Development of a reference material for routine performance monitoring of methods measuring polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls.

PubMed

Selliah, S S; Cussion, S; MacPherson, K A; Reiner, E J; Toner, D

2001-06-01

Matrix-matched environmental certified reference materials (CRMs) are one of the most useful tools to validate analytical methods, assess analytical laboratory performance and to assist in the resolution of data conflicts between laboratories. This paper describes the development of a lake sediment as a CRM for polychorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DLPCBs). The presence of DLPCBs in the environment is of increased concern and analytical methods are being developed internationally for monitoring DLPCBs in the environment. This paper also reports the results of an international interlaboratory study involving thirty-five laboratories from seventeen countries, conducted to characterize and validate levels of a sediment reference material for PCDDs, PCDFs and DLPCBs.

Using Stressor Gradients to Determine Reference Expectations for Great River Fish Assemblages

EPA Science Inventory

Determining reference conditions for large and great rivers like the Mississippi, Missouri, and Ohio Rivers is difficult because there are few, if any, reaches in minimally disturbed condition. In this paper, we describe a method for determining internal reference conditions usin...

Measurement of Moisture Content in Seeds of Some North American Hardwoods

Treesearch

F. T. Bonner

1972-01-01

Current International rules (International Seed Testing Association, 1966) for determination of moisture content specify the air-oven method at 105 °C for all tree seeds except those of Ables, Cedrus. Fagus, Picea, and Tsuga, for which the toluene distillation method must be used. Calibration of air-oven methods against a good reference method, such as toluene...

Calibration of BCR-ABL1 mRNA quantification methods using genetic reference materials is a valid strategy to report results on the international scale.

PubMed

Mauté, Carole; Nibourel, Olivier; Réa, Delphine; Coiteux, Valérie; Grardel, Nathalie; Preudhomme, Claude; Cayuela, Jean-Michel

2014-09-01

Until recently, diagnostic laboratories that wanted to report on the international scale had limited options: they had to align their BCR-ABL1 quantification methods through a sample exchange with a reference laboratory to derive a conversion factor. However, commercial methods calibrated on the World Health Organization genetic reference panel are now available. We report results from a study designed to assess the comparability of the two alignment strategies. Sixty follow-up samples from chronic myeloid leukemia patients were included. Two commercial methods calibrated on the genetic reference panel were compared to two conversion factor methods routinely used at Saint-Louis Hospital, Paris, and at Lille University Hospital. Results were matched against concordance criteria (i.e., obtaining at least two of the three following landmarks: 50, 75 and 90% of the patient samples within a 2-fold, 3-fold and 5-fold range, respectively). Out of the 60 samples, more than 32 were available for comparison. Compared to the conversion factor method, the two commercial methods were within a 2-fold, 3-fold and 5-fold range for 53 and 59%, 89 and 88%, 100 and 97%, respectively of the samples analyzed at Saint-Louis. At Lille, results were 45 and 85%, 76 and 97%, 100 and 100%, respectively. Agreements between methods were observed in the four comparisons performed. Our data show that the two commercial methods selected are concordant with the conversion factor methods. This study brings the proof of principle that alignment on the international scale using the genetic reference panel is compatible with the patient sample exchange procedure. We believe that these results are particularly important for diagnostic laboratories wishing to adopt commercial methods. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Guidelines for the detection of Trichinella larvae at the slaughterhouse in a quality assurance system.

PubMed

Rossi, Patrizia; Pozio, Edoardo

2008-01-01

The European Community Regulation (EC) No. 2075/2005 lays down specific rules on official controls for the detection of Trichinella in fresh meat for human consumption, recommending the pooled-sample digestion method as the reference method. The aim of this document is to provide specific guidance to implement an appropriate Trichinella digestion method by a laboratory accredited according to the ISO/IEC 17025:2005 international standard, and performing microbiological testing following the EA-04/10:2002 international guideline. Technical requirements for the correct implementation of the method, such as the personnel competence, specific equipments and reagents, validation of the method, reference materials, sampling, quality assurance of results and quality control of performance are provided, pointing out the critical control points for the correct implementation of the digestion method.

The height-, weight-, and BMI-for-age of Polish school-aged children and adolescents relative to international and local growth references

PubMed Central

2010-01-01

Background The growth of children is an indicator of health and society's wellbeing. Growth references are useful in monitoring a child's growth, which is a very important part of child care. Poland's growth references are not updated regularly. Although several growth reference ranges have been developed in Poland over recent years, sampling was restricted to urban populations of major cities. The aim of this study was to assess how well Polish children match with, or diverge from, regional charts and to compare them with international growth references. Methods Four Polish and two international (WHO 2007 and USCDC2000) growth references were used to calculate the height, weight and BMI z-scores in a recent, large, population-representative sample of school-aged children and adolescents in Poland. The distributions of z-scores were analysed with descriptive and inferential statistical methods. Results Mean height z-scores calculated with the use of the WHO 2007 and USCDC2000 references were positive and significantly different from zero over the entire age range. The mean height z-score was closest to zero in the Poznan reference for boys (0.05) and Warszawa reference for girls (0.01). Median weight z-scores were positive under all weight references over the entire age range with only the exception of 18-year-old girls' weight z-score calculated relative to USCDC2000. Median BMI z-scores were positive in males in early childhood, decreasing with age. In the case of girls, the median BMI z-score calculated using WHO 2007 and USCDC2000 was close to zero in early childhood, decreased in adolescents and reached minimum values at age 18 years. Median BMI z-scores calculated with the use of the Lodz reference fluctuated between 0.05 and 0.2 over the studied age range. Conclusions In this contemporary sample of Polish school-aged children, distributions of height, weight and BMI differed from those of children from the international growth references. These differences should be considered when using the references. There exist certain limitations to the analysis of height, weight, and BMI z-scores when Polish regional references are used. PMID:20199693

Quality evaluation of no-reference MR images using multidirectional filters and image statistics.

PubMed

Jang, Jinseong; Bang, Kihun; Jang, Hanbyol; Hwang, Dosik

2018-09-01

This study aimed to develop a fully automatic, no-reference image-quality assessment (IQA) method for MR images. New quality-aware features were obtained by applying multidirectional filters to MR images and examining the feature statistics. A histogram of these features was then fitted to a generalized Gaussian distribution function for which the shape parameters yielded different values depending on the type of distortion in the MR image. Standard feature statistics were established through a training process based on high-quality MR images without distortion. Subsequently, the feature statistics of a test MR image were calculated and compared with the standards. The quality score was calculated as the difference between the shape parameters of the test image and the undistorted standard images. The proposed IQA method showed a >0.99 correlation with the conventional full-reference assessment methods; accordingly, this proposed method yielded the best performance among no-reference IQA methods for images containing six types of synthetic, MR-specific distortions. In addition, for authentically distorted images, the proposed method yielded the highest correlation with subjective assessments by human observers, thus demonstrating its superior performance over other no-reference IQAs. Our proposed IQA was designed to consider MR-specific features and outperformed other no-reference IQAs designed mainly for photographic images. Magn Reson Med 80:914-924, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

The Joint Committee for Traceability in Laboratory Medicine (JCTLM) - its history and operation.

PubMed

Jones, Graham R D; Jackson, Craig

2016-01-30

The Joint Committee for Traceability in Laboratory Medicine (JCTLM) was formed to bring together the sciences of metrology, laboratory medicine and laboratory quality management. The aim of this collaboration is to support worldwide comparability and equivalence of measurement results in clinical laboratories for the purpose of improving healthcare. The JCTLM has its origins in the activities of international metrology treaty organizations, professional societies and federations devoted to improving measurement quality in physical, chemical and medical sciences. The three founding organizations, the International Committee for Weights and Measures (CIPM), the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the International Laboratory Accreditation Cooperation (ILAC) are the leaders of this activity. The main service of the JCTLM is a web-based database with a list of reference materials, reference methods and reference measurement services meeting appropriate international standards. This database allows manufacturers to select references for assay traceability and provides support for suppliers of these services. As of mid 2015 the database lists 295 reference materials for 162 analytes, 170 reference measurement procedures for 79 analytes and 130 reference measurement services for 39 analytes. There remains a need for the development and implementation of metrological traceability in many areas of laboratory medicine and the JCTLM will continue to promote these activities into the future. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation and selection of internal reference genes from two- and six-row U.S. malting barley varieties throughout micromalting for use in RT-qPCR

USDA-ARS?s Scientific Manuscript database

Reverse Transcription quantitative Polymerase Chain Reaction (qRT-PCR) is a popular method for measuring transcript abundance. The most commonly used method of interpretation is relative quantification and thus necessitates the use of normalization controls (i.e. reference genes) to standardize tran...

Validation of a modification to Performance-Tested Method 010403: microwell DNA hybridization assay for detection of Listeria spp. in selected foods and selected environmental surfaces.

PubMed

Alles, Susan; Peng, Linda X; Mozola, Mark A

2009-01-01

A modification to Performance-Tested Method 010403, GeneQuence Listeria Test (DNAH method), is described. The modified method uses a new media formulation, LESS enrichment broth, in single-step enrichment protocols for both foods and environmental sponge and swab samples. Food samples are enriched for 27-30 h at 30 degrees C, and environmental samples for 24-48 h at 30 degrees C. Implementation of these abbreviated enrichment procedures allows test results to be obtained on a next-day basis. In testing of 14 food types in internal comparative studies with inoculated samples, there were statistically significant differences in method performance between the DNAH method and reference culture procedures for only 2 foods (pasteurized crab meat and lettuce) at the 27 h enrichment time point and for only a single food (pasteurized crab meat) in one trial at the 30 h enrichment time point. Independent laboratory testing with 3 foods showed statistical equivalence between the methods for all foods, and results support the findings of the internal trials. Overall, considering both internal and independent laboratory trials, sensitivity of the DNAH method relative to the reference culture procedures was 90.5%. Results of testing 5 environmental surfaces inoculated with various strains of Listeria spp. showed that the DNAH method was more productive than the reference U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) culture procedure for 3 surfaces (stainless steel, plastic, and cast iron), whereas results were statistically equivalent to the reference method for the other 2 surfaces (ceramic tile and sealed concrete). An independent laboratory trial with ceramic tile inoculated with L. monocytogenes confirmed the effectiveness of the DNAH method at the 24 h time point. Overall, sensitivity of the DNAH method at 24 h relative to that of the USDA-FSIS method was 152%. The DNAH method exhibited extremely high specificity, with only 1% false-positive reactions overall.

Internal Labor Markets: An Empirical Investigation.

ERIC Educational Resources Information Center

Mahoney, Thomas A.; Milkovich, George T.

Methods of internal labor market analysis for three organizational areas are presented, along with some evidence about the validity and utility of conceptual descriptions of such markets. The general concept of an internal labor market refers to the process of pricing and allocation of manpower resources with an employing organization and rests…

Uncertainty evaluation in normalization of isotope delta measurement results against international reference materials.

PubMed

Meija, Juris; Chartrand, Michelle M G

2018-01-01

Isotope delta measurements are normalized against international reference standards. Although multi-point normalization is becoming a standard practice, the existing uncertainty evaluation practices are either undocumented or are incomplete. For multi-point normalization, we present errors-in-variables regression models for explicit accounting of the measurement uncertainty of the international standards along with the uncertainty that is attributed to their assigned values. This manuscript presents framework to account for the uncertainty that arises due to a small number of replicate measurements and discusses multi-laboratory data reduction while accounting for inevitable correlations between the laboratories due to the use of identical reference materials for calibration. Both frequentist and Bayesian methods of uncertainty analysis are discussed.

Chapter 23: International Standard reagents for harmonization of HPV serology and DNA assays--an update.

PubMed

Pagliusi, Sonia R; Dillner, Joakim; Pawlita, Michael; Quint, Wim G V; Wheeler, Cosette M; Ferguson, M

2006-08-31

International reference materials such as International Standard reagents facilitate quality assurance of essential biopharmaceutical products and related in vitro diagnostic tests. Standardization of antibody and DNA measurements and harmonization of laboratory procedures are key to the success of cancer prevention strategies through screening methods as well as for development and implementation of vaccination against the human papillomavirus (HPV). The WHO supported the preparation and initial analysis of a panel of candidate serological and DNA reference reagents aimed at facilitating inter-laboratory comparisons and detection of HPV worldwide. Two international collaborative studies assessed the performance of various HPV antibody and HPV-DNA detection assays and examined the feasibility of generating HPV antibody and DNA standard reagents. These studies showed that improvement in performance and comparability of assays is urgently needed and that the use of the same International Standard reference reagent could significantly improve performance and comparability. It is hoped that the establishment of International Units and International Standards for HPV antibody and DNA analysis will be pursued with high priority.

International Standards and Reference Materials for Quantitative Molecular Infectious Disease Testing

PubMed Central

Madej, Roberta M.; Davis, Jack; Holden, Marcia J.; Kwang, Stan; Labourier, Emmanuel; Schneider, George J.

2010-01-01

The utility of quantitative molecular diagnostics for patient management depends on the ability to relate patient results to prior results or to absolute values in clinical practice guidelines. To do this, those results need to be comparable across time and methods, either by producing the same value across methods and test versions or by using reliable and stable conversions. Universally available standards and reference materials specific to quantitative molecular technologies are critical to this process but are few in number. This review describes recent history in the establishment of international standards for nucleic acid test development, organizations involved in current efforts, and future issues and initiatives. PMID:20075208

Establishment and validation of analytical reference panels for the standardization of quantitative BCR-ABL1 measurements on the international scale.

PubMed

White, Helen E; Hedges, John; Bendit, Israel; Branford, Susan; Colomer, Dolors; Hochhaus, Andreas; Hughes, Timothy; Kamel-Reid, Suzanne; Kim, Dong-Wook; Modur, Vijay; Müller, Martin C; Pagnano, Katia B; Pane, Fabrizio; Radich, Jerry; Cross, Nicholas C P; Labourier, Emmanuel

2013-06-01

Current guidelines for managing Philadelphia-positive chronic myeloid leukemia include monitoring the expression of the BCR-ABL1 (breakpoint cluster region/c-abl oncogene 1, non-receptor tyrosine kinase) fusion gene by quantitative reverse-transcription PCR (RT-qPCR). Our goal was to establish and validate reference panels to mitigate the interlaboratory imprecision of quantitative BCR-ABL1 measurements and to facilitate global standardization on the international scale (IS). Four-level secondary reference panels were manufactured under controlled and validated processes with synthetic Armored RNA Quant molecules (Asuragen) calibrated to reference standards from the WHO and the NIST. Performance was evaluated in IS reference laboratories and with non-IS-standardized RT-qPCR methods. For most methods, percent ratios for BCR-ABL1 e13a2 and e14a2 relative to ABL1 or BCR were robust at 4 different levels and linear over 3 logarithms, from 10% to 0.01% on the IS. The intraassay and interassay imprecision was <2-fold overall. Performance was stable across 3 consecutive lots, in multiple laboratories, and over a period of 18 months to date. International field trials demonstrated the commutability of the reagents and their accurate alignment to the IS within the intra- and interlaboratory imprecision of IS-standardized methods. The synthetic calibrator panels are robust, reproducibly manufactured, analytically calibrated to the WHO primary standards, and compatible with most BCR-ABL1 RT-qPCR assay designs. The broad availability of secondary reference reagents will further facilitate interlaboratory comparative studies and independent quality assessment programs, which are of paramount importance for worldwide standardization of BCR-ABL1 monitoring results and the optimization of current and new therapeutic approaches for chronic myeloid leukemia. © 2013 American Association for Clinical Chemistry.

International energy outlook 1996

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

NONE

1996-05-01

This International Energy Outlook presents historical data from 1970 to 1993 and EIA`s projections of energy consumption and carbon emissions through 2015 for 6 country groups. Prospects for individual fuels are discussed. Summary tables of the IEO96 world energy consumption, oil production, and carbon emissions projections are provided in Appendix A. The reference case projections of total foreign energy consumption and of natural gas, coal, and renewable energy were prepared using EIA`s World Energy Projection System (WEPS) model. Reference case projections of foreign oil production and consumption were prepared using the International Energy Module of the National Energy Modeling Systemmore » (NEMS). Nuclear consumption projections were derived from the International Nuclear Model, PC Version (PC-INM). Alternatively, nuclear capacity projections were developed using two methods: the lower reference case projections were based on analysts` knowledge of the nuclear programs in different countries; the upper reference case was generated by the World Integrated Nuclear Evaluation System (WINES)--a demand-driven model. In addition, the NEMS Coal Export Submodule (CES) was used to derive flows in international coal trade. As noted above, foreign projections of electricity demand are now projected as part of the WEPS. 64 figs., 62 tabs.« less

Optically transmitted and inductively coupled electric reference to access in vivo concentrations for quantitative proton-decoupled ¹³C magnetic resonance spectroscopy.

PubMed

Chen, Xing; Pavan, Matteo; Heinzer-Schweizer, Susanne; Boesiger, Peter; Henning, Anke

2012-01-01

This report describes our efforts on quantification of tissue metabolite concentrations in mM by nuclear Overhauser enhanced and proton decoupled (13) C magnetic resonance spectroscopy and the Electric Reference To access In vivo Concentrations (ERETIC) method. Previous work showed that a calibrated synthetic magnetic resonance spectroscopy-like signal transmitted through an optical fiber and inductively coupled into a transmit/receive coil represents a reliable reference standard for in vivo (1) H magnetic resonance spectroscopy quantification on a clinical platform. In this work, we introduce a related implementation that enables simultaneous proton decoupling and ERETIC-based metabolite quantification and hence extends the applicability of the ERETIC method to nuclear Overhauser enhanced and proton decoupled in vivo (13) C magnetic resonance spectroscopy. In addition, ERETIC signal stability under the influence of simultaneous proton decoupling is investigated. The proposed quantification method was cross-validated against internal and external reference standards on human skeletal muscle. The ERETIC signal intensity stability was 100.65 ± 4.18% over 3 months including measurements with and without proton decoupling. Glycogen and unsaturated fatty acid concentrations measured with the ERETIC method were in excellent agreement with internal creatine and external phantom reference methods, showing a difference of 1.85 ± 1.21% for glycogen and 1.84 ± 1.00% for unsaturated fatty acid between ERETIC and creatine-based quantification, whereas the deviations between external reference and creatine-based quantification are 6.95 ± 9.52% and 3.19 ± 2.60%, respectively. Copyright © 2011 Wiley Periodicals, Inc.

Qualitative Educational Research in Developing Countries: Current Perspectives. Reference Books in International Education, Volume 35. Garland Reference Library of Social Science, Volume 927.

ERIC Educational Resources Information Center

Crossley, Michael, Ed.; Vulliamy, Graham, Ed.

This book contains 11 essays that offer in-depth accounts of qualitative research in developing countries. Each chapter focuses upon a specific method and considers related theoretical and practical issues with reference to recent experiences in selected developing countries. Key issues addressed include: (1) the identification of appropriate…

The gallium melting-point standard: its role in our temperature measurement system.

PubMed

Mangum, B W

1977-01-01

The latest internationally-adopted temperature scale, the International Practical Temperature Scale of 1968 (amended edition of 1975), is discussed in some detail and a brief description is given of its evolution. The melting point of high-purity gallium (stated to be at least 99.99999% pure) as a secondary temperature reference point is evaluated. I believe that this melting-point temperature of gallium should be adopted by the various medical professional societies and voluntary standards groups as the reaction temperature for enzyme reference methods in clinical enzymology. Gallium melting-point cells are available at the National Bureau of Standards as Standard Reference Material No. 1968.

Validating internal controls for quantitative plant gene expression studies.

PubMed

Brunner, Amy M; Yakovlev, Igor A; Strauss, Steven H

2004-08-18

Real-time reverse transcription PCR (RT-PCR) has greatly improved the ease and sensitivity of quantitative gene expression studies. However, accurate measurement of gene expression with this method relies on the choice of a valid reference for data normalization. Studies rarely verify that gene expression levels for reference genes are adequately consistent among the samples used, nor compare alternative genes to assess which are most reliable for the experimental conditions analyzed. Using real-time RT-PCR to study the expression of 10 poplar (genus Populus) housekeeping genes, we demonstrate a simple method for determining the degree of stability of gene expression over a set of experimental conditions. Based on a traditional method for analyzing the stability of varieties in plant breeding, it defines measures of gene expression stability from analysis of variance (ANOVA) and linear regression. We found that the potential internal control genes differed widely in their expression stability over the different tissues, developmental stages and environmental conditions studied. Our results support that quantitative comparisons of candidate reference genes are an important part of real-time RT-PCR studies that seek to precisely evaluate variation in gene expression. The method we demonstrated facilitates statistical and graphical evaluation of gene expression stability. Selection of the best reference gene for a given set of experimental conditions should enable detection of biologically significant changes in gene expression that are too small to be revealed by less precise methods, or when highly variable reference genes are unknowingly used in real-time RT-PCR experiments.

Giving Your Patrons the World: Barriers to, and the Value of, International Interlibrary Loan

ERIC Educational Resources Information Center

Munson, Kurt; Thompson, Hilary H.

2018-01-01

Using the 2011 and 2015 survey by the Reference and User Services Association Sharing and Transforming Access to Resources Section (RUSA STARS) of international interlibrary loans (ILL), the authors explore barriers to this method of meeting patrons' information needs. They evaluate international ILL in the context of developments in the…

Infrared non-destructive evaluation method and apparatus

DOEpatents

Baleine, Erwan; Erwan, James F; Lee, Ching-Pang; Stinelli, Stephanie

2014-10-21

A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

Communication: Extended multi-state complete active space second-order perturbation theory: Energy and nuclear gradients

NASA Astrophysics Data System (ADS)

Shiozaki, Toru; Győrffy, Werner; Celani, Paolo; Werner, Hans-Joachim

2011-08-01

The extended multireference quasi-degenerate perturbation theory, proposed by Granovsky [J. Chem. Phys. 134, 214113 (2011)], is combined with internally contracted multi-state complete active space second-order perturbation theory (XMS-CASPT2). The first-order wavefunction is expanded in terms of the union of internally contracted basis functions generated from all the reference functions, which guarantees invariance of the theory with respect to unitary rotations of the reference functions. The method yields improved potentials in the vicinity of avoided crossings and conical intersections. The theory for computing nuclear energy gradients for MS-CASPT2 and XMS-CASPT2 is also presented and the first implementation of these gradient methods is reported. A number of illustrative applications of the new methods are presented.

Citations of Brazilian physical therapy journals in national publications

PubMed Central

Teixeira, Renan K. C.; Yamaki, Vitor N.; Botelho, Nara M.; Teixeira, Renato C.

2014-01-01

Background Quotations in Brazilian journals are mainly obtained from national articles (articles from Brazilian journals); thus, it is essential to determine how frequently these articles reference Brazilian journals. Objective This study sought to verify how frequently national papers are cited in the references of three Brazilian physical therapy journals. Method All references for articles published in Fisioterapia em Movimento, Fisioterapia e Pesquisa and Revista Brasileira de Fisioterapia between 2010 and 2012 were evaluated. In particular, the numbers of national articles and international articles (articles from international journals) cited in these references were determined. Results A total of 13,009 references cited by 456 articles were analyzed, and 2,924 (22.47%) of the cited works were national articles. There were no significant differences among the three examined years. A total of 36 (7.89%) articles did not cite national articles, whereas 65 (13.25%) articles cited more national articles than international articles. Conclusion On average, 22.47% of the works cited by the evaluated articles were national articles. No significant differences were detected among the three analyzed years. PMID:24675917

Glucose Measurement: Time for a Gold Standard

PubMed Central

Hagvik, Joakim

2007-01-01

There is no internationally recognized reference method for the measurement of blood glucose. The Centers for Disease Control and Prevention (CDC) highlighted the need for standardization some years ago when a project was started. The project objectives were to (1) investigate whether there are significant differences in calibration levels among currently used glucose monitors for home use and (2) develop a reference method for glucose determination. A first study confirmed the assumption that currently used home-use monitors differ significantly and that standardization is necessary in order to minimize variability and to improve patient care. As a reference method, CDC recommended a method based on isotope dilution gas chromatography–mass spectrometry, an assay that has received support from clinical chemists worldwide. CDC initiated a preliminary study to establish the suitability of this method, but then the project came to a halt. It is hoped that CDC, with support from the industry, as well as academic and professional organizations such as the American Association for Clinical Chemistry and International Federation of Clinical Chemistry and Laboratory Medicine, will be able to finalize the project and develop the long-awaited and much needed “gold standard” for glucose measurement. PMID:19888402

An internal reference model-based PRF temperature mapping method with Cramer-Rao lower bound noise performance analysis.

PubMed

Li, Cheng; Pan, Xinyi; Ying, Kui; Zhang, Qiang; An, Jing; Weng, Dehe; Qin, Wen; Li, Kuncheng

2009-11-01

The conventional phase difference method for MR thermometry suffers from disturbances caused by the presence of lipid protons, motion-induced error, and field drift. A signal model is presented with multi-echo gradient echo (GRE) sequence using a fat signal as an internal reference to overcome these problems. The internal reference signal model is fit to the water and fat signals by the extended Prony algorithm and the Levenberg-Marquardt algorithm to estimate the chemical shifts between water and fat which contain temperature information. A noise analysis of the signal model was conducted using the Cramer-Rao lower bound to evaluate the noise performance of various algorithms, the effects of imaging parameters, and the influence of the water:fat signal ratio in a sample on the temperature estimate. Comparison of the calculated temperature map and thermocouple temperature measurements shows that the maximum temperature estimation error is 0.614 degrees C, with a standard deviation of 0.06 degrees C, confirming the feasibility of this model-based temperature mapping method. The influence of sample water:fat signal ratio on the accuracy of the temperature estimate is evaluated in a water-fat mixed phantom experiment with an optimal ratio of approximately 0.66:1. (c) 2009 Wiley-Liss, Inc.

Fibrinolysis standards: a review of the current status.

PubMed

Thelwell, C

2010-07-01

Biological standards are used to calibrate measurements of components of the fibrinolytic system, either for assigning potency values to therapeutic products, or to determine levels in human plasma as an indicator of thrombotic risk. Traditionally WHO International Standards are calibrated in International Units based on consensus values from collaborative studies. The International Unit is defined by the response activity of a given amount of the standard in a bioassay, independent of the method used. Assay validity is based on the assumption that both standard and test preparation contain the same analyte, and the response in an assay is a true function of this analyte. This principle is reflected in the diversity of source materials used to prepare fibrinolysis standards, which has depended on the contemporary preparations they were employed to measure. With advancing recombinant technology, and improved analytical techniques, a reference system based on reference materials and associated reference methods has been recommended for future fibrinolysis standards. Careful consideration and scientific judgement must however be applied when deciding on an approach to develop a new standard, with decisions based on the suitability of a standard to serve its purpose, and not just to satisfy a metrological ideal. 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Contribution to the certification of B, Cd, Cu, Mg and Pb in a synthetic water sample, by use of isotope-dilution ICP-MS, for Comparison 12 of the International Measurement Evaluation Programme.

PubMed

Diemer, J; Quétel, C R; Taylor, P D P

2002-09-01

The contribution of the Institute for Reference Materials and Measurements to the certification of the B, Cd, Cu, Mg, and Pb content of a synthetic water sample used in Comparison 12 of the International Measurement Evaluation Programme (IMEP-12) is described. The aim of the IMEP programme is to demonstrate objectively the degree of equivalence and quality of chemical measurements of individual laboratories on the international scene by comparing them with reference ranges traceable to the SI (Système International d'Unités). IMEP is organized in support of European Union policies and helps to improve the traceability of values produced by field chemical measurement laboratories. The analytical procedure used to establish the reference values for the B, Cd, Cu, Mg, and Pb content of the IMEP-12 sample is based on inductively coupled plasma-isotope-dilution mass spectrometry (ICP-IDMS) applied as a primary method of measurement. The measurements performed for the IMEP-12 study are described in detail. Focus is on the element boron, which is particularly difficult to analyze by ICP-MS because of potential problems of low sensitivity, high mass discrimination, memory effects, and abundance sensitivity. For each of the certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties according to ISO (International Organization for Standardization) and Eurachem guidelines. For all investigated elements with concentrations in the low micro g kg(-1) and mg kg(-1) range (corresponding to pmol kg(-1) to the high micro mol kg(-1) level), SI-traceable reference values with relative expanded uncertainties ( k=2) of less than 2 % were obtained.

Validating internal controls for quantitative plant gene expression studies

PubMed Central

Brunner, Amy M; Yakovlev, Igor A; Strauss, Steven H

2004-01-01

Background Real-time reverse transcription PCR (RT-PCR) has greatly improved the ease and sensitivity of quantitative gene expression studies. However, accurate measurement of gene expression with this method relies on the choice of a valid reference for data normalization. Studies rarely verify that gene expression levels for reference genes are adequately consistent among the samples used, nor compare alternative genes to assess which are most reliable for the experimental conditions analyzed. Results Using real-time RT-PCR to study the expression of 10 poplar (genus Populus) housekeeping genes, we demonstrate a simple method for determining the degree of stability of gene expression over a set of experimental conditions. Based on a traditional method for analyzing the stability of varieties in plant breeding, it defines measures of gene expression stability from analysis of variance (ANOVA) and linear regression. We found that the potential internal control genes differed widely in their expression stability over the different tissues, developmental stages and environmental conditions studied. Conclusion Our results support that quantitative comparisons of candidate reference genes are an important part of real-time RT-PCR studies that seek to precisely evaluate variation in gene expression. The method we demonstrated facilitates statistical and graphical evaluation of gene expression stability. Selection of the best reference gene for a given set of experimental conditions should enable detection of biologically significant changes in gene expression that are too small to be revealed by less precise methods, or when highly variable reference genes are unknowingly used in real-time RT-PCR experiments. PMID:15317655

Medicine prices, availability, and affordability in 36 developing and middle-income countries: a secondary analysis.

PubMed

Cameron, A; Ewen, M; Ross-Degnan, D; Ball, D; Laing, R

2009-01-17

WHO and Health Action International (HAI) have developed a standardised method for surveying medicine prices, availability, affordability, and price components in low-income and middle-income countries. Here, we present a secondary analysis of medicine availability in 45 national and subnational surveys done using the WHO/HAI methodology. Data from 45 WHO/HAI surveys in 36 countries were adjusted for inflation or deflation and purchasing power parity. International reference prices from open international procurements for generic products were used as comparators. Results are presented for 15 medicines included in at least 80% of surveys and four individual medicines. Average public sector availability of generic medicines ranged from 29.4% to 54.4% across WHO regions. Median government procurement prices for 15 generic medicines were 1.11 times corresponding international reference prices, although purchasing efficiency ranged from 0.09 to 5.37 times international reference prices. Low procurement prices did not always translate into low patient prices. Private sector patients paid 9-25 times international reference prices for lowest-priced generic products and over 20 times international reference prices for originator products across WHO regions. Treatments for acute and chronic illness were largely unaffordable in many countries. In the private sector, wholesale mark-ups ranged from 2% to 380%, whereas retail mark-ups ranged from 10% to 552%. In countries where value added tax was applied to medicines, the amount charged varied from 4% to 15%. Overall, public and private sector prices for originator and generic medicines were substantially higher than would be expected if purchasing and distribution were efficient and mark-ups were reasonable. Policy options such as promoting generic medicines and alternative financing mechanisms are needed to increase availability, reduce prices, and improve affordability.

Establishing International Blood Pressure References Among Non-Overweight Children and Adolescents Aged 6–17 Years

PubMed Central

Xi, Bo; Zong, Xin’nan; Kelishadi, Roya; Hong, Young Mi; Khadilkar, Anuradha; Steffen, Lyn M.; Nawarycz, Tadeusz; Krzywińska-Wiewiorowska, Małgorzata; Aounallah-Skhiri, Hajer; Bovet, Pascal; Chiolero, Arnaud; Pan, Haiyan; Litwin, Mieczysław; Poh, Bee Koon; Sung, Rita Y.T.; So, Hung-Kwan; Schwandt, Peter; Haas, Gerda-Maria; Neuhauser, Hannelore K.; Marinov, Lachezar; Galcheva, Sonya V; Motlagh, Mohammad Esmaeil; Kim, Hae Soon; Khadilkar, Vaman; Krzyżaniak, Alicja; Ben Romdhane, Habiba; Heshmat, Ramin; Chiplonkar, Shashi; Stawińska-Witoszyńska, Barbara; Ati, Jalila El; Qorbani, Mostafa; Kajale, Neha; Traissac, Pierre; Ostrowska-Nawarycz, Lidia; Ardalan, Gelayol; Parthasarathy, Lavanya; Zhao, Min; Zhang, Tao

2015-01-01

Background Several distributions of country-specific blood pressure (BP) percentiles by sex, age and height for children and adolescents have been established worldwide. However, there are no globally unified BP references for defining elevated BP in children and adolescents, which limit international comparisons of prevalence of pediatric elevated BP. We aimed to establish international BP references for children and adolescents using seven nationally representative data (China, India, Iran, Korea, Poland, Tunisia and USA). Methods and Results Data on BP for 52,636 non-overweight children and adolescents aged 6–19 years were obtained from seven large nationally representative cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and USA. BP values were obtained with certified mercury sphygmomanometers in all seven countries, using standard procedures for BP measurement. Smoothed BP percentiles (50th, 90th, 95th and 99th) by age and height were estimated using the Generalized Additive Model for Location Scale and Shape (GAMLSS) model. BP values were similar between males and females until the age of 13 years and were higher in males than females thereafter. Compared to BP level of the 90th and 95th percentiles of the U.S. Fourth Report at median height, systolic BP of the corresponding percentiles of these international references was lower while diastolic BP was similar. Conclusions These international BP references will be a useful tool for international comparison of the prevalence of elevated BP in children and adolescents and may help identify hypertensive youths in diverse populations. PMID:26671979

46 CFR 56.01-2 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) American Society of Mechanical Engineers (ASME) International, Three Park Avenue, New York, NY 10016-5990... (“ASME SA-675”), 56.60-2. (e) ASTM International (formerly American Society for Testing and Materials... 15540 Ships and Marine Technology-Fire Resistance of Hose Assemblies-Test Methods, First Edition (Aug. 1...

The establishment of tocopherol reference intervals for Hungarian adult population using a validated HPLC method.

PubMed

Veres, Gábor; Szpisjak, László; Bajtai, Attila; Siska, Andrea; Klivényi, Péter; Ilisz, István; Földesi, Imre; Vécsei, László; Zádori, Dénes

2017-09-01

Evidence suggests that decreased α-tocopherol (the most biologically active substance in the vitamin E group) level can cause neurological symptoms, most likely ataxia. The aim of the current study was to first provide reference intervals for serum tocopherols in the adult Hungarian population with appropriate sample size, recruiting healthy control subjects and neurological patients suffering from conditions without symptoms of ataxia, myopathy or cognitive deficiency. A validated HPLC method applying a diode array detector and rac-tocol as internal standard was utilized for that purpose. Furthermore, serum cholesterol levels were determined as well for data normalization. The calculated 2.5-97.5% reference intervals for α-, β/γ- and δ-tocopherols were 24.62-54.67, 0.81-3.69 and 0.29-1.07 μm, respectively, whereas the tocopherol/cholesterol ratios were 5.11-11.27, 0.14-0.72 and 0.06-0.22 μmol/mmol, respectively. The establishment of these reference intervals may improve the diagnostic accuracy of tocopherol measurements in certain neurological conditions with decreased tocopherol levels. Moreover, the current study draws special attention to the possible pitfalls in the complex process of the determination of reference intervals as well, including the selection of study population, the application of internal standard and method validation and the calculation of tocopherol/cholesterol ratios. Copyright © 2017 John Wiley & Sons, Ltd.

Quantitative determination and validation of octreotide acetate using 1 H-NMR spectroscopy with internal standard method.

PubMed

Yu, Chen; Zhang, Qian; Xu, Peng-Yao; Bai, Yin; Shen, Wen-Bin; Di, Bin; Su, Meng-Xiang

2018-01-01

Quantitative nuclear magnetic resonance (qNMR) is a well-established technique in quantitative analysis. We presented a validated 1 H-qNMR method for assay of octreotide acetate, a kind of cyclic octopeptide. Deuterium oxide was used to remove the undesired exchangeable peaks, which was referred to as proton exchange, in order to make the quantitative signals isolated in the crowded spectrum of the peptide and ensure precise quantitative analysis. Gemcitabine hydrochloride was chosen as the suitable internal standard. Experimental conditions, including relaxation delay time, the numbers of scans, and pulse angle, were optimized first. Then method validation was carried out in terms of selectivity, stability, linearity, precision, and robustness. The assay result was compared with that by means of high performance liquid chromatography, which is provided by Chinese Pharmacopoeia. The statistical F test, Student's t test, and nonparametric test at 95% confidence level indicate that there was no significant difference between these two methods. qNMR is a simple and accurate quantitative tool with no need for specific corresponding reference standards. It has the potential of the quantitative analysis of other peptide drugs and standardization of the corresponding reference standards. Copyright © 2017 John Wiley & Sons, Ltd.

Estimating clinical chemistry reference values based on an existing data set of unselected animals.

PubMed

Dimauro, Corrado; Bonelli, Piero; Nicolussi, Paola; Rassu, Salvatore P G; Cappio-Borlino, Aldo; Pulina, Giuseppe

2008-11-01

In an attempt to standardise the determination of biological reference values, the International Federation of Clinical Chemistry (IFCC) has published a series of recommendations on developing reference intervals. The IFCC recommends the use of an a priori sampling of at least 120 healthy individuals. However, such a high number of samples and laboratory analysis is expensive, time-consuming and not always feasible, especially in veterinary medicine. In this paper, an alternative (a posteriori) method is described and is used to determine reference intervals for biochemical parameters of farm animals using an existing laboratory data set. The method used was based on the detection and removal of outliers to obtain a large sample of animals likely to be healthy from the existing data set. This allowed the estimation of reliable reference intervals for biochemical parameters in Sarda dairy sheep. This method may also be useful for the determination of reference intervals for different species, ages and gender.

Measuring use of research evidence in public health policy: a policy content analysis

PubMed Central

2014-01-01

Background There are few Australian studies showing how research evidence is used to inform the development of public health policy. International research has shown that compensation for injury rehabilitation can have negative impacts on health outcomes. This study examined transport injury compensation policy in the Australian state of Victoria to: determine type and purpose of reference to information sources; and to identify the extent of reference to academic research evidence in transport related injury rehabilitation compensation policy. Methods Quantitative content analysis of injury rehabilitation compensation policies (N = 128) from the Victorian state government transport accident compensation authority. Results The most commonly referenced types of information were Internal Policy (median = 6 references per policy), Clinical/Medical (2.5), and Internal Legislation (1). Academic Research Evidence was the least often referenced source of information. The main purpose of reference to information was to support injury treatment and rehabilitation compensation claims decision-making. Conclusions Transport injury compensation policy development is complex; with multiple sources of information cited including legislation, internal policy, external policy and clinical/medical evidence. There is limited use of academic research evidence in Victorian state government injury treatment and rehabilitation compensation policies. Decisions regarding compensation for injury treatment and rehabilitation services could benefit from greater use of academic research evidence. This study is one of the first to examine the use of research evidence in existing Australian public health policy decision-making using rigorous quantitative methods. It provides a practical example of how use of research evidence in public health policy can be objectively measured. PMID:24886092

39 CFR 20.1 - International Mail Manual; incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-07-01

... reference. 20.1 Section 20.1 Postal Service UNITED STATES POSTAL SERVICE INTERNATIONAL MAIL INTERNATIONAL POSTAL SERVICE § 20.1 International Mail Manual; incorporation by reference. (a) Section 552(a) of Title... provided in this part, the U.S. Postal Service hereby incorporates by reference its International Mail...

Multireference configuration interaction theory using cumulant reconstruction with internal contraction of density matrix renormalization group wave function.

PubMed

Saitow, Masaaki; Kurashige, Yuki; Yanai, Takeshi

2013-07-28

We report development of the multireference configuration interaction (MRCI) method that can use active space scalable to much larger size references than has previously been possible. The recent development of the density matrix renormalization group (DMRG) method in multireference quantum chemistry offers the ability to describe static correlation in a large active space. The present MRCI method provides a critical correction to the DMRG reference by including high-level dynamic correlation through the CI treatment. When the DMRG and MRCI theories are combined (DMRG-MRCI), the full internal contraction of the reference in the MRCI ansatz, including contraction of semi-internal states, plays a central role. However, it is thought to involve formidable complexity because of the presence of the five-particle rank reduced-density matrix (RDM) in the Hamiltonian matrix elements. To address this complexity, we express the Hamiltonian matrix using commutators, which allows the five-particle rank RDM to be canceled out without any approximation. Then we introduce an approximation to the four-particle rank RDM by using a cumulant reconstruction from lower-particle rank RDMs. A computer-aided approach is employed to derive the exceedingly complex equations of the MRCI in tensor-contracted form and to implement them into an efficient parallel computer code. This approach extends to the size-consistency-corrected variants of MRCI, such as the MRCI+Q, MR-ACPF, and MR-AQCC methods. We demonstrate the capability of the DMRG-MRCI method in several benchmark applications, including the evaluation of single-triplet gap of free-base porphyrin using 24 active orbitals.

Citalopram Treatment of Pediatric Recurrent Abdominal Pain and Comorbid Internalizing Disorders: An Exploratory Study

ERIC Educational Resources Information Center

Campo, John V.; Perel, James; Lucas, Amanda; Bridge, Jeff; Ehmann, Mary; Kalas, Catherine; Monk, Kelly; Axelson, David; Birmaher, Boris; Ryan, Neal; Di Lorenzo, Carlo; Brent, David A.

2004-01-01

Objective: To assess the potential efficacy, tolerability, and safety of citalopram in the treatment of functional pediatric recurrent abdominal pain and comorbid internalizing disorders. Method: Twenty-five clinically referred children and adolescents with recurrent abdominal pain aged 7 to 18 years, inclusive, participated in a 12-week,…

The International Decision Support Initiative Reference Case for Economic Evaluation: An Aid to Thought.

PubMed

Wilkinson, Thomas; Sculpher, Mark J; Claxton, Karl; Revill, Paul; Briggs, Andrew; Cairns, John A; Teerawattananon, Yot; Asfaw, Elias; Lopert, Ruth; Culyer, Anthony J; Walker, Damian G

2016-12-01

Policymakers in high-, low-, and middle-income countries alike face challenging choices about resource allocation in health. Economic evaluation can be useful in providing decision makers with the best evidence of the anticipated benefits of new investments, as well as their expected opportunity costs-the benefits forgone of the options not chosen. To guide the decisions of health systems effectively, it is important that the methods of economic evaluation are founded on clear principles, are applied systematically, and are appropriate to the decision problems they seek to inform. The Bill and Melinda Gates Foundation, a major funder of economic evaluations of health technologies in low- and middle-income countries (LMICs), commissioned a "reference case" through the International Decision Support Initiative (iDSI) to guide future evaluations, and improve both the consistency and usefulness to decision makers. The iDSI Reference Case draws on previous insights from the World Health Organization, the US Panel on Cost-Effectiveness in Health Care, and the UK National Institute for Health and Care Excellence. Comprising 11 key principles, each accompanied by methodological specifications and reporting standards, the iDSI Reference Case also serves as a means of identifying priorities for methods research, and can be used as a framework for capacity building and technical assistance in LMICs. The iDSI Reference Case is an aid to thought, not a substitute for it, and should not be followed slavishly without regard to context, culture, or history. This article presents the iDSI Reference Case and discusses the rationale, approach, components, and application in LMICs. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

The height-, weight-, and BMI-for-age of Polish school-aged children and adolescents relative to international and local growth references.

PubMed

Kulaga, Zbigniew; Litwin, Mieczysław; Tkaczyk, Marcin; Rózdzyńska, Agnieszka; Barwicka, Katarzyna; Grajda, Aneta; Swiader, Anna; Gurzkowska, Beata; Napieralska, Ewelina; Pan, Huiqi

2010-03-04

The growth of children is an indicator of health and society's wellbeing. Growth references are useful in monitoring a child's growth, which is a very important part of child care. Poland's growth references are not updated regularly. Although several growth reference ranges have been developed in Poland over recent years, sampling was restricted to urban populations of major cities. The aim of this study was to assess how well Polish children match with, or diverge from, regional charts and to compare them with international growth references. Four Polish and two international (WHO 2007 and USCDC2000) growth references were used to calculate the height, weight and BMI z-scores in a recent, large, population-representative sample of school-aged children and adolescents in Poland. The distributions of z-scores were analysed with descriptive and inferential statistical methods. Mean height z-scores calculated with the use of the WHO 2007 and USCDC2000 references were positive and significantly different from zero over the entire age range. The mean height z-score was closest to zero in the Poznan reference for boys (0.05) and Warszawa reference for girls (0.01). Median weight z-scores were positive under all weight references over the entire age range with only the exception of 18-year-old girls' weight z-score calculated relative to USCDC2000. Median BMI z-scores were positive in males in early childhood, decreasing with age. In the case of girls, the median BMI z-score calculated using WHO 2007 and USCDC2000 was close to zero in early childhood, decreased in adolescents and reached minimum values at age 18 years. Median BMI z-scores calculated with the use of the Lodz reference fluctuated between 0.05 and 0.2 over the studied age range. In this contemporary sample of Polish school-aged children, distributions of height, weight and BMI differed from those of children from the international growth references. These differences should be considered when using the references. There exist certain limitations to the analysis of height, weight, and BMI z-scores when Polish regional references are used.

Evaluating new HbA1c methods for adoption by the IFCC and NGSP reference networks using international quality targets.

PubMed

Lenters-Westra, Erna; English, Emma

2017-08-28

As a reference laboratory for HbA1c, it is essential to have accurate and precise HbA1c methods covering a range of measurement principles. We report an evaluation of the Abbott Enzymatic (Architect c4000), Roche Gen.3 HbA1c (Cobas c513) and Tosoh G11 using different quality targets. The effect of hemoglobin variants, other potential interferences and the performance in comparison to both the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the National Glycohemoglobin Standardization Program (NGSP) reference systems was assessed using certified evaluation protocols. Each of the evaluated HbA1c methods had CVs <3% in SI units and <2% in NGSP units at 46 mmol/mol (6.4%) and 72 mmol/mol (8.7%) and passed the NGSP criteria when compared with six secondary reference measurement procedures (SRMPs). Sigma was 8.6 for Abbott Enzymatic, 3.3 for Roche Cobas c513 and 6.9 for Tosoh G11. No clinically significant interference was detected for the common Hb variants for the three methods. All three methods performed well and are suitable for clinical application in the analysis of HbA1c. Partly based on the result of this study, the Abbott Enzymatic method on the Architect c4000 and the Roche Gen.3 HbA1c on the Cobas c513 are now official, certified IFCC and NGSP SRMPs in the IFCC and NGSP networks. Sigma metrics quality criteria presented in a graph distinguish between good and excellent performance.

Validation studies and proficiency testing.

PubMed

Ankilam, Elke; Heinze, Petra; Kay, Simon; Van den Eede, Guy; Popping, Bert

2002-01-01

Genetically modified organisms (GMOs) entered the European food market in 1996. Current legislation demands the labeling of food products if they contain <1% GMO, as assessed for each ingredient of the product. To create confidence in the testing methods and to complement enforcement requirements, there is an urgent need for internationally validated methods, which could serve as reference methods. To date, several methods have been submitted to validation trials at an international level; approaches now exist that can be used in different circumstances and for different food matrixes. Moreover, the requirement for the formal validation of methods is clearly accepted; several national and international bodies are active in organizing studies. Further validation studies, especially on the quantitative polymerase chain reaction methods, need to be performed to cover the rising demand for new extraction methods and other background matrixes, as well as for novel GMO constructs.

Valid analytical performance specifications for combined analytical bias and imprecision for the use of common reference intervals.

PubMed

Hyltoft Petersen, Per; Lund, Flemming; Fraser, Callum G; Sandberg, Sverre; Sölétormos, György

2018-01-01

Background Many clinical decisions are based on comparison of patient results with reference intervals. Therefore, an estimation of the analytical performance specifications for the quality that would be required to allow sharing common reference intervals is needed. The International Federation of Clinical Chemistry (IFCC) recommended a minimum of 120 reference individuals to establish reference intervals. This number implies a certain level of quality, which could then be used for defining analytical performance specifications as the maximum combination of analytical bias and imprecision required for sharing common reference intervals, the aim of this investigation. Methods Two methods were investigated for defining the maximum combination of analytical bias and imprecision that would give the same quality of common reference intervals as the IFCC recommendation. Method 1 is based on a formula for the combination of analytical bias and imprecision and Method 2 is based on the Microsoft Excel formula NORMINV including the fractional probability of reference individuals outside each limit and the Gaussian variables of mean and standard deviation. The combinations of normalized bias and imprecision are illustrated for both methods. The formulae are identical for Gaussian and log-Gaussian distributions. Results Method 2 gives the correct results with a constant percentage of 4.4% for all combinations of bias and imprecision. Conclusion The Microsoft Excel formula NORMINV is useful for the estimation of analytical performance specifications for both Gaussian and log-Gaussian distributions of reference intervals.

Characterisation of a reference site for quantifying uncertainties related to soil sampling.

PubMed

Barbizzi, Sabrina; de Zorzi, Paolo; Belli, Maria; Pati, Alessandra; Sansone, Umberto; Stellato, Luisa; Barbina, Maria; Deluisa, Andrea; Menegon, Sandro; Coletti, Valter

2004-01-01

The paper reports a methodology adopted to face problems related to quality assurance in soil sampling. The SOILSAMP project, funded by the Environmental Protection Agency of Italy (APAT), is aimed at (i) establishing protocols for soil sampling in different environments; (ii) assessing uncertainties associated with different soil sampling methods in order to select the "fit-for-purpose" method; (iii) qualifying, in term of trace elements spatial variability, a reference site for national and international inter-comparison exercises. Preliminary results and considerations are illustrated.

Validation of a modification to Performance-Tested Method 070601: Reveal Listeria Test for detection of Listeria spp. in selected foods and selected environmental samples.

PubMed

Alles, Susan; Peng, Linda X; Mozola, Mark A

2009-01-01

A modification to Performance-Tested Method (PTM) 070601, Reveal Listeria Test (Reveal), is described. The modified method uses a new media formulation, LESS enrichment broth, in single-step enrichment protocols for both foods and environmental sponge and swab samples. Food samples are enriched for 27-30 h at 30 degrees C and environmental samples for 24-48 h at 30 degrees C. Implementation of these abbreviated enrichment procedures allows test results to be obtained on a next-day basis. In testing of 14 food types in internal comparative studies with inoculated samples, there was a statistically significant difference in performance between the Reveal and reference culture [U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM) or U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS)] methods for only a single food in one trial (pasteurized crab meat) at the 27 h enrichment time point, with more positive results obtained with the FDA/BAM reference method. No foods showed statistically significant differences in method performance at the 30 h time point. Independent laboratory testing of 3 foods again produced a statistically significant difference in results for crab meat at the 27 h time point; otherwise results of the Reveal and reference methods were statistically equivalent. Overall, considering both internal and independent laboratory trials, sensitivity of the Reveal method relative to the reference culture procedures in testing of foods was 85.9% at 27 h and 97.1% at 30 h. Results from 5 environmental surfaces inoculated with various strains of Listeria spp. showed that the Reveal method was more productive than the reference USDA-FSIS culture procedure for 3 surfaces (stainless steel, plastic, and cast iron), whereas results were statistically equivalent to the reference method for the other 2 surfaces (ceramic tile and sealed concrete). An independent laboratory trial with ceramic tile inoculated with L. monocytogenes confirmed the effectiveness of the Reveal method at the 24 h time point. Overall, sensitivity of the Reveal method at 24 h relative to that of the USDA-FSIS method was 153%. The Reveal method exhibited extremely high specificity, with only a single false-positive result in all trials combined for overall specificity of 99.5%.

Impacts of Earth rotation parameters on GNSS ultra-rapid orbit prediction: Derivation and real-time correction

NASA Astrophysics Data System (ADS)

Wang, Qianxin; Hu, Chao; Xu, Tianhe; Chang, Guobin; Hernández Moraleda, Alberto

2017-12-01

Analysis centers (ACs) for global navigation satellite systems (GNSSs) cannot accurately obtain real-time Earth rotation parameters (ERPs). Thus, the prediction of ultra-rapid orbits in the international terrestrial reference system (ITRS) has to utilize the predicted ERPs issued by the International Earth Rotation and Reference Systems Service (IERS) or the International GNSS Service (IGS). In this study, the accuracy of ERPs predicted by IERS and IGS is analyzed. The error of the ERPs predicted for one day can reach 0.15 mas and 0.053 ms in polar motion and UT1-UTC direction, respectively. Then, the impact of ERP errors on ultra-rapid orbit prediction by GNSS is studied. The methods for orbit integration and frame transformation in orbit prediction with introduced ERP errors dominate the accuracy of the predicted orbit. Experimental results show that the transformation from the geocentric celestial references system (GCRS) to ITRS exerts the strongest effect on the accuracy of the predicted ultra-rapid orbit. To obtain the most accurate predicted ultra-rapid orbit, a corresponding real-time orbit correction method is developed. First, orbits without ERP-related errors are predicted on the basis of ITRS observed part of ultra-rapid orbit for use as reference. Then, the corresponding predicted orbit is transformed from GCRS to ITRS to adjust for the predicted ERPs. Finally, the corrected ERPs with error slopes are re-introduced to correct the predicted orbit in ITRS. To validate the proposed method, three experimental schemes are designed: function extrapolation, simulation experiments, and experiments with predicted ultra-rapid orbits and international GNSS Monitoring and Assessment System (iGMAS) products. Experimental results show that using the proposed correction method with IERS products considerably improved the accuracy of ultra-rapid orbit prediction (except the geosynchronous BeiDou orbits). The accuracy of orbit prediction is enhanced by at least 50% (error related to ERP) when a highly accurate observed orbit is used with the correction method. For iGMAS-predicted orbits, the accuracy improvement ranges from 8.5% for the inclined BeiDou orbits to 17.99% for the GPS orbits. This demonstrates that the correction method proposed by this study can optimize the ultra-rapid orbit prediction.

