MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE MATTER (PMC) CONCENTRATIONS

EPA Science Inventory

Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discret...

MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE MATTER (PMC) CONCENTRATIONS

EPA Science Inventory

Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discrete ...

INNOVATIVE TECHNOLOGY VERIFICATION REPORT XRF ...

EPA Pesticide Factsheets

The Elvatech, Ltd. ElvaX (ElvaX) x-ray fluorescence (XRF) analyzer distributed in the United States by Xcalibur XRF Services (Xcalibur), was demonstrated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program. The field portion of the demonstration was conducted in January 2005 at the Kennedy Athletic, Recreational and Social Park (KARS) at Kennedy Space Center on Merritt Island, Florida. The demonstration was designed to collect reliable performance and cost data for the ElvaX analyzer and seven other commercially available XRF instruments for measuring trace elements in soil and sediment. The performance and cost data were evaluated to document the relative performance of each XRF instrument. This innovative technology verification report describes the objectives and the results of that evaluation and serves to verify the performance and cost of the ElvaX analyzer. Separate reports have been prepared for the other XRF instruments that were evaluated as part of the demonstration. The objectives of the evaluation included determining each XRF instrument’s accuracy, precision, sample throughput, and tendency for matrix effects. To fulfill these objectives, the field demonstration incorporated the analysis of 326 prepared samples of soil and sediment that contained 13 target elements. The prepared samples included blends of environmental samples from nine different sample collection sites as well as s

Analytical and clinical performance of the Hologic Aptima HCV Quant Dx Assay for the quantification of HCV RNA in plasma samples.

PubMed

Schønning, Kristian; Pedersen, Martin Schou; Johansen, Kim; Landt, Bodil; Nielsen, Lone Gilmor; Weis, Nina; Westh, Henrik

2017-10-01

Chronic hepatitis C virus (HCV) infection can be effectively treated with directly acting antiviral (DAA) therapy. Measurement of HCV RNA is used to evaluate patient compliance and virological response during and after treatment. To compare the analytical performance of the Aptima HCV Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HCV Test v2.0 (CAPCTMv2) for the quantification of HCV RNA in plasma samples, and compare the clinical utility of the two tests in patients undergoing treatment with DAA therapy. Analytical performance was evaluated on two sets of plasma samples: 125 genotyped samples and 172 samples referred for quantification of HCV RNA. Furthermore, performance was evaluated using dilutions series of four samples containing HCV genotype 1a, 2b, 3a, and 4a, respectively. Clinical utility was evaluated on 118 plasma samples obtained from 13 patients undergoing treatment with DAAs. Deming regression of results from 187 plasma samples with HCV RNA >2 Log IU/mL indicated that the Aptima assay quantified higher than the CAPCTMv2 test for HCV RNA >4.9 Log IU/mL. The linearity of the Aptima assay was excellent across dilution series of four HCV genotypes (slope of the regression line: 1.00-1.02). The Aptima assay detected significantly more replicates below targeted 2 Log IU/mL than the CAPCTMv2 test, and yielded clearly interpretable results when used to analyze samples from patients treated with DAAs. The analytical performance of the Aptima assay makes it well suited for monitoring patients with chronic HCV infection undergoing antiviral treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

[Assessment comparison between area sampling and personal sampling noise measurement in new thermal power plant].

PubMed

Zhang, Hua; Chen, Qing-song; Li, Nan; Hua, Yan; Zeng, Lin; Xu, Guo-yang; Tao, Li-yuan; Zhao, Yi-ming

2013-05-01

To compare the results of noise hazard evaluations based on area sampling and personal sampling in a new thermal power plant and to analyze the similarities and differences between the two measurement methods. According to Measurement of Physical agents in Workplace Part 8: Noise(GBZff 189.8-2007), area sampling was performed at various operating points for noise measurement, and meanwhile the workers under different types of work wore noise dosimeters for personal noise exposure measurement. The two measurement methods were used to evaluate the level of noise hazards in the enterprise according to the corresponding occupational health standards, and the evaluation results were compared. Area sampling was performed at 99 operating points, the mean noise level was 88.9 ± 11.1 dB (A)(range, 51.3-107.0 dB (A)), with an over-standard rate of 75.8%. Personal sampling was performed (73 person times),and the mean noise level was 79.3 ± 6.3 dB (A), with an over-standard rate of 6.6% ( 16/241 ). There was a statistically significant difference in the over-standard rate between the evaluation results of the two measurement methods ( x2=53.869, ?<0.001 ). Because of the characteristics of the work in new thermal power plants, the noise hazard evaluation based on area sampling cannot be used instead of personal noise exposure measurement among workers. Personal sampling should be used in the noise measurement in new thermal power plant.

The Evaluation of Teachers' Job Performance Based on Total Quality Management (TQM)

ERIC Educational Resources Information Center

Shahmohammadi, Nayereh

2017-01-01

This study aimed to evaluate teachers' job performance based on total quality management (TQM) model. This was a descriptive survey study. The target population consisted of all primary school teachers in Karaj (N = 2917). Using Cochran formula and simple random sampling, 340 participants were selected as sample. A total quality management…

EVALUATION OF A NEW MEAN SCALED AND MOMENT ADJUSTED TEST STATISTIC FOR SEM.

PubMed

Tong, Xiaoxiao; Bentler, Peter M

2013-01-01

Recently a new mean scaled and skewness adjusted test statistic was developed for evaluating structural equation models in small samples and with potentially nonnormal data, but this statistic has received only limited evaluation. The performance of this statistic is compared to normal theory maximum likelihood and two well-known robust test statistics. A modification to the Satorra-Bentler scaled statistic is developed for the condition that sample size is smaller than degrees of freedom. The behavior of the four test statistics is evaluated with a Monte Carlo confirmatory factor analysis study that varies seven sample sizes and three distributional conditions obtained using Headrick's fifth-order transformation to nonnormality. The new statistic performs badly in most conditions except under the normal distribution. The goodness-of-fit χ(2) test based on maximum-likelihood estimation performed well under normal distributions as well as under a condition of asymptotic robustness. The Satorra-Bentler scaled test statistic performed best overall, while the mean scaled and variance adjusted test statistic outperformed the others at small and moderate sample sizes under certain distributional conditions.

Low-Level Analytical Methodology Updates to Support Decontaminant Performance Evaluations

DTIC Science & Technology

2011-06-01

from EPDM and tire rubber coupon materials that were spiked with a known amount of the chemical agent VX, treated with bleach decontaminant, and...to evaluate the performance of bleach decontaminant on EPDM and tire rubber coupons. Dose-confirmation or Tool samples were collected by delivering...components • An aging or damaged analytical column • Dirty detector • Other factors related to general instrument and/or sample analysis performance

GICHD mine dog testing project : soil sample results #5.

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

Barnett, James L.; Phelan, James M.; Archuleta, Luisa M.

2004-01-01

A mine dog evaluation project initiated by the Geneva International Center for Humanitarian Demining is evaluating the capability and reliability of mine detection dogs. The performance of field-operational mine detection dogs will be measured in test minefields in Afghanistan containing actual, but unfused landmines. Repeated performance testing over two years through various seasonal weather conditions will provide data simulating near real world conditions. Soil samples will be obtained adjacent to the buried targets repeatedly over the course of the test. Chemical analysis results from these soil samples will be used to evaluate correlations between mine dog detection performance and seasonalmore » weather conditions. This report documents the analytical chemical methods and results from the fifth batch of soils received. This batch contained samples from Kharga, Afghanistan collected in June 2003.« less

Performance evaluation of no-reference image quality metrics for face biometric images

NASA Astrophysics Data System (ADS)

Liu, Xinwei; Pedersen, Marius; Charrier, Christophe; Bours, Patrick

2018-03-01

The accuracy of face recognition systems is significantly affected by the quality of face sample images. The recent established standardization proposed several important aspects for the assessment of face sample quality. There are many existing no-reference image quality metrics (IQMs) that are able to assess natural image quality by taking into account similar image-based quality attributes as introduced in the standardization. However, whether such metrics can assess face sample quality is rarely considered. We evaluate the performance of 13 selected no-reference IQMs on face biometrics. The experimental results show that several of them can assess face sample quality according to the system performance. We also analyze the strengths and weaknesses of different IQMs as well as why some of them failed to assess face sample quality. Retraining an original IQM by using face database can improve the performance of such a metric. In addition, the contribution of this paper can be used for the evaluation of IQMs on other biometric modalities; furthermore, it can be used for the development of multimodality biometric IQMs.

Rmax: A systematic approach to evaluate instrument sort performance using center stream catch☆

PubMed Central

Riddell, Andrew; Gardner, Rui; Perez-Gonzalez, Alexis; Lopes, Telma; Martinez, Lola

2015-01-01

Sorting performance can be evaluated with regard to Purity, Yield and/or Recovery of the sorted fraction. Purity is a check on the quality of the sample and the sort decisions made by the instrument. Recovery and Yield definitions vary with some authors regarding both as how efficient the instrument is at sorting the target particles from the original sample, others distinguishing Recovery from Yield, where the former is used to describe the accuracy of the instrument’s sort count. Yield and Recovery are often neglected, mostly due to difficulties in their measurement. Purity of the sort product is often cited alone but is not sufficient to evaluate sorting performance. All of these three performance metrics require re-sampling of the sorted fraction. But, unlike Purity, calculating Yield and/or Recovery calls for the absolute counting of particles in the sorted fraction, which may not be feasible, particularly when dealing with rare populations and precious samples. In addition, the counting process itself involves large errors. Here we describe a new metric for evaluating instrument sort Recovery, defined as the number of particles sorted relative to the number of original particles to be sorted. This calculation requires only measuring the ratios of target and non-target populations in the original pre-sort sample and in the waste stream or center stream catch (CSC), avoiding re-sampling the sorted fraction and absolute counting. We called this new metric Rmax, since it corresponds to the maximum expected Recovery for a particular set of instrument parameters. Rmax is ideal to evaluate and troubleshoot the optimum drop-charge delay of the sorter, or any instrument related failures that will affect sort performance. It can be used as a daily quality control check but can be particularly useful to assess instrument performance before single-cell sorting experiments. Because we do not perturb the sort fraction we can calculate Rmax during the sort process, being especially valuable to check instrument performance during rare population sorts. PMID:25747337

Skylab experiment performance evaluation manual. Appendix S: Experiment T027 contamination measurement sample array (MSFC)

NASA Technical Reports Server (NTRS)

Tonetti, B. B.

1973-01-01

Analyses for Experiment T027, Contamination Measurement Sample Array (MSFC), to be used for evaluating the performance of the Skylab corrollary experiments under preflight, inflight, and post-flight conditions are presented. Experiment contingency plan workaround procedure and malfunction analyses are presented in order to assist in making the experiment operationally successful.

Performance review using sequential sampling and a practice computer.

PubMed

Difford, F

1988-06-01

The use of sequential sample analysis for repeated performance review is described with examples from several areas of practice. The value of a practice computer in providing a random sample from a complete population, evaluating the parameters of a sequential procedure, and producing a structured worksheet is discussed. It is suggested that sequential analysis has advantages over conventional sampling in the area of performance review in general practice.

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

Bush, Richard; Lemke, Peter

The groundwater compliance strategy for the Tuba City, Arizona, Disposal Site is defined in the 1999 Phase I Ground Water Compliance Action Plan for the Tuba City, Arizona, UMTRA Site. Samples are collected and analyzed on a semiannual basis to evaluate the performance of the Phase I remediation system. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). U.S. Environmental Protection Agency (EPA) groundwater standards were exceeded in samples collected from monitoring wells as listed in Table 1. The data from this sampling eventmore » are generally consistent with previously obtained values and are acceptable for general use as qualified. Data anomalies are not significant with respect to the known nature and extent of contamination and progress of remedial action at the site. The data from this sampling event will be incorporated into the annual performance evaluation report that will present a comprehensive hydrologic summary and evaluation of groundwater remedial action performance at the Tuba City site through March 2016.« less

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

Bush, Richard; Lemke, Peter

The groundwater compliance strategy for the Tuba City, Arizona, Disposal Site is defined in the 1999 Phase I Ground Water Compliance Action Plan for the Tuba City, Arizona, UMTRA Site. Samples are collected and analyzed on a semiannual basis to evaluate the performance of the Phase I remediation system. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). U.S. Environmental Protection Agency (EPA) groundwater standards were exceeded in samples collected from monitoring wells and extraction wells as listed in Table 1. The data frommore » this sampling event are generally consistent with previously obtained values and are acceptable for general use as qualified. Data anomalies are not significant with respect to the known nature and extent of contamination and progress of remedial action at the site. The data from this sampling event will be incorporated into the annual performance evaluation report that will present a comprehensive hydrologic summary and evaluation of groundwater remedial action performance at the Tuba City site through March 2016.« less

Field evaluation of personal sampling methods for multiple bioaerosols.

PubMed

Wang, Chi-Hsun; Chen, Bean T; Han, Bor-Cheng; Liu, Andrew Chi-Yeu; Hung, Po-Chen; Chen, Chih-Yong; Chao, Hsing Jasmine

2015-01-01

Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols.

78 FR 11171 - Proposed Information Collection Request; Comment Request; RadNet (Renewal)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

...) Evaluate whether the proposed collection of information is necessary for the proper performance of the functions of the Agency, including whether the information will have practical utility; (ii) evaluate the... request descriptive information pertaining to sample location, e.g., sample type, sample location, length...

(PRESENTED NAQC SAN FRANCISCO, CA) COARSE PM METHODS STUDY: STUDY DESIGN AND RESULTS

EPA Science Inventory

Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discrete ...

European Multicenter Study on Analytical Performance of DxN Veris System HCV Assay.

PubMed

Braun, Patrick; Delgado, Rafael; Drago, Monica; Fanti, Diana; Fleury, Hervé; Gismondo, Maria Rita; Hofmann, Jörg; Izopet, Jacques; Kühn, Sebastian; Lombardi, Alessandra; Marcos, Maria Angeles; Sauné, Karine; O'Shea, Siobhan; Pérez-Rivilla, Alfredo; Ramble, John; Trimoulet, Pascale; Vila, Jordi; Whittaker, Duncan; Artus, Alain; Rhodes, Daniel W

2017-04-01

The analytical performance of the Veris HCV Assay for use on the new and fully automated Beckman Coulter DxN Veris Molecular Diagnostics System (DxN Veris System) was evaluated at 10 European virology laboratories. Precision, analytical sensitivity, specificity, and performance with negative samples, linearity, and performance with hepatitis C virus (HCV) genotypes were evaluated. Precision for all sites showed a standard deviation (SD) of 0.22 log 10 IU/ml or lower for each level tested. Analytical sensitivity determined by probit analysis was between 6.2 and 9.0 IU/ml. Specificity on 94 unique patient samples was 100%, and performance with 1,089 negative samples demonstrated 100% not-detected results. Linearity using patient samples was shown from 1.34 to 6.94 log 10 IU/ml. The assay demonstrated linearity upon dilution with all HCV genotypes. The Veris HCV Assay demonstrated an analytical performance comparable to that of currently marketed HCV assays when tested across multiple European sites. Copyright © 2017 American Society for Microbiology.

Routine low-level monitoring of polar pesticides and pesticide degradates by HPLC/ESI-MS: Evaluating long-term performance

USGS Publications Warehouse

Furlong, E.T.; Martin, Jeffrey D.; Werner, S.L.; Gates, Paul M.

2002-01-01

The sensitivity and selective determination of polar pesticides were analyzed using high-performance liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS). The effects of multiple operators and instruments on method performance were evaluated using 440 pairs of fortified reagent-water and blank reagent-water samples. The influence of varying environmental matrices on recovery and precision were also analyzed using 200 fortified ambient water samples and duplicate ambient water samples. The results show that compound stability in filtered water was matrix-, chemical class- and compound-dependent which ranged from 1 day to 2 weeks.

Results of the U. S. Geological Survey's analytical evaluation program for standard reference samples distributed in April 2001

USGS Publications Warehouse

Woodworth, M.T.; Connor, B.F.

2001-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-165 (trace constituents), M-158 (major constituents), N-69 (nutrient constituents), N-70 (nutrient constituents), P-36 (low ionic-strength constituents), and Hg-32 (mercury) -- that were distributed in April 2001 to laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data received from 73 laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U. S. Geological Survey's Analytical Evaluation Program for Standard Reference Samples Distributed in March 2002

USGS Publications Warehouse

Woodworth, M.T.; Conner, B.F.

2002-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T- 169 (trace constituents), M- 162 (major constituents), N-73 (nutrient constituents), N-74 (nutrient constituents), P-38 (low ionic-strength constituents), and Hg-34 (mercury) -- that were distributed in March 2002 to laboratories enrolled in the U.S. Geological Survey sponsored intedaboratory testing program. Analytical data received from 93 laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U.S. Geological Survey's analytical evaluation program for standard reference samples distributed in September 2002

USGS Publications Warehouse

Woodworth, Mark T.; Connor, Brooke F.

2003-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-171 (trace constituents), M-164 (major constituents), N-75 (nutrient constituents), N-76 (nutrient constituents), P-39 (low ionic-strength constituents), and Hg-35 (mercury) -- that were distributed in September 2002 to laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data received from 102 laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U.S. Geological Survey's analytical evaluation program for standard reference samples distributed in September 2001

USGS Publications Warehouse

Woodworth, Mark T.; Connor, Brooke F.

2002-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-167 (trace constituents), M-160 (major constituents), N-71 (nutrient constituents), N-72 (nutrient constituents), P-37 (low ionic-strength constituents), and Hg-33 (mercury) -- that were distributed in September 2001 to laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data received from 98 laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U.S. Geological Survey's Analytical Evaluation Program for Standard Reference Samples Distributed in March 2000

USGS Publications Warehouse

Farrar, Jerry W.; Copen, Ashley M.

2000-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-161 (trace constituents), M-154 (major constituents), N-65 (nutrient constituents), N-66 nutrient constituents), P-34 (low ionic strength constituents), and Hg-30 (mercury) -- that were distributed in March 2000 to 144 laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 132 of the laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U.S. Geological Survey's analytical evaluation program for standard reference samples distributed in October 1999

USGS Publications Warehouse

Farrar, T.W.

2000-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-159 (trace constituents), M-152 (major constituents), N-63 (nutrient constituents), N-64 (nutrient constituents), P-33 (low ionic strength constituents), and Hg-29 (mercury) -- that were distributed in October 1999 to 149 laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 131 of the laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U.S. Geological Survey's analytical evaluation program for standard reference samples distributed in March 2003

USGS Publications Warehouse

Woodworth, Mark T.; Connor, Brooke F.

2003-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-173 (trace constituents), M-166 (major constituents), N-77 (nutrient constituents), N-78 (nutrient constituents), P-40 (low ionic-strength constituents), and Hg-36 (mercury) -- that were distributed in March 2003 to laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data received from 110 laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U. S. Geological Survey's analytical evaluation program for standard reference samples distributed in October 2000

USGS Publications Warehouse

Connor, B.F.; Currier, J.P.; Woodworth, M.T.

2001-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-163 (trace constituents), M-156 (major constituents), N-67 (nutrient constituents), N-68 (nutrient constituents), P-35 (low ionic strength constituents), and Hg-31 (mercury) -- that were distributed in October 2000 to 126 laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 122 of the laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Challenges to Recruiting Population Representative Samples of Female Sex Workers in China Using Respondent Driven Sampling1

PubMed Central

Merli, M. Giovanna; Moody, James; Smith, Jeffrey; Li, Jing; Weir, Sharon; Chen, Xiangsheng

2014-01-01

We explore the network coverage of a sample of female sex workers (FSWs) in China recruited through Respondent Drive Sampling (RDS) as part of an effort to evaluate the claim of RDS of population representation with empirical data. We take advantage of unique information on the social networks of FSWs obtained from two overlapping studies --RDS and a venue-based sampling approach (PLACE) -- and use an exponential random graph modeling (ERGM) framework from local networks to construct a likely network from which our observed RDS sample is drawn. We then run recruitment chains over this simulated network to assess the assumption that the RDS chain referral process samples participants in proportion to their degree and the extent to which RDS satisfactorily covers certain parts of the network. We find evidence that, contrary to assumptions, RDS oversamples low degree nodes and geographically central areas of the network. Unlike previous evaluations of RDS which have explored the performance of RDS sampling chains on a non-hidden population, or the performance of simulated chains over previously mapped realistic social networks, our study provides a robust, empirically grounded evaluation of the performance of RDS chains on a real-world hidden population. PMID:24834869

Performance evaluation of laser induced breakdown spectroscopy in the measurement of liquid and solid samples

NASA Astrophysics Data System (ADS)

Bilge, Gonca; Sezer, Banu; Boyaci, Ismail Hakki; Eseller, Kemal Efe; Berberoglu, Halil

2018-07-01

Liquid analysis by using LIBS is a complicated process due to difficulties encountered during the collection of light and formation of plasma in liquid. To avoid these, some applications are performed such as aerosol formation and transforming liquid into solid state. However, performance of LIBS in liquid samples still remains a challenging issue. In this study, performance evaluation of LIBS and parameter optimizations in liquid and solid phase samples were performed. For this purpose, milk was chosen as model sample; milk powder was used as solid sample, and milk was used as liquid sample in the experiments. Different experimental setups have been constructed for each sampling technique, and optimizations were performed to determine suitable parameters such as delay time, laser energy, repetition rate and speed of rotary table for solid sampling technique, and flow rate of carrier gas for liquid sampling technique. Target element was determined as Ca, which is a critically important element in milk for determining its nutritional value and Ca addition. In optimum parameters, limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD) values were calculated as 0.11%, 0.36% and 8.29% respectively for milk powders samples; while LOD, LOQ and RSD values were calculated as 0.24%, 0.81%, and 10.93% respectively for milk samples. It can be said that LIBS is an applicable method in both liquid and solid samples with suitable systems and parameters. However, liquid analysis requires much more developed systems for more accurate results.

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

Kelly, Steve E.

The accuracy and precision of a new Isolok sampler configuration was evaluated using a recirculation flow loop. The evaluation was performed using two slurry simulants of Hanford high-level tank waste. Through testing, the capability of the Isolok sampler was evaluated. Sample concentrations were compared to reference samples that were simultaneously collected by a two-stage Vezin sampler. The capability of the Isolok sampler to collect samples that accurately reflect the contents in the test loop improved – biases between the Isolok and Vezin samples were greatly reduce for fast settling particles.

Determinants of Practice Patterns and Quality Gaps in Lung Cancer Staging and Diagnosis

PubMed Central

Niu, Jiangong; Elting, Linda S.; Buchholz, Thomas A.; Giordano, Sharon H.

2014-01-01

Background: Guidelines recommend mediastinal lymph node sampling as the first invasive diagnostic procedure in patients with suspected lung cancer with mediastinal lymphadenopathy without distant metastases. Methods: Patients were a retrospective cohort of 15,316 patients with lung cancer with regional spread without metastatic disease in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) or Texas Cancer Registry Medicare-linked databases. Patients were categorized based on the sequencing of invasive diagnostic tests performed: (1) evaluation consistent with guidelines, mediastinal sampling done first; (2) evaluation inconsistent with guidelines, non-small cell lung cancer (NSCLC) present, mediastinal sampling performed but not as part of the first invasive test; (3) evaluation inconsistent with guidelines, NSCLC present, mediastinal sampling never done; and (4) evaluation inconsistent with guidelines, small cell lung cancer. The primary outcome was whether guideline-consistent care was delivered. Secondary outcomes included whether patients with NSCLC ever had mediastinal sampling and use of transbronchial needle aspiration (TBNA) among pulmonologists. Results: Only 21% of patients had a diagnostic evaluation consistent with guidelines. Only 56% of patients with NSCLC had mediastinal sampling prior to treatment. There was significant regional variability in guideline-consistent care (range, 12%-29%). Guideline-consistent care was associated with lower patient age, metropolitan areas, and if the physician ordering or performing the test was male, trained in the United States, had seen more patients with lung cancer, and was a pulmonologist or thoracic surgeon who had graduated more recently. More recent pulmonary graduates were also more likely to perform TBNA (P < .001). Conclusions: Guideline-consistent care varied regionally and was associated with physician-level factors, suggesting that a lack of effective physician training may be contributing to the quality gaps observed. PMID:24202651

Quality evaluation of Shenmaidihuang Pills based on the chromatographic fingerprints and simultaneous determination of seven bioactive constituents.

PubMed

Liu, Sifei; Zhang, Guangrui; Qiu, Ying; Wang, Xiaobo; Guo, Lihan; Zhao, Yanxin; Tong, Meng; Wei, Lan; Sun, Lixin

2016-12-01

In this study, we aimed to establish a comprehensive and practical quality evaluation system for Shenmaidihuang pills. A simple and reliable high-performance liquid chromatography coupled with photodiode array detection method was developed both for fingerprint analysis and quantitative determination. In fingerprint analysis, relative retention time and relative peak area were used to identify the common peaks in 18 samples for investigation. Twenty one peaks were selected as the common peaks to evaluate the similarities of 18 Shenmaidihuang pills samples with different manufacture dates. Furthermore, similarity analysis was applied to evaluate the similarity of samples. Hierarchical cluster analysis and principal component analysis were also performed to evaluate the variation of Shenmaidihuang pills. In quantitative analysis, linear regressions, injection precisions, recovery, repeatability and sample stability were all tested and good results were obtained to simultaneously determine the seven identified compounds, namely, 5-hydroxymethylfurfural, morroniside, loganin, paeonol, paeoniflorin, psoralen, isopsoralen in Shenmaidihuang pills. The contents of some analytes in different batches of samples indicated significant difference, especially for 5-hydroxymethylfurfural. So, it was concluded that the chromatographic fingerprint method obtained by high-performance liquid chromatography coupled with photodiode array detection associated with multiple compounds determination is a powerful and meaningful tool to comprehensively conduct the quality control of Shenmaidihuang pills. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bench-scale performance testing and economic analyses of electrostatic dry coal cleaning. Final report, October 1980-July 1983

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

Rich, S.R.

1987-02-01

The report gives results of preliminary performance evaluations and economic analyses of the Advanced Energy Dynamics (AED) electrostatic dry coal-cleaning process. Grab samples of coal-feed-product coals were obtained from 25 operating physical coal-cleaning (PCC) plants. These samples were analyzed for ash, sulfur, and energy content and splits of the original samples of feed run-of-mine coal were provided for bench-scale testing in an electrostatic separation apparatus. The process showed superior sulfur-removal performance at equivalent cost and energy-recovery levels. The ash-removal capability of the process was not evaluated completely: overall, ash-removal results indicated that the process did not perform as well asmore » the PCC plants.« less

Noninvasive metabolic profiling using microfluidics for analysis of single preimplantation embryos.

PubMed

Urbanski, John Paul; Johnson, Mark T; Craig, David D; Potter, David L; Gardner, David K; Thorsen, Todd

2008-09-01

Noninvasive analysis of metabolism at the single cell level will have many applications in evaluating cellular physiology. One clinically relevant application would be to determine the metabolic activities of embryos produced through assisted reproduction. There is increasing evidence that embryos with greater developmental capacity have distinct metabolic profiles. One of the standard techniques for evaluating embryonic metabolism has been to evaluate consumption and production of several key energetic substrates (glucose, pyruvate, and lactate) using microfluorometric enzymatic assays. These assays are performed manually using constriction pipets, which greatly limits the utility of this system. Through multilayer soft-lithography, we have designed a microfluidic device that can perform these assays in an automated fashion. Following manual loading of samples and enzyme cocktail reagents, this system performs sample and enzyme cocktail aliquotting, mixing of reagents, data acquisition, and data analysis without operator intervention. Optimization of design and operating regimens has resulted in the ability to perform serial measurements of glucose, pyruvate, and lactate in triplicate with submicroliter sample volumes within 5 min. The current architecture allows for automated analysis of 10 samples and intermittent calibration over a 3 h period. Standard curves generated for each metabolite have correlation coefficients that routinely exceed 0.99. With the use of a standard epifluorescent microscope and CCD camera, linearity is obtained with metabolite concentrations in the low micromolar range (low femtomoles of total analyte). This system is inherently flexible, being easily adapted for any NAD(P)H-based assay and scaled up in terms of sample ports. Open source JAVA-based software allows for simple alterations in routine algorithms. Furthermore, this device can be used as a standalone device in which media samples are loaded or be integrated into microfluidic culture systems for in line, real time metabolic evaluation. With the improved throughput and flexibility of this system, many barriers to evaluating metabolism of embryos and single cells are eliminated. As a proof of principle, metabolic activities of single murine embryos were evaluated using this device.

Use of on-site high performance liquid chromatography to evaluate the magnitude and extent of organic contaminants in aquifers

USGS Publications Warehouse

Goerlitz, D.F.; Franks, B.J.

1989-01-01

Appraisal of ground water contaminated by organic substances raises problems of difficult sample collection and timely chemical analysis. High-performance liquid chromatography was evaluated for on-site determination of specific organic contaminants in ground water samples and was used at three study sites. Organic solutes were determined directly in water samples, with little or no preparation, and usually in less than an hour after collection. This information improved sampling efficiency and was useful in screening for subsequent laboratory analysis. On two occasions, on-site analysis revealed that samples were undergoing rapid change, with major solutes being upgraded and alteration products being formed. In addition to sample stability, this technique proved valuable for monitoring other sampling factors such as compositional changes with respect to pumping, filtration, and cross contamination. -Authors

Commutability of food microbiology proficiency testing samples.

PubMed

Abdelmassih, M; Polet, M; Goffaux, M-J; Planchon, V; Dierick, K; Mahillon, J

2014-03-01

Food microbiology proficiency testing (PT) is a useful tool to assess the analytical performances among laboratories. PT items should be close to routine samples to accurately evaluate the acceptability of the methods. However, most PT providers distribute exclusively artificial samples such as reference materials or irradiated foods. This raises the issue of the suitability of these samples because the equivalence-or 'commutability'-between results obtained on artificial vs. authentic food samples has not been demonstrated. In the clinical field, the use of noncommutable PT samples has led to erroneous evaluation of the performances when different analytical methods were used. This study aimed to provide a first assessment of the commutability of samples distributed in food microbiology PT. REQUASUD and IPH organized 13 food microbiology PTs including 10-28 participants. Three types of PT items were used: genuine food samples, sterile food samples and reference materials. The commutability of the artificial samples (reference material or sterile samples) was assessed by plotting the distribution of the results on natural and artificial PT samples. This comparison highlighted matrix-correlated issues when nonfood matrices, such as reference materials, were used. Artificially inoculated food samples, on the other hand, raised only isolated commutability issues. In the organization of a PT-scheme, authentic or artificially inoculated food samples are necessary to accurately evaluate the analytical performances. Reference materials, used as PT items because of their convenience, may present commutability issues leading to inaccurate penalizing conclusions for methods that would have provided accurate results on food samples. For the first time, the commutability of food microbiology PT samples was investigated. The nature of the samples provided by the organizer turned out to be an important factor because matrix effects can impact on the analytical results. © 2013 The Society for Applied Microbiology.

Evaluation of performance based concrete for bridge decks.

DOT National Transportation Integrated Search

2015-06-01

The Washington State Department of Transportation (WSDOT) revised the concrete : specification for bridge decks in 2011 to be more performance based with the desired effect of : having less early-age shrinkage cracking. This report evaluates a sample...

GICHD Mine Dog Testing Project - Soil Sample Results No.3

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

PHELAN, JAMES M.; BARNETT, JAMES L.; BENDER, SUSAN FAE ANN

2003-03-01

A mine dog evaluation project initiated by the Geneva International Center for Humanitarian Demining is evaluating the capability and reliability of mine detection dogs. The performance of field-operational mine detection dogs will be measured in test minefields in Afghanistan and Bosnia containing actual, but unfused landmines. Repeated performance testing over two years through various seasonal weather conditions will provide data simulating near real world conditions. Soil samples will be obtained adjacent to the buried targets repeatedly over the course of the test. Chemical analysis results from these soil samples will be used to evaluate correlations between mine dog detection performancemore » and seasonal weather conditions. This report documents the analytical chemical methods and results from the third batch of soils received. This batch contained samples from Kharga, Afghanistan collected in October 2002.« less

Benthic Flux Sampling Device, Prototype Design, Development, and Evaluation

DTIC Science & Technology

1993-08-01

collaboration with Clare Reimers and Matt Christianson at Scripps Institution of Oceanography. Trace metal chemistry was performed by John Andrews and...realistic levels for coastal and inshore sediments using a sample period of 2-4 days. The resulting flux rates will be useful in evaluating the risks...suffi= for detecting release rates at significant levels . Operation Depth. A depth capability of 50 m is sufficient to perform studies in most U.S. bays

Evaluation of natural language processing systems: Issues and approaches

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

Guida, G.; Mauri, G.

This paper encompasses two main topics: a broad and general analysis of the issue of performance evaluation of NLP systems and a report on a specific approach developed by the authors and experimented on a sample test case. More precisely, it first presents a brief survey of the major works in the area of NLP systems evaluation. Then, after introducing the notion of the life cycle of an NLP system, it focuses on the concept of performance evaluation and analyzes the scope and the major problems of the investigation. The tools generally used within computer science to assess the qualitymore » of a software system are briefly reviewed, and their applicability to the task of evaluation of NLP systems is discussed. Particular attention is devoted to the concepts of efficiency, correctness, reliability, and adequacy, and how all of them basically fail in capturing the peculiar features of performance evaluation of an NLP system is discussed. Two main approaches to performance evaluation are later introduced; namely, black-box- and model-based, and their most important characteristics are presented. Finally, a specific model for performance evaluation proposed by the authors is illustrated, and the results of an experiment with a sample application are reported. The paper concludes with a discussion on research perspective, open problems, and importance of performance evaluation to industrial applications.« less

MEASUREMENT OF VOLATILE ORGANIC COMPOUNDS BY THE US ENVIRONMENTAL PROTECTION AGENCY COMPENDIUM METHOD TO-17 - EVALUATION OF PERFORMANCE CRITERIA

EPA Science Inventory

An evaluation of performance criteria for US Environmental Protection Agency Compendium Method TO-17 for monitoring volatile organic compounds (VOCs) in air has been accomplished. The method is a solid adsorbent-based sampling and analytical procedure including performance crit...

Hydrogeochemical and stream sediment reconnaissance basic data for Las Cruces quadrangle, New Mexico

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

Not Available

1981-08-31

Field and laboratory data are presented for 501 water samples and 1817 sediment samples from the Las Cruces Quadrangle, New Mexico. The samples were collected and uranium analysis performed by Los Alamos National Laboratory; multielement analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

Efficient statistical tests to compare Youden index: accounting for contingency correlation.

PubMed

Chen, Fangyao; Xue, Yuqiang; Tan, Ming T; Chen, Pingyan

2015-04-30

Youden index is widely utilized in studies evaluating accuracy of diagnostic tests and performance of predictive, prognostic, or risk models. However, both one and two independent sample tests on Youden index have been derived ignoring the dependence (association) between sensitivity and specificity, resulting in potentially misleading findings. Besides, paired sample test on Youden index is currently unavailable. This article develops efficient statistical inference procedures for one sample, independent, and paired sample tests on Youden index by accounting for contingency correlation, namely associations between sensitivity and specificity and paired samples typically represented in contingency tables. For one and two independent sample tests, the variances are estimated by Delta method, and the statistical inference is based on the central limit theory, which are then verified by bootstrap estimates. For paired samples test, we show that the estimated covariance of the two sensitivities and specificities can be represented as a function of kappa statistic so the test can be readily carried out. We then show the remarkable accuracy of the estimated variance using a constrained optimization approach. Simulation is performed to evaluate the statistical properties of the derived tests. The proposed approaches yield more stable type I errors at the nominal level and substantially higher power (efficiency) than does the original Youden's approach. Therefore, the simple explicit large sample solution performs very well. Because we can readily implement the asymptotic and exact bootstrap computation with common software like R, the method is broadly applicable to the evaluation of diagnostic tests and model performance. Copyright © 2015 John Wiley & Sons, Ltd.

Field-based evaluation of a male-specific (F+) RNA coliphage ...

EPA Pesticide Factsheets

Fecal contamination of water poses a significant risk to public health due to the potential presence of pathogens, including enteric viruses. Thus, sensitive, reliable and easy to use methods for the detection of microorganisms are needed to evaluate water quality. In this study, we performed a field evaluation of an anion-exchange resin based platform to concentrate F-RNA coliphages (fecal/enteric virus indicators) from diverse fecally impacted environmental waters. In this platform, F-RNA coliphages are adsorbed to anion-exchange resin and direct nucleic acid isolation is performed, yielding a sample amenable to real-time reverse transcriptase PCR detection. Matrix-dependent inhibition was evaluated using known quantities of spiked F-RNA coliphage genogroups GI, GII, GII and GIV. Detection was successful in 97%, 72%, 85% and 98% of the samples for spiked F-RNA coliphage GI, GII, GIII and GIV, respectively, and was differentially affected by inhibitory properties specific to each water sample. No association between inhibition and the water samples’ physicochemical properties was apparent. Parallel evaluations of the spiked samples with internal amplification control (IAC) reactions (a widely used control to assess inhibition) demonstrated that IAC reaction inhibition was not agreement with that observed for spiked samples, suggesting that testing of spiked samples allows for better assessments of matrix-dependent inhibition. Additionally, the anion-

The Effect of Evaluation on Performance: Evidence from Longitudinal Student Achievement Data of Mid-Career Teachers. NBER Working Paper No. 16877

ERIC Educational Resources Information Center

Taylor, Eric S.; Tyler, John H.

2011-01-01

The effect of evaluation on employee performance is traditionally studied in the context of the principal-agent problem. Evaluation can, however, also be characterized as an investment in the evaluated employee's human capital. We study a sample of mid-career public school teachers where we can consider these two types of evaluation effect…

Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in October 1994 : T-131 (trace constituents), T-133 (trace constituents), M-132 (major constituents), N-43 (nutrients), N-44 (nutrients), P-23 (low ionic strength) and Hg-19 (mercury)

USGS Publications Warehouse

Long, H. Keith; Farrar, Jerry W.

1995-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for 7 standard reference samples--T-131 (trace constituents), T-133 (trace constituents), M-132 (major constituents), N-43 (nutrients), N-44 (nutrients), P-23 (low ionic strength), and Hg-19 (mercury). The samples were distributed in October 1994 to 131 laboratories registered in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 121 of the laboratories were evaluated with respect to: overall laboratory performance and relative laboratory performance for each analyte in the seven reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the seven standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Level 1 environmental assessment performance evaluation. Final report jun 77-oct 78

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

Estes, E.D.; Smith, F.; Wagoner, D.E.

1979-02-01

The report gives results of a two-phased evaluation of Level 1 environmental assessment procedures. Results from Phase I, a field evaluation of the Source Assessment Sampling System (SASS), showed that the SASS train performed well within the desired factor of 3 Level 1 accuracy limit. Three sample runs were made with two SASS trains sampling simultaneously and from approximately the same sampling point in a horizontal duct. A Method-5 train was used to estimate the 'true' particulate loading. The sampling systems were upstream of the control devices to ensure collection of sufficient material for comparison of total particulate, particle sizemore » distribution, organic classes, and trace elements. Phase II consisted of providing each of three organizations with three types of control samples to challenge the spectrum of Level 1 analytical procedures: an artificial sample in methylene chloride, an artificial sample on a flyash matrix, and a real sample composed of the combined XAD-2 resin extracts from all Phase I runs. Phase II results showed that when the Level 1 analytical procedures are carefully applied, data of acceptable accuracy is obtained. Estimates of intralaboratory and interlaboratory precision are made.« less

MULTI-SITE FIELD EVALUATION OF CANDIDATE SAMPLERS FOR MEASURING COARSE-MODE PM

EPA Science Inventory

In response to expected changes to the National Ambient Air Quality Standards for particulate matter, comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring coarse mode aerosols (i.e. PMc). Five separate PMc sampling approaches w...

Report on the U.S. Geological Survey's Evaluation Program Standard Reference Samples Distributed in October 1995: T-137 (Trace Constituents), M-136 (Major Constituents), N-47 (Nutrient Constituents), N-48 (Nutrient Constituents), P-25 (Low Ionic Strength Constituents), and Hg-21 (Mercury)

USGS Publications Warehouse

Farrar, Jerry W.; Long, H. Keith

1996-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for 6 standard reference samples--T-137 (trace constituents), M-136 (major constituents), N-47 (nutrient constituents), N-48 (nutrient constituents), P-25 (low ionic strength constituents), and Hg-21 (mercury)--that were distributed in October 1995 to 149 laboratories registered in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 136 of the laboratories were evaluated with respect to: overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in April 1994; T-129 (trace constituents), M-130 (major constituents), N-42 (nutrients), P-22 (low ionic strength), and Hg-18 (mercury)

USGS Publications Warehouse

Long, H. Keith; Farrar, Jerry W.

1994-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for five standard reference samples--T-129 (trace constituents), M-130 (major constituents), N-42 (nutrients), P-22 (low ionic strength), Hg-18(mercury),--that were distributed in April 1994 to 157 laboratories registered in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 133 of the laboratories were evaluated with respect to: overall laboratory performance and relative laboratory performance for each analyte in the five reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the five standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Report of the U.S. Geological Survey's evaluation program for standard reference samples distributed in April 1993; T-123 (trace constituents), T-125 (trace constituents), M-126 (major constituents, N-38 (nutrients), N-39 (nutrients), P-20 (low ionic strength, and Hg-16 (mercury)

USGS Publications Warehouse

Long, H.K.; Farrar, J.W.

1993-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for seven standard reference samples--T-123 (trace constituents), T-125 (trace constituents), M-126 (major constituents), N-38 (nutrients), N-39 (Nutrients), P-20 (precipitation-low ionic strength), and Hg-16 (mercury)--that were distributed in April 1993 to 175 laboratories registered in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data received from 131 of the laboratories were evaluated with respect to: overall laboratory performance and relative laboratory performance for each analyte in the 7 reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the seven standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Results of the U.S. Geological Survey's Analytical Evaluation Program for standard reference samples distributed in March 1999

USGS Publications Warehouse

Farrar, Jerry W.; Chleboun, Kimberly M.

1999-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for 8 standard reference samples -- T-157 (trace constituents), M-150 (major constituents), N-61 (nutrient constituents), N-62 (nutrient constituents), P-32 (low ionic strength constituents), GWT-5 (ground-water trace constituents), GWM- 4 (ground-water major constituents),and Hg-28 (mercury) -- that were distributed in March 1999 to 120 laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 111 of the laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the seven reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the 8 standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

The effects of temperature and pressure on airborne exposure concentrations when performing compliance evaluations using ACGIH TLVs and OSHA PELs.

PubMed

Stephenson, D J; Lillquist, D R

2001-04-01

Occupational hygienists perform air sampling to characterize airborne contaminant emissions, assess occupational exposures, and establish allowable workplace airborne exposure concentrations. To perform these air sampling applications, occupational hygienists often compare an airborne exposure concentration to a corresponding American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) or an Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL). To perform such comparisons, one must understand the physiological assumptions used to establish these occupational exposure limits, the relationship between a workplace airborne exposure concentration and its associated TLV or PEL, and the effect of temperature and pressure on the performance of an accurate compliance evaluation. This article illustrates the correct procedure for performing compliance evaluations using airborne exposure concentrations expressed in both parts per million and milligrams per cubic meter. In so doing, a brief discussion is given on the physiological assumptions used to establish TLVs and PELs. It is further shown how an accurate compliance evaluation is fundamentally based on comparison of a measured work site exposure dose (derived from the sampling site exposure concentration estimate) to an estimated acceptable exposure dose (derived from the occupational exposure limit concentration). In addition, this article correctly illustrates the effect that atmospheric temperature and pressure have on airborne exposure concentrations and the eventual performance of a compliance evaluation. This article also reveals that under fairly moderate conditions of temperature and pressure, 30 degrees C and 670 torr, a misunderstanding of how varying atmospheric conditions affect concentration values can lead to a 15 percent error in assessing compliance.

Thermal and frictional performance evaluation of nano lubricant with multi wall carbon nano tubes (MWCNTs) as nano-additive

NASA Astrophysics Data System (ADS)

Lijesh K., P.; Kumar, Deepak; Muzakkir S., M.; Hirani, Harish

2018-05-01

A Fluid Film Bearings (FFBs) operating in hydrodynamic boundary regime can provide moderate load carrying capacity, negligible wear and friction. However in extreme operating conditions i.e. at high load and low speed, asperities of journal and bearing surfaces come in contact with each other resulting in high wear and friction. During the contact of the asperities, the temperature of the lubricant increases due to frictional heating, resulting in reduction of the viscosity of lubricant. Variation of lubricant viscosity results in low load carrying capacity of the FFB and therefore resulting in detoriation of FFB performance. In the present work it is hypothesized that, by adding multi-functional Multi Wall Carbon Nano-Tubes (MWCNT) (having high thermal conductivity and anti-friction properties) as nano-additive in the base mineral oil, the aforementioned problems can be overcome. To validate the proposed hypothesis, five different samples of lubricant is considered: Sample 1: Base oil, Sample 2: Base oil +0.05% MWCNT, Sample 3: Base oil +0.05% MWCNT +0.5%surfactant, Sample 4: Base oil +0.1% MWCNT +0.5% surfactant, and Sample 5: Base oil +0.15% MWCNT +0.5%surfactant. To evaluate the performance of the developed lubricants, experiments were performed on the reduced scale conformal block on disc test setup. The experimental condition and dimension of the block and disc were decide for the Sommerfeld number equal to 0.0025, which indicates mixed lubrication regime. The performance of lubricant is evaluated by measuring the frictional force and temperature rise of the lubricant during the experiment.

Effect of finite sample size on feature selection and classification: a simulation study.

PubMed

Way, Ted W; Sahiner, Berkman; Hadjiiski, Lubomir M; Chan, Heang-Ping

2010-02-01

The small number of samples available for training and testing is often the limiting factor in finding the most effective features and designing an optimal computer-aided diagnosis (CAD) system. Training on a limited set of samples introduces bias and variance in the performance of a CAD system relative to that trained with an infinite sample size. In this work, the authors conducted a simulation study to evaluate the performances of various combinations of classifiers and feature selection techniques and their dependence on the class distribution, dimensionality, and the training sample size. The understanding of these relationships will facilitate development of effective CAD systems under the constraint of limited available samples. Three feature selection techniques, the stepwise feature selection (SFS), sequential floating forward search (SFFS), and principal component analysis (PCA), and two commonly used classifiers, Fisher's linear discriminant analysis (LDA) and support vector machine (SVM), were investigated. Samples were drawn from multidimensional feature spaces of multivariate Gaussian distributions with equal or unequal covariance matrices and unequal means, and with equal covariance matrices and unequal means estimated from a clinical data set. Classifier performance was quantified by the area under the receiver operating characteristic curve Az. The mean Az values obtained by resubstitution and hold-out methods were evaluated for training sample sizes ranging from 15 to 100 per class. The number of simulated features available for selection was chosen to be 50, 100, and 200. It was found that the relative performance of the different combinations of classifier and feature selection method depends on the feature space distributions, the dimensionality, and the available training sample sizes. The LDA and SVM with radial kernel performed similarly for most of the conditions evaluated in this study, although the SVM classifier showed a slightly higher hold-out performance than LDA for some conditions and vice versa for other conditions. PCA was comparable to or better than SFS and SFFS for LDA at small samples sizes, but inferior for SVM with polynomial kernel. For the class distributions simulated from clinical data, PCA did not show advantages over the other two feature selection methods. Under this condition, the SVM with radial kernel performed better than the LDA when few training samples were available, while LDA performed better when a large number of training samples were available. None of the investigated feature selection-classifier combinations provided consistently superior performance under the studied conditions for different sample sizes and feature space distributions. In general, the SFFS method was comparable to the SFS method while PCA may have an advantage for Gaussian feature spaces with unequal covariance matrices. The performance of the SVM with radial kernel was better than, or comparable to, that of the SVM with polynomial kernel under most conditions studied.

Towards a Better Understanding of the Legibility Bias in Performance Assessments: The Case of Gender-Based Inferences

ERIC Educational Resources Information Center

Greifeneder, Rainer; Zelt, Sarah; Seele, Tim; Bottenberg, Konstantin; Alt, Alexander

2012-01-01

Background: Handwriting legibility systematically biases evaluations in that highly legible handwriting results in more positive evaluations than less legible handwriting. Because performance assessments in educational contexts are not only based on computerized or multiple choice tests but often include the evaluation of handwritten work samples,…

GICHD mine dog testing project - soil sample results #4.

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

Barnett, James L.; Phelan, James M.; Archuleta, Luisa M.

2003-08-01

A mine dog evaluation project initiated by the Geneva International Center for Humanitarian Demining is evaluating the capability and reliability of mine detection dogs. The performance of field-operational mine detection dogs will be measured in test minefields in Afghanistan and Bosnia containing actual, but unfused landmines. Repeated performance testing over two years through various seasonal weather conditions will provide data simulating near real world conditions. Soil samples will be obtained adjacent to the buried targets repeatedly over the course of the test. Chemical analysis results from these soil samples will be used to evaluate correlations between mine dog detection performancemore » and seasonal weather conditions. This report documents the analytical chemical methods and results from the fourth batch of soils received. This batch contained samples from Kharga, Afghanistan collected in April 2003 and Sarajevo, Bosnia collected in May 2003.« less

High-Temperature Fluid-Wall Reactor Technology Research, Test and Evaluation Performed at Naval Construction Battalion Center, Gulfport, MS, for the USAF Installation/Restoration Program

DTIC Science & Technology

1988-01-01

under field conditions. Sampling and analytical laboratory activities were performed by Ecology and Environment, Inc., and California Analytical...the proposed AER3 test conditions. All test samples would be obtained onsite by Ecology and Environment, Inc., of Buffalo, New York, and sent to...ensuring its safe operation. Ecology and Environment performed onsite verification sampling. This activity was coordinated with the Huber project team

[Microbial air monitoring in operating theatre: active and passive samplings].

PubMed

Pasquarella, C; Masia, M D; Nnanga, Nga; Sansebastiano, G E; Savino, A; Signorelli, C; Veronesi, L

2004-01-01

Microbial air contamination was evaluated in 11 operating theatres using active and passive samplings. SAS (Surface Air System) air sampling was used to evaluate cfu/m3 and settle plates were used to measure the index of microbial air contamination (IMA). Samplings were performed at the same time on three different days, at three different times (before, during and after the surgical activity). Two points were monitored (patient area and perimeter of the operating theatre). Moreover, the cfu/m3 were evaluated at the air inlet of the conditioner system. 74.7% of samplings performed at the air inlet and 66.7% of the samplings performed at the patient area before the beginning of the surgical activity (at rest) exceeded the 35 cfu/m3 used as threshold value. 100% of IMA values exceeded the threshold value of 5. Using both active and passive sampling, the microbial contamination was shown to increase significantly during activity. The cfu values were higher at the patient area than at the perimeter of the operating theatre. Mean values of the cfu/m3 during activity at the patient area ranged from a minimum of 61+/-41 cfu/m3 to a maximum of 242+/-136 cfu/m3; IMA values ranged from a minimum of 19+/-10 to a maximum of 129+/-60. 15.2% of samplings performed at the patient area using SAS and 75.8% of samplings performed using settle plates exceeded the threshold values of 180 cfu/m3 and 25 respectively, with a significant difference of the percentages. The highest values were found in the operating theatre with inadequate structural and managerial conditions. These findings confirm that the microbiological quality of air may be considered a mirror of the hygienic conditions of the operating theatre. Settle plates proved to be more sensitive in detecting the increase of microbial air contamination related to conditions that could compromise the quality of the air in operating theatres.

Self-sampling for human papillomavirus DNA detection: a preliminary study of compliance and feasibility in BOLIVIA.

PubMed

Surriabre, Pedro; Allende, Gustavo; Prado, Marcela; Cáceres, Leyddy; Bellot, Diego; Torrico, Andrea; Ustariz, Karina; Rojas, Shirley; Barriga, Jaime; Calle, Pamela; Villarroel, Ligia; Yañez, Rosse Mary; Baay, Marc; Rodriguez, Patricia; Fontaine, Véronique

2017-12-22

Cervical cancer incidence and mortality rates in Bolivia are among the highest in Latin America. This investigation aims to evaluate the possibility of using simple devices, e.g. a cotton swab and a glass slide, for self-sampling in order to detect human papillomavirus (HPV) DNA by PCR in cervico-vaginal cells. In the first phase of our study we evaluated the use of a glass slide as a transport medium for cervical cells. A physician took paired-cervical samples from 235 women. One sample was transported in Easyfix® solution and the other sample was smeared over a glass slide. Both were further analyzed and compared for human DNA recovery and HPV detection. A kappa value was determined to evaluate the agreement between the HPV DNA detection rates. In the second phase of the study, 222 women from the urban, peri-urban and rural regions of Cochabamba were requested to perform self-sampling using the following devices: a cotton swab combined with a glass slide, and a vaginal tampon. Women gave their opinion about the self-sampling technique. Finally, the agreement for high risk-HPV detection between self- and physician-collected samples was performed in 201 samples in order to evaluate the self-sampling technique. Firstly, the comparison between Easyfix® solution and the glass slide to transport clinical samples gave a good agreement for HPV DNA detection (κ = 0.71, 95% CI 0.60-0.81). Secondly, self-sampling, especially with cotton swab combined with glass slide, would generally be preferred over clinician sampling for a screening program based on HPV detection. Finally, we showed a good agreement between self- and physician collected samples for high risk-HPV detection (κ = 0.71, 95% CI 0.55-0.88). Simple devices such as a cotton swab and a glass slide can be used to perform self-sampling and HPV DNA detection. Furthermore, most Bolivian women preferred self-sampling over clinician-sampling for cervical cancer screening.

Phase II test plan for the evaluation of the performance of container filling systems

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

BOGER, R.M.

The PHMC will provide tank wastes for final treatment by BNFL from Hanford's waste tanks. Concerns about the ability for ''grab'' sampling to provide large volumes of representative waste samples has led to the development of a nested, fixed-depth sampling system. Preferred concepts for filling sample containers that meet RCRA organic sample criteria were identified by a PHMC Decision Board. These systems will replace the needle based sampling ''T'' that is currently on the sampling system. This test plan document identifies cold tests with simulants that will demonstrate the preferred bottle filling concepts abilities to provide representative waste samples andmore » will meet RCRA criteria. Additional tests are identified that evaluate the potential for cross-contamination between samples and the ability for the system to decontaminate surfaces which have contacted tank wastes. These tests will be performed with kaolid/water and sand/water slurry simulants in the test rig that was used by AEAT to complete Phase 1 tests in FY 1999.« less

Factors Associated with the Performance and Cost-Effectiveness of Using Lymphatic Filariasis Transmission Assessment Surveys for Monitoring Soil-Transmitted Helminths: A Case Study in Kenya

PubMed Central

Smith, Jennifer L.; Sturrock, Hugh J. W.; Assefa, Liya; Nikolay, Birgit; Njenga, Sammy M.; Kihara, Jimmy; Mwandawiro, Charles S.; Brooker, Simon J.

2015-01-01

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8–10 years of age to assess STH but suggest that key consideration is given to evaluation unit size. PMID:25487730

Computer graphics for quality control in the INAA of geological samples

USGS Publications Warehouse

Grossman, J.N.; Baedecker, P.A.

1987-01-01

A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures have been developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time. ?? 1987 Akade??miai Kiado??.

Screening study on microsphere used in profile control under the environment of microbial oil recovery

NASA Astrophysics Data System (ADS)

Zhang, Tiantian; Xie, Gang; Gao, Shanshan; Wang, Zhiqiang; Wei, Junjie; Shi, Lei; Zheng, Ya; Gu, Yi; Lei, Xiaoyang; Wang, Ai

2017-12-01

The performance of four microspheres samples (MS-1, MS-2, MS-3, and MS-4) were evaluated and optimized by indoor experiments. Firstly, the basic physical and chemical properties of the four kinds of microspheres were evaluated by analyzing the solid contents and the solubility in the water. Results showed that the content of the precipitated solids in MS-1 was the lowest in the four kinds of microsphere samples. The contents of the other three microspheres were similar in the value of solid content. Besides, the three microspheres of the solubility in the simulated formation water were excellent. Secondly, the expansion properties of three kinds of microspheres (MS-2, MS-3, and MS-4) were investigated. Results revealed that the expansion performance of MS-3 was greatly affected by microbial metabolism. However, the other two samples had excellent expansion performance under the condition of microbial flooding. Finally, the sealing performance of MS-2 and MS-4 was evaluated by physical simulation Block test. Results showed that compared with MS-2, MS-4 was more suitable for Block B.

A European multicenter study on the analytical performance of the VERIS HBV assay.

PubMed

Braun, Patrick; Delgado, Rafael; Drago, Monica; Fanti, Diana; Fleury, Hervé; Izopet, Jacques; Lombardi, Alessandra; Mancon, Alessandro; Marcos, Maria Angeles; Sauné, Karine; O Shea, Siobhan; Pérez-Rivilla, Alfredo; Ramble, John; Trimoulet, Pascale; Vila, Jordi; Whittaker, Duncan; Artus, Alain; Rhodes, Daniel

Hepatitis B viral load monitoring is an essential part of managing patients with chronic Hepatits B infection. Beckman Coulter has developed the VERIS HBV Assay for use on the fully automated Beckman Coulter DxN VERIS Molecular Diagnostics System. 1 OBJECTIVES: To evaluate the analytical performance of the VERIS HBV Assay at multiple European virology laboratories. Precision, analytical sensitivity, negative sample performance, linearity and performance with major HBV genotypes/subtypes for the VERIS HBV Assay was evaluated. Precision showed an SD of 0.15 log 10 IU/mL or less for each level tested. Analytical sensitivity determined by probit analysis was between 6.8-8.0 IU/mL. Clinical specificity on 90 unique patient samples was 100.0%. Performance with 754 negative samples demonstrated 100.0% not detected results, and a carryover study showed no cross contamination. Linearity using clinical samples was shown from 1.23-8.23 log 10 IU/mL and the assay detected and showed linearity with major HBV genotypes/subtypes. The VERIS HBV Assay demonstrated comparable analytical performance to other currently marketed assays for HBV DNA monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

Staff Reductions and Performance Evaluations: Teacher Views on the Roles of Administrators and Colleagues.

ERIC Educational Resources Information Center

Phelan, William T.

As part of an ongoing three-year investigation into the effects of declining enrollment and reduction in force (RIF) on teachers, this paper explores: (1) teacher acceptance of exclusive administrative control over performance evaluations, and (2) teacher preferences for colleague input into the evaluation process. A sample of 85 schools was drawn…

Identifiability and Performance Analysis of Output Over-sampling Approach to Direct Closed-loop Identification

NASA Astrophysics Data System (ADS)

Sun, Lianming; Sano, Akira

Output over-sampling based closed-loop identification algorithm is investigated in this paper. Some instinct properties of the continuous stochastic noise and the plant input, output in the over-sampling approach are analyzed, and they are used to demonstrate the identifiability in the over-sampling approach and to evaluate its identification performance. Furthermore, the selection of plant model order, the asymptotic variance of estimated parameters and the asymptotic variance of frequency response of the estimated model are also explored. It shows that the over-sampling approach can guarantee the identifiability and improve the performance of closed-loop identification greatly.

Evaluating evaluation forms form.

PubMed

Smith, Roger P

2004-02-01

To provide a tool for evaluating evaluation forms. A new form has been developed and tested on itself and a sample of evaluation forms obtained from the graduate medical education offices of several local universities. Additional forms from hospital administration were also subjected to analysis. The new form performed well when applied to itself. The form performed equally well when applied to the other (subject) forms, although their scores were embarrassingly poor. A new form for evaluating evaluation forms is needed, useful, and now available.

Environmental assessment of creosote-treated pilings in the marine environment

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

Butala, J.H.; Webb, D.A.; Jop, K.M.

1995-12-31

A comprehensive ecological risk assessment was conducted to evaluate the environmental impact of creosote-treated pilings in the marine environment at Moss Landing Harbor, Moss Landing, California. Four areas of investigation comprising the risk assessment were (1) evaluation of environmental conditions around existing creosote-treated pilings (2) investigating effects related to restoration of pilings (3) assessing creosote migration into surrounding environment, one year after pile-driving and (4) confirmation of creosote toxicity in laboratory studies. Biological and chemical evaluation of the impact of creosote-treated pilings was conducted on surface sheen, water column and sediment samples collected at Moss Landing Harbor. Water samples (surfacemore » sheen, water column and sediment pore water) were evaluated using short-term chronic exposures with Mysidopsis bahia, while bulk sediment samples were evaluated with 10-day sediment toxicity tests with Ampelisca abdita. Samples of surface, column water and sediment were analyzed for the constituents of creosote by GC mass spectrometry. In addition, a sample of neat material used to preserve treated pilings represented a reference for the polyaromatic hydrocarbons. Verification of organism response and analyses of field collected samples was performed by conducting 10-day A. abdita sediment and 7-day M. bahia elutriate exposures with creosote applied to clean sediment collected at Moss Landing, Evaluations were also performed to determine the effects of photoinduced toxicity on test organisms exposed to PAHs. The biological and analytical results of the field and laboratory exposures are being used to evaluate and determine risk of creosote-treated pilings on the marine environment.« less

Development of NASA's Sample Cartridge Assembly: Summary of GEDS Design, Development Testing, and Thermal Analyses

NASA Technical Reports Server (NTRS)

O'Connor, Brian; Hernandez, Deborah; Hornsby, Linda; Brown, Maria; Horton-Mullins, Kathryn

2017-01-01

Outline: Background of ISS (International Space Station) Material Science Research Rack; NASA SCA (Sample Cartridge Assembly) Design; GEDS (Gravitational Effects in Distortion in Sintering) Experiment Ampoule Design; Development Testing Summary; Thermal Modeling and Analysis. Summary: GEDS design development challenging (GEDS Ampoule design developed through MUGS (Microgravity) testing; Short duration transient sample processing; Unable to measure sample temperatures); MUGS Development testing used to gather data (Actual LGF (Low Gradient Furnace)-like furnace response; Provided sample for sintering evaluation); Transient thermal model integral to successful GEDS experiment (Development testing provided furnace response; PI (Performance Indicator) evaluation of sintering anchored model evaluation of processing durations; Thermal transient model used to determine flight SCA sample processing profiles).

Evaluation of Two Surface Sampling Methods for Detection of Erwinia herbicola on a Variety of Materials by Culture and Quantitative PCR▿

PubMed Central

Buttner, Mark P.; Cruz, Patricia; Stetzenbach, Linda D.; Cronin, Tracy

2007-01-01

This research was designed to evaluate surface sampling protocols for use with culture and quantitative PCR (QPCR) amplification assay for detection of the gram-negative bacterial biothreat simulant Erwinia herbicola on a variety of surface materials. Surfaces selected for evaluation were wood laminate, glass and computer monitor screens, metal file cabinets, plastic arena seats, nylon seat cushions, finished concrete flooring, and vinyl tile flooring. Laboratory and test chamber studies were performed to evaluate two sampling methods, a sponge and a macrofoam swab, for detection of E. herbicola on surface materials. In laboratory trials, seven materials were inoculated with a known concentration of E. herbicola cells and samples were collected from the surfaces of the materials to determine sampling efficiencies. Culture analysis was ineffective for assessing E. herbicola collection efficiency because very few culturable cells were obtained from surface samples. QPCR demonstrated that E. herbicola DNA was present in high concentrations on all of the surface samples, and sampling efficiencies ranged from 0.7 to 52.2%, depending on the sampling method and the surface material. The swab was generally more efficient than the sponge for collection of E. herbicola from surfaces. Test chamber trials were also performed in which E. herbicola was aerosolized into the chamber and allowed to settle onto test materials. Surface sampling results supported those obtained in laboratory trials. The results of this study demonstrate the capabilities of QPCR to enhance the detection and enumeration of biocontaminants on surface materials and provide information on the comparability of sampling methods. PMID:17416685

Evaluation of two surface sampling methods for detection of Erwinia herbicola on a variety of materials by culture and quantitative PCR.

PubMed

Buttner, Mark P; Cruz, Patricia; Stetzenbach, Linda D; Cronin, Tracy

2007-06-01

This research was designed to evaluate surface sampling protocols for use with culture and quantitative PCR (QPCR) amplification assay for detection of the gram-negative bacterial biothreat simulant Erwinia herbicola on a variety of surface materials. Surfaces selected for evaluation were wood laminate, glass and computer monitor screens, metal file cabinets, plastic arena seats, nylon seat cushions, finished concrete flooring, and vinyl tile flooring. Laboratory and test chamber studies were performed to evaluate two sampling methods, a sponge and a macrofoam swab, for detection of E. herbicola on surface materials. In laboratory trials, seven materials were inoculated with a known concentration of E. herbicola cells and samples were collected from the surfaces of the materials to determine sampling efficiencies. Culture analysis was ineffective for assessing E. herbicola collection efficiency because very few culturable cells were obtained from surface samples. QPCR demonstrated that E. herbicola DNA was present in high concentrations on all of the surface samples, and sampling efficiencies ranged from 0.7 to 52.2%, depending on the sampling method and the surface material. The swab was generally more efficient than the sponge for collection of E. herbicola from surfaces. Test chamber trials were also performed in which E. herbicola was aerosolized into the chamber and allowed to settle onto test materials. Surface sampling results supported those obtained in laboratory trials. The results of this study demonstrate the capabilities of QPCR to enhance the detection and enumeration of biocontaminants on surface materials and provide information on the comparability of sampling methods.

Multidimensional assessment of homework: an analysis of students with ADHD.

PubMed

Mautone, Jennifer A; Marshall, Stephen A; Costigan, Tracy E; Clarke, Angela T; Power, Thomas J

2012-10-01

Homework can have beneficial effects for students; however, it presents challenges, particularly for students with attention problems. Although effective homework interventions exist, intervention development and evaluation has been hampered by the lack of psychometrically sound measures. The primary purpose of this study was to evaluate the construct validity of the Homework Performance Questionnaire (HPQ), Parent and Teacher Versions, in a sample of children with ADHD. A secondary purpose was to examine variations in homework performance as a function of individual characteristics, such as academic achievement, quality of the family-school relationship, and child's diagnostic status. The sample included 91 children (34% female) with ADHD in Grades 2 to 6. Measures included parent and teacher ratings of homework performance and the quality of the parent-teacher relationship as well as direct assessment of child academic achievement and homework performance (i.e., samples of completed assignments). Correlational analyses were used to examine construct validity, and ANOVAs were used to evaluate group differences. Each factor of the HPQ had a significant relationship with other measures of relevant constructs. There were no significant differences in homework performance between groups for ADHD subtype, medication status, or comorbidity, with the exception of learning disability. Children with ADHD and learning disabilities had significantly lower teacher ratings of academic competence. Results of the present study suggest that HPQ scores may be used to make valid inferences about the homework performance of children with attention problems. These rating scales may be helpful in progress monitoring and evaluating intervention effectiveness.

Decomposition of diverse solid inorganic matrices with molten ammonium bifluoride salt for constituent elemental analysis

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

O'Hara, Matthew J.; Kellogg, Cyndi M.; Parker, Cyrena M.

Ammonium bifluoride (ABF, NH4F·HF) is a well-known reagent for converting metal oxides to fluorides and for its applications in breaking down minerals and ores in order to extract useful components. It has been more recently applied to the decomposition of inorganic matrices prior to elemental analysis. Herein, a sample decomposition method that employs molten ABF sample treatment in the initial step is systematically evaluated across a range of inorganic sample types: glass, quartz, zircon, soil, and pitchblende ore. Method performance is evaluated across the two variables: duration of molten ABF treatment and ABF reagent mass to sample mass ratio. Themore » degree of solubilization of these sample classes are compared to the fluoride stoichiometry that is theoretically necessary to enact complete fluorination of the sample types. Finally, the sample decomposition method is performed on several soil and pitchblende ore standard reference materials, after which elemental constituent analysis is performed by ICP-OES and ICP-MS. Elemental recoveries are compared to the certified values; results indicate good to excellent recoveries across a range of alkaline earth, rare earth, transition metal, and actinide elements.« less

Results of the U.S. Geological Survey's Analytical Evaluation Program for standard reference samples: T-155 (trace constituents), M-148 (major constituents), N-59 (nutrient constituents), N-60 (nutrient constituents), P-31 (low ionic strength constituents), GWT-4 (ground-water trace constituents) and Hg-27 (Mercury) distributed in September 1998

USGS Publications Warehouse

Farrar, Jerry W.

