-2 Swedish Interactive Threshold Algorithm (SITA) Fast is comparable to 30-2 SITA Standard as a tool for perimetry among the patients with intracranial tumors. This was a prospective cross-sectional study involving 80 patients aged ≥18 years with imaging proven intracranial tumors and visual acuity better than 20/60. The patients underwent multiple visual field examinations using the two algorithms till consistent and repeatable results were obtained. A total of 140 eyes of 80 patients were analyzed. Almost 60% of patients undergoing perimetry with SITA Standard required two or more sessions to obtain consistent results, whereas the same could be obtained in 81.42% with SITA Fast in the first session itself. Of 140 eyes, 70 eyes had recordable field defects and the rest had no defects as detected by either of the two algorithms. Mean deviation (MD) (P = 0.56), pattern standard deviation (PSD) (P = 0.22), visual field index (P = 0.83) and number of depressed points at P < 5%, 2%, 1%, and 0.5% on MD and PSD probability plots showed no statistically significant difference between two algorithms. Bland-Altman test showed that considerable variability existed between two algorithms. Perimetry performed by SITA Standard and SITA Fast algorithm of Humphrey Field Analyzer gives comparable results among the patients of intracranial tumors. Being more time efficient and with a shorter learning curve, SITA Fast my be recommended as a standard test for the purpose of perimetry among these patients.

Valid internal standard technique for arson detection based on gas chromatography-mass spectrometry.

PubMed

Salgueiro, Pedro A S; Borges, Carlos M F; Bettencourt da Silva, Ricardo J N

2012-09-28

The most popular procedures for the detection of residues of accelerants in fire debris are the ones published by the American Society for Testing and Materials (ASTM E1412-07 and E1618-10). The most critical stages of these tests are the conservation of fire debris from the sampling to the laboratory, the extraction of residues of accelerants from the debris to the activated charcoal strips (ACS) and from those to the final solvent, as well as the analysis of sample extract by gas chromatography-mass spectrometry (GC-MS) and the interpretation of the instrumental signal. This work proposes a strategy for checking the quality of the sample conservation, the accelerant residues transference to final solvent and GC-MS analysis, using internal standard additions. It is used internal standards ranging from a highly volatile compound for checking debris conservation to low volatile compound for checking GC-MS repeatability. The developed quality control (QC) parameters are not affected by GC-MS sensitivity variation and, specifically, the GC-MS performance control is not affected by ACS adsorption saturation that may mask test performance deviations. The proposed QC procedure proved to be adequate to check GC-MS repeatability, ACS extraction and sample conservation since: (1) standard additions are affected by negligible uncertainty and (2) observed dispersion of QC parameters are fit for its intended use. Copyright © 2012 Elsevier B.V. All rights reserved.

Validation of Fourier analysis of videokeratographic data.

PubMed

Sideroudi, Haris; Labiris, Georgios; Ditzel, Fienke; Tsaragli, Efi; Georgatzoglou, Kimonas; Siganos, Haralampos; Kozobolis, Vassilios

2017-06-15

The aim was to assess the repeatability of Fourier transfom analysis of videokeratographic data using Pentacam in normal (CG), keratoconic (KC) and post-CXL (CXL) corneas. This was a prospective, clinic-based, observational study. One randomly selected eye from all study participants was included in the analysis: 62 normal eyes (CG group), 33 keratoconus eyes (KC group), while 34 eyes, which had already received CXL treatment, formed the CXL group. Fourier analysis of keratometric data were obtained using Pentacam, by two different operators within each of two sessions. Precision, repeatability and Intraclass Correlation Coefficient (ICC), were calculated for evaluating intrassesion and intersession repeatability for the following parameters: Spherical Component (SphRmin, SphEcc), Maximum Decentration (Max Dec), Regular Astigmatism, and Irregularitiy (Irr). Bland-Altman analysis was used for assessing interobserver repeatability. All parameters were presented to be repeatable, reliable and reproductible in all groups. Best intrasession and intersession repeatability and reliability were detected for parameters SphRmin, SphEcc and Max Dec parameters for both operators using ICC (intrasession: ICC > 98%, intersession: ICC > 94.7%) and within subject standard deviation. Best precision and lowest range of agreement was found for the SphRmin parameter (CG: 0.05, KC: 0.16, and CXL: 0.2) in all groups, while the lowest repeatability, reliability and reproducibility was detected for the Irr parameter. The Pentacam system provides accurate measurements of Fourier tranform keratometric data. A single Pentacam scan will be sufficient for most clinical applications.

Upgraded FAA Airfield Capacity Model. Volume 1. Supplemental User’s Guide

DTIC Science & Technology

1981-02-01

SIGMAR (P4.0) cc 1-4 -standard deviation, in seconds, of arrival runway occupancy time (R.O.T.). SIGMAA (F4.0) cc 5-8 -standard deviation, in seconds...iI SI GMAC - The standard deviation of the time from departure clearance to start of roll. SIGMAR - The standard deviation of the arrival runway

Toward the Standardization of Biochar Analysis: The COST Action TD1107 Interlaboratory Comparison.

PubMed

Bachmann, Hans Jörg; Bucheli, Thomas D; Dieguez-Alonso, Alba; Fabbri, Daniele; Knicker, Heike; Schmidt, Hans-Peter; Ulbricht, Axel; Becker, Roland; Buscaroli, Alessandro; Buerge, Diane; Cross, Andrew; Dickinson, Dane; Enders, Akio; Esteves, Valdemar I; Evangelou, Michael W H; Fellet, Guido; Friedrich, Kevin; Gasco Guerrero, Gabriel; Glaser, Bruno; Hanke, Ulrich M; Hanley, Kelly; Hilber, Isabel; Kalderis, Dimitrios; Leifeld, Jens; Masek, Ondrej; Mumme, Jan; Carmona, Marina Paneque; Calvelo Pereira, Roberto; Rees, Frederic; Rombolà, Alessandro G; de la Rosa, José Maria; Sakrabani, Ruben; Sohi, Saran; Soja, Gerhard; Valagussa, Massimo; Verheijen, Frank; Zehetner, Franz

2016-01-20

Biochar produced by pyrolysis of organic residues is increasingly used for soil amendment and many other applications. However, analytical methods for its physical and chemical characterization are yet far from being specifically adapted, optimized, and standardized. Therefore, COST Action TD1107 conducted an interlaboratory comparison in which 22 laboratories from 12 countries analyzed three different types of biochar for 38 physical-chemical parameters (macro- and microelements, heavy metals, polycyclic aromatic hydrocarbons, pH, electrical conductivity, and specific surface area) with their preferential methods. The data were evaluated in detail using professional interlaboratory testing software. Whereas intralaboratory repeatability was generally good or at least acceptable, interlaboratory reproducibility was mostly not (20% < mean reproducibility standard deviation < 460%). This paper contributes to better comparability of biochar data published already and provides recommendations to improve and harmonize specific methods for biochar analysis in the future.

Development and validation of new spectrophotometric ratio H-point standard addition method and application to gastrointestinal acting drugs mixtures.

PubMed

Yehia, Ali M

2013-05-15

New, simple, specific, accurate and precise spectrophotometric technique utilizing ratio spectra is developed for simultaneous determination of two different binary mixtures. The developed ratio H-point standard addition method (RHPSAM) was managed successfully to resolve the spectral overlap in itopride hydrochloride (ITO) and pantoprazole sodium (PAN) binary mixture, as well as, mosapride citrate (MOS) and PAN binary mixture. The theoretical background and advantages of the newly proposed method are presented. The calibration curves are linear over the concentration range of 5-60 μg/mL, 5-40 μg/mL and 4-24 μg/mL for ITO, MOS and PAN, respectively. Specificity of the method was investigated and relative standard deviations were less than 1.5. The accuracy, precision and repeatability were also investigated for the proposed method according to ICH guidelines. Copyright © 2013 Elsevier B.V. All rights reserved.

Development and validation of new spectrophotometric ratio H-point standard addition method and application to gastrointestinal acting drugs mixtures

NASA Astrophysics Data System (ADS)

Yehia, Ali M.

2013-05-01

New, simple, specific, accurate and precise spectrophotometric technique utilizing ratio spectra is developed for simultaneous determination of two different binary mixtures. The developed ratio H-point standard addition method (RHPSAM) was managed successfully to resolve the spectral overlap in itopride hydrochloride (ITO) and pantoprazole sodium (PAN) binary mixture, as well as, mosapride citrate (MOS) and PAN binary mixture. The theoretical background and advantages of the newly proposed method are presented. The calibration curves are linear over the concentration range of 5-60 μg/mL, 5-40 μg/mL and 4-24 μg/mL for ITO, MOS and PAN, respectively. Specificity of the method was investigated and relative standard deviations were less than 1.5. The accuracy, precision and repeatability were also investigated for the proposed method according to ICH guidelines.

Polycyclic aromatic hydrocarbons (PAHs) in yogurt samples.

PubMed

Battisti, Chiara; Girelli, Anna Maria; Tarola, Anna Maria

2015-01-01

The concentrations and distributions of major polycyclic aromatic hydrocarbons (PAHs) were determined in 20 kinds of yogurt specimens collected from Italian supermarkets using reversed phase high-performance liquid chromatography equipped with fluorescence detection. The method was validated by determination of recovery percentages, precision (repeatability) and sensitivity (limits of detection) with yogurt samples fortified at 0.25, 0.5 and 1 µg/kg concentration levels. The recovery of 13 PAHs, with the exception of naphthalene and acenaphthene, ranged from 61% to 130% and from 60% to 97% at all the levels for yogurts with low (0.1%) and high (3.9%) fat content, respectively. The method is repeatable with relative standard deviation values <20% for all analytes. The results obtained demonstrate that acenaphthene, fluorantene, phenanthrene, anthracene, fluoranthene and pyrene were found in all samples with a similar distribution, but different content when yogurts with low and high fats were compared.

Inter- and intra-observer variation in soft-tissue sarcoma target definition.

PubMed

Roberge, D; Skamene, T; Turcotte, R E; Powell, T; Saran, N; Freeman, C

2011-08-01

To evaluate inter- and intra-observer variability in gross tumor volume definition for adult limb/trunk soft tissue sarcomas. Imaging studies of 15 patients previously treated with preoperative radiation were used in this study. Five physicians (radiation oncologists, orthopedic surgeons and a musculoskeletal radiologist) were asked to contour each of the 15 tumors on T1-weighted, gadolinium-enhanced magnetic resonance images. These contours were drawn twice by each physician. The volume and center of mass coordinates for each gross tumor volume were extracted and a Boolean analysis was performed to measure the degree of volume overlap. The median standard deviation in gross tumor volumes across observers was 6.1% of the average volume (range: 1.8%-24.9%). There was remarkably little variation in the 3D position of the gross tumor volume center of mass. For the 15 patients, the standard deviation of the 3D distance between centers of mass ranged from 0.06 mm to 1.7 mm (median 0.1mm). Boolean analysis demonstrated that 53% to 90% of the gross tumor volume was common to all observers (median overlap: 79%). The standard deviation in gross tumor volumes on repeat contouring was 4.8% (range: 0.1-14.4%) with a standard deviation change in the position of the center of mass of 0.4mm (range: 0mm-2.6mm) and a median overlap of 93% (range: 73%-98%). Although significant inter-observer differences were seen in gross tumor volume definition of adult soft-tissue sarcoma, the center of mass of these volumes was remarkably consistent. Variations in volume definition did not correlate with tumor size. Radiation oncologists should not hesitate to review their contours with a colleague (surgeon, radiologist or fellow radiation oncologist) to ensure that they are not outliers in sarcoma gross tumor volume definition. Protocols should take into account variations in volume definition when considering tighter clinical target volumes. Copyright © 2011 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Tendency for interlaboratory precision in the GMO analysis method based on real-time PCR.

PubMed

Kodama, Takashi; Kurosawa, Yasunori; Kitta, Kazumi; Naito, Shigehiro

2010-01-01

The Horwitz curve estimates interlaboratory precision as a function only of concentration, and is frequently used as a method performance criterion in food analysis with chemical methods. The quantitative biochemical methods based on real-time PCR require an analogous criterion to progressively promote method validation. We analyzed the tendency of precision using a simplex real-time PCR technique in 53 collaborative studies of seven genetically modified (GM) crops. Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) of the genetically modified organism (GMO) amount (%) was more or less independent of GM crops (i.e., maize, soybean, cotton, oilseed rape, potato, sugar beet, and rice) and evaluation procedure steps. Some studies evaluated whole steps consisting of DNA extraction and PCR quantitation, whereas others focused only on the PCR quantitation step by using DNA extraction solutions. Therefore, SR and Sr for GMO amount (%) are functions only of concentration similar to the Horwitz curve. We proposed S(R) = 0.1971C 0.8685 and S(r) = 0.1478C 0.8424, where C is the GMO amount (%). We also proposed a method performance index in GMO quantitative methods that is analogous to the Horwitz Ratio.

A Visual Model for the Variance and Standard Deviation

ERIC Educational Resources Information Center

Orris, J. B.

2011-01-01

This paper shows how the variance and standard deviation can be represented graphically by looking at each squared deviation as a graphical object--in particular, as a square. A series of displays show how the standard deviation is the size of the average square.

Variability of pesticide detections and concentrations in field replicate water samples collected for the National Water-Quality Assessment Program, 1992-97

USGS Publications Warehouse

Martin, Jeffrey D.

2002-01-01

Correlation analysis indicates that for most pesticides and concentrations, pooled estimates of relative standard deviation rather than pooled estimates of standard deviation should be used to estimate variability because pooled estimates of relative standard deviation are less affected by heteroscedasticity. The 2 Variability of Pesticide Detections and Concentrations in Field Replicate Water Samples, 1992–97 median pooled relative standard deviation was calculated for all pesticides to summarize the typical variability for pesticide data collected for the NAWQA Program. The median pooled relative standard deviation was 15 percent at concentrations less than 0.01 micrograms per liter (µg/L), 13 percent at concentrations near 0.01 µg/L, 12 percent at concentrations near 0.1 µg/L, 7.9 percent at concentrations near 1 µg/L, and 2.7 percent at concentrations greater than 5 µg/L. Pooled estimates of standard deviation or relative standard deviation presented in this report are larger than estimates based on averages, medians, smooths, or regression of the individual measurements of standard deviation or relative standard deviation from field replicates. Pooled estimates, however, are the preferred method for characterizing variability because they provide unbiased estimates of the variability of the population. Assessments of variability based on standard deviation (rather than variance) underestimate the true variability of the population. Because pooled estimates of variability are larger than estimates based on other approaches, users of estimates of variability must be cognizant of the approach used to obtain the estimate and must use caution in the comparison of estimates based on different approaches.

Basic life support: evaluation of learning using simulation and immediate feedback devices1.

PubMed

Tobase, Lucia; Peres, Heloisa Helena Ciqueto; Tomazini, Edenir Aparecida Sartorelli; Teodoro, Simone Valentim; Ramos, Meire Bruna; Polastri, Thatiane Facholi

2017-10-30

to evaluate students' learning in an online course on basic life support with immediate feedback devices, during a simulation of care during cardiorespiratory arrest. a quasi-experimental study, using a before-and-after design. An online course on basic life support was developed and administered to participants, as an educational intervention. Theoretical learning was evaluated by means of a pre- and post-test and, to verify the practice, simulation with immediate feedback devices was used. there were 62 participants, 87% female, 90% in the first and second year of college, with a mean age of 21.47 (standard deviation 2.39). With a 95% confidence level, the mean scores in the pre-test were 6.4 (standard deviation 1.61), and 9.3 in the post-test (standard deviation 0.82, p <0.001); in practice, 9.1 (standard deviation 0.95) with performance equivalent to basic cardiopulmonary resuscitation, according to the feedback device; 43.7 (standard deviation 26.86) mean duration of the compression cycle by second of 20.5 (standard deviation 9.47); number of compressions 167.2 (standard deviation 57.06); depth of compressions of 48.1 millimeter (standard deviation 10.49); volume of ventilation 742.7 (standard deviation 301.12); flow fraction percentage of 40.3 (standard deviation 10.03). the online course contributed to learning of basic life support. In view of the need for technological innovations in teaching and systematization of cardiopulmonary resuscitation, simulation and feedback devices are resources that favor learning and performance awareness in performing the maneuvers.

Qualitative computer aided evaluation of dental impressions in vivo.

PubMed

Luthardt, Ralph G; Koch, Rainer; Rudolph, Heike; Walter, Michael H

2006-01-01

Clinical investigations dealing with the precision of different impression techniques are rare. Objective of the present study was to develop and evaluate a procedure for the qualitative analysis of the three-dimensional impression precision based on an established in-vitro procedure. The zero hypothesis to be tested was that the precision of impressions does not differ depending on the impression technique used (single-step, monophase and two-step-techniques) and on clinical variables. Digital surface data of patient's teeth prepared for crowns were gathered from standardized manufactured master casts after impressions with three different techniques were taken in a randomized order. Data-sets were analyzed for each patient in comparison with the one-step impression chosen as the reference. The qualitative analysis was limited to data-points within the 99.5%-range. Based on the color-coded representation areas with maximum deviations were determined (preparation margin and the mantle and occlusal surface). To qualitatively analyze the precision of the impression techniques, the hypothesis was tested in linear models for repeated measures factors (p < 0.05). For the positive 99.5% deviations no variables with significant influence were determined in the statistical analysis. In contrast, the impression technique and the position of the preparation margin significantly influenced the negative 99.5% deviations. The influence of clinical parameter on the deviations between impression techniques can be determined reliably using the 99.5 percentile of the deviations. An analysis regarding the areas with maximum deviations showed high clinical relevance. The preparation margin was pointed out as the weak spot of impression taking.

DETERMINATION OF AZOXYSTROBIN AND DIFENOCONAZOLE IN PESTICIDE PRODUCTS.

PubMed

Lazić, S; Šunjka, D

2015-01-01

In this study a high performance liquid chromatographic (HPLC-DAD) procedure has been developed for the simultaneous determination of azoxystrobin and difenoconazole in suspension concentrate pesticide formulations, with the aim of the product quality control. Azoxystrobin, strobilurin fungicide and difenoconazole (cis,trans-3-chloro-4-[4-methyl-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-2-yl]phenyl 4-chlorophenyl ether), triazole fungicide, are used for the protection of plants from wide spectrum of fungal diseases. For the analysis LC system an Agilent Technologies 1100 Series was used. Good separation was achieved on a Zorbax SB-C18 column (5 μm, 250 mm x 3 mm internal diameter) using a mobile phase consisting of acetonitrile/ultrapure water (90:10, v/v), at a flow rate of 0.9 ml/minute and UV detection at 218 nm. Column temperature was 25 degrees C, injected volume was 1 μl. Retention times for azoxystrobin and difenoconazole were 2.504 min and 1.963 min, respectively. This method is validated according to the requirements for new methods, which include linearity, precision, accuracy and selectivity. The method demonstrates good linearity with r2 > 0.997. The repeatability of the method, expressed as relative standard deviation (RSD, %), was found to be 1.9% for azoxystrobin and 0.5% for difenoconazole. The precision of the method was also considered to be acceptable as the experimental repeatability relative standard deviation (RSD) was lower than the RSD calculated using the Horwitz equation of 1.7% and 1.4% for azoxystrobin and difenoconazole, respectively. The accuracy of the proposed method was determined from recovery experiments through standard addition procedure. The average recoveries of the three fortification levels were 101.9% for azoxystrobin and 103.2% for difenoconazole with RSDs of 1.1% and 1.2%. The method described in this paper is simple, precise, accurate and selective and represents a new and reliable way of simultaneous determination of azoxystrobin and difenoconazole in formulated products.

Calibration campaign against the international prototype of the kilogram in anticipation of the redefinition of the kilogram part I: comparison of the international prototype with its official copies

NASA Astrophysics Data System (ADS)

Stock, Michael; Barat, Pauline; Davis, Richard S.; Picard, Alain; Milton, Martin J. T.

2015-04-01

This report presents the results of the first phase of the campaign of calibration carried out with respect to the international prototype of the kilogram (IPK) in anticipation of the redefinition of the kilogram (Extraordinary Calibrations). The definition of the kilogram was realized according to the procedure outlined in the 8th Edition of the SI Brochure. Thus the IPK and its six official copies have been cleaned and washed following the BIPM procedure. The mass comparisons carried out during this campaign showed a very good repeatability. The pooled standard deviation of repeated weighings of the prototypes was 0.4 µg. The effect of cleaning and washing of the IPK was to remove a mass of 16.8 µg. The effect of cleaning and washing of the six official copies was found to be very similar, giving an average mass removed from the seven prototypes of 15 µg with a standard deviation of 2 µg. The differences in mass between the IPK and the official copies have changed by an average of 1 µg since the 3rd Periodic Verification of National Prototypes of the Kilogram (1988-1992). These results do not confirm the trend for the masses of the six official copies to diverge from the mass of the IPK that was observed during the 2nd and 3rd Periodic Verifications. All BIPM working standards and the prototypes reserved for special use have been calibrated with respect to the IPK as part of this campaign. All of them were found to have lower masses than when they were calibrated during the 3rd Periodic Verification. As a consequence, the BIPM ‘as-maintained’ mass unit in 2014 has been found to be offset by 35 µg with respect to the IPK. This result will be analyzed in a further publication.

Alterations in in vivo knee joint kinematics following a femoral nerve branch block of the vastus medialis: Implications for patellofemoral pain syndrome.

PubMed

Sheehan, Frances T; Borotikar, Bhushan S; Behnam, Abrahm J; Alter, Katharine E

2012-07-01

A potential source of patellofemoral pain, one of the most common problems of the knee, is believed to be altered patellofemoral kinematics due to a force imbalance around the knee. Although no definitive etiology for this imbalance has been found, a weak vastus medialis is considered a primary factor. Therefore, this study's purpose was to determine how the loss of vastus medialis obliquus force alters three-dimensional in vivo knee joint kinematics during a volitional extension task. Eighteen asymptomatic female subjects with no history of knee pain or pathology participated in this IRB approved study. Patellofemoral and tibiofemoral kinematics were derived from velocity data acquired using dynamic cine-phase contrast MRI. The same kinematics were then acquired immediately after administering a motor branch block to the vastus medialis obliquus using 3-5ml of 1% lidocaine. A repeated measures analysis of variance was used to test the null hypothesis that the post- and pre-injection kinematics were no different. The null hypothesis was rejected for patellofemoral lateral shift (P=0.003, max change=1.8mm, standard deviation=1.7mm), tibiofemoral lateral shift (P<0.001, max change=2.1mm, standard deviation=2.9mm), and tibiofemoral external rotation (P<0.001, max change=3.7°, standard deviation=4.4°). The loss of vastus medialis obliquus function produced kinematic changes that mirrored the axial plane kinematics seen in individuals with patellofemoral pain, but could not account for the full extent of these changes. Thus, vastus medialis weakness is likely a major factor in, but not the sole source of, altered patellofemoral kinematics in such individuals. Published by Elsevier Ltd.

Development, validation, and application of a method for the GC-MS analysis of fipronil and three of its degradation products in samples of water, soil, and sediment.

PubMed

de Toffoli, Ana L; da Mata, Kamilla; Bisinoti, Márcia C; Moreira, Altair B

2015-01-01

A method for the identification and quantification of pesticide residues in water, soil, and sediment samples has been developed, validated, and applied for the analysis of real samples. The specificity was determined by the retention time and the confirmation and quantification of analyte ions. Linearity was demonstrated over the concentration range of 20 to 120 µg L(-1), and the correlation coefficients varied between 0.979 and 0.996, depending on the analytes. The recovery rates for all analytes in the studied matrix were between 86% and 112%. The intermediate precision and repeatability were determined at three concentration levels (40, 80, and 120 µg L(-1)), with the relative standard deviation for the intermediate precision between 1% and 5.3% and the repeatability varying between 2% and 13.4% for individual analytes. The limits of detection and quantification for fipronil, fipronil sulfide, fipronil-sulfone, and fipronil-desulfinyl were 6.2, 3.0, 6.6, and 4.0 ng L(-1) and 20.4, 9.0, 21.6, and 13.0 ng L(-1), respectively. The method developed was used in water, soil, and sediment samples containing 2.1 mg L(-1) and 1.2% and 5.3% of carbon, respectively. The recovery of pesticides in the environmental matrices varied from 88.26 to 109.63% for the lowest fortification level (40 and 100 µg kg(-1)), from 91.17 to 110.18% for the intermediate level (80 and 200 µg kg(-1)), and from 89.09 to 109.82% for the highest fortification level (120 and 300 µg kg(-1)). The relative standard deviation for the recovery of pesticides was under 15%.

Validation and long-term evaluation of a modified on-line chiral analytical method for therapeutic drug monitoring of (R,S)-methadone in clinical samples.

PubMed

Ansermot, Nicolas; Rudaz, Serge; Brawand-Amey, Marlyse; Fleury-Souverain, Sandrine; Veuthey, Jean-Luc; Eap, Chin B

2009-08-01

Matrix effects, which represent an important issue in liquid chromatography coupled to mass spectrometry or tandem mass spectrometry detection, should be closely assessed during method development. In the case of quantitative analysis, the use of stable isotope-labelled internal standard with physico-chemical properties and ionization behaviour similar to the analyte is recommended. In this paper, an example of the choice of a co-eluting deuterated internal standard to compensate for short-term and long-term matrix effect in the case of chiral (R,S)-methadone plasma quantification is reported. The method was fully validated over a concentration range of 5-800 ng/mL for each methadone enantiomer with satisfactory relative bias (-1.0 to 1.0%), repeatability (0.9-4.9%) and intermediate precision (1.4-12.0%). From the results obtained during validation, a control chart process during 52 series of routine analysis was established using both intermediate precision standard deviation and FDA acceptance criteria. The results of routine quality control samples were generally included in the +/-15% variability around the target value and mainly in the two standard deviation interval illustrating the long-term stability of the method. The intermediate precision variability estimated in method validation was found to be coherent with the routine use of the method. During this period, 257 trough concentration and 54 peak concentration plasma samples of patients undergoing (R,S)-methadone treatment were successfully analysed for routine therapeutic drug monitoring.

The performance of single and multi-collector ICP-MS instruments for fast and reliable 34S/32S isotope ratio measurements†

PubMed Central

Pröfrock, Daniel; Irrgeher, Johanna; Prohaska, Thomas

2016-01-01

The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC, measurement repeatability, within-lab reproducibility and deviation from certified values as well as a study on instrumental isotopic fractionation (IIF) and the calculation of the combined standard measurement uncertainty. Different approaches of correction for IIF applying external intra-elemental IIF correction (aka standard-sample bracketing) using certified S reference materials and internal inter-elemental IIF (aka internal standardization) correction using Si isotope ratios in MC ICP-MS are explained and compared. The resulting combined standard uncertainties of examined ICP-QMS systems were not better than 0.3–0.5% (uc,rel), which is in general insufficient to differentiate natural S isotope variations. Although the performance of the single collector ICP-SFMS is better (single measurement uc,rel = 0.08%), the measurement reproducibility (>0.2%) is the major limit of this system and leaves room for improvement. MC ICP-MS operated in the edge mass resolution mode, applying bracketing for correction of IIF, provided isotope ratio values with the highest quality (relative combined measurement uncertainty: 0.02%; deviation from the certified value: <0.002%). PMID:27812369

The performance of single and multi-collector ICP-MS instruments for fast and reliable 34S/32S isotope ratio measurements.

PubMed

Hanousek, Ondrej; Brunner, Marion; Pröfrock, Daniel; Irrgeher, Johanna; Prohaska, Thomas

2016-11-14

The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC, measurement repeatability, within-lab reproducibility and deviation from certified values as well as a study on instrumental isotopic fractionation (IIF) and the calculation of the combined standard measurement uncertainty. Different approaches of correction for IIF applying external intra-elemental IIF correction (aka standard-sample bracketing) using certified S reference materials and internal inter-elemental IIF (aka internal standardization) correction using Si isotope ratios in MC ICP-MS are explained and compared. The resulting combined standard uncertainties of examined ICP-QMS systems were not better than 0.3-0.5% ( u c,rel ), which is in general insufficient to differentiate natural S isotope variations. Although the performance of the single collector ICP-SFMS is better (single measurement u c,rel = 0.08%), the measurement reproducibility (>0.2%) is the major limit of this system and leaves room for improvement. MC ICP-MS operated in the edge mass resolution mode, applying bracketing for correction of IIF, provided isotope ratio values with the highest quality (relative combined measurement uncertainty: 0.02%; deviation from the certified value: <0.002%).

Accuracy of Digital vs. Conventional Implant Impressions

PubMed Central

Lee, Sang J.; Betensky, Rebecca A.; Gianneschi, Grace E.; Gallucci, German O.

2015-01-01

The accuracy of digital impressions greatly influences the clinical viability in implant restorations. The aim of this study is to compare the accuracy of gypsum models acquired from the conventional implant impression to digitally milled models created from direct digitalization by three-dimensional analysis. Thirty gypsum and 30 digitally milled models impressed directly from a reference model were prepared. The models were scanned by a laboratory scanner and 30 STL datasets from each group were imported to an inspection software. The datasets were aligned to the reference dataset by a repeated best fit algorithm and 10 specified contact locations of interest were measured in mean volumetric deviations. The areas were pooled by cusps, fossae, interproximal contacts, horizontal and vertical axes of implant position and angulation. The pooled areas were statistically analysed by comparing each group to the reference model to investigate the mean volumetric deviations accounting for accuracy and standard deviations for precision. Milled models from digital impressions had comparable accuracy to gypsum models from conventional impressions. However, differences in fossae and vertical displacement of the implant position from the gypsum and digitally milled models compared to the reference model, exhibited statistical significance (p<0.001, p=0.020 respectively). PMID:24720423

Experimental comparison of icing cloud instruments

NASA Technical Reports Server (NTRS)

Olsen, W.; Takeuchi, D. M.; Adams, K.

1983-01-01

Icing cloud instruments were tested in the spray cloud Icing Research Tunnel (IRT) in order to determine their relative accuracy and their limitations over a broad range of conditions. It was found that the average of the readings from each of the liquid water content (LWC) instruments tested agreed closely with each other and with the IRT calibration; but all have a data scatter (+ or - one standard deviation) of about + or - 20 percent. The effect of this + or - 20 percent uncertainty is probably acceptable in aero-penalty and deicer experiments. Existing laser spectrometers proved to be too inaccurate for LWC measurements. The error due to water runoff was the same for all ice accretion LWC instruments. Any given laser spectrometer proved to be highly repeatable in its indications of volume median drop size (DVM), LWC and drop size distribution. However, there was a significant disagreement between different spectrometers of the same model, even after careful standard calibration and data analysis. The scatter about the mean of the DVM data from five Axial Scattering Spectrometer Probes was + or - 20 percent (+ or - one standard deviation) and the average was 20 percent higher than the old IRT calibration. The + or - 20 percent uncertainty in DVM can cause an unacceptable variation in the drag coefficient of an airfoil with ice; however, the variation in a deicer performance test may be acceptable.

Standard error of measurement of five health utility indexes across the range of health for use in estimating reliability and responsiveness

PubMed Central

Palta, Mari; Chen, Han-Yang; Kaplan, Robert M.; Feeny, David; Cherepanov, Dasha; Fryback, Dennis

2011-01-01

Background Standard errors of measurement (SEMs) of health related quality of life (HRQoL) indexes are not well characterized. SEM is needed to estimate responsiveness statistics and provides guidance on using indexes on the individual and group level. SEM is also a component of reliability. Purpose To estimate SEM of five HRQoL indexes. Design The National Health Measurement Study (NHMS) was a population based telephone survey. The Clinical Outcomes and Measurement of Health Study (COMHS) provided repeated measures 1 and 6 months post cataract surgery. Subjects 3844 randomly selected adults from the non-institutionalized population 35 to 89 years old in the contiguous United States and 265 cataract patients. Measurements The SF6-36v2™, QWB-SA, EQ-5D, HUI2 and HUI3 were included. An item-response theory (IRT) approach captured joint variation in indexes into a composite construct of health (theta). We estimated: (1) the test-retest standard deviation (SEM-TR) from COMHS, (2) the structural standard deviation (SEM-S) around the composite construct from NHMS and (3) corresponding reliability coefficients. Results SEM-TR was 0.068 (SF-6D), 0.087 (QWB-SA), 0.093 (EQ-5D), 0.100 (HUI2) and 0.134 (HUI3), while SEM-S was 0.071, 0.094, 0.084, 0.074 and 0.117, respectively. These translate into reliability coefficients for SF-6D: 0.66 (COMHS) and 0.71 (NHMS), for QWB: 0.59 and 0.64, for EQ-5D: 0.61 and 0.70 for HUI2: 0.64 and 0.80, and for HUI3: 0.75 and 0.77, respectively. The SEM varied considerably across levels of health, especially for HUI2, HUI3 and EQ-5D, and was strongly influenced by ceiling effects. Limitations Repeated measures were five months apart and estimated theta contain measurement error. Conclusions The two types of SEM are similar and substantial for all the indexes, and vary across the range of health. PMID:20935280

An Evaluation of Partial Digestion Protocols for the Extraction and Measurement of Trace Metals of Environmental Concern in Marine and Estuarine Sediments

NASA Astrophysics Data System (ADS)

Winters, S. J.; Krahforst, C.; Sherman, L.; Kehm, K.

2013-12-01

As part of a broad study of the fate and transport of trace metals in estuarine sediments (Krahforst et al., 2013), the efficacy of commonly-used partial digestion protocols, including ISO 11466 (treatment with aqua regia), EPA 3050B (nitric acid followed by H2O2) and a modified rock digestion method ('RD' method- H2O2 followed by nitric), were evaluated for two NIST SRM materials, marine sediment 2702 and estuarine sediment 1646a. Unlike so-called total sediment digestions, the methods studied in this work do not employ hydrofluoric acid and are thought to leave silicates substantially or wholly intact. These methods can in principle compliment studies based on total digestions by providing information about trace metals in phases that are potentially more labile in the marine environment. Samples were digested in ~150 mg aliquots. Application of ISO 11466 and EPA 3050B followed published protocols except that digestions were carried out in trace-metal clean 15 mL capped Teflon vessels in an Al block digester and, at the end of the procedure, the supernatant was decanted from undigested material following repeated centrifugation in 2% nitric acid. Digested solutions were analyzed for Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Ag, Cd, Sn and Pb content by ICPMS. All elements were analyzed in collision reaction cell mode to minimize isobaric interferences, except Cd and Ag, which were analyzed in standard mode. Instrument performance was monitored in-run by analyzing the SRM 1643e and several quality-check standards. Two repeated digestions of SRM 2702 and SRM 1646a using EPA 3050B produced identical yields, within the standard deviation of repeated analyses (0 - 5%), for all analyzed elements except Cu, which varied by 30% for SRM 2702. The same was true for ISO 11466, although the standard deviation of repeated analyses for this digestion series tended to be larger (< ~15%). The RD method, which consists of pre-treatment with H2O2 followed by repeated treatments with nitric acid, produced the highest average yields for all elements, ranging from 50% of the Al in SRM 2702 up to ~100% for Cd and Pb. The higher recoveries for the RD method may indicate that pre-treatment with H2O2 more effectively removes organics compared with the conventional methods. Yields for ISO 11466 digestions typically range from 5 - 15% higher than EPA 3050B for all studied elements. Comparisons between the two sediments demonstrated that the acid-extractable fraction differs for several elements. For example results from all three digestion methods confirm a ~40% difference in yield for Mn between SRM 2702 and SRM 1646a. Overall, the results indicate that yields for trace element analyses of marine and estuarine sediments resulting from partial digestion are sensitive to the digestion technique, and in particular the methods employed for removal of organic phases. This work was supported by NSF Grant EAR-0922733 and a Maryland Sea Grant Program Development Award.

Statistical considerations for grain-size analyses of tills

USGS Publications Warehouse

Jacobs, A.M.

1971-01-01

Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in a t-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort. ?? 1971 Plenum Publishing Corporation.

Gas chromatographic sulphur speciation in heavy crude oil using a modified standard D5623 method and microfluidic Deans switching.

PubMed

Heshka, Nicole E; Choy, Joanne M; Chen, Jinwen

2017-12-29

A modification to American Society for Testing and Materials (ASTM) method D5623 is proposed to enable successful and repeatable analysis of heavy crude oil samples. A two-dimensional gas chromatography configuration was implemented, with separation of sulphur compounds occurring on two columns. A Deans switch is used to enable heart-cutting of volatile sulphur compounds onto a DB-Sulfur stationary phase, and separation occurs concurrently with the backflushing of the primary column. The use of a sulphur-selective detector increases selectivity, and 22 volatile sulphur species are quantified in less than 15min, which is almost half the time of the original ASTM method. Samples ranging from light distillation cuts to whole crudes (boiling from 100°C to >750°C) were analyzed with minimal sample preparation. The calculated limit of detection was 0.7mg/kg, repeatability was 3% relative standard deviation (RSD), and a linear range of 1-250mg/kg was obtained, with an R 2 value of 0.994 or better, depending on the compound. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Repeatability of Ophtha Top topography and comparison with IOL-Master and LenstarLS900 in cataract patients

PubMed Central

Yu, Sha-Sha; Song, Hui; Tang, Xin

2017-01-01

AIM To determine the repeatability of Ophtha Top topography and assess the consistency with intraocular lens (IOL)-Master and LenstarLS900 (Lenstar) in measuring corneal parameters among cataract patients. METHODS Totally 125 eyes were enrolled. Corneas were successively measured with Ophtha Top, IOL-Master and Lenstar at least three times. The flattest meridian power (Kf), the steepest meridian power (Ks), mean power (Km), J0 and J45 were recorded. Intra-class correlation coefficients (ICCs), the coefficient of variance (COV), within subject standard deviation (Sw), and test-retest repeatability (2.77Sw) were adopted to determine the repeatability. The 95% limit of agreement (95%LOA) and Bland-Altman plots were used to assess comparability. RESULTS Repeatability of Ophtha Top topography for measuring corneal parameters showed the ICCs were all above 0.93, 2.77Sw was lower than 0.31, and the COV of the Kf and Ks was lower than 0.25. The keratometric readings with Ophtha Top topography were flatter than with the IOL-Master and Lenstar devices, while the Pearson correlation coefficients were over 0.97. The J0 and J45 with Ophtha Top topography were smaller compared with Lenstar and IOL-Master, while was comparable between Lenstar and IOL-Master. CONCLUSION Ophtha Top topography shows excellent repeatability for measuring corneal parameters. However, differences between the Ophtha TOP topography and Lenstar, IOL-Master both in cornea curvature and the astigmatism should be noted clinically. PMID:29181314

Repeatability of Ophtha Top topography and comparison with IOL-Master and LenstarLS900 in cataract patients.

PubMed

Yu, Sha-Sha; Song, Hui; Tang, Xin

2017-01-01

To determine the repeatability of Ophtha Top topography and assess the consistency with intraocular lens (IOL)-Master and LenstarLS900 (Lenstar) in measuring corneal parameters among cataract patients. Totally 125 eyes were enrolled. Corneas were successively measured with Ophtha Top, IOL-Master and Lenstar at least three times. The flattest meridian power (Kf), the steepest meridian power (Ks), mean power (Km), J0 and J45 were recorded. Intra-class correlation coefficients (ICCs), the coefficient of variance (COV), within subject standard deviation (Sw), and test-retest repeatability (2.77Sw) were adopted to determine the repeatability. The 95% limit of agreement (95%LOA) and Bland-Altman plots were used to assess comparability. Repeatability of Ophtha Top topography for measuring corneal parameters showed the ICCs were all above 0.93, 2.77Sw was lower than 0.31, and the COV of the Kf and Ks was lower than 0.25. The keratometric readings with Ophtha Top topography were flatter than with the IOL-Master and Lenstar devices, while the Pearson correlation coefficients were over 0.97. The J0 and J45 with Ophtha Top topography were smaller compared with Lenstar and IOL-Master, while was comparable between Lenstar and IOL-Master. Ophtha Top topography shows excellent repeatability for measuring corneal parameters. However, differences between the Ophtha TOP topography and Lenstar, IOL-Master both in cornea curvature and the astigmatism should be noted clinically.

How do we assign punishment? The impact of minimal and maximal standards on the evaluation of deviants.

PubMed

Kessler, Thomas; Neumann, Jörg; Mummendey, Amélie; Berthold, Anne; Schubert, Thomas; Waldzus, Sven

2010-09-01

To explain the determinants of negative behavior toward deviants (e.g., punishment), this article examines how people evaluate others on the basis of two types of standards: minimal and maximal. Minimal standards focus on an absolute cutoff point for appropriate behavior; accordingly, the evaluation of others varies dichotomously between acceptable or unacceptable. Maximal standards focus on the degree of deviation from that standard; accordingly, the evaluation of others varies gradually from positive to less positive. This framework leads to the prediction that violation of minimal standards should elicit punishment regardless of the degree of deviation, whereas punishment in response to violations of maximal standards should depend on the degree of deviation. Four studies assessed or manipulated the type of standard and degree of deviation displayed by a target. Results consistently showed the expected interaction between type of standard (minimal and maximal) and degree of deviation on punishment behavior.

The retest distribution of the visual field summary index mean deviation is close to normal.

PubMed

Anderson, Andrew J; Cheng, Allan C Y; Lau, Samantha; Le-Pham, Anne; Liu, Victor; Rahman, Farahnaz

2016-09-01

When modelling optimum strategies for how best to determine visual field progression in glaucoma, it is commonly assumed that the summary index mean deviation (MD) is normally distributed on repeated testing. Here we tested whether this assumption is correct. We obtained 42 reliable 24-2 Humphrey Field Analyzer SITA standard visual fields from one eye of each of five healthy young observers, with the first two fields excluded from analysis. Previous work has shown that although MD variability is higher in glaucoma, the shape of the MD distribution is similar to that found in normal visual fields. A Shapiro-Wilks test determined any deviation from normality. Kurtosis values for the distributions were also calculated. Data from each observer passed the Shapiro-Wilks normality test. Bootstrapped 95% confidence intervals for kurtosis encompassed the value for a normal distribution in four of five observers. When examined with quantile-quantile plots, distributions were close to normal and showed no consistent deviations across observers. The retest distribution of MD is not significantly different from normal in healthy observers, and so is likely also normally distributed - or nearly so - in those with glaucoma. Our results increase our confidence in the results of influential modelling studies where a normal distribution for MD was assumed. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

[Detection of recombinant-DNA in foods from stacked genetically modified plants].

PubMed

Sorokina, E Iu; Chernyshova, O N

2012-01-01

A quantitative real-time multiplex polymerase chain reaction method was applied to the detection and quantification of MON863 and MON810 in stacked genetically modified maize MON 810xMON 863. The limit of detection was approximately 0,1%. The accuracy of the quantification, measured as bias from the accepted value and the relative repeatability standard deviation, which measures the intra-laboratory variability, were within 25% at each GM-level. A method verification has demonstrated that the MON 863 and the MON810 methods can be equally applied in quantification of the respective events in stacked MON810xMON 863.

On the improvement of signal repeatability in laser-induced air plasmas

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Sheta, Sahar; Hou, Zong-Yu; Wang, Zhe

2018-04-01

The relatively low repeatability of laser-induced breakdown spectroscopy (LIBS) severely hinders its wide commercialization. In the present work, we investigate the optimization of LIBS system for repeatability improvement for both signal generation (plasma evolution) and signal collection. Timeintegrated spectra and images were obtained under different laser energies and focal lengths to investigate the optimum configuration for stable plasmas and repeatable signals. Using our experimental setup, the optimum conditions were found to be a laser energy of 250 mJ and a focus length of 100 mm. A stable and homogeneous plasma with the largest hot core area in the optimum condition yielded the most stable LIBS signal. Time-resolved images showed that the rebounding processes through the air plasma evolution caused the relative standard deviation (RSD) to increase with laser energies of > 250 mJ. In addition, the emission collection was improved by using a concave spherical mirror. The line intensities doubled as their RSDs decreased by approximately 25%. When the signal generation and collection were optimized simultaneously, the pulse-to-pulse RSDs were reduced to approximately 3% for O(I), N(I), and H(I) lines, which are better than the RSDs reported for solid samples and showed great potential for LIBS quantitative analysis by gasifying the solid or liquid samples.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 1: January

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-07-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analyses produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of January. Included are global analyses of: (1) Mean temperature standard deviation; (2) Mean geopotential height standard deviation; (3) Mean density standard deviation; (4) Mean density standard deviation (all for 13 levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean dew point standard deviation for the 13 levels; and (6) Jet stream at levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Application of principal component analysis for improvement of X-ray fluorescence images obtained by polycapillary-based micro-XRF technique

NASA Astrophysics Data System (ADS)

Aida, S.; Matsuno, T.; Hasegawa, T.; Tsuji, K.

2017-07-01

Micro X-ray fluorescence (micro-XRF) analysis is repeated as a means of producing elemental maps. In some cases, however, the XRF images of trace elements that are obtained are not clear due to high background intensity. To solve this problem, we applied principal component analysis (PCA) to XRF spectra. We focused on improving the quality of XRF images by applying PCA. XRF images of the dried residue of standard solution on the glass substrate were taken. The XRF intensities for the dried residue were analyzed before and after PCA. Standard deviations of XRF intensities in the PCA-filtered images were improved, leading to clear contrast of the images. This improvement of the XRF images was effective in cases where the XRF intensity was weak.

Validation of standard method EN ISO 11290-part 2 for the enumeration of Listeria monocytogenes in food.

PubMed

Rollier, Patricia; Lombard, Bertrand; Guillier, Laurent; François, Danièle; Romero, Karol; Pierru, Sylvie; Bouhier, Laurence; Gnanou Besse, Nathalie

2018-05-01

The reference method for the detection and enumeration of L. monocytogenes in food (Standards EN ISO 11290-1&2) have been validated by inter-laboratory studies in the frame of the Mandate M381 from European Commission to CEN. In this paper, the inter-laboratory studies led in 2013 on 5 matrices (cold-smoked salmon, milk powdered infant food formula, vegetables, environment, and cheese) to validate Standard EN ISO 11290-2 are reported. According to the results obtained, the method of the revised Standard EN ISO 11290-2 can be considered as a good method for the enumeration of L. monocytogenes in foods and food processing environment, in particular for the matrices included in the study. Values of repeatability and reproducibility standard deviations can be considered satisfactory for this type of method with a confirmation stage, since most of them were below 0.3 log 10 , also at low levels, close to the regulatory limit of 100 CFU/g. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparing Standard Deviation Effects across Contexts

ERIC Educational Resources Information Center

Ost, Ben; Gangopadhyaya, Anuj; Schiman, Jeffrey C.

2017-01-01

Studies using tests scores as the dependent variable often report point estimates in student standard deviation units. We note that a standard deviation is not a standard unit of measurement since the distribution of test scores can vary across contexts. As such, researchers should be cautious when interpreting differences in the numerical size of…

Blood pressure variability in man: its relation to high blood pressure, age and baroreflex sensitivity.

PubMed

Mancia, G; Ferrari, A; Gregorini, L; Parati, G; Pomidossi, G; Bertinieri, G; Grassi, G; Zanchetti, A

1980-12-01

1. Intra-arterial blood pressure and heart rate were recorded for 24 h in ambulant hospitalized patients of variable age who had normal blood pressure or essential hypertension. Mean 24 h values, standard deviations and variation coefficient were obtained as the averages of values separately analysed for 48 consecutive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation aations and variation coefficient were obtained as the averages of values separately analysed for 48 consecurive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for heart rate were smaller. 3. In hypertensive subjects standard deviation for mean arterial pressure was greater than in normotensive subjects of similar ages, but this was not the case for variation coefficient, which was slightly smaller in the former than in the latter group. Normotensive and hypertensive subjects showed no difference in standard deviation and variation coefficient for heart rate. 4. In both normotensive and hypertensive subjects standard deviation and even more so variation coefficient were slightly or not related to arterial baroreflex sensitivity as measured by various methods (phenylephrine, neck suction etc.). 5. It is concluded that blood pressure variability increases and heart rate variability decreases with age, but that changes in variability are not so obvious in hypertension. Also, differences in variability among subjects are only marginally explained by differences in baroreflex function.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 7: July

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-07-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analysis produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of July. Included are global analyses of: (1) Mean temperature/standard deviation; (2) Mean geopotential height/standard deviation; (3) Mean density/standard deviation; (4) Height and vector standard deviation (all at 13 pressure levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean dew point standard deviation at levels 1000 through 30 mb; and (6) Jet stream at levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 10: October

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-07-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analysis produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of October. Included are global analyses of: (1) Mean temperature/standard deviation; (2) Mean geopotential height/standard deviation; (3) Mean density/standard deviation; (4) Height and vector standard deviation (all at 13 pressure levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean dew point/standard deviation at levels 1000 through 30 mb; and (6) Jet stream at levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 3: March

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-11-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analysis produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of March. Included are global analyses of: (1) Mean Temperature Standard Deviation; (2) Mean Geopotential Height Standard Deviation; (3) Mean Density Standard Deviation; (4) Height and Vector Standard Deviation (all for 13 pressure levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean Dew Point Standard Deviation for levels 1000 through 30 mb; and (6) Jet stream for levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 2: February

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-09-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analyses produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of February. Included are global analyses of: (1) Mean temperature standard deviation; (2) Mean geopotential height standard deviation; (3) Mean density standard deviation; (4) Height and vector standard deviation (all for 13 pressure levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean dew point standard deviation for the 13 levels; and (6) Jet stream for levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 4: April

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-07-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analyses produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of April. Included are global analyses of: (1) Mean temperature standard deviation; (2) Mean geopotential height standard deviation; (3) Mean density standard deviation; (4) Height and vector standard deviation (all for 13 pressure levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean dew point standard deviation for the 13 levels; and (6) Jet stream for levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Precision analysis for standard deviation measurements of immobile single fluorescent molecule images.

PubMed

DeSantis, Michael C; DeCenzo, Shawn H; Li, Je-Luen; Wang, Y M

2010-03-29

Standard deviation measurements of intensity profiles of stationary single fluorescent molecules are useful for studying axial localization, molecular orientation, and a fluorescence imaging system's spatial resolution. Here we report on the analysis of the precision of standard deviation measurements of intensity profiles of single fluorescent molecules imaged using an EMCCD camera.We have developed an analytical expression for the standard deviation measurement error of a single image which is a function of the total number of detected photons, the background photon noise, and the camera pixel size. The theoretical results agree well with the experimental, simulation, and numerical integration results. Using this expression, we show that single-molecule standard deviation measurements offer nanometer precision for a large range of experimental parameters.

Repeatability of FDG PET/CT metrics assessed in free breathing and deep inspiration breath hold in lung cancer patients.

PubMed

Nygård, Lotte; Aznar, Marianne C; Fischer, Barbara M; Persson, Gitte F; Christensen, Charlotte B; Andersen, Flemming L; Josipovic, Mirjana; Langer, Seppo W; Kjær, Andreas; Vogelius, Ivan R; Bentzen, Søren M

2018-01-01

We measured the repeatability of FDG PET/CT uptake metrics when acquiring scans in free breathing (FB) conditions compared with deep inspiration breath hold (DIBH) for locally advanced lung cancer. Twenty patients were enrolled in this prospective study. Two FDG PET/CT scans per patient were conducted few days apart and in two breathing conditions (FB and DIBH). This resulted in four scans per patient. Up to four FDG PET avid lesions per patient were contoured. The following FDG metrics were measured in all lesions and in all four scans: Standardized uptake value (SUV) peak , SUV max , SUV mean , metabolic tumor volume (MTV) and total lesion glycolysis (TLG), based on an isocontur of 50% of SUV max . FDG PET avid volumes were delineated by a nuclear medicine physician. The gross tumor volumes (GTV) were contoured on the corresponding CT scans. Nineteen patients were available for analysis. Test-retest standard deviations of FDG uptake metrics in FB and DIBH were: SUV peak FB/DIBH: 16.2%/16.5%; SUV max : 18.2%/22.1%; SUV mean : 18.3%/22.1%; TLG: 32.4%/40.5%. DIBH compared to FB resulted in higher values with mean differences in SUV max of 12.6%, SUV peak 4.4% and SUV mean 11.9%. MTV, TLG and GTV were all significantly smaller on day 1 in DIBH compared to FB. However, the differences between metrics under FB and DIBH were in all cases smaller than 1 SD of the day to day repeatability. FDG acquisition in DIBH does not have a clinically relevant impact on the uptake metrics and does not improve the test-retest repeatability of FDG uptake metrics in lung cancer patients.

Determination of flavanol and procyanidin (by degree of polymerization 1-10) content of chocolate, cocoa liquors, powder(s), and cocoa flavanol extracts by normal phase high-performance liquid chromatography: collaborative study.

PubMed

Robbins, Rebecca J; Leonczak, Jadwiga; Li, Julia; Johnson, J Christopher; Collins, Tom; Kwik-Uribe, Catherine; Schmitz, Harold H

2012-01-01

An international collaborative study was conducted on an HPLC method with fluorescent detection (FLD) for the determination of flavanols and procyanidins in materials containing chocolate and cocoa. The sum of the oligomeric fractions with degree of polymerization 1-10 was the determined content value. Sample materials included dark and milk chocolates, cocoa powder, cocoa liquors, and cocoa extracts. The content ranged from approximately 2 to 500 mg/g (defatted basis). Thirteen laboratories representing commercial, industrial, and academic institutions in six countries participated in the study. Fourteen samples were sent as blind duplicates to the collaborators. Results from 12 laboratories yielded repeatability relative standard deviation (RSDr) values that were below 10% for all materials analyzed, ranging from 4.17 to 9.61%. The reproducibility relative standard deviation (RSD(R)) values ranged from 5.03 to 12.9% for samples containing 8.07 to 484.7 mg/g. In one sample containing a low content of flavanols and procyanidins (approximately 2 mg/g), the RSD(R) was 17.68%. Based on these results, the method is recommended for Official First Action for the determination of flavanols and procyanidins in chocolate, cocoa liquors, powder(s), and cocoa extracts.

Inter-laboratory validation of bioaccessibility testing for metals.

PubMed

Henderson, Rayetta G; Verougstraete, Violaine; Anderson, Kim; Arbildua, José J; Brock, Thomas O; Brouwers, Tony; Cappellini, Danielle; Delbeke, Katrien; Herting, Gunilla; Hixon, Greg; Odnevall Wallinder, Inger; Rodriguez, Patricio H; Van Assche, Frank; Wilrich, Peter; Oller, Adriana R

2014-10-01

Bioelution assays are fast, simple alternatives to in vivo testing. In this study, the intra- and inter-laboratory variability in bioaccessibility data generated by bioelution tests were evaluated in synthetic fluids relevant to oral, inhalation, and dermal exposure. Using one defined protocol, five laboratories measured metal release from cobalt oxide, cobalt powder, copper concentrate, Inconel alloy, leaded brass alloy, and nickel sulfate hexahydrate. Standard deviations of repeatability (sr) and reproducibility (sR) were used to evaluate the intra- and inter-laboratory variability, respectively. Examination of the sR:sr ratios demonstrated that, while gastric and lysosomal fluids had reasonably good reproducibility, other fluids did not show as good concordance between laboratories. Relative standard deviation (RSD) analysis showed more favorable reproducibility outcomes for some data sets; overall results varied more between- than within-laboratories. RSD analysis of sr showed good within-laboratory variability for all conditions except some metals in interstitial fluid. In general, these findings indicate that absolute bioaccessibility results in some biological fluids may vary between different laboratories. However, for most applications, measures of relative bioaccessibility are needed, diminishing the requirement for high inter-laboratory reproducibility in absolute metal releases. The inter-laboratory exercise suggests that the degrees of freedom within the protocol need to be addressed. Copyright © 2014 Elsevier Inc. All rights reserved.

Graphene oxide decorated with silver nanoparticles as a coating on a stainless-steel fiber for solid-phase microextraction.

PubMed

Wang, Licheng; Hou, Xiudan; Li, Jubai; Liu, Shujuan; Guo, Yong

2015-07-01

A novel graphene oxide decorated with silver nanoparticles coating on a stainless-steel fiber for solid-phase microextraction was prepared. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the coating surface and showed that silver nanoparticles were dispersed on the wrinkled graphene oxide surface. Coupled to gas chromatography with flame ionization detection, the extraction abilities of the fiber for polycyclic aromatic hydrocarbons were examined in the headspace solid-phase microextraction mode. The extraction parameters including adsorption time, adsorption temperature, salt concentration, desorption time and desorption temperature were investigated. Under the optimized condition, wide linearity with low limits of detection from 2 to 10 ng/L was obtained. The relative standard deviations for single-fiber repeatability and fiber-to-fiber reproducibility were less than 10.6 and 17.5%, respectively. The enrichment factors were from 1712.5 to 4503.7, showing the fiber has good extraction abilities. Moreover, the fiber exhibited a good stability and could be reused for more than 120 times. The established method was also applied for determination of polycyclic aromatic hydrocarbons in two real water samples and the recoveries of analytes ranged from 84.4-116.3% with relative standard deviations less than 16.2%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exploration of attenuated total reflectance mid-infrared spectroscopy and multivariate calibration to measure immunoglobulin G in human sera.

PubMed

Hou, Siyuan; Riley, Christopher B; Mitchell, Cynthia A; Shaw, R Anthony; Bryanton, Janet; Bigsby, Kathryn; McClure, J Trenton

2015-09-01

Immunoglobulin G (IgG) is crucial for the protection of the host from invasive pathogens. Due to its importance for human health, tools that enable the monitoring of IgG levels are highly desired. Consequently there is a need for methods to determine the IgG concentration that are simple, rapid, and inexpensive. This work explored the potential of attenuated total reflectance (ATR) infrared spectroscopy as a method to determine IgG concentrations in human serum samples. Venous blood samples were collected from adults and children, and from the umbilical cord of newborns. The serum was harvested and tested using ATR infrared spectroscopy. Partial least squares (PLS) regression provided the basis to develop the new analytical methods. Three PLS calibrations were determined: one for the combined set of the venous and umbilical cord serum samples, the second for only the umbilical cord samples, and the third for only the venous samples. The number of PLS factors was chosen by critical evaluation of Monte Carlo-based cross validation results. The predictive performance for each PLS calibration was evaluated using the Pearson correlation coefficient, scatter plot and Bland-Altman plot, and percent deviations for independent prediction sets. The repeatability was evaluated by standard deviation and relative standard deviation. The results showed that ATR infrared spectroscopy is potentially a simple, quick, and inexpensive method to measure IgG concentrations in human serum samples. The results also showed that it is possible to build a united calibration curve for the umbilical cord and the venous samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Results of scatterometer systems analysis for NASA/MSC Earth observation sensor evaluation program

NASA Technical Reports Server (NTRS)

Krishen, K.; Vlahos, N.; Brandt, O.; Graybeal, G.

1970-01-01

A systems evaluation of the 13.3 GHz scatterometer system is presented. The effects of phase error between the scatterometer channels, antenna pattern deviations, aircraft attitude deviations, environmental changes, and other related factors such as processing errors, system repeatability, and propeller modulation, are established. Furthermore, the reduction in system errors and calibration improvement is investigated by taking into account these parameter deviations. Typical scatterometer data samples are presented.

Verification of spectrophotometric method for nitrate analysis in water samples

NASA Astrophysics Data System (ADS)

Kurniawati, Puji; Gusrianti, Reny; Dwisiwi, Bledug Bernanti; Purbaningtias, Tri Esti; Wiyantoko, Bayu

2017-12-01

The aim of this research was to verify the spectrophotometric method to analyze nitrate in water samples using APHA 2012 Section 4500 NO3-B method. The verification parameters used were: linearity, method detection limit, level of quantitation, level of linearity, accuracy and precision. Linearity was obtained by using 0 to 50 mg/L nitrate standard solution and the correlation coefficient of standard calibration linear regression equation was 0.9981. The method detection limit (MDL) was defined as 0,1294 mg/L and limit of quantitation (LOQ) was 0,4117 mg/L. The result of a level of linearity (LOL) was 50 mg/L and nitrate concentration 10 to 50 mg/L was linear with a level of confidence was 99%. The accuracy was determined through recovery value was 109.1907%. The precision value was observed using % relative standard deviation (%RSD) from repeatability and its result was 1.0886%. The tested performance criteria showed that the methodology was verified under the laboratory conditions.