Extended international (IOTF) body mass index cut-offs for thinness, overweight and obesity.

PubMed

Cole, T J; Lobstein, T

2012-08-01

The international (International Obesity Task Force; IOTF) body mass index (BMI) cut-offs are widely used to assess the prevalence of child overweight, obesity and thinness. Based on data from six countries fitted by the LMS method, they link BMI values at 18 years (16, 17, 18.5, 25 and 30 kg m(-2)) to child centiles, which are averaged across the countries. Unlike other BMI references, e.g. the World Health Organization (WHO) standard, these cut-offs cannot be expressed as centiles (e.g. 85th). To address this, we averaged the previously unpublished L, M and S curves for the six countries, and used them to derive new cut-offs defined in terms of the centiles at 18 years corresponding to each BMI value. These new cut-offs were compared with the originals, and with the WHO standard and reference, by measuring their prevalence rates based on US and Chinese data. The new cut-offs were virtually identical to the originals, giving prevalence rates differing by < 0.2% on average. The discrepancies were smaller for overweight and obesity than for thinness. The international and WHO prevalences were systematically different before/after age 5. Defining the international cut-offs in terms of the underlying LMS curves has several benefits. New cut-offs are easy to derive (e.g. BMI 35 for morbid obesity), and they can be expressed as BMI centiles (e.g. boys obesity = 98.9th centile), allowing them to be compared with other BMI references. For WHO, median BMI is relatively low in early life and high at older ages, probably due to its method of construction. © 2012 The Authors. Pediatric Obesity © 2012 International Association for the Study of Obesity.

Efficiency of personal dosimetry methods in vascular interventional radiology.

PubMed

Bacchim Neto, Fernando Antonio; Alves, Allan Felipe Fattori; Mascarenhas, Yvone Maria; Giacomini, Guilherme; Maués, Nadine Helena Pelegrino Bastos; Nicolucci, Patrícia; de Freitas, Carlos Clayton Macedo; Alvarez, Matheus; Pina, Diana Rodrigues de

2017-05-01

The aim of the present study was to determine the efficiency of six methods for calculate the effective dose (E) that is received by health professionals during vascular interventional procedures. We evaluated the efficiency of six methods that are currently used to estimate professionals' E, based on national and international recommendations for interventional radiology. Equivalent doses on the head, neck, chest, abdomen, feet, and hands of seven professionals were monitored during 50 vascular interventional radiology procedures. Professionals' E was calculated for each procedure according to six methods that are commonly employed internationally. To determine the best method, a more efficient E calculation method was used to determine the reference value (reference E) for comparison. The highest equivalent dose were found for the hands (0.34±0.93mSv). The two methods that are described by Brazilian regulations overestimated E by approximately 100% and 200%. The more efficient method was the one that is recommended by the United States National Council on Radiological Protection and Measurements (NCRP). The mean and median differences of this method relative to reference E were close to 0%, and its standard deviation was the lowest among the six methods. The present study showed that the most precise method was the one that is recommended by the NCRP, which uses two dosimeters (one over and one under protective aprons). The use of methods that employ at least two dosimeters are more efficient and provide better information regarding estimates of E and doses for shielded and unshielded regions. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Reference values assessment in a Mediterranean population for small dense low-density lipoprotein concentration isolated by an optimized precipitation method.

PubMed

Fernández-Cidón, Bárbara; Padró-Miquel, Ariadna; Alía-Ramos, Pedro; Castro-Castro, María José; Fanlo-Maresma, Marta; Dot-Bach, Dolors; Valero-Politi, José; Pintó-Sala, Xavier; Candás-Estébanez, Beatriz

2017-01-01

High serum concentrations of small dense low-density lipoprotein cholesterol (sd-LDL-c) particles are associated with risk of cardiovascular disease (CVD). Their clinical application has been hindered as a consequence of the laborious current method used for their quantification. Optimize a simple and fast precipitation method to isolate sd-LDL particles and establish a reference interval in a Mediterranean population. Forty-five serum samples were collected, and sd-LDL particles were isolated using a modified heparin-Mg 2+ precipitation method. sd-LDL-c concentration was calculated by subtracting high-density lipoprotein cholesterol (HDL-c) from the total cholesterol measured in the supernatant. This method was compared with the reference method (ultracentrifugation). Reference values were estimated according to the Clinical and Laboratory Standards Institute and The International Federation of Clinical Chemistry and Laboratory Medicine recommendations. sd-LDL-c concentration was measured in serums from 79 subjects with no lipid metabolism abnormalities. The Passing-Bablok regression equation is y = 1.52 (0.72 to 1.73) + 0.07 x (-0.1 to 0.13), demonstrating no significant statistical differences between the modified precipitation method and the ultracentrifugation reference method. Similarly, no differences were detected when considering only sd-LDL-c from dyslipidemic patients, since the modifications added to the precipitation method facilitated the proper sedimentation of triglycerides and other lipoproteins. The reference interval for sd-LDL-c concentration estimated in a Mediterranean population was 0.04-0.47 mmol/L. An optimization of the heparin-Mg 2+ precipitation method for sd-LDL particle isolation was performed, and reference intervals were established in a Spanish Mediterranean population. Measured values were equivalent to those obtained with the reference method, assuring its clinical application when tested in both normolipidemic and dyslipidemic subjects.

Expressing the joint moments of drop jumps and sidestep cutting in different reference frames--does it matter?

PubMed

Kristianslund, Eirik; Krosshaug, Tron; Mok, Kam-Ming; McLean, Scott; van den Bogert, Antonie J

2014-01-03

Joint moments help us understand joint loading and muscle function during movement. However, the interpretation depends on the choice of reference frame, but the different reference frames have not been compared in dynamic, high-impact sporting movements. We have compared the magnitude and the resulting ranking of hip and knee joint moments expressed in the laboratory coordinate system, the local system of the distal segment and projected or decomposed to the Joint Coordinate System (JCS) axes. Hip and knee joint moments of drop jumps and sidestep cutting in 70 elite female handball players were calculated based on recordings from an eight-camera 240 Hz system and two force platforms and expressed with the four methods. The greatest variations in magnitude between conditions were seen for drop jump hip internal rotation (range: 0.31-0.71 Nm/kg) and sidestep cutting knee flexion (2.87-3.39 Nm/kg) and hip internal rotation (0.87-2.36 Nm/kg) and knee internal rotation (0.10-0.40 Nm/kg) moments. The rank correlations were highest between conditions for flexion moments (0.88-1.00) and sidestep cutting abduction moments (0.71-0.98). The rank correlations ranged from 0.64 to 0.73 for drop jump knee abduction moments and between -0.17 and 0.67 for hip and knee internal rotation moments. Expression of joint moments in different reference systems affects the magnitude and ranking of athletes. This lack of consistency may complicate the comparison and combination of results. Projection to the JCS is the only method where joint moments correspond to muscle and ligament loading. More widespread adoption of this convention could facilitate comparison of studies and ease the interpretation of results. © 2013 Elsevier Ltd. All rights reserved.

Research-based recommendations for implementing international service-learning.

PubMed

Amerson, Roxanne

2014-01-01

An increasing number of schools of nursing are incorporating international service-learning and/or immersion experiences into their curriculum to promote cultural competence. The purpose of this paper is to identify research-based recommendations for implementing an international service-learning program. A review of literature was conducted in the Cumulative Index of Nursing and Allied Health Literature database using the keywords international, immersion, cultural competence, nursing, and international service-learning. Additional references were located from the reference lists of related articles. Planning of international or immersion experiences requires consideration of the type of country, the length of time, and design of the program; the use of a service-learning framework; opportunities that require the student to live and work in the community, provide hands-on care, participate in unstructured activities, and make home visits; and a method of reflection. Increasing cultural competence does not require foreign travel, but it does necessitate that students are challenged to move outside their comfort zone and work directly with diverse populations. These research-based recommendations may be used either internationally or locally to promote the most effective service-learning opportunities for nursing students. © 2014.

Indirect methods for reference interval determination - review and recommendations.

PubMed

Jones, Graham R D; Haeckel, Rainer; Loh, Tze Ping; Sikaris, Ken; Streichert, Thomas; Katayev, Alex; Barth, Julian H; Ozarda, Yesim

2018-04-19

Reference intervals are a vital part of the information supplied by clinical laboratories to support interpretation of numerical pathology results such as are produced in clinical chemistry and hematology laboratories. The traditional method for establishing reference intervals, known as the direct approach, is based on collecting samples from members of a preselected reference population, making the measurements and then determining the intervals. An alternative approach is to perform analysis of results generated as part of routine pathology testing and using appropriate statistical techniques to determine reference intervals. This is known as the indirect approach. This paper from a working group of the International Federation of Clinical Chemistry (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) aims to summarize current thinking on indirect approaches to reference intervals. The indirect approach has some major potential advantages compared with direct methods. The processes are faster, cheaper and do not involve patient inconvenience, discomfort or the risks associated with generating new patient health information. Indirect methods also use the same preanalytical and analytical techniques used for patient management and can provide very large numbers for assessment. Limitations to the indirect methods include possible effects of diseased subpopulations on the derived interval. The IFCC C-RIDL aims to encourage the use of indirect methods to establish and verify reference intervals, to promote publication of such intervals with clear explanation of the process used and also to support the development of improved statistical techniques for these studies.

Comparison method for uranium determination in ore sample by inductively coupled plasma optical emission spectrometry (ICP-OES).

PubMed

Sert, Şenol

2013-07-01

A comparison method for the determination (without sample pre-concentration) of uranium in ore by inductively coupled plasma optical emission spectrometry (ICP-OES) has been performed. The experiments were conducted using three procedures: matrix matching, plasma optimization, and internal standardization for three emission lines of uranium. Three wavelengths of Sm were tested as internal standard for the internal standardization method. The robust conditions were evaluated using applied radiofrequency power, nebulizer argon gas flow rate, and sample uptake flow rate by considering the intensity ratio of the Mg(II) 280.270 nm and Mg(I) 285.213 nm lines. Analytical characterization of method was assessed by limit of detection and relative standard deviation values. The certificated reference soil sample IAEA S-8 was analyzed, and the uranium determination at 367.007 nm with internal standardization using Sm at 359.260 nm has been shown to improve accuracy compared with other methods. The developed method was used for real uranium ore sample analysis.

The characterization and certification of a quantitative reference material for Legionella detection and quantification by qPCR.

PubMed

Baume, M; Garrelly, L; Facon, J P; Bouton, S; Fraisse, P O; Yardin, C; Reyrolle, M; Jarraud, S

2013-06-01

The characterization and certification of a Legionella DNA quantitative reference material as a primary measurement standard for Legionella qPCR. Twelve laboratories participated in a collaborative certification campaign. A candidate reference DNA material was analysed through PCR-based limiting dilution assays (LDAs). The validated data were used to statistically assign both a reference value and an associated uncertainty to the reference material. This LDA method allowed for the direct quantification of the amount of Legionella DNA per tube in genomic units (GU) and the determination of the associated uncertainties. This method could be used for the certification of all types of microbiological standards for qPCR. The use of this primary standard will improve the accuracy of Legionella qPCR measurements and the overall consistency of these measurements among different laboratories. The extensive use of this certified reference material (CRM) has been integrated in the French standard NF T90-471 (April 2010) and in the ISO Technical Specification 12 869 (Anon 2012 International Standardisation Organisation) for validating qPCR methods and ensuring the reliability of these methods. © 2013 The Society for Applied Microbiology.

Human blood metabolite timetable indicates internal body time

PubMed Central

Kasukawa, Takeya; Sugimoto, Masahiro; Hida, Akiko; Minami, Yoichi; Mori, Masayo; Honma, Sato; Honma, Ken-ichi; Mishima, Kazuo; Soga, Tomoyoshi; Ueda, Hiroki R.

2012-01-01

A convenient way to estimate internal body time (BT) is essential for chronotherapy and time-restricted feeding, both of which use body-time information to maximize potency and minimize toxicity during drug administration and feeding, respectively. Previously, we proposed a molecular timetable based on circadian-oscillating substances in multiple mouse organs or blood to estimate internal body time from samples taken at only a few time points. Here we applied this molecular-timetable concept to estimate and evaluate internal body time in humans. We constructed a 1.5-d reference timetable of oscillating metabolites in human blood samples with 2-h sampling frequency while simultaneously controlling for the confounding effects of activity level, light, temperature, sleep, and food intake. By using this metabolite timetable as a reference, we accurately determined internal body time within 3 h from just two anti-phase blood samples. Our minimally invasive, molecular-timetable method with human blood enables highly optimized and personalized medicine. PMID:22927403

BMI percentile curves for Chinese children aged 7-18 years, in comparison with the WHO and the US Centers for Disease Control and Prevention references.

PubMed

Ma, Jun; Wang, Zhiqiang; Song, Yi; Hu, Peijin; Zhang, Bing

2010-12-01

To establish BMI percentile curves that describe the contemporary BMI distribution among Chinese children, and to compare their BMI percentile curves with those in two recently developed international references: the WHO and the US Centers for Disease Control and Prevention (US CDC) growth references. A cross-sectional national survey. Thirty provinces, municipalities and autonomous regions in China. Nationally representative sample of 232 140 school students aged 7-18 years. BMI percentile curves were established using the LMS method, and were compared with the percentiles of the WHO and the US CDC references. BMI distributions and growth patterns in Chinese children were dramatically different from those in the two international reference populations. Compared with the international reference populations, younger Chinese boys (7-12 years of age) had higher values of the percentiles above the median and lower values of the percentiles below the median, suggesting that they had larger proportions of extreme BMI values in both directions. Chinese girls and older Chinese boys (15-18 years of age) had substantially lower BMI percentiles than their counterparts in the reference populations, particularly those high percentiles among older age groups. The present study described the unique patterns of BMI curves at the national level, and these curves are useful as a reference for comparing different regions and for monitoring changes over time in Chinese children. Higher proportions of children with extreme values in both directions indicate that China is currently facing both an increasing level of obesity and a high level of undernutrition, simultaneously.

A New Dual-purpose Quality Control Dosimetry Protocol for Diagnostic Reference-level Determination in Computed Tomography.

PubMed

Sohrabi, Mehdi; Parsi, Masoumeh; Sina, Sedigheh

2018-05-17

A diagnostic reference level is an advisory dose level set by a regulatory authority in a country as an efficient criterion for protection of patients from unwanted medical exposure. In computed tomography, the direct dose measurement and data collection methods are commonly applied for determination of diagnostic reference levels. Recently, a new quality-control-based dose survey method was proposed by the authors to simplify the diagnostic reference-level determination using a retrospective quality control database usually available at a regulatory authority in a country. In line with such a development, a prospective dual-purpose quality control dosimetry protocol is proposed for determination of diagnostic reference levels in a country, which can be simply applied by quality control service providers. This new proposed method was applied to five computed tomography scanners in Shiraz, Iran, and diagnostic reference levels for head, abdomen/pelvis, sinus, chest, and lumbar spine examinations were determined. The results were compared to those obtained by the data collection and quality-control-based dose survey methods, carried out in parallel in this study, and were found to agree well within approximately 6%. This is highly acceptable for quality-control-based methods according to International Atomic Energy Agency tolerance levels (±20%).

Sixth Form Examining Methods.

ERIC Educational Resources Information Center

Schools Council, London (England).

The methods of examining in the sixth form of secondary education in England and Wales is the basis for discussion by subject committees of the Schools Council. Special reference is made to internal examinations, oral assessments, teacher's assessments, the relaxing of the time limits for examination, and the use of aids during examinations. The…

Defining overweight and obesity among Greek children living in Thessaloniki: International versus local reference standards

PubMed Central

Christoforidis, A; Dimitriadou, M; Papadopolou, E; Stilpnopoulou, D; Katzos, G; Athanassiou-Metaxa, M

2011-01-01

Background: Body Mass Index (BMI) offers a simple and reasonable measure of obesity that, with the use of the appropriate reference, can help in the early detection of children with weight problems. Our aim was to compare the two most commonly used international BMI references and the national Greek BMI reference in identifying Greek children being overweight and obese. Methods: A group of 1557 children (820 girls and 737 boys, mean age: 11.42 ± 3.51 years) were studied. Weight and height was measured using standard methods, and BMI was calculated. Overweight and obesity were determined using the International Obesity Task Force (IOTF) standards, the Centers for Disease Control and Prevention (CDC) BMI-forage curves and the most recent Greek BMI-for-age curves. Results: Results showed that the IOTF's cut-off limits identifies a significantly higher prevalence of overweight (22.4%) compared with both the CDC's (11.8%, p=0.03) and the Greek's (7.4%, p=0.002) cut-off limits. However, the prevalence of obesity was generally increased when it was determined using the CDC's cut-off limits (13.9%) compared to the prevalence calculated with both the IOTF's (6.5%, p=0.05) and the Greek's (6.9%, n.s.) cut off limits. Conclusions: The use of the national Greek reference standards for BMI underestimates the true prevalence of overweight and obesity. On the contrary, both the IOTF and the CDC standards, although independently, detect an increased number of overweight and obese children and thus they should be adopted in the clinical practice for an earlier identification and a timelier intervention. PMID:22110296

The Importance of Measurement Errors for Deriving Accurate Reference Leaf Area Index Maps for Validation of Moderate-Resolution Satellite LAI Products

NASA Technical Reports Server (NTRS)

Huang, Dong; Yang, Wenze; Tan, Bin; Rautiainen, Miina; Zhang, Ping; Hu, Jiannan; Shabanov, Nikolay V.; Linder, Sune; Knyazikhin, Yuri; Myneni, Ranga B.

2006-01-01

The validation of moderate-resolution satellite leaf area index (LAI) products such as those operationally generated from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor data requires reference LAI maps developed from field LAI measurements and fine-resolution satellite data. Errors in field measurements and satellite data determine the accuracy of the reference LAI maps. This paper describes a method by which reference maps of known accuracy can be generated with knowledge of errors in fine-resolution satellite data. The method is demonstrated with data from an international field campaign in a boreal coniferous forest in northern Sweden, and Enhanced Thematic Mapper Plus images. The reference LAI map thus generated is used to assess modifications to the MODIS LAI/fPAR algorithm recently implemented to derive the next generation of the MODIS LAI/fPAR product for this important biome type.

Evaluating the construct of triage acuity against a set of reference vignettes developed via modified Delphi method.

PubMed

Twomey, Michèle; Wallis, Lee A; Myers, Jonathan E

2014-07-01

To evaluate the construct of triage acuity as measured by the South African Triage Scale (SATS) against a set of reference vignettes. A modified Delphi method was used to develop a set of reference vignettes. Delphi participants completed a 2-round consensus-building process, and independently assigned triage acuity ratings to 100 written vignettes unaware of the ratings given by others. Triage acuity ratings were summarised for all vignettes, and only those that reached 80% consensus during round 2 were included in the reference set. Triage ratings for the reference vignettes given by two independent experts using the SATS were compared with the ratings given by the international Delphi panel. Measures of sensitivity, specificity, associated percentages for over-triage/under-triage were used to evaluate the construct of triage acuity (as measured by the SATS) by examining the association between the ratings by the two experts and the international panel. On completion of the Delphi process, 42 of the 100 vignettes reached 80% consensus on their acuity rating and made up the reference set. On average, over all acuity levels, sensitivity was 74% (CI 64% to 82%), specificity 92% (CI 87% to 94%), under-triage occurred 14% (CI 8% to 23%) and over-triage 12% (CI 8% to 23%) of the time. The results of this study provide an alternative to evaluating triage scales against the construct of acuity as measured with the SATS. This method of using 80% consensus vignettes may, however, systematically bias the validity estimate towards better performance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Estimation of reference intervals from small samples: an example using canine plasma creatinine.

PubMed

Geffré, A; Braun, J P; Trumel, C; Concordet, D

2009-12-01

According to international recommendations, reference intervals should be determined from at least 120 reference individuals, which often are impossible to achieve in veterinary clinical pathology, especially for wild animals. When only a small number of reference subjects is available, the possible bias cannot be known and the normality of the distribution cannot be evaluated. A comparison of reference intervals estimated by different methods could be helpful. The purpose of this study was to compare reference limits determined from a large set of canine plasma creatinine reference values, and large subsets of this data, with estimates obtained from small samples selected randomly. Twenty sets each of 120 and 27 samples were randomly selected from a set of 1439 plasma creatinine results obtained from healthy dogs in another study. Reference intervals for the whole sample and for the large samples were determined by a nonparametric method. The estimated reference limits for the small samples were minimum and maximum, mean +/- 2 SD of native and Box-Cox-transformed values, 2.5th and 97.5th percentiles by a robust method on native and Box-Cox-transformed values, and estimates from diagrams of cumulative distribution functions. The whole sample had a heavily skewed distribution, which approached Gaussian after Box-Cox transformation. The reference limits estimated from small samples were highly variable. The closest estimates to the 1439-result reference interval for 27-result subsamples were obtained by both parametric and robust methods after Box-Cox transformation but were grossly erroneous in some cases. For small samples, it is recommended that all values be reported graphically in a dot plot or histogram and that estimates of the reference limits be compared using different methods.

Standardization in laboratory medicine: Adoption of common reference intervals to the Croatian population.

PubMed

Flegar-Meštrić, Zlata; Perkov, Sonja; Radeljak, Andrea

2016-03-26

Considering the fact that the results of laboratory tests provide useful information about the state of health of patients, determination of reference value is considered an intrinsic part in the development of laboratory medicine. There are still huge differences in the analytical methods used as well as in the associated reference intervals which could consequently significantly affect the proper assessment of patient health. In a constant effort to increase the quality of patients' care, there are numerous international initiatives for standardization and/or harmonization of laboratory diagnostics in order to achieve maximum comparability of laboratory test results and improve patient safety. Through the standardization and harmonization processes of analytical methods the ability to create unique reference intervals is achieved. Such reference intervals could be applied globally in all laboratories using methods traceable to the same reference measuring system and analysing the biological samples from the populations with similar socio-demographic and ethnic characteristics. In this review we outlined the results of the harmonization processes in Croatia in the field of population based reference intervals for clinically relevant blood and serum constituents which are in accordance with ongoing activity for worldwide standardization and harmonization based on traceability in laboratory medicine.

Standardization in laboratory medicine: Adoption of common reference intervals to the Croatian population

PubMed Central

Flegar-Meštrić, Zlata; Perkov, Sonja; Radeljak, Andrea

2016-01-01

Considering the fact that the results of laboratory tests provide useful information about the state of health of patients, determination of reference value is considered an intrinsic part in the development of laboratory medicine. There are still huge differences in the analytical methods used as well as in the associated reference intervals which could consequently significantly affect the proper assessment of patient health. In a constant effort to increase the quality of patients’ care, there are numerous international initiatives for standardization and/or harmonization of laboratory diagnostics in order to achieve maximum comparability of laboratory test results and improve patient safety. Through the standardization and harmonization processes of analytical methods the ability to create unique reference intervals is achieved. Such reference intervals could be applied globally in all laboratories using methods traceable to the same reference measuring system and analysing the biological samples from the populations with similar socio-demographic and ethnic characteristics. In this review we outlined the results of the harmonization processes in Croatia in the field of population based reference intervals for clinically relevant blood and serum constituents which are in accordance with ongoing activity for worldwide standardization and harmonization based on traceability in laboratory medicine. PMID:27019800

Sources of international migration statistics in Africa.

PubMed

1984-01-01

The sources of international migration data for Africa may be classified into 2 main categories: administrative records and 2) censuses and survey data. Both categories are sources for the direct measurement of migration, but the 2nd category can be used for the indirect estimation of net international migration. The administrative records from which data on international migration may be derived include 1) entry/departure cards or forms completed at international borders, 2) residence/work permits issued to aliens, and 3) general population registers and registers of aliens. The statistics derived from the entry/departure cards may be described as 1) land frontier control statistics and 2) port control statistics. The former refer to data derived from movements across land borders and the latter refer to information collected at international airports and seaports. Other administrative records which are potential sources of statistics on international migration in some African countries include some limited population registers, records of the registration of aliens, and particulars of residence/work permits issued to aliens. Although frontier control data are considered the most important source of international migration statistics, in many African countries these data are too deficient to provide a satisfactory indication of the level of international migration. Thus decennial population censuses and/or sample surveys are the major sources of the available statistics on the stock and characteristics of international migration. Indirect methods can be used to supplement census data with intercensal estimates of net migration using census data on the total population. This indirect method of obtaining information on migration can be used to evaluate estimates derived from frontier control records, and it also offers the means of obtaining alternative information on international migration in African countries which have not directly investigated migration topics in their censuses or surveys.

Theoretical studies of floating-reference method for NIR blood glucose sensing

NASA Astrophysics Data System (ADS)

Shi, Zhenzhi; Yang, Yue; Zhao, Huijuan; Chen, Wenliang; Liu, Rong; Xu, Kexin

2011-03-01

Non-invasive blood glucose monitoring using NIR light has been suffered from the variety of optical background that is mainly caused by the change of human body, such as the change of temperature, water concentration, and so on. In order to eliminate these internal influence and external interference a so called floating-reference method has been proposed to provide an internal reference. From the analysis of the diffuse reflectance spectrum, a position has been found where diffuse reflection of light is not sensitive to the glucose concentrations. Our previous work has proved the existence of reference position using diffusion equation. However, since glucose monitoring generally use the NIR light in region of 1000-2000nm, diffusion equation is not valid because of the high absorption coefficient and small source-detector separations. In this paper, steady-state high-order approximate model is used to further investigate the existence of the floating reference position in semi-infinite medium. Based on the analysis of different optical parameters on the impact of spatially resolved reflectance of light, we find that the existence of the floating-reference position is the result of the interaction of optical parameters. Comparing to the results of Monte Carlo simulation, the applicable region of diffusion approximation and higher-order approximation for the calculation of floating-reference position is discussed at the wavelength of 1000nm-1800nm, using the intralipid solution of different concentrations. The results indicate that when the reduced albedo is greater than 0.93, diffusion approximation results are more close to simulation results, otherwise the high order approximation is more applicable.

Individualized adjustments to reference phantom internal organ dosimetry—scaling factors given knowledge of patient internal anatomy

NASA Astrophysics Data System (ADS)

Wayson, Michael B.; Bolch, Wesley E.

2018-04-01

Various computational tools are currently available that facilitate patient organ dosimetry in diagnostic nuclear medicine, yet they are typically restricted to reporting organ doses to ICRP-defined reference phantoms. The present study, while remaining computational phantom based, provides straightforward tools to adjust reference phantom organ dose for both internal photon and electron sources. A wide variety of monoenergetic specific absorbed fractions were computed using radiation transport simulations for tissue spheres of varying size and separation distance. Scaling methods were then constructed for both photon and electron self-dose and cross-dose, with data validation provided from patient-specific voxel phantom simulations, as well as via comparison to the scaling methodology given in MIRD Pamphlet No. 11. Photon and electron self-dose was found to be dependent on both radiation energy and sphere size. Photon cross-dose was found to be mostly independent of sphere size. Electron cross-dose was found to be dependent on sphere size when the spheres were in close proximity, owing to differences in electron range. The validation studies showed that this dataset was more effective than the MIRD 11 method at predicting patient-specific photon doses for at both high and low energies, but gave similar results at photon energies between 100 keV and 1 MeV. The MIRD 11 method for electron self-dose scaling was accurate for lower energies but began to break down at higher energies. The photon cross-dose scaling methodology developed in this study showed gains in accuracy of up to 9% for actual patient studies, and the electron cross-dose scaling methodology showed gains in accuracy up to 9% as well when only the bremsstrahlung component of the cross-dose was scaled. These dose scaling methods are readily available for incorporation into internal dosimetry software for diagnostic phantom-based organ dosimetry.

Individualized adjustments to reference phantom internal organ dosimetry-scaling factors given knowledge of patient internal anatomy.

PubMed

Wayson, Michael B; Bolch, Wesley E

2018-04-13

Various computational tools are currently available that facilitate patient organ dosimetry in diagnostic nuclear medicine, yet they are typically restricted to reporting organ doses to ICRP-defined reference phantoms. The present study, while remaining computational phantom based, provides straightforward tools to adjust reference phantom organ dose for both internal photon and electron sources. A wide variety of monoenergetic specific absorbed fractions were computed using radiation transport simulations for tissue spheres of varying size and separation distance. Scaling methods were then constructed for both photon and electron self-dose and cross-dose, with data validation provided from patient-specific voxel phantom simulations, as well as via comparison to the scaling methodology given in MIRD Pamphlet No. 11. Photon and electron self-dose was found to be dependent on both radiation energy and sphere size. Photon cross-dose was found to be mostly independent of sphere size. Electron cross-dose was found to be dependent on sphere size when the spheres were in close proximity, owing to differences in electron range. The validation studies showed that this dataset was more effective than the MIRD 11 method at predicting patient-specific photon doses for at both high and low energies, but gave similar results at photon energies between 100 keV and 1 MeV. The MIRD 11 method for electron self-dose scaling was accurate for lower energies but began to break down at higher energies. The photon cross-dose scaling methodology developed in this study showed gains in accuracy of up to 9% for actual patient studies, and the electron cross-dose scaling methodology showed gains in accuracy up to 9% as well when only the bremsstrahlung component of the cross-dose was scaled. These dose scaling methods are readily available for incorporation into internal dosimetry software for diagnostic phantom-based organ dosimetry.

Contributions of satellite-determined gravity results in geodesy

NASA Technical Reports Server (NTRS)

Khan, M. A.

1974-01-01

Different forms of the theoretical gravity formula are summarized and methods of standardization of gravity anomalies obtained from satellite gravity and terrestrial gravity data are discussed in the context of three most commonly used reference figures, e.g., International Reference Ellipsoid, Reference Ellipsoid 1967, and Equilibrium Reference Ellipsoid. These methods are important in the comparison and combination of satellite gravity and gravimetric data as well as the integration of surface gravity data, collected with different objectives, in a single reference system. For ready reference, tables for such reductions are computed. Nature of the satellite gravity anomalies is examined to aid the geophysical and geodetic interpretation of these anomalies in terms of the tectonic features of the earth and the structure of the earth's crust and mantle. Computation of the Potsdam correction from satellite-determined geopotential is reviewed. The contribution of the satellite gravity results in decomposing the total observed gravity anomaly into components of geophysical interest is discussed. Recent work on the possible temporal variations in the geogravity field is briefly reviewed.

Recommendation for the review of biological reference intervals in medical laboratories.

PubMed

Henny, Joseph; Vassault, Anne; Boursier, Guilaine; Vukasovic, Ines; Mesko Brguljan, Pika; Lohmander, Maria; Ghita, Irina; Andreu, Francisco A Bernabeu; Kroupis, Christos; Sprongl, Ludek; Thelen, Marc H M; Vanstapel, Florent J L A; Vodnik, Tatjana; Huisman, Willem; Vaubourdolle, Michel

2016-12-01

This document is based on the original recommendation of the Expert Panel on the Theory of Reference Values of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), updated guidelines were recently published under the auspices of the IFCC and the Clinical and Laboratory Standards Institute (CLSI). This document summarizes proposals for recommendations on: (i) The terminology, which is often confusing, noticeably concerning the terms of reference limits and decision limits. (ii) The method for the determination of reference limits according to the original procedure and the conditions, which should be used. (iii) A simple procedure allowing the medical laboratories to fulfill the requirements of the regulation and standards. The updated document proposes to verify that published reference limits are applicable to the laboratory involved. Finally, the strengths and limits of the revised recommendations (especially the selection of the reference population, the maintenance of the analytical quality, the choice of the statistical method used…) will be briefly discussed.

Reference intervals for selected serum biochemistry analytes in cheetahs Acinonyx jubatus.

PubMed

Hudson-Lamb, Gavin C; Schoeman, Johan P; Hooijberg, Emma H; Heinrich, Sonja K; Tordiffe, Adrian S W

2016-02-26

Published haematologic and serum biochemistry reference intervals are very scarce for captive cheetahs and even more for free-ranging cheetahs. The current study was performed to establish reference intervals for selected serum biochemistry analytes in cheetahs. Baseline serum biochemistry analytes were analysed from 66 healthy Namibian cheetahs. Samples were collected from 30 captive cheetahs at the AfriCat Foundation and 36 free-ranging cheetahs from central Namibia. The effects of captivity-status, age, sex and haemolysis score on the tested serum analytes were investigated. The biochemistry analytes that were measured were sodium, potassium, magnesium, chloride, urea and creatinine. The 90% confidence interval of the reference limits was obtained using the non-parametric bootstrap method. Reference intervals were preferentially determined by the non-parametric method and were as follows: sodium (128 mmol/L - 166 mmol/L), potassium (3.9 mmol/L - 5.2 mmol/L), magnesium (0.8 mmol/L - 1.2 mmol/L), chloride (97 mmol/L - 130 mmol/L), urea (8.2 mmol/L - 25.1 mmol/L) and creatinine (88 µmol/L - 288 µmol/L). Reference intervals from the current study were compared with International Species Information System values for cheetahs and found to be narrower. Moreover, age, sex and haemolysis score had no significant effect on the serum analytes in this study. Separate reference intervals for captive and free-ranging cheetahs were also determined. Captive cheetahs had higher urea values, most likely due to dietary factors. This study is the first to establish reference intervals for serum biochemistry analytes in cheetahs according to international guidelines. These results can be used for future health and disease assessments in both captive and free-ranging cheetahs.

Determination of the platinum - Group elements (PGE) and gold (Au) in manganese nodule reference samples by nickel sulfide fire-assay and Te coprecipitation with ICP-MS

USGS Publications Warehouse

Balaram, V.; Mathur, R.; Banakar, V.K.; Hein, J.R.; Rao, C.R.M.; Gnaneswara, Rao T.; Dasaram, B.

2006-01-01

Platinum group elements (PGE) and Au data in polymetallic oceanic ferromanganese nodule reference samples and crust samples obtained by inductively coupled plasma mass spectrometry (ICP-MS), after separation and pre-concentration by nickel sulfide fire-assay and Te coprecipitation, are presented. By optimizing several critical parameters such as flux composition, matrix matching calibration, etc., best experimental conditions were established to develop a method suitable for routine analysis of manganese nodule samples for PGE and Au. Calibrations were performed using international PGE reference materials, WMG-1 and WMS-1. This improved procedure offers extremely low detection limits in the range of 0.004 to 0.016 ng/g. The results obtained in this study for the reference materials compare well with previously published data wherever available. New PGE data arc also provided on some international manganese nodule reference materials. The analytical methodology described here can be used for the routine analysis of manganese nodule and crust samples in marine geochemical studies.

Identification of appropriate reference genes for normalizing transcript expression by quantitative real-time PCR in Litsea cubeba.

PubMed

Lin, Liyuan; Han, Xiaojiao; Chen, Yicun; Wu, Qingke; Wang, Yangdong

2013-12-01

Quantitative real-time PCR has emerged as a highly sensitive and widely used method for detection of gene expression profiles, via which accurate detection depends on reliable normalization. Since no single control is appropriate for all experimental treatments, it is generally advocated to select suitable internal controls prior to use for normalization. This study reported the evaluation of the expression stability of twelve potential reference genes in different tissue/organs and six fruit developmental stages of Litsea cubeba in order to screen the superior internal reference genes for data normalization. Two softwares-geNorm, and NormFinder-were used to identify stability of these candidate genes. The cycle threshold difference and coefficient of variance were also calculated to evaluate the expression stability of candidate genes. F-BOX, EF1α, UBC, and TUA were selected as the most stable reference genes across 11 sample pools. F-BOX, EF1α, and EIF4α exhibited the highest expression stability in different tissue/organs and different fruit developmental stages. Besides, a combination of two stable reference genes would be sufficient for gene expression normalization in different fruit developmental stages. In addition, the relative expression profiles of DXS and DXR were evaluated by EF1α, UBC, and SAMDC. The results further validated the reliability of stable reference genes and also highlighted the importance of selecting suitable internal controls for L. cubeba. These reference genes will be of great importance for transcript normalization in future gene expression studies on L. cubeba.

An Exploration into the Writing Ability of Generation 1.5 and International Second Language Writers: A Mixed Methods Approach

ERIC Educational Resources Information Center

Di Gennaro, Kristen K.

2011-01-01

A growing body of research suggests that the writing ability of international second language learners (IL2) and US-resident second language learners, also referred to as Generation 1.5 (G1.5), differs, despite a dearth of substantial empirical evidence supporting such claims. The present study provides much-needed empirical evidence concerning…

Analysis of SMELS and reference materials for validation of the k0-based internal monostandard NAA method using in-situ detection efficiency

NASA Astrophysics Data System (ADS)

Acharya, R.; Swain, K. K.; Reddy, A. V. R.

2010-10-01

Three synthetic multielement standards (SMELS I, II and III) and two reference materials (RMs), SL-3 and Soil-7 of IAEA were analyzed for validation of the k0-based internal monostandard neutron activation analysis (IM-NAA) method utilizing in-situ relative detection efficiency. The internal monostandards used in SMELS and RMs were Au and Sc, respectively. The samples were irradiated in Apsara and Dhruva reactors, BARC and radioactive assay was carried out using a 40% relative efficiency HPGe detector coupled to an 8 k MCA. Concentrations of 23 elements were determined in both SMELS and RMs. In the case of RMs, concentrations of a few elements, whose certified values are not available, could also be determined. The % deviations for the elements determined in SMELS with respect to the assigned values and RMs with respect to certified values were within ±8%. The Z-score values at 95% confidence level for most of the elements in both the materials were within ±1.

Certification of a reference material for determination of total cyanide in soil to support implementation of the International Standard ISO 11262:2011.

PubMed

Scharf, Holger; Bremser, Wolfram

2015-04-01

Cyanides are among the most important inorganic pollutants to be tested and monitored in environmental compartments. They can be distinguished and determined as free cyanide, weak acid dissociable cyanide or as total cyanide. However, in any case obtained, measurement results are operationally defined referring to the applied analytical method. In 2011, the International Standard ISO 11262 has been published which specifies a normative analytical method for the determination of total cyanide in soil. The objective of the project described in this paper was to provide the first soil reference material (CRM) certified for its mass fraction of total cyanide on the basis of this standard. A total of 12 German laboratories with proven experience in the determination of cyanides in environmental samples participated in the certification study. Measurement results were evaluated in full compliance with the requirements of ISO Guide 35. Taking into account the results of the inter-laboratory comparison as well as the outcome of the homogeneity and stability studies, a certified mass fraction of total cyanide of 21.1 mg/kg and an expanded uncertainty (k = 2) of 1.3 mg/kg were assigned to the material. The reference material has been issued as CRM BAM-U114.

[Preparation and certification of mussel reference material for organochlorine pesticides and polychlorinated biphenyls using isotope dilution-high resolution mass spectrometry].

PubMed

Lu, Xianbo; Chen, Jiping; Wang, Shuqiu; Zou, Lili; Tian, Yuzeng; Ni, Yuwen; Su, Fan

2012-09-01

A method for the preparation and certification of the reference material of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in mussel tissue is described. The mussel tissue from Dalian Bay was frozen-dried, comminuted, sieved, homogenized, packaged, and sterilized by 60Co radiation sterilization in turn. The certified values for 18 OCPs and 16 PCBs were determined by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) using isotope dilution and internal standard quantitation techniques. The certified values were validated and given based on seven accredited laboratories, and these values are traceable to the SI (international system of units) through gravimetrically prepared standards of established purity and measurement intercomparisons. The certified values of PCBs and OCPs in mussel span 4 orders of magnitude with a relative uncertainty of about 10%. This material is a natural biological material with confirmed good homogeneity and stability, and it was approved as the grade "primary reference material" (GBW10069) in June 2012 in China. This reference material provided necessary quality control products for our country to implement the Stockholm Treaty on the monitoring of persistent organic pollutants (POPs). The material is intended to be used for the method validation and quality control in the determination of OCPs and PCBs in biota samples.

40 CFR 59.213 - Incorporations by reference.

Code of Federal Regulations, 2010 CFR

2010-07-01

...., Washington, DC 20460, the EPA Library (MD-35), U.S. EPA, Research Triangle Park, NC 27711, or at the National... University Microfilms International, 300 North Zeeb Road, Ann Arbor MI, 48106. (1) ASTM Method E220-86...

Application of quantitative 1H NMR for the calibration of protoberberine alkaloid reference standards.

PubMed

Wu, Yan; He, Yi; He, Wenyi; Zhang, Yumei; Lu, Jing; Dai, Zhong; Ma, Shuangcheng; Lin, Ruichao

2014-03-01

Quantitative nuclear magnetic resonance spectroscopy (qNMR) has been developed into an important tool in the drug analysis, biomacromolecule detection, and metabolism study. Compared with mass balance method, qNMR method bears some advantages in the calibration of reference standard (RS): it determines the absolute amount of a sample; other chemical compound and its certified reference material (CRM) can be used as internal standard (IS) to obtain the purity of the sample. Protoberberine alkaloids have many biological activities and have been used as reference standards for the control of many herbal drugs. In present study, the qNMR methods were developed for the calibration of berberine hydrochloride, palmatine hydrochloride, tetrahydropalmatine, and phellodendrine hydrochloride with potassium hydrogen phthalate as IS. Method validation was carried out according to the guidelines for the method validation of Chinese Pharmacopoeia. The results of qNMR were compared with those of mass balance method and the differences between the results of two methods were acceptable based on the analysis of estimated measurement uncertainties. Therefore, qNMR is an effective and reliable analysis method for the calibration of RS and can be used as a good complementarity to the mass balance method. Copyright © 2013 Elsevier B.V. All rights reserved.

Individualized adjustments to reference phantom internal organ dosimetry—scaling factors given knowledge of patient external anatomy

NASA Astrophysics Data System (ADS)

Wayson, Michael B.; Bolch, Wesley E.

2018-04-01

Internal radiation dose estimates for diagnostic nuclear medicine procedures are typically calculated for a reference individual. Resultantly, there is uncertainty when determining the organ doses to patients who are not at 50th percentile on either height or weight. This study aims to better personalize internal radiation dose estimates for individual patients by modifying the dose estimates calculated for reference individuals based on easily obtainable morphometric characteristics of the patient. Phantoms of different sitting heights and waist circumferences were constructed based on computational reference phantoms for the newborn, 10 year-old, and adult. Monoenergetic photons and electrons were then simulated separately at 15 energies. Photon and electron specific absorbed fractions (SAFs) were computed for the newly constructed non-reference phantoms and compared to SAFs previously generated for the age-matched reference phantoms. Differences in SAFs were correlated to changes in sitting height and waist circumference to develop scaling factors that could be applied to reference SAFs as morphometry corrections. A further set of arbitrary non-reference phantoms were then constructed and used in validation studies for the SAF scaling factors. Both photon and electron dose scaling methods were found to increase average accuracy when sitting height was used as the scaling parameter (~11%). Photon waist circumference-based scaling factors showed modest increases in average accuracy (~7%) for underweight individuals, but not for overweight individuals. Electron waist circumference-based scaling factors did not show increases in average accuracy. When sitting height and waist circumference scaling factors were combined, modest average gains in accuracy were observed for photons (~6%), but not for electrons. Both photon and electron absorbed doses are more reliably scaled using scaling factors computed in this study. They can be effectively scaled using sitting height alone as patient-specific morphometric parameter.

Individualized adjustments to reference phantom internal organ dosimetry-scaling factors given knowledge of patient external anatomy.

PubMed

Wayson, Michael B; Bolch, Wesley E

2018-04-13

Internal radiation dose estimates for diagnostic nuclear medicine procedures are typically calculated for a reference individual. Resultantly, there is uncertainty when determining the organ doses to patients who are not at 50th percentile on either height or weight. This study aims to better personalize internal radiation dose estimates for individual patients by modifying the dose estimates calculated for reference individuals based on easily obtainable morphometric characteristics of the patient. Phantoms of different sitting heights and waist circumferences were constructed based on computational reference phantoms for the newborn, 10 year-old, and adult. Monoenergetic photons and electrons were then simulated separately at 15 energies. Photon and electron specific absorbed fractions (SAFs) were computed for the newly constructed non-reference phantoms and compared to SAFs previously generated for the age-matched reference phantoms. Differences in SAFs were correlated to changes in sitting height and waist circumference to develop scaling factors that could be applied to reference SAFs as morphometry corrections. A further set of arbitrary non-reference phantoms were then constructed and used in validation studies for the SAF scaling factors. Both photon and electron dose scaling methods were found to increase average accuracy when sitting height was used as the scaling parameter (~11%). Photon waist circumference-based scaling factors showed modest increases in average accuracy (~7%) for underweight individuals, but not for overweight individuals. Electron waist circumference-based scaling factors did not show increases in average accuracy. When sitting height and waist circumference scaling factors were combined, modest average gains in accuracy were observed for photons (~6%), but not for electrons. Both photon and electron absorbed doses are more reliably scaled using scaling factors computed in this study. They can be effectively scaled using sitting height alone as patient-specific morphometric parameter.

Realization of ETRF2000 as a New Terrestrial Reference Frame in Republic of Serbia

NASA Astrophysics Data System (ADS)

Blagojevic, D.; Vasilic, V.

2012-12-01

The International Earth Rotation and Reference Systems Service (IERS) is a joint service of the International Association of Geodesy (IAG) and the International Astronomical Union (IAU), which provides the scientific community with the means for computing the transformation from the International Celestial Reference System (ICRS) to the International Terrestrial Reference System (ITRS). It further maintains the realizations of these systems by appropriate coordinate sets called "frames". The densification of terrestrial frame usually serves as official frame for positioning and navigation tasks within the territory of particular country. One of these densifications was recently performed in order to establish new reference frame for Republic of Serbia. The paper describes related activities resulting in ETRF2000 as a new Serbian terrestrial reference frame.

Accurate determination of brain metabolite concentrations using ERETIC as external reference.

PubMed

Zoelch, Niklaus; Hock, Andreas; Heinzer-Schweizer, Susanne; Avdievitch, Nikolai; Henning, Anke

2017-08-01

Magnetic Resonance Spectroscopy (MRS) can provide in vivo metabolite concentrations in standard concentration units if a reliable reference signal is available. For 1 H MRS in the human brain, typically the signal from the tissue water is used as the (internal) reference signal. However, a concentration determination based on the tissue water signal most often requires a reliable estimate of the water concentration present in the investigated tissue. Especially in clinically interesting cases, this estimation might be difficult. To avoid assumptions about the water in the investigated tissue, the Electric REference To access In vivo Concentrations (ERETIC) method has been proposed. In this approach, the metabolite signal is compared with a reference signal acquired in a phantom and potential coil-loading differences are corrected using a synthetic reference signal. The aim of this study, conducted with a transceiver quadrature head coil, was to increase the accuracy of the ERETIC method by correcting the influence of spatial B 1 inhomogeneities and to simplify the quantification with ERETIC by incorporating an automatic phase correction for the ERETIC signal. Transmit field ( B1+) differences are minimized with a volume-selective power optimization, whereas reception sensitivity changes are corrected using contrast-minimized images of the brain and by adapting the voxel location in the phantom measurement closely to the position measured in vivo. By applying the proposed B 1 correction scheme, the mean metabolite concentrations determined with ERETIC in 21 healthy subjects at three different positions agree with concentrations derived with the tissue water signal as reference. In addition, brain water concentrations determined with ERETIC were in agreement with estimations derived using tissue segmentation and literature values for relative water densities. Based on the results, the ERETIC method presented here is a valid tool to derive in vivo metabolite concentration, with potential advantages compared with internal water referencing in diseased tissue. Copyright © 2017 John Wiley & Sons, Ltd.

Assessment of opacimeter calibration according to International Standard Organization 10155.

PubMed

Gomes, J F

2001-01-01

This paper compares the calibration method for opacimeters issued by the International Standard Organization (ISO) 10155 with the manual reference method for determination of dust content in stack gases. ISO 10155 requires at least nine operational measurements, corresponding to three operational measurements per each dust emission range within the stack. The procedure is assessed by comparison with previous calibration methods for opacimeters using only two operational measurements from a set of measurements made at stacks from pulp mills. The results show that even if the international standard for opacimeter calibration requires that the calibration curve is to be obtained using 3 x 3 points, a calibration curve derived using 3 points could be, at times, acceptable in statistical terms, provided that the amplitude of individual measurements is low.

Prevalence of obesity among Arab school children in Nazareth, Israel: comparison with national (Jewish) and international data.

PubMed

Ram, E; Marcus, O; Joubran, S; Abdo, B; Asal, N R

2013-12-01

Lack of published data. Absence of Ethnic specific data. Lack of focus on obesity prevention in Arab schools. First set of data on obesity for Arab children. Data will be used as reference data. Alert health/school official for intervention. Objective The objective is to produce the first set of obesity prevalence data and use the data as reference values of body mass index (BMI) trends for Arab children in Israel and compare with Jewish and international data. Methods A prevalence study was carried out in 2009 in which 4130 children aged 6-12, were selected from eight Arab sector schools representing the Nazareth Municipality. Height, weight and BMI measurements were obtained and presented by age, mean age, size, weight, gender and percentile. Appropriate epidemiological and statistical methods used for comparison. Results The obesity and overweight prevalence rates in Arab children by age ranges from 0% to 2.6% and 0% to 11.2%, respectively. Comparison with international and Jewish data revealed differences in almost all age groups but higher rates in Arabs, especially boys. Discussion The higher rates/trends in Arab children may be explained by more Arab women entering the workforce, increase in single-parent families and changes in food and physical activity environments. Conclusion Based on our data, we recommend either an ethnic-specific BMI reference curves and/or inclusion of Arab data in the Israeli data system. Research need to focus on reasons for the increase and interventions to reverse/slow the trend. © 2013 The Authors. Pediatric Obesity © 2013 International Association for the Study of Obesity.

Towards a first realization of the International Height Reference System (IHRS)

NASA Astrophysics Data System (ADS)

Sanchez, Laura; Ihde, Johannes; Pail, Roland; Gruber, Thomas; Barzaghi, Riccardo; Marti, Urs; Agren, Jonas; Sideris, Michael; Novak, Pavel

2017-04-01

The IAG Resolution No. 1 released during the IUGG 2015 General Assembly outlines five conventions for the definition of the International Height Reference System (IHRS). The definition is given in terms of potential parameters: the vertical coordinates are geopotential numbers referring to an equipotential surface of the Earth's gravity field realized by the conventional value W0 = 62 636 853.4 m2s-2. The spatial reference of the position P for the potential W(P) = W(X) is given by coordinates X of the International Terrestrial Reference Frame (ITRF). This Resolution also states that parameters, observations, and data shall be related to the mean tidal system/mean crust. At present, the main challenge is the realization of the IHRS; i.e., the establishment of the International Height Reference Frame (IHRF). It is expected that the IHRF follows the same structure as the ITRF: a global network with regional and national densifications, whose geopotential numbers referring to the global IHRS are known. According to the GGOS objectives, the target accuracy of these global geopotential numbers is 1 x 10-2 m2s-2. In practice, the precise realization of the IHRS is limited by different aspects; for instance, no unified standards or methods for the determination of the potential values W(P); application of different conventions for the gravity field modelling and the estimation of the position vectors X; inhomogeneous distribution of the geodetic infrastructure; restricted accessibility to terrestrial gravity data to increase the GGM resolution; insufficient modelling of geodynamic phenomena, etc. This may restrict the expected accuracy of 1 x 10-2 m2s-2 to some orders lower (from 10 x 10-2 m2s-2 to 100 x 10-2 m2s-2). This contribution discusses the required steps to outline a sustainable realization of the IHRS.

Establishment of metrological traceability in porosity measurements by x-ray computed tomography

NASA Astrophysics Data System (ADS)

Hermanek, Petr; Carmignato, Simone

2017-09-01

Internal porosity is an inherent phenomenon to many manufacturing processes, such as casting, additive manufacturing, and others. Since these defects cannot be completely avoided by improving production processes, it is important to have a reliable method to detect and evaluate them accurately. The accurate evaluation becomes even more important concerning current industrial trends to minimize size and weight of products on one side, and enhance their complexity and performance on the other. X-ray computed tomography (CT) has emerged as a promising instrument for holistic porosity measurements offering several advantages over equivalent methods already established in the detection of internal defects. The main shortcomings of the conventional techniques pertain to too general information about total porosity content (e.g. Archimedes method) or the destructive way of testing (e.g. microscopy of cross-sections). On the contrary, CT is a nondestructive technique providing complete information about size, shape and distribution of internal porosity. However, due to the lack of international standards and the fact that it is relatively a new measurement technique, CT as a measurement technology has not yet reached maturity. This study proposes a procedure for the establishment of measurement traceability in porosity measurements by CT including the necessary evaluation of measurement uncertainty. The traceability transfer is carried out through a novel reference standard calibrated by optical and tactile coordinate measuring systems. The measurement uncertainty is calculated following international standards and guidelines. In addition, the accuracy of porosity measurements by CT with the associated measurement uncertainty is evaluated using the reference standard.