1999-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for seven standard reference samples -- T-155 (trace constituents), M-148 (major constituents), N-59 (nutrient constituents), N-60 (nutrient constituents), P-31 (low ionic strength constituents), GWT-4 (ground-water trace constituents), and Hg- 27 (mercury) -- which were distributed in September 1998 to 162 laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 136 of the laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the seven reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the seven standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Report on the U.S. Geological Survey's evaluation program for standard reference samples distributed in October 1993 : T-127 (trace constituents), M-128 (major constituents), N-40 (nutrients), N-41 (nutrients), P-21 (low ionic strength), Hg-17 (mercury), AMW-3 (acid mine water), and WW-1 (whole water)

USGS Publications Warehouse

Long, H.K.; Farrar, J.W.

1994-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for eight standard reference samples--T-127 (trace constituents), M-128 (major constituents), N-40 (nutrients), N-41 (nutrients), P-21 (low ionic strength), Hg-17 (mercury), AMW-3 (acid mine water), and WW-1 (whole water)--that were distributed in October 1993 to 158 laboratories registered in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 145 of the laboratories were evaluated with respect to: overall laboratory performance and relative laboratory performance for each analyte in the eight reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the eight standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

Evaluating markers for the early detection of cancer: overview of study designs and methods.

PubMed

Baker, Stuart G; Kramer, Barnett S; McIntosh, Martin; Patterson, Blossom H; Shyr, Yu; Skates, Steven

2006-01-01

The field of cancer biomarker development has been evolving rapidly. New developments both in the biologic and statistical realms are providing increasing opportunities for evaluation of markers for both early detection and diagnosis of cancer. To review the major conceptual and methodological issues in cancer biomarker evaluation, with an emphasis on recent developments in statistical methods together with practical recommendations. We organized this review by type of study: preliminary performance, retrospective performance, prospective performance and cancer screening evaluation. For each type of study, we discuss methodologic issues, provide examples and discuss strengths and limitations. Preliminary performance studies are useful for quickly winnowing down the number of candidate markers; however their results may not apply to the ultimate target population, asymptomatic subjects. If stored specimens from cohort studies with clinical cancer endpoints are available, retrospective studies provide a quick and valid way to evaluate performance of the markers or changes in the markers prior to the onset of clinical symptoms. Prospective studies have a restricted role because they require large sample sizes, and, if the endpoint is cancer on biopsy, there may be bias due to overdiagnosis. Cancer screening studies require very large sample sizes and long follow-up, but are necessary for evaluating the marker as a trigger of early intervention.

An Exploratory Investigation of the Periodic Performance Evaluation Processes for Marketing Faculty: A Comparison of Doctoral-Granting and Non-Doctoral-Granting Universities

ERIC Educational Resources Information Center

Shepherd, C. David; Carley, Susan S.; Stuart, Randy S.

2009-01-01

Whether a first entrant into the academic job market or a seasoned professional, career outcomes for marketing educators depend heavily on the evaluation process used at their institutions. This research explores the periodic performance evaluation process for marketing faculty members using data collected from a national sample of marketing…

Quarterly Performance/Technical Report of the National Marrow Donor Program

DTIC Science & Technology

2008-02-05

HLA-DRB1 High Resolution Typing Closed 9 IIB.1.3 Aim 3 – Evaluate HLA-C Typing of Donors Closed 9 IIB.1.4 Aim 4 – Evaluate Buccal Swabs Open 10 IIB...December 31, 2007 10 of 21 IIB.1.4 Aim 4: Evaluate Buccal Swabs Period 5 Activity: In April of 2006, the NMDP transitioned to the use of... buccal swabs for the collection of DNA samples from newly recruited donors. To support this change in sample type, Quality Control samples for donor

Manganese recycling in the United States in 1998

USGS Publications Warehouse

Jones, Thomas S.

2003-01-01

This report presents the results of the U.S. Geological Survey's analytical evaluation program for six standard reference samples -- T-163 (trace constituents), M-156 (major constituents), N-67 (nutrient constituents), N-68 (nutrient constituents), P-35 (low ionic strength constituents), and Hg-31 (mercury) -- that were distributed in October 2000 to 126 laboratories enrolled in the U.S. Geological Survey sponsored interlaboratory testing program. Analytical data that were received from 122 of the laboratories were evaluated with respect to overall laboratory performance and relative laboratory performance for each analyte in the six reference samples. Results of these evaluations are presented in tabular form. Also presented are tables and graphs summarizing the analytical data provided by each laboratory for each analyte in the six standard reference samples. The most probable value for each analyte was determined using nonparametric statistics.

THE RELATIONSHIP OF CERTAIN PREDICTION AND SELF-EVALUATION DISCREPANCIES TO ART PERFORMANCE AND ART JUDGMENT.

ERIC Educational Resources Information Center

HARVEY, THEODORE E.

NINTH-GRADE STUDENTS WERE SELECTED AS A SAMPLE TO STUDY THE RELATIONSHIP OF CERTAIN PREDICTION AND SELF-EVALUATION DISCREPANCIES TO ART PERFORMANCE AND ART JUDGMENT. STUDENTS WERE REQUIRED TO DEVELOP AN OIL CRAYON DRAWING, RESULTING FROM AN IMAGINARY SENTENCE SPOKEN TO AND SEEN BY ALL PARTICIPANTS. PREDICTIONS OF PERFORMANCE WERE ASKED PRIOR TO…

The Relationship between Mental Health, Acculturative Stress, and Academic Performance in a Latino Middle School Sample

ERIC Educational Resources Information Center

Albeg, Loren J.; Castro-Olivo, Sara M.

2014-01-01

This study evaluated the relationship between acculturative stress, symptoms of internalizing mental health problems, and academic performance in a sample of 94 Latino middle school students. Students reported on symptoms indicative of depression and anxiety related problems and acculturative stress. Teachers reported on students' academic…

Tier One Performance Screen Initial Operational Test and Evaluation: 2011 Interim Report

DTIC Science & Technology

2012-04-01

Alexandria, Virginia 22314 8 . PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) U. S. Army Research...DISTRIBUTION OF MOS IN THE FULL SCHOOLHOUSE DATA FILE ............ 8 TABLE 2.3. BACKGROUND AND DEMOGRAPHIC CHARACTERISTICS OF THE TOPS SAMPLES...SCHOOLHOUSE SAMPLE ....................................................................................................................B-6 TABLE B. 8

Performance Evaluation of Automated Passive Capillary Sampler for Estimating Water Drainage in the Vadose Zone

USDA-ARS?s Scientific Manuscript database

Passive capillary samplers (PCAPs) are widely used to monitor, measure and sample drainage water under saturated and unsaturated soil conditions in the vadose zone. The objective of this study was to evaluate the performance and accuracy of automated passive capillary sampler for estimating drainage...

Metastable Radioxenon Verification Laboratory (MRVL) Year-End Report

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

Cooper, Matthew W.; Hayes, James C.; Lidey, Lance S.

2014-11-07

This is the year end report that is due to the client. The MRVL system is designed to measure multiple radioxenon isotopes ( 135Xe, 133Xe, 133mXe and 133mXe) simultaneously. The system has 12 channels to load samples and make nuclear measurements. Although the MRVL system has demonstrated excellent stability in measurements of Xe-133 and Xe-135 over the year of evaluation prior to delivery, there has been concern about system stability over measurements performed on samples with orders of magnitude different radioactivity, and samples containing multiple isotopes. To address these concerns, a series of evaluation test have been performed at themore » end-user laboratory. The evaluation was performed in two separate phases. Phase 1 made measurements on isotopically pure Xe-133 from high radioactivity down to the system background levels of activity, addressing the potential count rate dependencies when activities change from extreme high to very low. The second phase performed measurements on samples containing multiple isotopes (Xe-135, Xe-133 and Xe-133m), and addressed concerns about the dependence of isotopic concentrations on the presence of additional isotopes. The MRVL showed a concentration dependence on the Xe-133 due to the amount of Xe-133m that was in the sample. The dependency is due to the decay of Xe-133m into Xe-133. This document focuses on the second phase and will address the analysis used to account for ingrowth of Xe-133 from Xe-133m.« less

Performance of Xpert MTB/RIF on Ascitic Fluid Samples for Detection of Abdominal Tuberculosis.

PubMed

Rufai, Syed Beenish; Singh, Sarman; Singh, Amit; Kumar, Parveen; Singh, Jitendra; Vishal, Anand

2017-01-01

Diagnosis of abdominal tuberculosis (TB) from ascitic fluid samples using routinely available diagnostic methods is challenging due to its paucibacillary nature. Although performance of Xpert MTB/RIF assay has been evaluated extensively on pulmonary samples, its performance on extrapulmonary samples is still under evaluation. The objective of this study was to find out the performance of Xpert MTB/RIF on ascitic fluid samples obtained from suspected cases of abdominal TB. Performance was compared with Mycobacterium growth indicator tube-960 (MGIT-960) culture and in-house multiplex polymerase chain reaction (PCR). The latter detects and differentiates Mycobacterium tuberculosis and nontuberculous mycobacteria simultaneously. Sixty-seven patients suspected of probable/possible abdominal TB were included in this observational, prospective study. All samples were tested by Ziehl-Neelsen staining, MGIT-960 culture, in-house multiplex PCR, and Xpert MTB/RIF assay. All 67 samples were smear negative. Seventeen (25.4%) were MGIT-960 culture positive while 12 (17.9%) were detected positive by the Xpert MTB/RIF assay and 9 (13.4%) by in-house multiplex PCR. Sensitivity and specificity of the Xpert MTB/RIF assay compared with the MGIT-960 culture were 70.6% (95%, confidence interval [CI]: 44.1-89.7) and 100% (95%, CI: 92.8-100) and that of in-house multiplex PCR were 52.9% (95%, CI: 30.9-73.8) and 100% (95%, CI: 92.8-100), respectively. Diagnostic yield of Xpert MTB/RIF assay on ascitic fluid samples was lower than MGIT-960 culture. We thus emphasize on the need for urgent discovery of new biomarkers for paucibacillary TB.

Evaluation of a Rapid Assay for Detection of Chlamydia trachomatis Infections in Outpatient Clinics in South Kalimantan, Indonesia

PubMed Central

Widjaja, Susana; Cohen, Surekha; Brady, William E.; O'reilly, Kevin; Susanto; Wibowo, Ajar; Cahyono; Graham, Robert R.; Porter, Kevin R.

1999-01-01

A multicenter cross-sectional survey was conducted comparing a commercially available chlamydial optical immunoassay (OIA) to the chlamydial ligase chain reaction (LCR). Endocervical samples from 415 outpatients visiting clinics from three hospitals in South Kalimantan, Indonesia, were evaluated. Relative to the LCR, the overall sensitivity and specificity of the OIA were 31.6 and 98.9%, respectively. The sensitivity of the OIA varied among the three hospital laboratories, ranging from 20 to 50%. The OIA performance was slightly lower on samples from patients attending dermatovenereology clinics than on samples from nondermatovenereology clinic patients. The results indicate that the OIA did not perform well compared to LCR. PMID:10565960

Evaluation of a rapid assay for detection of Chlamydia trachomatis infections in outpatient clinics in South Kalimantan, Indonesia.

PubMed

Widjaja, S; Cohen, S; Brady, W E; O'reilly, K; Susanto; Wibowo, A; Cahyono; Graham, R R; Porter, K R

1999-12-01

A multicenter cross-sectional survey was conducted comparing a commercially available chlamydial optical immunoassay (OIA) to the chlamydial ligase chain reaction (LCR). Endocervical samples from 415 outpatients visiting clinics from three hospitals in South Kalimantan, Indonesia, were evaluated. Relative to the LCR, the overall sensitivity and specificity of the OIA were 31.6 and 98.9%, respectively. The sensitivity of the OIA varied among the three hospital laboratories, ranging from 20 to 50%. The OIA performance was slightly lower on samples from patients attending dermatovenereology clinics than on samples from nondermatovenereology clinic patients. The results indicate that the OIA did not perform well compared to LCR.

Comparison of two modalities: a novel technique, 'chromohysteroscopy', and blind endometrial sampling for the evaluation of abnormal uterine bleeding.

PubMed

Alay, Asli; Usta, Taner A; Ozay, Pinar; Karadugan, Ozgur; Ates, Ugur

2014-05-01

The objective of this study was to compare classical blind endometrial tissue sampling with hysteroscopic biopsy sampling following methylene blue dyeing in premenopausal and postmenopausal patients with abnormal uterine bleeding. A prospective case-control study was carried out in the Office Hysteroscopy Unit. Fifty-four patients with complaints of abnormal uterine bleeding were evaluated. Data of 38 patients were included in the statistical analysis. Three groups were compared by examining samples obtained through hysteroscopic biopsy before and after methylene blue dyeing, and classical blind endometrial tissue sampling. First, uterine cavity was evaluated with office hysteroscopy. Methylene blue dye was administered through the hysteroscopic inlet. Tissue samples were obtained from stained and non-stained areas. Blind endometrial sampling was performed in the same patients immediately after the hysteroscopy procedure. The results of hysteroscopic biopsy from methylene blue stained and non-stained areas and blind biopsy were compared. No statistically significant differences were determined in the comparison of biopsy samples obtained from methylene-blue stained, non-stained areas and blind biopsy (P > 0.05). We suggest that chromohysteroscopy is not superior to endometrial sampling in cases of abnormal uterine bleeding. Further studies with greater sample sizes should be performed to assess the validity of routine use of endometrial dyeing. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Evaluation of magnetic nanoparticle samples made from biocompatible ferucarbotran by time-correlation magnetic particle imaging reconstruction method

PubMed Central

2013-01-01

Background Molecular imaging using magnetic nanoparticles (MNPs)—magnetic particle imaging (MPI)—has attracted interest for the early diagnosis of cancer and cardiovascular disease. However, because a steep local magnetic field distribution is required to obtain a defined image, sophisticated hardware is required. Therefore, it is desirable to realize excellent image quality even with low-performance hardware. In this study, the spatial resolution of MPI was evaluated using an image reconstruction method based on the correlation information of the magnetization signal in a time domain and by applying MNP samples made from biocompatible ferucarbotran that have adjusted particle diameters. Methods The magnetization characteristics and particle diameters of four types of MNP samples made from ferucarbotran were evaluated. A numerical analysis based on our proposed method that calculates the image intensity from correlation information between the magnetization signal generated from MNPs and the system function was attempted, and the obtained image quality was compared with that using the prototype in terms of image resolution and image artifacts. Results MNP samples obtained by adjusting ferucarbotran showed superior properties to conventional ferucarbotran samples, and numerical analysis showed that the same image quality could be obtained using a gradient magnetic field generator with 0.6 times the performance. However, because image blurring was included theoretically by the proposed method, an algorithm will be required to improve performance. Conclusions MNP samples obtained by adjusting ferucarbotran showed magnetizing properties superior to conventional ferucarbotran samples, and by using such samples, comparable image quality (spatial resolution) could be obtained with a lower gradient magnetic field intensity. PMID:23734917

CEA SMAD 2016 Digitizer Evaluation.

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

Merchant, Bion J.

Sandia National Laboratories has tested and evaluated an updated SMAD digitizer, developed by the French Alternative Energies and Atomic Energy Commission (CEA). The SMAD digitizers are intended to record sensor output for seismic and infrasound monitoring applications. The purpose of this digitizer evaluation is to measure the performance characteristics in such areas as power consumption, input impedance, sensitivity, full scale, self-noise, dynamic range, system noise, response, passband, and timing. The SMAD digitizers have been updated since their last evaluation by Sandia to improve their performance when recording at a sample rate of 20 Hz for infrasound applications and 100 Hzmore » for hydro-acoustic seismic stations. This evaluation focuses primarily on the 20 Hz and 100 Hz sample rates. The SMAD digitizers are being evaluated for potential use in the International Monitoring System (IMS) of the Comprehensive Nuclear Test- Ban-Treaty Organization (CTBTO).« less

Evaluation and optimization of a commercial blocking ELISA for detecting antibodies to influenza A virus for research and surveillance of mallards.

PubMed

Shriner, Susan A; VanDalen, Kaci K; Root, J Jeffrey; Sullivan, Heather J

2016-02-01

The availability of a validated commercial assay is an asset for any wildlife investigation. However, commercial products are often developed for use in livestock and are not optimized for wildlife. Consequently, it is incumbent upon researchers and managers to apply commercial products appropriately to optimize program outcomes. We tested more than 800 serum samples from mallards for antibodies to influenza A virus with the IDEXX AI MultiS-Screen Ab test to evaluate assay performance. Applying the test per manufacturer's recommendations resulted in good performance with 84% sensitivity and 100% specificity. However, performance was improved to 98% sensitivity and 98% specificity by increasing the recommended cut-off. Using this alternative threshold for identifying positive and negative samples would greatly improve sample classification, especially for field samples collected months after infection when antibody titers have waned from the initial primary immune response. Furthermore, a threshold that balances sensitivity and specificity reduces estimation bias in seroprevalence estimates. Published by Elsevier B.V.

Stability of handwriting performance following injury-induced hand-dominance transfer in adults: a pilot study.

PubMed

Yancosek, Kathleen E; Mullineaux, David R

2011-01-01

The aim of this study was to quantify stability of nondominant handwriting kinematics and legibility in participants with functional loss of the previously dominant hand. Twelve adult volunteers provided two handwriting samples 6 weeks apart. Handwriting tasks (Compose a Sentence, Copy Alphabet, Copy Date, Copy Sentence, and Draw Circles) were performed in cursive writing on standard white, lined paper taped to a digitizer to record kinematic and kinetic variables of velocity, displacement, force, and on-paper time. Results showed minimal performance variability within subjects and marked variability between subjects, as well as variability between tasks for all participants. Stylistic stability of the handwriting samples was assessed by two independent evaluators. These evaluators matched all handwriting samples at test to retest times with 89%-100% accuracy, suggesting value in the "whole" handwriting sample and emphasizing the idiosyncratic nature of handwriting. Results suggest that handwriting skill stability in the previously nondominant hand varies across subjects and task demands.

Evaluation of a PCR assay on overgrown environmental samples cultured for Mycobacterium avium subsp. paratuberculosis.

PubMed

Arango-Sabogal, Juan C; Labrecque, Olivia; Paré, Julie; Fairbrother, Julie-Hélène; Roy, Jean-Philippe; Wellemans, Vincent; Fecteau, Gilles

2016-11-01

Culture of Mycobacterium avium subsp. paratuberculosis (MAP) is the definitive antemortem test method for paratuberculosis. Microbial overgrowth is a challenge for MAP culture, as it complicates, delays, and increases the cost of the process. Additionally, herd status determination is impeded when noninterpretable (NI) results are obtained. The performance of PCR is comparable to fecal culture, thus it may be a complementary detection tool to classify NI samples. Our study aimed to determine if MAP DNA can be identified by PCR performed on NI environmental samples and to evaluate the performance of PCR before and after the culture of these samples in liquid media. A total of 154 environmental samples (62 NI, 62 negative, and 30 positive) were analyzed by PCR before being incubated in an automated system. Growth was confirmed by acid-fast bacilli stain and then the same PCR method was again applied on incubated samples, regardless of culture and stain results. Change in MAP DNA after incubation was assessed by converting the PCR quantification cycle (Cq) values into fold change using the 2 -ΔCq method (ΔCq = Cq after culture - Cq before culture). A total of 1.6% (standard error [SE] = 1.6) of the NI environmental samples had detectable MAP DNA. The PCR had a significantly better performance when applied after culture than before culture (p = 0.004). After culture, a 66-fold change (SE = 17.1) in MAP DNA was observed on average. Performing a PCR on NI samples improves MAP culturing. The PCR method used in our study is a reliable and consistent method to classify NI environmental samples. © 2016 The Author(s).

An Evaluation of Minority and Female Performance in Army Rotary Wing Aviation Training. Volume II: Evaluation Report. Research Report 1319.

ERIC Educational Resources Information Center

Brown, William R.; And Others

An evaluation was conducted of minority (Black, Hispanic, Asian, American Indian) and female performance in the Army's Initial Entry Rotary Wing flight training program. Each minority group was compared to a matched sample of majority students. The groups were matched on several test scores, education level, age, rank, and source of entry. The…

Utility of Gram Staining for Evaluation of the Quality of Cystic Fibrosis Sputum Samples

PubMed Central

Nair, Bindu; Stapp, Jenny; Stapp, Lynn; Bugni, Linda; Van Dalfsen, Jill; Burns, Jane L.

2002-01-01

The microscopic examination of Gram-stained sputum specimens is very helpful in the evaluation of patients with community-acquired pneumonia and has also been recommended for use in cystic fibrosis (CF) patients. This study was undertaken to evaluate that recommendation. One hundred one sputum samples from CF patients were cultured for gram-negative bacilli and examined by Gram staining for both sputum adequacy (using the quality [Q] score) and bacterial morphology. Subjective evaluation of adequacy was also performed and categorized. Based on Q score evaluation, 41% of the samples would have been rejected despite a subjective appearance of purulence. Only three of these rejected samples were culture negative for gram-negative CF pathogens. Correlation between culture results and quantitative Gram stain examination was also poor. These data suggest that subjective evaluation combined with comprehensive bacteriology is superior to Gram staining in identifying pathogens in CF sputum. PMID:12149331

Utility of gram staining for evaluation of the quality of cystic fibrosis sputum samples.

PubMed

Nair, Bindu; Stapp, Jenny; Stapp, Lynn; Bugni, Linda; Van Dalfsen, Jill; Burns, Jane L

2002-08-01

The microscopic examination of Gram-stained sputum specimens is very helpful in the evaluation of patients with community-acquired pneumonia and has also been recommended for use in cystic fibrosis (CF) patients. This study was undertaken to evaluate that recommendation. One hundred one sputum samples from CF patients were cultured for gram-negative bacilli and examined by Gram staining for both sputum adequacy (using the quality [Q] score) and bacterial morphology. Subjective evaluation of adequacy was also performed and categorized. Based on Q score evaluation, 41% of the samples would have been rejected despite a subjective appearance of purulence. Only three of these rejected samples were culture negative for gram-negative CF pathogens. Correlation between culture results and quantitative Gram stain examination was also poor. These data suggest that subjective evaluation combined with comprehensive bacteriology is superior to Gram staining in identifying pathogens in CF sputum.

Participation in Performance-Evaluation Studies by U.S. Geological Survey National Water Quality Laboratory

USGS Publications Warehouse

Glodt, Stephen R.; Pirkey, Kimberly D.

1998-01-01

Performance-evaluation studies provide customers of the U.S. Geological Survey National Water Quality Laboratory (NWQL) with data needed to evaluate performance and to compare of select laboratories for analytical work. The NWQL participates in national and international performance-evaluation (PE) studies that consist of samples of water, sediment, and aquatic biological materials for the analysis of inorganic constituents, organic compounds, and radionuclides. This Fact Sheet provides a summary of PE study results from January 1993 through April 1997. It should be of particular interest to USGS customers and potential customers of the NWQL, water-quality specialists, cooperators, and agencies of the Federal Government.

Pharmacokinetic Studies in Neonates: The Utility of an Opportunistic Sampling Design.

PubMed

Leroux, Stéphanie; Turner, Mark A; Guellec, Chantal Barin-Le; Hill, Helen; van den Anker, Johannes N; Kearns, Gregory L; Jacqz-Aigrain, Evelyne; Zhao, Wei

2015-12-01

The use of an opportunistic (also called scavenged) sampling strategy in a prospective pharmacokinetic study combined with population pharmacokinetic modelling has been proposed as an alternative strategy to conventional methods for accomplishing pharmacokinetic studies in neonates. However, the reliability of this approach in this particular paediatric population has not been evaluated. The objective of the present study was to evaluate the performance of an opportunistic sampling strategy for a population pharmacokinetic estimation, as well as dose prediction, and compare this strategy with a predetermined pharmacokinetic sampling approach. Three population pharmacokinetic models were derived for ciprofloxacin from opportunistic blood samples (SC model), predetermined (i.e. scheduled) samples (TR model) and all samples (full model used to previously characterize ciprofloxacin pharmacokinetics), using NONMEM software. The predictive performance of developed models was evaluated in an independent group of patients. Pharmacokinetic data from 60 newborns were obtained with a total of 430 samples available for analysis; 265 collected at predetermined times and 165 that were scavenged from those obtained as part of clinical care. All datasets were fit using a two-compartment model with first-order elimination. The SC model could identify the most significant covariates and provided reasonable estimates of population pharmacokinetic parameters (clearance and steady-state volume of distribution) compared with the TR and full models. Their predictive performances were further confirmed in an external validation by Bayesian estimation, and showed similar results. Monte Carlo simulation based on area under the concentration-time curve from zero to 24 h (AUC24)/minimum inhibitory concentration (MIC) using either the SC or the TR model gave similar dose prediction for ciprofloxacin. Blood samples scavenged in the course of caring for neonates can be used to estimate ciprofloxacin pharmacokinetic parameters and therapeutic dose requirements.

Mild test anxiety influences neurocognitive performance among African Americans and European Americans: identifying interfering and facilitating sources.

PubMed

Thames, April D; Panos, Stella E; Arentoft, Alyssa; Byrd, Desiree A; Hinkin, Charles H; Arbid, Natalie

2015-01-01

The current study examined ethnic/racial differences in test-related anxiety and its relationship to neurocognitive performance in a community sample of African American (n = 40) and European American (n = 36) adults. The authors hypothesized the following: (a) Test-anxiety related to negative performance evaluation would be associated with lower neurocognitive performance, whereas anxiety unrelated to negative evaluation would be associated with higher neurocognitive performance. (b) African American participants would report higher levels of anxiety about negative performance evaluation than European Americans. (c) European Americans would report higher levels of anxiety unrelated to negative performance evaluation. The first two hypotheses were supported: Ethnic/racial differences in test-taking anxiety emerged such that African Americans reported significantly higher levels of negative performance evaluation, which was associated with lower cognitive performance. The third hypothesis was not supported: African Americans and European Americans reported similar levels of test-anxiety unrelated to negative evaluation. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Evaluation of the COBAS Hepatitis C Virus (HCV) TaqMan analyte-specific reagent assay and comparison to the COBAS Amplicor HCV Monitor V2.0 and Versant HCV bDNA 3.0 assays.

PubMed

Konnick, Eric Q; Williams, Sheri M; Ashwood, Edward R; Hillyard, David R

2005-05-01

Performance characteristics of the COBAS hepatitis C virus (HCV) TaqMan analyte-specific reagent (TM-ASR) assay using the QIAGEN BioRobot 9604 for RNA extraction were evaluated and compared to the COBAS Amplicor HCV Monitor V2.0 (Amplicor) and Versant HCV bDNA 3.0 (Versant) assays using clinical samples. Calibration of TM-ASR using Armored RNA allowed determination of the distribution of HCV RNA in clinical samples, using 22,399 clinical samples. Limit of detection, linearity, and inter- and intraassay assay precision were determined for the TM-ASR assay using multiple clinical specimen panels across multiple determinations. Genotype specificity for the TM-ASR assay was determined using samples with different HCV RNA genotypes evaluated and compared against predetermined results. Contamination control of the TM-ASR assay was evaluated using pools of HCV RNA-positive and -negative samples tested in a checkerboard pattern over 12 runs of 96 samples. Correlation of the TM-ASR, Amplicor, and Versant assays was determined using 100 paired clinical samples and Deming regression analysis. The TM-ASR performed well with respect to linearity, precision, and contamination control. The correlation between TM-ASR and the Amplicor and Versant assays was poor, with large differences between assay results for individual samples. Calibration of the TM-ASR assay with Armored RNA allowed for a wide dynamic range and description of the distribution of HCV RNA in clinical samples.

Evaluation of the COBAS Hepatitis C Virus (HCV) TaqMan Analyte-Specific Reagent Assay and Comparison to the COBAS Amplicor HCV Monitor V2.0 and Versant HCV bDNA 3.0 Assays

PubMed Central

Konnick, Eric Q.; Williams, Sheri M.; Ashwood, Edward R.; Hillyard, David R.

2005-01-01

Performance characteristics of the COBAS hepatitis C virus (HCV) TaqMan analyte-specific reagent (TM-ASR) assay using the QIAGEN BioRobot 9604 for RNA extraction were evaluated and compared to the COBAS Amplicor HCV Monitor V2.0 (Amplicor) and Versant HCV bDNA 3.0 (Versant) assays using clinical samples. Calibration of TM-ASR using Armored RNA allowed determination of the distribution of HCV RNA in clinical samples, using 22,399 clinical samples. Limit of detection, linearity, and inter- and intraassay assay precision were determined for the TM-ASR assay using multiple clinical specimen panels across multiple determinations. Genotype specificity for the TM-ASR assay was determined using samples with different HCV RNA genotypes evaluated and compared against predetermined results. Contamination control of the TM-ASR assay was evaluated using pools of HCV RNA-positive and -negative samples tested in a checkerboard pattern over 12 runs of 96 samples. Correlation of the TM-ASR, Amplicor, and Versant assays was determined using 100 paired clinical samples and Deming regression analysis. The TM-ASR performed well with respect to linearity, precision, and contamination control. The correlation between TM-ASR and the Amplicor and Versant assays was poor, with large differences between assay results for individual samples. Calibration of the TM-ASR assay with Armored RNA allowed for a wide dynamic range and description of the distribution of HCV RNA in clinical samples. PMID:15872232

Progressive sparse representation-based classification using local discrete cosine transform evaluation for image recognition

NASA Astrophysics Data System (ADS)

Song, Xiaoning; Feng, Zhen-Hua; Hu, Guosheng; Yang, Xibei; Yang, Jingyu; Qi, Yunsong

2015-09-01

This paper proposes a progressive sparse representation-based classification algorithm using local discrete cosine transform (DCT) evaluation to perform face recognition. Specifically, the sum of the contributions of all training samples of each subject is first taken as the contribution of this subject, then the redundant subject with the smallest contribution to the test sample is iteratively eliminated. Second, the progressive method aims at representing the test sample as a linear combination of all the remaining training samples, by which the representation capability of each training sample is exploited to determine the optimal "nearest neighbors" for the test sample. Third, the transformed DCT evaluation is constructed to measure the similarity between the test sample and each local training sample using cosine distance metrics in the DCT domain. The final goal of the proposed method is to determine an optimal weighted sum of nearest neighbors that are obtained under the local correlative degree evaluation, which is approximately equal to the test sample, and we can use this weighted linear combination to perform robust classification. Experimental results conducted on the ORL database of faces (created by the Olivetti Research Laboratory in Cambridge), the FERET face database (managed by the Defense Advanced Research Projects Agency and the National Institute of Standards and Technology), AR face database (created by Aleix Martinez and Robert Benavente in the Computer Vision Center at U.A.B), and USPS handwritten digit database (gathered at the Center of Excellence in Document Analysis and Recognition at SUNY Buffalo) demonstrate the effectiveness of the proposed method.

Evaluation of single and two-stage adaptive sampling designs for estimation of density and abundance of freshwater mussels in a large river

USGS Publications Warehouse

Smith, D.R.; Rogala, J.T.; Gray, B.R.; Zigler, S.J.; Newton, T.J.

2011-01-01

Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non-adaptive versions of single and two-stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two-stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers.

Evaluation of species richness estimators based on quantitative performance measures and sensitivity to patchiness and sample grain size

NASA Astrophysics Data System (ADS)

Willie, Jacob; Petre, Charles-Albert; Tagg, Nikki; Lens, Luc

2012-11-01

Data from forest herbaceous plants in a site of known species richness in Cameroon were used to test the performance of rarefaction and eight species richness estimators (ACE, ICE, Chao1, Chao2, Jack1, Jack2, Bootstrap and MM). Bias, accuracy, precision and sensitivity to patchiness and sample grain size were the evaluation criteria. An evaluation of the effects of sampling effort and patchiness on diversity estimation is also provided. Stems were identified and counted in linear series of 1-m2 contiguous square plots distributed in six habitat types. Initially, 500 plots were sampled in each habitat type. The sampling process was monitored using rarefaction and a set of richness estimator curves. Curves from the first dataset suggested adequate sampling in riparian forest only. Additional plots ranging from 523 to 2143 were subsequently added in the undersampled habitats until most of the curves stabilized. Jack1 and ICE, the non-parametric richness estimators, performed better, being more accurate and less sensitive to patchiness and sample grain size, and significantly reducing biases that could not be detected by rarefaction and other estimators. This study confirms the usefulness of non-parametric incidence-based estimators, and recommends Jack1 or ICE alongside rarefaction while describing taxon richness and comparing results across areas sampled using similar or different grain sizes. As patchiness varied across habitat types, accurate estimations of diversity did not require the same number of plots. The number of samples needed to fully capture diversity is not necessarily the same across habitats, and can only be known when taxon sampling curves have indicated adequate sampling. Differences in observed species richness between habitats were generally due to differences in patchiness, except between two habitats where they resulted from differences in abundance. We suggest that communities should first be sampled thoroughly using appropriate taxon sampling curves before explaining differences in diversity.

Study on the influence of X-ray tube spectral distribution on the analysis of bulk samples and thin films: Fundamental parameters method and theoretical coefficient algorithms

NASA Astrophysics Data System (ADS)

Sitko, Rafał

2008-11-01

Knowledge of X-ray tube spectral distribution is necessary in theoretical methods of matrix correction, i.e. in both fundamental parameter (FP) methods and theoretical influence coefficient algorithms. Thus, the influence of X-ray tube distribution on the accuracy of the analysis of thin films and bulk samples is presented. The calculations are performed using experimental X-ray tube spectra taken from the literature and theoretical X-ray tube spectra evaluated by three different algorithms proposed by Pella et al. (X-Ray Spectrom. 14 (1985) 125-135), Ebel (X-Ray Spectrom. 28 (1999) 255-266), and Finkelshtein and Pavlova (X-Ray Spectrom. 28 (1999) 27-32). In this study, Fe-Cr-Ni system is selected as an example and the calculations are performed for X-ray tubes commonly applied in X-ray fluorescence analysis (XRF), i.e., Cr, Mo, Rh and W. The influence of X-ray tube spectra on FP analysis is evaluated when quantification is performed using various types of calibration samples. FP analysis of bulk samples is performed using pure-element bulk standards and multielement bulk standards similar to the analyzed material, whereas for FP analysis of thin films, the bulk and thin pure-element standards are used. For the evaluation of the influence of X-ray tube spectra on XRF analysis performed by theoretical influence coefficient methods, two algorithms for bulk samples are selected, i.e. Claisse-Quintin (Can. Spectrosc. 12 (1967) 129-134) and COLA algorithms (G.R. Lachance, Paper Presented at the International Conference on Industrial Inorganic Elemental Analysis, Metz, France, June 3, 1981) and two algorithms (constant and linear coefficients) for thin films recently proposed by Sitko (X-Ray Spectrom. 37 (2008) 265-272).

Evaluation of two 4th generation point-of-care assays for the detection of Human Immunodeficiency Virus infection.

PubMed

Stafylis, Chrysovalantis; Klausner, Jeffrey D

2017-01-01

Fourth generation assays detect simultaneously antibodies for HIV and the p24 antigen, identifying HIV infection earlier than previous generation tests. Previous studies have shown that the Alere Determine HIV-1/2 Combo has lower than anticipated performance in detecting antibodies for HIV and the p24 antigen. Furthermore, there are currently very few studies evaluating the performance of Standard Diagnostics BIOLINE HIV Ag/Ab Combo. To evaluate the performance of the Alere Determine HIV-1/2 Combo and the Standard Diagnostics BIOLINE HIV Ag/Ab Combo in a panel of frozen serum samples. The testing panel included 133 previously frozen serum specimens from the UCLA Clinical Microbiology & Immunoserology laboratory. Reference testing included testing for HIV antibodies by a 3rd generation enzyme immunoassay followed by HIV RNA detection. Antibody negative and RNA positive sera were also tested by a laboratory 4th generation HIV Ab/Ag enzyme immunoassay. Reference testing yielded 97 positives for HIV infection and 36 negative samples. Sensitivity of the Alere test was 95% (88-98%), while the SD Bioline sensitivity was 91% (83-96%). Both assays showed 100% (90-100%) specificity. No indeterminate or invalid results were recorded. Among 13 samples with acute infection (HIV RNA positive, HIV antibody negative), 12 were found positive by the first assay and 8 by the second. The antigen component of the Alere assay detected 10 acute samples, while the SD Bioline assay detected only one. Both rapid assays showed very good overall performance in detecting HIV infection in frozen serum samples, but further improvements are required to improve the performance in acute infection.

Airport Performance and Construction Enlargement Activities

NASA Astrophysics Data System (ADS)

Hanun, Y.; Setiawan, M. I.; Kurniasih, N.; Hasyim, C.; Ahmar, A. S.

2018-01-01

The evaluation of transportation infrastructure project should consider the contribution towards infrastructure growth. This research aims to analyze the effect of Construction enlargement activities towards airport performance. This research is correlation study. The population includes 148 airports in Indonesia. By using total sampling, there were 148 sample airports. The result shows that the construction enlargement activities variable has relatively strong relationship to Airport Performance variable, while the adjusted R Square score shows the increasing construction enlargement activities that affected by the other factors aside from airport performance.

Personality and Student Performance on Evaluation Methods Used in Business Administration Courses

ERIC Educational Resources Information Center

Lakhal, Sawsen; Sévigny, Serge; Frenette, Éric

2015-01-01

The objective of this study was to verify whether personality (Big Five model) influences performance on the evaluation methods used in business administration courses. A sample of 169 students enrolled in two compulsory undergraduate business courses responded to an online questionnaire. As it is difficult within the same course to assess…

Education and Child Welfare Supervisor Performance: Does a Social Work Degree Matter?

ERIC Educational Resources Information Center

Perry, Robin E.

2006-01-01

Objective: To empirically examine whether the educational background of child welfare supervisors in Florida affects performance evaluations of their work. Method: A complete population sample (yielding a 58.5% response rate) of administrator and peer evaluations of child welfare workers' supervisors. ANOVA procedures were utilized to test if…

DETERMINING COARSE PARTICULATE MATTER CONCENTRATIONS: A PERFORMANCE EVALUATION OF CANDIDATE METHODOLOGIES UNDER WINTERTIME CONDITIONS

EPA Science Inventory

The main objective of this study is to evaluate the performance of sampling methods for potential use as a Federal Reference Method (FRM) capable of providing an estimate of coarse particle (PMc: particulate matter with an aerodynamic diameter between 2.5 um and 10 um) mass con...

Convergent Validity Evidence regarding the Validity of the Chilean Standards-Based Teacher Evaluation System

ERIC Educational Resources Information Center

Santelices, Maria Veronica; Taut, Sandy

2011-01-01

This paper describes convergent validity evidence regarding the mandatory, standards-based Chilean national teacher evaluation system (NTES). The study examined whether NTES identifies--and thereby rewards or punishes--the "right" teachers as high- or low-performing. We collected in-depth teaching performance data on a sample of 58…

ACS sampling system: design, implementation, and performance evaluation

NASA Astrophysics Data System (ADS)

Di Marcantonio, Paolo; Cirami, Roberto; Chiozzi, Gianluca

2004-09-01

By means of ACS (ALMA Common Software) framework we designed and implemented a sampling system which allows sampling of every Characteristic Component Property with a specific, user-defined, sustained frequency limited only by the hardware. Collected data are sent to various clients (one or more Java plotting widgets, a dedicated GUI or a COTS application) using the ACS/CORBA Notification Channel. The data transport is optimized: samples are cached locally and sent in packets with a lower and user-defined frequency to keep network load under control. Simultaneous sampling of the Properties of different Components is also possible. Together with the design and implementation issues we present the performance of the sampling system evaluated on two different platforms: on a VME based system using VxWorks RTOS (currently adopted by ALMA) and on a PC/104+ embedded platform using Red Hat 9 Linux operating system. The PC/104+ solution offers, as an alternative, a low cost PC compatible hardware environment with free and open operating system.

Performance evaluation of direct saline stool microscopy, Formol ether concentration and Kato Katz diagnostic methods for intestinal parasitosis in the absence of gold standard methods.

PubMed

Hailu, Tadesse; Abera, Bayeh

2015-07-01

The parasite load within the sample and the amount of sample taken during examination greatly compromise the sensitivity of direct saline stool microscopy. A cross-sectional study was conducted in March 2011 in Bahir Dar city among 778 fresh single stool samples to evaluate the performance of direct saline (DS), Kato Katz (KK) and Formol ether concentration (FEC) methods against the 'Gold' standard. Among 778 stool samples from school age children, the highest prevalence of intestinal parasites was recorded by FEC (55.1%). The sensitivity of DS, FEC and KK were 61.1%, 92.3% and 58.7%, respectively. FEC is more sensitive than DS and KK. Hence, use of the latter is preferred. © The Author(s) 2015.

Evaluation of the rapid plasma reagin "teardrop" card test for screening of syphilis in field conditions.

PubMed

Van Dyck, E; Van de Velden, L; Ndoye, I; Piot, P; Meheus, A

1993-01-01

The availability of simple diagnostic methods may contribute to more efficient control of sexually transmitted diseases (STDs) in developing countries. For the detection of syphilis, a simple rapid plasma reagin (RPR) "teardrop" assay for finger-prick blood samples was developed in 1962. The reliability of this test is compared with RPR, Treponema pallidum hemagglutination assay (TPHA), and fluorescent treponemal antibody absorption (FTA-Abs) assays performed on venous blood samples. To evaluate the potential usefulness of the finger-stick RPR teardrop assay for diagnosis of syphilis in settings with poor medical resources. Pregnant women evaluated at two health centers in Pikine, Senegal were tested for STDs. The RPR teardrop assay was performed on plasma from blood samples obtained by finger prick, and standard RPR, TPHA, and FTA-Abs procedures were performed on serum obtained by vein puncture. The sensitivity and specificity of the finger-prick RPR teardrop assay were 69.7% and 96.5%, respectively, and its reactivity was correlated with RPR serum antibody titer. The finger-prick RPR teardrop assay is not a reliable alternative to the classic serum RPR test.

Emergency radiobioassay preparedness exercises through the NIST radiochemistry intercomparison program.

PubMed

Nour, Svetlana; LaRosa, Jerry; Inn, Kenneth G W

2011-08-01

The present challenge for the international emergency radiobioassay community is to analyze contaminated samples rapidly while maintaining high quality results. The National Institute of Standards and Technology (NIST) runs a radiobioassay measurement traceability testing program to evaluate the radioanalytical capabilities of participating laboratories. The NIST Radiochemistry Intercomparison Program (NRIP) started more than 10 years ago, and emergency performance testing was added to the program seven years ago. Radiobioassay turnaround times under the NRIP program for routine production and under emergency response scenarios are 60 d and 8 h, respectively. Because measurement accuracy and sample turnaround time are very critical in a radiological emergency, response laboratories' analytical systems are best evaluated and improved through traceable Performance Testing (PT) programs. The NRIP provides participant laboratories with metrology tools to evaluate their performance and to improve it. The program motivates the laboratories to optimize their methodologies and minimize the turnaround time of their results. Likewise, NIST has to make adjustments and periodical changes in the bioassay test samples in order to challenge the participating laboratories continually. With practice, radioanalytical measurements turnaround time can be reduced to 3-4 h.

Performance of hepatitis B assays on the Bayer ADVIA Centaur Immunoassay System.

PubMed

van Helden, Josef; Denoyel, Gérard; Karwowska, Sylwia; Reamer, Randy; Schmalz, John; Wright, Ted; Preisel-Simmons, Barbara

2004-01-01

Bayer HealthCare LLC, Diagnostics Division, has developed several new assays on the ADVIA Centaur immunoassay system for the detection of markers of hepatitis B virus infection in human serum and plasma. This panel includes assays for: hepatitis B surface antigen (HBsAg), a confirmatory test method for HBsAg, antibodies to hepatitis B surface antigen (anti-HBs), IgM and IgG antibodies to hepatitis B core antigen (anti-HBc Total) and IgM antibodies to hepatitis B core antigen (anti-HBc IgM). These assays employ magnetic particle separation technology with direct chemiluminescence for optimal assay performance. All of the assays are fully automated, require sample volumes ranging from 15 microl to 100 microl (with the exception of the ADVIA Centaur HBsAg Confirmatory Assay, which requires 2 x 100 microl), and have throughputs of up to 240 tests per hour. The five ADVIA Centaur HBV assays were tested in extensive performance evaluations conducted at two sites in Europe. The performance evaluations, which included samples from HBV-infected individuals, blood donors, hospitalized/clinical patients, and HBV vaccinees (for Anti-HBs evaluation), generated performance data in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The HBV performance evaluations resulted in an overall diagnostic specificity > 99%, i.e. 99.94% for the ADVIA Centaur HBsAg Assay, 100% for the ADVIA Centaur Anti-HBs Assay, 100% for the ADVIA Centaur HBc IgM Assay and 99.94% for the ADVIA Centaur HBc Total Assay. All of the ADVIA Centaur assays showed a very good diagnostic sensitivity on these populations with 100% for the ADVIA Centaur HBsAg Assay, 99.0% for the ADVIA Centaur Anti-HBs Assay, 98.53% for the ADVIA Centaur HBc IgM Assay and 100% for the ADVIA Centaur HBc Total Assay. The ADVIA Centaur HBsAg Confirmatory Test confirmed 100% of the positive HBsAg samples. Testing of interfering substances and potential cross-reacting samples for all ADVIA Centaur HBV assays resulted in no change in interpretation of the results. Assay performance was further evaluated using HBV seroconversion panels with comparable or better results when compared to the comparison assays. The performance evaluation data demonstrate that the ADVIA Centaur HBV assays are specific and sensitive automated immunoassays for detection of antigens and antibodies to hepatitis B virus with performance that is comparable to those of currently marketed assays. Additionally, these assays have the advantage of being available on the ADVIA Centaur immunoassay system, which provides for the flexibility of high throughput and full automation.

Use of Latent Class Analysis to define groups based on validity, cognition, and emotional functioning.

PubMed

Morin, Ruth T; Axelrod, Bradley N

Latent Class Analysis (LCA) was used to classify a heterogeneous sample of neuropsychology data. In particular, we used measures of performance validity, symptom validity, cognition, and emotional functioning to assess and describe latent groups of functioning in these areas. A data-set of 680 neuropsychological evaluation protocols was analyzed using a LCA. Data were collected from evaluations performed for clinical purposes at an urban medical center. A four-class model emerged as the best fitting model of latent classes. The resulting classes were distinct based on measures of performance validity and symptom validity. Class A performed poorly on both performance and symptom validity measures. Class B had intact performance validity and heightened symptom reporting. The remaining two Classes performed adequately on both performance and symptom validity measures, differing only in cognitive and emotional functioning. In general, performance invalidity was associated with worse cognitive performance, while symptom invalidity was associated with elevated emotional distress. LCA appears useful in identifying groups within a heterogeneous sample with distinct performance patterns. Further, the orthogonal nature of performance and symptom validities is supported.

Effects of Oxygen Content on Tensile and Fatigue Performance of Ti-6Al-4 V Manufactured by Selective Laser Melting

NASA Astrophysics Data System (ADS)

Quintana, Oscar A.; Tong, Weidong

2017-12-01

We investigated the selective laser melting (SLM) process for development of Ti-6Al-4 V solid material with oxygen content corresponding to the extra low interstitial (ELI) and non-ELI conditions. The microstructure, chemistry, and tensile properties of samples in as-built and hot isostatically pressed (HIPed) condition were evaluated for both material types, while fatigue performance was evaluated by rotating bending fatigue tests on both smooth and notched SLM ELI and non-ELI Ti-6Al-4 V samples in HIPed condition.

Assessing deep and shallow learning methods for quantitative prediction of acute chemical toxicity.

PubMed

Liu, Ruifeng; Madore, Michael; Glover, Kyle P; Feasel, Michael G; Wallqvist, Anders

2018-05-02

Animal-based methods for assessing chemical toxicity are struggling to meet testing demands. In silico approaches, including machine-learning methods, are promising alternatives. Recently, deep neural networks (DNNs) were evaluated and reported to outperform other machine-learning methods for quantitative structure-activity relationship modeling of molecular properties. However, most of the reported performance evaluations relied on global performance metrics, such as the root mean squared error (RMSE) between the predicted and experimental values of all samples, without considering the impact of sample distribution across the activity spectrum. Here, we carried out an in-depth analysis of DNN performance for quantitative prediction of acute chemical toxicity using several datasets. We found that the overall performance of DNN models on datasets of up to 30,000 compounds was similar to that of random forest (RF) models, as measured by the RMSE and correlation coefficients between the predicted and experimental results. However, our detailed analyses demonstrated that global performance metrics are inappropriate for datasets with a highly uneven sample distribution, because they show a strong bias for the most populous compounds along the toxicity spectrum. For highly toxic compounds, DNN and RF models trained on all samples performed much worse than the global performance metrics indicated. Surprisingly, our variable nearest neighbor method, which utilizes only structurally similar compounds to make predictions, performed reasonably well, suggesting that information of close near neighbors in the training sets is a key determinant of acute toxicity predictions.

Performance Characteristics of Middle-Class and Lower-Class Preschool Children on the Stanford-Binet, 1960 Revision.

ERIC Educational Resources Information Center

Meyer, William J.; Goldstein, David

The relative difficulty levels of Stanford-Binet items between the ages of four and six among prekindergarten Head Start children were studied. A comparison sample of prekindergarten white middle class children was included to evaluate the age norms on a culturally typical sample of children and to assess performance on the Binet as it might…

Diagnostic Performance of the CBCL-Attention Problem Scale as a Screening Measure in a Sample of Brazilian Children with ADHD

ERIC Educational Resources Information Center

Lampert, T. L.; Polanczyk, G.; Tramontina, S.; Mardini, V.; Rohde, L. A.

2004-01-01

Objective: To evaluate the diagnostic performance of the Attention Problem Scale of the Child Behavior Checklist (CBCL-APS) for the screening of Attention-Deficit/Hyperactivity Disorder (ADHD) in a sample of Brazilian children and adolescents. Methods: The CBCL-APS was given to 763 children and adolescents. Child psychiatrists using DSM-IV…

Performance Evaluation and Analysis for Gravity Matching Aided Navigation.

PubMed

Wu, Lin; Wang, Hubiao; Chai, Hua; Zhang, Lu; Hsu, Houtse; Wang, Yong

2017-04-05

Simulation tests were accomplished in this paper to evaluate the performance of gravity matching aided navigation (GMAN). Four essential factors were focused in this study to quantitatively evaluate the performance: gravity database (DB) resolution, fitting degree of gravity measurements, number of samples in matching, and gravity changes in the matching area. Marine gravity anomaly DB derived from satellite altimetry was employed. Actual dynamic gravimetry accuracy and operating conditions were referenced to design the simulation parameters. The results verified that the improvement of DB resolution, gravimetry accuracy, number of measurement samples, or gravity changes in the matching area generally led to higher positioning accuracies, while the effects of them were different and interrelated. Moreover, three typical positioning accuracy targets of GMAN were proposed, and the conditions to achieve these targets were concluded based on the analysis of several different system requirements. Finally, various approaches were provided to improve the positioning accuracy of GMAN.

Performance Evaluation and Analysis for Gravity Matching Aided Navigation

PubMed Central

Wu, Lin; Wang, Hubiao; Chai, Hua; Zhang, Lu; Hsu, Houtse; Wang, Yong

2017-01-01

Simulation tests were accomplished in this paper to evaluate the performance of gravity matching aided navigation (GMAN). Four essential factors were focused in this study to quantitatively evaluate the performance: gravity database (DB) resolution, fitting degree of gravity measurements, number of samples in matching, and gravity changes in the matching area. Marine gravity anomaly DB derived from satellite altimetry was employed. Actual dynamic gravimetry accuracy and operating conditions were referenced to design the simulation parameters. The results verified that the improvement of DB resolution, gravimetry accuracy, number of measurement samples, or gravity changes in the matching area generally led to higher positioning accuracies, while the effects of them were different and interrelated. Moreover, three typical positioning accuracy targets of GMAN were proposed, and the conditions to achieve these targets were concluded based on the analysis of several different system requirements. Finally, various approaches were provided to improve the positioning accuracy of GMAN. PMID:28379178

Quality assessment of lymph node sampling in rhabdomyosarcoma: A surveillance, epidemiology, and end results (SEER) program study.

PubMed

Lobeck, Inna; Dupree, Phylicia; Karns, Rebekah; Rodeberg, David; von Allmen, Daniel; Dasgupta, Roshni

2017-04-01

Lymph node sampling is integral in the management of extremity and paratesticular rhabdomyosarcoma (RMS). The aim of this study was to determine overall surgical compliance with treatment protocols and impact of nodal sampling outcomes in these tumors. A query of the surveillance, epidemiology, and end results program (SEER) database was performed from 2003 to 2008 for patients <19years of age with RMS. Data obtained included demographics, five-year survival and rate of nodal sampling. Analysis was performed utilizing chi-squared, Kaplan-Meier and hazard ratio modeling. Of 537 patients with extremity RMS, nodal sampling was performed in 25.7% (n=138). This lack of nodal sampling had a negative outcome on survival (p=0.004). Sixty five patients with paratesticular RMS aged greater than 10 were identified and also displayed low rates of lymph node sampling (47.7%, n=31). For paratesticular patients, a similar increase in survival was seen in patients who underwent nodal evaluation (p=0.024). Lymph node sampling is the standard of care in RMS. However, surgical compliance with treatment protocols is poor. Nodal evaluation correlated significantly with overall survival. These findings suggest a need for improved education among surgeons and oncologists regarding the need lymph node assessment in pediatric oncology patients. Evidence rating/classification: Prognosis study, Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

Colorimetric-Solid Phase Extraction Technology for Water Quality Monitoring: Evaluation of C-SPE and Debubbling Methods in Microgravity

NASA Technical Reports Server (NTRS)

Hazen-Bosveld, April; Lipert, Robert J.; Nordling, John; Shih, Chien-Ju; Siperko, Lorraine; Porter, Marc D.; Gazda, Daniel B.; Rutz, Jeff A.; Straub, John E.; Schultz, John R.;

Investing in Development: Six High-Performing, High-Poverty Schools Implement the Massachusetts Teacher Evaluation Policy

ERIC Educational Resources Information Center

Reinhorn, Stefanie K.; Johnson, Susan Moore; Simon, Nicole S.

2017-01-01

We studied how six high-performing, high-poverty schools in one large Massachusetts city implemented the state's new teacher evaluation policy. The sample includes traditional, turnaround, restart, and charter schools, each of which had received the state's highest accountability rating. We sought to learn how these successful schools approached…

PRELIMINARY RESULTS OF EPA'S PERFORMANCE EVALUATION OF FEDERAL REFERENCE METHODS AND FEDERAL EQUIVALENT METHODS FOR COARSE PARTICULATE MATTER

EPA Science Inventory

The main objective of this study is to evaluate the performance of sampling methods for potential use as a Federal Reference Method (FRM) capable of providing an estimate of coarse particle (PMc: particulate matter with an aerodynamic diameter between 2.5 µm and 10 µm) ...

DETERMINING COARSE PARTICULATE MATTER CONCENTRATIONS: A PERFORMANCE EVALUATION OF CANDIDATE METHODOLOGIES - STUDY DESIGN AND RESULTS FROM THE RTP EQUIPMENT SHAKEDOWN

EPA Science Inventory

The main objective of this study is to evaluate the performance of candidate sampling methods for potential use as a Federal Reference Method (FRM) capable of providing an estimate of coarse particle (PMc: particulate matter with an aerodynamic diameter between 2.5 um and 10 um...

Field performance of a semi-continuous monitor for ambient PM2.5 water-soluble inorganic ions and gases at a suburban site

NASA Astrophysics Data System (ADS)

Young, Li-Hao; Li, Chiao-Hsin; Lin, Ming-Yeng; Hwang, Bing-Fang; Hsu, Hui-Tsung; Chen, Yu-Cheng; Jung, Chau-Ren; Chen, Kuan-Chi; Cheng, Dung-Hung; Wang, Ven-Shing; Chiang, Hung-Che; Tsai, Perng-Jy

2016-11-01

To reduce sampling artifacts and to improve time-resolved measurements of inorganic aerosol system, a recently commercialized semi-continuous In-situ Gas and Aerosol Composition (IGAC) monitoring system was evaluated against a reference annular denuder system (ADS; denuder/two-stage filter pack) at a suburban site over a year, during which the average PM2.5 was 37.0 ± 24.8 μg/m3. A suite of eight ions SO42-, NO3-, Cl-, NH4+, Na+, K+, Ca2+ and Mg2+ and two gases SO2 and NH3 were the target species. In comparison to the reference ADS method, the IGAC performed well in measuring the major ions SO42-, NO3- and NH4+, and the SO2. For those species, the linear slopes, intercepts and R2 values between the two methods all passed the performance evaluation criteria outlined by earlier similar studies. The performance of IGAC on Cl-, Na+, K+ and NH3 was marginally acceptable, whereas Ca2+ and Mg2+ could not be properly evaluated due to the low concentrations (<0.2 μg/m3) and hence inadequate amount of sample size. The ionic balance of the hourly IGAC samples averaged very close to unity, as did the daily ADS samples, though the former was considerably more variable than the latter. The overall performance of the IGAC has been shown to be comparable to other similar monitors and its improvements are discussed.

Hydrogeochemical and stream sediment reconnaissance basic data for Roswell quadrangle, New Mexico

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

Not Available

Field and laboratory data are presented for 842 water samples and 1270 sediment samples from the Roswell Quadrangle, New Mexico. The samples were collected by Los Alamos National Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

Accounting for sensor calibration, data validation, measurement and sampling uncertainties in monitoring urban drainage systems.

PubMed

Bertrand-Krajewski, J L; Bardin, J P; Mourad, M; Béranger, Y

2003-01-01

Assessing the functioning and the performance of urban drainage systems on both rainfall event and yearly time scales is usually based on online measurements of flow rates and on samples of influent effluent for some rainfall events per year. In order to draw pertinent scientific and operational conclusions from the measurement results, it is absolutely necessary to use appropriate methods and techniques in order to i) calibrate sensors and analytical methods, ii) validate raw data, iii) evaluate measurement uncertainties, iv) evaluate the number of rainfall events to sample per year in order to determine performance indicator with a given uncertainty. Based an previous work, the paper gives a synthetic review of required and techniques, and illustrates their application to storage and settling tanks. Experiments show that, controlled and careful experimental conditions, relative uncertainties are about 20% for flow rates in sewer pipes, 6-10% for volumes, 25-35% for TSS concentrations and loads, and 18-276% for TSS removal rates. In order to evaluate the annual pollutant interception efficiency of storage and settling tanks with a given uncertainty, efforts should first be devoted to decrease the sampling uncertainty by increasing the number of sampled events.

Evaluation of dredged material proposed for ocean disposal from Hudson River, New York

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

Gardiner, W.W.; Barrows, E.S.; Antrim, L.D.

1996-09-01

The Hudson River (Federal Project No. 41) was one of seven waterways that the U.S. Army Corps of Engineers-New York District (USACE-NYD) requested the Battelle Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in March 1994. Sediment samples were collected from the Hudson River. Tests and analyses were conducted on Hudson River sediment core samples. The evaluation of proposed dredged material from the Hudson River included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Hudson River were analyzedmore » for grain size, moisture content, and total organic carbon (TOC). A composite sediment sample, representing the entire area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Site water and elutriate water, prepared from the suspended-particulate phase (SPP) of Hudson River sediment, were analyzed for metals, pesticides, and PCBS. Water-column or SPP toxicity tests were performed with three species. Benthic acute toxicity tests were performed. Bioaccumulation tests were also conducted.« less

Human breath metabolomics using an optimized noninvasive exhaled breath condensate sampler

PubMed Central

Zamuruyev, Konstantin O.; Aksenov, Alexander A.; Pasamontes, Alberto; Brown, Joshua F.; Pettit, Dayna R.; Foutouhi, Soraya; Weimer, Bart C.; Schivo, Michael; Kenyon, Nicholas J.; Delplanque, Jean-Pierre; Davis, Cristina E.

2017-01-01

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube™ and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017). PMID:28004639

Human breath metabolomics using an optimized non-invasive exhaled breath condensate sampler.

PubMed

Zamuruyev, Konstantin O; Aksenov, Alexander A; Pasamontes, Alberto; Brown, Joshua F; Pettit, Dayna R; Foutouhi, Soraya; Weimer, Bart C; Schivo, Michael; Kenyon, Nicholas J; Delplanque, Jean-Pierre; Davis, Cristina E

2016-12-22

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube ™ and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017).

Expression signature as a biomarker for prenatal diagnosis of trisomy 21.

PubMed

Volk, Marija; Maver, Aleš; Lovrečić, Luca; Juvan, Peter; Peterlin, Borut

2013-01-01

A universal biomarker panel with the potential to predict high-risk pregnancies or adverse pregnancy outcome does not exist. Transcriptome analysis is a powerful tool to capture differentially expressed genes (DEG), which can be used as biomarker-diagnostic-predictive tool for various conditions in prenatal setting. In search of biomarker set for predicting high-risk pregnancies, we performed global expression profiling to find DEG in Ts21. Subsequently, we performed targeted validation and diagnostic performance evaluation on a larger group of case and control samples. Initially, transcriptomic profiles of 10 cultivated amniocyte samples with Ts21 and 9 with normal euploid constitution were determined using expression microarrays. Datasets from Ts21 transcriptomic studies from GEO repository were incorporated. DEG were discovered using linear regression modelling and validated using RT-PCR quantification on an independent sample of 16 cases with Ts21 and 32 controls. The classification performance of Ts21 status based on expression profiling was performed using supervised machine learning algorithm and evaluated using a leave-one-out cross validation approach. Global gene expression profiling has revealed significant expression changes between normal and Ts21 samples, which in combination with data from previously performed Ts21 transcriptomic studies, were used to generate a multi-gene biomarker for Ts21, comprising of 9 gene expression profiles. In addition to biomarker's high performance in discriminating samples from global expression profiling, we were also able to show its discriminatory performance on a larger sample set 2, validated using RT-PCR experiment (AUC=0.97), while its performance on data from previously published studies reached discriminatory AUC values of 1.00. Our results show that transcriptomic changes might potentially be used to discriminate trisomy of chromosome 21 in the prenatal setting. As expressional alterations reflect both, causal and reactive cellular mechanisms, transcriptomic changes may thus have future potential in the diagnosis of a wide array of heterogeneous diseases that result from genetic disturbances.

Evaluation of the results of Mycobacterium tuberculosis direct test (MTD) and Mycobacterial culture in urine samples

PubMed Central

Sener, Asli Gamze; Kurultay, Nukhet; Afsar, Ilhan

2008-01-01

Tuberculosis remains a public health problem in Turkey. Rapid detection of Mycobacterium tuberculosis plays a key role in control of infection. In this article, the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) was evaluated for detection of M. tuberculosis in urine samples. The performance of the MTD was very good and appropriate for routine laboratory diagnosis. PMID:24031287

Evaluation of analytical performance of a new high-sensitivity immunoassay for cardiac troponin I.

PubMed

Masotti, Silvia; Prontera, Concetta; Musetti, Veronica; Storti, Simona; Ndreu, Rudina; Zucchelli, Gian Carlo; Passino, Claudio; Clerico, Aldo

2018-02-23

The study aim was to evaluate and compare the analytical performance of the new chemiluminescent immunoassay for cardiac troponin I (cTnI), called Access hs-TnI using DxI platform, with those of Access AccuTnI+3 method, and high-sensitivity (hs) cTnI method for ARCHITECT platform. The limits of blank (LoB), detection (LoD) and quantitation (LoQ) at 10% and 20% CV were evaluated according to international standardized protocols. For the evaluation of analytical performance and comparison of cTnI results, both heparinized plasma samples, collected from healthy subjects and patients with cardiac diseases, and quality control samples distributed in external quality assessment programs were used. LoB, LoD and LoQ at 20% and 10% CV values of the Access hs-cTnI method were 0.6, 1.3, 2.1 and 5.3 ng/L, respectively. Access hs-cTnI method showed analytical performance significantly better than that of Access AccuTnI+3 method and similar results to those of hs ARCHITECT cTnI method. Moreover, the cTnI concentrations measured with Access hs-cTnI method showed close linear regressions with both Access AccuTnI+3 and ARCHITECT hs-cTnI methods, although there were systematic differences between these methods. There was no difference between cTnI values measured by Access hs-cTnI in heparinized plasma and serum samples, whereas there was a significant difference between cTnI values, respectively measured in EDTA and heparin plasma samples. Access hs-cTnI has analytical sensitivity parameters significantly improved compared to Access AccuTnI+3 method and is similar to those of the high-sensitivity method using ARCHITECT platform.

Non-destructive testing of concrete.

DOT National Transportation Integrated Search

1979-11-01

This research project was initiated to evaluate the performance of an ultrasonic testing device device in predicting compressive strengths from tests performed on samples of fresh concrete. : The initial phase of this study involved laboratory perora...

Use of diagnostic accuracy as a metric for evaluating laboratory proficiency with microarray assays using mixed-tissue RNA reference samples.

PubMed

Pine, P S; Boedigheimer, M; Rosenzweig, B A; Turpaz, Y; He, Y D; Delenstarr, G; Ganter, B; Jarnagin, K; Jones, W D; Reid, L H; Thompson, K L

2008-11-01

Effective use of microarray technology in clinical and regulatory settings is contingent on the adoption of standard methods for assessing performance. The MicroArray Quality Control project evaluated the repeatability and comparability of microarray data on the major commercial platforms and laid the groundwork for the application of microarray technology to regulatory assessments. However, methods for assessing performance that are commonly applied to diagnostic assays used in laboratory medicine remain to be developed for microarray assays. A reference system for microarray performance evaluation and process improvement was developed that includes reference samples, metrics and reference datasets. The reference material is composed of two mixes of four different rat tissue RNAs that allow defined target ratios to be assayed using a set of tissue-selective analytes that are distributed along the dynamic range of measurement. The diagnostic accuracy of detected changes in expression ratios, measured as the area under the curve from receiver operating characteristic plots, provides a single commutable value for comparing assay specificity and sensitivity. The utility of this system for assessing overall performance was evaluated for relevant applications like multi-laboratory proficiency testing programs and single-laboratory process drift monitoring. The diagnostic accuracy of detection of a 1.5-fold change in signal level was found to be a sensitive metric for comparing overall performance. This test approaches the technical limit for reliable discrimination of differences between two samples using this technology. We describe a reference system that provides a mechanism for internal and external assessment of laboratory proficiency with microarray technology and is translatable to performance assessments on other whole-genome expression arrays used for basic and clinical research.

Performance evaluation of a chemiluminescence microparticle immunoassay for CK-MB.

PubMed

Lin, Zhi-Yuan; Fang, Yi-Zhen; Jin, Hong-Wei; Lin, Hua-Yue; Dai, Zhang; Luo, Qing; Li, Hong-Wei; Lin, Yan-Ling; Huang, Shui-Zhen; Gao, Lei; Xu, Fei-Hai; Zhang, Zhong-Ying

2018-03-31

To verify and evaluate the performance characteristics of a creatine kinase phosphokinase isoenzymes MB (CK-MB) assay kit, which produced by Xiamen Innodx Biotech Co. Ltd. Evaluation was carried out according to "Guidelines for principle of analysis performance evaluation of in vitro diagnostic reagent." The performance parameters included detection limit, linearity range, reportable range, recovery test, precision verification, interference test, cross-reactivity, matrix effect, and method comparison. The detection limit was 0.1 ng/mL. The assay had clinical linearity over range of 0.1 ng/mL-500 ng/mL. Reportable range was from 0.1 ng/mL to 1000 ng/mL. The average percent of recovery was 99.66%. The coefficient of variation (CV) for within-run and between-run of low CK-MB sample was 5.55% and 6.16%, respectively. As for high-level sample, it was 7.88% and 7.80%. In medical decision level, the relative deviation (Bias) of all interference tests was lower than 15%. When the sample had mild-hemolysis; hemoglobin ≤15 g/L; triglyceride ≤17 mmol/L; bilirubin ≤427.5 μmol/L; rheumatoid factor ≤206U/mL, there was no significant interference to be found. Moreover, assay kit had no cross-reaction with CK-MM and CK-BB. At last, total diagnostic accuracy of kit was 93.24%, when compared with refer kit. Overall the results of the verification study indicated the performance of kit is met the requirements of the clinical test. © 2018 Wiley Periodicals, Inc.