Video camera system for locating bullet holes in targets at a ballistics tunnel

NASA Technical Reports Server (NTRS)

Burner, A. W.; Rummler, D. R.; Goad, W. K.

1990-01-01

A system consisting of a single charge coupled device (CCD) video camera, computer controlled video digitizer, and software to automate the measurement was developed to measure the location of bullet holes in targets at the International Shooters Development Fund (ISDF)/NASA Ballistics Tunnel. The camera/digitizer system is a crucial component of a highly instrumented indoor 50 meter rifle range which is being constructed to support development of wind resistant, ultra match ammunition. The system was designed to take data rapidly (10 sec between shoots) and automatically with little operator intervention. The system description, measurement concept, and procedure are presented along with laboratory tests of repeatability and bias error. The long term (1 hour) repeatability of the system was found to be 4 microns (one standard deviation) at the target and the bias error was found to be less than 50 microns. An analysis of potential errors and a technique for calibration of the system are presented.

Note: An absolute X-Y-Θ position sensor using a two-dimensional phase-encoded binary scale

NASA Astrophysics Data System (ADS)

Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan

2018-04-01

This Note presents a new absolute X-Y-Θ position sensor for measuring planar motion of a precision multi-axis stage system. By analyzing the rotated image of a two-dimensional phase-encoded binary scale (2D), the absolute 2D position values at two separated points were obtained and the absolute X-Y-Θ position could be calculated combining these values. The sensor head was constructed using a board-level camera, a light-emitting diode light source, an imaging lens, and a cube beam-splitter. To obtain the uniform intensity profiles from the vignette scale image, we selected the averaging directions deliberately, and higher resolution in the angle measurement could be achieved by increasing the allowable offset size. The performance of a prototype sensor was evaluated in respect of resolution, nonlinearity, and repeatability. The sensor could resolve 25 nm linear and 0.001° angular displacements clearly, and the standard deviations were less than 18 nm when 2D grid positions were measured repeatedly.

Characterizing the Performance of the Wheel Electrostatic Spectrometer

NASA Technical Reports Server (NTRS)

Johansen, M. R.; Mackey, P. J.; Holbert, E.; Clements, J. S.; Calle, C. I.

2013-01-01

A Wheel Electrostatic Spectrometer has been developed as a surveying tool to be incorporated into a Martian rover design. Electrostatic sensors with various protruding cover insulators are embedded into a prototype rover wheel. When these insulators come into contact with a surface, a charge develops on the cover insulator through tribocharging. A charge spectrum is created by analyzing the accumulated charge on each of the dissimilar cover insulators. This charge spectrum can be used to determine differences in Martian regolith properties. In this study, we analyzed the repeatability of the measurements for this sensor package and found that the sensor repeatability lies within one standard deviation of the noise in the signal. In addition, we tested the need for neutralizing the surface charge on the cover insulators and discovered a need to discharge the sensor cover insulators after each revolution. Future work includes an electronics redesign to reduce noise and a Martian pressure static elimination tool that can be used to neutralize the charge on the sensor cover insulators after each wheel revolution.

Measurement uncertainty of the EU methods for microbiological examination of red meat.

PubMed

Corry, Janet E L; Hedges, Alan J; Jarvis, Basil

2007-09-01

Three parallel trials were made of EU methods proposed for the microbiological examination of red meat using two analysts in each of seven laboratories within the UK. The methods involved determination of aerobic colony count (ACC) and Enterobacteriaceae colony count (ECC) using simulated methods and a freeze-dried standardised culture preparation. Trial A was based on a simulated swab test, Trial B a simulated meat excision test and Trial C was a reference test on reconstituted inoculum. Statistical analysis (ANOVA) was carried out before and after rejection of outlying data. Expanded uncertainty values (relative standard deviation x2) for repeatability and reproducibility, based on the log10 cfu/ml, on the ACC ranged from +/-2.1% to +/-2.7% and from +/-5.5% to +/-10.5%, respectively, depending upon the test procedure. Similarly for the ECC, expanded uncertainty estimates for repeatability and reproducibility ranged from +/-4.6% to +/-16.9% and from +/-21.6% to +/-23.5%, respectively. The results are discussed in relation to the potential application of the methods.

Assessment of statistical uncertainty in the quantitative analysis of solid samples in motion using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Cabalín, L. M.; González, A.; Ruiz, J.; Laserna, J. J.

2010-08-01

Statistical uncertainty in the quantitative analysis of solid samples in motion by laser-induced breakdown spectroscopy (LIBS) has been assessed. For this purpose, a LIBS demonstrator was designed and constructed in our laboratory. The LIBS system consisted of a laboratory-scale conveyor belt, a compact optical module and a Nd:YAG laser operating at 532 nm. The speed of the conveyor belt was variable and could be adjusted up to a maximum speed of 2 m s - 1 . Statistical uncertainty in the analytical measurements was estimated in terms of precision (reproducibility and repeatability) and accuracy. The results obtained by LIBS on shredded scrap samples under real conditions have demonstrated that the analytical precision and accuracy of LIBS is dependent on the sample geometry, position on the conveyor belt and surface cleanliness. Flat, relatively clean scrap samples exhibited acceptable reproducibility and repeatability; by contrast, samples with an irregular shape or a dirty surface exhibited a poor relative standard deviation.

Measurement System Analyses - Gauge Repeatability and Reproducibility Methods

NASA Astrophysics Data System (ADS)

Cepova, Lenka; Kovacikova, Andrea; Cep, Robert; Klaput, Pavel; Mizera, Ondrej

2018-02-01

The submitted article focuses on a detailed explanation of the average and range method (Automotive Industry Action Group, Measurement System Analysis approach) and of the honest Gauge Repeatability and Reproducibility method (Evaluating the Measurement Process approach). The measured data (thickness of plastic parts) were evaluated by both methods and their results were compared on the basis of numerical evaluation. Both methods were additionally compared and their advantages and disadvantages were discussed. One difference between both methods is the calculation of variation components. The AIAG method calculates the variation components based on standard deviation (then a sum of variation components does not give 100 %) and the honest GRR study calculates the variation components based on variance, where the sum of all variation components (part to part variation, EV & AV) gives the total variation of 100 %. Acceptance of both methods among the professional society, future use, and acceptance by manufacturing industry were also discussed. Nowadays, the AIAG is the leading method in the industry.

Exploring Students' Conceptions of the Standard Deviation

ERIC Educational Resources Information Center

delMas, Robert; Liu, Yan

2005-01-01

This study investigated introductory statistics students' conceptual understanding of the standard deviation. A computer environment was designed to promote students' ability to coordinate characteristics of variation of values about the mean with the size of the standard deviation as a measure of that variation. Twelve students participated in an…

7 CFR 801.4 - Tolerances for dockage testers.

Code of Federal Regulations, 2012 CFR

2012-01-01

....10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Riddle separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Sieve separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Total...

7 CFR 801.4 - Tolerances for dockage testers.

Code of Federal Regulations, 2014 CFR

2014-01-01

....10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Riddle separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Sieve separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Total...

7 CFR 801.4 - Tolerances for dockage testers.

Code of Federal Regulations, 2011 CFR

2011-01-01

....10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Riddle separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Sieve separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Total...

7 CFR 801.4 - Tolerances for dockage testers.

Code of Federal Regulations, 2013 CFR

2013-01-01

....10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Riddle separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Sieve separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Total...

Statistics as Unbiased Estimators: Exploring the Teaching of Standard Deviation

ERIC Educational Resources Information Center

Wasserman, Nicholas H.; Casey, Stephanie; Champion, Joe; Huey, Maryann

2017-01-01

This manuscript presents findings from a study about the knowledge for and planned teaching of standard deviation. We investigate how understanding variance as an unbiased (inferential) estimator--not just a descriptive statistic for the variation (spread) in data--is related to teachers' instruction regarding standard deviation, particularly…

7 CFR 801.4 - Tolerances for dockage testers.

Code of Federal Regulations, 2010 CFR

2010-01-01

....10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Riddle separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Sieve separation ±0.10 percent, mean deviation from standard dockage tester using Hard Red Winter wheat Total...

7 CFR 801.6 - Tolerances for moisture meters.

Code of Federal Regulations, 2010 CFR

2010-01-01

... moisture, mean deviation from National standard moisture meter using Hard Red Winter wheat Mid ±0.05 percent moisture, mean deviation from National standard moisture meter using Hard Red Winter wheat High ±0.05 percent moisture, mean deviation from National standard moisture meter using Hard Red Winter wheat...

A framework for the meta-analysis of Bland-Altman studies based on a limits of agreement approach.

PubMed

Tipton, Elizabeth; Shuster, Jonathan

2017-10-15

Bland-Altman method comparison studies are common in the medical sciences and are used to compare a new measure to a gold-standard (often costlier or more invasive) measure. The distribution of these differences is summarized by two statistics, the 'bias' and standard deviation, and these measures are combined to provide estimates of the limits of agreement (LoA). When these LoA are within the bounds of clinically insignificant differences, the new non-invasive measure is preferred. Very often, multiple Bland-Altman studies have been conducted comparing the same two measures, and random-effects meta-analysis provides a means to pool these estimates. We provide a framework for the meta-analysis of Bland-Altman studies, including methods for estimating the LoA and measures of uncertainty (i.e., confidence intervals). Importantly, these LoA are likely to be wider than those typically reported in Bland-Altman meta-analyses. Frequently, Bland-Altman studies report results based on repeated measures designs but do not properly adjust for this design in the analysis. Meta-analyses of Bland-Altman studies frequently exclude these studies for this reason. We provide a meta-analytic approach that allows inclusion of estimates from these studies. This includes adjustments to the estimate of the standard deviation and a method for pooling the estimates based upon robust variance estimation. An example is included based on a previously published meta-analysis. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Validation of refraction and anterior segment parameters by a new multi-diagnostic platform (VX120).

PubMed

Gordon-Shaag, Ariela; Piñero, David P; Kahloun, Cyril; Markov, David; Parnes, Tzadok; Gantz, Liat; Shneor, Einat

2018-03-08

The VX120 (Visionix Luneau, France) is a novel multi-diagnostic platform that combines Hartmann-Shack based autorefraction, Placido-disk based corneal-topography and anterior segment measurements made with a stationary-Scheimpflug camera. We investigate the agreement between different parameters measured by the VX120 with accepted or gold-standard techniques to test if they are interchangeable, as well as to evaluate the repeatability and reproducibility. The right-eyes of healthy subjects were included in the study. Autorefraction of the VX120 was compared to subjective refraction. Agreement of anterior segment parameters was compared to the Sirius (CSO, Italy) including autokeratometry, central corneal thickness (CCT), iridiocorneal angle (IA). Inter and intra-test repeatability of the above parameters was assessed. Results were analyzed using Bland and Altman analyses. A total of 164 eyes were evaluated. The mean difference between VX120 autorefraction and subjective refraction for sphere, spherical equivalent (SE), and cylinder was 0.01±0.43D, 0.14±0.47D, and -0.26±0.30D, respectively and high correlation was found to all parameter (r>0.75) except for J 45 (r=0.61). The mean difference between VX120 and the Sirius system for CCT, IA, and keratometry (k1 and k2) was -3.51±8.64μm, 7.6±4.2°, 0.003±0.06mm and 0.004±0.04mm, respectively and high correlation was found to all parameter (r>0.97) except for IA (r=0.67). Intrasession repeatability of VX120 refraction, CCT, IA and keratometry yielded low within-subject standard deviations. Inter-session repeatability showed no statistically significant difference for most of the parameters measured. The VX120 provides consistent refraction and most anterior segment measurements in normal healthy eyes, with high levels of intra and inter-session repeatability. Copyright © 2018. Published by Elsevier España, S.L.U.

Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

NASA Astrophysics Data System (ADS)

Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

2014-11-01

In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L- 1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L- 1 and 36.4 mg L- 1, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93-105% with the repeatability in the range of 4.1-5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg- 1), egg white (2188 ± 29 mg kg- 1), mineral water (31.0 ± 0.9 mg L- 1), white wine (260 ± 4 mg L- 1) and red wine (82 ± 2 mg L- 1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L- 1).

Molecular weight distribution of polysaccharides from edible seaweeds by high-performance size-exclusion chromatography (HPSEC).

PubMed

Gómez-Ordóñez, Eva; Jiménez-Escrig, Antonio; Rupérez, Pilar

2012-05-15

Biological properties of polysaccharides from seaweeds are related to their composition and structure. Many factors such as the kind of sugar, type of linkage or sulfate content of algal biopolymers exert an influence in the relationship between structure and function. Besides, the molecular weight (MW) also plays an important role. Thus, a simple, reliable and fast HPSEC method with refractive index detection was developed and optimized for the MW estimation of soluble algal polysaccharides. Chromatogram shape and repeatability of retention time was considerably improved when sodium nitrate was used instead of ultrapure water as mobile phase. Pullulan and dextran standards of different MW were used for method calibration and validation. Also, main polysaccharide standards from brown (alginate, fucoidan, laminaran) and red seaweeds (kappa- and iota-carrageenan) were used for quantification and method precision and accuracy. Relative standard deviation (RSD) of repeatability for retention time, peak areas and inter-day precision was below 0.7%, 2.5% and 2.6%, respectively, which indicated good repeatability and precision. Recoveries (96.3-109.8%) also showed its fairly good accuracy. Regarding linearity, main polysaccharide standards from brown or red seaweeds showed a highly satisfactory correlation coefficient (r>0.999). Moreover, a good sensitivity was shown, with corresponding limits of detection and quantitation in mg/mL of 0.05-0.21 and 0.16-0.31, respectively. The method was applied to the MW estimation of standard algal polysaccharides, as well as to the soluble polysaccharide fractions from the brown seaweed Saccharina latissima and the red Mastocarpus stellatus, respectively. Although distribution of molecular weight was broad, the good repeatability for retention time provided a good precision in MW estimation of polysaccharides. Water- and alkali-soluble fractions from S. latissima ranged from very high (>2400 kDa) to low MW compounds (<6 kDa); this high heterogeneity could be attributable to the complex polysaccharide composition of brown algae. Regarding M. stellatus, sulfated galactans followed a descending order of MW (>1400 kDa to <10 kDa), related to the different solubility of carrageenans in red seaweeds. In summary, the method developed allows for the molecular weight analysis of seaweed polysaccharides with very good precision, accuracy, linearity and sensitivity within a short time. Copyright © 2012 Elsevier B.V. All rights reserved.

Minority game with arbitrary cutoffs

NASA Astrophysics Data System (ADS)

Johnson, N. F.; Hui, P. M.; Zheng, Dafang; Tai, C. W.

1999-07-01

We study a model of a competing population of N adaptive agents, with similar capabilities, repeatedly deciding whether to attend a bar with an arbitrary cutoff L. Decisions are based upon past outcomes. The agents are only told whether the actual attendance is above or below L. For L∼ N/2, the game reproduces the main features of Challet and Zhang's minority game. As L is lowered, however, the mean attendances in different runs tend to divide into two groups. The corresponding standard deviations for these two groups are very different. This grouping effect results from the dynamical feedback governing the game's time-evolution, and is not reproduced if the agents are fed a random history.

A novel amperometric biosensor based on banana peel (Musa cavendish) tissue homogenate for determination of phenolic compounds.

PubMed

Ozcan, Hakki Mevlut; Sagiroglu, Ayten

2010-08-01

In this study the biosensor was constructed by immobilizing tissue homogenate of banana peel onto a glassy carbon electrode surface. Effects of immobilization materials amounts, effects of pH, buffer concentration and temperature on biosensor response were studied. In addition, the detection ranges of 13 phenolic compounds were obtained with the help of the calibration graphs. Storage stability, repeatability of the biosensor, inhibitory effect and sample applications were also investigated. A typical calibration curve for the sensor revealed a linear range of 10-80 microM catechol. In reproducibility studies, variation coefficient and standard deviation were calculated as 2.69%, 1.44 x 10(-3) microM, respectively.

Precision of intraoral digital dental impressions with iTero and extraoral digitization with the iTero and a model scanner.

PubMed

Flügge, Tabea V; Schlager, Stefan; Nelson, Katja; Nahles, Susanne; Metzger, Marc C

2013-09-01

Digital impression devices are used alternatively to conventional impression techniques and materials. The aims of this study were to evaluate the precision of digital intraoral scanning under clinical conditions (iTero; Align Technologies, San Jose, Calif) and to compare it with the precision of extraoral digitization. One patient received 10 full-arch intraoral scans with the iTero and conventional impressions with a polyether impression material (Impregum Penta; 3M ESPE, Seefeld, Germany). Stone cast models manufactured from the impressions were digitized 10 times with an extraoral scanner (D250; 3Shape, Copenhagen, Denmark) and 10 times with the iTero. Virtual models provided by each method were roughly aligned, and the model edges were trimmed with cutting planes to create common borders (Rapidform XOR; Inus Technologies, Seoul, Korea). A second model alignment was then performed along the closest distances of the surfaces (Artec Studio software; Artec Group, Luxembourg, Luxembourg). To assess precision, deviations between corresponding models were compared. Repeated intraoral scanning was evaluated in group 1, repeated extraoral model scanning with the iTero was assessed in group 2, and repeated model scanning with the D250 was assessed in group 3. Deviations between models were measured and expressed as maximums, means, medians, and root mean square errors for quantitative analysis. Color-coded displays of the deviations allowed qualitative visualization of the deviations. The greatest deviations and therefore the lowest precision were in group 1, with mean deviations of 50 μm, median deviations of 37 μm, and root mean square errors of 73 μm. Group 2 showed a higher precision, with mean deviations of 25 μm, median deviations of 18 μm, and root mean square errors of 51 μm. Scanning with the D250 had the highest precision, with mean deviations of 10 μm, median deviations of 5 μm, and root mean square errors of 20 μm. Intraoral and extraoral scanning with the iTero resulted in deviations at the facial surfaces of the anterior teeth and the buccal molar surfaces. Scanning with the iTero is less accurate than scanning with the D250. Intraoral scanning with the iTero is less accurate than model scanning with the iTero, suggesting that the intraoral conditions (saliva, limited spacing) contribute to the inaccuracy of a scan. For treatment planning and manufacturing of tooth-supported appliances, virtual models created with the iTero can be used. An extended scanning protocol could improve the scanning results in some regions. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Visualizing the Sample Standard Deviation

ERIC Educational Resources Information Center

Sarkar, Jyotirmoy; Rashid, Mamunur

2017-01-01

The standard deviation (SD) of a random sample is defined as the square-root of the sample variance, which is the "mean" squared deviation of the sample observations from the sample mean. Here, we interpret the sample SD as the square-root of twice the mean square of all pairwise half deviations between any two sample observations. This…

Experimental Structural Dynamic Response of Plate Specimens Due to Sonic Loads in a Progressive Wave Tube

NASA Technical Reports Server (NTRS)

Betts, Juan F.

2001-01-01

The objective of the current study was to assess the repeatability of experiments at NASA Langley's Thermal Acoustic Fatigue Apparatus (TAFA) facility and to use these experiments to validate numerical models. Experiments show that power spectral density (PSD) curves were repeatable except at the resonant frequencies, which tended to vary between 5 Hz to 15 Hz. Results show that the thinner specimen had more variability in the resonant frequency location than the thicker sample, especially for modes higher than the first mode in the frequency range. Root Mean Square (RMS) tended to be more repeatable. The RMS behaved linearly through the SPL range of 135 to 153 dB. Standard Deviations (STDs) of the results tended to be relatively low constant up to about 147 dB. The RMS results were more repeatable than the PDS results. The STD results were less than 10% of the RMS results for both the 0.125 in (0.318 cm) and 0.062 in (0.1588 cm) thick plate. The STD of the PSD results were around 20% to 100% of the mean PSD results for non-resonant and resonant frequencies, respectively, for the 0.125 in (0.318 cm) thicker plate and between 25% to 125% of the mean PSD results, for nonresonant and resonant frequencies, respectively, for the thinner plate.

An integrative strategy for quantitative analysis of the N-glycoproteome in complex biological samples.

PubMed

Wang, Ji; Zhou, Chuang; Zhang, Wei; Yao, Jun; Lu, Haojie; Dong, Qiongzhu; Zhou, Haijun; Qin, Lunxiu

2014-01-15

The complexity of protein glycosylation makes it difficult to characterize glycosylation patterns on a proteomic scale. In this study, we developed an integrated strategy for comparatively analyzing N-glycosylation/glycoproteins quantitatively from complex biological samples in a high-throughput manner. This strategy entailed separating and enriching glycopeptides/glycoproteins using lectin affinity chromatography, and then tandem labeling them with 18O/16O to generate a mass shift of 6 Da between the paired glycopeptides, and finally analyzing them with liquid chromatography-mass spectrometry (LC-MS) and the automatic quantitative method we developed based on Mascot Distiller. The accuracy and repeatability of this strategy were first verified using standard glycoproteins; linearity was maintained within a range of 1:10-10:1. The peptide concentration ratios obtained by the self-build quantitative method were similar to both the manually calculated and theoretical values, with a standard deviation (SD) of 0.023-0.186 for glycopeptides. The feasibility of the strategy was further confirmed with serum from hepatocellular carcinoma (HCC) patients and healthy individuals; the expression of 44 glycopeptides and 30 glycoproteins were significantly different between HCC patient and control serum. This strategy is accurate, repeatable, and efficient, and may be a useful tool for identification of disease-related N-glycosylation/glycoprotein changes.

Variation in the standard deviation of the lure rating distribution: Implications for estimates of recollection probability.

PubMed

Dopkins, Stephen; Varner, Kaitlin; Hoyer, Darin

2017-10-01

In word recognition semantic priming of test words increased the false-alarm rate and the mean of confidence ratings to lures. Such priming also increased the standard deviation of confidence ratings to lures and the slope of the z-ROC function, suggesting that the priming increased the standard deviation of the lure evidence distribution. The Unequal Variance Signal Detection (UVSD) model interpreted the priming as increasing the standard deviation of the lure evidence distribution. Without additional parameters the Dual Process Signal Detection (DPSD) model could only accommodate the results by fitting the data for related and unrelated primes separately, interpreting the priming, implausibly, as decreasing the probability of target recollection (DPSD). With an additional parameter, for the probability of false (lure) recollection the model could fit the data for related and unrelated primes together, interpreting the priming as increasing the probability of false recollection. These results suggest that DPSD estimates of target recollection probability will decrease with increases in the lure confidence/evidence standard deviation unless a parameter is included for false recollection. Unfortunately the size of a given lure confidence/evidence standard deviation relative to other possible lure confidence/evidence standard deviations is often unspecified by context. Hence the model often has no way of estimating false recollection probability and thereby correcting its estimates of target recollection probability.

Down-Looking Interferometer Study II, Volume I,

DTIC Science & Technology

1980-03-01

g(standard deviation of AN )(standard deviation of(3) where T’rm is the "reference spectrum", an estimate of the actual spectrum v gv T ’V Cgv . If jpj...spectrum T V . cgv . According to Eq. (2), Z is the standard deviation of the observed contrast spectral radiance AN divided by the effective rms system

40 CFR 61.207 - Radium-226 sampling and measurement procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... B, Method 114. (3) Calculate the mean, x 1, and the standard deviation, s 1, of the n 1 radium-226... owner or operator of a phosphogypsum stack shall report the mean, standard deviation, 95th percentile..., Method 114. (4) Recalculate the mean and standard deviation of the entire set of n 2 radium-226...

Preparation of a novel sorptive stir bar based on vinylpyrrolidone-ethylene glycol dimethacrylate monolithic polymer for the simultaneous extraction of diazepam and nordazepam from human plasma.

PubMed

Torabizadeh, Mahsa; Talebpour, Zahra; Adib, Nuoshin; Aboul-Enein, Hassan Y

2016-04-01

A new monolithic coating based on vinylpyrrolidone-ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The polymerization step was performed using different contents of monomer, cross-linker and porogenic solvent, and the best formulation was selected. The quality of the prepared vinylpyrrolidone-ethylene glycol dimethacrylate stir bars was satisfactory, demonstrating good repeatability within batch (relative standard deviation < 3.5%) and acceptable reproducibility between batches (relative standard deviation < 6.0%). The prepared stir bar was utilized in combination with ultrasound-assisted liquid desorption, followed by high-performance liquid chromatography with ultraviolet detection for the simultaneous determination of diazepam and nordazepam in human plasma samples. To optimize the extraction step, a three-level, four-factor, three-block Box-Behnken design was applied. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for diazepam (36-1200 ng/mL) and nordazepam (25-1200 ng/mL), with correlation coefficients of 0.9986 and 0.9968 and detection limits of 12 and 10 ng/mL, respectively. The intra- and interday recovery ranged from 93 to 106%, and the relative standard deviations were less than 6%. Finally, the proposed method was successfully applied to the analysis of diazepam and nordazepam at their therapeutic levels in human plasma. The novelty of this study is the improved polarity of the stir bar coating and its application for the simultaneous extraction of diazepam and its active metabolite, nordazepam in human plasma sample. The method was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of diazepam and nordazepam in biological fluids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fattori di organizzazione del discorso nella memoria linguistica (Factors in Organizing Speech in Linguistic Memory)

ERIC Educational Resources Information Center

Baroni, Maria Rosa; And Others

1977-01-01

An experiment was carried out to study the processes of linguistic memory. Subjects were asked to read aloud brief prose passages and repeat what they had read. The "deviations" from the original passages were analyzed to determine the time of the deviation, during decoding or recall. (Text is in Italian.) (CFM)

Flexner 2.0-Longitudinal Study of Student Participation in a Campus-Wide General Pathology Course for Graduate Students at The University of Arizona.

PubMed

Briehl, Margaret M; Nelson, Mark A; Krupinski, Elizabeth A; Erps, Kristine A; Holcomb, Michael J; Weinstein, John B; Weinstein, Ronald S

2016-01-01

Faculty members from the Department of Pathology at The University of Arizona College of Medicine-Tucson have offered a 4-credit course on enhanced general pathology for graduate students since 1996. The course is titled, "Mechanisms of Human Disease." Between 1997 and 2016, 270 graduate students completed Mechanisms of Human Disease. The students came from 21 programs of study. Analysis of Variance, using course grade as the dependent and degree, program, gender, and year (1997-2016) as independent variables, indicated that there was no significant difference in final grade (F = 0.112; P = .8856) as a function of degree (doctorate: mean = 89.60, standard deviation = 5.75; master's: mean = 89.34, standard deviation = 6.00; certificate program: mean = 88.64, standard deviation = 8.25), specific type of degree program (F = 2.066, P = .1316; life sciences: mean = 89.95, standard deviation = 6.40; pharmaceutical sciences: mean = 90.71, standard deviation = 4.57; physical sciences: mean = 87.79, standard deviation = 5.17), or as a function of gender (F = 2.96, P = .0865; males: mean = 88.09, standard deviation = 8.36; females: mean = 89.58, standard deviation = 5.82). Students in the physical and life sciences performed equally well. Mechanisms of Human Disease is a popular course that provides students enrolled in a variety of graduate programs with a medical school-based course on mechanisms of diseases. The addition of 2 new medically oriented Master of Science degree programs has nearly tripled enrollment. This graduate level course also potentially expands the interdisciplinary diversity of participants in our interprofessional education and collaborative practice exercises.

Flexner 2.0—Longitudinal Study of Student Participation in a Campus-Wide General Pathology Course for Graduate Students at The University of Arizona

PubMed Central

Briehl, Margaret M.; Nelson, Mark A.; Krupinski, Elizabeth A.; Erps, Kristine A.; Holcomb, Michael J.; Weinstein, John B.

2016-01-01

Faculty members from the Department of Pathology at The University of Arizona College of Medicine-Tucson have offered a 4-credit course on enhanced general pathology for graduate students since 1996. The course is titled, “Mechanisms of Human Disease.” Between 1997 and 2016, 270 graduate students completed Mechanisms of Human Disease. The students came from 21 programs of study. Analysis of Variance, using course grade as the dependent and degree, program, gender, and year (1997-2016) as independent variables, indicated that there was no significant difference in final grade (F = 0.112; P = .8856) as a function of degree (doctorate: mean = 89.60, standard deviation = 5.75; master’s: mean = 89.34, standard deviation = 6.00; certificate program: mean = 88.64, standard deviation = 8.25), specific type of degree program (F = 2.066, P = .1316; life sciences: mean = 89.95, standard deviation = 6.40; pharmaceutical sciences: mean = 90.71, standard deviation = 4.57; physical sciences: mean = 87.79, standard deviation = 5.17), or as a function of gender (F = 2.96, P = .0865; males: mean = 88.09, standard deviation = 8.36; females: mean = 89.58, standard deviation = 5.82). Students in the physical and life sciences performed equally well. Mechanisms of Human Disease is a popular course that provides students enrolled in a variety of graduate programs with a medical school-based course on mechanisms of diseases. The addition of 2 new medically oriented Master of Science degree programs has nearly tripled enrollment. This graduate level course also potentially expands the interdisciplinary diversity of participants in our interprofessional education and collaborative practice exercises. PMID:28725783

Simultaneous Determination of Multiple Ginsenosides in Panax ginseng Herbal Medicines with One Single Reference Standard.

PubMed

Wu, Chunwei; Guan, Qingxiao; Wang, Shumei; Rong, Yueying

2017-01-01

Root of Panax ginseng C. A. Mey (Renseng in Chinese) is a famous Traditional Chinese Medicine. Ginsenosides are the major bioactive components. However, the shortage and high cost of some ginsenoside reference standards make it is difficult for quality control of P. ginseng . A method, single standard for determination of multicomponents (SSDMC), was developed for the simultaneous determination of nine ginsenosides in P. ginseng (ginsenoside Rg 1 , Re, Rf, Rg 2 , Rb 1 , Rc, Rb 2 , Rb 3 , Rd). The analytes were separated on Inertsil ODS-3 C18 (250 mm × 4.6 mm, 5 μm) with gradient elution of acetonitrile and water. The flow rate was 1 mL/min and detection wavelength was set at 203 nm. The feasibility and accuracy of SSDMC were checked by the external standard method, and various high-performance liquid chromatographic (HPLC) instruments and chromatographic conditions were investigated to verify its applicability. Using ginsenoside Rg 1 as the internal reference substance, the contents of other eight ginsenosides were calculated according to conversion factors (F) by HPLC. The method was validated with linearity ( r 2 ≥ 0.9990), precision (relative standard deviation [RSD] ≤2.9%), accuracy (97.5%-100.8%, RSD ≤ 1.6%), repeatability, and stability. There was no significant difference between the SSDMC method and the external standard method. New SSDMC method could be considered as an ideal mean to analyze the components for which reference standards are not readily available. A method, single standard for determination of multicomponents (SSDMC), was established by high-performance liquid chromatography for the simultaneous determination of nine ginsenosides in Panax ginseng (ginsenoside Rg1, Re, Rf, Rg2, Rb1, Rc, Rb2, Rb3, Rd)Various chromatographic conditions were investigated to verify applicability of FsThe feasibility and accuracy of SSDMC were checked by the external standard method. Abbreviations used: DRT: Different value of retention time; F: Conversion factor; HPLC: High-performance Liquid Chromatography; LOD: Limit of detection; LOQ: Limit of quantitation; PD: Percent difference; PPD: 20(S)-protopanaxadiol; PPT: 20(S)-protopanaxatriol; RSD: Relative standard deviation; SSDMC: Single Standard for Determination of Multicomponents; TCM: Traditional Chinese Medicine.

Separation of plant hormones from biofertilizer by capillary electrophoresis using a capillary coated dynamically with polycationic polymers.

PubMed

Jiang, Ting-Fu; Lv, Zhi-Hua; Wang, Yuan-Hong; Yue, Mei-E

2006-06-01

A new, simple and rapid capillary electrophoresis (CE) method, using hexadimethrine bromide (HDB) as electroosmotic flow (EOF) modifier, was developed for the identification and quantitative determination of four plant hormones, including gibberellin A3 (GA3), indole-3-acetic acid (IAA), alpha-naphthaleneacetic acid (NAA) and 4-chlorophenoxyacetic acid (4-CA). The optimum separation was achieved with 20 mM borate buffer at pH 10.00 containing 0.005% (w/v) of HDB. The applied voltage was -25 kV and the capillary temperature was kept constant at 25 degrees C. Salicylic acid was used as internal standard for quantification. The calibration dependencies exhibited good linearity within the ratios of the concentrations of standard samples and internal standard and the ratios of the peak areas of samples and internal standard. The correlation coefficients were from 0.9952 to 0.9997. The relative standard deviations of migration times and peak areas were < 1.93 and 6.84%, respectively. The effects of buffer pH, the concentration of HDB and the voltage on the resolution were studied systematically. By this method, the contents of plant hormone in biofertilizer were successfully determined within 7 min, with satisfactory repeatability and recovery.

Simultaneous determination of six active components by a single standard to determine multicomponents combined with fingerprint analysis for the quality control of Rhizoma Chuanxiong.

PubMed

He, Yufei; Li, Qing; Bi, Kaishun

2015-04-01

To control the quality of Rhizoma Chuanxiong, a method based on high-performance liquid chromatography method coupled with diode array detection was developed for the quantitative analysis of six active ingredients using a single standard to determine multi-components and chemical fingerprint analysis for the first time. The separation was performed on an Agilent Zorbax SB-C18 column by gradient elution with methanol and aqueous phase (containing 0.5% glacial acetic acid) at a flow rate of 1.0 mL/min. The UV wavelength was set at 274 nm. This assay was fully validated with respect to precision, repeatability, and accuracy. All calibration curves showed good linearity (R(2) > 0.9994) within test ranges. The limit of detection and limit of quantification were lower than 0.01 and 0.03 μg/mL, respectively. The relative standard deviation for repeatability and the intermediate precision of six analytes were less than 1.6 and 2.5%, respectively, the overall recovery was 96.1-103.1%. In addition, fingerprint chromatography using hierarchical clustering analysis and similarity analysis was performed to differentiate and classify the samples. The method described here could provide a more comprehensive and reasonable scientific assessment of the quality of Rhizoma Chuanxiong. Therefore, the strategy is feasible, credible, and is easily and effectively adapted for evaluating the quality control of Rhizoma Chuanxiong. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effectiveness of a Mindfulness-Based Intervention in the Management of Musculoskeletal Pain in Nursing Workers.

PubMed

Lopes, Shirlene Aparecida; Vannucchi, Bruna Pesce; Demarzo, Marcelo; Cunha, Ângelo Geraldo José; Nunes, Maria do Patrocínio Tenório

2018-05-17

Chronic pain is a prevalent disorder in nursing workers worldwide. Several studies have proposed measures to mitigate this critical scenario. Mindfulness-based interventions (MBI) have been found to have promising results in the treatment of this disorder. To quantify the effectiveness of an adapted mindfulness program (AMP) in the management of musculoskeletal pain (MSP) in nursing technicians of a Brazilian university hospital. This study was a clinical, prospective, open, repeated measures trial, with data collection between January and July 2015. Brazilian university hospital. Participants/Subjects: Sixty-four female nursing technicians with a mean age of 47.01 years (standard deviation = 9.50) with chronic pain symptoms. Sixty-four female nursing technicians with a mean age of 47.01 years (standard deviation = 9.50) and MSP participated in this prospective study. Before the intervention (T0), scores of anxiety, depression, mindfulness, musculoskeletal complaints, pain catastrophizing, self-compassion, and perception of quality of life were quantified. These scores were reevaluated after 8 weeks (T1) and 12 weeks (T2) of weekly AMP sessions (60 minutes each). The variables were evaluated by analysis of variance for repeated measures, followed by the Bonferroni test. AMP reduced the scores of musculoskeletal symptoms, anxiety, depression, and pain catastrophizing (p < .001). A significant increase was identified in self-compassion scores and perception of quality of life in the physical, psychological, and overall assessment (p ≤ .04). Positive effects of AMP occurred at T1 and remained unchanged at T2. AMP contributed to a reduction in painful symptoms and improved the quality of life of nursing workers, with a lasting effect until the 20th week of follow-up, indicating utility as an effective strategy for the management of MSP in the group studied. Copyright © 2018 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Analysis of Twenty-Two Performance Properties of Diesel, Gasoline, and Jet Fuels Using a Field-Portable Near-Infrared (NIR) Analyzer.

PubMed

Brouillette, Carl; Smith, Wayne; Shende, Chetan; Gladding, Zack; Farquharson, Stuart; Morris, Robert E; Cramer, Jeffrey A; Schmitigal, Joel

2016-05-01

The change in custody of fuel shipments at depots, pipelines, and ports could benefit from an analyzer that could rapidly verify that properties are within specifications. To meet this need, the design requirements for a fuel analyzer based on near-infrared (NIR) spectroscopy, such as spectral region and resolution, were examined. It was found that the 1000 to 1600 nm region, containing the second CH overtone and combination vibrational modes of hydrocarbons, provided the best near-infrared to fuel property correlations when path length was taken into account, whereas 4 cm(-1) resolution provided only a modest improvement compared to 16 cm(-1) resolution when four or more latent variables were used. Based on these results, a field-portable near-infrared fuel analyzer was built that employed an incandescent light source, sample compartment optics to hold 2 mL glass sample vials with ∼1 cm path length, a transmission grating, and a 256 channel InGaAs detector that measured the above stated wavelength range with 5-6 nm (∼32 cm(-1)) resolution. The analyzer produced high signal-to-noise ratio (SNR) spectra of samples in 5 s. Twenty-two property correlation models were developed for diesel, gasoline, and jet fuels with root mean squared error of correlation - cross-validated values that compared favorably to corresponding ASTM reproducibility values. The standard deviations of predicted properties for repeat measurements at 4, 24, and 38℃ were often better than ASTM documented repeatability values. The analyzer and diesel property models were tested by measuring seven diesel samples at a local ASTM certification laboratory. The standard deviations between the analyzer determined values and the ASTM measured values for these samples were generally better than the model root mean squared error of correlation-cross-validated values for each property. © The Author(s) 2016.

A Note on Standard Deviation and Standard Error

ERIC Educational Resources Information Center

Hassani, Hossein; Ghodsi, Mansoureh; Howell, Gareth

2010-01-01

Many students confuse the standard deviation and standard error of the mean and are unsure which, if either, to use in presenting data. In this article, we endeavour to address these questions and cover some related ambiguities about these quantities.

Analytical quality goals derived from the total deviation from patients' homeostatic set points, with a margin for analytical errors.

PubMed

Bolann, B J; Asberg, A

2004-01-01

The deviation of test results from patients' homeostatic set points in steady-state conditions may complicate interpretation of the results and the comparison of results with clinical decision limits. In this study the total deviation from the homeostatic set point is defined as the maximum absolute deviation for 95% of measurements, and we present analytical quality requirements that prevent analytical error from increasing this deviation to more than about 12% above the value caused by biology alone. These quality requirements are: 1) The stable systematic error should be approximately 0, and 2) a systematic error that will be detected by the control program with 90% probability, should not be larger than half the value of the combined analytical and intra-individual standard deviation. As a result, when the most common control rules are used, the analytical standard deviation may be up to 0.15 times the intra-individual standard deviation. Analytical improvements beyond these requirements have little impact on the interpretability of measurement results.

Determination of Coenzyme Q10 Content in Raw Materials and Dietary Supplements by High-Performance Liquid Chromatography-UV: Collaborative Study

PubMed Central

Lunetta, Steven; Roman, Mark

2008-01-01

An international collaborative study was conducted of a high-performance liquid chromatographic (HPLC)-UV method for the determination of coenzyme Q10 (CoQ10, ubidecarenone) in raw materials and dietary supplements. Ten collaborating laboratories determined the total CoQ10 content in 8 blind duplicate samples. Sample materials included CoQ10 raw material and 4 finished product dietary supplements representing softgels, hardshell gelatin capsules, and chewable wafers. In addition, collaborating laboratories received a negative control and negative control spiked with CoQ10 at low and high levels to determine recovery. Materials were extracted with an acetonitrile–tetrahydrofuran–water mixture. Ferric chloride was added to the test solutions to ensure all CoQ10 was in the oxidized form. The HPLC analyses were performed on a C18 column using UV detection at 275 nm. Repeatability relative standard deviations (RSDr) ranged from 0.94 to 5.05%. Reproducibility relative standard deviations (RSDR) ranged from 3.08 to 17.1%, with HorRat values ranging from 1.26 to 5.17. Recoveries ranged from 74.0 to 115%. Based on these results, the method is recommended for Official First Action for determination of CoQ10 in raw materials and dietary supplement finished products containing CoQ10 at a concentration of >100 mg CoQ10/g test material. PMID:18727527

Bright nanoscale source of deterministic entangled photon pairs violating Bell's inequality.

PubMed

Jöns, Klaus D; Schweickert, Lucas; Versteegh, Marijn A M; Dalacu, Dan; Poole, Philip J; Gulinatti, Angelo; Giudice, Andrea; Zwiller, Val; Reimer, Michael E

2017-05-10

Global, secure quantum channels will require efficient distribution of entangled photons. Long distance, low-loss interconnects can only be realized using photons as quantum information carriers. However, a quantum light source combining both high qubit fidelity and on-demand bright emission has proven elusive. Here, we show a bright photonic nanostructure generating polarization-entangled photon pairs that strongly violates Bell's inequality. A highly symmetric InAsP quantum dot generating entangled photons is encapsulated in a tapered nanowire waveguide to ensure directional emission and efficient light extraction. We collect ~200 kHz entangled photon pairs at the first lens under 80 MHz pulsed excitation, which is a 20 times enhancement as compared to a bare quantum dot without a photonic nanostructure. The performed Bell test using the Clauser-Horne-Shimony-Holt inequality reveals a clear violation (S CHSH  > 2) by up to 9.3 standard deviations. By using a novel quasi-resonant excitation scheme at the wurtzite InP nanowire resonance to reduce multi-photon emission, the entanglement fidelity (F = 0.817 ± 0.002) is further enhanced without temporal post-selection, allowing for the violation of Bell's inequality in the rectilinear-circular basis by 25 standard deviations. Our results on nanowire-based quantum light sources highlight their potential application in secure data communication utilizing measurement-device-independent quantum key distribution and quantum repeater protocols.

Determination of coenzyme Q10 content in raw materials and dietary supplements by high-performance liquid chromatography-UV: collaborative study.

PubMed

Lunetta, Steven; Roman, Mark

2008-01-01

An international collaborative study was conducted of a high-performance liquid chromatographic (HPLC)-UV method for the determination of coenzyme Q10 (CoQ10, ubidecarenone) in raw materials and dietary supplements. Ten collaborating laboratories determined the total CoQ10 content in 8 blind duplicate samples. Sample materials included CoQ10 raw material and 4 finished product dietary supplements representing softgels, hardshell gelatin capsules, and chewable wafers. In addition, collaborating laboratories received a negative control and negative control spiked with CoQ10 at low and high levels to determine recovery. Materials were extracted with an acetonitrile-tetrahydrofuran-water mixture. Ferric chloride was added to the test solutions to ensure all CoQ10 was in the oxidized form. The HPLC analyses were performed on a C18 column using UV detection at 275 nm. Repeatability relative standard deviations (RSDr) ranged from 0.94 to 5.05%. Reproducibility relative standard deviations (RSDR) ranged from 3.08 to 17.1%, with HorRat values ranging from 1.26 to 5.17. Recoveries ranged from 74.0 to 115%. Based on these results, the method is recommended for Official First Action for determination of CoQ10 in raw materials and dietary supplement finished products containing CoQ10 at a concentration of >100 mg CoQ10/g test material.

Species Identification of Fox-, Mink-, Dog-, and Rabbit-Derived Ingredients by Multiplex PCR and Real-Time PCR Assay.

PubMed

Wu, Qingqing; Xiang, Shengnan; Wang, Wenjun; Zhao, Jinyan; Xia, Jinhua; Zhen, Yueran; Liu, Bang

2018-05-01

Various detection methods have been developed to date for identification of animal species. New techniques based on PCR approach have raised the hope of developing better identification methods, which can overcome the limitations of the existing methods. PCR-based methods used the mitochondrial DNA (mtDNA) as well as nuclear DNA sequences. In this study, by targeting nuclear DNA, multiplex PCR and real-time PCR methods were developed to assist with qualitative and quantitative analysis. The multiplex PCR was found to simultaneously and effectively distinguish four species (fox, dog, mink, and rabbit) ingredients by the different sizes of electrophoretic bands: 480, 317, 220, and 209 bp. Real-time fluorescent PCR's amplification profiles and standard curves showed good quantitative measurement responses and linearity, as indicated by good repeatability and coefficient of determination R 2  > 0.99. The quantitative results of quaternary DNA mixtures including mink, fox, dog, and rabbit DNA are in line with our expectations: R.D. (relative deviation) varied between 1.98 and 12.23% and R.S.D. (relative standard deviation) varied between 3.06 and 11.51%, both of which are well within the acceptance criterion of ≤ 25%. Combining the two methods is suitable for the rapid identification and accurate quantification of fox-, dog-, mink-, and rabbit-derived ingredients in the animal products.

14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

Code of Federal Regulations, 2010 CFR

2010-01-01

... defined in section 1 of this appendix is as follows: (a) The standard deviation of lateral track errors shall be less than 6.3 NM (11.7 Km). Standard deviation is a statistical measure of data about a mean... standard deviation about the mean encompasses approximately 68 percent of the data and plus or minus 2...

Measurement of central corneal thickness with optical low-coherence reflectometry and ultrasound pachymetry in normal and post-femtosecond laser in situ keratomileusis eyes.

PubMed

Huang, Jinhai; Liao, Na; Savini, Giacomo; Li, Yuanguang; Bao, Fangjun; Yu, Ye; Yu, Ayong; Wang, Qinmei

2015-02-01

To determine the repeatability and reproducibility of measurements of central corneal thickness (CCT) using optical low-coherence reflectometry (Lenstar LS900; Haag Streit) in normal eyes and post-femtosecond laser in situ keratomileusis (post-FS-LASIK) eyes and evaluate their agreement with ultrasound (US) pachymetry. CCT was measured using Lenstar and US pachymetry sequentially in normal and post-FS-LASIK eyes by 2 experienced observers. Intraoperator repeatability and interoperator reproducibility were assessed by within-subject standard deviation, test-retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient. Paired t-tests and Bland-Altman plots were used for analyzing agreement between the 2 devices. In this study, 55 healthy subjects and 50 post-FS-LASIK patients were recruited. Test-retest repeatability of Lenstar was within 10 μm, CoV was less than 1.0%, and intraclass correlation coefficient was more than 0.9 in both normal and post-FS-LASIK groups. Mean difference between these methods was 1.4 ± 4.2 μm and -1.7 ± 5.4 μm, respectively. Moreover, measurements of CCT showed narrow 95% limits of agreement (range, normal group: -6.8 and 9.6 μm; post-FS-LASIK group: -12.4 and 8.9 μm), which implied good agreement. Measurements of CCT using Lenstar showed excellent intraoperator repeatability and interoperator reproducibility both in normal eyes and post-FS-LASIK eyes. Measurements of CCT using Lenstar and US pachymetry showed good agreement and both can be used interchangeably.

Accurate Micro-Tool Manufacturing by Iterative Pulsed-Laser Ablation

NASA Astrophysics Data System (ADS)

Warhanek, Maximilian; Mayr, Josef; Dörig, Christian; Wegener, Konrad

2017-12-01

Iterative processing solutions, including multiple cycles of material removal and measurement, are capable of achieving higher geometric accuracy by compensating for most deviations manifesting directly on the workpiece. Remaining error sources are the measurement uncertainty and the repeatability of the material-removal process including clamping errors. Due to the lack of processing forces, process fluids and wear, pulsed-laser ablation has proven high repeatability and can be realized directly on a measuring machine. This work takes advantage of this possibility by implementing an iterative, laser-based correction process for profile deviations registered directly on an optical measurement machine. This way efficient iterative processing is enabled, which is precise, applicable for all tool materials including diamond and eliminates clamping errors. The concept is proven by a prototypical implementation on an industrial tool measurement machine and a nanosecond fibre laser. A number of measurements are performed on both the machine and the processed workpieces. Results show production deviations within 2 μm diameter tolerance.

Development of an electrothermal vaporization ICP-MS method and assessment of its applicability to studies of the homogeneity of reference materials.

PubMed

Friese, K C; Grobecker, K H; Wätjen, U

2001-07-01

A method has been developed for measurement of the homogeneity of analyte distribution in powdered materials by use of electrothermal vaporization with inductively coupled plasma mass spectrometric (ETV-ICP-MS) detection. The method enabled the simultaneous determination of As, Cd, Cu, Fe, Mn, Pb, and Zn in milligram amounts of samples of biological origin. The optimized conditions comprised a high plasma power of 1,500 W, reduced aerosol transport flow, and heating ramps below 300 degrees C s(-1). A temperature ramp to 550 degrees C ensured effective pyrolysis of approximately 70% of the organic compounds without losses of analyte. An additional hold stage at 700 degrees C led to separation of most of the analyte signals from the evaporation of carbonaceous matrix compounds. The effect of time resolution of signal acquisition on the precision of the ETV measurements was investigated. An increase in the number of masses monitored up to 20 is possible with not more than 1% additional relative standard deviation of results caused by limited temporal resolution of the transient signals. Recording of signals from the nebulization of aqueous standards in each sample run enabled correction for drift of the sensitivity of the ETV-ICP-MS instrument. The applicability of the developed method to homogeneity studies was assessed by use of four certified reference materials. According to the best repeatability observed in these sample runs, the maximum contribution of the method to the standard deviation is approximately 5% to 6% for all the elements investigated.

Simulated Keratometry Repeatability in Subjects with & without Down Syndrome

PubMed Central

Ravikumar, Ayeswarya; Marsack, Jason D.; Benoit, Julia S.; Anderson, Heather A.

2016-01-01

Purpose To assess the repeatability of simulated keratometry measures obtained with Zeiss Atlas topography for subjects with and without Down syndrome (DS). Methods Corneal topography was attempted on 140 subjects with DS and 138 controls (aged 7 to 59 years). Subjects who had at least 3 measures in each eye were included in analysis (DS: n=140 eyes (70 subjects) and controls: n=264 eyes (132 subjects)). For each measurement the steep corneal power (K), corneal astigmatism, flat K orientation, power vector representation of astigmatism (J0, J45), and astigmatic dioptric difference were determined for each measurement (collectively termed keratometry values here). For flat K orientation comparisons, only eyes with >0.50 DC of astigmatism were included (DS: n=131 eyes (68 subjects) and control: n=217 eyes (119 subjects)). Repeatability was assessed using 1) group mean variability (average standard deviation (SD) across subjects), 2) coefficient of repeatability (COR) 3) coefficient of variation (COV), and 4) intraclass correlation coefficient (ICC). Results The keratometry values showed good repeatability as evidenced by low group mean variability for DS vs control eyes (≤0.26D vs ≤0.09D for all dioptric values; 4.51° vs 3.16° for flat K orientation); however, the group mean variability was significantly higher in DS eyes than control eyes for all parameters (p≤0.03). On average, group mean variability was 2.5× greater in the DS eyes compared to control eyes across the keratometry values. Other metrics of repeatability also indicated good repeatability for both populations for each keratometry value, although repeatability was always better in the control eyes. Conclusions DS eyes showed more variability (on average: 2.5×) compared to controls for all keratometry values. Although differences were statistically significant, on average 91% of DS eyes had variability ≤0.50D for steep K and astigmatism, and 75% of DS eyes had variability ≤5 degrees for flat K orientation. PMID:27741083

Dual-Phase Lock-In Amplifier Based on FPGA for Low-Frequencies Experiments

PubMed Central

Macias-Bobadilla, Gonzalo; Rodríguez-Reséndiz, Juvenal; Mota-Valtierra, Georgina; Soto-Zarazúa, Genaro; Méndez-Loyola, Maurino; Garduño-Aparicio, Mariano

2016-01-01

Photothermal techniques allow the detection of characteristics of material without invading it. Researchers have developed hardware for some specific Phase and Amplitude detection (Lock-In Function) applications, eliminating space and unnecessary electronic functions, among others. This work shows the development of a Digital Lock-In Amplifier based on a Field Programmable Gate Array (FPGA) for low-frequency applications. This system allows selecting and generating the appropriated frequency depending on the kind of experiment or material studied. The results show good frequency stability in the order of 1.0 × 10−9 Hz, which is considered good linearity and repeatability response for the most common Laboratory Amplitude and Phase Shift detection devices, with a low error and standard deviation. PMID:26999138

Dual-Phase Lock-In Amplifier Based on FPGA for Low-Frequencies Experiments.

PubMed

Macias-Bobadilla, Gonzalo; Rodríguez-Reséndiz, Juvenal; Mota-Valtierra, Georgina; Soto-Zarazúa, Genaro; Méndez-Loyola, Maurino; Garduño-Aparicio, Mariano

2016-03-16

Photothermal techniques allow the detection of characteristics of material without invading it. Researchers have developed hardware for some specific Phase and Amplitude detection (Lock-In Function) applications, eliminating space and unnecessary electronic functions, among others. This work shows the development of a Digital Lock-In Amplifier based on a Field Programmable Gate Array (FPGA) for low-frequency applications. This system allows selecting and generating the appropriated frequency depending on the kind of experiment or material studied. The results show good frequency stability in the order of 1.0 × 10(-9) Hz, which is considered good linearity and repeatability response for the most common Laboratory Amplitude and Phase Shift detection devices, with a low error and standard deviation.

New approach to estimating variability in visual field data using an image processing technique.

PubMed Central

Crabb, D P; Edgar, D F; Fitzke, F W; McNaught, A I; Wynn, H P

1995-01-01

AIMS--A new framework for evaluating pointwise sensitivity variation in computerised visual field data is demonstrated. METHODS--A measure of local spatial variability (LSV) is generated using an image processing technique. Fifty five eyes from a sample of normal and glaucomatous subjects, examined on the Humphrey field analyser (HFA), were used to illustrate the method. RESULTS--Significant correlation between LSV and conventional estimates--namely, HFA pattern standard deviation and short term fluctuation, were found. CONCLUSION--LSV is not dependent on normals' reference data or repeated threshold determinations, thus potentially reducing test time. Also, the illustrated pointwise maps of LSV could provide a method for identifying areas of fluctuation commonly found in early glaucomatous field loss. PMID:7703196

Fast BIA-amperometric determination of isoniazid in tablets.

PubMed

Quintino, Maria S M; Angnes, Lúcio

2006-09-26

This paper proposes a new, fast and precise method to analyze isoniazid based on the electrochemical oxidation of the analyte at a glassy carbon electrode in 0.1M NaOH. The quantification was performed utilizing amperometry associated with batch injection analysis (BIA) technique. Fast sequential analysis (60 determinations h(-1)) in an unusually wide linear dynamic range (from 2.5 x 10(-8) to 1.0 x 10(-3)M), with high sensitivity and low limits of detection (4.1 x 10(-9)M) and quantification (1.4 x 10(-8)M), was achieved. Such characteristics allied to a good repeatability of the current responses (relative standard deviation of 0.79% for 30 measurements), were explored for the specific determination of isoniazid in isoniazid-rifampin tablet.

A better norm-referenced grading using the standard deviation criterion.

PubMed

Chan, Wing-shing

2014-01-01

The commonly used norm-referenced grading assigns grades to rank-ordered students in fixed percentiles. It has the disadvantage of ignoring the actual distance of scores among students. A simple norm-referenced grading via standard deviation is suggested for routine educational grading. The number of standard deviation of a student's score from the class mean was used as the common yardstick to measure achievement level. Cumulative probability of a normal distribution was referenced to help decide the amount of students included within a grade. RESULTS of the foremost 12 students from a medical examination were used for illustrating this grading method. Grading by standard deviation seemed to produce better cutoffs in allocating an appropriate grade to students more according to their differential achievements and had less chance in creating arbitrary cutoffs in between two similarly scored students than grading by fixed percentile. Grading by standard deviation has more advantages and is more flexible than grading by fixed percentile for norm-referenced grading.

Personal Background Preparation Survey for early identification of nursing students at risk for attrition.

PubMed

Johnson, Craig W; Johnson, Ronald; Kim, Mira; McKee, John C

2009-11-01

During 2004 and 2005 orientations, all 187 and 188 new matriculates, respectively, in two southwestern U.S. nursing schools completed Personal Background and Preparation Surveys (PBPS) in the first predictive validity study of a diagnostic and prescriptive instrument for averting adverse academic status events (AASE) among nursing or health science professional students. One standard deviation increases in PBPS risks (p < 0.05) multiplied odds of first-year or second-year AASE by approximately 150%, controlling for school affiliation and underrepresented minority student (URMS) status. AASE odds one standard deviation above mean were 216% to 250% those one standard deviation below mean. Odds of first-year or second-year AASE for URMS one standard deviation above the 2004 PBPS mean were 587% those for non-URMS one standard deviation below mean. The PBPS consistently and significantly facilitated early identification of nursing students at risk for AASE, enabling proactive targeting of interventions for risk amelioration and AASE or attrition prevention. Copyright 2009, SLACK Incorporated.

Demonstration of the Gore Module for Passive Ground Water Sampling

DTIC Science & Technology

2014-06-01

ix ACRONYMS AND ABBREVIATIONS % RSD percent relative standard deviation 12DCA 1,2-dichloroethane 112TCA 1,1,2-trichloroethane 1122TetCA...Analysis of Variance ROD Record of Decision RSD relative standard deviation SBR Southern Bush River SVOC semi-volatile organic compound...replicate samples had a relative standard deviation ( RSD ) that was 20% or less. For the remaining analytes (PCE, cDCE, and chloroform), at least 70

Impact of baseline systolic blood pressure on visit-to-visit blood pressure variability: the Kailuan study.

PubMed

Wang, Anxin; Li, Zhifang; Yang, Yuling; Chen, Guojuan; Wang, Chunxue; Wu, Yuntao; Ruan, Chunyu; Liu, Yan; Wang, Yilong; Wu, Shouling

2016-01-01

To investigate the relationship between baseline systolic blood pressure (SBP) and visit-to-visit blood pressure variability in a general population. This is a prospective longitudinal cohort study on cardiovascular risk factors and cardiovascular or cerebrovascular events. Study participants attended a face-to-face interview every 2 years. Blood pressure variability was defined using the standard deviation and coefficient of variation of all SBP values at baseline and follow-up visits. The coefficient of variation is the ratio of the standard deviation to the mean SBP. We used multivariate linear regression models to test the relationships between SBP and standard deviation, and between SBP and coefficient of variation. Approximately 43,360 participants (mean age: 48.2±11.5 years) were selected. In multivariate analysis, after adjustment for potential confounders, baseline SBPs <120 mmHg were inversely related to standard deviation (P<0.001) and coefficient of variation (P<0.001). In contrast, baseline SBPs ≥140 mmHg were significantly positively associated with standard deviation (P<0.001) and coefficient of variation (P<0.001). Baseline SBPs of 120-140 mmHg were associated with the lowest standard deviation and coefficient of variation. The associations between baseline SBP and standard deviation, and between SBP and coefficient of variation during follow-ups showed a U curve. Both lower and higher baseline SBPs were associated with increased blood pressure variability. To control blood pressure variability, a good target SBP range for a general population might be 120-139 mmHg.

Physically Challenging Song Traits, Male Quality, and Reproductive Success in House Wrens

PubMed Central

Cramer, Emily R. A.