Growth in Indigenous and Nonindigenous Chilean Schoolchildren From 3 Poverty Strata

PubMed Central

Bustos, Patricia; Amigo, Hugo; Muñoz, Sergio R.; Martorell, Reynaldo

2001-01-01

Objectives. This study sought to determine whether the short stature of Mapuche children, an indigenous group in Chile, reflects poverty or genetic heritage and whether the international reference population, derived from studies of US children of mostly European origin, is appropriate for assessing growth failure in indigenous peoples of the Americas. Methods. The study assessed 768 schoolchildren of Mapuche and non-Mapuche ancestry, aged 6 to 9 years, living under conditions of extreme, medium, and low poverty. Results. Growth retardation was strongly related to poverty in both ethnic groups. Within poverty levels, there were no significant differences in stature between ethnic groups, and in low-poverty areas in Santiago, the capital city, mean stature was only slightly less than in the reference population. Conclusions. Poverty, not ancestry, explains the short stature of Mapuche children, and use of the international reference to assess growth in this population is appropriate. PMID:11574328

Connecting kinematic and dynamic reference frames by D-VLBI

NASA Astrophysics Data System (ADS)

Schuh, Harald; Plank, Lucia; Madzak, Matthias; Böhm, Johannes

2012-08-01

In geodetic and astrometric practice, terrestrial station coordinates are usually provided in the kinematic International Terrestrial Reference Frame (ITRF) and radio source coordinates in the International Celestial Reference Frame (ICRF), whereas measurements of space probes such as satellites and spacecrafts, or planetary ephemerides rest upon dynamical theories. To avoid inconsistencies and errors during measurement and calculation procedures, exact frame ties between quasi - inertial, kinematic and dynamic reference frames have to be secured. While the Earth Orientation Parameters (EOP), e.g. measured by VLBI, link the ITRF to the ICRF, the ties with the dynamic frames can be established with the differential Very Long Baseline Interferometry (D - VLBI) method. By observing space probes alternately t o radio sources, the relative position of the targets to each other on the sky can be determined with high accuracy. While D - VLBI is a common technique in astrophysics (source imaging) and deep space navigation, just recently there have been several effort s to use it for geodetic purposes. We present investigations concerning possible VLBI observations to satellites. This includes the potential usage of available GNNS satellites as well as specifically designed missions, as e.g. the GRASP mission proposed b y JPL/NASA and an international consortium, where the aspect of co - location in space of various techniques (VLBI, SLR, GNSS, DORIS) is the main focus.

Use of internal references for assessing CT density measurements of the pelvis as replacement for use of an external phantom.

PubMed

Boomsma, Martijn F; Slouwerhof, Inge; van Dalen, Jorn A; Edens, Mireille A; Mueller, Dirk; Milles, Julien; Maas, Mario

2015-11-01

The purpose of this research is to study the use of an internal reference standard for fat- and muscle as a replacement for an external reference standard with a phantom. By using a phantomless internal reference standard, Hounsfield unit (HU) measurements of various tissues can potentially be assessed in patients with a CT scan of the pelvis without an added phantom at time of CT acquisition. This paves the way for development of a tool for quantification of the change in tissue density in one patient over time and between patients. This could make every CT scan made without contrast available for research purposes. Fifty patients with unilateral metal-on-metal total hip replacements, scanned together with a calibration reference phantom used in bone mineral density measurements, were included in this study. On computed tomography scans of the pelvis without the use of intravenous iodine contrast, reference values for fat and muscle were measured in the phantom as well as within the patient's body. The conformity between the references was examined with the intra-class correlation coefficient. The mean HU (± SD) of reference values for fat for the internal- and phantom references were -91.5 (±7.0) and -90.9 (±7.8), respectively. For muscle, the mean HU (± SD) for the internal- and phantom references were 59.2 (±6.2) and 60.0 (±7.2), respectively. The intra-class correlation coefficients for fat and muscle were 0.90 and 0.84 respectively and show excellent agreement between the phantom and internal references. Internal references can be used with similar accuracy as references from an external phantom. There is no need to use an external phantom to asses CT density measurements of body tissue.

42 CFR 424.507 - Ordering and referring covered items and services for Medicare beneficiaries.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ordered or referred by a resident or an intern, the claim must identify the teaching physician as the... referred by a resident or an intern, the claim must identify the teaching physician as the ordering or... intern, the claim must identify the teaching physician as the ordering or referring physician. The claim...

42 CFR 424.507 - Ordering and referring covered items and services for Medicare beneficiaries.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ordered or referred by a resident or an intern, the claim must identify the teaching physician as the... referred by a resident or an intern, the claim must identify the teaching physician as the ordering or... intern, the claim must identify the teaching physician as the ordering or referring physician. The claim...

Linear time-dependent reference intervals where there is measurement error in the time variable-a parametric approach.

PubMed

Gillard, Jonathan

2015-12-01

This article re-examines parametric methods for the calculation of time specific reference intervals where there is measurement error present in the time covariate. Previous published work has commonly been based on the standard ordinary least squares approach, weighted where appropriate. In fact, this is an incorrect method when there are measurement errors present, and in this article, we show that the use of this approach may, in certain cases, lead to referral patterns that may vary with different values of the covariate. Thus, it would not be the case that all patients are treated equally; some subjects would be more likely to be referred than others, hence violating the principle of equal treatment required by the International Federation for Clinical Chemistry. We show, by using measurement error models, that reference intervals are produced that satisfy the requirement for equal treatment for all subjects. © The Author(s) 2011.

The Neural Network In Coordinate Transformation

NASA Astrophysics Data System (ADS)

Urusan, Ahmet Yucel

2011-12-01

In international literature, Coordinate operations is divided into two categories. They are coordinate conversion and coordinate transformation. Coordinates converted from coordinate system A to coordinate system B in the same datum (mean origine, scale and axis directions are same) by coordinate conversion. There are two different datum in coordinate transformation. The basis of each datum to a different coordinate reference system. In Coordinate transformation, coordinates are transformed from coordinate reference system A to coordinate referance system B. Geodetic studies based on physical measurements. Coordinate transformation needs identical points which were measured in each coordinate reference system (A and B). However it is difficult (and need a big reserved budget) to measure in some places like as top of mountain, boundry of countries and seaside. In this study, this sample problem solution was researched. The method of learning which is one of the neural network methods, was used for solution of this problem.

The importance of reference materials in doping-control analysis.

PubMed

Mackay, Lindsey G; Kazlauskas, Rymantas

2011-08-01

Currently a large range of pure substance reference materials are available for calibration of doping-control methods. These materials enable traceability to the International System of Units (SI) for the results generated by World Anti-Doping Agency (WADA)-accredited laboratories. Only a small number of prohibited substances have threshold limits for which quantification is highly important. For these analytes only the highest quality reference materials that are available should be used. Many prohibited substances have no threshold limits and reference materials provide essential identity confirmation. For these reference materials the correct identity is critical and the methods used to assess identity in these cases should be critically evaluated. There is still a lack of certified matrix reference materials to support many aspects of doping analysis. However, in key areas a range of urine matrix materials have been produced for substances with threshold limits, for example 19-norandrosterone and testosterone/epitestosterone (T/E) ratio. These matrix-certified reference materials (CRMs) are an excellent independent means of checking method recovery and bias and will typically be used in method validation and then regularly as quality-control checks. They can be particularly important in the analysis of samples close to threshold limits, in which measurement accuracy becomes critical. Some reference materials for isotope ratio mass spectrometry (IRMS) analysis are available and a matrix material certified for steroid delta values is currently under production. In other new areas, for example the Athlete Biological Passport, peptide hormone testing, designer steroids, and gene doping, reference material needs still need to be thoroughly assessed and prioritised.

The Third International Reference Preparation of Egg Lecithin

PubMed Central

Krag, P.; Bentzon, M. Weis

1961-01-01

The Third International Reference Preparation of Egg Lecithin was produced (in a quantity of 5000 ml) at the WHO Serological Reference Centre, Copenhagen, and assayed in 1958 against the Second International Reference Preparation by four laboratories in three countries. Complement-fixation and slide-flocculation tests were used. The new preparation was found acceptable, and its establishment was authorized by the WHO Expert Committee on Biological Standardization. The average log10 titres and results of analyses of variances are shown. The variances were of the usual order of magnitude, and the differences in titre between antigens containing the Second and the Third International Reference Preparations varied from -0.011 to 0.116; only one of the differences exceeded the 5% limit of significance. The use of the Third International Reference Preparation in tests for the acceptability of lecithin preparations is described. PMID:13753864

Pricing and availability of some essential child specific medicines in Odisha

PubMed Central

Swain, Trupti Rekha; Rath, Bandana; Dehury, Suhasini; Tarai, Anjali; Das, Priti; Samal, Rajashree; Samal, Satyajit; Nayak, Harshavardhan

2015-01-01

Objectives: Continuous availability of affordable medicines in appropriate formulations is essential to reduce morbidity and mortality in children. Odisha an eastern Indian state records very high mortality of children. The study aims at documenting the availability and prices paid for purchasing essential child-specific medicines. Materials and Methods: The survey of 34 essential medicines was conducted in six randomly selected districts of Odisha. Data were collected from medicine outlets of the public, private, and other sector (Nongovernmental Organization [NGO]/mission sectors) of six randomly selected districts, using WHO/Health Action International medicine price collection methodology. For each medicine surveyed, data were collected on the highest and lowest-priced formulations available in each facility. Results: Both public sector and other sector health facilities procure only one brand of medicines, mean percentage availability of medicines being 17% and 21.8%, respectively. In the private sector, the mean percentage availability of the high and lowest-priced medicines for a particular drug product was 10.8% and 38.5%, respectively. The public sector procurement price is 48% lower than international reference prices. In the private sector, high-priced, and low-priced products are sold at 1.83 and 1.46 times the international reference price, respectively. Substantial price variation was observed for some medicines across individual outlets. Medicines were found to cost 2.08 times their international reference price in NGO/mission sector facilities. Conclusions: The availability of children's medicines in public sector facilities of Odisha state is poor. Medicines for children cost relatively high in both private and NGO sectors compared to the international reference price. The availability medicines should be improved on an urgent basis to improve access of medicines for children of Odisha. PMID:26600637

26 CFR 49.4253-12 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Cross reference. 49.4253-12 Section 49.4253-12 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES FACILITIES AND SERVICES EXCISE TAXES Communications § 49.4253-12 Cross reference. For exemptions...

26 CFR 44.4906-1 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Cross reference. 44.4906-1 Section 44.4906-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE... Taxes on Wagering General Provisions Relating to Occupational Taxes § 44.4906-1 Cross reference. For...

26 CFR 1.162-16 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Cross reference. 1.162-16 Section 1.162-16 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Itemized Deductions for Individuals and Corporations § 1.162-16 Cross reference...

Reference Intervals of Common Clinical Chemistry Analytes for Adults in Hong Kong.

PubMed

Lo, Y C; Armbruster, David A

2012-04-01

Defining reference intervals is a major challenge because of the difficulty in recruiting volunteers to participate and testing samples from a significant number of healthy reference individuals. Historical literature citation intervals are often suboptimal because they're be based on obsolete methods and/or only a small number of poorly defined reference samples. Blood donors in Hong Kong gave permission for additional blood to be collected for reference interval testing. The samples were tested for twenty-five routine analytes on the Abbott ARCHITECT clinical chemistry system. Results were analyzed using the Rhoads EP evaluator software program, which is based on the CLSI/IFCC C28-A guideline, and defines the reference interval as the 95% central range. Method specific reference intervals were established for twenty-five common clinical chemistry analytes for a Chinese ethnic population. The intervals were defined for each gender separately and for genders combined. Gender specific or combined gender intervals were adapted as appropriate for each analyte. A large number of healthy, apparently normal blood donors from a local ethnic population were tested to provide current reference intervals for a new clinical chemistry system. Intervals were determined following an accepted international guideline. Laboratories using the same or similar methodologies may adapt these intervals if deemed validated and deemed suitable for their patient population. Laboratories using different methodologies may be able to successfully adapt the intervals for their facilities using the reference interval transference technique based on a method comparison study.

Reference values of thirty-one frequently used laboratory markers for 75-year-old males and females

PubMed Central

Ryden, Ingvar; Lind, Lars

2012-01-01

Background We have previously reported reference values for common clinical chemistry tests in healthy 70-year-old males and females. We have now repeated this study 5 years later to establish reference values also at the age of 75. It is important to have adequate reference values for elderly patients as biological markers may change over time, and adequate reference values are essential for correct clinical decisions. Methods We have investigated 31 frequently used laboratory markers in 75-year-old males (n = 354) and females (n = 373) without diabetes. The 2.5 and 97.5 percentiles for these markers were calculated according to the recommendations of the International Federation of Clinical Chemistry. Results Reference values are reported for 75-year-old males and females for 31 frequently used laboratory markers. Conclusion There were minor differences between reference intervals calculated with and without individuals with cardiovascular diseases. Several of the reference intervals differed from Scandinavian reference intervals based on younger individuals (Nordic Reference Interval Project). PMID:22300333

Spectroscopic characterization and quantitative determination of atorvastatin calcium impurities by novel HPLC method

NASA Astrophysics Data System (ADS)

Gupta, Lokesh Kumar

2012-11-01

Seven process related impurities were identified by LC-MS in the atorvastatin calcium drug substance. These impurities were identified by LC-MS. The structure of impurities was confirmed by modern spectroscopic techniques like 1H NMR and IR and physicochemical studies conducted by using synthesized authentic reference compounds. The synthesized reference samples of the impurity compounds were used for the quantitative HPLC determination. These impurities were detected by newly developed gradient, reverse phase high performance liquid chromatographic (HPLC) method. The system suitability of HPLC analysis established the validity of the separation. The analytical method was validated according to International Conference of Harmonization (ICH) with respect to specificity, precision, accuracy, linearity, robustness and stability of analytical solutions to demonstrate the power of newly developed HPLC method.

26 CFR 1.503(d)-1 - Cross references.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Cross references. 1.503(d)-1 Section 1.503(d)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Exempt Organizations § 1.503(d)-1 Cross references. For provisions relating to...

26 CFR 1.811-3 - Cross-reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross-reference. 1.811-3 Section 1.811-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Gain and Loss from Operations § 1.811-3 Cross-reference. For special rules regarding the...

26 CFR 301.9001-3 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Cross reference. 301.9001-3 Section 301.9001-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND... reference. See the Coast Guard regulations under 33 CFR parts 135 and 136 for rules relating to the...

26 CFR 1.812-9 - Cross-reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross-reference. 1.812-9 Section 1.812-9 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Gain and Loss from Operations § 1.812-9 Cross-reference. For special rules regarding the...

26 CFR 1.807-2 - Cross-reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross-reference. 1.807-2 Section 1.807-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Investment Income § 1.807-2 Cross-reference. For special rules regarding the treatment of...

26 CFR 1.681(b)-1 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross reference. 1.681(b)-1 Section 1.681(b)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Miscellaneous § 1.681(b)-1 Cross reference. For disallowance of certain charitable, etc...

The role of internal reference prices in consumers' willingness to pay judgments: Thaler's Beer Pricing Task revisited.

PubMed

Ranyard, R; Charlton, J P; Williamson, J

2001-02-01

Alternative reference prices, either displayed in the environment (external) or recalled from memory (internal) are known to influence consumer judgments and decisions. In one line of previous research, internal reference prices have been defined in terms of general price expectations. However, Thaler (Marketing Science 4 (1985) 199; Journal of Behavioral Decision Making 12 (1999) 183) defined them as fair prices expected from specific types of seller. Using a Beer Pricing Task, he found that seller context had a substantial effect on willingness to pay, and concluded that this was due to specific internal reference prices evoked by specific contexts. In a think aloud study using the same task (N = 48), we found only a marginal effect of seller context. In a second study using the Beer Pricing Task and seven analogous ones (N = 144), general internal reference prices were estimated by asking people what they normally paid for various commodities. Both general internal reference prices and seller context influenced willingness to pay, although the effect of the latter was again rather small. We conclude that general internal reference prices have a greater impact in these scenarios than specific ones, because of the lower cognitive load involved in their storage and retrieval.

Development of a candidate reference measurement procedure for the analysis of cortisol in human serum samples by isotope dilution-gas chromatography-mass spectrometry.

PubMed

Kawaguchi, Migaku; Takatsu, Akiko

2009-08-01

A candidate reference measurement procedure involving isotope dilution coupled with gas chromatography-mass spectrometry (GC-MS) has been developed and critically evaluated. An isotopically labeled internal standard, cortisol-d(2), was added to a serum sample. After equilibration, solid-phase extractions (SPE) for sample preparation and derivatization with heptafluorobutyric anhydride (HFBA) were performed for GC-MS analysis. The limit of detection (LOD) and the limit of quantification (LOQ) were 5 and 20 ng g(-1), respectively. The recovery of the added cortisol ranged from 99.8 to 101.0%. Excellent precision was obtained with a within-day variation (RSD) of 0.7% for GC-MS analysis. The accuracy of the measurement was evaluated by comparing of results of this reference measurement procedure on lyophilized human serum reference materials for cortisol (European Reference Materials (ERM)-DA 192) as Certified Reference Materials (CRMs). The results of this method for total cortisol agreed with the certified values within some uncertainty. This method, which demonstrates simply, easy, good accuracy, high precision, and is free from interferences from structural analogues, qualifies as a reference measurement procedure.

Internal consistency of the self-reporting questionnaire-20 in occupational groups

PubMed Central

Santos, Kionna Oliveira Bernardes; Carvalho, Fernando Martins; de Araújo, Tânia Maria

2016-01-01

ABSTRACT OBJECTIVE To assess the internal consistency of the measurements of the Self-Reporting Questionnaire (SRQ-20) in different occupational groups. METHODS A validation study was conducted with data from four surveys with groups of workers, using similar methods. A total of 9,959 workers were studied. In all surveys, the common mental disorders were assessed via SRQ-20. The internal consistency considered the items belonging to dimensions extracted by tetrachoric factor analysis for each study. Item homogeneity assessment compared estimates of Cronbach’s alpha (KD-20), the alpha applied to a tetrachoric correlation matrix and stratified Cronbach’s alpha. RESULTS The SRQ-20 dimensions showed adequate values, considering the reference parameters. The internal consistency of the instrument items, assessed by stratified Cronbach’s alpha, was high (> 0.80) in the four studies. CONCLUSIONS The SRQ-20 showed good internal consistency in the professional categories evaluated. However, there is still a need for studies using alternative methods and additional information able to refine the accuracy of latent variable measurement instruments, as in the case of common mental disorders. PMID:27007682

Identification and validation of suitable reference genes for RT-qPCR analysis in mouse testis development.

PubMed

Gong, Zu-Kang; Wang, Shuang-Jie; Huang, Yong-Qi; Zhao, Rui-Qiang; Zhu, Qi-Fang; Lin, Wen-Zhen

2014-12-01

RT-qPCR is a commonly used method for evaluating gene expression; however, its accuracy and reliability are dependent upon the choice of appropriate reference gene(s), and there is limited information available on suitable reference gene(s) that can be used in mouse testis at different stages. In this study, using the RT-qPCR method, we investigated the expression variations of six reference genes representing different functional classes (Actb, Gapdh, Ppia, Tbp, Rps29, Hprt1) in mice testis during embryonic and postnatal development. The expression stabilities of putative reference genes were evaluated using five algorithms: geNorm, NormFinder, Bestkeeper, the comparative delta C(t) method and integrated tool RefFinder. Analysis of the results showed that Ppia, Gapdh and Actb were identified as the most stable genes and the geometric mean of Ppia, Gapdh and Actb constitutes an appropriate normalization factor for gene expression studies. The mRNA expression of AT1 as a test gene of interest varied depending upon which of the reference gene(s) was used as an internal control(s). This study suggested that Ppia, Gapdh and Actb are suitable reference genes among the six genes used for RT-qPCR normalization and provide crucial information for transcriptional analyses in future studies of gene expression in the developing mouse testis.

Development of liquid chromatographic methods for the determination of phytosterols in Standard Reference Materials containing saw palmetto.

PubMed

Bedner, Mary; Schantz, Michele M; Sander, Lane C; Sharpless, Katherine E

2008-05-23

Liquid chromatographic (LC) methods using atmospheric pressure chemical ionization/mass spectrometric (APCI-MS) detection were developed for the separation and analysis of the phytosterols campesterol, cycloartenol, lupenone, lupeol, beta-sitosterol, and stigmasterol. Brassicasterol and cholesterol were also included for investigation as internal standards. The methods were used to identify and quantify the phytosterols in each of two Serenoa repens (saw palmetto) Standard Reference Materials (SRMs) developed by the National Institute of Standards and Technology (NIST). Values obtained by LC-MS were compared to those obtained using the more traditional approach of gas chromatography with flame ionization detection. This is the first reported use of LC-MS to determine phytosterols in saw palmetto dietary supplement materials.

Who cites non-English-language pharmaceutical articles?

PubMed Central

Edouard, Bruno

2009-01-01

PURPOSE The objective was to determine a link between the number of non-English language references in the bibliographies of publications in international pharmaceutical journals and the geographic origin of these publications. METHODS A systematic prospective analysis of 7 international pharmaceutical journals in 2005–2006. All research articles whom corresponding author was a pharmacist were included. For each article, were recorded: the geographic origin of the corresponding author (classified in: North America, Latin America, Oceania, Europe, Asia, others); the title of the journal; the number of non-English language references in the bibliography (classified in: Spanish, German, French, Portuguese, Dutch, Russian, Japanese, Chinese, others). RESULTS 1,568 articles were included, corresponding to 45,949 bibliographic references, of whom 542 where non-English references. North America is the geographic zone of the world with the lowest rate of non-English language references in bibliographies of published articles; significant differences appear between North America and Europe, Latin America and Asia. A sub-analysis by countries shows that United States, United Kingdom, Australia and China present a specific low rate of non-English language references. The two journals with the lowest rate of non-English language references in bibliographies of published articles are edited in the USA. CONCLUSIONS Despite some limitations, this study shows that pharmacists from regions where English language is the only or predominant language are refractory to include non-English language references in the bibliographies of their publications. The fundamental reasons of this restriction are not clear. PMID:19240258

Committee on Diabetes Mellitus Indices of the Japan Society of Clinical Chemistry-recommended reference measurement procedure and reference materials for glycated albumin determination.

PubMed

Takei, Izumi; Hoshino, Tadao; Tominaga, Makoto; Ishibashi, Midori; Kuwa, Katsuhiko; Umemoto, Masao; Tani, Wataru; Okahashi, Mikiko; Yasukawa, Keiko; Kohzuma, Takuji; Sato, Asako

2016-01-01

Glycated albumin is an intermediate glycaemic control marker for which there are several measurement procedures with entirely different reference intervals. We have developed a reference measurement procedure for the purpose of standardizing glycated albumin measurements. The isotope dilution liquid chromatography/tandem mass spectrometry method was developed as a reference measurement procedure for glycated albumin. The stable isotopes of lysine and fructosyl-lysine, which serve as an internal standard, were added to albumin isolated from serum, followed by hydrogenation. After hydrolysis of albumin with hot hydrochloric acid, the liberated lysine and fructosyl-lysine were measured by liquid chromatography/tandem mass spectrometry, and their concentrations were determined from each isotope ratio. The reference materials (JCCRM611) for determining of glycated albumin were prepared from pooled patient blood samples. The isotope dilution-tandem mass spectrometry calibration curve of fructosyl-lysine and lysine showed good linearity (r = 0.999). The inter-assay and intra-assay coefficient of variation values of glycated albumin measurement were 1.2 and 1.4%, respectively. The glycated albumin values of serum in patients with diabetes assessed through the use of this method showed a good relationship with routine measurement procedures (r = 0.997). The relationship of glycated albumin values of the reference material (JCCRM611) between these two methods was the same as the relationship with the patient serum samples. The Committee on Diabetes Mellitus Indices of the Japan Society of Clinical Chemistry recommends the isotope dilution liquid chromatography/tandem mass spectrometry method as a reference measurement procedure, and JCCRM611 as a certified reference material for glycated albumin measurement. In addition, we recommend the traceability system for glycated albumin measurement. © The Author(s) 2015.

Beam-modulation methods in quantitative and flow visualization holographic interferometry

NASA Technical Reports Server (NTRS)

Decker, A.

1986-01-01

This report discusses heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam. Both methods will be used for the measurement and visualization of internal transonic flows, where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

Beam-modulation methods in quantitative and flow-visualization holographic interferometry

NASA Technical Reports Server (NTRS)

Decker, Arthur J.

1986-01-01

Heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam are discussed. Both methods will be used for the measurement and visualization of internal transonic flows where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

Reference Materials: Critical Importance to the Infant Formula Industry.

PubMed

Wargo, Wayne F

2017-09-01

Infant formula is one of the most regulated foods in the world. It has advanced in complexity over the years as a result of numerous research innovations. To ensure product safety and quality, analytical technologies have also had to advance to keep pace. Given the rigorous performance demands expected of these methods and the ever-growing array of complex matrixes, there is the potential for gaps to exist in current Official MethodsSM and other recognized international methods for infant formula and adult nutritionals. Food safety concerns, particularly for infants, drive the need for extensive testing by manufacturers and regulators. The net effect is the potential for an increase in time- and resource-consuming regulatory disputes. In an effort to mitigate such costly activities, AOAC INTERNATIONAL, under the direction of the Infant Formula Council of America-a trade association of manufacturers and marketers of formulated nutritional products-agreed to establish voluntary consensus Standard Method Performance Requirements, and, ultimately, to identify and publish globally recognized, fit-for-purpose standard methods. To accomplish this task, nutritional reference materials (RMs), representing all major commercially available nutritional formulations, were (and continue to be) a critical necessity. In this paper, various types of RMs will be defined, followed by review and discussion of their importance to the infant formula industry.

26 CFR 1.691(f)-1 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross reference. 1.691(f)-1 Section 1.691(f)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Income in Respect of Decedents § 1.691(f)-1 Cross reference. See section 753 and the...

Macromolecule mapping of the brain using ultrashort-TE acquisition and reference-based metabolite removal.

PubMed

Lam, Fan; Li, Yudu; Clifford, Bryan; Liang, Zhi-Pei

2018-05-01

To develop a practical method for mapping macromolecule distribution in the brain using ultrashort-TE MRSI data. An FID-based chemical shift imaging acquisition without metabolite-nulling pulses was used to acquire ultrashort-TE MRSI data that capture the macromolecule signals with high signal-to-noise-ratio (SNR) efficiency. To remove the metabolite signals from the ultrashort-TE data, single voxel spectroscopy data were obtained to determine a set of high-quality metabolite reference spectra. These spectra were then incorporated into a generalized series (GS) model to represent general metabolite spatiospectral distributions. A time-segmented algorithm was developed to back-extrapolate the GS model-based metabolite distribution from truncated FIDs and remove it from the MRSI data. Numerical simulations and in vivo experiments have been performed to evaluate the proposed method. Simulation results demonstrate accurate metabolite signal extrapolation by the proposed method given a high-quality reference. For in vivo experiments, the proposed method is able to produce spatiospectral distributions of macromolecules in the brain with high SNR from data acquired in about 10 minutes. We further demonstrate that the high-dimensional macromolecule spatiospectral distribution resides in a low-dimensional subspace. This finding provides a new opportunity to use subspace models for quantification and accelerated macromolecule mapping. Robustness of the proposed method is also demonstrated using multiple data sets from the same and different subjects. The proposed method is able to obtain macromolecule distributions in the brain from ultrashort-TE acquisitions. It can also be used for acquiring training data to determine a low-dimensional subspace to represent the macromolecule signals for subspace-based MRSI. Magn Reson Med 79:2460-2469, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Physical Growth of the Shuar: Height, Weight, and BMI References for an Indigenous Amazonian Population

PubMed Central

URLACHER, SAMUEL S.; BLACKWELL, AARON D.; LIEBERT, MELISSA A.; MADIMENOS, FELICIA C.; CEPON-ROBINS, TARA J.; GILDNER, THERESA E.; SNODGRASS, J. JOSH; SUGIYAMA, LAWRENCE S.

2015-01-01

Objectives Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. Methods Mixed-longitudinal measures of height, weight, and BMI were collected from Shuar participants (n = 2,463; age 0–29 years). Centile growth curves and tables were created for each anthropometric variable of interest using GAMLSS. Pseudo-velocity and LMS curves were generated to further investigate Shuar patterns of growth and to facilitate comparison with U.S. CDC and multinational WHO growth references. Results The Shuar are small throughout life and exhibit complex patterns of growth that differ substantially from those of international references. Similar to other Amazonians, Shuar growth in weight compares more favorably to references than growth in height, resulting in BMI curves that approximate international medians. Several additional characteristics of Shuar development are noteworthy, including large observed variation in body size early in life, significant infant growth faltering, extended male growth into adulthood, and a markedly early female pubertal growth spurt in height. Phenotypic plasticity and genetic selection in response to local environmental factors may explain many of these patterns. Conclusions Providing a detailed reference of growth for the Shuar and other Amazonian populations, this study possesses direct clinical application and affords valuable insight into childhood health and the ecology of human growth. PMID:26126793

Free energy and internal energy of electron-screened plasmas in a modified hypernetted-chain approximation

NASA Astrophysics Data System (ADS)

Perrot, F.

1991-12-01

We report results of Helmholtz-free-energy and internal-energy calculations using the modified hypernetted-chain (MHNC) equation method, in the formulation of Lado, Foiles, and Ashcroft [Phys. Rev. A 28, 2374 (1983)], for a model plasma of ions linearly screened by electrons. The results are compared with HNC calculations (no Bridge term), with variational calculations using a hard-spheres reference system, and with a numerical fit of Monte Carlo simulations.

[Limited access to the international medical literature in Russia].

PubMed

Jargin, Sergei V

2012-06-01

Limited access to foreign professional literature in the former Soviet Union had consequences for public health: persistence of some outdated methods and approaches. Several examples are discussed in this letter. The shortage of foreign literature has been partly compensated by domestic editions, sometimes containing compilations from foreign sources, borrowings without references, and mistranslations. International literature is on average scarcely quoted in Russian language scientific publications. Today, however, there are grounds for optimism: the economic upturn must bring improvements.

International reference reagents: antihuman globulin. An ISBT/ICSH joint working party report. International Society of Blood Transfusion. International Committee for Standardization in Haematology.

PubMed

Case, J; Ford, D S; Chung, A; Collins, R; Kochman, S; Mazda, T; Overbeeke, M; Perera, R; Sakuldamrongpanich, T; Scott, M; Voak, D; Zupańska, B

1999-01-01

An international working party has conducted a study designed to select a suitable reference reagent for antihuman globulin, to replace those first made available in 1987. The chosen preparation contains levels of anti-IgG and anti-C3 (anti-C3c and anti-C3d) potency that are considered suitable to serve for reference when evaluating either polyspecific antihuman globulin reagents or those containing their separate monospecific components. The reference material is available in 2-ml freeze-dried aliquots from seven assigned distribution centres.

GMOMETHODS: the European Union database of reference methods for GMO analysis.

PubMed

Bonfini, Laura; Van den Bulcke, Marc H; Mazzara, Marco; Ben, Enrico; Patak, Alexandre

2012-01-01

In order to provide reliable and harmonized information on methods for GMO (genetically modified organism) analysis we have published a database called "GMOMETHODS" that supplies information on PCR assays validated according to the principles and requirements of ISO 5725 and/or the International Union of Pure and Applied Chemistry protocol. In addition, the database contains methods that have been verified by the European Union Reference Laboratory for Genetically Modified Food and Feed in the context of compliance with an European Union legislative act. The web application provides search capabilities to retrieve primers and probes sequence information on the available methods. It further supplies core data required by analytical labs to carry out GM tests and comprises information on the applied reference material and plasmid standards. The GMOMETHODS database currently contains 118 different PCR methods allowing identification of 51 single GM events and 18 taxon-specific genes in a sample. It also provides screening assays for detection of eight different genetic elements commonly used for the development of GMOs. The application is referred to by the Biosafety Clearing House, a global mechanism set up by the Cartagena Protocol on Biosafety to facilitate the exchange of information on Living Modified Organisms. The publication of the GMOMETHODS database can be considered an important step toward worldwide standardization and harmonization in GMO analysis.

41 CFR 302-17.13 - Source references.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false Source references. 302... references. The following references or publications have been used as source material for this part. (a...) Internal Revenue Service Publication 521, “Moving Expenses.” (c) Internal Revenue Service, Circular E...

26 CFR 1.642(a)(3)-3 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross reference. 1.642(a)(3)-3 Section 1.642(a)(3)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.642(a)(3)-3 Cross reference. See § 1.683-2(c...

40 CFR Appendix 8 to Subpart A of... - Reference C16-C18 Internal Olefin Drilling Fluid Formulation

Code of Federal Regulations, 2014 CFR

2014-07-01

... Drilling Fluid Formulation 8 Appendix 8 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) OIL AND GAS EXTRACTION POINT...—Reference C16-C18 Internal Olefin Drilling Fluid Formulation The reference C16-C18 internal olefin drilling...

40 CFR Appendix 8 to Subpart A of... - Reference C16-C18 Internal Olefin Drilling Fluid Formulation

Code of Federal Regulations, 2012 CFR

2012-07-01

... Drilling Fluid Formulation 8 Appendix 8 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) OIL AND GAS EXTRACTION POINT...—Reference C16-C18 Internal Olefin Drilling Fluid Formulation The reference C16-C18 internal olefin drilling...

40 CFR Appendix 8 to Subpart A of... - Reference C16-C18 Internal Olefin Drilling Fluid Formulation

Code of Federal Regulations, 2013 CFR

2013-07-01

... Drilling Fluid Formulation 8 Appendix 8 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) OIL AND GAS EXTRACTION POINT...—Reference C16-C18 Internal Olefin Drilling Fluid Formulation The reference C16-C18 internal olefin drilling...

Bias Assessment of General Chemistry Analytes using Commutable Samples.

PubMed

Koerbin, Gus; Tate, Jillian R; Ryan, Julie; Jones, Graham Rd; Sikaris, Ken A; Kanowski, David; Reed, Maxine; Gill, Janice; Koumantakis, George; Yen, Tina; St John, Andrew; Hickman, Peter E; Simpson, Aaron; Graham, Peter

2014-11-01

Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.

International BMI-for-age references underestimate thinness and overestimate overweight and obesity in Bolivian adolescents.

PubMed

Baya Botti, A; Pérez-Cueto, F J A; Vasquez Monllor, P A; Kolsteren, P W

2010-01-01

Since no growth standards for adolescents exist and a single reference applicable everywhere is still in debate, it is recognized that the best reference should be derived from the growth pattern of the healthy population that will use it. In 2007 a study developed references for body mass index for 12th to 18th y Bolivian school adolescent (BAP. To compare nutritional status outcomes applying BMI references from the BAP, the Center for Disease Control and Prevention CDC 2000, the International Task Force (IOTF), and the 2007 WHO, to determine appropriateness of use in Bolivian adolescents. References were applied in 3306 adolescents, 45.0% male, 55% female, 12th to 18th y selected from a nationally representative sample. Main findings reveal that the CDC and the 2007 WHO underestimate underweight (p<0.001) and the three international references overestimate overweight (p<0.001) with variation between ages and gender. Bolivian health providers are advised to replace CDC, OITF and 2007 WHO references for the use of BAP in Bolivia which reflects its healthy adolescent population growth pattern. International references may lead to incorrect conclusions when applied on Bolivian adolescents. They could deflect efforts from population which need prompt intervention and mislead treatments and budget to unnecessary ones. We recommend validation of international references where appropriate until a standard is released.

Definition and Proposed Realization of the International Height Reference System (IHRS)

NASA Astrophysics Data System (ADS)

Ihde, Johannes; Sánchez, Laura; Barzaghi, Riccardo; Drewes, Hermann; Foerste, Christoph; Gruber, Thomas; Liebsch, Gunter; Marti, Urs; Pail, Roland; Sideris, Michael

2017-05-01

Studying, understanding and modelling global change require geodetic reference frames with an order of accuracy higher than the magnitude of the effects to be actually studied and with high consistency and reliability worldwide. The International Association of Geodesy, taking care of providing a precise geodetic infrastructure for monitoring the Earth system, promotes the implementation of an integrated global geodetic reference frame that provides a reliable frame for consistent analysis and modelling of global phenomena and processes affecting the Earth's gravity field, the Earth's surface geometry and the Earth's rotation. The definition, realization, maintenance and wide utilization of the International Terrestrial Reference System guarantee a globally unified geometric reference frame with an accuracy at the millimetre level. An equivalent high-precision global physical reference frame that supports the reliable description of changes in the Earth's gravity field (such as sea level variations, mass displacements, processes associated with geophysical fluids) is missing. This paper addresses the theoretical foundations supporting the implementation of such a physical reference surface in terms of an International Height Reference System and provides guidance for the coming activities required for the practical and sustainable realization of this system. Based on conceptual approaches of physical geodesy, the requirements for a unified global height reference system are derived. In accordance with the practice, its realization as the International Height Reference Frame is designed. Further steps for the implementation are also proposed.

Spike-In Normalization of ChIP Data Using DNA-DIG-Antibody Complex.

PubMed

Eberle, Andrea B

2018-01-01

Chromatin immunoprecipitation (ChIP) is a widely used method to determine the occupancy of specific proteins within the genome, helping to unravel the function and activity of specific genomic regions. In ChIP experiments, normalization of the obtained data by a suitable internal reference is crucial. However, particularly when comparing differently treated samples, such a reference is difficult to identify. Here, a simple method to improve the accuracy and reliability of ChIP experiments by the help of an external reference is described. An artificial molecule, composed of a well-defined digoxigenin (DIG) labeled DNA fragment in complex with an anti-DIG antibody, is synthesized and added to each chromatin sample before immunoprecipitation. During the ChIP procedure, the DNA-DIG-antibody complex undergoes the same treatments as the chromatin and is therefore purified and quantified together with the chromatin of interest. This external reference compensates for variability during the ChIP routine and improves the similarity between replicates, thereby emphasizing the biological differences between samples.

Defining overweight and obesity among Greek children living in Thessaloniki: International versus local reference standards.

PubMed

Christoforidis, A; Dimitriadou, M; Papadopolou, E; Stilpnopoulou, D; Katzos, G; Athanassiou-Metaxa, M

2011-04-01

Body Mass Index (BMI) offers a simple and reasonable measure of obesity that, with the use of the appropriate reference, can help in the early detection of children with weight problems. Our aim was to compare the two most commonly used international BMI references and the national Greek BMI reference in identifying Greek children being overweight and obese. A group of 1557 children (820 girls and 737 boys, mean age: 11.42 ± 3.51 years) were studied. Weight and height was measured using standard methods, and BMI was calculated. Overweight and obesity were determined using the International Obesity Task Force (IOTF) standards, the Centers for Disease Control and Prevention (CDC) BMI-forage curves and the most recent Greek BMI-for-age curves. RESULTS showed that the IOTF's cut-off limits identifies a significantly higher prevalence of overweight (22.4%) compared with both the CDC's (11.8%, p=0.03) and the Greek's (7.4%, p=0.002) cut-off limits. However, the prevalence of obesity was generally increased when it was determined using the CDC's cut-off limits (13.9%) compared to the prevalence calculated with both the IOTF's (6.5%, p=0.05) and the Greek's (6.9%, n.s.) cut off limits. The use of the national Greek reference standards for BMI underestimates the true prevalence of overweight and obesity. On the contrary, both the IOTF and the CDC standards, although independently, detect an increased number of overweight and obese children and thus they should be adopted in the clinical practice for an earlier identification and a timelier intervention.

Recent developments in the field of environmental reference materials at the JRC Ispra.

PubMed

Muntau, H

2001-06-01

The production of reference materials for environmental analysis started in the Joint Research Centre at Ispra/Italy in 1972 with the objective of later certification by the BCR, but for obvious budget reasons only a fraction of the total production achieved at Ispra ever reached certification level, although all materials were produced according to the severe quality requirements requested for certified reference materials. Therefore, the materials not destinated to certification are in growing demand as inter-laboratory test materials and as laboratory reference materials, for internal quality control, e.g., by control charts. The history of reference material production within the Joint Research Centre is briefly reviewed and the latest additions described. New developments such as micro-scale reference materials intended for analytical methods requiring sample intakes at milligram or sub-milligram level and therefor not finding supply on the reference material market, and "wet" environmental reference materials, which meet more precisely the "real-world" environmental analysis conditions, are presented and the state-of-the-art discussed.

Systematic review of serum steroid reference intervals developed using mass spectrometry.

PubMed

Tavita, Nevada; Greaves, Ronda F

2017-12-01

The aim of this study was to perform a systematic review of the published literature to determine the available serum/plasma steroid reference intervals generated by mass spectrometry (MS) methods across all age groups in healthy subjects and to suggest recommendations to achieve common MS based reference intervals for serum steroids. MEDLINE, EMBASE and PubMed databases were used to conduct a comprehensive search for English language, MS-based reference interval studies for serum/plasma steroids. Selection of steroids to include was based on those listed in the Royal College of Pathologists of Australasia Quality Assurance Programs, Chemical Pathology, Endocrine Program. This methodology has been registered onto the PROSPERO International prospective register of systematic reviews (ID number: CRD42015029637). After accounting for duplicates, a total of 60 manuscripts were identified through the search strategy. Following critical evaluation, a total of 16 studies were selected. Of the 16 studies, 12 reported reference intervals for testosterone, 11 for 17 hydroxy-progesterone, nine for androstenedione, six for cortisol, three for progesterone, two for dihydrotestosterone and only one for aldosterone and dehydroepiandrosterone sulphate. No studies established MS-based reference intervals for oestradiol. As far as we are aware, this report provides the first comparison of the peer reviewed literature for serum/plasma steroid reference intervals generated by MS-based methods. The reference intervals based on these published studies can be used to inform the process to develop common reference intervals, and agreed reporting units for mass spectrometry based steroid methods. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Selection of reference genes for quantitative real time RT-PCR during dimorphism in the zygomycete Mucor circinelloides.

PubMed

Valle-Maldonado, Marco I; Jácome-Galarza, Irvin E; Gutiérrez-Corona, Félix; Ramírez-Díaz, Martha I; Campos-García, Jesús; Meza-Carmen, Víctor

2015-03-01

Mucor circinelloides is a dimorphic fungal model for studying several biological processes including cell differentiation (yeast-mold transitions) as well as biodiesel and carotene production. The recent release of the first draft sequence of the M. circinelloides genome, combined with the availability of analytical methods to determine patterns of gene expression, such as quantitative Reverse transcription-Polymerase chain reaction (qRT-PCR), and the development of molecular genetic tools for the manipulation of the fungus, may help identify M. circinelloides gene products and analyze their relevance in different biological processes. However, no information is available on M. circinelloides genes of stable expression that could serve as internal references in qRT-PCR analyses. One approach to solve this problem consists in the use of housekeeping genes as internal references. However, validation of the usability of these reference genes is a fundamental step prior to initiating qRT-PCR assays. This work evaluates expression of several constitutive genes by qRT-PCR throughout the morphological differentiation stages of M. circinelloides; our results indicate that tfc-1 and ef-1 are the most stable genes for qRT-PCR assays during differentiation studies and they are proposed as reference genes to carry out gene expression studies in this fungus.

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

Periodic reference tracking control approach for smart material actuators with complex hysteretic characteristics

NASA Astrophysics Data System (ADS)

Sun, Zhiyong; Hao, Lina; Song, Bo; Yang, Ruiguo; Cao, Ruimin; Cheng, Yu

2016-10-01

Micro/nano positioning technologies have been attractive for decades for their various applications in both industrial and scientific fields. The actuators employed in these technologies are typically smart material actuators, which possess inherent hysteresis that may cause systems behave unexpectedly. Periodic reference tracking capability is fundamental for apparatuses such as scanning probe microscope, which employs smart material actuators to generate periodic scanning motion. However, traditional controller such as PID method cannot guarantee accurate fast periodic scanning motion. To tackle this problem and to conduct practical implementation in digital devices, this paper proposes a novel control method named discrete extended unparallel Prandtl-Ishlinskii model based internal model (d-EUPI-IM) control approach. To tackle modeling uncertainties, the robust d-EUPI-IM control approach is investigated, and the associated sufficient stabilizing conditions are derived. The advantages of the proposed controller are: it is designed and represented in discrete form, thus practical for digital devices implementation; the extended unparallel Prandtl-Ishlinskii model can precisely represent forward/inverse complex hysteretic characteristics, thus can reduce modeling uncertainties and benefits controllers design; in addition, the internal model principle based control module can be utilized as a natural oscillator for tackling periodic references tracking problem. The proposed controller was verified through comparative experiments on a piezoelectric actuator platform, and convincing results have been achieved.

A comparison of the BAX system method to the U.S. Food and Drug Administration's Bacteriological Analytical Manual and International Organization for Standardization reference methods for the detection of Salmonella in a variety of soy ingredients.

PubMed

Belete, Tamrat; Crowley, Erin; Bird, Patrick; Gensic, Joseph; Wallace, F Morgan

2014-10-01

The performances of two DuPont BAX System PCR assays for detecting Salmonella on a variety of low-moisture soy ingredients were evaluated against the U. S. Food and Drug Administration's Bacteriological Analytical Manual (FDA BAM) method or the International Organization for Standardization (ISO) 6579 reference method. These evaluations were conducted as a single laboratory validation at an ISO 17025 accredited third-party laboratory. Validations were conducted on five soy ingredients: isolated soy protein (ISP), soy fiber, fluid soy lecithin, deoiled soy lecithin, and soy nuggets, using a paired-study design. The ISP was analyzed as both 25- and 375-g composite test portions, whereas all other sample matrices were analyzed as 375-g composite test portions. To evaluate 25-g test portions of ISP, the test material was inoculated using Salmonella enterica subsp. enterica serovar Mbandaka (Q Laboratories isolate 11031.1). Salmonella enterica subsp. enterica serovar Tennessee (Q Laboratories isolate 11031.3) was used for all other trials. For each trial of the method comparison, 25 samples were analyzed for each matrix: 5 uninoculated controls and 20 samples inoculated at low levels (0.2 to 2 CFU per test portion) that were targeted to achieve fractionally positive results (25 to 75%). Using McNemar's chi-square analysis, no significant difference at P ≥ 0.05 (χ(2) ≤ 3.84) was observed between the number of positives obtained by the BAX System and the reference methods for all five test matrices evaluated. These studies indicate that the BAX System PCR assays, in combination with the single buffered peptone water primary enrichment and subsequent brain heart infusion regrowth step, demonstrate equivalent sensitivity and robustness compared with the FDA BAM and ISO reference methods for both 25- and 375-g composite samples. Moreover, there was no observed reduction of sensitivity in the larger 375-g composite samples for all five matrices.

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.

Alcohol marketing in televised international football: frequency analysis

PubMed Central

2014-01-01

Background Alcohol marketing includes sponsorship of individuals, organisations and sporting events. Football (soccer) is one of the most popular spectator sports worldwide. No previous studies have quantified the frequency of alcohol marketing in a high profile international football tournament. The aims were to determine: the frequency and nature of visual references to alcohol in a representative sample of EURO2012 matches broadcast in the UK; and if frequency or nature varied between matches broadcast on public service and commercial channels, or between matches that did and did not feature England. Methods Eight matches selected by stratified random sampling were recorded. All visual references to alcohol were identified using a tool with high inter-rater reliability. Results 1846 visual references to alcohol were identified over 1487 minutes of broadcast - an average of 1.24 references per minute. The mean number of references per minute was higher in matches that did vs did not feature England (p = 0.004), but did not differ between matches broadcast on public service vs commercial channels (p = 0.92). Conclusions The frequency of visual references to alcohol was universally high and higher in matches featuring the only UK home team - England - suggesting that there may be targeting of particularly highly viewed matches. References were embedded in broadcasts, and not particular to commercial channels including paid-for advertising. New UK codes-of-conduct on alcohol marketing at sporting events will not reduce the level of marketing reported here. PMID:24885718

26 CFR 1.6851-3 - Furnishing of bond to insure payment; cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Furnishing of bond to insure payment; cross reference. 1.6851-3 Section 1.6851-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Penalties § 1.6851-3 Furnishing of bond to insure payment; cross reference. See section 6863 and § 301.6863...

The Reciprocal Internal/External Frame of Reference Model: An Integration of Models of Relations between Academic Achievement and Self-Concept

ERIC Educational Resources Information Center

Moller, Jens; Retelsdorf, Jan; Koller, Olaf; Marsh, Herb W.

2011-01-01

The reciprocal internal/external frame of reference model (RI/EM) combines the internal/external frame of reference model and the reciprocal effects model. The RI/EM predicts positive effects of mathematics and verbal achievement and academic self-concepts (ASC) on subsequent mathematics and verbal achievements and ASCs within domains and negative…

Operational use of the GPS to build the "Temps Atomique Français" TA(F).

NASA Astrophysics Data System (ADS)

Fréon, G.; Tourde, R.

The clock comparisons by the observations of the satellites of the GPS in common view between several laboratories have been used by the BNM-LPTF since 1983. They have contributed to improve the stability of the national reference time scale: the "Temps Atomique Français". This time comparison method is also used by the Bureau International des Poids et Mesures and all the time and frequency laboratories which participate to the calculation of the International Atomic Time (TAI).

Refractory post visual internal urethrotomy bleeding managed by angioembolization

PubMed Central

Dhabalia, Jayesh V; Nelivigi, Girish G; Punia, Mahendra Singh; Kumar, Vikash

2010-01-01

Post visual internal urethrotomy (VIU) bleeding is usually treated successfully with local compression. Angioembolization for post VIU bleeding has not been previously reported to the best of our knowledge. This is a case report of a 55-year-old man who was referred with persistent per urethral bleeding around a Foley catheter, three days following VIU. When standard methods of treatment were unsuccessful, the bleeding was controlled by embolizing the bulbourethral artery with polyvinyl alcohol (PVA) particles. PMID:20351990

Research on volume metrology method of large vertical energy storage tank based on internal electro-optical distance-ranging method

NASA Astrophysics Data System (ADS)

Hao, Huadong; Shi, Haolei; Yi, Pengju; Liu, Ying; Li, Cunjun; Li, Shuguang

2018-01-01

A Volume Metrology method based on Internal Electro-optical Distance-ranging method is established for large vertical energy storage tank. After analyzing the vertical tank volume calculation mathematical model, the key processing algorithms, such as gross error elimination, filtering, streamline, and radius calculation are studied for the point cloud data. The corresponding volume values are automatically calculated in the different liquids by calculating the cross-sectional area along the horizontal direction and integrating from vertical direction. To design the comparison system, a vertical tank which the nominal capacity is 20,000 m3 is selected as the research object, and there are shown that the method has good repeatability and reproducibility. Through using the conventional capacity measurement method as reference, the relative deviation of calculated volume is less than 0.1%, meeting the measurement requirements. And the feasibility and effectiveness are demonstrated.

Construction Theory and Noise Analysis Method of Global CGCS2000 Coordinate Frame

NASA Astrophysics Data System (ADS)

Jiang, Z.; Wang, F.; Bai, J.; Li, Z.

2018-04-01

The definition, renewal and maintenance of geodetic datum has been international hot issue. In recent years, many countries have been studying and implementing modernization and renewal of local geodetic reference coordinate frame. Based on the precise result of continuous observation for recent 15 years from state CORS (continuously operating reference system) network and the mainland GNSS (Global Navigation Satellite System) network between 1999 and 2007, this paper studies the construction of mathematical model of the Global CGCS2000 frame, mainly analyzes the theory and algorithm of two-step method for Global CGCS2000 Coordinate Frame formulation. Finally, the noise characteristic of the coordinate time series are estimated quantitatively with the criterion of maximum likelihood estimation.

76 FR 50414 - International Mail Manual; Incorporation by Reference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-15

... POSTAL SERVICE 39 CFR Part 20 International Mail Manual; Incorporation by Reference AGENCY: Postal... Standards of the United States Postal Service, International Mail Manual (IMM[supreg]) dated April 17, 2011.... SUPPLEMENTARY INFORMATION: The International Mail Manual was issued on April 17, 2011, and was updated with...

75 FR 34017 - International Mail Manual; Incorporation by Reference

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... POSTAL SERVICE 39 CFR Part 20 International Mail Manual; Incorporation by Reference AGENCY: Postal... Mailing Standards of the United States Postal Service, International Mail Manual (IMM[supreg]) and its..., (202) 268-3789. SUPPLEMENTARY INFORMATION: Issue 36 of the International Mail Manual was issued on May...

Imaging Lenticular Autofluorescence in Older Subjects

PubMed Central

Charng, Jason; Tan, Rose; Luu, Chi D.; Sadigh, Sam; Stambolian, Dwight; Guymer, Robyn H.; Jacobson, Samuel G.; Cideciyan, Artur V.

2017-01-01

Purpose To evaluate whether a practical method of imaging lenticular autofluorescence (AF) can provide an individualized measure correlated with age-related lens yellowing in older subjects undergoing tests involving shorter wavelength lights. Methods Lenticular AF was imaged with 488-nm excitation using a confocal scanning laser ophthalmoscope (cSLO) routinely used for retinal AF imaging. There were 75 older subjects (ages 47–87) at two sites; a small cohort of younger subjects served as controls. At one site, the cSLO was equipped with an internal reference to allow quantitative AF measurements; at the other site, reduced-illuminance AF imaging (RAFI) was used. In a subset of subjects, lens density index was independently estimated from dark-adapted spectral sensitivities performed psychophysically. Results Lenticular AF intensity was significantly higher in the older eyes than the younger cohort when measured with the internal reference (59.2 ± 15.4 vs. 134.4 ± 31.7 gray levels; P < 0.05) as well as when recorded with RAFI without the internal reference (10.9 ± 1.5 vs. 26.1 ± 5.7 gray levels; P < 0.05). Lenticular AF was positively correlated with age; however, there could also be large differences between individuals of similar age. Lenticular AF intensity correlated well with lens density indices estimated from psychophysical measures. Conclusions Lenticular AF measured with a retinal cSLO can provide a practical and individualized measure of lens yellowing, and may be a good candidate to distinguish between preretinal and retinal deficits involving short-wavelength lights in older eyes. PMID:28973367

Evaluation of a rabies ELISA as an alternative method to seroneutralisation tests in the context of international trade of domestic carnivores.