Design and implementation of an optical Gaussian noise generator

NASA Astrophysics Data System (ADS)

Za~O, Leonardo; Loss, Gustavo; Coelho, Rosângela

2009-08-01

A design of a fast and accurate optical Gaussian noise generator is proposed and demonstrated. The noise sample generation is based on the Box-Muller algorithm. The functions implementation was performed on a high-speed Altera Stratix EP1S25 field-programmable gate array (FPGA) development kit. It enabled the generation of 150 million 16-bit noise samples per second. The Gaussian noise generator required only 7.4% of the FPGA logic elements, 1.2% of the RAM memory, 0.04% of the ROM memory, and a laser source. The optical pulses were generated by a laser source externally modulated by the data bit samples using the frequency-shift keying technique. The accuracy of the noise samples was evaluated for different sequences size and confidence intervals. The noise sample pattern was validated by the Bhattacharyya distance (Bd) and the autocorrelation function. The results showed that the proposed design of the optical Gaussian noise generator is very promising to evaluate the performance of optical communications channels with very low bit-error-rate values.

Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel 'V-plot' methodology to display accuracy values.

PubMed

Petraco, Ricardo; Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

2018-01-01

Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test's performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Chol rapid and Chol gold ) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard.

LIMS for Lasers 2015 for achieving long-term accuracy and precision of δ2H, δ17O, and δ18O of waters using laser absorption spectrometry

USGS Publications Warehouse

Coplen, Tyler B.; Wassenaar, Leonard I

2015-01-01

Although laser absorption spectrometry (LAS) instrumentation is easy to use, its incorporation into laboratory operations is not easy, owing to extensive offline manipulation of comma-separated-values files for outlier detection, between-sample memory correction, nonlinearity (δ-variation with water amount) correction, drift correction, normalization to VSMOW-SLAP scales, and difficulty in performing long-term QA/QC audits. METHODS: A Microsoft Access relational-database application, LIMS (Laboratory Information Management System) for Lasers 2015, was developed. It automates LAS data corrections and manages clients, projects, samples, instrument-sample lists, and triple-isotope (δ(17) O, δ(18) O, and δ(2) H values) instrumental data for liquid-water samples. It enables users to (1) graphically evaluate sample injections for variable water yields and high isotope-delta variance; (2) correct for between-sample carryover, instrumental drift, and δ nonlinearity; and (3) normalize final results to VSMOW-SLAP scales. RESULTS: Cost-free LIMS for Lasers 2015 enables users to obtain improved δ(17) O, δ(18) O, and δ(2) H values with liquid-water LAS instruments, even those with under-performing syringes. For example, LAS δ(2) HVSMOW measurements of USGS50 Lake Kyoga (Uganda) water using an under-performing syringe having ±10 % variation in water concentration gave +31.7 ± 1.6 ‰ (2-σ standard deviation), compared with the reference value of +32.8 ± 0.4 ‰, after correction for variation in δ value with water concentration, between-sample memory, and normalization to the VSMOW-SLAP scale. CONCLUSIONS: LIMS for Lasers 2015 enables users to create systematic, well-founded instrument templates, import δ(2) H, δ(17) O, and δ(18) O results, evaluate performance with automatic graphical plots, correct for δ nonlinearity due to variable water concentration, correct for between-sample memory, adjust for drift, perform VSMOW-SLAP normalization, and perform long-term QA/QC audits easily.

Malaria rapid diagnostic test as point-of-care test: study protocol for evaluating the VIKIA Malaria Ag Pf/Pan.

PubMed

Kim, Saorin; Nhem, Sina; Dourng, Dany; Ménard, Didier

2015-03-14

Malaria rapid diagnostic tests (RDTs) are generally considered as point-of-care tests. However, most of the studies assessing the performance of malaria RDTs are conducted by research teams that are not representative of the classical end-users, who are typically unskilled in traditional laboratory techniques for diagnosing malaria. To evaluate the performance of a malaria RDT by end-users in a malaria-endemic area, a study protocol was designed and the VIKIA Malaria Ag Pf/Pan test, previously evaluated in 2013, was re-evaluated by representative end-users. Twenty end-users with four different profiles in seven communes in Kampot Province (Cambodia) were selected. A set of 20 calibrated aliquots, including negative samples, low positive samples (200 parasites/μL of Plasmodium falciparum and Plasmodium vivax) and high positive samples (2,000 parasites/μL of P. falciparum and P. vivax) was used. Testing was performed directly by the end-users without any practical training on the VIKIA Malaria Ag Pf/Pan kit. All results obtained by the end-users were consistent with the expected results, except for the low positive (200 parasites/μL) P. vivax aliquot (35% of concordant results). No significant difference was observed between the different end-users. End-user interviews evaluating ease-of-use and ease-of-reading of the VIKIA Malaria Ag Pf/Pan kit recorded 159 positive answers and only one negative answer. Out of 20 end-users, only one considered the test was not easy to perform with the support of the quick guide. The data presented in this study clearly demonstrate that the performance of the VIKIA Malaria Ag Pf/Pan test when performed by traditional end-users in field conditions is similar to that obtained by a research team and that this RDT can be considered as a point-of-care tool/assay. Furthermore, the protocol designed for this study could be used systematically in parallel to conventional evaluation studies to determine the performance of malaria RDTs in field conditions.

Evaluation of hemoglobin A1c measurement from filter paper using high-performance liquid chromatography and immunoturbidimetric assay.

PubMed

Wu, Yonghua; Yang, Xu; Wang, Haining; Li, Zhenrong; Wang, Tiancheng

2017-04-01

Glycated hemoglobin (HbA 1c ) measurement from whole blood (WB) samples is inconvenient for epidemic surveillance and self-monitoring of glycemic level. We evaluated HbA 1c measurement from WB blotted on filter paper (FP), which can be easily transported to central laboratories, with high-performance liquid chromatography (HPLC) and immunoturbidimetric assay (ITA). WB was applied to Whatman filter paper. By using HPLC and WB samples as reference methods, these FP samples were evaluated on HPLC and ITA. Inter- and intra-assay variation, WB vs. FP agreement and sample stability at 20-25 °C and -70 °C were assessed by statistical analysis. Results showed that the coefficient of variation (CV, %) of FP samples for HPLC and ITA were 0.44-1.02% and 1.47-2.72%, respectively (intra-assay); 2.13-3.56% and 3.21-4.82%, respectively (inter-assay). The correlation of WB HPLC with FP analyzed using HPLC and ITA are both significant (p < 0.001). Sample stability showed that FP method up to 5 days at 20-25 °C and 5 weeks at -70 °C is accurate and reproducible. In conclusion, FP samples analyzed by HPLC and ITA can both provide an alternative to WB for HbA 1c measurement, supporting the use of FP method in epidemic surveillance and healthcare units.

Innovative Sensory Methods to Access Acceptability of Mixed Polymer Semisoft Ovules for Microbicide Applications

PubMed Central

Zaveri, Toral; Running, Cordelia A; Surapaneni, Lahari; Ziegler, Gregory R; Hayes, John E

2016-01-01

Vaginal microbicides are a promising means to prevent the transmission of HIV, empowering women by putting protection under their control. We have been using gel technology to develop microbicides in the intermediate texture space to overcome shortcomings of current solid and liquid forms. We recently formulated semisoft ovules from mixed polymer combinations of carrageenan and Carbopol 940P to overcome some of the flaws with our previous generation of formulations based solely on carrageenan. To determine the user acceptability of the reformulated gels, women first evaluated intact semisoft ovules before evaluating ovules that had been subjected to mechanical crushing to simulate samples that represent post-use discharge. Women then evaluated combinations of intact and discharge samples to understand how ovule textures correlated with texture of the resulting discharge samples. Carbopol concentration directly and inversely correlated with willingness to try for discharge samples and intact samples respectively. When evaluating intact samples, women focused on the ease of inserting the product and preferred firmer samples; conversely, when evaluating discharge samples, softer samples that resulted in a smooth paste were preferred. Significant differences between samples were lost when evaluating pairs as women made varying tradeoffs between their preference for ease of inserting intact ovules and acceptability of discharge appearance. Evaluating samples that represent different stages of the use cycle reveals a more holistic measure of product acceptability. Studying sensory acceptability in parallel with biophysical performance enables an iterative design process that considers what women prefer in terms of insertion as well as possibility of leakage. PMID:27357703

Innovative sensory methods to access acceptability of mixed polymer semisoft ovules for microbicide applications.

PubMed

Zaveri, Toral; Running, Cordelia A; Surapaneni, Lahari; Ziegler, Gregory R; Hayes, John E

2016-10-01

Vaginal microbicides are a promising means to prevent the transmission of HIV, empowering women by putting protection under their control. We have been using gel technology to develop microbicides in the intermediate texture space to overcome shortcomings of current solid and liquid forms. We recently formulated semisoft ovules from mixed polymer combinations of carrageenan and Carbopol 940P to overcome some of the flaws with our previous generation of formulations based solely on carrageenan. To determine the user acceptability of the reformulated gels, women first evaluated intact semisoft ovules before evaluating ovules that had been subjected to mechanical crushing to simulate samples that represent post-use discharge. Women then evaluated combinations of intact and discharge samples to understand how ovule textures correlated with texture of the resulting discharge samples. Carbopol concentration directly and inversely correlated with willingness to try for discharge samples and intact samples, respectively. When evaluating intact samples, women focused on the ease of inserting the product and preferred firmer samples; conversely, when evaluating discharge samples, softer samples that resulted in a smooth paste were preferred. Significant differences between samples were lost when evaluating pairs as women made varying trade-offs between their preference for ease of inserting intact ovules and acceptability of discharge appearance. Evaluating samples that represent different stages of the use cycle reveals a more holistic measure of product acceptability. Studying sensory acceptability in parallel with biophysical performance enables an iterative design process that considers what women prefer in terms of insertion as well as possibility of leakage.

Development of a Multiplexed Liquid Chromatography Multiple-Reaction-Monitoring Mass Spectrometry (LC-MRM/MS) Method for Evaluation of Salivary Proteins as Oral Cancer Biomarkers*

PubMed Central

Chen, Hsiao-Wei; Wu, Chun-Feng; Chu, Lichieh Julie; Chiang, Wei-Fang; Wu, Chih-Ching; Yu, Jau-Song; Tsai, Cheng-Han; Liang, Kung-Hao; Chang, Yu-Sun; Wu, Maureen; Ou Yang, Wei-Ting

2017-01-01

Multiple (selected) reaction monitoring (MRM/SRM) of peptides is a growing technology for target protein quantification because it is more robust, precise, accurate, high-throughput, and multiplex-capable than antibody-based techniques. The technique has been applied clinically to the large-scale quantification of multiple target proteins in different types of fluids. However, previous MRM-based studies have placed less focus on sample-preparation workflow and analytical performance in the precise quantification of proteins in saliva, a noninvasively sampled body fluid. In this study, we evaluated the analytical performance of a simple and robust multiple reaction monitoring (MRM)-based targeted proteomics approach incorporating liquid chromatography with mass spectrometry detection (LC-MRM/MS). This platform was used to quantitatively assess the biomarker potential of a group of 56 salivary proteins that have previously been associated with human cancers. To further enhance the development of this technology for assay of salivary samples, we optimized the workflow for salivary protein digestion and evaluated quantification performance, robustness and technical limitations in analyzing clinical samples. Using a clinically well-characterized cohort of two independent clinical sample sets (total n = 119), we quantitatively characterized these protein biomarker candidates in saliva specimens from controls and oral squamous cell carcinoma (OSCC) patients. The results clearly showed a significant elevation of most targeted proteins in saliva samples from OSCC patients compared with controls. Overall, this platform was capable of assaying the most highly multiplexed panel of salivary protein biomarkers, highlighting the clinical utility of MRM in oral cancer biomarker research. PMID:28235782

A Prospective Evaluation of Circulating Tumor Cells and Cell-Free DNA in EGFR-Mutant Non-Small Cell Lung Cancer Patients Treated with Erlotinib on a Phase II Trial.

PubMed

Yanagita, Masahiko; Redig, Amanda J; Paweletz, Cloud P; Dahlberg, Suzanne E; O'Connell, Allison; Feeney, Nora; Taibi, Myriam; Boucher, David; Oxnard, Geoffrey R; Johnson, Bruce E; Costa, Daniel B; Jackman, David M; Jänne, Pasi A

2016-12-15

Genotype-directed therapy is the standard of care for advanced non-small cell lung cancer (NSCLC), but obtaining tumor tissue for genotyping remains a challenge. Circulating tumor cell (CTC) or cell-free DNA (cfDNA) analysis may allow for noninvasive evaluation. This prospective trial evaluated CTCs and cfDNA in EGFR-mutant NSCLC patients treated with erlotinib until progression. EGFR-mutant NSCLC patients were enrolled in a phase II trial of erlotinib. Blood was collected at baseline, every 2 months on study, and at disease progression. Plasma genotyping was performed by droplet digital PCR for EGFR19del, L858R, and T790M. CTCs were isolated by CellSave, enumerated, and analyzed by immunofluorescence for CD45 and pan-cytokeratin and EGFR and MET FISH were also performed. Rebiopsy was performed at disease progression. Sixty patients were enrolled; 44 patients discontinued therapy for disease progression. Rebiopsy occurred in 35 of 44 patients (80%), with paired CTC/cfDNA analysis in 41 of 44 samples at baseline and 36 of 44 samples at progression. T790M was identified in 23 of 35 (66%) tissue biopsies and 9 of 39 (23%) cfDNA samples. CTC analysis at progression identified MET amplification in 3 samples in which tissue analysis could not be performed. cfDNA analysis identified T790M in 2 samples in which rebiopsy was not possible. At diagnosis, high levels of cfDNA but not high levels of CTCs correlated with progression-free survival. cfDNA and CTCs are complementary, noninvasive assays for evaluation of acquired resistance to first-line EGFR TKIs and may expand the number of patients in whom actionable genetic information can be obtained at acquired resistance. Serial cfDNA monitoring may offer greater clinical utility than serial monitoring of CTCs. Clin Cancer Res; 22(24); 6010-20. ©2016 AACR. ©2016 American Association for Cancer Research.

Reduced-cost Chlamydia trachomatis-specific multiplex real-time PCR diagnostic assay evaluated for ocular swabs and use by trachoma research programmes.

PubMed

Butcher, Robert; Houghton, Jo; Derrick, Tamsyn; Ramadhani, Athumani; Herrera, Beatriz; Last, Anna R; Massae, Patrick A; Burton, Matthew J; Holland, Martin J; Roberts, Chrissy H

2017-08-01

Trachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), is the leading infectious cause of preventable blindness. Many commercial platforms are available that provide highly sensitive and specific detection of Ct DNA. However, the majority of these commercial platforms are inaccessible for population-level surveys in resource-limited settings typical to trachoma control programmes. We developed two low-cost quantitative PCR (qPCR) tests for Ct using readily available reagents on standard real-time thermocyclers. Each multiplex qPCR test targets one genomic and one plasmid Ct target in addition to an endogenous positive control for Homo sapiens DNA. The quantitative performance of the qPCR assays in clinical samples was determined by comparison to a previously evaluated droplet digital PCR (ddPCR) test. The diagnostic performance of the qPCR assays were evaluated against a commercial assay (artus C. trachomatis Plus RG PCR, Qiagen) using molecular diagnostics quality control standards and clinical samples. We examined the yield of Ct DNA prepared from five different DNA extraction kits and a cold chain-free dry-sample preservation method using swabs spiked with fixed concentrations of human and Ct DNA. The qPCR assay was highly reproducible (Ct plasmid and genomic targets mean total coefficients of variance 41.5% and 48.3%, respectively). The assay detected 8/8 core specimens upon testing of a quality control panel and performed well in comparison to commercially marketed comparator test (sensitivity and specificity>90%). Optimal extraction and sample preservation methods for research applications were identified. We describe a pipeline from collection to diagnosis providing the most efficient sample preservation and extraction with significant per test cost savings over a commercial qPCR diagnostic assay. The assay and its evaluation should allow control programs wishing to conduct independent research within the context of trachoma control, access to an affordable test with defined performance characteristics. Copyright © 2017. Published by Elsevier B.V.

CAPSTONE REPORT ON THE APPLICATION, MONITORING, AND PERFORMANCE OF PERMEABLE REACTIVE BARRIERS FOR GROUND-WATER REMEDIATION: VOL. 2 LONG-TERM MONITORING OF PRBS: SOIL AND GROUND WATER SAMPLING

EPA Science Inventory

This report discusses soil and ground-water sampling methods and procedures used to evaluate the long-term performance of permeable reactive barriers (PRBS) at two sites, Elizabeth City, NC, and the Denver Federal Center near Lakewood, CO. Both PRBs were installed in 1996 and hav...

The Common Core Writing Standards: A Descriptive Study of Content and Alignment with a Sample of Former State Standards

ERIC Educational Resources Information Center

Troia, Gary A.; Olinghouse, Natalie G.; Wilson, Joshua; Stewart, Kelly A.; Mo, Ya; Hawkins, Lisa; Kopke, Rachel A.

2016-01-01

Many students do not meet expected standards of writing performance, despite the need for writing competence in and out of school. As policy instruments, writing content standards have an impact on what is taught and how students perform. This study reports findings from an evaluation of the content of a sample of seven diverse states' current…

Testing of a simplified LED based vis/NIR system for rapid ripeness evaluation of white grape (Vitis vinifera L.) for Franciacorta wine.

PubMed

Giovenzana, Valentina; Civelli, Raffaele; Beghi, Roberto; Oberti, Roberto; Guidetti, Riccardo

2015-11-01

The aim of this work was to test a simplified optical prototype for a rapid estimation of the ripening parameters of white grape for Franciacorta wine directly in field. Spectral acquisition based on reflectance at four wavelengths (630, 690, 750 and 850 nm) was proposed. The integration of a simple processing algorithm in the microcontroller software would allow to visualize real time values of spectral reflectance. Non-destructive analyses were carried out on 95 grape bunches for a total of 475 berries. Samplings were performed weekly during the last ripening stages. Optical measurements were carried out both using the simplified system and a portable commercial vis/NIR spectrophotometer, as reference instrument for performance comparison. Chemometric analyses were performed in order to extract the maximum useful information from optical data. Principal component analysis (PCA) was performed for a preliminary evaluation of the data. Correlations between the optical data matrix and ripening parameters (total soluble solids content, SSC; titratable acidity, TA) were carried out using partial least square (PLS) regression for spectra and using multiple linear regression (MLR) for data from the simplified device. Classification analysis were also performed with the aim of discriminate ripe and unripe samples. PCA, MLR and classification analyses show the effectiveness of the simplified system in separating samples among different sampling dates and in discriminating ripe from unripe samples. Finally, simple equations for SSC and TA prediction were calculated. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of the performance of a point-of-care method for total and differential white blood cell count in clozapine users.

PubMed

Bui, H N; Bogers, J P A M; Cohen, D; Njo, T; Herruer, M H

2016-12-01

We evaluated the performance of the HemoCue WBC DIFF, a point-of-care device for total and differential white cell count, primarily to test its suitability for the mandatory white blood cell monitoring in clozapine use. Leukocyte count and 5-part differentiation was performed by the point-of-care device and by routine laboratory method in venous EDTA-blood samples from 20 clozapine users, 20 neutropenic patients, and 20 healthy volunteers. From the volunteers, also a capillary sample was drawn. Intra-assay reproducibility and drop-to-drop variation were tested. The correlation between both methods in venous samples was r > 0.95 for leukocyte, neutrophil, and lymphocyte counts. The correlation between point-of-care (capillary sample) and routine (venous sample) methods for these cells was 0.772; 0.817 and 0.798, respectively. Only for leukocyte and neutrophil counts, the intra-assay reproducibility was sufficient. The point-of-care device can be used to screen for leukocyte and neutrophil counts. Because of the relatively high measurement uncertainty and poor correlation with venous samples, we recommend to repeat the measurement with a venous sample if cell counts are in the lower reference range. In case of clozapine therapy, neutropenia can probably be excluded if high neutrophil counts are found and patients can continue their therapy. © 2016 John Wiley & Sons Ltd.

The Influence of Reading and Writing Habits Associated with Education on the Neuropsychological Performance of Brazilian Adults

ERIC Educational Resources Information Center

Pawlowski, Josiane; Remor, Eduardo; de Mattos Pimenta Parente, Maria Alice; de Salles, Jerusa Fumagalli; Fonseca, Rochele Paz; Bandeira, Denise Ruschel

2012-01-01

This study evaluated the influence of the frequency of reading and writing habits (RWH) associated with education on the performance of adults in brief neuropsychological tasks. A sample of 489 Brazilian subjects, composed of 71% women, aged 21-80 years, with 2-23 years of formal education, was evaluated by the Brazilian Brief Neuropsychological…

Geant4 Computing Performance Benchmarking and Monitoring

DOE PAGES

Dotti, Andrea; Elvira, V. Daniel; Folger, Gunter; ...

2015-12-23

Performance evaluation and analysis of large scale computing applications is essential for optimal use of resources. As detector simulation is one of the most compute intensive tasks and Geant4 is the simulation toolkit most widely used in contemporary high energy physics (HEP) experiments, it is important to monitor Geant4 through its development cycle for changes in computing performance and to identify problems and opportunities for code improvements. All Geant4 development and public releases are being profiled with a set of applications that utilize different input event samples, physics parameters, and detector configurations. Results from multiple benchmarking runs are compared tomore » previous public and development reference releases to monitor CPU and memory usage. Observed changes are evaluated and correlated with code modifications. Besides the full summary of call stack and memory footprint, a detailed call graph analysis is available to Geant4 developers for further analysis. The set of software tools used in the performance evaluation procedure, both in sequential and multi-threaded modes, include FAST, IgProf and Open|Speedshop. In conclusion, the scalability of the CPU time and memory performance in multi-threaded application is evaluated by measuring event throughput and memory gain as a function of the number of threads for selected event samples.« less

On the Analysis of Case-Control Studies in Cluster-correlated Data Settings.

PubMed

Haneuse, Sebastien; Rivera-Rodriguez, Claudia

2018-01-01

In resource-limited settings, long-term evaluation of national antiretroviral treatment (ART) programs often relies on aggregated data, the analysis of which may be subject to ecological bias. As researchers and policy makers consider evaluating individual-level outcomes such as treatment adherence or mortality, the well-known case-control design is appealing in that it provides efficiency gains over random sampling. In the context that motivates this article, valid estimation and inference requires acknowledging any clustering, although, to our knowledge, no statistical methods have been published for the analysis of case-control data for which the underlying population exhibits clustering. Furthermore, in the specific context of an ongoing collaboration in Malawi, rather than performing case-control sampling across all clinics, case-control sampling within clinics has been suggested as a more practical strategy. To our knowledge, although similar outcome-dependent sampling schemes have been described in the literature, a case-control design specific to correlated data settings is new. In this article, we describe this design, discuss balanced versus unbalanced sampling techniques, and provide a general approach to analyzing case-control studies in cluster-correlated settings based on inverse probability-weighted generalized estimating equations. Inference is based on a robust sandwich estimator with correlation parameters estimated to ensure appropriate accounting of the outcome-dependent sampling scheme. We conduct comprehensive simulations, based in part on real data on a sample of N = 78,155 program registrants in Malawi between 2005 and 2007, to evaluate small-sample operating characteristics and potential trade-offs associated with standard case-control sampling or when case-control sampling is performed within clusters.

Accurate clinical detection of exon copy number variants in a targeted NGS panel using DECoN.

PubMed

Fowler, Anna; Mahamdallie, Shazia; Ruark, Elise; Seal, Sheila; Ramsay, Emma; Clarke, Matthew; Uddin, Imran; Wylie, Harriet; Strydom, Ann; Lunter, Gerton; Rahman, Nazneen

2016-11-25

Background: Targeted next generation sequencing (NGS) panels are increasingly being used in clinical genomics to increase capacity, throughput and affordability of gene testing. Identifying whole exon deletions or duplications (termed exon copy number variants, 'exon CNVs') in exon-targeted NGS panels has proved challenging, particularly for single exon CNVs.  Methods: We developed a tool for the Detection of Exon Copy Number variants (DECoN), which is optimised for analysis of exon-targeted NGS panels in the clinical setting. We evaluated DECoN performance using 96 samples with independently validated exon CNV data. We performed simulations to evaluate DECoN detection performance of single exon CNVs and to evaluate performance using different coverage levels and sample numbers. Finally, we implemented DECoN in a clinical laboratory that tests BRCA1 and BRCA2 with the TruSight Cancer Panel (TSCP). We used DECoN to analyse 1,919 samples, validating exon CNV detections by multiplex ligation-dependent probe amplification (MLPA).  Results: In the evaluation set, DECoN achieved 100% sensitivity and 99% specificity for BRCA exon CNVs, including identification of 8 single exon CNVs. DECoN also identified 14/15 exon CNVs in 8 other genes. Simulations of all possible BRCA single exon CNVs gave a mean sensitivity of 98% for deletions and 95% for duplications. DECoN performance remained excellent with different levels of coverage and sample numbers; sensitivity and specificity was >98% with the typical NGS run parameters. In the clinical pipeline, DECoN automatically analyses pools of 48 samples at a time, taking 24 minutes per pool, on average. DECoN detected 24 BRCA exon CNVs, of which 23 were confirmed by MLPA, giving a false discovery rate of 4%. Specificity was 99.7%.  Conclusions: DECoN is a fast, accurate, exon CNV detection tool readily implementable in research and clinical NGS pipelines. It has high sensitivity and specificity and acceptable false discovery rate. DECoN is freely available at www.icr.ac.uk/decon.

Capacity building and predictors of success for HIV-1 drug resistance testing in the Asia-Pacific region and Africa

PubMed Central

Land, Sally; Zhou, Julian; Cunningham, Philip; Sohn, Annette H; Singtoroj, Thida; Katzenstein, David; Mann, Marita; Sayer, David; Kantor, Rami

2013-01-01

Background The TREAT Asia Quality Assessment Scheme (TAQAS) was developed as a quality assessment programme through expert education and training, for laboratories in the Asia-Pacific and Africa that perform HIV drug-resistance (HIVDR) genotyping. We evaluated the programme performance and factors associated with high-quality HIVDR genotyping. Methods Laboratories used their standard protocols to test panels of human immunodeficiency virus (HIV)-positive plasma samples or electropherograms. Protocols were documented and performance was evaluated according to a newly developed scoring system, agreement with panel-specific consensus sequence, and detection of drug-resistance mutations (DRMs) and mixtures of wild-type and resistant virus (mixtures). High-quality performance was defined as detection of ≥95% DRMs. Results Over 4.5 years, 23 participating laboratories in 13 countries tested 45 samples (30 HIV-1 subtype B; 15 non-B subtypes) in nine panels. Median detection of DRMs was 88–98% in plasma panels and 90–97% in electropherogram panels. Laboratories were supported to amend and improve their test outcomes as appropriate. Three laboratories that detected <80% DRMs in early panels demonstrated subsequent improvement. Sample complexity factors – number of DRMs (p<0.001) and number of DRMs as mixtures (p<0.001); and laboratory performance factors – detection of mixtures (p<0.001) and agreement with consensus sequence (p<0.001), were associated with high performance; sample format (plasma or electropherogram), subtype and genotyping protocol were not. Conclusion High-quality HIVDR genotyping was achieved in the TAQAS collaborative laboratory network. Sample complexity and detection of mixtures were associated with performance quality. Laboratories conducting HIVDR genotyping are encouraged to participate in quality assessment programmes. PMID:23845227

Microarc Oxidation Coating Combined with Surface Pore-Sealing Treatment Enhances Corrosion Fatigue Performance of 7075-T7351 Al Alloy in Different Media

PubMed Central

Yang, Hui-Hui; Wang, Xi-Shu; Wang, Ya-Ming; Wang, Yan-Ling; Zhang, Zhi-Hao

2017-01-01

Rotating bending fatigue tests have been performed to evaluate the corrosion fatigue performance and its influence factors of 7075-T7351 Al alloy in different media, namely air and a 5.0 wt % NaCl aqueous solution. All samples were coated by microarc oxidation (MAO) coating technology; some samples were followed by an epoxy resin pore-sealing treatment. Microscopic analyses of the surfaces and fracture cross-sections of samples were carried out. The results reveal that the sample with a MAO coating of 10 μm thickness and pore-sealing treatment by epoxy resin possesses optimal corrosion fatigue performance in the different media. The MAO coating with a pore-sealing treatment significantly improves the corrosion fatigue limit of 7075-T7351 Al alloy. PMID:28772970

Risk assessment of brine contamination to aquatic resources from energy development in glacial drift deposits: Williston Basin, USA

USGS Publications Warehouse

Preston, Todd M.; Chesley-Preston, Tara

2015-01-01

Our goal was to improve the Sheridan County assessment (SCA) and evaluate the use of this new Williston Basin assessment (WBA) across 31 counties mantled by glacial drift in the Williston Basin. To determine if the WBA model improved the SCA model, results from both assessments were compared to CI values from 37 surface and groundwater samples collected to evaluate the SCA. The WBA (R2 = 0.65) outperformed the SCA (R2 = 0.52) indicating improved model performance. Applicability across the Williston Basin was evaluated by comparing WBA results to CI values from 123 surface water samples collected from 97 sections. Based on the WBA, the majority (83.5%) of sections lacked an oil well and had minimal risk. Sections with one or more oil wells comprised low (8.4%), moderate (6.5%), or high (1.7%) risk areas. The percentage of contaminated water samples, percentage of sections with at least one contaminated sample, and the average CI value of contaminated samples increased from low to high risk indicating applicability across the Williston Basin. Furthermore, the WBA performed better compared to only the contaminated samples (R2 = 0.62) versus all samples (R2 = 0.38). This demonstrates that the WBA was successful at identifying sections, but not individual aquatic resources, with an increased risk of contamination; therefore, WBA results can prioritize future sampling within areas of increased risk.

Multi-species attributes as the condition for adaptive sampling of rare species using two-stage sequential sampling with an auxiliary variable

USGS Publications Warehouse

Panahbehagh, B.; Smith, D.R.; Salehi, M.M.; Hornbach, D.J.; Brown, D.J.; Chan, F.; Marinova, D.; Anderssen, R.S.

2011-01-01

Assessing populations of rare species is challenging because of the large effort required to locate patches of occupied habitat and achieve precise estimates of density and abundance. The presence of a rare species has been shown to be correlated with presence or abundance of more common species. Thus, ecological community richness or abundance can be used to inform sampling of rare species. Adaptive sampling designs have been developed specifically for rare and clustered populations and have been applied to a wide range of rare species. However, adaptive sampling can be logistically challenging, in part, because variation in final sample size introduces uncertainty in survey planning. Two-stage sequential sampling (TSS), a recently developed design, allows for adaptive sampling, but avoids edge units and has an upper bound on final sample size. In this paper we present an extension of two-stage sequential sampling that incorporates an auxiliary variable (TSSAV), such as community attributes, as the condition for adaptive sampling. We develop a set of simulations to approximate sampling of endangered freshwater mussels to evaluate the performance of the TSSAV design. The performance measures that we are interested in are efficiency and probability of sampling a unit occupied by the rare species. Efficiency measures the precision of population estimate from the TSSAV design relative to a standard design, such as simple random sampling (SRS). The simulations indicate that the density and distribution of the auxiliary population is the most important determinant of the performance of the TSSAV design. Of the design factors, such as sample size, the fraction of the primary units sampled was most important. For the best scenarios, the odds of sampling the rare species was approximately 1.5 times higher for TSSAV compared to SRS and efficiency was as high as 2 (i.e., variance from TSSAV was half that of SRS). We have found that design performance, especially for adaptive designs, is often case-specific. Efficiency of adaptive designs is especially sensitive to spatial distribution. We recommend that simulations tailored to the application of interest are highly useful for evaluating designs in preparation for sampling rare and clustered populations.

Stratification and sample selection for multicrop experiments. [Arkansas, Kentucky, Michigan, Missouri, Mississippi, Ohio, Wisconsin, Illinois, Indiana, Minnesota, Iowa, Louisiana, Nebraska, South Dakota, and North Dakota

NASA Technical Reports Server (NTRS)

Landgrebe, D. A. (Principal Investigator); Hixson, M. M.; Davis, B. J.; Bauer, M. E.

1978-01-01

The author has identified the following significant results. A stratification was performed and sample segments were selected for an initial investigation of multicrop problems in order to support development and evaluation of procedures for using LACIE and other technologies for the classification of corn and soybeans, to identify factors likely to affect classification performance, and to evaluate problems encountered and techniques which are applicable to the crop estimation problem in foreign countries. Two types of samples, low density and high density, supporting these requirements were selected as research data set for an initial evaluation of technical issues. Looking at the geographic location of the strata, the system appears to be logical and the various segments seem to represent different conditions. This result is supportive not only of the variables and the methodology employed in the stratification, but also of the validity of the data sets employed.

[Detection of KRAS mutation in colorectal cancer patients' cfDNA with droplet digital PCR].

PubMed

Luo, Yuwen; Li, Yao

2018-03-25

This study aims to develop a new method for the detection of KRAS mutations related to colorectal cancer in cfDNA, and to evaluate the sensitivity and accuracy of the detection. We designed a method of cfDNA based KRAS detection by droplets digital PCR (ddPCR). The theoretical performance of the method is evaluated by reference standard and compared to the ARMS PCR method. Two methods, ddPCR and qPCR, were successfully established to detect KRAS wild type and 7 mutants. Both methods were validated using plasmid standards and actual samples. The results were evaluated by false positive rate, linearity, and limit of detection. Finally, 52 plasma cfDNA samples from patients and 20 samples from healthy people were tested, the clinical sensitivity is 97.64%, clinical specificity is 81.43%. ddPCR method shows higher performance than qPCR. The LOD of ddPCR method reached single digits of cfDNA copies, it can detect as low as 0.01% to 0.04% mutation abundance.

Set covering algorithm, a subprogram of the scheduling algorithm for mission planning and logistic evaluation

NASA Technical Reports Server (NTRS)

Chang, H.

1976-01-01

A computer program using Lemke, Salkin and Spielberg's Set Covering Algorithm (SCA) to optimize a traffic model problem in the Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE) was documented. SCA forms a submodule of SAMPLE and provides for input and output, subroutines, and an interactive feature for performing the optimization and arranging the results in a readily understandable form for output.

Performance Model and Sensitivity Analysis for a Solar Thermoelectric Generator

NASA Astrophysics Data System (ADS)

Rehman, Naveed Ur; Siddiqui, Mubashir Ali

2017-03-01

In this paper, a regression model for evaluating the performance of solar concentrated thermoelectric generators (SCTEGs) is established and the significance of contributing parameters is discussed in detail. The model is based on several natural, design and operational parameters of the system, including the thermoelectric generator (TEG) module and its intrinsic material properties, the connected electrical load, concentrator attributes, heat transfer coefficients, solar flux, and ambient temperature. The model is developed by fitting a response curve, using the least-squares method, to the results. The sample points for the model were obtained by simulating a thermodynamic model, also developed in this paper, over a range of values of input variables. These samples were generated employing the Latin hypercube sampling (LHS) technique using a realistic distribution of parameters. The coefficient of determination was found to be 99.2%. The proposed model is validated by comparing the predicted results with those in the published literature. In addition, based on the elasticity for parameters in the model, sensitivity analysis was performed and the effects of parameters on the performance of SCTEGs are discussed in detail. This research will contribute to the design and performance evaluation of any SCTEG system for a variety of applications.

Evaluation of concrete pavements with materials-related distress : appendix G.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : final report.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors : contributing to pavement distress observed in the field were determined, including expansive : alkali-silica reactivity and freeze-thaw deterioration related to poor ...

Evaluation of concrete pavements with materials-related distress : appendix F.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix E.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix D.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix B.

DOT National Transportation Integrated Search

2010-02-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix C.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Report of sampling and analysis results, Addison Army housing units, Addison, Illinois. Final report

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

Not Available

1990-09-01

The objectives of this sampling and analysis effort include further characterization of environmental contamination identified in an enhanced preliminary assessment carried out in 1989. The specific activities performed at this site were identification, evaluation of the condition, and collection of samples from specific suspected asbestos-containing materials, including floor tiles, pipe run and pipe fitting insulation, dust in the ductwork, and exterior siding, where present. These evaluation were necessary to clarify potential environmental issues identified in the earlier report, prior to the sale or realignment of the property.

Clinical value of the VMI supplemental tests: a modified replication study.

PubMed

Avi-Itzhak, Tamara; Obler, Doris Richard

2008-10-01

To carry out a modified replication of the study performed by Kulp and Sortor evaluating the clinical value of the information provided by Beery's visual-motor supplemental tests of Visual Perception (VP) and Motor Coordination (MC) in normally developed children. The objectives were to (a) estimate the correlations among the three tests scores; (b) assess the predictive power of the VP and MC scores in explaining the variance in Visual-Motor Integration (VMI) scores; and (c) examine whether poor performance on the VMI is related to poor performance on VP or MC. METHODS.: A convenience sample of 71 children ages 4 and 5 years (M = 4.62 +/- 0.43) participated in the study. The supplemental tests significantly (F = 9.59; dF = 2; p < or = 0. 001) explained 22% of the variance in VMI performance. Only VP was significantly related to VMI (beta = 0.39; T = 3.49) accounting for the total amount of explained variance. Using the study population norms, 11 children (16% of total sample) did poorly on the VMI; of those 11, 73% did poorly on the VP, and none did poorly on the MC. None of these 11 did poorly on both the VP and MC. Nine percent of total sample who did poorly on the VP performed within the norm on the VMI. Thirteen percent who performed poorly on the MC performed within the norm on the VMI. Using the VMI published norms, 14 children (20% of total sample) who did poorly on the VP performed within the norm on the VMI. Forty-eight percent who did poorly on MC performed within the norm on the VMI. Findings supported Kulp and Sortor's conclusions that each area should be individually evaluated during visual-perceptual assessment of children regardless of performance on the VMI.

Pre-Clinical Evaluation of a Real-Time PCR Assay on a Portable Instrument as a Possible Field Diagnostic Tool: Experiences from the Testing of Clinical Samples for African and Classical Swine Fever Viruses.

PubMed

Liu, L; Luo, Y; Accensi, F; Ganges, L; Rodríguez, F; Shan, H; Ståhl, K; Qiu, H-J; Belák, S

2017-10-01

African swine fever (ASF) and classical swine fever (CSF) are two highly infectious transboundary animal diseases (TADs) that are serious threats to the pig industry worldwide, including in China, the world's largest pork producer. In this study, a duplex real-time PCR assay was developed for the rapid detection and differentiation of African swine fever virus (ASFV) and classical swine fever virus (CSFV). The assay was performed on a portable, battery-powered PCR thermocycler with a low sample throughput (termed as 'T-COR4 assay'). The feasibility and reliability of the T-COR4 assay as a possible field method was investigated by testing clinical samples collected in China. When evaluated with reference materials or samples from experimental infections, the assay performed in a reliable manner, producing results comparable to those obtained from stationary PCR platforms. Of 59 clinical samples, 41 had results identical to a two-step CSFV real-time PCR assay. No ASFV was detected in these samples. The T-COR4 assay was technically easy to perform and produced results within 3 h, including sample preparation. In combination with a simple sample preparation method, the T-COR4 assay provides a new tool for the field diagnosis and differentiation of ASF and CSF, which could be of particular value in remote areas. © 2016 Blackwell Verlag GmbH.

INNOVATIVE TECHNOLOGY VERIFICATION REPORT " ...

EPA Pesticide Factsheets

The EnSys Petro Test System developed by Strategic Diagnostics Inc. (SDI), was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in June 2000 at the Navy Base Ventura County site in Port Hueneme, California. The purpose of the demonstration was to collect reliable performance and cost data for the EnSys Petro Test System and six other field measurement devices for total petroleum hydrocarbons (TPH) in soil. In addition to assessing ease of device operation, the key objectives of the demonstration included determining the (1) method detection limit, (2) accuracy and precision, (3) effects of interferents and soil moisture content on TPH measurement, (4) sample throughput, and (5) TPH measurement costs for each device. The demonstration involved analysis of both performance evaluation samples and environmental samples collected in four areas contaminated with gasoline, diesel, or other petroleum products. The performance and cost results for a given field measurement device were compared to those for an off-site laboratory reference method,

INNOVATIVE TECHNOLOGY VERIFICATION REPORT " ...

EPA Pesticide Factsheets

The Synchronous Scanning Luminoscope (Luminoscope) developed by the Oak Ridge National Laboratory in collaboration with Environmental Systems Corporation (ESC) was demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in June 2000 at the Navy Base Ventura County site in Port Hueneme, California. The purpose of the demonstration was to collect reliable performance and cost data for the Luminoscope and six other field measurement devices for total petroleum hydrocarbons (TPH) in soil. In addition to assessing ease of device operation, the key objectives of the demonstration included determining the (1) method detection limit, (2) accuracy and precision, (3) effects of interferents and soil moisture content on TPH measurement, (4) sample throughput, and (5) TPH measurement costs for each device. The demonstration involved analysis of both performance evaluation samples and environmental samples collected in five areas contaminated with gasoline, diesel, lubricating oil, or other petroleum products. The performance and cost results for a given field measurement device were compared to those for an off-site laboratory reference method,

A study of active learning methods for named entity recognition in clinical text.

PubMed

Chen, Yukun; Lasko, Thomas A; Mei, Qiaozhu; Denny, Joshua C; Xu, Hua

2015-12-01

Named entity recognition (NER), a sequential labeling task, is one of the fundamental tasks for building clinical natural language processing (NLP) systems. Machine learning (ML) based approaches can achieve good performance, but they often require large amounts of annotated samples, which are expensive to build due to the requirement of domain experts in annotation. Active learning (AL), a sample selection approach integrated with supervised ML, aims to minimize the annotation cost while maximizing the performance of ML-based models. In this study, our goal was to develop and evaluate both existing and new AL methods for a clinical NER task to identify concepts of medical problems, treatments, and lab tests from the clinical notes. Using the annotated NER corpus from the 2010 i2b2/VA NLP challenge that contained 349 clinical documents with 20,423 unique sentences, we simulated AL experiments using a number of existing and novel algorithms in three different categories including uncertainty-based, diversity-based, and baseline sampling strategies. They were compared with the passive learning that uses random sampling. Learning curves that plot performance of the NER model against the estimated annotation cost (based on number of sentences or words in the training set) were generated to evaluate different active learning and the passive learning methods and the area under the learning curve (ALC) score was computed. Based on the learning curves of F-measure vs. number of sentences, uncertainty sampling algorithms outperformed all other methods in ALC. Most diversity-based methods also performed better than random sampling in ALC. To achieve an F-measure of 0.80, the best method based on uncertainty sampling could save 66% annotations in sentences, as compared to random sampling. For the learning curves of F-measure vs. number of words, uncertainty sampling methods again outperformed all other methods in ALC. To achieve 0.80 in F-measure, in comparison to random sampling, the best uncertainty based method saved 42% annotations in words. But the best diversity based method reduced only 7% annotation effort. In the simulated setting, AL methods, particularly uncertainty-sampling based approaches, seemed to significantly save annotation cost for the clinical NER task. The actual benefit of active learning in clinical NER should be further evaluated in a real-time setting. Copyright © 2015 Elsevier Inc. All rights reserved.

Glycemic penalty index for adequately assessing and comparing different blood glucose control algorithms

PubMed Central

Van Herpe, Tom; De Brabanter, Jos; Beullens, Martine; De Moor, Bart; Van den Berghe, Greet

2008-01-01

Introduction Blood glucose (BG) control performed by intensive care unit (ICU) nurses is becoming standard practice for critically ill patients. New (semi-automated) 'BG control' algorithms (or 'insulin titration' algorithms) are under development, but these require stringent validation before they can replace the currently used algorithms. Existing methods for objectively comparing different insulin titration algorithms show weaknesses. In the current study, a new approach for appropriately assessing the adequacy of different algorithms is proposed. Methods Two ICU patient populations (with different baseline characteristics) were studied, both treated with a similar 'nurse-driven' insulin titration algorithm targeting BG levels of 80 to 110 mg/dl. A new method for objectively evaluating BG deviations from normoglycemia was founded on a smooth penalty function. Next, the performance of this new evaluation tool was compared with the current standard assessment methods, on an individual as well as a population basis. Finally, the impact of four selected parameters (the average BG sampling frequency, the duration of algorithm application, the severity of disease, and the type of illness) on the performance of an insulin titration algorithm was determined by multiple regression analysis. Results The glycemic penalty index (GPI) was proposed as a tool for assessing the overall glycemic control behavior in ICU patients. The GPI of a patient is the average of all penalties that are individually assigned to each measured BG value based on the optimized smooth penalty function. The computation of this index returns a number between 0 (no penalty) and 100 (the highest penalty). For some patients, the assessment of the BG control behavior using the traditional standard evaluation methods was different from the evaluation with GPI. Two parameters were found to have a significant impact on GPI: the BG sampling frequency and the duration of algorithm application. A higher BG sampling frequency and a longer algorithm application duration resulted in an apparently better performance, as indicated by a lower GPI. Conclusion The GPI is an alternative method for evaluating the performance of BG control algorithms. The blood glucose sampling frequency and the duration of algorithm application should be similar when comparing algorithms. PMID:18302732

Proficiency program for real-time PCR diagnosis of Bordetella pertussis infections in French hospital laboratories and at the French National Reference Center for Whooping Cough and other Bordetelloses.

PubMed

Caro, Valérie; Guiso, Nicole; Alberti, Corinne; Liguori, Sandrine; Burucoa, Christophe; Couetdic, Gérard; Doucet-Populaire, Florence; Ferroni, Agnès; Papin-Gibaud, Sophie; Grattard, Florence; Réglier-Poupet, Hélène; Raymond, Josette; Soler, Catherine; Bouchet, Sylvie; Charreau, Sandrine; Couzon, Brigitte; Leymarie, Isabelle; Tavares, Nicole; Choux, Mathilde; Bingen, Edouard; Bonacorsi, Stéphane

2009-10-01

With the support of a ministerial program for innovative and expensive technologies, dedicated to the economic evaluation of laboratory diagnosis of pertussis by real-time PCR, external quality assessment for real-time IS481 PCR was carried out. Coordinated by the National Centre of Reference of Pertussis and other Bordetelloses (NCR), this study aimed to harmonize and to assess the performances of eight participating microbiology hospital laboratories throughout the French territory. Between January 2006 and February 2007, 10 proficiency panels were sent by the NCR (ascending proficiency program), representing a total of 49 samples and including eight panels to analyze and evaluate the global sensitivity and specificity of real-time PCR, one to assess the limit of detection, and one to evaluate nucleic acid extraction methods. As part of the descending proficiency program, extracted DNA from clinical samples was sent by the eight participating laboratories in different panels and analyzed by the NCR. In the ascending proficiency analysis, the sensitivity and specificity of the real-time PCR methods were 92.2% and 94.3%, respectively. The limit of detection of the different methods ranged between 0.1 and 1 fg/microl (0.2 to 2 CFU/microl). The nucleic acid extraction methods showed similar performances. During the descending proficiency analysis, performed with 126 samples, the result of the NCR for 15 samples (11.9%) was discordant with the result obtained by the source laboratory. Despite several initial differences, harmonization was easy and performances were homogeneous. However, the risk of false-positive results remains quite high, and we strongly recommend establishment of uniform quality control procedures performed regularly.

Application of a Multivariant, Caucasian-Specific, Genotyped Donor Panel for Performance Validation of MDmulticard®, ID-System®, and Scangel® RhD/ABO Serotyping

PubMed Central

Gassner, Christoph; Rainer, Esther; Pircher, Elfriede; Markut, Lydia; Körmöczi, Günther F.; Jungbauer, Christof; Wessin, Dietmar; Klinghofer, Roswitha; Schennach, Harald; Schwind, Peter; Schönitzer, Diether

2009-01-01

Summary Background Validations of routinely used serological typing methods require intense performance evaluations typically including large numbers of samples before routine application. However, such evaluations could be improved considering information about the frequency of standard blood groups and their variants. Methods Using RHD and ABO population genetic data, a Caucasian-specific donor panel was compiled for a performance comparison of the three RhD and ABO serological typing methods MDmulticard (Medion Diagnostics), ID-System (DiaMed) and ScanGel (Bio-Rad). The final test panel included standard and variant RHD and ABO genotypes, e.g. RhD categories, partial and weak RhDs, RhD DELs, and ABO samples, mainly to interpret weak serological reactivity for blood group A specificity. All samples were from individuals recorded in our local DNA blood group typing database. Results For ‘standard’ blood groups, results of performance were clearly interpretable for all three serological methods compared. However, when focusing on specific variant phenotypes, pronounced differences in reaction strengths and specificities were observed between them. Conclusions A genetically and ethnically predefined donor test panel consisting of 93 individual samples only, delivered highly significant results for serological performance comparisons. Such small panels offer impressive representative powers, higher as such based on statistical chances and large numbers only. PMID:21113264

Solid rocket booster performance evaluation model. Volume 3: Sample case. [propellant combustion simulation/internal ballistics

NASA Technical Reports Server (NTRS)

1974-01-01

The solid rocket booster performance evaluation model (SRB-11) is used to predict internal ballistics in a sample motor. This motor contains a five segmented grain. The first segment has a 14 pointed star configuration with a web which wraps partially around the forward dome. The other segments are circular in cross-section and are tapered along the interior burning surface. Two of the segments are inhibited on the forward face. The nozzle is not assumed to be submerged. The performance prediction is broken into two simulation parts: the delivered end item specific impulse and the propellant properties which are required as inputs for the internal ballistics module are determined; and the internal ballistics for the entire burn duration of the motor are simulated.

Study of emissions from passenger cars in six cities, FY79. Volume I. Final report

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

Not Available

1980-10-01

The standard mass emission test (Federal Test Procedure) was performed for emission factors determination on samples of passenger cars operating in Los Angeles, Houston, Denver, Phoenix, St. Louis and Washington, DC. These samples were also used for obtaining abbreviated emission test (short cycle test), fuel economy test, emission related maintenance and other data. Two-thousand forty-two (2,042) vehicles were tested under the program. The FTP and the Highway Fuel Economy Test were performed on all vehicles at all sites. Some vehicles which exceed Federal standards (excluding the Houston site) were subjected to a restorative maintenance evaluation. The evaluation employed in Losmore » Angeles was designed to address three-way catalyst technology. Some vehicles in all but the Los Angeles site were used to evaluate commercial repair facility performance in relation to idle speed and mixture adjustments. Other actions were taken in relation to each vehicle tested. These included an emission control system maladjustment/disablement and status inspection driveability evaluations and owner interviews to obtain vehicle maintenance and usage data.« less

Evaluation of Two Highly-Multiplexed Custom Panels for Massively Parallel Semiconductor Sequencing on Paraffin DNA

PubMed Central

Kotoula, Vassiliki; Lyberopoulou, Aggeliki; Papadopoulou, Kyriaki; Charalambous, Elpida; Alexopoulou, Zoi; Gakou, Chryssa; Lakis, Sotiris; Tsolaki, Eleftheria; Lilakos, Konstantinos; Fountzilas, George

2015-01-01

Background—Aim Massively parallel sequencing (MPS) holds promise for expanding cancer translational research and diagnostics. As yet, it has been applied on paraffin DNA (FFPE) with commercially available highly multiplexed gene panels (100s of DNA targets), while custom panels of low multiplexing are used for re-sequencing. Here, we evaluated the performance of two highly multiplexed custom panels on FFPE DNA. Methods Two custom multiplex amplification panels (B, 373 amplicons; T, 286 amplicons) were coupled with semiconductor sequencing on DNA samples from FFPE breast tumors and matched peripheral blood samples (n samples: 316; n libraries: 332). The two panels shared 37% DNA targets (common or shifted amplicons). Panel performance was evaluated in paired sample groups and quartets of libraries, where possible. Results Amplicon read ratios yielded similar patterns per gene with the same panel in FFPE and blood samples; however, performance of common amplicons differed between panels (p<0.001). FFPE genotypes were compared for 1267 coding and non-coding variant replicates, 999 out of which (78.8%) were concordant in different paired sample combinations. Variant frequency was highly reproducible (Spearman’s rho 0.959). Repeatedly discordant variants were of high coverage / low frequency (p<0.001). Genotype concordance was (a) high, for intra-run duplicates with the same panel (mean±SD: 97.2±4.7, 95%CI: 94.8–99.7, p<0.001); (b) modest, when the same DNA was analyzed with different panels (mean±SD: 81.1±20.3, 95%CI: 66.1–95.1, p = 0.004); and (c) low, when different DNA samples from the same tumor were compared with the same panel (mean±SD: 59.9±24.0; 95%CI: 43.3–76.5; p = 0.282). Low coverage / low frequency variants were validated with Sanger sequencing even in samples with unfavourable DNA quality. Conclusions Custom MPS may yield novel information on genomic alterations, provided that data evaluation is adjusted to tumor tissue FFPE DNA. To this scope, eligibility of all amplicons along with variant coverage and frequency need to be assessed. PMID:26039550

Using Electrical Resistivity Imaging to Evaluate Permanganate Performance During an In Situ Treatment of a RDX-Contaminated Aquifer

DTIC Science & Technology

2009-08-01

assess the performance of remedial efforts. These techniques are expensive and, by themselves, are effectively random samples guided by the training...technology should be further explored and developed for use in pre-amendment tracer tests and quantitative remedial assessments . 15. SUBJECT TERMS...and flow of injectate. Site assessment following groundwater remediation efforts typically involves discrete point sampling using wells or

Evaluation Study Effect of Allowances and Job Creativity--The Performance of the Teacher in Secondary Vocational School Province of East Nusa Tenggara

ERIC Educational Resources Information Center

Parsa, I. Made

2017-01-01

This research aims to know the influence of the allowances and the creativity of work on the performance of Secondary Vocational School teacher (SMK) in the Province of East Nusa Tenggara (Province NTT). Implementation of the survey method, i.e. to know the obvious problems with the picture of samples in field. The sample selected by random…

PAVENET OS: A Compact Hard Real-Time Operating System for Precise Sampling in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Saruwatari, Shunsuke; Suzuki, Makoto; Morikawa, Hiroyuki

The paper shows a compact hard real-time operating system for wireless sensor nodes called PAVENET OS. PAVENET OS provides hybrid multithreading: preemptive multithreading and cooperative multithreading. Both of the multithreading are optimized for two kinds of tasks on wireless sensor networks, and those are real-time tasks and best-effort ones. PAVENET OS can efficiently perform hard real-time tasks that cannot be performed by TinyOS. The paper demonstrates the hybrid multithreading realizes compactness and low overheads, which are comparable to those of TinyOS, through quantitative evaluation. The evaluation results show PAVENET OS performs 100 Hz sensor sampling with 0.01% jitter while performing wireless communication tasks, whereas optimized TinyOS has 0.62% jitter. In addition, PAVENET OS has a small footprint and low overheads (minimum RAM size: 29 bytes, minimum ROM size: 490 bytes, minimum task switch time: 23 cycles).

Analytical and Clinical Performance Evaluation of the Abbott Architect PIVKA Assay.

PubMed

Ko, Dae-Hyun; Hyun, Jungwon; Kim, Hyun Soo; Park, Min-Jeong; Kim, Jae-Seok; Park, Ji-Young; Shin, Dong Hoon; Cho, Hyoun Chan

2018-01-01

Protein induced by vitamin K absence (PIVKA) is measured using various assays and is used to help diagnose hepatocellular carcinoma. The present study evaluated the analytical and clinical performances of the recently released Abbott Architect PIVKA assay. Precision, linearity, and correlation tests were performed in accordance with the Clinical Laboratory Standardization Institute guidelines. Sample type suitability was assessed using serum and plasma samples from the same patients, and the reference interval was established using sera from 204 healthy individuals. The assay had coefficients of variation of 3.2-3.5% and intra-laboratory variation of 3.6-5.5%. Linearity was confirmed across the entire measurable range. The Architect PIVKA assay was comparable to the Lumipulse PIVKA assay, and the plasma and serum samples provided similar results. The lower reference limit was 13.0 mAU/mL and the upper reference limit was 37.4 mAU/mL. The ability of the Architect PIVKA assay to detect hepatocellular carcinoma was comparable to that of the alpha-fetoprotein test and the Lumipulse PIVKA assay. The Architect PIVKA assay provides excellent analytical and clinical performance, is simple for clinical laboratories to adopt, and has improved sample type suitability that could broaden the assay's utility. © 2018 by the Association of Clinical Scientists, Inc.

[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.

Non-parametric early seizure detection in an animal model of temporal lobe epilepsy

NASA Astrophysics Data System (ADS)

Talathi, Sachin S.; Hwang, Dong-Uk; Spano, Mark L.; Simonotto, Jennifer; Furman, Michael D.; Myers, Stephen M.; Winters, Jason T.; Ditto, William L.; Carney, Paul R.

2008-03-01

The performance of five non-parametric, univariate seizure detection schemes (embedding delay, Hurst scale, wavelet scale, nonlinear autocorrelation and variance energy) were evaluated as a function of the sampling rate of EEG recordings, the electrode types used for EEG acquisition, and the spatial location of the EEG electrodes in order to determine the applicability of the measures in real-time closed-loop seizure intervention. The criteria chosen for evaluating the performance were high statistical robustness (as determined through the sensitivity and the specificity of a given measure in detecting a seizure) and the lag in seizure detection with respect to the seizure onset time (as determined by visual inspection of the EEG signal by a trained epileptologist). An optimality index was designed to evaluate the overall performance of each measure. For the EEG data recorded with microwire electrode array at a sampling rate of 12 kHz, the wavelet scale measure exhibited better overall performance in terms of its ability to detect a seizure with high optimality index value and high statistics in terms of sensitivity and specificity.

Classification of Tree Species in Overstorey Canopy of Subtropical Forest Using QuickBird Images.

PubMed

Lin, Chinsu; Popescu, Sorin C; Thomson, Gavin; Tsogt, Khongor; Chang, Chein-I

2015-01-01

This paper proposes a supervised classification scheme to identify 40 tree species (2 coniferous, 38 broadleaf) belonging to 22 families and 36 genera in high spatial resolution QuickBird multispectral images (HMS). Overall kappa coefficient (OKC) and species conditional kappa coefficients (SCKC) were used to evaluate classification performance in training samples and estimate accuracy and uncertainty in test samples. Baseline classification performance using HMS images and vegetation index (VI) images were evaluated with an OKC value of 0.58 and 0.48 respectively, but performance improved significantly (up to 0.99) when used in combination with an HMS spectral-spatial texture image (SpecTex). One of the 40 species had very high conditional kappa coefficient performance (SCKC ≥ 0.95) using 4-band HMS and 5-band VIs images, but, only five species had lower performance (0.68 ≤ SCKC ≤ 0.94) using the SpecTex images. When SpecTex images were combined with a Visible Atmospherically Resistant Index (VARI), there was a significant improvement in performance in the training samples. The same level of improvement could not be replicated in the test samples indicating that a high degree of uncertainty exists in species classification accuracy which may be due to individual tree crown density, leaf greenness (inter-canopy gaps), and noise in the background environment (intra-canopy gaps). These factors increase uncertainty in the spectral texture features and therefore represent potential problems when using pixel-based classification techniques for multi-species classification.

Routine conventional karyotyping of lymphoma staging bone marrow samples does not contribute clinically relevant information.

PubMed

Nardi, Valentina; Pulluqi, Olja; Abramson, Jeremy S; Dal Cin, Paola; Hasserjian, Robert P

2015-06-01

Bone marrow (BM) evaluation is an important part of lymphoma staging, which guides patient management. Although positive staging marrow is defined as morphologically identifiable disease, such samples often also include flow cytometric analysis and conventional karyotyping. Cytogenetic analysis is a labor-intensive and costly procedure and its utility in this setting is uncertain. We retrospectively reviewed pathological reports of 526 staging marrow specimens in which conventional karyotyping had been performed. All samples originated from a single institution from patients with previously untreated Hodgkin and non-Hodgkin lymphomas presenting in an extramedullary site. Cytogenetic analysis revealed clonal abnormalities in only eight marrow samples (1.5%), all of which were positive for lymphoma by morphologic evaluation. Flow cytometry showed a small clonal lymphoid population in three of the 443 morphologically negative marrow samples (0.7%). Conventional karyotyping is rarely positive in lymphoma staging marrow samples and, in our cohort, the BM karyotype did not contribute clinically relevant information in the vast majority of cases. Our findings suggest that karyotyping should not be performed routinely on BM samples taken to stage previously diagnosed extramedullary lymphomas unless there is pathological evidence of BM involvement by lymphoma. © 2015 Wiley Periodicals, Inc.

Evaluation of Performance Characteristics of the Aptima HIV-1 Quant Dx Assay for Detection and Quantitation of Human Immunodeficiency Virus Type 1 in Plasma and Cervicovaginal Lavage Samples.

PubMed

Sam, Soya S; Kurpewski, Jaclynn R; Cu-Uvin, Susan; Caliendo, Angela M

2016-04-01

Quantification of HIV-1 RNA has become the standard of care in the clinical management of HIV-1-infected individuals. The objective of this study was to evaluate performance characteristics and relative workflow of the Aptima HIV-1 Quant Dx assay in comparison with the Abbott RealTime HIV-1 assay using plasma and cervicovaginal lavage (CVL) specimens. Assay performance was evaluated by using an AcroMetrix HIV-1 panel, AcroMetrix positive controls, Qnostics and SeraCare HIV-1 evaluation panels, 208 clinical plasma samples, and 205 matched CVL specimens on the Panther and m2000 platforms. The Aptima assay demonstrated good linearity over the quantification range tested (2 to 5 log10copies/ml), and there was strong linear correlation between the assays (R(2)= 0.99), with a comparable coefficient of variance of <5.5%. For the plasma samples, Deming regression analyses and Bland-Altman plots showed excellent agreement between the assays, with an interassay concordance of 91.35% (kappa = 0.75; 95% confidence interval [CI], 0.65 to 0.85), and on average, the viral loads determined by the Aptima assay were 0.21 log10copies/ml higher than those determined by the RealTime assay. The assays differed in their sensitivity for quantifying HIV-1 RNA loads in CVL samples, with the Aptima and RealTime assays detecting 30% and 20%, respectively. Aptima had fewer invalid results, and on average, the viral loads in CVL samples quantified by the Aptima assay were 0.072 log10copies/ml higher than those of the RealTime assay. Our results demonstrate that the Aptima assay is sensitive and accurate in quantifying viral loads in both plasma and CVL specimens and that the fully automated Panther system has all the necessary features suitable for clinical laboratories demanding high-throughput sample processing. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Evaluation of Performance Characteristics of the Aptima HIV-1 Quant Dx Assay for Detection and Quantitation of Human Immunodeficiency Virus Type 1 in Plasma and Cervicovaginal Lavage Samples

PubMed Central

Kurpewski, Jaclynn R.; Cu-Uvin, Susan; Caliendo, Angela M.

2016-01-01

Quantification of HIV-1 RNA has become the standard of care in the clinical management of HIV-1-infected individuals. The objective of this study was to evaluate performance characteristics and relative workflow of the Aptima HIV-1 Quant Dx assay in comparison with the Abbott RealTime HIV-1 assay using plasma and cervicovaginal lavage (CVL) specimens. Assay performance was evaluated by using an AcroMetrix HIV-1 panel, AcroMetrix positive controls, Qnostics and SeraCare HIV-1 evaluation panels, 208 clinical plasma samples, and 205 matched CVL specimens on the Panther and m2000 platforms. The Aptima assay demonstrated good linearity over the quantification range tested (2 to 5 log10 copies/ml), and there was strong linear correlation between the assays (R2 = 0.99), with a comparable coefficient of variance of <5.5%. For the plasma samples, Deming regression analyses and Bland-Altman plots showed excellent agreement between the assays, with an interassay concordance of 91.35% (kappa = 0.75; 95% confidence interval [CI], 0.65 to 0.85), and on average, the viral loads determined by the Aptima assay were 0.21 log10 copies/ml higher than those determined by the RealTime assay. The assays differed in their sensitivity for quantifying HIV-1 RNA loads in CVL samples, with the Aptima and RealTime assays detecting 30% and 20%, respectively. Aptima had fewer invalid results, and on average, the viral loads in CVL samples quantified by the Aptima assay were 0.072 log10 copies/ml higher than those of the RealTime assay. Our results demonstrate that the Aptima assay is sensitive and accurate in quantifying viral loads in both plasma and CVL specimens and that the fully automated Panther system has all the necessary features suitable for clinical laboratories demanding high-throughput sample processing. PMID:26842702

An improved SRC method based on virtual samples for face recognition

NASA Astrophysics Data System (ADS)

Fu, Lijun; Chen, Deyun; Lin, Kezheng; Li, Ao

2018-07-01

The sparse representation classifier (SRC) performs classification by evaluating which class leads to the minimum representation error. However, in real world, the number of available training samples is limited due to noise interference, training samples cannot accurately represent the test sample linearly. Therefore, in this paper, we first produce virtual samples by exploiting original training samples at the aim of increasing the number of training samples. Then, we take the intra-class difference as data representation of partial noise, and utilize the intra-class differences and training samples simultaneously to represent the test sample in a linear way according to the theory of SRC algorithm. Using weighted score level fusion, the respective representation scores of the virtual samples and the original training samples are fused together to obtain the final classification results. The experimental results on multiple face databases show that our proposed method has a very satisfactory classification performance.

Evaluation of two types of swabs for sampling allograft musculoskeletal tissue.

PubMed

Varettas, Kerry

2015-01-01

Allograft musculoskeletal tissue is commonly sampled by a swab for bioburden screening. To determine if bioburden recovery could be improved at the pre-analytical stage, two swab systems were evaluated: the Amies gel swab and the ESwab. In vitro studies were performed to determine the recovery of each swab system with <100 colony-forming unit of challenge organisms using inoculated swabs and by sampling inoculated femoral heads. The standard culture protocol used in this laboratory was also evaluated after sampling of inoculated femoral heads. A prospective study was performed with both swab systems used in parallel to sample cadaveric allograft musculoskeletal tissue. The challenge organisms could be recovered from the in vitro inoculated studies. The standard culture protocol in this laboratory recovered all challenge organisms from both swab systems. One hundred and six paired Amies and ESwabs were collected from eight cadaveric donors with skin commensals the predominant isolates. The sampling of an inoculated femoral head was included to reflect routine swab sampling practice as was the inclusion of the standard method used in this laboratory. This appears to be the first study to compare Amies gel swabs with ESwabs to sample allograft femoral heads and in a prospective study with cadaveric allograft musculoskeletal tissue. Other comparative studies of swab systems have used a much higher inoculum to mimic an infection; however, sepsis is an exclusion criterion for allograft donors. It was found that the Amies gel swab and ESwab are both suitable sampling devices for bioburden testing of allograft musculoskeletal tissue. © 2014 Royal Australasian College of Surgeons.

Electrodeposited Zinc-Nickel as an Alternative to Cadmium Plating for Aerospace Application

NASA Technical Reports Server (NTRS)

Mcmillan, V. C.

1991-01-01

Corrosion evaluation studies were conducted on 4130 alloy steel samples coated with electrodeposited zinc-nickel and samples coated with electrodeposited cadmium. The zinc nickel was deposited by the selection electrochemical metallizing process. These coated samples were exposed to a 5-percent salt fog environment at 35 plus or minus 2 C for a period ranging from 96 to 240 hours. An evaluation of the effect of dichromate coatings on the performance of each plating was conducted. The protection afforded by platings with a dichromate seal was compared to platings without the seal. During the later stages of testing, deposit adhesion and the potential for hydrogen entrapment were also evaluated.

Evaluation of concrete pavements with materials-related distress : appendix A, part 1.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix A, part 3.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix A, part 2.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Assessment of Oral Skills: A Comparison of Scores Obtained through Audio Recording to Those Obtained through Face-to-Face Evaluation.