2013-01-01

Physically challenging signals are likely to honestly indicate signaler quality. In trilled bird song two physically challenging parameters are vocal deviation (the speed of sound frequency modulation) and trill consistency (how precisely syllables are repeated). As predicted, in several species, they correlate with male quality, are preferred by females, and/or function in male-male signaling. Species may experience different selective pressures on their songs, however; for instance, there may be opposing selection between song complexity and song performance difficulty, such that in species where song complexity is strongly selected, there may not be strong selection on performance-based traits. I tested whether vocal deviation and trill consistency are signals of male quality in house wrens (Troglodytes aedon), a species with complex song structure. Males’ singing ability did not correlate with male quality, except that older males sang with higher trill consistency, and males with more consistent trills responded more aggressively to playback (although a previous study found no effect of stimulus trill consistency on males’ responses to playback). Males singing more challenging songs did not gain in polygyny, extra-pair paternity, or annual reproductive success. Moreover, none of the standard male quality measures I investigated correlated with mating or reproductive success. I conclude that vocal deviation and trill consistency do not signal male quality in this species. PMID:23527137

Flexner 3.0-Democratization of Medical Knowledge for the 21st Century: Teaching Medical Science Using K-12 General Pathology as a Gateway Course.

PubMed

Weinstein, Ronald S; Krupinski, Elizabeth A; Weinstein, John B; Graham, Anna R; Barker, Gail P; Erps, Kristine A; Holtrust, Angelette L; Holcomb, Michael J

2016-01-01

A medical school general pathology course has been reformatted into a K-12 general pathology course. This new course has been implemented at a series of 7 to 12 grade levels and the student outcomes compared. Typically, topics covered mirrored those in a medical school general pathology course serving as an introduction to the mechanisms of diseases. Assessment of student performance was based on their score on a multiple-choice final examination modeled after an examination given to medical students. Two Tucson area schools, in a charter school network, participated in the study. Statistical analysis of examination performances showed that there were no significant differences as a function of school ( F = 0.258, P = .6128), with students at school A having an average test scores of 87.03 (standard deviation = 8.99) and school B 86.00 (standard deviation = 8.18; F = 0.258, P = .6128). Analysis of variance was also conducted on the test scores as a function of gender and class grade. There were no significant differences as a function of gender ( F = 0.608, P = .4382), with females having an average score of 87.18 (standard deviation = 7.24) and males 85.61 (standard deviation = 9.85). There were also no significant differences as a function of grade level ( F = 0.627, P = .6003), with 7th graders having an average of 85.10 (standard deviation = 8.90), 8th graders 86.00 (standard deviation = 9.95), 9th graders 89.67 (standard deviation = 5.52), and 12th graders 86.90 (standard deviation = 7.52). The results demonstrated that middle and upper school students performed equally well in K-12 general pathology. Student course evaluations showed that the course met the student's expectations. One class voted K-12 general pathology their "elective course-of-the-year."

Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range.

PubMed

Wan, Xiang; Wang, Wenqian; Liu, Jiming; Tong, Tiejun

2014-12-19

In systematic reviews and meta-analysis, researchers often pool the results of the sample mean and standard deviation from a set of similar clinical trials. A number of the trials, however, reported the study using the median, the minimum and maximum values, and/or the first and third quartiles. Hence, in order to combine results, one may have to estimate the sample mean and standard deviation for such trials. In this paper, we propose to improve the existing literature in several directions. First, we show that the sample standard deviation estimation in Hozo et al.'s method (BMC Med Res Methodol 5:13, 2005) has some serious limitations and is always less satisfactory in practice. Inspired by this, we propose a new estimation method by incorporating the sample size. Second, we systematically study the sample mean and standard deviation estimation problem under several other interesting settings where the interquartile range is also available for the trials. We demonstrate the performance of the proposed methods through simulation studies for the three frequently encountered scenarios, respectively. For the first two scenarios, our method greatly improves existing methods and provides a nearly unbiased estimate of the true sample standard deviation for normal data and a slightly biased estimate for skewed data. For the third scenario, our method still performs very well for both normal data and skewed data. Furthermore, we compare the estimators of the sample mean and standard deviation under all three scenarios and present some suggestions on which scenario is preferred in real-world applications. In this paper, we discuss different approximation methods in the estimation of the sample mean and standard deviation and propose some new estimation methods to improve the existing literature. We conclude our work with a summary table (an Excel spread sheet including all formulas) that serves as a comprehensive guidance for performing meta-analysis in different situations.

Flexner 3.0—Democratization of Medical Knowledge for the 21st Century

PubMed Central

Krupinski, Elizabeth A.; Weinstein, John B.; Graham, Anna R.; Barker, Gail P.; Erps, Kristine A.; Holtrust, Angelette L.; Holcomb, Michael J.

2016-01-01

A medical school general pathology course has been reformatted into a K-12 general pathology course. This new course has been implemented at a series of 7 to 12 grade levels and the student outcomes compared. Typically, topics covered mirrored those in a medical school general pathology course serving as an introduction to the mechanisms of diseases. Assessment of student performance was based on their score on a multiple-choice final examination modeled after an examination given to medical students. Two Tucson area schools, in a charter school network, participated in the study. Statistical analysis of examination performances showed that there were no significant differences as a function of school (F = 0.258, P = .6128), with students at school A having an average test scores of 87.03 (standard deviation = 8.99) and school B 86.00 (standard deviation = 8.18; F = 0.258, P = .6128). Analysis of variance was also conducted on the test scores as a function of gender and class grade. There were no significant differences as a function of gender (F = 0.608, P = .4382), with females having an average score of 87.18 (standard deviation = 7.24) and males 85.61 (standard deviation = 9.85). There were also no significant differences as a function of grade level (F = 0.627, P = .6003), with 7th graders having an average of 85.10 (standard deviation = 8.90), 8th graders 86.00 (standard deviation = 9.95), 9th graders 89.67 (standard deviation = 5.52), and 12th graders 86.90 (standard deviation = 7.52). The results demonstrated that middle and upper school students performed equally well in K-12 general pathology. Student course evaluations showed that the course met the student’s expectations. One class voted K-12 general pathology their “elective course-of-the-year.” PMID:28725762

Estimation of the neural drive to the muscle from surface electromyograms

NASA Astrophysics Data System (ADS)

Hofmann, David

Muscle force is highly correlated with the standard deviation of the surface electromyogram (sEMG) produced by the active muscle. Correctly estimating this quantity of non-stationary sEMG and understanding its relation to neural drive and muscle force is of paramount importance. The single constituents of the sEMG are called motor unit action potentials whose biphasic amplitude can interfere (named amplitude cancellation), potentially affecting the standard deviation (Keenan etal. 2005). However, when certain conditions are met the Campbell-Hardy theorem suggests that amplitude cancellation does not affect the standard deviation. By simulation of the sEMG, we verify the applicability of this theorem to myoelectric signals and investigate deviations from its conditions to obtain a more realistic setting. We find no difference in estimated standard deviation with and without interference, standing in stark contrast to previous results (Keenan etal. 2008, Farina etal. 2010). Furthermore, since the theorem provides us with the functional relationship between standard deviation and neural drive we conclude that complex methods based on high density electrode arrays and blind source separation might not bear substantial advantages for neural drive estimation (Farina and Holobar 2016). Funded by NIH Grant Number 1 R01 EB022872 and NSF Grant Number 1208126.

Validation of a reversed-phase high-performance liquid chromatographic method for the determination of free amino acids in rice using l-theanine as the internal standard.

PubMed

Liyanaarachchi, G V V; Mahanama, K R R; Somasiri, H P P S; Punyasiri, P A N

2018-02-01

The study presents the validation results of the method carried out for analysis of free amino acids (FAAs) in rice using l-theanine as the internal standard (IS) with o-phthalaldehyde (OPA) reagent using high-performance liquid chromatography-fluorescence detection. The detection and quantification limits of the method were in the range 2-16μmol/kg and 3-19μmol/kg respectively. The method had a wide working range from 25 to 600μmol/kg for each individual amino acid, and good linearity with regression coefficients greater than 0.999. Precision measured in terms of repeatability and reproducibility, expressed as percentage relative standard deviation (% RSD) was below 9% for all the amino acids analyzed. The recoveries obtained after fortification at three concentration levels were in the range 75-105%. In comparison to l-norvaline, findings revealed that l-theanine is suitable as an IS and the validated method can be used for FAA determination in rice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Precise determination of N-acetylcysteine in pharmaceuticals by microchip electrophoresis.

PubMed

Rudašová, Marína; Masár, Marián

2016-01-01

A novel microchip electrophoresis method for the rapid and high-precision determination of N-acetylcysteine, a pharmaceutically active ingredient, in mucolytics has been developed. Isotachophoresis separations were carried out at pH 6.0 on a microchip with conductivity detection. The methods of external calibration and internal standard were used to evaluate the results. The internal standard method effectively eliminated variations in various working parameters, mainly run-to-run fluctuations of an injected volume. The repeatability and accuracy of N-acetylcysteine determination in all mucolytic preparations tested (Solmucol 90 and 200, and ACC Long 600) were more than satisfactory with the relative standard deviation and relative error values <0.7 and <1.9%, respectively. A recovery range of 99-101% of N-acetylcysteine in the analyzed pharmaceuticals predetermines the proposed method for accurate analysis as well. This work, in general, indicates analytical possibilities of microchip isotachophoresis for the quantitative analysis of simplified samples such as pharmaceuticals that contain the analyte(s) at relatively high concentrations. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative analysis of synthetic dyes in lipstick by micellar electrokinetic capillary chromatography.

PubMed

Desiderio, C; Marra, C; Fanali, S

1998-06-01

The separation of synthetic dyes, used as color additives in cosmetics, by micellar electrokinetic capillary chromatography (MEKC) is described in this study. The separation of seven dyes, namely eosine, erythrosine, cyanosine, rhodamine B, orange II, chromotrope FB and tartrazine has been achieved in about 3 min in an untreated fused silica capillary containing as background electrolyte a 25 mM tetraborate/phosphate buffer, pH 8.0, and 30 mM sodium dodecyl sulfate. The electrophoretic method exhibits precision and relatively high sensitivity. A detection limit (LOD, signal/noise = 3) in the range of 5-7.5 X 10(-7) M of standard compounds was recorded. Intra-day repeatability of all the studied dye determinations (8 runs) gave the following results (limit values), % standard deviation: 0.24-1.54% for migration time, 0.99-1.24% for corrected peak areas, 0.99-1.24% for corrected peak area ratio (analyte/internal standard) and 1.56-2.74% for peak areas. The optimized method was successfully applied to the analysis of a lipstick sample where eosine and cyanosine were present.

Comparison of a novel fixation device with standard suturing methods for spinal cord stimulators.

PubMed

Bowman, Richard G; Caraway, David; Bentley, Ishmael

2013-01-01

Spinal cord stimulation is a well-established treatment for chronic neuropathic pain of the trunk or limbs. Currently, the standard method of fixation is to affix the leads of the neuromodulation device to soft tissue, fascia or ligament, through the use of manually tying general suture. A novel semiautomated device is proposed that may be advantageous to the current standard. Comparison testing in an excised caprine spine and simulated bench top model was performed. Three tests were performed: 1) perpendicular pull from fascia of caprine spine; 2) axial pull from fascia of caprine spine; and 3) axial pull from Mylar film. Six samples of each configuration were tested for each scenario. Standard 2-0 Ethibond was compared with a novel semiautomated device (Anulex fiXate). Upon completion of testing statistical analysis was performed for each scenario. For perpendicular pull in the caprine spine, the failure load for standard suture was 8.95 lbs with a standard deviation of 1.39 whereas for fiXate the load was 15.93 lbs with a standard deviation of 2.09. For axial pull in the caprine spine, the failure load for standard suture was 6.79 lbs with a standard deviation of 1.55 whereas for fiXate the load was 12.31 lbs with a standard deviation of 4.26. For axial pull in Mylar film, the failure load for standard suture was 10.87 lbs with a standard deviation of 1.56 whereas for fiXate the load was 19.54 lbs with a standard deviation of 2.24. These data suggest a novel semiautomated device offers a method of fixation that may be utilized in lieu of standard suturing methods as a means of securing neuromodulation devices. Data suggest the novel semiautomated device in fact may provide a more secure fixation than standard suturing methods. © 2012 International Neuromodulation Society.

Cross-cultural application of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS): performances of elderly Chinese Singaporeans.

PubMed

Lim, May-Li; Collinson, Simon Lowes; Feng, Lei; Ng, Tze-Pin

2010-01-01

There is a paucity of normative studies outside of North America and on elderly populations with very low education level. In the present study we examined the performance of poorly educated elderly on the Repeatable Battery Assessment of Neuropsychological Status (RBANS) with 352 cognitively normal elderly Chinese persons living in the community in Singapore who were enrolled in the Singapore Longitudinal Ageing Study (SLAS). Those with no formal education performed significantly less well than those with some years of formal education across four of five RBANS indices as well as the Total Scale score. Age- and education-adjusted normative data for the RBANS were established for the sample. The means and standard deviations of each of 12 subtests raw scores, five Index scores and the Total Scale score were calculated and stratified by age and education. Data from the present study should considerably advance the clinical utility of the RBANS in Chinese geriatric evaluations in Singapore, and can serve as a reference source for poorly educated elderly Chinese from around the region and beyond.

Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in (60)Co beams.

PubMed

Mrčela, I; Bokulić, T; Izewska, J; Budanec, M; Fröbe, A; Kusić, Z

2011-09-21

A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in (60)Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems.

Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in 60Co beams

NASA Astrophysics Data System (ADS)

Mrčela, I.; Bokulić, T.; Izewska, J.; Budanec, M.; Fröbe, A.; Kusić, Z.

2011-09-01

A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in 60Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems.

Binocular Goggle Augmented Imaging and Navigation System provides real-time fluorescence image guidance for tumor resection and sentinel lymph node mapping

NASA Astrophysics Data System (ADS)

B. Mondal, Suman; Gao, Shengkui; Zhu, Nan; Sudlow, Gail P.; Liang, Kexian; Som, Avik; Akers, Walter J.; Fields, Ryan C.; Margenthaler, Julie; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

2015-07-01

The inability to identify microscopic tumors and assess surgical margins in real-time during oncologic surgery leads to incomplete tumor removal, increases the chances of tumor recurrence, and necessitates costly repeat surgery. To overcome these challenges, we have developed a wearable goggle augmented imaging and navigation system (GAINS) that can provide accurate intraoperative visualization of tumors and sentinel lymph nodes in real-time without disrupting normal surgical workflow. GAINS projects both near-infrared fluorescence from tumors and the natural color images of tissue onto a head-mounted display without latency. Aided by tumor-targeted contrast agents, the system detected tumors in subcutaneous and metastatic mouse models with high accuracy (sensitivity = 100%, specificity = 98% ± 5% standard deviation). Human pilot studies in breast cancer and melanoma patients using a near-infrared dye show that the GAINS detected sentinel lymph nodes with 100% sensitivity. Clinical use of the GAINS to guide tumor resection and sentinel lymph node mapping promises to improve surgical outcomes, reduce rates of repeat surgery, and improve the accuracy of cancer staging.

Significantly Reduced Blood Pressure Measurement Variability for Both Normotensive and Hypertensive Subjects: Effect of Polynomial Curve Fitting of Oscillometric Pulses

PubMed Central

Zhu, Mingping; Chen, Aiqing

2017-01-01

This study aimed to compare within-subject blood pressure (BP) variabilities from different measurement techniques. Cuff pressures from three repeated BP measurements were obtained from 30 normotensive and 30 hypertensive subjects. Automatic BPs were determined from the pulses with normalised peak amplitude larger than a threshold (0.5 for SBP, 0.7 for DBP, and 1.0 for MAP). They were also determined from cuff pressures associated with the above thresholds on a fitted curve polynomial curve of the oscillometric pulse peaks. Finally, the standard deviation (SD) of three repeats and its coefficient of variability (CV) were compared between the two automatic techniques. For the normotensive group, polynomial curve fitting significantly reduced SD of repeats from 3.6 to 2.5 mmHg for SBP and from 3.7 to 2.1 mmHg for MAP and reduced CV from 3.0% to 2.2% for SBP and from 4.3% to 2.4% for MAP (all P < 0.01). For the hypertensive group, SD of repeats decreased from 6.5 to 5.5 mmHg for SBP and from 6.7 to 4.2 mmHg for MAP, and CV decreased from 4.2% to 3.6% for SBP and from 5.8% to 3.8% for MAP (all P < 0.05). In conclusion, polynomial curve fitting of oscillometric pulses had the ability to reduce automatic BP measurement variability. PMID:28785580

Computer Programs for the Semantic Differential: Further Modifications.

ERIC Educational Resources Information Center

Lawson, Edwin D.; And Others

The original nine programs for semantic differential analysis have been condensed into three programs which have been further refined and augmented. They yield: (1) means, standard deviations, and standard errors for each subscale on each concept; (2) Evaluation, Potency, and Activity (EPA) means, standard deviations, and standard errors; (3)…

Determination of opiates and cocaine in urine by high pH mobile phase reversed phase UPLC-MS/MS.

PubMed

Berg, Thomas; Lundanes, Elsa; Christophersen, Asbjørg S; Strand, Dag Helge

2009-02-01

A fast and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of opiates (morphine, codeine, 6-monoacetylmorphine (6-MAM), pholcodine, oxycodone, ethylmorphine), cocaine and benzoylecgonine in urine has been developed and validated. Sample preparation was performed by solid phase extraction (SPE) on a mixed mode cation exchange (MCX) cartridge. For optimized chromatographic performance with repeatable retention times, narrow and symmetrical peaks, and focusing of all analytes at the column inlet at gradient start, a basic mobile phase consisting of 5mM ammonium bicarbonate, pH 10.2, and methanol (MeOH) was chosen. Positive electrospray ionization (ESI(+)) MS/MS detection was performed with a minimum of two multiple reaction monitoring (MRM) transitions for each analyte. Deuterium labelled-internal standards were used for six of the analytes. Between-assay retention time repeatabilities (n=10 series, 225 injections in total) had relative standard deviation (RSD) values within 0.1-0.6%. Limit of detection (LOD) and limit of quantification (LOQ) values were in the range 0.003-0.05 microM (0.001-0.02 microg/mL) and 0.01-0.16 microM (0.003-0.06 microg/mL), respectively. The RSD values of the between-assay repeatabilities of concentrations were

A Correction for the Epsilon Approximate Test in Repeated Measures Designs with Two or More Independent Groups.

ERIC Educational Resources Information Center

Lecoutre, Bruno

1991-01-01

The routine epsilon approximate test in repeated measures designs when the condition of circularity is unfulfilled uses an erroneous formula in the case of two or more groups. Because this may lead to underestimation of the deviation from circularity when the subject number is small, a correction is proposed. (Author/SLD)

Characterization of a multilayer ionization chamber prototype for fast verification of relative depth ionization curves and spread-out-Bragg-peaks in light ion beam therapy.

PubMed

Mirandola, Alfredo; Magro, Giuseppe; Lavagno, Marco; Mairani, Andrea; Molinelli, Silvia; Russo, Stefania; Mastella, Edoardo; Vai, Alessandro; Maestri, Davide; La Rosa, Vanessa; Ciocca, Mario

2018-05-01

To dosimetrically characterize a multilayer ionization chamber (MLIC) prototype for quality assurance (QA) of pristine integral ionization curves (ICs) and spread-out-Bragg-peaks (SOBPs) for scanning light ion beams. QUBE (De.Tec.Tor., Torino, Italy) is a modular detector designed for QA in particle therapy (PT). Its main module is a MLIC detector, able to evaluate particle beam relative depth ionization distributions at different beam energies and modulations. The charge collecting electrodes are made of aluminum, for a nominal water equivalent thickness (WET) of ~75 mm. The detector prototype was calibrated by acquiring the signals in the initial plateau region of a pristine BP and in terms of WET. Successively, it was characterized in terms of repeatability response, linearity, short-term stability and dose rate dependence. Beam-induced measurements of activation in terms of ambient dose equivalent rate were also performed. To increase the detector coarse native spatial resolution (~2.3 mm), several consecutive acquisitions with a set of certified 0.175-mm-thick PMMA sheets (Goodfellow, Cambridge Limited, UK), placed in front of the QUBE mylar entrance window, were performed. The ICs/SOBPs were achieved as the result of the sum of the set of measurements, made up of a one-by-one PMMA layer acquisition. The newly obtained detector spatial resolution allowed the experimental measurements to be properly comparable against the reference curves acquired in water with the PTW Peakfinder. Furthermore, QUBE detector was modeled in the FLUKA Monte Carlo (MC) code following the technical design details and ICs/SOBPs were calculated. Measurements showed a high repeatability: mean relative standard deviation within ±0.5% for all channels and both particle types. Moreover, the detector response was linear with dose (R 2  > 0.998) and independent on the dose rate. The mean deviation over the channel-by-channel readout respect to the reference beam flux (100%) was equal to 0.7% (1.9%) for the 50% (20%) beam flux level. The short-term stability of the gain calibration was very satisfying for both particle types: the channel mean relative standard deviation was within ±1% for all the acquisitions performed at different times. The ICs obtained with the MLIC QUBE at improved resolution satisfactorily matched both the MC simulations and the reference curves acquired with Peakfinder. Deviations from the reference values in terms of BP position, peak width and distal fall-off were submillimetric for both particle types in the whole investigated energy range. For modulated SOBPs, a submillimetric deviation was found when comparing both experimental MLIC QUBE data against the reference values and MC calculations. The relative dose deviations for the experimental MLIC QUBE acquisitions, with respect to Peakfinder data, ranged from ~1% to ~3.5%. Maximum value of 14.1 μSv/h was measured in contact with QUBE entrance window soon after a long irradiation with carbon ions. MLIC QUBE appears to be a promising detector for accurately measuring pristine ICs and SOBPs. A simple procedure to improve the intrinsic spatial resolution of the detector is proposed. Being the detector very accurate, precise, fast responding, and easy to handle, it is therefore well suited for daily checks in PT. © 2018 American Association of Physicists in Medicine.

Cognitive impairment in neuromyelitis optica spectrum disorders: A comparison of the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale Revised with the Rao Brief Repeatable Neuropsychological Battery.

PubMed

Fujimori, Juichi; Nakashima, Ichiro; Baba, Toru; Meguro, Yuko; Ogawa, Ryo; Fujihara, Kazuo

2017-12-01

Approximately 55% of patients with neuromyelitis optica spectrum disorder (NMOSD) show cognitive impairment as evaluated using the Rao Brief Repeatable Neuropsychological Battery (BRBN), but this frequency appears to be higher than the frequency of specific brain lesions in NMOSD. We studied whether cognitive impairment could be observed in NMOSD patients with no or minor non-specific brain lesions. We evaluated cognitive function in 12 NMOSD and 14 MS patients using the Wechsler Adult Intelligence Scale-III (WAIS-III), the Wechsler Memory Scale-Revised (WMS-R), and the BRBN. We judged as cognitively impaired patients whose scores were below the average by 2 standard deviations or greater in 2 or more cognitive domains. Cognitive impairment was observed in 5 MS patients (35.7%) and in the only NMOSD patient (8.3%) with symptomatic brain lesions, but not in the other NMOSD patients who had no or minor non-specific brain lesions. Meanwhile, 5 NMOSD (41.7%) and 4 MS (28.6%) patients who had normal cognition according to the WAIS-III and WMS-R were assessed as cognitively impaired by the BRBN (which is not standardized for age). Cognitive function in NMOSD patients with no or mild non-specific brain lesions was preserved according to the WAIS-III and WMS-R.

An integrative strategy for quantitative analysis of the N-glycoproteome in complex biological samples

PubMed Central

2014-01-01

Background The complexity of protein glycosylation makes it difficult to characterize glycosylation patterns on a proteomic scale. In this study, we developed an integrated strategy for comparatively analyzing N-glycosylation/glycoproteins quantitatively from complex biological samples in a high-throughput manner. This strategy entailed separating and enriching glycopeptides/glycoproteins using lectin affinity chromatography, and then tandem labeling them with 18O/16O to generate a mass shift of 6 Da between the paired glycopeptides, and finally analyzing them with liquid chromatography-mass spectrometry (LC-MS) and the automatic quantitative method we developed based on Mascot Distiller. Results The accuracy and repeatability of this strategy were first verified using standard glycoproteins; linearity was maintained within a range of 1:10–10:1. The peptide concentration ratios obtained by the self-build quantitative method were similar to both the manually calculated and theoretical values, with a standard deviation (SD) of 0.023–0.186 for glycopeptides. The feasibility of the strategy was further confirmed with serum from hepatocellular carcinoma (HCC) patients and healthy individuals; the expression of 44 glycopeptides and 30 glycoproteins were significantly different between HCC patient and control serum. Conclusions This strategy is accurate, repeatable, and efficient, and may be a useful tool for identification of disease-related N-glycosylation/glycoprotein changes. PMID:24428921

[Analysis of the results of the HIV-1, HCV and HBV viral load of SEIMC External Quality Control Program. Year 2014].

PubMed

Medina González, Rafael; Orta Mira, Nieves; Guna Serrano, María Del Remedio; Latorre Martínez, José-Carlos; Gopegui, Enrique Ruiz de; Rosario Ovies, María; Poveda, Marta; Gimeno Cardona, Concepción

2016-07-01

Human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV) viral load determinations are among the most relevant markers for the follow up of patients infected with these viruses. External quality control tools are crucial to ensure the accuracy of results obtained by microbiology laboratories. This article summarizes the results obtained from the 2014 SEIMC (Spanish Society of Infectious Diseases and Clinical Microbiology) External Quality Control Programme for HIV-1, HCV, and HBV viral loads. In the HIV-1 program, a total of 5 standards were sent. One standard consisted in seronegative human plasma, while the remaining 4 contained plasma from 3 different viremic patients, in the range of 2-5 log10 copies/mL; 2 of these standards were identical aiming to determine repeatability. A significant proportion of the laboratories (30.8% on average) obtained values out of the accepted range (mean ± 0.25 log10 copies/mL), depending on the standard and on the method used for quantification. Repeatability was excellent, with up to 95.8% of laboratories reporting results within the limits (Δ < 0.5 log10 copies/mL). The HBV and HCV program consisted of 2 standards with different viral load contents. Most of the participants, 83.7% in the case of HCV and 87.9% in the HBV, obtained all the results within the accepted range (mean ± 1.96 standard deviations log10 IU/mL). Data from this analysis reinforce the utility of proficiency programmes to ensure the quality of the results obtained by a particular laboratory, as well as the importance of the post-analytical phase on the overall quality. Due to the remarkable interlaboratory variability, it is advisable to use the same method and the same laboratory for patient follow up. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Packing Fraction of a Two-dimensional Eden Model with Random-Sized Particles

NASA Astrophysics Data System (ADS)

Kobayashi, Naoki; Yamazaki, Hiroshi

2018-01-01

We have performed a numerical simulation of a two-dimensional Eden model with random-size particles. In the present model, the particle radii are generated from a Gaussian distribution with mean μ and standard deviation σ. First, we have examined the bulk packing fraction for the Eden cluster and investigated the effects of the standard deviation and the total number of particles NT. We show that the bulk packing fraction depends on the number of particles and the standard deviation. In particular, for the dependence on the standard deviation, we have determined the asymptotic value of the bulk packing fraction in the limit of the dimensionless standard deviation. This value is larger than the packing fraction obtained in a previous study of the Eden model with uniform-size particles. Secondly, we have investigated the packing fraction of the entire Eden cluster including the effect of the interface fluctuation. We find that the entire packing fraction depends on the number of particles while it is independent of the standard deviation, in contrast to the bulk packing fraction. In a similar way to the bulk packing fraction, we have obtained the asymptotic value of the entire packing fraction in the limit NT → ∞. The obtained value of the entire packing fraction is smaller than that of the bulk value. This fact suggests that the interface fluctuation of the Eden cluster influences the packing fraction.

Complexities of follicle deviation during selection of a dominant follicle in Bos taurus heifers.

PubMed

Ginther, O J; Baldrighi, J M; Siddiqui, M A R; Araujo, E R

2016-11-01

Follicle deviation during a follicular wave is a continuation in growth rate of the dominant follicle (F1) and decreased growth rate of the largest subordinate follicle (F2). The reliability of using an F1 of 8.5 mm to represent the beginning of expected deviation for experimental purposes during waves 1 and 2 (n = 26 per wave) was studied daily in heifers. Each wave was subgrouped as follows: standard subgroup (F1 larger than F2 for 2 days preceding deviation and F2 > 7.0 mm on the day of deviation), undersized subgroup (F2 did not attain 7.0 mm by the day of deviation), and switched subgroup (F2 larger than F1 at least once on the 2 days before or on the day of deviation). For each wave, mean differences in diameter between F1 and F2 changed abruptly at expected deviation in the standard subgroup but began 1 day before expected deviation in the undersized and switched subgroups. Concentrations of FSH in the wave-stimulating FSH surge and an increase in LH centered on expected deviation did not differ among subgroups. Results for each wave indicated that (1) expected deviation (F1, 8.5 mm) was a reliable representation of actual deviation in the standard subgroup but not in the undersized and switched subgroups; (2) concentrations of the gonadotropins normalized to expected deviation were similar among the three subgroups, indicating that the day of deviation was related to diameter of F1 and not F2; and (3) defining an expected day of deviation for experimental use should consider both diameter of F1 and the characteristics of deviation. Copyright © 2016 Elsevier Inc. All rights reserved.

Anatomy of emotion: a 3D study of facial mimicry.

PubMed

Ferrario, V F; Sforza, C

2007-01-01

Alterations in facial motion severely impair the quality of life and social interaction of patients, and an objective grading of facial function is necessary. A method for the non-invasive detection of 3D facial movements was developed. Sequences of six standardized facial movements (maximum smile; free smile; surprise with closed mouth; surprise with open mouth; right side eye closure; left side eye closure) were recorded in 20 healthy young adults (10 men, 10 women) using an optoelectronic motion analyzer. For each subject, 21 cutaneous landmarks were identified by 2-mm reflective markers, and their 3D movements during each facial animation were computed. Three repetitions of each expression were recorded (within-session error), and four separate sessions were used (between-session error). To assess the within-session error, the technical error of the measurement (random error, TEM) was computed separately for each sex, movement and landmark. To assess the between-session repeatability, the standard deviation among the mean displacements of each landmark (four independent sessions) was computed for each movement. TEM for the single landmarks ranged between 0.3 and 9.42 mm (intrasession error). The sex- and movement-related differences were statistically significant (two-way analysis of variance, p=0.003 for sex comparison, p=0.009 for the six movements, p<0.001 for the sex x movement interaction). Among four different (independent) sessions, the left eye closure had the worst repeatability, the right eye closure had the best one; the differences among various movements were statistically significant (one-way analysis of variance, p=0.041). In conclusion, the current protocol demonstrated a sufficient repeatability for a future clinical application. Great care should be taken to assure a consistent marker positioning in all the subjects.

Method validation for control determination of mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry.

PubMed

Torres, Daiane Placido; Martins-Teixeira, Maristela Braga; Cadore, Solange; Queiroz, Helena Müller

2015-01-01

A method for the determination of total mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) has been validated following international foodstuff protocols in order to fulfill the Brazilian National Residue Control Plan. The experimental parameters have been previously studied and optimized according to specific legislation on validation and inorganic contaminants in foodstuff. Linearity, sensitivity, specificity, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness as well as accuracy of the method have been evaluated. Linearity of response was satisfactory for the two range concentrations available on the TDA AAS equipment, between approximately 25.0 and 200.0 μg kg(-1) (square regression) and 250.0 and 2000.0 μg kg(-1) (linear regression) of mercury. The residues for both ranges were homoscedastic and independent, with normal distribution. Correlation coefficients obtained for these ranges were higher than 0.995. Limits of quantification (LOQ) and of detection of the method (LDM), based on signal standard deviation (SD) for a low-in-mercury sample, were 3.0 and 1.0 μg kg(-1), respectively. Repeatability of the method was better than 4%. Within-laboratory reproducibility achieved a relative SD better than 6%. Robustness of the current method was evaluated and pointed sample mass as a significant factor. Accuracy (assessed as the analyte recovery) was calculated on basis of the repeatability, and ranged from 89% to 99%. The obtained results showed the suitability of the present method for direct mercury measurement in fresh fish and shrimp samples and the importance of monitoring the analysis conditions for food control purposes. Additionally, the competence of this method was recognized by accreditation under the standard ISO/IEC 17025.

40 CFR 90.708 - Cumulative Sum (CumSum) procedure.

Code of Federal Regulations, 2010 CFR

2010-07-01

... is 5.0×σ, and is a function of the standard deviation, σ. σ=is the sample standard deviation and is... individual engine. FEL=Family Emission Limit (the standard if no FEL). F=.25×σ. (2) After each test pursuant...

Acoustic Correlates of Compensatory Adjustments to the Glottic and Supraglottic Structures in Patients with Unilateral Vocal Fold Paralysis

PubMed Central

2015-01-01

The goal of this study was to analyse perceptually and acoustically the voices of patients with Unilateral Vocal Fold Paralysis (UVFP) and compare them to the voices of normal subjects. These voices were analysed perceptually with the GRBAS scale and acoustically using the following parameters: mean fundamental frequency (F0), standard-deviation of F0, jitter (ppq5), shimmer (apq11), mean harmonics-to-noise ratio (HNR), mean first (F1) and second (F2) formants frequency, and standard-deviation of F1 and F2 frequencies. Statistically significant differences were found in all of the perceptual parameters. Also the jitter, shimmer, HNR, standard-deviation of F0, and standard-deviation of the frequency of F2 were statistically different between groups, for both genders. In the male data differences were also found in F1 and F2 frequencies values and in the standard-deviation of the frequency of F1. This study allowed the documentation of the alterations resulting from UVFP and addressed the exploration of parameters with limited information for this pathology. PMID:26557690

Dynamics of the standard deviations of three wind velocity components from the data of acoustic sounding

NASA Astrophysics Data System (ADS)

Krasnenko, N. P.; Kapegesheva, O. F.; Shamanaeva, L. G.

2017-11-01

Spatiotemporal dynamics of the standard deviations of three wind velocity components measured with a mini-sodar in the atmospheric boundary layer is analyzed. During the day on September 16 and at night on September 12 values of the standard deviation changed for the x- and y-components from 0.5 to 4 m/s, and for the z-component from 0.2 to 1.2 m/s. An analysis of the vertical profiles of the standard deviations of three wind velocity components for a 6-day measurement period has shown that the increase of σx and σy with altitude is well described by a power law dependence with exponent changing from 0.22 to 1.3 depending on the time of day, and σz depends linearly on the altitude. The approximation constants have been found and their errors have been estimated. The established physical regularities and the approximation constants allow the spatiotemporal dynamics of the standard deviation of three wind velocity components in the atmospheric boundary layer to be described and can be recommended for application in ABL models.

Procedures for determination of detection limits: application to high-performance liquid chromatography analysis of fat-soluble vitamins in human serum.

PubMed

Browne, Richard W; Whitcomb, Brian W

2010-07-01

Problems in the analysis of laboratory data commonly arise in epidemiologic studies in which biomarkers subject to lower detection thresholds are used. Various thresholds exist including limit of detection (LOD), limit of quantification (LOQ), and limit of blank (LOB). Choosing appropriate strategies for dealing with data affected by such limits relies on proper understanding of the nature of the detection limit and its determination. In this paper, we demonstrate experimental and statistical procedures generally used for estimating different detection limits according to standard procedures in the context of analysis of fat-soluble vitamins and micronutrients in human serum. Fat-soluble vitamins and micronutrients were analyzed by high-performance liquid chromatography with diode array detection. A simulated serum matrix blank was repeatedly analyzed for determination of LOB parametrically by using the observed blank distribution as well as nonparametrically by using ranks. The LOD was determined by combining information regarding the LOB with data from repeated analysis of standard reference materials (SRMs), diluted to low levels; from LOB to 2-3 times LOB. The LOQ was determined experimentally by plotting the observed relative standard deviation (RSD) of SRM replicates compared with the concentration, where the LOQ is the concentration at an RSD of 20%. Experimental approaches and example statistical procedures are given for determination of LOB, LOD, and LOQ. These quantities are reported for each measured analyte. For many analyses, there is considerable information available below the LOQ. Epidemiologic studies must understand the nature of these detection limits and how they have been estimated for appropriate treatment of affected data.

Determination of Minor and Trace Metals in Aluminum and Aluminum Alloys by ICP-AES; Evaluation of the Uncertainty and Limit of Quantitation from Interlaboratory Testing.

PubMed

Uemoto, Michihisa; Makino, Masanori; Ota, Yuji; Sakaguchi, Hiromi; Shimizu, Yukari; Sato, Kazuhiro

2018-01-01

Minor and trace metals in aluminum and aluminum alloys have been determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) as an interlaboratory testing toward standardization. The trueness of the measured data was successfully investigated to improve the analytical protocols, using certified reference materials of aluminum. Their precision could also be evaluated, feasible to estimate the uncertainties separately. The accuracy (trueness and precision) of the data were finally in good agreement with the certified values and assigned uncertainties. Repeated measurements of aluminum solutions with different concentrations of the analytes revealed the relative standard deviations of the measurements with concentrations, thus enabling their limits of quantitation. They differed separately and also showed slightly higher values with an aluminum matrix than those without one. In addition, the upper limit of the detectable concentration of silicon with simple acid digestion was estimated to be 0.03 % in the mass fraction.

Enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens by liquid chromatography/mass spectrometry.

PubMed

Hasegawa, Takashi; Takahashi, Kazunaga; Fukiwake, Tomohide; Saijo, Masaaki; Motoki, Yuji

2013-01-01

We developed a simple and rapid liquid chromatography/mass spectrometry (LC/MS) method for the enantiomeric determination of DOPA in dietary supplements containing Mucuna pruriens. L- and D-DOPA were ultrasonically extracted with 1% formic acid aqueous solution. The isolated extracts were analyzed by LC/MS using a Crownpak CR (-) column at 30℃. The mass spectrometer was operated in the positive mode of electrospray ionization, and the mobile phase was aqueous formic acid (pH 2.0). L-DOPA-ring-d3 was used as an internal standard. The method was validated for a dietary supplement spiked with L- and D-DOPA at 50 and 500 μg/g, respectively, and the recoveries of the DOPA enantiomers were between 97.5% and 101.3%. Relative standard deviation values of repeatability and intermediate precision were less than 7%. The method was applied to 14 dietary supplements. L-DOPA was detected in these supplements in the range of 0.88-12.8 mg/unit. D-DOPA was not detected.

Determination of uranium in tap water by ICP-MS.

PubMed

El Himri, M; Pastor, A; de la Guardia, M

2000-05-01

A fast and accurate procedure has been developed for the determination of uranium at microg L(-1) level in tap and mineral water. The method is based on the direct introduction of samples, without any chemical pre-treatment, into an inductively coupled plasma mass spectrometer (ICP-MS). Uranium was determined at the mass number 238 using Rh as internal standard. The method provides a limit of detection of 2 ng L(-1) and a good repeatability with relative standard deviation values (RSD) about 3% for five independent analyses of samples containing 73 microg L(-1) of uranium. Recovery percentage values found for the determination of uranium in spiked natural samples varied between 91% and 106%. Results obtained are comparable with those found by radiochemical methods for natural samples and of the same order for the certified content of a reference material, thus indicating the accuracy of the ICP-MS procedure without the need of using isotope dilution. A series of mineral and tap waters from different parts of Spain and Morocco were analysed.

A proof for Rhiel's range estimator of the coefficient of variation for skewed distributions.

PubMed

Rhiel, G Steven

2007-02-01

In this research study is proof that the coefficient of variation (CV(high-low)) calculated from the highest and lowest values in a set of data is applicable to specific skewed distributions with varying means and standard deviations. Earlier Rhiel provided values for d(n), the standardized mean range, and a(n), an adjustment for bias in the range estimator of micro. These values are used in estimating the coefficient of variation from the range for skewed distributions. The d(n) and an values were specified for specific skewed distributions with a fixed mean and standard deviation. In this proof it is shown that the d(n) and an values are applicable for the specific skewed distributions when the mean and standard deviation can take on differing values. This will give the researcher confidence in using this statistic for skewed distributions regardless of the mean and standard deviation.

Detecting Glaucoma With a Portable Brain-Computer Interface for Objective Assessment of Visual Function Loss.

PubMed

Nakanishi, Masaki; Wang, Yu-Te; Jung, Tzyy-Ping; Zao, John K; Chien, Yu-Yi; Diniz-Filho, Alberto; Daga, Fabio B; Lin, Yuan-Pin; Wang, Yijun; Medeiros, Felipe A

2017-06-01

The current assessment of visual field loss in diseases such as glaucoma is affected by the subjectivity of patient responses and the lack of portability of standard perimeters. To describe the development and initial validation of a portable brain-computer interface (BCI) for objectively assessing visual function loss. This case-control study involved 62 eyes of 33 patients with glaucoma and 30 eyes of 17 healthy participants. Glaucoma was diagnosed based on a masked grading of optic disc stereophotographs. All participants underwent testing with a BCI device and standard automated perimetry (SAP) within 3 months. The BCI device integrates wearable, wireless, dry electroencephalogram and electrooculogram systems and a cellphone-based head-mounted display to enable the detection of multifocal steady state visual-evoked potentials associated with visual field stimulation. The performances of global and sectoral multifocal steady state visual-evoked potentials metrics to discriminate glaucomatous from healthy eyes were compared with global and sectoral SAP parameters. The repeatability of the BCI device measurements was assessed by collecting results of repeated testing in 20 eyes of 10 participants with glaucoma for 3 sessions of measurements separated by weekly intervals. Receiver operating characteristic curves summarizing diagnostic accuracy. Intraclass correlation coefficients and coefficients of variation for assessing repeatability. Among the 33 participants with glaucoma, 19 (58%) were white, 12 (36%) were black, and 2 (6%) were Asian, while among the 17 participants with healthy eyes, 9 (53%) were white, 8 (47%) were black, and none were Asian. The receiver operating characteristic curve area for the global BCI multifocal steady state visual-evoked potentials parameter was 0.92 (95% CI, 0.86-0.96), which was larger than for SAP mean deviation (area under the curve, 0.81; 95% CI, 0.72-0.90), SAP mean sensitivity (area under the curve, 0.80; 95% CI, 0.69-0.88; P = .03), and SAP pattern standard deviation (area under the curve, 0.77; 95% CI, 0.66-0.87; P = .01). No statistically significant differences were seen for the sectoral measurements between the BCI and SAP. Intraclass coefficients for global and sectoral parameters ranged from 0.74 to 0.92, and mean coefficients of variation ranged from 3.03% to 7.45%. The BCI device may be useful for assessing the electrical brain responses associated with visual field stimulation. The device discriminated eyes with glaucomatous neuropathy from healthy eyes in a clinically based setting. Further studies should investigate the feasibility of the BCI device for home-based testing as well as for detecting visual function loss over time.

Random errors in interferometry with the least-squares method

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

Wang Qi

2011-01-20

This investigation analyzes random errors in interferometric surface profilers using the least-squares method when random noises are present. Two types of random noise are considered here: intensity noise and position noise. Two formulas have been derived for estimating the standard deviations of the surface height measurements: one is for estimating the standard deviation when only intensity noise is present, and the other is for estimating the standard deviation when only position noise is present. Measurements on simulated noisy interferometric data have been performed, and standard deviations of the simulated measurements have been compared with those theoretically derived. The relationships havemore » also been discussed between random error and the wavelength of the light source and between random error and the amplitude of the interference fringe.« less

N2/O2/H2 Dual-Pump Cars: Validation Experiments

NASA Technical Reports Server (NTRS)

OByrne, S.; Danehy, P. M.; Cutler, A. D.

2003-01-01

The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) method is used to measure temperature and the relative species densities of N2, O2 and H2 in two experiments. Average values and root-mean-square (RMS) deviations are determined. Mean temperature measurements in a furnace containing air between 300 and 1800 K agreed with thermocouple measurements within 26 K on average, while mean mole fractions agree to within 1.6 % of the expected value. The temperature measurement standard deviation averaged 64 K while the standard deviation of the species mole fractions averaged 7.8% for O2 and 3.8% for N2, based on 200 single-shot measurements. Preliminary measurements have also been performed in a flat-flame burner for fuel-lean and fuel-rich flames. Temperature standard deviations of 77 K were measured, and the ratios of H2 to N2 and O2 to N2 respectively had standard deviations from the mean value of 12.3% and 10% of the measured ratio.

Agreement and repeatability of objective systems for assessment of the tear film.

PubMed

Fernández, Joaquín; Rodríguez-Vallejo, Manuel; Martínez, Javier; Tauste, Ana; García-Montesinos, Javier; Piñero, David P

2018-04-18

To assess the agreement and repeatability of two objective systems for measuring the tear film stability. Retrospective analysis of the tear film stability of 99 healthy right eyes measured with a videokeratoscope (VK) and the Optical Quality Analysis System (OQAS, Visiometrics). Two consecutive measures were taken with both systems, with an interval of 10 min between them. Variables included in the study were first and mean non-invasive break-up times (NIBUT and MNIBUT) measured with VK, and mean and standard deviation of the optical scattering index (OSIm and OSIsd) measured with OQAS. The agreement and repeatability of grading scales provided by both devices were also evaluated using the Cohen's k with quadratic weights. The Ocular Surface Disease index (OSDI) questionnaire was also passed out to all subjects. Correlations and associations between subjective and objective metrics were analyzed. Significant differences were found between consecutive measurements of NIBUT (p = 0.04) and MNIBUT (p = 0.01), but not for OSIm (p = 0.11) and OSIsd (p = 0.50). Grading scales resulted in fair (k = 0.20) or poor agreement (k = 0.04) between systems depending if the first or second trial was considered. The repeatability of the grading scale was good for OQAS (k = 0.59) and fair for VK (k = 0.37). No significant correlations or associations were found between OSDI and any of the metrics obtained with both devices (p ≥ 0.36). The two devices evaluated cannot be used interchangeably for the assessment of tear film stability. Good intrasession repeatability was obtained for tear film grading of the OQAS whereas it was fair for VK.

A novel Hartman Shack-based topography system: repeatability and agreement for corneal power with Scheimpflug+Placido topographer and rotating prism auto-keratorefractor.

PubMed

Prakash, Gaurav; Srivastava, Dhruv; Choudhuri, Sounak

2015-12-01

The purpose of this study is to analyze the repeatability and agreement of corneal power using a new Hartman type topographer in comparison to Scheimpflug+Placido and autorefractor devices. In this cross sectional, observational study performed at the cornea services of a specialty hospital, 100 normal eyes (100 consecutive candidates) without any previous ocular surgery or morbidity except refractive error were evaluated. All candidates underwent three measurements each on a Full gradient, Hartman type topographer (FG) (iDesign, AMO), Scheimpflug+Placido topographer (SP) (Sirius, CSO) and rotating prism auto-keratorefractor (AR) (KR1, Nidek). The parameters assessed were flat keratometry (K1), steep keratometry (K2), steep axis (K2 axis), mean K, J 0 and J 45. Intra-device repeatability and inter-device agreement were evaluated. On repeatability analysis, the intra-device means were not significantly different (ANOVA, p > 0.05). Intraclass correlations (ICC) were >0.98 except for J 0 and J 45. In terms of intra-measurement standard deviation (Sw), the SP and FG groups fared better than AR group (p < 0.001, ANOVA). On Sw versus Average plots, no significantly predictive fit was seen (p > 0.05, R (2) < 0.1 for all the values). On inter-device agreement analysis, there was no difference in means (ANOVA, p > 0.05). ICC ranged from 0.92 to 0.99 (p < 0.001). Regression fits on Bland-Altman plots suggested no clinically significant effect of average values over difference in means. The repeatability of Hartman type topographer in normal eyes is comparable to SP combination device and better than AR. The agreement between the three devices is good. However, we recommend against interchanging these devices between follow-ups or pooling their data.

Thirty-minute compared to standardised office blood pressure measurement in general practice

PubMed Central

Scherpbier-de Haan, Nynke; van der Wel, Mark; Schoenmakers, Gijs; Boudewijns, Steve; Peer, Petronella; van Weel, Chris; Thien, Theo; Bakx, Carel

2011-01-01

Background Although blood pressure measurement is one of the most frequently performed measurements in clinical practice, there are concerns about its reliability. Serial, automated oscillometric blood pressure measurement has the potential to reduce measurement bias and white-coat effect' Aim To study agreement of 30-minute office blood pressure measurement (OBPM) with standardised OBPM, and to compare repeatability Design and setting Method comparison study in two general practices in the Netherlands Method Thirty-minute and standardised OBPM was carried out with the same, validated device in 83 adult patients, and the procedure was repeated after 2 weeks. During 30-minute OBPM, blood pressure was measured automatically every 3 minutes, with the patient in a sitting position, alone in a quiet room. Agreement between 30-minute and standardised OBPM was assessed by Bland–Altman analysis. Repeatability of the blood pressure measurement methods after 2 weeks was expressed as the mean difference in combination with the standard deviation of difference (SDD) Results Mean 30-minute OBPM readings were 7.6/2.5 mmHg (95% confidence interval [CI] = 6.1 to 9.1/1.5 to 3.4 mmHg) lower than standardised OBPM readings. The mean difference and SDD between repeated 30-minute OBPMs (mean difference = 3/1 mmHg, 95% CI = 1 to 5/0 to 2 mmHg; SDD 9.5/5.3 mmHg) were lower than those of standardised OBPMs (mean difference = 6/2 mmHg, 95% CI = 4 to 8/1 to 4 mmHg; SDD 10.9/6.3 mmHg). Conclusion Thirty-minute OBPM resulted in lower readings than standardised OBPM and had a better repeatability. These results suggest that 30-minute OBPM better reflects the patient's true blood pressure than standardised OBPM does. PMID:22152748

Comparisons of the underlying mechanisms of left atrial remodeling after repeat circumferential pulmonary vein isolation with or without additional left atrial linear ablation in patients with recurrent atrial fibrillation.

PubMed

Yang, Chia-Hung; Chou, Chung-Chuan; Hung, Kuo-Chun; Wen, Ming-Shien; Chang, Po-Cheng; Wo, Hung-Ta; Lee, Cheng-Hung; Lin, Fen-Chiung

2017-02-01

Radiofrequency catheter ablation (RFCA) is a potentially curative treatment for atrial fibrillation (AF), however, whether or not additional left atrial (LA) linear ablation for recurrent AF adversely affects LA remodeling is unknown. Thirty-eight patients experiencing AF recurrence after the 1st circumferential pulmonary vein isolation (CPVI) underwent a repeat RFCA, including 20 and 18 patients receiving a repeat CPVI (group I) or CPVI plus LA linear ablation (group II), respectively. 2-D echocardiography was performed during sinus rhythm within 24h, at 1-m and 6-m after RFCA. Longitudinal strains and strain rate were measured with speckle-tracking echocardiography. The standard deviation of contraction duration was defined as LA mechanical dispersion. One and two patients experienced AF recurrence after the 2nd RFCA in group I and II, respectively (P=NS). The 1st CPVI with AF recurrence did not reduce LA size significantly in two groups. After a repeat CPVI, LA diameter but not LA maximal and minimal volume was significantly reduced in group I; additional LA linear ablation significantly decreased LA diameter, maximal and minimal volume in group II. However, there was no significant difference in LA emptying function, global and segmental LA strain and strain rate among the baseline, 1-m and 6-m follow-up in two groups. RFCA did not significantly increase LA mechanical dispersion regardless of the AF ablation strategies. In patients with recurrent AF, a successful repeat CPVI with or without additional LA linear ablation reduced LA size without significant deleterious effects on LA function and mechanical dispersion. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Uncertainty, variability, and earthquake physics in ground‐motion prediction equations

USGS Publications Warehouse

Baltay, Annemarie S.; Hanks, Thomas C.; Abrahamson, Norm A.

2017-01-01

Residuals between ground‐motion data and ground‐motion prediction equations (GMPEs) can be decomposed into terms representing earthquake source, path, and site effects. These terms can be cast in terms of repeatable (epistemic) residuals and the random (aleatory) components. Identifying the repeatable residuals leads to a GMPE with reduced uncertainty for a specific source, site, or path location, which in turn can yield a lower hazard level at small probabilities of exceedance. We illustrate a schematic framework for this residual partitioning with a dataset from the ANZA network, which straddles the central San Jacinto fault in southern California. The dataset consists of more than 3200 1.15≤M≤3 earthquakes and their peak ground accelerations (PGAs), recorded at close distances (R≤20  km). We construct a small‐magnitude GMPE for these PGA data, incorporating VS30 site conditions and geometrical spreading. Identification and removal of the repeatable source, path, and site terms yield an overall reduction in the standard deviation from 0.97 (in ln units) to 0.44, for a nonergodic assumption, that is, for a single‐source location, single site, and single path. We give examples of relationships between independent seismological observables and the repeatable terms. We find a correlation between location‐based source terms and stress drops in the San Jacinto fault zone region; an explanation of the site term as a function of kappa, the near‐site attenuation parameter; and a suggestion that the path component can be related directly to elastic structure. These correlations allow the repeatable source location, site, and path terms to be determined a priori using independent geophysical relationships. Those terms could be incorporated into location‐specific GMPEs for more accurate and precise ground‐motion prediction.

Comparative study of navigated versus freehand osteochondral graft transplantation of the knee.

PubMed

Koulalis, Dimitrios; Di Benedetto, Paolo; Citak, Mustafa; O'Loughlin, Padhraig; Pearle, Andrew D; Kendoff, Daniel O

2009-04-01

Osteochondral lesions are a common sports-related injury for which osteochondral grafting, including mosaicplasty, is an established treatment. Computer navigation has been gaining popularity in orthopaedic surgery to improve accuracy and precision. Navigation improves angle and depth matching during harvest and placement of osteochondral grafts compared with conventional freehand open technique. Controlled laboratory study. Three cadaveric knees were used. Reference markers were attached to the femur, tibia, and donor/recipient site guides. Fifteen osteochondral grafts were harvested and inserted into recipient sites with computer navigation, and 15 similar grafts were inserted freehand. The angles of graft removal and placement as well as surface congruity (graft depth) were calculated for each surgical group. The mean harvesting angle at the donor site using navigation was 4 degrees (standard deviation, 2.3 degrees ; range, 1 degrees -9 degrees ) versus 12 degrees (standard deviation, 5.5 degrees ; range, 5 degrees -24 degrees ) using freehand technique (P < .0001). The recipient plug removal angle using the navigated technique was 3.3 degrees (standard deviation, 2.1 degrees ; range, 0 degrees -9 degrees ) versus 10.7 degrees (standard deviation, 4.9 degrees ; range, 2 degrees -17 degrees ) in freehand (P < .0001). The mean navigated recipient plug placement angle was 3.6 degrees (standard deviation, 2.0 degrees ; range, 1 degrees -9 degrees ) versus 10.6 degrees (standard deviation, 4.4 degrees ; range, 3 degrees -17 degrees ) with freehand technique (P = .0001). The mean height of plug protrusion under navigation was 0.3 mm (standard deviation, 0.2 mm; range, 0-0.6 mm) versus 0.5 mm (standard deviation, 0.3 mm; range, 0.2-1.1 mm) using a freehand technique (P = .0034). Significantly greater accuracy and precision were observed in harvesting and placement of the osteochondral grafts in the navigated procedures. Clinical studies are needed to establish a benefit in vivo. Improvement in the osteochondral harvest and placement is desirable to optimize clinical outcomes. Navigation shows great potential to improve both harvest and placement precision and accuracy, thus optimizing ultimate surface congruity.

Polyethylene glycol-based ultrasound-assisted extraction of magnolol and honokiol from Cortex Magnoliae Officinalis.

PubMed

He, Lei; Fan, Tao; Hu, Jianguo; Zhang, Lijin

2015-01-01

In this study, a kind of green solvent named polyethylene glycol (PEG) was developed for the ultrasound-assisted extraction (UAE) of magnolol and honokiol from Cortex Magnoliae Officinalis. The effects of PEG molecular weight, PEG concentration, sample size, pH, ultrasonic power and extraction time on the extraction of magnolol and honokiol were investigated to optimise the extraction conditions. Under the optimal extraction conditions, the PEG-based UAE supplied higher extraction efficiencies of magnolol and honokiol than the ethanol-based UAE and traditional ethanol-reflux extraction. Furthermore, the correlation coefficient (R(2)), repeatability (relative standard deviation, n = 6) and recovery confirmed the validation of the proposed extraction method, which were 0.9993-0.9996, 3.1-4.6% and 92.3-106.8%, respectively.

A new pyruvate oxidase biosensor based on 3-mercaptopropionic acid/6-aminocaproic acid modified gold electrode.

PubMed

Bayram, Ezgi; Akyilmaz, Erol

2014-12-01

In the biosensor construction, 3-mercaptopropionic acid (3-MPA) and 6-aminocaproic acid (6-ACA) were used for forming self-assembled monolayer (SAM) on a gold disc electrode and pyruvate oxidase was immobilized on the modified electrode surface by using glutaraldehyde. Biosensor response is linearly related to pyruvate concentration at 2.5-50 μM, detection limit is 1.87 μM and response time of the biosensor is 6 s for differential pulse voltammograms. From the repeatability studies (n = 6) for 30.0 μM pyruvate revealed that the average value ([Formula: see text]), standard deviation (S.D) and coefficient of variation (CV %) were calculated to be 31.02 μM, ± 0.1914 μM and 0.62%, respectively.

Silicone sensing phase for detection of aromatic hydrocarbons in water employing near-infrared spectroscopy.

PubMed

Albuquerque, Jackson S; Pimentel, M Fernanda; Silva, Valdinete L; Raimundo, Ivo M; Rohwedder, Jarbas J R; Pasquini, Celio

2005-01-01

The use of silicone for detection of aromatic hydrocarbons in water using near-infrared spectroscopy is proposed. A sensing phase of poly(dimethylsiloxane) (PDMS) was prepared, and a rod of this material was adapted to a transflectance probe for measurements from 850 to 1800 nm. Deionized water samples contaminated separately with known amounts of benzene, toluene, ethylbenzene, and m-xylene were used for evaluation of the PDMS sensing phase, and measurements were made in a closed reactor with constant stirring. Equilibrium states were obtained after 90, 180, 360, and 405 min for benzene, toluene, ethylbenzene, and m-xylene, respectively. The PDMS sensing phase showed a reversible response, presenting linear response ranges up to 360, 290, 100, and 80 mg L(-1), with detection limits of 8.0, 7.0, 2.6, and 3.0 mg L(-1) for benzene, toluene, ethylbenzene, and m-xylene, respectively. Reference spectra obtained with different rods showed a relative standard deviation of 0.5%, indicating repeatability in the sensing phase preparation. A relative standard deviation of 6.7% was obtained for measurements performed with six different rods, using a 52 mg L(-1) toluene aqueous solution. The sensing phase was evaluated for identification of sources of contamination of water in simulated studies, employing Brazilian gasoline type A (without ethanol), gasoline type C (with 25% of anhydrous ethanol), and diesel fuel. Principal component analysis was able to classify the water in distinct groups, contaminated by gasoline A, gasoline C, or diesel fuel.

Surveillance of hemodialysis vascular access with ultrasound vector flow imaging

NASA Astrophysics Data System (ADS)

Brandt, Andreas H.; Olesen, Jacob B.; Hansen, Kristoffer L.; Rix, Marianne; Jensen, Jørgen A.; Nielsen, Michael B.