PubMed

Wasniewski, M; Labbe, A; Tribout, L; Rieder, J; Labadie, A; Schereffer, J L; Cliquet, F

2014-01-01

For several years, international movements with pets have greatly increased. Most countries have relaxed their quarantine measures and adopted a scheme combining vaccination of pets against rabies followed by a serological test to check the efficacy of vaccination. This new scheme has been strongly supported by the OIE, WHO and the European Commission to facilitate the free movement of people and pets around the world. Currently, only two reference methods are recognised and prescribed (the FAVN test and the RFFIT) to measure rabies antibody levels in serum samples for international trade. They are reliable and valuable methods of assessing the efficacy of rabies vaccination but they are time-consuming and require well-trained people and specialised laboratory facilities. A few years ago, an ELISA (Platelia™ Rabies II kit ad usum Veterinarium) was developed for domestic carnivores and wildlife. To our knowledge, this ELISA is the only one certified and prescribed by the OIE. Following its marketing, one task of the EURL for rabies serology was to evaluate the performance of laboratories using this new kit. The results revealed that 26% of the participants, which were already approved laboratories for rabies serology, failed the inter-laboratory trial. Such unsatisfactory results have never been observed during any of the previous proficiency tests organised annually since 2000 by the EURL for rabies serology using reference methods. More investigations were undertaken through internal and collaborative studies to assess the performance of this newly marketed ELISA kit. The results of the internal study revealed that even with a specificity of 100%, the sensitivity evaluated on 593 samples of domestic carnivores came to 78.2%. An issue regarding the underestimation of serum titres was also revealed during the study. The results of a collaborative study involving 23 international laboratories reinforced the preliminary conclusions regarding lack of sensitivity. Indeed, only 5 laboratories out of the 23 obtained satisfactory results. We therefore suggest adopting a threshold of 0.3 EU/mL instead of 0.5 EU/mL to increase the sensitivity of the test. Copyright © 2013 Elsevier B.V. All rights reserved.

Use of the ICRP system for the protection of marine ecosystems.

PubMed

Telleria, D; Cabianca, T; Proehl, G; Kliaus, V; Brown, J; Bossio, C; Van der Wolf, J; Bonchuk, I; Nilsen, M

2015-06-01

The International Commission on Radiological Protection (ICRP) recently reinforced the international system of radiological protection, initially focused on humans, by identifying principles of environmental protection and proposing a framework for assessing impacts of ionising radiation on non-human species, based on a reference flora and fauna approach. For this purpose, ICRP developed dosimetric models for a set of Reference Animals and Plants, which are representative of flora and fauna in different environments (terrestrial, freshwater, marine), and produced criteria based on information on radiation effects, with the aim of evaluating the level of potential or actual radiological impacts, and as an input for decision making. The approach developed by ICRP for flora and fauna is consistent with the approach used to protect humans. The International Atomic Energy Agency (IAEA) includes considerations on the protection of the environment in its safety standards, and is currently developing guidelines to assess radiological impacts based on the aforementioned ICRP approach. This paper presents the method developed by IAEA, in a series of meetings with international experts, to enable assessment of the radiological impact to the marine environment in connection with the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972 (London Convention 1972). This method is based on IAEA's safety standards and ICRP's recommendations, and was presented in 2013 for consideration by representatives of the contracting parties of the London Convention 1972; it was approved for inclusion in its procedures, and is in the process of being incorporated into guidelines. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

77 FR 64724 - International Mail Manual; Incorporation by Reference

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

... POSTAL SERVICE 39 CFR Part 20 International Mail Manual; Incorporation by Reference AGENCY: Postal... Standards of the United States Postal Service, International Mail Manual (IMM[supreg]) dated June 24, 2012... International Mail Manual was issued on June 24, 2012, and was updated with postal bulletin revisions through...

SU-E-P-10: Establishment of Local Diagnostic Reference Levels of Routine Exam in Computed Tomography

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

Yeh, M; Wang, Y; Weng, H

Introduction National diagnostic reference levels (NDRLs) can be used as a reference dose of radiological examination can provide radiation dose as the basis of patient dose optimization. Local diagnostic reference levels (LDRLs) by periodically view and check doses, more efficiency to improve the way of examination. Therefore, the important first step is establishing a diagnostic reference level. Computed Tomography in Taiwan had been built up the radiation dose limit value,in addition, many studies report shows that CT scan contributed most of the radiation dose in different medical. Therefore, this study was mainly to let everyone understand DRL’s international status. Formore » computed tomography in our hospital to establish diagnostic reference levels. Methods and Materials: There are two clinical CT scanners (a Toshiba Aquilion and a Siemens Sensation) were performed in this study. For CT examinations the basic recommended dosimetric quantity is the Computed Tomography Dose Index (CTDI). Each exam each different body part, we collect 10 patients at least. Carried out the routine examinations, and all exposure parameters have been collected and the corresponding CTDIv and DLP values have been determined. Results: The majority of patients (75%) were between 60–70 Kg of body weight. There are 25 examinations in this study. Table 1 shows the LDRL of each CT routine examination. Conclusions: Therefore, this study would like to let everyone know DRL’s international status, but also establishment of computed tomography of the local reference levels for our hospital, and providing radiation reference, as a basis for optimizing patient dose.« less

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

Daleu, C. L.; Plant, R. S.; Woolnough, S. J.

Here, as part of an international intercomparison project, a set of single-column models (SCMs) and cloud-resolving models (CRMs) are run under the weak-temperature gradient (WTG) method and the damped gravity wave (DGW) method. For each model, the implementation of the WTG or DGW method involves a simulated column which is coupled to a reference state defined with profiles obtained from the same model in radiative-convective equilibrium. The simulated column has the same surface conditions as the reference state and is initialized with profiles from the reference state. We performed systematic comparison of the behavior of different models under a consistentmore » implementation of the WTG method and the DGW method and systematic comparison of the WTG and DGW methods in models with different physics and numerics. CRMs and SCMs produce a variety of behaviors under both WTG and DGW methods. Some of the models reproduce the reference state while others sustain a large-scale circulation which results in either substantially lower or higher precipitation compared to the value of the reference state. CRMs show a fairly linear relationship between precipitation and circulation strength. SCMs display a wider range of behaviors than CRMs. Some SCMs under the WTG method produce zero precipitation. Within an individual SCM, a DGW simulation and a corresponding WTG simulation can produce different signed circulation. When initialized with a dry troposphere, DGW simulations always result in a precipitating equilibrium state. The greatest sensitivities to the initial moisture conditions occur for multiple stable equilibria in some WTG simulations, corresponding to either a dry equilibrium state when initialized as dry or a precipitating equilibrium state when initialized as moist. Multiple equilibria are seen in more WTG simulations for higher SST. In some models, the existence of multiple equilibria is sensitive to some parameters in the WTG calculations.« less

Collaborative study for the establishment of the WHO 3(rd) International Standard for Endotoxin, the Ph. Eur. endotoxin biological reference preparation batch 5 and the USP Reference Standard for Endotoxin Lot H0K354.

PubMed

Findlay, L; Desai, T; Heath, A; Poole, S; Crivellone, M; Hauck, W; Ambrose, M; Morris, T; Daas, A; Rautmann, G; Buchheit, K H; Spieser, J M; Terao, E

2015-01-01

An international collaborative study was organised jointly by the World Health Organization (WHO)/National Institute for Biological Standards and Control (NIBSC), the United States Pharmacopeia (USP) and the European Directorate for the Quality of Medicines & HealthCare (EDQM/Council of Europe) for the establishment of harmonised replacement endotoxin standards for these 3 organisations. Thirty-five laboratories worldwide, including Official Medicines Control Laboratories (OMCLs) and manufacturers enrolled in the study. Three candidate preparations (10/178, 10/190 and 10/196) were produced with the same material and same formulation as the current reference standards with the objective of generating a new (3(rd)) International Standard (IS) with the same potency (10 000 IU/vial) as the current (2(nd)) IS, as well as new European Pharmacopoeia (Ph. Eur.). and USP standards. The suitability of the candidate preparations to act as the reference standard in assays for endotoxin performed according to compendial methods was evaluated. Their potency was calibrated against the WHO 2(nd) IS for Endotoxin (94/580). Gelation and photometric methods produced similar results for each of the candidate preparations. The overall potency estimates for the 3 batches were comparable. Given the intrinsic assay precision, the observed differences between the batches may be considered unimportant for the intended use of these materials. Overall, these results were in line with those generated for the establishment of the current preparations of reference standards. Accelerated degradation testing of vials stored at elevated temperatures supported the long-term stability of the 3 candidate preparations. It was agreed between the 3 organisations that batch 10/178 be shared between WHO and EDQM and that batches 10/190 and 10/196 be allocated to USP, with a common assigned value of 10 000 IU/vial. This value maintains the continuity of the global harmonisation of reference materials and unitage for the testing of endotoxins in parenteral pharmaceutical products. Based on the results of the collaborative study, batch 10/178 was established by the European Pharmacopoeia Commission as the Ph. Eur. Endotoxin Biological Reference Preparation (BRP) batch 5. The same batch was also established by the Expert Committee on Biological Standardisation (ECBS) of WHO as the WHO 3(rd) IS for Endotoxin. Batch 10/190 was adopted as the USP Endotoxin Reference Standard, lot H0K354 and vials from this same batch (10/190) will serve as the United States Food and Drug Administration (USFDA) Endotoxin Standard, EC-7.

Customized Internal Reference Controls for Improved Assessment of Circulating MicroRNAs in Disease

PubMed Central

Schlosser, Kenny; McIntyre, Lauralyn A.; White, R. James; Stewart, Duncan J.

2015-01-01

Background Altered levels of circulating extracellular miRNA in plasma and serum have shown promise as non-invasive biomarkers of disease. However, unlike the assessment of cellular miRNA levels for which there are accepted housekeeping genes, analogous reference controls for normalization of circulating miRNA are lacking. Here, we provide an approach to identify and validate circulating miRNA reference controls on a de novo basis, and demonstrate the advantages of these customized internal controls in different disease settings. Importantly, these internal controls overcome key limitations of external spike-in controls. Methods Using a global RT-qPCR screen of 1066 miRNAs in plasma from pulmonary hypertension patients (PAH) and healthy subjects as a case example, we identified a large pool of initial candidate miRNAs that were systematically ranked according to their plasma level stability using a predefined algorithm. The performance of the top candidates was validated against multiple comparators, and in a second independent cohort of PAH and control subjects. The broader utility of this approach was demonstrated in a completely different disease setting with 372 miRNAs screened in plasma from septic shock patients and healthy controls. Results Normalization of data with specific internal reference controls significantly reduced the overall variation in circulating miRNA levels between subjects (relative to raw data), provided a more balanced distribution of up- and down-regulated miRNAs, replicated the results obtained by the benchmark geometric averaging of all detected miRNAs, and outperformed the commonly used external spike-in strategy. Conclusions We demonstrate the feasibility of identifying circulating reference controls that can reduce extraneous technical variations, and improve the assessment of disease-related changes in plasma miRNA levels. This study provides a novel conceptual framework that addresses a critical and previously unmet need if circulating miRNAs are to advance as reliable diagnostic tools in medicine. PMID:26010841

Differential School Contextual Effects for Math and English: Integrating the Big-Fish-Little-Pond Effect and the Internal/External Frame of Reference

ERIC Educational Resources Information Center

Parker, Philip D.; Marsh, Herbert W.; Ludtke, Oliver; Trautwein, Ulrich

2013-01-01

The internal/external frame of reference and the big-fish-little-pond effect are two major models of academic self-concept formation which have considerable theoretical and empirical support. Integrating the domain specific and compensatory processes of the internal/external frame of reference model with the big-fish-little-pond effect suggests a…

Overweight and Obesity among Children (10-13 years) in Bahrain:A comparison between Two International Standards

PubMed Central

O. Musaiger, Abdulrahman; Al-Mannai, Mariam; Al-Marzog, Qazi

2014-01-01

Objective: Obesity has become one of the main public health problems worldwide. Childhood obesity rate is growing very fast in both developed and developing countries. This paper aimed to explore the prevalence of overweight and obesity among school children aged 10-13 years in Bahrain, and to find out the difference in this prevalence when using two international standards. Methods: A multistage stratified sampling procedure was used to select 2146 students (1068 males, 1078 females) from public schools in Bahrain. Weight and height were measured and Body Mass Index for age and sex was calculated to determine the obesity levels. Both International Obesity Task Force (IOTF) and World Health Organization (WHO) references were used to determine the prevalence of overweight and obesity. Results: The findings revealed that the prevalence of overweight and obesity ranged from 15.7% to 28.9% among males and from 21.1% to 30.7% among females. The WHO reference standard provided higher prevalence of overweight and obesity than IOTF reference. Conclusion: The study confirmed that obesity is a problem of concern in Bahraini school children and calls for intervention programme to combat obesity in schools. However, the standard used to determine obesity levels should be carefully selected and interpreted. PMID:24948966

Accurate determination of arsenic in arsenobetaine standard solutions of BCR-626 and NMIJ CRM 7901-a by neutron activation analysis coupled with internal standard method.

PubMed

Miura, Tsutomu; Chiba, Koichi; Kuroiwa, Takayoshi; Narukawa, Tomohiro; Hioki, Akiharu; Matsue, Hideaki

2010-09-15

Neutron activation analysis (NAA) coupled with an internal standard method was applied for the determination of As in the certified reference material (CRM) of arsenobetaine (AB) standard solutions to verify their certified values. Gold was used as an internal standard to compensate for the difference of the neutron exposure in an irradiation capsule and to improve the sample-to-sample repeatability. Application of the internal standard method significantly improved linearity of the calibration curve up to 1 microg of As, too. The analytical reliability of the proposed method was evaluated by k(0)-standardization NAA. The analytical results of As in AB standard solutions of BCR-626 and NMIJ CRM 7901-a were (499+/-55)mgkg(-1) (k=2) and (10.16+/-0.15)mgkg(-1) (k=2), respectively. These values were found to be 15-20% higher than the certified values. The between-bottle variation of BCR-626 was much larger than the expanded uncertainty of the certified value, although that of NMIJ CRM 7901-a was almost negligible. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Reference scenarios for deforestation and forest degradation in support of REDD: a review of data and methods

NASA Astrophysics Data System (ADS)

Olander, Lydia P.; Gibbs, Holly K.; Steininger, Marc; Swenson, Jennifer J.; Murray, Brian C.

2008-04-01

Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including FAO (Food and Agricultural Organization of the United Nations) national statistics and various remote sensing sources. The freely available and corrected global Landsat imagery for 1990, 2000 and soon to come for 2005 may be the best primary data source for most developing countries with other coarser resolution high frequency or radar data as a valuable complement for addressing problems with cloud cover and for distinguishing larger scale degradation. While sampling of imagery has been effectively useful for pan-tropical and continental estimates of deforestation, wall-to-wall (or full coverage) allows more detailed assessments for measuring national-level reference emissions. It is possible to measure historical deforestation with sufficient certainty for determining reference emissions, but there must be continued calls at the international level for making high-resolution imagery available, and for financial and technical assistance to help countries determine credible reference scenarios. The data available for past years may not be sufficient for assessing all forms of forest degradation, but new data sources will have greater potential in 2007 and after. This paper focuses only on the methods for measuring changes in forest area, but this information must be coupled with estimates of change in forest carbon stocks in order to quantify emissions from deforestation and forest degradation.

Analysis of acrylamide in coffee and cocoa by isotope dilution liquid chromatography-tandem mass spectrometry.

PubMed

Aguas, Patricia C; Fitzhenry, Matthew J; Giannikopoulos, Georgina; Varelis, Peter

2006-08-01

An accurate and precise method for the quantification of acrylamide using stable isotope dilution liquid chromatography-tandem mass spectrometry was developed and used to measure acrylamide in coffee and cocoa samples. The sample preparation involved extraction of the analyte and its internal standard, 13C3-acrylamide, into water and subsequent defatting of the aqueous extract with dichloromethane. An aliquot of the resulting aqueous extract was then azeotropically dried under reduced pressure and subsequently purified using an aminopropyl-bonded silica cartridge. The purified extracts were then chromatographed on a 5-microm 2.1 x 150 mm Hypercarb column, the effluent of which was monitored for the analyte and its internal standard using positive-ion APCI-selected reaction monitoring. The intra-laboratory reproducibility of the method, expressed as a relative coefficient of variation (%, n=5), was determined at four levels of concentration (12.3, 42.3, 139.3 and 464.8 microg kg(-1)) and was found to vary between 0.6-2.5%. The accuracy of the method was assessed using a reference sample of coffee. The average result obtained using our method differed from the assigned value of the reference material by less than 1%. An analysis of a cocoa sample revealed that the method is capable of precisely estimating acrylamide in challenging matrices down to a level of at least 12.3 microg kg(-1).

Overview of the 2014 Edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhEP Handbook)

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

John D. Bess; J. Blair Briggs; Jim Gulliford

2014-10-01

The International Reactor Physics Experiment Evaluation Project (IRPhEP) is a widely recognized world class program. The work of the IRPhEP is documented in the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhEP Handbook). Integral data from the IRPhEP Handbook is used by reactor safety and design, nuclear data, criticality safety, and analytical methods development specialists, worldwide, to perform necessary validations of their calculational techniques. The IRPhEP Handbook is among the most frequently quoted reference in the nuclear industry and is expected to be a valuable resource for future decades.

The Second Realization of the International Celestial Reference Frame by Very Long Baseline Interferometry

NASA Astrophysics Data System (ADS)

Fey, A. L.; Gordon, D.; Jacobs, C. S.; Ma, C.; Gaume, R. A.; Arias, E. F.; Bianco, G.; Boboltz, D. A.; Böckmann, S.; Bolotin, S.; Charlot, P.; Collioud, A.; Engelhardt, G.; Gipson, J.; Gontier, A.-M.; Heinkelmann, R.; Kurdubov, S.; Lambert, S.; Lytvyn, S.; MacMillan, D. S.; Malkin, Z.; Nothnagel, A.; Ojha, R.; Skurikhina, E.; Sokolova, J.; Souchay, J.; Sovers, O. J.; Tesmer, V.; Titov, O.; Wang, G.; Zharov, V.

2015-08-01

We present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. ICRF2 contains precise positions of 3414 compact radio astronomical objects and has a positional noise floor of ∼40 μas and a directional stability of the frame axes of ∼10 μas. A set of 295 new “defining” sources was selected on the basis of positional stability and the lack of extensive intrinsic source structure. The positional stability of these 295 defining sources and their more uniform sky distribution eliminates the two greatest weaknesses of the first realization of the International Celestial Reference Frame (ICRF1). Alignment of ICRF2 with the International Celestial Reference System was made using 138 positionally stable sources common to both ICRF2 and ICRF1. The resulting ICRF2 was adopted by the International Astronomical Union as the new fundamental celestial reference frame, replacing ICRF1 as of 2010 January 1.

Standardized methods and quality control limits for agar and broth microdilution susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum.

PubMed

Waites, Ken B; Duffy, Lynn B; Bébéar, Cécile M; Matlow, Anne; Talkington, Deborah F; Kenny, George E; Totten, Patricia A; Bade, Donald J; Zheng, Xiaotian; Davidson, Maureen K; Shortridge, Virginia D; Watts, Jeffrey L; Brown, Steven D

2012-11-01

An international multilaboratory collaborative study was conducted to develop standard media and consensus methods for the performance and quality control of antimicrobial susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum using broth microdilution and agar dilution techniques. A reference strain from the American Type Culture Collection was designated for each species, which was to be used for quality control purposes. Repeat testing of replicate samples of each reference strain by participating laboratories utilizing both methods and different lots of media enabled a 3- to 4-dilution MIC range to be established for drugs in several different classes, including tetracyclines, macrolides, ketolides, lincosamides, and fluoroquinolones. This represents the first multilaboratory collaboration to standardize susceptibility testing methods and to designate quality control parameters to ensure accurate and reliable assay results for mycoplasmas and ureaplasmas that infect humans.

Nationwide Multicenter Reference Interval Study for 28 Common Biochemical Analytes in China.

PubMed

Xia, Liangyu; Chen, Ming; Liu, Min; Tao, Zhihua; Li, Shijun; Wang, Liang; Cheng, Xinqi; Qin, Xuzhen; Han, Jianhua; Li, Pengchang; Hou, Li'an; Yu, Songlin; Ichihara, Kiyoshi; Qiu, Ling

2016-03-01

A nationwide multicenter study was conducted in the China to explore sources of variation of reference values and establish reference intervals for 28 common biochemical analytes, as a part of the International Federation of Clinical Chemistry and Laboratory Medicine, Committee on Reference Intervals and Decision Limits (IFCC/C-RIDL) global study on reference values. A total of 3148 apparently healthy volunteers were recruited in 6 cities covering a wide area in China. Blood samples were tested in 2 central laboratories using Beckman Coulter AU5800 chemistry analyzers. Certified reference materials and value-assigned serum panel were used for standardization of test results. Multiple regression analysis was performed to explore sources of variation. Need for partition of reference intervals was evaluated based on 3-level nested ANOVA. After secondary exclusion using the latent abnormal values exclusion method, reference intervals were derived by a parametric method using the modified Box-Cox formula. Test results of 20 analytes were made traceable to reference measurement procedures. By the ANOVA, significant sex-related and age-related differences were observed in 12 and 12 analytes, respectively. A small regional difference was observed in the results for albumin, glucose, and sodium. Multiple regression analysis revealed BMI-related changes in results of 9 analytes for man and 6 for woman. Reference intervals of 28 analytes were computed with 17 analytes partitioned by sex and/or age. In conclusion, reference intervals of 28 common chemistry analytes applicable to Chinese Han population were established by use of the latest methodology. Reference intervals of 20 analytes traceable to reference measurement procedures can be used as common reference intervals, whereas others can be used as the assay system-specific reference intervals in China.

Nationwide Multicenter Reference Interval Study for 28 Common Biochemical Analytes in China

PubMed Central

Xia, Liangyu; Chen, Ming; Liu, Min; Tao, Zhihua; Li, Shijun; Wang, Liang; Cheng, Xinqi; Qin, Xuzhen; Han, Jianhua; Li, Pengchang; Hou, Li’an; Yu, Songlin; Ichihara, Kiyoshi; Qiu, Ling

2016-01-01

Abstract A nationwide multicenter study was conducted in the China to explore sources of variation of reference values and establish reference intervals for 28 common biochemical analytes, as a part of the International Federation of Clinical Chemistry and Laboratory Medicine, Committee on Reference Intervals and Decision Limits (IFCC/C-RIDL) global study on reference values. A total of 3148 apparently healthy volunteers were recruited in 6 cities covering a wide area in China. Blood samples were tested in 2 central laboratories using Beckman Coulter AU5800 chemistry analyzers. Certified reference materials and value-assigned serum panel were used for standardization of test results. Multiple regression analysis was performed to explore sources of variation. Need for partition of reference intervals was evaluated based on 3-level nested ANOVA. After secondary exclusion using the latent abnormal values exclusion method, reference intervals were derived by a parametric method using the modified Box–Cox formula. Test results of 20 analytes were made traceable to reference measurement procedures. By the ANOVA, significant sex-related and age-related differences were observed in 12 and 12 analytes, respectively. A small regional difference was observed in the results for albumin, glucose, and sodium. Multiple regression analysis revealed BMI-related changes in results of 9 analytes for man and 6 for woman. Reference intervals of 28 analytes were computed with 17 analytes partitioned by sex and/or age. In conclusion, reference intervals of 28 common chemistry analytes applicable to Chinese Han population were established by use of the latest methodology. Reference intervals of 20 analytes traceable to reference measurement procedures can be used as common reference intervals, whereas others can be used as the assay system-specific reference intervals in China. PMID:26945390

Isometric Shoulder Strength Reference Values for Physically Active Collegiate Males and Females

PubMed Central

Westrick, Richard B.; Duffey, Michele L.; Cameron, Kenneth L.; Gerber, J. Parry; Owens, Brett D.

2013-01-01

Background: It is common clinical practice to assess muscle strength during examination of patients following shoulder injury or surgery. Strength comparisons are often made between the patient’s injured and uninjured shoulders, with the uninjured side used as a reference without regard to upper extremity dominance. Despite the importance of strength measurements, little is known about expected normal baselines of the uninjured shoulder. The purpose of this study was to report normative values for isometric shoulder strength for physically active college-age men and women without history of shoulder injury. Methods: University students—546 males (18.8 ± 1.0 years, 75.3 ± 12.2 kg) and 73 females (18.7 ± 0.9 years, 62.6 ± 7.0 kg)—underwent thorough shoulder evaluations by an orthopaedic surgeon and completed bilateral isometric strength measurements with a handheld dynamometer. Variables measured included internal rotation, external rotation, abduction, supine internal rotation and external rotation at 45°, and lower trapezius in prone flexion. Results: Significant differences were found between the dominant and nondominant shoulder for internal rotation, internal rotation at 45°, abduction, and prone flexion in males and in internal rotation at 45° and prone flexion for females (P ≤ 0.01). PMID:24381696

14 CFR 221.152 - Method of withdrawing portion of authority conferred by power of attorney.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Giving and Revoking Powers... attorney. If a carrier desires to issue a power of attorney conferring less authority than a previous power... the Office of International Aviation. Such revocation notice shall include reference to the new power...

14 CFR 221.152 - Method of withdrawing portion of authority conferred by power of attorney.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Giving and Revoking Powers... attorney. If a carrier desires to issue a power of attorney conferring less authority than a previous power... the Office of International Aviation. Such revocation notice shall include reference to the new power...

14 CFR 221.152 - Method of withdrawing portion of authority conferred by power of attorney.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Giving and Revoking Powers... attorney. If a carrier desires to issue a power of attorney conferring less authority than a previous power... the Office of International Aviation. Such revocation notice shall include reference to the new power...

14 CFR 221.152 - Method of withdrawing portion of authority conferred by power of attorney.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Giving and Revoking Powers... attorney. If a carrier desires to issue a power of attorney conferring less authority than a previous power... the Office of International Aviation. Such revocation notice shall include reference to the new power...

14 CFR 221.152 - Method of withdrawing portion of authority conferred by power of attorney.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Giving and Revoking Powers... attorney. If a carrier desires to issue a power of attorney conferring less authority than a previous power... the Office of International Aviation. Such revocation notice shall include reference to the new power...

40 CFR 59.213 - Incorporations by reference.

Code of Federal Regulations, 2014 CFR

2014-07-01

... available for inspection at the Air and Radiation Docket and Information Center, U.S. EPA, 401 M St., SW., Washington, DC 20460, the EPA Library (MD-35), U.S. EPA, Research Triangle Park, NC 27711, or at the National... University Microfilms International, 300 North Zeeb Road, Ann Arbor MI, 48106. (1) ASTM Method E220-86...

40 CFR 59.213 - Incorporations by reference.

Code of Federal Regulations, 2011 CFR

2011-07-01

... available for inspection at the Air and Radiation Docket and Information Center, U.S. EPA, 401 M St., SW., Washington, DC 20460, the EPA Library (MD-35), U.S. EPA, Research Triangle Park, NC 27711, or at the National... University Microfilms International, 300 North Zeeb Road, Ann Arbor MI, 48106. (1) ASTM Method E220-86...

40 CFR 59.213 - Incorporations by reference.

Code of Federal Regulations, 2012 CFR

2012-07-01

... available for inspection at the Air and Radiation Docket and Information Center, U.S. EPA, 401 M St., SW., Washington, DC 20460, the EPA Library (MD-35), U.S. EPA, Research Triangle Park, NC 27711, or at the National... University Microfilms International, 300 North Zeeb Road, Ann Arbor MI, 48106. (1) ASTM Method E220-86...

40 CFR 59.213 - Incorporations by reference.

Code of Federal Regulations, 2013 CFR

2013-07-01

... available for inspection at the Air and Radiation Docket and Information Center, U.S. EPA, 401 M St., SW., Washington, DC 20460, the EPA Library (MD-35), U.S. EPA, Research Triangle Park, NC 27711, or at the National... University Microfilms International, 300 North Zeeb Road, Ann Arbor MI, 48106. (1) ASTM Method E220-86...

Standards Are Good (For) Business: Standardised Comparison and the Private Sector in Education

ERIC Educational Resources Information Center

Steiner-Khamsi, Gita

2016-01-01

The article examines how and why the method of "comparison against standards" has benefited non-state actors and businesses in the education sector. Drawing on brief examples from international standard schools in Qatar, Indonesia and Mongolia, the author examines how the global education industry uses the reference to…

"Who Is Sylvia?" Reflections on Personality, Pedagogy, and Populism: A Review Essay.

ERIC Educational Resources Information Center

Rooke, Patricia T.

1990-01-01

Reviews "Sylvia? The Biography of Sylvia Ashton-Warner," by L. Hood. Uses a feminist approach to examine the life of the New Zealand teacher whose teaching methods with Maori children led to international acclaim and imitation. Discusses the dynamics between pedagogy and personality. Contains 40 references. (Author/SV)

Rapid and reliable detection and identification of GM events using multiplex PCR coupled with oligonucleotide microarray.

PubMed

Xu, Xiaodan; Li, Yingcong; Zhao, Heng; Wen, Si-yuan; Wang, Sheng-qi; Huang, Jian; Huang, Kun-lun; Luo, Yun-bo

2005-05-18

To devise a rapid and reliable method for the detection and identification of genetically modified (GM) events, we developed a multiplex polymerase chain reaction (PCR) coupled with a DNA microarray system simultaneously aiming at many targets in a single reaction. The system included probes for screening gene, species reference gene, specific gene, construct-specific gene, event-specific gene, and internal and negative control genes. 18S rRNA was combined with species reference genes as internal controls to assess the efficiency of all reactions and to eliminate false negatives. Two sets of the multiplex PCR system were used to amplify four and five targets, respectively. Eight different structure genes could be detected and identified simultaneously for Roundup Ready soybean in a single microarray. The microarray specificity was validated by its ability to discriminate two GM maizes Bt176 and Bt11. The advantages of this method are its high specificity and greatly reduced false-positives and -negatives. The multiplex PCR coupled with microarray technology presented here is a rapid and reliable tool for the simultaneous detection of GM organism ingredients.

Gross alpha and beta activity analyses in urine-a routine laboratory method for internal human radioactivity detection.

PubMed

Chen, Xiaowen; Zhao, Luqian; Qin, Hongran; Zhao, Meijia; Zhou, Yirui; Yang, Shuqiang; Su, Xu; Xu, Xiaohua

2014-05-01

The aim of this work was to develop a method to provide rapid results for humans with internal radioactive contamination. The authors hypothesized that valuable information could be obtained from gas proportional counter techniques by screening urine samples from potentially exposed individuals rapidly. Recommended gross alpha and beta activity screening methods generally employ gas proportional counting techniques. Based on International Standards Organization (ISO) methods, improvements were made in the evaporation process to develop a method to provide rapid results, adequate sensitivity, and minimum sample preparation and operator intervention for humans with internal radioactive contamination. The method described by an American National Standards Institute publication was used to calibrate the gas proportional counter, and urine samples from patients with or without radionuclide treatment were measured to validate the method. By improving the evaporation process, the time required to perform the assay was reduced dramatically. Compared with the reference data, the results of the validation samples were very satisfactory with respect to gross-alpha and gross-beta activities. The gas flow proportional counting method described here has the potential for radioactivity monitoring in the body. This method was easy, efficient, and fast, and its application is of great utility in determining whether a sample should be analyzed by a more complicated method, for example radiochemical and/or γ-spectroscopy. In the future, it may be used commonly in medical examination and nuclear emergency treatment.Health Phys. 106(5):000-000; 2014.

How Should Blood Glucose Meter System Analytical Performance Be Assessed?

PubMed

Simmons, David A

2015-08-31

Blood glucose meter system analytical performance is assessed by comparing pairs of meter system and reference instrument blood glucose measurements measured over time and across a broad array of glucose values. Consequently, no single, complete, and ideal parameter can fully describe the difference between meter system and reference results. Instead, a number of assessment tools, both graphical (eg, regression plots, modified Bland-Altman plots, and error grid analysis) and tabular (eg, International Organization for Standardization guidelines, mean absolute difference, and mean absolute relative difference) have been developed to evaluate meter system performance. The strengths and weaknesses of these methods of presenting meter system performance data, including a new method known as Radar Plots, are described here. © 2015 Diabetes Technology Society.

Steps to standardization and validation of hippocampal volumetry as a biomarker in clinical trials and diagnostic criteria for Alzheimer’s disease

PubMed Central

Jack, Clifford R; Barkhof, Frederik; Bernstein, Matt A; Cantillon, Marc; Cole, Patricia E; DeCarli, Charles; Dubois, Bruno; Duchesne, Simon; Fox, Nick C; Frisoni, Giovanni B; Hampel, Harald; Hill, Derek LG; Johnson, Keith; Mangin, Jean-François; Scheltens, Philip; Schwarz, Adam J; Sperling, Reisa; Suhy, Joyce; Thompson, Paul M; Weiner, Michael; Foster, Norman L

2012-01-01

Background The promise of Alzheimer’s disease (AD) biomarkers has led to their incorporation in new diagnostic criteria and in therapeutic trials; however, significant barriers exist to widespread use. Chief among these is the lack of internationally accepted standards for quantitative metrics. Hippocampal volumetry is the most widely studied quantitative magnetic resonance imaging (MRI) measure in AD and thus represents the most rational target for an initial effort at standardization. Methods and Results The authors of this position paper propose a path toward this goal. The steps include: 1) Establish and empower an oversight board to manage and assess the effort, 2) Adopt the standardized definition of anatomic hippocampal boundaries on MRI arising from the EADC-ADNI hippocampal harmonization effort as a Reference Standard, 3) Establish a scientifically appropriate, publicly available Reference Standard Dataset based on manual delineation of the hippocampus in an appropriate sample of subjects (ADNI), and 4) Define minimum technical and prognostic performance metrics for validation of new measurement techniques using the Reference Standard Dataset as a benchmark. Conclusions Although manual delineation of the hippocampus is the best available reference standard, practical application of hippocampal volumetry will require automated methods. Our intent is to establish a mechanism for credentialing automated software applications to achieve internationally recognized accuracy and prognostic performance standards that lead to the systematic evaluation and then widespread acceptance and use of hippocampal volumetry. The standardization and assay validation process outlined for hippocampal volumetry is envisioned as a template that could be applied to other imaging biomarkers. PMID:21784356

37 CFR 1.78 - Claiming benefit of earlier filing date and cross-references to other applications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and cross-references to other applications. (a)(1) A nonprovisional application or international...-filed copending nonprovisional applications or international applications designating the United States... nonprovisional application or international application designating the United States of America, each prior...

Issues concerning international comparison of free-field calibrations of acoustical standards

NASA Astrophysics Data System (ADS)

Nedzelnitsky, Victor

2002-11-01

Primary free-field calibrations of laboratory standard microphones by the reciprocity method establish these microphones as reference standard devices for calibrating working standard microphones, other measuring microphones, and practical instruments such as sound level meters and personal sound exposure meters (noise dosimeters). These primary, secondary, and other calibrations are indispensable to the support of regulatory requirements, standards, and product characterization and quality control procedures important for industry, commerce, health, and safety. International Electrotechnical Commission (IEC) Technical Committee 29 Electroacoustics produces international documentary standards, including standards for primary and secondary free-field calibration and measurement procedures and their critically important application to practical instruments. This paper addresses some issues concerning calibrations, standards activities, and the international key comparison of primary free-field calibrations of IEC-type LS2 laboratory standard microphones that is being planned by the Consultative Committee for Acoustics, Ultrasound, and Vibration (CCAUV) of the International Committee for Weights and Measures (CIPM). This comparison will include free-field calibrations by the reciprocity method at participating major national metrology laboratories throughout the world.

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

Besemer, A; Marsh, I; Bednarz, B

Purpose: The calculation of 3D internal dose calculations in targeted radionuclide therapy requires the acquisition and temporal coregistration of a serial PET/CT or SPECT/CT images. This work investigates the dosimetric impact of different temporal coregistration methods commonly used for 3D internal dosimetry. Methods: PET/CT images of four mice were acquired at 1, 24, 48, 72, 96, 144 hrs post-injection of {sup 124}I-CLR1404. The therapeutic {sup 131}I-CLR1404 absorbed dose rate (ADR) was calculated at each time point using a Geant4-based MC dosimetry platform using three temporal image coregistration Methods: (1) no coregistration (NC), whole body sequential CT-CT affine coregistration (WBAC), andmore » individual sequential ROI-ROI affine coregistration (IRAC). For NC, only the ROI mean ADR was integrated to obtain ROI mean doses. For WBAC, the CT at each time point was coregistered to a single reference CT. The CT transformations were applied to the corresponding ADR images and the dose was calculated on a voxel-basis within the whole CT volume. For IRAC, each individual ROI was isolated and sequentially coregistered to a single reference ROI. The ROI transformations were applied to the corresponding ADR images and the dose was calculated on a voxel-basis within the ROI volumes. Results: The percent differences in the ROI mean doses were as large as 109%, 88%, and 32%, comparing the WBAC vs. IRAC, NC vs. IRAC, and NC vs. WBAC methods, respectively. The CoV in the mean dose between the all three methods ranged from 2–36%. The pronounced curvature of the spinal cord was not adequately coregistered using WBAC which resulted in large difference between the WBAC and IRAC. Conclusion: The method used for temporal image coregistration can result in large differences in 3D internal dosimetry calculations. Care must be taken to choose the most appropriate method depending on the imaging conditions, clinical site, and specific application. This work is partially funded by NIH Grant R21 CA198392-01.« less

Controlled mutual quantum entity authentication with an untrusted third party

NASA Astrophysics Data System (ADS)

Kang, Min-Sung; Heo, Jino; Hong, Chang-Ho; Yang, Hyung-Jin; Han, Sang-Wook; Moon, Sung

2018-07-01

We propose a quantum control entity mutual authentication protocol that can be executed in environments involving an untrusted third party. In general, the third party, referred to as Charlie, can be an entity such as a telephone company, server, financial company, or login webpage for a portal service. Most communication protocols controlled by third parties are vulnerable to internal attacks. In this study, we present two solutions that make use of an entanglement correlation checking method and random numbers against an internal attack by an untrusted third party.

Multigrid Computations of 3-D Incompressible Internal and External Viscous Rotating Flows

NASA Technical Reports Server (NTRS)

Sheng, Chunhua; Taylor, Lafayette K.; Chen, Jen-Ping; Jiang, Min-Yee; Whitfield, David L.

1996-01-01

This report presents multigrid methods for solving the 3-D incompressible viscous rotating flows in a NASA low-speed centrifugal compressor and a marine propeller 4119. Numerical formulations are given in both the rotating reference frame and the absolute frame. Comparisons are made for the accuracy, efficiency, and robustness between the steady-state scheme and the time-accurate scheme for simulating viscous rotating flows for complex internal and external flow applications. Prospects for further increase in efficiency and accuracy of unsteady time-accurate computations are discussed.

EC comparison on the determination of 226Ra, 228Ra, 234U and 238U in water among European monitoring laboratories.

PubMed

Wätjen, U; Benedik, L; Spasova, Y; Vasile, M; Altzitzoglou, T; Beyermann, M

2010-01-01

In anticipation of new European requirements for monitoring radioactivity concentration in drinking water, IRMM organized an interlaboratory comparison on the determination of low levels of activity concentrations (about 10-100 mBq L(-1)) of the naturally occurring radionuclides (226)Ra, (228)Ra, (234)U and (238)U in three commercially available mineral waters. Using two or three different methods with traceability to the International System of Reference (SIR), the reference values of the water samples were determined prior to the proficiency test within combined standard uncertainties of the order of 3%-10%. An overview of radiochemical separation and measurement methods used by the 45 participating laboratories are given. The results of the participants are evaluated versus the reference values. Several of the participants' results deviate by more than a factor of two from the reference values, in particular for the radium isotopes. Such erroneous analysis results may lead to a crucial omission of remedial actions on drinking water supplies or to economic loss by an unjustified action. Copyright 2009 Elsevier Ltd. All rights reserved.

Growth references for Tsimane forager-horticulturalists of the Bolivian Amazon

PubMed Central

Blackwell, Aaron D.; Urlacher, Samuel S.; Beheim, Bret; von Rueden, Christopher; Jaeggi, Adrian; Stieglitz, Jonathan; Trumble, Benjamin C.; Gurven, Michael; Kaplan, Hillard

2016-01-01

Objectives Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists. Methods Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0–29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for height-for-age, weight-for-age, body mass index (BMI)-for-age, and weight-for-height (WFH) using Generalized Additive Models for Location Shape and Scale (GAMLSS). Velocity curves were generated using SuperImposition by Translation and Rotation (SITAR). Tsimane ≤5 years were compared World Health Organization (WHO) standards while those >5 years were compared to WHO school age references. All ages were compared to published references for Shuar forager-horticulturalists of the Ecuadorian Amazon. Results Tsimane growth differs from WHO values in height and weight, but is similar for BMI and WFH. Tsimane growth is characterized by slow height velocity in childhood and early adolescent peak height velocity at 11.3 and 13.2 years for girls and boys. Tsimane growth patterns are similar to Shuar, suggesting shared features of growth among indigenous South Americans. Conclusions International references for BMI-for-age and WFH are likely appropriate for Tsimane, but differences in height-for-age and weight-for-age suggest Tsimane specific references may be useful for these measures. PMID:28218400

Calibrating NIST SRM 683 as A New International Reference Standard for Zn Isotopes

NASA Astrophysics Data System (ADS)

Yang, Y.; Zhang, X.; Yu, H.; Huang, F.

2017-12-01

Zinc isotopes have been widely applied in the cosmochemical, geochemical, and environmental studies (Moynier et al. 2017). Obtaining precise Zn isotopic data for inter-laboratory comparison is a prerequisite to these applications. Currently, the JMC3-0749L is the primary reference standard for Zn isotopes (Albarède 2004), but it is not commercially available now. Thus, it is necessary to calibrate a new international primary reference standard for Zn isotopic analysis. Chen et al. (2016) showed that NIST SRM 683 (a pure Zn metal nugget of 140 grams) has a δ66ZnJMC of 0.12‰, which is falling within the range of natural Zn isotopic compositions, and it may a good candidate for the next generation of international reference standard (Chen et al. 2016). In order to further examine whether NIST SRM 683 has a homogeneous Zn isotopic composition, we measured more NIST SRM 683 by double-spike methods using MC-ICPMS (Conway et al. 2013). The metal nuggets of NIST SRM 683 were intensively sampled by micro-drilling. Zinc isotope analyses for two nuggets show that they have δ66Zn of 0.14 ± 0.02‰ (2SD, N = 32) and 0.13 ± 0.02‰ (2SD, N = 33), respectively. These values are similar to those of two Zn metal nuggets (0.11 ± 0.02‰ vs. 0.12 ± 0.02‰) reported previously by Chen et al. (2016). We fully dissolved one nugget, producing pure Zn solution with identical Zn isotopic composition with the drilling samples. All results strongly support that NIST SRM 683 is homogeneous in Zn isotopic compositions which could be an ideal candidate for the next reference for Zn isotopes. Tests on more metal nuggets will be performed in a few months for further confirming the Zn isotope compositions and homogeneity. Reference: Albarède et al., 2004. 'The stable isotope geochemistry of copper and zinc', Reviews in Mineralogy and Geochemistry, 55: 409-27. Chen et al., 2016. 'Zinc Isotopic Compositions of NIST SRM 683 and Whole-Rock Reference Materials', Geostandards and Geoanalytical Research, 40: 417-32. Conway et al., 2013. 'A new method for precise determination of iron, zinc and cadmium stable isotope ratios in seawater by double-spike mass spectrometry', Analytica chimica acta, 793: 44-52. Moynier et al., 2017. 'The isotope geochemistry of zinc and copper', Reviews in Mineralogy and Geochemistry, 82: 543-600.

Simultaneous use of multiplex ligation-dependent probe amplification assay and flow cytometric DNA ploidy analysis in patients with acute leukemia.

PubMed

Reyes-Núñez, Virginia; Galo-Hooker, Evelyn; Pérez-Romano, Beatriz; Duque, Ricardo E; Ruiz-Arguelles, Alejandro; Garcés-Eisele, Javier

2018-01-01

The aim of this work was to simultaneously use multiplex ligation-dependent probe amplification (MLPA) assay and flow cytometric DNA ploidy analysis (FPA) to detect aneuploidy in patients with newly diagnosed acute leukemia. MLPA assay and propidium iodide FPA were used to test samples from 53 consecutive patients with newly diagnosed acute leukemia referred to our laboratory for immunophenotyping. Results were compared by nonparametric statistics. The combined use of both methods significantly increased the rate of detection of aneuploidy as compared to that obtained by each method alone. The limitations of one method are somehow countervailed by the other and vice versa. MPLA and FPA yield different yet complementary information concerning aneuploidy in acute leukemia. The simultaneous use of both methods might be recommended in the clinical setting. © 2017 International Clinical Cytometry Society. © 2017 International Clinical Cytometry Society.

International Laser Ranging Service (ILRS): Terms of Reference

NASA Technical Reports Server (NTRS)

Husson, Van; Noll, Carey

2000-01-01

The International Laser Ranging Service (ILRS) is an established Service within Section II , Advanced Space Technology, of the International Association of Geodesy (IAG). The primary objective of the ILRS is to provide a service to support, through Satellite and Lunar Laser Ranging data and related products, geodetic and geophysical research activities as well as International Earth Rotation Service (IERS) products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). The service also develops the necessary standards/specifications and encourages international adherence to its conventions.

Assessment of international reference materials for isotope-ratio analysis (IUPAC Technical Report)

USGS Publications Warehouse

Brand, Willi A.; Coplen, Tyler B.; Vogl, Jochen; Rosner, Martin; Prohaska, Thomas

2014-01-01

Since the early 1950s, the number of international measurement standards for anchoring stable isotope delta scales has mushroomed from 3 to more than 30, expanding to more than 25 chemical elements. With the development of new instrumentation, along with new and improved measurement procedures for studying naturally occurring isotopic abundance variations in natural and technical samples, the number of internationally distributed, secondary isotopic reference materials with a specified delta value has blossomed in the last six decades to more than 150 materials. More than half of these isotopic reference materials were produced for isotope-delta measurements of seven elements: H, Li, B, C, N, O, and S. The number of isotopic reference materials for other, heavier elements has grown considerably over the last decade. Nevertheless, even primary international measurement standards for isotope-delta measurements are still needed for some elements, including Mg, Fe, Te, Sb, Mo, and Ge. It is recommended that authors publish the delta values of internationally distributed, secondary isotopic reference materials that were used for anchoring their measurement results to the respective primary stable isotope scale.

Standardization of Laser Methods and Techniques for Vibration Measurements and Calibrations

NASA Astrophysics Data System (ADS)

von Martens, Hans-Jürgen

2010-05-01

The realization and dissemination of the SI units of motion quantities (vibration and shock) have been based on laser interferometer methods specified in international documentary standards. New and refined laser methods and techniques developed by national metrology institutes and by leading manufacturers in the past two decades have been swiftly specified as standard methods for inclusion into in the series ISO 16063 of international documentary standards. A survey of ISO Standards for the calibration of vibration and shock transducers demonstrates the extended ranges and improved accuracy (measurement uncertainty) of laser methods and techniques for vibration and shock measurements and calibrations. The first standard for the calibration of laser vibrometers by laser interferometry or by a reference accelerometer calibrated by laser interferometry (ISO 16063-41) is on the stage of a Draft International Standard (DIS) and may be issued by the end of 2010. The standard methods with refined techniques proved to achieve wider measurement ranges and smaller measurement uncertainties than that specified in the ISO Standards. The applicability of different standardized interferometer methods to vibrations at high frequencies was recently demonstrated up to 347 kHz (acceleration amplitudes up to 350 km/s2). The relative deviations between the amplitude measurement results of the different interferometer methods that were applied simultaneously, differed by less than 1% in all cases.

Microarsecond models for the celestial motions of the CIP and CEO

NASA Astrophysics Data System (ADS)

Capitaine, N.

2004-09-01

The Celestial intermediate pole (CIP) and Celestial ephemeris (orintermediate) origin (CEO/CIO) have been adopted by the IAU (c.f. IAU2000 Resolution B1.8) as the celestial pole and origin, respectively,to be used for realizing the intermediate celestial system between theInternational Terrestrial System (ITRS) and Geocentric CelestialReference System (GCRS). Resolution B1.8 has also recommended that theInternational Earth Rotation and Reference Systems Service (IERS)continue to provide users with data and algorithms for the conventionaltransformation. The IAU 2000 Resolutions have been implemented in theIERS 2003 Conventions including Tables and routines that provide thecelestial motions of the CIP and the CEO with a theoretical accuracy ofone microarcsecond after one century using either the classical or thenew transformation. This paper reports on the method used for achievingthis accuracy in the positions of the CIP and CIO and on the differencebetween this rigorous procedure and the pre-2003 classical one.

Two new computational methods for universal DNA barcoding: a benchmark using barcode sequences of bacteria, archaea, animals, fungi, and land plants.

PubMed

Tanabe, Akifumi S; Toju, Hirokazu

2013-01-01

Taxonomic identification of biological specimens based on DNA sequence information (a.k.a. DNA barcoding) is becoming increasingly common in biodiversity science. Although several methods have been proposed, many of them are not universally applicable due to the need for prerequisite phylogenetic/machine-learning analyses, the need for huge computational resources, or the lack of a firm theoretical background. Here, we propose two new computational methods of DNA barcoding and show a benchmark for bacterial/archeal 16S, animal COX1, fungal internal transcribed spacer, and three plant chloroplast (rbcL, matK, and trnH-psbA) barcode loci that can be used to compare the performance of existing and new methods. The benchmark was performed under two alternative situations: query sequences were available in the corresponding reference sequence databases in one, but were not available in the other. In the former situation, the commonly used "1-nearest-neighbor" (1-NN) method, which assigns the taxonomic information of the most similar sequences in a reference database (i.e., BLAST-top-hit reference sequence) to a query, displays the highest rate and highest precision of successful taxonomic identification. However, in the latter situation, the 1-NN method produced extremely high rates of misidentification for all the barcode loci examined. In contrast, one of our new methods, the query-centric auto-k-nearest-neighbor (QCauto) method, consistently produced low rates of misidentification for all the loci examined in both situations. These results indicate that the 1-NN method is most suitable if the reference sequences of all potentially observable species are available in databases; otherwise, the QCauto method returns the most reliable identification results. The benchmark results also indicated that the taxon coverage of reference sequences is far from complete for genus or species level identification in all the barcode loci examined. Therefore, we need to accelerate the registration of reference barcode sequences to apply high-throughput DNA barcoding to genus or species level identification in biodiversity research.

Two New Computational Methods for Universal DNA Barcoding: A Benchmark Using Barcode Sequences of Bacteria, Archaea, Animals, Fungi, and Land Plants

PubMed Central

Tanabe, Akifumi S.; Toju, Hirokazu

2013-01-01

Taxonomic identification of biological specimens based on DNA sequence information (a.k.a. DNA barcoding) is becoming increasingly common in biodiversity science. Although several methods have been proposed, many of them are not universally applicable due to the need for prerequisite phylogenetic/machine-learning analyses, the need for huge computational resources, or the lack of a firm theoretical background. Here, we propose two new computational methods of DNA barcoding and show a benchmark for bacterial/archeal 16S, animal COX1, fungal internal transcribed spacer, and three plant chloroplast (rbcL, matK, and trnH-psbA) barcode loci that can be used to compare the performance of existing and new methods. The benchmark was performed under two alternative situations: query sequences were available in the corresponding reference sequence databases in one, but were not available in the other. In the former situation, the commonly used “1-nearest-neighbor” (1-NN) method, which assigns the taxonomic information of the most similar sequences in a reference database (i.e., BLAST-top-hit reference sequence) to a query, displays the highest rate and highest precision of successful taxonomic identification. However, in the latter situation, the 1-NN method produced extremely high rates of misidentification for all the barcode loci examined. In contrast, one of our new methods, the query-centric auto-k-nearest-neighbor (QCauto) method, consistently produced low rates of misidentification for all the loci examined in both situations. These results indicate that the 1-NN method is most suitable if the reference sequences of all potentially observable species are available in databases; otherwise, the QCauto method returns the most reliable identification results. The benchmark results also indicated that the taxon coverage of reference sequences is far from complete for genus or species level identification in all the barcode loci examined. Therefore, we need to accelerate the registration of reference barcode sequences to apply high-throughput DNA barcoding to genus or species level identification in biodiversity research. PMID:24204702

[Study on seed testing for Salvia miltiorrhiza].

PubMed

Dan, Hong-mei; Qi, Jian-jun; Zhou, Li-li; Li, Xian-en

2008-09-01

To establish a seed testing methods for Salvia miltiorrhiza. Referring to the International Seed Testing Rules made by ISTA and the Seed Testing for Crops (GB/T3543. 1-1995) issued by China. The seeds are selected by winnowing; the seed purity is about 50%-60%; 100 grain weight is used to determine the quality of the seed; the seed moisture content is determined by air drying, the drying hour is 3 h. Seed viability is tested by TFC method.

Soft tissue examination of the fetal rat and rabbit head by magnetic resonance imaging.

PubMed

French, Julian M; Woodhouse, Neil

2013-01-01

The use of magnetic resonance imaging of the fetal rat and rabbit head, as an alternative to the traditional methods of fixation and preparation of serial sections, is described. Labeled magnetic resonance images of normal head anatomy have been provided as a reference for use when evaluating the internal structures of the head.

Assessing the Generalizability of Estimates of Causal Effects from Regression Discontinuity Designs

ERIC Educational Resources Information Center

Bloom, Howard S.; Porter, Kristin E.