ERIC Educational Resources Information Center

Nambiar, Mohana K; Goon, Cecilia

1993-01-01

The oral performance of a sample of 87 undergraduates was evaluated first in a face-to-face setting and then through audio recordings of that same performance. Results confirm that effectiveness in oral communication clearly is not dependent on words and sounds alone but that paralinguistic and extralinguistic data also play a significant role.…

Statistical evaluation of vibration analysis techniques

NASA Technical Reports Server (NTRS)

Milner, G. Martin; Miller, Patrice S.

1987-01-01

An evaluation methodology is presented for a selection of candidate vibration analysis techniques applicable to machinery representative of the environmental control and life support system of advanced spacecraft; illustrative results are given. Attention is given to the statistical analysis of small sample experiments, the quantification of detection performance for diverse techniques through the computation of probability of detection versus probability of false alarm, and the quantification of diagnostic performance.

Towards establishing a human fecal contamination index in microbial source tracking

EPA Science Inventory

There have been significant advances in development of PCR-based methods to detect source associated DNA sequences (markers), but method evaluation has focused on performance with individual challenge samples. Little attention has been given to integration of multiple samples fro...

Non-destructive evaluation of UV pulse laser-induced damage performance of fused silica optics.

PubMed

Huang, Jin; Wang, Fengrui; Liu, Hongjie; Geng, Feng; Jiang, Xiaodong; Sun, Laixi; Ye, Xin; Li, Qingzhi; Wu, Weidong; Zheng, Wanguo; Sun, Dunlu

2017-11-24

The surface laser damage performance of fused silica optics is related to the distribution of surface defects. In this study, we used chemical etching assisted by ultrasound and magnetorheological finishing to modify defect distribution in a fused silica surface, resulting in fused silica samples with different laser damage performance. Non-destructive test methods such as UV laser-induced fluorescence imaging and photo-thermal deflection were used to characterize the surface defects that contribute to the absorption of UV laser radiation. Our results indicate that the two methods can quantitatively distinguish differences in the distribution of absorptive defects in fused silica samples subjected to different post-processing steps. The percentage of fluorescence defects and the weak absorption coefficient were strongly related to the damage threshold and damage density of fused silica optics, as confirmed by the correlation curves built from statistical analysis of experimental data. The results show that non-destructive evaluation methods such as laser-induced fluorescence and photo-thermal absorption can be effectively applied to estimate the damage performance of fused silica optics at 351 nm pulse laser radiation. This indirect evaluation method is effective for laser damage performance assessment of fused silica optics prior to utilization.

Case-based fracture image retrieval.

PubMed

Zhou, Xin; Stern, Richard; Müller, Henning

2012-05-01

Case-based fracture image retrieval can assist surgeons in decisions regarding new cases by supplying visually similar past cases. This tool may guide fracture fixation and management through comparison of long-term outcomes in similar cases. A fracture image database collected over 10 years at the orthopedic service of the University Hospitals of Geneva was used. This database contains 2,690 fracture cases associated with 43 classes (based on the AO/OTA classification). A case-based retrieval engine was developed and evaluated using retrieval precision as a performance metric. Only cases in the same class as the query case are considered as relevant. The scale-invariant feature transform (SIFT) is used for image analysis. Performance evaluation was computed in terms of mean average precision (MAP) and early precision (P10, P30). Retrieval results produced with the GNU image finding tool (GIFT) were used as a baseline. Two sampling strategies were evaluated. One used a dense 40 × 40 pixel grid sampling, and the second one used the standard SIFT features. Based on dense pixel grid sampling, three unsupervised feature selection strategies were introduced to further improve retrieval performance. With dense pixel grid sampling, the image is divided into 1,600 (40 × 40) square blocks. The goal is to emphasize the salient regions (blocks) and ignore irrelevant regions. Regions are considered as important when a high variance of the visual features is found. The first strategy is to calculate the variance of all descriptors on the global database. The second strategy is to calculate the variance of all descriptors for each case. A third strategy is to perform a thumbnail image clustering in a first step and then to calculate the variance for each cluster. Finally, a fusion between a SIFT-based system and GIFT is performed. A first comparison on the selection of sampling strategies using SIFT features shows that dense sampling using a pixel grid (MAP = 0.18) outperformed the SIFT detector-based sampling approach (MAP = 0.10). In a second step, three unsupervised feature selection strategies were evaluated. A grid parameter search is applied to optimize parameters for feature selection and clustering. Results show that using half of the regions (700 or 800) obtains the best performance for all three strategies. Increasing the number of clusters in clustering can also improve the retrieval performance. The SIFT descriptor variance in each case gave the best indication of saliency for the regions (MAP = 0.23), better than the other two strategies (MAP = 0.20 and 0.21). Combining GIFT (MAP = 0.23) and the best SIFT strategy (MAP = 0.23) produced significantly better results (MAP = 0.27) than each system alone. A case-based fracture retrieval engine was developed and is available for online demonstration. SIFT is used to extract local features, and three feature selection strategies were introduced and evaluated. A baseline using the GIFT system was used to evaluate the salient point-based approaches. Without supervised learning, SIFT-based systems with optimized parameters slightly outperformed the GIFT system. A fusion of the two approaches shows that the information contained in the two approaches is complementary. Supervised learning on the feature space is foreseen as the next step of this study.

A critical investigation of post-liquefaction strength and steady-state flow behavior of saturated soils

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

Jong, H.L.

1988-01-01

The first objective was to perform a critical evaluation of the recently proposed steady-state analysis methodology for evaluation of post-liquefaction stability of potentially liquefiable soils. This analysis procedure is based on direct comparison between the in-situ undrained residual (steady state) strength of soils in an embankment or foundation, and the driving shear stresses in these soils. A laboratory investigation was performed to investigate factors affecting steady-state strengths, and also to evaluate the validity of assumptions involved in correcting the results of laboratory steady-state strength tests on undisturbed samples for effects of sampling disturbance in order to estimate in-situ strengths. Next,more » a field case study was performed using the steady-state analysis and testing methodologies to analyze Lower San Fernando Dam, which suffered a liquefaction-induced slope failure as a results of a 1971 earthquake. This leads to the second objective which was to extend the Lower San Fernando Dam case study to consideration of analysis methods used to evaluate the likelihood of triggering liquefaction during an earthquake. Finally, a number of the high quality undisturbed samples were subjected to undrained cyclic testing in order to repeat an earlier (1973) study of the use of cyclic tests data to predict liquefaction behavior at Lower San Fernando Dam.« less

Quantitative assessment of prevalence of pre-analytical variables and their effect on coagulation assay. Can intervention improve patient safety?

PubMed

Bhushan, Ravi; Sen, Arijit

2017-04-01

Very few Indian studies exist on evaluation of pre-analytical variables affecting "Prothrombin Time" the commonest coagulation assay performed. The study was performed in an Indian tertiary care setting with an aim to assess quantitatively the prevalence of pre-analytical variables and their effects on the results (patient safety), for Prothrombin time test. The study also evaluated their effects on the result and whether intervention, did correct the results. The firstly evaluated the prevalence for various pre-analytical variables detected in samples sent for Prothrombin Time testing. These samples with the detected variables wherever possible were tested and result noted. The samples from the same patients were repeated and retested ensuring that no pre-analytical variable is present. The results were again noted to check for difference the intervention produced. The study evaluated 9989 samples received for PT/INR over a period of 18 months. The prevalence of different pre-analytical variables was found to be 862 (8.63%). The proportion of various pre-analytical variables detected were haemolysed samples 515 (5.16%), over filled vacutainers 62 (0.62%), under filled vacutainers 39 (0.39%), low values 205 (2.05%), clotted samples 11 (0.11%), wrong labeling 4 (0.04%), wrong vacutainer use 2 (0.02%), chylous samples 7 (0.07%) and samples with more than one variable 17 (0.17%). The comparison of percentage of samples showing errors were noted for the first variables since they could be tested with and without the variable in place. The reduction in error percentage was 91.5%, 69.2%, 81.5% and 95.4% post intervention for haemolysed, overfilled, under filled and samples collected with excess pressure at phlebotomy respectively. Correcting the variables did reduce the error percentage to a great extent in these four variables and hence the variables are found to affect "Prothrombin Time" testing and can hamper patient safety.

Evaluation of high throughput gene expression platforms using a genomic biomarker signature for prediction of skin sensitization.

PubMed

Forreryd, Andy; Johansson, Henrik; Albrekt, Ann-Sofie; Lindstedt, Malin

2014-05-16

Allergic contact dermatitis (ACD) develops upon exposure to certain chemical compounds termed skin sensitizers. To reduce the occurrence of skin sensitizers, chemicals are regularly screened for their capacity to induce sensitization. The recently developed Genomic Allergen Rapid Detection (GARD) assay is an in vitro alternative to animal testing for identification of skin sensitizers, classifying chemicals by evaluating transcriptional levels of a genomic biomarker signature. During assay development and biomarker identification, genome-wide expression analysis was applied using microarrays covering approximately 30,000 transcripts. However, the microarray platform suffers from drawbacks in terms of low sample throughput, high cost per sample and time consuming protocols and is a limiting factor for adaption of GARD into a routine assay for screening of potential sensitizers. With the purpose to simplify assay procedures, improve technical parameters and increase sample throughput, we assessed the performance of three high throughput gene expression platforms--nCounter®, BioMark HD™ and OpenArray®--and correlated their performance metrics against our previously generated microarray data. We measured the levels of 30 transcripts from the GARD biomarker signature across 48 samples. Detection sensitivity, reproducibility, correlations and overall structure of gene expression measurements were compared across platforms. Gene expression data from all of the evaluated platforms could be used to classify most of the sensitizers from non-sensitizers in the GARD assay. Results also showed high data quality and acceptable reproducibility for all platforms but only medium to poor correlations of expression measurements across platforms. In addition, evaluated platforms were superior to the microarray platform in terms of cost efficiency, simplicity of protocols and sample throughput. We evaluated the performance of three non-array based platforms using a limited set of transcripts from the GARD biomarker signature. We demonstrated that it was possible to achieve acceptable discriminatory power in terms of separation between sensitizers and non-sensitizers in the GARD assay while reducing assay costs, simplify assay procedures and increase sample throughput by using an alternative platform, providing a first step towards the goal to prepare GARD for formal validation and adaption of the assay for industrial screening of potential sensitizers.

Performance of two alternative methods for Listeria detection throughout Serro Minas cheese ripening.

PubMed

Mata, Gardênia Márcia Silva Campos; Martins, Evandro; Machado, Solimar Gonçalves; Pinto, Maximiliano Soares; de Carvalho, Antônio Fernandes; Vanetti, Maria Cristina Dantas

2016-01-01

The ability of pathogens to survive cheese ripening is a food-security concern. Therefore, this study aimed to evaluate the performance of two alternative methods of analysis of Listeria during the ripening of artisanal Minas cheese. These methods were tested and compared with the conventional method: Lateral Flow System™, in cheeses produced on laboratory scale using raw milk collected from different farms and inoculated with Listeria innocua; and VIDAS(®)-LMO, in cheese samples collected from different manufacturers in Serro, Minas Gerais, Brazil. These samples were also characterized in terms of lactic acid bacteria, coliforms and physical-chemical analysis. In the inoculated samples, L. innocua was detected by Lateral Flow System™ method with 33% false-negative and 68% accuracy results. L. innocua was only detected in the inoculated samples by the conventional method at 60-days of cheese ripening. L. monocytogenes was not detected by the conventional and the VIDAS(®)-LMO methods in cheese samples collected from different manufacturers, which impairs evaluating the performance of this alternative method. We concluded that the conventional method provided a better recovery of L. innocua throughout cheese ripening, being able to detect L. innocua at 60-day, aging period which is required by the current legislation. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of dextromethorphan in human plasma samples.

PubMed

Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-Adergani, Behrouz

2011-04-01

In this paper, a novel method is described for automated determination of dextromethorphan in biological fluids using molecularly imprinted solid-phase extraction (MISPE) as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, chloroform as porogen and dextromethorphan as template molecule. These imprinted polymers were used as solid-phase extraction sorbent for the extraction of dextromethorphan from human plasma samples. Various parameters affecting the extraction efficiency of the MIP cartridges were evaluated. The high selectivity of the sorbent coupled to the high performance liquid chromatographic system permitted a simple and rapid analysis of this drug in plasma samples with limits of detection (LOD) and quantification (LOQ) of 0.12 ng/mL and 0.35 ng/mL, respectively. The MIP selectivity was evaluated by analyzing of the dextromethorphan in presence of several substances with similar molecular structures and properties. Results from the HPLC analyses showed that the recoveries of dextromethorphan using MIP cartridges from human plasma samples in the range of 1-50 ng/mL were higher than 87%. Copyright © 2011 Elsevier B.V. All rights reserved.

A Performance Appraisal System for School Principals.

ERIC Educational Resources Information Center

Knoop, Robert; Common, Ronald W.

The Performance Review, Analysis, and Improvement System for Educators (PRAISE) is a formative evaluation instrument designed to improve the performance of school principals. The system appears to be reliable and valid and is flexible enough to accommodate the needs of a variety of schools. Sample items and categories of the instrument include…

Evaluation of automated enzyme immunoassays for five anticonvulsants and theophylline adapted to a centrifugal analyzer.

PubMed

Urquhart, N; Godolphin, W; Campbell, D J

1979-05-01

We report a clinical evaluation of the enzyme immunoassay (EMIT) performed with the GEMSAEC centrifugal analyzer as compared to gas-liquid and liquid chromatography for anticonvulsant drugs and theophylline, respectively. A good correlation was obtained for all drugs, although some difficulties were experienced with one lot of reagent for ethosuximide. The analyzer has an economic advantage if many samples are being analyzed for few drugs in each sample.

Development of a Multiplexed Liquid Chromatography Multiple-Reaction-Monitoring Mass Spectrometry (LC-MRM/MS) Method for Evaluation of Salivary Proteins as Oral Cancer Biomarkers.

PubMed

Chen, Yi-Ting; Chen, Hsiao-Wei; Wu, Chun-Feng; Chu, Lichieh Julie; Chiang, Wei-Fang; Wu, Chih-Ching; Yu, Jau-Song; Tsai, Cheng-Han; Liang, Kung-Hao; Chang, Yu-Sun; Wu, Maureen; Ou Yang, Wei-Ting

2017-05-01

Multiple (selected) reaction monitoring (MRM/SRM) of peptides is a growing technology for target protein quantification because it is more robust, precise, accurate, high-throughput, and multiplex-capable than antibody-based techniques. The technique has been applied clinically to the large-scale quantification of multiple target proteins in different types of fluids. However, previous MRM-based studies have placed less focus on sample-preparation workflow and analytical performance in the precise quantification of proteins in saliva, a noninvasively sampled body fluid. In this study, we evaluated the analytical performance of a simple and robust multiple reaction monitoring (MRM)-based targeted proteomics approach incorporating liquid chromatography with mass spectrometry detection (LC-MRM/MS). This platform was used to quantitatively assess the biomarker potential of a group of 56 salivary proteins that have previously been associated with human cancers. To further enhance the development of this technology for assay of salivary samples, we optimized the workflow for salivary protein digestion and evaluated quantification performance, robustness and technical limitations in analyzing clinical samples. Using a clinically well-characterized cohort of two independent clinical sample sets (total n = 119), we quantitatively characterized these protein biomarker candidates in saliva specimens from controls and oral squamous cell carcinoma (OSCC) patients. The results clearly showed a significant elevation of most targeted proteins in saliva samples from OSCC patients compared with controls. Overall, this platform was capable of assaying the most highly multiplexed panel of salivary protein biomarkers, highlighting the clinical utility of MRM in oral cancer biomarker research. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Evaluation of the human immunodeficiency virus type 1 and 2 antibodies detection in dried whole blood spots (DBS) samples.

PubMed

Castro, Andréa Cauduro de; Borges, Luiz Gustavo dos Anjos; Souza, Ricardo da Silva de; Grudzinski, Melina; D'Azevedo, Pedro Alves

2008-01-01

Human Immunodeficiency Virus Type 1 and 2 antibodies detection was performed in 457 dried whole blood spots samples (S&S 903). Q-Preven HIV 1+2 was the screening test used. The results were compared with the gold standard serum tests by ELISA (Cobas Core e Axsym HIV1/2 gO) and immunofluorescence was the definitive confirmatory test. The samples were obtained from the Hospital Nossa Senhora da Conceição in Porto Alegre, RS - Brazil, through whole blood transfer to filter paper card and sent to Caxias do Sul, RS-Brazil where the tests were performed. The dried whole blood spot stability was evaluated with two different panels. The first one was composed of five negative and five positive samples stored at room temperature, 4 degrees C, -20 degrees C and -70 degrees C, while the second was composed of two negative and three positive samples stored at 37 degrees C (humidity <50%). Each sample was screened every week for six weeks. These measurement results didn't show variation during the study period. The detected sensibility was 100%, specificity was 99.6%, the positive predictive value was 99.5% and negative predictive values were 100%. The results demonstrated high performance characteristics, opening a new perspective of dried whole blood spot utilization in HIV screening diagnosis.

Seasonal distribution of Legionella spp. and L. pneumophila in a river in Taiwan evaluated with culture-confirmed and direct DNA extraction methods

NASA Astrophysics Data System (ADS)

Tung, Min-Che; Chang, Tien-Yu; Hsu, Bing-Mu; Shen, Shu-Min; Huang, Jen-Te; Kao, Po-Min; Chiu, Yi-Chou; Fan, Cheng-Wei; Huang, Yu-Li

2013-07-01

In this study, we evaluated the presence and amount of Legionella in along a river in Taiwan, and the relations between seasonal distribution of Legionella spp. and geographic characteristics in the watershed were also evaluated. Water samples were pre-treated and analyzed with culture-confirmed and direct DNA extraction methods. For culture-confirmed method, water samples were cultivated through a series of selective media, and candidate colonies were confirmed by PCR. For direct DNA extraction method, direct DNA extraction was performed from pre-treated water samples. The DNA extracts were analyzed with PCR and DNA sequence analysis for species determination, quantitative PCR (qPCR) was performed to quantify Legionella concentration in the water sample. In all, 150 water samples were included in this study, with 73 (48.6%) water samples detected with Legionella spp., and 17 with L. pneumophila. Over 80% Legionella spp. detections were through direct DNA extraction method, but more than 80% L. pneumophila detections were through culture-confirmed method. While detection of Legionella spp. was done with two methods, positive results were found through only one method. Legionella spp. was detected in all seasons with detection rate ranging between 34.3-58.8% and seasonal average concentration from 1.9 × 102 to 7.1 × 103 CFU/L. Most of the L. pneumophila detections were from samples collected in fall (38.2%) and summer (6.0%), which also coincided with increased cases of Legionellosis reported through Center of Disease Control in Taiwan. The high prevalence and concentration of Legionella spp. and L. pneumophila in the surface waters should be further evaluated for potential health risks.

External evaluation of the Dimension Vista 1500® intelligent lab system.

PubMed

Bruneel, Arnaud; Dehoux, Monique; Barnier, Anne; Boutten, Anne

2012-09-01

Dimension Vista® analyzer combines four technologies (photometry, nephelometry, V-LYTE® integrated multisensor potentiometry, and LOCI® chemiluminescence) into one high-throughput system. We assessed analytical performance of assays routinely performed in our emergency laboratory according to the VALTEC protocol, and practicability. Precision was good for most parameters. Analytical domain was large and suitable for undiluted analysis in most clinical settings encountered in our hospital. Data were comparable and correlated to our routine analyzers (Roche Modular DP®, Abbott AXSYM®, Siemens Dimension® RxL, and BN ProSpec®). Performance of nephelometric and LOCI modules was excellent. Functional sensitivity of high-sensitivity C-reactive protein and cardiac troponin I were 0.165 mg/l and 0.03 ng/ml, respectively (coefficient of variation; CV < 10%). The influence of interfering substances (i.e., hemoglobin, bilirubin, or lipids) was moderate, and Dimension Vista® specifically alerted for interference according to HIL (hemolysis, icterus, lipemia) indices. Good instrument performance and full functionality (no reagent or sample carryover in the conditions evaluated, effective sample-volume detection, and clot detection) were confirmed. Simulated routine testing demonstrated excellent practicability, throughput, ease of use of software and security. Performance and practicability of Dimension Vista® are highly suitable for both routine and emergency use. Since no volume detection and thus no warning is available on limited sample racks, pediatric samples require special caution to the Siemens protocol to be analyzed in secured conditions. Our experience in routine practice is also discussed, i.e., the impact of daily workload, "manual" steps resulting from dilutions and pediatric samples, maintenances, flex hydration on instrument's performance on throughput and turnaround time. © 2012 Wiley Periodicals, Inc.

Seeking excellence: An evaluation of 235 international laboratories conducting water isotope analyses by isotope-ratio and laser-absorption spectrometry.

PubMed

Wassenaar, L I; Terzer-Wassmuth, S; Douence, C; Araguas-Araguas, L; Aggarwal, P K; Coplen, T B

2018-03-15

Water stable isotope ratios (δ 2 H and δ 18 O values) are widely used tracers in environmental studies; hence, accurate and precise assays are required for providing sound scientific information. We tested the analytical performance of 235 international laboratories conducting water isotope analyses using dual-inlet and continuous-flow isotope ratio mass spectrometers and laser spectrometers through a water isotope inter-comparison test. Eight test water samples were distributed by the IAEA to international stable isotope laboratories. These consisted of a core set of five samples spanning the common δ-range of natural waters, and three optional samples (highly depleted, enriched, and saline). The fifth core sample contained unrevealed trace methanol to assess analyst vigilance to the impact of organic contamination on water isotopic measurements made by all instrument technologies. For the core and optional samples ~73 % of laboratories gave acceptable results within 0.2 ‰ and 1.5 ‰ of the reference values for δ 18 O and δ 2 H, respectively; ~27 % produced unacceptable results. Top performance for δ 18 O values was dominated by dual-inlet IRMS laboratories; top performance for δ 2 H values was led by laser spectrometer laboratories. Continuous-flow instruments yielded comparatively intermediate results. Trace methanol contamination of water resulted in extreme outlier δ-values for laser instruments, but also affected reactor-based continuous-flow IRMS systems; however, dual-inlet IRMS δ-values were unaffected. Analysis of the laboratory results and their metadata suggested inaccurate or imprecise performance stemmed mainly from skill- and knowledge-based errors including: calculation mistakes, inappropriate or compromised laboratory calibration standards, poorly performing instrumentation, lack of vigilance to contamination, or inattention to unreasonable isotopic outcomes. To counteract common errors, we recommend that laboratories include 1-2 'known' control standards in all autoruns; laser laboratories should screen each autorun for spectral contamination; and all laboratories should evaluate whether derived d-excess values are realistic when both isotope ratios are measured. Combined, these data evaluation strategies should immediately inform the laboratory about fundamental mistakes or compromised samples. Copyright © 2018 John Wiley & Sons, Ltd.

Seeking excellence: An evaluation of 235 international laboratories conducting water isotope analyses by isotope-ratio and laser-absorption spectrometry

USGS Publications Warehouse

Wassenaar, L. I.; Terzer-Wassmuth, S.; Douence, C.; Araguas-Araguas, L.; Aggarwal, P. K.; Coplen, Tyler B.

2018-01-01

RationaleWater stable isotope ratios (δ2H and δ18O values) are widely used tracers in environmental studies; hence, accurate and precise assays are required for providing sound scientific information. We tested the analytical performance of 235 international laboratories conducting water isotope analyses using dual-inlet and continuous-flow isotope ratio mass spectrometers and laser spectrometers through a water isotope inter-comparison test.MethodsEight test water samples were distributed by the IAEA to international stable isotope laboratories. These consisted of a core set of five samples spanning the common δ-range of natural waters, and three optional samples (highly depleted, enriched, and saline). The fifth core sample contained unrevealed trace methanol to assess analyst vigilance to the impact of organic contamination on water isotopic measurements made by all instrument technologies.ResultsFor the core and optional samples ~73 % of laboratories gave acceptable results within 0.2 ‰ and 1.5 ‰ of the reference values for δ18O and δ2H, respectively; ~27 % produced unacceptable results. Top performance for δ18O values was dominated by dual-inlet IRMS laboratories; top performance for δ2H values was led by laser spectrometer laboratories. Continuous-flow instruments yielded comparatively intermediate results. Trace methanol contamination of water resulted in extreme outlier δ-values for laser instruments, but also affected reactor-based continuous-flow IRMS systems; however, dual-inlet IRMS δ-values were unaffected.ConclusionsAnalysis of the laboratory results and their metadata suggested inaccurate or imprecise performance stemmed mainly from skill- and knowledge-based errors including: calculation mistakes, inappropriate or compromised laboratory calibration standards, poorly performing instrumentation, lack of vigilance to contamination, or inattention to unreasonable isotopic outcomes. To counteract common errors, we recommend that laboratories include 1–2 'known' control standards in all autoruns; laser laboratories should screen each autorun for spectral contamination; and all laboratories should evaluate whether derived d-excess values are realistic when both isotope ratios are measured. Combined, these data evaluation strategies should immediately inform the laboratory about fundamental mistakes or compromised samples.

Preliminary Figures of Merit for Isotope Ratio Measurements: The Liquid Sampling-Atmospheric Pressure Glow Discharge Microplasma Ionization Source Coupled to an Orbitrap Mass Analyzer

NASA Astrophysics Data System (ADS)

Hoegg, Edward D.; Barinaga, Charles J.; Hager, George J.; Hart, Garret L.; Koppenaal, David W.; Marcus, R. Kenneth

2016-08-01

In order to meet a growing need for fieldable mass spectrometer systems for precise elemental and isotopic analyses, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) has a number of very promising characteristics. One key set of attributes that await validation deals with the performance characteristics relative to isotope ratio precision and accuracy. Owing to its availability and prior experience with this research team, the initial evaluation of isotope ratio (IR) performance was performed on a Thermo Scientific Exactive Orbitrap instrument. While the mass accuracy and resolution performance for Orbitrap analyzers are well-documented, no detailed evaluations of the IR performance have been published. Efforts described here involve two variables: the inherent IR precision and accuracy delivered by the LS-APGD microplasma and the inherent IR measurement qualities of Orbitrap analyzers. Important to the IR performance, the various operating parameters of the Orbitrap sampling interface, high-energy collisional dissociation (HCD) stage, and ion injection/data acquisition have been evaluated. The IR performance for a range of other elements, including natural, depleted, and enriched uranium isotopes was determined. In all cases, the precision and accuracy are degraded when measuring low abundance (<0.1% isotope fractions). In the best case, IR precision on the order of 0.1% RSD can be achieved, with values of 1%-3% RSD observed for low-abundance species. The results suggest that the LS-APGD is a promising candidate for field deployable MS analysis and that the high resolving powers of the Orbitrap may be complemented with a here-to-fore unknown capacity to deliver high-precision IRs.

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...

INTERIM REPORT ON THE EVOLUTION AND ...

EPA Pesticide Factsheets

A demonstration of screening technologies for determining the presence of dioxin and dioxin-like compounds in soil and sediment was conducted under the U.S. Environmental Protection Agency's(EPA's) Superfund Innovative Technology Evaluation Program in Saginaw, Michigan in 2004. The objectives of the demonstration included evaluating each participating technology's accuracy, precision, sensitivity, sample throughput, tendency for matrix effects, and cost. The test also included an assessment of how well the technology's results compared to those generated by established laboratory methods using high-resolution mass spectrometry (HRMS). The demonstration objectives were accomplished by evaluating the results generated by each technology from 209 soil, sediment, and extract samples. The test samples included performance evaluation (PE) samples (i.e., contaminant concentrations were certified or the samples were spiked with known contaminants) and environmental samples collected from 10 different sampling locations. The PE and environmental samples were distributed to the technology developers in blind, random order. One of the participants in the original SITE demonstration was Hybrizyme Corporation, which demonstrated the use of the AhRC PCR Kit. The AhRC PCR Kit was a technology that reported the concentration of aryl hydrocarbon receptor (AhR) binding compounds in a sample, with units reported as Ah Receptor Binding Units (AhRBU). At the time of the original dem

Comparison of cross-sectional HIV incidence assay results from dried blood spots and plasma.

PubMed

Schlusser, Katherine E; Pilcher, Christopher; Kallas, Esper G; Santos, Breno R; Deeks, Steven G; Facente, Shelley; Keating, Sheila M; Busch, Michael P; Murphy, Gary; Welte, Alex; Quinn, Thomas; Eshleman, Susan H; Laeyendecker, Oliver

2017-01-01

Assays have been developed for cross-sectional HIV incidence estimation using plasma samples. Large scale surveillance programs are planned using dried blood spot (DBS) specimens for incidence assessment. However, limited information exists on the performance of HIV cross-sectional incidence assays using DBS. The assays evaluated were: Maxim HIV-1 Limiting Antigen Avidity EIA (LAg-Avidity), Sedia HIV-1 BED-Capture EIA (BED-CEIA), and CDC modified BioRad HIV-1/2 Plus O Avidity-based Assay (CDC-BioRad Avidity) using pre-determined cutoff values. 100 matched HIV-1 positive plasma and DBS samples, with known duration of infection, from the Consortium for the Evaluation and Performance of HIV Incidence Assays repository were tested. All assays were run in duplicate. To examine the degree of variability within and between results for each sample type, both categorical and continuous results were analyzed. Associations were assessed with Bland Altman, R2 values and Cohen's kappa coefficient (ĸ). Intra-assay variability using the same sample type was similar for all assays (R2 0.96 to 1.00). The R2 values comparing DBS and plasma results for LAg-Avidity, BED-CEIA, and CDC-BioRad Avidity were 0.96, 0.94, and 0.84, respectively. The concordance and ĸ values between DBS and plasma for all three assays were >87% and >0.64, respectively. The Bland-Altman analysis showed significant differences between plasma and DBS samples. For all three assays, a higher number of samples were classified as recent infections using DBS samples. DBS and plasma sample results were highly correlated. However, when compared to plasma, each assay performed somewhat differently in DBS at the lower and higher ends of the dynamic range. DBS samples were more likely to be classified as recently infected by all three assays, which may lead to overestimation of incidence in surveys using performance criteria derived for plasma samples.

Test plan for evaluating the operational performance of the prototype nested, fixed-depth fluidic sampler

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

REICH, F.R.

The PHMC will provide Low Activity Wastes (LAW) tank wastes for final treatment by a privatization contractor from two double-shell feed tanks, 241-AP-102 and 241-AP-104. Concerns about the inability of the baseline ''grab'' sampling to provide large volume samples within time constraints has led to the development of a nested, fixed-depth sampling system. This sampling system will provide large volume, representative samples without the environmental, radiation exposure, and sample volume impacts of the current base-line ''grab'' sampling method. A plan has been developed for the cold testing of this nested, fixed-depth sampling system with simulant materials. The sampling system willmore » fill the 500-ml bottles and provide inner packaging to interface with the Hanford Sites cask shipping systems (PAS-1 and/or ''safe-send''). The sampling system will provide a waste stream that will be used for on-line, real-time measurements with an at-tank analysis system. The cold tests evaluate the performance and ability to provide samples that are representative of the tanks' content within a 95 percent confidence interval, to sample while mixing pumps are operating, to provide large sample volumes (1-15 liters) within a short time interval, to sample supernatant wastes with over 25 wt% solids content, to recover from precipitation- and settling-based plugging, and the potential to operate over the 20-year expected time span of the privatization contract.« less

Assessment of beryllium and molybdenum nuclear data files with the RPI neutron scattering system in the energy region from 0.5 to 20 MeV

NASA Astrophysics Data System (ADS)

Daskalakis, Adam; Blain, Ezekiel; Leinweber, Gregory; Rapp, Michael; Barry, Devin; Block, Robert; Danon, Yaron

2017-09-01

A series of neutron scattering benchmark measurements were performed on beryllium and molybdenum with the Rensselaer Polytechnic Institute's Neutron Scattering System. The pulsed neutron source was produced by the Rensselaer Polytechnic Institute's Linear Accelerator and a well collimated neutron beam was incident onto the samples located at a distance of 30.07 m. Neutrons that scattered from the sample were measured using the time-of-flight by eight EJ-301 liquid scintillator detectors positioned 0.5 m from the sample of interest. A total of eight experiments were performed with two sample thicknesses each, measured by detectors placed at two sets of angles. All data were processed using pulse shape analysis that separated the neutron and gamma ray events and included a gamma misclassification correction to account for erroneously identified gamma rays. A detailed model of the neutron scattering system simulated each experiment with several current evaluated nuclear data libraries and their predecessors. Results for each evaluation were compared to the experimental data using a figure-of-merit. The neutron scattering system has been used as a means to quantify a library's performance.

Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel ‘V-plot’ methodology to display accuracy values

PubMed Central

Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

2018-01-01

Background Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test’s performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. Methods and findings We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Cholrapid and Cholgold) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). Conclusion No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard. PMID:29387424

Performance Evaluation and Online Realization of Data-driven Normalization Methods Used in LC/MS based Untargeted Metabolomics Analysis.

PubMed

Li, Bo; Tang, Jing; Yang, Qingxia; Cui, Xuejiao; Li, Shuang; Chen, Sijie; Cao, Quanxing; Xue, Weiwei; Chen, Na; Zhu, Feng

2016-12-13

In untargeted metabolomics analysis, several factors (e.g., unwanted experimental &biological variations and technical errors) may hamper the identification of differential metabolic features, which requires the data-driven normalization approaches before feature selection. So far, ≥16 normalization methods have been widely applied for processing the LC/MS based metabolomics data. However, the performance and the sample size dependence of those methods have not yet been exhaustively compared and no online tool for comparatively and comprehensively evaluating the performance of all 16 normalization methods has been provided. In this study, a comprehensive comparison on these methods was conducted. As a result, 16 methods were categorized into three groups based on their normalization performances across various sample sizes. The VSN, the Log Transformation and the PQN were identified as methods of the best normalization performance, while the Contrast consistently underperformed across all sub-datasets of different benchmark data. Moreover, an interactive web tool comprehensively evaluating the performance of 16 methods specifically for normalizing LC/MS based metabolomics data was constructed and hosted at http://server.idrb.cqu.edu.cn/MetaPre/. In summary, this study could serve as a useful guidance to the selection of suitable normalization methods in analyzing the LC/MS based metabolomics data.

Performance Evaluation and Online Realization of Data-driven Normalization Methods Used in LC/MS based Untargeted Metabolomics Analysis

PubMed Central

Li, Bo; Tang, Jing; Yang, Qingxia; Cui, Xuejiao; Li, Shuang; Chen, Sijie; Cao, Quanxing; Xue, Weiwei; Chen, Na; Zhu, Feng

2016-01-01

In untargeted metabolomics analysis, several factors (e.g., unwanted experimental & biological variations and technical errors) may hamper the identification of differential metabolic features, which requires the data-driven normalization approaches before feature selection. So far, ≥16 normalization methods have been widely applied for processing the LC/MS based metabolomics data. However, the performance and the sample size dependence of those methods have not yet been exhaustively compared and no online tool for comparatively and comprehensively evaluating the performance of all 16 normalization methods has been provided. In this study, a comprehensive comparison on these methods was conducted. As a result, 16 methods were categorized into three groups based on their normalization performances across various sample sizes. The VSN, the Log Transformation and the PQN were identified as methods of the best normalization performance, while the Contrast consistently underperformed across all sub-datasets of different benchmark data. Moreover, an interactive web tool comprehensively evaluating the performance of 16 methods specifically for normalizing LC/MS based metabolomics data was constructed and hosted at http://server.idrb.cqu.edu.cn/MetaPre/. In summary, this study could serve as a useful guidance to the selection of suitable normalization methods in analyzing the LC/MS based metabolomics data. PMID:27958387

Evaluation of Cooling Conditions for a High Heat Flux Testing Facility Based on Plasma-Arc Lamps

DOE PAGES

Charry, Carlos H.; Abdel-khalik, Said I.; Yoda, Minami; ...

2015-07-31

The new Irradiated Material Target Station (IMTS) facility for fusion materials at Oak Ridge National Laboratory (ORNL) uses an infrared plasma-arc lamp (PAL) to deliver incident heat fluxes as high as 27 MW/m 2. The facility is being used to test irradiated plasma-facing component materials as part of the joint US-Japan PHENIX program. The irradiated samples are to be mounted on molybdenum sample holders attached to a water-cooled copper rod. Depending on the size and geometry of samples, several sample holders and copper rod configurations have been fabricated and tested. As a part of the effort to design sample holdersmore » compatible with the high heat flux (HHF) testing to be conducted at the IMTS facility, numerical simulations have been performed for two different water-cooled sample holder designs using the ANSYS FLUENT 14.0 commercial computational fluid dynamics (CFD) software package. The primary objective of this work is to evaluate the cooling capability of different sample holder designs, i.e. to estimate their maximum allowable incident heat flux values. 2D axisymmetric numerical simulations are performed using the realizable k-ε turbulence model and the RPI nucleate boiling model within ANSYS FLUENT 14.0. The results of the numerical model were compared against the experimental data for two sample holder designs tested in the IMTS facility. The model has been used to parametrically evaluate the effect of various operational parameters on the predicted temperature distributions. The results were used to identify the limiting parameter for safe operation of the two sample holders and the associated peak heat flux limits. The results of this investigation will help guide the development of new sample holder designs.« less

Blind Biobanking of the Prostatectomy Specimen: Critical Evaluation of the Existing Techniques and Development of the New 4-Level Tissue Extraction Model With High Sampling Efficacy.

PubMed

Tolkach, Yuri; Eminaga, Okyaz; Wötzel, Fabian; Huss, Sebastian; Bettendorf, Olaf; Eltze, Elke; Abbas, Mahmoud; Imkamp, Florian; Semjonow, Axel

2017-03-01

Fresh tissue is mandatory to perform high-quality translation studies. Several models for tissue extraction from prostatectomy specimens without guidance by frozen sections are already introduced. However, little is known about the sampling efficacy of these models, which should provide representative tissue in adequate volumes, account for multifocality and heterogeneity of tumor, not violate the routine final pathological examination, and perform quickly without frozen section-based histological control. The aim of the study was to evaluate the sampling efficacy of the existing tissue extraction models without guidance by frozen sections ("blind") and to develop an optimized model for tissue extraction. Five hundred thirty-three electronic maps of the tumor distribution in prostates from a single-center cohort of the patients subjected to radical prostatectomy were used for analysis. Six available models were evaluated in silico for their sampling efficacy. Additionally, a novel model achieving the best sampling efficacy was developed. The available models showed high efficacies for sampling "any part" from the tumor (up to 100%), but were uniformly low in efficacy to sample all tumor foci from the specimens (with the best technique sampling only 51.6% of the all tumor foci). The novel 4-level extraction model achieved a sampling efficacy of 93.1% for all tumor foci. The existing "blind" tissue extraction models from prostatectomy specimens without frozen sections control are suitable to target tumor tissues but these tissues do not represent the whole tumor. The novel 4-level model provides the highest sampling efficacy and a promising potential for integration into routine. Prostate 77: 396-405, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Performance Characteristics of Lithium Ion Prototype Cells for 2003 Mars Sample Return Athena Rover

NASA Technical Reports Server (NTRS)

Ratnakumar, B. V.; Smart, M. C.; Ewell, R.; Surampudi, S.; Marsh, R. A.

2000-01-01

A viewgraph presentation outlines the mission objectives and power subsystem for the Mars Sample Return (MSR) Athena Rover. The NASA-DOD (depth of discharge) Interagency Li Ion program objectives are discussed. Evaluation tests performed at JPL are listed, and test results are shown for the Li-Ion cell initial capacity, charge/discharge capacity, voltage and ratio, specific energy, watt-hour efficiency, and cell voltage at various temperatures.

Evaluation of the proposed social anxiety disorder specifier change for DSM-5 in a treatment-seeking sample of anxious youth.

PubMed

Kerns, Caroline E; Comer, Jonathan S; Pincus, Donna B; Hofmann, Stefan G

2013-08-01

The current proposal for the DSM-5 definition of social anxiety disorder (SAD) is to replace the DSM-IV generalized subtype specifier with one that specifies fears in performance situations only. Relevant evaluations to support this change in youth samples are sparse. The present study examined rates and correlates of the DSM-IV and proposed DSM-5 specifiers in a sample of treatment-seeking children and adolescents with SAD (N = 204). When applying DSM-IV subtypes, 64.2% of the sample was classified as having a generalized subtype of SAD, with the remaining 35.2% classifying as having a nongeneralized subtype SAD. Youth with generalized SAD, relative to those with nongeneralized SAD, were older, had more clinically severe SAD, showed greater depressive symptoms, and were more likely to have a comorbid depressive disorder. No children in the current sample endorsed discrete fear in performance situations only in the absence of fear in other social situations. The present findings call into question the meaningfulness of the proposed changes in treatment-seeking youth with SAD. © 2013 Wiley Periodicals, Inc.

Science and Art of Setting Performance Standards and Cutoff Scores in Kinesiology

ERIC Educational Resources Information Center

Zhu, Weimo

2013-01-01

Setting standards and cutoff scores is essential to any measurement and evaluation practice. Two evaluation frameworks, norm-referenced (NR) and criterion-referenced (CR), have often been used for setting standards. Although setting fitness standards based on the NR evaluation is relatively easy as long as a nationally representative sample can be…

Evaluation of the 1985-86 Beginning Teacher Program.

ERIC Educational Resources Information Center

Feldman, H. S.

The Florida Beginning Teacher Program was evaluated in 1985-86 to determine its impact on teacher performance and to study problem areas identified in the 1984-85 evaluation. A sample of 43 beginning teachers and their support team members (a peer teacher, a building-level administrator, and one or more professional educators) completed surveys.…

Inadequacy of Conventional Grab Sampling for Remediation Decision-Making for Metal Contamination at Small-Arms Ranges.

PubMed

Clausen, J L; Georgian, T; Gardner, K H; Douglas, T A

2018-01-01

Research shows grab sampling is inadequate for evaluating military ranges contaminated with energetics because of their highly heterogeneous distribution. Similar studies assessing the heterogeneous distribution of metals at small-arms ranges (SAR) are lacking. To address this we evaluated whether grab sampling provides appropriate data for performing risk analysis at metal-contaminated SARs characterized with 30-48 grab samples. We evaluated the extractable metal content of Cu, Pb, Sb, and Zn of the field data using a Monte Carlo random resampling with replacement (bootstrapping) simulation approach. Results indicate the 95% confidence interval of the mean for Pb (432 mg/kg) at one site was 200-700 mg/kg with a data range of 5-4500 mg/kg. Considering the U.S. Environmental Protection Agency screening level for lead is 400 mg/kg, the necessity of cleanup at this site is unclear. Resampling based on populations of 7 and 15 samples, a sample size more realistic for the area yielded high false negative rates.

Quality Evaluation of Potentilla fruticosa L. by High Performance Liquid Chromatography Fingerprinting Associated with Chemometric Methods.

PubMed

Liu, Wei; Wang, Dongmei; Liu, Jianjun; Li, Dengwu; Yin, Dongxue

2016-01-01

The present study was performed to assess the quality of Potentilla fruticosa L. sampled from distinct regions of China using high performance liquid chromatography (HPLC) fingerprinting coupled with a suite of chemometric methods. For this quantitative analysis, the main active phytochemical compositions and the antioxidant activity in P. fruticosa were also investigated. Considering the high percentages and antioxidant activities of phytochemicals, P. fruticosa samples from Kangding, Sichuan were selected as the most valuable raw materials. Similarity analysis (SA) of HPLC fingerprints, hierarchical cluster analysis (HCA), principle component analysis (PCA), and discriminant analysis (DA) were further employed to provide accurate classification and quality estimates of P. fruticosa. Two principal components (PCs) were collected by PCA. PC1 separated samples from Kangding, Sichuan, capturing 57.64% of the variance, whereas PC2 contributed to further separation, capturing 18.97% of the variance. Two kinds of discriminant functions with a 100% discrimination ratio were constructed. The results strongly supported the conclusion that the eight samples from different regions were clustered into three major groups, corresponding with their morphological classification, for which HPLC analysis confirmed the considerable variation in phytochemical compositions and that P. fruticosa samples from Kangding, Sichuan were of high quality. The results of SA, HCA, PCA, and DA were in agreement and performed well for the quality assessment of P. fruticosa. Consequently, HPLC fingerprinting coupled with chemometric techniques provides a highly flexible and reliable method for the quality evaluation of traditional Chinese medicines.

Quality Evaluation of Potentilla fruticosa L. by High Performance Liquid Chromatography Fingerprinting Associated with Chemometric Methods

PubMed Central

Liu, Wei; Wang, Dongmei; Liu, Jianjun; Li, Dengwu; Yin, Dongxue

2016-01-01

The present study was performed to assess the quality of Potentilla fruticosa L. sampled from distinct regions of China using high performance liquid chromatography (HPLC) fingerprinting coupled with a suite of chemometric methods. For this quantitative analysis, the main active phytochemical compositions and the antioxidant activity in P. fruticosa were also investigated. Considering the high percentages and antioxidant activities of phytochemicals, P. fruticosa samples from Kangding, Sichuan were selected as the most valuable raw materials. Similarity analysis (SA) of HPLC fingerprints, hierarchical cluster analysis (HCA), principle component analysis (PCA), and discriminant analysis (DA) were further employed to provide accurate classification and quality estimates of P. fruticosa. Two principal components (PCs) were collected by PCA. PC1 separated samples from Kangding, Sichuan, capturing 57.64% of the variance, whereas PC2 contributed to further separation, capturing 18.97% of the variance. Two kinds of discriminant functions with a 100% discrimination ratio were constructed. The results strongly supported the conclusion that the eight samples from different regions were clustered into three major groups, corresponding with their morphological classification, for which HPLC analysis confirmed the considerable variation in phytochemical compositions and that P. fruticosa samples from Kangding, Sichuan were of high quality. The results of SA, HCA, PCA, and DA were in agreement and performed well for the quality assessment of P. fruticosa. Consequently, HPLC fingerprinting coupled with chemometric techniques provides a highly flexible and reliable method for the quality evaluation of traditional Chinese medicines. PMID:26890416

Comparison of serum, EDTA plasma and P100 plasma for luminex-based biomarker multiplex assays in patients with chronic obstructive pulmonary disease in the SPIROMICS study.

PubMed

O'Neal, Wanda K; Anderson, Wayne; Basta, Patricia V; Carretta, Elizabeth E; Doerschuk, Claire M; Barr, R Graham; Bleecker, Eugene R; Christenson, Stephanie A; Curtis, Jeffrey L; Han, Meilan K; Hansel, Nadia N; Kanner, Richard E; Kleerup, Eric C; Martinez, Fernando J; Miller, Bruce E; Peters, Stephen P; Rennard, Stephen I; Scholand, Mary Beth; Tal-Singer, Ruth; Woodruff, Prescott G; Couper, David J; Davis, Sonia M

2014-01-08

As a part of the longitudinal Chronic Obstructive Pulmonary Disease (COPD) study, Subpopulations and Intermediate Outcome Measures in COPD study (SPIROMICS), blood samples are being collected from 3200 subjects with the goal of identifying blood biomarkers for sub-phenotyping patients and predicting disease progression. To determine the most reliable sample type for measuring specific blood analytes in the cohort, a pilot study was performed from a subset of 24 subjects comparing serum, Ethylenediaminetetraacetic acid (EDTA) plasma, and EDTA plasma with proteinase inhibitors (P100). 105 analytes, chosen for potential relevance to COPD, arranged in 12 multiplex and one simplex platform (Myriad-RBM) were evaluated in duplicate from the three sample types from 24 subjects. The reliability coefficient and the coefficient of variation (CV) were calculated. The performance of each analyte and mean analyte levels were evaluated across sample types. 20% of analytes were not consistently detectable in any sample type. Higher reliability and/or smaller CV were determined for 12 analytes in EDTA plasma compared to serum, and for 11 analytes in serum compared to EDTA plasma. While reliability measures were similar for EDTA plasma and P100 plasma for a majority of analytes, CV was modestly increased in P100 plasma for eight analytes. Each analyte within a multiplex produced independent measurement characteristics, complicating selection of sample type for individual multiplexes. There were notable detectability and measurability differences between serum and plasma. Multiplexing may not be ideal if large reliability differences exist across analytes measured within the multiplex, especially if values differ based on sample type. For some analytes, the large CV should be considered during experimental design, and the use of duplicate and/or triplicate samples may be necessary. These results should prove useful for studies evaluating selection of samples for evaluation of potential blood biomarkers.

Comparison of serum, EDTA plasma and P100 plasma for luminex-based biomarker multiplex assays in patients with chronic obstructive pulmonary disease in the SPIROMICS study

PubMed Central

2014-01-01

Background As a part of the longitudinal Chronic Obstructive Pulmonary Disease (COPD) study, Subpopulations and Intermediate Outcome Measures in COPD study (SPIROMICS), blood samples are being collected from 3200 subjects with the goal of identifying blood biomarkers for sub-phenotyping patients and predicting disease progression. To determine the most reliable sample type for measuring specific blood analytes in the cohort, a pilot study was performed from a subset of 24 subjects comparing serum, Ethylenediaminetetraacetic acid (EDTA) plasma, and EDTA plasma with proteinase inhibitors (P100™). Methods 105 analytes, chosen for potential relevance to COPD, arranged in 12 multiplex and one simplex platform (Myriad-RBM) were evaluated in duplicate from the three sample types from 24 subjects. The reliability coefficient and the coefficient of variation (CV) were calculated. The performance of each analyte and mean analyte levels were evaluated across sample types. Results 20% of analytes were not consistently detectable in any sample type. Higher reliability and/or smaller CV were determined for 12 analytes in EDTA plasma compared to serum, and for 11 analytes in serum compared to EDTA plasma. While reliability measures were similar for EDTA plasma and P100 plasma for a majority of analytes, CV was modestly increased in P100 plasma for eight analytes. Each analyte within a multiplex produced independent measurement characteristics, complicating selection of sample type for individual multiplexes. Conclusions There were notable detectability and measurability differences between serum and plasma. Multiplexing may not be ideal if large reliability differences exist across analytes measured within the multiplex, especially if values differ based on sample type. For some analytes, the large CV should be considered during experimental design, and the use of duplicate and/or triplicate samples may be necessary. These results should prove useful for studies evaluating selection of samples for evaluation of potential blood biomarkers. PMID:24397870

The PneuCarriage Project: A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies.

PubMed

Satzke, Catherine; Dunne, Eileen M; Porter, Barbara D; Klugman, Keith P; Mulholland, E Kim

2015-11-01

The pneumococcus is a diverse pathogen whose primary niche is the nasopharynx. Over 90 different serotypes exist, and nasopharyngeal carriage of multiple serotypes is common. Understanding pneumococcal carriage is essential for evaluating the impact of pneumococcal vaccines. Traditional serotyping methods are cumbersome and insufficient for detecting multiple serotype carriage, and there are few data comparing the new methods that have been developed over the past decade. We established the PneuCarriage project, a large, international multi-centre study dedicated to the identification of the best pneumococcal serotyping methods for carriage studies. Reference sample sets were distributed to 15 research groups for blinded testing. Twenty pneumococcal serotyping methods were used to test 81 laboratory-prepared (spiked) samples. The five top-performing methods were used to test 260 nasopharyngeal (field) samples collected from children in six high-burden countries. Sensitivity and positive predictive value (PPV) were determined for the test methods and the reference method (traditional serotyping of >100 colonies from each sample). For the alternate serotyping methods, the overall sensitivity ranged from 1% to 99% (reference method 98%), and PPV from 8% to 100% (reference method 100%), when testing the spiked samples. Fifteen methods had ≥70% sensitivity to detect the dominant (major) serotype, whilst only eight methods had ≥70% sensitivity to detect minor serotypes. For the field samples, the overall sensitivity ranged from 74.2% to 95.8% (reference method 93.8%), and PPV from 82.2% to 96.4% (reference method 99.6%). The microarray had the highest sensitivity (95.8%) and high PPV (93.7%). The major limitation of this study is that not all of the available alternative serotyping methods were included. Most methods were able to detect the dominant serotype in a sample, but many performed poorly in detecting the minor serotype populations. Microarray with a culture amplification step was the top-performing method. Results from this comprehensive evaluation will inform future vaccine evaluation and impact studies, particularly in low-income settings, where pneumococcal disease burden remains high.

The PneuCarriage Project: A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies

PubMed Central

Satzke, Catherine; Dunne, Eileen M.; Porter, Barbara D.; Klugman, Keith P.; Mulholland, E. Kim

2015-01-01

Background The pneumococcus is a diverse pathogen whose primary niche is the nasopharynx. Over 90 different serotypes exist, and nasopharyngeal carriage of multiple serotypes is common. Understanding pneumococcal carriage is essential for evaluating the impact of pneumococcal vaccines. Traditional serotyping methods are cumbersome and insufficient for detecting multiple serotype carriage, and there are few data comparing the new methods that have been developed over the past decade. We established the PneuCarriage project, a large, international multi-centre study dedicated to the identification of the best pneumococcal serotyping methods for carriage studies. Methods and Findings Reference sample sets were distributed to 15 research groups for blinded testing. Twenty pneumococcal serotyping methods were used to test 81 laboratory-prepared (spiked) samples. The five top-performing methods were used to test 260 nasopharyngeal (field) samples collected from children in six high-burden countries. Sensitivity and positive predictive value (PPV) were determined for the test methods and the reference method (traditional serotyping of >100 colonies from each sample). For the alternate serotyping methods, the overall sensitivity ranged from 1% to 99% (reference method 98%), and PPV from 8% to 100% (reference method 100%), when testing the spiked samples. Fifteen methods had ≥70% sensitivity to detect the dominant (major) serotype, whilst only eight methods had ≥70% sensitivity to detect minor serotypes. For the field samples, the overall sensitivity ranged from 74.2% to 95.8% (reference method 93.8%), and PPV from 82.2% to 96.4% (reference method 99.6%). The microarray had the highest sensitivity (95.8%) and high PPV (93.7%). The major limitation of this study is that not all of the available alternative serotyping methods were included. Conclusions Most methods were able to detect the dominant serotype in a sample, but many performed poorly in detecting the minor serotype populations. Microarray with a culture amplification step was the top-performing method. Results from this comprehensive evaluation will inform future vaccine evaluation and impact studies, particularly in low-income settings, where pneumococcal disease burden remains high. PMID:26575033

Effect of final evaluation on job motivation from the perspective of nurses in Ahvaz Hospitals in 2012

PubMed Central

Faraji Khiavi, F; Amiri, E; Ghobadian, S; Roshankar, R

2015-01-01

Background: Increasing nurses’ motivation is among the most important and complex nursing duties. Performance evaluation system could be used as a means to improve the quantity and quality of the human resources. Therefore, current research objected to evaluate the effect of final evaluation on job motivation from the perspective of nurses in Ahvaz hospitals according to Herzberg scheme. Methods: This investigation conducted in 2012. Research population included nurses in Ahvaz educational hospitals. The sample size was calculated 120 and sampling was performed based on classification and random sampling. Research instrument was a self-made questionnaire with confirmed validity through content analysis and Cronbach’s alpha calculated at 0.94. Data examined utilizing ANOVA, T-Test, and descriptive statistics. Results: The nurses considered the final evaluation on management policy (3.2 ± 1.11) and monitoring (3.15 ± 1.15) among health items and responsibility (3.15 ± 1.15) and progress (3.06 ± 1.24) among motivational factors relatively effective. There was a significant association between scores of nurses' views in different age and sex groups (P = 0.01), but there was no significant association among respondents in educational level and marital status. Conclusion: Experienced nurses believed that evaluation has little effect on job motivation. If annual assessment of the various job aspects are considered, managers could use it as an efficient tool to motivate nurses. PMID:28316733

Effect of final evaluation on job motivation from the perspective of nurses in Ahvaz Hospitals in 2012.

PubMed

Faraji Khiavi, F; Amiri, E; Ghobadian, S; Roshankar, R

2015-01-01

Background: Increasing nurses' motivation is among the most important and complex nursing duties. Performance evaluation system could be used as a means to improve the quantity and quality of the human resources. Therefore, current research objected to evaluate the effect of final evaluation on job motivation from the perspective of nurses in Ahvaz hospitals according to Herzberg scheme. Methods: This investigation conducted in 2012. Research population included nurses in Ahvaz educational hospitals. The sample size was calculated 120 and sampling was performed based on classification and random sampling. Research instrument was a self-made questionnaire with confirmed validity through content analysis and Cronbach's alpha calculated at 0.94. Data examined utilizing ANOVA, T-Test, and descriptive statistics. Results: The nurses considered the final evaluation on management policy (3.2 ± 1.11) and monitoring (3.15 ± 1.15) among health items and responsibility (3.15 ± 1.15) and progress (3.06 ± 1.24) among motivational factors relatively effective. There was a significant association between scores of nurses' views in different age and sex groups (P = 0.01), but there was no significant association among respondents in educational level and marital status. Conclusion: Experienced nurses believed that evaluation has little effect on job motivation. If annual assessment of the various job aspects are considered, managers could use it as an efficient tool to motivate nurses.

LIMS for Lasers 2015 for achieving long-term accuracy and precision of δ2H, δ17O, and δ18O of waters using laser absorption spectrometry

USGS Publications Warehouse

Coplen, Tyler B.; Wassenaar, Leonard I

2015-01-01

RationaleAlthough laser absorption spectrometry (LAS) instrumentation is easy to use, its incorporation into laboratory operations is not easy, owing to extensive offline manipulation of comma-separated-values files for outlier detection, between-sample memory correction, nonlinearity (δ-variation with water amount) correction, drift correction, normalization to VSMOW-SLAP scales, and difficulty in performing long-term QA/QC audits.MethodsA Microsoft Access relational-database application, LIMS (Laboratory Information Management System) for Lasers 2015, was developed. It automates LAS data corrections and manages clients, projects, samples, instrument-sample lists, and triple-isotope (δ17O, δ18O, and δ2H values) instrumental data for liquid-water samples. It enables users to (1) graphically evaluate sample injections for variable water yields and high isotope-delta variance; (2) correct for between-sample carryover, instrumental drift, and δ nonlinearity; and (3) normalize final results to VSMOW-SLAP scales.ResultsCost-free LIMS for Lasers 2015 enables users to obtain improved δ17O, δ18O, and δ2H values with liquid-water LAS instruments, even those with under-performing syringes. For example, LAS δ2HVSMOW measurements of USGS50 Lake Kyoga (Uganda) water using an under-performing syringe having ±10 % variation in water concentration gave +31.7 ± 1.6 ‰ (2-σ standard deviation), compared with the reference value of +32.8 ± 0.4 ‰, after correction for variation in δ value with water concentration, between-sample memory, and normalization to the VSMOW-SLAP scale.ConclusionsLIMS for Lasers 2015 enables users to create systematic, well-founded instrument templates, import δ2H, δ17O, and δ18O results, evaluate performance with automatic graphical plots, correct for δ nonlinearity due to variable water concentration, correct for between-sample memory, adjust for drift, perform VSMOW-SLAP normalization, and perform long-term QA/QC audits easily. Published in 2015. This article is a U.S. Government work and is in the public domain in the USA.

Long-term Performance of Permeable Reactive Barriers Using Zero-valent Iron: An Evaluation at Two Sites

DTIC Science & Technology

2002-01-01

samples were placed in a glass reaction vessel and purged with CO2- scrubbed air. The samples were then acidified with hot, 5% perchloric acid and...extractable carbon. Total sulfur measurements were made with a UIC sulfur coulometer system. Iron samples were covered with V2O5 and combusted in the

Hydrogeochemical and stream sediment reconnaissance basic data for Cheyenne Quadrangle, Wyoming

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

Not Available

1981-07-31

Field and laboratory data are presented for 884 water samples and 598 sediment samples from the Cheyenne Quadrangle, Wyoming. Uranium values have been reported by Los Alamos National Laboratory in Report GJBX-106(78). The samples were collected by Los Alamos National Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

Safety Evaluation of Red Light Running Camera Intersections in Illinois

DOT National Transportation Integrated Search

2017-04-01

As a part of this research, the safety performance of red light running (RLR) camera systems was evaluated for a sample of 41 intersections and 60 RLR camera approaches located on state routes under IDOTs jurisdiction in the Chicago suburbs. Compr...

Evaluation of the locations of Kentucky's traffic crash data.

DOT National Transportation Integrated Search

2010-11-01

An evaluation of a random sample of crashes from 2009 was performed to assess the current accuracy of the crash data's location information.The location of the crash was compared to the presumed location using several report data elements such as nea...

SEPARATION AND ISOLATION OF VOLATILE ORGANIC COMPOUNDS USING VACUUM DISTILLATION WITH GC/MS DETERMINATION

EPA Science Inventory

Vacuum distillation of water, soil, oil, and fish samples is presented as an alternative technique for determining volatile organic compounds (VOCs). Analyses of samples containing VOCs and non-VOCs at 50ppb concentrations were performed to evaluate method limitations. Analyte re...

Performance Evaluation of the Sysmex CS-5100 Automated Coagulation Analyzer.

PubMed

Chen, Liming; Chen, Yu

2015-01-01

Coagulation testing is widely applied clinically, and laboratories increasingly demand automated coagulation analyzers with short turn-around times and high-throughput. The purpose of this study was to evaluate the performance of the Sysmex CS-5100 automated coagulation analyzer for routine use in a clinical laboratory. The prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (Fbg), and D-dimer were compared between the Sysmex CS-5100 and Sysmex CA-7000 analyzers, and the imprecision, comparison, throughput, STAT function, and performance for abnormal samples were measured in each. The within-run and between-run coefficients of variation (CV) for the PT, APTT, INR, and D-dimer analyses showed excellent results both in the normal and pathologic ranges. The correlation coefficients between the Sysmex CS-5100 and Sysmex CA-7000 were highly correlated. The throughput of the Sysmex CS-5100 was faster than that of the Sysmex CA-7000. There was no interference at all by total bilirubin concentrations and triglyceride concentrations in the Sysmex CS-5100 analyzer. We demonstrated that the Sysmex CS-5100 performs with satisfactory imprecision and is well suited for coagulation analysis in laboratories processing large sample numbers and icteric and lipemic samples.

Maternal and neonatal evaluation of derivated reactive oxygen metabolites (d-ROMs) and biological antioxidant potential in the horse.

PubMed

Sgorbini, M; Bonelli, F; Marmorini, P; Biagi, G; Corazza, M; Pasquini, A

2015-01-01

The aim of the present work was to evaluate derivated reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) in mares and foals to study perinatal oxidative status. A total of 60 animals were included in the present study. Maternal and foal venous blood samples were collected immediately after delivery along with a sample drawn from one of the umbilical arteries, and plasma samples were evaluated for lactatemia, d-ROMs, and BAP. The t test for unpaired data was applied between mares versus umbilical artery blood versus foals, both for d-ROMs and BAP. The Pearson test with two-tailed P value and a confidence interval of 95% was performed between d-ROMs and BAP and between d-ROMs and lactatemia, both for mares and foals. Finally, the t test for unpaired data was performed between fillies and colts. The t test showed differences between mares versus their own foals versus umbilical artery blood but not foals versus. umbilical artery blood, both for d-ROMs and BAP. A positive correlation was found both in mares and foals between BAP and d-ROMs and in mares between lactatemia and d-ROM. No differences in gender were found in BAP concentration. Our data are in line to previous studies performed in women and cattle.

Selected laboratory evaluations of the whole-water sample-splitting capabilities of a prototype fourteen-liter Teflon churn splitter

USGS Publications Warehouse

Horowitz, A.J.; Smith, J.J.; Elrick, K.A.

2001-01-01

A prototype 14-L Teflon? churn splitter was evaluated for whole-water sample-splitting capabilities over a range of sediment concentratons and grain sizes as well as for potential chemical contamination from both organic and inorganic constituents. These evaluations represent a 'best-case' scenario because they were performed in the controlled environment of a laboratory, and used monomineralic silica sand slurries of known concentration made up in deionized water. Further, all splitting was performed by a single operator, and all the requisite concentration analyses were performed by a single laboratory. The prototype Teflon? churn splitter did not appear to supply significant concentrations of either organic or inorganic contaminants at current U.S. Geological Survey (USGS) National Water Quality Laboratory detection and reporting limits when test samples were prepared using current USGS protocols. As with the polyethylene equivalent of the prototype Teflon? churn, the maximum usable whole-water suspended sediment concentration for the prototype churn appears to lie between 1,000 and 10,000 milligrams per liter (mg/L). Further, the maximum grain-size limit appears to lie between 125- and 250-microns (m). Tests to determine the efficacy of the valve baffle indicate that it must be retained to facilitate representative whole-water subsampling.

Association between Measures of Academic Performance and Psychosocial Adjustment for Asian/Pacific-Islander Adolescents.

ERIC Educational Resources Information Center

Hishinuma, Earl S.; Foster, Judy E.; Miyamoto, Robin H.; Nishimura, Stephanie T.; Andrade, Naleen N.; Nahulu, Linda B.; Goebert, Deborah A.; Yuen, Noelle Y. C.; Makini, George K., Jr.; Kim, S. Peter; Carlton, Barry S.

2001-01-01

Examines the association between different measures of academic performance and psychological adjustment for a sample of under-researched Asian/Pacific Islander adolescents from Hawaii. Results support the use of the actual quantification of academic performance (i.e. cumulative grade point average or self reported evaluation) in predicting…

Sleep Patterns and Academic Performance during Preparation for College Entrance Exam in Chinese Adolescents

ERIC Educational Resources Information Center

Wang, Guanghai; Ren, Fen; Liu, Zhijun; Xu, Guangxing; Jiang, Fan; Skora, Elizabeth; Lewin, Daniel S.

2016-01-01

Background: Deficient sleep is linked to detrimental outcomes in health and school performance for adolescents. This study characterized sleep patterns in Chinese adolescents preparing for the College Entrance Exam (CEE) and evaluated the association between sleep patterns, self-rated academic performance, and the CEE scores. Methods: A sample of…

Evaluation of DuPont Qualicon Bax System PCR assay for yeast and mold.

PubMed

Wallace, F Morgan; Burns, Frank; Fleck, Lois; Andaloro, Bridget; Farnum, Andrew; Tice, George; Ruebl, Joanne

2010-01-01

Evaluations were conducted to test the performance of the BAX System PCR assay which was certified as Performance Tested Method 010902 for screening yeast and mold in yogurt, corn starch, and milk-based powdered infant formula. Method comparison studies performed on samples with low-level inoculates showed that the BAX System demonstrates a sensitivity equivalent to the U.S. Food and Drug Administration's Bacteriological Analytical Manual culture method, but with a significantly shorter time to obtain results. Tests to evaluate inclusivity and exclusivity returned no false-negative and no false-positive results on a diverse panel of isolates, and tests for lot-to-lot variability and tablet stability demonstrated consistent performance. Ruggedness studies determined that none of the factors examined affected the performance of the assay.

Prospective safety performance evaluation on construction sites.

PubMed

Wu, Xianguo; Liu, Qian; Zhang, Limao; Skibniewski, Miroslaw J; Wang, Yanhong

2015-05-01

This paper presents a systematic Structural Equation Modeling (SEM) based approach for Prospective Safety Performance Evaluation (PSPE) on construction sites, with causal relationships and interactions between enablers and the goals of PSPE taken into account. According to a sample of 450 valid questionnaire surveys from 30 Chinese construction enterprises, a SEM model with 26 items included for PSPE in the context of Chinese construction industry is established and then verified through the goodness-of-fit test. Three typical types of construction enterprises, namely the state-owned enterprise, private enterprise and Sino-foreign joint venture, are selected as samples to measure the level of safety performance given the enterprise scale, ownership and business strategy are different. Results provide a full understanding of safety performance practice in the construction industry, and indicate that the level of overall safety performance situation on working sites is rated at least a level of III (Fair) or above. This phenomenon can be explained that the construction industry has gradually matured with the norms, and construction enterprises should improve the level of safety performance as not to be eliminated from the government-led construction industry. The differences existing in the safety performance practice regarding different construction enterprise categories are compared and analyzed according to evaluation results. This research provides insights into cause-effect relationships among safety performance factors and goals, which, in turn, can facilitate the improvement of high safety performance in the construction industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Glufosinate ammonium clean-up procedure from water samples using SPE

NASA Astrophysics Data System (ADS)

Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

2015-09-01

For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

Comparison of machine learning techniques to predict all-cause mortality using fitness data: the Henry ford exercIse testing (FIT) project.