2015-03-01

The aim of this study was prospectively to monitor the volume flow in patients with arteriovenous fistula (AVF) with the angle independent ultrasound technique Vector Flow Imaging (VFI). Volume flow values were compared with Ultrasound dilution technique (UDT). Hemodialysis patients need a well-functioning vascular access with as few complications as possible and preferred vascular access is an AVF. Dysfunction due to stenosis is a common complication, and regular monitoring of volume flow is recommended to preserve AVF patency. UDT is considered the gold standard for volume flow surveillance, but VFI has proven to be more precise, when performing single repeated instantaneous measurements. Three patients with AVF were monitored with UDT and VFI monthly for five months. A commercial ultrasound scanner with a 9 MHz linear array transducer with integrated VFI was used to obtain data. UDT values were obtained with Transonic HD03 Flow-QC Hemodialysis Monitor. Three independent measurements at each scan session were obtained with UDT and VFI each month. Average deviation of volume flow between UDT and VFI was 25.7 % (Cl: 16.7% to 34.7%) (p= 0.73). The standard deviation for all patients, calculated from the mean variance of each individual scan sessions, was 199.8 ml/min for UDT and 47.6 ml/min for VFI (p = 0.002). VFI volume flow values were not significantly different from the corresponding estimates obtained using UDT, and VFI measurements were more precise than UDT. The study indicates that VFI can be used for surveillance of volume flow.

In vivo evaluation of the effect of stimulus distribution on FIR statistical efficiency in event-related fMRI

PubMed Central

Jansma, J Martijn; de Zwart, Jacco A; van Gelderen, Peter; Duyn, Jeff H; Drevets, Wayne C; Furey, Maura L

2013-01-01

Technical developments in MRI have improved signal to noise, allowing use of analysis methods such as Finite impulse response (FIR) of rapid event related functional MRI (er-fMRI). FIR is one of the most informative analysis methods as it determines onset and full shape of the hemodynamic response function (HRF) without any a-priori assumptions. FIR is however vulnerable to multicollinearity, which is directly related to the distribution of stimuli over time. Efficiency can be optimized by simplifying a design, and restricting stimuli distribution to specific sequences, while more design flexibility necessarily reduces efficiency. However, the actual effect of efficiency on fMRI results has never been tested in vivo. Thus, it is currently difficult to make an informed choice between protocol flexibility and statistical efficiency. The main goal of this study was to assign concrete fMRI signal to noise values to the abstract scale of FIR statistical efficiency. Ten subjects repeated a perception task with five random and m-sequence based protocol, with varying but, according to literature, acceptable levels of multicollinearity. Results indicated substantial differences in signal standard deviation, while the level was a function of multicollinearity. Experiment protocols varied up to 55.4% in standard deviation. Results confirm that quality of fMRI in an FIR analysis can significantly and substantially vary with statistical efficiency. Our in vivo measurements can be used to aid in making an informed decision between freedom in protocol design and statistical efficiency. PMID:23473798

Flow electrochemical biosensors based on enzymatic porous reactor and tubular detector of silver solid amalgam.

PubMed

Josypčuk, Bohdan; Barek, Jiří; Josypčuk, Oksana

2013-05-17

A flow amperometric enzymatic biosensor for the determination of glucose was constructed. The biosensor consists of a flow reactor based on porous silver solid amalgam (AgSA) and a flow tubular detector based on compact AgSA. The preparation of the sensor and the determination of glucose occurred in three steps. First, a self-assembled monolayer of 11-mercaptoundecanoic acid (MUA) was formed at the porous surface of the reactor. Second, enzyme glucose oxidase (GOx) was covalently immobilized at MUA-layer using N-ethyl-N'-(3-dimethylaminopropyl) carboimide and N-hydroxysuccinimide chemistry. Finally, a decrease of oxygen concentration (directly proportional to the concentration of glucose) during enzymatic reaction was amperometrically measured on the tubular detector under flow injection conditions. The following parameters of glucose determination were optimized with respect to amperometric response: composition of the mobile phase, its concentration, the potential of detection and the flow rate. The calibration curve of glucose was linear in the concentration range of 0.02-0.80 mmol L(-1) with detection limit of 0.01 mmol L(-1). The content of glucose in the sample of honey was determined as 35.5±1.0 mass % (number of the repeated measurements n=7; standard deviation SD=1.2%; relative standard deviation RSD=3.2%) which corresponds well with the declared values. The tested biosensor proved good long-term stability (77% of the current response of glucose was retained after 35 days). Copyright © 2013 Elsevier B.V. All rights reserved.

Performance of Al2O3:C optically stimulated luminescence dosimeters for clinical radiation therapy applications.

PubMed

Hu, B; Wang, Y; Zealey, W

2009-12-01

A commercial Optical Stimulated Luminescence (OSL) dosimetry system developed by Landauer was tested to analyse the possibility of using OSL dosimetry for external beam radiotherapy planning checks. Experiments were performed to determine signal sensitivity, dose response range, beam type/energy dependency, reproducibility and linearity. Optical annealing processes to test OSL material reusability were also studied. In each case the measurements were converted into absorbed dose. The experimental results show that OSL dosimetry provides a wide dose response range, good linearity and reproducibility for the doses up to 800cGy. The OSL output is linear with dose up to 600cGy range showing a maximum deviation from linearity of 2.0% for the doses above 600cGy. The standard deviation in response of 20 dosimeters was 3.0%. After optical annealing using incandescent light, the readout intensity decreased by approximately 98% in the first 30 minutes. The readout intensity, I, decreased after repeated optical annealing as a power law, given by I infinity t (-1.3). This study concludes that OSL dosimetry can provide an alternative dosimetry technique for use in in-vivo dosimetry if rigorous measurement protocols are established.

[Optimization of cluster analysis based on drug resistance profiles of MRSA isolates].

PubMed

Tani, Hiroya; Kishi, Takahiko; Gotoh, Minehiro; Yamagishi, Yuka; Mikamo, Hiroshige

2015-12-01

We examined 402 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from clinical specimens in our hospital between November 19, 2010 and December 27, 2011 to evaluate the similarity between cluster analysis of drug susceptibility tests and pulsed-field gel electrophoresis (PFGE). The results showed that the 402 strains tested were classified into 27 PFGE patterns (151 subtypes of patterns). Cluster analyses of drug susceptibility tests with the cut-off distance yielding a similar classification capability showed favorable results--when the MIC method was used, and minimum inhibitory concentration (MIC) values were used directly in the method, the level of agreement with PFGE was 74.2% when 15 drugs were tested. The Unweighted Pair Group Method with Arithmetic mean (UPGMA) method was effective when the cut-off distance was 16. Using the SIR method in which susceptible (S), intermediate (I), and resistant (R) were coded as 0, 2, and 3, respectively, according to the Clinical and Laboratory Standards Institute (CLSI) criteria, the level of agreement with PFGE was 75.9% when the number of drugs tested was 17, the method used for clustering was the UPGMA, and the cut-off distance was 3.6. In addition, to assess the reproducibility of the results, 10 strains were randomly sampled from the overall test and subjected to cluster analysis. This was repeated 100 times under the same conditions. The results indicated good reproducibility of the results, with the level of agreement with PFGE showing a mean of 82.0%, standard deviation of 12.1%, and mode of 90.0% for the MIC method and a mean of 80.0%, standard deviation of 13.4%, and mode of 90.0% for the SIR method. In summary, cluster analysis for drug susceptibility tests is useful for the epidemiological analysis of MRSA.

"Push as hard as you can" instruction for telephone cardiopulmonary resuscitation: a randomized simulation study.

PubMed

van Tulder, Raphael; Roth, Dominik; Havel, Christof; Eisenburger, Philip; Heidinger, Benedikt; Chwojka, Christof Constantin; Novosad, Heinz; Sterz, Fritz; Herkner, Harald; Schreiber, Wolfgang

2014-03-01

The medical priority dispatch system (MPDS®) assists lay rescuers in protocol-driven telephone-assisted cardiopulmonary resuscitation (CPR). Our aim was to clarify which CPR instruction leads to sufficient compression depth. This was an investigator-blinded, randomized, parallel group, simulation study to investigate 10 min of chest compressions after the instruction "push down firmly 5 cm" vs. "push as hard as you can." Primary outcome was defined as compression depth. Secondary outcomes were participants exertion measured by Borg scale, provider's systolic and diastolic blood pressure, and quality values measured by the skill-reporting program of the Resusci(®) Anne Simulator manikin. For the analysis of the primary outcome, we used a linear random intercept model to allow for the repeated measurements with the intervention as a covariate. Thirteen participants were allocated to control and intervention. One participant (intervention) dropped out after min 7 because of exhaustion. Primary outcome showed a mean compression depth of 44.1 mm, with an inter-individual standard deviation (SDb) of 13.0 mm and an intra-individual standard deviation (SDw) of 6.7 mm for the control group vs. 46.1 mm and a SDb of 9.0 mm and SDw of 10.3 mm for the intervention group (difference: 1.9; 95% confidence interval -6.9 to 10.8; p = 0.66). Secondary outcomes showed no difference for exhaustion and CPR-quality values. There is no difference in compression depth, quality of CPR, or physical strain on lay rescuers using the initial instruction "push as hard as you can" vs. the standard MPDS(®) instruction "push down firmly 5 cm." Copyright © 2014 Elsevier Inc. All rights reserved.

On-the-Road Driving Performance the Morning after Bedtime Use of Suvorexant 20 and 40 mg: A Study in Non-Elderly Healthy Volunteers.

PubMed

Vermeeren, Annemiek; Sun, Hong; Vuurman, Eric F P M; Jongen, Stefan; Van Leeuwen, Cees J; Van Oers, Anita C M; Palcza, John; Li, Xiadong; Laethem, Tine; Heirman, Ingeborg; Bautmans, An; Troyer, Matthew D; Wrishko, Rebecca; McCrea, Jacqueline

2015-11-01

To evaluate next-morning driving performance in adults younger than 65 years, after single and repeated doses of suvorexant 20 and 40 mg. Double-blind, placebo-controlled, 4-period crossover study. Maastricht University, The Netherlands. 28 healthy volunteers (15 females), aged 23 to 64 years. Suvorexant (20 and 40 mg) for 8 consecutive nights; zopiclone 7.5 mg nightly on day 1 and 8; placebo. Performance on day 2 and 9 (9 h after dosing) using a one-hour standardized highway driving test in normal traffic, measuring standard deviation of lateral position (SDLP). Drug-placebo changes in SDLP > 2.4 cm were considered to reflect meaningful driving impairment. Mean drug-placebo changes in SDLP following suvorexant 20 and 40 mg were 1.01 and 1.66 cm on day 2, and 0.48 and 1.31 cm on Day 9, respectively. The 90% CIs of these changes were all below 2.4 cm. Symmetry analysis showed that more subjects had SDLP changes > 2.4 cm than < -2.4 cm following suvorexant 20 and 40 mg on day 2, and following suvorexant 40 mg on day 9. Four female subjects requested that a total of 5 driving tests--all following suvorexant--stop prematurely due to self-reported somnolence. As assessed by mean changes in standard deviation of lateral position (SDLP), there was no clinically meaningful residual effect of suvorexant in doses of 20 and 40 mg on next-morning driving (9 h after bedtime dosing) in healthy subjects < 65 years old. There may be some individuals who experience next-day effects, as suggested by individual changes in SDLP and prematurely stopped tests. clinicaltrials.gov NCT01311882. © 2015 Associated Professional Sleep Societies, LLC.

Matrix Summaries Improve Research Reports: Secondary Analyses Using Published Literature

ERIC Educational Resources Information Center

Zientek, Linda Reichwein; Thompson, Bruce

2009-01-01

Correlation matrices and standard deviations are the building blocks of many of the commonly conducted analyses in published research, and AERA and APA reporting standards recommend their inclusion when reporting research results. The authors argue that the inclusion of correlation/covariance matrices, standard deviations, and means can enhance…

30 CFR 74.8 - Measurement, accuracy, and reliability requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... concentration, as defined by the relative standard deviation of the distribution of measurements. The relative standard deviation shall be less than 0.1275 without bias for both full-shift measurements of 8 hours or... Standards, Regulations, and Variances, 1100 Wilson Boulevard, Room 2350, Arlington, Virginia 22209-3939...

Tissue elasticity of in vivo skeletal muscles measured in the transverse and longitudinal planes using shear wave elastography.

PubMed

Chino, Kentaro; Kawakami, Yasuo; Takahashi, Hideyuki

2017-07-01

The aim of the present study was to measure in vivo skeletal muscle elasticity in the transverse and longitudinal planes using shear wave elastography and then to compare the image stability, measurement values and measurement repeatability between these imaging planes. Thirty-one healthy males participated in this study. Tissue elasticity (shear wave velocity) of the medial gastrocnemius, rectus femoris, biceps brachii and rectus abdominis was measured in both the transverse and longitudinal planes using shear wave elastography. Image stability was evaluated by the standard deviation of the colour distribution in the shear wave elastography image. Measurement repeatability was assessed by the coefficient of variance obtained from three measurement values. Image stability of all tested muscles was significantly higher in the longitudinal plane (P<0·001), but measurement repeatability did not differ significantly between the imaging planes (P>0·05), except in the biceps brachii (P = 0·001). Measurement values of the medial gastrocnemius, rectus femoris and biceps brachii were significantly different between the imaging planes (P<0·001). Image stability and measurement values of shear wave elastography images varied with imaging plane, which indicates that imaging plane should be considered when measuring skeletal muscle tissue elasticity by shear wave elastography. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

The effects of auditory stimulation with music on heart rate variability in healthy women.

PubMed

Roque, Adriano L; Valenti, Vitor E; Guida, Heraldo L; Campos, Mônica F; Knap, André; Vanderlei, Luiz Carlos M; Ferreira, Lucas L; Ferreira, Celso; Abreu, Luiz Carlos de

2013-07-01

There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. The triangular index and the standard deviation of the long-term RR interval indices were reduced during exposure to both music styles in the first group and tended to decrease in the second group whereas the white noise exposure decreased the high frequency index. We observed no changes regarding the triangular interpolation of RR intervals, standard deviation of instantaneous beat-by-beat variability and standard deviation of instantaneous beat-by-beat variability/standard deviation in the long-term RR interval ratio. We suggest that relaxant baroque and excitatory heavy metal music slightly decrease global heart rate variability because of the equivalent sound level.

The effects of auditory stimulation with music on heart rate variability in healthy women

PubMed Central

Roque, Adriano L.; Valenti, Vitor E.; Guida, Heraldo L.; Campos, Mônica F.; Knap, André; Vanderlei, Luiz Carlos M.; Ferreira, Lucas L.; Ferreira, Celso; de Abreu, Luiz Carlos

2013-01-01

OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of the long-term RR interval indices were reduced during exposure to both music styles in the first group and tended to decrease in the second group whereas the white noise exposure decreased the high frequency index. We observed no changes regarding the triangular interpolation of RR intervals, standard deviation of instantaneous beat-by-beat variability and standard deviation of instantaneous beat-by-beat variability/standard deviation in the long-term RR interval ratio. CONCLUSION: We suggest that relaxant baroque and excitatory heavy metal music slightly decrease global heart rate variability because of the equivalent sound level. PMID:23917660

USL/DBMS NASA/PC R and D project C programming standards

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Moreau, Dennis R.

1984-01-01

A set of programming standards intended to promote reliability, readability, and portability of C programs written for PC research and development projects is established. These standards must be adhered to except where reasons for deviation are clearly identified and approved by the PC team. Any approved deviation from these standards must also be clearly documented in the pertinent source code.

Standard deviation index for stimulated Brillouin scattering suppression with different homogeneities.

PubMed

Ran, Yang; Su, Rongtao; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Si, Lei

2016-05-10

We present a new quantitative index of standard deviation to measure the homogeneity of spectral lines in a fiber amplifier system so as to find the relation between the stimulated Brillouin scattering (SBS) threshold and the homogeneity of the corresponding spectral lines. A theoretical model is built and a simulation framework has been established to estimate the SBS threshold when input spectra with different homogeneities are set. In our experiment, by setting the phase modulation voltage to a constant value and the modulation frequency to different values, spectral lines with different homogeneities can be obtained. The experimental results show that the SBS threshold increases negatively with the standard deviation of the modulated spectrum, which is in good agreement with the theoretical results. When the phase modulation voltage is confined to 10 V and the modulation frequency is set to 80 MHz, the standard deviation of the modulated spectrum equals 0.0051, which is the lowest value in our experiment. Thus, at this time, the highest SBS threshold has been achieved. This standard deviation can be a good quantitative index in evaluating the power scaling potential in a fiber amplifier system, which is also a design guideline in suppressing the SBS to a better degree.

[Determination of eight pesticide residues in tea by liquid chromatography-tandem mass spectrometry and its uncertainty evaluation].

PubMed

Hu, Beizhen; Cai, Haijiang; Song, Weihua

2012-09-01

A method was developed for the determination of eight pesticide residues (fipronil, imidacloprid, acetamiprid, buprofezin, triadimefon, triadimenol, profenofos, pyridaben) in tea by liquid chromatography-tandem mass spectrometry. The sample was extracted by accelerated solvent extraction with acetone-dichloromethane (1:1, v/v) as solvent, and the extract was then cleaned-up with a Carb/NH2 solid phase extraction (SPE) column. The separation was performed on a Hypersil Gold C, column (150 mm x 2. 1 mm, 5 microm) and with the gradient elution of acetonitrile and 0. 1% formic acid. The eight pesticides were determined in the modes of electrospray ionization (ESI) and multiple reaction monitoring (MRM). The analytes were quantified by matrix-matched internal standard method for imidacloprid and acetamiprid, by matrix-matched external standard method for the other pesticides. The calibration curves showed good linearity in 1 - 100 microg/L for fipronil, and in 5 -200 microg/L for the other pesticides. The limits of quantification (LOQs, S/N> 10) were 2 p.g/kg for fipronil and 10 microg/kg for the other pesticides. The average recoveries ranged from 75. 5% to 115.0% with the relative standard deviations of 2.7% - 7.7% at the spiked levels of 2, 5, 50 microg/kg for fipronil and 10, 50, 100 microg/kg for the other pesticides. The uncertainty evaluation for the results was carried out according to JJF 1059-1999 "Evaluation and Expression of Uncertainty in Measurement". Items constituting measurement uncertainty involved standard solution, weighing of sample, sample pre-treatment, and the measurement repeatability of the equipment were evaluated. The results showed that the measurement uncertainty is mainly due to sample pre-treatment, standard curves and measurement repeatability of the equipment. The method developed is suitable for the conformation and quantification of the pesticides in tea.

Scapula kinematics of pull-up techniques: Avoiding impingement risk with training changes.

PubMed

Prinold, Joe A I; Bull, Anthony M J

2016-08-01

Overhead athletic activities and scapula dyskinesia are linked with shoulder pathology; pull-ups are a common training method for some overhead sports. Different pull-up techniques exist: anecdotally some are easier to perform, and others linked to greater incidences of pathology. This study aims to quantify scapular kinematics and external forces for three pull-up techniques, thus discussing potential injury implications. An observational study was performed with eleven participants (age=26.8±2.4 years) who regularly perform pull-ups. The upward motions of three pull-up techniques were analysed: palms facing anterior, palms facing posterior and wide-grip. A skin-fixed scapula tracking technique with attached retro-reflective markers was used. High intra-participant repeatability was observed: mean coefficients of multiple correlations of 0.87-1.00 in humerothoracic rotations and 0.77-0.90 for scapulothoracic rotations. Standard deviations of hand force was low: <5% body weight. Significantly different patterns of humerothoracic, scapulothoracic and glenohumeral kinematics were observed between the pull-up techniques. The reverse technique has extreme glenohumeral internal-external rotation and large deviation from the scapula plane. The wide technique has a reduced range of pro/retraction in the same HT plane of elevation and 90° of arm abduction with 45° external rotation was observed. All these factors suggest increased sub-acromial impingement risk. The scapula tracking technique showed high repeatability. High arm elevation during pull-ups reduces sub-acromial space and increases pressure, increasing the risk of impingement injury. Wide and reverse pull-ups demonstrate kinematics patterns linked with increased impingement risk. Weight-assisted front pull-ups require further investigation and could be recommended for weaker participants. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Gait Deviation Index, Gait Profile Score and Gait Variable Score in children with spastic cerebral palsy: Intra-rater reliability and agreement across two repeated sessions.

PubMed

Rasmussen, Helle Mätzke; Nielsen, Dennis Brandborg; Pedersen, Niels Wisbech; Overgaard, Søren; Holsgaard-Larsen, Anders

2015-07-01

The Gait Deviation Index (GDI) and Gait Profile Score (GPS) are the most used summary measures of gait in children with cerebral palsy (CP). However, the reliability and agreement of these indices have not been investigated, limiting their clinimetric quality for research and clinical practice. The aim of this study was to investigate the intra-rater reliability and agreement of summary measures of gait (GDI; GPS; and the Gait Variable Score (GVS) derived from the GPS). The intra-rater reliability and agreement were investigated across two repeated sessions in 18 children aged 5-12 years diagnosed with spastic CP. No systematic bias was observed between the sessions and no heteroscedasticity was observed in Bland-Altman plots. For the GDI and GPS, excellent reliability with intraclass correlation coefficient (ICC) values of 0.8-0.9 was found, while the GVS was found to have fair to good reliability with ICCs of 0.4-0.7. The agreement for the GDI and the logarithmically transformed GPS, in terms of the standard error of measurement as a percentage of the grand mean (SEM%) varied from 4.1 to 6.7%, whilst the smallest detectable change in percent (SDC%) ranged from 11.3 to 18.5%. For the logarithmically transformed GVS, we found a fair to large variation in SEM% from 7 to 29% and in SDC% from 18 to 81%. The GDI and GPS demonstrated excellent reliability and acceptable agreement proving that they can both be used in research and clinical practice. However, the observed large variability for some of the GVS requires cautious consideration when selecting outcome measures. Copyright © 2015 Elsevier B.V. All rights reserved.

figure1.nc

EPA Pesticide Factsheets

NetCDF file of the SREF standard deviation of wind speed and direction that was used to inject variability in the FDDA input.variable U_NDG_OLD contains standard deviation of wind speed (m/s)variable V_NDG_OLD contains the standard deviation of wind direction (deg)This dataset is associated with the following publication:Gilliam , R., C. Hogrefe , J. Godowitch, S. Napelenok , R. Mathur , and S.T. Rao. Impact of inherent meteorology uncertainty on air quality model predictions. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES. American Geophysical Union, Washington, DC, USA, 120(23): 12,259–12,280, (2015).

Test–retest repeatability of human speech biomarkers from static and real-time dynamic magnetic resonance imaging

PubMed Central

Töger, Johannes; Sorensen, Tanner; Somandepalli, Krishna; Toutios, Asterios; Lingala, Sajan Goud; Narayanan, Shrikanth; Nayak, Krishna

2017-01-01

Static anatomical and real-time dynamic magnetic resonance imaging (RT-MRI) of the upper airway is a valuable method for studying speech production in research and clinical settings. The test–retest repeatability of quantitative imaging biomarkers is an important parameter, since it limits the effect sizes and intragroup differences that can be studied. Therefore, this study aims to present a framework for determining the test–retest repeatability of quantitative speech biomarkers from static MRI and RT-MRI, and apply the framework to healthy volunteers. Subjects (n = 8, 4 females, 4 males) are imaged in two scans on the same day, including static images and dynamic RT-MRI of speech tasks. The inter-study agreement is quantified using intraclass correlation coefficient (ICC) and mean within-subject standard deviation (σe). Inter-study agreement is strong to very strong for static measures (ICC: min/median/max 0.71/0.89/0.98, σe: 0.90/2.20/6.72 mm), poor to strong for dynamic RT-MRI measures of articulator motion range (ICC: 0.26/0.75/0.90, σe: 1.6/2.5/3.6 mm), and poor to very strong for velocities (ICC: 0.21/0.56/0.93, σe: 2.2/4.4/16.7 cm/s). In conclusion, this study characterizes repeatability of static and dynamic MRI-derived speech biomarkers using state-of-the-art imaging. The introduced framework can be used to guide future development of speech biomarkers. Test–retest MRI data are provided free for research use. PMID:28599561

The structures of non-CG-repeat Z-DNAs co-crystallized with the Z-DNA-binding domain, hZ alpha(ADAR1).

PubMed

Ha, Sung Chul; Choi, Jongkeun; Hwang, Hye-Yeon; Rich, Alexander; Kim, Yang-Gyun; Kim, Kyeong Kyu

2009-02-01

The Z-DNA conformation preferentially occurs at alternating purine-pyrimidine repeats, and is specifically recognized by Z alpha domains identified in several Z-DNA-binding proteins. The binding of Z alpha to foreign or chromosomal DNA in various sequence contexts is known to influence various biological functions, including the DNA-mediated innate immune response and transcriptional modulation of gene expression. For these reasons, understanding its binding mode and the conformational diversity of Z alpha bound Z-DNAs is of considerable importance. However, structural studies of Z alpha bound Z-DNA have been mostly limited to standard CG-repeat DNAs. Here, we have solved the crystal structures of three representative non-CG repeat DNAs, d(CACGTG)(2), d(CGTACG)(2) and d(CGGCCG)(2) complexed to hZ alpha(ADAR1) and compared those structures with that of hZ alpha(ADAR1)/d(CGCGCG)(2) and the Z alpha-free Z-DNAs. hZ alpha(ADAR1) bound to each of the three Z-DNAs showed a well conserved binding mode with very limited structural deviation irrespective of the DNA sequence, although varying numbers of residues were in contact with Z-DNA. Z-DNAs display less structural alterations in the Z alpha-bound state than in their free form, thereby suggesting that conformational diversities of Z-DNAs are restrained by the binding pocket of Z alpha. These data suggest that Z-DNAs are recognized by Z alpha through common conformational features regardless of the sequence and structural alterations.

Distribution and Characteristics of Repeating Earthquakes in Northern California

NASA Astrophysics Data System (ADS)

Waldhauser, F.; Schaff, D. P.; Zechar, J. D.; Shaw, B. E.

2012-12-01

Repeating earthquakes are playing an increasingly important role in the study of fault processes and behavior, and have the potential to improve hazard assessment, earthquake forecast, and seismic monitoring capabilities. These events rupture the same fault patch repeatedly, generating virtually identical seismograms. In California, repeating earthquakes have been found predominately along the creeping section of the central San Andreas Fault, where they are believed to represent failing asperities on an otherwise creeping fault. Here, we use the northern California double-difference catalog of 450,000 precisely located events (1984-2009) and associated database of 2 billion waveform cross-correlation measurements to systematically search for repeating earthquakes across various tectonic regions. An initial search for pairs of earthquakes with high-correlation coefficients and similar magnitudes resulted in 4,610 clusters including a total of over 26,000 earthquakes. A subsequent double-difference re-analysis of these clusters resulted in 1,879 sequences (8,640 events) where a common rupture area can be resolved to the precision of a few tens of meters or less. These repeating earthquake sequences (RES) include between 3 and 24 events with magnitudes up to ML=4. We compute precise relative magnitudes between events in each sequence from differential amplitude measurements. Differences between these and standard coda-duration magnitudes have a standard deviation of 0.09. The RES occur throughout northern California, but RES with 10 or more events (6%) only occur along the central San Andreas and Calaveras faults. We are establishing baseline characteristics for each sequence, such as recurrence intervals and their coefficient of variation (CV), in order to compare them across tectonic regions. CVs for these clusters range from 0.002 to 2.6, indicating a range of behavior between periodic occurrence (CV~0), random occurrence, and temporal clustering. 10% of the RES show burst-like behavior with mean recurrence times smaller than one month. 5% of the RES have mean recurrence times greater than one year and include more than 10 earthquakes. Earthquakes in the 50 most periodic sequences (CV<0.2) do not appear to be predictable by either time- or slip-predictable models, consistent with previous findings. We demonstrate that changes in recurrence intervals of repeating earthquakes can be routinely monitored. This is especially important for sequences with CV~0, as they may indicate changes in the loading rate. We also present results from retrospective forecast experiments based on near-real time hazard functions.

Results of scatterometer systems analysis for NASA/MSC Earth Observation Sensor Evaluation Program.

NASA Technical Reports Server (NTRS)

Krishen, K.; Vlahos, N.; Brandt, O.; Graybeal, G.

1971-01-01

Radar scatterometers have applications in the NASA/MSC Earth Observation Aircraft Program. Over a period of several years, several missions have been flown over both land and ocean. In this paper a system evaluation of the NASA/MSC 13.3-GHz Scatterometer System is presented. The effects of phase error between the Scatterometer channels, antenna pattern deviations, aircraft attitude deviations, environmental changes, and other related factors such as processing errors, system repeatability, and propeller modulation, were established. Furthermore, the reduction in system errors and calibration improvement was investigated by taking into account these parameter deviations. Typical scatterometer data samples are presented.

75 FR 67093 - Iceberg Water Deviating From Identity Standard; Temporary Permit for Market Testing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-P-0517] Iceberg Water Deviating From Identity Standard; Temporary Permit for Market Testing AGENCY: Food and Drug... from the requirements of the standards of identity issued under section 401 of the Federal Food, Drug...

78 FR 2273 - Canned Tuna Deviating From Identity Standard; Temporary Permit for Market Testing

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-10

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-P-1189] Canned Tuna Deviating From Identity Standard; Temporary Permit for Market Testing AGENCY: Food and Drug... interstate shipment of experimental packs of food varying from the requirements of standards of identity...

Upgraded FAA Airfield Capacity Model. Volume 2. Technical Description of Revisions

DTIC Science & Technology

1981-02-01

the threshold t k a the time at which departure k is released FIGURE 3-1 TIME AXIS DIAGRAM OF SINGLE RUNWAY OPERATIONS 3-2 J"- SIGMAR the standard...standard deviation of the interarrival time. SIGMAR - the standard deviation of the arrival runway occupancy time. A-5 SINGLE - program subroutine for

A three-dimensional evaluation of a laser scanner and a touch-probe scanner.

PubMed

Persson, Anna; Andersson, Matts; Oden, Agneta; Sandborgh-Englund, Gunilla

2006-03-01

The fit of a dental restoration depends on quality throughout the entire manufacturing process. There is difficulty in assessing the surface topography of an object with a complex form, such as teeth, since there is no exact reference form. The purpose of this study was to determine the repeatability and relative accuracy of 2 dental surface digitization devices. A computer-aided design (CAD) technique was used for evaluation to calculate and present the deviations 3-dimensionally. Ten dies of teeth prepared for complete crowns were fabricated in presintered yttria-stabilized tetragonal zirconia (Y-TZP). The surfaces were digitized 3 times each with an optical or mechanical digitizer. The number of points in the point clouds from each reading were calculated and used as the CAD reference model (CRM). Alignments were performed by registration software that works by minimizing a distance criterion. In color-difference maps, the distribution of the discrepancies between the surfaces in the CRM and the 3-dimensional surface models was identified and located. The repeatability of both scanners was within 10 microm, based on SD and absolute mean values. The qualitative evaluation resulted in an even distribution of the deviations in the optical digitizer, whereas the dominating part of the surfaces in the mechanical digitizer showed no deviations. The relative accuracy of the 2 surface digitization devices was within +/- 6 microm, based on median values. The repeatability of the optical digitizer was comparable with the mechanical digitization device, and the relative accuracy was similar.

Methods of editing cloud and atmospheric layer affected pixels from satellite data

NASA Technical Reports Server (NTRS)

Nixon, P. R.; Wiegand, C. L.; Richardson, A. J.; Johnson, M. P. (Principal Investigator)

1982-01-01

Subvisible cirrus clouds (SCi) were easily distinguished in mid-infrared (MIR) TIROS-N daytime data from south Texas and northeast Mexico. The MIR (3.55-3.93 micrometer) pixel digital count means of the SCi affected areas were more than 3.5 standard deviations on the cold side of the scene means. (These standard deviations were made free of the effects of unusual instrument error by factoring out the Ch 3 MIR noise on the basis of detailed examination of noisy and noise-free pixels). SCi affected areas in the IR Ch 4 (10.5-11.5 micrometer) appeared cooler than the general scene, but were not as prominent as in Ch 3, being less than 2 standard deviations from the scene mean. Ch 3 and 4 standard deviations and coefficients of variation are not reliable indicators, by themselves, of the presence of SCi because land features can have similar statistical properties.

TH-AB-201-07: Filmless Treatment Localization QA for the CyberKnife System

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

Gersh, J; Spectrum Medical Physics, LLC, Greenville, SC; Noll, M

Purpose: Accuray recommends daily evaluation of the treatment localization and delivery systems (TLS/TDS) of the CyberKnife. The vendor-provided solution is a Winston-Lutz-type test that evaluates film shadows from an orthogonal beam pair (known as AQA). Since film-based techniques are inherently inefficient and potentially inconsistent and uncertain, this study explores a method which provides a comparable test with greater efficiency, consistency, and certainty. This test uses the QAStereoChecker (QASC, Standard Imaging, Inc., Middleton, WI), a high-resolution flat-panel detector with coupled fiducial markers for automated alignment. Fiducial tracking is used to achieve high translational and rotational position accuracy. Methods: A plan ismore » generated delivering five circular beams, with varying orientation and angular incidence. Several numeric quantities are calculated for each beam: eccentricity, centroid location, area, major-axis length, minor-axis length, and orientation angle. Baseline values were acquired and repeatability of baselines analyzed. Next, errors were induced in the path calibration of the CK, and the test repeated. A correlative study was performed between the induced errors and quantities measured using the QASC. Based on vendor recommendations, this test should be able to detect a TLS/TDS offset of 0.5mm. Results: Centroid shifts correlated well with induced plane-perpendicular offsets (p < 0.01). Induced vertical shifts correlated best with the absolute average deviation of eccentricities (p < 0.05). The values of these metrics which correlated with the threshold of 0.5mm induced deviation were used as individual pass/fail criteria. These were then used to evaluate induced offsets which shifted the CK in all axes (a clinically-realistic offset), with a total offset of 0.5mm. This test provided high and specificity and sensitivity. Conclusion: From setup to analysis, this filmless TLS/TDS test requires 4 minutes, as opposed to 15–20 minutes for film-based methods. The techniques introduced can potentially isolate errors in individual joints of the CK robot. Spectrum Medical Physics, LLC of Greenville, SC has a consulting contract with Standard Imaging of Middleton, WI.« less

A Taxonomy of Delivery and Documentation Deviations During Delivery of High-Fidelity Simulations.

PubMed

McIvor, William R; Banerjee, Arna; Boulet, John R; Bekhuis, Tanja; Tseytlin, Eugene; Torsher, Laurence; DeMaria, Samuel; Rask, John P; Shotwell, Matthew S; Burden, Amanda; Cooper, Jeffrey B; Gaba, David M; Levine, Adam; Park, Christine; Sinz, Elizabeth; Steadman, Randolph H; Weinger, Matthew B

2017-02-01

We developed a taxonomy of simulation delivery and documentation deviations noted during a multicenter, high-fidelity simulation trial that was conducted to assess practicing physicians' performance. Eight simulation centers sought to implement standardized scenarios over 2 years. Rules, guidelines, and detailed scenario scripts were established to facilitate reproducible scenario delivery; however, pilot trials revealed deviations from those rubrics. A taxonomy with hierarchically arranged terms that define a lack of standardization of simulation scenario delivery was then created to aid educators and researchers in assessing and describing their ability to reproducibly conduct simulations. Thirty-six types of delivery or documentation deviations were identified from the scenario scripts and study rules. Using a Delphi technique and open card sorting, simulation experts formulated a taxonomy of high-fidelity simulation execution and documentation deviations. The taxonomy was iteratively refined and then tested by 2 investigators not involved with its development. The taxonomy has 2 main classes, simulation center deviation and participant deviation, which are further subdivided into as many as 6 subclasses. Inter-rater classification agreement using the taxonomy was 74% or greater for each of the 7 levels of its hierarchy. Cohen kappa calculations confirmed substantial agreement beyond that expected by chance. All deviations were classified within the taxonomy. This is a useful taxonomy that standardizes terms for simulation delivery and documentation deviations, facilitates quality assurance in scenario delivery, and enables quantification of the impact of deviations upon simulation-based performance assessment.

Peripheral tissue oximetry: comparing three commercial near-infrared spectroscopy oximeters on the forearm.

PubMed

Hyttel-Sorensen, Simon; Hessel, Trine Witzner; Greisen, Gorm

2014-04-01

Estimation of regional tissue oxygenation (rStO2) by near infrared spectroscopy enables non-invasive end-organ oxygen balance monitoring and could be a valuable tool in intensive care. However, the diverse absolute values and dynamics of different devices, and overall poor repeatability of measurements are a problem. The aim of the present study is to test the hypothesis that INVOS 5100C, FORE-SIGHT and NONIN EQUANOX 7600 have similar properties concerning absolute values, repeatability, and sensitivity to changes in rStO2. To test repeatability the sensors were repositioned 20 times during hemodynamic steady state on the adult forearm. Afterwards six vascular occlusions by inflation of an upper arm cuff were done to achieve low oxygenation in the forearm. Absolute values were compared by repeated-measures ANOVA, repeatability was estimated by the within-subject standard deviation, Sw, and response to changing oxygenation by the down slope of rStO2 during vascular occlusion in the respective arm. 10 healthy adults, 21-29 years old, with double skinfolds on the forearm less than 10 mm participated. The median rStO2 was 70.7% (interquartile range (IQR) 7.7%), 68.4% (IQR 8.4%), and 64.6% (IQR 4.8) with INVOS, NONIN, and FORE-SIGHT, respectively, the median rate of decline was 13.2%/min (IQR 9.6), 22.8 %/min (IQR 18.0), and 10.8%/min (IQR 6.0), and the same-site repeatability was 2.9% (95% CI 2.4-3.3), 4.6% (CI 3.9-5.3), and 2.0% (CI 1.7-2.3). INVOS gave significantly higher steady state values than FORE-SIGHT, and NONIN had the steepest decline in rStO2, but the poorest repeatability. Two measures of signal-to-noise were similar among devices. This suggests that good repeatability comes at the expense of low sensitivity to changes in oxygenation. Values of rStO2 on the forearm from INVOS, NONIN and FORE-SIGTH cannot be used interchangeably.

Improving the efficiency of quantitative (1)H NMR: an innovative external standard-internal reference approach.

PubMed

Huang, Yande; Su, Bao-Ning; Ye, Qingmei; Palaniswamy, Venkatapuram A; Bolgar, Mark S; Raglione, Thomas V

2014-01-01

The classical internal standard quantitative NMR (qNMR) method determines the purity of an analyte by the determination of a solution containing the analyte and a standard. Therefore, the standard must meet the requirements of chemical compatibility and lack of resonance interference with the analyte as well as a known purity. The identification of such a standard can be time consuming and must be repeated for each analyte. In contrast, the external standard qNMR method utilizes a standard with a known purity to calibrate the NMR instrument. The external standard and the analyte are measured separately, thereby eliminating the matter of chemical compatibility and resonance interference between the standard and the analyte. However, the instrumental factors, including the quality of NMR tubes, must be kept the same. Any deviations will compromise the accuracy of the results. An innovative qNMR method reported herein utilizes an internal reference substance along with an external standard to assume the role of the standard used in the traditional internal standard qNMR method. In this new method, the internal reference substance must only be chemically compatible and be free of resonance-interference with the analyte or external standard whereas the external standard must only be of a known purity. The exact purity or concentration of the internal reference substance is not required as long as the same quantity is added to the external standard and the analyte. The new method reduces the burden of searching for an appropriate standard for each analyte significantly. Therefore the efficiency of the qNMR purity assay increases while the precision of the internal standard method is retained. Copyright © 2013 Elsevier B.V. All rights reserved.

TU-C-12A-05: Repeatability Study of Reduced Field-Of-View Diffusion-Weighted MRI On Human Thyroid Gland

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

Shukla-Dave, A; Lu, Y; Hatzoglou, V

2014-06-15

Purpose: To investigate the repeatability of reduced field-of-view diffusion-weighted imaging (rFOV DWI) in quantifying apparent diffusion coefficients (ADCs) for human thyroid glands in a clinical setting. Methods: Nine healthy human volunteers were enrolled and underwent 3T MRI exams. For each volunteer, 3 longitudinal exams (2 weeks apart) with 2 repetitive sessions within each exam, including rFOV and conventional full field-of-view (fFOV) DWI scans, were performed. In the acquired DWI images, a fixed-size region of interest (ROI; diameter=8mm) was placed on thyroid glands to calculate ADC. ADC was calculated using a monoexponential function with a noise correction scheme. The repeatability ofmore » ADC was assessed by using coefficient variation (CV) across sessions or exams, which was defined to be: r = 1-CV, 0 < r < 1, where CV=STD/m, STD is the standard deviation of ADC, and m is the average of ADC across sessions or exams. An experienced radiologist assessed and scored rFOV and fFOV DW images based on image characteristics (1, nondiagnostic; 2, poor; 3, satisfactory; 4, good; and 5, excellent).Analysis of variance (ANOVA) was performed to compare ADC values, CV of ADC, repeatability of ADC across sessions and exams, and radiologic scores between rFOV and fFOV DWI techniques. Results: There was no significant difference in ADC values across sessions and exams either in rFOV or fFOV DWI. The average CVs of both rFOV and fFOV DWI were less than 13%. The repeatability of ADC measurement between rFOV and fFOV DWI was not significantly different. The overall image quality was significantly higher with rFOV DWI than with fFOV DWI. Conclusion: This study suggested that ADCs from both rFOV and fFOV DWI were repeatable, but rFOV DWI had superior imaging quality for human thyroid glands in a clinical setting.« less

Simulation-based estimation of mean and standard deviation for meta-analysis via Approximate Bayesian Computation (ABC).

PubMed

Kwon, Deukwoo; Reis, Isildinha M

2015-08-12

When conducting a meta-analysis of a continuous outcome, estimated means and standard deviations from the selected studies are required in order to obtain an overall estimate of the mean effect and its confidence interval. If these quantities are not directly reported in the publications, they must be estimated from other reported summary statistics, such as the median, the minimum, the maximum, and quartiles. We propose a simulation-based estimation approach using the Approximate Bayesian Computation (ABC) technique for estimating mean and standard deviation based on various sets of summary statistics found in published studies. We conduct a simulation study to compare the proposed ABC method with the existing methods of Hozo et al. (2005), Bland (2015), and Wan et al. (2014). In the estimation of the standard deviation, our ABC method performs better than the other methods when data are generated from skewed or heavy-tailed distributions. The corresponding average relative error (ARE) approaches zero as sample size increases. In data generated from the normal distribution, our ABC performs well. However, the Wan et al. method is best for estimating standard deviation under normal distribution. In the estimation of the mean, our ABC method is best regardless of assumed distribution. ABC is a flexible method for estimating the study-specific mean and standard deviation for meta-analysis, especially with underlying skewed or heavy-tailed distributions. The ABC method can be applied using other reported summary statistics such as the posterior mean and 95 % credible interval when Bayesian analysis has been employed.

Determination of Flavonol Aglycones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography: Single Laboratory Validation

PubMed Central

Gray, Dean; LeVanseler, Kerri; Pan, Meide

2008-01-01

A single laboratory validation (SLV) was completed for a method to determine the flavonol aglycones quercetin, kaempferol, and isorhamnetin in Ginkgo biloba products. The method calculates total glycosides based on these aglycones formed following acid hydrolysis. Nine matrixes were chosen for the study, including crude leaf material, standardized dry powder extract, single and multiple entity finished products, and ethanol and glycerol tinctures. For the 9 matrixes evaluated as part of this SLV, the method appeared to be selective and specific, with no observed interferences. The simplified 60 min oven heating hydrolysis procedure was effective for each of the matrixes studied, with no apparent or consistent differences between 60, 75, and 90 min at 90°C. A Youden ruggedness trial testing 7 factors with the potential to affect quantitative results showed that 2 factors (volume hydrolyzed and test sample extraction/hydrolysis weight) were the most important parameters for control during sample preparation. The method performed well in terms of precision, with 4 matrixes tested in triplicate over a 3-day period showing an overall repeatability (relative standard deviation, RSD) of 2.3%. Analysis of variance testing at α = 0.05 showed no significant differences among the within- or between-group sources of variation, although comparisons of within-day (Sw), between-day (Sb), and total (St) precision showed that a majority of the standard deviation came from within-day determinations for all matrixes. Accuracy testing at 2 levels (approximately 30 and 90% of the determined concentrations in standardized dry powder extract) from 2 complex negative control matrixes showed an overall 96% recovery and RSD of 1.0% for the high spike, and 94% recovery and RSD of 2.5% for the low spike. HorRat scores were within the limits for performance acceptability, ranging from 0.4 to 1.3. Based on the performance results presented herein, it is recommended that this method progress to the collaborative laboratory trial. PMID:16001841

Quantitative comparison between a multiecho sequence and a single-echo sequence for susceptibility-weighted phase imaging.

PubMed

Gilbert, Guillaume; Savard, Geneviève; Bard, Céline; Beaudoin, Gilles

2012-06-01

The aim of this study was to investigate the benefits arising from the use of a multiecho sequence for susceptibility-weighted phase imaging using a quantitative comparison with a standard single-echo acquisition. Four healthy adult volunteers were imaged on a clinical 3-T system using a protocol comprising two different three-dimensional susceptibility-weighted gradient-echo sequences: a standard single-echo sequence and a multiecho sequence. Both sequences were repeated twice in order to evaluate the local noise contribution by a subtraction of the two acquisitions. For the multiecho sequence, the phase information from each echo was independently unwrapped, and the background field contribution was removed using either homodyne filtering or the projection onto dipole fields method. The phase information from all echoes was then combined using a weighted linear regression. R2 maps were also calculated from the multiecho acquisitions. The noise standard deviation in the reconstructed phase images was evaluated for six manually segmented regions of interest (frontal white matter, posterior white matter, globus pallidus, putamen, caudate nucleus and lateral ventricle). The use of the multiecho sequence for susceptibility-weighted phase imaging led to a reduction of the noise standard deviation for all subjects and all regions of interest investigated in comparison to the reference single-echo acquisition. On average, the noise reduction ranged from 18.4% for the globus pallidus to 47.9% for the lateral ventricle. In addition, the amount of noise reduction was found to be strongly inversely correlated to the estimated R2 value (R=-0.92). In conclusion, the use of a multiecho sequence is an effective way to decrease the noise contribution in susceptibility-weighted phase images, while preserving both contrast and acquisition time. The proposed approach additionally permits the calculation of R2 maps. Copyright © 2012 Elsevier Inc. All rights reserved.

Measurement of global functional performance in patients with rheumatoid arthritis using rheumatology function tests

PubMed Central

Escalante, Agustín; Haas, Roy W; del Rincón, Inmaculada

2004-01-01

Outcome assessment in patients with rheumatoid arthritis (RA) includes measurement of physical function. We derived a scale to quantify global physical function in RA, using three performance-based rheumatology function tests (RFTs). We measured grip strength, walking velocity, and shirt button speed in consecutive RA patients attending scheduled appointments at six rheumatology clinics, repeating these measurements after a median interval of 1 year. We extracted the underlying latent variable using principal component factor analysis. We used the Bayesian information criterion to assess the global physical function scale's cross-sectional fit to criterion standards. The criteria were joint tenderness, swelling, and deformity, pain, physical disability, current work status, and vital status at 6 years after study enrolment. We computed Guyatt's responsiveness statistic for improvement according to the American College of Rheumatology (ACR) definition. Baseline functional performance data were available for 777 patients, and follow-up data were available for 681. Mean ± standard deviation for each RFT at baseline were: grip strength, 14 ± 10 kg; walking velocity, 194 ± 82 ft/min; and shirt button speed, 7.1 ± 3.8 buttons/min. Grip strength and walking velocity departed significantly from normality. The three RFTs loaded strongly on a single factor that explained ≥70% of their combined variance. We rescaled the factor to vary from 0 to 100. Its mean ± standard deviation was 41 ± 20, with a normal distribution. The new global scale had a stronger fit than the primary RFT to most of the criterion standards. It correlated more strongly with physical disability at follow-up and was more responsive to improvement defined according to the ACR20 and ACR50 definitions. We conclude that a performance-based physical function scale extracted from three RFTs has acceptable distributional and measurement properties and is responsive to clinically meaningful change. It provides a parsimonious scale to measure global physical function in RA. PMID:15225367

[Determination of 27 elements in Maca nationality's medicine by microwave digestion ICP-MS].

PubMed

Yu, Gui-fang; Zhong, Hai-jie; Hu, Jun-hua; Wang, Jing; Huang, Wen-zhe; Wang, Zhen-zhong; Xiao, Wei

2015-12-01

An analysis method has been established to test 27 elements (Li, Be, B, Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Sr, Mo, Cd, Sn, Sb, Ba, La, Hg, Pb, Bi) in Maca nationality's medicine with microwave digestion-ICP-MS. Sample solutions were analyzed by ICP-MS after microwave digestion, and the contents of elements were calculated according to their calibration curves, and internal standard method was adopted to reduce matrix effect and other interference effects. The experimental results showed that the linear relations of all the elements were very good; the correlation coefficient (r) was 0.9994-1.0000 (Hg was 0.9982) ; the limits of detection were 0.003-2.662 microg x L(-1); the relative standard deviations for all elements of reproducibility were lower than 5% (except the individual elements); the recovery rate were 78.5%-123.7% with RSD lower than 5% ( except the individual elements). The analytical results of standard material showed acceptable agreement with the certified values. This method was applicable to determinate the contents of multi-elements in Maca which had a high sensitivity, good specificity and good repeatability, and provide basis for the quality control of Maca.

Accurate Measurements of the Dielectric Constant of Seawater at L Band

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

On Teaching about the Coefficient of Variation in Introductory Statistics Courses

ERIC Educational Resources Information Center

Trafimow, David

2014-01-01

The standard deviation is related to the mean by virtue of the coefficient of variation. Teachers of statistics courses can make use of that fact to make the standard deviation more comprehensible for statistics students.

[Analytical performances of real-time PCR by Abbott RealTime CMV with m2000 for the detection of cytomegalovirus in urine].

PubMed

De Monte, Anne; Cannavo, Isabelle; Caramella, Anne; Ollier, Laurence; Giordanengo, Valérie

2016-01-01

Congenital cytomegalovirus (CMV) infection is the leading cause of sensoneurinal disability due to infectious congenital disease. The diagnosis of congenital CMV infection is based on the search of CMV in the urine within the first two weeks of life. Viral culture of urine is the gold standard. However, the PCR is highly sensitive and faster. It is becoming an alternative choice. The objective of this study is the validation of real-time PCR by Abbott RealTime CMV with m2000 for the detection of cytomegalovirus in urine. Repeatability, reproducibility, detection limit and inter-sample contamination were evaluated. Urine samples from patients (n=141) were collected and analyzed simultaneously in culture and PCR in order to assess the correlation of these two methods. The sensitivity and specificity of PCR were also calculated. The Abbott RealTime CMV PCR in urine is an automated and sensitive method (detection limit 200 UI/mL). Fidelity is very good (standard deviation of repeatability: 0.08 to 0.15 LogUI/mL and reproducibility 0.18 LogUI/mL). We can note a good correlation between culture and Abbott RealTime CMV PCR (kappa 96%). When considering rapid culture as reference, real-time PCR was highly sensitive (100%) and specific (98.2%). The real-time PCR by Abbott RealTime CMV with m2000 is optimal for CMV detection in urine.

Improved high-performance liquid chromatography (HPLC) method for qualitative and quantitative analysis of allantoin in Zea mays.

PubMed

Haghi, Ghasem; Arshi, Rohollah; Safaei, Alireza

2008-02-27

A high-performance liquid chromatography (HPLC) method for the qualitative and quantitative analysis of allantoin in silk and seed of Zea mays has been developed. Allantoin separation in crude extract was achieved using a C 18 column and phosphate buffer solution (pH 3.0) as a mobile phase at ambient temperature at a flow rate of 1.0 mL/min and detected at 210 nm. The results showed that the amount of allantoin in samples was between 14 and 271 mg/100 g of dry plant material. A comprehensive validation of the method including sensitivity, linearity, repeatability, and recovery was conducted. The calibration curve was linear over the range of 0.2-200 microg/mL with a correlation coefficient of r2>0.999. Limit of detection (LOD, S/N=3) and limit of quantification (LOQ) values of the allantoin were 0.05 and 0.2 microg/mL (1.0 and 4.0 ng) respectively. The relative standard deviation (RSD) value of the repeatability was reported within 1.2%. The average recovery of allantoin added to samples was 100.6% with RSD of 1.5%.

Verification of intensity modulated profiles using a pixel segmented liquid-filled linear array.

PubMed

Pardo, J; Roselló, J V; Sánchez-Doblado, F; Gómez, F

2006-06-07

A liquid isooctane (C8H18) filled ionization chamber linear array developed for radiotherapy quality assurance, consisting of 128 pixels (each of them with a 1.7 mm pitch), has been used to acquire profiles of several intensity modulated fields. The results were compared with film measurements using the gamma test. The comparisons show a very good matching, even in high gradient dose regions. The volume-averaging effect of the pixels is negligible and the spatial resolution is enough to verify these regions. However, some mismatches between the detectors have been found in regions where low-energy scattered photons significantly contribute to the total dose. These differences are not very important (in fact, the measurements of both detectors are in agreement using the gamma test with tolerances of 3% and 3 mm in most of those regions), and may be associated with the film energy dependence. In addition, the linear array repeatability (0.27% one standard deviation) is much better than the film one ( approximately 3%). The good repeatability, small pixel size and high spatial resolution make the detector ideal for the real time profile verification of high gradient beam profiles like those present in intensity modulated radiation therapy and radiosurgery.

Planar solid-phase microextraction-ion mobility spectrometry: a diethoxydiphenylsilane-based coating for the detection of explosives and explosive taggants.

PubMed

Mattarozzi, M; Bianchi, F; Bisceglie, F; Careri, M; Mangia, A; Mori, G; Gregori, A

2011-03-01

A novel diethoxydiphenylsilane-based coating for planar solid-phase microextraction was developed using sol-gel technology and used for ion mobility spectrometric detection of the explosives 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and of the explosive taggant ethylene glycol dinitrate. The trap was characterized in terms of coating thickness, morphology, inter-batch repeatability, and extraction efficiency. An average thickness of 143 ± 13 μm with a uniform distribution of the coating was obtained. Good performances of the developed procedure in terms of both intra-batch and inter-batch repeatability with relative standard deviations <7% were obtained. Experimental design and desirability function were used to find the optimal conditions for simultaneous headspace extraction of the investigated compounds: the optimal values were found in correspondence of a time and a temperature of extraction of 45 min and 40 °C, respectively. Detection and quantitation limits in low nanogram levels were achieved proving the superior extraction capability of the developed coating, obtaining ion mobility spectrometric responses at least two times higher than those achieved using commercial teflon and paper traps.

Binocular Goggle Augmented Imaging and Navigation System provides real-time fluorescence image guidance for tumor resection and sentinel lymph node mapping

PubMed Central

B. Mondal, Suman; Gao, Shengkui; Zhu, Nan; Sudlow, Gail P.; Liang, Kexian; Som, Avik; Akers, Walter J.; Fields, Ryan C.; Margenthaler, Julie; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

2015-01-01

The inability to identify microscopic tumors and assess surgical margins in real-time during oncologic surgery leads to incomplete tumor removal, increases the chances of tumor recurrence, and necessitates costly repeat surgery. To overcome these challenges, we have developed a wearable goggle augmented imaging and navigation system (GAINS) that can provide accurate intraoperative visualization of tumors and sentinel lymph nodes in real-time without disrupting normal surgical workflow. GAINS projects both near-infrared fluorescence from tumors and the natural color images of tissue onto a head-mounted display without latency. Aided by tumor-targeted contrast agents, the system detected tumors in subcutaneous and metastatic mouse models with high accuracy (sensitivity = 100%, specificity = 98% ± 5% standard deviation). Human pilot studies in breast cancer and melanoma patients using a near-infrared dye show that the GAINS detected sentinel lymph nodes with 100% sensitivity. Clinical use of the GAINS to guide tumor resection and sentinel lymph node mapping promises to improve surgical outcomes, reduce rates of repeat surgery, and improve the accuracy of cancer staging. PMID:26179014

Flavonoid detection in hydroethanolic extract of Pouteria torta (Sapotaceae) leaves by HPLC-DAD and the determination of its mutagenic activity.

PubMed

Costa, Daryne L M G; Rinaldo, Daniel; Varanda, Eliana A; de Sousa, Juliana F; Nasser, Ana L M; Silva, Ana C Z; Baldoqui, Débora C; Vilegas, Wagner; dos Santos, Lourdes Campaner

2014-10-01

It is well known that phytotherapy has grown in popularity in recent years. Because a drug cannot be administered without ensuring its effectiveness and safety, the standardization and regulation of phytotherapeutic drugs are required by the global market and governmental authorities. This article describes a simple and reliable high-performance liquid chromatography-diode array detection analysis method for the simultaneous detection of myricetin-3-O-β-D-galactopyranoside, myricetin-3-O-α-L-arabinopyranoside, and myricetin-3-O-α-L-rhaminopyranoside present in the hydroethanolic extract (ethanol/H2O, 7:3, v/v) of Pouteria torta. The mutagenic activity of the extract was evaluated on Salmonella typhimurium and by an in vivo micronucleus test on the peripheral blood cells of Swiss mice. The linearity, sensitivity, selectivity, repeatability, accuracy, and precision of the assay were evaluated. The analytical curves were linear and exhibited good repeatability (with a deviation of less than 5%) and demonstrated good recovery (within the 83-107% range). The results demonstrate that the hydroethanolic extract exhibited a mutagenic activity in both assays, suggesting caution in the use of this plant in folk medicine.

Leaner and greener analysis of cannabinoids.

PubMed

Mudge, Elizabeth M; Murch, Susan J; Brown, Paula N

2017-05-01

There is an explosion in the number of labs analyzing cannabinoids in marijuana (Cannabis sativa L., Cannabaceae) but existing methods are inefficient, require expert analysts, and use large volumes of potentially environmentally damaging solvents. The objective of this work was to develop and validate an accurate method for analyzing cannabinoids in cannabis raw materials and finished products that is more efficient and uses fewer toxic solvents. An HPLC-DAD method was developed for eight cannabinoids in cannabis flowers and oils using a statistically guided optimization plan based on the principles of green chemistry. A single-laboratory validation determined the linearity, selectivity, accuracy, repeatability, intermediate precision, limit of detection, and limit of quantitation of the method. Amounts of individual cannabinoids above the limit of quantitation in the flowers ranged from 0.02 to 14.9% w/w, with repeatability ranging from 0.78 to 10.08% relative standard deviation. The intermediate precision determined using HorRat ratios ranged from 0.3 to 2.0. The LOQs for individual cannabinoids in flowers ranged from 0.02 to 0.17% w/w. This is a significant improvement over previous methods and is suitable for a wide range of applications including regulatory compliance, clinical studies, direct patient medical services, and commercial suppliers.

Flavonoid Detection in Hydroethanolic Extract of Pouteria torta (Sapotaceae) Leaves by HPLC-DAD and the Determination of Its Mutagenic Activity

PubMed Central

Costa, Daryne L.M.G.; Rinaldo, Daniel; Varanda, Eliana A.; de Sousa, Juliana F.; Nasser, Ana L.M.; Silva, Ana C.Z.; Baldoqui, Débora C.; Vilegas, Wagner

2014-01-01

Abstract It is well known that phytotherapy has grown in popularity in recent years. Because a drug cannot be administered without ensuring its effectiveness and safety, the standardization and regulation of phytotherapeutic drugs are required by the global market and governmental authorities. This article describes a simple and reliable high-performance liquid chromatography–diode array detection analysis method for the simultaneous detection of myricetin-3-O-β-D-galactopyranoside, myricetin-3-O-α-L-arabinopyranoside, and myricetin-3-O-α-L-rhaminopyranoside present in the hydroethanolic extract (ethanol/H2O, 7:3, v/v) of Pouteria torta. The mutagenic activity of the extract was evaluated on Salmonella typhimurium and by an in vivo micronucleus test on the peripheral blood cells of Swiss mice. The linearity, sensitivity, selectivity, repeatability, accuracy, and precision of the assay were evaluated. The analytical curves were linear and exhibited good repeatability (with a deviation of less than 5%) and demonstrated good recovery (within the 83–107% range). The results demonstrate that the hydroethanolic extract exhibited a mutagenic activity in both assays, suggesting caution in the use of this plant in folk medicine. PMID:25055245

Botulinum neurotoxin type A injections for vaginismus secondary to vulvar vestibulitis syndrome.