2012-01-01

In recent years, the regression discontinuity design (RDD) has gained widespread recognition as a quasi-experimental method that when used correctly, can produce internally valid estimates of causal effects of a treatment, a program or an intervention (hereafter referred to as treatment effects). In an RDD study, subjects or groups of subjects…

Handbook of Research on Literacy in Technology at the K-12 Level

ERIC Educational Resources Information Center

Hin, Leo Tan Wee, Ed.; Subramaniam, R., Ed.

2006-01-01

The "Handbook of Research on Literacy in Technology at the K-12 Level" is the first reference work to provide comprehensive coverage of the issues, methods, and theories that define the converging worlds of literacy and technology at the pre-collegiate level. Over 50 international experts have combined their research and practical experience into…

26 CFR 1.163-12 - Deduction of original issue discount on instrument held by related foreign person.

Code of Federal Regulations, 2012 CFR

2012-04-01

... on which the amount is includible in income is determined with reference to the method of accounting... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Deduction of original issue discount on... Deductions for Individuals and Corporations § 1.163-12 Deduction of original issue discount on instrument...

26 CFR 1.163-12 - Deduction of original issue discount on instrument held by related foreign person.

Code of Federal Regulations, 2014 CFR

2014-04-01

... on which the amount is includible in income is determined with reference to the method of accounting... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Deduction of original issue discount on... Deductions for Individuals and Corporations § 1.163-12 Deduction of original issue discount on instrument...

26 CFR 1.163-12 - Deduction of original issue discount on instrument held by related foreign person.

Code of Federal Regulations, 2013 CFR

2013-04-01

... on which the amount is includible in income is determined with reference to the method of accounting... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Deduction of original issue discount on... Deductions for Individuals and Corporations § 1.163-12 Deduction of original issue discount on instrument...

26 CFR 49.4264(d)-1 - Cross reference.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Cross reference. 49.4264(d)-1 Section 49.4264(d)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES FACILITIES AND SERVICES EXCISE TAXES Transportation of Persons § 49.4264(d)-1 Cross...

Capillary whole blood testing by a new portable monitor. Comparison with standard determination of the international normalized ratio.

PubMed

de Miguel, Dunia; Burgaleta, Carmen; Reyes, Eduardo; Pascual, Teresa

2003-07-01

We evaluated a new portable monitor (AvoSure PT PRO, Menarini Diagnostics, Firenze, Italy) developed to test the prothrombin time in capillary blood and plasma by comparing it with the standard laboratory determination. We studied 62 patients receiving acenocoumarol therapy. The international normalized ratio (INR) in capillary blood was analyzed by 2 methods: AvoSure PT PRO and Thrombotrack Nycomed Analyzer (Axis-Shield, Dundee, Scotland). Parallel studies were performed in plasma samples by a reference method using the Behring Coagulation Timer (Behring Diagnostics, Marburg, Germany). Plasma samples also were tested with the AvoSure PT PRO. Correlation was good for INR values for capillary blood and plasma samples by AvoSure PT PRO and our reference method (R2 = 0.8596) and for capillary blood samples tested by the AvoSure PT PRO and Thrombotrack Nycomed Analyzer (R2 = 0.8875). The correlation for INR in capillary blood and plasma samples by AvoSure PT PRO was 0.6939 (P < .0004). Capillary blood determinations are rapid and effective for monitoring oral anticoagulation therapy and have a high correlation to plasma determinations. AvoSure PT PRO is accurate for controlling INR in plasma and capillary blood samples, may be used in outpatient clinics, and has advantages over previous portable monitors.

Impact of implementing an Internal Bed Regulation Committee on administrative and care indicators at a teaching hospital

PubMed Central

Rodrigues, Luciane Cristine Ribeiro; Juliani, Carmen Maria Casquel Monti

2015-01-01

Objective To compare hospital indicators before and after implementing an Internal Bed Regulation Committee at a reference hospital. Methods It is an quantitative, evaluation, exploratory, descriptive and cross-sectional research. The data was gathered from the hospital administrative reports for the period 2008-2013, provided by the Information Technology Center of the Complexo FAMEMA. Results The indicators improved after implementation of the Internal Bed Regulation Committee. Conclusion The individuals involved in the process acknowledged the improvement. It is necessary to carry on the regulatory actions, especially in a comprehensive and complex healthcare system, such as the brazilian Sistema Único de Saúde. PMID:25993075

Intercomparison of methods of coupling between convection and large-scale circulation. 1. Comparison over uniform surface conditions

DOE PAGES

Daleu, C. L.; Plant, R. S.; Woolnough, S. J.; ...

2015-10-24

Here, as part of an international intercomparison project, a set of single-column models (SCMs) and cloud-resolving models (CRMs) are run under the weak-temperature gradient (WTG) method and the damped gravity wave (DGW) method. For each model, the implementation of the WTG or DGW method involves a simulated column which is coupled to a reference state defined with profiles obtained from the same model in radiative-convective equilibrium. The simulated column has the same surface conditions as the reference state and is initialized with profiles from the reference state. We performed systematic comparison of the behavior of different models under a consistentmore » implementation of the WTG method and the DGW method and systematic comparison of the WTG and DGW methods in models with different physics and numerics. CRMs and SCMs produce a variety of behaviors under both WTG and DGW methods. Some of the models reproduce the reference state while others sustain a large-scale circulation which results in either substantially lower or higher precipitation compared to the value of the reference state. CRMs show a fairly linear relationship between precipitation and circulation strength. SCMs display a wider range of behaviors than CRMs. Some SCMs under the WTG method produce zero precipitation. Within an individual SCM, a DGW simulation and a corresponding WTG simulation can produce different signed circulation. When initialized with a dry troposphere, DGW simulations always result in a precipitating equilibrium state. The greatest sensitivities to the initial moisture conditions occur for multiple stable equilibria in some WTG simulations, corresponding to either a dry equilibrium state when initialized as dry or a precipitating equilibrium state when initialized as moist. Multiple equilibria are seen in more WTG simulations for higher SST. In some models, the existence of multiple equilibria is sensitive to some parameters in the WTG calculations.« less

Reference States and Relative Values of Internal Energy, Enthalpy, and Entropy.

ERIC Educational Resources Information Center

Fredrickson, A. G.

1983-01-01

Discusses two reference states (pure chemical compounds and pure elements at specified condition of temperature and pressure) and the relation between these reference states for internal energy and enthalpy. Problem 5.11 from Modell and Reid's "Thermodynamics and its Applications" (p. 141) is used to apply the ideas discussed. (JN)

Longitudinal Lung Function Growth of Mexican Children Compared with International Studies

PubMed Central

Martínez-Briseño, David; Fernández-Plata, Rosario; Gochicoa-Rangel, Laura; Torre-Bouscoulet, Luis; Rojas-Martínez, Rosalba; Mendoza, Laura; García-Sancho, Cecilia; Pérez-Padilla, Rogelio

2013-01-01

Introduction Our aim was to compare the longitudinal lung function growth of Mexican children and adolescents with the collated spirometric reference proposed for international use and with that of Mexican-Americans from the National Health State Examination Survey III (NHANES) III study. Materials and Methods A cohort of Mexican children in third year of primary school was followed with spirometry twice a year through secondary school. Multilevel mixed-effects lineal models separated by gender were fit for the spirometric variables of 2,641 respiratory-healthy Mexican children expressed as Z-scores of tested reference equations. Impact of adjustment by sitting height on differences with Mexican-American children was observed in a subsample of 1,987 children. Results At same gender, age, and height, Mexican children had increasingly higher forced expiratory volume in 1 s (FEV1) and Forced vital capacity (FVC) than the children from the collated reference study (mean Z-score, 0.68 for FEV1 and 0.51 for FVC) and than Mexican-American children (Z-score, 0.23 for FEV1 and 0.21 for FVC) respectively. Differences with Mexican-Americans were not reduced by adjusting by sitting height. Conclusions For reasons that remain unclear, the gender-, age-, and height-adjusted lung function of children from Mexico City is higher than that reported by several international studies. PMID:24143231

Nontargeted quantitation of lipid classes using hydrophilic interaction liquid chromatography-electrospray ionization mass spectrometry with single internal standard and response factor approach.

PubMed

Cífková, Eva; Holčapek, Michal; Lísa, Miroslav; Ovčačíková, Magdaléna; Lyčka, Antonín; Lynen, Frédéric; Sandra, Pat

2012-11-20

The identification and quantitation of a wide range of lipids in complex biological samples is an essential requirement for the lipidomic studies. High-performance liquid chromatography-mass spectrometry (HPLC/MS) has the highest potential to obtain detailed information on the whole lipidome, but the reliable quantitation of multiple lipid classes is still a challenging task. In this work, we describe a new method for the nontargeted quantitation of polar lipid classes separated by hydrophilic interaction liquid chromatography (HILIC) followed by positive-ion electrospray ionization mass spectrometry (ESI-MS) using a single internal lipid standard to which all class specific response factors (RFs) are related to. The developed method enables the nontargeted quantitation of lipid classes and molecules inside these classes in contrast to the conventional targeted quantitation, which is based on predefined selected reaction monitoring (SRM) transitions for selected lipids only. In the nontargeted quantitation method described here, concentrations of lipid classes are obtained by the peak integration in HILIC chromatograms multiplied by their RFs related to the single internal standard (i.e., sphingosyl PE, d17:1/12:0) used as common reference for all polar lipid classes. The accuracy, reproducibility and robustness of the method have been checked by various means: (1) the comparison with conventional lipidomic quantitation using SRM scans on a triple quadrupole (QqQ) mass analyzer, (2) (31)P nuclear magnetic resonance (NMR) quantitation of the total lipid extract, (3) method robustness test using subsequent measurements by three different persons, (4) method transfer to different HPLC/MS systems using different chromatographic conditions, and (5) comparison with previously published results for identical samples, especially human reference plasma from the National Institute of Standards and Technology (NIST human plasma). Results on human plasma, egg yolk and porcine liver extracts are presented and discussed.

Methods for detection of GMOs in food and feed.

PubMed

Marmiroli, Nelson; Maestri, Elena; Gullì, Mariolina; Malcevschi, Alessio; Peano, Clelia; Bordoni, Roberta; De Bellis, Gianluca

2008-10-01

This paper reviews aspects relevant to detection and quantification of genetically modified (GM) material within the feed/food chain. The GM crop regulatory framework at the international level is evaluated with reference to traceability and labelling. Current analytical methods for the detection, identification, and quantification of transgenic DNA in food and feed are reviewed. These methods include quantitative real-time PCR, multiplex PCR, and multiplex real-time PCR. Particular attention is paid to methods able to identify multiple GM events in a single reaction and to the development of microdevices and microsensors, though they have not been fully validated for application.

Establishment of a biological reference preparation for hepatitis A vaccine (inactivated, non-adsorbed).

PubMed

Stalder, J; Costanzo, A; Daas, A; Rautmann, G; Buchheit, K-H

2010-04-01

A reference standard calibrated in International Units (IU) is needed for the in vitro potency assay of hepatitis A vaccines prepared by formalin-inactivation of purified hepatitis A virus grown in cell cultures. Thus, a project was launched by the European Directorate for the Quality of Medicines & HealthCare (EDQM) to establish one or more non-adsorbed inactivated hepatitis A vaccine reference preparation(s) as working standard(s), calibrated against the 1st International Standard (IS), for the in vitro potency assay (ELISA) of all vaccines present on the European market. Four non-adsorbed liquid preparations of formalin-inactivated hepatitis A antigen with a known antigen content were obtained from 3 manufacturers as candidate Biological Reference Preparations (BRPs). Thirteen laboratories participated in the collaborative study. They were asked to use an in vitro ELISA method adapted from a commercially available kit for the detection of antibodies to hepatitis A virus. In-house validated assays were to be run in parallel, where available. Some participants also included commercially available hepatitis A vaccines in the assays, after appropriate desorption. During the collaborative study, several participants using the standard method were faced with problems with some of the most recent lots of the test kits. Due to these problems, the standard method did not perform satisfactorily and a high number of assays were invalid, whereas the in-house methods appeared to perform better. Despite this, the overall mean results of the valid assays using both methods were in agreement. Nonetheless, it was decided to base the assignment of the potency values on the in-house methods only. The results showed that all candidate BRPs were suitable for the intended purpose. However, based on availability of the material and on the results of end-product testing, 2 candidate reference preparations, Samples C and D, were selected. Both were from the same batch but filled on different days; no statistically significant difference in potency was observed. They were thus combined in 1 single batch. The candidate preparation (Sample C/D) was adopted at the June 2009 session of the European Pharmacopoeia (Ph. Eur.) Commission as the Ph. Eur. BRP batch 1 for hepatitis A vaccine (inactivated, non-adsorbed), with an assigned potency of 12 IU/ml for in vitro antigen content assays. Accelerated degradation studies have been initiated. The preliminary data show that the BRP is stable at the recommended storage temperature (< -50 degrees C). The BRP will be monitored at regular intervals throughout its lifetime.

Improved reliability of pH measurements.

PubMed

Spitzer, Petra; Werner, Barbara

2002-11-01

Measurements of pH are performed on a large scale at laboratory level, and in industry. To meet the quality-control requirements and other technical specifications there is a need for traceability in measurement results. The prerequisite for the international acceptance of analytical data is reliability. To measure means to compare. Comparability entails use of recognised references to which the standard buffer solutions used for calibration of pH meter-electrode assemblies can be traced. The new recommendation on the measurement of pH recently published as a provisional document by the International Union on Pure and Applied Chemistry (IUPAC) enables traceability for measured pH values to a conventional reference frame which is recognised world-wide. The primary method for pH will be described. If analytical data are to be accepted internationally it is necessary to demonstrate the equivalence of the national traceability structures, including national measurement standards. For the first time key comparisons for pH have been performed by the Consultative Committee for Amount of Substance (CCQM, set up by the International Bureau of Weights and Measures, BIPM) to assess the equivalence of the national measurement procedures used to determine the pH of primary standard buffer solutions. The results of the first key comparison on pH CCQM-K9, and other international initiatives to improve the consistency of the results of measurement for pH, are reported.

A framework for combining multiple soil moisture retrievals based on maximizing temporal correlation

NASA Astrophysics Data System (ADS)

Kim, Seokhyeon; Parinussa, Robert M.; Liu, Yi. Y.; Johnson, Fiona M.; Sharma, Ashish

2015-08-01

A method for combining two microwave satellite soil moisture products by maximizing the temporal correlation with a reference data set has been developed. The method was applied to two global soil moisture data sets, Japan Aerospace Exploration Agency (JAXA) and Land Parameter Retrieval Model (LPRM), retrieved from the Advanced Microwave Scanning Radiometer 2 observations for the period 2012-2014. A global comparison revealed superior results of the combined product compared to the individual products against the reference data set of ERA-Interim volumetric water content. The global mean temporal correlation coefficient of the combined product with this reference was 0.52 which outperforms the individual JAXA (0.35) as well as the LPRM (0.45) product. Additionally, the performance was evaluated against in situ observations from the International Soil Moisture Network. The combined data set showed a significant improvement in temporal correlation coefficients in the validation compared to JAXA and minor improvements for the LPRM product.

Residual stress analysis for oxide thin film deposition on flexible substrate using finite element method

NASA Astrophysics Data System (ADS)

Chen, Hsi-Chao; Huang, Chen-Yu; Lin, Ssu-Fan; Chen, Sheng-Hui

2011-09-01

Residual or internal stresses directly affect a variety of phenomena including adhesion, generation of crystalline defects, perfection of epitaxial layers and formation of film surface growths such as hillocks and whiskers. Sputtering oxide films with high density promote high compressive stress, and it offers researchers a reference if the value of residual stress could be analyzed directly. Since, the study of residual stress of SiO2 and Nb2O5 thin film deposited by DC magnetron sputtered on hard substrate (BK7) and flexible substrate (PET and PC). A finite element method (FEM) with an equivalent-reference-temperature (ERT) technique had been proposed and used to model and evaluate the intrinsic strains of layered structures. The research has improved the equivalent reference temperature (ERT) technique of the simulation of intrinsic strain for oxygen film. The results have also generalized two models connecting to the lattice volume to predict the residual stress of hard substrate and flexible substrate with error of 3% and 6%, respectively.

International Relations: A Student's Guide to Reference Resources.

ERIC Educational Resources Information Center

Silvester, Elizabeth

Intended for students, this annotated bibliography describes reference materials in International Relations that may be found in either the McLennan or Law Library of McGill University. Scope includes political science, international law, and related areas in the social and behavioral sciences, but titles which relate to the foreign relations of a…

TIGO: a geodetic observatory for the improvement of the global reference frame

NASA Astrophysics Data System (ADS)

Schlueter, Wolfgang; Hase, Hayo; Boeer, Armin

1999-12-01

The Bundesamt fuer Kartographie und Geodaesie (BKG) will provide a major contribution to the improvement and maintenance of the global reference frames: ICRF (International Celestial Reference Frame), ITRF (International Terrestrial Reference Frame) with the operation of TIGO (Transportable Integrated Geodetic Observatory). TIGO is designed as a transportable geodetic observatory which consists of all relevant geodetic space techniques for a fundamental station (including VLBI, SLR, GPS). The transportability of the observatory enables to fill up gaps in the International Space Geodetic Network and to optimize the contribution to the global reference frames. TIGO should operate for a period of 2 to 3 years (at minimum) at one location. BKG is looking for a cooperation with countries willing to contribute to the ITRF and to support the operation of TIGO.

New ab initio adiabatic potential energy surfaces and bound state calculations for the singlet ground X˜ 1A1 and excited C˜ 1B2(21A') states of SO2

NASA Astrophysics Data System (ADS)

Kłos, Jacek; Alexander, Millard H.; Kumar, Praveen; Poirier, Bill; Jiang, Bin; Guo, Hua

2016-05-01

We report new and more accurate adiabatic potential energy surfaces (PESs) for the ground X˜ 1A1 and electronically excited C˜ 1B2(21A') states of the SO2 molecule. Ab initio points are calculated using the explicitly correlated internally contracted multi-reference configuration interaction (icMRCI-F12) method. A second less accurate PES for the ground X ˜ state is also calculated using an explicitly correlated single-reference coupled-cluster method with single, double, and non-iterative triple excitations [CCSD(T)-F12]. With these new three-dimensional PESs, we determine energies of the vibrational bound states and compare these values to existing literature data and experiment.

Reveal Listeria 2.0 test for detection of Listeria spp. in foods and environmental samples.

PubMed

Alles, Susan; Curry, Stephanie; Almy, David; Jagadeesan, Balamurugan; Rice, Jennifer; Mozola, Mark

2012-01-01

A Performance Tested Method validation study was conducted for a new lateral flow immunoassay (Reveal Listeria 2.0) for detection of Listeria spp. in foods and environmental samples. Results of inclusivity testing showed that the test detects all species of Listeria, with the exception of L. grayi. In exclusivity testing conducted under nonselective growth conditions, all non-listeriae tested produced negative Reveal assay results, except for three strains of Lactobacillus spp. However, these lactobacilli are inhibited by the selective Listeria Enrichment Single Step broth enrichment medium used with the Reveal method. Six foods were tested in parallel by the Reveal method and the U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) reference culture procedure. Considering data from both internal and independent laboratory trials, overall sensitivity of the Reveal method relative to that of the FDA/BAM procedure was 101%. Four foods were tested in parallel by the Reveal method and the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) reference culture procedure. Overall sensitivity of the Reveal method relative to that of the USDA-FSIS procedure was 98.2%. There were no statistically significant differences in the number of positives obtained by the Reveal and reference culture procedures in any food trials. In testing of swab or sponge samples from four types of environmental surfaces, sensitivity of Reveal relative to that of the USDA-FSIS reference culture procedure was 127%. For two surface types, differences in the number of positives obtained by the Reveal and reference methods were statistically significant, with more positives by the Reveal method in both cases. Specificity of the Reveal assay was 100%, as there were no unconfirmed positive results obtained in any phase of the testing. Results of ruggedness experiments showed that the Reveal assay is tolerant of modest deviations in test sample volume and device incubation time.

Optical monitoring of QSO in the framework of the Gaia space mission

NASA Astrophysics Data System (ADS)

Taris, F.; Damljanovic, G.; Andrei, A.; Klotz, A.; Vachier, F.

2015-08-01

The Gaia astrometric mission of the European Space Agency has been launched the 19th December 2013. It will provide an astrometric catalogue of 500 000 extragalactic sources that could be the basis of a new optical reference frame. On the other hand, the current International Celestial Reference Frame (ICRF) is based on the observations of extragalactic sources at radio wavelength. The astrometric coordinates of sources in these two reference systems will have roughly the same uncertainty. It is then mandatory to observe a set of common targets at both optical and radio wavelength to link the ICRF with what could be called the GCRF (Gaia Celestial Reference Frame). We will show in this paper some results obtained with the TJO, Telescopi Juan Oro, from Observatori Astronomic del Montsec in Spain. It also presents some results obtained with the Lomb-Scargle and CLEAN algorithm methods applied to optical magnitude obtained with the TAROT telescopes.

The International Gravity Field Service (IGFS): Present Day Activities And Future Plans

NASA Astrophysics Data System (ADS)

Barzaghi, R.; Vergos, G. S.

2016-12-01

IGFS is a unified "umbrella" IAG service that coordinates the servicing of the geodetic and geophysical community with gravity field related data, software and information. The combined data of the IGFS entities will include global geopotential models, terrestrial, airborne, satellite and marine gravity observations, Earth tide data, GPS/levelling data, digital models of terrain and bathymetry, as well as ocean gravity field and geoid from satellite altimetry. The IGFS structure is based on the Gravity Services, the "operating arms" of IGFS. These Services related to IGFS are: BGI (Bureau Gravimetrique International), Toulouse, France ISG (International Service for the Geoid), Politecnico di Milano, Milano, Italy IGETS (International Geodynamics and Earth Tides Service), EOST, Strasbourg, France ICGEM (International Center for Global Earth Models), GFZ, Potsdam, Germany IDEMS (International Digital Elevation Model Service), ESRI, Redlands, CA, USA The Central Bureau, hosted at the Aristotle Thessaloniki University, is in charge for all the interactions among the services and the other IAG bodies, particularly GGOS. In this respect, connections with the GGOS Bureaus of Products and Standards and of Networks and Observations have been recently strengthened in order to align the Gravity services to the GGOS standards. IGFS is also strongly involved in the most relevant projects related to the gravity field such as the establishment of the new Global Absolute Gravity Reference System and of the International Height Reference System. These projects, along with the organization of Geoid Schools devoted to methods for gravity and geoid estimate, will play a central role in the IGFS future actions in the framework of GGOS.

Growth Curves of Preschool Children in the Northeast of Iran: A Population Based Study Using Quantile Regression Approach

PubMed Central

Payande, Abolfazl; Tabesh, Hamed; Shakeri, Mohammad Taghi; Saki, Azadeh; Safarian, Mohammad

2013-01-01

Introduction: Growth charts are widely used to assess children’s growth status and can provide a trajectory of growth during early important months of life. The objectives of this study are going to construct growth charts and normal values of weight-for-age for children aged 0 to 5 years using a powerful and applicable methodology. The results compare with the World Health Organization (WHO) references and semi-parametric LMS method of Cole and Green. Methods: A total of 70737 apparently healthy boys and girls aged 0 to 5 years were recruited in July 2004 for 20 days from those attending community clinics for routine health checks as a part of a national survey. Anthropometric measurements were done by trained health staff using WHO methodology. The nonparametric quantile regression method obtained by local constant kernel estimation of conditional quantiles curves using for estimation of curves and normal values. Results: The weight-for-age growth curves for boys and girls aged from 0 to 5 years were derived utilizing a population of children living in the northeast of Iran. The results were similar to the ones obtained by the semi-parametric LMS method in the same data. Among all age groups from 0 to 5 years, the median values of children’s weight living in the northeast of Iran were lower than the corresponding values in WHO reference data. The weight curves of boys were higher than those of girls in all age groups. Conclusion: The differences between growth patterns of children living in the northeast of Iran versus international ones necessitate using local and regional growth charts. International normal values may not properly recognize the populations at risk for growth problems in Iranian children. Quantile regression (QR) as a flexible method which doesn’t require restricted assumptions, proposed for estimation reference curves and normal values. PMID:23618470

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

Miller, D. C.; Gu, X.; Haldenman, S.

The curing of cross-linkable encapsulation is a critical consideration for photovoltaic (PV) modules manufactured using a lamination process. Concerns related to ethylene-co-vinyl acetate (EVA) include the quality (e.g., expiration and uniformity) of the films or completion (duration) of the cross-linking of the EVA within a laminator. Because these issues are important to both EVA and module manufacturers, an international standard has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the degree of cure for EVA encapsulation. The present draft of themore » standard calls for the use of differential scanning calorimetry (DSC) as the rapid, enabling secondary (test) method. Both the residual enthalpy- and melt/freeze-DSC methods are identified. The DSC methods are calibrated against the gel content test, the primary (reference) method. Aspects of other established methods, including indentation and rotor cure metering, were considered by the group. Key details of the test procedure will be described.« less

IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 °C. Part 9: reference procedure for the measurement of catalytic concentration of alkaline phosphatase International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Scientific Division, Committee on Reference Systems of Enzymes (C-RSE) (1)).

PubMed

Schumann, Gerhard; Klauke, Rainer; Canalias, Francesca; Bossert-Reuther, Steffen; Franck, Paul F H; Gella, F-Javier; Jørgensen, Poul J; Kang, Dongchon; Lessinger, Jean-Marc; Panteghini, Mauro; Ceriotti, Ferruccio

2011-09-01

Abstract This paper is the ninth in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 °C and the certification of reference preparations. Other parts deal with: Part 1. The concept of reference procedures for the measurement of catalytic activity concentrations of enzymes; Part 2. Reference procedure for the measurement of catalytic concentration of creatine kinase; Part 3. Reference procedure for the measurement of catalytic concentration of lactate dehydrogenase; Part 4. Reference procedure for the measurement of catalytic concentration of alanine aminotransferase; Part 5. Reference procedure for the measurement of catalytic concentration of aspartate aminotransferase; Part 6. Reference procedure for the measurement of catalytic concentration of γ-glutamyltransferase; Part 7. Certification of four reference materials for the determination of enzymatic activity of γ-glutamyltransferase, lactate dehydrogenase, alanine aminotransferase and creatine kinase at 37 °C; Part 8. Reference procedure for the measurement of catalytic concentration of α-amylase. The procedure described here is derived from the previously described 30 °C IFCC reference method. Differences are tabulated and commented on in Appendix 1.

Development of certified reference materials for electrolytes in human serum (GBW09124-09126).

PubMed

Feng, Liuxing; Wang, Jun; Cui, Yanjie; Shi, Naijie; Li, Haifeng; Li, Hongmei

2017-05-01

Three reference materials, at relatively low, middle, and high concentrations, were developed for analysis of the mass fractions of electrolytes (K, Ca, Na, Mg, Cl, and Li) in human serum. The reference materials were prepared by adding high purity chloride salts to normal human serum. The concentration range of the three levels is within ±20% of normal human serum. It was shown that 14 units with duplicate analysis is enough to demonstrate the homogeneity of these candidate reference materials. The statistical results also showed no significant trends in both short-term stability test for 1 week at 40 °C and long-term stability test for 14 months. The certification methods of the six elements include isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES), atomic absorption spectroscopy (AAS), ion chromatography (IC), and ion-selective electrode (ISE). The certification methods were validated by international comparisons among a number of national metrology institutes (NMIs). The combined relative standard uncertainties of the property values were estimated by considering the uncertainties of the analytical methods, homogeneity, and stability. The range of the expanded uncertainties of all the elements is from 2.2% to 3.9%. The certified reference materials (CRMs) are primarily intended for use in the calibration and validation of procedures in clinical analysis for the determination of electrolytes in human serum or plasma. Graphical Abstract Certified reference materials for K, Ca, Mg, Na, Cl and Li in human serum (GBW09124-09126).

Evaluation of reference genes for insect olfaction studies.

PubMed

Omondi, Bonaventure Aman; Latorre-Estivalis, Jose Manuel; Rocha Oliveira, Ivana Helena; Ignell, Rickard; Lorenzo, Marcelo Gustavo

2015-04-22

Quantitative reverse transcription PCR (qRT-PCR) is a robust and accessible method to assay gene expression and to infer gene regulation. Being a chain of procedures, this technique is subject to systematic error due to biological and technical limitations mainly set by the starting material and downstream procedures. Thus, rigorous data normalization is critical to grant reliability and repeatability of gene expression quantification by qRT-PCR. A number of 'housekeeping genes', involved in basic cellular functions, have been commonly used as internal controls for this normalization process. However, these genes could themselves be regulated and must therefore be tested a priori. We evaluated eight potential reference genes for their stability as internal controls for RT-qPCR studies of olfactory gene expression in the antennae of Rhodnius prolixus, a Chagas disease vector. The set of genes included were: α-tubulin; β-actin; Glyceraldehyde-3-phosphate dehydrogenase; Eukaryotic initiation factor 1A; Glutathione-S-transferase; Serine protease; Succinate dehydrogenase; and Glucose-6-phosphate dehydrogenase. Five experimental conditions, including changes in age,developmental stage and feeding status were tested in both sexes. We show that the evaluation of candidate reference genes is necessary for each combination of sex, tissue and physiological condition analyzed in order to avoid inconsistent results and conclusions. Although, Normfinder and geNorm software yielded different results between males and females, five genes (SDH, Tub, GAPDH, Act and G6PDH) appeared in the first positions in all rankings obtained. By using gene expression data of a single olfactory coreceptor gene as an example, we demonstrated the extent of changes expected using different internal standards. This work underlines the need for a rigorous selection of internal standards to grant the reliability of normalization processes in qRT-PCR studies. Furthermore, we show that particular physiological or developmental conditions require independent evaluation of a diverse set of potential reference genes.

The reference individual of radiation protection

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

Eckerman, K.F.; Cristy, M.

1995-12-31

The 70-kg {open_quotes}standard man{close_quotes} representing a typical Western adult male has been used in physiological models since at least the 1920s. In 1949 at the Chalk River conference, health physicists from the U.S., UK, and Canada agreed on the concept of a standard man to facilitate comparison of internal dose estimates. The 70-kg standard man included specifications of the masses of 25 organs and tissues, total body content of 15 elements, total water intake and output, water content of the body, and some anatomical and physiological data for the respiratory and gastrointestinal tracts. In 1959, in its Publication 2{sup 2}more » on permissible doses for internal radiation the International Commission on Radiological Protection (ICRP) modified standard man. In 1963 the ICRP established a task group to revise and extend the standard man concept. The name was changed later to Reference Man and the task group`s work was published in 1975 as ICRP Publication 23{sup 3}. Publication 23 similar to Publication 2, updates and documents the sources of the data. Data on women, children, and fetuses were also collected, where available, but these data were limited primarily to anatomical data and only a few reference values were established for these groups. Information assembled during the course of the effort on the Reference Man report was used at Oak Ridge National Laboratory (ORNL) to construct a mathematical representation of the body (a phantom) that was suitable for use with Monte Carlo methods in the calculation of organ doses. That effort was undertaken to improve estimates of dose from photon-emitting radionuclides residing within organs, so-called internal emitters. The phantom, although updated throughout the years, remains today as the basis for organ dose estimates in nuclear medicine and radiation protection and underlies the radiation risk data derived from the epidemiologic studies of the atomic bomb survivors of Hiroshima and Nagasaki.« less

Extract-filter-shoot liquid chromatography with mass spectrometry for the analysis of vitamin D2 in a powdered supplement capsule and standard reference material 3280.

PubMed

Byrdwell, William Craig

2014-08-01

An "extract-filter-shoot" method for the analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in a National Institute of Standards and Technology standard reference material 3280 is reported. Quantification of vitamin D2 was done by atmospheric pressure chemical ionization mass spectrometry using selected ion monitoring, two transitions of selected reaction monitoring, and extracted ion chromatograms from full scans. UV detection was used for the quantification of Vitamin D2 in the dry powder capsule, whereas interfering species rendered UV detection unreliable for standard reference material 3280. Average values for standard reference material 3280 ranged from 8.27 ± 0.58 to 8.33 ± 0.57 μg/g using internal standard calibration and response factor approaches, compared to the previous National Institute of Standards and Technology internal value for vitamin D2 of 8.78 ± 0.11 μg/g, and the recently updated reference value of 8.6 ± 2.6 μg/g. The powdered supplement capsule was found to contain 28.19 ± 0.35 to 28.67 ± 0.90 μg/capsule for a capsule labeled to contain 25.00 μg. The triacylglycerol composition of the rice flour excipient in the powdered supplement capsule determined by atmospheric pressure chemical ionization mass spectrometry is also reported. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Endoscope field of view measurement.

PubMed

Wang, Quanzeng; Khanicheh, Azadeh; Leiner, Dennis; Shafer, David; Zobel, Jurgen

2017-03-01

The current International Organization for Standardization (ISO) standard (ISO 8600-3: 1997 including Amendment 1: 2003) for determining endoscope field of view (FOV) does not accurately characterize some novel endoscopic technologies such as endoscopes with a close focus distance and capsule endoscopes. We evaluated the endoscope FOV measurement method (the FOV WS method) in the current ISO 8600-3 standard and proposed a new method (the FOV EP method). We compared the two methods by measuring the FOV of 18 models of endoscopes (one device for each model) from seven key international manufacturers. We also estimated the device to device variation of two models of colonoscopes by measuring several hundreds of devices. Our results showed that the FOV EP method was more accurate than the FOV WS method, and could be used for all endoscopes. We also found that the labelled FOV values of many commercial endoscopes are significantly overstated. Our study can help endoscope users understand endoscope FOV and identify a proper method for FOV measurement. This paper can be used as a reference to revise the current endoscope FOV measurement standard.

Endoscope field of view measurement

PubMed Central

Wang, Quanzeng; Khanicheh, Azadeh; Leiner, Dennis; Shafer, David; Zobel, Jurgen

2017-01-01

The current International Organization for Standardization (ISO) standard (ISO 8600-3: 1997 including Amendment 1: 2003) for determining endoscope field of view (FOV) does not accurately characterize some novel endoscopic technologies such as endoscopes with a close focus distance and capsule endoscopes. We evaluated the endoscope FOV measurement method (the FOVWS method) in the current ISO 8600-3 standard and proposed a new method (the FOVEP method). We compared the two methods by measuring the FOV of 18 models of endoscopes (one device for each model) from seven key international manufacturers. We also estimated the device to device variation of two models of colonoscopes by measuring several hundreds of devices. Our results showed that the FOVEP method was more accurate than the FOVWS method, and could be used for all endoscopes. We also found that the labelled FOV values of many commercial endoscopes are significantly overstated. Our study can help endoscope users understand endoscope FOV and identify a proper method for FOV measurement. This paper can be used as a reference to revise the current endoscope FOV measurement standard. PMID:28663840

Datasets of Odontocete Sounds Annotated for Developing Automatic Detection Methods

DTIC Science & Technology

2010-12-01

Passive acoustic detection of Minke whales (Balaenoptera acutorostrata) off the West Coast of Kauai, HI. Book of abstracts, Fourth International...Workshop on Detection , Classification and Localization of Marine Mammals using Passive Acoustics , Pavia, Italy, Sept. 10- 13, 2009, p. 57. Roch, M., Y...Mellinger, and D. Gillespie. 2010. Comparison of beaked whale detection algorithms. Applied Acoustics 71:1043-1049. 8 References

Using different growth references to measure thinness and overweight among Swedish primary school children showed considerable variations.

PubMed

Nilsen, Bente B; Yngve, Agneta; Sjöberg, Agneta; Moraeus, Lotta; Lissner, Lauren; Werner, Bo

2016-10-01

The study compared how four different growth references determined the prevalence of thinness and overweight, based on height and weight measurements from a nationally representative sample of Swedish children from seven to nine years of age. The height and weight measurements of 4518 Swedish schoolchildren aged seven to nine years were carried out in 2008 using a standardised protocol. The prevalence of different degrees of thinness and overweight was calculated using international growth references from the World Health Organization, the International Obesity Task Force and two Swedish growth references from Werner and Karlberg. Depending on which growth reference we used, the prevalence of different degrees of thinness varied from 7.5% to 16.9% for the boys and 6.9% to 13.7% for the girls, while the prevalence of overweight, including obesity and severe obesity, varied from 16.5% to 25.7% for the boys and 18.2 to 25.2% for the girls. There were also significant gender differences depending on the growth reference we used. Using four different growth references, two international and two Swedish, produced wide variations in the prevalence of thinness and overweight, together with significant gender differences. In the absence of a global definition, we need both national and international growth references. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Quantitative analysis of a brass alloy using CF-LIBS and a laser ablation time-of-flight mass spectrometer

NASA Astrophysics Data System (ADS)

Ahmed, Nasar; Abdullah, M.; Ahmed, Rizwan; Piracha, N. K.; Aslam Baig, M.

2018-01-01

We present a quantitative analysis of a brass alloy using laser induced breakdown spectroscopy, energy dispersive x-ray spectroscopy (EDX) and laser ablation time-of-flight mass spectrometry (LA-TOF-MS). The emission lines of copper (Cu I) and zinc (Zn I), and the constituent elements of the brass alloy were used to calculate the plasma parameters. The plasma temperature was calculated from the Boltzmann plot as (10 000  ±  1000) K and the electron number density was determined as (2.0  ±  0.5)  ×  1017 cm-3 from the Stark-broadened Cu I line as well as using the Saha-Boltzmann equation. The elemental composition was deduced using these techniques: the Boltzmann plot method (70% Cu and 30% Zn), internal reference self-absorption correction (63.36% Cu and 36.64% Zn), EDX (61.75% Cu and 38.25% Zn), and LA-TOF (62% Cu and 38% Zn), whereas, the certified composition is (62% Cu and 38% Zn). It was observed that the internal reference self-absorption correction method yields analytical results comparable to that of EDX and LA-TOF-MS.

Analysis of difference between direct and geodetic mass balance measurements at South Cascade Glacier, Washington

USGS Publications Warehouse

Krimmel, R.M.

1999-01-01

Net mass balance has been measured since 1958 at South Cascade Glacier using the 'direct method,' e.g. area averages of snow gain and firn and ice loss at stakes. Analysis of cartographic vertical photography has allowed measurement of mass balance using the 'geodetic method' in 1970, 1975, 1977, 1979-80, and 1985-97. Water equivalent change as measured by these nearly independent methods should give similar results. During 1970-97, the direct method shows a cumulative balance of about -15 m, and the geodetic method shows a cumulative balance of about -22 m. The deviation between the two methods is fairly consistent, suggesting no gross errors in either, but rather a cumulative systematic error. It is suspected that the cumulative error is in the direct method because the geodetic method is based on a non-changing reference, the bedrock control, whereas the direct method is measured with reference to only the previous year's summer surface. Possible sources of mass loss that are missing from the direct method are basal melt, internal melt, and ablation on crevasse walls. Possible systematic measurement errors include under-estimation of the density of lost material, sinking stakes, or poorly represented areas.

The Generalized Internal/External Frame of Reference Model: An Extension to Dimensional Comparison Theory

ERIC Educational Resources Information Center

Möller, Jens; Müller-Kalthoff, Hanno; Helm, Friederike; Nagy, Nicole; Marsh, Herb W.

2016-01-01

The dimensional comparison theory (DCT) focuses on the effects of internal, dimensional comparisons (e.g., "How good am I in math compared to English?") on academic self-concepts with widespread consequences for students' self-evaluation, motivation, and behavioral choices. DCT is based on the internal/external frame of reference model…

Magnetic Stirrer Method for the Detection of Trichinella Larvae in Muscle Samples.

PubMed

Mayer-Scholl, Anne; Pozio, Edoardo; Gayda, Jennifer; Thaben, Nora; Bahn, Peter; Nöckler, Karsten

2017-03-03

Trichinellosis is a debilitating disease in humans and is caused by the consumption of raw or undercooked meat of animals infected with the nematode larvae of the genus Trichinella. The most important sources of human infections worldwide are game meat and pork or pork products. In many countries, the prevention of human trichinellosis is based on the identification of infected animals by means of the artificial digestion of muscle samples from susceptible animal carcasses. There are several methods based on the digestion of meat but the magnetic stirrer method is considered the gold standard. This method allows the detection of Trichinella larvae by microscopy after the enzymatic digestion of muscle samples and subsequent filtration and sedimentation steps. Although this method does not require special and expensive equipment, internal controls cannot be used. Therefore, stringent quality management should be applied throughout the test. The aim of the present work is to provide detailed handling instructions and critical control points of the method to analysts, based on the experience of the European Union Reference Laboratory for Parasites and the National Reference Laboratory of Germany for Trichinella.

A novel and eco-friendly analytical method for phosphorus and sulfur determination in animal feed.

PubMed

Novo, Diogo L R; Pereira, Rodrigo M; Costa, Vanize C; Hartwig, Carla A; Mesko, Marcia F

2018-04-25

An eco-friendly method for indirect determining phosphorus and sulfur in animal feed by ion chromatography was proposed. Using this method, it was possible to digest 500 mg of animal feed in a microwave system under oxygen pressure (20 bar) using only a diluted acid solution (2 mol L -1 HNO 3 ). The accuracy of the proposed method was evaluated by recovery tests, by analysis of reference material (RM) and by comparison of the results with those obtained using conventional microwave-assisted digestion. Moreover, P results were compared with those obtained from the method recommended by AOAC International for animal feed (Method nr. 965.17) and no significant differences were found between the results. Recoveries for P and S were between 94 and 97%, and agreements with the reference values of RM were better than 94%. Phosphorus and S concentrations in animal feeds ranged from 10,026 to 28,357 mg kg -1 and 2259 to 4601 mg kg -1 , respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection by real-time PCR and pyrosequencing of the cry1Ab and cry1Ac genes introduced in genetically modified (GM) constructs.

PubMed

Debode, Frederic; Janssen, Eric; Bragard, Claude; Berben, Gilbert

2017-08-01

The presence of genetically modified organisms (GMOs) in food and feed is mainly detected by the use of targets focusing on promoters and terminators. As some genes are frequently used in genetically modified (GM) construction, they also constitute excellent screening elements and their use is increasing. In this paper we propose a new target for the detection of cry1Ab and cry1Ac genes by real-time polymerase chain reaction (PCR) and pyrosequencing. The specificity, sensitivity and robustness of the real-time PCR method were tested following the recommendations of international guidelines and the method met the expected performance criteria. This paper also shows how the robustness testing was assessed. This new cry1Ab/Ac method can provide a positive signal with a larger number of GM events than do the other existing methods using double dye-probes. The method permits the analysis of results with less ambiguity than the SYBRGreen method recommended by the European Reference Laboratory (EURL) GM Food and Feed (GMFF). A pyrosequencing method was also developed to gain additional information thanks to the sequence of the amplicon. This method of sequencing-by-synthesis can determine the sequence between the primers used for PCR. Pyrosequencing showed that the sequences internal to the primers present differences following the GM events considered and three different sequences were observed. The sensitivity of the pyrosequencing was tested on reference flours with a low percentage GM content and different copy numbers. Improvements in the pyrosequencing protocol provided correct sequences with 50 copies of the target. Below this copy number, the quality of the sequence was more random.

26 CFR 56.6001-1 - Notice or regulations requiring records, statements, and special returns.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., statements, and special returns. 56.6001-1 Section 56.6001-1 Internal Revenue INTERNAL REVENUE SERVICE..., of the Code, by treating each reference to chapter 42 in § 53.6001-1 as a reference to chapter 41. (b) Cross references. See § 56.4911-6 for general information on records of lobbying expenditures. See §§ 56...

Uncertainty Analysis for Angle Calibrations Using Circle Closure

PubMed Central

Estler, W. Tyler

1998-01-01

We analyze two types of full-circle angle calibrations: a simple closure in which a single set of unknown angular segments is sequentially compared with an unknown reference angle, and a dual closure in which two divided circles are simultaneously calibrated by intercomparison. In each case, the constraint of circle closure provides auxiliary information that (1) enables a complete calibration process without reference to separately calibrated reference artifacts, and (2) serves to reduce measurement uncertainty. We derive closed-form expressions for the combined standard uncertainties of angle calibrations, following guidelines published by the International Organization for Standardization (ISO) and NIST. The analysis includes methods for the quantitative evaluation of the standard uncertainty of small angle measurement using electronic autocollimators, including the effects of calibration uncertainty and air turbulence. PMID:28009359

USDA FSIS, FDA BAM, and ISO culture methods BD BBL CHROMagar O157 media.

PubMed

Ritter, Vicki; Kircher, Susan; Dick, Nancy

2009-01-01

BBL CHROMagar O157 media (CO) was evaluated for detection of Escherichia coli O157:H7 in raw ground beef and unpasteurized apple cider. The recovery of E. coli O157:H7 on CO was compared to the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM), U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS), and International Organization for Standardization (ISO) reference-plated media using the recommended enrichment broths. Of the 180 food samples tested, 45 were tested using BAM, 45 using the USDA method, and 90 using the ISO method. CO produced comparable results with the reference methods on all matrixes with a sensitivity of 100% and a specificity of 100%. No false negatives were found in testing the food matrixes. There was no statistical difference in recovery based on Chi-square analysis. Method agreement for raw ground beef was 85% for the USDAFSIS method and 95% for the ISO method. Method agreement for unpasteurized apple cider was 100% for the ISO and FDA BAM methods. In all cases where method agreement was <100%, CO detected more positives than the reference method media. Evaluation of known isolates on CO in inclusivity and exclusivity testing had a sensitivity and specificity of 100%. The results of this study demonstrate that CO is an effective medium for the recovery and detection of E. coli O157:H7 in raw ground beef and unpasteurized apple cider using FDA BAM, USDA FSIS, and ISO methods.

Rigorous Combination of GNSS and VLBI: How it Improves Earth Orientation and Reference Frames

NASA Astrophysics Data System (ADS)

Lambert, S. B.; Richard, J. Y.; Bizouard, C.; Becker, O.

2017-12-01

Current reference series (C04) of the International Earth Rotation and Reference Systems Service (IERS) are produced by a weighted combination of Earth orientation parameters (EOP) time series built up by combination centers of each technique (VLBI, GNSS, Laser ranging, DORIS). In the future, we plan to derive EOP from a rigorous combination of the normal equation systems of the four techniques.We present here the results of a rigorous combination of VLBI and GNSS pre-reduced, constraint-free, normal equations with the DYNAMO geodetic analysis software package developed and maintained by the French GRGS (Groupe de Recherche en GeÌodeÌsie Spatiale). The used normal equations are those produced separately by the IVS and IGS combination centers to which we apply our own minimal constraints.We address the usefulness of such a method with respect to the classical, a posteriori, combination method, and we show whether EOP determinations are improved.Especially, we implement external validations of the EOP series based on comparison with geophysical excitation and examination of the covariance matrices. Finally, we address the potential of the technique for the next generation celestial reference frames, which are currently determined by VLBI only.

Towards higher stability of resonant absorption measurements in pulsed plasmas.

PubMed

Britun, Nikolay; Michiels, Matthieu; Snyders, Rony

2015-12-01

Possible ways to increase the reliability of time-resolved particle density measurements in pulsed gaseous discharges using resonant absorption spectroscopy are proposed. A special synchronization, called "dynamic source triggering," between a gated detector and two pulsed discharges, one representing the discharge of interest and another being used as a reference source, is developed. An internal digital delay generator in the intensified charge coupled device camera, used at the same time as a detector, is utilized for this purpose. According to the proposed scheme, the light pulses from the reference source follow the gates of detector, passing through the discharge of interest only when necessary. This allows for the utilization of short-pulse plasmas as reference sources, which is critical for time-resolved absorption analysis of strongly emitting pulsed discharges. In addition to dynamic source triggering, the reliability of absorption measurements can be further increased using simultaneous detection of spectra relevant for absorption method, which is also demonstrated in this work. The proposed methods are illustrated by the time-resolved measurements of the metal atom density in a high-power impulse magnetron sputtering (HiPIMS) discharge, using either a hollow cathode lamp or another HiPIMS discharge as a pulsed reference source.

Enumeration of total aerobic microorganisms in foods by SimPlate Total Plate Count-Color Indicator methods and conventional culture methods: collaborative study.

PubMed

Feldsine, Philip T; Leung, Stephanie C; Lienau, Andrew H; Mui, Linda A; Townsend, David E

2003-01-01

The relative efficacy of the SimPlate Total Plate Count-Color Indicator (TPC-CI) method (SimPlate 35 degrees C) was compared with the AOAC Official Method 966.23 (AOAC 35 degrees C) for enumeration of total aerobic microorganisms in foods. The SimPlate TPC-CI method, incubated at 30 degrees C (SimPlate 30 degrees C), was also compared with the International Organization for Standardization (ISO) 4833 method (ISO 30 degrees C). Six food types were analyzed: ground black pepper, flour, nut meats, frozen hamburger patties, frozen fruits, and fresh vegetables. All foods tested were naturally contaminated. Nineteen laboratories throughout North America and Europe participated in the study. Three method comparisons were conducted. In general, there was <0.3 mean log count difference in recovery among the SimPlate methods and their corresponding reference methods. Mean log counts between the 2 reference methods were also very similar. Repeatability (Sr) and reproducibility (SR) standard deviations were similar among the 3 method comparisons. The SimPlate method (35 degrees C) and the AOAC method were comparable for enumerating total aerobic microorganisms in foods. Similarly, the SimPlate method (30 degrees C) was comparable to the ISO method when samples were prepared and incubated according to the ISO method.

Optimal Reference Genes for Gene Expression Normalization in Trichomonas vaginalis.

PubMed

dos Santos, Odelta; de Vargas Rigo, Graziela; Frasson, Amanda Piccoli; Macedo, Alexandre José; Tasca, Tiana

2015-01-01

Trichomonas vaginalis is the etiologic agent of trichomonosis, the most common non-viral sexually transmitted disease worldwide. This infection is associated with several health consequences, including cervical and prostate cancers and HIV acquisition. Gene expression analysis has been facilitated because of available genome sequences and large-scale transcriptomes in T. vaginalis, particularly using quantitative real-time polymerase chain reaction (qRT-PCR), one of the most used methods for molecular studies. Reference genes for normalization are crucial to ensure the accuracy of this method. However, to the best of our knowledge, a systematic validation of reference genes has not been performed for T. vaginalis. In this study, the transcripts of nine candidate reference genes were quantified using qRT-PCR under different cultivation conditions, and the stability of these genes was compared using the geNorm and NormFinder algorithms. The most stable reference genes were α-tubulin, actin and DNATopII, and, conversely, the widely used T. vaginalis reference genes GAPDH and β-tubulin were less stable. The PFOR gene was used to validate the reliability of the use of these candidate reference genes. As expected, the PFOR gene was upregulated when the trophozoites were cultivated with ferrous ammonium sulfate when the DNATopII, α-tubulin and actin genes were used as normalizing gene. By contrast, the PFOR gene was downregulated when the GAPDH gene was used as an internal control, leading to misinterpretation of the data. These results provide an important starting point for reference gene selection and gene expression analysis with qRT-PCR studies of T. vaginalis.

Optimal Reference Genes for Gene Expression Normalization in Trichomonas vaginalis

PubMed Central

dos Santos, Odelta; de Vargas Rigo, Graziela; Frasson, Amanda Piccoli; Macedo, Alexandre José; Tasca, Tiana

2015-01-01

Trichomonas vaginalis is the etiologic agent of trichomonosis, the most common non-viral sexually transmitted disease worldwide. This infection is associated with several health consequences, including cervical and prostate cancers and HIV acquisition. Gene expression analysis has been facilitated because of available genome sequences and large-scale transcriptomes in T. vaginalis, particularly using quantitative real-time polymerase chain reaction (qRT-PCR), one of the most used methods for molecular studies. Reference genes for normalization are crucial to ensure the accuracy of this method. However, to the best of our knowledge, a systematic validation of reference genes has not been performed for T. vaginalis. In this study, the transcripts of nine candidate reference genes were quantified using qRT-PCR under different cultivation conditions, and the stability of these genes was compared using the geNorm and NormFinder algorithms. The most stable reference genes were α-tubulin, actin and DNATopII, and, conversely, the widely used T. vaginalis reference genes GAPDH and β-tubulin were less stable. The PFOR gene was used to validate the reliability of the use of these candidate reference genes. As expected, the PFOR gene was upregulated when the trophozoites were cultivated with ferrous ammonium sulfate when the DNATopII, α-tubulin and actin genes were used as normalizing gene. By contrast, the PFOR gene was downregulated when the GAPDH gene was used as an internal control, leading to misinterpretation of the data. These results provide an important starting point for reference gene selection and gene expression analysis with qRT-PCR studies of T. vaginalis. PMID:26393928

A comparison of the coupled cluster and internally contracted averaged coupled-pair functional levels of theory for the calculation of the MCH2(+) binding energies for M = Sc to Cu

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Scuseria, Gustavo E.

1992-01-01

The correlation contribution to the M-C binding energy for the MCH2(+) systems can exceed 100 kcal/mol. At the self-consistent field (SCF) level, these systems can be more than 50 kcal/mol above the fragment energies. In spite of the poor zeroth-order reference, the coupled cluster single and double excitation method with a perturbational estimate of triple excitations, CCSD(T), method is shown to provide an accurate description of these systems. The maximum difference between the CCSD(T) and internally contracted averaged coupled-pair functional binding energies is 1.5 kcal/mol for CrCH2(+), with the remaining systems agreeing to within 1.0 kcal/mol.

CoFe-microwires with stress-dependent magnetostriction as embedded sensing elements

NASA Astrophysics Data System (ADS)

Salem, M. M.; Nematov, M. G.; Uddin, A.; Panina, L. V.; Churyukanova, M. N.; Marchenko, A. T.