PubMed

Sakr, Sherif; Elshawi, Radwa; Ahmed, Amjad M; Qureshi, Waqas T; Brawner, Clinton A; Keteyian, Steven J; Blaha, Michael J; Al-Mallah, Mouaz H

2017-12-19

Prior studies have demonstrated that cardiorespiratory fitness (CRF) is a strong marker of cardiovascular health. Machine learning (ML) can enhance the prediction of outcomes through classification techniques that classify the data into predetermined categories. The aim of this study is to present an evaluation and comparison of how machine learning techniques can be applied on medical records of cardiorespiratory fitness and how the various techniques differ in terms of capabilities of predicting medical outcomes (e.g. mortality). We use data of 34,212 patients free of known coronary artery disease or heart failure who underwent clinician-referred exercise treadmill stress testing at Henry Ford Health Systems Between 1991 and 2009 and had a complete 10-year follow-up. Seven machine learning classification techniques were evaluated: Decision Tree (DT), Support Vector Machine (SVM), Artificial Neural Networks (ANN), Naïve Bayesian Classifier (BC), Bayesian Network (BN), K-Nearest Neighbor (KNN) and Random Forest (RF). In order to handle the imbalanced dataset used, the Synthetic Minority Over-Sampling Technique (SMOTE) is used. Two set of experiments have been conducted with and without the SMOTE sampling technique. On average over different evaluation metrics, SVM Classifier has shown the lowest performance while other models like BN, BC and DT performed better. The RF classifier has shown the best performance (AUC = 0.97) among all models trained using the SMOTE sampling. The results show that various ML techniques can significantly vary in terms of its performance for the different evaluation metrics. It is also not necessarily that the more complex the ML model, the more prediction accuracy can be achieved. The prediction performance of all models trained with SMOTE is much better than the performance of models trained without SMOTE. The study shows the potential of machine learning methods for predicting all-cause mortality using cardiorespiratory fitness data.

A comparison of fitness-case sampling methods for genetic programming

NASA Astrophysics Data System (ADS)

Martínez, Yuliana; Naredo, Enrique; Trujillo, Leonardo; Legrand, Pierrick; López, Uriel

2017-11-01

Genetic programming (GP) is an evolutionary computation paradigm for automatic program induction. GP has produced impressive results but it still needs to overcome some practical limitations, particularly its high computational cost, overfitting and excessive code growth. Recently, many researchers have proposed fitness-case sampling methods to overcome some of these problems, with mixed results in several limited tests. This paper presents an extensive comparative study of four fitness-case sampling methods, namely: Interleaved Sampling, Random Interleaved Sampling, Lexicase Selection and Keep-Worst Interleaved Sampling. The algorithms are compared on 11 symbolic regression problems and 11 supervised classification problems, using 10 synthetic benchmarks and 12 real-world data-sets. They are evaluated based on test performance, overfitting and average program size, comparing them with a standard GP search. Comparisons are carried out using non-parametric multigroup tests and post hoc pairwise statistical tests. The experimental results suggest that fitness-case sampling methods are particularly useful for difficult real-world symbolic regression problems, improving performance, reducing overfitting and limiting code growth. On the other hand, it seems that fitness-case sampling cannot improve upon GP performance when considering supervised binary classification.

Data splitting for artificial neural networks using SOM-based stratified sampling.

PubMed

May, R J; Maier, H R; Dandy, G C

2010-03-01

Data splitting is an important consideration during artificial neural network (ANN) development where hold-out cross-validation is commonly employed to ensure generalization. Even for a moderate sample size, the sampling methodology used for data splitting can have a significant effect on the quality of the subsets used for training, testing and validating an ANN. Poor data splitting can result in inaccurate and highly variable model performance; however, the choice of sampling methodology is rarely given due consideration by ANN modellers. Increased confidence in the sampling is of paramount importance, since the hold-out sampling is generally performed only once during ANN development. This paper considers the variability in the quality of subsets that are obtained using different data splitting approaches. A novel approach to stratified sampling, based on Neyman sampling of the self-organizing map (SOM), is developed, with several guidelines identified for setting the SOM size and sample allocation in order to minimize the bias and variance in the datasets. Using an example ANN function approximation task, the SOM-based approach is evaluated in comparison to random sampling, DUPLEX, systematic stratified sampling, and trial-and-error sampling to minimize the statistical differences between data sets. Of these approaches, DUPLEX is found to provide benchmark performance with good model performance, with no variability. The results show that the SOM-based approach also reliably generates high-quality samples and can therefore be used with greater confidence than other approaches, especially in the case of non-uniform datasets, with the benefit of scalability to perform data splitting on large datasets. Copyright 2009 Elsevier Ltd. All rights reserved.

Evaluation of electrostatic precipitator during SRC combustion tests. Final task report Apr--Aug 1977

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

Nichols, G.B.; Barrett, W.J.

1978-07-01

The report deals with the evaluation of an electrostatic precipitator (ESP) and associated environmental factors during the burning of solvent refined coal (SRC) in a boiler at Plant Mitchell of the Georgia Power Company. The effort was part of an overall study of the use of SRC in a full-scale electric power plant. Results of a performance evaluation of the ESP are reported and interpreted. Samples of stack emissions were collected with a Source Assessment Sampling System (SASS) train for chemical analysis: results of the analysis are to be reported later.

[Evaluation of the surface of the new intraocular lenses in the scanning electron microscope].

PubMed

Kałuzny, B J; Szatkowski, J; Kałuzny, J J

2001-01-01

To evaluate the surface of the new PC IOLs commercially available in Poland in 2000. Representative samples of new posterior chamber IOLs produced by 6 different companies (Alcon, Lensita, Medicontur, Opsia, Rayner, Storz), 5 of each, underwent surface examination with Novoscan 30 scanning electron microscope. Although, in general, smooth surface of optic and haptic parts were observed, three samples with irregularities were found. Comparing to previous evaluation performed in 1994, significant improvement in quality of IOLs surface was noted. No considerable differences in this field between above mentioned producers were observed.

A 2D MTF approach to evaluate and guide dynamic imaging developments.

PubMed

Chao, Tzu-Cheng; Chung, Hsiao-Wen; Hoge, W Scott; Madore, Bruno

2010-02-01

As the number and complexity of partially sampled dynamic imaging methods continue to increase, reliable strategies to evaluate performance may prove most useful. In the present work, an analytical framework to evaluate given reconstruction methods is presented. A perturbation algorithm allows the proposed evaluation scheme to perform robustly without requiring knowledge about the inner workings of the method being evaluated. A main output of the evaluation process consists of a two-dimensional modulation transfer function, an easy-to-interpret visual rendering of a method's ability to capture all combinations of spatial and temporal frequencies. Approaches to evaluate noise properties and artifact content at all spatial and temporal frequencies are also proposed. One fully sampled phantom and three fully sampled cardiac cine datasets were subsampled (R = 4 and 8) and reconstructed with the different methods tested here. A hybrid method, which combines the main advantageous features observed in our assessments, was proposed and tested in a cardiac cine application, with acceleration factors of 3.5 and 6.3 (skip factors of 4 and 8, respectively). This approach combines features from methods such as k-t sensitivity encoding, unaliasing by Fourier encoding the overlaps in the temporal dimension-sensitivity encoding, generalized autocalibrating partially parallel acquisition, sensitivity profiles from an array of coils for encoding and reconstruction in parallel, self, hybrid referencing with unaliasing by Fourier encoding the overlaps in the temporal dimension and generalized autocalibrating partially parallel acquisition, and generalized autocalibrating partially parallel acquisition-enhanced sensitivity maps for sensitivity encoding reconstructions.

Accuracy of five serologic tests for the follow up of Strongyloides stercoralis infection.

PubMed

Buonfrate, Dora; Sequi, Marco; Mejia, Rojelio; Cimino, Ruben O; Krolewiecki, Alejandro J; Albonico, Marco; Degani, Monica; Tais, Stefano; Angheben, Andrea; Requena-Mendez, Ana; Muñoz, José; Nutman, Thomas B; Bisoffi, Zeno

2015-02-01

Traditional faecal-based methods have poor sensitivity for the detection of S. stercoralis, therefore are inadequate for post-treatment evaluation of infected patients who should be carefully monitored to exclude the persistence of the infection. In a previous study, we demonstrated high accuracy of five serology tests for the screening and diagnosis of strongyloidiasis. Aim of this study is to evaluate the performance of the same five tests for the follow up of patients infected with S. stercoralis. Retrospective study on anonymized, cryo-preserved samples available at the Centre for Tropical Diseases (Negrar, Verona, Italy). Samples were collected before and from 3 to 12 months after treatment. The samples were tested with two commercially-available ELISA tests (IVD, Bordier), two techniques based on a recombinant antigen (NIE-ELISA and NIE-LIPS) and one in-house IFAT. The results of each test were evaluated both in relation to the results of fecal examination and to those of a composite reference standard (classifying as positive a sample with positive stools and/or at least three positive serology tests). The associations between the independent variables age and time and the dependent variable value of serological test (for all five tests), were analyzed by linear mixed-effects regression model. A high proportion of samples demonstrated for each test a seroreversion or a relevant decline (optical density/relative light units halved or decrease of at least two titers for IFAT) at follow up, results confirmed by the linear mixed effects model that showed a trend to seroreversion over time for all tests. In particular, IVD-ELISA (almost 90% samples demonstrated relevant decline) and IFAT (almost 87%) had the best performance. Considering only samples with a complete negativization, NIE-ELISA showed the best performance (72.5% seroreversion). Serology is useful for the follow up of patients infected with S. stercoralis and determining test of cure.

Comparison between Urine and Cervical Samples for HPV DNA Detection and Typing in Young Women in Colombia.

PubMed

Cómbita, Alba Lucía; Gheit, Tarik; González, Paula; Puerto, Devi; Murillo, Raúl Hernando; Montoya, Luisa; Vorsters, Alex; Van Keer, Severien; Van Damme, Pierre; Tommasino, Massimo; Hernández-Suárez, Gustavo; Sánchez, Laura; Herrero, Rolando; Wiesner, Carolina

2016-09-01

Urine sampling for HPV DNA detection has been proposed as an effective method for monitoring the impact of HPV vaccination programs; however, conflicting results have been reported. The goal of this study was to evaluate the performance of optimized urine HPV DNA testing in women aged 19 to 25 years. Optimization process included the use of first void urine, immediate mixing of urine with DNA preservative, and the concentration of all HPV DNA, including cell-free DNA fragments. Urine and cervical samples were collected from 535 young women attending cervical screening at health centers from two Colombian cities. HPV DNA detection and genotyping was performed using an HPV type-specific multiplex genotyping assay, which combines multiplex polymerase chain reaction with bead-based Luminex technology. Concordance between HPV DNA detection in urine and cervical samples was determined using kappa statistics and McNemar tests. The accuracy of HPV DNA testing in urine samples was evaluated measuring sensitivity and specificity using as reference the results obtained from cervical samples. Statistical analysis was performed using STATA11.2 software. The findings revealed an overall HPV prevalence of 60.00% in cervical samples and 64.72% in urine samples, HPV-16 being the most frequent HPV type detected in both specimens. Moreover, our results indicate that detection of HPV DNA in first void urine provides similar results to those obtained with cervical samples and can be used to monitor HPV vaccination trials and programs as evidenced by the substantial concordance found for the detection of the four vaccine types. Cancer Prev Res; 9(9); 766-71. ©2016 AACR. ©2016 American Association for Cancer Research.

Investigations related to evaluation of ultramicrofluorometer

NASA Technical Reports Server (NTRS)

Whitcomb, B.

1981-01-01

High resolution emission and excitation fluorescent spectra were obtained for several samples in an effort to determine the optimum operational design for the instrument. The instrument was used to determine the required nature of a sample which could be detected, and in so doing, several different sample preparation techniques were considered. Numerous experiments were performed to determine the capabilities of the instrument with regard to the detection of suitably prepared virus specimens. Significant results were obtained in several areas. The fluorescent spectra indicated that substantial changes in the laser might be used advantageously to greatly improve the performance of the instrument. In the existing configuration, the instrument was shown to be capable of detecting the presence of suitably prepared virus samples.

Evaluating sampling designs by computer simulation: A case study with the Missouri bladderpod

USGS Publications Warehouse

Morrison, L.W.; Smith, D.R.; Young, C.; Nichols, D.W.

2008-01-01

To effectively manage rare populations, accurate monitoring data are critical. Yet many monitoring programs are initiated without careful consideration of whether chosen sampling designs will provide accurate estimates of population parameters. Obtaining accurate estimates is especially difficult when natural variability is high, or limited budgets determine that only a small fraction of the population can be sampled. The Missouri bladderpod, Lesquerella filiformis Rollins, is a federally threatened winter annual that has an aggregated distribution pattern and exhibits dramatic interannual population fluctuations. Using the simulation program SAMPLE, we evaluated five candidate sampling designs appropriate for rare populations, based on 4 years of field data: (1) simple random sampling, (2) adaptive simple random sampling, (3) grid-based systematic sampling, (4) adaptive grid-based systematic sampling, and (5) GIS-based adaptive sampling. We compared the designs based on the precision of density estimates for fixed sample size, cost, and distance traveled. Sampling fraction and cost were the most important factors determining precision of density estimates, and relative design performance changed across the range of sampling fractions. Adaptive designs did not provide uniformly more precise estimates than conventional designs, in part because the spatial distribution of L. filiformis was relatively widespread within the study site. Adaptive designs tended to perform better as sampling fraction increased and when sampling costs, particularly distance traveled, were taken into account. The rate that units occupied by L. filiformis were encountered was higher for adaptive than for conventional designs. Overall, grid-based systematic designs were more efficient and practically implemented than the others. ?? 2008 The Society of Population Ecology and Springer.

Hydrogeochemical and stream sediment reconnaissance basic data for Philip Smith Mountains Quadrangle, Alaska

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

Not Available

1981-05-29

Field and laboratory data are presented for 1128 water samples from the Philip Smith Mountains Quadrangle, Alaska. The samples were collected by Los Alamos Scientific Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

Prediction of Asbestos Exposure Resulting From Asbestos Aerosolization Determined Using the Releasable Asbestos Field Sampler (RAFS)

EPA Science Inventory

Activity-based sampling (ABS) used to evaluate breathing zone exposure to a contaminant present in soil resulting from various activities, involves breathing zone sampling for contaminants while that activity is performed. A probabilistic model based upon aerosol physics and flui...

Evaluation of Line Immunoassay to Detect HTLV-1 Infection in an Endemic Area, Southwestern Japan; Comparison with Polymerase Chain Reaction and Western Blot.

PubMed

Umeki, Kazumi; Umekita, Kunihiko; Hashikura, Yuuki; Yamamoto, Ikuo; Kubo, Kazuyoshi; Nagatomo, Yasuhiro; Okayama, Akihiko

2017-02-01

Human T-lymphotropic virus type 1 (HTLV-1) has been recognized as a cause of adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy/tropical spastic paraparesis, and HTLV-1-associated uveitis. HTLV-1 infection is normally detected by screening for HTLV-1 antibodies, and positive samples are confirmed by Western blot (WB). However, WB fails to confirm some samples that were positive for HTLV-1 antibodies on screening. Line immunoassay (LIA) is commonly used in Europe and Brazil, but not in Japan. Therefore, we evaluated the performance of LIA as a method of confirming HTLV-1 antibodies using samples in Japan. LIA was compared with polymerase chain reaction (PCR) and WB using 50 negative and 70 positive samples tested by chemiluminescent enzyme immunoassay (CLEIA) in Miyazaki, Japan, an HTLV-1 endemic area. LIA (INNO-LIA HTLVI/II Score) and WB (Problot HTLV-I) were performed according to the manufacturer's instructions. Real-time PCR for HTLV-1 pX region was performed using DNA derived from white blood cells. The samples that tested negative by real-time PCR were further tested by nested PCR. All 50 CLEIA negative samples were determined to be negative by LIA and PCR. Of the 70 positive samples, 66 tested positive by both of LIA and PCR. Three samples tested negative by LIA and PCR, and the remaining sample (PCR negative) showed non-specific staining in LIA and WB. WB showed more indeterminate results than LIA. Gp21 antibody in LIA demonstrated a high ability to discriminate between positive and negative PCR results. Furthermore, the degree of gp21 antibody reaction by LIA showed correlation with HTLV-1 proviral loads (PVLs). Our results indicate that LIA performs well in confirming HTLV-1 seropositivity by showing a low incidence of indeterminate results and good agreement with PCR using samples in Japan, although the number of samples tested was small. In addition, semi-quantitative antibody titer to gp21 correlated well with HTLV-1 PVLs. Further study including larger samples is necessary to determine the positioning of LIA for HTLV-1 detection in Japan.

Evaluation of a New Mean Scaled and Moment Adjusted Test Statistic for SEM

ERIC Educational Resources Information Center

Tong, Xiaoxiao; Bentler, Peter M.

2013-01-01

Recently a new mean scaled and skewness adjusted test statistic was developed for evaluating structural equation models in small samples and with potentially nonnormal data, but this statistic has received only limited evaluation. The performance of this statistic is compared to normal theory maximum likelihood and 2 well-known robust test…

Intelligent evaluation of color sensory quality of black tea by visible-near infrared spectroscopy technology: A comparison of spectra and color data information

NASA Astrophysics Data System (ADS)

Ouyang, Qin; Liu, Yan; Chen, Quansheng; Zhang, Zhengzhu; Zhao, Jiewen; Guo, Zhiming; Gu, Hang

2017-06-01

Instrumental test of black tea samples instead of human panel test is attracting massive attention recently. This study focused on an investigation of the feasibility for estimation of the color sensory quality of black tea samples using the VIS-NIR spectroscopy technique, comparing the performances of models based on the spectra and color information. In model calibration, the variables were first selected by genetic algorithm (GA); then the nonlinear back propagation-artificial neural network (BPANN) models were established based on the optimal variables. In comparison with the other models, GA-BPANN models from spectra data information showed the best performance, with the correlation coefficient of 0.8935, and the root mean square error of 0.392 in the prediction set. In addition, models based on the spectra information provided better performance than that based on the color parameters. Therefore, the VIS-NIR spectroscopy technique is a promising tool for rapid and accurate evaluation of the sensory quality of black tea samples.

Intelligent evaluation of color sensory quality of black tea by visible-near infrared spectroscopy technology: A comparison of spectra and color data information.

PubMed

Ouyang, Qin; Liu, Yan; Chen, Quansheng; Zhang, Zhengzhu; Zhao, Jiewen; Guo, Zhiming; Gu, Hang

2017-06-05

Instrumental test of black tea samples instead of human panel test is attracting massive attention recently. This study focused on an investigation of the feasibility for estimation of the color sensory quality of black tea samples using the VIS-NIR spectroscopy technique, comparing the performances of models based on the spectra and color information. In model calibration, the variables were first selected by genetic algorithm (GA); then the nonlinear back propagation-artificial neural network (BPANN) models were established based on the optimal variables. In comparison with the other models, GA-BPANN models from spectra data information showed the best performance, with the correlation coefficient of 0.8935, and the root mean square error of 0.392 in the prediction set. In addition, models based on the spectra information provided better performance than that based on the color parameters. Therefore, the VIS-NIR spectroscopy technique is a promising tool for rapid and accurate evaluation of the sensory quality of black tea samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of six nucleic acid amplification tests used for diagnosis of Neisseria gonorrhoeae in Russia compared with an international strictly validated real-time porA pseudogene polymerase chain reaction.

PubMed

Shipitsyna, E; Zolotoverkhaya, E; Hjelmevoll, S O; Maximova, A; Savicheva, A; Sokolovsky, E; Skogen, V; Domeika, M; Unemo, M

2009-11-01

In Russia, laboratory diagnosis of gonorrhoea has been mainly based on microscopy only and, in some settings, relatively rare suboptimal culturing. In recent years, Russian developed and manufactured nucleic acid amplification tests (NAAT) have been implemented for routine diagnosis of Neisseria gonorrhoeae. However, these NAATs have never been validated to any international well-recognized diagnostic NAAT. This study aims to evaluate the performance characteristics of six Russian NAATs for N. gonorrhoeae diagnostics. In total, 496 symptomatic patients were included. Five polymerase chain reaction (PCR) assays and one real-time nucleic acid sequence based amplification (NASBA) assay, developed by three Russian companies, were evaluated on urogenital samples, i.e. cervical and first voided urine (FVU) samples from females (n = 319), urethral and FVU samples from males (n = 127), and extragenital samples, i.e. rectal and pharyngeal samples, from 50 additional female patients with suspicion of gonorrhoea. As reference method, an international strictly validated real-time porA pseudogene PCR was applied. The prevalence of N. gonorrhoeae was 2.7% and 16% among the patients providing urogenital and extragenital samples, respectively. The Russian NAATs and the reference method displayed high level of concordance (99.4-100%). The sensitivities, specificities, positive predictive values and negative predictive values of the Russian tests in different specimens were 66.7-100%, 100%, 100%, and 99.4-100%, respectively. Russian N. gonorrhoeae diagnostic NAATs comprise relatively good performance characteristics. However, larger studies are crucial and, beneficially, the Russian assays should also be evaluated to other international highly sensitive and specific, and ideally Food and Drug Administration approved, NAATs such as Aptima Combo 2 (Gen-Probe).

A Psychometric Evaluation of the STAI-Y, BDI-II, and PAI Using Single and Multifactorial Models in Young Adults Seeking Psychoeducational Evaluation

ERIC Educational Resources Information Center

Hill, Benjamin D.; Musso, Mandi; Jones, Glenn N.; Pella, Russell D.; Gouvier, Wm. Drew

2013-01-01

A psychometric evaluation on the measurement of self-report anxiety and depression using the Beck Depression Inventory (BDI-II), State Trait Anxiety Inventory, Form-Y (STAI-Y), and the Personality Assessment Inventory (PAI) was performed using a sample of 534 generally young adults seeking psychoeducational evaluation at a university-based clinic.…

Base rate of performance invalidity among non-clinical undergraduate research participants.

PubMed

Silk-Eglit, Graham M; Stenclik, Jessica H; Gavett, Brandon E; Adams, Jason W; Lynch, Julie K; Mccaffrey, Robert J

2014-08-01

Neuropsychological research frequently uses non-clinical undergraduate participants to evaluate neuropsychological tests. However, a recent study by An and colleagues (2012, Archives of Clinical Neuropsychology, 27, 849-857) called into question that the extent to which the interpretation of these participants' performance on neuropsychological tests is valid. This study found that in a sample of 36 participants, 55.6% exhibited performance invalidity at an initial session and 30.8% exhibited performance invalidity at a follow-up session. The current study attempted to replicate these findings in a larger, more representative sample using a more rigorous methodology. Archival data from 133 non-clinical undergraduate research participants were analyzed. Participants were classified as performance invalid if they failed any one PVT. In the current sample, only 2.26% of participants exhibited performance invalidity. Thus, concerns regarding insufficient effort and performance invalidity when using undergraduate research participants appear to be overstated. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Performance evaluation of the latest fully automated hematology analyzers in a large, commercial laboratory setting: a 4-way, side-by-side study.

PubMed

Bourner, G; Dhaliwal, J; Sumner, J

2005-01-01

Gamma-Dynacare is a Canadian-based community laboratory partnership formed in the mid-1990s through the merger of 3 prominent Ontario medical diagnostic laboratories. Laboratory Corporation of America acquired an interest in the GD partnership in mid 2002. We service more than 10,000 community-based Canadian clinicians, hospital partners, and private clients with an integrated customer-focused system that includes specimen collection, transportation, and results reporting services. With more than 1,700 highly qualified medical, technical, and support staff and a network of laboratories, Gamma Dynacare aims to be at the forefront of technological innovation to better service the clinician base and ultimately deliver better patient care. We were looking for a hematology analyzer that would allow. (1) standardization throughout Ontario in our 4 largest sites and (2) better performance to effectively handle aged samples and minimize slide review. To select the best, most productive hematology analyzer for our environment, it was decided to perform a side-by-side comparison of the top hematology analyzers from Abbott (Cell-Dyn 3500), Beckman Coulter (LH 750), Bayer (Advia 120), and Sysmex (XE 2100), utilizing the same samples. CBC, differential and reticulocyte parameters were all evaluated according to CLSI (formerly NCCLS) and established hematology analyzer evaluation guidelines. We assessed each analyzer for precision, linearity, carryover, stability, differential capabilities, slide review rates, and throughput (clean bench studies). Two hundred samples were assessed for differential and morphology flagging on each analyzer using the reference 400 cell manual differential for comparison. Throughput was assessed by analyzing 700 consecutive samples representative of our workload mix. Stability studies at 24 hours showed that the Beckman Coulter LH 750 was least affected by EDTA, effect with minimal changes in the mean corpuscular volume (MCV) and hematocrit. Both the Bayer Advia 120 and Sysmex XE 2100 showed an elevation of the MCV (up to 5 fL) and Hematocrit over the 24 hours. Analysis of the 200 randomly selected patient samples showed that, while the false-negative rates on each of the instruments were comparable, there were significant differences in the false-positive rates. This has important implications for slide review rates. For our specimen mix, the Sysmex XE 2100 had the highest false-positive rate (15%), followed by the Cell-Dyn 3500 (8%), Advia 120 (6.5%) and the Beckman Coulter LH 750 (1.5%). Reticulocyte analysis performance was observed to be satisfactory with the Beckman Coulter LH 750, Cell-Dyn 3500, and XE 2100, while the Bayer Advia 120 showed a decrease in retic values after 12 hours. In conclusion, many laboratories will not be able to perform a 4-way evaluation such as described here due to time, space, and resource constraints. For our laboratories, result quality, sample stability performance, slide review rates, and efficiency were the primary criteria in selection of the most suitable hematology analyzer. Our 4-way evaluation resulted in selection of the Beckman Coulter LH 750 for Gamma-Dynacare Laboratories because it enabled the lowest slide review rate and handled aged samples better than the other analyzers.

Research and development of a field-ready protocol for sampling of phosgene from stationary source emissions: Diethylamine reagent studies. Research report, 11 July 1995--30 September 1996

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

Steger, J.L.; Bursey, J.T.; Merrill, R.G.

1999-03-01

This report presents the results of laboratory studies to develop and evaluate a method for the sampling and analysis of phosgene from stationary sources of air emissions using diethylamine (DEA) in toluene as the collection media. The method extracts stack gas from emission sources and stabilizes the reactive gas for subsequent analysis. DEA was evaluated both in a benchtop study and in a laboratory train spiking study. This report includes results for both the benchtop study and the train spiking study. Benchtop studies to evaluate the suitability of DEA for collecting and analyzing phosgene investigated five variables: storage time, DEAmore » concentration, moisture/pH, phosgene concentration, and sample storage temperature. Prototype sampling train studies were performed to determine if the benchtop chemical studies were transferable to a Modified Method 5 sampling train collecting phosgene in the presence of clean air mixed with typical stack gas components. Four conditions, which varied the moisture and phosgene spike were evaluated in triplicate. In addition to research results, the report includes a detailed draft method for sampling and analysis of phosgene from stationary source emissions.« less

Characterization and phenol adsorption performance of activated carbon prepared from tea residue by NaOH activation.

PubMed

Tao, Jun; Huo, Peili; Fu, Zongheng; Zhang, Jin; Yang, Zhen; Zhang, Dengfeng

2017-10-05

The preparation of activated carbon (AC) using tea residue was addressed in this work. The preparation process incorporated two-step pyrolysis and activation using NaOH. The influence of activation temperature between 500°C and 700°C on the properties of the AC sample was investigated. The physicochemical properties of the AC sample were characterized. The results show that the optimum temperature for the activation process is 700°C, which generates the AC sample with higher specific surface area and total pore volume, respectively, of 819 m 2  g -1 and 0.443 cm 3  g -1 . The oxygen-containing functional groups evolve on the AC sample during the activation process. The phenol adsorption test was performed to evaluate the adsorption performance of the AC sample. The adsorption data confirm that phenol adsorption on the AC sample obtained at 700°C follows the pseudo-second-order kinetics model. Hereby, the electron donor-acceptor interaction mechanism can describe the adsorption process. The AC sample obtained at 700°C performs superior phenol adsorption performance. The maximum phenol adsorption capacity is 320 mg g -1 , which is higher than that of several AC samples reported previously. Thus, the tea residue acts as a good precursor for the AC with promising adsorption capacity by the NaOH chemical activation method.

Analysis of spreadable cheese by Raman spectroscopy and chemometric tools.

PubMed

Oliveira, Kamila de Sá; Callegaro, Layce de Souza; Stephani, Rodrigo; Almeida, Mariana Ramos; de Oliveira, Luiz Fernando Cappa

2016-03-01

In this work, FT-Raman spectroscopy was explored to evaluate spreadable cheese samples. A partial least squares discriminant analysis was employed to identify the spreadable cheese samples containing starch. To build the models, two types of samples were used: commercial samples and samples manufactured in local industries. The method of supervised classification PLS-DA was employed to classify the samples as adulterated or without starch. Multivariate regression was performed using the partial least squares method to quantify the starch in the spreadable cheese. The limit of detection obtained for the model was 0.34% (w/w) and the limit of quantification was 1.14% (w/w). The reliability of the models was evaluated by determining the confidence interval, which was calculated using the bootstrap re-sampling technique. The results show that the classification models can be used to complement classical analysis and as screening methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of the synoptic and mesoscale predictive capabilities of a mesoscale atmospheric simulation system

NASA Technical Reports Server (NTRS)

Koch, S. E.; Skillman, W. C.; Kocin, P. J.; Wetzel, P. J.; Brill, K.; Keyser, D. A.; Mccumber, M. C.

1983-01-01

The overall performance characteristics of a limited area, hydrostatic, fine (52 km) mesh, primitive equation, numerical weather prediction model are determined in anticipation of satellite data assimilations with the model. The synoptic and mesoscale predictive capabilities of version 2.0 of this model, the Mesoscale Atmospheric Simulation System (MASS 2.0), were evaluated. The two part study is based on a sample of approximately thirty 12h and 24h forecasts of atmospheric flow patterns during spring and early summer. The synoptic scale evaluation results benchmark the performance of MASS 2.0 against that of an operational, synoptic scale weather prediction model, the Limited area Fine Mesh (LFM). The large sample allows for the calculation of statistically significant measures of forecast accuracy and the determination of systematic model errors. The synoptic scale benchmark is required before unsmoothed mesoscale forecast fields can be seriously considered.

Real-time and accelerated outdoor endurance testing of solar cells

NASA Technical Reports Server (NTRS)

Forestieri, A. F.; Anagnostou, E.

1977-01-01

Real-time and accelerated outdoor endurance testing was performed on a variety of samples of interest to the National Photovoltaic Conversion Program. The real-time tests were performed at seven different sites and the accelerated tests were performed at one of those sites in the southwestern United States. The purpose of the tests were to help evaluate the lifetime of photovoltaic systems. Three types of samples were tested; transmission samples of possible cover materials, sub-modules constructed using these materials attached to solar cells, and solar cell modules produced by the manufacturers for the ERDA program. Results indicate that suitable cover materials are glass, FEP-A and PFA. Dirt accumulation and cleanability are important factors in the selection of solar cell module covers and encapsulants.

Evaluation of the Aptima HBV Quant assay vs. the COBAS TaqMan HBV test using the high pure system for the quantitation of HBV DNA in plasma and serum samples.

PubMed

Schalasta, Gunnar; Börner, Anna; Speicher, Andrea; Enders, Martin

2018-03-28

Proper management of patients with chronic hepatitis B virus (HBV) infection requires monitoring of plasma or serum HBV DNA levels using a highly sensitive nucleic acid amplification test. Because commercially available assays differ in performance, we compared herein the performance of the Hologic Aptima HBV Quant assay (Aptima) to that of the Roche Cobas TaqMan HBV test for use with the high pure system (HPS/CTM). Assay performance was assessed using HBV reference panels as well as plasma and serum samples from chronically HBV-infected patients. Method correlation, analytical sensitivity, precision/reproducibility, linearity, bias and influence of genotype were evaluated. Data analysis was performed using linear regression, Deming correlation analysis and Bland-Altman analysis. Agreement between the assays for the two reference panels was good, with a difference in assay values vs. target <0.5 log. Qualitative assay results for 159 clinical samples showed good concordance (88.1%; κ=0.75; 95% confidence interval: 0.651-0.845). For the 106 samples quantitated by both assays, viral load results were highly correlated (R=0.92) and differed on average by 0.09 log, with 95.3% of the samples being within the 95% limit of agreement of the assays. Linearity for viral loads 1-7 log was excellent for both assays (R2>0.98). The two assays had similar bias and precision across the different genotypes tested at low viral loads (25-1000 IU/mL). Aptima has a performance comparable with that of HPS/CTM, making it suitable for use for HBV infection monitoring. Aptima runs on a fully automated platform (the Panther system) and therefore offers a significantly improved workflow compared with HPS/CTM.

Performance evaluation of the Abbott CELL-DYN Ruby and the Sysmex XT-2000i haematology analysers.

PubMed

Leers, M P G; Goertz, H; Feller, A; Hoffmann, J J M L

2011-02-01

Two mid-range haematology analysers (Abbott CELL-DYN Ruby and Sysmex XT-2000i) were evaluated to determine their analytical performance and workflow efficiency in the haematology laboratory. In total 418 samples were processed for determining equivalence of complete blood count (CBC) measurements, and 100 for reticulocyte comparison. Blood smears served for assessing the agreement of the differential counts. Inter-instrument agreement for most parameters was good although small numbers of discrepancies were observed. Systematic biases were found for mean cell volume, reticulocytes, platelets and mean platelet volume. CELL-DYN Ruby WBC differentials were obtained with all samples while the XT-2000i suppressed differentials partially or completely in 13 samples (3.1%). WBC subpopulation counts were otherwise in good agreement with no major outliers. Following first-pass CBC/differential analysis, 88 (21%) of XT-2000i samples required further analyser processing compared to 18 (4.3%) for the CELL-DYN Ruby. Smear referrals for suspected WBC/nucleated red blood cells and platelet abnormalities were indicated for 106 (25.4%) and 95 (22.7%) of the XT-2000i and CELL-DYN Ruby samples respectively. Flagging efficiencies for both analysers were found to be similar. The Sysmex XT-2000i and Abbott CELL-DYN Ruby analysers have broadly comparable analytical performance, but the CELL-DYN Ruby showed superior first-pass efficiency. © 2010 Blackwell Publishing Ltd.

Hydrogeochemical and stream sediment reconnaissance basic data for Aztec Quadrangle, New Mexico

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

Not Available

1981-07-31

Field and laboratory data are presented for 331 water samples and 1693 sediment samples from the Aztec Quadrangle, New Mexico. Uranium values have been reported by Los Alamos National Laboratory in Report GJBX-129(78). The samples were collected by Los Alamos National Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

Oxygen Toxicity and Lung Collagenous Protein.

DTIC Science & Technology

1981-02-28

Analysis Samples for amino acid analysis qera hydrolyzed at 110C f)r 22 h constant boiling HCI under nitrogen. Samples were driea at room tereratre over...was performed by a gas chromatographic procedure modified from the method of Grimes and Greegor [8]. Samples were hydrolyzed in 2 N trifluoroacetic...evaluated by their ability to incorporate radiolabeled choline and acetate into the saturated lecithin components of chloroform-methanol extractable

Pneumatic Microvalve-Based Hydrodynamic Sample Injection for High-Throughput, Quantitative Zone Electrophoresis in Capillaries

PubMed Central

2015-01-01

A hybrid microchip/capillary electrophoresis (CE) system was developed to allow unbiased and lossless sample loading and high-throughput repeated injections. This new hybrid CE system consists of a poly(dimethylsiloxane) (PDMS) microchip sample injector featuring a pneumatic microvalve that separates a sample introduction channel from a short sample loading channel, and a fused-silica capillary separation column that connects seamlessly to the sample loading channel. The sample introduction channel is pressurized such that when the pneumatic microvalve opens briefly, a variable-volume sample plug is introduced into the loading channel. A high voltage for CE separation is continuously applied across the loading channel and the fused-silica capillary separation column. Analytes are rapidly separated in the fused-silica capillary, and following separation, high-sensitivity MS detection is accomplished via a sheathless CE/ESI-MS interface. The performance evaluation of the complete CE/ESI-MS platform demonstrated that reproducible sample injection with well controlled sample plug volumes could be achieved by using the PDMS microchip injector. The absence of band broadening from microchip to capillary indicated a minimum dead volume at the junction. The capabilities of the new CE/ESI-MS platform in performing high-throughput and quantitative sample analyses were demonstrated by the repeated sample injection without interrupting an ongoing separation and a linear dependence of the total analyte ion abundance on the sample plug volume using a mixture of peptide standards. The separation efficiency of the new platform was also evaluated systematically at different sample injection times, flow rates, and CE separation voltages. PMID:24865952

Pneumatic Microvalve-Based Hydrodynamic Sample Injection for High-Throughput, Quantitative Zone Electrophoresis in Capillaries

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

Kelly, Ryan T.; Wang, Chenchen; Rausch, Sarah J.

2014-07-01

A hybrid microchip/capillary CE system was developed to allow unbiased and lossless sample loading and high throughput repeated injections. This new hybrid CE system consists of a polydimethylsiloxane (PDMS) microchip sample injector featuring a pneumatic microvalve that separates a sample introduction channel from a short sample loading channel and a fused silica capillary separation column that connects seamlessly to the sample loading channel. The sample introduction channel is pressurized such that when the pneumatic microvalve opens briefly, a variable-volume sample plug is introduced into the loading channel. A high voltage for CE separation is continuously applied across the loading channelmore » and the fused silica capillary separation column. Analytes are rapidly separated in the fused silica capillary with high resolution. High sensitivity MS detection after CE separation is accomplished via a sheathless CE/ESI-MS interface. The performance evaluation of the complete CE/ESI-MS platform demonstrated that reproducible sample injection with well controlled sample plug volumes could be achieved by using the PDMS microchip injector. The absence of band broadening from microchip to capillary indicated a minimum dead volume at the junction. The capabilities of the new CE/ESI-MS platform in performing high throughput and quantitative sample analyses were demonstrated by the repeated sample injection without interrupting an ongoing separation and a good linear dependence of the total analyte ion abundance on the sample plug volume using a mixture of peptide standards. The separation efficiency of the new platform was also evaluated systematically at different sample injection times, flow rates and CE separation voltages.« less

QC-ART: A tool for real-time quality control assessment of mass spectrometry-based proteomics data.

PubMed

Stanfill, Bryan A; Nakayasu, Ernesto S; Bramer, Lisa M; Thompson, Allison M; Ansong, Charles K; Clauss, Therese; Gritsenko, Marina A; Monroe, Matthew E; Moore, Ronald J; Orton, Daniel J; Piehowski, Paul D; Schepmoes, Athena A; Smith, Richard D; Webb-Robertson, Bobbie-Jo; Metz, Thomas O

2018-04-17

Liquid chromatography-mass spectrometry (LC-MS)-based proteomics studies of large sample cohorts can easily require from months to years to complete. Acquiring consistent, high-quality data in such large-scale studies is challenging because of normal variations in instrumentation performance over time, as well as artifacts introduced by the samples themselves, such as those due to collection, storage and processing. Existing quality control methods for proteomics data primarily focus on post-hoc analysis to remove low-quality data that would degrade downstream statistics; they are not designed to evaluate the data in near real-time, which would allow for interventions as soon as deviations in data quality are detected.  In addition to flagging analyses that demonstrate outlier behavior, evaluating how the data structure changes over time can aide in understanding typical instrument performance or identify issues such as a degradation in data quality due to the need for instrument cleaning and/or re-calibration.  To address this gap for proteomics, we developed Quality Control Analysis in Real-Time (QC-ART), a tool for evaluating data as they are acquired in order to dynamically flag potential issues with instrument performance or sample quality.  QC-ART has similar accuracy as standard post-hoc analysis methods with the additional benefit of real-time analysis.  We demonstrate the utility and performance of QC-ART in identifying deviations in data quality due to both instrument and sample issues in near real-time for LC-MS-based plasma proteomics analyses of a sample subset of The Environmental Determinants of Diabetes in the Young cohort. We also present a case where QC-ART facilitated the identification of oxidative modifications, which are often underappreciated in proteomic experiments. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

40 CFR 63.5990 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing...) Performance and equipment specifications for the sample interface, the pollutant concentration or parametric signal analyzer, and the data collection and reduction system; and (3) Performance evaluation procedures...

Evaluating Cost when Selecting Performance Reference Compounds for the Environmental Deployment of Polyethylene Passive Samplers

EPA Science Inventory

A challenge in environmental passive sampling is determining when equilibrium is achieved between the sampler, target contaminants, and environmental phases. A common approach is the use of performance reference compounds (PRCs) to indicate degree of equilibrium. One logistical...

Soil sampling strategies: evaluation of different approaches.

PubMed

de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Mufato, Renzo; Sartori, Giuseppe; Stocchero, Giulia

2008-11-01

The National Environmental Protection Agency of Italy (APAT) performed a soil sampling intercomparison, inviting 14 regional agencies to test their own soil sampling strategies. The intercomparison was carried out at a reference site, previously characterised for metal mass fraction distribution. A wide range of sampling strategies, in terms of sampling patterns, type and number of samples collected, were used to assess the mean mass fraction values of some selected elements. The different strategies led in general to acceptable bias values (D) less than 2sigma, calculated according to ISO 13258. Sampling on arable land was relatively easy, with comparable results between different sampling strategies.

Static-99R reporting practices in sexually violent predator cases: Does norm selection reflect adversarial allegiance?

PubMed

Chevalier, Caroline S; Boccaccini, Marcus T; Murrie, Daniel C; Varela, Jorge G

2015-06-01

We surveyed experts (N = 109) who conduct sexually violent predator (SVP) evaluations to obtain information about their Static-99R score reporting and interpretation practices. Although most evaluators reported providing at least 1 normative sample recidivism rate estimate, there were few other areas of consensus. Instead, reporting practices differed depending on the side for which evaluators typically performed evaluations. Defense evaluators were more likely to endorse reporting practices that convey the lowest possible level of risk (e.g., routine sample recidivism rates, 5-year recidivism rates) and the highest level of uncertainty (e.g., confidence intervals, classification accuracy), whereas prosecution evaluators were more likely to endorse practices suggesting the highest possible level of risk (e.g., high risk/need sample recidivism rates, 10-year recidivism rates). Reporting practices from state-agency evaluators tended to be more consistent with those of prosecution evaluators than defense evaluators, although state-agency evaluators were more likely than other evaluators to report that it was at least somewhat difficult to choose an appropriate normative comparison group. Overall, findings provide evidence for adversarial allegiance in Static-99R score reporting and interpretation practices. (c) 2015 APA, all rights reserved).

Comparison of the AdvanSure human papillomavirus screening real-time PCR, the Abbott RealTime High Risk human papillomavirus test, and the Hybrid Capture human papillomavirus DNA test for the detection of human papillomavirus.

PubMed

Hwang, Yusun; Lee, Miae

2012-05-01

We evaluated the performance of various commercial assays for the molecular detection of human papillomavirus (HPV); the recently developed AdvanSure HPV Screening real-time PCR assay (AdvanSure PCR) and the Abbott RealTime High Risk HPV PCR assay (Abbott PCR) were compared with the Hybrid Capture 2 HPV DNA Test (HC2). All 3 tests were performed on 177 samples, and any sample that showed a discrepancy in any of the 3 tests was genotyped using INNO-LiPA HPV genotyping and/or sequencing. On the basis of these results, we obtained a consensus HPV result, and the performance of each test was evaluated. We also evaluated high-risk HPV 16/18 detection by using the 2 real-time PCR assays. Among the 177 samples, 65 were negative and 75 were positive in all 3 assays; however, the results of the 3 assays with 37 samples were discrepant. Compared with the consensus HPV result, the sensitivities and specificities of HC2, AdvanSure PCR, and Abbott PCR were 97.6%, 91.7%, and 86.9% and 83.9%, 98.8%, and 100.0%, respectively. For HPV type 16/18 detection, the concordance rate between the AdvanSure PCR and Abbott PCR assays was 98.3%; however, 3 samples were discrepant (positive in AdvanSure PCR and negative in Abbott PCR) and were confirmed as HPV type 16 by INNO-LiPA genotyping and/or sequencing. For HPV detection, the AdvanSure HPV Screening real-time PCR assay and the Abbott PCR assay are less sensitive but more specific than the HC2 assay, but can simultaneously differentiate type 16/18 HPV from other types.

Analytical evaluation of the automated galectin-3 assay on the Abbott ARCHITECT immunoassay instruments.

PubMed

Gaze, David C; Prante, Christian; Dreier, Jens; Knabbe, Cornelius; Collet, Corinne; Launay, Jean-Marie; Franekova, Janka; Jabor, Antonin; Lennartz, Lieselotte; Shih, Jessie; del Rey, Jose Manuel; Zaninotto, Martina; Plebani, Mario; Collinson, Paul O

2014-06-01

Galectin-3 is secreted from macrophages and binds and activates fibroblasts forming collagen. Tissue fibrosis is central to the progression of chronic heart failure (CHF). We performed a European multicentered evaluation of the analytical performance of the two-step routine and Short Turn-Around-Time (STAT) galectin-3 immunoassay on the ARCHITECT i1000SR, i2000SR, and i4000SR (Abbott Laboratories). We evaluated the assay precision and dilution linearity for both routine and STAT assays and compared serum and plasma, and fresh vs. frozen samples. The reference interval and biological variability were also assessed. Measurable samples were compared between ARCHITECT instruments and between the routine and STAT assays and also to a galectin-3 ELISA (BG Medicine). The total assay coefficient of variation (CV%) was 2.3%-6.2% and 1.7%-7.4% for the routine and STAT assays, respectively. Both assays demonstrated linearity up to 120 ng/mL. Galectin-3 concentrations were higher in plasma samples than in serum samples and correlated well between fresh and frozen samples (R=0.997), between the routine and STAT assays, between the ARCHITECT i1000 and i2000 instruments and with the galectin-3 ELISA. The reference interval on 627 apparently healthy individuals (53% male) yielded upper 95th and 97.5th percentiles of 25.2 and 28.4 ng/mL, respectively. Values were significantly lower in subjects younger than 50 years. The galectin-3 routine and STAT assays on the Abbott ARCHITECT instruments demonstrated good analytical performance. Further clinical studies are required to demonstrate the diagnostic and prognostic potential of this novel marker in patients with CHF.

Improving the performances of autofocus based on adaptive retina-like sampling model

NASA Astrophysics Data System (ADS)

Hao, Qun; Xiao, Yuqing; Cao, Jie; Cheng, Yang; Sun, Ce

2018-03-01

An adaptive retina-like sampling model (ARSM) is proposed to balance autofocusing accuracy and efficiency. Based on the model, we carry out comparative experiments between the proposed method and the traditional method in terms of accuracy, the full width of the half maxima (FWHM) and time consumption. Results show that the performances of our method are better than that of the traditional method. Meanwhile, typical autofocus functions, including sum-modified-Laplacian (SML), Laplacian (LAP), Midfrequency-DCT (MDCT) and Absolute Tenengrad (ATEN) are compared through comparative experiments. The smallest FWHM is obtained by the use of LAP, which is more suitable for evaluating accuracy than other autofocus functions. The autofocus function of MDCT is most suitable to evaluate the real-time ability.

Comparative evaluation of simple indices of insulin resistance.

PubMed

Vaccaro, Olga; Masulli, Maria; Cuomo, Vincenzo; Rivellese, Angela Albarosa; Uusitupa, Matti; Vessby, Bengt; Hermansen, Kjeld; Tapsell, Linda; Riccardi, Gabriele

2004-12-01

Various surrogate methods for the quantification of insulin sensitivity have been proposed. A comparative evaluation is lacking and is relevant for the standardization of investigative methods and comparability of results. The aims of the study were to perform a comparative validation of fasting insulin, homeostasis model assessment (HOMA), Quantitative Insulin Sensitivity Check Index (QUICKI), and revised-QUICKI (R-QUICKI) against minimal model derived estimates of insulin sensitivity (SI(MM)) in nondiabetic people and to carry out a comparative evaluation of the ability of these indices as means for the identification of individuals with the metabolic syndrome (MS) on a population basis. We used 2 data sets defined as "validation sample" and "prevalence sample". Validation sample: a total of 162 healthy men and women aged 30 to 65 years were studied by frequently sampled intravenous glucose tolerance test (FSIVGTT). SI(MM) was calculated with the Minmod program. Prevalence sample: a total of 2,731 nondiabetic men and women aged 35 to 65 years were studied. In both samples, anthropometry, blood pressure, fasting glucose, insulin, triglycerides, high-density lipoprotein (HDL) cholesterol, and free fatty acid (FFA) were measured. HOMA, QUICKI, and R-QUICKI were calculated. The MS was defined according to the Adult Treatment Panel III. Validation sample: insulin, HOMA, QUICKI, and R-QUICKI significantly correlated with SI(MM) (r = -0,53, -0.52, 0.41, 0.33; all P < .001). The finding was confirmed in obese (body mass index [BMI] > or =25 kg/m(2)), but in the normal weight, the correlation coefficient for QUICKI was significantly smaller than for the other indices. Receiver operator characteristic (ROC) curve analysis performed with SI(MM) below or above the lowest 25th percentile (ie, insulin resistance yes, no) as the outcome variable and each of the 4 indices as the test variable showed no significant differences in the areas under the curve. Prevalence sample: prevalence of the MS progressively increased across quartiles of insulin resistance as evaluated by any of the 4 indices, with no significant differences between them. The novel indices QUICKI and R-QUICKI do not perform better than HOMA and fasting insulin as surrogate measures of insulin resistance or means for the identification of people with MS in the general population.

Performance Evaluation of the Bioneer AccuPower® HIV-1 Quantitative RT-PCR kit: Comparison with the Roche COBAS® AmpliPrep/COBAS TaqMan® HIV-1 Test Ver.2.0 for Quantification of HIV-1 Viral Load in Indonesia.

PubMed

Kosasih, Agus Susanto; Sugiarto, Christine; Hayuanta, Hubertus Hosti; Juhaendi, Runingsih; Setiawan, Lyana

2017-08-08

Measurement of viral load in human immunodeficiency virus type 1 (HIV-1) infected patients is essential for the establishment of a therapeutic strategy. Several assays based on qPCR are available for the measurement of viral load; they differ in sample volume, technology applied, target gene, sensitivity and dynamic range. The Bioneer AccuPower® HIV-1 Quantitative RT-PCR is a novel commercial kit that has not been evaluated for its performance. This study aimed to evaluate the performance of the Bioneer AccuPower® HIV-1 Quantitative RT-PCR kit. In total, 288 EDTA plasma samples from the Dharmais Cancer Hospital were analyzed with the Bioneer AccuPower® HIV-1 Quantitative RT-PCR kit and the Roche COBAS? AmpliPrep/COBAS® TaqMan® HIV-1 version 2.0 (CAP/CTM v2.0). The performance of the Bioneer assay was then evaluated against the Roche CAP/CTM v2.0. Overall, there was good agreement between the two assays. The Bioneer assay showed significant linear correlation with CAP/CTM v2.0 (R2=0.963, p<0.001) for all samples (N=118) which were quantified by both assays, with high agreement (94.9%, 112/118) according to the Bland-Altman model. The mean difference between the quantitative values measured by Bioneer assay and CAP/CTM v2.0 was 0.11 Log10 IU/mL (SD=0.26). Based on these results, the Bioneer assay can be used to quantify HIV-1 RNA in clinical laboratories.

Evaluation of Raman spectroscopy in comparison to commonly performed dengue diagnostic tests

NASA Astrophysics Data System (ADS)

Khan, Saranjam; Ullah, Rahat; Khurram, Muhammad; Ali, Hina; Mahmood, Arshad; Khan, Ajmal; Ahmed, Mushtaq

2016-09-01

This study demonstrates the evaluation of Raman spectroscopy as a rapid diagnostic test in comparison to commonly performed tests for an accurate detection of dengue fever in human blood sera. Blood samples of 104 suspected dengue patients collected from Holy Family Hospital, Rawalpindi, Pakistan, have been used in this study. Out of 104 samples, 52 (50%) were positive based on immunoglobulin G (IgG), whereas 54 (52%) were positive based on immunoglobulin M (IgM) antibody tests. For the determination of the diagnostic capabilities of Raman spectroscopy, accuracy, sensitivity, specificity and false positive rate have been calculated in comparison to normally performed IgM and IgG captured enzyme-linked immunosorbent assay tests. Accuracy, precision, specificity, and sensitivity for Raman spectroscopy in comparison to IgM were found to be 66%, 70%, 72%, and 61%, whereas based on IgG they were 47%, 46%, 52%, and 43%, respectively.

High Resolution Neutron Radiography and Tomography of Hydrided Zircaloy-4 Cladding Materials

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

Smith, Tyler S; Bilheux, Hassina Z; Ray, Holly B

2015-01-01

Neutron radiography for hydrogen analysis was performed with several Zircaloy-4 cladding samples with controlled hydrogen concentrations up to 1100 ppm. Hydrogen charging was performed in a process tube that was heated to facilitate hydrogen absorption by the metal. A correlation between the hydrogen concentration in the hydrided tubes and the neutron intensity was established, by which hydrogen content can be determined precisely in a small area (55 m x 55 m). Radiography analysis was also performed to evaluate the heating rate and its correlation with the hydrogen distribution through hydrided materials. In addition to radiography analysis, tomography experiments were performedmore » on Zircaloy-4 tube samples to study the local hydrogen distribution. Through tomography analysis a 3D reconstruction of the tube was evaluated in which an uneven hydrogen distribution in the circumferential direction can be observed.« less

Energy-dispersive X-ray fluorescence systems as analytical tool for assessment of contaminated soils.

PubMed

Vanhoof, Chris; Corthouts, Valère; Tirez, Kristof

2004-04-01

To determine the heavy metal content in soil samples at contaminated locations, a static and time consuming procedure is used in most cases. Soil samples are collected and analyzed in the laboratory at high quality and high analytical costs. The demand by government and consultants for a more dynamic approach and by customers requiring performances in which analyses are performed in the field with immediate feedback of the analytical results, is growing. Especially during the follow-up of remediation projects or during the determination of the sampling strategy, field analyses are advisable. For this purpose four types of ED-XRF systems, ranging from portable up to high performance laboratory systems, have been evaluated. The evaluation criteria are based on the performance characteristics for all the ED-XRF systems such as limit of detection, accuracy and the measurement uncertainty on one hand, and also the influence of the sample pretreatment on the obtained results on the other hand. The study proved that the field portable system and the bench top system, placed in a mobile van, can be applied as field techniques, resulting in semi-quantitative analytical results. A limited homogenization of the analyzed sample significantly increases the representativeness of the soil sample. The ED-XRF systems can be differentiated by their limits of detection which are a factor of 10 to 20 higher for the portable system. The accuracy of the results and the measurement uncertainty also improved using the bench top system. Therefore, the selection criteria for applicability of both field systems are based on the required detection level and also the required accuracy of the results.

Random forests ensemble classifier trained with data resampling strategy to improve cardiac arrhythmia diagnosis.

PubMed

Ozçift, Akin

2011-05-01

Supervised classification algorithms are commonly used in the designing of computer-aided diagnosis systems. In this study, we present a resampling strategy based Random Forests (RF) ensemble classifier to improve diagnosis of cardiac arrhythmia. Random forests is an ensemble classifier that consists of many decision trees and outputs the class that is the mode of the class's output by individual trees. In this way, an RF ensemble classifier performs better than a single tree from classification performance point of view. In general, multiclass datasets having unbalanced distribution of sample sizes are difficult to analyze in terms of class discrimination. Cardiac arrhythmia is such a dataset that has multiple classes with small sample sizes and it is therefore adequate to test our resampling based training strategy. The dataset contains 452 samples in fourteen types of arrhythmias and eleven of these classes have sample sizes less than 15. Our diagnosis strategy consists of two parts: (i) a correlation based feature selection algorithm is used to select relevant features from cardiac arrhythmia dataset. (ii) RF machine learning algorithm is used to evaluate the performance of selected features with and without simple random sampling to evaluate the efficiency of proposed training strategy. The resultant accuracy of the classifier is found to be 90.0% and this is a quite high diagnosis performance for cardiac arrhythmia. Furthermore, three case studies, i.e., thyroid, cardiotocography and audiology, are used to benchmark the effectiveness of the proposed method. The results of experiments demonstrated the efficiency of random sampling strategy in training RF ensemble classification algorithm. Copyright © 2011 Elsevier Ltd. All rights reserved.

A new framework to enhance the interpretation of external validation studies of clinical prediction models.

PubMed

Debray, Thomas P A; Vergouwe, Yvonne; Koffijberg, Hendrik; Nieboer, Daan; Steyerberg, Ewout W; Moons, Karel G M

2015-03-01

It is widely acknowledged that the performance of diagnostic and prognostic prediction models should be assessed in external validation studies with independent data from "different but related" samples as compared with that of the development sample. We developed a framework of methodological steps and statistical methods for analyzing and enhancing the interpretation of results from external validation studies of prediction models. We propose to quantify the degree of relatedness between development and validation samples on a scale ranging from reproducibility to transportability by evaluating their corresponding case-mix differences. We subsequently assess the models' performance in the validation sample and interpret the performance in view of the case-mix differences. Finally, we may adjust the model to the validation setting. We illustrate this three-step framework with a prediction model for diagnosing deep venous thrombosis using three validation samples with varying case mix. While one external validation sample merely assessed the model's reproducibility, two other samples rather assessed model transportability. The performance in all validation samples was adequate, and the model did not require extensive updating to correct for miscalibration or poor fit to the validation settings. The proposed framework enhances the interpretation of findings at external validation of prediction models. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

DETERMINING THE CAUSES OF ADVERSE EFFECTS IN NEAR COASTAL ECOSYSTEMS: FROM TOXICITY IDENTIFICATION EVALUATIONS TO WATERSHED DIAGNOTICS

EPA Science Inventory

Several approaches are available for evaluating adverse effects in near coastal ecosystems. These range from performing toxicity tests with individual organisms on water column and sediment samples to conducting macrofaunal compositional analyses on pelagic and benthic communiti...

Variation in Baiting Intensity Among CO2-Baited Traps Used to Collect Hematophagous Arthropods

PubMed Central

Springer, Yuri P.; Taylor, Jeffrey R.; Travers, Patrick D.

2015-01-01

Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. We report results of a laboratory study in which the performance of carbon dioxide-baited traps was evaluated using measures of baiting intensity, the amount of carbon dioxide released per unit time during trap deployment. We evaluated the effects of trap design, carbon dioxide source, and wind speed on baiting intensity and documented significant effects of these factors on the length of sampling (time to baiting intensity = 0), maximum baiting intensity, and variation in baiting intensity during experimental trials. Among the three dry ice-baited trap types evaluated, traps utilizing insulated beverage coolers as dry ice containers sampled for the longest period of time, had the lowest maximum but most consistent baiting intensity within trials and were least sensitive to effects of wind speed and dry ice form (block vs. pellet) on baiting intensity. Results of trials involving traps baited with carbon dioxide released from pressurized cylinders suggested that this trap type had performance comparable to dry ice-baited insulated cooler traps but at considerably higher cost. PMID:26160803

Directly Comparing Computer and Human Performance in Language Understanding and Visual Reasoning.

ERIC Educational Resources Information Center

Baker, Eva L.; And Others

Evaluation models are being developed for assessing artificial intelligence (AI) systems in terms of similar performance by groups of people. Natural language understanding and vision systems are the areas of concentration. In simplest terms, the goal is to norm a given natural language system's performance on a sample of people. The specific…

A soil sampling intercomparison exercise for the ALMERA network.

PubMed

Belli, Maria; de Zorzi, Paolo; Sansone, Umberto; Shakhashiro, Abduhlghani; Gondin da Fonseca, Adelaide; Trinkl, Alexander; Benesch, Thomas

2009-11-01

Soil sampling and analysis for radionuclides after an accidental or routine release is a key factor for the dose calculation to members of the public, and for the establishment of possible countermeasures. The IAEA organized for selected laboratories of the ALMERA (Analytical Laboratories for the Measurement of Environmental Radioactivity) network a Soil Sampling Intercomparison Exercise (IAEA/SIE/01) with the objective of comparing soil sampling procedures used by different laboratories. The ALMERA network is a world-wide network of analytical laboratories located in IAEA member states capable of providing reliable and timely analysis of environmental samples in the event of an accidental or intentional release of radioactivity. Ten ALMERA laboratories were selected to participate in the sampling exercise. The soil sampling intercomparison exercise took place in November 2005 in an agricultural area qualified as a "reference site", aimed at assessing the uncertainties associated with soil sampling in agricultural, semi-natural, urban and contaminated environments and suitable for performing sampling intercomparison. In this paper, the laboratories sampling performance were evaluated.

Determination of artificial sweeteners in water samples by solid-phase extraction and liquid chromatography-tandem mass spectrometry.

PubMed

Ordóñez, Edgar Y; Quintana, José Benito; Rodil, Rosario; Cela, Rafael

2012-09-21

The development and performance evaluation of an analytical method for the determination of six artificial sweeteners in environmental waters using solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry are presented. To this end, different SPE alternatives have been evaluated: polymeric reversed-phase (Oasis HLB, Env+, Plexa and Strata X), and mixed-mode with either weak (Oasis WAX) or strong anionic-exchange (Oasis MAX and Plexa PAX) sorbents. Among them, reversed-phase sorbents, particularly Oasis HLB and Strata X, showed the best performance. Oasis HLB provided good trueness (recoveries: 73-112%), precision (RSD<10%) and limits of quantification (LOQ: 0.01-0.5 μg/L). Moreover, two LC separation mechanisms were evaluated: reversed-phase (RPLC) and hydrophilic interaction (HILIC), with RPLC providing better performance than HILIC. The final application of the method showed the presence of acesulfame, cyclamate, saccharin and sucralose in the wastewater and surface water samples analyzed at concentrations up to 54 μg/L. Copyright © 2012 Elsevier B.V. All rights reserved.

An Evaluation of the Texas Functional Living Scale's Latent Structure and Subscales.

PubMed

González, David Andrés; Soble, Jason R; Marceaux, Janice C; McCoy, Karin J M

2017-02-01

Performance-based functional assessment is a critical component of neuropsychological practice. The Texas Functional Living Scale (TFLS) has promise given its brevity, nationally representative norms, and co-norming with Wechsler scales. However, its subscale structure has not been evaluated. The purpose of this study was to evaluate the TFLS in a mixed clinical sample (n = 197). Reliability and convergent and discriminant validity coefficients were calculated with neurocognitive testing and collateral reports and factor analysis was performed. The Money and Calculation subscale had the best psychometric properties of the subscales. The evidence did not support solitary interpretation of the Time subscale. A three-factor latent structure emerged representing memory and semantic retrieval, performance and visual scanning, and financial calculation. This study added psychometric support for interpretation of the TFLS total score and some of its subscales. Study limitations included sample characteristics (e.g., gender ratio) and low power for collateral report analyses. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Performance evaluation of image segmentation algorithms on microscopic image data.

PubMed

Beneš, Miroslav; Zitová, Barbara

2015-01-01

In our paper, we present a performance evaluation of image segmentation algorithms on microscopic image data. In spite of the existence of many algorithms for image data partitioning, there is no universal and 'the best' method yet. Moreover, images of microscopic samples can be of various character and quality which can negatively influence the performance of image segmentation algorithms. Thus, the issue of selecting suitable method for a given set of image data is of big interest. We carried out a large number of experiments with a variety of segmentation methods to evaluate the behaviour of individual approaches on the testing set of microscopic images (cross-section images taken in three different modalities from the field of art restoration). The segmentation results were assessed by several indices used for measuring the output quality of image segmentation algorithms. In the end, the benefit of segmentation combination approach is studied and applicability of achieved results on another representatives of microscopic data category - biological samples - is shown. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

High-throughput screening of chemical effects on steroidogenesis using H295R human adrenocortical carcinoma cells

EPA Pesticide Factsheets

Disruption of steroidogenesis by environmental chemicals can result in altered hormone levels causing adverse reproductive and developmental effects. A high-throughput assay using H295R human adrenocortical carcinoma cells was used to evaluate the effect of 2060 chemical samples on steroidogenesis via high-performance liquid chromatography followed by tandem mass spectrometry quantification of 10 steroid hormones, including progestagens, glucocorticoids, androgens, and estrogens. The study employed a 3 stage screening strategy. The first stage established the maximum tolerated concentration (MTC; ? 70% viability) per sample. The second stage quantified changes in hormone levels at the MTC whereas the third stage performed concentration-response (CR) on a subset of samples. At all stages, cells were prestimulated with 10 00b5M forskolin for 48??h to induce steroidogenesis followed by chemical treatment for 48??h. Of the 2060 chemical samples evaluated, 524 samples were selected for 6-point CR screening, based in part on significantly altering at least 4 hormones at the MTC. CR screening identified 232 chemical samples with concentration-dependent effects on 1703b2-estradiol and/or testosterone, with 411 chemical samples showing an effect on at least one hormone across the steroidogenesis pathway. Clustering of the concentration-dependent chemical-mediated steroid hormone effects grouped chemical samples into 5 distinct profiles generally representing putative mec

Quantitative Analysis of Defects in Silicon. [to predict energy conversion efficiency of silicon samples for solar cells

NASA Technical Reports Server (NTRS)

Natesh, R.; Smith, J. M.; Qidwai, H. A.; Bruce, T.

1979-01-01

The evaluation and prediction of the conversion efficiency for a variety of silicon samples with differences in structural defects, such as grain boundaries, twin boundaries, precipitate particles, dislocations, etc. are discussed. Quantitative characterization of these structural defects, which were revealed by etching the surface of silicon samples, is performed by using an image analyzer. Due to different crystal growth and fabrication techniques the various types of silicon contain a variety of trace impurity elements and structural defects. The two most important criteria in evaluating the various silicon types for solar cell applications are cost and conversion efficiency.

Deductive Evaluation: Formal Code Analysis With Low User Burden

NASA Technical Reports Server (NTRS)

Di Vito, Ben. L

2016-01-01

We describe a framework for symbolically evaluating iterative C code using a deductive approach that automatically discovers and proves program properties. Although verification is not performed, the method can infer detailed program behavior. Software engineering work flows could be enhanced by this type of analysis. Floyd-Hoare verification principles are applied to synthesize loop invariants, using a library of iteration-specific deductive knowledge. When needed, theorem proving is interleaved with evaluation and performed on the fly. Evaluation results take the form of inferred expressions and type constraints for values of program variables. An implementation using PVS (Prototype Verification System) is presented along with results for sample C functions.

Evaluation of a new automated microscopy urine sediment analyser - sediMAX conTRUST®.

PubMed

Bogaert, Laura; Peeters, Bart; Billen, Jaak

2017-04-01

This study evaluated the performance of the stand-alone sediMAX conTRUST (77Elektronika, Budapest, Hungary) analyser as an alternative to microscopic analysis of urine. The validation included a precision, carry-over, categorical correlation and diagnostic performance study with manual phase-contrast microscopy as reference method. A total of 260 routine urine samples were assessed. The within-run precision was much better at higher concentrations than at very low concentrations. The precision met our predefined limits for all the elements at the different concentrations, with the exception of the lowest RBC, the WBC, pathological casts and crystals count. There was no sample carry-over. The analyser showed good categorical agreement with manual microscopy for RBC and WBC counts, moderate agreement for yeast cells, crystals and squamous epithelial cells and bad agreement for non-squamous epithelial cells, bacteria and casts. Diagnostic performance was satisfying only for RBC, WBC and yeast cells. The number of false negative results was acceptable (≤4%) for all elements after connecting the sediMAX conTRUST with an automatic strip reader (AutionMAX) and after implementation of review rules. We conclude that the sediMAX conTRUST should be used as a screening tool in combination with an automatic strip reader, for the identification of normal samples. Therefore, adequate review rules should be defined. Manual microscopy is still required in 'flagged' pathological samples. Despite the poor analytical performance on pathological samples, the images on the screen can be used for interpretation without the microscope and can be stored as PDF-documents for archiving the results.

Friction Stir Processing of Stainless Steel for Ascertaining Its Superlative Performance in Bioimplant Applications.