PubMed

Bertolasi, Laura; Frasson, Emma; Cappelletti, Jee Yun; Vicentini, Silvana; Bordignon, Monia; Graziottin, Alessandra

2009-11-01

To investigate whether botulinum neurotoxin type A improves vaginismus and study its efficacy with repeated treatments. Outpatients were referred because standard cognitive-behavioral and medical treatment for vaginismus and vulvar vestibular syndrome failed. From this group, we prospectively recruited consecutive women (n=39) whose diagnostic electromyogram (EMG) recordings from the levator ani muscle showed hyperactivity at rest and reduced inhibition during straining. These women were followed for a mean (+/-standard deviation) of 105 (+/-50) weeks. Recruited patients underwent repeated cycles of botulinum neurotoxin type A injected into the levator ani under EMG guidance and EMG monitoring thereafter. At enrollment and 4 weeks after each cycle, women were asked about sexual intercourse; underwent EMG evaluation and examinations to grade vaginal resistance according to Lamont; and completed a visual analog scale (VAS) for pain, the Female Sexual Function Index Scale, a quality-of-life questionnaire (Short-Form 12 Health Survey), and bowel and bladder symptom assessment. At 4 weeks after the first botulinum neurotoxin type A cycle, the primary outcome measures (the possibility of having sexual intercourse, and levator ani EMG hyperactivity) both improved, as did the secondary outcomes, Lamont scores, VAS, Female Sexual Function Index Scales, Short-Form 12 Health Survey, and bowel-bladder symptoms. These benefits persisted through later cycles. When follow-up ended, 63.2% of the patients completely recovered from vaginismus and vulvar vestibular syndrome, 15.4% still needed reinjections (censored), and 15.4% had dropped out. Botulinum neurotoxin type A is an effective treatment option for vaginismus secondary to vulvar vestibular syndrome refractory to standard cognitive-behavioral and medical management. After patients received botulinum neurotoxin type A, their sexual activity improved and reinjections provided sustained benefits. III.

A SIMPLE METHOD FOR EVALUATING DATA FROM AN INTERLABORATORY STUDY

EPA Science Inventory

Large-scale laboratory-and method-performance studies involving more than about 30 laboratories may be evaluated by calculating the HORRAT ratio for each test sample (HORRAT=[experimentally found among-laboratories relative standard deviation] divided by [relative standard deviat...

Histogram-based quantitative evaluation of endobronchial ultrasonography images of peripheral pulmonary lesion.

PubMed

Morikawa, Kei; Kurimoto, Noriaki; Inoue, Takeo; Mineshita, Masamichi; Miyazawa, Teruomi

2015-01-01

Endobronchial ultrasonography using a guide sheath (EBUS-GS) is an increasingly common bronchoscopic technique, but currently, no methods have been established to quantitatively evaluate EBUS images of peripheral pulmonary lesions. The purpose of this study was to evaluate whether histogram data collected from EBUS-GS images can contribute to the diagnosis of lung cancer. Histogram-based analyses focusing on the brightness of EBUS images were retrospectively conducted: 60 patients (38 lung cancer; 22 inflammatory diseases), with clear EBUS images were included. For each patient, a 400-pixel region of interest was selected, typically located at a 3- to 5-mm radius from the probe, from recorded EBUS images during bronchoscopy. Histogram height, width, height/width ratio, standard deviation, kurtosis and skewness were investigated as diagnostic indicators. Median histogram height, width, height/width ratio and standard deviation were significantly different between lung cancer and benign lesions (all p < 0.01). With a cutoff value for standard deviation of 10.5, lung cancer could be diagnosed with an accuracy of 81.7%. Other characteristics investigated were inferior when compared to histogram standard deviation. Histogram standard deviation appears to be the most useful characteristic for diagnosing lung cancer using EBUS images. © 2015 S. Karger AG, Basel.

Role of the standard deviation in the estimation of benchmark doses with continuous data.

PubMed

Gaylor, David W; Slikker, William

2004-12-01

For continuous data, risk is defined here as the proportion of animals with values above a large percentile, e.g., the 99th percentile or below the 1st percentile, for the distribution of values among control animals. It is known that reducing the standard deviation of measurements through improved experimental techniques will result in less stringent (higher) doses for the lower confidence limit on the benchmark dose that is estimated to produce a specified risk of animals with abnormal levels for a biological effect. Thus, a somewhat larger (less stringent) lower confidence limit is obtained that may be used as a point of departure for low-dose risk assessment. It is shown in this article that it is important for the benchmark dose to be based primarily on the standard deviation among animals, s(a), apart from the standard deviation of measurement errors, s(m), within animals. If the benchmark dose is incorrectly based on the overall standard deviation among average values for animals, which includes measurement error variation, the benchmark dose will be overestimated and the risk will be underestimated. The bias increases as s(m) increases relative to s(a). The bias is relatively small if s(m) is less than one-third of s(a), a condition achieved in most experimental designs.

Statistical models for estimating daily streamflow in Michigan

USGS Publications Warehouse

Holtschlag, D.J.; Salehi, Habib

1992-01-01

Statistical models for estimating daily streamflow were analyzed for 25 pairs of streamflow-gaging stations in Michigan. Stations were paired by randomly choosing a station operated in 1989 at which 10 or more years of continuous flow data had been collected and at which flow is virtually unregulated; a nearby station was chosen where flow characteristics are similar. Streamflow data from the 25 randomly selected stations were used as the response variables; streamflow data at the nearby stations were used to generate a set of explanatory variables. Ordinary-least squares regression (OLSR) equations, autoregressive integrated moving-average (ARIMA) equations, and transfer function-noise (TFN) equations were developed to estimate the log transform of flow for the 25 randomly selected stations. The precision of each type of equation was evaluated on the basis of the standard deviation of the estimation errors. OLSR equations produce one set of estimation errors; ARIMA and TFN models each produce l sets of estimation errors corresponding to the forecast lead. The lead-l forecast is the estimate of flow l days ahead of the most recent streamflow used as a response variable in the estimation. In this analysis, the standard deviation of lead l ARIMA and TFN forecast errors were generally lower than the standard deviation of OLSR errors for l < 2 days and l < 9 days, respectively. Composite estimates were computed as a weighted average of forecasts based on TFN equations and backcasts (forecasts of the reverse-ordered series) based on ARIMA equations. The standard deviation of composite errors varied throughout the length of the estimation interval and generally was at maximum near the center of the interval. For comparison with OLSR errors, the mean standard deviation of composite errors were computed for intervals of length 1 to 40 days. The mean standard deviation of length-l composite errors were generally less than the standard deviation of the OLSR errors for l < 32 days. In addition, the composite estimates ensure a gradual transition between periods of estimated and measured flows. Model performance among stations of differing model error magnitudes were compared by computing ratios of the mean standard deviation of the length l composite errors to the standard deviation of OLSR errors. The mean error ratio for the set of 25 selected stations was less than 1 for intervals l < 32 days. Considering the frequency characteristics of the length of intervals of estimated record in Michigan, the effective mean error ratio for intervals < 30 days was 0.52. Thus, for intervals of estimation of 1 month or less, the error of the composite estimate is substantially lower than error of the OLSR estimate.

Repeatability of normal multifocal VEP: implications for detecting progression.

PubMed

Fortune, Brad; Demirel, Shaban; Zhang, Xian; Hood, Donald C; Johnson, Chris A

2006-04-01

To assess the repeatability of the multifocal visual evoked potential (mfVEP) and to compare it with the repeatability of standard automated perimetry (SAP) in the same group of 50 normal controls retested after 1 year. Our second aim was to assess the repeatability of false alarm rates determined previously for the mfVEP using various cluster criteria. Fifty individuals with normal vision participated in this study (33 females and 17 males). The age range was 26.7 to 77.9 years and the group average age (+/- SD) was 51.4 (+/- 12.1) years. Pattern-reversal mfVEPs were obtained using a dartboard stimulus pattern in VERIS and two 8-minute runs per eye were averaged. The average number of days between the first and second mfVEP tests was 378 (+/- 58). SAP visual fields were obtained within 17.4 (+/- 20.3) days of the mfVEP using the SITA-standard threshold algorithm. Repeatability of mfVEPs and SAP total deviation values were evaluated by calculating point-wise limits of agreement (LOA). Specificity (1-false alarm rate) was evaluated for a range of cluster criteria, whereby the number and probability level of the points defining a cluster were varied. Point-wise LOA for the mfVEP signal-to-noise ratio (SNR) ranged from 2.0 to 4.3 dB, with an average of 2.9 dB across all 60 locations. For SAP, LOA ranged from 2.4 to 8.9 dB, with an average of 4.0 dB (excluding the points immediately above and below the blind spot). Clusters of abnormal points were not likely to repeat on either mfVEP or SAP. When an mfVEP abnormality was defined as the repeat presence (confirmation) of a 3-point (P < 0.05) cluster anywhere within a single hemifield, only 1 (of 200) monocular hemifield was deemed abnormal. Although the LOA of the mfVEP were similar throughout the field, the limited dynamic range of SNR at superior field locations will limit the ability to follow progression in "depth" at those locations. Repeatability of the mfVEP was slightly better than SAP visual fields in this group of controls with a 1-year retest interval. This suggests that progression in early stages should be more easily detectable by mfVEP. However, in certain field locations (eg, superior periphery), the relatively more narrow dynamic range of the SNR of the mfVEP may limit detection of progression to just 1 event. Confirmation of a 3-point cluster abnormality is highly suggestive of a true defect on the mfVEP.

[Nuclear medicine diagnosis of pulmonary capillary protein leakage].

PubMed

Creutzig, H; Sturm, J A; Schober, O; Nerlich, M L; Kant, C J

1984-10-01

Pulmonary extravascular albumin extravasation in patients with adult respiratory distress syndrome can be quantified with radionuclide techniques. While imaging procedures with a computerized gamma camera will allow reproducible ROIs, this will be the main limitation in nonimaging measurements with small scintillation probes. Repeated positioning by one operator results in a mean spatial variation of position of about 2 cm and a variation in count rate of 25%. For the estimation of PCPL the small probes must be positioned under scintigraphic control. Under these conditions the results of both techniques are identical. The upper limit of normal was estimated to be 1 x E-5/sec. The standard deviation of abnormal measurements was about 10%. The pulmonary capillary protein leakage can be quantified by radionuclide techniques with good accuracy, using the combination of imaging and nonimaging techniques.

Quantitative determination of dimethylaminoethanol in cosmetic formulations by nuclear magnetic resonance spectroscopy.

PubMed

Batista, Ivani Aparecida Soares de Andrade; Gonçalves, Maria Inês de Almeida; Singh, Anil Kumar; Hackmann, Erika Rosa Maria Kedor; Santoro, Maria Inês Rocha Miritello

2008-01-01

A nuclear magnetic resonance (NMR) spectroscopic method was validated for the quantitative determination of dimethylaminoethanol (DMAE) in cosmetic formulations. The linearity in the range from 0.5000 to 1.5000 g (DMAE salt/mass maleic acid) presents a correlation coefficient > 0.99 for all DMAE salts. The repeatability (intraday), expressed as relative standard deviation, ranged from 1.08 to 1.44% for samples and 1.31 to 1.88% for raw materials. The detection limit and quantitation limit were 0.0017 and 0.0051 g for DMAE, 0.0018 and 0.0054 g for DMAE bitartrate, and 0.0023 and 0.0071 g for DMAE acetamidobenzoate, respectively. The proposed method is simple, precise, and accurate and can be used in the quality control of raw materials and cosmetic gels containing these compounds as active substances.

DEM generation and tidal deformation detection for sulzberger ice shelf, West Antarctica using SAR interferometry

USGS Publications Warehouse

Baek, S.; Kwoun, Oh-Ig; Bassler, M.; Lu, Z.; Shum, C.K.; Dietrich, R.

2004-01-01

In this study we generated a relative Digital Elevation Model (DEM) over the Sulzberger Ice Shelf, West Antarctica using ERS1/2 synthetic aperture radar (SAR) interferometry data. Four repeat pass differential interferograms are used to find the grounding zone and to classify the study area. An interferometrically derived DEM is compared with laser altimetry profile from ICESat. Standard deviation of the relative height difference is 5.12 m and 1.34 m in total length of the profile and at the center of the profile respectively. The magnitude and the direction of tidal changes estimated from interferogram are compared with those predicted tidal differences from four ocean tide models. Tidal deformation measured in InSAR is -16.7 cm and it agrees well within 3 cm with predicted ones from tide models.

Determination and identification of malathion, ethion and dichlorovos using ion mobility spectrometry.

PubMed

Jafari, Mohammad T

2006-07-15

Positive ion mobility spectra of different organophosphorus pesticides such as malathion (s-(1,2-dicarb-ethoxyethyl) o,o-dimethyl dithiophosphate), ethion (o,o,o',o'-tetraethyl s,s'-methylene bis(phosphorodithioate)) and dichlorovos (2,2-dichlorovinyl dimethyl phosphate) have been studied in air at ambient pressure using ion mobility spectrometry method with (63)Ni ionization source. The limits of quantification (LOQs) were 1.0 x 10(-9), 1.0 x 10(-9) and 5.0 x 10(-9)g for malathion, ethion and dichlorovos, respectively. The working range of these compounds was about three orders of magnitude and the relative standard deviation (R.S.D.) of repeatability at the 5 microg ml(-1) level were all below 15%. Furthermore, in this study, the influences of IMS cell temperature on the ion mobility spectra of these compounds were investigated.

Radiometric calibration and SNR calculation of a SWIR imaging telescope

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

Yilmaz, Ozgur; Turk, Fethi; Selimoglu, Ozgur

2012-09-06

Radiometric calibration of an imaging telescope is usually made using a uniform illumination sphere in a laboratory. In this study, we used the open-sky images taken during bright day conditions to calibrate our telescope. We found a dark signal offset value and a linear response coefficient value for each pixel by using three different algorithms. Then we applied these coefficients to the taken images, and considerably lowered the image non-uniformity. Calibration can be repeated during the operation of telescope with an object that has better uniformity than open-sky. Also SNR (Signal to Noise Ratio) of each pixel was calculated frommore » the open-sky images using the temporal mean and standard deviations. It is found that SNR is greater than 80 for all pixels even at low light levels.« less

Preliminary Results on the Use of Leather Chrome Shavings for Air Passive Sampling

PubMed Central

Sanjuán-Herráez, D.; Chabaane, L.; Tahiri, S.; Pastor, A.; de la Guardia, M.

2012-01-01

A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler−1 and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and results were compared with those obtained using empty LDPE tubes, to demonstrate the capacity of chrome shavings to adsorb VOCs. PMID:22900233

Determination of fragrances at ng/L levels using CLSA and GC/MS detection.

PubMed

Mitjans, D; Ventura, F

2005-01-01

Polycyclic and nitro musks and two fragrances (Acetyl cedrene and Amberonne) have been determined and quantified in influent and effluent waste water, river water and tap water samples from different European countries by closed loop stripping analysis (CLSA) as a method of preconcentration and GC/MS operating in the SIM mode. Limits of detection; precision expressed as repeatability and reproducibility relative standard deviations of the method; matrix effects and the estimation of the uncertainty have been evaluated. All samples contained different musks at ng/l levels being the polycyclic musks Galaxolide and Tonalide and both fragrances, Amberonne and Acetyl cedrene the most abundant. Removal of these main compounds is achieved partially in all waste water treatment plants studied. These results suggest the importance of studying and controlling the presence of these ubiquitous environmental compounds in water systems.

Method development for gypenosides fingerprint by high performance liquid chromatography with diode-array detection and the addition of internal standard.

PubMed

Liu, Fang; Ren, Dequan; Guo, De-an; Pan, Yifeng; Zhang, Huzhe; Hu, Ping

2008-03-01

In this paper, a new method for liquid chromatographic fingerprint of saponins in Gynostemma pentaphyllum (THUNB.) MAKINO was developed. The G. pentaphyllum powder was defatted by Soxhlet extraction with petroleum ether and then gypenosides were extracted from the residue with methanol by sonicating. Column chromatography with macro pore resin was then used to separate and enrich gypenosides. HPLC fingerprint analysis of gypenosides fraction was performed on a C18 column, with an isocratic elution of 34% acetonitrile for 60 min at 0.8 ml/min, sample injection volume was 20 microl and the wavelength was 203 nm. To cover the lack of standard compounds, the addition of an internal standard of ginsenoside Rb2 was employed in the gypenosides fingerprint profile. The relative retention time (RRT) and relative peak area (RPA) of the gypenosides peaks in the fingerprint were calculated by setting the ginsenoside Rb2 as the marker compound. The relative standard deviation (RSDs) of RRT of five common peaks vs. ginsenoside Rb2 in precision, repeatability and stability test were less than 1%, and the RSDs of RPA were less than 5%. The method validation data proved that the proposed method for the fingerprint with internal standard of G. pentaphyllum saponins is adequate, valid and applicable. Finally, three batches of crude drug samples collected from Shanxi province were tested by following the established method.

Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation.

PubMed

Christophe, Laure; Chabanat, Eric; Delporte, Ludovic; Revol, Patrice; Volckmann, Pierre; Jacquin-Courtois, Sophie; Rossetti, Yves

Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations.

Advanced GPS-Based Time Link Calibration with PTB’s New GPS Calibration Setup

DTIC Science & Technology

2010-11-01

the BIPM to the Ku-band TWSTFT link. A deviation of 3.7 ns compared to the 2008 result was found. INTRODUCTION UTC generation and...adjustment made earlier by the BIPM to the Ku-band TWSTFT link. A deviation of 3.7 ns compared to the 2008 result was found. 15. SUBJECT TERMS 16...Frequency Transfer ( TWSTFT ) were in operation, with signals exchanged in X-band and in Ku-band, respectively. The links were repeatedly calibrated using

10 CFR 961.4 - Deviations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Deviations. 961.4 Section 961.4 Energy DEPARTMENT OF ENERGY STANDARD CONTRACT FOR DISPOSAL OF SPENT NUCLEAR FUEL AND/OR HIGH-LEVEL RADIOACTIVE WASTE General § 961.4 Deviations. Requests for authority to deviate from this part shall be submitted in writing to...

10 CFR 961.4 - Deviations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Deviations. 961.4 Section 961.4 Energy DEPARTMENT OF ENERGY STANDARD CONTRACT FOR DISPOSAL OF SPENT NUCLEAR FUEL AND/OR HIGH-LEVEL RADIOACTIVE WASTE General § 961.4 Deviations. Requests for authority to deviate from this part shall be submitted in writing to...

10 CFR 961.4 - Deviations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Deviations. 961.4 Section 961.4 Energy DEPARTMENT OF ENERGY STANDARD CONTRACT FOR DISPOSAL OF SPENT NUCLEAR FUEL AND/OR HIGH-LEVEL RADIOACTIVE WASTE General § 961.4 Deviations. Requests for authority to deviate from this part shall be submitted in writing to...

10 CFR 961.4 - Deviations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Deviations. 961.4 Section 961.4 Energy DEPARTMENT OF ENERGY STANDARD CONTRACT FOR DISPOSAL OF SPENT NUCLEAR FUEL AND/OR HIGH-LEVEL RADIOACTIVE WASTE General § 961.4 Deviations. Requests for authority to deviate from this part shall be submitted in writing to...

10 CFR 961.4 - Deviations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Deviations. 961.4 Section 961.4 Energy DEPARTMENT OF ENERGY STANDARD CONTRACT FOR DISPOSAL OF SPENT NUCLEAR FUEL AND/OR HIGH-LEVEL RADIOACTIVE WASTE General § 961.4 Deviations. Requests for authority to deviate from this part shall be submitted in writing to...

Do health care workforce, population, and service provision significantly contribute to the total health expenditure? An econometric analysis of Serbia.

PubMed

Santric-Milicevic, M; Vasic, V; Terzic-Supic, Z

2016-08-15

In times of austerity, the availability of econometric health knowledge assists policy-makers in understanding and balancing health expenditure with health care plans within fiscal constraints. The objective of this study is to explore whether the health workforce supply of the public health care sector, population number, and utilization of inpatient care significantly contribute to total health expenditure. The dependent variable is the total health expenditure (THE) in Serbia from the years 2003 to 2011. The independent variables are the number of health workers employed in the public health care sector, population number, and inpatient care discharges per 100 population. The statistical analyses include the quadratic interpolation method, natural logarithm and differentiation, and multiple linear regression analyses. The level of significance is set at P < 0.05. The regression model captures 90 % of all variations of observed dependent variables (adjusted R square), and the model is significant (P < 0.001). Total health expenditure increased by 1.21 standard deviations, with an increase in health workforce growth rate by 1 standard deviation. Furthermore, this rate decreased by 1.12 standard deviations, with an increase in (negative) population growth rate by 1 standard deviation. Finally, the growth rate increased by 0.38 standard deviation, with an increase of the growth rate of inpatient care discharges per 100 population by 1 standard deviation (P < 0.001). Study results demonstrate that the government has been making an effort to control strongly health budget growth. Exploring causality relationships between health expenditure and health workforce is important for countries that are trying to consolidate their public health finances and achieve universal health coverage at the same time.

In vivo evaluation of the effect of stimulus distribution on FIR statistical efficiency in event-related fMRI.

PubMed

Jansma, J Martijn; de Zwart, Jacco A; van Gelderen, Peter; Duyn, Jeff H; Drevets, Wayne C; Furey, Maura L

2013-05-15

Technical developments in MRI have improved signal to noise, allowing use of analysis methods such as Finite impulse response (FIR) of rapid event related functional MRI (er-fMRI). FIR is one of the most informative analysis methods as it determines onset and full shape of the hemodynamic response function (HRF) without any a priori assumptions. FIR is however vulnerable to multicollinearity, which is directly related to the distribution of stimuli over time. Efficiency can be optimized by simplifying a design, and restricting stimuli distribution to specific sequences, while more design flexibility necessarily reduces efficiency. However, the actual effect of efficiency on fMRI results has never been tested in vivo. Thus, it is currently difficult to make an informed choice between protocol flexibility and statistical efficiency. The main goal of this study was to assign concrete fMRI signal to noise values to the abstract scale of FIR statistical efficiency. Ten subjects repeated a perception task with five random and m-sequence based protocol, with varying but, according to literature, acceptable levels of multicollinearity. Results indicated substantial differences in signal standard deviation, while the level was a function of multicollinearity. Experiment protocols varied up to 55.4% in standard deviation. Results confirm that quality of fMRI in an FIR analysis can significantly and substantially vary with statistical efficiency. Our in vivo measurements can be used to aid in making an informed decision between freedom in protocol design and statistical efficiency. Published by Elsevier B.V.

Microfabricated plastic chips by hot embossing methods and their applications for DNA separation and detection

NASA Astrophysics Data System (ADS)

Lee, Gwo-Bin; Chen, Shu-Hui; Huang, Guan-Ruey; Lin, Yen-Heng; Sung, Wang-Chou

2000-08-01

Design and fabrication of microfluidic devices on polymethylmethacrylate (PMMA) substrates using novel microfabrication methods are described. The image of microfluidic devices is transferred from quartz master templates possessing inverse image of the devices to plastic plates by using hot embossing method. The micro channels on master templates are formed by the combination of metal etch mask and wet chemical etching. The micromachined quartz templates can be used repeatedly to fabricate cheap and disposable plastic devices. The reproducibility of the hot embossing method is evaluated after using 10 channels on different plastics. The relative standard deviation of the plastic channel profile from ones on quartz templates is less than 1%. In this study, the PMMA chips have been demonstrated as a micro capillary electrophoresis ((mu) -CE) device for DNA separation and detection. The capability of the fabricated chip for electrophoretic injection and separation is characterized via the analysis of DNA fragments (phi) X174. Results indicate that all of the 11 DNA fragments of the size marker could be identified in less than 3 minutes with relative standard deviations less than 0.4% and 8% for migration time and peak area, respectively. Moreover, with the use of near IR dye, fluorescence signals of the higher molecular weight fragments ($GTR 603 bp in length) could be detected at total DNA concentrations as low as 0.1 (mu) g/mL. In addition to DNA fragments (phi) X174, DNA sizing of hepatitis C viral (HCV) amplicon is also achieved using microchip electrophoresis fabricated on PMMA substrate.

Comparison of direct, headspace and headspace cold fiber modes in solid phase microextraction of polycyclic aromatic hydrocarbons by a new coating based on poly(3,4-ethylenedioxythiophene)/graphene oxide composite.

PubMed

Banitaba, Mohammad Hossein; Hosseiny Davarani, Saied Saeed; Kazemi Movahed, Siyavash

2014-01-17

A novel nanocomposite coating made of poly(3,4-ethylenedioxythiophene) (PEDOT) and graphene oxide was electrochemically prepared on gold wire. The prepared fiber was applied to the solid-phase microextraction (SPME) and gas chromatographic analysis of six polycyclic aromatic hydrocarbons (PAHs). Three modes of extraction i.e. direct immersion (DI), headspace (HS) and headspace cold fiber (HS-CF) in SPME were investigated. The results were compared under optimized conditions of each mode, considering the effects of the three most important parameters which are extraction temperature, extraction time and ionic strength. The comparison showed that HS-CF-SPME results in the best outcome for the extraction of PAHs from water samples. Under the optimized conditions of this mode, the calibration curves were linear within the range of 0.4-600μgL(-1) and the detection limits were between 0.05 and 0.13μgL(-1). The intra-day and inter-day relative standard deviations obtained at 10μgL(-1) (n=5), using a single fiber, were 4.1-6.8% and 4.8-8.4%, respectively. The fiber-to-fiber repeatabilities (n=4), expressed as the relative standard deviations (RSD%), were between 6.5% and 10.7% at a 10μgL(-1) concentration level. The method was successfully applied to the analysis of PAHs in seawater samples showing recoveries from 85% to 107%. Copyright © 2013 Elsevier B.V. All rights reserved.

Improved ambiguity resolution for URTK with dynamic atmosphere constraints

NASA Astrophysics Data System (ADS)

Tang, Weiming; Liu, Wenjian; Zou, Xuan; Li, Zongnan; Chen, Liang; Deng, Chenlong; Shi, Chuang

2016-12-01

Raw observation processing method with prior knowledge of ionospheric delay could strengthen the ambiguity resolution (AR), but it does not make full use of the relatively longer wavelength of wide-lane (WL) observation. Furthermore, the accuracy of calculated atmospheric delays from the regional augmentation information has quite different in quality, while the atmospheric constraint used in the current methods is usually set to an empirical value. A proper constraint, which matches the accuracy of calculated atmospheric delays, can most effectively compensate the residual systematic biases caused by large inter-station distances. Therefore, the standard deviation of the residual atmospheric parameters should be fine-tuned. This paper presents an atmosphere-constrained AR method for undifferenced network RTK (URTK) rover, whose ambiguities are sequentially fixed according to their wavelengths. Furthermore, this research systematically analyzes the residual atmospheric error and finds that it mainly varies along the positional relationship between the rover and the chosen reference stations. More importantly, its ionospheric part of certain location will also be cyclically influenced every day. Therefore, the standard deviation of residual ionospheric error can be modeled by a daily repeated cosine or other functions with the help of data one day before, and applied by rovers as pseudo-observation. With the data collected at 29 stations from a continuously operating reference station network in Guangdong Province (GDCORS) in China, the efficiency of the proposed approach is confirmed by improving the success and error rates of AR for 10-20 % compared to that of the WL-L1-IF one, as well as making much better positioning accuracy.

The truly remarkable universality of half a standard deviation: confirmation through another look.

PubMed

Norman, Geoffrey R; Sloan, Jeff A; Wyrwich, Kathleen W

2004-10-01

In this issue of Expert Review of Pharmacoeconomics and Outcomes Research, Farivar, Liu, and Hays present their findings in 'Another look at the half standard deviation estimate of the minimally important difference in health-related quality of life scores (hereafter referred to as 'Another look') . These researchers have re-examined the May 2003 Medical Care article 'Interpretation of changes in health-related quality of life: the remarkable universality of half a standard deviation' (hereafter referred to as 'Remarkable') in the hope of supporting their hypothesis that the minimally important difference in health-related quality of life measures is undoubtedly closer to 0.3 standard deviations than 0.5. Nonetheless, despite their extensive wranglings with the exclusion of many articles that we included in our review; the inclusion of articles that we did not include in our review; and the recalculation of effect sizes using the absolute value of the mean differences, in our opinion, the results of the 'Another look' article confirm the same findings in the 'Remarkable' paper.

Static Scene Statistical Non-Uniformity Correction

DTIC Science & Technology

2015-03-01

Error NUC Non-Uniformity Correction RMSE Root Mean Squared Error RSD Relative Standard Deviation S3NUC Static Scene Statistical Non-Uniformity...Deviation ( RSD ) which normalizes the standard deviation, σ, to the mean estimated value, µ using the equation RS D = σ µ × 100. The RSD plot of the gain...estimates is shown in Figure 4.1(b). The RSD plot shows that after a sample size of approximately 10, the different photocount values and the inclusion

Effect of multizone refractive multifocal contact lenses on standard automated perimetry.

PubMed

Madrid-Costa, David; Ruiz-Alcocer, Javier; García-Lázaro, Santiago; Albarrán-Diego, César; Ferrer-Blasco, Teresa

2012-09-01

The aim of this study was to evaluate whether the creation of 2 foci (distance and near) provided by multizone refractive multifocal contact lenses (CLs) for presbyopia correction affects the measurements on Humphreys 24-2 Swedish interactive threshold algorithm (SITA) standard automated perimetry (SAP). In this crossover study, 30 subjects were fitted in random order with either a multifocal CL or a monofocal CL. After 1 month, a Humphrey 24-2 SITA standard strategy was performed. The visual field global indices (the mean deviation [MD] and pattern standard deviation [PSD]), reliability indices, test duration, and number of depressed points deviating at P<5%, P<2%, P<1%, and P<0.5% on pattern deviation probability plots were determined and compared between multifocal and monofocal CLs. Thirty eyes of 30 subjects were included in this study. There were no statistically significant differences in reliability indices or test duration. There was a statistically significant reduction in the MD with the multifocal CL compared with monfocal CL (P=0.001). Differences were not found in PSD nor in the number of depressed points deviating at P<5%, P<2%, P<1%, and P<0.5% in the pattern deviation probability maps studied. The results of this study suggest that the multizone refractive lens produces a generalized depression in threshold sensitivity as measured by the Humphreys 24-2 SITA SAP.

Layered double hydroxide-enhanced luminescence in a Fenton-like system for selective sensing of cobalt in Hela cells

NASA Astrophysics Data System (ADS)

Yu, Mei; Yuan, Zhiqin; Lu, Chao

2017-09-01

This work presented a facile and eco-friendly method for the determination of cobalt ions (Co(II)) in living cells based on layered double hydroxides (Mg-Al CO3-LDHs) enhanced chemiluminescence (CL) emission of a Co(II)-hydrogen peroxide-sodium hydroxide system. The enhanced CL emission was attributed to the large specific surface area of Mg-Al CO3-LDHs, which facilitates the generation of an excited-stated intermediate. The proposed method displayed high selectivity toward Co(II) over other metal ions. Under the optimal conditions, the increased CL intensity showed a linear response versus Co(II) concentration in the range of 5.0-1000 nM with a detection limit of 3.7 nM (S/N = 3). The relative standard deviation for nine repeated measurements of 100 nM Co(II) was 3.2%. Furthermore, the proposed method was successfully applied to detect Co(II) in living cell samples, and the results were agreed with those obtained by the standard ICP-MS method.

Photo-acoustic sensor for detection of oil contamination in compressed air systems.

PubMed

Lassen, Mikael; Harder, David Baslev; Brusch, Anders; Nielsen, Ole Stender; Heikens, Dita; Persijn, Stefan; Petersen, Jan C

2017-02-06

We demonstrate an online (in-situ) sensor for continuous detection of oil contamination in compressed air systems complying with the ISO-8573 standard. The sensor is based on the photo-acoustic (PA) effect. The online and real-time PA sensor system has the potential to benefit a wide range of users that require high purity compressed air. Among these are hospitals, pharmaceutical industries, electronics manufacturers, and clean room facilities. The sensor was tested for sensitivity, repeatability, robustness to molecular cross-interference, and stability of calibration. Explicit measurements of hexane (C₆H₁₄) and decane (C₁₀H₂₂) vapors via excitation of molecular C-H vibrations at approx. 2950 cm^-1 (3.38 μm) were conducted with a custom made interband cascade laser (ICL). For the decane measurements a (1 σ) standard deviation (STD) of 0.3 ppb was demonstrated, which corresponds to a normalized noise equivalent absorption (NNEA) coefficient for the prototype PA sensor of 2.8×10^-9 W cm^-1 Hz^1/2.

Apparatus for measuring Seebeck coefficient and electrical resistivity of small dimension samples using infrared microscope as temperature sensor.

PubMed

Jaafar, W M N Wan; Snyder, J E; Min, Gao

2013-05-01

An apparatus for measuring the Seebeck coefficient (α) and electrical resistivity (ρ) was designed to operate under an infrared microscope. A unique feature of this apparatus is its capability of measuring α and ρ of small-dimension (sub-millimeter) samples without the need for microfabrication. An essential part of this apparatus is a four-probe assembly that has one heated probe, which combines the hot probe technique with the Van der Pauw method for "simultaneous" measurements of the Seebeck coefficient and electrical resistivity. The repeatability of the apparatus was investigated over a temperature range of 40 °C-100 °C using a nickel plate as a standard reference. The results show that the apparatus has an uncertainty of ±4.9% for Seebeck coefficient and ±5.0% for electrical resistivity. The standard deviation of the apparatus against a nickel reference sample is -2.43 μVK(-1) (-12.5%) for the Seebeck coefficient and -0.4 μΩ cm (-4.6%) for the electrical resistivity, respectively.

Simultaneous Myocardial Strain and Dark-Blood Perfusion Imaging Using a Displacement-Encoded MRI Pulse Sequence

PubMed Central

Le, Yuan; Stein, Ashley; Berry, Colin; Kellman, Peter; Bennett, Eric E.; Taylor, Joni; Lucas, Katherine; Kopace, Rael; Chefd’Hotel, Christophe; Lorenz, Christine H.; Croisille, Pierre; Wen, Han

2010-01-01

The purpose of this study is to develop and evaluate a displacement-encoded pulse sequence for simultaneous perfusion and strain imaging. Displacement-encoded images in 2–3 myocardial slices were repeatedly acquired using a single shot pulse sequence for 3 to 4 minutes, which covers a bolus infusion of Gd. The magnitudes of the images were T1 weighted and provided quantitative measures of perfusion, while the phase maps yielded strain measurements. In an acute coronary occlusion swine protocol (n=9), segmental perfusion measurements were validated against microsphere reference standard with a linear regression (slope 0.986, R2 = 0.765, Bland-Altman standard deviation = 0.15 ml/min/g). In a group of ST-elevation myocardial infarction(STEMI) patients (n=11), the scan success rate was 76%. Short-term contrast washout rate and perfusion are highly correlated (R2=0.72), and the pixel-wise relationship between circumferential strain and perfusion was better described with a sigmoidal Hill curve than linear functions. This study demonstrates the feasibility of measuring strain and perfusion from a single set of images. PMID:20544714

Metabolomics approach of infant formula for the evaluation of contamination and degradation using hydrophilic interaction liquid chromatography coupled with mass spectrometry.

PubMed

Inoue, Koichi; Tanada, Chihiro; Sakamoto, Tasuku; Tsutsui, Haruhito; Akiba, Takashi; Min, Jun Zhe; Todoroki, Kenichiro; Yamano, Yutaka; Toyo'oka, Toshimasa

2015-08-15

In this study including the field of metabolomics approach for food, the evaluation of untargeted compounds using HILIC-ESI/TOF/MS and multivariate statistical analysis method is proposed for the assessment of classification, contamination and degradation of infant formula. HILIC mode is used to monitor more detected numbers in infant formulas in the ESI-positive scan mode than the reversed phase. The repeatability of the non-targeted contents from 4 kinds of infant formulas based on PCA was less than the relative standard deviation of 15% in all groups. The PCA pattern showed that significant differences in the classification of types and origins, the contamination of melamine and the degradations for one week were evaluated using HILIC-ESI/TOF/MS. In the S-plot from the degradation test, we could identify two markers by comparison to standards as nicotinic acid and nicotinamide. With this strategy, the differences from the untargeted compounds could be utilized for quality and safety assessment of infant formula. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modified Gas Chromatographic Method to Determine Monoacylglycerol and Diacylglycerol Contents in Edible Fats and Oils.

PubMed

Satou, Chiemi; Goto, Hirofumi; Yamazaki, Yuya; Saitou, Katsuyoshi; Matsumoto, Shoji; Takahashi, Ou; Miyazaki, Yosuke; Ikuta, Keiichi; Yajima, Yosuke

2017-06-01

Monoacylglycerol (MAG) and diacylglycerol (DAG) are minor components of edible fats and oils, and they relate to the quality of these foods. The AOCS official method Cd 11b-91 has been used to determine MAG and DAG contents in fats and oils. There are, however, difficulties in the determination of MAG and DAG using this analytical procedure. Therefore, we improved this method by modifying the trimethylsilyl derivatization procedure and replacing the internal standard (IS) material. In our modified method, TMS-HT (mixture of hexamethyldisilazane and trimethylchlorosilane) was used for derivatization of MAG and DAG, which was followed by liquid-liquid extraction with water and n-hexane solution containing the IS, tricaprin. Using the modified method, we demonstrated superior repeatability in comparison with that of the AOCS method by reducing procedural difficulties. The relative standard deviation of distearin peak areas was 1.8% or 2.9% in the modified method, while it was 5.6% in the AOCS method. In addition, capillary columns, such as DB-1ht and DB-5ht could be used in this method.

Iridium oxide pH sensor for biomedical applications. Case urea-urease in real urine samples.

PubMed

Prats-Alfonso, Elisabet; Abad, Llibertat; Casañ-Pastor, Nieves; Gonzalo-Ruiz, Javier; Baldrich, Eva

2013-01-15

This work demonstrates the implementation of iridium oxide films (IROF) grown on silicon-based thin-film platinum microelectrodes, their utilization as a pH sensor, and their successful formatting into a urea pH sensor. In this context, Pt electrodes were fabricated on Silicon by using standard photolithography and lift-off procedures and IROF thin films were growth by a dynamic oxidation electrodeposition method (AEIROF). The AEIROF pH sensor reported showed a super-Nerstian (72.9±0.9mV/pH) response between pH 3 and 11, with residual standard deviation of both repeatability and reproducibility below 5%, and resolution of 0.03 pH units. For their application as urea pH sensors, AEIROF electrodes were reversibly modified with urease-coated magnetic microparticles (MP) using a magnet. The urea pH sensor provided fast detection of urea between 78μM and 20mM in saline solution, in sample volumes of just 50μL. The applicability to urea determination in real urine samples is discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

[Determination of heavy metals for RoHS compliance by ICP-OES spectrometry coupled with microwave extraction system].

PubMed

Hua, Li; Wu, Yi-Ping; An, Bing; Lai, Xiao-Wei

2008-11-01

The harm of heavy metals contained in electronic and electrical equipment (EEE) on environment is of high concern by human. Aiming to handle the great challenge of RoHS compliance, the determinations of trace or ultratrace chromium (Cr), cadmium (Cd), mercury (Hg) and lead (Pb) by inductively coupled plasma optical emission spectrometry (ICP-OES) was performed in the present paper, wherein, microwave extraction technology was used to prepare the sample solutions. In addition, the precision, recovery, repeatability and interference issues of this method were also discussed. The results exhibited that using the microwave extraction system to prepare samples is more quick, lossless, contamination-free in comparison with the conventional extraction methods such as dry ashing, wet-oven extraction etc. By analyzing the recoveries of these four heavy metals over different working time and wavelengths, the good recovery range between 85% and 115% showed that there was only tiny loss or contamination during the process of microwave extraction, sample introduction and ICP detection. Repeatability experiments proved that ICP plasma had a good stability during the working time and the matrix effect was small. Interference was a problem troublesome for atomic absorption spectrometry (AAS), however, the techniques of standard additions or inter-element correction (IEC) method can effectively eliminated the interferences of Ni, As, Fe etc. with the Cd determination. By employing the multi-wavelengths and two correction point methods, the issues of background curve sloping shift and spectra overlap were successfully overcome. Besides, for the determinations of trace heavy metal elements, the relative standard deviation (RSD) was less than 3% and the detection limits were less than 1 microg x L(-10 (3sigma, n = 5) for samples, standard solutions, and standard additions, which proved that ICP-OES has a good precision and high reliability. This provided a reliable technique support for electronic and electrical (EE) industries to comply with RoHS directive.

Closed-form confidence intervals for functions of the normal mean and standard deviation.

PubMed

Donner, Allan; Zou, G Y

2012-08-01

Confidence interval methods for a normal mean and standard deviation are well known and simple to apply. However, the same cannot be said for important functions of these parameters. These functions include the normal distribution percentiles, the Bland-Altman limits of agreement, the coefficient of variation and Cohen's effect size. We present a simple approach to this problem by using variance estimates recovered from confidence limits computed for the mean and standard deviation separately. All resulting confidence intervals have closed forms. Simulation results demonstrate that this approach performs very well for limits of agreement, coefficients of variation and their differences.

Reliable detection of fluence anomalies in EPID-based IMRT pretreatment quality assurance using pixel intensity deviations

PubMed Central

Gordon, J. J.; Gardner, J. K.; Wang, S.; Siebers, J. V.

2012-01-01

Purpose: This work uses repeat images of intensity modulated radiation therapy (IMRT) fields to quantify fluence anomalies (i.e., delivery errors) that can be reliably detected in electronic portal images used for IMRT pretreatment quality assurance. Methods: Repeat images of 11 clinical IMRT fields are acquired on a Varian Trilogy linear accelerator at energies of 6 MV and 18 MV. Acquired images are corrected for output variations and registered to minimize the impact of linear accelerator and electronic portal imaging device (EPID) positioning deviations. Detection studies are performed in which rectangular anomalies of various sizes are inserted into the images. The performance of detection strategies based on pixel intensity deviations (PIDs) and gamma indices is evaluated using receiver operating characteristic analysis. Results: Residual differences between registered images are due to interfraction positional deviations of jaws and multileaf collimator leaves, plus imager noise. Positional deviations produce large intensity differences that degrade anomaly detection. Gradient effects are suppressed in PIDs using gradient scaling. Background noise is suppressed using median filtering. In the majority of images, PID-based detection strategies can reliably detect fluence anomalies of ≥5% in ∼1 mm2 areas and ≥2% in ∼20 mm2 areas. Conclusions: The ability to detect small dose differences (≤2%) depends strongly on the level of background noise. This in turn depends on the accuracy of image registration, the quality of the reference image, and field properties. The longer term aim of this work is to develop accurate and reliable methods of detecting IMRT delivery errors and variations. The ability to resolve small anomalies will allow the accuracy of advanced treatment techniques, such as image guided, adaptive, and arc therapies, to be quantified. PMID:22894421

Comparing biomarker measurements to a normal range: when to use standard error of the mean (SEM) or standard deviation (SD) confidence intervals tests.

PubMed

Pleil, Joachim D

2016-01-01

This commentary is the second of a series outlining one specific concept in interpreting biomarkers data. In the first, an observational method was presented for assessing the distribution of measurements before making parametric calculations. Here, the discussion revolves around the next step, the choice of using standard error of the mean or the calculated standard deviation to compare or predict measurement results.

High-Frame-Rate Doppler Ultrasound Using a Repeated Transmit Sequence

PubMed Central

Podkowa, Anthony S.; Oelze, Michael L.; Ketterling, Jeffrey A.

2018-01-01

The maximum detectable velocity of high-frame-rate color flow Doppler ultrasound is limited by the imaging frame rate when using coherent compounding techniques. Traditionally, high quality ultrasonic images are produced at a high frame rate via coherent compounding of steered plane wave reconstructions. However, this compounding operation results in an effective downsampling of the slow-time signal, thereby artificially reducing the frame rate. To alleviate this effect, a new transmit sequence is introduced where each transmit angle is repeated in succession. This transmit sequence allows for direct comparison between low resolution, pre-compounded frames at a short time interval in ways that are resistent to sidelobe motion. Use of this transmit sequence increases the maximum detectable velocity by a scale factor of the transmit sequence length. The performance of this new transmit sequence was evaluated using a rotating cylindrical phantom and compared with traditional methods using a 15-MHz linear array transducer. Axial velocity estimates were recorded for a range of ±300 mm/s and compared to the known ground truth. Using these new techniques, the root mean square error was reduced from over 400 mm/s to below 50 mm/s in the high-velocity regime compared to traditional techniques. The standard deviation of the velocity estimate in the same velocity range was reduced from 250 mm/s to 30 mm/s. This result demonstrates the viability of the repeated transmit sequence methods in detecting and quantifying high-velocity flow. PMID:29910966

Preparation of open tubular capillary columns by in situ ring-opening polymerization and their applications in cLC-MS/MS analysis of tryptic digest.

PubMed

Wang, Hongwei; Yao, Yating; Li, Ya; Ma, Shujuan; Peng, Xiaojun; Ou, Junjie; Ye, Mingliang

2017-08-01

An open tubular (OT) column (25 μm i.d.) was prepared by in situ ring-opening polymerization of octaglycidyldimethylsilyl polyhedral oligomeric silsesquioxanes (POSS-epoxy) with 4-aminophenyl disulfide (APDS) in a binary porogenic system of ethanol/H 2 O. It was found that porogenic composition played an important role in the formation of OT stationary phases. The ratio of ethanol/H 2 O at 6/1 (v/v) would lead to the fabrication of hybrid monoliths, while the ratio of ethanol/H 2 O at 13/1 (v/v) would result in the synthesis of OT phases. In addition, the effects of precursor content and reaction duration on the thickness of OT stationary phases were investigated. Either lower precursor content or shorter reaction duration would produce thinner layer of OT column. The repeatability of OT columns was evaluated through relative standard deviation (RSD%) with benzene as the analyte. The run-to-run, column-to-column and batch-to-batch repeatabilities were 1.7%, 4.8% and 5.6%, respectively, exhibiting satisfactory repeatability of the OT column. Then tryptic digest of mouse liver proteins was used to evaluate the performance of the resulting OT columns (25 μm i.d. × 2.5 m in length) by cLC-MS/MS analysis, demonstrating their potential in proteome analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Introducing the Mean Absolute Deviation "Effect" Size

ERIC Educational Resources Information Center

Gorard, Stephen

2015-01-01

This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

Effects of repeated snowboard exercise in virtual reality with time lags of visual scene behind body rotation on head stability and subjective slalom run performance in healthy young subjects.

PubMed

Wada, Yoshiro; Nishiike, Suetaka; Kitahara, Tadashi; Yamanaka, Toshiaki; Imai, Takao; Ito, Taeko; Sato, Go; Matsuda, Kazunori; Kitamura, Yoshiaki; Takeda, Noriaki

2016-11-01

After repeated snowboard exercises in the virtual reality (VR) world with increasing time lags in trials 3-8, it is suggested that the adaptation to repeated visual-vestibulosomatosensory conflict in the VR world improved dynamic posture control and motor performance in the real world without the development of motion sickness. The VR technology was used and the effects of repeated snowboard exercise examined in the VR world with time lags between visual scene and body rotation on the head stability and slalom run performance during exercise in healthy subjects. Forty-two healthy young subjects participated in the study. After trials 1 and 2 of snowboard exercise in the VR world without time lag, trials 3-8 were conducted with 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 s time lags of the visual scene that the computer creates behind board rotation, respectively. Finally, trial 9 was conducted without time lag. Head linear accelerations and subjective slalom run performance were evaluated. The standard deviations of head linear accelerations in inter-aural direction were significantly increased in trial 8, with a time lag of 0.6 s, but significantly decreased in trial 9 without a time lag, compared with those in trial 2 without a time lag. The subjective scores of slalom run performance were significantly decreased in trial 8, with a time lag of 0.6 s, but significantly increased in trial 9 without a time lag, compared with those in trial 2 without a time lag. Motion sickness was not induced in any subjects.

Accommodative amplitude using the minus lens at different near distances

PubMed Central

Momeni-Moghaddam, Hamed; Ng, Jason S; Cesana, Bruno Mario; Yekta, Abbas Ali; Sedaghat, Mohammad Reza

2017-01-01

Purpose: The purpose of this study was to compare the mean findings and the repeatability of the minus lens (ML) amplitude of accommodation (AA) at 33 cm and 40 cm. Materials and Methods: AA was measured from the dominant eye of 120 fully corrected subjects using the ML procedure when viewing the target at both 33 and 40 cm. Each measurement was repeated between 24 and 48 hours after the first trial. Results: Mean AA when tested at 33 cm and 40 cm was 10.20 diopter (D) (standard deviation [SD] =1.24) and 8.85 D (SD = 1.23), respectively (P < 0.001). The limits of agreement of the measured amplitude calculated with taking into account of the replicates at 33 and 40 cm were − 0.19 (95% confidence interval [CI]: −0.34 to −0.04) and 2.53 (95% CI: 2.38 to 2.68), respectively. The repeatability of testing at the two distances 33 and 40 cm was ± 1.24 and ± 0.99, respectively. In addition, the retest reliability of measured amplitude using the intraclass correlation coefficient was 0.87 (95% CI: 0.789–0.920) at 33 cm and 0.91 (95% CI: 0.872–0.945) at 40 cm. Conclusion: There is no agreement in the obtained amplitude at the two measurement distances. Testing the ML AA at 40 cm may be superior given that a lower repeatability coefficient was observed. However, it is unclear whether the larger amplitude measured at 33 cm reflects a larger increase in accommodation (greater proximity effect) or a decrease in the ability to perceive the first slight sustained blur. PMID:28440251

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

Pollard, J; Prajapati, S; Gao, S

Purpose: To evaluate correlation between the reproducibility of tumor position under feedback guided voluntary deep inspiration breath hold gating at simulation and at treatment. Methods: All patients treated with breath hold (BH) have 3-6 BH CTs taken at simulation (sim). In addition, if the relationship between the tumor and nearby bony anatomy on treatment BH CT(or CBCT) is found to be greater than 5 mm different at treatment than it was at sim, a repeat BH CT is taken before treatment. We retrospectively analyzed the sim CTs for 19 patients who received BH SBRT lung treatments and had repeat BHmore » CT on treatment. We evaluated the reproducibility of the tumor position during the simulation CTs and compared this to the reproducibility of the tumor position on the repeat treatment CT with our in-house CT alignment software (CT-Assisted Targeting for Radiotherapy). Results: Comparing the tumor position for multiple simulation BH CTs, we calculated: maximum difference (max) = 0.69cm; average difference (x) = 0.28cm; standard deviation (σ) = 0.18cm. Comparing the repeat BH CBCTs on treatment days we calculated: max = 0.44cm; x = 0.16cm; σ = 0.22cm. We also found that for 95% of our BH cases, the absolute variation in tumor position within the same imaging day was within 5mm of the range at the time of simulation and treatment. We found that 75% of the BH cases had less residual tumor motion on treatment days than at simulation. Conclusion: This suggests that a GTV contour based upon the residual tumor motion in multiple BH datasets plus 2 mm margin should be sufficient to cover the full range of residual tumor motion on treatment days.« less

Pharmacokinetic Profile and Tolerability of Liposomal Bupivacaine Following a Repeated Dose via Local Subcutaneous Infiltration in Healthy Volunteers.

PubMed

Rice, David; Heil, Justin W; Biernat, Lukasz

2017-03-01

Liposomal bupivacaine is indicated for administration into the surgical site to produce post-surgical analgesia. The objectives of this study were to characterize the pharmacokinetic and safety profiles of liposomal bupivacaine following a repeated dose in healthy volunteers. Healthy adults were assigned to receive liposomal bupivacaine via subcutaneous infiltration in a single 266 mg dose (cohort 1) or in two 266 mg doses, with the second dose given immediately, 24, 48, or 72 h after the first dose (cohorts 2-5). Pharmacokinetic parameters were estimated from blood samples collected up to day 14. Subjects were monitored for adverse events and assessed for neurologic function, cardiac function, and infiltration area abnormalities. Twelve subjects were assigned to each cohort. The mean ± standard deviation maximum observed plasma concentration (C max ) of bupivacaine after a single dose was 129 ± 47 ng/mL. The mean C max after the second dose was higher, but always less than double the C max for cohort 1. The highest individual C max (589 ng/mL) was observed in a subject who received the second dose 24 h after the first dose (cohort 4), but was well below the reported thresholds for neurotoxicity and cardiac toxicity (2000 and 4000 ng/mL, respectively). A single and repeated dose were well-tolerated, and there were no clinically meaningful findings regarding neurologic examinations and electrocardiography. The mean C max following a repeated dose of liposomal bupivacaine remained well below accepted values for central nervous system and cardiac toxicity. Liposomal bupivacaine was well-tolerated and revealed no clinically important safety signals. CLINICALTRIALS. NCT02210247.

Reference values for respiratory rate in the first 3 years of life.

PubMed

Rusconi, F; Castagneto, M; Gagliardi, L; Leo, G; Pellegatta, A; Porta, N; Razon, S; Braga, M

1994-09-01

Raised respiratory rate is a useful sign to diagnose lower respiratory infections in childhood. However, the normal range for respiratory rate has not been defined in a proper, large sample. To assess the respiratory rate in a large number of infants and young children in order to construct percentile curves by age; to determine the repeatability to the assessment using a stethoscope and compare it with observation. Respiratory rate was recorded for 1 minute with a stethoscope in 618 infants and children, aged 15 days to 3 years old, without respiratory infections or any other severe disease when awake and calm and when asleep. In 50 subjects we compared respiratory rate taken 30 to 60 minutes apart to assess repeatability, and in 50 others we compared simultaneous counts obtained by stethoscope versus observation. Repeatability was good as the standard deviation of differences was 2.5 breaths/minute in awake and 1.7 breaths/minute in asleep children. Respiratory rate obtained with a stethoscope was systematically higher than that obtained by observation (mean difference 2.6 breaths/minute in awake and 1.8 breaths/minute in asleep children; P = .015 and P < .001, respectively). A decrease in respiratory rate with age was seen for both states, and it was faster in the first few months of life when also a greater dispersion of values was observed. A second degree polynomial curve accurately fitted the data. Reference percentile values were developed from these data. The repeatability of respiratory rate measured with a stethoscope was good. Percentile curves would be particularly helpful in the first months of life when the decline in respiratory rate is very rapid and prevents to use cut off values for defining "normality."

Odds per Adjusted Standard Deviation: Comparing Strengths of Associations for Risk Factors Measured on Different Scales and Across Diseases and Populations

PubMed Central

Hopper, John L.

2015-01-01

How can the “strengths” of risk factors, in the sense of how well they discriminate cases from controls, be compared when they are measured on different scales such as continuous, binary, and integer? Given that risk estimates take into account other fitted and design-related factors—and that is how risk gradients are interpreted—so should the presentation of risk gradients. Therefore, for each risk factor X0, I propose using appropriate regression techniques to derive from appropriate population data the best fitting relationship between the mean of X0 and all the other covariates fitted in the model or adjusted for by design (X1, X2, … , Xn). The odds per adjusted standard deviation (OPERA) presents the risk association for X0 in terms of the change in risk per s = standard deviation of X0 adjusted for X1, X2, … , Xn, rather than the unadjusted standard deviation of X0 itself. If the increased risk is relative risk (RR)-fold over A adjusted standard deviations, then OPERA = exp[ln(RR)/A] = RRs. This unifying approach is illustrated by considering breast cancer and published risk estimates. OPERA estimates are by definition independent and can be used to compare the predictive strengths of risk factors across diseases and populations. PMID:26520360

Selection of vegetation indices for mapping the sugarcane condition around the oil and gas field of North West Java Basin, Indonesia

NASA Astrophysics Data System (ADS)

Muji Susantoro, Tri; Wikantika, Ketut; Saepuloh, Asep; Handoyo Harsolumakso, Agus

2018-05-01

Selection of vegetation indices in plant mapping is needed to provide the best information of plant conditions. The methods used in this research are the standard deviation and the linear regression. This research tried to determine the vegetation indices used for mapping the sugarcane conditions around oil and gas fields. The data used in this study is Landsat 8 OLI/TIRS. The standard deviation analysis on the 23 vegetation indices with 27 samples has resulted in the six highest standard deviations of vegetation indices, termed as GRVI, SR, NLI, SIPI, GEMI and LAI. The standard deviation values are 0.47; 0.43; 0.30; 0.17; 0.16 and 0.13. Regression correlation analysis on the 23 vegetation indices with 280 samples has resulted in the six vegetation indices, termed as NDVI, ENDVI, GDVI, VARI, LAI and SIPI. This was performed based on regression correlation with the lowest value R2 than 0,8. The combined analysis of the standard deviation and the regression correlation has obtained the five vegetation indices, termed as NDVI, ENDVI, GDVI, LAI and SIPI. The results of the analysis of both methods show that a combination of two methods needs to be done to produce a good analysis of sugarcane conditions. It has been clarified through field surveys and showed good results for the prediction of microseepages.

[Precision of digital impressions with TRIOS under simulated intraoral impression taking conditions].

PubMed

Yang, Xin; Sun, Yi-fei; Tian, Lei; Si, Wen-jie; Feng, Hai-lan; Liu, Yi-hong

2015-02-18

To evaluate the precision of digital impressions taken under simulated clinical impression taking conditions with TRIOS and to compare with the precision of extraoral digitalizations. Six #14-#17 epoxy resin dentitions with extracted #16 tooth preparations embedded were made. For each artificial dentition, (1)a silicone rubber impression was taken with individual tray, poured with type IV plaster,and digitalized with 3Shape D700 model scanner for 10 times; (2) fastened to a dental simulator, 10 digital impressions for each were taken with 3Shape TRIOS intraoral scanner. To assess the precision, best-fit algorithm and 3D comparison were conducted between repeated scan models pairwise by Geomagic Qualify 12.0, exported as averaged errors (AE) and color-coded diagrams. Non-parametric analysis was performed to compare the precisions of digital impressions and model images. The color-coded diagrams were used to show the deviations distributions. The mean of AE for digital impressions was 7.058 281 μm, which was greater than that of 4.092 363 μm for the model images (P<0.05). However, the means and medians of AE for digital impressions were no more than 10 μm, which meant that the consistency between the digital impressions was good. The deviations distribution was uniform in the model images,while nonuniform in the digital impressions with greater deviations lay mainly around the shoulders and interproximal surfaces. Digital impressions with TRIOS are of good precision and up to the clinical standard. Shoulders and interproximal surfaces scanning are more difficult.

Electro-optic analysis of the influence of target geometry on electromagnetic pulses generated by petawatt laser-matter interactions

NASA Astrophysics Data System (ADS)

Robinson, Timothy; Giltrap, Samuel; Eardley, Samuel; Consoli, Fabrizio; De Angelis, Riccardo; Ingenito, Francesco; Stuart, Nicholas; Verona, Claudio; Smith, Roland A.

2018-01-01

We present an analysis of strong laser-driven electromagnetic pulses using novel electro-optic diagnostic techniques. A range of targets were considered, including thin plastic foils (20-550 nm) and mass-limited, optically-levitated micro-targets. Results from foils indicate a dependence of EMP on target thickness, with larger peak electric fields observed with thinner targets. Spectral analysis suggests high repeatability between shots, with identified spectral features consistently detected with <1 MHz standard deviations of the peak position. This deviation is reduced for shots taken on the same day, suggesting that local conditions, such as movement of metal objects within the target chamber, are more likely to lead to minor spectral modifications, highlighting the role of the local environment in determining the details of EMP production. Levitated targets are electrically isolated from their environment, hence these targets should be unable to draw a neutralization current from the earth following ejection of hot electrons from the plasma, in contrast to predictions for pin-mounted foils in the Poyé EMP generation model. With levitated targets, no EMP was measurable above the noise threshold of any diagnostic, despite observation of protons accelerated to >30 MeV energies, suggesting the discharge current contribution to EMP is dominant.