2017-10-01

Testing internal stress/strain condition of polymer composite materials is of high importance in structural health monitoring. We are presenting here a new method of monitoring internal stresses. The method can be referred to as embedded sensing technique, where the sensing element is a glass-coated ferromagnetic microwire with a specific magnetic anisotropy and stress-dependent magnetostriction. When the microwire is remagnetized the sharp voltage is induced which is characterized by high frequency harmonics. The amplitude of these harmonics sensitively depends on various stresses. The microwire of composition Co71Fe5B11Si10Cr3 with the metallic core diameter of 22.8 μm show abrupt transformation of the magnetization process under applied tensile stress owing to the stress-dependent magnetostriction.

The International Standard for Anti-Brucella abortus Serum

PubMed Central

Stableforth, A. W.

1954-01-01

In field trials on the eradication of brucellosis from dairy herds in Great Britain, which began in 1933, a serum standard of reference was used for the examination of agglutinating suspensions prepared in different laboratories. In 1937, the Office International des Epizooties (OIE) adopted this standard and made recommendations for its use internationally. These recommendations were revised by OIE in 1948, by the Third Inter-American Congress on Brucellosis and by the Joint FAO/WHO Expert Panel on Brucellosis in 1950, and again by the latter body in 1952. A new batch equivalent in potency to the original standard was established by the WHO Expert Committee on Biological Standardization in 1952 as the International Standard for Anti-Brucella abortus Serum. The International Standard, or a national standard of equivalent potency, ensures comparability of the titres obtained in different countries by different methods, and the results of such comparisons can be expressed in a simple manner by describing the titres in terms of International Units of Brucella antibody. PMID:13199656

International collaborative study of the endogenous reference gene, sucrose phosphate synthase (SPS), used for qualitative and quantitative analysis of genetically modified rice.

PubMed

Jiang, Lingxi; Yang, Litao; Zhang, Haibo; Guo, Jinchao; Mazzara, Marco; Van den Eede, Guy; Zhang, Dabing

2009-05-13

One rice ( Oryza sativa ) gene, sucrose phosphate synthase (SPS), has been proven to be a suitable endogenous reference gene for genetically modified (GM) rice detection in a previous study. Herein are the reported results of an international collaborative ring trial for validation of the SPS gene as an endogenous reference gene and its optimized qualitative and quantitative polymerase chain reaction (PCR) systems. A total of 12 genetically modified organism (GMO) detection laboratories from seven countries participated in the ring trial and returned their results. The validated results confirmed the species specificity of the method through testing 10 plant genomic DNAs, low heterogeneity, and a stable single-copy number of the rice SPS gene among 7 indica varieties and 5 japonica varieties. The SPS qualitative PCR assay was validated with a limit of detection (LOD) of 0.1%, which corresponded to about 230 copies of haploid rice genomic DNA, while the limit of quantification (LOQ) for the quantitative PCR system was about 23 copies of haploid rice genomic DNA, with acceptable PCR efficiency and linearity. Furthermore, the bias between the test and true values of eight blind samples ranged from 5.22 to 26.53%. Thus, we believe that the SPS gene is suitable for use as an endogenous reference gene for the identification and quantification of GM rice and its derivates.

Observational study: microgravity testing of a phase-change reference on the International Space Station

PubMed Central

Topham, T Shane; Bingham, Gail E; Latvakoski, Harri; Podolski, Igor; Sychev, Vladimir S; Burdakin, Andre

2015-01-01

Background: Orbital sensors to monitor global climate change during the next decade require low-drift rates for onboard thermometry, which is currently unattainable without on-orbit recalibration. Phase-change materials (PCMs), such as those that make up the ITS-90 standard, are seen as the most reliable references on the ground and could be good candidates for orbital recalibration. Space Dynamics Lab (SDL) has been developing miniaturized phase-change references capable of deployment on an orbital blackbody for nearly a decade. Aims: Improvement of orbital temperature measurements for long duration earth observing and remote sensing. Methods: To determine whether and how microgravity will affect the phase transitions, SDL conducted experiments with ITS-90 standard material (gallium, Ga) on the International Space Station (ISS) and compared the phase-change temperature with earth-based measurements. The miniature on-orbit thermal reference (MOTR) experiment launched to the ISS in November 2013 on Soyuz TMA-11M with the Expedition 38 crew and returned to Kazakhstan in March 2014 on the Soyuz TMA-10 spacecraft. Results: MOTR tested melts and freezes of Ga using repeated 6-h cycles. Melt cycles obtained on the ground before and after launch were compared with those obtained on the ISS. Conclusions: To within a few mK uncertainty, no significant difference between the melt temperature of Ga at 1 g and in microgravity was observed. PMID:28725713

[Child-juvenile prostitution: a systematic literature review].

PubMed

Ribeiro, Moneda Oliveira; Dias, Aretuzza de Fátima

2009-06-01

The purpose of this study was to understand how infant-juvenile prostitution is being explained by researchers through an extensive bibliographical survey on national and international scientific sources. It was possible to access 20 references in full text form, which were analyzed according to the Content Analysis method. The analysis consisted in answering how infant-juvenile prostitution is represented by the author in relation to the concepts, causes, effects and solutions described in the references. It was found that the authors approached the subject as a way of survival, resulting from an unequal society, adult-centered and male chauvinist causing mental and physical diseases in children.

Climate change

USGS Publications Warehouse

Cronin, Thomas M.

2016-01-01

Climate change (including climate variability) refers to regional or global changes in mean climate state or in patterns of climate variability over decades to millions of years often identified using statistical methods and sometimes referred to as changes in long-term weather conditions (IPCC, 2012). Climate is influenced by changes in continent-ocean configurations due to plate tectonic processes, variations in Earth’s orbit, axial tilt and precession, atmospheric greenhouse gas (GHG) concentrations, solar variability, volcanism, internal variability resulting from interactions between the atmosphere, oceans and ice (glaciers, small ice caps, ice sheets, and sea ice), and anthropogenic activities such as greenhouse gas emissions and land use and their effects on carbon cycling.

[On the way to national reference system of laboratory medicine].

PubMed

Muravskaia, N P; Men'shikov, V V

2014-10-01

The application of standard samples and reference techniques of implementation of measurements is needed for a valid support of reliability of analyses applied in clinical diagnostic laboratories. They play role of landmarks under metrologic monitoring, calibration of devices and control of quality of results. The article presents analysis of shortcomings interfering with formation of national reference system in Russia harmonized with possibilities provided by international organizations. Among them are the joint Committee on metrologic monitoring in laboratory medicine under the auspices of the International Bureau of Weights and Measures, the International Federation of clinical chemistry and laboratory medicine, etc. The results of the recent development of national normative documents, standard samples and techniques assisted by the authors of article are considered. They are the first steps to organization of national reference system which would comprise all range of modern analytical technologies of laboratory medicine. The national and international measures are proposed to enhance the promptest resolving of task of organization of national reference system for laboratory medicine in the interests of increasing of effectiveness of medical care to citizen of Russia.

An Adaptive Filter for the Removal of Drifting Sinusoidal Noise Without a Reference.

PubMed

Kelly, John W; Siewiorek, Daniel P; Smailagic, Asim; Wang, Wei

2016-01-01

This paper presents a method for filtering sinusoidal noise with a variable bandwidth filter that is capable of tracking a sinusoid's drifting frequency. The method, which is based on the adaptive noise canceling (ANC) technique, will be referred to here as the adaptive sinusoid canceler (ASC). The ASC eliminates sinusoidal contamination by tracking its frequency and achieving a narrower bandwidth than typical notch filters. The detected frequency is used to digitally generate an internal reference instead of relying on an external one as ANC filters typically do. The filter's bandwidth adjusts to achieve faster and more accurate convergence. In this paper, the focus of the discussion and the data is physiological signals, specifically electrocorticographic (ECoG) neural data contaminated with power line noise, but the presented technique could be applicable to other recordings as well. On simulated data, the ASC was able to reliably track the noise's frequency, properly adjust its bandwidth, and outperform comparative methods including standard notch filters and an adaptive line enhancer. These results were reinforced by visual results obtained from real ECoG data. The ASC showed that it could be an effective method for increasing signal to noise ratio in the presence of drifting sinusoidal noise, which is of significant interest for biomedical applications.

International Laser Ranging Service (ILRS) 2003-2004 Annual Report

NASA Technical Reports Server (NTRS)

Pearlman, Michael (Editor); Noll, Carey (Editor)

2005-01-01

The International Laser Ranging Service (ILRS) organizes and coordinates Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) to support programs in geodetic, geophysical, and lunar research activities and provides the International Earth Rotation and Reference Systems Service (IERS) with products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). This reference frame provides the stability through which systematic measurements of the Earth can be made over thousands of kilometers, decades of time, and evolution of measurement technology. This 2003-2004 ILRS annual report is comprised of individual contributions from ILRS components within the international geodetic community for the years 2003-2004. The report documents changes and progress of the ILRS and is also available on the ILRS Web site at http://ilrs.gsfc.nasa.gov/reports/ilrs_reports/ilrsar_2003.html.

A Kernel-Free Particle-Finite Element Method for Hypervelocity Impact Simulation. Chapter 4

NASA Technical Reports Server (NTRS)

Park, Young-Keun; Fahrenthold, Eric P.

2004-01-01

An improved hybrid particle-finite element method has been developed for the simulation of hypervelocity impact problems. Unlike alternative methods, the revised formulation computes the density without reference to any kernel or interpolation functions, for either the density or the rate of dilatation. This simplifies the state space model and leads to a significant reduction in computational cost. The improved method introduces internal energy variables as generalized coordinates in a new formulation of the thermomechanical Lagrange equations. Example problems show good agreement with exact solutions in one dimension and good agreement with experimental data in a three dimensional simulation.

Nuclear reference materials to meet the changing needs of the global nuclear community

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

Martin, H.R.; Gradle, C.G.; Narayanan, U.I.

New Brunswick Laboratory (NBL) serves as the US Government`s Certifying Authority for nuclear reference materials and measurement calibration standards. In this role, NBL provides nuclear reference materials certified for chemical and/or isotopic compositions traceable to a nationally accepted, internationally compatible reference base. Emphasis is now changing as to the types of traceable nuclear reference materials needed as operations change within the Department of Energy (DOE) complex and at nuclear facilities around the world. Environmental and waste minimization issues, facilities and materials transitioning from processing to storage modes with corresponding changes in the types of measurements being performed, emphasis on requirementsmore » for characterization of waste materials, difficulties in transporting nuclear materials, and International factors, including International Atomic Energy Agency (IAEA) inspection of excess US nuclear materials, are all contributing influences. During these changing times, ft is critical that traceable reference materials be provided for calibration or validation of the performance of measurement systems. This paper will describe actions taken and planned to meet the changing reference material needs of the global nuclear community.« less

Hydrophilic interaction liquid chromatography of anthranilic acid-labelled oligosaccharides with a 4-aminobenzoic acid ethyl ester-labelled dextran hydrolysate internal standard.

PubMed

Neville, David C A; Alonzi, Dominic S; Butters, Terry D

2012-04-13

Hydrophilic interaction liquid chromatography (HILIC) of fluorescently labelled oligosaccharides is used in many laboratories to analyse complex oligosaccharide mixtures. Separations are routinely performed using a TSK gel-Amide 80 HPLC column, and retention times of different oligosaccharide species are converted to glucose unit (GU) values that are determined with reference to an external standard. However, if retention times were to be compared with an internal standard, consistent and more accurate GU values would be obtained. We present a method to perform internal standard-calibrated HILIC of fluorescently labelled oligosaccharides. The method relies on co-injection of 4-aminobenzoic acid ethyl ester (4-ABEE)-labelled internal standard and detection by UV absorption, with 2-AA (2-aminobenzoic acid)-labelled oligosaccharides. 4-ABEE is a UV chromophore and a fluorophore, but there is no overlap of the fluorescent spectrum of 4-ABEE with the commonly used fluorescent reagents. The dual nature of 4-ABEE allows for accurate calculation of the delay between UV and fluorescent signals when determining the GU values of individual oligosaccharides. The GU values obtained are inherently more accurate as slight differences in gradients that can influence retention are negated by use of an internal standard. Therefore, this paper provides the first method for determination of HPLC-derived GU values of fluorescently labelled oligosaccharides using an internal calibrant. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of fully internally and strongly contracted multireference configuration interaction procedures

NASA Astrophysics Data System (ADS)

Sivalingam, Kantharuban; Krupicka, Martin; Auer, Alexander A.; Neese, Frank

2016-08-01

Multireference (MR) methods occupy an important class of approaches in quantum chemistry. In many instances, for example, in studying complex magnetic properties of transition metal complexes, they are actually the only physically satisfactory choice. In traditional MR approaches, single and double excitations are performed with respect to all reference configurations (or configuration state functions, CSFs), which leads to an explosive increase of computational cost for larger reference spaces. This can be avoided by the internal contraction scheme proposed by Meyer and Siegbahn, which effectively reduces the number of wavefunction parameters to their single-reference counterpart. The "fully internally contracted" scheme (FIC) is well known from the popular CASPT2 approach. An even shorter expansion of the wavefunction is possible with the "strong contraction" (SC) scheme proposed by Angeli and Malrieu in their NEVPT2 approach. Promising multireference configuration interaction formulations (MRCI) employing internal contraction and strong contraction have been reported by several authors. In this work, we report on the implementation of the FIC-MRCI and SC-MRCI methodologies, using a computer assisted implementation strategy. The methods are benchmarked against the traditional uncontracted MRCI approach for ground and excited states of small molecules (N2, O2, CO, CO+, OH, CH, and CN). For ground states, the comparison includes the "partially internally contracted" MRCI based on the Celani-Werner ansatz (PC-MRCI). For the three contraction schemes, the average errors range from 2% to 6% of the uncontracted MRCI correlation energies. Excitation energies are reproduced with ˜0.2 eV accuracy. In most cases, the agreement is better than 0.2 eV, even in cases with very large differential correlation contributions as exemplified for the d-d and ligand-to-metal charge transfer transitions of a Cu [NH 3 ] 4 2 + model complex. The benchmark is supplemented with the investigation of typical potential energy surfaces (i.e., N2, HF, LiF, BeH2, ethane C-C bond stretching, and the ethylene double bond torsion). Our results indicate that the SC-scheme, which is successful in the context of second- and third-order perturbation theory, does not offer computational advantages and at the same time leads to much larger errors than the PC and FIC schemes. We discuss the advantages and disadvantages of the PC and FIC schemes, which are of comparable accuracy and, for the systems tested, also of comparable efficiency.

Certified Reference Material for Use in 1H, 31P, and 19F Quantitative NMR, Ensuring Traceability to the International System of Units.

PubMed

Rigger, Romana; Rück, Alexander; Hellriegel, Christine; Sauermoser, Robert; Morf, Fabienne; Breitruck, KathrinBreitruck; Obkircher, Markus

2017-09-01

In recent years, quantitative NMR (qNMR) spectroscopy has become one of the most important tools for content determination of organic substances and quantitative evaluation of impurities. Using Certified Reference Materials (CRMs) as internal or external standards, the extensively used qNMR method can be applied for purity determination, including unbroken traceability to the International System of Units (SI). The implementation of qNMR toward new application fields, e.g., metabolomics, environmental analysis, and physiological pathway studies, brings along more complex molecules and systems, thus making use of 1H qNMR challenging. A smart workaround is possible by the use of other NMR active nuclei, namely 31P and 19F. This article presents the development of three classes of qNMR CRMs based on different NMR active nuclei (1H, 31P, and 19F), and the corresponding approaches to establish traceability to the SI through primary CRMs from the National Institute of Standards and Technology and the National Metrology Institute of Japan. These TraceCERT® qNMR CRMs are produced under ISO/IEC 17025 and ISO Guide 34 using high-performance qNMR.

Validation of endogenous internal real-time PCR controls in renal tissues.

PubMed

Cui, Xiangqin; Zhou, Juling; Qiu, Jing; Johnson, Martin R; Mrug, Michal

2009-01-01

Endogenous internal controls ('reference' or 'housekeeping' genes) are widely used in real-time PCR (RT-PCR) analyses. Their use relies on the premise of consistently stable expression across studied experimental conditions. Unfortunately, none of these controls fulfills this premise across a wide range of experimental conditions; consequently, none of them can be recommended for universal use. To determine which endogenous RT-PCR controls are suitable for analyses of renal tissues altered by kidney disease, we studied the expression of 16 commonly used 'reference genes' in 7 mildly and 7 severely affected whole kidney tissues from a well-characterized cystic kidney disease model. Expression levels of these 16 genes, determined by TaqMan RT-PCR analyses and Affymetrix GeneChip arrays, were normalized and tested for overall variance and equivalence of the means. Both statistical approaches and both TaqMan- and GeneChip-based methods converged on 3 out of the 4 top-ranked genes (Ppia, Gapdh and Pgk1) that had the most constant expression levels across the studied phenotypes. A combination of the top-ranked genes will provide a suitable endogenous internal control for similar studies of kidney tissues across a wide range of disease severity. Copyright 2009 S. Karger AG, Basel.

Alternative microbial methods: An overview and selection criteria.

PubMed

Jasson, Vicky; Jacxsens, Liesbeth; Luning, Pieternel; Rajkovic, Andreja; Uyttendaele, Mieke

2010-09-01

This study provides an overview and criteria for the selection of a method, other than the reference method, for microbial analysis of foods. In a first part an overview of the general characteristics of rapid methods available, both for enumeration and detection, is given with reference to relevant bibliography. Perspectives on future development and the potential of the rapid method for routine application in food diagnostics are discussed. As various alternative "rapid" methods in different formats are available on the market, it can be very difficult for a food business operator or for a control authority to select the most appropriate method which fits its purpose. Validation of a method by a third party, according to international accepted protocol based upon ISO 16140, may increase the confidence in the performance of a method. A list of at the moment validated methods for enumeration of both utility indicators (aerobic plate count) and hygiene indicators (Enterobacteriaceae, Escherichia coli, coagulase positive Staphylococcus) as well as for detection of the four major pathogens (Salmonella spp., Listeria monocytogenes, E. coli O157 and Campylobacter spp.) is included with reference to relevant websites to check for updates. In a second part of this study, selection criteria are introduced to underpin the choice of the appropriate method(s) for a defined application. The selection criteria link the definition of the context in which the user of the method functions - and thus the prospective use of the microbial test results - with the technical information on the method and its operational requirements and sustainability. The selection criteria can help the end user of the method to obtain a systematic insight into all relevant factors to be taken into account for selection of a method for microbial analysis. Copyright 2010 Elsevier Ltd. 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).

Imaging Lenticular Autofluorescence in Older Subjects.

PubMed

Charng, Jason; Tan, Rose; Luu, Chi D; Sadigh, Sam; Stambolian, Dwight; Guymer, Robyn H; Jacobson, Samuel G; Cideciyan, Artur V

2017-10-01

To evaluate whether a practical method of imaging lenticular autofluorescence (AF) can provide an individualized measure correlated with age-related lens yellowing in older subjects undergoing tests involving shorter wavelength lights. Lenticular AF was imaged with 488-nm excitation using a confocal scanning laser ophthalmoscope (cSLO) routinely used for retinal AF imaging. There were 75 older subjects (ages 47-87) at two sites; a small cohort of younger subjects served as controls. At one site, the cSLO was equipped with an internal reference to allow quantitative AF measurements; at the other site, reduced-illuminance AF imaging (RAFI) was used. In a subset of subjects, lens density index was independently estimated from dark-adapted spectral sensitivities performed psychophysically. Lenticular AF intensity was significantly higher in the older eyes than the younger cohort when measured with the internal reference (59.2 ± 15.4 vs. 134.4 ± 31.7 gray levels; P < 0.05) as well as when recorded with RAFI without the internal reference (10.9 ± 1.5 vs. 26.1 ± 5.7 gray levels; P < 0.05). Lenticular AF was positively correlated with age; however, there could also be large differences between individuals of similar age. Lenticular AF intensity correlated well with lens density indices estimated from psychophysical measures. Lenticular AF measured with a retinal cSLO can provide a practical and individualized measure of lens yellowing, and may be a good candidate to distinguish between preretinal and retinal deficits involving short-wavelength lights in older eyes.

[Interest and limits of inductively coupled plasma mass spectrometry (ICP-MS) for urinary diagnosis of radionuclide internal contamination].

PubMed

Lecompte, Yannick; Bohand, Sandra; Laroche, Pierre; Cazoulat, Alain

2013-01-01

After a review of radiometric reference methods used in radiotoxicology, analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the workplace urinary diagnosis of internal contamination by radionuclides are evaluated. A literature review (covering the period from 2000 to 2012) is performed to identify the different applications of ICP-MS in radiotoxicology for urine analysis. The limits of detection are compared to the recommendations of the International commission on radiological protection (ICRP 78: "Individual monitoring for internal exposure of workers"). Except one publication describing the determination of strontium-90 (β emitter), all methods using ICP-MS reported in the literature concern actinides (α emitters). For radionuclides with a radioactive period higher than 10(4) years, limits of detection are most often in compliance with ICRP publication 78 and frequently lower than radiometric methods. ICP-MS allows the specific determination of plutonium-239 + 240 isotopes which cannot be discriminated by α spectrometry. High resolution ICP-MS can also measure uranium isotopic ratios in urine for total uranium concentrations lower than 20 ng/L. The interest of ICP-MS in radiotoxicology concerns essentially the urinary measurement of long radioactive period actinides, particularly for uranium isotope ratio determination and 239 and 240 plutonium isotopes discrimination. Radiometric methods remain the most efficient for the majority of other radionuclides.

Analytical Methods for Determining the Motion of a Rigid Body Equipped with Internal Motion-Sensing Transducers

DTIC Science & Technology

1976-10-01

should be easily converted into software for use on high-speed digital computers. Since no readily available references were found containing relationships...L31 Library 1 ONR Boston 4 NSWC, White Oak 1 J.E. Goeller 1 ONR Chicago 1 V.C.D. Dawson 1 H.K. Steves 1 ONR Pasadena 1 Libary 1 NRL/CODE 2627 Lib 1

The Iranian Version of the Exercise Self-Efficacy Scale (ESES): Factor Structure, Internal Consistency and Construct Validity

ERIC Educational Resources Information Center

Noroozi, Azita; Ghofranipour, Fazlollah; Heydarnia, Ali Reza; Nabipour, Iraj; Tahmasebi, Rahim; Tavafian, Sedighe Sadat

2011-01-01

Purpose: The exercise self-efficacy scale (ESES) is largely used among diabetic patients to enhance exercise behaviour. However, the Iranian version of ESES was not available. The aim of this study was to validate ESES in this country. Method: Data were collected from 348 women who referred to a diabetes institute in Iran through convenience…

Desertification. (Latest citations from the Biobusiness database). Published Search

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

Not Available

1993-09-01

The bibliography contains citations concerning desertification. Citations reference satellite monitoring; methods to halt or reverse desertification; and international treaties and national policies to stop desertification. Desertification causes, including cattle overgrazing, salinization, deforestation, and soil erosion, are discussed. Analyses of how desertification contributes to global warming and famine are described. (Contains a minimum of 54 citations and includes a subject term index and title list.)

40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

Code of Federal Regulations, 2014 CFR

2014-07-01

... or an alternative external leak test technique may be required for samplers whose design or... alternative internal, filter bypass leak test technique may be required for samplers whose design or... variation or better has been established for the operational precision of PM2.5 monitoring data. 5.1 Tests...

Proceedings of International Conference on Oral Education of the Deaf. Volume II (Northampton, Massachusetts, June 17-21, 1967; New York, New York, June 22-24, 1967).

ERIC Educational Resources Information Center

Clarke School for the Deaf, Northampton, MA.

Papers from five plenary sessions and a number of sectional meetings consider oral education of the deaf. Elementary and secondary deaf education programs are discussed with reference to teaching the multiply handicapped, curriculum development, programed instruction, and teaching methods and materials. The following are also treated: the subject…

Motivation and Dual Enrollment: An Analysis of the Motivation of High School Students to Participate in Dual Enrollment in Association of Christian Schools International Schools

ERIC Educational Resources Information Center

Salerno, Mitchell Acri

2011-01-01

A phenomenological study utilizing the Consensual Qualitative Research method was conducted to understand the motivation of high school students dually enrolled in high school and college, commonly referred to as dual enrollment, in relation to the Self-Determination Theory and to connect this motivation to research on personal calling. This…

40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

Code of Federal Regulations, 2012 CFR

2012-07-01

... or an alternative external leak test technique may be required for samplers whose design or... alternative internal, filter bypass leak test technique may be required for samplers whose design or... variation or better has been established for the operational precision of PM2.5 monitoring data. 5.1 Tests...

40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

Code of Federal Regulations, 2013 CFR

2013-07-01

... or an alternative external leak test technique may be required for samplers whose design or... alternative internal, filter bypass leak test technique may be required for samplers whose design or... variation or better has been established for the operational precision of PM2.5 monitoring data. 5.1 Tests...

Estimating alcohol content of traditional brew in Western Kenya using culturally relevant methods: the case for cost over volume.

PubMed

Papas, Rebecca K; Sidle, John E; Wamalwa, Emmanuel S; Okumu, Thomas O; Bryant, Kendall L; Goulet, Joseph L; Maisto, Stephen A; Braithwaite, R Scott; Justice, Amy C

2010-08-01

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang'aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang'aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang'aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang'aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard.

Datum maintenance of the main Egyptian geodetic control networks by utilizing Precise Point Positioning "PPP" technique

NASA Astrophysics Data System (ADS)

Rabah, Mostafa; Elmewafey, Mahmoud; Farahan, Magda H.

2016-06-01

A geodetic control network is the wire-frame or the skeleton on which continuous and consistent mapping, Geographic Information Systems (GIS), and surveys are based. Traditionally, geodetic control points are established as permanent physical monuments placed in the ground and precisely marked, located, and documented. With the development of satellite surveying methods and their availability and high degree of accuracy, a geodetic control network could be established by using GNSS and referred to an international terrestrial reference frame used as a three-dimensional geocentric reference system for a country. Based on this concept, in 1992, the Egypt Survey Authority (ESA) established two networks, namely High Accuracy Reference Network (HARN) and the National Agricultural Cadastral Network (NACN). To transfer the International Terrestrial Reference Frame to the HARN, the HARN was connected with four IGS stations. The processing results were 1:10,000,000 (Order A) for HARN and 1:1,000,000 (Order B) for NACN relative network accuracy standard between stations defined in ITRF1994 Epoch1996. Since 1996, ESA did not perform any updating or maintaining works for these networks. To see how non-performing maintenance degrading the values of the HARN and NACN, the available HARN and NACN stations in the Nile Delta were observed. The Processing of the tested part was done by CSRS-PPP Service based on utilizing Precise Point Positioning "PPP" and Trimble Business Center "TBC". The study shows the feasibility of Precise Point Positioning in updating the absolute positioning of the HARN network and its role in updating the reference frame (ITRF). The study also confirmed the necessity of the absent role of datum maintenance of Egypt networks.

Validation of Reference Genes for Quantitative Expression Analysis by Real-Time RT-PCR in Four Lepidopteran Insects

PubMed Central

Teng, Xiaolu; Zhang, Zan; He, Guiling; Yang, Liwen; Li, Fei

2012-01-01

Quantitative real-time polymerase chain reaction (qPCR) is an efficient and widely used technique to monitor gene expression. Housekeeping genes (HKGs) are often empirically selected as the reference genes for data normalization. However, the suitability of HKGs used as the reference genes has been seldom validated. Here, six HKGs were chosen (actin A3, actin A1, GAPDH, G3PDH, E2F, rp49) in four lepidopteran insects Bombyx mori L. (Lepidoptera: Bombycidae), Plutella xylostella L. (Plutellidae), Chilo suppressalis Walker (Crambidae), and Spodoptera exigua Hübner (Noctuidae) to study their expression stability. The algorithms of geNorm, NormFinder, stability index, and ΔCt analysis were used to evaluate these HKGs. Across different developmental stages, actin A1 was the most stable in P. xylostella and C. suppressalis, but it was the least stable in B. mori and S. exigua. Rp49 and GAPDH were the most stable in B. mori and S. exigua, respectively. In different tissues, GAPDH, E2F, and Rp49 were the most stable in B. mori, S. exigua, and C. suppressalis, respectively. The relative abundances of Siwi genes estimated by 2-ΔΔCt method were tested with different HKGs as the reference gene, proving the importance of internal controls in qPCR data analysis. The results not only presented a list of suitable reference genes in four lepidopteran insects, but also proved that the expression stabilities of HKGs were different among evolutionarily close species. There was no single universal reference gene that could be used in all situations. It is indispensable to validate the expression of HKGs before using them as the internal control in qPCR. PMID:22938136

Validation of reference genes for quantitative expression analysis by real-time rt-PCR in four lepidopteran insects.

PubMed

Teng, Xiaolu; Zhang, Zan; He, Guiling; Yang, Liwen; Li, Fei

2012-01-01

Quantitative real-time polymerase chain reaction (qPCR) is an efficient and widely used technique to monitor gene expression. Housekeeping genes (HKGs) are often empirically selected as the reference genes for data normalization. However, the suitability of HKGs used as the reference genes has been seldom validated. Here, six HKGs were chosen (actin A3, actin A1, GAPDH, G3PDH, E2F, rp49) in four lepidopteran insects Bombyx mori L. (Lepidoptera: Bombycidae), Plutella xylostella L. (Plutellidae), Chilo suppressalis Walker (Crambidae), and Spodoptera exigua Hübner (Noctuidae) to study their expression stability. The algorithms of geNorm, NormFinder, stability index, and ΔCt analysis were used to evaluate these HKGs. Across different developmental stages, actin A1 was the most stable in P. xylostella and C. suppressalis, but it was the least stable in B. mori and S. exigua. Rp49 and GAPDH were the most stable in B. mori and S. exigua, respectively. In different tissues, GAPDH, E2F, and Rp49 were the most stable in B. mori, S. exigua, and C. suppressalis, respectively. The relative abundances of Siwi genes estimated by 2(-ΔΔCt) method were tested with different HKGs as the reference gene, proving the importance of internal controls in qPCR data analysis. The results not only presented a list of suitable reference genes in four lepidopteran insects, but also proved that the expression stabilities of HKGs were different among evolutionarily close species. There was no single universal reference gene that could be used in all situations. It is indispensable to validate the expression of HKGs before using them as the internal control in qPCR.

Prevalence of abnormal findings when adopting new national and international Global Lung Function Initiative reference values for spirometry in the Finnish general population

PubMed Central

Kainu, Annette; Lindqvist, Ari; Sovijärvi, Anssi R. A.

2016-01-01

Background New Finnish (Kainu2015) and international Global Lung Function Initiative (GLI2012) reference values for spirometry were recently published. The aim of this study is to compare the interpretative consequences of adopting these new reference values with older, currently used Finnish reference values (Viljanen1982) in the general population of native Finns. Methods Two Finnish general population samples including 1,328 adults (45% males) aged 21–74 years were evaluated. Airway obstruction was defined as a reduced ratio of forced expiratory volume in one second (FEV1)/forced vital capacity (FVC), possible restrictive pattern as reduced FVC, and decreased ventilatory capacity as reduced FEV1 below their respective 2.5th percentiles. The severity gradings of reduced lung function were also compared. Results Using the Kainu2015 reference values, the prevalence of airway obstruction in the population was 5.6%; using GLI2012 it was 4.0% and with Viljanen1982 it was 13.0%. Possible restrictive pattern was found in 4.2% using the Kainu2015 values, in 2.0% with GLI2012, and 7.9% with the Viljanen1982 values. The prevalence of decreased ventilatory capacity was 6.8, 4.0, and 13.3% with the Kainu2015, GLI2012 and Viljanen1982 values, respectively. Conclusions The application of the GLI2012 reference values underestimates the prevalence of abnormal spirometric findings in native Finns. The adoption of the Kainu2015 reference values reduces the prevalences of airways obstruction, decreased ventilatory capacity, and restrictive impairment by approximately 50%. Changing from the 2.5th percentile, the previously used lower limit of normal, to the 5th percentile recommended by the American Thoracic Society/European Respiratory Society will not increase the prevalence of abnormal findings in the implementation of spirometry reference values. PMID:27608270

Search Codes for a Bibliography for the Study of African International Relations

DTIC Science & Technology

1975-01-01

Soja (1970). A high speed ln-house reference system was needed to facilitate storage, search, and retrieval of bibliographic reference materlal...REfUBLIC 0F (N0R™ KUW KUWAIT LAB LABOR UNIONS, INTERNATIONAL ASPECTS l- LA LAND LOCKED NATIONS LAO LAOS LAT LATIN AliERICA LAW I AW, INTERNATIONAL...IOCRATIC PEOPLE’S REPUBLIC OF (NORTH) KÜS KOREA (SOUTH) KUW KUWA I T LAb LABOR UNIONS, INTERNATIONAL ASPECTS LAU LA )S I.AT LATIN AiiEUICA LAN

Japanese Society for Laboratory Hematology flow cytometric reference method of determining the differential leukocyte count: external quality assurance using fresh blood samples.

PubMed

Kawai, Y; Nagai, Y; Ogawa, E; Kondo, H

2017-04-01

To provide target values for the manufacturers' survey of the Japanese Society for Laboratory Hematology (JSLH), accurate standard data from healthy volunteers were needed for the five-part differential leukocyte count. To obtain such data, JSLH required an antibody panel that achieved high specificity (particularly for mononuclear cells) using simple gating procedures. We developed a flow cytometric method for determining the differential leukocyte count (JSLH-Diff) and validated it by comparison with the flow cytometric differential leukocyte count of the International Council for Standardization in Haematology (ICSH-Diff) and the manual differential count obtained by microscopy (Manual-Diff). First, the reference laboratory performed an imprecision study of JSLH-Diff and ICSH-Diff, as well as performing comparison among JSLH-Diff, Manual-Diff, and ICSH-Diff. Then two reference laboratories and seven participating laboratories performed imprecision and accuracy studies of JSLH-Diff, Manual-Diff, and ICSH-Diff. Simultaneously, six manufacturers' laboratories provided their own representative values by using automated hematology analyzers. The precision of both JSLH-Diff and ICSH-Diff methods was adequate. Comparison by the reference laboratory showed that all correlation coefficients, slopes and intercepts obtained by the JSLH-Diff, ICSH-Diff, and Manual-Diff methods conformed to the criteria. When the imprecision and accuracy of JSLH-Diff were assessed at seven laboratories, the CV% for lymphocytes, neutrophils, monocytes, eosinophils, and basophils was 0.5~0.9%, 0.3~0.7%, 1.7~2.6%, 3.0~7.9%, and 3.8~10.4%, respectively. More than 99% of CD45 positive leukocytes were identified as normal leukocytes by JSLH-Diff. When JSLH-Diff method were validated by comparison with Manual-Diff and ICSH-Diff, JSLH-Diff showed good performance as a reference method. © 2016 John Wiley & Sons Ltd.

Global standardization measurement of cerebral spinal fluid for Alzheimer's disease: an update from the Alzheimer's Association Global Biomarkers Consortium.

PubMed

Carrillo, Maria C; Blennow, Kaj; Soares, Holly; Lewczuk, Piotr; Mattsson, Niklas; Oberoi, Pankaj; Umek, Robert; Vandijck, Manu; Salamone, Salvatore; Bittner, Tobias; Shaw, Leslie M; Stephenson, Diane; Bain, Lisa; Zetterberg, Henrik

2013-03-01

Recognizing that international collaboration is critical for the acceleration of biomarker standardization efforts and the efficient development of improved diagnosis and therapy, the Alzheimer's Association created the Global Biomarkers Standardization Consortium (GBSC) in 2010. The consortium brings together representatives of academic centers, industry, and the regulatory community with the common goal of developing internationally accepted common reference standards and reference methods for the assessment of cerebrospinal fluid (CSF) amyloid β42 (Aβ42) and tau biomarkers. Such standards are essential to ensure that analytical measurements are reproducible and consistent across multiple laboratories and across multiple kit manufacturers. Analytical harmonization for CSF Aβ42 and tau will help reduce confusion in the AD community regarding the absolute values associated with the clinical interpretation of CSF biomarker results and enable worldwide comparison of CSF biomarker results across AD clinical studies. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

The International Celestial Reference Frame (ICRF) and the Relationship Between Frames

NASA Technical Reports Server (NTRS)

Ma, Chopo

2000-01-01

The International Celestial Reference Frame (ICRF), a catalog of VLBI source positions, is now the basis for astrometry and geodesy. Its construction and extension/maintenance will be discussed as well as the relationship of the ICRF, ITRF, and EOP/nutation.

Uranium and Calcium Isotope Ratio Measurements using the Modified Total Evaporation Method in TIMS

NASA Astrophysics Data System (ADS)

Richter, S.; Kuehn, H.; Berglund, M.; Hennessy, C.

2010-12-01

A new version of the "modified total evaporation" (MTE) method for isotopic analysis by multi-collector thermal ionization mass spectrometry (TIMS), with high analytical performance and designed in a more user-friendly and routinely applicable way, is described in detail. It is mainly being used for nuclear safeguards measurements of U and Pu and nuclear metrology, but can readily be applied to other scientific tasks in geochemistry, e.g. for Sr, Nd and Ca, as well. The development of the MTE method was organized in collaboration of several "key nuclear mass spectrometry laboratories", namely the New Brunswick Laboratory (NBL), the Institute for Transuranium Elements (ITU), the Safeguards Analytical Laboratory (now Safeguards Analytical Services, SGAS) of the International Atomic Energy Agency (IAEA) and the Institute for Reference Materials and Measurements (IRMM), with IRMM taking the leading role. The manufacturer of the TRITON TIMS instrument, Thermo Fisher Scientific, integrated this method into the software of the instrument. The development has now reached its goal to become a user-friendly and routinely useable method for uranium isotope ratio measurements with high precision and accuracy. Due to the use of the “total evaporation” (TE) method the measurement of the "major" uranium isotope ratio 235U/238U is routinely being performed with a precision of 0.01% to 0.02%. The use of a (certified) reference material measured under comparable conditions is emphasized to achieve an accuracy at a level of 0.02% - depending on the stated uncertainty of the certified value of the reference material. In contrast to the total evaporation method (TE), in the MTE method the total evaporation sequence is interrupted on a regular basis to allow for correction for background from peak tailing, internal calibration of a secondary electron multiplier (SEM) detector versus the Faraday cups, and ion source re-focusing. Therefore, the most significant improvement using the MTE method is in the analytical performance achieved for the "minor" ratios 234U/238U and 236U/238U. The MTE method is now routinely used at all collaborating laboratories and possibly more in the future. Additional applications for the MTE method, e.g. to take advantage of the good external precision in combination with the possibilities of internal background and detector calibrations or mass jumps between different cup configurations, are presented as well. One interesting application concerns new absolute isotope ratio measurements for Ca with an unprecedented level of accuracy. This is important because up to now most reported Ca isotope data are only calculated as relative deviations from a standard like NIST-SRM 915. Using the MTE method measurements on new gravimetrically prepared Ca isotope mixtures were performed. A significantly improved level of accuracy at the level of about 0.02% for both the 42Ca/40Ca and 44Ca/40Ca ratios was obtained.

Growth curves of preschool children in the northeast of iran: a population based study using quantile regression approach.

PubMed

Payande, Abolfazl; Tabesh, Hamed; Shakeri, Mohammad Taghi; Saki, Azadeh; Safarian, Mohammad

2013-01-14

Growth charts are widely used to assess children's growth status and can provide a trajectory of growth during early important months of life. The objectives of this study are going to construct growth charts and normal values of weight-for-age for children aged 0 to 5 years using a powerful and applicable methodology. The results compare with the World Health Organization (WHO) references and semi-parametric LMS method of Cole and Green. A total of 70737 apparently healthy boys and girls aged 0 to 5 years were recruited in July 2004 for 20 days from those attending community clinics for routine health checks as a part of a national survey. Anthropometric measurements were done by trained health staff using WHO methodology. The nonparametric quantile regression method obtained by local constant kernel estimation of conditional quantiles curves using for estimation of curves and normal values. The weight-for-age growth curves for boys and girls aged from 0 to 5 years were derived utilizing a population of children living in the northeast of Iran. The results were similar to the ones obtained by the semi-parametric LMS method in the same data. Among all age groups from 0 to 5 years, the median values of children's weight living in the northeast of Iran were lower than the corresponding values in WHO reference data. The weight curves of boys were higher than those of girls in all age groups. The differences between growth patterns of children living in the northeast of Iran versus international ones necessitate using local and regional growth charts. International normal values may not properly recognize the populations at risk for growth problems in Iranian children. Quantile regression (QR) as a flexible method which doesn't require restricted assumptions, proposed for estimation reference curves and normal values.

Collaborative study for the establishment of erythropoietin BRP batch 4.

PubMed

Burns, C; Bristow, A F; Daas, A; Costanzo, A

2015-01-01

The European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) for erythropoietin (EPO) is used as a working standard for potency determination of EPO preparations by in vivo bioassay as prescribed in the Ph. Eur. monograph Erythropoietin concentrated solution (1316). The BRP batch 3 was calibrated in 2006 and its stocks are depleted. The European Directorate for the Quality of Medicines & HealthCare (EDQM) thus initiated a project to calibrate a replacement batch in International Units against the WHO 3(rd) International Standard (IS) for Erythropoietin, recombinant, for bioassay (11/170). A Ph. Eur. Chemical Reference Substance (CRS) was established recently for use as reference in some of the physicochemical tests prescribed in the monograph. Therefore, the EPO BRP batch 4 was only calibrated for the normocythaemic and polycythaemic mouse in vivo bioassays described in the Assay section of the Ph. Eur. monograph (1316). The collaborative study involved seven laboratories from Europe, the USA and South America. The results confirmed that the candidate BRP (cBRP) is suitable for use as a reference preparation in the potency determination of EPO medicinal products by bioassay (using the normocythaemic or polycythaemic mouse methods). The outcome of the study enabled the Ph. Eur. Commission to establish the proposed standard as erythropoietin BRP batch 4 in November 2014 for use as a reference preparation solely for the polycythaemic and normocythaemic mouse bioassay, with an assigned potency of 13 000 IU/vial. Furthermore, the potency of BRP3 was confirmed during the study, thus warranting a good continuity of the IU.

On the establishment and maintenance of a modern conventional terrestrial reference system

NASA Technical Reports Server (NTRS)

Bock, Y.; Zhu, S. Y.

1982-01-01

The frame of the Conventional Terrestrial Reference System (CTS) is defined by an adopted set of coordinates, at a fundamental epoxh, of a global network of stations which contribute the vertices of a fundamental polyhedron. A method to estimate this set of coordinates using a combination of modern three dimensional geodetic systems is presented. Once established, the function of the CTS is twofold. The first is to monitor the external (or global) motions of the polyhedron with respect to the frame of a Conventional Inertial Reference System, i.e., those motions common to all stations. The second is to monitor the internal motions (or deformations) of the polyhedron, i.e., those motions that are not common to all stations. Two possible estimators for use in earth deformation analysis are given and their statistical and physical properties are described.

New reference materials for nitrogen-isotope-ratio measurements

USGS Publications Warehouse

Böhlke, John Karl; Gwinn, C. J.; Coplen, T. B.

1993-01-01

Three new reference materials were manufactured for calibration of relative stable nitrogen-isotope-ratio measurements: USGS25 (ammonium sulfate) d15N' = -30 per mil; USGS26 (ammonium sulfate) d15N' = +54 per mil; USGS32 (potassium nitrate) d15N' = +180 per mil, where d15N', relative to atmospheric nitrogen, is an approximate value subject to change following interlaboratory comparisons. These materials are isotopically homogeneous in aliquots at least as small as 10 µmol N2 (or about 1-2 mg of salt). The new reference materials greatly extend the range of d15N values of internationally distributed standards, and they allow normalization of d15N measurements over almost the full range of known natural isotope variation on Earth. The methods used to produce these materials may be adapted to produce homogeneous local laboratory standards for routine use.

Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision

PubMed Central

Ender, Andreas; Mehl, Albert

2014-01-01

Reference scanners are used in dental medicine to verify a lot of procedures. The main interest is to verify impression methods as they serve as a base for dental restorations. The current limitation of many reference scanners is the lack of accuracy scanning large objects like full dental arches, or the limited possibility to assess detailed tooth surfaces. A new reference scanner, based on focus variation scanning technique, was evaluated with regards to highest local and general accuracy. A specific scanning protocol was tested to scan original tooth surface from dental impressions. Also, different model materials were verified. The results showed a high scanning accuracy of the reference scanner with a mean deviation of 5.3 ± 1.1 µm for trueness and 1.6 ± 0.6 µm for precision in case of full arch scans. Current dental impression methods showed much higher deviations (trueness: 20.4 ± 2.2 µm, precision: 12.5 ± 2.5 µm) than the internal scanning accuracy of the reference scanner. Smaller objects like single tooth surface can be scanned with an even higher accuracy, enabling the system to assess erosive and abrasive tooth surface loss. The reference scanner can be used to measure differences for a lot of dental research fields. The different magnification levels combined with a high local and general accuracy can be used to assess changes of single teeth or restorations up to full arch changes. PMID:24836007

Simultaneous determination of glucose, triglycerides, urea, cholesterol, albumin and total protein in human plasma by Fourier transform infrared spectroscopy: direct clinical biochemistry without reagents.

PubMed

Jessen, Torben E; Höskuldsson, Agnar T; Bjerrum, Poul J; Verder, Henrik; Sørensen, Lars; Bratholm, Palle S; Christensen, Bo; Jensen, Lene S; Jensen, Maria A B

2014-09-01

Direct measurement of chemical constituents in complex biologic matrices without the use of analyte specific reagents could be a step forward toward the simplification of clinical biochemistry. Problems related to reagents such as production errors, improper handling, and lot-to-lot variations would be eliminated as well as errors occurring during assay execution. We describe and validate a reagent free method for direct measurement of six analytes in human plasma based on Fourier-transform infrared spectroscopy (FTIR). Blood plasma is analyzed without any sample preparation. FTIR spectrum of the raw plasma is recorded in a sampling cuvette specially designed for measurement of aqueous solutions. For each analyte, a mathematical calibration process is performed by a stepwise selection of wavelengths giving the optimal least-squares correlation between the measured FTIR signal and the analyte concentration measured by conventional clinical reference methods. The developed calibration algorithms are subsequently evaluated for their capability to predict the concentration of the six analytes in blinded patient samples. The correlation between the six FTIR methods and corresponding reference methods were 0.87

Analysis of internal flow characteristics of a smooth-disk water-brake dynamometer

NASA Technical Reports Server (NTRS)

Evans, D. G.

1973-01-01

The principal of absorbing power with an enclosed partially submerged rotating disk through the turbulent viscous shearing of water is discussed. Reference information is used to develop a flow model of the water brake. A method is then presented that uses vector diagrams to relate the effects of rotational flow, through flow, and secondary flow to power absorption. The method is used to describe the operating characteristics of an example 111-cm (43.7-in.) diameter water brake. Correlating performance parameters are developed in a dimensional analysis.

Isotope reference materials

USGS Publications Warehouse

Coplen, Tyler B.

2010-01-01

Measurement of the same isotopically homogeneous sample by any laboratory worldwide should yield the same isotopic composition within analytical uncertainty. International distribution of light element isotopic reference materials by the International Atomic Energy Agency and the U.S. National Institute of Standards and Technology enable laboratories to achieve this goal.

Establishment of the 2nd Korean national biological reference standard for blood coagulation factor VIII:C concentrate.

PubMed

Lee, Naery; Seo, Ji Suk; Kim, Jae Ok; Ban, Sang Ja

2017-05-01

Since the 1st Korean national biological reference standard for factor (F)VIII concentrate, established in 2001, has shown declining potency, we conducted this study to replace this standard with a 2nd Korean national biological reference standard for blood coagulation FVIII concentrate. The candidate materials for the 2nd standard were prepared in 8000 vials with 10 IU/ml of target potency, according to the approved manufacturing process of blood coagulation Factor VIII:C Monoclonal Antibody-purified, Freeze-dried Human Blood Coagulation Factor VIII:C. Potency was evaluated by one-stage clotting and chromogenic methods and the stability was confirmed to meet the specifications during a period of 73 months. Since the potencies obtained by the two methods differed significantly (P < 0.015), the values were determined separately according to the geometric means (8.9 and 7.4 IU/vial, respectively). The geometric coefficients of interlaboratory variability were 3.4% and 7.6% by the one-stage clotting and chromogenic assays, respectively. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Corrigendum to "Enhancing endmember selection in multiple endmember spectral mixture analysis (MESMA) for urban impervious surface area mapping using spectral angle and spectral distance parameters" [Int. J. Appl. Earth Observ. Geoinf. 33 (2014) 290-301

NASA Astrophysics Data System (ADS)

Fan, Fenglei; Deng, Yingbin

2015-04-01

Since publication, the authors have been advised of one prior methodological article not cited in our original paper. The missed reference from the paper is "Andreou, C., Karathanassi, V., 2012. A novel multiple endmember spectral mixture analysis using spectral angle distance. Geoscience and Remote Sensing Symposium (IGARSS) 2012 IEEE International, 4110-4113." This reference "Andreou, C., Karathanassi, V., 2012 in proceeding of IGARSS" should be cited in the Part 3 and Table 1, whereby in the fist sentence of Part 3 and the last sentence of caption of Table 1. The following should be added (in Part 3: According to the traditional MESMA and referring to MESMA-SAD method which is reported by Andreou and Karathanassi; in caption of Table 1: Based on the MESMA-SAD method of Andreou and Karathanassi). We apologize to the authors and workers concerned for this oversight and are pleased to acknowledge their contributions.

Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

PubMed

Nelson, Bryant C; Sharpless, Katherine E

2003-01-29

Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

"I Wish My People Can Be Like the Ducks": Children's References to Internal States with Siblings and Friends from Early to Middle Childhood

ERIC Educational Resources Information Center

Leach, Jamie; Howe, Nina; DeHart, Ganie

2017-01-01

The present study investigated children's internal state language during play with their sibling and friend across early and middle childhood. Specifically, the category type of internal state language (e.g., cognitions and goals), referent (e.g., own and other), and associations with children's birth order were examined. A total of 65 (T1: Time…

Certified reference materials (GBW09170 and 09171) of creatinine in human serum.

PubMed

Dai, Xinhua; Fang, Xiang; Shao, Mingwu; Li, Ming; Huang, Zejian; Li, Hongmei; Jiang, You; Song, Dewei; He, Yajuan

2011-02-15

Creatinine is the most widely used clinical marker for assessing renal function. Concentrations of creatinine in human serum need to be carefully checked in order to ensure accurate diagnosis of renal function. Therefore, development of certified reference materials (CRMs) of creatinine in serum is of increasing importance. In this study, two new CRMs (Nos. GBW09170 and 09171) for creatinine in human serum have been developed. They were prepared with mixtures of several dozens of healthy people's and kidney disease patient's serum, respectively. The certified values of 8.10, 34.1 mg/kg for these two CRMs have been assigned by liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) method which was validated by using standard reference material (SRM) of SRM909b (a reference material obtained from National Institute of Standards and Technology, NIST). The expanded uncertainties of certified values for low and high concentrations were estimated to be 1.2 and 1.1%, respectively. The certified values were further confirmed by an international intercomparison for the determination of creatinine in human serum (Consultative Committee for Amount of Substance, CCQM) of K80 (CCQM-K80). These new CRMs of creatinine in human serum pool are totally native without additional creatinine spiked for enrichment. These new CRMs are capable of validating routine clinical methods for ensuring accuracy, reliability and comparability of analytical results from different clinical laboratories. They can also be used for instrument validation, development of secondary reference materials, and evaluating the accuracy of high order clinical methods for the determination of creatinine in human serum. Copyright © 2011 Elsevier B.V. All rights reserved.

Validation of powder X-ray diffraction following EN ISO/IEC 17025.

PubMed

Eckardt, Regina; Krupicka, Erik; Hofmeister, Wolfgang

2012-05-01

Powder X-ray diffraction (PXRD) is used widely in forensic science laboratories with the main focus of qualitative phase identification. Little is found in literature referring to the topic of validation of PXRD in the field of forensic sciences. According to EN ISO/IEC 17025, the method has to be tested for several parameters. Trueness, specificity, and selectivity of PXRD were tested using certified reference materials or a combination thereof. All three tested parameters showed the secure performance of the method. Sample preparation errors were simulated to evaluate the robustness of the method. These errors were either easily detected by the operator or nonsignificant for phase identification. In case of the detection limit, a statistical evaluation of the signal-to-noise ratio showed that a peak criterion of three sigma is inadequate and recommendations for a more realistic peak criterion are given. Finally, the results of an international proficiency test showed the secure performance of PXRD. © 2012 American Academy of Forensic Sciences.

The International Geomagnetic Reference Field: the twelfth generation

NASA Astrophysics Data System (ADS)

Thebault, Erwan; Finlay, Christopher; The IGRF Working Group

2015-04-01

The IGRF is an internationally-agreed reference model of the Earth's magnetic field produced under the auspices of the International Association of Geomagnetism and Aeronomy. The IGRF-12 is the latest update of this well-known model which is used each year by many thousands of users for both industrial and scientific purposes. In October 2014, ten institutions worldwide have made contributions to the IGRF. These models were evaluated and the twelfth generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014. In this presentation, we will report on the IGRF activities, briefly describe the candidate models, summarize the evaluation of models performed by different independent teams, show how the IGRF-12 models were calculated and finally discuss some of the main magnetic features of this new model.

AOAC Official MethodSM Matrix Extension Validation Study of Assurance GDSTM for the Detection of Salmonella in Selected Spices.