PubMed

Perumal, G; Ayyagari, A; Chakrabarti, A; Kannan, D; Pati, S; Grewal, H S; Mukherjee, S; Singh, S; Arora, H S

2017-10-25

Substrate-cell interactions for a bioimplant are driven by substrate's surface characteristics. In addition, the performance of an implant and resistance to degradation are primarily governed by its surface properties. A bioimplant typically degrades by wear and corrosion in the physiological environment, resulting in metallosis. Surface engineering strategies for limiting degradation of implants and enhancing their performance may reduce or eliminate the need for implant removal surgeries and the associated cost. In the current study, we tailored the surface properties of stainless steel using submerged friction stir processing (FSP), a severe plastic deformation technique. FSP resulted in significant microstructural refinement from 22 μm grain size for the as-received alloy to 0.8 μm grain size for the processed sample with increase in hardness by nearly 1.5 times. The wear and corrosion behavior of the processed alloy was evaluated in simulated body fluid. The processed sample demonstrated remarkable improvement in both wear and corrosion resistance, which is explained by surface strengthening and formation of a highly stable passive layer. The methylthiazol tetrazolium assay demonstrated that the processed sample is better in supporting cell attachment, proliferation with minimal toxicity, and hemolysis. The athrombogenic characteristic of the as-received and processed samples was evaluated by fibrinogen adsorption and platelet adhesion via the enzyme-linked immunosorbent assay and lactate dehydrogenase assay, respectively. The processed sample showed less platelet and fibrinogen adhesion compared with the as-received alloy, signifying its high thromboresistance. The current study suggests friction stir processing to be a versatile toolbox for enhancing the performance and reliability of currently used bioimplant materials.

A Trade Study and Metric for Penetration and Sampling Devices for Possible Use on the NASA 2003 and 2005 Mars Sample Return Missions

NASA Technical Reports Server (NTRS)

McConnell, Joshua B.

2000-01-01

The scientific exploration of Mars will require the collection and return of subterranean samples to Earth for examination. This necessitates the use of some type of device or devices that possesses the ability to effectively penetrate the Martian surface, collect suitable samples and return them to the surface in a manner consistent with imposed scientific constraints. The first opportunity for such a device will occur on the 2003 and 2005 Mars Sample Return missions, being performed by NASA. This paper reviews the work completed on the compilation of a database containing viable penetrating and sampling devices, the performance of a system level trade study comparing selected devices to a set of prescribed parameters and the employment of a metric for the evaluation and ranking of the traded penetration and sampling devices, with respect to possible usage on the 03 and 05 sample return missions. The trade study performed is based on a select set of scientific, engineering, programmatic and socio-political criterion. The use of a metric for the various penetration and sampling devices will act to expedite current and future device selection.

Evaluation of the methods for enumerating coliform bacteria from water samples using precise reference standards.

PubMed

Wohlsen, T; Bates, J; Vesey, G; Robinson, W A; Katouli, M

2006-04-01

To use BioBall cultures as a precise reference standard to evaluate methods for enumeration of Escherichia coli and other coliform bacteria in water samples. Eight methods were evaluated including membrane filtration, standard plate count (pour and spread plate methods), defined substrate technology methods (Colilert and Colisure), the most probable number method and the Petrifilm disposable plate method. Escherichia coli and Enterobacter aerogenes BioBall cultures containing 30 organisms each were used. All tests were performed using 10 replicates. The mean recovery of both bacteria varied with the different methods employed. The best and most consistent results were obtained with Petrifilm and the pour plate method. Other methods either yielded a low recovery or showed significantly high variability between replicates. The BioBall is a very suitable quality control tool for evaluating the efficiency of methods for bacterial enumeration in water samples.

Electromembrane extraction of tartrazine from food samples: Effects of nano-sorbents on membrane performance.

PubMed

Yaripour, Saeid; Mohammadi, Ali; Nojavan, Saeed

2016-07-01

In the present study, for the first time electromembrane extraction followed by high-performance liquid chromatography coupled with ultraviolet detection was developed and validated for the determination of tartrazine in some food samples. The parameters influencing electromembrane extraction were evaluated and optimized. The membrane consists of 1-octanol immobilized in the pores of a hollow fiber. As a driving force, a 30 V electrical field was applied to make the analyte migrate from sample solution with pH 3, through the supported liquid membrane into an acceptor solution with pH 10. Best preconcentration (enrichment factor >21) was obtained in extraction duration of 15 min. Effects of some solid nano-sorbents like carbon nanotubes and molecularly imprinted polymers on membrane performance and electromembrane extraction efficiency were evaluated. The method provided the linearity in the range 25-1000 ng/mL for tartrazine (R(2) > 0.9996) with repeatability range (RSD) between 3.8 and 8.5% (n = 3). The limits of detection and quantitation were 7.5 and 25 ng/mL, respectively. Finally, the method was applied to the determination and quantification of tartrazine from some food samples with relative recoveries in the range between 90 and 98%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated ecological risk assessment of pesticides in tropical ecosystems: a case study with carbofuran in Brazil.

PubMed

Chelinho, Sónia; Lopes, Isabel; Natal-da-Luz, Tiago; Domene, Xaxier; Nunes, Maria Edna Tenorio; Espíndola, Evaldo L G; Ribeiro, Rui; Sousa, Jose P

2012-02-01

The aim of the present study is to contribute an ecologically relevant assessment of the ecotoxicological effects of pesticide applications in agricultural areas in the tropics, using an integrated approach with information gathered from soil and aquatic compartments. Carbofuran, an insecticide/nematicide used widely on sugarcane crops, was selected as a model substance. To evaluate the toxic effects of pesticide spraying for soil biota, as well as the potential indirect effects on aquatic biota resulting from surface runoff and/or leaching, field and laboratory (using a cost-effective simulator of pesticide applications) trials were performed. Standard ecotoxicological tests were performed with soil (Eisenia andrei, Folsomia candida, and Enchytraeus crypticus) and aquatic (Ceriodaphnia silvestrii) organisms, using serial dilutions of soil, eluate, leachate, and runoff samples. Among soil organisms, sensitivity was found to be E. crypticus < E. andrei < F. candida. Among the aqueous extracts, mortality of C. silvestrii was extreme in runoff samples, whereas eluates were by far the least toxic samples. A generally higher toxicity was found in the bioassays performed with samples from the field trial, indicating the need for improvements in the laboratory simulator. However, the tool developed proved to be valuable in evaluating the toxic effects of pesticide spraying in soils and the potential risks for aquatic compartments. Copyright © 2011 SETAC.

Memory performance and affect: are there gender differences in community-residing older adults?

PubMed

McDougall, Graham Joseph; Pituch, Keenan A; Stanton, Marietta P; Chang, Wanchen

2014-08-01

After age 65, the incidence of episodic memory decline in males is greater than in females. We explored the influence of anxiety and depression on objective and subjective memory performance in a diverse sample of community-residing older adults. The study was a secondary analysis of data on three samples of adults from two states, Ohio and Texas: a community sample (n = 177); a retirement community sample (n = 97); and the SeniorWISE Study (n = 265). The sample of 529 adults was 74% female, the average age was 76.58 years (range = 59-100 years), and educational attainment was 13.12 years (±3.68); 68% were Caucasian, and 17% had depressive symptoms. We found no memory performance differences by gender. Males and females were similarly classified into the four memory performance groups, with almost half of each gender in the poor memory category. Even though males had greater years of education, they used fewer compensatory memory strategies. The observed gender differences in memory were subjective evaluations, specifically metamemory. Age was not a significant predictor of cognition or memory performance, nor did males have greater memory impairment than females.

Influences of Electrification and Salt on Hydrophobicity of Sample Surface in Dynamic Drop Test

NASA Astrophysics Data System (ADS)

Shiibara, Daiki; Arata, Yoshihiro; Haji, Kenichi; Miyake, Takuma; Sakoda, Tatsuya; Otsubo, Masahisa

Studies on the development of deterioration/ performance evaluation method for outdoor electric insulation of polymer materials are pushed forward now in the International Council on Large Electric Systems (CIGRE). The small scale test method (Dynamic drop test; DDT) which could evaluate disappearance characteristics of hydrophobicity easily was suggested. This test is to evaluate resistance of a sample to loss of hydrophobicity due to moisture and simultaneous electric stress. As factors for deterioration of hydrophobicity on a sample in DDT, various factors such as electrical influence, physical influence by water droplets and so on were considered. In this study, we investigated two kinds of factors (electrification and salt) affecting deterioration of hydrophobicity on the surface of a silicone rubber until ignition of continuous electrical discharge in DDT.

Optimal Order of Successive Office Hysteroscopy and Endometrial Biopsy for the Evaluation of Abnormal Uterine Bleeding: A Randomized Controlled Trial.

PubMed

Sarkar, Papri; Mikhail, Emad; Schickler, Robyn; Plosker, Shayne; Imudia, Anthony N

2017-09-01

To estimate the optimal order of office hysteroscopy and endometrial biopsy when performed successively for evaluation of abnormal uterine bleeding. Patients undergoing successive office hysteroscopy and endometrial biopsy were included in a single-blind, prospective, randomized trial. The primary outcome was to evaluate the effect of order of procedures on patients' pain score. Prespecified secondary outcomes include procedure duration, hysteroscopic visualization of the uterine cavity, endometrial sample adequacy, and number of attempts at biopsy. Pain scores were assessed using a visual analog scale from 0 to 10 and endometrial sample adequacy was determined from the histopathology report. Hysteroscopy images were recorded. Sample size of 34 per group (n=68) was determined to be adequate to detect a difference of 20% in visual analog scale score between hysteroscopy first (group A) and biopsy first (group B) at α of 0.05 and 80% power. Between October 2015 and January 2017, 78 women were randomized to group A (n=40) and group B (n=38). There was no difference in global pain perception [7 (0-10) vs 7 (0-10); P=.57, 95% CI 5.8-7.1]. Procedure duration [3 (1-9) vs 3 (2-10), P=.32, 95% CI 3.3-4.1] and endometrial sample adequacy (78.9% vs 75.7%, P=.74) were similar in both groups. Group A patients had better endometrial visualization (P<.001) than group B based on the hysteroscopic images: excellent (50% vs 7.9%), good (20% vs 34.2%), and fair (22.5% vs 44.7%); group B participants required fewer endometrial biopsy attempts at obtaining adequate tissue sample (two vs one; P<.001, 1.6-1.9). Patients having successive office hysteroscopy and endometrial biopsy for evaluation of abnormal uterine bleeding, the global pain perception, and time required are independent of the order in which procedures are performed. Performing hysteroscopy first ensures better image, whereas biopsy first yields adequate tissue sample with fewer attempts. ClinicalTrials.gov, NCT02472184.

Characteristic Performance Evaluation of a new SAGe Well Detector for Small and Large Sample Geometries

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

Adekola, A.S.; Colaresi, J.; Douwen, J.

2015-07-01

Environmental scientific research requires a detector that has sensitivity low enough to reveal the presence of any contaminant in the sample at a reasonable counting time. Canberra developed the germanium detector geometry called Small Anode Germanium (SAGe) Well detector, which is now available commercially. The SAGe Well detector is a new type of low capacitance germanium well detector manufactured using small anode technology capable of advancing many environmental scientific research applications. The performance of this detector has been evaluated for a range of sample sizes and geometries counted inside the well, and on the end cap of the detector. Themore » detector has energy resolution performance similar to semi-planar detectors, and offers significant improvement over the existing coaxial and Well detectors. Energy resolution performance of 750 eV Full Width at Half Maximum (FWHM) at 122 keV γ-ray energy and resolution of 2.0 - 2.3 keV FWHM at 1332 keV γ-ray energy are guaranteed for detector volumes up to 425 cm{sup 3}. The SAGe Well detector offers an optional 28 mm well diameter with the same energy resolution as the standard 16 mm well. Such outstanding resolution performance will benefit environmental applications in revealing the detailed radionuclide content of samples, particularly at low energy, and will enhance the detection sensitivity resulting in reduced counting time. The detector is compatible with electric coolers without any sacrifice in performance and supports the Canberra Mathematical efficiency calibration method (In situ Object Calibration Software or ISOCS, and Laboratory Source-less Calibration Software or LABSOCS). In addition, the SAGe Well detector supports true coincidence summing available in the ISOCS/LABSOCS framework. The improved resolution performance greatly enhances detection sensitivity of this new detector for a range of sample sizes and geometries counted inside the well. This results in lower minimum detectable concentrations compared to Traditional Well detectors. The SAGe Well detectors are compatible with Marinelli beakers and compete very well with semi-planar and coaxial detectors for large samples in many applications. (authors)« less

A broad range assay for rapid detection and etiologic characterization of bacterial meningitis: performance testing in samples from sub-Sahara.

PubMed

Won, Helen; Yang, Samuel; Gaydos, Charlotte; Hardick, Justin; Ramachandran, Padmini; Hsieh, Yu-Hsiang; Kecojevic, Alexander; Njanpop-Lafourcade, Berthe-Marie; Mueller, Judith E; Tameklo, Tsidi Agbeko; Badziklou, Kossi; Gessner, Bradford D; Rothman, Richard E

2012-09-01

This study aimed to conduct a pilot evaluation of broad-based multiprobe polymerase chain reaction (PCR) in clinical cerebrospinal fluid (CSF) samples compared to local conventional PCR/culture methods used for bacterial meningitis surveillance. A previously described PCR consisting of initial broad-based detection of Eubacteriales by a universal probe, followed by Gram typing, and pathogen-specific probes was designed targeting variable regions of the 16S rRNA gene. The diagnostic performance of the 16S rRNA assay in "127 CSF samples was evaluated in samples from patients from Togo, Africa, by comparison to conventional PCR/culture methods. Our probes detected Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Uniprobe sensitivity and specificity versus conventional PCR were 100% and 54.6%, respectively. Sensitivity and specificity of uniprobe versus culture methods were 96.5% and 52.5%, respectively. Gram-typing probes correctly typed 98.8% (82/83) and pathogen-specific probes identified 96.4% (80/83) of the positives. This broad-based PCR algorithm successfully detected and provided species level information for multiple bacterial meningitis agents in clinical samples. Copyright © 2012 Elsevier Inc. All rights reserved.

A broad range assay for rapid detection and etiologic characterization of bacterial meningitis: performance testing in samples from sub-Sahara☆, ☆☆,★

PubMed Central

Won, Helen; Yang, Samuel; Gaydos, Charlotte; Hardick, Justin; Ramachandran, Padmini; Hsieh, Yu-Hsiang; Kecojevic, Alexander; Njanpop-Lafourcade, Berthe-Marie; Mueller, Judith E.; Tameklo, Tsidi Agbeko; Badziklou, Kossi; Gessner, Bradford D.; Rothman, Richard E.

2012-01-01

This study aimed to conduct a pilot evaluation of broad-based multiprobe polymerase chain reaction (PCR) in clinical cerebrospinal fluid (CSF) samples compared to local conventional PCR/culture methods used for bacterial meningitis surveillance. A previously described PCR consisting of initial broad-based detection of Eubacteriales by a universal probe, followed by Gram typing, and pathogen-specific probes was designed targeting variable regions of the 16S rRNA gene. The diagnostic performance of the 16S rRNA assay in “”127 CSF samples was evaluated in samples from patients from Togo, Africa, by comparison to conventional PCR/culture methods. Our probes detected Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Uniprobe sensitivity and specificity versus conventional PCR were 100% and 54.6%, respectively. Sensitivity and specificity of uniprobe versus culture methods were 96.5% and 52.5%, respectively. Gram-typing probes correctly typed 98.8% (82/83) and pathogen-specific probes identified 96.4% (80/83) of the positives. This broad-based PCR algorithm successfully detected and provided species level information for multiple bacterial meningitis agents in clinical samples. PMID:22809694

Improvement of microwave-assisted digestion of milk powder with diluted nitric acid using oxygen as auxiliary reagent

NASA Astrophysics Data System (ADS)

Bizzi, Cezar A.; Barin, Juliano S.; Garcia, Edivaldo E.; Nóbrega, Joaquim A.; Dressler, Valderi L.; Flores, Erico M. M.

2011-05-01

The feasibility of using diluted HNO 3 solutions under oxygen pressure for decomposition of whole and non-fat milk powders and whey powder samples has been evaluated. Digestion efficiency was evaluated by determining the carbon content in solution (digests) and the determination of Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Na, Pb and Zn was performed by inductively coupled plasma optical emission spectrometry and Hg by chemical vapor generation coupled to inductively coupled plasma mass spectrometry. Samples (up to 500 mg) were digested using HNO 3 solutions (1 to 14 mol L - 1 ) and the effect of oxygen pressure was evaluated between 2.5 and 20 bar. It was possible to perform the digestion of 500 mg of milk powder using 2 mol L - 1 HNO 3 with oxygen pressure ranging from 7.5 to 20 bar with resultant carbon content in digests lower than 1700 mg L - 1 . Using optimized conditions, less than 0.86 mL of concentrated nitric acid (14 mol L - 1 ) was enough to digest 500 mg of sample. The accuracy was evaluated by determination of metal concentrations in certified reference materials, which presented an agreement better than 95% (Student's t test, P < 0.05) for all the analytes.

Nonparametric EROC analysis for observer performance evaluation on joint detection and estimation tasks

NASA Astrophysics Data System (ADS)

Wunderlich, Adam; Goossens, Bart

2014-03-01

The majority of the literature on task-based image quality assessment has focused on lesion detection tasks, using the receiver operating characteristic (ROC) curve, or related variants, to measure performance. However, since many clinical image evaluation tasks involve both detection and estimation (e.g., estimation of kidney stone composition, estimation of tumor size), there is a growing interest in performance evaluation for joint detection and estimation tasks. To evaluate observer performance on such tasks, Clarkson introduced the estimation ROC (EROC) curve, and the area under the EROC curve as a summary figure of merit. In the present work, we propose nonparametric estimators for practical EROC analysis from experimental data, including estimators for the area under the EROC curve and its variance. The estimators are illustrated with a practical example comparing MRI images reconstructed from different k-space sampling trajectories.

Overview of the U.S. EPA/SERDP/ESTCP: Laboratory, Field, and Analytical Procedures for Using Passive Sampling in the Evaluation of Contaminated Sediments: User’s Manual

EPA Science Inventory

Passive sampling can be used for applications at contaminated sediment sites including performing assessments of contaminant bioavailability (i.e., freely dissolved concentration (Cfree)), conducting remedial investigations and feasibility studies, and assessing the potential for...

Overview of the U.S. EPA/SERDP/ESTCP: Laboratory, Field, and Analytical Procedures for Using Passive Sampling in the Evaluation of Contaminated Sediments: User’s Manual.

EPA Science Inventory

Passive sampling is used for applications at contaminated sediment sites including performing assessments of contaminant bioavailability (i.e., freely dissolved concentration (Cfree)), conducting remedial investigations and feasibility studies, and assessing the potential for con...

The Children's Perceived Locus of Causality Scale for Physical Education

ERIC Educational Resources Information Center

Pannekoek, Linda; Piek, Jan P.; Hagger, Martin S.

2014-01-01

A mixed methods design was applied to evaluate the application of the Perceived Locus of Causality scale (PLOC) to preadolescent samples in physical education settings. Subsequent to minor item adaptations to accommodate the assessment of younger samples, qualitative pilot tests were performed (N = 15). Children's reports indicated the need…

EPA Critical Path Science Plan Projects 19, 20 and 21: Human and Bovine Source Detection

EPA Science Inventory

The U.S. EPA Critical Path Science Plan Projects are: Project 19: develop novel bovine and human host-specific PCR assays and complete performance evaluation with other published methods. Project 20: Evaluate human-specific assays with water samples impacted with different lev...

Do Social Workers Make Better Child Welfare Workers than Non-Social Workers?

ERIC Educational Resources Information Center

Perry, Robin E.

2006-01-01

Objective: To empirically examine whether the educational background of child welfare workers in Florida impacts on performance evaluations of their work. Method: A proportionate, stratified random sample of supervisor and peer evaluations of child protective investigators and child protective service workers is conducted. ANOVA procedures are…

Performance of forty-one microbial source tracking methods: A twenty-seven lab evaluation study

EPA Science Inventory

The last decade has seen development of numerous new microbial source tracking (MST) methodologies, but many of these have been tested in just a few laboratories with a limited number of fecal samples. This method evaluation study examined the specificity and sensitivity of 43 ...

A priori evaluation of two-stage cluster sampling for accuracy assessment of large-area land-cover maps

USGS Publications Warehouse

Wickham, J.D.; Stehman, S.V.; Smith, J.H.; Wade, T.G.; Yang, L.

2004-01-01

Two-stage cluster sampling reduces the cost of collecting accuracy assessment reference data by constraining sample elements to fall within a limited number of geographic domains (clusters). However, because classification error is typically positively spatially correlated, within-cluster correlation may reduce the precision of the accuracy estimates. The detailed population information to quantify a priori the effect of within-cluster correlation on precision is typically unavailable. Consequently, a convenient, practical approach to evaluate the likely performance of a two-stage cluster sample is needed. We describe such an a priori evaluation protocol focusing on the spatial distribution of the sample by land-cover class across different cluster sizes and costs of different sampling options, including options not imposing clustering. This protocol also assesses the two-stage design's adequacy for estimating the precision of accuracy estimates for rare land-cover classes. We illustrate the approach using two large-area, regional accuracy assessments from the National Land-Cover Data (NLCD), and describe how the a priorievaluation was used as a decision-making tool when implementing the NLCD design.

Quantification of proteins in urine samples using targeted mass spectrometry methods.

PubMed

Khristenko, Nina; Domon, Bruno

2015-01-01

Numerous clinical proteomics studies are focused on the development of biomarkers to improve either diagnostics for early disease detection or the monitoring of the response to the treatment. Although, a wealth of biomarker candidates are available, their evaluation and validation in a true clinical setup remains challenging. In biomarkers evaluation studies, a panel of proteins of interest are systematically analyzed in a large cohort of samples. However, in spite of the latest progresses in mass spectrometry, the consistent detection of pertinent proteins in high complex biological samples is still a challenging task. Thus, targeted LC-MS/MS methods are better suited for the systematic analysis of biomarkers rather than shotgun approaches. This chapter describes the workflow used to perform targeted quantitative analyses of proteins in urinary samples. The peptides, as surrogates of the protein of interest, are commonly measured using a triple quadrupole mass spectrometers operated in selected reaction monitoring (SRM) mode. More recently, the advances in targeted LC-MS/MS analysis based on parallel reaction monitoring (PRM) performed on a quadrupole-orbitrap instrument have allowed to increase the specificity and selectivity of the measurements.

Development of an analytical microbial consortia method for enhancing performance monitoring at aerobic wastewater treatment plants.

PubMed

Razban, Behrooz; Nelson, Kristina Y; McMartin, Dena W; Cullimore, D Roy; Wall, Michelle; Wang, Dunling

2012-01-01

An analytical method to produce profiles of bacterial biomass fatty acid methyl esters (FAME) was developed employing rapid agitation followed by static incubation (RASI) using selective media of wastewater microbial communities. The results were compiled to produce a unique library for comparison and performance analysis at a Wastewater Treatment Plant (WWTP). A total of 146 samples from the aerated WWTP, comprising 73 samples of each secondary and tertiary effluent, were included analyzed. For comparison purposes, all samples were evaluated via a similarity index (SI) with secondary effluents producing an SI of 0.88 with 2.7% variation and tertiary samples producing an SI 0.86 with 5.0% variation. The results also highlighted significant differences between the fatty acid profiles of the tertiary and secondary effluents indicating considerable shifts in the bacterial community profile between these treatment phases. The WWTP performance results using this method were highly replicable and reproducible indicating that the protocol has potential as a performance-monitoring tool for aerated WWTPs. The results quickly and accurately reflect shifts in dominant bacterial communities that result when processes operations and performance change.

C-Arm Cone-Beam CT-Guided Transthoracic Lung Core Needle Biopsy as a Standard Diagnostic Tool

PubMed Central

Jaconi, Marta; Pagni, Fabio; Vacirca, Francesco; Leni, Davide; Corso, Rocco; Cortinovis, Diego; Bidoli, Paolo; Bono, Francesca; Cuttin, Maria S.; Valente, Maria G.; Pesci, Alberto; Bedini, Vittorio A.; Leone, Biagio E.

2015-01-01

Abstract C-arm cone-beam computed tomography (CT)-guided transthoracic lung core needle biopsy (CNB) is a safe and accurate procedure for the evaluation of patients with pulmonary nodules. This article will focus on the clinical features related to CNB in terms of diagnostic performance and complication rate. Moreover, the concept of categorizing pathological diagnosis into 4 categories, which could be used for clinical management, follow-up, and quality assurance is also introduced. We retrospectively collected data regarding 375 C-arm cone-beam CT-guided CNBs from January 2010 and June 2014. Clinical and radiological variables were evaluated in terms of success or failure rate. Pathological reports were inserted in 4 homogenous groups (nondiagnostic-L1, benign-L2, malignant not otherwise specified-L3, and malignant with specific histotype-L4), defining for each category a hierarchy of suggested actions. The sensitivity, specificity, and positive and negative predictive value and accuracy for patients subjected to CNBs were of 96.8%, 100%, 100%, 100%, and 97.2%, respectively. Roughly 75% of our samples were diagnosed as malignant, with 60% lung adenocarcinoma diagnoses. Molecular analyses were performed on 85 malignant samples to verify applicability of targeted therapy. The rate of “nondiagnostic” samples was 12%. C-arm cone-beam CT-guided transthoracic lung CNB can represent the gold standard for the diagnostic evaluation of pulmonary nodules. A clinical and pathological multidisciplinary evaluation of CNBs was needed in terms of integration of radiological, histological, and oncological data. This approach provided exceptional performances in terms of specificity, positive and negative predictive values; sensitivity in our series was lower compared with other large studies, probably due to the application of strong criteria of adequacy for CNBs (L1 class rate). The satisfactory rate of collected material was evaluated not only in terms of merely diagnostic performances but also for predictive results by molecular analysis. PMID:25816042

C-arm cone-beam CT-guided transthoracic lung core needle biopsy as a standard diagnostic tool: an observational study.

PubMed

Jaconi, Marta; Pagni, Fabio; Vacirca, Francesco; Leni, Davide; Corso, Rocco; Cortinovis, Diego; Bidoli, Paolo; Bono, Francesca; Cuttin, Maria S; Valente, Maria G; Pesci, Alberto; Bedini, Vittorio A; Leone, Biagio E

2015-03-01

C-arm cone-beam computed tomography (CT)-guided transthoracic lung core needle biopsy (CNB) is a safe and accurate procedure for the evaluation of patients with pulmonary nodules. This article will focus on the clinical features related to CNB in terms of diagnostic performance and complication rate. Moreover, the concept of categorizing pathological diagnosis into 4 categories, which could be used for clinical management, follow-up, and quality assurance is also introduced. We retrospectively collected data regarding 375 C-arm cone-beam CT-guided CNBs from January 2010 and June 2014. Clinical and radiological variables were evaluated in terms of success or failure rate. Pathological reports were inserted in 4 homogenous groups (nondiagnostic--L1, benign--L2, malignant not otherwise specified--L3, and malignant with specific histotype--L4), defining for each category a hierarchy of suggested actions. The sensitivity, specificity, and positive and negative predictive value and accuracy for patients subjected to CNBs were of 96.8%, 100%, 100%, 100%, and 97.2%, respectively. Roughly 75% of our samples were diagnosed as malignant, with 60% lung adenocarcinoma diagnoses. Molecular analyses were performed on 85 malignant samples to verify applicability of targeted therapy. The rate of "nondiagnostic" samples was 12%. C-arm cone-beam CT-guided transthoracic lung CNB can represent the gold standard for the diagnostic evaluation of pulmonary nodules. A clinical and pathological multidisciplinary evaluation of CNBs was needed in terms of integration of radiological, histological, and oncological data. This approach provided exceptional performances in terms of specificity, positive and negative predictive values; sensitivity in our series was lower compared with other large studies, probably due to the application of strong criteria of adequacy for CNBs (L1 class rate). The satisfactory rate of collected material was evaluated not only in terms of merely diagnostic performances but also for predictive results by molecular analysis.

How Many Oral and Maxillofacial Surgeons Does It Take to Perform Virtual Orthognathic Surgical Planning?

PubMed

Borba, Alexandre Meireles; Haupt, Dustin; de Almeida Romualdo, Leiliane Teresinha; da Silva, André Luis Fernandes; da Graça Naclério-Homem, Maria; Miloro, Michael

2016-09-01

Virtual surgical planning (VSP) has become routine practice in orthognathic treatment planning; however, most surgeons do not perform the planning without technical assistance, nor do they routinely evaluate the accuracy of the postoperative outcomes. The purpose of the present study was to propose a reproducible method that would allow surgeons to have an improved understanding of VSP orthognathic planning and to compare the planned surgical movements with the results obtained. A retrospective cohort of bimaxillary orthognathic surgery cases was used to evaluate the variability between the predicted and obtained movements using craniofacial landmarks and McNamara 3-dimensional cephalometric analysis from computed tomography scans. The demographic data (age, gender, and skeletal deformity type) were gathered from the medical records. The data analysis included the level of variability from the predicted to obtained surgical movements as assessed by the mean and standard deviation. For the overall sample, statistical analysis was performed using the 1-sample t test. The statistical analysis between the Class II and III patient groups used an unpaired t test. The study sample consisted of 50 patients who had undergone bimaxillary orthognathic surgery. The overall evaluation of the mean values revealed a discrepancy between the predicted and obtained values of less than 2.0 ± 2.0 mm for all maxillary landmarks, although some mandibular landmarks were greater than this value. An evaluation of the influence of gender and deformity type on the accuracy of surgical movements did not demonstrate statistical significance for most landmarks (P > .05). The method provides a reproducible tool for surgeons who use orthognathic VSP to perform routine evaluation of the postoperative outcomes, permitting the identification of specific variables that could assist in improving the accuracy of surgical planning and execution. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Mars rover 1988 concepts

NASA Technical Reports Server (NTRS)

Pivirotto, Donna Shirley; Penn, Thomas J.; Dias, William C.

1989-01-01

Results of FY88 studies of a sample-collecting Mars rover are presented. A variety of rover concepts are discussed which include different technical approaches to rover functions. The performance of rovers with different levels of automation is described and compared to the science requirement for 20 to 40 km to be traversed on the Martian surface and for 100 rock and soil samples to be collected. The analysis shows that a considerable amount of automation in roving and sampling is required to meet this requirement. Additional performance evaluation shows that advanced RTG's producing 500 W and 350 WHr of battery storage are needed to supply the rover.

Use of Multiple Displacement Amplification as Pre-polymerase Chain Reaction (Pre-PCR) to amplify genomic DNA of siphonapterids preserved for long periods in scientific collections.

PubMed

Avelar, Daniel M; Linardi, Pedro M

2010-09-15

The recently developed Multiple Displacement Amplification technique (MDA) allows for the production of a large quantity of high quality genomic DNA from low amounts of the original DNA. The goal of this study was to evaluate the performance of the MDA technique to amplify genomic DNA of siphonapterids that have been stored for long periods in 70% ethanol at room temperature. We subjected each DNA sample to two different methodologies: (1) amplification of mitochondrial 16S sequences without MDA; (2) amplification of 16S after MDA. All the samples obtained from these procedures were then sequenced. Only 4 samples (15.4%) subjected to method 1 showed amplification. In contrast, the application of MDA (method 2) improved the performance substantially, with 24 samples (92.3%) showing amplification, with significant difference. Interestingly, one of the samples successfully amplified with this method was originally collected in 1909. All of the sequenced samples displayed satisfactory results in quality evaluations (Phred ≥ 20) and good similarities, as identified with the BLASTn tool. Our results demonstrate that the use of MDA may be an effective tool in molecular studies involving specimens of fleas that have traditionally been considered inadequately preserved for such purposes.

Use of Multiple Displacement Amplification as Pre-polymerase Chain Reaction (Pre-PCR) to amplify genomic DNA of siphonapterids preserved for long periods in scientific collections

PubMed Central

2010-01-01

The recently developed Multiple Displacement Amplification technique (MDA) allows for the production of a large quantity of high quality genomic DNA from low amounts of the original DNA. The goal of this study was to evaluate the performance of the MDA technique to amplify genomic DNA of siphonapterids that have been stored for long periods in 70% ethanol at room temperature. We subjected each DNA sample to two different methodologies: (1) amplification of mitochondrial 16S sequences without MDA; (2) amplification of 16S after MDA. All the samples obtained from these procedures were then sequenced. Only 4 samples (15.4%) subjected to method 1 showed amplification. In contrast, the application of MDA (method 2) improved the performance substantially, with 24 samples (92.3%) showing amplification, with significant difference. Interestingly, one of the samples successfully amplified with this method was originally collected in 1909. All of the sequenced samples displayed satisfactory results in quality evaluations (Phred ≥ 20) and good similarities, as identified with the BLASTn tool. Our results demonstrate that the use of MDA may be an effective tool in molecular studies involving specimens of fleas that have traditionally been considered inadequately preserved for such purposes. PMID:20840790

Clinical evaluation of β-tubulin real-time PCR for rapid diagnosis of dermatophytosis, a comparison with mycological methods.

PubMed

Motamedi, Marjan; Mirhendi, Hossein; Zomorodian, Kamiar; Khodadadi, Hossein; Kharazi, Mahboobeh; Ghasemi, Zeinab; Shidfar, Mohammad Reza; Makimura, Koichi

2017-10-01

Following our previous report on evaluation of the beta tubulin real-time PCR for detection of dermatophytosis, this study aimed to compare the real-time PCR assay with conventional methods for the clinical assessment of its diagnostic performance. Samples from a total of 853 patients with suspected dermatophyte lesions were subjected to direct examination (all samples), culture (499 samples) and real-time PCR (all samples). Fungal DNA was extracted directly from clinical samples using a conical steel bullet, followed by purification with a commercial kit and subjected to the Taq-Man probe-based real-time PCR. The study showed that among the 499 specimens for which all three methods were used, 156 (31.2%), 128 (25.6%) and 205 (41.0%) were found to be positive by direct microscopy, culture and real-time PCR respectively. Real-time PCR significantly increased the detection rate of dermatophytes compared with microscopy (288 vs 229) with 87% concordance between the two methods. The sensitivity, specificity, positive predictive value, and negative predictive value of the real-time PCR was 87.5%, 85%, 66.5% and 95.2% respectively. Although real-time PCR performed better on skin than on nail samples, it should not yet fully replace conventional diagnosis. © 2017 Blackwell Verlag GmbH.

Performance of a Limiting-Antigen Avidity Enzyme Immunoassay for Cross-Sectional Estimation of HIV Incidence in the United States

PubMed Central

Konikoff, Jacob; Brookmeyer, Ron; Longosz, Andrew F.; Cousins, Matthew M.; Celum, Connie; Buchbinder, Susan P.; Seage, George R.; Kirk, Gregory D.; Moore, Richard D.; Mehta, Shruti H.; Margolick, Joseph B.; Brown, Joelle; Mayer, Kenneth H.; Koblin, Beryl A.; Justman, Jessica E.; Hodder, Sally L.; Quinn, Thomas C.; Eshleman, Susan H.; Laeyendecker, Oliver

2013-01-01

Background A limiting antigen avidity enzyme immunoassay (HIV-1 LAg-Avidity assay) was recently developed for cross-sectional HIV incidence estimation. We evaluated the performance of the LAg-Avidity assay alone and in multi-assay algorithms (MAAs) that included other biomarkers. Methods and Findings Performance of testing algorithms was evaluated using 2,282 samples from individuals in the United States collected 1 month to >8 years after HIV seroconversion. The capacity of selected testing algorithms to accurately estimate incidence was evaluated in three longitudinal cohorts. When used in a single-assay format, the LAg-Avidity assay classified some individuals infected >5 years as assay positive and failed to provide reliable incidence estimates in cohorts that included individuals with long-term infections. We evaluated >500,000 testing algorithms, that included the LAg-Avidity assay alone and MAAs with other biomarkers (BED capture immunoassay [BED-CEIA], BioRad-Avidity assay, HIV viral load, CD4 cell count), varying the assays and assay cutoffs. We identified an optimized 2-assay MAA that included the LAg-Avidity and BioRad-Avidity assays, and an optimized 4-assay MAA that included those assays, as well as HIV viral load and CD4 cell count. The two optimized MAAs classified all 845 samples from individuals infected >5 years as MAA negative and estimated incidence within a year of sample collection. These two MAAs produced incidence estimates that were consistent with those from longitudinal follow-up of cohorts. A comparison of the laboratory assay costs of the MAAs was also performed, and we found that the costs associated with the optimal two assay MAA were substantially less than with the four assay MAA. Conclusions The LAg-Avidity assay did not perform well in a single-assay format, regardless of the assay cutoff. MAAs that include the LAg-Avidity and BioRad-Avidity assays, with or without viral load and CD4 cell count, provide accurate incidence estimates. PMID:24386116

Evaluation of confocal microscopy system performance.

PubMed

Zucker, R M; Price, O

2001-08-01

The confocal laser scanning microscope (CLSM) has been used by scientists to visualize three-dimensional (3D) biological samples. Although this system involves lasers, electronics, optics, and microscopes, there are few published tests that can be used to assess the performance of this equipment. Usually the CLSM is assessed by subjectively evaluating a biological/histological test slide for image quality. Although there is a use for the test slide, there are many other components in the CLSM that need to be assessed. It would be useful if tests existed that produced reference values for machine performance. The aim of this research was to develop quality assurance tests to ensure that the CLSM was stable while delivering reproducible intensity measurements with excellent image quality. Our ultimate research objective was to quantify fluorescence using a CLSM. To achieve this goal, it is essential that the CLSM be stable while delivering known parameters of performance. Using Leica TCS-SP1 and TCS-4D systems, a number of tests have been devised to evaluate equipment performance. Tests measuring dichroic reflectivity, field illumination, lens performance, laser power output, spectral registration, axial resolution, laser stability, photomultiplier tube (PMT) reliability, and system noise were either incorporated from the literature or derived in our laboratory to measure performance. These tests are also applicable to other manufacturer's systems with minor modifications. A preliminary report from our laboratory has addressed a number of the QA issues necessary to achieve CLSM performance. This report extends our initial work on the evaluation of CLSM system performance. Tests that were described previously have been modified and new tests involved in laser stability and sensitivity are described. The QA tests on the CLSM measured laser power, PMT function, dichroic reflection, spectral registration, axial registration, system noise and sensitivity, lens performance, and laser stability. Laser power stability varied between 3% and 30% due to various factors, which may include incompatibility of the fiber-optic polarization with laser polarization, thermal instability of the acoustical optical transmission filter (AOTF), and laser noise. The sensitivity of the system was measured using a 10-microm Spherotech bead and the PMTs were assessed with the CV concept (image noise). The maximum sensitivity obtainable on our TCS-SP1 system measured on the 10-microm Spherotech beads was approximately 4% for 488 nm, 2.5% for 568 nm, 20% for 647 nm, and 19% for 365 nm laser light. The values serve as a comparison to test machine sensitivity from the same or different manufacturers. QA tests are described on the CLSM to assess performance and ensure that reproducing data are obtained. It is suggested strongly that these tests be used in place of a biological/histological sample to evaluate system performance. The tests are more specific and can recognize instrument functionality and problems better than a biological/histological sample. Utilization of this testing approach will eliminate the subjective assessment of the CLSM and may allow the data from different machines to be compared. These tests are essential if one is interested in making intensity measurements on experimental samples as well as obtaining the best signal detection and image resolution from a CLSM. Published 2001 Wiley-Liss, Inc.

Performance evaluation of digital phase-locked loops for advanced deep space transponders

NASA Technical Reports Server (NTRS)

Nguyen, T. M.; Hinedi, S. M.; Yeh, H.-G.; Kyriacou, C.

1994-01-01

The performances of the digital phase-locked loops (DPLL's) for the advanced deep-space transponders (ADT's) are investigated. DPLL's considered in this article are derived from the analog phase-locked loop, which is currently employed by the NASA standard deep space transponder, using S-domain to Z-domain mapping techniques. Three mappings are used to develop digital approximations of the standard deep space analog phase-locked loop, namely the bilinear transformation (BT), impulse invariant transformation (IIT), and step invariant transformation (SIT) techniques. The performance in terms of the closed loop phase and magnitude responses, carrier tracking jitter, and response of the loop to the phase offset (the difference between in incoming phase and reference phase) is evaluated for each digital approximation. Theoretical results of the carrier tracking jitter for command-on and command-off cases are then validated by computer simulation. Both theoretical and computer simulation results show that at high sampling frequency, the DPLL's approximated by all three transformations have the same tracking jitter. However, at low sampling frequency, the digital approximation using BT outperforms the others. The minimum sampling frequency for adequate tracking performance is determined for each digital approximation of the analog loop. In addition, computer simulation shows that the DPLL developed by BT provides faster response to the phase offset than IIT and SIT.

Evaluating language environment analysis system performance for Chinese: a pilot study in Shanghai.

PubMed

Gilkerson, Jill; Zhang, Yiwen; Xu, Dongxin; Richards, Jeffrey A; Xu, Xiaojuan; Jiang, Fan; Harnsberger, James; Topping, Keith

2015-04-01

The purpose of this study was to evaluate performance of the Language Environment Analysis (LENA) automated language-analysis system for the Chinese Shanghai dialect and Mandarin (SDM) languages. Volunteer parents of 22 children aged 3-23 months were recruited in Shanghai. Families provided daylong in-home audio recordings using LENA. A native speaker listened to 15 min of randomly selected audio samples per family to label speaker regions and provide Chinese character and SDM word counts for adult speakers. LENA segment labeling and counts were compared with rater-based values. LENA demonstrated good sensitivity in identifying adult and child; this sensitivity was comparable to that of American English validation samples. Precision was strong for adults but less so for children. LENA adult word count correlated strongly with both Chinese characters and SDM word counts. LENA conversational turn counts correlated similarly with rater-based counts after the exclusion of three unusual samples. Performance related to some degree to child age. LENA adult word count and conversational turn provided reasonably accurate estimates for SDM over the age range tested. Theoretical and practical considerations regarding LENA performance in non-English languages are discussed. Despite the pilot nature and other limitations of the study, results are promising for broader cross-linguistic applications.

Performance of an in-house human immunodeficiency virus type 1 genotyping system for assessment of drug resistance in Cuba.

PubMed

Alemán, Yoan; Vinken, Lore; Kourí, Vivian; Pérez, Lissette; Álvarez, Alina; Abrahantes, Yeissel; Fonseca, Carlos; Pérez, Jorge; Correa, Consuelo; Soto, Yudira; Schrooten, Yoeri; Vandamme, Anne-Mieke; Van Laethem, Kristel

2015-01-01

As commercial human immunodeficiency virus type 1 drug resistance assays are expensive, they are not commonly used in resource-limited settings. Hence, a more affordable in-house procedure was set up taking into account the specific epidemiological and economic circumstances of Cuba. The performance characteristics of the in-house assay were evaluated using clinical samples with various subtypes and resistance patterns. The lower limit of amplification was determined on dilutions series of 20 clinical isolates and ranged from 84 to 529 RNA copies/mL. For the assessment of trueness, 14 clinical samples were analyzed and the ViroSeq HIV-1 Genotyping System v2.0 was used as the reference standard. The mean nucleotide sequence identity between the two assays was 98.7% ± 1.0. Additionally, 99.0% of the amino acids at drug resistance positions were identical. The sensitivity and specificity in detecting drug resistance mutations was respectively 94.1% and 99.5%. Only few discordances in drug resistance interpretation patterns were observed. The repeatability and reproducibility were evaluated using 10 clinical samples with 3 replicates per sample. The in-house test was very precise as nucleotide sequence identity among paired nucleotide sequences ranged from 98.7% to 99.9%. The acceptance criteria were met by the in-house test for all performance characteristics, demonstrating a high degree of accuracy. Subsequently, the applicability in routine clinical practice was evaluated on 380 plasma samples. The amplification success rate was 91% and good quality consensus sequences encoding the entire protease and the first 335 codons in reverse transcriptase could be obtained for 99% of the successful amplicons. The reagent cost per sample using the in-house procedure was around € 80 per genotyping attempt. Overall, the in-house assay provided good results, was feasible with equipment and reagents available in Cuba and was half as expensive as commercial assays.

The Influence of Interpersonal and Intrapersonal Self-Regulatory Variables on Performance Outcomes of Counseling Interns

ERIC Educational Resources Information Center

McCarley, Page Roberts

2014-01-01

This study explored the influence of supervisee intrapersonal and interpersonal regulatory characteristics on supervisor-rated evaluation of supervisee performance given within the context of a counseling supervision relationship. A sample of 60 counseling supervisee and supervisor dyads from University Counseling Centers were surveyed, both…

EXPERIMENTAL DESIGN CONSIDERATIONS WHEN VERIFYING THE PERFORMANCE OF MONITORING TECHNOLOGIES FOR DIOXIN AND DIOXIN-LIKE COMPOUNDS IN SOILS AND SEDIMENTS

EPA Science Inventory

A performance verification demonstration of technologies capable of detecting dioxin and dioxin-like compounds in soil and sediment samples was conducted in April 2004 under the U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation (SITE) Monitoring an...

Interactions of Task and Subject Variables among Continuous Performance Tests

ERIC Educational Resources Information Center

Denney, Colin B.; Rapport, Mark D.; Chung, Kyong-Mee

2005-01-01

Background: Contemporary models of working memory suggest that target paradigm (TP) and target density (TD) should interact as influences on error rates derived from continuous performance tests (CPTs). The present study evaluated this hypothesis empirically in a typically developing, ethnically diverse sample of children. The extent to which…

Brief Report: Development of a Robotic Intervention Platform for Young Children with ASD.

PubMed

Warren, Zachary; Zheng, Zhi; Das, Shuvajit; Young, Eric M; Swanson, Amy; Weitlauf, Amy; Sarkar, Nilanjan

2015-12-01

Increasingly researchers are attempting to develop robotic technologies for children with autism spectrum disorder (ASD). This pilot study investigated the development and application of a novel robotic system capable of dynamic, adaptive, and autonomous interaction during imitation tasks with embedded real-time performance evaluation and feedback. The system was designed to incorporate both a humanoid robot and a human examiner. We compared child performance within system across these conditions in a sample of preschool children with ASD (n = 8) and a control sample of typically developing children (n = 8). The system was well-tolerated in the sample, children with ASD exhibited greater attention to the robotic system than the human administrator, and for children with ASD imitation performance appeared superior during the robotic interaction.

Measurement of serum 3-epi-25-hydroxyvitamin D3, 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 in infant, paediatric and adolescent populations of Korea using ultra-performance liquid chromatography-tandem mass spectrometry.

PubMed

Cho, Sung E; Kim, Sollip; Kim, Young D; Lee, Hyojung; Seo, Dong H; Song, Junghan; Um, Tae H; Cho, Chong R; Kim, Nam H; Hwang, Jong H

2017-09-01

Background We evaluated the performance of ultra-performance liquid chromatography-tandem mass spectrometry to measure serum 3-epi-25-hydroxyvitamin D 3 , 25-hydroxyvitamin D 3 and 25-hydroxyvitamin D 2 concentrations in 519 infant, paediatric and adolescent serum samples in Korea. Methods We used a Kinetex XB-C18 column and isocratic methanol/water (77.5/22.5, v/v) with 0.025% (v/v) high-performance liquid chromatography solvent additive flowing at 0.25 mL/min, yielding an 11 min/sample run time. A TQD triple quadrupole mass spectrometer in electrospray ionization positive ion mode with multiple reaction monitoring transition via an MSMS vitamin D kit was used to evaluate precision, carryover, ion suppression and linearity. Samples were prepared using the 4-phenyl-1,2,4-triazoline-3,5-dione derivatization method. Results Intra- and inter-run precisions were 1.23-13.28% and 1.02-10.08%, respectively. Group carryovers were -0.27% and 0.10%, respectively. There was no ion suppression. The calibration curve showed good linearity from calibrator Level 1 (11.75 nmol/L) to 6 (375 nmol/L) with R 2  > 0.9999. The 3-epi-25-hydroxyvitamin D 3 and 25-hydroxyvitamin D 3 peaks were clearly separated in the extracted ion chromatogram. Infant serum samples 3-epi-25-hydroxyvitamin D 3 concentrations were significantly higher than paediatric and adolescent concentrations. Conclusions The ultra-performance liquid chromatography-tandem mass spectrometry assay performed acceptably, clearly separating 3-epi-25-hydroxyvitamin D 3 from 25-hydroxyvitamin D 3 . High 3-epi-25-hydroxyvitamin D 3 concentrations were observed in infant but not in paediatric and adolescent serum samples.

Temperature dependence on the pesticide sampling rate of polar organic chemical integrative samplers (POCIS).

PubMed

Yabuki, Yoshinori; Nagai, Takashi; Inao, Keiya; Ono, Junko; Aiko, Nobuyuki; Ohtsuka, Nobutoshi; Tanaka, Hitoshi; Tanimori, Shinji

2016-10-01

Laboratory experiments were performed to determine the sampling rates of pesticides for the polar organic chemical integrative samplers (POCIS) used in Japan. The concentrations of pesticides in aquatic environments were estimated from the accumulated amounts of pesticide on POCIS, and the effect of water temperature on the pesticide sampling rates was evaluated. The sampling rates of 48 pesticides at 18, 24, and 30 °C were obtained, and this study confirmed that increasing trend of sampling rates was resulted with increasing water temperature for many pesticides.

Maps showing mines, quarries, and prospects, with analyses of samples, Gee Creek Wilderness, Polk and Monroe counties, Tennessee

USGS Publications Warehouse

Gazdik, Gertrude C.; Behum, Paul T.

1983-01-01

During the recent U.S. Bureau of Mines field investigation, 21 samples were collected (fig. 2) and were submitted to the Bureau's Reno Metallurgy Research Center, Reno, Nev., for analysis. All samples were tested for 40 elements by semiquantitative spectrographic analyses. Additional testing by atomic absorption, neutron activation, and wet chemical techniques was performed for selected elements on some samples. Two shale samples were submitted to the Bureau of Mines, Tuscaloosa Metallurgy Research Center, Tuscaloosa, Ala., for the evaluation of ceramic properties. 

Faculty performance evaluation in accredited U.S. public health graduate schools and programs: a national study.

PubMed

Gimbel, Ronald W; Cruess, David F; Schor, Kenneth; Hooper, Tomoko I; Barbour, Galen L

2008-10-01

To provide baseline data on evaluation of faculty performance in U.S. schools and programs of public health. The authors administered an anonymous Internet-based questionnaire using PHP Surveyor. The invited sample consisted of individuals listed in the Council on Education for Public Health (CEPH) Directory of Accredited Schools and Programs of Public Health. The authors explored performance measures in teaching, research, and service, and assessed how faculty performance measures are used. A total of 64 individuals (60.4%) responded to the survey, with 26 (40.6%) reporting accreditation/reaccreditation by CEPH within the preceding 24 months. Although all schools and programs employ faculty performance evaluations, a significant difference exists between schools and programs in the use of results for merit pay increases and mentoring purposes. Thirty-one (48.4%) of the organizations published minimum performance expectations. Fifty-nine (92.2%) of the respondents counted number of publications, but only 22 (34.4%) formally evaluated their quality. Sixty-two (96.9%) evaluated teaching through student course evaluations, and only 29 (45.3%) engaged in peer assessment. Although aggregate results of teaching evaluation are available to faculty and administrators, this information is often unavailable to students and the public. Most schools and programs documented faculty service activities qualitatively but neither assessed it quantitatively nor evaluated its impact. This study provides insight into how schools and programs of public health evaluate faculty performance. Results suggest that although schools and programs do evaluate faculty performance on a basic level, many do not devote substantial attention to this process.

An Improvement To The k-Nearest Neighbor Classifier For ECG Database

NASA Astrophysics Data System (ADS)

Jaafar, Haryati; Hidayah Ramli, Nur; Nasir, Aimi Salihah Abdul

2018-03-01

The k nearest neighbor (kNN) is a non-parametric classifier and has been widely used for pattern classification. However, in practice, the performance of kNN often tends to fail due to the lack of information on how the samples are distributed among them. Moreover, kNN is no longer optimal when the training samples are limited. Another problem observed in kNN is regarding the weighting issues in assigning the class label before classification. Thus, to solve these limitations, a new classifier called Mahalanobis fuzzy k-nearest centroid neighbor (MFkNCN) is proposed in this study. Here, a Mahalanobis distance is applied to avoid the imbalance of samples distribition. Then, a surrounding rule is employed to obtain the nearest centroid neighbor based on the distributions of training samples and its distance to the query point. Consequently, the fuzzy membership function is employed to assign the query point to the class label which is frequently represented by the nearest centroid neighbor Experimental studies from electrocardiogram (ECG) signal is applied in this study. The classification performances are evaluated in two experimental steps i.e. different values of k and different sizes of feature dimensions. Subsequently, a comparative study of kNN, kNCN, FkNN and MFkCNN classifier is conducted to evaluate the performances of the proposed classifier. The results show that the performance of MFkNCN consistently exceeds the kNN, kNCN and FkNN with the best classification rates of 96.5%.

A Big Apple for Educators: New York City's Experiment with Schoolwide Performance Bonuses. Final Evaluation Report. Monograph

ERIC Educational Resources Information Center

Marsh, Julie A.; Springer, Matthew G.; McCaffrey, Daniel F.; Yuan, Kun; Epstein, Scott; Koppich, Julia; Kalra, Nidhi; DiMartino, Catherine; Peng, Art

2011-01-01

In the 2007-2008 school year, the New York City Department of Education and the United Federation of Teachers jointly implemented the Schoolwide Performance Bonus Program in a random sample of the city's high-needs public schools. The program lasted for three school years, and its broad objective was to improve student performance through…

Performance Evaluation of Fusing Protected Fingerprint Minutiae Templates on the Decision Level

PubMed Central

Yang, Bian; Busch, Christoph; de Groot, Koen; Xu, Haiyun; Veldhuis, Raymond N. J.

2012-01-01

In a biometric authentication system using protected templates, a pseudonymous identifier is the part of a protected template that can be directly compared. Each compared pair of pseudonymous identifiers results in a decision testing whether both identifiers are derived from the same biometric characteristic. Compared to an unprotected system, most existing biometric template protection methods cause to a certain extent degradation in biometric performance. Fusion is therefore a promising way to enhance the biometric performance in template-protected biometric systems. Compared to feature level fusion and score level fusion, decision level fusion has not only the least fusion complexity, but also the maximum interoperability across different biometric features, template protection and recognition algorithms, templates formats, and comparison score rules. However, performance improvement via decision level fusion is not obvious. It is influenced by both the dependency and the performance gap among the conducted tests for fusion. We investigate in this paper several fusion scenarios (multi-sample, multi-instance, multi-sensor, multi-algorithm, and their combinations) on the binary decision level, and evaluate their biometric performance and fusion efficiency on a multi-sensor fingerprint database with 71,994 samples. PMID:22778583

Evaluation of tribological properties of selected engine oils during operation of the friction pairs of steel-on-steel

NASA Astrophysics Data System (ADS)

Barszcz, Marcin; Józwik, Jerzy; Dziedzic, Krzysztof; Stec, Kamil

2017-10-01

The paper includes an assessment of the tribological properties of mineral and synthetic Lotos oil marked SAE 15W/40 and SAE 5W/40 at ambient temperature and 100 °C. The evaluation was based on the analysis of the tribological properties of friction couple consumables. Tribological tests were performed using the Anton Paar THT 1000 high temperature tribotester according to ASTM G133. Tribological properties were investigated using the "ball on disc" method. The change of friction coefficient, friction couple temperature, volume wear of samples and counter-samples and Hertz stresses were evaluated. In addition, hardness tests of the friction couple materials as well as surface roughness before and after friction were performed. On the basis of tribological studies, it was noted that Lotos Synthetic 5W/40 oil has better cooling properties compared. For both oils the coefficient of friction was lower at ambient temperature than at 100 °C. The highest value of volume wear of the sample was noted for the combination lubricated with Mineral Oil 15W/40 at 100 °C (0.0143 mm3) while for counter-sample lubricated with synthetic oil at ambient temperature (0.0039 mm3). The highest sample wear coefficient was recorded for the mineral oil lubricated at temperature of 100 °C (3.585*10-7 mm3/N/m) while for counter-sample lubricated with synthetic oil at ambient temperature (9.8768*10-8 mm3/N/m). The Hertz stress for each test couple had a value of 1.787 GPa.

Population Pharmacokinetics of Metronidazole Evaluated Using Scavenged Samples from Preterm Infants

PubMed Central

Ouellet, Daniele; Smith, P. Brian; James, Laura P.; Ross, Ashley; Sullivan, Janice E.; Walsh, Michele C.; Zadell, Arlene; Newman, Nancy; White, Nicole R.; Kashuba, Angela D. M.; Benjamin, Daniel K.

2012-01-01

Pharmacokinetic (PK) studies in preterm infants are rarely conducted due to the research challenges posed by this population. To overcome these challenges, minimal-risk methods such as scavenged sampling can be used to evaluate the PK of commonly used drugs in this population. We evaluated the population PK of metronidazole using targeted sparse sampling and scavenged samples from infants that were ≤32 weeks of gestational age at birth and <120 postnatal days. A 5-center study was performed. A population PK model using nonlinear mixed-effect modeling (NONMEM) was developed. Covariate effects were evaluated based on estimated precision and clinical significance. Using the individual Bayesian PK estimates from the final population PK model and the dosing regimen used for each subject, the proportion of subjects achieving the therapeutic target of trough concentrations >8 mg/liter was calculated. Monte Carlo simulations were performed to evaluate the adequacy of different dosing recommendations per gestational age group. Thirty-two preterm infants were enrolled: the median (range) gestational age at birth was 27 (22 to 32) weeks, postnatal age was 41 (0 to 97) days, postmenstrual age (PMA) was 32 (24 to 43) weeks, and weight was 1,495 (678 to 3,850) g. The final PK data set contained 116 samples; 104/116 (90%) were scavenged from discarded clinical specimens. Metronidazole population PK was best described by a 1-compartment model. The population mean clearance (CL; liter/h) was determined as 0.0397 × (weight/1.5) × (PMA/32)2.49 using a volume of distribution (V) (liter) of 1.07 × (weight/1.5). The relative standard errors around parameter estimates ranged between 11% and 30%. On average, metronidazole concentrations in scavenged samples were 30% lower than those measured in scheduled blood draws. The majority of infants (>70%) met predefined pharmacodynamic efficacy targets. A new, simplified, postmenstrual-age-based dosing regimen is recommended for this population. Minimal-risk methods such as scavenged PK sampling provided meaningful information related to development of metronidazole PK models and dosing recommendations. PMID:22252819

Performance study of SKIROC2/A ASIC for ILD Si-W ECAL

NASA Astrophysics Data System (ADS)

Suehara, T.; Sekiya, I.; Callier, S.; Balagura, V.; Boudry, V.; Brient, J.-C.; de la Taille, C.; Kawagoe, K.; Irles, A.; Magniette, F.; Nanni, J.; Pöschl, R.; Yoshioka, T.

2018-03-01

The ILD Si-W ECAL is a sampling calorimeter with tungsten absorber and highly segmented silicon layers for the International Large Detector (ILD), one of the two detector concepts for the International Linear Collider. SKIROC2 is an ASIC for the ILD Si-W ECAL. To investigate the issues found in prototype detectors, we prepared dedicated ASIC evaluation boards with either BGA sockets or directly soldered SKIROC2. We report a performance study with the evaluation boards, including signal-to-noise ratio and TDC performance with comparing SKIROC2 and an updated version, SKIROC2A.

Reduction in training time of a deep learning model in detection of lesions in CT

NASA Astrophysics Data System (ADS)

Makkinejad, Nazanin; Tajbakhsh, Nima; Zarshenas, Amin; Khokhar, Ashfaq; Suzuki, Kenji

2018-02-01

Deep learning (DL) emerged as a powerful tool for object detection and classification in medical images. Building a well-performing DL model, however, requires a huge number of images for training, and it takes days to train a DL model even on a cutting edge high-performance computing platform. This study is aimed at developing a method for selecting a "small" number of representative samples from a large collection of training samples to train a DL model for the could be used to detect polyps in CT colonography (CTC), without compromising the classification performance. Our proposed method for representative sample selection (RSS) consists of a K-means clustering algorithm. For the performance evaluation, we applied the proposed method to select samples for the training of a massive training artificial neural network based DL model, to be used for the classification of polyps and non-polyps in CTC. Our results show that the proposed method reduce the training time by a factor of 15, while maintaining the classification performance equivalent to the model trained using the full training set. We compare the performance using area under the receiveroperating- characteristic curve (AUC).

Methods for the field evaluation of quantitative G6PD diagnostics: a review.

PubMed

Ley, Benedikt; Bancone, Germana; von Seidlein, Lorenz; Thriemer, Kamala; Richards, Jack S; Domingo, Gonzalo J; Price, Ric N

2017-09-11

Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency are at risk of severe haemolysis following the administration of 8-aminoquinoline compounds. Primaquine is the only widely available 8-aminoquinoline for the radical cure of Plasmodium vivax. Tafenoquine is under development with the potential to simplify treatment regimens, but point-of-care (PoC) tests will be needed to provide quantitative measurement of G6PD activity prior to its administration. There is currently a lack of appropriate G6PD PoC tests, but a number of new tests are in development and are likely to enter the market in the coming years. As these are implemented, they will need to be validated in field studies. This article outlines the technical details for the field evaluation of novel quantitative G6PD diagnostics such as sample handling, reference testing and statistical analysis. Field evaluation is based on the comparison of paired samples, including one sample tested by the new assay at point of care and one sample tested by the gold-standard reference method, UV spectrophotometry in an established laboratory. Samples can be collected as capillary or venous blood; the existing literature suggests that potential differences in capillary or venous blood are unlikely to affect results substantially. The collection and storage of samples is critical to ensure preservation of enzyme activity, it is recommended that samples are stored at 4 °C and testing occurs within 4 days of collection. Test results can be visually presented as scatter plot, Bland-Altman plot, and a histogram of the G6PD activity distribution of the study population. Calculating the adjusted male median allows categorizing results according to G6PD activity to calculate standard performance indicators and to perform receiver operating characteristic (ROC) analysis.

HIV avidity index performance using a modified fourth-generation immunoassay to detect recent HIV infections.

PubMed

Suligoi, Barbara; Regine, Vincenza; Raimondo, Mariangela; Rodella, Anna; Terlenghi, Luigina; Caruso, Arnaldo; Bagnarelli, Patrizia; Capobianchi, Maria Rosaria; Zanchetta, Nadia; Ghisetti, Valeria; Galli, Claudio

2017-10-26

Detecting recent HIV infections is important to evaluate incidence and monitor epidemic trends. We aimed to evaluate the diagnostic performance and accuracy of the avidity index (AI) for discriminating for recent HIV infections. We collected serum samples from HIV-1 positive individuals: A) with known date of infection (midpoint in time between last HIV-negative and first HIV-positive test); B) infected for >1 year. Samples were divided into two aliquots: one diluted with phosphate buffered saline (PBS) and the other with 1 M guanidine. Both aliquots were assayed by the Architect HIV Ag/Ab Combo 4th generation assay (Abbott). We compared AI found in recent (RI=<6 months from seroconversion) and established (EI) infections. The diagnostic accuracy was evaluated by receiver operating characteristic (ROC) curve analysis. The proportion of samples misclassified as recent (FRR) was calculated. In total, 647 samples were collected: 455 in group A (51.6% RI and 48.4% EI) and 192 in group B. Among these, sixteen samples were from elite controllers, 294 from treated patients, 328 from patients infected with non-B subtypes. Samples before antiretroviral initiation showed a mean AI significantly lower among RI compared to EI (0.66+0.28 vs. 1.00±0.12; p<0.000). The FRR was 0% using a cut-off of ≤0.70. An extremely low FRR was observed among elite controllers, samples with low VL or CD4. HIV subtype had no impact on AI misclassifications. All individuals in group A reached the AI threshold of 0.80 within 24 months after seroconversion. The AI is an accurate serological marker for discriminating recent from established HIV infections and meets WHO requirements for HIV incidence assays.

Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products.

PubMed

Chen, Yi; Pouillot, Régis; S Burall, Laurel; Strain, Errol A; Van Doren, Jane M; De Jesus, Antonio J; Laasri, Anna; Wang, Hua; Ali, Laila; Tatavarthy, Aparna; Zhang, Guodong; Hu, Lijun; Day, James; Sheth, Ishani; Kang, Jihun; Sahu, Surasri; Srinivasan, Devayani; Brown, Eric W; Parish, Mickey; Zink, Donald L; Datta, Atin R; Hammack, Thomas S; Macarisin, Dumitru

2017-01-16

A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods. Published by Elsevier B.V.

An Approach Based on HPLC-Fingerprint and Chemometrics to Quality Consistency Evaluation of Matricaria chamomilla L. Commercial Samples

PubMed Central

Viapiana, Agnieszka; Struck-Lewicka, Wiktoria; Konieczynski, Pawel; Wesolowski, Marek; Kaliszan, Roman

2016-01-01

Chamomile has been used as an herbal medication since ancient times and is still popular because it contains various bioactive phytochemicals that could provide therapeutic effects. In this study, a simple and reliable HPLC method was developed to evaluate the quality consistency of nineteen chamomile samples through establishing a chromatographic fingerprint, quantification of phenolic compounds and determination of antioxidant activity. For fingerprint analysis, 12 peaks were selected as the common peaks to evaluate the similarities of commercial samples of chamomile obtained from different manufacturers. A similarity analysis was performed to assess the similarity/dissimilarity of chamomile samples where values varied from 0.868 to 0.990 what indicating that samples from different manufacturers were consistent. Additionally, simultaneous quantification of five phenolic acids (gallic, caffeic, syringic, p-coumaric, ferulic) and four flavonoids (rutin, myricetin, quercetin and keampferol) was performed to interpret the quality consistency. In quantitative analysis, the nine individual phenolic compounds showed good regression (r > 0.9975). Inter- and intra-day precisions for all analyzed compounds expressed as relative standard deviation (CV) ranged from 0.05% to 3.12%. Since flavonoids and other polyphenols are commonly recognized as natural antioxidants, the antioxidant activity of chamomile samples was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP) assay. Correlation analysis was used to assess the relationship between antioxidant activity and phenolic composition, and multivariate analysis (PCA and HCA) were applied to distinguish chamomile samples. Results shown in the study indicate high similarity of chamomile samples among them, widely spread in the market and commonly used by people as infusions or teas, as well as that there were no statistically significant differences among them, which in turn is a proof of high quality of commercially available samples of chamomile. The study indicated that the combination of chromatographic fingerprint and quantitative analysis can be readily utilized as a quality consistency method for chamomile and related medicinal preparations. Moreover, the applied strategy seems to be the most promising for the assessment of the investigated plant material. PMID:27818668

The effect of different drinks on tooth color after home bleaching

PubMed Central

Karadas, Muhammet; Seven, Nilgun

2014-01-01

Objective: This study evaluated the influence of coffee, tea, cola, and red wine staining on the color of teeth after home bleaching. Materials and Methods: A total of 45 samples were obtained from 45 sound maxillary central incisors. The home bleaching procedure was performed using 10% carbamide peroxide gel applied to the sample surface for a period of 6 h each day, for 14 days. After bleaching, baseline color measurements were taken, and the samples were immersed in four staining solutions (coffee, tea, cola, and red wine) or artificial saliva (n = 9). Following 15 min and 6 h of immersion on the first day and next day, respectively, the samples were washed with distilled water for 10 s. After 15 min, 6 h, 1 week, and 1 month immersions, the color values of each sample were remeasured and the color change values (∆E) were calculated. Color change analysis was performed using a spectrophotometer. The results were analyzed using analysis of variance and Tukey's honestly significant difference test (P <0.05). Results: Of all the staining solutions, the lowest ∆E values were observed with coffee staining versus artificial saliva (control group), for all time intervals evaluated after whitening. Although no statistically differences were observed between the coffee and control group at all the time points evaluated, there were statistically significant differences between the red wine, cola, and tea solutions. Conclusion: Following tooth whitening, patients should avoid drinks that cause tooth staining, particularly red wine, tea and cola. PMID:24966778

a Thermally Desorbable Miniature Passive Dosimeter for Organic Vapors

NASA Astrophysics Data System (ADS)

Gonzalez, Jesus Antonio

A thermally desorbable miniature passive dosimeter (MPD) for organic vapors has been developed in conformity with theoretical and practical aspects of passive dosimeter design. The device was optimized for low sample loadings resulting from short-term and/or low concentration level exposure. This was accomplished by the use of thermal desorption rather than solvent elution, which provided the GC method with significantly higher sensitivity. Laboratory evaluation of this device for factors critical to the performance of passive dosimeters using benzene as the test vapor included: desorption efficiency (97.2%), capacity (1400 ppm-min), sensitivity (7ng/sample or 0.06 ppmv for 15 minutes sampling) accuracy and precision, concentration level, environmental conditions (i.e., air face velocity, relative humidity) and sample stability during short (15 minutes) and long periods of time (15 days). This device has demonstrated that its overall accuracy meets NIOSH and OSHA requirements for a sampling and analytical method for the exposure concentration range of 0.1 to 50 ppm (v/v) and 15 minutes exposures. It was demonstrated that the MPD operates in accordance with theoretically predicted performance and should be adequate for short-term and/or low concentration exposure monitoring of organic vapors in the workplace. In addition a dynamic vapor exposure evaluation system for passive dosimeters have been validated using benzene as the test vapor. The system is capable of generating well defined short-square wave concentration profiles suitable for the evaluation of passive dosimeters for ceiling exposure monitoring.