Technical note: 3D from standard digital photography of human crania-a preliminary assessment.

PubMed

Katz, David; Friess, Martin

2014-05-01

This study assessed three-dimensional (3D) photogrammetry as a tool for capturing and quantifying human skull morphology. While virtual reconstruction with 3D surface scanning technology has become an accepted part of the paleoanthropologist's tool kit, recent advances in 3D photogrammetry make it a potential alternative to dedicated surface scanners. The principal advantages of photogrammetry are more rapid raw data collection, simplicity and portability of setup, and reduced equipment costs. We tested the precision and repeatability of 3D photogrammetry by comparing digital models of human crania reconstructed from conventional, 2D digital photographs to those generated using a 3D surface scanner. Overall, the photogrammetry and scanner meshes showed low degrees of deviation from one another. Surface area estimates derived from photogrammetry models tended to be slightly larger. Landmark configurations generally did not cluster together based upon whether the reconstruction was created with photogrammetry or surface scanning technology. Average deviations of landmark coordinates recorded on photogrammetry models were within the generally allowable range of error in osteometry. Thus, while dependent upon the needs of the particular research project, 3D photogrammetry appears to be a suitable, lower-cost alternative to 3D imaging and scanning options. Copyright © 2014 Wiley Periodicals, Inc.

Measurement of stream channel habitat using sonar

USGS Publications Warehouse

Flug, Marshall; Seitz, Heather; Scott, John

1998-01-01

An efficient and low cost technique using a sonar system was evaluated for describing channel geometry and quantifying inundated area in a large river. The boat-mounted portable sonar equipment was used to record water depths and river width measurements for direct storage on a laptop computer. The field data collected from repeated traverses at a cross-section were evaluated to determine the precision of the system and field technique. Results from validation at two different sites showed average sample standard deviations (S.D.s) of 0.12 m for these complete cross-sections, with coefficient of variations of 10%. Validation using only the mid-channel river cross-section data yields an average sample S.D. of 0.05 m, with a coefficient of variation below 5%, at a stable and gauged river site using only measurements of water depths greater than 0.6 m. Accuracy of the sonar system was evaluated by comparison to traditionally surveyed transect data from a regularly gauged site. We observed an average mean squared deviation of 46.0 cm2, considering only that portion of the cross-section inundated by more than 0.6 m of water. Our procedure proved to be a reliable, accurate, safe, quick, and economic method to record river depths, discharges, bed conditions, and substratum composition necessary for stream habitat studies.

Collinearity in Least-Squares Analysis

ERIC Educational Resources Information Center

de Levie, Robert

2012-01-01

How useful are the standard deviations per se, and how reliable are results derived from several least-squares coefficients and their associated standard deviations? When the output parameters obtained from a least-squares analysis are mutually independent, as is often assumed, they are reliable estimators of imprecision and so are the functions…

Robust Confidence Interval for a Ratio of Standard Deviations

ERIC Educational Resources Information Center

Bonett, Douglas G.

2006-01-01

Comparing variability of test scores across alternate forms, test conditions, or subpopulations is a fundamental problem in psychometrics. A confidence interval for a ratio of standard deviations is proposed that performs as well as the classic method with normal distributions and performs dramatically better with nonnormal distributions. A simple…

Standard Deviation for Small Samples

ERIC Educational Resources Information Center

Joarder, Anwar H.; Latif, Raja M.

2006-01-01

Neater representations for variance are given for small sample sizes, especially for 3 and 4. With these representations, variance can be calculated without a calculator if sample sizes are small and observations are integers, and an upper bound for the standard deviation is immediate. Accessible proofs of lower and upper bounds are presented for…

Estimating maize water stress by standard deviation of canopy temperature in thermal imagery

USDA-ARS?s Scientific Manuscript database

A new crop water stress index using standard deviation of canopy temperature as an input was developed to monitor crop water status. In this study, thermal imagery was taken from maize under various levels of deficit irrigation treatments in different crop growing stages. The Expectation-Maximizatio...

Experiments with central-limit properties of spatial samples from locally covariant random fields

USGS Publications Warehouse

Barringer, T.H.; Smith, T.E.

1992-01-01

When spatial samples are statistically dependent, the classical estimator of sample-mean standard deviation is well known to be inconsistent. For locally dependent samples, however, consistent estimators of sample-mean standard deviation can be constructed. The present paper investigates the sampling properties of one such estimator, designated as the tau estimator of sample-mean standard deviation. In particular, the asymptotic normality properties of standardized sample means based on tau estimators are studied in terms of computer experiments with simulated sample-mean distributions. The effects of both sample size and dependency levels among samples are examined for various value of tau (denoting the size of the spatial kernel for the estimator). The results suggest that even for small degrees of spatial dependency, the tau estimator exhibits significantly stronger normality properties than does the classical estimator of standardized sample means. ?? 1992.

YALE NATURAL RADIOCARBON MEASUREMENTS. PART VI

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

Stuiver, M.; Deevey, E.S.

1961-01-01

Most of the measurements made since publication of Yale V are included; some measurements, such as a series collected in Greenland, are withneld pending additional information or field work that will make better interpretations possible. In addition to radiocarbon dates of geologic and/or archaeologic interest, recent assays are given of C/sup 14/ in lake waters and other lacustrine materials, now normalized for C/sup 13/ content. The newly accepted convention is followed in expressing normalized C/sup 14/ values as DELTA = delta C/sup 14/ (2 delta C/sup 13/ + 50)STAl + ( delta C/sup 14//1000)! where DELTA is the per milmore » deviation of the C/sup 14/ if the sample from any contemporary standard (whether organic or a carbonate) after correction of sample and/or standard for real age, for the Suess effect, for normal isotopic fractionation, and for deviations of C/sup 14/ content of the age- and pollution- corrected l9th-century wood standard from that of 95% of the NBS oxalic acid standard; delta C/sup 14/ is the measured deviation from 95% of the NBS standard, and delta C/sup 13/ is the deviation from the NBS limestone standard, both in per mil. These assays are variously affected by artificial C/sup 14/ resulting from nuclear tests. (auth)« less

Inverse correlation between the standard deviation of R-R intervals in supine position and the simplified menopausal index in women with climacteric symptoms.

PubMed

Yanagihara, Nobuyuki; Seki, Meikan; Nakano, Masahiro; Hachisuga, Toru; Goto, Yukio

2014-06-01

Disturbance of autonomic nervous activity has been thought to play a role in the climacteric symptoms of postmenopausal women. This study was therefore designed to investigate the relationship between autonomic nervous activity and climacteric symptoms in postmenopausal Japanese women. The autonomic nervous activity of 40 Japanese women with climacteric symptoms and 40 Japanese women without climacteric symptoms was measured by power spectral analysis of heart rate variability using a standard hexagonal radar chart. The scores for climacteric symptoms were determined using the simplified menopausal index. Sympathetic excitability and irritability, as well as the standard deviation of mean R-R intervals in supine position, were significantly (P < 0.01, 0.05, and 0.001, respectively) decreased in women with climacteric symptoms. There was a negative correlation between the standard deviation of mean R-R intervals in supine position and the simplified menopausal index score. The lack of control for potential confounding variables was a limitation of this study. In climacteric women, the standard deviation of mean R-R intervals in supine position is negatively correlated with the simplified menopausal index score.

Improvement of the repeatability of parallel transmission at 7T using interleaved acquisition in the calibration scan.

PubMed

Kameda, Hiroyuki; Kudo, Kohsuke; Matsuda, Tsuyoshi; Harada, Taisuke; Iwadate, Yuji; Uwano, Ikuko; Yamashita, Fumio; Yoshioka, Kunihiro; Sasaki, Makoto; Shirato, Hiroki

2017-12-04

Respiration-induced phase shift affects B 0 /B 1 + mapping repeatability in parallel transmission (pTx) calibration for 7T brain MRI, but is improved by breath-holding (BH). However, BH cannot be applied during long scans. To examine whether interleaved acquisition during calibration scanning could improve pTx repeatability and image homogeneity. Prospective. Nine healthy subjects. 7T MRI with a two-channel RF transmission system was used. Calibration scanning for B 0 /B 1 + mapping was performed under sequential acquisition/free-breathing (Seq-FB), Seq-BH, and interleaved acquisition/FB (Int-FB) conditions. The B 0 map was calculated with two echo times, and the B 1 + map was obtained using the Bloch-Siegert method. Actual flip-angle imaging (AFI) and gradient echo (GRE) imaging were performed using pTx and quadrature-Tx (qTx). All scans were acquired in five sessions. Repeatability was evaluated using intersession standard deviation (SD) or coefficient of variance (CV), and in-plane homogeneity was evaluated using in-plane CV. A paired t-test with Bonferroni correction for multiple comparisons was used. The intersession CV/SDs for the B 0 /B 1 + maps were significantly smaller in Int-FB than in Seq-FB (Bonferroni-corrected P < 0.05 for all). The intersession CVs for the AFI and GRE images were also significantly smaller in Int-FB, Seq-BH, and qTx than in Seq-FB (Bonferroni-corrected P < 0.05 for all). The in-plane CVs for the AFI and GRE images in Seq-FB, Int-FB, and Seq-BH were significantly smaller than in qTx (Bonferroni-corrected P < 0.01 for all). Using interleaved acquisition during calibration scans of pTx for 7T brain MRI improved the repeatability of B 0 /B 1 + mapping, AFI, and GRE images, without BH. 1 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

Repeated onabotulinumtoxin-a injections provide better results than single injection in treatment of painful bladder syndrome.

PubMed

Kuo, Hann-Chorng

2013-01-01

Onabotulinumtoxin-A (BoNT-A) is effective for the treatment of interstitial cystitis/painful bladder syndrome (IC/PBS). However, long-term follow-up does not show successful outcome after a single injection. To evaluate the efficacy and safety of repeated intravesical BoNT-A injections for treatment of IC/PBS and compare the success rates among patient groups receiving different injection numbers. Prospective interventional study. Tertiary medical center. Intravesical injection of 100 U of BoNT-A was performed in 81 patients every 6 months for up to 4 times or until patients' symptoms significantly improved. Patients who received a single injection served as active controls. Measured parameters included O'Leary-Sant symptom indexes (ICSI) and problem indexes (ICPI), visual analogue score (VAS) for pain, voiding diary variables, urodynamic parameters, maximal bladder capacity under anesthesia, glomerulation grade, and global response assessment. Multiple measurements and Kaplan-Meier analysis were used for comparison of consecutive data and success rates among groups. Among 81 patients, 20 received single injections, 19 received 2 injections, 12 received 3 injections, and 30 received 4 injections. The mean (± standard deviation) of ICSI, ICPI, total scores, VAS, functional bladder capacity, and daytime frequency all showed significant improvement after repeated BoNT-A treatment with different injections. Significantly better success rates were noted in patients who received 4 repeated injections (P = 0.0242) and 3 injections (P = 0.050), compared to those who received a single injection. However, there was no significant difference of long-term success rates among patients who received 2, 3, and 4 injections. Lack of placebo control group is the main limitation. Repeated intravesical BoNT-A injections were safe and effective for pain relief and they increased bladder capacity and provided a better long-term success rate than a single injection did for treatment of IC/PBS.

Repeated measurements of NT-pro-B-type natriuretic peptide, troponin T or C-reactive protein do not predict future allograft rejection in heart transplant recipients.

PubMed

Battes, Linda C; Caliskan, Kadir; Rizopoulos, Dimitris; Constantinescu, Alina A; Robertus, Jan L; Akkerhuis, Martijn; Manintveld, Olivier C; Boersma, Eric; Kardys, Isabella

2015-03-01

Studies on the prognostic value of serial biomarker assays for future occurrence of allograft rejection (AR) are scarce. We examined whether repeated measurements of NT-pro-B-type natriuretic peptide (NT-proBNP), troponin T (TropT) and C-reactive protein (CRP) predict AR. From 2005 to 2010, 77 consecutive heart transplantation (HTx) recipients were included. The NT-proBNP, TropT, and CRP were measured at 16 ± 4 (mean ± standard deviation) consecutive routine endomyocardial biopsy surveillance visits during the first year of follow-up. Allograft rejection was defined as International Society for Heart and Lung Transplantation (ISHLT) grade 2R or higher at endomyocardial biopsy. Joint modeling was used to assess the association between repeated biomarker measurements and occurrence of future AR. Joint modeling accounts for dependence among repeated observations in individual patients. The mean age of the patients at HTx was 49 ± 9.2 years, and 68% were men. During the first year of follow-up, 1,136 biopsies and concurrent blood samples were obtained, and 56 patients (73%) experienced at least one episode of AR. All biomarkers were elevated directly after HTx and achieved steady-state after ∼ 12 weeks, both in patients with or without AR. No associations were present between the repeated measurements of NT-proBNP, TropT, or CRP and AR both early (weeks 0-12) and late (weeks 13-52) in the course after HTx (hazard ratios for weeks 13-52: 0.96 (95% confidence interval, 0.55-1.68), 0.67 (0.27-1.69), and 1.44 (0.90-2.30), respectively, per ln[unit]). Combining the three biomarkers in one model also rendered null results. The temporal evolution of NT-proBNP, TropT, and CRP before AR did not predict occurrence of acute AR both in the early and late course of the first year after HTx.

Oxygen-weighted Hyperpolarized 3He MR Imaging: A Short-term Reproducibility Study in Human Subjects

PubMed Central

Ishii, Masaru; Hamedani, Hooman; Clapp, Justin T.; Kadlecek, Stephen J.; Xin, Yi; Gefter, Warren B.; Rossman, Milton D.

2015-01-01

Purpose To determine whether hyperpolarized helium 3 magnetic resonance (MR) imaging to measure alveolar partial pressure of oxygen (Pao2) shows sufficient test-retest repeatability and between-cohort differences to be used as a reliable technique for detection of alterations in gas exchange in asymptomatic smokers. Materials and Methods The protocol was approved by the local institutional review board and was HIPAA compliant. Informed consent was obtained from all subjects. Two sets of MR images were obtained 10 minutes apart in 25 subjects: 10 nonsmokers (five men, five women; mean ± standard deviation age, 50 years ± 6) and 15 smokers (seven women, eight men; mean age, 50 years ± 8). A mixed-effects model was developed to identify the regional repeatability of Pao2 measurements as an intraclass correlation coefficient. Ten smokers were matched with the 10 nonsmokers on the basis of signal-to-noise ratio (SNR). Three separate models were generated: one for nonsmokers, one for the SNR-matched smokers, and one for the five remaining smokers, who were imaged with a significantly higher SNR. Results Short-term back-to-back regional reproducibility was assessed by using intraclass correlation coefficients, which were 0.67 and 0.65 for SNR case-matched nonsmokers and smokers, respectively. Repeatability was a strong function of SNR; a 50% increase in SNR in the remaining smokers improved the intraclass correlation coefficient to 0.82. Although repeatability was not significantly different between the SNR-matched cohorts (P = .44), the smoker group showed higher spatial and temporal variability in Pao2. Conclusion The short-term test-retest repeatability of hyperpolarized gas MR imaging of regional Pao2 was good. Asymptomatic smokers exhibited greater spatial and temporal variability in Pao2 than did the nonsmokers, which suggests that this parameter allows detection of small functional alterations associated with smoking. © RSNA, 2015 Online supplemental material is available for this article. PMID:26110668

Determination of oleamide and erucamide in polyethylene films by pressurised fluid extraction and gas chromatography.

PubMed

Garrido-López, Alvaro; Esquiu, Vanesa; Tena, María Teresa

2006-08-18

A pressurized fluid extraction (PFE) and gas chromatography-flame ionization detection (GC-FID) method is proposed to determine the slip agents in polyethylene (PE) films. The study of PFE variables was performed using a fractional factorial design (FFD) for screening and a central composite design (CCD) for optimizing the main variables obtained from the Pareto charts. The variables that were studied include temperature, static time, percentage of cyclohexane and the number of extraction cycles. The final condition selected was pure isopropanol (two times) at 105 degrees C for 16min. The recovery of spiked oleamide and erucamide was around 100%. The repeatability of the method was between 9.6% for oleamide and 8% for erucamide, expressed as relative standard deviation. Finally, the method was applied to determine oleamide and erucamide in several polyethylene films and the results were statistically equal to those obtained by pyrolysis and gas-phase chemiluminescence (CL).

Hybrid approach of selecting hyperparameters of support vector machine for regression.

PubMed

Jeng, Jin-Tsong

2006-06-01

To select the hyperparameters of the support vector machine for regression (SVR), a hybrid approach is proposed to determine the kernel parameter of the Gaussian kernel function and the epsilon value of Vapnik's epsilon-insensitive loss function. The proposed hybrid approach includes a competitive agglomeration (CA) clustering algorithm and a repeated SVR (RSVR) approach. Since the CA clustering algorithm is used to find the nearly "optimal" number of clusters and the centers of clusters in the clustering process, the CA clustering algorithm is applied to select the Gaussian kernel parameter. Additionally, an RSVR approach that relies on the standard deviation of a training error is proposed to obtain an epsilon in the loss function. Finally, two functions, one real data set (i.e., a time series of quarterly unemployment rate for West Germany) and an identification of nonlinear plant are used to verify the usefulness of the hybrid approach.

Determination of isocyanate groups in the organic intermediates by reaction-based headspace gas chromatography.

PubMed

Xie, Wei-Qi; Chai, Xin-Sheng

2016-10-14

This work reports on a novel method for the determination of isocyanate groups in the related organic intermediates by a reaction-based headspace gas chromatography. The method is based on measuring the CO 2 formed from the reaction between the isocyanate groups in the organic intermediates and water in a closed headspace sample vial at 45°C for 20min. The results showed that the method has a good precision and accuracy, in which the relative standard deviation in the repeatability measurement was 5.26%, and the relative differences between the data obtained by the HS-GC method and the reference back-titration method were within 9.42%. The present method is simple and efficient and is particularly suitable to be used for determining the isocyanate groups in the batch sample analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Evidence for Coincident Fusion Products Using Silicon Surface-barrier Detectors

NASA Astrophysics Data System (ADS)

Jones, Steven; Scott, Mark; Keeney, Frank

2002-10-01

We report experimental results showing coincident proton and triton production from the reaction: d + d --> t (1.01 MeV) + p (3.02 MeV). Partially-deuterided thin titanium foils were positioned between two silicon surface-barrier detectors which were mounted in a small cylindrical vacuum chamber which also served as a Faraday cage. We performed Monte Carlo studies using the SRIM code to determine the expected energies of arriving particles after they exit the host foil. The dual-coincidence requirement reduces background to very low levels so that low yields from very thin TiD foils can be readily detected. In one sequence of experiments, we observed 74 foreground coincidences in the regions of interest compared with 24 background counts; the statistical significance is approximately ten standard deviations. A striking advance is that the repeatability from the dual-coincidence experiments is currently greater than 70%.

Development and characterization of a FIA system for selective assay of L-ascorbic acid in food samples.

PubMed

Vig, Attila; Igloi, Attila; Adanyi, Nora; Gyemant, Gyongyi; Csutoras, Csaba; Kiss, Attila

2010-10-01

An amperometric detector and an enzymatic reaction were combined for the measurement of L-ascorbic acid. The enzyme cell (containing immobilized ascorbate oxidase) was connected to a flow injection analyzer (FIA) system with a glassy carbon electrode as an amperometric detector. During optimization and measurements two sample injectors were used, one before and one after the enzyme cell, thus eliminating the background interferences. Subtraction of the signal area given in the presence of enzyme from the one given in the absence of enzyme was applied for measuring analyte concentrations and calibration at 400 mV. Analysis capacity of system is 25 samples/hour. The relative standard deviation (RSD) was below 5% (5 times repeated, 400 μmol/L conc.), linearity up to 400 μmol/L, limit of detection (LOD) 5 μmol/L, fitting of calibration curve in 25-400 μmol/L range was R (2) = 0.99.

Neglect assessment as an application of virtual reality.

PubMed

Broeren, J; Samuelsson, H; Stibrant-Sunnerhagen, K; Blomstrand, C; Rydmark, M

2007-09-01

In this study a cancellation task in a virtual environment was applied to describe the pattern of search and the kinematics of hand movements in eight patients with right hemisphere stroke. Four of these patients had visual neglect and four had recovered clinically from initial symptoms of neglect. The performance of the patients was compared with that of a control group consisting of eight subjects with no history of neurological deficits. Patients with neglect as well as patients clinically recovered from neglect showed aberrant search performance in the virtual reality (VR) task, such as mixed search pattern, repeated target pressures and deviating hand movements. The results indicate that in patients with a right hemispheric stroke, this VR application can provide an additional tool for assessment that can identify small variations otherwise not detectable with standard paper-and-pencil tests. VR technology seems to be well suited for the assessment of visually guided manual exploration in space.

Optimization of β-cyclodextrin cross-linked polymer for monitoring of quercetin

NASA Astrophysics Data System (ADS)

Zhu, Xiashi; Ping, Wenhui

2014-11-01

A novel method for the separation/analysis of quercetin was described, which was based on the investigation of the inclusion interactions of β-cyclodextrin cross-linked polymer (β-CDCP) with quercetin (Qu) and the adsorption behavior of Qu on β-CDCP. The inclusion interaction of β-CDCP with Qu was studied through FTIR, TGA and 13C NMR. Under the optimum conditions, the preconcentration factor of the proposed method was approximately 8.8, the β-CDCP could be used repeatedly for 30 times and offered better recovery. The linear range, limit of detection (LOD) and the relative standard deviation (RSD) was found to be 0.10-12.0 μg mL-1, 4.6 ng mL-1 and 3.10% (n = 3, c = 2.0 μg mL-1) respectively. This technique had been successfully applied to the determination of Qu in real samples.

It's time to move on from the bell curve.

PubMed

Robinson, Lawrence R

2017-11-01

The bell curve was first described in the 18th century by de Moivre and Gauss to depict the distribution of binomial events, such as coin tossing, or repeated measures of physical objects. In the 19th and 20th centuries, the bell curve was appropriated, or perhaps misappropriated, to apply to biologic and social measures across people. For many years we used it to derive reference values for our electrophysiologic studies. There is, however, no reason to believe that electrophysiologic measures should approximate a bell-curve distribution, and empiric evidence suggests they do not. The concept of using mean ± 2 standard deviations should be abandoned. Reference values are best derived by using non-parametric analyses, such as percentile values. This proposal aligns with the recommendation of the recent normative data task force of the American Association of Neuromuscular & Electrodiagnostic Medicine and follows sound statistical principles. Muscle Nerve 56: 859-860, 2017. © 2017 Wiley Periodicals, Inc.

Three different spectrophotometric methods manipulating ratio spectra for determination of binary mixture of Amlodipine and Atorvastatin

NASA Astrophysics Data System (ADS)

Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeiny, Badr A.

2011-12-01

Three simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra are developed for the simultaneous determination of Amlodipine besylate (AM) and Atorvastatin calcium (AT) in tablet dosage forms. The first method is first derivative of the ratio spectra ( 1DD), the second is ratio subtraction and the third is the method of mean centering of ratio spectra. The calibration curve is linear over the concentration range of 3-40 and 8-32 μg/ml for AM and AT, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and they are applied to commercial pharmaceutical preparation of the subjected drugs. Standard deviation is <1.5 in the assay of raw materials and tablets. Methods are validated as per ICH guidelines and accuracy, precision, repeatability and robustness are found to be within the acceptable limit.

Biosensor based on tyrosinase immobilized on a single-walled carbon nanotube-modified glassy carbon electrode for detection of epinephrine

PubMed Central

Apetrei, Irina Mirela; Apetrei, Constantin

2013-01-01

A biosensor comprising tyrosinase immobilized on a single-walled carbon nanotube-modified glassy carbon electrode has been developed. The sensitive element, ie, tyrosinase, was immobilized using a drop-and-dry method followed by cross-linking. Tyrosinase maintained high bioactivity on this nanomaterial, catalyzing the oxidation of epinephrine to epinephrine-quinone, which was electrochemically reduced (−0.07 V versus Ag/AgCl) on the biosensor surface. Under optimum conditions, the biosensor showed a linear response in the range of 10–110 μM. The limit of detection was calculated to be 2.54 μM with a correlation coefficient of 0.977. The repeatability, expressed as the relative standard deviation for five consecutive determinations of 10−5 M epinephrine solution was 3.4%. A good correlation was obtained between results obtained by the biosensor and those obtained by ultraviolet spectrophotometric methods. PMID:24348034

Spatial generalised linear mixed models based on distances.

PubMed

Melo, Oscar O; Mateu, Jorge; Melo, Carlos E

2016-10-01

Risk models derived from environmental data have been widely shown to be effective in delineating geographical areas of risk because they are intuitively easy to understand. We present a new method based on distances, which allows the modelling of continuous and non-continuous random variables through distance-based spatial generalised linear mixed models. The parameters are estimated using Markov chain Monte Carlo maximum likelihood, which is a feasible and a useful technique. The proposed method depends on a detrending step built from continuous or categorical explanatory variables, or a mixture among them, by using an appropriate Euclidean distance. The method is illustrated through the analysis of the variation in the prevalence of Loa loa among a sample of village residents in Cameroon, where the explanatory variables included elevation, together with maximum normalised-difference vegetation index and the standard deviation of normalised-difference vegetation index calculated from repeated satellite scans over time. © The Author(s) 2013.

[Determination of Butroxydim in Agricultural Products by LC-MS].

PubMed

Minatani, Tomiaki; Nagai, Hiroyuki; Tada, Hiroyuki; Goto, Kotaro; Nemoto, Satoru

2015-01-01

An analytical method for the determination of butroxydim in agricultural products by LC-MS was developed. Butroxydim was extracted with acetonitrile and an aliquot of the crude extract was cleaned up on an octadecyl silanized silica gel (C18) cartridge column (1,000 mg), followed by a salting-out step to remove water. Before purification on a silica gel (SI) cartridge column (690 mg), polar matrices were precipitated by adding ethyl acetate, n-hexane and anhydrous sodium sulfate successively. This process effectively removed caffeine and catechins and improved recovery when analyzing residual butroxydim in tea leaves. Recovery and repeatability were good; the relative standard deviations were less than 5% for all 12 tested agricultural products (brown rice, soybean, potato, spinach, cabbage, apple, orange, grapefruit, lemon, tomato, peas with pods, and tea). Average recoveries for 11 agricultural products, except for lemon, were 74-92%.

Determination of anionic surface active agents using silica coated magnetite nanoparticles modified with cationic surfactant aggregates.

PubMed

Pena-Pereira, Francisco; Duarte, Regina M B O; Trindade, Tito; Duarte, Armando C

2013-07-19

The development of a novel methodology for extraction and preconcentration of the most commonly used anionic surface active agents (SAAs), linear alkylbenzene sulfonates (LAS), is presented herein. The present method, based on the use of silica-magnetite nanoparticles modified with cationic surfactant aggregates, was developed for determination of C10-C13 LAS homologues. The proposed methodology allowed quantitative recoveries of C10-C13 LAS homologues by using a reduced amount of magnetic nanoparticles. Limits of detection were in the range 0.8-1.9μgL(-1) for C10-C13 LAS homologues, while the repeatability, expressed as relative standard deviation (RSD), ranged from 2.0 to 3.9% (N=6). Finally, the proposed method was successfully applied to the analysis of a variety of natural water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Determination of Small Animal Long Bone Properties Using Densitometry

NASA Technical Reports Server (NTRS)

Breit, Gregory A.; Goldberg, BethAnn K.; Whalen, Robert T.; Hargens, Alan R. (Technical Monitor)

1996-01-01

Assessment of bone structural property changes due to loading regimens or pharmacological treatment typically requires destructive mechanical testing and sectioning. Our group has accurately and non-destructively estimated three dimensional cross-sectional areal properties (principal moments of inertia, Imax and Imin, and principal angle, Theta) of human cadaver long bones from pixel-by-pixel analysis of three non-coplanar densitometry scans. Because the scanner beam width is on the order of typical small animal diapbyseal diameters, applying this technique to high-resolution scans of rat long bones necessitates additional processing to minimize errors induced by beam smearing, such as dependence on sample orientation and overestimation of Imax and Imin. We hypothesized that these errors are correctable by digital image processing of the raw scan data. In all cases, four scans, using only the low energy data (Hologic QDR-1000W, small animal mode), are averaged to increase image signal-to-noise ratio. Raw scans are additionally processed by interpolation, deconvolution by a filter derived from scanner beam characteristics, and masking using a variable threshold based on image dynamic range. To assess accuracy, we scanned an aluminum step phantom at 12 orientations over a range of 180 deg about the longitudinal axis, in 15 deg increments. The phantom dimensions (2.5, 3.1, 3.8 mm x 4.4 mm; Imin/Imax: 0.33-0.74) were comparable to the dimensions of a rat femur which was also scanned. Cross-sectional properties were determined at 0.25 mm increments along the length of the phantom and femur. The table shows average error (+/- SD) from theory of Imax, Imin, and Theta) over the 12 orientations, calculated from raw and fully processed phantom images, as well as standard deviations about the mean for the femur scans. Processing of phantom scans increased agreement with theory, indicating improved accuracy. Smaller standard deviations with processing indicate increased precision and repeatability. Standard deviations for the femur are consistent with those of the phantom. We conclude that in conjunction with digital image enhancement, densitometry scans are suitable for non-destructive determination of areal properties of small animal bones of comparable size to our phantom, allowing prediction of Imax and Imin within 2.5% and Theta within a fraction of a degree. This method represents a considerable extension of current methods of analyzing bone tissue distribution in small animal bones.

Feature selection for elderly faller classification based on wearable sensors.

PubMed

Howcroft, Jennifer; Kofman, Jonathan; Lemaire, Edward D

2017-05-30

Wearable sensors can be used to derive numerous gait pattern features for elderly fall risk and faller classification; however, an appropriate feature set is required to avoid high computational costs and the inclusion of irrelevant features. The objectives of this study were to identify and evaluate smaller feature sets for faller classification from large feature sets derived from wearable accelerometer and pressure-sensing insole gait data. A convenience sample of 100 older adults (75.5 ± 6.7 years; 76 non-fallers, 24 fallers based on 6 month retrospective fall occurrence) walked 7.62 m while wearing pressure-sensing insoles and tri-axial accelerometers at the head, pelvis, left and right shanks. Feature selection was performed using correlation-based feature selection (CFS), fast correlation based filter (FCBF), and Relief-F algorithms. Faller classification was performed using multi-layer perceptron neural network, naïve Bayesian, and support vector machine classifiers, with 75:25 single stratified holdout and repeated random sampling. The best performing model was a support vector machine with 78% accuracy, 26% sensitivity, 95% specificity, 0.36 F1 score, and 0.31 MCC and one posterior pelvis accelerometer input feature (left acceleration standard deviation). The second best model achieved better sensitivity (44%) and used a support vector machine with 74% accuracy, 83% specificity, 0.44 F1 score, and 0.29 MCC. This model had ten input features: maximum, mean and standard deviation posterior acceleration; maximum, mean and standard deviation anterior acceleration; mean superior acceleration; and three impulse features. The best multi-sensor model sensitivity (56%) was achieved using posterior pelvis and both shank accelerometers and a naïve Bayesian classifier. The best single-sensor model sensitivity (41%) was achieved using the posterior pelvis accelerometer and a naïve Bayesian classifier. Feature selection provided models with smaller feature sets and improved faller classification compared to faller classification without feature selection. CFS and FCBF provided the best feature subset (one posterior pelvis accelerometer feature) for faller classification. However, better sensitivity was achieved by the second best model based on a Relief-F feature subset with three pressure-sensing insole features and seven head accelerometer features. Feature selection should be considered as an important step in faller classification using wearable sensors.

WE-FG-207B-08: Dual-Energy CT Iodine Accuracy Across Vendors and Platforms

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

Jacobsen, M; Wood, C; Cody, D

Purpose: Although a major benefit of dual-energy CT is its quantitative capabilities, it is critical to understand how results vary by scanner manufacturer and/or model before making clinical patient management decisions. Each manufacturer utilizes a specific dual-energy CT approach; cross-calibration may be required for facilities with more than one dual-energy CT scanner type. Methods: A solid dual-energy quality control phantom (Gammex, Inc.; Appleton, WI) representing a large body cross-section containing three Iodine inserts (2mg/ml, 5mg/ml, 15 mg/ml) was scanned on these CT systems: GE HD-750 (80/140kVp), prototype GE Revolution CT with GSI (80/140kVp), Siemens Flash (80/140kVp and 100/140kVp), and Philipsmore » IQon (120kVp and 140kVp). Iodine content was measured in units of concentration (mg/ml) from a single 5mm-thick central image. Three to five acquisitions were performed on each scanner platform in order to compute standard deviation. Scan acquisitions were approximately dose-matched (∼25mGy CTDIvol) and image parameters were as consistent as possible (thickness, kernel, no noise reduction applied). Results: Iodine measurement error ranges were −0.24-0.16 mg/ml for the 2mg/ml insert (−12.0 − 8.0%), −0.28–0.26 mg/ml for the 5mg/ml insert (−5.6 − 5.2%), and −1.16−0.99 mg/ml for the 15mg/ml insert (−7.7 − 6.6%). Standard deviations ranged from 0 to 0.19 mg/ml for the repeated acquisitions from each scanner. The average iodine measurement error and standard deviation across all systems and inserts was −0.21 ± 0.48 mg/ml (−1.5 ± 6.48%). The largest absolute measurement error was found in the 15mg/ml iodine insert. Conclusion: There was generally good agreement in Iodine quantification across 3 dual-energy CT manufacturers and 4 scanner models. This was unexpected given the widely different underlying dual-energy CT mechanisms employed. Future work will include additional scanner platforms, independent verification of the Iodine insert standard concentrations (especially the 15 mg/ml insert), and how much measurement variability can be clinically tolerated. This research has been supported by funds from Dr. William Murphy, Jr., the John S. Dunn, Sr. Distinguished Chair in Diagnostic Imaging at MD Anderson Cancer Center.« less

Cavum Septum Pellucidum in Retired American Pro-Football Players.

PubMed

Gardner, Raquel C; Hess, Christopher P; Brus-Ramer, Marcel; Possin, Katherine L; Cohn-Sheehy, Brendan I; Kramer, Joel H; Berger, Mitchel S; Yaffe, Kristine; Miller, Bruce; Rabinovici, Gil D

2016-01-01

Previous studies report that cavum septum pellucidum (CSP) is frequent among athletes with a history of repeated traumatic brain injury (TBI), such as boxers. Few studies of CSP in athletes, however, have assessed detailed features of the septum pellucidum in a case-control fashion. This is important because prevalence of CSP in the general population varies widely (2% to 85%) between studies. Further, rates of CSP among American pro-football players have not been described previously. We sought to characterize MRI features of the septum pellucidum in a series of retired pro-football players with a history of repeated concussive/subconcussive head traumas compared with controls. We retrospectively assessed retired American pro-football players presenting to our memory clinic with cognitive/behavioral symptoms in whom structural MRI was available with slice thickness ≤2 mm (n=17). Each player was matched to a memory clinic control patient with no history of TBI. Scans were interpreted by raters blinded to clinical information and TBI/football history, who measured CSP grade (0-absent, 1-equivocal, 2-mild, 3-moderate, 4-severe) and length according to a standard protocol. Sixteen of 17 (94%) players had a CSP graded ≥2 compared with 3 of 17 (18%) controls. CSP was significantly higher grade (p<0.001) and longer in players than controls (mean length±standard deviation: 10.6 mm±5.4 vs. 1.1 mm±1.3, p<0.001). Among patients presenting to a memory clinic, long high-grade CSP was more frequent in retired pro-football players compared with patients without a history of TBI.

Reusable electrochemical sensor for bisphenol A based on ionic liquid functionalized conducting polymer platform.

PubMed

Wang, Jhe-Yi; Su, Ya-Ling; Wu, Bo-Hao; Cheng, Shu-Hua

2016-01-15

The toxicity of bisphenol A (BPA) has attracted considerable attention, and the reported electrochemical sensors for BPA need further improvement in reusability due to serious surface fouling. In this study, a composite film is designed aiming to provide both an accurate and repeatable platform for BPA determination. The conducting poly(3,4-ethylenedioxythiophene) film (PEDOT) and ionic liquid 1-butyl-3-methylimidazolium bromide (BMIMBr) were modified onto screen-printed carbon electrodes (SPCE) by electropolymerization and drop/spin methods, respectively. The surface characteristics of the composite film were characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and surface water contact angle experiments. The composite film-modified electrodes exhibited a linear response to BPA in the range of 0.1-500µM in pH 7.0 phosphate buffer solution (PBS) under optimized flow-injection amperometry. The method sensitivity and detection limit (S/N=3) were 0.2661μA μM(-1) (2.419μA μM(-1)cm(-2)) and 0.02µM, respectively. A relative standard deviation of 1.95% was obtained for 77 successive measurements of 10µM BPA, and the repeatability outperformed previously reported work. The proposed method was applied to detect BPA released from plastic water bottles using the standard addition method, and satisfactory recoveries were obtained. The electrochemical assay was validated by comparison with the chromatographic method, and the results showed good agreement between the two methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Individual Test Point Fluctuations of Macular Sensitivity in Healthy Eyes and Eyes With Age-Related Macular Degeneration Measured With Microperimetry.

PubMed

Barboni, Mirella Telles Salgueiro; Szepessy, Zsuzsanna; Ventura, Dora Fix; Németh, János

2018-04-01

To establish fluctuation limits, it was considered that not only overall macular sensitivity but also fluctuations of individual test points in the macula might have clinical value. Three repeated measurements of microperimetry were performed using the Standard Expert test of Macular Integrity Assessment (MAIA) in healthy subjects ( N = 12, age = 23.8 ± 1.5 years old) and in patients with age-related macular degeneration (AMD) ( N = 11, age = 68.5 ± 7.4 years old). A total of 37 macular points arranged in four concentric rings and in four quadrants were analyzed individually and in groups. The data show low fluctuation of macular sensitivity of individual test points in healthy subjects (average = 1.38 ± 0.28 dB) and AMD patients (average = 2.12 ± 0.60 dB). Lower sensitivity points are more related to higher fluctuation than to the distance from the central point. Fixation stability showed no effect on the sensitivity fluctuation. The 95th percentile of the standard deviations of healthy subjects was, on average, 2.7 dB, ranging from 1.2 to 4 dB, depending on the point tested. Point analysis and regional analysis might be considered prior to evaluating macular sensitivity fluctuation in order to distinguish between normal variation and a clinical change. S tatistical methods were used to compare repeated microperimetry measurements and to establish fluctuation limits of the macular sensitivity. This analysis could add information regarding the integrity of different macular areas and provide new insights into fixation points prior to the biofeedback fixation training.

Palm-Based Standard Reference Materials for Iodine Value and Slip Melting Point

PubMed Central

Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai; Kuntom, Ainie

2008-01-01

This work described study protocols on the production of Palm-Based Standard Reference Materials for iodine value and slip melting point. Thirty-three laboratories collaborated in the inter-laboratory proficiency tests for characterization of iodine value, while thirty-two laboratories for characterization of slip melting point. The iodine value and slip melting point of palm oil, palm olein and palm stearin were determined in accordance to MPOB Test Methods p3.2:2004 and p4.2:2004, respectively. The consensus values and their uncertainties were based on the acceptability of statistical agreement of results obtained from collaborating laboratories. The consensus values and uncertainties for iodine values were 52.63 ± 0.14 Wijs in palm oil, 56.77 ± 0.12 Wijs in palm olein and 33.76 ± 0.18 Wijs in palm stearin. For the slip melting points, the consensus values and uncertainties were 35.6 ± 0.3 °C in palm oil, 22.7 ± 0.4 °C in palm olein and 53.4 ± 0.2 °C in palm stearin. Repeatability and reproducibility relative standard deviations were found to be good and acceptable, with values much lower than that of 10%. Stability of Palm-Based Standard Reference Materials remained stable at temperatures of −20 °C, 0 °C, 6 °C and 24 °C upon storage for one year. PMID:19609396

Selection and Classification Using a Forecast Applicant Pool.

ERIC Educational Resources Information Center

Hendrix, William H.

The document presents a forecast model of the future Air Force applicant pool. By forecasting applicants' quality (means and standard deviations of aptitude scores) and quantity (total number of applicants), a potential enlistee could be compared to the forecasted pool. The data used to develop the model consisted of means, standard deviation, and…

Test of the principle of operation of a wideband magnetic direction finder for lightning return strokes

NASA Technical Reports Server (NTRS)

Herrman, B. D.; Uman, M. A.; Brantley, R. D.; Krider, E. P.

1976-01-01

The principle of operation of a wideband crossed-loop magnetic-field direction finder is studied by comparing the bearing determined from the NS and EW magnetic fields at various times up to 155 microsec after return stroke initiation with the TV-determined lightning channel base direction. For 40 lightning strokes in the 3 to 12 km range, the difference between the bearings found from magnetic fields sampled at times between 1 and 10 microsec and the TV channel-base data has a standard deviation of 3-4 deg. Included in this standard deviation is a 2-3 deg measurement error. For fields sampled at progressively later times, both the mean and the standard deviation of the difference between the direction-finder bearing and the TV bearing increase. Near 150 microsec, means are about 35 deg and standard deviations about 60 deg. The physical reasons for the late-time inaccuracies in the wideband direction finder and the occurrence of these effects in narrow-band VLF direction finders are considered.

Wavelength selection method with standard deviation: application to pulse oximetry.

PubMed

Vazquez-Jaccaud, Camille; Paez, Gonzalo; Strojnik, Marija

2011-07-01

Near-infrared spectroscopy provides useful biological information after the radiation has penetrated through the tissue, within the therapeutic window. One of the significant shortcomings of the current applications of spectroscopic techniques to a live subject is that the subject may be uncooperative and the sample undergoes significant temporal variations, due to his health status that, from radiometric point of view, introduce measurement noise. We describe a novel wavelength selection method for monitoring, based on a standard deviation map, that allows low-noise sensitivity. It may be used with spectral transillumination, transmission, or reflection signals, including those corrupted by noise and unavoidable temporal effects. We apply it to the selection of two wavelengths for the case of pulse oximetry. Using spectroscopic data, we generate a map of standard deviation that we propose as a figure-of-merit in the presence of the noise introduced by the living subject. Even in the presence of diverse sources of noise, we identify four wavelength domains with standard deviation, minimally sensitive to temporal noise, and two wavelengths domains with low sensitivity to temporal noise.

How random is a random vector?

NASA Astrophysics Data System (ADS)

Eliazar, Iddo

2015-12-01

Over 80 years ago Samuel Wilks proposed that the "generalized variance" of a random vector is the determinant of its covariance matrix. To date, the notion and use of the generalized variance is confined only to very specific niches in statistics. In this paper we establish that the "Wilks standard deviation" -the square root of the generalized variance-is indeed the standard deviation of a random vector. We further establish that the "uncorrelation index" -a derivative of the Wilks standard deviation-is a measure of the overall correlation between the components of a random vector. Both the Wilks standard deviation and the uncorrelation index are, respectively, special cases of two general notions that we introduce: "randomness measures" and "independence indices" of random vectors. In turn, these general notions give rise to "randomness diagrams"-tangible planar visualizations that answer the question: How random is a random vector? The notion of "independence indices" yields a novel measure of correlation for Lévy laws. In general, the concepts and results presented in this paper are applicable to any field of science and engineering with random-vectors empirical data.

Estimation of Tooth Size Discrepancies among Different Malocclusion Groups.

PubMed

Hasija, Narender; Bala, Madhu; Goyal, Virender

2014-05-01

Regards and Tribute: Late Dr Narender Hasija was a mentor and visionary in the light of knowledge and experience. We pay our regards with deepest gratitude to the departed soul to rest in peace. Bolton's ratios help in estimating overbite, overjet relationships, the effects of contemplated extractions on posterior occlusion, incisor relationships and identification of occlusal misfit produced by tooth size discrepancies. To determine any difference in tooth size discrepancy in anterior as well as overall ratio in different malocclusions and comparison with Bolton's study. After measuring the teeth on all 100 patients, Bolton's analysis was performed. Results were compared with Bolton's means and standard deviations. The results were also subjected to statistical analysis. Results show that the mean and standard deviations of ideal occlusion cases are comparable with those Bolton but, when the mean and standard deviation of malocclusion groups are compared with those of Bolton, the values of standard deviation are higher, though the mean is comparable. How to cite this article: Hasija N, Bala M, Goyal V. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups. Int J Clin Pediatr Dent 2014;7(2):82-85.

Association of auricular pressing and heart rate variability in pre-exam anxiety students.

PubMed

Wu, Wocao; Chen, Junqi; Zhen, Erchuan; Huang, Huanlin; Zhang, Pei; Wang, Jiao; Ou, Yingyi; Huang, Yong

2013-03-25

A total of 30 students scoring between 12 and 20 on the Test Anxiety Scale who had been exhibiting an anxious state > 24 hours, and 30 normal control students were recruited. Indices of heart rate variability were recorded using an Actiheart electrocardiogram recorder at 10 minutes before auricular pressing, in the first half of stimulation and in the second half of stimulation. The results revealed that the standard deviation of all normal to normal intervals and the root mean square of standard deviation of normal to normal intervals were significantly increased after stimulation. The heart rate variability triangular index, very-low-frequency power, low-frequency power, and the ratio of low-frequency to high-frequency power were increased to different degrees after stimulation. Compared with normal controls, the root mean square of standard deviation of normal to normal intervals was significantly increased in anxious students following auricular pressing. These results indicated that auricular pressing can elevate heart rate variability, especially the root mean square of standard deviation of normal to normal intervals in students with pre-exam anxiety.

Association of auricular pressing and heart rate variability in pre-exam anxiety students

PubMed Central

Wu, Wocao; Chen, Junqi; Zhen, Erchuan; Huang, Huanlin; Zhang, Pei; Wang, Jiao; Ou, Yingyi; Huang, Yong

2013-01-01

A total of 30 students scoring between 12 and 20 on the Test Anxiety Scale who had been exhibiting an anxious state > 24 hours, and 30 normal control students were recruited. Indices of heart rate variability were recorded using an Actiheart electrocardiogram recorder at 10 minutes before auricular pressing, in the first half of stimulation and in the second half of stimulation. The results revealed that the standard deviation of all normal to normal intervals and the root mean square of standard deviation of normal to normal intervals were significantly increased after stimulation. The heart rate variability triangular index, very-low-frequency power, low-frequency power, and the ratio of low-frequency to high-frequency power were increased to different degrees after stimulation. Compared with normal controls, the root mean square of standard deviation of normal to normal intervals was significantly increased in anxious students following auricular pressing. These results indicated that auricular pressing can elevate heart rate variability, especially the root mean square of standard deviation of normal to normal intervals in students with pre-exam anxiety. PMID:25206734

Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation

PubMed Central

Volckmann, Pierre; Jacquin-Courtois, Sophie

2016-01-01

Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations. PMID:27668094

Offshore fatigue design turbulence

NASA Astrophysics Data System (ADS)

Larsen, Gunner C.

2001-07-01

Fatigue damage on wind turbines is mainly caused by stochastic loading originating from turbulence. While onshore sites display large differences in terrain topology, and thereby also in turbulence conditions, offshore sites are far more homogeneous, as the majority of them are likely to be associated with shallow water areas. However, despite this fact, specific recommendations on offshore turbulence intensities, applicable for fatigue design purposes, are lacking in the present IEC code. This article presents specific guidelines for such loading. These guidelines are based on the statistical analysis of a large number of wind data originating from two Danish shallow water offshore sites. The turbulence standard deviation depends on the mean wind speed, upstream conditions, measuring height and thermal convection. Defining a population of turbulence standard deviations, at a given measuring position, uniquely by the mean wind speed, variations in upstream conditions and atmospheric stability will appear as variability of the turbulence standard deviation. Distributions of such turbulence standard deviations, conditioned on the mean wind speed, are quantified by fitting the measured data to logarithmic Gaussian distributions. By combining a simple heuristic load model with the parametrized conditional probability density functions of the turbulence standard deviations, an empirical offshore design turbulence intensity is determined. For pure stochastic loading (as associated with standstill situations), the design turbulence intensity yields a fatigue damage equal to the average fatigue damage caused by the distributed turbulence intensity. If the stochastic loading is combined with a periodic deterministic loading (as in the normal operating situation), the proposed design turbulence intensity is shown to be conservative.

Estimating extreme stream temperatures by the standard deviate method

NASA Astrophysics Data System (ADS)

Bogan, Travis; Othmer, Jonathan; Mohseni, Omid; Stefan, Heinz

2006-02-01

It is now widely accepted that global climate warming is taking place on the earth. Among many other effects, a rise in air temperatures is expected to increase stream temperatures indefinitely. However, due to evaporative cooling, stream temperatures do not increase linearly with increasing air temperatures indefinitely. Within the anticipated bounds of climate warming, extreme stream temperatures may therefore not rise substantially. With this concept in mind, past extreme temperatures measured at 720 USGS stream gauging stations were analyzed by the standard deviate method. In this method the highest stream temperatures are expressed as the mean temperature of a measured partial maximum stream temperature series plus its standard deviation multiplied by a factor KE (standard deviate). Various KE-values were explored; values of KE larger than 8 were found physically unreasonable. It is concluded that the value of KE should be in the range from 7 to 8. A unit error in estimating KE translates into a typical stream temperature error of about 0.5 °C. Using a logistic model for the stream temperature/air temperature relationship, a one degree error in air temperature gives a typical error of 0.16 °C in stream temperature. With a projected error in the enveloping standard deviate dKE=1.0 (range 0.5-1.5) and an error in projected high air temperature d Ta=2 °C (range 0-4 °C), the total projected stream temperature error is estimated as d Ts=0.8 °C.

Herschel Extreme Lensing Line Observations: Dynamics of Two Strongly Lensed Star-Forming Galaxies near Redshift z=2*

NASA Technical Reports Server (NTRS)

Rhoads, James E.; Rigby, Jane Rebecca; Malhotra, Sangeeta; Allam, Sahar; Carilli, Chris; Combes, Francoise; Finkelstein, Keely; Finkelstein, Steven; Frye, Brenda; Gerin, Maryvonne;

A New Test Unit for Disintegration End-Point Determination of Orodispersible Films.

PubMed

Low, Ariana; Kok, Si Ling; Khong, Yuet Mei; Chan, Sui Yung; Gokhale, Rajeev

2015-11-01

No standard time or pharmacopoeia disintegration test method for orodispersible films (ODFs) exists. The USP disintegration test for tablets and capsules poses significant challenges for end-point determination when used for ODFs. We tested a newly developed disintegration test unit (DTU) against the USP disintegration test. The DTU is an accessory to the USP disintegration apparatus. It holds the ODF in a horizontal position, allowing top-view of the ODF during testing. A Gauge R&R study was conducted to assign relative contributions of the total variability from the operator, sample or the experimental set-up. Precision was compared using commercial ODF products in different media. Agreement between the two measurement methods was analysed. The DTU showed improved repeatability and reproducibility compared to the USP disintegration system with tighter standard deviations regardless of operator or medium. There is good agreement between the two methods, with the USP disintegration test giving generally longer disintegration times possibly due to difficulty in end-point determination. The DTU provided clear end-point determination and is suitable for quality control of ODFs during product developmental stage or manufacturing. This may facilitate the development of a standardized methodology for disintegration time determination of ODFs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

A rapid method for estimation of Pu-isotopes in urine samples using high volume centrifuge.

PubMed

Kumar, Ranjeet; Rao, D D; Dubla, Rupali; Yadav, J R

2017-07-01

The conventional radio-analytical technique used for estimation of Pu-isotopes in urine samples involves anion exchange/TEVA column separation followed by alpha spectrometry. This sequence of analysis consumes nearly 3-4 days for completion. Many a times excreta analysis results are required urgently, particularly under repeat and incidental/emergency situations. Therefore, there is need to reduce the analysis time for the estimation of Pu-isotopes in bioassay samples. This paper gives the details of standardization of a rapid method for estimation of Pu-isotopes in urine samples using multi-purpose centrifuge, TEVA resin followed by alpha spectrometry. The rapid method involves oxidation of urine samples, co-precipitation of plutonium along with calcium phosphate followed by sample preparation using high volume centrifuge and separation of Pu using TEVA resin. Pu-fraction was electrodeposited and activity estimated using 236 Pu tracer recovery by alpha spectrometry. Ten routine urine samples of radiation workers were analyzed and consistent radiochemical tracer recovery was obtained in the range 47-88% with a mean and standard deviation of 64.4% and 11.3% respectively. With this newly standardized technique, the whole analytical procedure is completed within 9h (one working day hour). Copyright © 2017 Elsevier Ltd. All rights reserved.

Enumeration procedure for monitoring test microbe populations on inoculated carriers in AOAC use-dilution methods.

PubMed

Tomasino, Stephen F; Fiumara, Rebecca M; Cottrill, Michele P

2006-01-01

The AOAC Use-Dilution methods do not provide procedures to enumerate the test microbe on stainless steel carriers (penicylinders) or guidance on the expected target populations of the test microbe (i.e., a performance standard). This report describes the procedures used by the U.S. Environmental Protection Agency to enumerate the test microbe (carrier counts) associated with conducting the Use-Dilution method with Staphylococcus aureus (Method 955.15) and Pseudomonas aeruginosa (Method 964.02) and the examination of historical data. The carrier count procedure involves the random selection of carriers, shearing bacterial cells from the carrier surface through sonication, and plating of serially diluted inoculum on trypticase soy agar. For each Use-Dilution test conducted, the official AOAC method was strictly followed for carrier preparation, culture initiation, test culture preparation, and carrier inoculation steps. Carrier count data from 78 Use-Dilution tests conducted over a 6-year period were compiled and analyzed. A mean carrier count of 6.6 logs (approximately 4.0 x 10(6) colony-forming units/carrier) was calculated for both S. aureus and P. aeruginosa. Of the mean values, 95% fell within +/- 2 repeatability standard deviations. The enumeration procedure and target carrier counts are desirable for standardizing the Use-Dilution methods, increasing their reproducibility, and ensuring the quality of the data.

Trace level voltammetric determination of heavy metals and total mercury in tea matrices (Camellia sinensis).

PubMed

Melucci, Dora; Locatelli, Marcello; Locatelli, Clinio

2013-12-01

An analytical procedure regarding the voltammetric determination of mercury(II), copper(II), lead(II), cadmium(II) and zinc(II) by square wave anodic stripping voltammetry (SWASV) in matrices involved in food chain is proposed. In particular, tea leaves were analyzed as real samples. The digestion of each matrix was carried out using a concentrated HCl-HNO3-H2SO4 acidic attack mixture; 0.01 mol L(-1) EDTA-Na2+ 0.15 mol L(-1) NaCl + 0.5 mol L(-1) HCl was employed as the supporting electrolyte. The voltammetric measurements were carried out using a conventional three electrode cell, employing, as working electrodes, a gold electrode (GE) and a stationary hanging mercury drop electrode (HMDE). The analytical procedure has been verified on the standard reference materials Spinach Leaves NIST-SRM 1570a, Tomato Leaves NIST-SRM 1573a and Apple Leaves NIST-SRM 1515. For all the elements, the precision as repeatability, expressed as relative standard deviation (sr) was of the order of 3-5%, while the trueness, expressed as relative error (e) was of the order of 3-7%. Once set up on the standard reference materials, the analytical procedure was applied to commercial tea leaves samples. A critical comparison with spectroscopic measurements is also discussed.

Do pattern deviation values accurately estimate glaucomatous visual field damage in eyes with glaucoma and cataract?

PubMed

Matsuda, Aya; Hara, Takeshi; Miyata, Kazunori; Matsuo, Hiroshi; Murata, Hiroshi; Mayama, Chihiro; Asaoka, Ryo

2015-09-01

To study the efficacy of pattern deviation (PD) values in the estimation of visual field compensating the influence of cataract in eyes with glaucoma. The study subjects comprised of 48 eyes of 37 glaucoma patients. Mean total deviation value (mTDs) on Humphrey Field Analyzer after cataract surgery was compared with mean PD (mPD) before the surgery. Visual field measurements were carried out ≤6 months before (VF(pre)) and following (VF(post)) successful cataract surgery. The difference between the mPD or mTD values in the VF(pre) and mTD values in the VF(post) (denoted as εmPD/ΔmTD) was calculated, and the influence of the extent of 'true' glaucomatous visual field damage or cataract (as represented by εmPD and ΔmTD, respectively) on this difference was also investigated. There was a significant difference between mTD in the VF(pre) and mTD in the VF(post) (p<0.001, repeated measures analysis of variance). There was not a significant difference between mPD in the VF(pre) and mTD in the VF(post) (p=0.06); however, εmPD was significantly correlated with the mTD in VF(post) and also ΔmTD (R(2)=0.56 and 0.27, p<0.001, Pearson's correlation). The accurate prediction of the mTD in the VF(post) can be achieved using the pattern standard deviation (PSD), mTD and also visual acuity before surgery. Clinicians should be very careful when reviewing the VF of a patient with glaucoma and cataract since PD values may underestimate glaucomatous VF damage in patients with advanced disease and also overestimate glaucomatous VF damage in patients with early to moderate cataract. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

Fried, D; Meier, J; Mawlawi, O

Purpose: Use a NEMA-IEC PET phantom to assess the robustness of FDG-PET-based radiomics features to changes in reconstruction parameters across different scanners. Methods: We scanned a NEMA-IEC PET phantom on 3 different scanners (GE Discovery VCT, GE Discovery 710, and Siemens mCT) using a FDG source-to-background ratio of 10:1. Images were retrospectively reconstructed using different iterations (2–3), subsets (21–24), Gaussian filter widths (2, 4, 6mm), and matrix sizes (128,192,256). The 710 and mCT used time-of-flight and point-spread-functions in reconstruction. The axial-image through the center of the 6 active spheres was used for analysis. A region-of-interest containing all spheres was ablemore » to simulate a heterogeneous lesion due to partial volume effects. Maximum voxel deviations from all retrospectively reconstructed images (18 per scanner) was compared to our standard clinical protocol. PET Images from 195 non-small cell lung cancer patients were used to compare feature variation. The ratio of a feature’s standard deviation from the patient cohort versus the phantom images was calculated to assess for feature robustness. Results: Across all images, the percentage of voxels differing by <1SUV and <2SUV ranged from 61–92% and 88–99%, respectively. Voxel-voxel similarity decreased when using higher resolution image matrices (192/256 versus 128) and was comparable across scanners. Taking the ratio of patient and phantom feature standard deviation was able to identify features that were not robust to changes in reconstruction parameters (e.g. co-occurrence correlation). Metrics found to be reasonably robust (standard deviation ratios > 3) were observed for routinely used SUV metrics (e.g. SUVmean and SUVmax) as well as some radiomics features (e.g. co-occurrence contrast, co-occurrence energy, standard deviation, and uniformity). Similar standard deviation ratios were observed across scanners. Conclusions: Our method enabled a comparison of feature variability across scanners and was able to identify features that were not robust to changes in reconstruction parameters.« less

Host model uncertainties in aerosol radiative forcing estimates: results from the AeroCom prescribed intercomparison study

NASA Astrophysics Data System (ADS)

Stier, P.; Schutgens, N. A. J.; Bian, H.; Boucher, O.; Chin, M.; Ghan, S.; Huneeus, N.; Kinne, S.; Lin, G.; Myhre, G.; Penner, J. E.; Randles, C.; Samset, B.; Schulz, M.; Yu, H.; Zhou, C.