PubMed

Feldsine, Philip; Kaur, Mandeep; Shah, Khyati; Immerman, Amy; Jucker, Markus; Lienau, Andrew

2015-01-01

Assurance GDSTM for Salmonella Tq has been validated according to the AOAC INTERNATIONAL Methods Committee Guidelines for Validation of Microbiological Methods for Food and Environmental Surfaces for the detection of selected foods and environmental surfaces (Official Method of AnalysisSM 2009.03, Performance Tested MethodSM No. 050602). The method also completed AFNOR validation (following the ISO 16140 standard) compared to the reference method EN ISO 6579. For AFNOR, GDS was given a scope covering all human food, animal feed stuff, and environmental surfaces (Certificate No. TRA02/12-01/09). Results showed that Assurance GDS for Salmonella (GDS) has high sensitivity and is equivalent to the reference culture methods for the detection of motile and non-motile Salmonella. As part of the aforementioned validations, inclusivity and exclusivity studies, stability, and ruggedness studies were also conducted. Assurance GDS has 100% inclusivity and exclusivity among the 100 Salmonella serovars and 35 non-Salmonella organisms analyzed. To add to the scope of the Assurance GDS for Salmonella method, a matrix extension study was conducted, following the AOAC guidelines, to validate the application of the method for selected spices, specifically curry powder, cumin powder, and chili powder, for the detection of Salmonella.

InstantLabs Listeria monocytogenes food safety kit. Performance tested method 051304.

PubMed

Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit

2014-01-01

The InstantLabs Listeria monocytogenes Food Safety Kit was validated against the International Organization for Standardization (ISO) reference method 11290-1 for the detection of Listeria monocytogenes and other Listeria species. The matrixes (stainless steel, sealed concrete, ice cream, whole milk, cheddar cheese, raw shrimp, hot dogs, deli turkey, and lettuce) were inoculated with approximately 1 CFU/test portion of L. monocytogenes to generate fractional positives (5-15) in 20 inoculated samples. Enrichments were also fractionally inoculated with L. grayii for side-by-side testing of the Listeria Species Food Safety Kit. Stainless steel and sealed concrete samples were validated using 4 x 4" and 1 x 1 " test areas, respectively, and enriched in Buffered Listeria Enrichment Broth (BLEB) at 35 +/- 1degreesC for 22-28 h. All food samples were tested at 25 g and enriched in BLEB at 35 +/- 1 degreesC for 24-28 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of L. monocytogenes on stainless steel and sealed concrete and in ice cream, whole milk, cheddar cheese, raw shrimp, hot dogs, deli turkey, and lettuce. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 L. monocytogenes serovars and 30 non-L. monocytogenes species examined. The method was shown to be robust when the enrichment times, volumes for DNA extraction, and heat block times were varied.

InstantLabs Listeria species food safety kit. Performance tested methods 041304.

PubMed

Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit

2014-01-01

The InstantLabs Listeria Species Food SafetyKitwas validated against the International Organization for Standardization (ISO) reference method 11290-1 for the detection of Listeria monocytogenes and other Listeria species. The matrixes (stainless steel, sealed concrete, cheddar cheese, raw shrimp, and hot dogs) were inoculated with approximately 1 CFU/test portion of various Listeria species to generate fractional positives (5-15) in 20 inoculated samples. Enrichments were also fractionally inoculated with L. monocytogenes for side-by-side testing of the InstantLabs Listeria monocytogenes Food Safety Kit. Stainless steel and sealed concrete samples were validated using 4 x 4" and 1 x 1" test areas, respectively, and enriched in Buffered Listeria Enrichment Broth (BLEB) at 35 +/- 1 degrees C for 22-28 h. All food samples were tested at 25 g or 25 mL and enriched in BLEB at 35 +/- 1 degrees C for 24-28 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of Listeria species on stainless steel, sealed concrete, cheddar cheese, raw shrimp, and hot dogs. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 80 Listeria species and 30 non-Listeria species examined. The method was shown to be robust when variations were introduced to the enrichment time, the volume for DNA extraction, and the heat block time (data not shown).

Standardization of gamma-glutamyltransferase assays by intermethod calibration. Effect on determining common reference limits.

PubMed

Steinmetz, Josiane; Schiele, Françoise; Gueguen, René; Férard, Georges; Henny, Joseph

2007-01-01

The improvement of the consistency of gamma-glutamyltransferase (GGT) activity results among different assays after calibration with a common material was estimated. We evaluated if this harmonization could lead to reference limits common to different routine methods. Seven laboratories measured GGT activity using their own routine analytical system both according to the manufacturer's recommendation and after calibration with a multi-enzyme calibrator [value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference procedure]. All samples were re-measured using the IFCC reference procedure. Two groups of subjects were selected in each laboratory: a group of healthy men aged 18-25 years without long-term medication and with alcohol consumption less than 44 g/day and a group of subjects with elevated GGT activity. The day-to-day coefficients of variation were less than 2.9% in each laboratory. The means obtained in the group of healthy subjects without common calibration (range of the means 16-23 U/L) were significantly different from those obtained by the IFCC procedure in five laboratories. After calibration, the means remained significantly different from the IFCC procedure results in only one laboratory. For three calibrated methods, the slope values of linear regression vs. the IFCC procedure were not different from the value 1. The results obtained with these three methods for healthy subjects (n=117) were gathered and reference limits were calculated. These were 11-49 U/L (2.5th-97.5th percentiles). The calibration also improved the consistency of elevated results when compared to the IFCC procedure. The common calibration improved the level of consistency between different routine methods. It permitted to define common reference limits which are quite similar to those proposed by the IFCC. This approach should lead to a real benefit in terms of prevention, screening, diagnosis, therapeutic monitoring and for epidemiological studies.

International reference ionosphere 1990

NASA Technical Reports Server (NTRS)

Bilitza, Dieter; Rawer, K.; Bossy, L.; Kutiev, I.; Oyama, K.-I.; Leitinger, R.; Kazimirovsky, E.

1990-01-01

The International Reference Ionosphere 1990 (IRI-90) is described. IRI described monthly averages of the electron density, electron temperature, ion temperature, and ion composition in the altitude range from 50 to 1000 km for magnetically quiet conditions in the non-auroral ionosphere. The most important improvements and new developments are summarized.

Analysis of penicillin G in milk by liquid chromatography.

PubMed

Boison, J O; Keng, L J; MacNeil, J D

1994-01-01

A liquid chromatographic (LC) method that was previously developed for penicillin G residues in animal tissues has been adapted to milk and milk products. After protein precipitation with sodium tungstate, samples are applied to a C18 solid-phase extraction cartridge, from which penicillin is eluted, derivatized with 1,2,4-triazole-mercuric chloride solution, and analyzed by isocratic liquid chromatography (LC) on a C18 column with UV detection at 325 nm. Quantitation is done with reference to penicillin V as an internal standard. Penicillin G recoveries were determined to be > 70% on standards fortified at 3-60 ppb. Accuracy approached 100% using the penicillin V internal standard. The detection limit for penicillin G residues was 3 ppb in fluid milk. Samples may be confirmed by thermospray/LC at concentrations approaching the detection limit of the UV method.

The Comparison of Iranian Normative Reference Data with Five Countries ‎Across Variables in Eight Rorschach Comprehensive System (CS) Clusters

PubMed Central

Hosseininasab, Abufazel; Mohammadi, Mohammadreza; Jouzi, Samira; Esmaeilinasab, Maryam; Delavar, Ali

2016-01-01

Objective: This study aimed to provide a normative study documenting how 114 five-seven year-old non-‎patient Iranian children respond to the Rorschach test. We compared this especial sample to ‎international normative reference values for the Comprehensive System (CS).‎ Method: One hundred fourteen 5- 7- year-old non-patient Iranian children were recruited from public ‎schools. Using five child and adolescent samples from five countries, we compared Iranian ‎Normative Reference Data- based on reference means and standard deviations for each sample.‎ Results: Findings revealed that how the scores in each sample were distributed and how the samples were ‎compared across variables in eight Rorschach Comprehensive System (CS) clusters. We reported ‎all descriptive statistics such as reference mean and standard deviation for all variables.‎ Conclusion: Iranian clinicians could rely on country specific or “local norms” when assessing children. We ‎discourage Iranian clinicians to use many CS scores to make nomothetic, score-based inferences ‎about psychopathology in children and adolescents.‎ PMID:27928247

Introducing a true internal standard for the Comet assay to minimize intra- and inter-experiment variability in measures of DNA damage and repair

PubMed Central

Zainol, Murizal; Stoute, Julia; Almeida, Gabriela M.; Rapp, Alexander; Bowman, Karen J.; Jones, George D. D.

2009-01-01

The Comet assay (CA) is a sensitive/simple measure of genotoxicity. However, many features of CA contribute variability. To minimize these, we have introduced internal standard materials consisting of ‘reference’ cells which have their DNA substituted with BrdU. Using a fluorescent anti-BrdU antibody, plus an additional barrier filter, comets derived from these cells could be readily distinguished from the ‘test’-cell comets, present in the same gel. In experiments to evaluate the reference cell comets as external and internal standards, the reference and test cells were present in separate gels on the same slide or mixed together in the same gel, respectively, before their co-exposure to X-irradiation. Using the reference cell comets as internal standards led to substantial reductions in the coefficient of variation (CoV) for intra- and inter-experimental measures of comet formation and DNA damage repair; only minor reductions in CoV were noted when the reference and test cell comets were in separate gels. These studies indicate that differences between individual gels appreciably contribute to CA variation. Further studies using the reference cells as internal standards allowed greater significance to be obtained between groups of replicate samples. Ultimately, we anticipate that development will deliver robust quality assurance materials for CA. PMID:19828597

The gravity field observations and products at IGFS

NASA Astrophysics Data System (ADS)

Barzaghi, Riccardo; Vergos, George; Bonvalot, Sylvain; Barthelmes, Franz; Reguzzoni, Mirko; Wziontek, Hartmut; Kelly, Kevin

2017-04-01

The International Gravity Field Service (IGFS) is a service of the International Association of Geodesy (IAG) that was established in 2003 at the IAG/IUGG General Assembly in Sapporo (Japan). This service aims at coordinating the actions of the IAG services related to the Earth gravity field, i.e. the Bureau Gravimétrique International (BGI), the International Service for the Geoid (ISG), the International Geodynamics and Earth Tides Service (IGETS), the International Center for Global Earth Models (ICGEM) and the International Digital Elevation Model Service (IDEMS). Also, via its Central Bureau hosted at the Aristotle University of Thessaloniki (Greece), IGFS provides a link to the Global Geodetic Observing System (GGOS) bureaus in order to communicate their requirements and recommendations to the IGFS-Centers. In this work, a presentation is given on the recent activities of the service, namely those related to the contributions to the implementation of: the International Height Reference System/Frame; the Global Geodetic Reference System/Frame; the new Global Absolute Gravity Reference System/Frame. Particularly, the impact that these activities have in improving the estimation of the Earth's gravity field, either at global and local scale, is highlighted also in the framework of GGOS.

Examination of a Standardized Test for Evaluating the Degree of Cure of EVA Encapsulation (Presentation)

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

Miller, D.; Wohlgemuth, J.; Gu, X.

2013-11-01

The curing of cross-linkable encapsulation is a critical consideration for photovoltaic (PV) modules manufactured using a lamination process. Concerns related to ethylene-co-vinyl acetate (EVA) include the quality (e.g., expiration and uniformity) of the films or completion (duration) of the cross-linking of the EVA within a laminator. Because these issues are important to both EVA and module manufacturers, an international standard has recently been proposed by the Encapsulation Task-Group within the Working Group 2 (WG2) of the International Electrotechnical Commission (IEC) Technical Committee 82 (TC82) for the quantification of the degree of cure for EVA encapsulation. The present draft of themore » standard calls for the use of differential scanning calorimetry (DSC) as the rapid, enabling secondary (test) method. Both the residual enthalpy- and melt/freeze-DSC methods are identified. The DSC methods are calibrated against the gel content test, the primary (reference) method. Aspects of other established methods, including indentation and rotor cure metering, were considered by the group. Key details of the test procedure will be described.« less

Time evolution of an SLR reference frame

NASA Astrophysics Data System (ADS)

Angermann, D.; Gerstl, M.; Kelm, R.; Müller, H.; Seemüller, W.; Vei, M.

2002-07-01

On the basis of LAGEOS-1 and LAGEOS-2 data we computed a 10-years (1990-2000) solution for SLR station positions and velocities. The paper describes the data processing with the DGFI software package DOGS. We present results for station coordinates and their time variation for 41 stations of the global SLR network, and discuss the stability and time evolution of the SLR reference frame established in the same way. We applied different methods to assess the quality and consistency of the SLR results. The results presented in this paper include: (1) a time series of weekly estimated station coordinates; (2) a comparison of a 10-year LAGEOS-1 and LAGEOS-2 solution; (3) a comparison of 2.5-year solutions with the combined 10-year solution to assess the internal stability and the time evolution of the SLR reference frame; (4) a comparison of the SLR reference frame with ITRF97; and (5) a comparison of SLR station velocities with those of ITRF97 and NNR NUVEL-1A.

Mortality in a Combined Cohort of Uranium Enrichment Workers

PubMed Central

Yiin, James H.; Anderson, Jeri L.; Daniels, Robert D.; Bertke, Stephen J.; Fleming, Donald A.; Tollerud, David J.; Tseng, Chih-Yu; Chen, Pi-Hsueh; Waters, Kathleen M.

2017-01-01

Objective To examine the patterns of cause-specific mortality and relationship between internal exposure to uranium and specific causes in a pooled cohort of 29,303 workers employed at three former uranium enrichment facilities in the United States with follow-up through 2011. Methods Cause-specific standardized mortality ratios (SMRs) for the full cohort were calculated with the U.S. population as referent. Internal comparison of the dose-response relation between selected outcomes and estimated organ doses was evaluated using regression models. Results External comparison with the U.S. population showed significantly lower SMRs in most diseases in the pooled cohort. Internal comparison showed positive associations of absorbed organ doses with multiple myeloma, and to a lesser degree with kidney cancer. Conclusion In general, these gaseous diffusion plant workers had significantly lower SMRs than the U.S. population. The internal comparison however, showed associations between internal organ doses and diseases associated with uranium exposure in previous studies. PMID:27753121

Report of the American Commissioners of the International Commission on the Teaching of Mathematics. Bulletin, 1912, No. 14. Whole Number 486

ERIC Educational Resources Information Center

United States Bureau of Education, Department of the Interior, 1912

1912-01-01

In the following general report the aim is to present a concise view of the organization, methods, and problems of the teaching of mathematics in the United States, touching particularly upon the larger questions that seem to merit especial emphasis, and referring to the special reports for details with respect lo the various types of schools. The…

A proposed protocol for acceptance and constancy control of computed tomography systems: a Nordic Association for Clinical Physics (NACP) work group report.

PubMed

Kuttner, Samuel; Bujila, Robert; Kortesniemi, Mika; Andersson, Henrik; Kull, Love; Østerås, Bjørn Helge; Thygesen, Jesper; Tarp, Ivanka Sojat

2013-03-01

Quality assurance (QA) of computed tomography (CT) systems is one of the routine tasks for medical physicists in the Nordic countries. However, standardized QA protocols do not yet exist and the QA methods, as well as the applied tolerance levels, vary in scope and extent at different hospitals. To propose a standardized protocol for acceptance and constancy testing of CT scanners in the Nordic Region. Following a Nordic Association for Clinical Physics (NACP) initiative, a group of medical physicists, with representatives from four Nordic countries, was formed. Based on international literature and practical experience within the group, a comprehensive standardized test protocol was developed. The proposed protocol includes tests related to the mechanical functionality, X-ray tube, detector, and image quality for CT scanners. For each test, recommendations regarding the purpose, equipment needed, an outline of the test method, the measured parameter, tolerance levels, and the testing frequency are stated. In addition, a number of optional tests are briefly discussed that may provide further information about the CT system. Based on international references and medical physicists' practical experiences, a comprehensive QA protocol for CT systems is proposed, including both acceptance and constancy tests. The protocol may serve as a reference for medical physicists in the Nordic countries.

Determination of trichloroethylene by using self-referenced SERS and gold-core/silver-shell nanoparticles.

PubMed

Yu, Zhao; Smith, Michael E; Zhang, Jinnan; Zhou, Yan; Zhang, Peng

2018-06-18

A surface-enhanced Raman scattering (SERS) method has been developed to determine the concentration of trichloroethylene (TCE) in environmental water. Au-core/Ag-shell nanoparticles containing 4-mercaptophenylboronic acid (4-MPBA) between the core and shell are used as the SERS substrate. 4-MPBA serves as an internal reference with a Raman shift at 534 cm -1 . TCE reacts with 4-mercaptopyridine (4-MPy) in a so-called Fujiwara reaction. With the presence of TCE in water, the consumption of 4-MPy results in a change in the intensity of its Raman signal at 1220 cm -1 . The ratio of the Raman shift at 1220 cm -1 and 534 cm -1 decreases linearly in the 0.2 to 1.0 μM TCE concentration range, and the detection limit of TCE is as low as 8 ppb (60 nM). The method has been successfully applied to the determination of TCE in spiked lake water. Graphical abstract Gold-core/silver-shell nanoparticles with internal reference embedded have been fabracated to improve the quantitative measurement of SERS. These nanoparticles as SERS substrates, are used to indirectly quantify the concentration of trichloroethylene (a typical halogenated organic compound) by the consumption of 4-mercaptopyridine through the Fujiwara reaction.

Method Modification Study for the Thermo Scientific SureTect™ Listeria Species Assay-Matrix Extension.

PubMed

Cloke, Jonathan; Evans, Katharine; Crabtree, David; Hughes, Annette; Simpson, Helen; Holopainen, Jani; Wickstrand, Nina; Kauppinen, Mikko; Leon-Velarde, Carlos; Larson, Nathan; Dave, Keron; Chen, Yi; Ryser, Elliot; Carter, Mark

2016-01-01

The Thermo Scientific™ SureTect™ Listeria species assay is a new real-time PCR assay for the detection of all species of Listeria in food and environmental samples. The assay was originally certified as Performance Tested Methods(SM) (PTM) 071304 in 2013. This report details the method modification study undertaken to extend the performance claims of the assay for matrixes of raw ground turkey, raw ground pork, bagged lettuce, raw pork sausages, pasteurized 2% fat milk, raw cod, pasteurized brie cheese, and ice cream. The method modification study was conducted using the AOAC Research Institute (RI) PTM program to validate the SureTect PCR assay in comparison to the reference method detailed in ISO 11290-1:1996 including amendment 1:2004. All matrixes were tested by Thermo Fisher Scientific (Basingstoke, United Kingdom). In addition, three matrixes (raw cod, bagged lettuce, and pasteurized brie cheese) were analyzed independently as part of the AOAC RI-controlled independent laboratory study by the University of Guelph, Canada. Using probability of detection statistical analysis, there was no significant difference in the performance between the SureTect assay and the International Organization for Standardization reference method for any of the matrixes analyzed in this study.

Establishment of the first international repository for transfusion-relevant bacteria reference strains: ISBT working party transfusion-transmitted infectious diseases (WP-TTID), subgroup on bacteria.

PubMed

Störmer, M; Arroyo, A; Brachert, J; Carrero, H; Devine, D; Epstein, J S; Gabriel, C; Gelber, C; Goodrich, R; Hanschmann, K-M; Heath, D G; Jacobs, M R; Keil, S; de Korte, D; Lambrecht, B; Lee, C-K; Marcelis, J; Marschner, S; McDonald, C; McGuane, S; McKee, M; Müller, T H; Muthivhi, T; Pettersson, A; Radziwon, P; Ramirez-Arcos, S; Reesink, H W; Rojo, J; Rood, I; Schmidt, M; Schneider, C K; Seifried, E; Sicker, U; Wendel, S; Wood, E M; Yomtovian, R A; Montag, T

2012-01-01

Bacterial contamination of platelet concentrates (PCs) still remains a significant problem in transfusion with potential important clinical consequences, including death. The International Society of Blood Transfusion Working Party on Transfusion-Transmitted Infectious Diseases, Subgroup on Bacteria, organised an international study on Transfusion-Relevant Bacteria References to be used as a tool for development, validation and comparison of both bacterial screening and pathogen reduction methods. Four Bacteria References (Staphylococcus epidermidis PEI-B-06, Streptococcus pyogenes PEI-B-20, Klebsiella pneumoniae PEI-B-08 and Escherichia coli PEI-B-19) were selected regarding their ability to proliferate to high counts in PCs and distributed anonymised to 14 laboratories in 10 countries for identification, enumeration and bacterial proliferation in PCs after low spiking (0·3 and 0·03 CFU/ml), to simulate contamination occurring during blood donation. Bacteria References were correctly identified in 98% of all 52 identifications. S. pyogenes and E. coli grew in PCs in 11 out of 12 laboratories, and K. pneumoniae and S. epidermidis replicated in all participating laboratories. The results of bacterial counts were very consistent between laboratories: the 95% confidence intervals were for S. epidermidis: 1·19-1·32 × 10(7) CFU/ml, S. pyogenes: 0·58-0·69 × 10(7) CFU/ml, K. pneumoniae: 18·71-20·26 × 10(7) CFU/ml and E. coli: 1·78-2·10 × 10(7) CFU/ml. The study was undertaken as a proof of principle with the aim to demonstrate (i) the quality, stability and suitability of the bacterial strains for low-titre spiking of blood components, (ii) the property of donor-independent proliferation in PCs, and (iii) their suitability for worldwide shipping of deep frozen, blinded pathogenic bacteria. These aims were successfully fulfilled. The WHO Expert Committee Biological Standardisation has approved the adoption of these four bacteria strains as the first Repository for Transfusion-Relevant Bacteria Reference Strains and, additionally, endorsed as a project the addition of six further bacteria strain preparations suitable for control of platelet contamination as the next step of enlargement of the repository. © 2011 The Author(s). Vox Sanguinis © 2011 International Society of Blood Transfusion.

Metrology in Medicine: From Measurements to Decision, with Specific Reference to Anesthesia and Intensive Care

PubMed Central

Imhoff, Michael; Cecconi, Maurizio

2015-01-01

Metrology is the science of measurements. Although of critical importance in medicine and especially in critical care, frequent confusion in terms and definitions impact either interphysician communications or understanding of manufacturers’ and engineers’ instructions and limitations when using devices. In this review, we first list the terms defined by the International Bureau of Weights and Measures regarding quantities and units, measurements, devices for measurement, properties of measuring devices, and measurement standards. The traditional tools for assessing the most important measurement quality criteria are also reviewed with clinical examples for diagnosis, alarm, and titration purposes, as well as for assessing the uncertainty of reference methods. PMID:25625255

Method and apparatus for detecting internal structures of bulk objects using acoustic imaging

DOEpatents

Deason, Vance A.; Telschow, Kenneth L.

2002-01-01

Apparatus for producing an acoustic image of an object according to the present invention may comprise an excitation source for vibrating the object to produce at least one acoustic wave therein. The acoustic wave results in the formation of at least one surface displacement on the surface of the object. A light source produces an optical object wavefront and an optical reference wavefront and directs the optical object wavefront toward the surface of the object to produce a modulated optical object wavefront. A modulator operatively associated with the optical reference wavefront modulates the optical reference wavefront in synchronization with the acoustic wave to produce a modulated optical reference wavefront. A sensing medium positioned to receive the modulated optical object wavefront and the modulated optical reference wavefront combines the modulated optical object and reference wavefronts to produce an image related to the surface displacement on the surface of the object. A detector detects the image related to the surface displacement produced by the sensing medium. A processing system operatively associated with the detector constructs an acoustic image of interior features of the object based on the phase and amplitude of the surface displacement on the surface of the object.

Can the Afinion HbA1c Point-of-Care instrument be an alternative method for the Tosoh G8 in the case of Hb-Tacoma?

PubMed

Lenters-Westra, Erna; Strunk, Annuska; Campbell, Paul; Slingerland, Robbert J

2017-02-01

Hb-variant interference when reporting HbA1c has been an ongoing challenge since HbA1c was introduced to monitor patients with diabetes mellitus. Most Hb-variants show an abnormal chromatogram when cation-exchange HPLC is used for the determination of HbA1c. Unfortunately, the Tosoh G8 generates what appears to be normal chromatogram in the presence of Hb-Tacoma, yielding a falsely high HbA1c value. The primary aim of the study was to investigate if the Afinion HbA1c point-of-care (POC) instrument could be used as an alternative method for the Tosoh G8 when testing for HbA1c in the presence of Hb-Tacoma. Whole blood samples were collected in K 2 EDTA tubes from individuals homozygous for HbA (n = 40) and heterozygous for Hb-Tacoma (n = 20). Samples were then immediately analyzed with the Afinion POC instrument. After analysis, aliquots of each sample were frozen at -80 °C. The frozen samples were shipped on dry ice to the European Reference Laboratory for Glycohemoglobin (ERL) and analyzed with three International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and National Glycohemoglobin Standardization Program (NGSP) Secondary Reference Measurement Procedures (SRMPs). The Premier Hb9210 was used as the reference method. When compared to the reference method, samples with Hb-Tacoma yielded mean relative differences of 31.8% on the Tosoh G8, 21.5% on the Roche Tina-quant Gen. 2 and 16.8% on the Afinion. The Afinion cannot be used as an alternative method for the Tosoh G8 when testing for HbA1c in the presence of Hb-Tacoma.

Effective Solar Indices for Ionospheric Modeling: A Review and a Proposal for a Real-Time Regional IRI

NASA Astrophysics Data System (ADS)

Pignalberi, A.; Pezzopane, M.; Rizzi, R.; Galkin, I.

2018-01-01

The first part of this paper reviews methods using effective solar indices to update a background ionospheric model focusing on those employing the Kriging method to perform the spatial interpolation. Then, it proposes a method to update the International Reference Ionosphere (IRI) model through the assimilation of data collected by a European ionosonde network. The method, called International Reference Ionosphere UPdate (IRI UP), that can potentially operate in real time, is mathematically described and validated for the period 9-25 March 2015 (a time window including the well-known St. Patrick storm occurred on 17 March), using IRI and IRI Real Time Assimilative Model (IRTAM) models as the reference. It relies on foF2 and M(3000)F2 ionospheric characteristics, recorded routinely by a network of 12 European ionosonde stations, which are used to calculate for each station effective values of IRI indices IG_{12} and R_{12} (identified as IG_{{12{eff}}} and R_{{12{eff}}}); then, starting from this discrete dataset of values, two-dimensional (2D) maps of IG_{{12{eff}}} and R_{{12{eff}}} are generated through the universal Kriging method. Five variogram models are proposed and tested statistically to select the best performer for each effective index. Then, computed maps of IG_{{12{eff}}} and R_{{12{eff}}} are used in the IRI model to synthesize updated values of foF2 and hmF2. To evaluate the ability of the proposed method to reproduce rapid local changes that are common under disturbed conditions, quality metrics are calculated for two test stations whose measurements were not assimilated in IRI UP, Fairford (51.7°N, 1.5°W) and San Vito (40.6°N, 17.8°E), for IRI, IRI UP, and IRTAM models. The proposed method turns out to be very effective under highly disturbed conditions, with significant improvements of the foF2 representation and noticeable improvements of the hmF2 one. Important improvements have been verified also for quiet and moderately disturbed conditions. A visual analysis of foF2 and hmF2 maps highlights the ability of the IRI UP method to catch small-scale changes occurring under disturbed conditions which are not seen by IRI.

Citations of Brazilian physical therapy journals in national publications.

PubMed

Teixeira, Renan K C; Yamaki, Vitor N; Botelho, Nara M; Teixeira, Renato C

2014-01-01

Quotations in Brazilian journals are mainly obtained from national articles (articles from Brazilian journals); thus, it is essential to determine how frequently these articles reference Brazilian journals. This study sought to verify how frequently national papers are cited in the references of three Brazilian physical therapy journals. All references for articles published in Fisioterapia em Movimento, Fisioterapia e Pesquisa and Revista Brasileira de Fisioterapia between 2010 and 2012 were evaluated. In particular, the numbers of national articles and international articles (articles from international journals) cited in these references were determined. A total of 13,009 references cited by 456 articles were analyzed, and 2,924 (22.47%) of the cited works were national articles. There were no significant differences among the three examined years. A total of 36 (7.89%) articles did not cite national articles, whereas 65 (13.25%) articles cited more national articles than international articles. On average, 22.47% of the works cited by the evaluated articles were national articles. No significant differences were detected among the three analyzed years.

Automated vocabulary discovery for geo-parsing online epidemic intelligence.

PubMed

Keller, Mikaela; Freifeld, Clark C; Brownstein, John S

2009-11-24

Automated surveillance of the Internet provides a timely and sensitive method for alerting on global emerging infectious disease threats. HealthMap is part of a new generation of online systems designed to monitor and visualize, on a real-time basis, disease outbreak alerts as reported by online news media and public health sources. HealthMap is of specific interest for national and international public health organizations and international travelers. A particular task that makes such a surveillance useful is the automated discovery of the geographic references contained in the retrieved outbreak alerts. This task is sometimes referred to as "geo-parsing". A typical approach to geo-parsing would demand an expensive training corpus of alerts manually tagged by a human. Given that human readers perform this kind of task by using both their lexical and contextual knowledge, we developed an approach which relies on a relatively small expert-built gazetteer, thus limiting the need of human input, but focuses on learning the context in which geographic references appear. We show in a set of experiments, that this approach exhibits a substantial capacity to discover geographic locations outside of its initial lexicon. The results of this analysis provide a framework for future automated global surveillance efforts that reduce manual input and improve timeliness of reporting.

Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines

PubMed Central

Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

2009-01-01

The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines. PMID:18927105

Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines.

PubMed

Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

2009-01-01

The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines.

Reveal Salmonella 2.0 test for detection of Salmonella spp. in foods and environmental samples. Performance Tested Method 960801.

PubMed

Hoerner, Rebecca; Feldpausch, Jill; Gray, R Lucas; Curry, Stephanie; Islam, Zahidul; Goldy, Tim; Klein, Frank; Tadese, Theodros; Rice, Jennifer; Mozola, Mark

2011-01-01

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.

Applying the silver-tube introduction method for thermal conversion elemental analyses and a new δ2H value for NBS 22 oil

USGS Publications Warehouse

Coplen, Tyler B.; Qi, Haiping

2010-01-01

The δ2HVSMOW–SLAP value of total hydrogen of the international measurement standard NBS 22 oil was determined by a new method of sealing water in silver tubes for use in a thermal conversion elemental analysis (TC/EA) reduction unit. The isotopic fractionation of water due to evaporation is virtually non-existent in this silver-tube method. A new value for the δ2HVSMOW–SLAP of NBS 22 oil, calibrated with isotopic reference waters, was determined to be −116.9 ± 0.8‰ (1σ and n = 31).

Establishing International Blood Pressure References Among Nonoverweight Children and Adolescents Aged 6 to 17 Years.

PubMed

Xi, Bo; Zong, Xin'nan; Kelishadi, Roya; Hong, Young Mi; Khadilkar, Anuradha; Steffen, Lyn M; Nawarycz, Tadeusz; Krzywińska-Wiewiorowska, Małgorzata; Aounallah-Skhiri, Hajer; Bovet, Pascal; Chiolero, Arnaud; Pan, Haiyan; Litwin, Mieczysław; Poh, Bee Koon; Sung, Rita Y T; So, Hung-Kwan; Schwandt, Peter; Haas, Gerda-Maria; Neuhauser, Hannelore K; Marinov, Lachezar; Galcheva, Sonya V; Motlagh, Mohammad Esmaeil; Kim, Hae Soon; Khadilkar, Vaman; Krzyżaniak, Alicja; Romdhane, Habiba Ben; Heshmat, Ramin; Chiplonkar, Shashi; Stawińska-Witoszyńska, Barbara; El Ati, Jalila; Qorbani, Mostafa; Kajale, Neha; Traissac, Pierre; Ostrowska-Nawarycz, Lidia; Ardalan, Gelayol; Parthasarathy, Lavanya; Zhao, Min; Zhang, Tao

2016-01-26

Several distributions of country-specific blood pressure (BP) percentiles by sex, age, and height for children and adolescents have been established worldwide. However, there are no globally unified BP references for defining elevated BP in children and adolescents, which limits international comparisons of the prevalence of pediatric elevated BP. We aimed to establish international BP references for children and adolescents by using 7 nationally representative data sets (China, India, Iran, Korea, Poland, Tunisia, and the United States). Data on BP for 52 636 nonoverweight children and adolescents aged 6 to 19 years were obtained from 7 large nationally representative cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and the United States. BP values were obtained with certified mercury sphygmomanometers in all 7 countries by using standard procedures for BP measurement. Smoothed BP percentiles (50th, 90th, 95th, and 99th) by age and height were estimated by using the Generalized Additive Model for Location Scale and Shape model. BP values were similar between males and females until the age of 13 years and were higher in males than females thereafter. In comparison with the BP levels of the 90th and 95th percentiles of the US Fourth Report at median height, systolic BP of the corresponding percentiles of these international references was lower, whereas diastolic BP was similar. These international BP references will be a useful tool for international comparison of the prevalence of elevated BP in children and adolescents and may help to identify hypertensive youths in diverse populations. © 2015 American Heart Association, Inc.

A new method for the visualization and quantification of internal skin elasticity by ultrasound imaging.

PubMed

Osanai, Osamu; Ohtsuka, Mayumi; Hotta, Mitsuyuki; Kitaharai, Takashi; Takema, Yoshinori

2011-08-01

Skin elasticity has been assessed previously only in the surface layer. We developed a new method that uses tissue strain imaging (TSI) technology, and the aim of this study was to test this new method to assess internal skin elasticity. Using a pressure device with a 12 MHz ultrasound transducer, constant and linear compressions were applied to the cheek skin of 35 volunteers (aged: 20-60 years). The elasticity of each layer (dermis, subcutaneous and muscle) was measured and analyzed using the TSI application software incorporated into the Toshiba Aplio(™) XV ultrasound system. A skin tissue-equivalent phantom, which is a block of material with the acoustic velocity (1530 m/s) of human skin, was collaboratively developed by OST Inc. This phantom was placed between the skin and the transducer as a reference material. Skin elasticity was clearly visualized and quantified in each layer of the skin. Age-dependent decreases in elasticity were determined in all layers of the skin. Among the three internal skin layers, the highest elasticity was determined in the subcutaneous layer followed by the muscle layer. These findings support the validity and sensitivity of the TSI method to assess the elasticity of various layers of skin. © 2011 John Wiley & Sons A/S.

Practical Methods for Including Torsional Anharmonicity in Thermochemical Calculations on Complex Molecules: The Internal-Coordinate Multi-Structural Approximation

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

Zheng, J.; Yu, T.; Papajak, E.

2011-01-01

Many methods for correcting harmonic partition functions for the presence of torsional motions employ some form of one-dimensional torsional treatment to replace the harmonic contribution of a specific normal mode. However, torsions are often strongly coupled to other degrees of freedom, especially other torsions and low-frequency bending motions, and this coupling can make assigning torsions to specific normal modes problematic. Here, we present a new class of methods, called multi-structural (MS) methods, that circumvents the need for such assignments by instead adjusting the harmonic results by torsional correction factors that are determined using internal coordinates. We present three versions ofmore » the MS method: (i) MS-AS based on including all structures (AS), i.e., all conformers generated by internal rotations; (ii) MS-ASCB based on all structures augmented with explicit conformational barrier (CB) information, i.e., including explicit calculations of all barrier heights for internal-rotation barriers between the conformers; and (iii) MS-RS based on including all conformers generated from a reference structure (RS) by independent torsions. In the MS-AS scheme, one has two options for obtaining the local periodicity parameters, one based on consideration of the nearly separable limit and one based on strongly coupled torsions. The latter involves assigning the local periodicities on the basis of Voronoi volumes. The methods are illustrated with calculations for ethanol, 1-butanol, and 1-pentyl radical as well as two one-dimensional torsional potentials. The MS-AS method is particularly interesting because it does not require any information about conformational barriers or about the paths that connect the various structures.« less

Practical methods for including torsional anharmonicity in thermochemical calculations on complex molecules: the internal-coordinate multi-structural approximation.

PubMed

Zheng, Jingjing; Yu, Tao; Papajak, Ewa; Alecu, I M; Mielke, Steven L; Truhlar, Donald G

2011-06-21

Many methods for correcting harmonic partition functions for the presence of torsional motions employ some form of one-dimensional torsional treatment to replace the harmonic contribution of a specific normal mode. However, torsions are often strongly coupled to other degrees of freedom, especially other torsions and low-frequency bending motions, and this coupling can make assigning torsions to specific normal modes problematic. Here, we present a new class of methods, called multi-structural (MS) methods, that circumvents the need for such assignments by instead adjusting the harmonic results by torsional correction factors that are determined using internal coordinates. We present three versions of the MS method: (i) MS-AS based on including all structures (AS), i.e., all conformers generated by internal rotations; (ii) MS-ASCB based on all structures augmented with explicit conformational barrier (CB) information, i.e., including explicit calculations of all barrier heights for internal-rotation barriers between the conformers; and (iii) MS-RS based on including all conformers generated from a reference structure (RS) by independent torsions. In the MS-AS scheme, one has two options for obtaining the local periodicity parameters, one based on consideration of the nearly separable limit and one based on strongly coupled torsions. The latter involves assigning the local periodicities on the basis of Voronoi volumes. The methods are illustrated with calculations for ethanol, 1-butanol, and 1-pentyl radical as well as two one-dimensional torsional potentials. The MS-AS method is particularly interesting because it does not require any information about conformational barriers or about the paths that connect the various structures.

Influence of echo time in quantitative proton MR spectroscopy using LCModel.

PubMed

Yamamoto, Tetsuya; Isobe, Tomonori; Akutsu, Hiroyoshi; Masumoto, Tomohiko; Ando, Hiroki; Sato, Eisuke; Takada, Kenta; Anno, Izumi; Matsumura, Akira

2015-06-01

The objective of this study was to elucidate the influence on quantitative analysis using LCModel with the condition of echo time (TE) longer than the recommended values in the spectrum acquisition specifications. A 3T magnetic resonance system was used to perform proton magnetic resonance spectroscopy. The participants were 5 healthy volunteers and 11 patients with glioma. Data were collected at TE of 72, 144 and 288ms. LCModel was used to quantify several metabolites (N-acetylaspartate, creatine and phosphocreatine, and choline-containing compounds). The results were compared with quantitative values obtained by using the T2-corrected internal reference method. In healthy volunteers, when TE was long, the quantitative values obtained using LCModel were up to 6.8-fold larger (p<0.05) than those obtained using the T2-corrected internal reference method. The ratios of the quantitative values obtained by the two methods differed between metabolites (p<0.05). In patients with glioma, the ratios of quantitative values obtained by the two methods tended to be larger at longer TE, similarly to the case of healthy volunteers, and large between-individual variation in the ratios was observed. In clinical practice, TE is sometimes set longer than the value recommended for LCModel. If TE is long, LCModel overestimates the quantitative value since it cannot compensate for signal attenuation, and this effect is different for each metabolite and condition. Therefore, if TE is longer than recommended, it is necessary to account for the possibly reduced reliability of quantitative values calculated using LCModel. Copyright © 2015 Elsevier Inc. All rights reserved.

Multivariate reference technique for quantitative analysis of fiber-optic tissue Raman spectroscopy.

PubMed

Bergholt, Mads Sylvest; Duraipandian, Shiyamala; Zheng, Wei; Huang, Zhiwei

2013-12-03

We report a novel method making use of multivariate reference signals of fused silica and sapphire Raman signals generated from a ball-lens fiber-optic Raman probe for quantitative analysis of in vivo tissue Raman measurements in real time. Partial least-squares (PLS) regression modeling is applied to extract the characteristic internal reference Raman signals (e.g., shoulder of the prominent fused silica boson peak (~130 cm(-1)); distinct sapphire ball-lens peaks (380, 417, 646, and 751 cm(-1))) from the ball-lens fiber-optic Raman probe for quantitative analysis of fiber-optic Raman spectroscopy. To evaluate the analytical value of this novel multivariate reference technique, a rapid Raman spectroscopy system coupled with a ball-lens fiber-optic Raman probe is used for in vivo oral tissue Raman measurements (n = 25 subjects) under 785 nm laser excitation powers ranging from 5 to 65 mW. An accurate linear relationship (R(2) = 0.981) with a root-mean-square error of cross validation (RMSECV) of 2.5 mW can be obtained for predicting the laser excitation power changes based on a leave-one-subject-out cross-validation, which is superior to the normal univariate reference method (RMSE = 6.2 mW). A root-mean-square error of prediction (RMSEP) of 2.4 mW (R(2) = 0.985) can also be achieved for laser power prediction in real time when we applied the multivariate method independently on the five new subjects (n = 166 spectra). We further apply the multivariate reference technique for quantitative analysis of gelatin tissue phantoms that gives rise to an RMSEP of ~2.0% (R(2) = 0.998) independent of laser excitation power variations. This work demonstrates that multivariate reference technique can be advantageously used to monitor and correct the variations of laser excitation power and fiber coupling efficiency in situ for standardizing the tissue Raman intensity to realize quantitative analysis of tissue Raman measurements in vivo, which is particularly appealing in challenging Raman endoscopic applications.

A principal component analysis of the relationship between the external body shape and internal skeleton for the upper body.

PubMed

Nerot, A; Skalli, W; Wang, X

2016-10-03

Recent progress in 3D scanning technologies allows easy access to 3D human body envelope. To create personalized human models with an articulated linkage for realistic re-posturing and motion analyses, an accurate estimation of internal skeleton points, including joint centers, from the external envelope is required. For this research project, 3D reconstructions of both internal skeleton and external envelope from low dose biplanar X-rays of 40 male adults were obtained. Using principal component analysis technique (PCA), a low-dimensional dataset was used to predict internal points of the upper body from the trunk envelope. A least squares method was used to find PC scores that fit the PCA-based model to the envelope of a new subject. To validate the proposed approach, estimated internal points were evaluated using a leave-one-out (LOO) procedure, i.e. successively considering each individual from our dataset as an extra-subject. In addition, different methods were proposed to reduce the variability in data and improve the performance of the PCA-based prediction. The best method was considered as the one providing the smallest errors between estimated and reference internal points with an average error of 8.3mm anterior-posteriorly, 6.7mm laterally and 6.5mm vertically. As the proposed approach relies on few or no bony landmarks, it could be easily applicable and generalizable to surface scans from any devices. Combined with automatic body scanning techniques, this study could potentially constitute a new step towards automatic generation of external/internal subject-specific manikins. Copyright © 2016 Elsevier Ltd. All rights reserved.

In situ LTE exposure of the general public: Characterization and extrapolation.

PubMed

Joseph, Wout; Verloock, Leen; Goeminne, Francis; Vermeeren, Günter; Martens, Luc

2012-09-01

In situ radiofrequency (RF) exposure of the different RF sources is characterized in Reading, United Kingdom, and an extrapolation method to estimate worst-case long-term evolution (LTE) exposure is proposed. All electric field levels satisfy the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels with a maximal total electric field value of 4.5 V/m. The total values are dominated by frequency modulation (FM). Exposure levels for LTE of 0.2 V/m on average and 0.5 V/m maximally are obtained. Contributions of LTE to the total exposure are limited to 0.4% on average. Exposure ratios from 0.8% (LTE) to 12.5% (FM) are obtained. An extrapolation method is proposed and validated to assess the worst-case LTE exposure. For this method, the reference signal (RS) and secondary synchronization signal (S-SYNC) are measured and extrapolated to the worst-case value using an extrapolation factor. The influence of the traffic load and output power of the base station on in situ RS and S-SYNC signals are lower than 1 dB for all power and traffic load settings, showing that these signals can be used for the extrapolation method. The maximal extrapolated field value for LTE exposure equals 1.9 V/m, which is 32 times below the ICNIRP reference levels for electric fields. Copyright © 2012 Wiley Periodicals, Inc.

Comparison of tiered formularies and reference pricing policies: a systematic review

PubMed Central

Morgan, Steve; Hanley, Gillian; Greyson, Devon

2009-01-01

Objectives To synthesize methodologically comparable evidence from the published literature regarding the outcomes of tiered formularies and therapeutic reference pricing of prescription drugs. Methods We searched the following electronic databases: ABI/Inform, CINAHL, Clinical Evidence, Digital Dissertations & Theses, Evidence-Based Medicine Reviews (which incorporates ACP Journal Club, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Cochrane Methodology Register, Database of Abstracts of Reviews of Effectiveness, Health Technology Assessments and NHS Economic Evaluation Database), EconLit, EMBASE, International Pharmaceutical Abstracts, MEDLINE, PAIS International and PAIS Archive, and the Web of Science. We also searched the reference lists of relevant articles and several grey literature sources. We sought English-language studies published from 1986 to 2007 that examined the effects of either therapeutic reference pricing or tiered formularies, reported on outcomes relevant to patient care and cost-effectiveness, and employed quantitative study designs that included concurrent or historical comparison groups. We abstracted and assessed potentially appropriate articles using a modified version of the data abstraction form developed by the Cochrane Effective Practice and Organisation of Care Group. Results From an initial list of 2964 citations, 12 citations (representing 11 studies) were deemed eligible for inclusion in our review: 3 studies (reported in 4 articles) of reference pricing and 8 studies of tiered formularies. The introduction of reference pricing was associated with reduced plan spending, switching to preferred medicines, reduced overall drug utilization and short-term increases in the use of physician services. Reference pricing was not associated with adverse health impacts. The introduction of tiered formularies was associated with reduced plan expenditures, greater patient costs and increased rates of non-compliance with prescribed drug therapy. From the data available, we were unable to examine the hypothesis that tiered formulary policies result in greater use of physician services and potentially worse health outcomes. Conclusion The available evidence does not clearly differentiate between reference pricing and tiered formularies in terms of policy outcomes. Reference pricing appears to have a slight evidentiary advantage, given that patients’ health outcomes under tiered formularies have not been well studied and that tiered formularies are associated with increased rates of medicine discontinuation. PMID:21603047

CisLunar Habitat Internal Architecture Design Criteria

NASA Technical Reports Server (NTRS)

Jones, R.; Kennedy, K.; Howard, R.; Whitmore, M.; Martin, C.; Garate, J.

2017-01-01

BACKGROUND: In preparation for human exploration to Mars, there is a need to define the development and test program that will validate deep space operations and systems. In that context, a Proving Grounds CisLunar habitat spacecraft is being defined as the next step towards this goal. This spacecraft will operate differently from the ISS or other spacecraft in human history. The performance envelope of this spacecraft (mass, volume, power, specifications, etc.) is being defined by the Future Capabilities Study Team. This team has recognized the need for a human-centered approach for the internal architecture of this spacecraft and has commissioned a CisLunar Phase-1 Habitat Internal Architecture Study Team to develop a NASA reference configuration, providing the Agency with a "smart buyer" approach for future acquisition. THE CISLUNAR HABITAT INTERNAL ARCHITECTURE STUDY: Overall, the CisLunar Habitat Internal Architecture study will address the most significant questions and risks in the current CisLunar architecture, habitation, and operations concept development. This effort is achieved through definition of design criteria, evaluation criteria and process, design of the CisLunar Habitat Phase-1 internal architecture, and the development and fabrication of internal architecture concepts combined with rigorous and methodical Human-in-the-Loop (HITL) evaluations and testing of the conceptual innovations in a controlled test environment. The vision of the CisLunar Habitat Internal Architecture Study is to design, build, and test a CisLunar Phase-1 Habitat Internal Architecture that will be used for habitation (e.g. habitability and human factors) evaluations. The evaluations will mature CisLunar habitat evaluation tools, guidelines, and standards, and will interface with other projects such as the Advanced Exploration Systems (AES) Program integrated Power, Avionics, Software (iPAS), and Logistics for integrated human-in-the-loop testing. The mission of the CisLunar Habitat Internal Architecture Study is to become a forcing function to establish a common understanding of CisLunar Phase-1 Habitation Internal Architecture design criteria, processes, and tools. The scope of the CisLunar Habitat Internal Architecture study is to design, develop, demonstrate, and evaluate a Phase-1 CisLunar Habitat common module internal architecture based on design criteria agreed to by NASA, the International Partners, and Commercial Exploration teams. This task is to define the CisLunar Phase-1 Internal Architecture Government Reference Design, assist NASA in becoming a "smart buyer" for Phase-1 Habitat Concepts, and ultimately to derive standards and requirements from the Internal Architecture Design Process. The first step was to define a Habitat Internal Architecture Design Criteria and create a structured philosophy to be used by design teams as a filter by which critical aspects of consideration would be identified for the purpose of organizing and utilizing interior spaces. With design criteria in place, the team will develop a series of iterative internal architecture concept designs which will be assessed by means of an evaluation criteria and process. These assessments will successively drive and refine the design, leading to the combination and down-selection of design concepts. A single refined reference design configuration will be developed into in a medium-to-high fidelity mockup. A multi-day human-in-the-loop mission test will fully evaluate the reference design and validate its configuration. Lessons learned from the design and evaluation will enable the team to identify appropriate standards for Phase-1 CisLunar Habitat Internal Architecture and will enable NASA to develop derived requirements in support of maturing CisLunar Habitation capabilities. This paper will describe the criteria definition process, workshop event, and resulting CisLunar Phase-1 Habitat Internal Architecture Design Criteria.

Development and certification of the new SRM 695 trace elements in multi-nutrient fertilizer

USGS Publications Warehouse

MacKey, E.A.; Cronise, M.P.; Fales, C.N.; Greenberg, R.R.; Leigh, S.D.; Long, S.E.; Marlow, A.F.; Murphy, K.E.; Oflaz, R.; Sieber, J.R.; Rearick, M.S.; Wood, L.J.; Yu, L.L.; Wilson, S.A.; Briggs, P.H.; Brown, Z.A.; Budahn, J.; Kane, P.F.; Hall, W.L.

2007-01-01

During the past seven years, several states within the US have enacted regulations that limit the amounts of selected non-nutritive elements in fertilizers. Internationally, several countries, including Japan, China, and Australia, and the European Union also limit the amount of selected elements in fertilizers. The elements of interest include As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn. Fertilizer manufacturers and state regulatory authorities, faced with meeting and verifying these limits, need to develop analytical methods for determination of the elements of concern and to validate results obtained using these methods. Until now, there were no certified reference materials available with certified mass fraction values for all elements of interest in a blended, multi-nutrient fertilizer matrix. A new standard reference material (SRM) 695 trace elements in multi-nutrient fertilizer, has been developed to help meet these needs. SRM 695 has recently been issued with certified mass fraction values for seventeen elements, reference values for an additional five elements, and information values for two elements. The certificate of analysis includes an addendum listing percentage recovery for eight of these elements, determined using an acid-extraction inductively-coupled plasma optical-emission spectrometry (ICP-OES) method recently developed and tested by members of the Association of American Plant Food Control Officials. ?? Springer-Verlag 2007.

Fundamental Importance of Reference Glucose Analyzer Accuracy for Evaluating the Performance of Blood Glucose Monitoring Systems (BGMSs)

PubMed Central

Bailey, Timothy S.; Klaff, Leslie J.; Wallace, Jane F.; Greene, Carmine; Pardo, Scott; Harrison, Bern; Simmons, David A.

2016-01-01

Background: As blood glucose monitoring system (BGMS) accuracy is based on comparison of BGMS and laboratory reference glucose analyzer results, reference instrument accuracy is important to discriminate small differences between BGMS and reference glucose analyzer results. Here, we demonstrate the important role of reference glucose analyzer accuracy in BGMS accuracy evaluations. Methods: Two clinical studies assessed the performance of a new BGMS, using different reference instrument procedures. BGMS and YSI analyzer results were compared for fingertip blood that was obtained by untrained subjects’ self-testing and study staff testing, respectively. YSI analyzer accuracy was monitored using traceable serum controls. Results: In study 1 (N = 136), 94.1% of BGMS results were within International Organization for Standardization (ISO) 15197:2013 accuracy criteria; YSI analyzer serum control results showed a negative bias (−0.64% to −2.48%) at the first site and a positive bias (3.36% to 6.91%) at the other site. In study 2 (N = 329), 97.8% of BGMS results were within accuracy criteria; serum controls showed minimal bias (<0.92%) at both sites. Conclusions: These findings suggest that the ability to demonstrate that a BGMS meets accuracy guidelines is influenced by reference instrument accuracy. PMID:26902794

Review of national research ethics regulations and guidelines in Middle Eastern Arab countries

PubMed Central

2012-01-01

Background Research ethics guidelines are essential for conducting medical research. Recently, numerous attempts have been made to establish national clinical research documents in the countries of the Middle East. This article analyzes these documents. Methods Thirteen Arab countries in the Middle East were explored for available national codes, regulations, and guidelines concerning research ethics, and 10 documents from eight countries were found. We studied these documents, considering the ethical principles stated in the Declaration of Helsinki, the Council for International Organizations of Medical Sciences (CIOMS) guidelines, and the International Conference of Harmonization - Guidelines for Good Clinical Practice (ICH-GCP). Our paper comprises a complete list of protections, such as confidentiality, informed consent, ethics committees, and others. Results This study found different levels and kinds of research ethics regulations and guidelines in the countries examined. Two groups can be distinguished: the countries in the first group have one or more research ethics regulations or guidelines, while the countries in the second group have not yet established any. Most of the documents showed various degrees of deficiencies in regard to ethical protection. The majority of the documents that were examined refer to one or more international documents on biomedical research ethics. Conclusions Recently, a lot of efforts have been made in many countries in the Middle East. However, compared with international documents, most of the research ethics documents in use in this region demonstrate numerous deficiencies. As it relates to these documents, extensive differences could be observed in regard to development, structure, content, and reference to international guidelines. PMID:23234422

Physical and hormonal examination of Missouri River shovelnose sturgeon reproductive stage: A reference guide

USGS Publications Warehouse

Wildhaber, M.L.; Papoulias, D.M.; DeLonay, A.J.; Tillitt, D.E.; Bryan, J.L.; Annis, M.L.