Symptom and performance validity with veterans assessed for attention-deficit/hyperactivity disorder (ADHD).

PubMed

Shura, Robert D; Denning, John H; Miskey, Holly M; Rowland, Jared A

2017-12-01

Little is known about attention-deficit/hyperactivity disorder (ADHD) in veterans. Practice standards recommend the use of both symptom and performance validity measures in any assessment, and there are salient external incentives associated with ADHD evaluation (stimulant medication access and academic accommodations). The purpose of this study was to evaluate symptom and performance validity measures in a clinical sample of veterans presenting for specialty ADHD evaluation. Patients without a history of a neurocognitive disorder and for whom data were available on all measures (n = 114) completed a clinical interview structured on DSM-5 ADHD symptoms, the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF), and the Test of Memory Malingering Trial 1 (TOMM1) as part of a standardized ADHD diagnostic evaluation. Veterans meeting criteria for ADHD were not more likely to overreport symptoms on the MMPI-2-RF nor to fail TOMM1 (score ≤ 41) compared with those who did not meet criteria. Those who overreported symptoms did not endorse significantly more ADHD symptoms; however, those who failed TOMM1 did report significantly more ADHD symptoms (g = 0.90). In the total sample, 19.3% failed TOMM1, 44.7% overreported on the MMPI-2-RF, and 8.8% produced both an overreported MMPI-2-RF and invalid TOMM1. F-r had the highest correlation to TOMM1 scores (r = -.30). These results underscore the importance of assessing both symptom and performance validity in a clinical ADHD evaluation with veterans. In contrast to certain other conditions (e.g., mild traumatic brain injury), ADHD as a diagnosis is not related to higher rates of invalid report/performance in veterans. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Evaluation of limited sampling models for prediction of oral midazolam AUC for CYP3A phenotyping and drug interaction studies.

PubMed

Mueller, Silke C; Drewelow, Bernd

2013-05-01

The area under the concentration-time curve (AUC) after oral midazolam administration is commonly used for cytochrome P450 (CYP) 3A phenotyping studies. The aim of this investigation was to evaluate a limited sampling strategy for the prediction of AUC with oral midazolam. A total of 288 concentration-time profiles from 123 healthy volunteers who participated in four previously performed drug interaction studies with intense sampling after a single oral dose of 7.5 mg midazolam were available for evaluation. Of these, 45 profiles served for model building, which was performed by stepwise multiple linear regression, and the remaining 243 datasets served for validation. Mean prediction error (MPE), mean absolute error (MAE) and root mean squared error (RMSE) were calculated to determine bias and precision The one- to four-sampling point models with the best coefficient of correlation were the one-sampling point model (8 h; r (2) = 0.84), the two-sampling point model (0.5 and 8 h; r (2) = 0.93), the three-sampling point model (0.5, 2, and 8 h; r (2) = 0.96), and the four-sampling point model (0.5,1, 2, and 8 h; r (2) = 0.97). However, the one- and two-sampling point models were unable to predict the midazolam AUC due to unacceptable bias and precision. Only the four-sampling point model predicted the very low and very high midazolam AUC of the validation dataset with acceptable precision and bias. The four-sampling point model was also able to predict the geometric mean ratio of the treatment phase over the baseline (with 90 % confidence interval) results of three drug interaction studies in the categories of strong, moderate, and mild induction, as well as no interaction. A four-sampling point limited sampling strategy to predict the oral midazolam AUC for CYP3A phenotyping is proposed. The one-, two- and three-sampling point models were not able to predict midazolam AUC accurately.

False-Negative Rate and Recovery Efficiency Performance of a Validated Sponge Wipe Sampling Method

PubMed Central

Piepel, Greg F.; Boucher, Raymond; Tezak, Matt; Amidan, Brett G.; Einfeld, Wayne

2012-01-01

Recovery of spores from environmental surfaces varies due to sampling and analysis methods, spore size and characteristics, surface materials, and environmental conditions. Tests were performed to evaluate a new, validated sponge wipe method using Bacillus atrophaeus spores. Testing evaluated the effects of spore concentration and surface material on recovery efficiency (RE), false-negative rate (FNR), limit of detection (LOD), and their uncertainties. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show roughly linear dependences of RE and FNR on surface roughness, with smoother surfaces resulting in higher mean REs and lower FNRs. REs were not influenced by the low spore concentrations tested (3.10 × 10−3 to 1.86 CFU/cm2). Stainless steel had the lowest mean FNR (0.123), and plastic had the highest mean FNR (0.479). The LOD90 (≥1 CFU detected 90% of the time) varied with surface material, from 0.015 CFU/cm2 on stainless steel up to 0.039 on plastic. It may be possible to improve sampling results by considering surface roughness in selecting sampling locations and interpreting spore recovery data. Further, FNR values (calculated as a function of concentration and surface material) can be used presampling to calculate the numbers of samples for statistical sampling plans with desired performance and postsampling to calculate the confidence in characterization and clearance decisions. PMID:22138998

Evaluation of the performance of the IQ-check kits and the USDA microbiology laboratory guidebook methods for detection of Shiga Toxin-Producing E. coli (STEC) and STEC and Salmonella simultaneously in ground beef

USDA-ARS?s Scientific Manuscript database

Aims: To evaluate the performance of the IQ-Check kits and the USDA Microbiology Laboratory Guidebook (MLG) methods for detection of the top 7 Shiga toxin-producing E. coli (STEC) (O157:H7, O26, O45, O103, O111, O121, and O145) in ground beef and both STEC and Salmonella in co-inoculated samples. M...

Formaldehyde: a comparative evaluation of four monitoring methods

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

Coyne, L.B.; Cook, R.E.; Mann, J.R.

1985-10-01

The performances of four formaldehyde monitoring devices were compared in a series of laboratory and field experiments. The devices evaluated included the DuPont C-60 formaldehyde badge, the SKC impregnated charcoal tube, an impinger/polarographic method and the MDA Lion formaldemeter. The major evaluation parameters included: concentration range, effects of humidity, sample storage, air velocity, accuracy, precision, interferences from methanol, styrene, 1,3-butadiene, sulfur dioxide and dimethylamine. Based on favorable performances in the laboratory and field, each device was useful for monitoring formaldehyde in the industrial work environment; however, these devices were not evaluated for residential exposure assessment. The impinger/polarographic method had amore » sensitivity of 0.06 ppm, based on a 20-liter air sample volume, and accurately determined the short-term excursion limit (STEL). It was useful for area monitoring but was not very practical for time-weighted average (TWA) personal monitoring measurements. The DuPont badge had a sensitivity of 2.8 ppm-hr and accurately and simply determined TWA exposures. It was not sensitive enough to measure STEL exposures, however, and positive interferences resulted if 1,3-butadiene was present. The SKC impregnated charcoal tube measured both TWA and STEL concentrations and had a sensitivity of 0.06 ppm based on a 25-liter air sample volume. Lightweight and simple to use, the MDA Lion formaldemeter had a sensitivity of 0.2 ppm. It had the advantage of giving an instantaneous reading in the field; however, it must be used with caution because it responded to many interferences. The method of choice depended on the type of sampling required, field conditions encountered during sampling and an understanding of the limitations of each monitoring device.« less

Monitoring endemic livestock diseases using laboratory diagnostic data: A simulation study to evaluate the performance of univariate process monitoring control algorithms.

PubMed

Lopes Antunes, Ana Carolina; Dórea, Fernanda; Halasa, Tariq; Toft, Nils

2016-05-01

Surveillance systems are critical for accurate, timely monitoring and effective disease control. In this study, we investigated the performance of univariate process monitoring control algorithms in detecting changes in seroprevalence for endemic diseases. We also assessed the effect of sample size (number of sentinel herds tested in the surveillance system) on the performance of the algorithms. Three univariate process monitoring control algorithms were compared: Shewart p Chart(1) (PSHEW), Cumulative Sum(2) (CUSUM) and Exponentially Weighted Moving Average(3) (EWMA). Increases in seroprevalence were simulated from 0.10 to 0.15 and 0.20 over 4, 8, 24, 52 and 104 weeks. Each epidemic scenario was run with 2000 iterations. The cumulative sensitivity(4) (CumSe) and timeliness were used to evaluate the algorithms' performance with a 1% false alarm rate. Using these performance evaluation criteria, it was possible to assess the accuracy and timeliness of the surveillance system working in real-time. The results showed that EWMA and PSHEW had higher CumSe (when compared with the CUSUM) from week 1 until the end of the period for all simulated scenarios. Changes in seroprevalence from 0.10 to 0.20 were more easily detected (higher CumSe) than changes from 0.10 to 0.15 for all three algorithms. Similar results were found with EWMA and PSHEW, based on the median time to detection. Changes in the seroprevalence were detected later with CUSUM, compared to EWMA and PSHEW for the different scenarios. Increasing the sample size 10 fold halved the time to detection (CumSe=1), whereas increasing the sample size 100 fold reduced the time to detection by a factor of 6. This study investigated the performance of three univariate process monitoring control algorithms in monitoring endemic diseases. It was shown that automated systems based on these detection methods identified changes in seroprevalence at different times. Increasing the number of tested herds would lead to faster detection. However, the practical implications of increasing the sample size (such as the costs associated with the disease) should also be taken into account. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of semen preparation on casa motility results in cryopreserved bull spermatozoa.

PubMed

Contri, Alberto; Valorz, Claudio; Faustini, Massimo; Wegher, Laura; Carluccio, Augusto

2010-08-01

Computer-assisted sperm analyzers (CASA) have become the standard tool for evaluating sperm motility and kinetic patterns because they provide objective data for thousands of sperm tracks. However, these devices are not ready-to-use and standardization of analytical practices is a fundamental requirement. In this study, we evaluated the effects of some settings, such as frame rate and frames per field, chamber and time of analysis, and samples preparations, including thawing temperature, sperm sample concentration, and media used for dilution, on the kinetic results of bovine frozen-thawed semen using a CASA. In Experiment 1, the frame rate (30-60 frame/s) significantly affected motility parameters, whereas the number of frames per field (30 or 45) did not seem to affect sperm kinetics. In Experiment 2, the thawing protocol affects sperm motility and kinetic parameters. Sperm sample concentration significantly limited the opportunity to perform the analysis and the kinetic results. A concentration of 100 and 50 x 10(6) sperm/mL limited the device's ability to perform the analysis or gave wrong results, whereas 5, 10, 20, and 30 x 10(6) sperm/mL concentrations allowed the analysis to be performed, but with different results (Experiment 3). The medium used for the dilution of the sample, which is fundamental for a correct sperm head detection, affects sperm motility results (Experiment 4). In this study, Makler and Leja chambers were used to perform the semen analysis with CASA devices. The chamber used significantly affected motility results (Experiment 5). The time between chamber loading and analysis affected sperm velocities, regardless of chamber used. Based on results recorded in this study, we propose that the CASA evaluation of motility of bovine frozen-thawed semen using Hamilton-Thorne IVOS 12.3 should be performed using a frame rate of 60 frame/s and 30 frames per field. Semen should be diluted at least at 20 x 10(6) sperm/mL using PBS. Furthermore, it is necessary to consider the type of chamber used and perform the analysis within 1 or 2 min, regardless of the chamber used. Copyright 2010 Elsevier Inc. All rights reserved.

External quality assessment for CD4 + T-lymphocyte count test: Performance of the Brazilian public health laboratories network.

PubMed

Gaspar, Pâmela Cristina; Wohlke, Bruna Lovizutto Protti; Brunialti, Milena Karina Coló; Pires, Ana Flávia; Kohiyama, Igor Massaki; Salomão, Reinaldo; Alonso Neto, José Boullosa; Júnior, Orlando da Costa Ferreira; Franchini, Miriam; Bazzo, Maria Luiza; Benzaken, Adele Schwartz

2018-05-01

The National Network for CD4+ T-lymphocyte counting of Brazil comprises 93 laboratories. This study reports the laboratory performances achieved in external quality assessment (EQA) rounds provides by Ministry of Health to evaluate the quality of the kits used and the performance of test by the technicians.Ten EQA rounds were analyzed according the EQA criteria aimed to evaluate individual laboratory performance on the basis of the accuracy of their results compared to the general mean obtained by all participating laboratories and the reproducibility of the results obtained between 2 samples from the same donor.The percentage of approved and failed laboratories in the EQAs tends to follow a uniform pattern. Since 2011, approval has remained above 80% and the failure rate has never exceeded 15%.EQA is very important to evaluate the performance of the laboratories, to identify monitor, and to resolve errors as quickly as possible.

Performance evaluation of the HepB Typer-Entecavir kit for detection of entecavir resistance mutations in chronic hepatitis B.

PubMed

Ahn, Sang Hoon; Chun, Ji-Yong; Shin, Soo-Kyung; Park, Jun Yong; Yoo, Wangdon; Hong, Sun Pyo; Kim, Soo-Ok; Han, Kwang-Hyub

2013-12-01

Molecular diagnostic methods have enabled the rapid diagnosis of drug-resistant mutations in hepatitis B virus (HBV) and have reduced both unnecessary therapeutic interventions and medical costs. In this study we evaluated the analytical and clinical performances of the HepB Typer-Entecavir kit (GeneMatrix, Korea) in detecting entecavir-resistance-associated mutations. The HepB Typer-Entecavir kit was evaluated for its limit of detection, interference, cross-reactivity, and precision using HBV reference standards made by diluting high-titer viral stocks in HBV-negative human serum. The performance of the HepB Typer-Entecavir kit for detecting mutations related to entecavir resistance was compared with direct sequencing for 396 clinical samples from 108 patients. Using the reference standards, the detection limit of the HepB Typer-Entecavir kit was found to be as low as 500 copies/mL. No cross-reactivity was observed, and elevated levels of various interfering substances did not adversely affect its analytical performance. The precision test conducted by repetitive analysis of 2,400 replicates with reference standards at various concentrations showed 99.9% agreement (2398/2400). The overall concordance rate between the HepB Typer-Entecavir kit and direct sequencing assays in 396 clinical samples was 99.5%. The HepB Typer-Entecavir kit showed high reliability and precision, and comparable sensitivity and specificity for detecting mutant virus populations in reference and clinical samples in comparison with direct sequencing. Therefore, this assay would be clinically useful in the diagnosis of entecavir-resistance-associated mutations in chronic hepatitis B.

NASA and Deere to study effects of low-g on iron processing

NASA Technical Reports Server (NTRS)

1981-01-01

A technical exchange agreement to study the effects of processing iron alloys in microgravity is described. Alloy solidification experiments are to be performed in the low-g facilities at Marshall Space Center. Deere is to prepare and evaluate the samples, and perform thermal characterization studies of the furnace used for melting and solidifying the samples. Experiment planning and analysis are to be performed jointly and data shared between the two parties. The technical exchange concept, developed by NASA to involve the private sector in low gravity research programs, is described. Other low gravity processing fields in which industry is invited to participate are listed.

Comparative Evaluation of Three Nucleic Acid-Based Assays for BK Virus Quantification

PubMed Central

Descamps, Veronique; Martin, Elodie; Morel, Virginie; François, Catherine; Helle, François; Duverlie, Gilles; Castelain, Sandrine

2015-01-01

With the growing importance of BK virus (BKV), effective and efficient screening for BKV replication in plasma and urine samples is very important for monitoring renal transplant and hematopoietic stem cell transplant recipients, who are at increased risk of BKV-associated diseases. However, recent assays proposed by many manufacturers have not been tested, and the available tests have not been standardized. The aim of the present study was to evaluate and compare the performances of three commercially available kits, R-gene, GeneProof, and RealStar, on plasma and urine specimens from patients infected with various genotypes and to determine the correlations with the results from a reference laboratory. A qualitatively excellent global agreement (96.8%) was obtained. RealStar PCR tended to give a higher sensitivity, especially for subtype Ib1 samples. Comparison of 30 plasma samples and 53 urine samples showed a good agreement between the three assays, with Spearman's Rho correlation coefficient values falling between 0.92 and 0.98 (P < 0.001). Moreover, a perfect correlation was obtained for comparison of the assay performances with the AcroMetrix BKV panel (P < 0.001 for all comparisons). According to Bland-Altman analysis, more than 95% (240/249 comparisons) of sample comparisons were situated in the range of the mean ± 2 standard deviations (SD). The greatest variability between assays was observed for 10.2% of subtype Ib2 samples, with differences of >1 log10 copies/ml. In conclusion, this study demonstrated the reliable and comparable performances of the R-gene, GeneProof, and RealStar real-time PCR systems for quantification of BKV in urine and plasma samples. All three real-time PCR assays are appropriate for screening of BKV replication in patients. PMID:26424842

Performance of the Fecal Immunochemical Test for Colorectal Cancer Screening Using Different Stool-Collection Devices: Preliminary Results from a Randomized Controlled Trial.

PubMed

Shin, Hye Young; Suh, Mina; Baik, Hyung Won; Choi, Kui Son; Park, Boyoung; Jun, Jae Kwan; Hwang, Sang-Hyun; Kim, Byung Chang; Lee, Chan Wha; Oh, Jae Hwan; Lee, You Kyoung; Han, Dong Soo; Lee, Do-Hoon

2016-11-15

We are in the process of conducting a randomized trial to determine whether compliance with the fecal immunochemical test (FIT) for colorectal cancer screening differs according to the stool-collection method. This study was an interim analysis of the performance of two stool-collection devices (sampling bottle vs conventional container). In total, 1,701 individuals (age range, 50 to 74 years) were randomized into the sampling bottle group (intervention arm) or the conventional container group (control arm). In both groups, we evaluated the FIT positivity rate, the positive predictive value for advanced neoplasia, and the detection rate for advanced neoplasia. The FIT positivity rates were 4.1% for the sampling bottles and 2.0% for the conventional containers; these values were significantly different. The positive predictive values for advanced neoplasia in the sampling bottles and conventional containers were 11.1% (95% confidence interval [CI], -3.4 to 25.6) and 12.0% (95% CI, -0.7 to 24.7), respectively. The detection rates for advanced neoplasia in the sampling bottles and conventional containers were 4.5 per 1,000 persons (95% CI, 2.0 to 11.0) and 2.4 per 1,000 persons (95% CI, 0.0 to 5.0), respectively. The impact of these findings on FIT screening performance was unclear in this interim analysis. This impact should therefore be evaluated in the final analysis following the final enrollment period.

Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

USGS Publications Warehouse

Layton, Blythe A.; Cao, Yiping; Ebentier, Darcy L.; Hanley, Kaitlyn; Ballesté, Elisenda; Brandão, João; Byappanahalli, Muruleedhara N.; Converse, Reagan; Farnleitner, Andreas H.; Gentry-Shields, Jennifer; Gourmelon, Michèle; Lee, Chang Soo; Lee, Jiyoung; Lozach, Solen; Madi, Tania; Meijer, Wim G.; Noble, Rachel; Peed, Lindsay; Reischer, Georg H.; Rodrigues, Raquel; Rose, Joan B.; Schriewer, Alexander; Sinigalliano, Chris; Srinivasan, Sangeetha; Stewart, Jill; ,; Laurie, C.; Wang, Dan; Whitman, Richard; Wuertz, Stefan; Jay, Jenny; Holden, Patricia A.; Boehm, Alexandria B.; Shanks, Orin; Griffith, John F.

2013-01-01

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, Bacteroides thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman®, HumM2, and Methanobrevibacter smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while varying the following: 1) classification of samples that were detected but not quantifiable (DNQ) as positive or negative; 2) reference fecal sample concentration unit of measure (such as culturable indicator bacteria, wet mass, total DNA, etc); and 3) human fecal source type (stool, sewage or septage). Assay performance using presence/absence metrics was found to depend on the classification of DNQ samples. The assays that performed best quantitatively varied based on the fecal concentration unit of measure and laboratory protocol. All methods were consistently more sensitive to human stools compared to sewage or septage in both the presence/absence and quantitative analysis. Overall, HF183 Taqman® was found to be the most effective marker of human fecal contamination in this California-based study.

Evaluation of the Clinical Performance of the HPV-Risk Assay Using the VALGENT-3 Panel.

PubMed

Polman, N J; Oštrbenk, A; Xu, L; Snijders, P J F; Meijer, C J L M; Poljak, M; Heideman, D A M; Arbyn, M

2017-12-01

Human papillomavirus (HPV) testing is increasingly being incorporated into cervical cancer screening. The Validation of HPV Genotyping Tests (VALGENT) is a framework designed to evaluate the clinical performance of various HPV tests relative to that of the validated and accepted comparator test in a formalized and uniform manner. The aim of this study was to evaluate the clinical performance of the HPV-Risk assay with samples from the VALGENT-3 panel and to compare its performance to that of the clinically validated Hybrid Capture 2 assay (HC2). The VALGENT-3 panel comprises 1,300 consecutive samples from women participating in routine cervical cancer screening and is enriched with 300 samples from women with abnormal cytology. DNA was extracted from original ThinPrep PreservCyt medium aliquots, and HPV testing was performed using the HPV-Risk assay by investigators blind to the clinical data. HPV prevalence was analyzed, and the clinical performance of the HPV-Risk assay for the detection of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) and CIN2 or worse (CIN2+) relative to the performance of HC2 was assessed. The sensitivity of the HPV-Risk assay for the detection of CIN3+ was similar to that of HC2 (relative sensitivity, 1.00; 95% confidence interval [CI], 0.95 to 1.05; P = 1.000), but the specificity of the HPV-Risk assay was significantly higher than that of HC2 (relative specificity, 1.02; 95% CI, 1.01 to 1.04; P < 0.001). For the detection of CIN2+, similar results were obtained, with the relative sensitivity being 0.98 (95% CI, 0.93 to 1.02; P = 0.257) and the relative specificity being 1.02 (95% CI, 1.01 to 1.03; P < 0.001). The performance of the HPV-Risk assay for the detection of CIN3+ and CIN2+ was noninferior to that of HC2, with all P values being ≤0.006. In conclusion, the HPV-Risk assay demonstrated noninferiority to the clinically validated HC2 by the use of samples from the VALGENT-3 panel for test validation and comparison. Copyright © 2017 Polman et al.

Evaluating the fracture toughness and flexural strength of pressable dental ceramics: an in vitro study.

PubMed

Gurram, Ravi; Krishna, C H Vamsi; Reddy, K Mahendranadh; Reddy, G V K Mohan; Shastry, Y Mahadev

2014-12-01

The study was undertaken to evaluate the biaxial flexural strength, biaxial flexural strength after etching with 9 % HF acid and fracture toughness of three commonly used pressable all ceramic core materials. Ninety glass ceramic specimens were fabricated from three commercially available leucite based core ceramic material (1) Esthetic Empress, (2) Cergo, and (3) Performance Plus. Thirty discs of each material were divided into three groups of 10 discs each. Biaxial flexural strength (30 discs,) Biaxial flexural strength for samples treated with 9 % HF acid (30 discs) and fracture toughness (30 discs) were evaluated. Core material Performance Plus had the lowest biaxial strength of 124.89 MPa, Cergo had strength of 152.22 MPa and the highest value of 163.95 was reported for Esthetic Empress. For samples treated 9 % HF, Performance Plus had the lowest biaxial strength of 98.37 MPa, Cergo had strength of 117.42 MPa and the highest value of 143.74 was reported for Esthetic Empress. Core material Performance Plus had the lowest fracture toughness of 1.063 MPa, Cergo had strength of 1.112 MPa and the highest value of 1.225 was reported for Esthetic Empress. The results shows that Esthetic Empress had better mechanical properties compared to Cergo had Performance Plus in relation to the parameters tested.

[Experimental evaluation of the spraying disinfection efficiency on dental models].

PubMed

Zhang, Yi; Fu, Yuan-fei; Xu, Kan

2013-08-01

To evaluate the disinfect effect after spraying a new kind of disinfectant on the dental plaster models. The germ-free plaster samples, which were smeared with bacteria compound including Staphylococcus aureus, Escherichia coli, Saccharomyces albicans, Streptococcus mutans and Actinomyces viscosus were sprayed with disinfectants (CaviCide) and glutaraldehyde individually. In one group(5 minutes later) and another group(15 minutes later), the colonies were counted for statistical analysis after sampling, inoculating, and culturing which were used for evaluation of disinfecting efficiency. ANOVA was performed using SPSS12.0 software package. All sample bacteria were eradicated after spraying disinfectants(CaviCide) within 5 minutes and effective bacteria control was retained after 15 minutes. There was significant difference between the disinfecting efficiency of CaviCide and glutaraldehyde. The effect of disinfection with spraying disinfectants (CaviCide) on dental models is quick and effective.

Quantitative comparison of randomization designs in sequential clinical trials based on treatment balance and allocation randomness.

PubMed

Zhao, Wenle; Weng, Yanqiu; Wu, Qi; Palesch, Yuko

2012-01-01

To evaluate the performance of randomization designs under various parameter settings and trial sample sizes, and identify optimal designs with respect to both treatment imbalance and allocation randomness, we evaluate 260 design scenarios from 14 randomization designs under 15 sample sizes range from 10 to 300, using three measures for imbalance and three measures for randomness. The maximum absolute imbalance and the correct guess (CG) probability are selected to assess the trade-off performance of each randomization design. As measured by the maximum absolute imbalance and the CG probability, we found that performances of the 14 randomization designs are located in a closed region with the upper boundary (worst case) given by Efron's biased coin design (BCD) and the lower boundary (best case) from the Soares and Wu's big stick design (BSD). Designs close to the lower boundary provide a smaller imbalance and a higher randomness than designs close to the upper boundary. Our research suggested that optimization of randomization design is possible based on quantified evaluation of imbalance and randomness. Based on the maximum imbalance and CG probability, the BSD, Chen's biased coin design with imbalance tolerance method, and Chen's Ehrenfest urn design perform better than popularly used permuted block design, EBCD, and Wei's urn design. Copyright © 2011 John Wiley & Sons, Ltd.

Evaluation of the Air Quality Monitor's Performance on the International Space Station

NASA Technical Reports Server (NTRS)

Limero, Thomas; Reese, Eric; Ballard, Ken; Durham, Tamara

2010-01-01

The Air Quality Monitor (AQM) was flown to the International Space Station (ISS) as an experiment to evaluate its potential to replace the aging Volatile Organic Analyzer (VOA), which ceased operations in August 2009. The AQM (Figure 1) is a small gas chromatography/differential mobility spectrometer (GC/DMS) manufactured by Sionex. Data was presented at last year s ISIMS conference that detailed the preparation of the AQM for flight, including instrument calibration. Furthermore, initial AQM data was compared to VOA results from simultaneous runs of the two instruments. Although comparison with VOA data provided a measure of confidence in the AQM performance, it is the comparison with results from simultaneously acquired air samples (grab sample containers-GSCs) that will define the success (or failure) of the AQM performance. This paper will update the progress in the AQM investigation by comparing AQM data to results from the analyses of GSC samples, returned from ISS. Additionally, a couple of example will illustrate the AQM s ability to detect disruptions in the spacecraft s air quality. Discussion will also focus upon a few unexpected issues that have arisen and how these will be a addressed in the final operational unit now being built.

Serviceable pavement marking retroreflectivity levels : technical report.

DOT National Transportation Integrated Search

2009-03-01

This research addressed an array of issues related to measuring pavement markings retroreflectivity, factors : related to pavement marking performance, subjective evaluation process, best practices for using mobile : retroreflectometers, sampling pav...

Evaluation and Validation of a Real-Time PCR Assay for Detection and Quantitation of Human Adenovirus 14 from Clinical Samples

DTIC Science & Technology

2009-09-01

Legionella Pneumophila (ATCC 33152) were acquired from the American Type Culture Collection (ATCC; Manassas, VA, USA). Conventional PCR testing The primers... Legionella Pneumophila – One nanogram of genomic DNA was used as a DNA template in each assay. Assays were performed in triplicate. Samples were negative at

Performance of Bootstrapping Approaches To Model Test Statistics and Parameter Standard Error Estimation in Structural Equation Modeling.

ERIC Educational Resources Information Center

Nevitt, Jonathan; Hancock, Gregory R.

2001-01-01

Evaluated the bootstrap method under varying conditions of nonnormality, sample size, model specification, and number of bootstrap samples drawn from the resampling space. Results for the bootstrap suggest the resampling-based method may be conservative in its control over model rejections, thus having an impact on the statistical power associated…

A RAPID METHOD FOR THE EXTRACTION OF FUNGAL DNA FROM ENVIRONMENTAL SAMPLES: EVALUATION IN THE QUANTITATIVE ANALYSIS OF MEMNONIELLA ECHINATA CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS

EPA Science Inventory

New technologies are creating the potential for using nucleic acid sequence detection to perform routine microbiological analyses of environmental samples. Our laboratory has recently reported on the development of a method for the quantitative detection of Stachybotrys chartarum...

The procedures manual of the Environmental Measurements Laboratory. Volume 2, 28. edition

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

Chieco, N.A.

1997-02-01

This report contains environmental sampling and analytical chemistry procedures that are performed by the Environmental Measurements Laboratory. The purpose of environmental sampling and analysis is to obtain data that describe a particular site at a specific point in time from which an evaluation can be made as a basis for possible action.

Accuracy and suitability of selected sampling methods within conifer dominated riparian zones

Treesearch

Theresa Marquardt; Hailemariam Temesgen; Paul D. Anderson

2010-01-01

Sixteen sampling alternatives were examined for their performance to quantify selected attributes of overstory conifers in riparian areas of western Oregon. Each alternative was examined at eight headwater forest locations based on 0.52 ha square stem maps. The alternatives were evaluated for selected stand attributes (tree per hectare, basal area per hectare, and...

Comparative measurement of collagen bundle orientation by Fourier analysis and semiquantitative evaluation: reliability and agreement in Masson's trichrome, Picrosirius red and confocal microscopy techniques.

PubMed

Marcos-Garcés, V; Harvat, M; Molina Aguilar, P; Ferrández Izquierdo, A; Ruiz-Saurí, A

2017-08-01

Measurement of collagen bundle orientation in histopathological samples is a widely used and useful technique in many research and clinical scenarios. Fourier analysis is the preferred method for performing this measurement, but the most appropriate staining and microscopy technique remains unclear. Some authors advocate the use of Haematoxylin-Eosin (H&E) and confocal microscopy, but there are no studies comparing this technique with other classical collagen stainings. In our study, 46 human skin samples were collected, processed for histological analysis and stained with Masson's trichrome, Picrosirius red and H&E. Five microphotographs of the reticular dermis were taken with a 200× magnification with light microscopy, polarized microscopy and confocal microscopy, respectively. Two independent observers measured collagen bundle orientation with semiautomated Fourier analysis with the Image-Pro Plus 7.0 software and three independent observers performed a semiquantitative evaluation of the same parameter. The average orientation for each case was calculated with the values of the five pictures. We analyzed the interrater reliability, the consistency between Fourier analysis and average semiquantitative evaluation and the consistency between measurements in Masson's trichrome, Picrosirius red and H&E-confocal. Statistical analysis for reliability and agreement was performed with the SPSS 22.0 software and consisted of intraclass correlation coefficient (ICC), Bland-Altman plots and limits of agreement and coefficient of variation. Interrater reliability was almost perfect (ICC > 0.8) with all three histological and microscopy techniques and always superior in Fourier analysis than in average semiquantitative evaluation. Measurements were consistent between Fourier analysis by one observer and average semiquantitative evaluation by three observers, with an almost perfect agreement with Masson's trichrome and Picrosirius red techniques (ICC > 0.8) and a strong agreement with H&E-confocal (0.7 < ICC < 0.8). Comparison of measurements between the three techniques for the same observer showed an almost perfect agreement (ICC > 0.8), better with Fourier analysis than with semiquantitative evaluation (single and average). These results in nonpathological skin samples were also confirmed in a preliminary analysis in eight scleroderma skin samples. Our results show that Masson's trichrome and Picrosirius red are consistent with H&E-confocal for measuring collagen bundle orientation in histological samples and could thus be used indistinctly for this purpose. Fourier analysis is superior to average semiquantitative evaluation and should keep being used as the preferred method. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Woodstove Emission Sampling Methods Comparability Analysis and In-situ Evaluation of New Technology Woodstoves.

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

Simons, Carl A.

1988-06-01

One major objective of this study was to compare several woodstove particulate emission sampling methods under laboratory and in-situ conditions. The laboratory work compared the EPA Method 5H, EPA Method 5G, and OMNI Automated Woodstove Emission Sampler (AWES)/Data LOG'r particulate emission sampling systems. A second major objective of the study was to evaluate the performance of two integral catalytic, two low emission non-catalytic, and two conventional technology woodstoves under in-situ conditions with AWES/Data LOG'r system. The AWES/Data LOG'r and EPA Method 5G sampling systems were also compared in an in-situ test on one of the integral catalytic woodstove models. 7more » figs., 12 tabs.« less

Evaluation of a neuropsychological screen in an incarcerated population.

PubMed

Ball, Tabitha D; Pastore, Richard E; Sollman, Miriam J; Burright, Richard G; Donovick, Peter J

2009-08-01

The Brief Neuropsychological Cognitive Examination (BNCE) is a screening device designed to rapidly assess neuropsychological functioning. The availability of an effective and efficient screen for neuropsychological and/or cognitive disorders is an important concern within various settings such as correctional facilities, where there are likely to be large numbers of individuals in need of evaluation. In the current study the utility of the BNCE in detecting cognitive impairments among a clinical sample of incarcerated individuals was evaluated by comparing performance on this instrument to performance on measures of general cognitive functioning. Results indicate that the BNCE demonstrates some utility in its ability to determine those in need of further evaluation of cognitive functioning.

Flexibility for Vocational Education through Computer Scheduling. Quarterly Report.

ERIC Educational Resources Information Center

Allen, Dwight W.

This progress report of a 2-year project (ending April 30, 1968) offers a random sampling of course schedule configurations and specific course performance criteria submitted to the Stanford project staff for evaluation and comment, and a brief statement of the project's data collection and data evaluation objectives. The project seeks to…

Generic particulate-monitoring system for retrofit to Hanford exhaust stacks

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

Camman, J.W.; Carbaugh, E.H.

1982-11-01

Evaluations of 72 sampling and monitoring systems were performed at Hanford as the initial phase of a program to upgrade such systems. Each evaluation included determination of theoretical sampling efficiencies for particle sizes ranging from 0.5 to 10 micrometers aerodynamic equivalent diameter, addressing anisokinetic bias, sample transport line losses, and collector device efficiency. Upgrades needed to meet current Department of Energy guidance for effluent sampling and monitoring were identified, and a cost for each upgrade was estimated. A relative priority for each system's upgrade was then established based on evaluation results, current operational status, and future plans for the facilitymore » being exhausted. Common system upgrade requirements lead to the development of a generic design for common components of an exhaust stack sampling and monitoring system for airborne radioactive particulates. The generic design consists of commercially available off-the-shelf components to the extent practical and will simplify future stack sampling and monitoring system design, fabrication, and installation efforts. Evaluation results and their significance to system upgrades are empasized. A brief discussion of the analytical models used and experience to date with the upgrade program is included. Development of the generic stack sampling and monitoring system design is outlined. Generic system design features and limitations are presented. Requirements for generic system retrofitting to existing exhaust stacks are defined and benefits derived from generic system application are discussed.« less

ESDA®-Lite collection of DNA from latent fingerprints on documents.

PubMed

Plaza, Dane T; Mealy, Jamia L; Lane, J Nicholas; Parsons, M Neal; Bathrick, Abigail S; Slack, Donia P

2015-05-01

The ability to detect and non-destructively collect biological samples for DNA processing would benefit the forensic community by preserving the physical integrity of evidentiary items for more thorough evaluations by other forensic disciplines. The Electrostatic Detection Apparatus (ESDA®) was systemically evaluated for its ability to non-destructively collect DNA from latent fingerprints deposited on various paper substrates for short tandem repeat (STR) DNA profiling. Fingerprints were deposited on a variety of paper substrates that included resume paper, cotton paper, magazine paper, currency, copy paper, and newspaper. Three DNA collection techniques were performed: ESDA collection, dry swabbing, and substrate cutting. Efficacy of each collection technique was evaluated by the quantity of DNA present in each sample and the percent profile generated by each sample. Both the ESDA and dry swabbing non-destructive sampling techniques outperformed the destructive methodology of substrate cutting. A greater number of full profiles were generated from samples collected with the non-destructive dry swabbing collection technique than were generated from samples collected with the ESDA; however, the ESDA also allowed the user to visualize the area of interest while non-destructively collecting the biological material. The ability to visualize the biological material made sampling straightforward and eliminated the need for numerous, random swabbings/cuttings. Based on these results, the evaluated non-destructive ESDA collection technique has great potential for real-world forensic implementation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Associations of elevated nonesterified fatty acids and beta-hydroxybutyrate concentrations with early lactation reproductive performance and milk production in transition dairy cattle in the northeastern United States.

PubMed

Ospina, P A; Nydam, D V; Stokol, T; Overton, T R

2010-04-01

The objectives were to evaluate the effects of elevated pre- and postpartum nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) concentrations during the transition period on reproductive performance and milk production in dairy cattle. In a prospective cohort study of 91 freestall, total mixed ration-fed herds in the northeastern United States, blood samples were collected from approximately 15 prepartum and 15 different postpartum transition animals in each herd. All samples were stratified based on pre- or postpartum status at the time of sample collection, and 2,259 and 2,290 animals were used to evaluate reproductive and milk production performance, respectively. Reproductive performance was assessed by time to conception within 70 d post-voluntary waiting period (VWP) and milk production was assessed using mature-equivalent 305-d (ME305) milk yield estimated at 120 d in milk. While controlling for body condition score (BCS), calving season, median ME305 milk production, and parity, NEFA and BHBA concentrations were evaluated with time to event analysis to investigate reproductive performance. These same predictor variables were used to determine the effects of elevated NEFA and BHBA concentrations on ME305 milk yield with herd as a random effect. Heifers and cows were grouped in the final analyses if the results between groups were similar. In all animals sampled prepartum, the risk of pregnancy within 70 d post-VWP was reduced by 19% when NEFA concentrations were >or=0.27 mEq/L. In all animals sampled postpartum, those with NEFA concentrations >or=0.72 mEq/L had a 16% decrease in risk of pregnancy and those with BHBA concentrations >or=10mg/dL had a 13% decrease in risk. In cows and heifers, ME305 milk yield was decreased by 683 kg when prepartum NEFA concentrations were >or=0.33 mEq/L. In heifers sampled postpartum, ME305 milk yield was increased by 488 kg when NEFA concentrations were >or=0.57 mEq/L and increased by 403 kg when BHBA concentrations were >or=9 mg/dL. In cows sampled postpartum, ME305 milk yield was decreased by 647 kg when NEFA concentrations were >or=0.72 mEq/L and decreased by 393 kg when BHBA concentrations were >or=10mg/dL. With the exception of milk production in heifers, this study indicates that increased concentrations of serum NEFA and BHBA had a detrimental effect on reproductive performance and milk production. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Experimental evaluation of environmental scanning electron microscopes at high chamber pressure.

PubMed

Fitzek, H; Schroettner, H; Wagner, J; Hofer, F; Rattenberger, J

2015-11-01

In environmental scanning electron microscopy (ESEM) high pressure applications have become increasingly important. Wet or biological samples can be investigated without time-consuming sample preparation and potential artefacts from this preparation can be neglected. Unfortunately, the signal-to-noise ratio strongly decreases with increasing chamber pressure. To evaluate the high pressure performance of ESEM and to compare different electron microscopes, information about spatial resolution and detector type is not enough. On the one hand, the scattering of the primary electron beam increases, which vanishes the contrast in images; and on the other hand, the secondary electrons (SE) signal amplification decreases. The stagnation gas thickness (effective distance the beam has to travel through the imaging gas) as well as the SE detection system depend on the microscope and for a complete and serious evaluation of an ESEM or low vacuum SEM it is necessary to specify these two parameters. A method is presented to determine the fraction of scattered and unscattered electrons and to calculate the stagnation gas thickness (θ). To evaluate the high pressure performance of the SE detection system, a method is presented that allows for an analysis of a single image and the calculation of the signal-to-noise ratio of this image. All investigations are performed on an FEI ESEM Quanta 600 (field emission gun) and an FEI ESEM Quanta 200 (thermionic gun). These methods and measurements should represent opportunities for evaluating the high pressure performance of an ESEM. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

When Is Rapid On-Site Evaluation Cost-Effective for Fine-Needle Aspiration Biopsy?

PubMed Central

Schmidt, Robert L.; Walker, Brandon S.; Cohen, Michael B.

2015-01-01

Background Rapid on-site evaluation (ROSE) can improve adequacy rates of fine-needle aspiration biopsy (FNAB) but increases operational costs. The performance of ROSE relative to fixed sampling depends on many factors. It is not clear when ROSE is less costly than sampling with a fixed number of needle passes. The objective of this study was to determine the conditions under which ROSE is less costly than fixed sampling. Methods Cost comparison of sampling with and without ROSE using mathematical modeling. Models were based on a societal perspective and used a mechanistic, micro-costing approach. Sampling policies (ROSE, fixed) were compared using the difference in total expected costs per case. Scenarios were based on procedure complexity (palpation-guided or image-guided), adequacy rates (low, high) and sampling protocols (stopping criteria for ROSE and fixed sampling). One-way, probabilistic, and scenario-based sensitivity analysis was performed to determine which variables had the greatest influence on the cost difference. Results ROSE is favored relative to fixed sampling under the following conditions: (1) the cytologist is accurate, (2) the total variable cost ($/hr) is low, (3) fixed costs ($/procedure) are high, (4) the setup time is long, (5) the time between needle passes for ROSE is low, (6) when the per-pass adequacy rate is low, and (7) ROSE stops after observing one adequate sample. The model is most sensitive to variation in the fixed cost, the per-pass adequacy rate, and the time per needle pass with ROSE. Conclusions Mathematical modeling can be used to predict the difference in cost between sampling with and without ROSE. PMID:26317785

Antimicrobial activity and rutin identification of honey produced by the stingless bee Melipona compressipes manaosensis and commercial honey.

PubMed

Pimentel, Renah Boanerges de Queiroz; da Costa, Cristovão Alves; Albuquerque, Patrícia Melchionna; Junior, Sergio Duvoisin

2013-07-01

Honey has been identified as a potential alternative to the widespread use of antibiotics, which are of significant concern considering the emergence of resistant bacteria. In this context, this study aimed to evaluate the antimicrobial activity of honey samples produced by a stingless bee species and by Apis sp. against pathogenic bacteria, as well as to identify the presence of phenolic compounds. Honey samples from the stingless bee M. compressipes manaosensis were collected twice, during the dry and rainy seasons. Three commercial honey samples from Apis sp. were also included in this study. Two different assays were performed to evaluate the antibacterial potential of the honey samples: agar-well diffusion and broth macrodilution. Liquid-liquid extraction was used to assess phenolic compounds from honey. HPLC analysis was performed in order to identify rutin and apigenin on honey samples. Chromatograms were recorded at 340 and 290 nm. Two honey samples were identified as having the highest antimicrobial activity using the agar diffusion method. Honey produced by Melipona compressipes manaosensis inhibited the growth of Staphylococcus aureus, Escherichia coli (0157: H7), Proteus vulgaris, Shigella sonnei and Klebsiella sp. A sample of honey produced by Apis sp. also inhibited the growth of Salmonella paratyphi. The macrodilution technique presented greater sensitivity for the antibacterial testing, since all honey samples showed activity. Flavonoid rutin was identified in the honey sample produced by the stingless bee. Honey samples tested in this work showed antibacterial activity against Gram-positive and Gram-negative bacteria. The results reported herein highlight the potential of using honey to control bacterial growth.

Montreal Cognitive Assessment for screening mild cognitive impairment: variations in test performance and scores by education in Singapore.

PubMed

Ng, Tze Pin; Feng, Lei; Lim, Wee Shiong; Chong, Mei Sian; Lee, Tih Shih; Yap, Keng Bee; Tsoi, Tung; Liew, Tau Ming; Gao, Qi; Collinson, Simon; Kandiah, Nagaendran; Yap, Philip

2015-01-01

The Montreal Cognitive Assessment (MoCA) was developed as a screening instrument for mild cognitive impairment (MCI). We evaluated the MoCA's test performance by educational groups among older Singaporean Chinese adults. The MoCA and Mini-Mental State Examination (MMSE) were evaluated in two independent studies (clinic-based sample and community-based sample) of MCI and normal cognition (NC) controls, using receiver operating characteristic curve analyses: area under the curve (AUC), sensitivity (Sn), and specificity (Sp). The MoCA modestly discriminated MCI from NC in both study samples (AUC = 0.63 and 0.65): Sn = 0.64 and Sp = 0.36 at a cut-off of 28/29 in the clinic-based sample, and Sn = 0.65 and Sp = 0.55 at a cut-off of 22/23 in the community-based sample. The MoCA's test performance was least satisfactory in the highest (>6 years) education group: AUC = 0.50 (p = 0.98), Sn = 0.54, and Sp = 0.51 at a cut-off of 27/28. Overall, the MoCA's test performance was not better than that of the MMSE. In multivariate analyses controlling for age and gender, MCI diagnosis was associated with a <1-point decrement in MoCA score (η(2) = 0.010), but lower (1-6 years) and no education was associated with a 3- to 5-point decrement (η(2) = 0.115 and η(2) = 0.162, respectively). The MoCA's ability to discriminate MCI from NC was modest in this Chinese population, because it was far more sensitive to the effect of education than MCI diagnosis. © 2015 S. Karger AG, Basel.

Variation in Baiting Intensity Among CO2-Baited Traps Used to Collect Hematophagous Arthropods.

PubMed

Springer, Yuri P; Taylor, Jeffrey R; Travers, Patrick D

2015-01-01

Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. We report results of a laboratory study in which the performance of carbon dioxide-baited traps was evaluated using measures of baiting intensity, the amount of carbon dioxide released per unit time during trap deployment. We evaluated the effects of trap design, carbon dioxide source, and wind speed on baiting intensity and documented significant effects of these factors on the length of sampling (time to baiting intensity = 0), maximum baiting intensity, and variation in baiting intensity during experimental trials. Among the three dry ice-baited trap types evaluated, traps utilizing insulated beverage coolers as dry ice containers sampled for the longest period of time, had the lowest maximum but most consistent baiting intensity within trials and were least sensitive to effects of wind speed and dry ice form (block vs. pellet) on baiting intensity. Results of trials involving traps baited with carbon dioxide released from pressurized cylinders suggested that this trap type had performance comparable to dry ice-baited insulated cooler traps but at considerably higher cost. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Effects of aniracetam on delayed matching-to-sample performance of monkeys and pigeons.

PubMed

Pontecorvo, M J; Evans, H L

1985-05-01

A 3-choice, variable-delay, matching-to-sample procedure was used to evaluate drugs in both pigeons and monkeys while tested under nearly-identical conditions. Aniracetam (Roche 13-5057) improved accuracy of matching at all retention intervals following oral administration (12.5, 25 and 50 mg/kg) to macaque monkeys, with a maximal effect at 25 mg/kg. Aniracetam also antagonized scopolamine-induced impairment of the monkey's performance. Intramuscular administration of these same doses of aniracetam produced a similar, but not significant trend toward improved matching accuracy in pigeons.

The etiology of mathematical self-evaluation and mathematics achievement: understanding the relationship using a cross-lagged twin study from age 9 to 12

PubMed Central

Luo, Yu L.L.; Kovas, Yulia; Haworth, Claire M.A.; Plomin, Robert

2011-01-01

The genetic and environmental origins of individual differences in mathematical self-evaluation over time and its association with later mathematics achievement were investigated in a UK sample of 2138 twin pairs at ages 9 and 12. Self-evaluation indexed how good children think they are at mathematical activities and how much they like those activities. Mathematics achievement was assessed by teachers based on UK National Curriculum standards. At both ages self-evaluation was approximately 40% heritable, with the rest of the variance explained by non-shared environment. The results also suggested moderate reciprocal associations between self-evaluation and mathematics achievement across time, with earlier self-evaluation predicting later performance and earlier performance predicting later self-evaluation. These cross-lagged relationships were genetically rather than environmentally mediated. PMID:22102781

Evaluation of antistripping additives.

DOT National Transportation Integrated Search

1989-01-01

Several chemical antistripping additives were used in field installations and compared to a similar installation using hydrated lime. The performance of the installations was monitored periodically, and material that was sampled during construction w...

The Role of Performance Quality in Adolescents' Self-Evaluation and Rumination after a Speech: Is it Contingent on Social Anxiety Level?

PubMed

Blöte, Anke W; Miers, Anne C; Van den Bos, Esther; Westenberg, P Michiel

2018-05-17

Cognitive behavioural therapy (CBT) has relatively poor outcomes for youth with social anxiety, possibly because broad-based CBT is not tailored to their specific needs. Treatment of social anxiety in youth may need to pay more attention to negative social cognitions that are considered a key factor in social anxiety development and maintenance. The aim of the present study was to learn more about the role of performance quality in adolescents' cognitions about their social performance and, in particular, the moderating role social anxiety plays in the relationship between performance quality and self-cognitions. A community sample of 229 participants, aged 11 to 18 years, gave a speech and filled in questionnaires addressing social anxiety, depression, expected and self-evaluated performance, and post-event rumination. Independent observers rated the quality of the speech. The data were analysed using moderated mediation analysis. Performance quality mediated the link between expected and self-evaluated performance in adolescents with low and medium levels of social anxiety. For adolescents with high levels of social anxiety, only a direct link between expected and self-evaluated performance was found. Their self-evaluation was not related to the quality of their performance. Performance quality also mediated the link between expected performance and rumination, but social anxiety did not moderate this mediation effect. Results suggest that a good performance does not help socially anxious adolescents to replace their negative self-evaluations with more realistic ones. Specific cognitive intervention strategies should be tailored to the needs of socially anxious adolescents who perform well.

Thermal Diffusivity of High-Density Polyethylene Samples of Different Crystallinity Evaluated by Indirect Transmission Photoacoustics

NASA Astrophysics Data System (ADS)

Nesic, M.; Popovic, M.; Rabasovic, M.; Milicevic, D.; Suljovrujic, E.; Markushev, D.; Stojanovic, Z.

2018-02-01

In this work, thermal diffusivity of crystalline high-density polyethylene samples of various thickness, and prepared using different procedures, was evaluated by transmission gas-microphone frequency photoacoustics. The samples' composition analysis and their degree of crystallinity were determined from the wide-angle X-ray diffraction, which confirmed that high-density polyethylene samples, obtained by slow and fast cooling, were equivalent in composition but with different degrees of crystallinity. Structural analysis, performed by differential scanning calorimetry, demonstrated that all of the used samples had different levels of crystallinity, depending not only on the preparing procedure, but also on sample thickness. Therefore, in order to evaluate the samples' thermal diffusivity, it was necessary to modify standard photoacoustic fitting procedures (based on the normalization of photoacoustic amplitude and phase characteristics on two thickness levels) for the interpretation of photoacoustic measurements. The calculated values of thermal diffusivity were in the range of the expected literature values. Besides that, the obtained results indicate the unexpected correlation between the values of thermal diffusivity and thermal conductivity with the degree of crystallinity of the investigated geometrically thin samples. The results indicate the necessity of additional investigation of energy transport in macromolecular systems, as well as the possible employment of the photoacoustic techniques in order to clarify its mechanism.

Opportunities for Improved Management Efficiency of the Head Start Program: Performance Evaluation and High Risk Determination.

ERIC Educational Resources Information Center

Gall, Mary Sheila

This report provides results of a review of the methodology used by the Office of Human Development Services (HDS) to measure Head Start performance and to control high risk Head Start agencies. The review was performed at HDS headquarters and regional locations nationwide. The review was based on a sample of 200 Head Start agencies and focused on…

Academic Performance and Perceived Stress among University Students

ERIC Educational Resources Information Center

Talib, Nadeem; Zia-ur-Rehman, Muhammad

2012-01-01

This study aims to investigate the effect of factor such as perceived stress on the academic performance of the students. A sample of 199 university graduates and undergraduates in Rawalpindi and Islamabad was selected as a statistical frame. Instrumentation used for this study is previously validated construct in order to evaluate the effect of…

Business Telephone Etiquette. Comptetency Test Package. Office Occupations. Instructor's Guide.

ERIC Educational Resources Information Center

Hines, Donna

This competency test package, one of a series of test packages for office occupations education, contains a list of performance objectives: a sample, 50-point objective test; and several performance test activities. The package also includes complete directions for the student and the instructor, plus answer keys and a guide for evaluating the…

Optimal two-phase sampling design for comparing accuracies of two binary classification rules.

PubMed

Xu, Huiping; Hui, Siu L; Grannis, Shaun

2014-02-10

In this paper, we consider the design for comparing the performance of two binary classification rules, for example, two record linkage algorithms or two screening tests. Statistical methods are well developed for comparing these accuracy measures when the gold standard is available for every unit in the sample, or in a two-phase study when the gold standard is ascertained only in the second phase in a subsample using a fixed sampling scheme. However, these methods do not attempt to optimize the sampling scheme to minimize the variance of the estimators of interest. In comparing the performance of two classification rules, the parameters of primary interest are the difference in sensitivities, specificities, and positive predictive values. We derived the analytic variance formulas for these parameter estimates and used them to obtain the optimal sampling design. The efficiency of the optimal sampling design is evaluated through an empirical investigation that compares the optimal sampling with simple random sampling and with proportional allocation. Results of the empirical study show that the optimal sampling design is similar for estimating the difference in sensitivities and in specificities, and both achieve a substantial amount of variance reduction with an over-sample of subjects with discordant results and under-sample of subjects with concordant results. A heuristic rule is recommended when there is no prior knowledge of individual sensitivities and specificities, or the prevalence of the true positive findings in the study population. The optimal sampling is applied to a real-world example in record linkage to evaluate the difference in classification accuracy of two matching algorithms. Copyright © 2013 John Wiley & Sons, Ltd.

Sample size calculation in economic evaluations.

PubMed

Al, M J; van Hout, B A; Michel, B C; Rutten, F F

1998-06-01

A simulation method is presented for sample size calculation in economic evaluations. As input the method requires: the expected difference and variance of costs and effects, their correlation, the significance level (alpha) and the power of the testing method and the maximum acceptable ratio of incremental effectiveness to incremental costs. The method is illustrated with data from two trials. The first compares primary coronary angioplasty with streptokinase in the treatment of acute myocardial infarction, in the second trial, lansoprazole is compared with omeprazole in the treatment of reflux oesophagitis. These case studies show how the various parameters influence the sample size. Given the large number of parameters that have to be specified in advance, the lack of knowledge about costs and their standard deviation, and the difficulty of specifying the maximum acceptable ratio of incremental effectiveness to incremental costs, the conclusion of the study is that from a technical point of view it is possible to perform a sample size calculation for an economic evaluation, but one should wonder how useful it is.

3D elemental sensitive imaging using transmission X-ray microscopy.

PubMed

Liu, Yijin; Meirer, Florian; Wang, Junyue; Requena, Guillermo; Williams, Phillip; Nelson, Johanna; Mehta, Apurva; Andrews, Joy C; Pianetta, Piero

2012-09-01

Determination of the heterogeneous distribution of metals in alloy/battery/catalyst and biological materials is critical to fully characterize and/or evaluate the functionality of the materials. Using synchrotron-based transmission x-ray microscopy (TXM), it is now feasible to perform nanoscale-resolution imaging over a wide X-ray energy range covering the absorption edges of many elements; combining elemental sensitive imaging with determination of sample morphology. We present an efficient and reliable methodology to perform 3D elemental sensitive imaging with excellent sample penetration (tens of microns) using hard X-ray TXM. A sample of an Al-Si piston alloy is used to demonstrate the capability of the proposed method.

Improving semi-automated segmentation by integrating learning with active sampling

NASA Astrophysics Data System (ADS)

Huo, Jing; Okada, Kazunori; Brown, Matthew

2012-02-01

Interactive segmentation algorithms such as GrowCut usually require quite a few user interactions to perform well, and have poor repeatability. In this study, we developed a novel technique to boost the performance of the interactive segmentation method GrowCut involving: 1) a novel "focused sampling" approach for supervised learning, as opposed to conventional random sampling; 2) boosting GrowCut using the machine learned results. We applied the proposed technique to the glioblastoma multiforme (GBM) brain tumor segmentation, and evaluated on a dataset of ten cases from a multiple center pharmaceutical drug trial. The results showed that the proposed system has the potential to reduce user interaction while maintaining similar segmentation accuracy.

Development and verification of a model for estimating the screening utility in the detection of PCBs in transformer oil.

PubMed

Terakado, Shingo; Glass, Thomas R; Sasaki, Kazuhiro; Ohmura, Naoya

2014-01-01

A simple new model for estimating the screening performance (false positive and false negative rates) of a given test for a specific sample population is presented. The model is shown to give good results on a test population, and is used to estimate the performance on a sampled population. Using the model developed in conjunction with regulatory requirements and the relative costs of the confirmatory and screening tests allows evaluation of the screening test's utility in terms of cost savings. Testers can use the methods developed to estimate the utility of a screening program using available screening tests with their own sample populations.

An evaluation of potential sampling locations in a reservoir with emphasis on conserved spatial correlation structure.

PubMed

Yenilmez, Firdes; Düzgün, Sebnem; Aksoy, Aysegül

2015-01-01

In this study, kernel density estimation (KDE) was coupled with ordinary two-dimensional kriging (OK) to reduce the number of sampling locations in measurement and kriging of dissolved oxygen (DO) concentrations in Porsuk Dam Reservoir (PDR). Conservation of the spatial correlation structure in the DO distribution was a target. KDE was used as a tool to aid in identification of the sampling locations that would be removed from the sampling network in order to decrease the total number of samples. Accordingly, several networks were generated in which sampling locations were reduced from 65 to 10 in increments of 4 or 5 points at a time based on kernel density maps. DO variograms were constructed, and DO values in PDR were kriged. Performance of the networks in DO estimations were evaluated through various error metrics, standard error maps (SEM), and whether the spatial correlation structure was conserved or not. Results indicated that smaller number of sampling points resulted in loss of information in regard to spatial correlation structure in DO. The minimum representative sampling points for PDR was 35. Efficacy of the sampling location selection method was tested against the networks generated by experts. It was shown that the evaluation approach proposed in this study provided a better sampling network design in which the spatial correlation structure of DO was sustained for kriging.

Performance of the TB-LAMP diagnostic assay in reference laboratories: Results from a multicentre study.

PubMed

Pham, Thu Hang; Peter, Jonathan; Mello, Fernanda C Q; Parraga, Tommy; Lan, Nguyen Thi Ngoc; Nabeta, Pamela; Valli, Eloise; Caceres, Tatiana; Dheda, Keertan; Dorman, Susan E; Hillemann, Doris; Gray, Christen M; Perkins, Mark D

2018-03-01

To evaluate the diagnostic performance of TB-LAMP, a manual molecular tuberculosis (TB) detection method, and provide comparison to the Xpert MTB/RIF assay. In a large multicentre study, two sputum samples were collected from participants with TB symptoms in reference laboratories in Peru, South Africa, Brazil, and Vietnam. Each sample was tested with TB-LAMP. The reference standard consisted of four direct smears, four cultures, and clinical and radiological findings. Individuals negative on conventional tests were followed up after 8 weeks. The Xpert MTB/RIF assay was performed on fresh or frozen samples as a molecular test comparison. A total of 1036 adults with suspected TB were enrolled. Among 375 culture-confirmed TB cases with 750 sputum samples, TB-LAMP detected 75.6% (95% confidence interval (CI) 71.8-79.4%), including 97.9% (95% CI 96.4-99.4%) of smear-positive TB samples and 46.6% (95% CI 40.6-52.7%) of smear-negative TB samples. Specificity in 477 culture-negative participants not treated for TB (954 sputum samples) was 98.7% (95% CI 97.9-99.6%). TB-LAMP test results were indeterminate in 0.3% of cases. TB-LAMP detects nearly all smear-positive and half of smear-negative TB cases and has a high specificity when performed in reference laboratories. Performance was similar to the Xpert MTB/RIF assay. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

One Sample, One Shot - Evaluation of sample preparation protocols for the mass spectrometric proteome analysis of human bile fluid without extensive fractionation.

PubMed

Megger, Dominik A; Padden, Juliet; Rosowski, Kristin; Uszkoreit, Julian; Bracht, Thilo; Eisenacher, Martin; Gerges, Christian; Neuhaus, Horst; Schumacher, Brigitte; Schlaak, Jörg F; Sitek, Barbara

2017-02-10

The proteome analysis of bile fluid represents a promising strategy to identify biomarker candidates for various diseases of the hepatobiliary system. However, to obtain substantive results in biomarker discovery studies large patient cohorts necessarily need to be analyzed. Consequently, this would lead to an unmanageable number of samples to be analyzed if sample preparation protocols with extensive fractionation methods are applied. Hence, the performance of simple workflows allowing for "one sample, one shot" experiments have been evaluated in this study. In detail, sixteen different protocols implying modifications at the stages of desalting, delipidation, deglycosylation and tryptic digestion have been examined. Each method has been individually evaluated regarding various performance criteria and comparative analyses have been conducted to uncover possible complementarities. Here, the best performance in terms of proteome coverage has been assessed for a combination of acetone precipitation with in-gel digestion. Finally, a mapping of all obtained protein identifications with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) revealed several proteins easily detectable in bile fluid. These results can build the basis for future studies with large and well-defined patient cohorts in a more disease-related context. Human bile fluid is a proximal body fluid and supposed to be a potential source of disease markers. However, due to its biochemical composition, the proteome analysis of bile fluid still represents a challenging task and is therefore mostly conducted using extensive fractionation procedures. This in turn leads to a high number of mass spectrometric measurements for one biological sample. Considering the fact that in order to overcome the biological variability a high number of biological samples needs to be analyzed in biomarker discovery studies, this leads to the dilemma of an unmanageable number of necessary MS-based analyses. Hence, easy sample preparation protocols are demanded representing a compromise between proteome coverage and simplicity. In the presented study, such protocols have been evaluated regarding various technical criteria (e.g. identification rates, missed cleavages, chromatographic separation) uncovering the strengths and weaknesses of various methods. Furthermore, a cumulative bile proteome list has been generated that extends the current bile proteome catalog by 248 proteins. Finally, a mapping with putative biomarkers for hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) derived from tissue-based studies, revealed several of these proteins being easily and reproducibly detectable in human bile. Therefore, the presented technical work represents a solid base for future disease-related studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Deconvoluting simulated metagenomes: the performance of hard- and soft- clustering algorithms applied to metagenomic chromosome conformation capture (3C)

PubMed Central

DeMaere, Matthew Z.

2016-01-01

Background Chromosome conformation capture, coupled with high throughput DNA sequencing in protocols like Hi-C and 3C-seq, has been proposed as a viable means of generating data to resolve the genomes of microorganisms living in naturally occuring environments. Metagenomic Hi-C and 3C-seq datasets have begun to emerge, but the feasibility of resolving genomes when closely related organisms (strain-level diversity) are present in the sample has not yet been systematically characterised. Methods We developed a computational simulation pipeline for metagenomic 3C and Hi-C sequencing to evaluate the accuracy of genomic reconstructions at, above, and below an operationally defined species boundary. We simulated datasets and measured accuracy over a wide range of parameters. Five clustering algorithms were evaluated (2 hard, 3 soft) using an adaptation of the extended B-cubed validation measure. Results When all genomes in a sample are below 95% sequence identity, all of the tested clustering algorithms performed well. When sequence data contains genomes above 95% identity (our operational definition of strain-level diversity), a naive soft-clustering extension of the Louvain method achieves the highest performance. Discussion Previously, only hard-clustering algorithms have been applied to metagenomic 3C and Hi-C data, yet none of these perform well when strain-level diversity exists in a metagenomic sample. Our simple extension of the Louvain method performed the best in these scenarios, however, accuracy remained well below the levels observed for samples without strain-level diversity. Strain resolution is also highly dependent on the amount of available 3C sequence data, suggesting that depth of sequencing must be carefully considered during experimental design. Finally, there appears to be great scope to improve the accuracy of strain resolution through further algorithm development. PMID:27843713

Smart Sampling and HPC-based Probabilistic Look-ahead Contingency Analysis Implementation and its Evaluation with Real-world Data

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

Chen, Yousu; Etingov, Pavel V.; Ren, Huiying

This paper describes a probabilistic look-ahead contingency analysis application that incorporates smart sampling and high-performance computing (HPC) techniques. Smart sampling techniques are implemented to effectively represent the structure and statistical characteristics of uncertainty introduced by different sources in the power system. They can significantly reduce the data set size required for multiple look-ahead contingency analyses, and therefore reduce the time required to compute them. High-performance-computing (HPC) techniques are used to further reduce computational time. These two techniques enable a predictive capability that forecasts the impact of various uncertainties on potential transmission limit violations. The developed package has been tested withmore » real world data from the Bonneville Power Administration. Case study results are presented to demonstrate the performance of the applications developed.« less

Evaluation of Classifier Performance for Multiclass Phenotype Discrimination in Untargeted Metabolomics.

PubMed

Trainor, Patrick J; DeFilippis, Andrew P; Rai, Shesh N

2017-06-21

Statistical classification is a critical component of utilizing metabolomics data for examining the molecular determinants of phenotypes. Despite this, a comprehensive and rigorous evaluation of the accuracy of classification techniques for phenotype discrimination given metabolomics data has not been conducted. We conducted such an evaluation using both simulated and real metabolomics datasets, comparing Partial Least Squares-Discriminant Analysis (PLS-DA), Sparse PLS-DA, Random Forests, Support Vector Machines (SVM), Artificial Neural Network, k -Nearest Neighbors ( k -NN), and Naïve Bayes classification techniques for discrimination. We evaluated the techniques on simulated data generated to mimic global untargeted metabolomics data by incorporating realistic block-wise correlation and partial correlation structures for mimicking the correlations and metabolite clustering generated by biological processes. Over the simulation studies, covariance structures, means, and effect sizes were stochastically varied to provide consistent estimates of classifier performance over a wide range of possible scenarios. The effects of the presence of non-normal error distributions, the introduction of biological and technical outliers, unbalanced phenotype allocation, missing values due to abundances below a limit of detection, and the effect of prior-significance filtering (dimension reduction) were evaluated via simulation. In each simulation, classifier parameters, such as the number of hidden nodes in a Neural Network, were optimized by cross-validation to minimize the probability of detecting spurious results due to poorly tuned classifiers. Classifier performance was then evaluated using real metabolomics datasets of varying sample medium, sample size, and experimental design. We report that in the most realistic simulation studies that incorporated non-normal error distributions, unbalanced phenotype allocation, outliers, missing values, and dimension reduction, classifier performance (least to greatest error) was ranked as follows: SVM, Random Forest, Naïve Bayes, sPLS-DA, Neural Networks, PLS-DA and k -NN classifiers. When non-normal error distributions were introduced, the performance of PLS-DA and k -NN classifiers deteriorated further relative to the remaining techniques. Over the real datasets, a trend of better performance of SVM and Random Forest classifier performance was observed.