2012-09-01

Simulated multi-model "diversity" in aerosol direct radiative forcing estimates is often perceived as measure of aerosol uncertainty. However, current models used for aerosol radiative forcing calculations vary considerably in model components relevant for forcing calculations and the associated "host-model uncertainties" are generally convoluted with the actual aerosol uncertainty. In this AeroCom Prescribed intercomparison study we systematically isolate and quantify host model uncertainties on aerosol forcing experiments through prescription of identical aerosol radiative properties in nine participating models. Even with prescribed aerosol radiative properties, simulated clear-sky and all-sky aerosol radiative forcings show significant diversity. For a purely scattering case with globally constant optical depth of 0.2, the global-mean all-sky top-of-atmosphere radiative forcing is -4.51 W m-2 and the inter-model standard deviation is 0.70 W m-2, corresponding to a relative standard deviation of 15%. For a case with partially absorbing aerosol with an aerosol optical depth of 0.2 and single scattering albedo of 0.8, the forcing changes to 1.26 W m-2, and the standard deviation increases to 1.21 W m-2, corresponding to a significant relative standard deviation of 96%. However, the top-of-atmosphere forcing variability owing to absorption is low, with relative standard deviations of 9% clear-sky and 12% all-sky. Scaling the forcing standard deviation for a purely scattering case to match the sulfate radiative forcing in the AeroCom Direct Effect experiment, demonstrates that host model uncertainties could explain about half of the overall sulfate forcing diversity of 0.13 W m-2 in the AeroCom Direct Radiative Effect experiment. Host model errors in aerosol radiative forcing are largest in regions of uncertain host model components, such as stratocumulus cloud decks or areas with poorly constrained surface albedos, such as sea ice. Our results demonstrate that host model uncertainties are an important component of aerosol forcing uncertainty that require further attention.

Robust Alternatives to the Standard Deviation in Processing of Physics Experimental Data

NASA Astrophysics Data System (ADS)

Shulenin, V. P.

2016-10-01

Properties of robust estimations of the scale parameter are studied. It is noted that the median of absolute deviations and the modified estimation of the average Gini differences have asymptotically normal distributions and bounded influence functions, are B-robust estimations, and hence, unlike the estimation of the standard deviation, are protected from the presence of outliers in the sample. Results of comparison of estimations of the scale parameter are given for a Gaussian model with contamination. An adaptive variant of the modified estimation of the average Gini differences is considered.

Evaluation of two new STR loci 9q2h2 and wg3f12 in a Japanese population.

PubMed

Mizutani, M; Huang, X L; Tamaki, K; Yoshimoto, T; Uchihi, R; Yamamoto, T; Katsumata, Y; Armour, J A

1999-09-01

Two short tandem repeat (STR) loci (9q2h2 and wg3f12) have been evaluated in a Japanese population. Ten and seven different alleles were observed in 9q2h2 and wg3f12 respectively. 9q2h2 displayed simple polymorphism in tetrameric repeat structure; by contrast, wg3f12 contained variable numbers of tetrameric repeats and a 30-bp deletion/insertion polymorphism. No "interalleles" were found. The expected heterozygosities of 9q2h2 and wg3fl2 were 0.749 and 0.574, respectively. No deviation from Hardy-Weinberg equilibrium was found.

Prism under cover test in alternate fixation horizontal strabismus.

PubMed

Tejedor, Jaime; Gutiérrez-Carmona, Francisco José

2018-02-01

To evaluate the applicability of the prism under cover test (PUCT) to quantify manifest deviation in horizontal strabismus with alternate fixation when simultaneous prism and cover test (SPCT) is not feasible. Children aged 4-11 years, with alternate fixation horizontal strabismus and alternate prism and cover test (APCT) distance deviation (DD) up to 25 PD were eligible. In group 1 of the study, SPCT was not feasible (n = 18), whereas in group 2, it was feasible (n = 24). Refraction, PUCT, APCT, central/peripheral fusion, and stereoacuity were measured. Repeatability of PUCT, agreement between PUCT and SPCT, and Pearson correlations between variables were studied. In group 1, mean DD was 15.6 and 9.5 PD using APCT and PUCT, respectively (intraclass correlation, ICC: 0.90). Mean stereoacuity was 201.1 arc seconds. PUCT was better correlated with stereoacuity than APCT, but not significantly (p = 0.12). Coefficient of repeatability for PUCT was 3.4 PD. In group 2, mean DD was 17.6, 14.1, and 12.5 PD using APCT, PUCT, and SPCT, respectively. Mean stereoacuity was 285.9 arc seconds. Correlations APCT-PUCT (0.87), APCT-SPCT (0.82), and SPCT-PUCT (0.95) were significant. APCT did not show as good correlation with stereoacuity (0.58) as SPCT and PUCT (0.74 and 0.78, respectively). Concordance correlation coefficient between SPCT and PUCT was 0.91, and Bland Altman agreement between the two variables was also good. PUCT is a procedure with good repeatability, of interest in children to estimate manifest deviation when SPCT is not feasible, and in support of the diagnosis of monofixation syndrome.

40 CFR 63.7751 - What reports must I submit and when?

Code of Federal Regulations, 2010 CFR

2010-07-01

... deviations from any emissions limitations (including operating limit), work practice standards, or operation and maintenance requirements, a statement that there were no deviations from the emissions limitations...-of-control during the reporting period. (7) For each deviation from an emissions limitation...

Effect of single-dose Ginkgo biloba and Panax ginseng on driving performance.

PubMed

LaSala, Gregory S; McKeever, Rita G; Patel, Urvi; Okaneku, Jolene; Vearrier, David; Greenberg, Michael I

2015-02-01

Panax ginseng and Gingko biloba are commonly used herbal supplements in the United States that have been reported to increase alertness and cognitive function. The objective of this study was to investigate the effects of these specific herbals on driving performance. 30 volunteers were tested using the STISIM3® Driving Simulator (Systems Technology Inc., Hawthorne, CA, USA) in this double-blind, placebo-controlled study. The subjects were randomized into 3 groups of 10 subjects per group. After 10-min of simulated driving, subjects received either ginseng (1200 mg), Gingko (240 mg), or placebo administered orally. The test herbals and placebo were randomized and administered by a research assistant outside of the study to maintain blinding. One hour following administration of the herbals or placebo, the subjects completed an additional 10-min of simulated driving. Standard driving parameters were studied including reaction time, standard deviation of lateral positioning, and divided attention. Data collected for the divided attention parameter included time to response and number of correct responses. The data was analyzed with repeated-measures analysis of variance (ANOVA) and Kruskal-Wallis test using SPSS 22 (IBM, Armonk, NY, USA). There was no difference in reaction time or standard deviation of lateral positioning for both the ginseng and Ginkgo arms. For the divided attention parameter, the response time in the Ginkgo arm decreased from 2.9 to 2.5 s. The ginseng arm also decreased from 3.2 to 2.4 s. None of these values were statistically significant when between group differences were analyzed. The data suggests there was no statistically significant difference between ginseng, Ginkgo or placebo on driving performance. We postulate this is due to the relatively small numbers in our study. Further study with a larger sample size may be needed in order to elucidate more fully the effects of Ginkgo and ginseng on driving ability.

Validation and Recommendation of Methods to Measure Biogas Production Potential of Animal Manure

PubMed Central

Pham, C. H.; Triolo, J. M.; Cu, T. T. T.; Pedersen, L.; Sommer, S. G.

2013-01-01

In developing countries, biogas energy production is seen as a technology that can provide clean energy in poor regions and reduce pollution caused by animal manure. Laboratories in these countries have little access to advanced gas measuring equipment, which may limit research aimed at improving local adapted biogas production. They may also be unable to produce valid estimates of an international standard that can be used for articles published in international peer-reviewed science journals. This study tested and validated methods for measuring total biogas and methane (CH4) production using batch fermentation and for characterizing the biomass. The biochemical methane potential (BMP) (CH4 NL kg−1 VS) of pig manure, cow manure and cellulose determined with the Moller and VDI methods was not significantly different in this test (p>0.05). The biodegradability using a ratio of BMP and theoretical BMP (TBMP) was slightly higher using the Hansen method, but differences were not significant. Degradation rate assessed by methane formation rate showed wide variation within the batch method tested. The first-order kinetics constant k for the cumulative methane production curve was highest when two animal manures were fermented using the VDI 4630 method, indicating that this method was able to reach steady conditions in a shorter time, reducing fermentation duration. In precision tests, the repeatability of the relative standard deviation (RSDr) for all batch methods was very low (4.8 to 8.1%), while the reproducibility of the relative standard deviation (RSDR) varied widely, from 7.3 to 19.8%. In determination of biomethane concentration, the values obtained using the liquid replacement method (LRM) were comparable to those obtained using gas chromatography (GC). This indicates that the LRM method could be used to determine biomethane concentration in biogas in laboratories with limited access to GC. PMID:25049861

Longitudinal inter- and intra-individual human brain metabolic quantification over 3 years with proton MR spectroscopy at 3 T.

PubMed

Kirov, Ivan I; George, Ilena C; Jayawickrama, Nikhil; Babb, James S; Perry, Nissa N; Gonen, Oded

2012-01-01

The longitudinal repeatability of proton MR spectroscopy ((1) H-MRS) in the healthy human brain at high fields over long periods is not established. Therefore, we assessed the inter- and intra-subject repeatability of (1) H-MRS in an approach suited for diffuse pathologies in 10 individuals, at 3T, annually for 3 years. Spectra from 480 voxels over 360 cm(3) (∼30%) of the brain, were individually phased, frequency-aligned, and summed into one average spectrum. This dramatically increases metabolites' signal-to-noise-ratios while maintaining narrow linewidths that improve quantification precision. The resulting concentrations of the N-acetylaspartate, creatine, choline, and myo-inositol are: 8.9 ± 0.8, 5.9 ± 0.6, 1.4 ± 0.1, and 4.5 ± 0.5 mM (mean ± standard-deviation). the inter-subject coefficients of variation are 8.7%, 10.2%, 10.7%, and 11.8%; and the longitudinal (intra-subject) coefficients of variation are lower still: 6.6%, 6.8%, 6.8%, and 10%, much better than the 35%, 44%, 55%, and 62% intra-voxel coefficients of variation. The biological and nonbiological components of the summed spectra coefficients of variation had similar contributions to the overall variance. Copyright © 2011 Wiley-Liss, Inc.

Qualification of a Quantitative Laryngeal Imaging System Using Videostroboscopy and Videokymography

PubMed Central

Popolo, Peter S.; Titze, Ingo R.

2008-01-01

Objectives: We sought to determine whether full-cycle glottal width measurements could be obtained with a quantitative laryngeal imaging system using videostroboscopy, and whether glottal width and vocal fold length measurements were repeatable and reliable. Methods: Synthetic vocal folds were phonated on a laboratory bench, and dynamic images were obtained in repeated trials by use of videostroboscopy and videokymography (VKG) with an imaging system equipped with a 2-point laser projection device for measuring absolute dimensions. Video images were also obtained with an industrial videoscope system with a built-in laser measurement capability. Maximum glottal width and vocal fold length were compared among these 3 methods. Results: The average variation in maximum glottal width measurements between stroboscopic data and VKG data was 3.10%. The average variations in width measurements between the clinical system and the industrial system were 1.93% (stroboscopy) and 3.49% (VKG). The variations in vocal fold length were similarly small. The standard deviations across trials were 0.29 mm for width and 0.48 mm for length (stroboscopy), 0.18 mm for width (VKG), and 0.25 mm for width and 0.84 mm for length (industrial). Conclusions: For stable, periodic vibration, the full extent of the glottal width can be reliably measured with the quantitative videostroboscopy system. PMID:18646436

Acute and subchronic effects of bilastine (20 and 40 mg) and hydroxyzine (50 mg) on actual driving performance in healthy volunteers.

PubMed

Conen, Silke; Theunissen, Eef L; Van Oers, Anita C M; Valiente, Román; Ramaekers, Johannes G

2011-11-01

Bilastine is a new second-generation H1 antagonist. Although bilastine has been demonstrated to produce little or no performance impairment in laboratory tests, it cannot be excluded that it produces impairments in real-life performance such as driving. This study aims to assess the effects of two doses of bilastine (20 and 40 mg) on actual driving after single and repeated administration. Hydroxyzine 50 mg was included as an active control. Twenty-two participants (11 females, 11 males) were tested in a placebo-controlled, randomized, double-blind, four-way cross-over design. Participants were treated with once-daily doses for eight consecutive days. On day 1 and 8 of each treatment period participants performed an actual highway driving test. The primary variable was standard deviation of lateral position (SDLP), a measure of weaving. Results demonstrated that hydroxyzine significantly increased SDLP on days 1 and 8 of treatment. Bilastine did not affect SDLP. It is concluded that hydroxyzine produces severe driving impairment after single doses and that this impairment only partly mitigates over time due to a lack of complete tolerance. Bilastine did not produce any driving impairment after single and repeated doses and can be safely used in traffic in doses up to 40 mg.

Consistency of kinematic and kinetic patterns during a prolonged spell of cricket fast bowling: an exploratory laboratory study.

PubMed

Schaefer, Andrew; O'dwyer, Nicholas; Ferdinands, René E D; Edwards, Suzi

2018-03-01

Due to the high incidence of lumbar spine injury in fast bowlers, international cricket organisations advocate limits on workload for bowlers under 19 years of age in training/matches. The purpose of this study was to determine whether significant changes in either fast bowling technique or movement variability could be detected throughout a 10-over bowling spell that exceeded the recommended limit. Twenty-five junior male fast bowlers bowled at competition pace while three-dimensional kinematic and kinetic data were collected for the leading leg, trunk and bowling arm. Separate analyses for the mean and within-participant standard deviation of each variable were performed using repeated measures factorial analyses of variance and computation of effect sizes. No substantial changes were observed in mean values or variability of any kinematic, kinetic or performance variables, which instead revealed a high degree of consistency in kinematic and kinetic patterns. Therefore, the suggestion that exceeding the workload limit per spell causes technique- and loading-related changes associated with lumbar injury risk is not valid and cannot be used to justify the restriction of bowling workload. For injury prevention, the focus instead should be on the long-term effect of repeated spells and on the fast bowling technique itself.

A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis

PubMed Central

Maguire Jr., Gerald Q.; Noz, Marilyn E.; Olivecrona, Henrik; Zeleznik, Michael P.

2014-01-01

As the most advantageous total hip arthroplasty (THA) operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT) volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD) of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (±SD) for the diameter of the acetabular cup of 54.21 (±0.011) mm and for the femoral component head of 22.09 (±0.02) mm. The wear error was ±0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction. PMID:24587727

Theoretical repeatability assessment without repetitive measurements in gradient high-performance liquid chromatography.

PubMed

Kotani, Akira; Tsutsumi, Risa; Shoji, Asaki; Hayashi, Yuzuru; Kusu, Fumiyo; Yamamoto, Kazuhiro; Hakamata, Hideki

2016-07-08

This paper puts forward a time and material-saving method for evaluating the repeatability of area measurements in gradient HPLC with UV detection (HPLC-UV), based on the function of mutual information (FUMI) theory which can theoretically provide the measurement standard deviation (SD) and detection limits through the stochastic properties of baseline noise with no recourse to repetitive measurements of real samples. The chromatographic determination of terbinafine hydrochloride and enalapril maleate is taken as an example. The best choice of the number of noise data points, inevitable for the theoretical evaluation, is shown to be 512 data points (10.24s at 50 point/s sampling rate of an A/D converter). Coupled with the relative SD (RSD) of sample injection variability in the instrument used, the theoretical evaluation is proved to give identical values of area measurement RSDs to those estimated by the usual repetitive method (n=6) over a wide concentration range of the analytes within the 95% confidence intervals of the latter RSD. The FUMI theory is not a statistical one, but the "statistical" reliability of its SD estimates (n=1) is observed to be as high as that attained by thirty-one measurements of the same samples (n=31). Copyright © 2016 Elsevier B.V. All rights reserved.

A brief neurocognitive assessment of patients with psychosis following traumatic brain injury (PFTBI): Use of the Repeatable battery for the Assessment of Neuropsychological Status (RBANS).

PubMed

Batty, Rachel A; Francis, Andrew; Thomas, Neil; Hopwood, Malcolm; Ponsford, Jennie; Rossell, Susan L

2016-03-30

Patients who develop psychosis following a traumatic brain injury (PFTBI) show impaired neurocognition; however, the degree of impairment has not been empirically investigated using a standardised battery. We administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to patients with PFTBI (n=10), and to three groups of controls: traumatic brain injury (TBI) (n=10), schizophrenia (n=23), and nonclinical controls (n=23). The results confirmed that the cognitive neuropsychological profile of dually-diagnosed patients with PFTBI is significantly and substantially impaired. Seventy per cent of patients with PFTBI received a neuropsychological classification between the "extremely low" and "low average" ranges. Group-wise analyses on the RBANS indices indicated that patients with PFTBI had the lowest (Immediate Memory, Attention, Delayed Memory, Total Score), or equal lowest (visuospatial, equivalent with schizophrenia patients) scores, with the exception of the Language Index where no group differences were shown (however, the mean PFTBI score on the Language Index was two standard deviations below the RBANS normative score). These findings provide novel evidence of impaired cognitive neuropsychological processing in patients with PFTBI using a standardised and replicable battery. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Automated dynamic liquid-liquid-liquid microextraction followed by high-performance liquid chromatography-ultraviolet detection for the determination of phenoxy acid herbicides in environmental waters.

PubMed

Wu, Jingming; Ee, Kim Huey; Lee, Hian Kee

2005-08-05

Automated dynamic liquid-liquid-liquid microextraction (D-LLLME) controlled by a programmable syringe pump and combined with HPLC-UV was investigated for the extraction and determination of 5 phenoxy acid herbicides in aqueous samples. In the extraction procedure, the acceptor phase was repeatedly withdrawn into and discharged from the hollow fiber by the syringe pump. The repetitive movement of acceptor phase into and out of the hollow fiber channel facilitated the transfer of analytes into donor phase, from the organic phase held in the pore of the fiber. Parameters such as the organic solvent, concentrations of the donor and acceptor phases, plunger movement pattern, speed of agitation and ionic strength of donor phase were evaluated. Good linearity of analytes was achieved in the range of 0.5-500 ng/ml with coefficients of determination, r2 > 0.9994. Good repeatabilities of extraction performance were obtained with relative standard deviations lower than 7.5%. The method provided up-to 490-fold enrichment within 13 min. In addition, the limits of detection (LODs) ranged from 0.1 to 0.4 ng/mL (S/N = 3). D-LLLME was successfully applied for the analysis of phenoxy acid herbicides from real environmental water samples.

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

Levegruen, Sabine, E-mail: sabine.levegruen@uni-due.de; Poettgen, Christoph; Abu Jawad, Jehad

Purpose: To evaluate megavoltage computed tomography (MVCT)-based image guidance with helical tomotherapy in patients with vertebral tumors by analyzing factors influencing interobserver variability, considered as quality criterion of image guidance. Methods and Materials: Five radiation oncologists retrospectively registered 103 MVCTs in 10 patients to planning kilovoltage CTs by rigid transformations in 4 df. Interobserver variabilities were quantified using the standard deviations (SDs) of the distributions of the correction vector components about the observers' fraction mean. To assess intraobserver variabilities, registrations were repeated after {>=}4 weeks. Residual deviations after setup correction due to uncorrectable rotational errors and elastic deformations were determinedmore » at 3 craniocaudal target positions. To differentiate observer-related variations in minimizing these residual deviations across the 3-dimensional MVCT from image resolution effects, 2-dimensional registrations were performed in 30 single transverse and sagittal MVCT slices. Axial and longitudinal MVCT image resolutions were quantified. For comparison, image resolution of kilovoltage cone-beam CTs (CBCTs) and interobserver variability in registrations of 43 CBCTs were determined. Results: Axial MVCT image resolution is 3.9 lp/cm. Longitudinal MVCT resolution amounts to 6.3 mm, assessed as full-width at half-maximum of thin objects in MVCTs with finest pitch. Longitudinal CBCT resolution is better (full-width at half-maximum, 2.5 mm for CBCTs with 1-mm slices). In MVCT registrations, interobserver variability in the craniocaudal direction (SD 1.23 mm) is significantly larger than in the lateral and ventrodorsal directions (SD 0.84 and 0.91 mm, respectively) and significantly larger compared with CBCT alignments (SD 1.04 mm). Intraobserver variabilities are significantly smaller than corresponding interobserver variabilities (variance ratio [VR] 1.8-3.1). Compared with 3-dimensional registrations, 2-dimensional registrations have significantly smaller interobserver variability in the lateral and ventrodorsal directions (VR 3.8 and 2.8, respectively) but not in the craniocaudal direction (VR 0.75). Conclusion: Tomotherapy image guidance precision is affected by image resolution and residual deviations after setup correction. Eliminating the effect of residual deviations yields small interobserver variabilities with submillimeter precision in the axial plane. In contrast, interobserver variability in the craniocaudal direction is dominated by the poorer longitudinal MVCT image resolution. Residual deviations after image guidance exist and need to be considered when dose gradients ultimately achievable with image guided radiation therapy techniques are analyzed.« less

Megavoltage computed tomography image guidance with helical tomotherapy in patients with vertebral tumors: analysis of factors influencing interobserver variability.

PubMed

Levegrün, Sabine; Pöttgen, Christoph; Jawad, Jehad Abu; Berkovic, Katharina; Hepp, Rodrigo; Stuschke, Martin

2013-02-01

To evaluate megavoltage computed tomography (MVCT)-based image guidance with helical tomotherapy in patients with vertebral tumors by analyzing factors influencing interobserver variability, considered as quality criterion of image guidance. Five radiation oncologists retrospectively registered 103 MVCTs in 10 patients to planning kilovoltage CTs by rigid transformations in 4 df. Interobserver variabilities were quantified using the standard deviations (SDs) of the distributions of the correction vector components about the observers' fraction mean. To assess intraobserver variabilities, registrations were repeated after ≥4 weeks. Residual deviations after setup correction due to uncorrectable rotational errors and elastic deformations were determined at 3 craniocaudal target positions. To differentiate observer-related variations in minimizing these residual deviations across the 3-dimensional MVCT from image resolution effects, 2-dimensional registrations were performed in 30 single transverse and sagittal MVCT slices. Axial and longitudinal MVCT image resolutions were quantified. For comparison, image resolution of kilovoltage cone-beam CTs (CBCTs) and interobserver variability in registrations of 43 CBCTs were determined. Axial MVCT image resolution is 3.9 lp/cm. Longitudinal MVCT resolution amounts to 6.3 mm, assessed as full-width at half-maximum of thin objects in MVCTs with finest pitch. Longitudinal CBCT resolution is better (full-width at half-maximum, 2.5 mm for CBCTs with 1-mm slices). In MVCT registrations, interobserver variability in the craniocaudal direction (SD 1.23 mm) is significantly larger than in the lateral and ventrodorsal directions (SD 0.84 and 0.91 mm, respectively) and significantly larger compared with CBCT alignments (SD 1.04 mm). Intraobserver variabilities are significantly smaller than corresponding interobserver variabilities (variance ratio [VR] 1.8-3.1). Compared with 3-dimensional registrations, 2-dimensional registrations have significantly smaller interobserver variability in the lateral and ventrodorsal directions (VR 3.8 and 2.8, respectively) but not in the craniocaudal direction (VR 0.75). Tomotherapy image guidance precision is affected by image resolution and residual deviations after setup correction. Eliminating the effect of residual deviations yields small interobserver variabilities with submillimeter precision in the axial plane. In contrast, interobserver variability in the craniocaudal direction is dominated by the poorer longitudinal MVCT image resolution. Residual deviations after image guidance exist and need to be considered when dose gradients ultimately achievable with image guided radiation therapy techniques are analyzed. Copyright © 2013 Elsevier Inc. All rights reserved.

Use of Standard Deviations as Predictors in Models Using Large-Scale International Data Sets

ERIC Educational Resources Information Center

Austin, Bruce; French, Brian; Adesope, Olusola; Gotch, Chad

2017-01-01

Measures of variability are successfully used in predictive modeling in research areas outside of education. This study examined how standard deviations can be used to address research questions not easily addressed using traditional measures such as group means based on index variables. Student survey data were obtained from the Organisation for…

Screen Twice, Cut Once: Assessing the Predictive Validity of Teacher Selection Tools

ERIC Educational Resources Information Center

Goldhaber, Dan; Grout, Cyrus; Huntington-Klein, Nick

2015-01-01

It is well documented that teachers can have profound effects on student outcomes. Empirical estimates find that a one standard deviation increase in teacher quality raises student test achievement by 10 to 25 percent of a standard deviation. More recent evidence shows that the effectiveness of teachers can affect long-term student outcomes, such…

Parabolic trough receiver heat loss and optical efficiency round robin 2015/2016

NASA Astrophysics Data System (ADS)

Pernpeintner, Johannes; Schiricke, Björn; Sallaberry, Fabienne; de Jalón, Alberto García; López-Martín, Rafael; Valenzuela, Loreto; de Luca, Antonio; Georg, Andreas

2017-06-01

A round robin for parabolic trough receiver heat loss and optical efficiency in the laboratory was performed between five institutions using five receivers in 2015/2016. Heat loss testing was performed at three cartridge heater test benches and one Joule heating test bench in the temperature range between 100 °C and 550 °C. Optical efficiency testing was performed with two spectrometric test bench and one calorimetric test bench. Heat loss testing results showed standard deviations at the order of 6% to 12 % for most temperatures and receivers and a standard deviation of 17 % for one receiver at 100 °C. Optical efficiency is presented normalized for laboratories showing standard deviations of 0.3 % to 1.3 % depending on the receiver.

Benign positional vertigo and hyperuricaemia.

PubMed

Adam, A M

2005-07-01

To find out if there is any association between serum uric acid level and positional vertigo. A prospective, case controlled study. A private neurological clinic. All patients presenting with vertigo. Ninety patients were seen in this period with 78 males and 19 females. Mean age was 47 +/- 3 years (at 95% confidence level) with a standard deviation of 12.4. Their mean uric acid level was 442 +/- 16 (at 95% confidence level) with a standard deviation of 79.6 umol/l as compared to 291 +/- 17 (at 95% confidence level) with a standard deviation of 79.7 umol/l in the control group. The P-value was less than 0.001. That there is a significant association between high uric acid and benign positional vertigo.

Palus Somni - Anomalies in the correlation of Al/Si X-ray fluorescence intensity ratios and broad-spectrum visible albedos. [lunar surface mineralogy

NASA Technical Reports Server (NTRS)

Clark, P. E.; Andre, C. G.; Adler, I.; Weidner, J.; Podwysocki, M.

1976-01-01

The positive correlation between Al/Si X-ray fluorescence intensity ratios determined during the Apollo 15 lunar mission and a broad-spectrum visible albedo of the moon is quantitatively established. Linear regression analysis performed on 246 1 degree geographic cells of X-ray fluorescence intensity and visible albedo data points produced a statistically significant correlation coefficient of .78. Three distinct distributions of data were identified as (1) within one standard deviation of the regression line, (2) greater than one standard deviation below the line, and (3) greater than one standard deviation above the line. The latter two distributions of data were found to occupy distinct geographic areas in the Palus Somni region.

Screening Samples for Arsenic by Inductively Coupled Plasma-Mass Spectrometry for Treaty Samples

DTIC Science & Technology

2014-02-01

2.274 3.657 10.06 14.56 30.36 35.93 % RSD : 15.87% 4.375% 2.931% 4.473% 3.349% 3.788% 2.802% 3.883% 3.449% RSD , relative standard deviation 9   Table...107.9% 106.4% Standard Deviation: 0.3171 0.3498 0.8024 2.964 4.526 10.06 13.83 16.38 11.81 % RSD : 5.657% 3.174% 3.035% 5.507% 4.332% 3.795% 2.626...119.1% 116.5% 109.4% 106.8% 105.2% 105.5% 105.8% 108.6% 107.8% Standard Deviation: 0.2379 0.5595 1.173 2.375 2.798 5.973 11.79 15.10 30.54 % RSD

Brief communication: Swimming and diving behavior in apes (Pan troglodytes and Pongo pygmaeus): first documented report.

PubMed

Bender, Renato; Bender, Nicole

2013-09-01

Extant hominoids, including humans, are well known for their inability to swim instinctively. We report swimming and diving in two captive apes using visual observation and video recording. One common chimpanzee and one orangutan swam repeatedly at the water surface over a distance of 2-6 m; both individuals submerged repeatedly. We show that apes are able to overcome their negative buoyancy by deliberate swimming, using movements which deviate from the doggy-paddle pattern observed in other primates. We suggest that apes' poor swimming ability is due to behavioral, anatomical, and neuromotor changes related to an adaptation to arboreal life in their early phylogeny. This strong adaptive focus on arboreal life led to decreased opportunities to interact with water bodies and consequently to a reduction of selective pressure to maintain innate swimming behavior. As the doggy paddle is associated with quadrupedal walking, a deviation from terrestrial locomotion might have interfered with the fixed rhythmic action patterns responsible for innate swimming. Copyright © 2013 Wiley Periodicals, Inc.

Intra- and inter-examination repeatability of magnetic resonance spectroscopy, magnitude-based MRI, and complex-based MRI for estimation of hepatic proton density fat fraction in overweight and obese children and adults.

PubMed

Tyagi, Avishkar; Yeganeh, Omid; Levin, Yakir; Hooker, Jonathan C; Hamilton, Gavin C; Wolfson, Tanya; Gamst, Anthony; Zand, Amir K; Heba, Elhamy; Loomba, Rohit; Schwimmer, Jeffrey; Middleton, Michael S; Sirlin, Claude B

2015-10-01

Determine intra- and inter-examination repeatability of magnitude-based magnetic resonance imaging (MRI-M), complex-based magnetic resonance imaging (MRI-C), and magnetic resonance spectroscopy (MRS) at 3T for estimating hepatic proton density fat fraction (PDFF), and using MRS as a reference, confirm MRI-M and MRI-C accuracy. Twenty-nine overweight and obese pediatric (n = 20) and adult (n = 9) subjects (23 male, 6 female) underwent three same-day 3T MR examinations. In each examination MRI-M, MRI-C, and single-voxel MRS were acquired three times. For each MRI acquisition, hepatic PDFF was estimated at the MRS voxel location. Intra- and inter-examination repeatability were assessed by computing standard deviations (SDs) and intra-class correlation coefficients (ICCs). Aggregate SD was computed for each method as the square root of the average of first repeat variances. MRI-M and MRI-C PDFF estimation accuracy was assessed using linear regression with MRS as a reference. For MRI-M, MRI-C, and MRS acquisitions, respectively, mean intra-examination SDs were 0.25%, 0.42%, and 0.49%; mean intra-examination ICCs were 0.999, 0.997, and 0.995; mean inter-examination SDs were 0.42%, 0.45%, and 0.46%; and inter-examination ICCs were 0.995, 0.992, and 0.990. Aggregate SD for each method was <0.9%. Using MRS as a reference, regression slope, intercept, average bias, and R (2), respectively, for MRI-M were 0.99%, 1.73%, 1.61%, and 0.986, and for MRI-C were 0.96%, 0.43%, 0.40%, and 0.991. MRI-M, MRI-C, and MRS showed high intra- and inter-examination hepatic PDFF estimation repeatability in overweight and obese subjects. Longitudinal hepatic PDFF change >1.8% (twice the maximum aggregate SD) may represent real change rather than measurement imprecision. Further research is needed to assess whether examinations performed on different days or with different MR technologists affect repeatability of MRS voxel placement and MRS-based PDFF measurements.

Intra- and inter-examination repeatability of magnetic resonance spectroscopy, magnitude-based MRI, and complex-based MRI for estimation of hepatic proton density fat fraction in overweight and obese children and adults

PubMed Central

Tyagi, Avishkar; Yeganeh, Omid; Levin, Yakir; Hooker, Jonathan C.; Hamilton, Gavin C.; Wolfson, Tanya; Gamst, Anthony; Zand, Amir K.; Heba, Elhamy; Loomba, Rohit; Schwimmer, Jeffrey; Middleton, Michael S.; Sirlin, Claude B.

2016-01-01

Purpose Determine intra- and inter-examination repeatability of magnitude-based magnetic resonance imaging (MRI-M), complex-based magnetic resonance imaging (MRI-C), and magnetic resonance spectroscopy (MRS) at 3T for estimating hepatic proton density fat fraction (PDFF), and using MRS as a reference, confirm MRI-M and MRI-C accuracy. Methods Twenty-nine overweight and obese pediatric (n = 20) and adult (n = 9) subjects (23 male, 6 female) underwent three same-day 3T MR examinations. In each examination MRI-M, MRI-C, and single-voxel MRS were acquired three times. For each MRI acquisition, hepatic PDFF was estimated at the MRS voxel location. Intra- and inter-examination repeatability were assessed by computing standard deviations (SDs) and intra-class correlation coefficients (ICCs). Aggregate SD was computed for each method as the square root of the average of first repeat variances. MRI-M and MRI-C PDFF estimation accuracy was assessed using linear regression with MRS as a reference. Results For MRI-M, MRI-C, and MRS acquisitions, respectively, mean intra-examination SDs were 0.25%, 0.42%, and 0.49%; mean intra-examination ICCs were 0.999, 0.997, and 0.995; mean inter-examination SDs were 0.42%, 0.45%, and 0.46%; and inter-examination ICCs were 0.995, 0.992, and 0.990. Aggregate SD for each method was <0.9%. Using MRS as a reference, regression slope, intercept, average bias, and R2, respectively, for MRI-M were 0.99%, 1.73%, 1.61%, and 0.986, and for MRI-C were 0.96%, 0.43%, 0.40%, and 0.991. Conclusion MRI-M, MRI-C, and MRS showed high intra- and inter-examination hepatic PDFF estimation repeatability in overweight and obese subjects. Longitudinal hepatic PDFF change >1.8% (twice the maximum aggregate SD) may represent real change rather than measurement imprecision. Further research is needed to assess whether examinations performed on different days or with different MR technologists affect repeatability of MRS voxel placement and MRS-based PDFF measurements. PMID:26350282

A deviation display method for visualising data in mobile gamma-ray spectrometry.

PubMed

Kock, Peder; Finck, Robert R; Nilsson, Jonas M C; Ostlund, Karl; Samuelsson, Christer

2010-09-01

A real time visualisation method, to be used in mobile gamma-spectrometric search operations using standard detector systems is presented. The new method, called deviation display, uses a modified waterfall display to present relative changes in spectral data over energy and time. Using unshielded (137)Cs and (241)Am point sources and different natural background environments, the behaviour of the deviation displays is demonstrated and analysed for two standard detector types (NaI(Tl) and HPGe). The deviation display enhances positive significant changes while suppressing the natural background fluctuations. After an initialization time of about 10min this technique leads to a homogeneous display dominated by the background colour, where even small changes in spectral data are easy to discover. As this paper shows, the deviation display method works well for all tested gamma energies and natural background radiation levels and with both tested detector systems.

Labor union members play an OLG repeated game

PubMed Central

Kandori, Michihiro; Obayashi, Shinya

2014-01-01

Humans are capable of cooperating with one another even when it is costly and a deviation provides an immediate gain. An important reason is that cooperation is reciprocated or rewarded and deviations are penalized in later stages. For cooperation to be sustainable, not only must rewards and penalties be strong enough but individuals should also have the right incentives to provide rewards and punishments. Codes of conduct with such properties have been studied extensively in game theory (as repeated game equilibria), and the literature on the evolution of cooperation shows how equilibrium behavior might emerge and proliferate in society. We found that community unions, a subclass of labor unions that admits individual affiliations, are ideal to corroborate these theories with reality, because (i) their activities are simple and (ii) they have a structure that closely resembles a theoretical model, the overlapping generations repeated game. A detailed case study of a community union revealed a possible equilibrium that can function under the very limited observability in the union. The equilibrium code of conduct appears to be a natural focal point based on simple heuristic reasoning. The union we studied was created out of necessity for cooperation, without knowing or anticipating how cooperation might be sustained. The union has successfully resolved about 3,000 labor disputes and created a number of offspring. PMID:25024211

Vertical repositioning accuracy of magnetic mounting systems on 4 articulator models.

PubMed

Lee, Wonsup; Kwon, Ho-Beom

2018-03-01

Research of the ability of a cast mounted on an articulator on maintaining the identical position of a cast mounted on an articulator after repeated repositioning is lacking, despite the possible effects this may have on the occlusion of a mounted cast. The purpose of this in vitro study was to verify and compare the vertical repositioning accuracy of 4 different, commercially available articulator magnetic mounting plate systems. Four articulators and their associated magnetic mounting plates were selected for the study. These were the Artex AR articulator (Amann Girrbach AG), the Denar Mark II articulator (Whip Mix Corp), the Kavo Protar Evo articulator (Kavo Dental GmbH), and the SAM3 articulator (SAM Präzisionstechnik GmbH). Three new magnetic mounting plates were prepared for each articulator system. The repositioning accuracy of each mounting plate was evaluated by comparing the standard deviation of the vertical distances measured between the mounting plate and a laser displacement sensor. The lower arm of the articulator was secured, and the vertical distance was measured by positioning the laser displacement sensor positioned vertically above the mounting plate. Once the vertical distance was measured, the mounting plate was detached from the articulator and reattached manually to prepare for the next measurement. This procedure was repeated 30 times for each of the 3 magnetic mounting plates. Data were analyzed by ANOVA for 2-stage nested design and the Levene test (α=.05). Significant differences were detected among articulator systems and between magnetic mounting plates of the same type. The standard deviations of the measurements made with the Artex AR articulator, Denar Mark II articulator, Kavo Protar Evo articulator, and SAM3 articulator were 0.0027, 0.0308, 0.0214, and 0.0215 mm, respectively. Thus, the repositioning accuracy could be ranked in the order as follows: Artex AR, Kavo Protar Evo, SAM3, and Denar Mark II. The position of the magnetic mounting plate after repositioning did not maintain an identical position in the vertical dimension on any of the 4 articulator models tested. The repositioning accuracy of the mounting plates showed significant differences among the articulators tested in this study. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Computed tomography imaging for the characterisation of drugs with radiation density measurements and HU spectroscopy.

PubMed

Sieron, Dominik A; Steib, Moritz; Suter, Dominik; Obmann, Verena C; Huber, Adrian T; Ebner, Lukas; Inderbitzin, Daniel; Christe, Andreas

2018-01-29

To investigate the computed tomography (CT) density of frequently administered medications (1) for the better characterisation of substances on abdominal CT, (2) to allow radiologists to narrow down possibilities in the identification of hyperdense material in the bowel and (3) to provide forensic doctors with a tool to identify gastric contents before an autopsy. From the list of the local hospital pharmacy, the 50 most frequently used medications were identified and scanned twice with a 128 row CT scanner (Acquillion, Toshiba, Tokyo, Japan). The protocol comprised two tube voltages of 100 kVp and 120 kVp, with a tube current of 100 mAs, a collimation of 0.5 mm and a slice thickness of 0.5 mm. Two readers were asked to measure the density (in Hounsfield units) and the noise (standard deviation of the Hounsfield units) of each pill in the two scans (100/120 kVp). After 4 weeks, both readers repeated the measurements to test repeatability (intra-rater agreement). The behaviour of each pill in hydrochloric acid (pH 2) was examined and the dissolution time was determined. The most dense pill was Cordarone (7265 HU), and the least was Perenterol (529 HU), with an attenuation that was lower than fat density (<120 HU). The standard deviation of pixel density (noise) reflects inhomogeneity of the pharmacological product, varying from 9 to 1592 HU among the different pills (at 120 kVp). The absolute average HU increase per pill when changing to lower voltage was 78 ± 253 HU, with a linear fitting line with a slope of 0.21 as a constant variable in the density spectroscopy. After 4 hours in hydrochloric acid, only six tablets were still intact, including Flagyl and Dafalgan. The intra- and inter-rater agreements for all measurements were nearly perfect, with a correlation coefficient r of ≥0.99 (p <0.0001). Our data suggest that measuring the attenuation of drugs on CT images, including the homogeneity, and applying CT spectroscopy can narrow down possible identities of the most frequently medications. Other clinicians and forensic pathologists can perform this easy measurement, as the intra- and inter-reader variability is very small.

A randomized controlled trial investigating the effects of craniosacral therapy on pain and heart rate variability in fibromyalgia patients.

PubMed

Castro-Sánchez, Adelaida María; Matarán-Peñarrocha, Guillermo A; Sánchez-Labraca, Nuria; Quesada-Rubio, José Manuel; Granero-Molina, José; Moreno-Lorenzo, Carmen

2011-01-01

Fibromyalgia is a prevalent musculoskeletal disorder associated with widespread mechanical tenderness, fatigue, non-refreshing sleep, depressed mood and pervasive dysfunction of the autonomic nervous system: tachycardia, postural intolerance, Raynaud's phenomenon and diarrhoea. To determine the effects of craniosacral therapy on sensitive tender points and heart rate variability in patients with fibromyalgia. A randomized controlled trial. Ninety-two patients with fibromyalgia were randomly assigned to an intervention group or placebo group. Patients received treatments for 20 weeks. The intervention group underwent a craniosacral therapy protocol and the placebo group received sham treatment with disconnected magnetotherapy equipment. Pain intensity levels were determined by evaluating tender points, and heart rate variability was recorded by 24-hour Holter monitoring. After 20 weeks of treatment, the intervention group showed significant reduction in pain at 13 of the 18 tender points (P < 0.05). Significant differences in temporal standard deviation of RR segments, root mean square deviation of temporal standard deviation of RR segments and clinical global impression of improvement versus baseline values were observed in the intervention group but not in the placebo group. At two months and one year post therapy, the intervention group showed significant differences versus baseline in tender points at left occiput, left-side lower cervical, left epicondyle and left greater trochanter and significant differences in temporal standard deviation of RR segments, root mean square deviation of temporal standard deviation of RR segments and clinical global impression of improvement. Craniosacral therapy improved medium-term pain symptoms in patients with fibromyalgia.

41 CFR 102-38.30 - How does an executive agency request a deviation from the provisions of this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... which are distinct from the standard deviation process and specific to the requirements of the Federal... agency request a deviation from the provisions of this part? 102-38.30 Section 102-38.30 Public Contracts... executive agency request a deviation from the provisions of this part? Refer to §§ 102-2.60 through 102-2...

Simulation of in vivo dynamics during robot assisted joint movement.

PubMed

Bobrowitsch, Evgenij; Lorenz, Andrea; Wülker, Nikolaus; Walter, Christian

2014-12-16

Robots are very useful tools in orthopedic research. They can provide force/torque controlled specimen motion with high repeatability and precision. A method to analyze dissipative energy outcome in an entire joint was developed in our group. In a previous study, a sheep knee was flexed while axial load remained constant during the measurement of dissipated energy. We intend to apply this method for the investigation of osteoarthritis. Additionally, the method should be improved by simulation of in vivo knee dynamics. Thus, a new biomechanical testing tool will be developed for analyzing in vitro joint properties after different treatments. Discretization of passive knee flexion was used to construct a complex flexion movement by a robot and simulate altering axial load similar to in vivo sheep knee dynamics described in a previous experimental study. The robot applied an in vivo like axial force profile with high reproducibility during the corresponding knee flexion (total standard deviation of 0.025 body weight (BW)). A total residual error between the in vivo and simulated axial force was 0.16 BW. Posterior-anterior and medio-lateral forces were detected by the robot as a backlash of joint structures. Their curve forms were similar to curve forms of corresponding in vivo measured forces, but in contrast to the axial force, they showed higher total standard deviation of 0.118 and 0.203 BW and higher total residual error of 0.79 and 0.21 BW for posterior-anterior and medio-lateral forces respectively. We developed and evaluated an algorithm for the robotic simulation of complex in vivo joint dynamics using a joint specimen. This should be a new biomechanical testing tool for analyzing joint properties after different treatments.

Intra- and inter-radiation therapist reproducibility of daily isocenter verification using prostatic fiducial markers

PubMed Central

Ullman, Karen L; Ning, Holly; Susil, Robert C; Ayele, Asna; Jocelyn, Lucresse; Havelos, Jan; Guion, Peter; Xie, Huchen; Li, Guang; Arora, Barbara C; Cannon, Angela; Miller, Robert W; Norman Coleman, C; Camphausen, Kevin; Ménard, Cynthia

2006-01-01

Background We sought to determine the intra- and inter-radiation therapist reproducibility of a previously established matching technique for daily verification and correction of isocenter position relative to intraprostatic fiducial markers (FM). Materials and methods With the patient in the treatment position, anterior-posterior and left lateral electronic images are acquired on an amorphous silicon flat panel electronic portal imaging device. After each portal image is acquired, the therapist manually translates and aligns the fiducial markers in the image to the marker contours on the digitally reconstructed radiograph. The distances between the planned and actual isocenter location is displayed. In order to determine the reproducibility of this technique, four therapists repeated and recorded this operation two separate times on 20 previously acquired portal image datasets from two patients. The data were analyzed to obtain the mean variability in the distances measured between and within observers. Results The mean and median intra-observer variability ranged from 0.4 to 0.7 mm and 0.3 to 0.6 mm respectively with a standard deviation of 0.4 to 1.0 mm. Inter-observer results were similar with a mean variability of 0.9 mm, a median of 0.6 mm, and a standard deviation of 0.7 mm. When using a 5 mm threshold, only 0.5% of treatments will undergo a table shift due to intra or inter-observer error, increasing to an error rate of 2.4% if this threshold were reduced to 3 mm. Conclusion We have found high reproducibility with a previously established method for daily verification and correction of isocenter position relative to prostatic fiducial markers using electronic portal imaging. PMID:16722575

Air Pollution and Autonomic and Vascular Dysfunction in Patients With Cardiovascular Disease: Interactions of Systemic Inflammation, Overweight, and Gender

PubMed Central

Huang, Wei; Zhu, Tong; Pan, Xiaochuan; Hu, Min; Lu, Shou-En; Lin, Yong; Wang, Tong; Zhang, Yuanhang; Tang, Xiaoyan

2012-01-01

The authors conducted a 2-year follow-up of 40 cardiovascular disease patients (mean age = 65.6 years (standard deviation, 5.8)) who underwent repeated measurements of cardiovascular response before and during the 2008 Beijing Olympics (Beijing, China), when air pollution was strictly controlled. Ambient levels of particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5), black carbon, nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide were measured continuously, with validation of concurrent real-time measurements of personal exposure to PM2.5 and carbon monoxide. Linear mixed-effects models were used with adjustment for individual risk factors, time-varying factors, and meteorologic effects. Significant heart rate variability reduction and blood pressure elevation were observed in association with exposure to air pollution. Specifically, interquartile-range increases of 51.8 µg/m3, 2.02 µg/m3, and 13.7 ppb in prior 4-hour exposure to PM2.5, black carbon, and nitrogen dioxide were associated with significant reductions in the standard deviation of the normal-to-normal intervals of 4.2% (95% confidence interval (CI): 1.9, 6.4), 4.2% (95% CI: 1.8, 6.6), and 3.9% (95% CI: 2.2, 5.7), respectively. Greater heart rate variability declines were observed among subjects with C-reactive protein values above the 90th percentile, subjects with a body mass index greater than 25, and females. The authors conclude that autonomic and vascular dysfunction may be one of the mechanisms through which air pollution exposure can increase cardiovascular disease risk, especially among persons with systemic inflammation and overweight. PMID:22763390

Sci—Thur PM: Imaging — 01: Position-sensitive noise characteristics in multi-pinhole cardiac SPECT imaging

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

Cuddy-Walsh, SG; University of Ottawa Heart Institute; Wells, RG

2014-08-15

Myocardial perfusion imaging (MPI) with Single Photon Emission Computed Tomography (SPECT) is invaluable in the diagnosis and management of heart disease. It provides essential information on myocardial blood flow and ischemia. Multi-pinhole dedicated cardiac-SPECT cameras offer improved count sensitivity, and spatial and energy resolutions over parallel-hole camera designs however variable sensitivity across the field-of-view (FOV) can lead to position-dependent noise variations. Since MPI evaluates differences in the signal-to-noise ratio, noise variations in the camera could significantly impact the sensitivity of the test for ischemia. We evaluated the noise characteristics of GE Healthcare's Discovery NM530c camera with a goal of optimizingmore » the accuracy of our patient assessment and thereby improving outcomes. Theoretical sensitivity maps of the camera FOV, including attenuation effects, were estimated analytically based on the distance and angle between the spatial position of a given voxel and each pinhole. The standard deviation in counts, σ was inferred for each voxel position from the square root of the sensitivity mapped at that position. Noise was measured experimentally from repeated (N=16) acquisitions of a uniform spherical Tc-99m-water phantom. The mean (μ) and standard deviation (σ) were calculated for each voxel position in the reconstructed FOV. Noise increased ∼2.1× across a 12 cm sphere. A correlation of 0.53 is seen when experimental noise is compared with theory suggesting that ∼53% of the noise is attributed to the combined effects of attenuation and the multi-pinhole geometry. Further investigations are warranted to determine the clinical impact of the position-dependent noise variation.« less

Effects of humerus intraosseous versus intravenous amiodarone administration in a hypovolemic porcine model.

PubMed

Holloway, Cpt Monica M; Jurina, Cpt Shannan L; Orszag, Cpt Joshua D; Bragdon, Lt George R; Green, Lt Rustin D; Garcia-Blanco, Jose C; Benham, Brian E; Adams, Ltc Timothy S; Johnson, Don

2016-01-01

To compare the effects of amiodarone administration by humerus intraosseous (HIO) and intravenous (IV) routes on return of spontaneous circulation (ROSC), time to maximum concentration (Tmax), maximum plasma drug concentration (Cmax), time to ROSC, and mean concentrations over time in a hypovolemic cardiac arrest model. Prospective, between subjects, randomized experimental design. TriService Research Facility. Yorkshire-cross swine (n = 28). Swine were anesthetized and placed into cardiac arrest. After 2 minutes, cardiopulmonary resuscitation was initiated. After an additional 2 minutes, amiodarone 300 mg was administered via the HIO or the IV route. Blood samples were collected over 5 minutes. The samples were analyzed using high-performance liquid chromatography tandem mass spectrometry. ROSC, Tmax, Cmax, time to ROSC, and mean concentrations over time. There was no difference in ROSC between the HIO and IV groups; each had five achieve ROSC and two that did not (p = 1). There was no difference in Tmax (p = 0.501) or in Cmax between HIO and IV groups (p = 0.232). Means ± standard deviations in seconds were 94.3 ± 78.3 compared to 115.7 ± 87.3 in the IV versus HIO groups, respectively. The mean ± standard deviation in nanograms per milliliter for the HIO was 49,041 ± 21,107 and 74,258 ± 33,176 for the IV group. There were no significant differences between the HIO and IV groups relative to time to ROSC (p = 0.220). A repeated analysis of variance indicated that there were no significant differences between the groups relative to concentrations over time (p > 0.05). The humerus intraosseous provides rapid and reliable access to administer life-saving medications during cardiac arrest.

The Patient-Oriented Eczema Measure in young children: responsiveness and minimal clinically important difference.

PubMed

Gaunt, D M; Metcalfe, C; Ridd, M

2016-11-01

The Patient-Oriented Eczema Measure (POEM) has been recommended as the core patient-reported outcome measure for trials of eczema treatments. Using data from the Choice of Moisturiser for Eczema Treatment randomized feasibility study, we assess the responsiveness to change and determine the minimal clinically important difference (MCID) of the POEM in young children with eczema. Responsiveness to change by repeated administrations of the POEM was investigated in relation to change recalled using the Parent Global Assessment (PGA) measure. Five methods of determining the MCID of the POEM were employed; three anchor-based methods using PGA as the anchor: the within-patient score change, between-patient score change and sensitivity and specificity method, and two distribution-based methods: effect size estimate and the one half standard deviation of the baseline distribution of POEM scores. Successive POEM scores were found to be responsive to change in eczema severity. The MCID of the POEM change score, in relation to a slight improvement in eczema severity as recalled by parents on the PGA, estimated by the within-patient score change (4.27), the between-patient score change (2.89) and the sensitivity and specificity method (3.00) was similar to the one half standard deviation of the POEM baseline scores (2.94) and the effect size estimate (2.50). The Patient-Oriented Eczema Measure as applied to young children is responsive to change, and the MCID is around 3. This study will encourage the use of POEM and aid in determining sample size for future randomized controlled trials of treatments for eczema in young children. © 2016 The Authors. Allergy Published by John Wiley & Sons Ltd.

Quantitative metrics for evaluating parallel acquisition techniques in diffusion tensor imaging at 3 Tesla.

PubMed

Ardekani, Siamak; Selva, Luis; Sayre, James; Sinha, Usha

2006-11-01

Single-shot echo-planar based diffusion tensor imaging is prone to geometric and intensity distortions. Parallel imaging is a means of reducing these distortions while preserving spatial resolution. A quantitative comparison at 3 T of parallel imaging for diffusion tensor images (DTI) using k-space (generalized auto-calibrating partially parallel acquisitions; GRAPPA) and image domain (sensitivity encoding; SENSE) reconstructions at different acceleration factors, R, is reported here. Images were evaluated using 8 human subjects with repeated scans for 2 subjects to estimate reproducibility. Mutual information (MI) was used to assess the global changes in geometric distortions. The effects of parallel imaging techniques on random noise and reconstruction artifacts were evaluated by placing 26 regions of interest and computing the standard deviation of apparent diffusion coefficient and fractional anisotropy along with the error of fitting the data to the diffusion model (residual error). The larger positive values in mutual information index with increasing R values confirmed the anticipated decrease in distortions. Further, the MI index of GRAPPA sequences for a given R factor was larger than the corresponding mSENSE images. The residual error was lowest in the images acquired without parallel imaging and among the parallel reconstruction methods, the R = 2 acquisitions had the least error. The standard deviation, accuracy, and reproducibility of the apparent diffusion coefficient and fractional anisotropy in homogenous tissue regions showed that GRAPPA acquired with R = 2 had the least amount of systematic and random noise and of these, significant differences with mSENSE, R = 2 were found only for the fractional anisotropy index. Evaluation of the current implementation of parallel reconstruction algorithms identified GRAPPA acquired with R = 2 as optimal for diffusion tensor imaging.

Immediate effect of a functional wrist orthosis for children with cerebral palsy or brain injury: A randomized controlled trial.

PubMed

Jackman, Michelle; Novak, Iona; Lannin, Natasha; Galea, Claire

2017-10-28

Two-group randomized controlled trial. Upper limb orthoses worn during functional tasks are commonly used in pediatric neurologic rehabilitation, despite a paucity of high-level evidence. The purpose of this study was to investigate if a customized functional wrist orthosis, when placed on the limb, leads to an immediate improvement in hand function for children with cerebral palsy or brain injury. A 2-group randomized controlled trial involving 30 children was conducted. Participants were randomized to either receive a customized functional wrist orthosis (experimental, n = 15) or not receive an orthosis (control, n = 15). The box and blocks test was administered at baseline and repeated 1 hour after experimental intervention, with the orthosis on if randomized to the orthotic group. After intervention, there were no significant differences on the box and blocks test between the orthotic group (mean, 10.13; standard deviation, 11.476) and the no orthotic group (mean, 14.07; standard deviation, 11.106; t[28], -0.954; P = .348; and 95% confidence interval, -12.380 to 4.513). In contrast to the findings of previous studies, our results suggest that a functional wrist orthosis, when supporting the joint in a 'typical' position, may not lead to an immediate improvement in hand function. Wearing a functional wrist orthosis did not lead to an immediate improvement in the ability of children with cerebral palsy or brain injury to grasp and release. Further research is needed combining upper limb orthoses with task-specific training and measuring outcomes over the medium to long term. Copyright © 2017 Hanley & Belfus. All rights reserved.

Determination of bisphenol A, 4-octylphenol, and 4-nonylphenol in soft drinks and dairy products by ultrasound-assisted dispersive liquid-liquid microextraction combined with derivatization and high-performance liquid chromatography with fluorescence detection.

PubMed

Lv, Tao; Zhao, Xian-En; Zhu, Shuyun; Qu, Fei; Song, Cuihua; You, Jinmao; Suo, Yourui

2014-10-01

A novel hyphenated method based on ultrasound-assisted dispersive liquid-liquid microextraction coupled to precolumn derivatization has been established for the simultaneous determination of bisphenol A, 4-octylphenol, and 4-nonylphenol by high-performance liquid chromatography with fluorescence detection. Different parameters that influence microextraction and derivatization have been optimized. The quantitative linear range of analytes is 5.0-400.0 ng/L, and the correlation coefficients are more than 0.9998. Limits of detection for soft drinks and dairy products have been obtained in the range of 0.5-1.2 ng/kg and 0.01-0.04 μg/kg, respectively. Relative standard deviations of intra- and inter-day precision for retention time and peak area are in the range of 0.47-2.31 and 2.76-8.79%, respectively. Accuracy is satisfactory in the range of 81.5-118.7%. Relative standard deviations of repeatability are in the range of 0.35-1.43 and 2.36-4.75% for retention time and peak area, respectively. Enrichment factors for bisphenol A, 4-octylphenol, and 4-nonylphenol are 170.5, 240.3, and 283.2, respectively. The results of recovery and matrix effect are in the range of 82.7-114.9 and 92.0-109.0%, respectively. The proposed method has been applied to the determination of bisphenol A, 4-octylphenol, and 4-nonylphenol in soft drinks and dairy products with much higher sensitivity than many other methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of major elements by wavelength-dispersive X-ray fluorescence spectrometry and trace elements by inductively coupled plasma mass spectrometry in igneous rocks from the same fused sample (110 mg)

NASA Astrophysics Data System (ADS)

Amosova, Alena A.; Panteeva, Svetlana V.; Chubarov, Victor M.; Finkelshtein, Alexandr L.

2016-08-01

The fusion technique is proposed for simultaneous determination of 35 elements from the same sample. Only 110 mg of rock sample was used to obtain fused glasses for quantitative determination of 10 major elements by wavelength dispersive X-ray fluorescence analysis, 16 rare earth elements and some other trace elements by inductively coupled plasma mass spectrometry analysis. Fusion was performed with 1.1 g of lithium metaborate and LiBr solution as the releasing agent in platinum crucible in electric furnace at 1100 °C. The certified reference materials of ultramafic, mafic, intermediate and felsic igneous rocks have been applied to obtain the calibration curves for rock-forming oxides (Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3) and some trace elements (Ba, Sr, Zr) determination by X-ray fluorescence analysis. The repeatability does not exceed the allowable standard deviation for a wide range of concentrations. In the most cases the relative standard deviation was less than 5%. Obtained glasses were utilized for the further determination of rare earth (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and some other (Ba, Sr, Zr, Rb, Cs, Y, Nb, Hf, Ta, Th and U) trace elements by inductively coupled plasma mass spectrometry analysis with the same certified reference materials employed. The results could mostly be accepted as satisfactory. The proposed procedure essentially reduces the expenses in comparison with separate sample preparation for inductively coupled plasma mass spectrometry and X-ray fluorescence analysis.

Family structure and childhood anthropometry in Saint Paul, Minnesota in 1918

PubMed Central

Warren, John Robert

2017-01-01

Concern with childhood nutrition prompted numerous surveys of children’s growth in the United States after 1870. The Children’s Bureau’s 1918 “Weighing and Measuring Test” measured two million children to produce the first official American growth norms. Individual data for 14,000 children survives from the Saint Paul, Minnesota survey whose stature closely approximated national norms. As well as anthropometry the survey recorded exact ages, street address and full name. These variables allow linkage to the 1920 census to obtain demographic and socioeconomic information. We matched 72% of children to census families creating a sample of nearly 10,000 children. Children in the entire survey (linked set) averaged 0.74 (0.72) standard deviations below modern WHO height-for-age standards, and 0.48 (0.46) standard deviations below modern weight-for-age norms. Sibship size strongly influenced height-for-age, and had weaker influence on weight-for-age. Each additional child six or underreduced height-for-age scores by 0.07 standard deviations (95% CI: −0.03, 0.11). Teenage siblings had little effect on height-forage. Social class effects were substantial. Children of laborers averaged half a standard deviation shorter than children of professionals. Family structure and socio-economic status had compounding impacts on children’s stature. PMID:28943749

Models of Lift and Drag Coefficients of Stalled and Unstalled Airfoils in Wind Turbines and Wind Tunnels

NASA Technical Reports Server (NTRS)

Spera, David A.