Evaluation of Coptidis Rhizoma-Euodiae Fructus couple and Zuojin products based on HPLC fingerprint chromatogram and simultaneous determination of main bioactive constituents.

PubMed

Gao, Xin; Yang, Xiu-Wei; Marriott, Philip J

2013-11-01

Coptidis Rhizoma-Euodiae Fructus couple (CEC) is a classic traditional Chinese medicine preparation consisting of Coptidis Rhizoma and Euodiae Fructus at the ratio of 6:1, and used to treat gastro-intestinal disorders. Alkaloids are the main bioactive component. This research provides comprehensive analysis information for the quality control of CEC. To develop a high-performance liquid chromatography-diode array detection fingerprint for chemical composition characteristics of CEC and its products. The samples were separated with a Gemini C18 column by using gradient elution with water-formic acid (100:0.03) and acetonitrile as mobile phase. Flow rate was 1.0 mL/min and detection wavelength was 250 nm. Similarity analysis and principal component analysis (PCA) were employed to evaluate quality consistencies of analytes. Mean chromatograms and correlation coefficients of analytes were calculated by the software "Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine". Fingerprint chromatogram comparison determined 20 representative general fingerprint peaks, and the fingerprint chromatogram resemblances are all better than 0.988. Consistent results were obtained to show that CEC and its related samples could be successfully divided into three groups. Contribution plots generated by PCA were performed to interpret differences among the sample groups while peaks which significantly contributed to classification were identified. Seven bioactive constituents in the samples were verified by quantitative analysis. The chromatographic fingerprint with similarity evaluation and PCA assay combined with quantification of seven compounds could be utilized as a quality control method for the herbal couple.

Solid-propellant rocket motor ballistic performance variation analyses

NASA Technical Reports Server (NTRS)

Sforzini, R. H.; Foster, W. A., Jr.

1975-01-01

Results are presented of research aimed at improving the assessment of off-nominal internal ballistic performance including tailoff and thrust imbalance of two large solid-rocket motors (SRMs) firing in parallel. Previous analyses using the Monte Carlo technique were refined to permit evaluation of the effects of radial and circumferential propellant temperature gradients. Sample evaluations of the effect of the temperature gradients are presented. A separate theoretical investigation of the effect of strain rate on the burning rate of propellant indicates that the thermoelastic coupling may cause substantial variations in burning rate during highly transient operating conditions. The Monte Carlo approach was also modified to permit the effects on performance of variation in the characteristics between lots of propellants and other materials to be evaluated. This permits the variabilities for the total SRM population to be determined. A sample case shows, however, that the effect of these between-lot variations on thrust imbalances within pairs of SRMs is minor in compariosn to the effect of the within-lot variations. The revised Monte Carlo and design analysis computer programs along with instructions including format requirements for preparation of input data and illustrative examples are presented.

An Overview and Evaluation of Recent Machine Learning Imputation Methods Using Cardiac Imaging Data.

PubMed

Liu, Yuzhe; Gopalakrishnan, Vanathi

2017-03-01

Many clinical research datasets have a large percentage of missing values that directly impacts their usefulness in yielding high accuracy classifiers when used for training in supervised machine learning. While missing value imputation methods have been shown to work well with smaller percentages of missing values, their ability to impute sparse clinical research data can be problem specific. We previously attempted to learn quantitative guidelines for ordering cardiac magnetic resonance imaging during the evaluation for pediatric cardiomyopathy, but missing data significantly reduced our usable sample size. In this work, we sought to determine if increasing the usable sample size through imputation would allow us to learn better guidelines. We first review several machine learning methods for estimating missing data. Then, we apply four popular methods (mean imputation, decision tree, k-nearest neighbors, and self-organizing maps) to a clinical research dataset of pediatric patients undergoing evaluation for cardiomyopathy. Using Bayesian Rule Learning (BRL) to learn ruleset models, we compared the performance of imputation-augmented models versus unaugmented models. We found that all four imputation-augmented models performed similarly to unaugmented models. While imputation did not improve performance, it did provide evidence for the robustness of our learned models.

Measurement of total Zn and Zn isotope ratios by quadrupole ICP-MS for evaluation of Zn uptake in gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Wolf, R.E.; Todd, A.S.; Brinkman, S.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

2009-01-01

This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the 67Zn/66Zn ratios for planned exposure levels and duration. After completion of the pilot study, a full-scale zinc exposure study using rainbow trout was performed. The results of these studies indicate that there are several factors that affect the precision of the measured 67Zn/66Zn ratios in the sample digests, including variations in sample size, endogenous zinc levels, and zinc uptake rates by individual fish. However, since these factors were incorporated in the calculation of the total zinc accumulated by the gills during the exposures, the data obtained were adequate for their intended use in calculating zinc binding and evaluating the influences of differences in water quality parameters.

Statistical process control applied to mechanized peanut sowing as a function of soil texture.

PubMed

Zerbato, Cristiano; Furlani, Carlos Eduardo Angeli; Ormond, Antonio Tassio Santana; Gírio, Lucas Augusto da Silva; Carneiro, Franciele Morlin; da Silva, Rouverson Pereira

2017-01-01

The successful establishment of agricultural crops depends on sowing quality, machinery performance, soil type and conditions, among other factors. This study evaluates the operational quality of mechanized peanut sowing in three soil types (sand, silt, and clay) with variable moisture contents. The experiment was conducted in three locations in the state of São Paulo, Brazil. The track-sampling scheme was used for 80 sampling locations of each soil type. Descriptive statistics and statistical process control (SPC) were used to evaluate the quality indicators of mechanized peanut sowing. The variables had normal distributions and were stable from the viewpoint of SPC. The best performance for peanut sowing density, normal spacing, and the initial seedling growing stand was found for clayey soil followed by sandy soil and then silty soil. Sandy or clayey soils displayed similar results regarding sowing depth, which was deeper than in the silty soil. Overall, the texture and the moisture of clayey soil provided the best operational performance for mechanized peanut sowing.

Statistical process control applied to mechanized peanut sowing as a function of soil texture

PubMed Central

Furlani, Carlos Eduardo Angeli; da Silva, Rouverson Pereira

2017-01-01

The successful establishment of agricultural crops depends on sowing quality, machinery performance, soil type and conditions, among other factors. This study evaluates the operational quality of mechanized peanut sowing in three soil types (sand, silt, and clay) with variable moisture contents. The experiment was conducted in three locations in the state of São Paulo, Brazil. The track-sampling scheme was used for 80 sampling locations of each soil type. Descriptive statistics and statistical process control (SPC) were used to evaluate the quality indicators of mechanized peanut sowing. The variables had normal distributions and were stable from the viewpoint of SPC. The best performance for peanut sowing density, normal spacing, and the initial seedling growing stand was found for clayey soil followed by sandy soil and then silty soil. Sandy or clayey soils displayed similar results regarding sowing depth, which was deeper than in the silty soil. Overall, the texture and the moisture of clayey soil provided the best operational performance for mechanized peanut sowing. PMID:28742095

Ultra compact spectrometer using linear variable filters

NASA Astrophysics Data System (ADS)

Dami, M.; De Vidi, R.; Aroldi, G.; Belli, F.; Chicarella, L.; Piegari, A.; Sytchkova, A.; Bulir, J.; Lemarquis, F.; Lequime, M.; Abel Tibérini, L.; Harnisch, B.

2017-11-01

The Linearly Variable Filters (LVF) are complex optical devices that, integrated in a CCD, can realize a "single chip spectrometer". In the framework of an ESA Study, a team of industries and institutes led by SELEX-Galileo explored the design principles and manufacturing techniques, realizing and characterizing LVF samples based both on All-Dielectric (AD) and Metal-Dielectric (MD) Coating Structures in the VNIR and SWIR spectral ranges. In particular the achieved performances on spectral gradient, transmission bandwidth and Spectral Attenuation (SA) are presented and critically discussed. Potential improvements will be highlighted. In addition the results of a feasibility study of a SWIR Linear Variable Filter are presented with the comparison of design prediction and measured performances. Finally criticalities related to the filter-CCD packaging are discussed. The main achievements reached during these activities have been: - to evaluate by design, manufacturing and test of LVF samples the achievable performances compared with target requirements; - to evaluate the reliability of the projects by analyzing their repeatability; - to define suitable measurement methodologies

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

Hoegg, Edward D.; Barinaga, Charles J.; Hager, George J.

ABSTRACT In order to meet a growing need for fieldable mass spectrometer systems for precise elemental and isotopic analyses, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) has a number of very promising characteristics. One key set of attributes that await validation deals with the performance characteristics relative to isotope ratio precision and accuracy. Due to its availability and prior experience with this research team, the initial evaluation of isotope ratio (IR) performance was performed on a Thermo Scientific Exactive Orbitrap instrument. While the mass accuracy and resolution performance for orbitrap analyzers are very well documented, no detailed evaluations of themore » IR performance have been published. Efforts described here involve two variables: the inherent IR precision and accuracy delivered by the LSAPGD microplasma and the inherent IR measurement qualities of orbitrap analyzers. Important to the IR performance, the various operating parameters of the orbitrap sampling interface, HCD dissociation stage, and ion injection/data acquisition have been evaluated. The IR performance for a range of other elements, including natural, depleted, and enriched uranium isotopes was determined. In all cases the precision and accuracy are degraded when measuring low abundance (<0.1% isotope fractions). In the best case, IR precision on the order of 0.1 %RSD can be achieved, with values of 1-3 %RSD observed for low-abundance species. The results suggest that the LSAPGD is a very good candidate for field deployable MS analysis and that the high resolving powers of the orbitrap may be complemented with a here-to-fore unknown capacity to deliver high-precision isotope ratios.« less

Evaluating cryostat performance for naval applications

NASA Astrophysics Data System (ADS)

Knoll, David; Willen, Dag; Fesmire, James; Johnson, Wesley; Smith, Jonathan; Meneghelli, Barry; Demko, Jonathan; George, Daniel; Fowler, Brian; Huber, Patti

2012-06-01

The Navy intends to use High Temperature Superconducting Degaussing (HTSDG) coil systems on future Navy platforms. The Navy Metalworking Center (NMC) is leading a team that is addressing cryostat configuration and manufacturing issues associated with fabricating long lengths of flexible, vacuum-jacketed cryostats that meet Navy shipboard performance requirements. The project includes provisions to evaluate the reliability performance, as well as proofing of fabrication techniques. Navy cryostat performance specifications include less than 1 Wm-1 heat loss, 2 MPa working pressure, and a 25-year vacuum life. Cryostat multilayer insulation (MLI) systems developed on the project have been validated using a standardized cryogenic test facility and implemented on 5-meterlong test samples. Performance data from these test samples, which were characterized using both LN2 boiloff and flow-through measurement techniques, will be presented. NMC is working with an Integrated Project Team consisting of Naval Sea Systems Command, Naval Surface Warfare Center-Carderock Division, Southwire Company, nkt cables, Oak Ridge National Laboratory (ORNL), ASRC Aerospace, and NASA Kennedy Space Center (NASA-KSC) to complete these efforts. Approved for public release; distribution is unlimited. This material is submitted with the understanding that right of reproduction for governmental purposes is reserved for the Office of Naval Research, Arlington, Virginia 22203-1995.

Evaluation of Apical Vapor Lock Formation and comparative Evaluation of its Elimination using Three different Techniques: An in vitro Study.

PubMed

Agarwal, Anand; Deore, Rahul B; Rudagi, Kavitarani; Nanda, Zinnie; Baig, Mirza Osman; Fareez, Md Adil

2017-09-01

The aim of this study was (i) to evaluate the formation of air bubbles in the apical region of root canal (apical vapor lock) during syringe irrigation, using cone beam computed tomography (CBCT) and (ii) comparative evaluation of the elimination of an established vapor lock by EndoActivator, ultrasonics, and manual dynamic agitation (MDA), using CBCT. A total of 60 extracted human single-rooted teeth were equally divided into three groups of 20 teeth each. The samples were decoronated 17 mm from the apex, cleaned, and shaped to size F4 Protaper using 3% sodium hypochlorite. Samples were irrigated with 3% sodium hypochlorite + cesium chloride radiopaque dye, and preoperative CBCT images were obtained. After formation of apical vapor lock in the scanned teeth, EndoActivator (group I), passive ultrasonic irrigation (group II), and MDA with K-file (group III) were performed and the teeth were again placed in CBCT scanner and results analyzed using the chi-square test. The apical vapor lock was formed in all the samples. Out of the 20 teeth in each group, the apical vapor lock was eliminated in 18 samples of EndoActivator group (90%), 16 samples of ultrasonic group (80%), while it was eliminated in 10 samples by MDA (50%). It is concluded that (1) apical vapor lock is consistently formed during endodontic irrigation in closed canal systems and (2) sonic activation performs better than the ultrasonics and MDA in eliminating the apical vapor lock, with statistically significant difference between all the three groups (p < 0.05). The results suggest that the apical vapor lock (dead water zone) is consistently formed during routine endodontic irrigation which impedes irrigant penetration till the working length, thereby leading to inefficient debridement. Hence, to eliminate this vapor lock, techniques, such as sonics or ultrasonics should be used along with the irrigant after shaping and cleaning of the root canal.

Lessons learned in preparing method 29 filters for compliance testing audits.

PubMed

Martz, R F; McCartney, J E; Bursey, J T; Riley, C E

2000-01-01

Companies conducting compliance testing are required to analyze audit samples at the time they collect and analyze the stack samples if audit samples are available. Eastern Research Group (ERG) provides technical support to the EPA's Emission Measurements Center's Stationary Source Audit Program (SSAP) for developing, preparing, and distributing performance evaluation samples and audit materials. These audit samples are requested via the regulatory Agency and include spiked audit materials for EPA Method 29-Metals Emissions from Stationary Sources, as well as other methods. To provide appropriate audit materials to federal, state, tribal, and local governments, as well as agencies performing environmental activities and conducting emission compliance tests, ERG has recently performed testing of blank filter materials and preparation of spiked filters for EPA Method 29. For sampling stationary sources using an EPA Method 29 sampling train, the use of filters without organic binders containing less than 1.3 microg/in.2 of each of the metals to be measured is required. Risk Assessment testing imposes even stricter requirements for clean filter background levels. Three vendor sources of quartz fiber filters were evaluated for background contamination to ensure that audit samples would be prepared using filters with the lowest metal background levels. A procedure was developed to test new filters, and a cleaning procedure was evaluated to see if a greater level of cleanliness could be achieved using an acid rinse with new filters. Background levels for filters supplied by different vendors and within lots of filters from the same vendor showed a wide variation, confirmed through contact with several analytical laboratories that frequently perform EPA Method 29 analyses. It has been necessary to repeat more than one compliance test because of suspect metals background contamination levels. An acid cleaning step produced improvement in contamination level, but the difference was not significant for most of the Method 29 target metals. As a result of our studies, we conclude: Filters for Method 29 testing should be purchased in lots as large as possible. Testing firms should pre-screen new boxes and/or new lots of filters used for Method 29 testing. Random analysis of three filters (top, middle, bottom of the box) from a new box of vendor filters before allowing them to be used in field tests is a prudent approach. A box of filters from a given vendor should be screened, and filters from this screened box should be used both for testing and as field blanks in each test scenario to provide the level of quality assurance required for stationary source testing.

INNOVATIVE TECHNOLOGY EVALUATION REPORT ...

EPA Pesticide Factsheets

The Split Core Sampler for Submerged Sediments (Split Core Sampler) designed and fabricated by Arts Manufacturing & Supply, Inc., was demonstrated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation Program in April and May 1999 at sites in EPA Regions 1 and 5, respectively. In addition to assessing ease of sampler operation, key objectives of the demonstration included evaluating the samplers ability to (1) consistently collect a given volume of sediment, (2) consistently collect sediment in a given depth interval, (3) collect samples with consistent characteristics from a homogenous layer of sediment, and (4) collect samples under a variety of site conditions. This report describes the demonstration results for the Split Core Sampler and two conventional samplers (the Hand Corer and Vibrocorer) used as reference samplers. During the demonstration, the Split Core Sampler performed as well as or better than the reference samplers. Based on visual observations, both the Split Core Sampler and reference samplers collected partially compressed samples of consolidated and unconsolidated sediments from the sediment surface downward; sample representativeness may be questionable because of core shortening and core compression. Sediment stratification was preserved for both consolidated and unconsolidated sediment samples collected by the Split Core Sampler and reference samplers. No sampler was able to collect samples

Preliminary Problem Definition Study of 48 Munitions-Related Chemicals. Volume II. Propellant-Related Chemicals

DTIC Science & Technology

1978-04-01

34analysis of sediment and biota samples from Radford AAP aquatic toxicity studies if the literature evaluation reveals the need for more information... Sampling and analysis at Radford be performed to determine the quantity of the compound entering the New River Best Available Co. -7- V - A literature...chemical properties of this compound if they can not be obtained from the manufacturer - Sampling and analysis of sediment and biota at Radford AAP to

Analytical performance of benchtop total reflection X-ray fluorescence instrumentation for multielemental analysis of wine samples

NASA Astrophysics Data System (ADS)

Dalipi, Rogerta; Marguí, Eva; Borgese, Laura; Bilo, Fabjola; Depero, Laura E.

2016-06-01

Recent technological improvements have led to a widespread adoption of benchtop total reflection X-ray fluorescence systems (TXRF) for analysis of liquid samples. However, benchtop TXRF systems usually present limited sensitivity compared with high-scale instrumentation which can restrict its application in some fields. The aim of the present work was to evaluate and compare the analytical capabilities of two TXRF systems, equipped with low power Mo and W target X-ray tubes, for multielemental analysis of wine samples. Using the Mo-TXRF system, the detection limits for most elements were one order of magnitude lower than those attained using the W-TXRF system. For the detection of high Z elements like Cd and Ag, however, W-TXRF remains a very good option due to the possibility of K-Lines detection. Accuracy and precision of the obtained results have been evaluated analyzing spiked real wine samples and comparing the TXRF results with those obtained by inductively coupled plasma emission spectroscopy (ICP-OES). In general, good agreement was obtained between ICP-OES and TXRF results for the analysis of both red and white wine samples except for light elements (i.e., K) which TXRF concentrations were underestimated. However, a further achievement of analytical quality of TXRF results can be achieved if wine analysis is performed after dilution of the sample with de-ionized water.

Performance evaluation of the Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA, a 4th generation HIV assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma.

PubMed

Bentsen, Christopher; McLaughlin, Lisa; Mitchell, Elizabeth; Ferrera, Carol; Liska, Sally; Myers, Robert; Peel, Sheila; Swenson, Paul; Gadelle, Stephane; Shriver, M Kathleen

2011-12-01

A multi-center study was conducted to evaluate the Bio-Rad GS HIV Combo Ag/Ab EIA, a 4th generation HIV-1/HIV-2 assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma in adult and pediatric populations. The objectives of the study were to assess assay performance for the detection of acute HIV infections; sensitivity in known HIV positive samples; percent agreement with HIV status; specificity in low and high risk individuals of unknown HIV status; and to compare assay performance to a 3rd generation HIV assay. The evaluation included testing 9150 samples at four U.S. clinical trial sites, using three kit lots. Unlinked samples were from routine testing, repositories or purchased from vendors. GS HIV Combo Ag/Ab EIA detection in samples from individuals in two separate populations with acute HIV infection was 95.2% (20/21) and 86.4% (38/44). Sensitivity was 100% (1603/1603) in known antibody positive [HIV-1 Groups M and O, and HIV-2] samples. HIV p24 antigen detection was 100% (53/53) in HIV-1 culture supernatants. HIV-1 seroconversion panel detection improved by a range of 0-20 days compared to a 3rd generation HIV test. Specificity was 99.9% (5989/5996) in low risk, 99.9% (959/960) in high risk and 100% (100/100) in pediatric populations. The GS HIV Combo Ag/Ab EIA significantly reduced the diagnostic window when compared to the 3rd generation screening assay, enabling earlier diagnosis of HIV infection. The performance parameters of the Bio-Rad GS HIV Combo Ag/Ab EIA are well suited for use in HIV diagnostic settings. Copyright © 2011 Elsevier B.V. All rights reserved.

Internal quality assurance in a clinical virology laboratory. II. Internal quality control.

PubMed Central

Gray, J J; Wreghitt, T G; McKee, T A; McIntyre, P; Roth, C E; Smith, D J; Sutehall, G; Higgins, G; Geraghty, R; Whetstone, R

1995-01-01

AIMS--In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera. METHODS--From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera. RESULTS--The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests). CONCLUSIONS--The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results. PMID:7730475

Headspace solid-phase microextraction (HS-SPME) and liquid-liquid extraction (LLE): comparison of the performance in classification of ecstasy tablets. Part 2.

PubMed

Bonadio, Federica; Margot, Pierre; Delémont, Olivier; Esseiva, Pierre

2008-11-20

Headspace solid-phase microextraction (HS-SPME) is assessed as an alternative to liquid-liquid extraction (LLE) currently used for 3,4-methylenedioxymethampethamine (MDMA) profiling. Both methods were compared evaluating their performance in discriminating and classifying samples. For this purpose 62 different seizures were analysed using both extraction techniques followed by gas chromatography-mass spectroscopy (GC-MS). A previously validated method provided data for HS-SPME, whereas LLE data were collected applying a harmonized methodology developed and used in the European project CHAMP. After suitable pre-treatment, similarities between sample pairs were studied using the Pearson correlation. Both methods enable to distinguish between samples coming from the same pre-tabletting batches and samples coming from different pre-tabletting batches. This finding emphasizes the use of HS-SPME as an effective alternative to LLE, with additional advantages such as sample preparation and a solvent-free process.

Modulation transfer function cascade model for a sampled IR imaging system.

PubMed

de Luca, L; Cardone, G

1991-05-01

The performance of the infrared scanning radiometer (IRSR) is strongly stressed in convective heat transfer applications where high spatial frequencies in the signal that describes the thermal image are present. The need to characterize more deeply the system spatial resolution has led to the formulation of a cascade model for the evaluation of the actual modulation transfer function of a sampled IR imaging system. The model can yield both the aliasing band and the averaged modulation response for a general sampling subsystem. For a line scan imaging system, which is the case of a typical IRSR, a rule of thumb that states whether the combined sampling-imaging system is either imaging-dependent or sampling-dependent is proposed. The model is tested by comparing it with other noncascade models as well as by ad hoc measurements performed on a commercial digitized IRSR.

Evaluation of Surlyn 8920 as PHE Visor Material and Evaluations of New Adhesives for Improving Bonding Between Teflon and Stainless Steel at Cryogenic Temperature

NASA Technical Reports Server (NTRS)

Ray, Asit K.

1991-01-01

Two studies are presented, and in the first study, Surlyn 8920 (an ionic and amorphous low density polyethylene made by Dupont) was evaluated as a possible replacement of Plexyglass G as PHE visor material. Four formulations of the polymer were made by adding different amounts of UV stabilizer, energy quencher, and antioxident in a Brabender Plasticorder. The formulated polymers were molded in the form of sheets in a compression molder. Cut samples from the molded sheets were exposed in a weatherometer and tested on Instron Tensile Tester for strength and elongation. Specially molded samples of the formulated polymers were subjected to Charpy Impact Tests. In the second study, preliminary evaluations of adhesives for improvement of bonding between Teflon and stainless steel (SS) were performed. Kapton, a high temperature polyimide made by Dupont, and a rubber based adhesive made by Potter Paint Co., were evaluated against industrial quality epoxy, the current material used to bond Teflon and SS. The degreased surfaces of the SS discs were etched mechanically, with a few of these etched chemically. The surfaces of the SS discs were etched mechanically, with a few of these etched chemically. Bonding strengths were evaluated using lap shear tests on the Instron Tensile Tester for the samples bonded by Kapton and industrial quality epoxy. Bond strengths were also evaluated using a pull test on the Instron for the samples bonded by Potter adhesive (CWL-152) and industrial quality epoxy. Based on limited lap shear data, Kapton gave bond strength favorable compared to that of industrial epoxy. Based on limited pull test data, Kapton bonded and CWL-152 bonded samples showed poor strength compared to epoxy bonded sample.

Urine Monitoring System

NASA Technical Reports Server (NTRS)

Feedback, Daniel L.; Cibuzar, Branelle R.

2009-01-01

The Urine Monitoring System (UMS) is a system designed to collect an individual crewmember's void, gently separate urine from air, accurately measure void volume, allow for void sample acquisition, and discharge remaining urine into the Waste Collector Subsystem (WCS) onboard the International Space Station. The Urine Monitoring System (UMS) is a successor design to the existing Space Shuttle system and will resolve anomalies such as: liquid carry-over, inaccurate void volume measurements, and cross contamination in void samples. The crew will perform an evaluation of airflow at the ISS UMS urinal hose interface, a calibration evaluation, and a full user interface evaluation. o The UMS can be used to facilitate non-invasive methods for monitoring crew health, evaluation of countermeasures, and implementation of a variety of biomedical research protocols on future exploration missions.

Application of Advanced Nondestructive Evaluation Techniques for Cylindrical Composite Test Samples

NASA Technical Reports Server (NTRS)

Martin, Richard E.; Roth, Donald J.; Salem, Jonathan A.

2013-01-01

Two nondestructive methods were applied to composite cylinder samples pressurized to failure in order to determine manufacturing quality and monitor damage progression under load. A unique computed tomography (CT) image processing methodology developed at NASA Glenn Research was used to assess the condition of the as-received samples while acoustic emission (AE) monitoring was used to identify both the extent and location of damage within the samples up to failure. Results show the effectiveness of both of these methods in identifying potentially critical fabrication issues and their resulting impact on performance.

Arc Jet Testing of Carbon Phenolic for Mars Sample Return and Future NASA Missions

NASA Technical Reports Server (NTRS)

Laub, Bernard; Chen, Yih-Kanq; Skokova, Kristina; Delano, Chad

2004-01-01

The objective of the Mars Sample Return (MSR) Mission is to return a sample of MArtian soil to Earth. The Earth Entry Vehicle (EEV) brings te samples through the atmosphere to the ground.The program aims to: Model aerothermal environment during EEV flight; On the basis of results, select potential TPS materials for EEV forebody; Fabricate TPS materials; Test the materials in the arc jet environment representative of predicted flight environment;Evaluate material performance; Compare results of modeling predictions with test results.

Using Google Docs to Enhance the Teacher Work Sample: Building e-Portfolios for Learning and Practice

ERIC Educational Resources Information Center

Gugino, Jessica

2018-01-01

The use of teaching portfolios in teacher education programs is a widely accepted practice. This article describes how a traditional teacher work sample was transformed using the online platform, Google Docs. The use of online digital portfolios may help to satisfy both the need to evaluate teacher candidates' performance in special education…

Imaging system design for improved information capacity

NASA Technical Reports Server (NTRS)

Fales, C. L.; Huck, F. O.; Samms, R. W.

1984-01-01

Shannon's theory of information for communication channels is used to assess the performance of line-scan and sensor-array imaging systems and to optimize the design trade-offs involving sensitivity, spatial response, and sampling intervals. Formulations and computational evaluations account for spatial responses typical of line-scan and sensor-array mechanisms, lens diffraction and transmittance shading, defocus blur, and square and hexagonal sampling lattices.

FIELD METHOD COMPARISON BETWEEN PASSIVE AIR SAMPLERS AND CONTINUOUS MONITORS FOR VOLATILE ORGANIC COMPOUNDS AND NO2 IN EL PASO, TEXAS, USA

EPA Science Inventory

Passive sampling of gas-phase air toxics and criteria pollutants has become an attractive monitoring method in human exposure studies due to the relatively low sampling cost and ease of use. This study evaluates the performance of Model 3300 Ogawa(TM) Passive NO2 Samplers and 3...

Quality control of measurements made on fixed-area sample plots

Treesearch

Ola Lindgren

2000-01-01

The paper describes results from a large program for quality control of forest measurements. The performance of 87 surveyors was evaluated. Tree heights were usually measured well, whereas the counting of tree-rings on increment cores was a source of considerable bias for many surveyors. During tree count on sample plots, many surveyors had a tendency to forget trees,...

Tank 241-AY-101 Privatization Push Mode Core Sampling and Analysis Plan

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

TEMPLETON, A.M.

2000-05-19

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AY-101. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AY-101 required to satisfy ''Data Quality Objectives For RPP Privatization Phase I: Confirm Tank T Is An Appropriate Feed Source For High-Level Waste Feed Batch X(HLW DQO)' (Nguyen 1999a), ''Data Quality Objectives For TWRS Privatization Phase I: Confirm Tank T Is An Appropriate Feed Source For Low-Activity Waste Feed Butch X (LAW DQO) (Nguyen 1999b)'', ''Low Activity Wastemore » and High-Level Waste Feed Data Quality Objectives (L&H DQO)'' (Patello et al. 1999), and ''Characterization Data Needs for Development, Design, and Operation of Retrieval Equipment Developed through the Data Quality Objective Process (Equipment DQO)'' (Bloom 1996). Special instructions regarding support to the LAW and HLW DQOs are provided by Baldwin (1999). Push mode core samples will be obtained from risers 15G and 150 to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives. The 222-S Laboratory will extrude core samples; composite the liquids and solids; perform chemical analyses on composite and segment samples; archive half-segment samples; and provide sub-samples to the Process Chemistry Laboratory. The Process Chemistry Laboratory will prepare test plans and perform process tests to evaluate the behavior of the 241-AY-101 waste undergoing the retrieval and treatment scenarios defined in the applicable DQOs. Requirements for analyses of samples originating in the process tests will be documented in the corresponding test plans and are not within the scope of this SAP.« less

An optimization based sampling approach for multiple metrics uncertainty analysis using generalized likelihood uncertainty estimation

NASA Astrophysics Data System (ADS)

Zhou, Rurui; Li, Yu; Lu, Di; Liu, Haixing; Zhou, Huicheng

2016-09-01

This paper investigates the use of an epsilon-dominance non-dominated sorted genetic algorithm II (ɛ-NSGAII) as a sampling approach with an aim to improving sampling efficiency for multiple metrics uncertainty analysis using Generalized Likelihood Uncertainty Estimation (GLUE). The effectiveness of ɛ-NSGAII based sampling is demonstrated compared with Latin hypercube sampling (LHS) through analyzing sampling efficiency, multiple metrics performance, parameter uncertainty and flood forecasting uncertainty with a case study of flood forecasting uncertainty evaluation based on Xinanjiang model (XAJ) for Qing River reservoir, China. Results obtained demonstrate the following advantages of the ɛ-NSGAII based sampling approach in comparison to LHS: (1) The former performs more effective and efficient than LHS, for example the simulation time required to generate 1000 behavioral parameter sets is shorter by 9 times; (2) The Pareto tradeoffs between metrics are demonstrated clearly with the solutions from ɛ-NSGAII based sampling, also their Pareto optimal values are better than those of LHS, which means better forecasting accuracy of ɛ-NSGAII parameter sets; (3) The parameter posterior distributions from ɛ-NSGAII based sampling are concentrated in the appropriate ranges rather than uniform, which accords with their physical significance, also parameter uncertainties are reduced significantly; (4) The forecasted floods are close to the observations as evaluated by three measures: the normalized total flow outside the uncertainty intervals (FOUI), average relative band-width (RB) and average deviation amplitude (D). The flood forecasting uncertainty is also reduced a lot with ɛ-NSGAII based sampling. This study provides a new sampling approach to improve multiple metrics uncertainty analysis under the framework of GLUE, and could be used to reveal the underlying mechanisms of parameter sets under multiple conflicting metrics in the uncertainty analysis process.

Analysis of EML4-ALK rearrangement in non-small cell lung cancer in Argentina.

PubMed

Verzura, María; Batagelj, Emilio; Bagnes, Claudia; Martin, Claudio; Enrico, Diego; Richardet, Eduardo; De la Iglesia, Paola

2018-02-26

Identification of EML4-ALK rearrangement by FISH test has become standard in advanced NSCLC patients. There is limited information about the prevalence and clinical characteristics of ALK translocation in Latin America. The aim of our study was to evaluate this lung cancer subtype features in Argentinian patients and the factibility of FISH test with different methods used for obtaining tissue samples. Between August 2014 and February 2017, 183 non-squamous NSCLC patients were prospectively enrolled from five Argentinian institutions. Different techniques and procedures were used to obtained tissue samples material. ALK determination was performed by FISH and immunohistochemistry (IHC). Correlation with clinico-pathological information and different biopsy procedures was assessed. From 183 non-squamous NSCLC samples, 131 could perform FISH test, finding 123 (93.9%) negative and 8 (6.1%) positive patients. Fifty-one samples were not evaluable by FISH, 35 because of technical problems and 16 due to not/weak signal. The difficulties in obtaining adequate FISH tests were observed significantly more frequently for fine-needle aspiration (FNA) and core-needle biopsy than for excisional and incisional biopsy (p = 0.009). Regarding the procedures, surgery was the most efficient, obtaining only 12.7% (10/79) of not evaluable samples for FISH, while CT guided biopsy and transbronchial biopsy (TBB) failed in 43.8% (21/48) and 41.3% (19/46) of patients respectively (p < 0.001). We observed a significant association between ALK translocation and never smoking habit (p = 0.004). Our ALK rearrangements frequency (6.1%) was similar to the reports worldwide. One of the major determinants for the ALK FISH test success is the quality of the tissue sample obtained. Copyright © 2018 Elsevier Inc. All rights reserved.

Stability of extemporaneously prepared glycopyrrolate oral suspensions.

PubMed

Cober, Mary Petrea; Johnson, Cary E; Sudekum, David; Penprase, Kimberly

2011-05-01

The stability of extemporaneously prepared glycopyrrolate 0.5-mg/mL suspensions was evaluated. An oral suspension of glycopyrrolate 0.5 mg/mL was prepared by thoroughly grinding 30 1-mg tablets of glycopyrrolate in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of the formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and stored at room temperature (23-25 °C). A 1-mL sample was withdrawn from each of the three bottles with a micropipette immediately after preparation and 7, 15, 30, 60, and 90 days afterward. After further dilution to an expected concentration of 50 μg/mL with sample diluent, the samples were assayed in duplicate by stability-indicating high-performance liquid chromatography. The samples were visually examined for any color change and evaluated for pH on each day of analysis. Taste evaluations were performed at the beginning and end of the study. Stability was defined as the retention of at least 90% of the initial concentration. At least 95% of the initial glycopyrrolate remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH, and no visible microbial growth was observed in any sample. Extemporaneously compounded suspensions of glycopyrrolate 0.5 mg/mL in a 1:1 mixture of Ora-Plus/Ora-Sweet or Ora-Plus/Ora-Sweet SF were stable for at least 90 days when stored in amber plastic bottles at room temperature.

Algorithm and Architecture Independent Benchmarking with SEAK

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

Tallent, Nathan R.; Manzano Franco, Joseph B.; Gawande, Nitin A.

2016-05-23

Many applications of high performance embedded computing are limited by performance or power bottlenecks. We have designed the Suite for Embedded Applications & Kernels (SEAK), a new benchmark suite, (a) to capture these bottlenecks in a way that encourages creative solutions; and (b) to facilitate rigorous, objective, end-user evaluation for their solutions. To avoid biasing solutions toward existing algorithms, SEAK benchmarks use a mission-centric (abstracted from a particular algorithm) and goal-oriented (functional) specification. To encourage solutions that are any combination of software or hardware, we use an end-user black-box evaluation that can capture tradeoffs between performance, power, accuracy, size, andmore » weight. The tradeoffs are especially informative for procurement decisions. We call our benchmarks future proof because each mission-centric interface and evaluation remains useful despite shifting algorithmic preferences. It is challenging to create both concise and precise goal-oriented specifications for mission-centric problems. This paper describes the SEAK benchmark suite and presents an evaluation of sample solutions that highlights power and performance tradeoffs.« less

The Suite for Embedded Applications and Kernels

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

2016-05-10

Many applications of high performance embedded computing are limited by performance or power bottlenecks. We havedesigned SEAK, a new benchmark suite, (a) to capture these bottlenecks in a way that encourages creative solutions to these bottlenecks? and (b) to facilitate rigorous, objective, end-user evaluation for their solutions. To avoid biasing solutions toward existing algorithms, SEAK benchmarks use a mission-centric (abstracted from a particular algorithm) andgoal-oriented (functional) specification. To encourage solutions that are any combination of software or hardware, we use an end-user blackbox evaluation that can capture tradeoffs between performance, power, accuracy, size, and weight. The tradeoffs are especially informativemore » for procurement decisions. We call our benchmarks future proof because each mission-centric interface and evaluation remains useful despite shifting algorithmic preferences. It is challenging to create both concise and precise goal-oriented specifications for mission-centric problems. This paper describes the SEAK benchmark suite and presents an evaluation of sample solutions that highlights power and performance tradeoffs.« less

Comparative performance of contact plates, electrostatic wipes, swabs and a novel sampling device for the detection of Staphylococcus aureus on environmental surfaces.

PubMed

Lutz, J K; Crawford, J; Hoet, A E; Wilkins, J R; Lee, J

2013-07-01

To evaluate the performance of four sampling methods [contact plates, electrostatic wipes (wipe), swabs and a novel roller sampler] for recovery of Staphylococcus aureus from a stainless steel surface. Stainless steel test plates were inoculated with Staph. aureus, dried for 24 h and sampled using each of the four methods. Samples were either incubated directly (roller, contact plate) or processed using elution and membrane filtration (swab, wipe). Performance was assessed by calculating the apparent sampling efficiency (ASE), analytical sensitivity (Sn) and percentage of replications with positive growth. The wipe demonstrated the best performance across all inoculating concentrations (ASE(48 h) = 18%; Sn(48 h) = 7 CFU per 100 cm(2)). The swab performed well when corrected for area actually sampled (ASE(48 h) = 24%; Sn(48 h) = 76 CFU per 100 cm(2)). Of the contact-based methods, the newly developed roller sampler outperformed the contact plate (roller: ASE(48 h) = 10%; Sn(48 h) = 17 CFU per 100 cm(2); contact plate: ASE(48 h) = 0·04%; Sn(48 h) = 1412 CFU per 100 cm(2)); both contact samplers performed better at higher inoculating concentrations (6E3 CFU per 100 cm(2) for the roller and 6E6 CFU per 100 cm(2) for the contact plate). Overall, the electrostatic wipe produced the highest number of replications resulting in positive growth (74%(24 h), 91%(48 h)). This study demonstrates that selection of the sampling method must be carefully considered, given that different methods have varying performance. This is the first study assessing static wipes for sampling and one that uses a more real-world-relevant 24-h drying time. The results help with infection control, and environmental health professionals choose better sampling methodologies. Journal of Applied Microbiology © 2013 The Society for Applied Microbiology.

The Viewpoints of Students and Evaluation Experts About Performance Processes of Faculty Member Evaluation at Mazandaran University of Medical Sciences, 2014

PubMed Central

Ghahrani, Nassim; Balaghafari, Azita; Aligolbandi, Kobra; Vahedi, Mohammad; Siamian, Hasan

2015-01-01

Background and purpose: One of the most common ways used in most of the countries and Iran to determine the status of teacher training is the evaluation by students. The most common method of evaluation is the survey questionnaire, the content of a number of questions about educational activities provided to the students. The researchers plan to evaluate the students’ and experts’ performances at Mazandaran University of Medical Sciences on the process of evaluating the performance of teachers, they examined in 2014. Materials and methods: This study surveys the students and experts in the evaluation of faculty members’ performance process. The study subjects were 3904 students and 37 evaluation expert of Mazandaran University of Medical Sciences. Using Cochran sampling formula of 350 students through proportional stratified random sampling were selected. The experts’ viewpoint, method was used. Data collection tools consisted of 14 questions with answers Yes, or, I don’t know. Descriptive Statistical analysis of the data and chi-square test was performed. Results: From total of 350 students, 346 and the entire 37 evaluations expert participated in this study. Most of the students, 80 (23.12%) and the largest number of experts, 8 (21.62%) were from Sari Allied Medical Sciences Faculty. Most of the demographic information about gender were, 255 female students (74.56%) and 29 female experts (78.37%). In most age groups of students, 188 (55.62 percent) were in the category of 18 to 20 years, and the experts, 19 (51.35%) were in the category of 22 and 31 years. Most students, 232 of them (70.95%) were in semester 2 and 4. Most experts, 20 (54.05 percent) were under 10 years of work experience. The comparison between the views of students and experts in the evaluation process between the schools of Mazandaran University of Medical Sciences, Sari School of Nursing and Midwifery, there was difference between the opinions of experts and students (p-value=0.01. It showed 86.7% student and 33.3% of experts is satisfied with the evaluation process. Conclusion: on comparison of students and experts viewpoints on the implementation of the evaluation process, it is noteworthy that among students of different opinions on how the evaluation process. It worth to mention that there is insignificant difference between their viewpoints and majority of students and evaluation experts with the evaluation the process. In addition, the experts evaluated at different schools, most of them are satisfied the process. PMID:26236169

The Viewpoints of Students and Evaluation Experts About Performance Processes of Faculty Member Evaluation at Mazandaran University of Medical Sciences, 2014.

PubMed

Ghahrani, Nassim; Balaghafari, Azita; Aligolbandi, Kobra; Vahedi, Mohammad; Siamian, Hasan

2015-06-01

One of the most common ways used in most of the countries and Iran to determine the status of teacher training is the evaluation by students. The most common method of evaluation is the survey questionnaire, the content of a number of questions about educational activities provided to the students. The researchers plan to evaluate the students' and experts' performances at Mazandaran University of Medical Sciences on the process of evaluating the performance of teachers, they examined in 2014. This study surveys the students and experts in the evaluation of faculty members' performance process. The study subjects were 3904 students and 37 evaluation expert of Mazandaran University of Medical Sciences. Using Cochran sampling formula of 350 students through proportional stratified random sampling were selected. The experts' viewpoint, method was used. Data collection tools consisted of 14 questions with answers Yes, or, I don't know. Descriptive Statistical analysis of the data and chi-square test was performed. From total of 350 students, 346 and the entire 37 evaluations expert participated in this study. Most of the students, 80 (23.12%) and the largest number of experts, 8 (21.62%) were from Sari Allied Medical Sciences Faculty. Most of the demographic information about gender were, 255 female students (74.56%) and 29 female experts (78.37%). In most age groups of students, 188 (55.62 percent) were in the category of 18 to 20 years, and the experts, 19 (51.35%) were in the category of 22 and 31 years. Most students, 232 of them (70.95%) were in semester 2 and 4. Most experts, 20 (54.05 percent) were under 10 years of work experience. The comparison between the views of students and experts in the evaluation process between the schools of Mazandaran University of Medical Sciences, Sari School of Nursing and Midwifery, there was difference between the opinions of experts and students (p-value=0.01. It showed 86.7% student and 33.3% of experts is satisfied with the evaluation process. on comparison of students and experts viewpoints on the implementation of the evaluation process, it is noteworthy that among students of different opinions on how the evaluation process. It worth to mention that there is insignificant difference between their viewpoints and majority of students and evaluation experts with the evaluation the process. In addition, the experts evaluated at different schools, most of them are satisfied the process.

Impaired information sampling in mild dementia of Alzheimer's type but not in healthy aging.

PubMed

Zamarian, Laura; Benke, Thomas; Brand, Matthias; Djamshidian, Atbin; Delazer, Margarete

2015-05-01

It is unknown whether aging affects predecisional processing, that is, gathering information and evaluating options before making a decision. Here, we investigated information sampling in mild Dementia of Alzheimer's type (DAT) and healthy aging by using the Information Sampling Task (IST). In a first investigation, we compared patients with mild DAT (n = 20) with healthy controls (n = 20) on the IST and several neuropsychological background tests. In a second investigation, healthy older adults (n = 30) were compared with younger adults (n = 30) on the IST and executive-function tasks. Results of the first investigation demonstrated that, in the IST, patients gathered significantly less information, made riskier and less accurate decisions, and showed less reward sensitivity relative to controls. We found a significant correlation between performance on the IST and performance on tests of verbal fluency, working memory, and recognition in patients but not in controls. Results of the second investigation indicated a largely similar performance pattern between healthy older adults and younger adults. There were no significant correlations for both groups between the IST and executive-function tasks. There are no relevant changes with healthy aging in predecisional processing. In contrast, mild DAT significantly affects predecisional information sampling. Thus, the problems shown in patients with mild DAT in decision making might be related to the patients' difficulties in predecisional processing. Decision-making performance in mild DAT might be improved by helping the patients at a predecisional stage to gather sufficient information and evaluate options more accurately. (c) 2015 APA, all rights reserved).

EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA TREATED WOOD, INTERIM DATA REPORT

EPA Science Inventory

EPA is approximately 20 months into a project to evaluate the performance of wood coatings as a way to prevent arsenic, chromium and copper exposure from the surfaces of CCA treated wood. Potential dermal exposure, as measured by wipe sampling dislodgeable CCA chemical from wood ...

Evaluation of four methods for estimating leaf area of isolated trees

Treesearch

P.J. Peper; E.G. McPherson

2003-01-01

The accurate modeling of the physiological and functional processes of urban forests requires information on the leaf area of urban tree species. Several non-destructive, indirect leaf area sampling methods have shown good performance for homogenous canopies. These methods have not been evaluated for use in urban settings where trees are typically isolated and...

A Model of Planning for School Improvement and Obstacles to Implementation.

ERIC Educational Resources Information Center

Taylor, Dianne L.; Tashakkori, Abbas; Crone-Koshel, Linda

2001-01-01

Reports results of two separate but related studies: The first involves the use of a rubric to evaluate improvement plans from low-performing schools; the second involves a sample of teacher and administrator perceptions of their involvement in improvement planning. Finds poor-quality plans in evaluation study to be related to teacher-involvement…

A PILOT STUDY USING AN ACCELEROMETER TO EVALUATE A CAREGIVER'S INTERPRETATION OF AN INFANT OR TODDLER'S ACTIVITY LEVEL AS RECORDED IN A TIME ACTIVITY DIARY

EPA Science Inventory

Linking a young child's activity pattern data with samples that are collected during an exposure assessment is important in evaluating uptake dose rates associated with environmental contaminant exposures. A pilot study (N=9) was performed to test how well categorical activity-le...

USE OF MARINE TOXICITY IDENTIFICATION AND EVALUATION (TIE) METHODS IN DETERMINING CAUSES OF TOXICITY TO FISH IN A MARINE AQUARIUM FACILITY

EPA Science Inventory

We obtained a water sample containing broken pieces of a tropical coral reef decor that was suspected of causing fish toxicity in a major aquarium. A toxicity identification and evaluation (TIE) was performed using three species: a mysid shrimp, Americamysis bahia; inland silvers...

Dynamic spiking studies using the DNPH sampling train

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

Steger, J.L.; Knoll, J.E.

1996-12-31

The proposed aldehyde and ketone sampling method using aqueous 2,4-dinitrophenylhydrazine (DNPH) was evaluated in the laboratory and in the field. The sampling trains studied were based on the train described in SW 846 Method 0011. Nine compounds were evaluated: formaldehyde, acetaldehyde, quinone, acrolein, propionaldeyde, methyl isobutyl ketone, methyl ethyl ketone, acetophenone, and isophorone. In the laboratory, the trains were spiked both statistically and dynamically. Laboratory studies also investigated potential interferences to the method. Based on their potential to hydrolyze in acid solution to form formaldehyde, dimethylolurea, saligenin, s-trioxane, hexamethylenetetramine, and paraformaldehyde were investigated. Ten runs were performed using quadruplicate samplingmore » trains. Two of the four trains were dynamically spiked with the nine aldehydes and ketones. The test results were evaluated using the EPA method 301 criteria for method precision (< + pr - 50% relative standard deviation) and bias (correction factor of 1.00 + or - 0.30).« less

Performance testing of a semi-automatic card punch system, using direct STR profiling of DNA from blood samples on FTA™ cards.

PubMed

Ogden, Samantha J; Horton, Jeffrey K; Stubbs, Simon L; Tatnell, Peter J

2015-01-01

The 1.2 mm Electric Coring Tool (e-Core™) was developed to increase the throughput of FTA(™) sample collection cards used during forensic workflows and is similar to a 1.2 mm Harris manual micro-punch for sampling dried blood spots. Direct short tandem repeat (STR) DNA profiling was used to compare samples taken by the e-Core tool with those taken by the manual micro-punch. The performance of the e-Core device was evaluated using a commercially available PowerPlex™ 18D STR System. In addition, an analysis was performed that investigated the potential carryover of DNA via the e-Core punch from one FTA disc to another. This contamination study was carried out using Applied Biosystems AmpflSTR™ Identifiler™ Direct PCR Amplification kits. The e-Core instrument does not contaminate FTA discs when a cleaning punch is used following excision of discs containing samples and generates STR profiles that are comparable to those generated by the manual micro-punch. © 2014 American Academy of Forensic Sciences.

Balancing a U-Shaped Assembly Line by Applying Nested Partitions Method

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

Bhagwat, Nikhil V.

2005-01-01

In this study, we applied the Nested Partitions method to a U-line balancing problem and conducted experiments to evaluate the application. From the results, it is quite evident that the Nested Partitions method provided near optimal solutions (optimal in some cases). Besides, the execution time is quite short as compared to the Branch and Bound algorithm. However, for larger data sets, the algorithm took significantly longer times for execution. One of the reasons could be the way in which the random samples are generated. In the present study, a random sample is a solution in itself which requires assignment ofmore » tasks to various stations. The time taken to assign tasks to stations is directly proportional to the number of tasks. Thus, if the number of tasks increases, the time taken to generate random samples for the different regions also increases. The performance index for the Nested Partitions method in the present study was the number of stations in the random solutions (samples) generated. The total idle time for the samples can be used as another performance index. ULINO method is known to have used a combination of bounds to come up with good solutions. This approach of combining different performance indices can be used to evaluate the random samples and obtain even better solutions. Here, we used deterministic time values for the tasks. In industries where majority of tasks are performed manually, the stochastic version of the problem could be of vital importance. Experimenting with different objective functions (No. of stations was used in this study) could be of some significance to some industries where in the cost associated with creation of a new station is not the same. For such industries, the results obtained by using the present approach will not be of much value. Labor costs, task incompletion costs or a combination of those can be effectively used as alternate objective functions.« less

Evaluation of a new automated instrument for pretransfusion testing.

PubMed

Morelati, F; Revelli, N; Maffei, L M; Poretti, M; Santoro, C; Parravicini, A; Rebulla, P; Cole, R; Sirchia, G

1998-10-01

A number of automated devices for pretransfusion testing have recently become available. This study evaluated a fully automated device based on column agglutination technology (AutoVue System, Ortho, Raritan, NJ). Some 6747 tests including forward and reverse ABO group, Rh type and phenotype, antibody screen, autocontrol, and crossmatch were performed on random samples from 1069 blood donors, 2063 patients, and 98 newborns and cord blood. Also tested were samples from 168 immunized patients and 53 donors expressing weak or variant A and D antigens. Test results and technician times required for their performance were compared with those obtained by standard methods (manual column agglutination technology, slide, semiautomatic handler). No erroneous conclusions were found in regard to the 5028 ABO group and Rh type or phenotype determinations carried out with the device. The device rejected 1.53 percent of tests for sample inadequacy. Of the remaining 18 tests with discrepant results found with the device and not confirmed with the standard methods, 6 gave such results because of mixed-field reactions, 10 gave negative results with A2 RBCs in reverse ABO grouping, and 2 gave very weak positive reactions in antibody screening and crossmatching. In the samples from immunized patients, the device missed one weak anti-K, whereas standard methods missed five weak antibodies. In addition, 48, 34, and 31 of the 53 weak or variant antigens were detected by the device, the slide method, and the semiautomated handler, respectively. Technician time with the standard methods was 1.6 to 7 times higher than that with the device. The technical performance of the device compared favorably with that of standard methods, with a number of advantages, including in particular the saving of technician time. Sample inadequacy was the most common cause of discrepancy, which suggests that standardization of sample collection can further improve the performance of the device.

Towards Optical Coherence Tomography-based elastographic evaluation of human cartilage.

PubMed

Nebelung, Sven; Brill, Nicolai; Müller, Felix; Tingart, Markus; Pufe, Thomas; Merhof, Dorit; Schmitt, Robert; Jahr, Holger; Truhn, Daniel

2016-03-01

Optical Coherence Tomography (OCT) is an imaging technique that allows the surface and subsurface evaluation of semitransparent tissues by generating microscopic cross-sectional images in real time, to millimetre depths and at micrometre resolutions. As the differentiation of cartilage degeneration remains diagnostically challenging to standard imaging modalities, an OCT- and MRI-compatible indentation device for the assessment of cartilage functional properties was developed and validated in the present study. After describing the system design and performing its comprehensive validation, macroscopically intact human cartilage samples (n=5) were indented under control of displacement (δ1=202µm; δ2=405µm; δ3=607µm; δ4=810µm) and simultaneous OCT imaging through a transparent indenter piston in direct contact with the sample; thus, 3-D OCT datasets from surface and subsurface areas were obtained. OCT-based evaluation of loading-induced changes included qualitative assessment of image morphology and signal characteristics. For inter-method cross referencing, the device׳s compatibility with MRI as well as qualitative morphology changes under analogous indentation loading conditions were evaluated by a series of T2 weighted gradient echo sequences. Cartilage thickness measurements were performed using the needle-probe technique prior to OCT and MRI imaging, and subsequently referenced to sample thickness as determined by MRI and histology. Dynamic indentation testing was performed to determine Young׳s modulus for biomechanical reference purposes. Distinct differences in sample thickness as well as corresponding strains were found; however, no significant differences in cartilage thickness were found between the used techniques. Qualitative assessment of OCT and MRI images revealed either distinct or absent sample-specific patterns of morphological changes in relation to indentation loading. For OCT, the tissue area underneath the indenter piston could be qualitatively assessed and displayed in multiple reconstructions, while for MRI, T2 signal characteristics indicated the presence of water and related tissue pressurisation within the sample. In conclusion, the present indentation device has been developed, constructed and validated for qualitative assessment of human cartilage and its response to loading by OCT and MRI. Thereby, it may provide the basis for future quantitative approaches that measure loading-induced deformations within the tissue to generate maps of local tissue properties as well as investigate their relation to degeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Classification of small lesions on dynamic breast MRI: Integrating dimension reduction and out-of-sample extension into CADx methodology

PubMed Central

Nagarajan, Mahesh B.; Huber, Markus B.; Schlossbauer, Thomas; Leinsinger, Gerda; Krol, Andrzej; Wismüller, Axel

2014-01-01

Objective While dimension reduction has been previously explored in computer aided diagnosis (CADx) as an alternative to feature selection, previous implementations of its integration into CADx do not ensure strict separation between training and test data required for the machine learning task. This compromises the integrity of the independent test set, which serves as the basis for evaluating classifier performance. Methods and Materials We propose, implement and evaluate an improved CADx methodology where strict separation is maintained. This is achieved by subjecting the training data alone to dimension reduction; the test data is subsequently processed with out-of-sample extension methods. Our approach is demonstrated in the research context of classifying small diagnostically challenging lesions annotated on dynamic breast magnetic resonance imaging (MRI) studies. The lesions were dynamically characterized through topological feature vectors derived from Minkowski functionals. These feature vectors were then subject to dimension reduction with different linear and non-linear algorithms applied in conjunction with out-of-sample extension techniques. This was followed by classification through supervised learning with support vector regression. Area under the receiver-operating characteristic curve (AUC) was evaluated as the metric of classifier performance. Results Of the feature vectors investigated, the best performance was observed with Minkowski functional ’perimeter’ while comparable performance was observed with ’area’. Of the dimension reduction algorithms tested with ’perimeter’, the best performance was observed with Sammon’s mapping (0.84 ± 0.10) while comparable performance was achieved with exploratory observation machine (0.82 ± 0.09) and principal component analysis (0.80 ± 0.10). Conclusions The results reported in this study with the proposed CADx methodology present a significant improvement over previous results reported with such small lesions on dynamic breast MRI. In particular, non-linear algorithms for dimension reduction exhibited better classification performance than linear approaches, when integrated into our CADx methodology. We also note that while dimension reduction techniques may not necessarily provide an improvement in classification performance over feature selection, they do allow for a higher degree of feature compaction. PMID:24355697

Development, Evaluation, and Integration of a Quantitative Reverse-Transcription Polymerase Chain Reaction Diagnostic Test for Ebola Virus on a Molecular Diagnostics Platform

PubMed Central

Cnops, Lieselotte; Van den Eede, Peter; Pettitt, James; Heyndrickx, Leo; De Smet, Birgit; Coppens, Sandra; Andries, Ilse; Pattery, Theresa; Van Hove, Luc; Meersseman, Geert; Van Den Herrewegen, Sari; Vergauwe, Nicolas; Thijs, Rein; Jahrling, Peter B.; Nauwelaers, David; Ariën, Kevin K.

2016-01-01

Background. The 2013–2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV). Methods. The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood. The sample is directly added to a disposable cartridge containing all reagents for sample preparation, RNA extraction, and amplification by reverse-transcription polymerase chain reaction analysis. The performance was evaluated with a variety of sample types, including synthetic constructs and whole blood samples from healthy volunteers spiked with viral RNA, inactivated virus, and infectious virus. Results. The 95% limits of detection for EBOV and SUDV were 465 plaque-forming units (PFU)/mL (1010 copies/mL) and 324 PFU/mL (8204 copies/mL), respectively. In silico and in vitro analyses demonstrated 100% correct reactivity for EBOV and SUDV and no cross-reactivity with relevant pathogens. The diagnostic sensitivity was 97.4% (for EBOV) and 91.7% (for SUDV), the specificity was 100%, and the diagnostic accuracy was 95.9%. Conclusions. The Idylla™ prototype Ebola virus test is a fast, safe, easy-to-use, and near-patient test that meets the performance criteria to detect EBOV in patients with suspected Ebola. PMID:27247341

External quality-assurance programs managed by the U.S. Geological Survey in support of the National Atmospheric Deposition Program/National Trends Network

USGS Publications Warehouse

Latysh, Natalie E.; Wetherbee, Gregory A.

2005-01-01

The U.S. Geological Survey, Branch of Quality Systems, operates the external quality-assurance programs for the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Beginning in 1978, six different programs have been implemented?the intersite-comparison program, the blind-audit program, the sample-handling evaluation program, the field-audit program, the interlaboratory-comparison program, and the collocated-sampler program. Each program was designed to measure error contributed by specific components in the data-collection process. The intersite-comparison program, which was discontinued in 2004, was designed to assess the accuracy and reliability of field pH and specific-conductance measurements made by site operators. The blind-audit and sample-handling evaluation programs, which also were discontinued in 2002 and 2004, respectively, assessed contamination that may result from sampling equipment and routine handling and processing of the wet-deposition samples. The field-audit program assesses the effects of sample handling, processing, and field exposure. The interlaboratory-comparison program evaluates bias and precision of analytical results produced by the contract laboratory for NADP, the Illinois State Water Survey, Central Analytical Laboratory, and compares its performance with the performance of international laboratories. The collocated-sampler program assesses the overall precision of wet-deposition data collected by NADP/NTN. This report documents historical operations and the operating procedures for each of these external quality-assurance programs. USGS quality-assurance information allows NADP/NTN data users to discern between actual environmental trends and inherent measurement variability.

Non-targeted analysis of unexpected food contaminants using LC-HRMS.

PubMed

Kunzelmann, Marco; Winter, Martin; Åberg, Magnus; Hellenäs, Karl-Erik; Rosén, Johan

2018-03-29

A non-target analysis method for unexpected contaminants in food is described. Many current methods referred to as "non-target" are capable of detecting hundreds or even thousands of contaminants. However, they will typically still miss all other possible contaminants. Instead, a metabolomics approach might be used to obtain "true non-target" analysis. In the present work, such a method was optimized for improved detection capability at low concentrations. The method was evaluated using 19 chemically diverse model compounds spiked into milk samples to mimic unknown contamination. Other milk samples were used as reference samples. All samples were analyzed with UHPLC-TOF-MS (ultra-high-performance liquid chromatography time-of-flight mass spectrometry), using reversed-phase chromatography and electrospray ionization in positive mode. Data evaluation was performed by the software TracMass 2. No target lists of specific compounds were used to search for the contaminants. Instead, the software was used to sort out all features only occurring in the spiked sample data, i.e., the workflow resembled a metabolomics approach. Procedures for chemical identification of peaks were outside the scope of the study. Method, study design, and settings in the software were optimized to minimize manual evaluation and faulty or irrelevant hits and to maximize hit rate of the spiked compounds. A practical detection limit was established at 25 μg/kg. At this concentration, most compounds (17 out of 19) were detected as intact precursor ions, as fragments or as adducts. Only 2 irrelevant hits, probably natural compounds, were obtained. Limitations and possible practical use of the approach are discussed.

A whole-cell bioreporter assay for quantitative genotoxicity evaluation of environmental samples.

PubMed

Jiang, Bo; Li, Guanghe; Xing, Yi; Zhang, Dayi; Jia, Jianli; Cui, Zhisong; Luan, Xiao; Tang, Hui

2017-10-01

Whole-cell bioreporters have emerged as promising tools for genotoxicity evaluation, due to their rapidity, cost-effectiveness, sensitivity and selectivity. In this study, a method for detecting genotoxicity in environmental samples was developed using the bioluminescent whole-cell bioreporter Escherichia coli recA::luxCDABE. To further test its performance in a real world scenario, the E. coli bioreporter was applied in two cases: i) soil samples collected from chromium(VI) contaminated sites; ii) crude oil contaminated seawater collected after the Jiaozhou Bay oil spill which occurred in 2013. The chromium(VI) contaminated soils were pretreated by water extraction, and directly exposed to the bioreporter in two phases: aqueous soil extraction (water phase) and soil supernatant (solid phase). The results indicated that both extractable and soil particle fixed chromium(VI) were bioavailable to the bioreporter, and the solid-phase contact bioreporter assay provided a more precise evaluation of soil genotoxicity. For crude oil contaminated seawater, the response of the bioreporter clearly illustrated the spatial and time change in genotoxicity surrounding the spill site, suggesting that the crude oil degradation process decreased the genotoxic risk to ecosystem. In addition, the performance of the bioreporter was simulated by a modified cross-regulation gene expression model, which quantitatively described the DNA damage response of the E. coli bioreporter. Accordingly, the bioluminescent response of the bioreporter was calculated as the mitomycin C equivalent, enabling quantitative comparison of genotoxicities between different environmental samples. This bioreporter assay provides a rapid and sensitive screening tool for direct genotoxicity assessment of environmental samples. Copyright © 2017. Published by Elsevier Ltd.

Surfactant-assisted hydrothermal crystallization of nanostructured lithium metasilicate (Li{sub 2}SiO{sub 3}) hollow spheres: II-Textural analysis and CO{sub 2}-H{sub 2}O sorption evaluation

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

Ortiz-Landeros, Jose; Gomez-Yanez, Carlos; Pfeiffer, Heriberto, E-mail: pfeiffer@iim.unam.mx

In a previous work, the synthesis and structural-microstructural characterization of different nanocrystalline lithium metasilicate (Li{sub 2}SiO{sub 3}) samples were performed. Then, in this work, initially, a textural analysis was performed over the same samples. Li{sub 2}SiO{sub 3} samples prepared with a non-ionic surfactant (TRITON X-114) presented the best textural properties. Therefore, this sample was selected to evaluate its water vapor (H{sub 2}O) and carbon dioxide (CO{sub 2}) sorption properties. Sorption experiments were performed at low temperatures (30-80 deg. C) in presence of water vapor using N{sub 2} or CO{sub 2} as carrier gases. Results clearly evidenced that CO{sub 2} sorptionmore » on these materials is highly improved by H{sub 2}O vapor, and of course, textural properties enhanced the H{sub 2}O-CO{sub 2} sorption efficiency, in comparison with the solid-state reference sample. - Graphical abstract: Li{sub 2}SiO{sub 3} varied significantly its capacity of CO{sub 2} absorption as a function of the microstructural properties and by the water presence. Highlights: > We studied the CO{sub 2} absorption on different Li{sub 2}SiO{sub 3} samples in presence of H{sub 2}O vapor. > It was proved that CO{sub 2} absorption on Li{sub 2}SiO{sub 3} is controlled by different factors. > Li{sub 2}SiO{sub 3} with a porous microstructure produces a higher CO{sub 2} absorption. > H{sub 2}O vapor favors the CO{sub 2} absorption on Li{sub 2}SiO{sub 3} due to a surface hydroxylation.« less

Molecular diagnosis of symptomatic toxoplasmosis: a 9-year retrospective and prospective study in a referral laboratory in São Paulo, Brazil.

PubMed

Camilo, Lilian Muniz; Pereira-Chioccola, Vera Lucia; Gava, Ricardo; Meira-Strejevitch, Cristina da Silva; Vidal, Jose Ernesto; Brandão de Mattos, Cinara Cássia; Frederico, Fábio Batista; De Mattos, Luiz Carlos; Spegiorin, Lígia Cosentino Junqueira Franco

Symptomatic forms of toxoplasmosis are a serious public health problem and occur in around 10-20% of the infected people. Aiming to improve the molecular diagnosis of symptomatic toxoplasmosis in Brazilian patients, this study evaluated the performance of real time PCR testing two primer sets (B1 and REP-529) in detecting Toxoplasma gondii DNA. The methodology was assayed in 807 clinical samples with known clinical diagnosis, ELISA, and conventional PCR results in a 9-year period. All samples were from patients with clinical suspicion of several features of toxoplasmosis. According to the minimum detection limit curve (in C T ), REP-529 had greater sensitivity to detect T. gondii DNA than B1. Both primer sets were retrospectively evaluated using 515 DNA from different clinical samples. The 122 patients without toxoplasmosis provided high specificity (REP-529, 99.2% and B1, 100%). From the 393 samples with positive ELISA, 146 had clinical diagnosis of toxoplasmosis and positive conventional PCR. REP-529 and B1 sensitivities were 95.9% and 83.6%, respectively. Comparison of REP-529 and B1 performances was further analyzed prospectively in 292 samples. Thus, from a total of 807 DNA analyzed, 217 (26.89%) had positive PCR with, at least one primer set and symptomatic toxoplasmosis confirmed by clinical diagnosis. REP-529 was positive in 97.23%, whereas B1 amplified only 78.80%. After comparing several samples in a Brazilian referral laboratory, this study concluded that REP-529 primer set had better performance than B1 one. These observations were based after using cases with defined clinical diagnosis, ELISA, and conventional PCR. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

A dilute-and-shoot sample preparation strategy for new and used lubricating oils for Ca, P, S and Zn determination by total reflection X-ray fluorescence

NASA Astrophysics Data System (ADS)

Mota, Mariana F. B.; Gama, Ednilton M.; Rodrigues, Gabrielle de C.; Rodrigues, Guilherme D.; Nascentes, Clésia C.; Costa, Letícia M.

2018-01-01

In this work, a dilute-and-shoot method was developed for Ca, P, S and Zn determination in new and used lubricating oil samples by total reflection X-ray fluorescence (TXRF). The oil samples were diluted with organic solvents followed by addition of yttrium as internal standard and the TXRF measurements were performed after solvent evaporation. The method was optimized using an interlaboratorial reference material. The experimental parameters evaluated were sample volume (50 or 100 μL), measurement time (250 or 500 s) and volume deposited on the quartz glass sample carrier (5 or 10 μL). All of them were evaluated and optimized using xylene, kerosene and hexane. Analytical figures of merit (accuracy, precision, limit of detection and quantification) were used to evaluate the performance of the analytical method for all solvents. The recovery rates varied from 99 to 111% and the relative standard deviation remained between 1.7% and 10% (n = 8). For all elements, the results obtained by applying the new method were in agreement with the certified value. After the validation step, the method was applied for Ca, P, S and Zn quantification in eight new and four used lubricating oil samples, for all solvents. The concentration of the elements in the samples varied in the ranges of 1620-3711 mg L- 1 for Ca, 704-1277 mg L- 1 for P, 2027-9147 mg L- 1 for S, and 898-1593 mg L- 1 for Zn. The association of TXRF with a dilute-and-shoot sample preparation strategy was efficient for Ca, P, S and Zn determination in lubricating oils, presenting accurate results. Additionally, the time required for analysis is short, the reagent volumes are low minimizing waste generation, and the technique does not require calibration curves.