2008-01-01

Equations are developed with which to calculate lift and drag coefficients along the spans of torsionally-stiff rotating airfoils of the type used in wind turbine rotors and wind tunnel fans, at angles of attack in both the unstalled and stalled aerodynamic regimes. Explicit adjustments are made for the effects of aspect ratio (length to chord width) and airfoil thickness ratio. Calculated lift and drag parameters are compared to measured parameters for 55 airfoil data sets including 585 test points. Mean deviation was found to be -0.4 percent and standard deviation was 4.8 percent. When the proposed equations were applied to the calculation of power from a stall-controlled wind turbine tested in a NASA wind tunnel, mean deviation from 54 data points was -1.3 percent and standard deviation was 4.0 percent. Pressure-rise calculations for a large wind tunnel fan deviated by 2.7 percent (mean) and 4.4 percent (standard). The assumption that a single set of lift and drag coefficient equations can represent the stalled aerodynamic behavior of a wide variety of airfoils was found to be satisfactory.

SU-F-T-326: Diode Array Transmission Detector Systems Evaluation

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

Hoffman, D; Dyer, B; Kumaran Nair, C

2016-06-15

Purpose: A new transmission detector, Delta4 Discover, developed by Scandidos (Uppsala, Sweden) was evaluated for external photon beam verification and quality assurance. The device is an array of 4040 diodes designed to be mounted on the linac accessory tray to measure photon field shape, position and fluence during patient treatment. Interfractional measurements are compared to a baseline measurement made during delivery quality assurance. The aim of this work is to evaluate the stability of the device and its effect on the shape and magnitude of the treatment beam. Methods: Beam profiles, percent depth dose, and beam attenuation was measured formore » 6, 10, and 15 MV photon beams with and without the device in place for 1×1 and 30×30 cm2 fields. Changes in profile and percent depth dose was quantified to evaluate the need to recommission the treatment beam, or account for the device with a tray factor. The stability of the radiation measurements was evaluated by measuring the deviation of each diode measurement during repeated prostate VMAT treatment delivery. Results: Photon beam profiles changed by < 1.25% in the nonpenumbra regions of the 30×30 cm2 beam. Percent depth dose curves show a 5–7% increased dose at depths < 2.5cm, but agreed within 1% at depths > 2.5cm. This indicates increased skin dose, similar to the use of a physical beam wedge. The device attenuated 6, 10, and 15 MV photon beams by 1.71±0.02%, 1.36±0.03%, and 1.17±0.03%, respectively. The diode array reproduced dosimetric measurements within 0.5% standard deviation for repeated prostate VMAT measurement. Conclusion: The device demonstrated stabile radiation measurements, while not changing the treatment beam shape in a clinically significantly manner. Use of this device can be accounted for with a tray factor, as opposed to recommissioning the treatment beam.« less

Measurement system with high accuracy for laser beam quality.

PubMed

Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

2015-05-20

Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M² factor is less than 0.6%.

SU-F-T-552: A One-Year Evaluation of the QABeamChecker+ for Use with the CyberKnife System

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

Gersh, J; Spectrum Medical Physics, LLC, Greenville, SC

Purpose: By attaching an adapter plate with fiducial markers to the QA BeamChecker+ (Standard Imaging, Inc., Middleton, WI), the output of the CyberKnife can be accurately, efficiently, and consistently evaluated. The adapter plate, known as the Cutting Board, allows for automated alignment of the QABC+ using the CK’s stereoscopic kV image-based treatment localization system (TLS). Described herein is an evaluation of the system following a year of clinical utilization. Methods: Based on a CT scan of the QABC+ and CB, a treatment plan is generated which delivers a beam to each of the 5 plane-parallel ionization chambers. Following absolute calibrationmore » of the CK, the QA plan is delivered, and baseline measurements are acquired (and automatically corrected for temperature and pressure). This test was performed at the beginning of each treatment day for a year. A calibration evaluation (using a water-equivalent slab and short thimble chamber) is performed every four weeks, or whenever the QABC+ detects a deviation of more than 1.0%. Results: During baseline evaluation, repeat measurements (n=10) were performed, with an average output of 0.25% with an SD of 0.11%. As a test of the reposition of the QABC+ and CB, ten additional measurements were performed where between each acquisition, the entire system was removed and re-positioned using the TLS. The average output deviation was 0.30% with a SD of 0.13%. During the course of the year, 187 QABC+ measurements and 13 slab-based measurements were performed. The output measurements of the QABC+ correlated well with slab-based measurements (R2=0.909). Conclusion: By using the QABC+ and CB, daily output was evaluated accurately, efficiently, and consistently. From setup to break-down (including analysis), this test required 5 minutes instead of approximately 15 using traditional techniques (collimator-mounted ionization chambers). Additionally, by automatically saving resultant output deviation to a database, trend analysis was simplified. Spectrum Medical Physics, LLC of Greenville, SC has a consulting contract with Standard Imaging of Middleton, WI.« less

Variability in CT lung-nodule quantification: Effects of dose reduction and reconstruction methods on density and texture based features.

PubMed

Lo, P; Young, S; Kim, H J; Brown, M S; McNitt-Gray, M F

2016-08-01

To investigate the effects of dose level and reconstruction method on density and texture based features computed from CT lung nodules. This study had two major components. In the first component, a uniform water phantom was scanned at three dose levels and images were reconstructed using four conventional filtered backprojection (FBP) and four iterative reconstruction (IR) methods for a total of 24 different combinations of acquisition and reconstruction conditions. In the second component, raw projection (sinogram) data were obtained for 33 lung nodules from patients scanned as a part of their clinical practice, where low dose acquisitions were simulated by adding noise to sinograms acquired at clinical dose levels (a total of four dose levels) and reconstructed using one FBP kernel and two IR kernels for a total of 12 conditions. For the water phantom, spherical regions of interest (ROIs) were created at multiple locations within the water phantom on one reference image obtained at a reference condition. For the lung nodule cases, the ROI of each nodule was contoured semiautomatically (with manual editing) from images obtained at a reference condition. All ROIs were applied to their corresponding images reconstructed at different conditions. For 17 of the nodule cases, repeat contours were performed to assess repeatability. Histogram (eight features) and gray level co-occurrence matrix (GLCM) based texture features (34 features) were computed for all ROIs. For the lung nodule cases, the reference condition was selected to be 100% of clinical dose with FBP reconstruction using the B45f kernel; feature values calculated from other conditions were compared to this reference condition. A measure was introduced, which the authors refer to as Q, to assess the stability of features across different conditions, which is defined as the ratio of reproducibility (across conditions) to repeatability (across repeat contours) of each feature. The water phantom results demonstrated substantial variability among feature values calculated across conditions, with the exception of histogram mean. Features calculated from lung nodules demonstrated similar results with histogram mean as the most robust feature (Q ≤ 1), having a mean and standard deviation Q of 0.37 and 0.22, respectively. Surprisingly, histogram standard deviation and variance features were also quite robust. Some GLCM features were also quite robust across conditions, namely, diff. variance, sum variance, sum average, variance, and mean. Except for histogram mean, all features have a Q of larger than one in at least one of the 3% dose level conditions. As expected, the histogram mean is the most robust feature in their study. The effects of acquisition and reconstruction conditions on GLCM features vary widely, though trending toward features involving summation of product between intensities and probabilities being more robust, barring a few exceptions. Overall, care should be taken into account for variation in density and texture features if a variety of dose and reconstruction conditions are used for the quantification of lung nodules in CT, otherwise changes in quantification results may be more reflective of changes due to acquisition and reconstruction conditions than in the nodule itself.

Comparison of two methods of standard setting: the performance of the three-level Angoff method.

PubMed

Jalili, Mohammad; Hejri, Sara M; Norcini, John J

2011-12-01

Cut-scores, reliability and validity vary among standard-setting methods. The modified Angoff method (MA) is a well-known standard-setting procedure, but the three-level Angoff approach (TLA), a recent modification, has not been extensively evaluated. This study aimed to compare standards and pass rates in an objective structured clinical examination (OSCE) obtained using two methods of standard setting with discussion and reality checking, and to assess the reliability and validity of each method. A sample of 105 medical students participated in a 14-station OSCE. Fourteen and 10 faculty members took part in the MA and TLA procedures, respectively. In the MA, judges estimated the probability that a borderline student would pass each station. In the TLA, judges estimated whether a borderline examinee would perform the task correctly or not. Having given individual ratings, judges discussed their decisions. One week after the examination, the procedure was repeated using normative data. The mean score for the total test was 54.11% (standard deviation: 8.80%). The MA cut-scores for the total test were 49.66% and 51.52% after discussion and reality checking, respectively (the consequent percentages of passing students were 65.7% and 58.1%, respectively). The TLA yielded mean pass scores of 53.92% and 63.09% after discussion and reality checking, respectively (rates of passing candidates were 44.8% and 12.4%, respectively). Compared with the TLA, the MA showed higher agreement between judges (0.94 versus 0.81) and a narrower 95% confidence interval in standards (3.22 versus 11.29). The MA seems a more credible and reliable procedure with which to set standards for an OSCE than does the TLA, especially when a reality check is applied. © Blackwell Publishing Ltd 2011.

Regional placental blood oxygen level dependent (BOLD) changes with gestational age in normally developing pregnancies using long duration R2* mapping in utero

NASA Astrophysics Data System (ADS)

Dighe, Manjiri; Kim, Yun Jung; Seshamani, Sharmishtaa; Blazejewska, Ania I.; Mckown, Susan; Caucutt, Jason; Gatenby, Christopher; Studholme, Colin

2016-03-01

The aim of this study was to examine the use of R2* mapping in maternal and fetal sub-regions of the placenta with the aim of providing a reference for blood oxygenation levels during normative development. There have been a number of MR relaxation studies of placental tissues in-utero, but none have reported R2* value changes with age, or examined differences in sub-regions of the placenta. Here specialized long-duration Multi-frame R2* imaging was used to create a stable estimate for R2* values in different placental regions in healthy pregnant volunteers not imaged for clinical reasons. 27 subjects were recruited and scanned up to 3 times during their pregnancy. A multi-slice dual echo EPI based BOLD acquisition was employed and repeated between 90 and 150 times over 3 to 5 minutes to provide a high accuracy estimate of the R2* signal level. Acquisitions were also repeated in 13 cases within a visit to evaluate reproducibility of the method in a given subject. Experimental results showed R2* measurements were highly repeatable within a visit with standard deviation of (0.76). Plots of all visits against gestational age indicated clear correlations showing decreases in R2* with age. This increase was consistent was also consistent over time in multiple visits of the same volunteer during their pregnancy. Maternal and fetal regional changes with gestational age followed the same trend with increase in R2* over the gestational age.

Repeated-dose effects of mequitazine, cetirizine and dexchlorpheniramine on driving and psychomotor performance.

PubMed

Theunissen, Eef L; Vermeeren, Annemiek; Ramaekers, Johannes G

2006-01-01

Previous studies have demonstrated that the antihistamines mequitazine, cetirizine and dexchlorpheniramine produce mild sedation after single doses. It is unknown, however, whether acute sedation persists after repeated dosing. Therefore, this study assessed the effects of repeated dosing of these antihistamines on driving and psychomotor performance. Sixteen healthy volunteers were treated with mequitazine 10 mg q.a.m., cetirizine 10 mg q.a.m., dexchlorpheniramine Repetab 6 mg b.i.d. and placebo for four separate 8-day periods. Drug effects were assessed on days 1 and 8 using on-the-road driving tests (highway driving and car following), psychomotor tests (tracking and divided attention) and subjective questionnaires. Dexchlorpheniramine and mequitazine significantly impaired driving performance on the highway driving test on the first day; dexchlorpheniramine increased Standard Deviation of Lateral Position by 2 cm [95% confidence interval (CI) 0.5, 3.8] and mequitazine by 2.5 cm (CI 1.0, 4.3). These effects on driving performance disappeared after 8 days of treatment. No effect of treatment was found on car following, tracking and divided attention. Although subjective ratings confirmed that subjects knew their driving had been impaired in the mequitazine and dexchlorpheniramine condition after completion of the highway driving test on day 1, they did not expect their driving to be affected before the start of the test. Cetirizine did not impair performance on any of the tests. Single doses of mequitazine 10 mg and dexchlorpheniramine Repetab 6 mg cause mild driving impairment. However, when taken over several days, the impairing effect wears off, possibly as a result of tolerance.

The impact of different cone beam computed tomography and multi-slice computed tomography scan parameters on virtual three-dimensional model accuracy using a highly precise ex vivo evaluation method.

PubMed

Matta, Ragai-Edward; von Wilmowsky, Cornelius; Neuhuber, Winfried; Lell, Michael; Neukam, Friedrich W; Adler, Werner; Wichmann, Manfred; Bergauer, Bastian

2016-05-01

Multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) are indispensable imaging techniques in advanced medicine. The possibility of creating virtual and corporal three-dimensional (3D) models enables detailed planning in craniofacial and oral surgery. The objective of this study was to evaluate the impact of different scan protocols for CBCT and MSCT on virtual 3D model accuracy using a software-based evaluation method that excludes human measurement errors. MSCT and CBCT scans with different manufacturers' predefined scan protocols were obtained from a human lower jaw and were superimposed with a master model generated by an optical scan of an industrial noncontact scanner. To determine the accuracy, the mean and standard deviations were calculated, and t-tests were used for comparisons between the different settings. Averaged over 10 repeated X-ray scans per method and 19 measurement points per scan (n = 190), it was found that the MSCT scan protocol 140 kV delivered the most accurate virtual 3D model, with a mean deviation of 0.106 mm compared to the master model. Only the CBCT scans with 0.2-voxel resolution delivered a similar accurate 3D model (mean deviation 0.119 mm). Within the limitations of this study, it was demonstrated that the accuracy of a 3D model of the lower jaw depends on the protocol used for MSCT and CBCT scans. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Quantitative characterization of color Doppler images: reproducibility, accuracy, and limitations.

PubMed

Delorme, S; Weisser, G; Zuna, I; Fein, M; Lorenz, A; van Kaick, G

1995-01-01

A computer-based quantitative analysis for color Doppler images of complex vascular formations is presented. The red-green-blue-signal from an Acuson XP10 is frame-grabbed and digitized. By matching each image pixel with the color bar, color pixels are identified and assigned to the corresponding flow velocity (color value). Data analysis consists of delineation of a region of interest and calculation of the relative number of color pixels in this region (color pixel density) as well as the mean color value. The mean color value was compared to flow velocities in a flow phantom. The thyroid and carotid artery in a volunteer were repeatedly examined by a single examiner to assess intra-observer variability. The thyroids in five healthy controls were examined by three experienced physicians to assess the extent of inter-observer variability and observer bias. The correlation between the mean color value and flow velocity ranged from 0.94 to 0.96 for a range of velocities determined by pulse repetition frequency. The average deviation of the mean color value from the flow velocity was 22% to 41%, depending on the selected pulse repetition frequency (range of deviations, -46% to +66%). Flow velocity was underestimated with inadequately low pulse repetition frequency, or inadequately high reject threshold. An overestimation occurred with inadequately high pulse repetition frequency. The highest intra-observer variability was 22% (relative standard deviation) for the color pixel density, and 9.1% for the mean color value. The inter-observer variation was approximately 30% for the color pixel density, and 20% for the mean color value. In conclusion, computer assisted image analysis permits an objective description of color Doppler images. However, the user must be aware that image acquisition under in vivo conditions as well as physical and instrumental factors may considerably influence the results.

Computer-aided analysis of digital dental impressions obtained from intraoral and extraoral scanners.

PubMed

Bohner, Lauren Oliveira Lima; De Luca Canto, Graziela; Marció, Bruno Silva; Laganá, Dalva Cruz; Sesma, Newton; Tortamano Neto, Pedro

2017-11-01

The internal and marginal adaptation of a computer-aided design and computer-aided manufacturing (CAD-CAM) prosthesis relies on the quality of the 3-dimensional image. The quality of imaging systems requires evaluation. The purpose of this in vitro study was to evaluate and compare the trueness of intraoral and extraoral scanners in scanning prepared teeth. Ten acrylic resin teeth to be used as a reference dataset were prepared according to standard guidelines and scanned with an industrial computed tomography system. Data were acquired with 4 scanner devices (n=10): the Trios intraoral scanner (TIS), the D250 extraoral scanner (DES), the Cerec Bluecam intraoral scanner (CBIS), and the Cerec InEosX5 extraoral scanner (CIES). For intraoral scanners, each tooth was digitized individually. Extraoral scanning was obtained from dental casts of each prepared tooth. The discrepancy between each scan and its respective reference model was obtained by deviation analysis (μm) and volume/area difference (μm). Statistical analysis was performed using linear models for repeated measurement factors test and 1-way ANOVA (α=.05). No significant differences in deviation values were found among scanners. For CBIS and CIES, the deviation was significantly higher (P<.05) for occlusal and cervical surfaces. With regard to volume differences, no statistically significant differences were found (TIS=340 ±230 μm; DES=380 ±360 μm; CBIS=780 ±770 μm; CIES=340 ±300 μm). Intraoral and extraoral scanners showed similar trueness in scanning prepared teeth. Higher discrepancies are expected to occur in the cervical region and on the occlusal surface. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Spatiotemporal Parameters are not Substantially Influenced by Load Carriage or Inclination During Treadmill and Overground Walking

PubMed Central

Seay, Joseph F.; Gregorczyk, Karen N.; Hasselquist, Leif

2016-01-01

Abstract Influences of load carriage and inclination on spatiotemporal parameters were examined during treadmill and overground walking. Ten soldiers walked on a treadmill and overground with three load conditions (00 kg, 20 kg, 40 kg) during level, uphill (6% grade) and downhill (-6% grade) inclinations at self-selected speed, which was constant across conditions. Mean values and standard deviations for double support percentage, stride length and a step rate were compared across conditions. Double support percentage increased with load and inclination change from uphill to level walking, with a 0.4% stance greater increase at the 20 kg condition compared to 00 kg. As inclination changed from uphill to downhill, the step rate increased more overground (4.3 ± 3.5 steps/min) than during treadmill walking (1.7 ± 2.3 steps/min). For the 40 kg condition, the standard deviations were larger than the 00 kg condition for both the step rate and double support percentage. There was no change between modes for step rate standard deviation. For overground compared to treadmill walking, standard deviation for stride length and double support percentage increased and decreased, respectively. Changes in the load of up to 40 kg, inclination of 6% grade away from the level (i.e., uphill or downhill) and mode (treadmill and overground) produced small, yet statistically significant changes in spatiotemporal parameters. Variability, as assessed by standard deviation, was not systematically lower during treadmill walking compared to overground walking. Due to the small magnitude of changes, treadmill walking appears to replicate the spatiotemporal parameters of overground walking. PMID:28149338

Odds per adjusted standard deviation: comparing strengths of associations for risk factors measured on different scales and across diseases and populations.

PubMed

Hopper, John L

2015-11-15

How can the "strengths" of risk factors, in the sense of how well they discriminate cases from controls, be compared when they are measured on different scales such as continuous, binary, and integer? Given that risk estimates take into account other fitted and design-related factors-and that is how risk gradients are interpreted-so should the presentation of risk gradients. Therefore, for each risk factor X0, I propose using appropriate regression techniques to derive from appropriate population data the best fitting relationship between the mean of X0 and all the other covariates fitted in the model or adjusted for by design (X1, X2, … , Xn). The odds per adjusted standard deviation (OPERA) presents the risk association for X0 in terms of the change in risk per s = standard deviation of X0 adjusted for X1, X2, … , Xn, rather than the unadjusted standard deviation of X0 itself. If the increased risk is relative risk (RR)-fold over A adjusted standard deviations, then OPERA = exp[ln(RR)/A] = RR(s). This unifying approach is illustrated by considering breast cancer and published risk estimates. OPERA estimates are by definition independent and can be used to compare the predictive strengths of risk factors across diseases and populations. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

Code of Federal Regulations, 2014 CFR

2014-07-01

... any repeatable deviation from normal Postage Evidencing System performance. (3) Cyber attacks that... misappropriating assets or sensitive information, corrupting data, or causing operational disruption. Cyber attacks... causing denial-of-service attacks on Web sites. Cyber attacks may be carried out by third parties or...

39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

Code of Federal Regulations, 2013 CFR

2013-07-01

... any repeatable deviation from normal Postage Evidencing System performance. (3) Cyber attacks that... misappropriating assets or sensitive information, corrupting data, or causing operational disruption. Cyber attacks... causing denial-of-service attacks on Web sites. Cyber attacks may be carried out by third parties or...

39 CFR 501.11 - Reporting Postage Evidencing System security weaknesses.

Code of Federal Regulations, 2012 CFR

2012-07-01

... any repeatable deviation from normal Postage Evidencing System performance. (3) Cyber attacks that... misappropriating assets or sensitive information, corrupting data, or causing operational disruption. Cyber attacks... causing denial-of-service attacks on Web sites. Cyber attacks may be carried out by third parties or...

The human brain processes repeated auditory feature conjunctions of low sequential probability.

PubMed

Ruusuvirta, Timo; Huotilainen, Minna

2004-01-23

The human brain is known to preattentively trace repeated sounds as holistic entities. It is not clear, however, whether the same holds true if these sounds are rare among other repeated sounds. Adult humans passively listened to a repeated tone with frequent (standard) and rare (deviant) conjunctions of its three features. Six equiprobable variants per conjunction type were assigned from a space built from these features so that the standard variants (P=0.15 each) were not inseparably traceable by means of their linear alignment in this space. Differential scalp-recorded event-related potentials to deviants indicate that the standard variants were traced as repeated wholes despite their preperceptual distinctiveness and resulting rarity among one another.

Gender Differences in Numeracy in Indonesia: Evidence from a Longitudinal Dataset

ERIC Educational Resources Information Center

Suryadarma, Daniel

2015-01-01

This paper uses a rich longitudinal dataset to measure the evolution of the gender differences in numeracy among school-age children in Indonesia. Girls outperformed boys by 0.08 standard deviations when the sample was around 11 years old. Seven years later, the gap has widened to 0.19 standard deviations, equivalent to around 18 months of…

A Survey Data Response to the Teaching of Utility Curves and Risk Aversion

ERIC Educational Resources Information Center

Hobbs, Jeffrey; Sharma, Vivek

2011-01-01

In many finance and economics courses as well as in practice, the concept of risk aversion is reduced to the standard deviation of returns, whereby risk-averse investors prefer to minimize their portfolios' standard deviations. In reality, the concept of risk aversion is richer and more interesting than this, and can easily be conveyed through…

On the Linear Relation between the Mean and the Standard Deviation of a Response Time Distribution

ERIC Educational Resources Information Center

Wagenmakers, Eric-Jan; Brown, Scott

2007-01-01

Although it is generally accepted that the spread of a response time (RT) distribution increases with the mean, the precise nature of this relation remains relatively unexplored. The authors show that in several descriptive RT distributions, the standard deviation increases linearly with the mean. Results from a wide range of tasks from different…

A novel sorbent based on carbon nanotube/amino-functionalized sol-gel for the headspace solid-phase microextraction of α-bisabolol from medicinal plant samples using experimental design.

PubMed

Yarazavi, Mina; Noroozian, Ebrahim

2018-02-13

A novel sol-gel coating on a stainless-steel fiber was developed for the first time for the headspace solid-phase microextraction and determination of α-bisabolol with gas chromatography and flame ionization detection. The parameters influencing the efficiency of solid-phase microextraction process, such as extraction time and temperature, pH, and ionic strength, were optimized by the experimental design method. Under optimized conditions, the linear range was between 0.0027 and 100 μg/mL. The relative standard deviations determined at 0.01 and 1.0 μg/mL concentration levels (n = 3), respectively, were as follows: intraday relative standard deviations 3.4 and 3.3%; interday relative standard deviations 5.0 and 4.3%; and fiber-to-fiber relative standard deviations 6.0 and 3.5%. The relative recovery values were 90.3 and 101.4% at 0.01 and 1.0 μg/mL spiking levels, respectively. The proposed method was successfully applied to various real samples containing α-bisabolol. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Estimation of Tooth Size Discrepancies among Different Malocclusion Groups

PubMed Central

Bala, Madhu; Goyal, Virender

2014-01-01

ABSTRACT Regards and Tribute: Late Dr Narender Hasija was a mentor and visionary in the light of knowledge and experience. We pay our regards with deepest gratitude to the departed soul to rest in peace. Bolton’s ratios help in estimating overbite, overjet relationships, the effects of contemplated extractions on posterior occlusion, incisor relationships and identification of occlusal misfit produced by tooth size discrepancies. Aim: To determine any difference in tooth size discrepancy in anterior as well as overall ratio in different malocclusions and comparison with Bolton’s study. Materials and methods: After measuring the teeth on all 100 patients, Bolton’s analysis was performed. Results were compared with Bolton’s means and standard deviations. The results were also subjected to statistical analysis. Results show that the mean and standard deviations of ideal occlusion cases are comparable with those Bolton but, when the mean and standard deviation of malocclusion groups are compared with those of Bolton, the values of standard deviation are higher, though the mean is comparable. How to cite this article: Hasija N, Bala M, Goyal V. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups. Int J Clin Pediatr Dent 2014;7(2):82-85. PMID:25356005

Development and operation of a quality assurance system for deviations from standard operating procedures in a clinical cell therapy laboratory.

PubMed

McKenna, D; Kadidlo, D; Sumstad, D; McCullough, J

2003-01-01

Errors and accidents, or deviations from standard operating procedures, other policy, or regulations must be documented and reviewed, with corrective actions taken to assure quality performance in a cellular therapy laboratory. Though expectations and guidance for deviation management exist, a description of the framework for the development of such a program is lacking in the literature. Here we describe our deviation management program, which uses a Microsoft Access database and Microsoft Excel to analyze deviations and notable events, facilitating quality assurance (QA) functions and ongoing process improvement. Data is stored in a Microsoft Access database with an assignment to one of six deviation type categories. Deviation events are evaluated for potential impact on patient and product, and impact scores for each are determined using a 0- 4 grading scale. An immediate investigation occurs, and corrective actions are taken to prevent future similar events from taking place. Additionally, deviation data is collectively analyzed on a quarterly basis using Microsoft Excel, to identify recurring events or developing trends. Between January 1, 2001 and December 31, 2001 over 2500 products were processed at our laboratory. During this time period, 335 deviations and notable events occurred, affecting 385 products and/or patients. Deviations within the 'technical error' category were most common (37%). Thirteen percent of deviations had a patient and/or a product impact score > or = 2, a score indicating, at a minimum, potentially affected patient outcome or moderate effect upon product quality. Real-time analysis and quarterly review of deviations using our deviation management program allows for identification and correction of deviations. Monitoring of deviation trends allows for process improvement and overall successful functioning of the QA program in the cell therapy laboratory. Our deviation management program could serve as a model for other laboratories in need of such a program.

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.

Standard deviation analysis of the mastoid fossa temperature differential reading: a potential model for objective chiropractic assessment.

PubMed

Hart, John

2011-03-01

This study describes a model for statistically analyzing follow-up numeric-based chiropractic spinal assessments for an individual patient based on his or her own baseline. Ten mastoid fossa temperature differential readings (MFTD) obtained from a chiropractic patient were used in the study. The first eight readings served as baseline and were compared to post-adjustment readings. One of the two post-adjustment MFTD readings fell outside two standard deviations of the baseline mean and therefore theoretically represents improvement according to pattern analysis theory. This study showed how standard deviation analysis may be used to identify future outliers for an individual patient based on his or her own baseline data. Copyright © 2011 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Effects of Random Shadings, Phasing Errors, and Element Failures on the Beam Patterns of Linear and Planar Arrays

DTIC Science & Technology

1980-03-14

failure Sigmar (Or) in line 50, the standard deviation of the relative error of the weights Sigmap (o) in line 60, the standard deviation of the phase...200, the weight structures in the x and y coordinates Q in line 210, the probability of element failure Sigmar (Or) in line 220, the standard...NUMBER OF ELEMENTS =u;2*H 120 PRINT "Pr’obability of elemenit failure al;O 130 PRINT "Standard dtvi&t ion’ oe r.1&tive ýrror of wl; Sigmar 14 0 PRINT

Development, optimization and validation of a rapid colorimetric microplate bioassay for neomycin sulfate in pharmaceutical drug products.

PubMed

Francisco, Fabiane Lacerda; Saviano, Alessandro Morais; Pinto, Terezinha de Jesus Andreoli; Lourenço, Felipe Rebello

2014-08-01

Microbiological assays have been used to evaluate antimicrobial activity since the discovery of the first antibiotics. Despite their limitations, microbiological assays are widely employed to determine antibiotic potency of pharmaceutical dosage forms, since they provide a measure of biological activity. The aim of this work is to develop, optimize and validate a rapid colorimetric microplate bioassay for the potency of neomycin in pharmaceutical drug products. Factorial and response surface methodologies were used in the development and optimization of the choice of microorganism, culture medium composition, amount of inoculum, triphenyltetrazolium chloride (TTC) concentration and neomycin concentration. The optimized bioassay method was validated by the assessment of linearity (range 3.0 to 5.0μg/mL, r=0.998 and 0.994 for standard and sample curves, respectively), precision (relative standard deviation (RSD) of 2.8% and 4.0 for repeatability and intermediate precision, respectively), accuracy (mean recovery=100.2%) and robustness. Statistical analysis showed equivalency between agar diffusion microbiological assay and rapid colorimetric microplate bioassay. In addition, microplate bioassay had advantages concerning the sensitivity of response, time of incubation, and amount of culture medium and solutions required. Copyright © 2014 Elsevier B.V. All rights reserved.

Performance of Mercury Triple-Point Cells Made in Brazil

NASA Astrophysics Data System (ADS)

Petkovic, S. G.; Santiago, J. F. N.; Filho, R. R.; Teixeira, R. N.; Santos, P. R. F.

2003-09-01

Fixed-points cells are primary standards in ITS-90. They contain reference material with a purity of 99.999 % or more. The gallium in a melting-point cell, for example, can reach a purity of 99.99999 %. This level of purity is not easy to obtain. However, substances like water and mercury can be purified by means of distillation and chemical procedures. This paper presents the results of mercury triple-point cells made in Brazil that were directly compared to a mercury triple-point cell of 99.999% purity. This reference cell, made by Isotech (England), was previously compared to cells from CENAM (Mexico) and NRC (Canada) and the maximum deviation found was approximately 0.4 mK. The purification stage started with a sample of mercury 99.3 % pure, and the repeated use of both mechanical and chemical processes led to a purification grade considered good enough for calibration of standard platinum resistance thermometers. The purification procedures, the method of construction of the cell, the laboratory facilities, the comparison results and the budget of uncertainties are described in this paper. All of the cells tested have a triple-point temperature within 0.25 mK of the triple-point temperature of the Inmetro reference cell.

PACS photometer calibration block analysis

NASA Astrophysics Data System (ADS)

Moór, A.; Müller, T. G.; Kiss, C.; Balog, Z.; Billot, N.; Marton, G.

2014-07-01

The absolute stability of the PACS bolometer response over the entire mission lifetime without applying any corrections is about 0.5 % (standard deviation) or about 8 % peak-to-peak. This fantastic stability allows us to calibrate all scientific measurements by a fixed and time-independent response file, without using any information from the PACS internal calibration sources. However, the analysis of calibration block observations revealed clear correlations of the internal source signals with the evaporator temperature and a signal drift during the first half hour after the cooler recycling. These effects are small, but can be seen in repeated measurements of standard stars. From our analysis we established corrections for both effects which push the stability of the PACS bolometer response to about 0.2 % (stdev) or 2 % in the blue, 3 % in the green and 5 % in the red channel (peak-to-peak). After both corrections we still see a correlation of the signals with PACS FPU temperatures, possibly caused by parasitic heat influences via the Kevlar wires which connect the bolometers with the PACS Focal Plane Unit. No aging effect or degradation of the photometric system during the mission lifetime has been found.

[Determination of metals in waste bag filter of steel works by microwave digestion-flame atomic absorption spectrometry].

PubMed

Ning, Xun-An; Zhou, Yun; Liu, Jing-Yong; Wang, Jiang-Hui; Li, Lei; Ma, Xiao-Guo

2011-09-01

A method of microwave digestion technique-flame atomic absorption spectrometry was proposed to determine the total contents of Cu, Zn, Pb, Cd, Cr and Ni in five different kinds of waste bag filters from a steel plant. The digestion effects of the six acid systems on the heavy metals digestion were studied for the first time. The relative standard deviation (RSD) of the method was between 1.02% and 9.35%, and the recovery rates obtained by standard addition method ranged from 87.7% to 105.6%. The results indicated that the proposed method exhibited the advantages of simplicity, speediness, accuracy and repeatability, and it was suitable for determining the metal elements of the waste bag filter. The results also showed that different digestion systems should be used according to different waste bag filters. The waste bag filter samples from different production processes had different metal elements content. The Pb and Zn were the highest in the waste bag filters, while the Cu, Ni, Cd and Cr were relatively lower. These determination results provided the scientific data for further treatment and disposal of the waste bag filter.

SU-E-I-59: Investigation of the Usefulness of a Standard Deviation and Mammary Gland Density as Indexes for Mammogram Classification.

PubMed

Takarabe, S; Yabuuchi, H; Morishita, J

2012-06-01

To investigate the usefulness of the standard deviation of pixel values in a whole mammary glands region and the percentage of a high- density mammary glands region to a whole mammary glands region as features for classification of mammograms into four categories based on the ACR BI-RADS breast composition. We used 36 digital mediolateral oblique view mammograms (18 patients) approved by our IRB. These images were classified into the four categories of breast compositions by an experienced breast radiologist and the results of the classification were regarded as a gold standard. First, a whole mammary region in a breast was divided into two regions such as a high-density mammary glands region and a low/iso-density mammary glands region by using a threshold value that was obtained from the pixel values corresponding to a pectoral muscle region. Then the percentage of a high-density mammary glands region to a whole mammary glands region was calculated. In addition, as a new method, the standard deviation of pixel values in a whole mammary glands region was calculated as an index based on the intermingling of mammary glands and fats. Finally, all mammograms were classified by using the combination of the percentage of a high-density mammary glands region and the standard deviation of each image. The agreement rates of the classification between our proposed method and gold standard was 86% (31/36). This result signified that our method has the potential to classify mammograms. The combination of the standard deviation of pixel values in a whole mammary glands region and the percentage of a high-density mammary glands region to a whole mammary glands region was available as features to classify mammograms based on the ACR BI- RADS breast composition. © 2012 American Association of Physicists in Medicine.

The use of three-dimensional ultrasound does not improve training in fetal biometric measurements.

PubMed

Chan, Lin W; Ting, Yuen H; Lao, Terence T; Chau, Macy M C; Fung, Tak Y; Leung, Tak Y; Sahota, Daljit S; Lau, Tze K

2011-09-01

To investigate whether three-dimensional (3D) technology offers any advantage over two-dimensional (2D) ultrasound in fetal biometric measurement training. Ten midwives with no hands-on experience in ultrasound were randomized to receive training on 2D or 3D ultrasound fetal biometry assessment. Midwives were taught how to obtain fetal biometric measurements (biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL)) by a trainer. Subsequently, each midwife measured the parameters on another 10 fetuses. The same set of measurements was repeated by the trainer. The percentage deviation between the midwives' and the trainer's measurements was determined and compared between training groups. Time required for completion was recorded. Frozen images were reviewed by another sonographer to assess the image quality using a standardized scoring system. The median time for the complete set of measurements was significantly shorter in the 2D than in 3D group (13.4 min versus 17.8 min, P = 0.03). The mean percentage deviations did not reach statistical significance between the two groups except for FL (3.83% in 2D group versus 2.23% in 3D group (P = 0.046)). There were no significant differences in the quality scores. This study showed that the only demonstrable advantage of 3D ultrasound was a slightly more accurate measurement of FL, at the expense of a significantly longer time required.

Inter- and intraobserver repeatability of the Salford Gait Tool: an observation-based clinical gait assessment tool.

PubMed

Toro, Brigitte; Nester, Christopher J; Farren, Pauline C

2007-03-01

To evaluate the inter- and intraobserver repeatability of the Salford Gait Tool (SF-GT), a new observation-based gait assessment tool for evaluating sagittal plane cerebral palsy (CP) gait. Masked comparative evaluation. University in the United Kingdom. A convenience sample of 23 pediatric physical therapists with varying degrees of clinical experience recruited from the Greater Manchester area. Participants viewed videotapes of the sagittal plane gait of 13 children and used the SF-GT to analyze their 13 different gait styles on 2 occasions. Eleven children had hemiplegic, diplegic, or quadriplegic CP and 2 were neurologically intact. Inter- and intraobserver repeatability of hip, knee, and ankle joint positions at 6 different phases of the gait cycle. The SF-GT demonstrated good interobserver (77%) and intraobserver (75%) repeatability. We have established that the SF-GT is a repeatable clinical assessment tool with which to guide the diagnosis, treatment planning, and evaluation of interventions by pediatric physical therapists of sagittal plane gait deviations in CP.

40 CFR 63.7951 - What reports must I submit and when?

Code of Federal Regulations, 2010 CFR

2010-07-01

... the information in § 63.10(d)(5)(i). (5) If there were no deviations from any emissions limitations... that there were no deviations from the emissions limitations, work practice standards, or operation and...) For each deviation from an emissions limitation (including an operating limit) that occurs at an...

Comparison of standardized uptake value-based positron emission tomography and computed tomography target volumes in esophageal cancer patients undergoing radiotherapy.

PubMed

Vali, Faisal S; Nagda, Suneel; Hall, William; Sinacore, James; Gao, Mingcheng; Lee, Steven H; Hong, Robert; Shoup, Margaret; Emami, Bahman

2010-11-15

To study various standardized uptake value (SUV)-based approaches to ascertain the best strategy for delineating metabolic tumor volumes (MTV). Twenty-two consecutive previously treated esophageal cancer patients with positron emission tomography (PET) imaging and computed tomography (CT)-based radiotherapy plans were studied. At the level of the tumor epicenter, MTVs were delineated at 11 different thresholds: SUV ≥2, ≥2.5, ≥3, ≥3.5 (SUV(n)); ≥40%, ≥45%, and ≥50% of the maximum (SUV(n%)); and mean liver SUV + 1, 2, 3, and 4 standard deviations (SUV(Lnσ)). The volume ratio and conformality index were determined between MTVs, and the corresponding CT/endoscopic ultrasound-based gross tumor volume (GTV) at the epicenter. Means were analyzed by one-way analysis of variance for repeated measures and further compared using a paired t test for repeated measures. The mean conformality indices ranged from 0.33 to 0.48, being significantly (p < 0.05) closest to 1 at SUV(2.5) (0.47 ± 0.03) and SUV(L4σ) (0.48 ± 0.03). The mean volume ratios ranged from 0.39 to 2.82, being significantly closest to 1 at SUV(2.5) (1.18 ± 0.36) and SUV(L4σ) (1.09 ± 0.15). The mean value of the SUVs calculated using the SUV(L4σ) approach was 2.4. Regardless of the SUV thresholding method used (i.e., absolute or relative to liver mean), a threshold of approximately 2.5 yields the highest conformality index and best approximates the CT-based GTV at the epicenter. These findings may ultimately aid radiation oncologists in the delineation of the entire GTV in esophageal cancer patients. Copyright © 2010 Elsevier Inc. All rights reserved.

[Fast determination of induction period of motor gasoline using Fourier transform attenuated total reflection infrared spectroscopy].

PubMed

Liu, Ya-Fei; Yuan, Hong-Fu; Song, Chun-Feng; Xie, Jin-Chun; Li, Xiao-Yu; Yan, De-Lin

2014-11-01

A new method is proposed for the fast determination of the induction period of gasoline using Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR). A dedicated analysis system with the function of spectral measurement, data processing, display and storage was designed and integrated using a Fourier transform infrared spectrometer module and chemometric software. The sample presentation accessory designed which has advantages of constant optical path, convenient sample injection and cleaning is composed of a nine times reflection attenuated total reflectance (ATR) crystal of zinc selenide (ZnSe) coated with a diamond film and a stainless steel lid with sealing device. The influence of spectral scanning number and repeated sample loading times on the spectral signal-to-noise ratio was studied. The optimum spectral scanning number is 15 times and the optimum sample loading number is 4 times. Sixty four different gasoline samples were collected from the Beijing-Tianjin area and the induction period values were determined as reference data by standard method GB/T 8018-87. The infrared spectra of these samples were collected in the operating condition mentioned above using the dedicated fast analysis system. Spectra were pretreated using mean centering and 1st derivative to reduce the influence of spectral noise and baseline shift A PLS calibration model for the induction period was established by correlating the known induction period values of the samples with their spectra. The correlation coefficient (R2), standard error of calibration (SEC) and standard error of prediction (SEP) of the model are 0.897, 68.3 and 91.9 minutes, respectively. The relative deviation of the model for gasoline induction period prediction is less than 5%, which meets the requirements of repeatability tolerance in GB method. The new method is simple and fast. It takes no more than 3 minutes to detect one sample. Therefore, the method is feasible for implementing fast determination of gasoline induction period, and of a positive meaning in the evaluation of fuel quality.

Repeated testing improves achievement in a blended learning approach for risk competence training of medical students: results of a randomized controlled trial.

PubMed

Spreckelsen, C; Juenger, J

2017-09-26

Adequate estimation and communication of risks is a critical competence of physicians. Due to an evident lack of these competences, effective training addressing risk competence during medical education is needed. Test-enhanced learning has been shown to produce marked effects on achievements. This study aimed to investigate the effect of repeated tests implemented on top of a blended learning program for risk competence. We introduced a blended-learning curriculum for risk estimation and risk communication based on a set of operationalized learning objectives, which was integrated into a mandatory course "Evidence-based Medicine" for third-year students. A randomized controlled trial addressed the effect of repeated testing on achievement as measured by the students' pre- and post-training score (nine multiple-choice items). Basic numeracy and statistical literacy were assessed at baseline. Analysis relied on descriptive statistics (histograms, box plots, scatter plots, and summary of descriptive measures), bootstrapped confidence intervals, analysis of covariance (ANCOVA), and effect sizes (Cohen's d, r) based on adjusted means and standard deviations. All of the 114 students enrolled in the course consented to take part in the study and were assigned to either the intervention or control group (both: n = 57) by balanced randomization. Five participants dropped out due to non-compliance (control: 4, intervention: 1). Both groups profited considerably from the program in general (Cohen's d for overall pre vs. post scores: 2.61). Repeated testing yielded an additional positive effect: while the covariate (baseline score) exhibits no relation to the post-intervention score, F(1, 106) = 2.88, p > .05, there was a significant effect of the intervention (repeated tests scenario) on learning achievement, F(1106) = 12.72, p < .05, d = .94, r = .42 (95% CI: [.26, .57]). However, in the subgroup of participants with a high initial numeracy score no similar effect could be observed. Dedicated training can improve relevant components of risk competence of medical students. An already promising overall effect of the blended learning approach can be improved significantly by implementing a test-enhanced learning design, namely repeated testing. As students with a high initial numeracy score did not profit equally from repeated testing, target-group specific opt-out may be offered.

Coherence Properties of Strongly Interacting Atomic Vapors in Waveguides

DTIC Science & Technology

2011-12-31

lattice in the mean-field regime [22]. There the goal was to repeat, for our system, the Chirikiov-lzrailev program for Fermi- Pasta -Ulam chain and...define a typical deviation from ergodicity), we introduce a geometric structure— based on the Frobenius or Hilbert-Schmidt inner product—to the space of

MO-F-CAMPUS-T-03: Data Driven Approaches for Determination of Treatment Table Tolerance Values for Record and Verification Systems

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

Gupta, N; DiCostanzo, D; Fullenkamp, M

2015-06-15

Purpose: To determine appropriate couch tolerance values for modern radiotherapy linac R&V systems with indexed patient setup. Methods: Treatment table tolerance values have been the most difficult to lower, due to many factors including variations in patient positioning and differences in table tops between machines. We recently installed nine linacs with similar tables and started indexing every patient in our clinic. In this study we queried our R&V database and analyzed the deviation of couch position values from the acquired values at verification simulation for all patients treated with indexed positioning. Mean and standard deviations of daily setup deviations weremore » computed in the longitudinal, lateral and vertical direction for 343 patient plans. The mean, median and standard error of the standard deviations across the whole patient population and for some disease sites were computed to determine tolerance values. Results: The plot of our couch deviation values showed a gaussian distribution, with some small deviations, corresponding to setup uncertainties on non-imaging days, and SRS/SRT/SBRT patients, as well as some large deviations which were spot checked and found to be corresponding to indexing errors that were overriden. Setting our tolerance values based on the median + 1 standard error resulted in tolerance values of 1cm lateral and longitudinal, and 0.5 cm vertical for all non- SRS/SRT/SBRT cases. Re-analizing the data, we found that about 92% of the treated fractions would be within these tolerance values (ignoring the mis-indexed patients). We also analyzed data for disease site based subpopulations and found no difference in the tolerance values that needed to be used. Conclusion: With the use of automation, auto-setup and other workflow efficiency tools being introduced into radiotherapy workflow, it is very essential to set table tolerances that allow safe treatments, but flag setup errors that need to be reassessed before treatments.« less

Repeatability of pleural adenosine deaminase measurements in diagnostic evaluation of pleural effusions.

PubMed

Kotsiou, Ourania S; Tzortzi, Panagiota; Beta, Rafailia A A; Kyritsis, Athanasios; Gourgoulianis, Konstantinos I

2018-06-01

A follow-up thoracentesis is proposed in suspected atypical tuberculosis cases. The study aimed to define the variability of pleural ADA values across repeated thoracenteses in different types of pleural effusions (PEs) and to evaluate whether ADA variance, in regard to the cutoff value of 40 U/L, affected final diagnosis. A total of 131 patients with PEs of various etiologies underwent three repeated thoracenteses. ADA values were subsequently estimated. 82% and 55% of patients had greater than 10% and 20% deviation from the highest ADA value, respectively. From those patients who had a variance of 20%, 36% had only increasing ADA values, while 19% had only decreasing values. Considering the cutoff value of 40 U/L, only in two cases, ADA decreased below this threshold, which concerned a man with tuberculous pleurisy and a woman with lymphoma both in the course of treatment. Furthermore, only in two cases with rising values, ADA finally exceeded the cutoff limit, which concerned a man with rheumatoid pleurisy and a man with tuberculous pleurisy. Surprisingly, malignant PEs (MPEs) showed a higher percentage of increasing values compared to all other exudates that did not, however, exceed the threshold. The determination of pleural ADA levels is a reproducible method for rapid tuberculosis diagnosis. The detected measurement deviations do not appear to affect final diagnosis. In specific situations, repeated ADA measurements may be valuable in directing further diagnostic evaluation. More investigation is needed to elucidate the possible prognostic significance of the increasing trend in ADA values in MPEs. © 2017 Wiley Periodicals, Inc.

Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector

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

Aaboud, M.; Aad, G.; Abbott, B.

Here, a search for the associated production of the Higgs boson with a top quark pair (more » $$t\\bar{t}$$H) is reported. The search is performed in multilepton final states using a data set corresponding to an integrated luminosity of 36.1 fb -1 of proton-proton collision data recorded by the ATLAS experiment at a center-of-mass energy $$\\sqrt{s}$$ = 13 TeV at the Large Hadron Collider. Higgs boson decays to WW*, ττ, and ZZ* are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the $$t\\bar{t}$$H production cross section is σ($$t\\bar{t}$$H) = $${790}_{-210}^{+230}$$ fb, in agreement with the Standard Model prediction of $${507}_{-50}^{+35}$$ fb. The combination of this result with other $$t\\bar{t}$$H searches from the ATLAS experiment using the Higgs boson decay modes to $$b\\bar{b}$$, γγ and ZZ* → 4ℓ, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the $$t\\bar{t}$$H production mode.« less

Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2018-04-09

Here, a search for the associated production of the Higgs boson with a top quark pair (more » $$t\\bar{t}$$H) is reported. The search is performed in multilepton final states using a data set corresponding to an integrated luminosity of 36.1 fb -1 of proton-proton collision data recorded by the ATLAS experiment at a center-of-mass energy $$\\sqrt{s}$$ = 13 TeV at the Large Hadron Collider. Higgs boson decays to WW*, ττ, and ZZ* are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the $$t\\bar{t}$$H production cross section is σ($$t\\bar{t}$$H) = $${790}_{-210}^{+230}$$ fb, in agreement with the Standard Model prediction of $${507}_{-50}^{+35}$$ fb. The combination of this result with other $$t\\bar{t}$$H searches from the ATLAS experiment using the Higgs boson decay modes to $$b\\bar{b}$$, γγ and ZZ* → 4ℓ, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the $$t\\bar{t}$$H production mode.« less

Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector

NASA Astrophysics Data System (ADS)

Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.; Abeloos, B.; Abidi, S. H.; Abouzeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adachi, S.; Adamczyk, L.; Adelman, J.; Adersberger, M.; Adye, T.; Affolder, A. A.; Afik, Y.; Agheorghiesei, C.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akatsuka, S.; Åkesson, T. P. A.; Akilli, E.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albicocco, P.; Alconada Verzini, M. J.; Alderweireldt, S. C.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Ali, B.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allaire, C.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alshehri, A. A.; Alstaty, M. I.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amaral Coutinho, Y.; Ambroz, L.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amoroso, S.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Angerami, A.; Anisenkov, A. V.; Annovi, A.; Antel, C.; Antonelli, M.; Antonov, A.; Antrim, D. J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Araujo Ferraz, V.; Arce, A. T. H.; Ardell, R. E.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkin, R. J.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Avramidou, R.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Bagnaia, P.; Bahmani, M.; Bahrasemani, H.; Baines, J. T.; Bajic, M.; Baker, O. K.; Bakker, P. J.; Bakshi Gupta, D.; Baldin, E. M.; Balek, P.; Balli, F.; Balunas, W. K.; Banas, E.; Bandyopadhyay, A.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisits, M.-S.; Barkeloo, J. T.; Barklow, T.; Barlow, N.; Barnea, R.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska-Blenessy, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barranco Navarro, L.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bauer, K. T.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Beck, H. C.; Becker, K.; Becker, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beermann, T. A.; Begalli, M.; Begel, M.; Behera, A.; Behr, J. K.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez, J.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Bergsten, L. J.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernardi, G.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertram, I. A.; Bertsche, C.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Bethani, A.; Bethke, S.; Betti, A.; Bevan, A. J.; Beyer, J.; Bianchi, R. M.; Biebel, O.; Biedermann, D.; Bielski, R.; Bierwagen, K.; Biesuz, N. V.; Biglietti, M.; Billoud, T. R. V.; Bindi, M.; Bingul, A.; Bini, C.; Biondi, S.; Bisanz, T.; Bittrich, C.; Bjergaard, D. M.; Black, J. E.; Black, K. M.; Blair, R. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blue, A.; Blumenschein, U.; Blunier, Dr.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. 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I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tu, Y.; Tudorache, A.; Tudorache, V.; Tulbure, T. T.; Tuna, A. N.; Turchikhin, S.; Turgeman, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Ucchielli, G.; Ueda, I.; Ughetto, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Uno, K.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usui, J.; Vacavant, L.; Vacek, V.; Vachon, B.; Vadla, K. O. H.; Vaidya, A.; Valderanis, C.; Valdes Santurio, E.; Valente, M.; Valentinetti, S.; Valero, A.; Valéry, L.; Vallier, A.; Valls Ferrer, J. A.; van den Wollenberg, W.; van der Graaf, H.; van Gemmeren, P.; van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vari, R.; Varnes, E. W.; Varni, C.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasquez, J. G.; Vasquez, G. A.; Vazeille, F.; Vazquez Furelos, D.; Vazquez Schroeder, T.; Veatch, J.; Vecchio, V.; Veloce, L. M.; Veloso, F.; Veneziano, S.; Ventura, A.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, A. T.; Vermeulen, J. C.; Vetterli, M. C.; Viaux Maira, N.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigani, L.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vishwakarma, A.; Vittori, C.; Vivarelli, I.; Vlachos, S.; Vogel, M.; Vokac, P.; Volpi, G.; von Buddenbrock, S. E.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Wagner, W.; Wagner-Kuhr, J.; Wahlberg, H.; Wahrmund, S.; Wakamiya, K.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, A. M.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, Q.; Wang, R.-J.; Wang, R.; Wang, S. M.; Wang, T.; Wang, W.; Wang, W.; Wang, Z.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. 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M.; Xella, S.; Xi, Z.; Xia, L.; Xu, D.; Xu, L.; Xu, T.; Xu, W.; Yabsley, B.; Yacoob, S.; Yajima, K.; Yallup, D. P.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamanaka, T.; Yamane, F.; Yamatani, M.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, S.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yigitbasi, E.; Yildirim, E.; Yorita, K.; Yoshihara, K.; Young, C.; Young, C. J. S.; Yu, J.; Yu, J.; Yuen, S. P. Y.; Yusuff, I.; Zabinski, B.; Zacharis, G.; Zaidan, R.; Zaitsev, A. M.; Zakharchuk, N.; Zalieckas, J.; Zambito, S.; Zanzi, D.; Zeitnitz, C.; Zemaityte, G.; Zeng, J. C.; Zeng, Q.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, L.; Zhang, M.; Zhang, P.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Y.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, M.; Zhou, M.; Zhou, N.; Zhou, Y.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zhulanov, V.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zou, R.; Zur Nedden, M.; Zwalinski, L.; Atlas Collaboration

2018-04-01

A search for the associated production of the Higgs boson with a top quark pair (t t ¯H ) is reported. The search is performed in multilepton final states using a data set corresponding to an integrated luminosity of 36.1 fb-1 of proton-proton collision data recorded by the ATLAS experiment at a center-of-mass energy √{s }=13 TeV at the Large Hadron Collider. Higgs boson decays to W W*, τ τ , and Z Z* are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the t t ¯H production cross section is σ (t t ¯H )=79 0-210+230 fb , in agreement with the Standard Model prediction of 50 7-50+35 fb . The combination of this result with other t t ¯H searches from the ATLAS experiment using the Higgs boson decay modes to b b ¯, γ γ and Z Z*→4 ℓ, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the t t ¯H production mode.

WASP (Write a Scientific Paper) using Excel -5: Quartiles and standard deviation.

PubMed

Grech, Victor

2018-03-01

The almost inevitable descriptive statistics exercise that is undergone once data collection is complete, prior to inferential statistics, requires the acquisition of basic descriptors which may include standard deviation and quartiles. This paper provides pointers as to how to do this in Microsoft Excel™ and explains the relationship between the two. Copyright © 2018 Elsevier B.V. All rights reserved.

Validation Test Report for GDEM4

DTIC Science & Technology

2010-08-19

standard deviations called the Generalized Digital Environmental Model ( GDEM ). The present document describes the development and evaluation of GDEM4...the newest version of GDEM . As part of the evaluation of GDEM4, comparisons are made in this report to GDEM3 and to four other ocean climatologies...depth climatology of temperature and salinity and their standard deviations called the Generalized Digital Environmental Model ( GDEM ). The history of

40 CFR 91.508 - Cumulative Sum (CumSum) procedure.

Code of Federal Regulations, 2010 CFR

2010-07-01

... family may be determined to be in noncompliance for purposes of § 91.510. H = The Action Limit. It is 5.0 × σ, and is a function of the standard deviation, σ. σ = is the sample standard deviation and is... Equation must be final deteriorated test results as defined in § 91.509(c). Ci = max[0 0R (Ci-1 + Xi − (FEL...

Modeling the Zeeman effect in high altitude SSMIS channels for numerical weather prediction profiles: comparing a fast model and a line-by-line model

NASA Astrophysics Data System (ADS)

Larsson, R.; Milz, M.; Rayer, P.; Saunders, R.; Bell, W.; Booton, A.; Buehler, S. A.; Eriksson, P.; John, V.

2015-10-01

We present a comparison of a reference and a fast radiative transfer model using numerical weather prediction profiles for the Zeeman-affected high altitude Special Sensor Microwave Imager/Sounder channels 19-22. We find that the models agree well for channels 21 and 22 compared to the channels' system noise temperatures (1.9 and 1.3 K, respectively) and the expected profile errors at the affected altitudes (estimated to be around 5 K). For channel 22 there is a 0.5 K average difference between the models, with a standard deviation of 0.24 K for the full set of atmospheric profiles. Same channel, there is 1.2 K in average between the fast model and the sensor measurement, with 1.4 K standard deviation. For channel 21 there is a 0.9 K average difference between the models, with a standard deviation of 0.56 K. Same channel, there is 1.3 K in average between the fast model and the sensor measurement, with 2.4 K standard deviation. We consider the relatively small model differences as a validation of the fast Zeeman effect scheme for these channels. Both channels 19 and 20 have smaller average differences between the models (at below 0.2 K) and smaller standard deviations (at below 0.4 K) when both models use a two-dimensional magnetic field profile. However, when the reference model is switched to using a full three-dimensional magnetic field profile, the standard deviation to the fast model is increased to almost 2 K due to viewing geometry dependencies causing up to ± 7 K differences near the equator. The average differences between the two models remain small despite changing magnetic field configurations. We are unable to compare channels 19 and 20 to sensor measurements due to limited altitude range of the numerical weather prediction profiles. We recommended that numerical weather prediction software using the fast model takes the available fast Zeeman scheme into account for data assimilation of the affected sensor channels to better constrain the upper atmospheric temperatures.

Modeling the Zeeman effect in high-altitude SSMIS channels for numerical weather prediction profiles: comparing a fast model and a line-by-line model

NASA Astrophysics Data System (ADS)

Larsson, Richard; Milz, Mathias; Rayer, Peter; Saunders, Roger; Bell, William; Booton, Anna; Buehler, Stefan A.; Eriksson, Patrick; John, Viju O.

2016-03-01

We present a comparison of a reference and a fast radiative transfer model using numerical weather prediction profiles for the Zeeman-affected high-altitude Special Sensor Microwave Imager/Sounder channels 19-22. We find that the models agree well for channels 21 and 22 compared to the channels' system noise temperatures (1.9 and 1.3 K, respectively) and the expected profile errors at the affected altitudes (estimated to be around 5 K). For channel 22 there is a 0.5 K average difference between the models, with a standard deviation of 0.24 K for the full set of atmospheric profiles. Concerning the same channel, there is 1.2 K on average between the fast model and the sensor measurement, with 1.4 K standard deviation. For channel 21 there is a 0.9 K average difference between the models, with a standard deviation of 0.56 K. Regarding the same channel, there is 1.3 K on average between the fast model and the sensor measurement, with 2.4 K standard deviation. We consider the relatively small model differences as a validation of the fast Zeeman effect scheme for these channels. Both channels 19 and 20 have smaller average differences between the models (at below 0.2 K) and smaller standard deviations (at below 0.4 K) when both models use a two-dimensional magnetic field profile. However, when the reference model is switched to using a full three-dimensional magnetic field profile, the standard deviation to the fast model is increased to almost 2 K due to viewing geometry dependencies, causing up to ±7 K differences near the equator. The average differences between the two models remain small despite changing magnetic field configurations. We are unable to compare channels 19 and 20 to sensor measurements due to limited altitude range of the numerical weather prediction profiles. We recommended that numerical weather prediction software using the fast model takes the available fast Zeeman scheme into account for data assimilation of the affected sensor channels to better constrain the upper atmospheric temperatures.