2007-01-01

From May 2001 to June 2002 Wildhaber et al. (2005) conducted monthly sampling of Lower Missouri River shovelnose sturgeon (Scaphirhynchus platorynchus) to develop methods for determination of sex and the reproductive stage of sturgeons in the field. Shovelnose sturgeon were collected from the Missouri River and ultrasonic and endoscopic imagery and blood and gonadal tissue samples were taken. The full set of data was used to develop monthly reproductive stage profiles for S. platorynchus that could be compared to data collected on pallid sturgeon (Scaphirhynchus albus). This paper presents a comprehensive reference set of images, sex steroids, and vitellogenin (VTG, an egg protein precursor) data for assessing shovelnose sturgeon sex and reproductive stage. This reference set includes ultrasonic, endoscopic, histologic, and internal images of male and female gonads of shovelnose sturgeon at each reproductive stage along with complementary data on average 17-β estradiol, 11-ketotestosterone, VTG, gonadosomatic index, and polarization index.

Synchronization trigger control system for flow visualization

NASA Technical Reports Server (NTRS)

Chun, K. S.

1987-01-01

The use of cinematography or holographic interferometry for dynamic flow visualization in an internal combustion engine requires a control device that globally synchronizes camera and light source timing at a predefined shaft encoder angle. The device is capable of 0.35 deg resolution for rotational speeds of up to 73 240 rpm. This was achieved by implementing the shaft encoder signal addressed look-up table (LUT) and appropriate latches. The developed digital signal processing technique achieves 25 nsec of high speed triggering angle detection by using direct parallel bit comparison of the shaft encoder digital code with a simulated angle reference code, instead of using angle value comparison which involves more complicated computation steps. In order to establish synchronization to an AC reference signal whose magnitude is variant with the rotating speed, a dynamic peak followup synchronization technique has been devised. This method scrutinizes the reference signal and provides the right timing within 40 nsec. Two application examples are described.

Hirarchical emotion calculation model for virtual human modellin - biomed 2010.

PubMed

Zhao, Yue; Wright, David

2010-01-01

This paper introduces a new emotion generation method for virtual human modelling. The method includes a novel hierarchical emotion structure, a group of emotion calculation equations and a simple heuristics decision making mechanism, which enables virtual humans to perform emotionally in real-time according to their internal and external factors. Emotion calculation equations used in this research were derived from psychologic emotion measurements. Virtual humans can utilise the information in virtual memory and emotion calculation equations to generate their own numerical emotion states within the hierarchical emotion structure. Those emotion states are important internal references for virtual humans to adopt appropriate behaviours and also key cues for their decision making. A simple heuristics theory is introduced and integrated into decision making process in order to make the virtual humans decision making more like a real human. A data interface which connects the emotion calculation and the decision making structure together has also been designed and simulated to test the method in Virtools environment.

Energy Facts 1988.

ERIC Educational Resources Information Center

Energy Information Administration (DOE), Washington, DC.

This booklet is a compilation of energy data providing a reference to a much broader range of domestic and international energy data. It is designed especially as a quick reference to major facts about energy. The data includes information for 1976 through 1988, except for international energy data, which is for 1977 through 1987. Graphs, charts,…

Complete internal audit of a mammography service in a reference institution for breast imaging.

PubMed

Badan, Gustavo Machado; Roveda Júnior, Décio; Ferreira, Carlos Alberto Pecci; de Noronha Junior, Ozeas Alves

2014-01-01

Undertaking of a complete audit of the service of mammography, as recommended by BI-RADS(®), in a private reference institution for breast cancer diagnosis in the city of São Paulo, SP, Brazil, and comparison of results with those recommended by the literature. Retrospective, analytical and cross-sectional study including 8,000 patients submitted to mammography in the period between April 2010 and March 2011, whose results were subjected to an internal audit. The patients were followed-up until December 2012. The radiological classification of 7,249 screening mammograms, according to BI-RADS, was the following: category 0 (1.43%), 1 (7.82%), 2 (80.76%), 3 (8.35%), 4 (1.46%), 5 (0.15%) and 6 (0.03%). The breast cancer detection ratio was 4.8 cases per 1,000 mammograms. Ductal carcinoma in situ was found in 22.8% of cases. Positive predictive values for categories 3, 4 and 5 were 1.3%, 41.3% and 100%, respectively. In the present study, the sensitivity of the method was 97.1% and specificity, 97.4%. The complete internal audit of a service of mammography is essential to evaluate the quality of such service, which reflects on an early breast cancer detection and reduction of mortality rates.

The international growth standard for preadolescent and adolescent children: statistical considerations.

PubMed

Cole, T J

2006-12-01

This article discusses statistical considerations for the design of a new study intended to provide an International Growth Standard for Preadolescent and Adolescent Children, including issues such as cross-sectional, longitudinal, and mixed designs; sample-size derivation for the number of populations and number of children per population; modeling of growth centiles of height, weight, and other measurements; and modeling of the adolescent growth spurt. The conclusions are that a mixed longitudinal design will provide information on both growth distance and velocity; samples of children from 5 to 10 sites should be suitable for an international standard (based on political rather than statistical arguments); the samples should be broadly uniform across age but oversampled during puberty, and should include data into adulthood. The LMS method is recommended for constructing measurement centiles, and parametric or semiparametric approaches are available to estimate the timing of the adolescent growth spurt in individuals. If the new standard is to be grafted onto the 2006 World Health Organization (WHO) reference, caution is needed at the join point of 5 years, where children from the new standard are likely to be appreciably more obese than those from the WHO reference, due to the rising trends in obesity and the time gap in data collection between the two surveys.

Validation of psychoanalytic theories: towards a conceptualization of references.

PubMed

Zachrisson, Anders; Zachrisson, Henrik Daae

2005-10-01

The authors discuss criteria for the validation of psychoanalytic theories and develop a heuristic and normative model of the references needed for this. Their core question in this paper is: can psychoanalytic theories be validated exclusively from within psychoanalytic theory (internal validation), or are references to sources of knowledge other than psychoanalysis also necessary (external validation)? They discuss aspects of the classic truth criteria correspondence and coherence, both from the point of view of contemporary psychoanalysis and of contemporary philosophy of science. The authors present arguments for both external and internal validation. Internal validation has to deal with the problems of subjectivity of observations and circularity of reasoning, external validation with the problem of relevance. They recommend a critical attitude towards psychoanalytic theories, which, by carefully scrutinizing weak points and invalidating observations in the theories, reduces the risk of wishful thinking. The authors conclude by sketching a heuristic model of validation. This model combines correspondence and coherence with internal and external validation into a four-leaf model for references for the process of validating psychoanalytic theories.

Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method.

PubMed

Khosravi, H; Hashemi, B; Mahdavi, S R; Hejazi, P

2015-03-01

Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions. The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices. A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared. The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively. There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external radiotherapy practices.

International Geomagnetic Reference Field: the third generation.

USGS Publications Warehouse

Peddie, N.W.

1982-01-01

In August 1981 the International Association of Geomagnetism and Aeronomy revised the International Geomagnetic Reference Field (IGRF). It is the second revision since the inception of the IGRF in 1968. The revision extends the earlier series of IGRF models from 1980 to 1985, introduces a new series of definitive models for 1965-1976, and defines a provisional reference field for 1975- 1980. The revision consists of: 1) a model of the main geomagnetic field at 1980.0, not continuous with the earlier series of IGRF models together with a forecast model of the secular variation of the main field during 1980-1985; 2) definitive models of the main field at 1965.0, 1970.0, and 1975.0, with linear interpolation of the model coefficients specified for intervening dates; and 3) a provisional reference field for 1975-1980, defined as the linear interpolation of the 1975 and 1980 main-field models.-from Author

Monitoring Species of Concern Using Noninvasive Genetic Sampling and Capture-Recapture Methods

DTIC Science & Technology

2016-06-01

contents be construed as reflecting the official policy or position of the Department of Defense. Reference herein to any specific commercial product...Reserve in Mexico, and is home to more than 400 plant species and over 300 wildlife species. Construction of a border fence along the international...pronghorn mortality, a semi- captive breeding pen was constructed to facilitate pronghorn recovery (Otte 2006). The one- square mile facility is double

[Genetic engineering of forest woody plants].

PubMed

Mashkina, O S; Butorina, A K

2003-03-01

The present state of genetic engineering (GE) of forest woody plants is considered with special reference to the materials of the International Conference "Wood, Breeding, Biotechnology and Industrial Expectations" held in France in June, 2001. Main tree species subjected to GE are listed, aims of constructing transgenic plants discussed, and methods described. Major achievements in the field are considered along with the problems associated with the employment of GE in the breeding of forest woody plants.

Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States

USGS Publications Warehouse

Knight, Rodney R.; Murphy, Jennifer C.; Wolfe, William J.; Saylor, Charles F.; Wales, Amy K.

2014-01-01

Ecological limit functions relating streamflow and aquatic ecosystems remain elusive despite decades of research. We investigated functional relationships between species richness and changes in streamflow characteristics at 662 fish sampling sites in the Tennessee River basin. Our approach included the following: (1) a brief summary of relevant literature on functional relations between fish and streamflow, (2) the development of ecological limit functions that describe the strongest discernible relationships between fish species richness and streamflow characteristics, (3) the evaluation of proposed definitions of hydrologic reference conditions, and (4) an investigation of the internal structures of wedge-shaped distributions underlying ecological limit functions.Twenty-one ecological limit functions were developed across three ecoregions that relate the species richness of 11 fish groups and departures from hydrologic reference conditions using multivariate and quantile regression methods. Each negatively sloped function is described using up to four streamflow characteristics expressed in terms of cumulative departure from hydrologic reference conditions. Negative slopes indicate increased departure results in decreased species richness.Sites with the highest measured fish species richness generally had near-reference hydrologic conditions for a given ecoregion. Hydrology did not generally differ between sites with the highest and lowest fish species richness, indicating that other environmental factors likely limit species richness at sites with reference hydrology.Use of ecological limit functions to make decisions regarding proposed hydrologic regime changes, although commonly presented as a management tool, is not as straightforward or informative as often assumed. We contend that statistical evaluation of the internal wedge structure below limit functions may provide a probabilistic understanding of how aquatic ecology is influenced by altered hydrology and may serve as the basis for evaluating the potential effect of proposed hydrologic changes.

Physical growth of the shuar: Height, Weight, and BMI references for an indigenous amazonian population.

PubMed

Urlacher, Samuel S; Blackwell, Aaron D; Liebert, Melissa A; Madimenos, Felicia C; Cepon-Robins, Tara J; Gildner, Theresa E; Snodgrass, J Josh; Sugiyama, Lawrence S

2016-01-01

Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. Mixed-longitudinal measures of height, weight, and body mass index (BMI) were collected from Shuar participants (n = 2,463; age: 0-29 years). Centile growth curves and tables were created for each anthropometric variable of interest using Generalized Additive Models for Location, Scale, and Shape (GAMLSS). Pseudo-velocity and Lambda-Mu-Sigma curves were generated to further investigate Shuar patterns of growth and to facilitate comparison with United States Center for Disease Control and Prevention and multinational World Health Organization growth references. The Shuar are small throughout life and exhibit complex patterns of growth that differ substantially from those of international references. Similar to other Amazonians, Shuar growth in weight compares more favorably to references than growth in height, resulting in BMI curves that approximate international medians. Several additional characteristics of Shuar development are noteworthy, including large observed variation in body size early in life, significant infant growth faltering, extended male growth into adulthood, and a markedly early female pubertal growth spurt in height. Phenotypic plasticity and genetic selection in response to local environmental factors may explain many of these patterns. Providing a detailed reference of growth for the Shuar and other Amazonian populations, this study possesses direct clinical application and affords valuable insight into childhood health and the ecology of human growth. © 2015 Wiley Periodicals, Inc.

Pregnancy testing with hCG--future prospects.

PubMed

Berger, Peter; Sturgeon, Catharine

2014-12-01

Pregnancy tests for human chorionic gonadotrophin (hCG) are used widely in hospital and home settings. Assays measuring hCG also have uses in prenatal screening and oncology. The output from three recent international workshops provides a framework for reliable measurement of hCG. Requirements for future hCG assays include use of clear descriptive nomenclature, informed selection of antibodies of well-defined epitope specificities, and design of robust methods. Tests will be precisely characterized and calibrated in SI units using six International Reference Reagents (IRR) for hCG and variants, and the Fifth International Standard for hCG 07/364, making it possible to report clinical results in molar units. These measures will help to increase patient safety by reducing the risk of erroneous or misleading hCG results. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modeling of R/C Servo Motor and Application to Underactuated Mechanical Systems

NASA Astrophysics Data System (ADS)

Ishikawa, Masato; Kitayoshi, Ryohei; Wada, Takashi; Maruta, Ichiro; Sugie, Toshiharu

An R/C servo motor is a compact package of a DC geard-motor associated with a position servo controller. They are widely used in small-sized robotics and mechatronics by virtue of their compactness, easiness-to-use and high/weight ratio. However, it is crucial to clarify their internal model (including the embedded position servo) in order to improve control performance of mechatronic systems using R/C servo motors, such as biped robots or underactuted sysyems. In this paper, we propose a simple and realistic internal model of the R/C servo motors including the embedded servo controller, and estimate their physical parameters using continuous-time system identification method. We also provide a model of reference-to-torque transfer function so that we can estimate the internal torque acting on the load.

Determination of dabigatran, rivaroxaban and apixaban by ultra-performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS) and coagulation assays for therapy monitoring of novel direct oral anticoagulants.

PubMed

Schmitz, E M H; Boonen, K; van den Heuvel, D J A; van Dongen, J L J; Schellings, M W M; Emmen, J M A; van der Graaf, F; Brunsveld, L; van de Kerkhof, D

2014-10-01

Three novel direct oral anticoagulants (DOACs) have recently been registered by the Food and Drug Administration and European Medicines Agency Commission: dabigatran, rivaroxaban, and apixaban. To quantify DOACs in plasma, various dedicated coagulation assays have been developed. To develop and validate a reference ultra-performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS) method and to evaluate the analytical performance of several coagulation assays for quantification of dabigatran, rivaroxaban, and apixaban. The developed UPLC-MS/MS method was validated by determination of precision, accuracy, specificity, matrix effects, lower limits of detection, carry-over, recovery, stability, and robustness. The following coagulation assays were evaluated for accuracy and precision: laboratory-developed (LD) diluted thrombin time (dTT), Hemoclot dTT, Pefakit PiCT, ECA, Liquid anti-Xa, Biophen Heparin (LRT), and Biophen DiXal anti-Xa. Agreement between the various coagulation assays and UPLC-MS/MS was determined with random samples from patients using dabigatran or rivaroxaban. The UPLC-MS/MS method was shown to be accurate, precise, sensitive, stable, and robust. The dabigatran coagulation assay showing the best precision, accuracy and agreement with the UPLC-MS/MS method was the LD dTT test. For rivaroxaban, the anti-factor Xa assays were superior to the PiCT-Xa assay with regard to precision, accuracy, and agreement with the reference method. For apixaban, the Liquid anti-Xa assay was superior to the PiCT-Xa assay. Statistically significant differences were observed between the various coagulation assays as compared with the UPLC-MS/MS reference method. It is currently unknown whether these differences are clinically relevant. When DOACs are quantified with coagulation assays, comparison with a reference method as part of proficiency testing is therefore pivotal. © 2014 International Society on Thrombosis and Haemostasis.

Biscayne aquifer drinking water (USGS45): a new isotopic reference material for δ2H and δ18O measurements of water

USGS Publications Warehouse

Lorenz, Jennifer M.; Tarbox, Lauren V.; Buck, Bryan; Qi, Haiping; Coplen, Tyler B.

2014-01-01

RATIONALE As a result of the scarcity of isotopic reference waters for daily use, a new secondary isotopic reference material for international distribution has been prepared from drinking water collected from the Biscayne aquifer in Ft. Lauderdale, Florida. METHODS This isotopic reference water was filtered, homogenized, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity, and measured by dual-inlet isotope-ratio mass spectrometry. This reference material is available by the case of 144 glass ampoules containing either 4 mL or 5 mL of water in each ampoule. RESULTS The δ2H and δ18O values of this reference material are –10.3 ± 0.4 ‰ and –2.238 ± 0.011 ‰, respectively, relative to VSMOW, on scales normalized such that the δ2H and δ18O values of SLAP reference water are, respectively, –428 and –55.5 ‰. Each uncertainty is an estimated expanded uncertainty (U = 2uc) about the reference value that provides an interval that has about a 95 % probability of encompassing the true value. CONCLUSIONS This isotopic reference material, designated as USGS45, is intended as one of two isotopic reference waters for daily normalization of stable hydrogen and oxygen isotopic analysis of water with an isotope-ratio mass spectrometer or a laser absorption spectrometer. 

Development of discrete choice model considering internal reference points and their effects in travel mode choice context

NASA Astrophysics Data System (ADS)

Sarif; Kurauchi, Shinya; Yoshii, Toshio

2017-06-01

In the conventional travel behavior models such as logit and probit, decision makers are assumed to conduct the absolute evaluations on the attributes of the choice alternatives. On the other hand, many researchers in cognitive psychology and marketing science have been suggesting that the perceptions of attributes are characterized by the benchmark called “reference points” and the relative evaluations based on them are often employed in various choice situations. Therefore, this study developed a travel behavior model based on the mental accounting theory in which the internal reference points are explicitly considered. A questionnaire survey about the shopping trip to the CBD in Matsuyama city was conducted, and then the roles of reference points in travel mode choice contexts were investigated. The result showed that the goodness-of-fit of the developed model was higher than that of the conventional model, indicating that the internal reference points might play the major roles in the choice of travel mode. Also shown was that the respondents seem to utilize various reference points: some tend to adopt the lowest fuel price they have experienced, others employ fare price they feel in perceptions of the travel cost.

Estimating Alcohol Content of Traditional Brew in Western Kenya Using Culturally Relevant Methods: The Case for Cost Over Volume

PubMed Central

Sidle, John E.; Wamalwa, Emmanuel S.; Okumu, Thomas O.; Bryant, Kendall L.; Goulet, Joseph L.; Maisto, Stephen A.; Braithwaite, R. Scott; Justice, Amy C.

2010-01-01

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang’aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang’aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang’aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang’aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard. PMID:19015972

Methodological proposal for validation of the disinfecting efficacy of an automated flexible endoscope reprocessor

PubMed Central

Graziano, Kazuko Uchikawa; Pereira, Marta Elisa Auler; Koda, Elaine

2016-01-01

ABSTRACT Objective: to elaborate and apply a method to assess the efficacy of automated flexible endoscope reprocessors at a time when there is not an official method or trained laboratories to comply with the requirements described in specific standards for this type of health product in Brazil. Method: the present methodological study was developed based on the following theoretical references: International Organization for Standardization (ISO) standard ISO 15883-4/2008 and Brazilian Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA) Collegiate Board Resolution (Resolução de Diretoria Colegiada - RDC) no. 35/2010 and 15/2012. The proposed method was applied to a commercially available device using a high-level 0.2% peracetic acid-based disinfectant. Results: the proposed method of assessment was found to be robust when the recommendations made in the relevant legislation were incorporated with some adjustments to ensure their feasibility. Application of the proposed method provided evidence of the efficacy of the tested equipment for the high-level disinfection of endoscopes. Conclusion: the proposed method may serve as a reference for the assessment of flexible endoscope reprocessors, thereby providing solid ground for the purchase of this category of health products. PMID:27508915

Handbook of ecotoxicology, second edition

USGS Publications Warehouse

Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

2003-01-01

Handbook of Ecotoxicology, Second Edition focuses on toxic substances and how they affect ecosystems worldwide. It presents methods for quantifying and measuring ecotoxicological effects in the field and in the lab, as well as methods for estimating, predicting, and modeling in ecotoxicology studies. Completely revised and updated with 18 new chapters, this second edition includes contributions from over 75 international experts. Also, a Technical Review Board reviewed all manuscripts for accuracy and currency. This authoritative work is the definitive reference for students, researchers, consultants, and other professionals in the environmental sciences, toxicology, chemistry, biology, and ecology - in academia, industry, and government.

The International Human Epigenome Consortium Data Portal.

PubMed

Bujold, David; Morais, David Anderson de Lima; Gauthier, Carol; Côté, Catherine; Caron, Maxime; Kwan, Tony; Chen, Kuang Chung; Laperle, Jonathan; Markovits, Alexei Nordell; Pastinen, Tomi; Caron, Bryan; Veilleux, Alain; Jacques, Pierre-Étienne; Bourque, Guillaume

2016-11-23

The International Human Epigenome Consortium (IHEC) coordinates the production of reference epigenome maps through the characterization of the regulome, methylome, and transcriptome from a wide range of tissues and cell types. To define conventions ensuring the compatibility of datasets and establish an infrastructure enabling data integration, analysis, and sharing, we developed the IHEC Data Portal (http://epigenomesportal.ca/ihec). The portal provides access to >7,000 reference epigenomic datasets, generated from >600 tissues, which have been contributed by seven international consortia: ENCODE, NIH Roadmap, CEEHRC, Blueprint, DEEP, AMED-CREST, and KNIH. The portal enhances the utility of these reference maps by facilitating the discovery, visualization, analysis, download, and sharing of epigenomics data. The IHEC Data Portal is the official source to navigate through IHEC datasets and represents a strategy for unifying the distributed data produced by international research consortia. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Focus Upon Implementing the GGOS Decadal Vision for Geohazards Monitoring

NASA Astrophysics Data System (ADS)

LaBrecque, John; Stangl, Gunter

2017-04-01

The Global Geodetic Observing System of the IAG identified present and future roles for Geodesy in the development and well being of the global society. The GGOS is focused upon the development of infrastructure, information, analysis, and educational systems to advance the International Global Reference Frame, the International Celestial Reference System, the International Height Reference System, atmospheric dynamics, sea level change and geohazards monitoring. The geohazards initiative is guided by an eleven nation working group initially focused upon the development and integration of regional multi-GNSS networks and analysis systems for earthquake and tsunami early warning. The opportunities and challenges being addressed by the Geohazards working group include regional network design, algorithm development and implementation, communications, funding, and international agreements on data access. This presentation will discuss in further detail these opportunities and challenges for the GGOS focus upon earthquake and tsunami early warning.

Nonorthogonal orbital based N-body reduced density matrices and their applications to valence bond theory. I. Hamiltonian matrix elements between internally contracted excited valence bond wave functions

NASA Astrophysics Data System (ADS)

Chen, Zhenhua; Chen, Xun; Wu, Wei

2013-04-01

In this series, the n-body reduced density matrix (n-RDM) approach for nonorthogonal orbitals and their applications to ab initio valence bond (VB) methods are presented. As the first paper of this series, Hamiltonian matrix elements between internally contracted VB wave functions are explicitly provided by means of nonorthogonal orbital based RDM approach. To this end, a more generalized Wick's theorem, called enhanced Wick's theorem, is presented both in arithmetical and in graphical forms, by which the deduction of expressions for the matrix elements between internally contracted VB wave functions is dramatically simplified, and the matrix elements are finally expressed in terms of tensor contractions of electronic integrals and n-RDMs of the reference VB self-consistent field wave function. A string-based algorithm is developed for the purpose of evaluating n-RDMs in an efficient way. Using the techniques presented in this paper, one is able to develop new methods and efficient algorithms for nonorthogonal orbital based many-electron theory much easier than by use of the first quantized formulism.

Gravimetric Analysis of Particulate Matter using Air Samplers Housing Internal Filtration Capsules.

PubMed

O'Connor, Sean; O'Connor, Paula Fey; Feng, H Amy; Ashley, Kevin

2014-10-01

An evaluation was carried out to investigate the suitability of polyvinyl chloride (PVC) internal capsules, housed within air sampling devices, for gravimetric analysis of airborne particles collected in workplaces. Experiments were carried out using blank PVC capsules and PVC capsules spiked with 0,1 - 4 mg of National Institute of Standards and Technology Standard Reference Material ® (NIST SRM) 1648 (Urban Particulate Matter) and Arizona Road Dust (Air Cleaner Test Dust). The capsules were housed within plastic closed-face cassette samplers (CFCs). A method detection limit (MDL) of 0,075 mg per sample was estimated. Precision S r at 0,5 - 4 mg per sample was 0,031 and the estimated bias was 0,058. Weight stability over 28 days was verified for both blanks and spiked capsules. Independent laboratory testing on blanks and field samples verified long-term weight stability as well as sampling and analysis precision and bias estimates. An overall precision estimate Ŝ rt of 0,059 was obtained. An accuracy measure of ±15,5% was found for the gravimetric method using PVC internal capsules.

Gravimetric Analysis of Particulate Matter using Air Samplers Housing Internal Filtration Capsules

PubMed Central

O'Connor, Sean; O'Connor, Paula Fey; Feng, H. Amy

2015-01-01

Summary An evaluation was carried out to investigate the suitability of polyvinyl chloride (PVC) internal capsules, housed within air sampling devices, for gravimetric analysis of airborne particles collected in workplaces. Experiments were carried out using blank PVC capsules and PVC capsules spiked with 0,1 – 4 mg of National Institute of Standards and Technology Standard Reference Material® (NIST SRM) 1648 (Urban Particulate Matter) and Arizona Road Dust (Air Cleaner Test Dust). The capsules were housed within plastic closed-face cassette samplers (CFCs). A method detection limit (MDL) of 0,075 mg per sample was estimated. Precision Sr at 0,5 - 4 mg per sample was 0,031 and the estimated bias was 0,058. Weight stability over 28 days was verified for both blanks and spiked capsules. Independent laboratory testing on blanks and field samples verified long-term weight stability as well as sampling and analysis precision and bias estimates. An overall precision estimate Ŝrt of 0,059 was obtained. An accuracy measure of ±15,5% was found for the gravimetric method using PVC internal capsules. PMID:26435581

International Access to Bibliographic Data: MARC and MARC-Related Activities.

ERIC Educational Resources Information Center

Hopkinson, Alan

1984-01-01

This review of international information exchange formats focuses on the international standard ISO 2709 and MARC formats, "UNISIST Reference Manual," UNIMARC (Universal MARC format), the Common Communications Format, centralized network formats (International Serials Data System, MINISIS, regional), International MARC network study…

Accurate quantitation standards of glutathione via traceable sulfur measurement by inductively coupled plasma optical emission spectrometry and ion chromatography

PubMed Central

Rastogi, L.; Dash, K.; Arunachalam, J.

2013-01-01

The quantitative analysis of glutathione (GSH) is important in different fields like medicine, biology, and biotechnology. Accurate quantitative measurements of this analyte have been hampered by the lack of well characterized reference standards. The proposed procedure is intended to provide an accurate and definitive method for the quantitation of GSH for reference measurements. Measurement of the stoichiometrically existing sulfur content in purified GSH offers an approach for its quantitation and calibration through an appropriate characterized reference material (CRM) for sulfur would provide a methodology for the certification of GSH quantity, that is traceable to SI (International system of units). The inductively coupled plasma optical emission spectrometry (ICP-OES) approach negates the need for any sample digestion. The sulfur content of the purified GSH is quantitatively converted into sulfate ions by microwave-assisted UV digestion in the presence of hydrogen peroxide prior to ion chromatography (IC) measurements. The measurement of sulfur by ICP-OES and IC (as sulfate) using the “high performance” methodology could be useful for characterizing primary calibration standards and certified reference materials with low uncertainties. The relative expanded uncertainties (% U) expressed at 95% confidence interval for ICP-OES analyses varied from 0.1% to 0.3%, while in the case of IC, they were between 0.2% and 1.2%. The described methods are more suitable for characterizing primary calibration standards and certifying reference materials of GSH, than for routine measurements. PMID:29403814

Metrological approaches to organic chemical purity: primary reference materials for vitamin D metabolites.

PubMed

Nelson, Michael A; Bedner, Mary; Lang, Brian E; Toman, Blaza; Lippa, Katrice A

2015-11-01

Given the critical role of pure, organic compound primary reference standards used to characterize and certify chemical Certified Reference Materials (CRMs), it is essential that associated mass purity assessments be fit-for-purpose, represented by an appropriate uncertainty interval, and metrologically sound. The mass fraction purities (% g/g) of 25-hydroxyvitamin D (25(OH)D) reference standards used to produce and certify values for clinical vitamin D metabolite CRMs were investigated by multiple orthogonal quantitative measurement techniques. Quantitative (1)H-nuclear magnetic resonance spectroscopy (qNMR) was performed to establish traceability of these materials to the International System of Units (SI) and to directly assess the principal analyte species. The 25(OH)D standards contained volatile and water impurities, as well as structurally-related impurities that are difficult to observe by chromatographic methods or to distinguish from the principal 25(OH)D species by one-dimensional NMR. These impurities have the potential to introduce significant biases to purity investigations in which a limited number of measurands are quantified. Combining complementary information from multiple analytical methods, using both direct and indirect measurement techniques, enabled mitigation of these biases. Purities of 25(OH)D reference standards and associated uncertainties were determined using frequentist and Bayesian statistical models to combine data acquired via qNMR, liquid chromatography with UV absorbance and atmospheric pressure-chemical ionization mass spectrometric detection (LC-UV, LC-ACPI-MS), thermogravimetric analysis (TGA), and Karl Fischer (KF) titration.

Accuracy of body mass index for age to diagnose obesity in Mexican schoolchildren.

PubMed

Mendoza Pablo, Pedro A; Valdés, Jesús; Ortiz-Hernández, Luis

2015-06-01

To compare the accuracy of three BMI-forage references (World Health Organization reference, WHO; the updated International Obesity Task Force reference, IOTF; and Centers for Disease Control and Prevention (CDC) growth charts) to diagnose obesity in Mexican children. A convenience sample of Mexican schoolchildren (n = 218) was assessed. The gold standard was the percentage of body fat estimated by deuterium dilution technique. Sensitivity and specificity of the classical cutoff point of BMI-for-age to identify obesity (i.e. > 2.00 standard deviation, SD) were estimated. The accuracy (i.e. area under the curve, AUC) of three BMI-for-age references for the diagnosis of obesity was estimated with the receiver operating characteristic (ROC) curves method. The optimal cutoff point (OCP) was determined. The cutoff points to identify obesity had low (WHO reference: 57.6%, CDC: 53.5%) to very low (IOTF reference: 40.4%) sensitivities, but adequate specificities (91.6%, 95.0%, and, 97.5%, respectively). The AUC of the three references were adequate (0.89). For the IOTF reference, the AUC was lower among the older children. The OCP for the CDC reference (1.24 SD) was lower than the OCP for WHO (1.53 SD) and IOTF charts (1.47 SD). The classical cutoff point for obesity has low sensitivity--especially for the IOTF reference. The accuracy of the three references was similar. However, to obtain comparable diagnosis of obesity different cutoff points should be used depending of the reference. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Linking Comparisons of Absolute Gravimeters: A Proof of Concept for a new Global Absolute Gravity Reference System.

NASA Astrophysics Data System (ADS)

Wziontek, H.; Palinkas, V.; Falk, R.; Vaľko, M.

2016-12-01

Since decades, absolute gravimeters are compared on a regular basis on an international level, starting at the International Bureau for Weights and Measures (BIPM) in 1981. Usually, these comparisons are based on constant reference values deduced from all accepted measurements acquired during the comparison period. Temporal changes between comparison epochs are usually not considered. Resolution No. 2, adopted by IAG during the IUGG General Assembly in Prague 2015, initiates the establishment of a Global Absolute Gravity Reference System based on key comparisons of absolute gravimeters (AG) under the International Committee for Weights and Measures (CIPM) in order to establish a common level in the microGal range. A stable and unique reference frame can only be achieved, if different AG are taking part in different kind of comparisons. Systematic deviations between the respective comparison reference values can be detected, if the AG can be considered stable over time. The continuous operation of superconducting gravimeters (SG) on selected stations further supports the temporal link of comparison reference values by establishing a reference function over time. By a homogenous reprocessing of different comparison epochs and including AG and SG time series at selected stations, links between several comparisons will be established and temporal comparison reference functions will be derived. By this, comparisons on a regional level can be traced to back to the level of key comparisons, providing a reference for other absolute gravimeters. It will be proved and discussed, how such a concept can be used to support the future absolute gravity reference system.

Cognitive Ability, Academic Achievement and Academic Self-Concept: Extending the Internal/External Frame of Reference Model

ERIC Educational Resources Information Center

Chen, Ssu-Kuang; Hwang, Fang-Ming; Yeh, Yu-Chen; Lin, Sunny S. J.

2012-01-01

Background: Marsh's internal/external (I/E) frame of reference model depicts the relationship between achievement and self-concept in specific academic domains. Few efforts have been made to examine concurrent relationships among cognitive ability, achievement, and academic self-concept (ASC) within an I/E model framework. Aim: To simultaneously…

40 CFR Appendix 8 to Subpart A of... - Reference C16-C18 Internal Olefin Drilling Fluid Formulation

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Reference C16-C18 Internal Olefin Drilling Fluid Formulation 8 Appendix 8 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS OIL AND GAS EXTRACTION POINT SOURCE CATEGORY...

40 CFR Appendix 8 to Subpart A of... - Reference C16-C18 Internal Olefin Drilling Fluid Formulation

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Reference C16-C18 Internal Olefin Drilling Fluid Formulation 8 Appendix 8 to Subpart A of Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS OIL AND GAS EXTRACTION POINT SOURCE CATEGORY...

Certification of the reference material of water content in water saturated 1-octanol by Karl Fischer coulometry, Karl Fischer volumetry and quantitative nuclear magnetic resonance.

PubMed

Wang, Haifeng; Ma, Kang; Zhang, Wei; Li, Jia; Sun, Guohua; Li, Hongmei

2012-10-15

Certified reference materials (CRMs) of water content are widely used in the calibration and validation of Karl Fischer coulometry and volumetry. In this study, the water content of the water saturated 1-octanol (WSO) CRM was certified by Karl Fischer coulometry, volumetry and quantitative nuclear magnetic resonance (Q NMR). The water content recovery by coulometry was 99.76% with a diaphragm-less electrode and Coulomat AG anolyte. The relative bias between the coulometry and volumetry results was 0.06%. In Q NMR, the water content of WSO is traceable to the International System (SI) of units through the purity of internal standard. The relative bias of water content in WSO between Q NMR and volumetry was 0.50%. The consistency of results for these three independent methods improves the accuracy of the certification of the RM. The certified water content of the WSO CRM was 4.76% with an expanded uncertainty of 0.09%. Copyright © 2012 Elsevier Ltd. All rights reserved.

Study on temperature distribution effect on internal charging by computer simulation

NASA Astrophysics Data System (ADS)

Yi, Zhong

2016-07-01

Internal charging (or deep dielectric charging) is a great threaten to spacecraft. Dielectric conductivity is an important parameter for internal charging and it is sensitive to temperature. Considering the exposed dielectric outside a spacecraft may experience a relatively large temperature range, temperature effect can't be ignored in internal charging assessment. We can see some reporters on techniques of computer simulation of internal charging, but the temperature effect has not been taken into accounts. In this paper, we realize the internal charging simulation with consideration of temperature distribution inside the dielectric. Geant4 is used for charge transportation, and a numerical method is proposed for solving the current reservation equation. The conductivity dependences on temperature, radiation dose rate and intense electric field are considered. Compared to the case of uniform temperature, the internal charging with temperature distribution is more complicated. Results show that temperature distribution can cause electric field distortion within the dielectric. This distortion refers to locally considerable enlargement of electric field. It usually corresponds to the peak electric field which is critical for dielectric breakdown judgment. The peak electric field can emerge inside the dielectric, or appear on the boundary. This improvement of internal charging simulation is beneficial for the assessment of internal charging under multiple factors.

Laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF): performance, reference spectra and classification of atmospheric samples

NASA Astrophysics Data System (ADS)

Shen, Xiaoli; Ramisetty, Ramakrishna; Mohr, Claudia; Huang, Wei; Leisner, Thomas; Saathoff, Harald

2018-04-01

The laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF, AeroMegt GmbH) is able to identify the chemical composition and mixing state of individual aerosol particles, and thus is a tool for elucidating their impacts on human health, visibility, ecosystem, and climate. The overall detection efficiency (ODE) of the instrument we use was determined to range from ˜ (0.01 ± 0.01) to ˜ (4.23 ± 2.36) % for polystyrene latex (PSL) in the size range of 200 to 2000 nm, ˜ (0.44 ± 0.19) to ˜ (6.57 ± 2.38) % for ammonium nitrate (NH4NO3), and ˜ (0.14 ± 0.02) to ˜ (1.46 ± 0.08) % for sodium chloride (NaCl) particles in the size range of 300 to 1000 nm. Reference mass spectra of 32 different particle types relevant for atmospheric aerosol (e.g. pure compounds NH4NO3, K2SO4, NaCl, oxalic acid, pinic acid, and pinonic acid; internal mixtures of e.g. salts, secondary organic aerosol, and metallic core-organic shell particles; more complex particles such as soot and dust particles) were determined. Our results show that internally mixed aerosol particles can result in spectra with new clusters of ions, rather than simply a combination of the spectra from the single components. An exemplary 1-day ambient data set was analysed by both classical fuzzy clustering and a reference-spectra-based classification method. Resulting identified particle types were generally well correlated. We show how a combination of both methods can greatly improve the interpretation of single-particle data in field measurements.

Dosimetry and image quality assessment in a direct radiography system

PubMed Central

Oliveira, Bruno Beraldo; de Oliveira, Marcio Alves; Paixão, Lucas; Teixeira, Maria Helena Araújo; Nogueira, Maria do Socorro

2014-01-01

Objective To evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and Methods Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results Considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion The present study contributes to verify the equipment conformity as regards dose values and image quality. PMID:25741119

Quality assurance and quality control in light stable isotope laboratories: A case study of Rio Grande, Texas, water samples

USGS Publications Warehouse

Coplen, T.B.; Qi, H.

2009-01-01

New isotope laboratories can achieve the goal of reporting the same isotopic composition within analytical uncertainty for the same material analysed decades apart by (1) writing their own acceptance testing procedures and putting them into their mass spectrometric or laser-based isotope-ratio equipment procurement contract, (2) requiring a manufacturer to demonstrate acceptable performance using all sample ports provided with the instrumentation, (3) for each medium to be analysed, prepare two local reference materials substantially different in isotopic composition to encompass the range in isotopic composition expected in the laboratory and calibrated them with isotopic reference materials available from the International Atomic Energy Agency (IAEA) or the US National Institute of Standards and Technology (NIST), (4) using the optimum storage containers (for water samples, sealing in glass ampoules that are sterilised after sealing is satisfactory), (5) interspersing among sample unknowns local laboratory isotopic reference materials daily (internationally distributed isotopic reference materials can be ordered at three-year intervals, and can be used for elemental analyser analyses and other analyses that consume less than 1 mg of material) - this process applies to H, C, N, O, and S isotope ratios, (6) calculating isotopic compositions of unknowns by normalising isotopic data to that of local reference materials, which have been calibrated to internationally distributed isotopic reference materials, (7) reporting results on scales normalised to internationally distributed isotopic reference materials (where they are available) and providing to sample submitters the isotopic compositions of internationally distributed isotopic reference materials of the same substance had they been analysed with unknowns, (8) providing an audit trail in the laboratory for analytical results - this trail commonly will be in electronic format and might include a laboratory information management system, (9) making at regular intervals a complete backup of laboratory analytical data (both of samples logged into the laboratory and of mass spectrometric analyses), being sure to store one copy of this backup offsite, and (10) participating in interlaboratory comparison exercises sponsored by the IAEA and other agencies at regular intervals. ?? Taylor & Francis.

The Geochemical Databases GEOROC and GeoReM - What's New?

NASA Astrophysics Data System (ADS)

Sarbas, B.; Jochum, K. P.; Nohl, U.; Weis, U.

2017-12-01

The geochemical databases GEOROC (http: georoc.mpch-mainz.gwdg.de) and GeoReM (http: georem.mpch-mainz.gwdg.de) are maintained by the Max Planck Institute for Chemistry in Mainz, Germany. Both online databases became crucial tools for geoscientists from different research areas. They are regularly upgraded by new tools and new data from recent publications obtained from a wide range of international journals. GEOROC is a collection of published analyses of volcanic rocks and mantle xenoliths. Since recently, data for plutonic rocks are added. The analyses include major and trace element concentrations, radiogenic and non-radiogenic isotope ratios as well as analytical ages for whole rocks, glasses, minerals and inclusions. Samples come from eleven geological settings and span the whole geological age scale from Archean to Recent. Metadata include, among others, geographic location, rock class and rock type, geological age, degree of alteration, analytical method, laboratory, and reference. The GEOROC web page allows selection of samples by geological setting, geography, chemical criteria, rock or sample name, and bibliographic criteria. In addition, it provides a large number of precompiled files for individual locations, minerals and rock classes. GeoReM is a database collecting information about reference materials of geological and environmental interest, such as rock powders, synthetic and natural glasses as well as mineral, isotopic, biological, river water and seawater reference materials. It contains published data and compilation values (major and trace element concentrations and mass fractions, radiogenic and stable isotope ratios). Metadata comprise, among others, uncertainty, analytical method and laboratory. Reference materials are important for calibration, method validation, quality control and to establish metrological traceability. GeoReM offers six different search strategies: samples or materials (published values), samples (GeoReM preferred values), chemical criteria, chemical criteria based on bibliography, bibliography, as well as methods and institutions.

Comparison between B·R·A·H·M·S PCT direct, a new sensitive point-of-care testing device for rapid quantification of procalcitonin in emergency department patients and established reference methods - a prospective multinational trial.

PubMed

Kutz, Alexander; Hausfater, Pierre; Oppert, Michael; Alan, Murat; Grolimund, Eva; Gast, Claire; Alonso, Christine; Wissmann, Christoph; Kuehn, Christian; Bernard, Maguy; Huber, Andreas; Mueller, Beat; Schuetz, Philipp

2016-04-01

Procalcitonin (PCT) is increasingly being used for the diagnostic and prognostic work up of patients with suspected infections in the emergency department (ED). Recently, B·R·A·H·M·S PCT direct, the first high sensitive point-of-care test (POCT), has been developed for fast PCT measurement on capillary or venous blood samples. This is a prospective, international comparison study conducted in three European EDs. Consecutive patients with suspicion of bacterial infection were included. Duplicate determination of PCT was performed in capillary (fingertip) and venous whole blood (EDTA), and compared to the reference method. The diagnostic accuracy was evaluated by correlation and concordance analyses. Three hundred and three patients were included over a 6-month period (60.4% male, median age 65.2 years). The correlation between capillary or venous whole blood and the reference method was excellent: r2=0.96 and 0.97, sensitivity 88.1% and 93.0%, specificity 96.5% and 96.8%, concordance 93% and 95%, respectively at a 0.25 μg/L threshold. No significant bias was observed (-0.04 and -0.02 for capillary and venous whole blood) although there were 6.8% and 5.1% outliers, respectively. B·R·A·H·M·S PCT direct had a shorter time to result as compared to the reference method (25 vs. 144 min, difference 119 min, 95% CI 110-134 min, p<0.0001). This study found a high diagnostic accuracy and a faster time to result of B·R·A·H·M·S PCT direct in the ED setting, allowing shortening time to therapy and a more wide-spread use of PCT.

A surface spherical harmonic expansion of gravity anomalies on the ellipsoid

NASA Astrophysics Data System (ADS)

Claessens, S. J.; Hirt, C.

2015-10-01

A surface spherical harmonic expansion of gravity anomalies with respect to a geodetic reference ellipsoid can be used to model the global gravity field and reveal its spectral properties. In this paper, a direct and rigorous transformation between solid spherical harmonic coefficients of the Earth's disturbing potential and surface spherical harmonic coefficients of gravity anomalies in ellipsoidal approximation with respect to a reference ellipsoid is derived. This transformation cannot rigorously be achieved by the Hotine-Jekeli transformation between spherical and ellipsoidal harmonic coefficients. The method derived here is used to create a surface spherical harmonic model of gravity anomalies with respect to the GRS80 ellipsoid from the EGM2008 global gravity model. Internal validation of the model shows a global RMS precision of 1 nGal. This is significantly more precise than previous solutions based on spherical approximation or approximations to order or , which are shown to be insufficient for the generation of surface spherical harmonic coefficients with respect to a geodetic reference ellipsoid. Numerical results of two applications of the new method (the computation of ellipsoidal corrections to gravimetric geoid computation, and area means of gravity anomalies in ellipsoidal approximation) are provided.

Stable isotope analyses of oxygen (18O:17O:16O) and chlorine (37Cl:35Cl) in perchlorate: reference materials, calibrations, methods, and interferences

USGS Publications Warehouse

Böhlke, John Karl; Mroczkowski, Stanley J.; Sturchio, Neil C.; Heraty, Linnea J.; Richman, Kent W.; Sullivan, Donald B.; Griffith, Kris N.; Gu, Baohua; Hatzinger, Paul B.

2017-01-01

RationalePerchlorate (ClO4−) is a common trace constituent of water, soils, and plants; it has both natural and synthetic sources and is subject to biodegradation. The stable isotope ratios of Cl and O provide three independent quantities for ClO4− source attribution and natural attenuation studies: δ37Cl, δ18O, and δ17O (or Δ17O or 17Δ) values. Documented reference materials, calibration schemes, methods, and interferences will improve the reliability of such studies.MethodsThree large batches of KClO4 with contrasting isotopic compositions were synthesized and analyzed against VSMOW-SLAP, atmospheric O2, and international nitrate and chloride reference materials. Three analytical methods were tested for O isotopes: conversion of ClO4− to CO for continuous-flow IRMS (CO-CFIRMS), decomposition to O2 for dual-inlet IRMS (O2-DIIRMS), and decomposition to O2 with molecular-sieve trap (O2-DIIRMS+T). For Cl isotopes, KCl produced by thermal decomposition of KClO4 was reprecipitated as AgCl and converted into CH3Cl for DIIRMS.ResultsKClO4 isotopic reference materials (USGS37, USGS38, USGS39) represent a wide range of Cl and O isotopic compositions, including non-mass-dependent O isotopic variation. Isotopic fractionation and exchange can affect O isotope analyses of ClO4− depending on the decomposition method. Routine analyses can be adjusted for such effects by normalization, using reference materials prepared and analyzed as samples. Analytical errors caused by SO42−, NO3−, ReO42−, and C-bearing contaminants include isotope mixing and fractionation effects on CO and O2, plus direct interference from CO2 in the mass spectrometer. The results highlight the importance of effective purification of ClO4− from environmental samples.ConclusionsKClO4 reference materials are available for testing methods and calibrating isotopic data for ClO4− and other substances with widely varying Cl or O isotopic compositions. Current ClO4−extraction, purification, and analysis techniques provide relative isotope-ratio measurements with uncertainties much smaller than the range of values in environmental ClO4−, permitting isotopic evaluation of environmental ClO4− sources and natural attenuation.

Methods and apparatus for measuring the tightness of enclosures

DOEpatents

Modera, Mark P.; Sherman, Max H.

1987-01-13

Disclosed are methods and apparatus for measuring tightness of an enclosure such as a building by utilizing alternating pressurization techniques. One method comprises providing apparatus capable of causing an internal volume change for the enclosure, the apparatus including a means for determining the instantaneous volume change, and a means for determining the instantaneous pressure within the enclosure. The apparatus is operated within the enclosure to change the volume thereof, and at least one of the frequency and the displacement is adjusted to achieve a root mean square pressure in the enclosure approximately equal to a reference pressure. At that pressure, the leakage of the enclosure is determined from the instantaneous displacement and instantaneous pressure values.

Methods and apparatus for measuring the tightness of enclosures

DOEpatents

Modera, M.P.; Sherman, M.H.

1987-01-13

Disclosed are methods and apparatus for measuring tightness of an enclosure such as a building by utilizing alternating pressurization techniques. One method comprises providing apparatus capable of causing an internal volume change for the enclosure, the apparatus including a means for determining the instantaneous volume change, and a means for determining the instantaneous pressure within the enclosure. The apparatus is operated within the enclosure to change the volume thereof, and at least one of the frequency and the displacement is adjusted to achieve a root mean square pressure in the enclosure approximately equal to a reference pressure. At that pressure, the leakage of the enclosure is determined from the instantaneous displacement and instantaneous pressure values. 3 figs.

Can the super model (SUMO) method improve hydrological simulations? Exploratory tests with the GR hydrological models

NASA Astrophysics Data System (ADS)

Santos, Léonard; Thirel, Guillaume; Perrin, Charles

2017-04-01

Errors made by hydrological models may come from a problem in parameter estimation, uncertainty on observed measurements, numerical problems and from the model conceptualization that simplifies the reality. Here we focus on this last issue of hydrological modeling. One of the solutions to reduce structural uncertainty is to use a multimodel method, taking advantage of the great number and the variability of existing hydrological models. In particular, because different models are not similarly good in all situations, using multimodel approaches can improve the robustness of modeled outputs. Traditionally, in hydrology, multimodel methods are based on the output of the model (the simulated flow series). The aim of this poster is to introduce a different approach based on the internal variables of the models. The method is inspired by the SUper MOdel (SUMO, van den Berge et al., 2011) developed for climatology. The idea of the SUMO method is to correct the internal variables of a model taking into account the values of the internal variables of (an)other model(s). This correction is made bilaterally between the different models. The ensemble of the different models constitutes a super model in which all the models exchange information on their internal variables with each other at each time step. Due to this continuity in the exchanges, this multimodel algorithm is more dynamic than traditional multimodel methods. The method will be first tested using two GR4J models (in a state-space representation) with different parameterizations. The results will be presented and compared to traditional multimodel methods that will serve as benchmarks. In the future, other rainfall-runoff models will be used in the super model. References van den Berge, L. A., Selten, F. M., Wiegerinck, W., and Duane, G. S. (2011). A multi-model ensemble method that combines imperfect models through learning. Earth System Dynamics, 2(1) :161-177.

Citation analysis of five journals in andrology.

PubMed

Yang, H; Pan, B-C; Chen, J

2006-01-01

To find out features in literature demand by researchers in the field of andrology and to offer advice on literature utilization and journal management. Five andrology journals indexed by Science Citation Index Expanded (SCI-E) (Andrologia, Archives of Andrology, Asian Journal of Andrology, International Journal of Andrology, and Journal of Andrology) were included in the study. Original articles, editorials, reviews, corrections and letters from these journals were analyzed with bibliometric method for document loading, citations, information absorbing ability, and geographical coverage. The average number of references in each paper was 28.78. The main type of references was periodicals (94.32%), while books and other sources accounted for only 5.68%. Average Price index was 30.14%. The number of references in the first ranking 10 periodicals cited by the five journals made up 34.53% of the total references cited. Geographically, the five journals covered 6 continents with 42 countries or regions. Andrology journals have a wide coverage of literatures, which are related to reproductive medicine, urology, endocrinology and biochemistry. References in andrology journals are mainly periodicals and are relatively old. US, China and Japan lead the world in andrology researches for the number of papers published.

Methods and Models of the Hanford Internal Dosimetry Program, PNNL-MA-860

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

Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

2009-09-30

The Hanford Internal Dosimetry Program (HIDP) provides internal dosimetry support services for operations at the Hanford Site. The HIDP is staffed and managed by the Radiation and Health Technology group, within the Pacific Northwest National Laboratory (PNNL). Operations supported by the HIDP include research and development, the decontamination and decommissioning of facilities formerly used to produce and purify plutonium, and waste management activities. Radioelements of particular interest are plutonium, uranium, americium, tritium, and the fission and activation product radionuclides 137Cs, 90Sr, and 60Co. This manual describes the technical basis for the design of the routine bioassay monitoring program and formore » assessment of internal dose. The purposes of the manual are as follows: • Provide assurance that the HIDP derives from a sound technical base. • Promote the consistency and continuity of routine program activities. • Provide a historical record. • Serve as a technical reference for radiation protection personnel. • Aid in identifying and planning for future needs.« less

Developing a fatigue questionnaire for Chinese civil aviation pilots.

PubMed

Dai, Jing; Luo, Min; Hu, Wendong; Ma, Jin; Wen, Zhihong

2018-03-23

To assess the fatigue risk is an important challenge in improving flight safety in aviation industry. The aim of this study was to develop a comprehensive fatigue risk management indicators system and a fatigue questionnaire for Chinese civil aviation pilots. Participants included 74 (all males) civil aviation pilots. They finished the questionnaire in 20 minutes before a flight mission. The estimation of internal consistency with Cronbach's α and Student's t test as well as Pearson's correlation analysis were the main statistical methods. The results revealed that the fatigue questionnaire had acceptable internal consistency reliability and construct validity; there were significant differences on fatigue scores between international and domestic flight pilots. And some international flight pilots, who had taken medications as a sleep aid, had worse sleep quality than those had not. The long-endurance flight across time zones caused significant differences in circadian rhythm. The fatigue questionnaire can be used to measure Chinese civil aviation pilots' fatigue, which provided a reference for fatigue risk management system to civil aviation pilots.

LEOrbit: A program to calculate parameters relevant to modeling Low Earth Orbit spacecraft-plasma interaction

NASA Astrophysics Data System (ADS)

Marchand, R.; Purschke, D.; Samson, J.

2013-03-01

Understanding the physics of interaction between satellites and the space environment is essential in planning and exploiting space missions. Several computer models have been developed over the years to study this interaction. In all cases, simulations are carried out in the reference frame of the spacecraft and effects such as charging, the formation of electrostatic sheaths and wakes are calculated for given conditions of the space environment. In this paper we present a program used to compute magnetic fields and a number of space plasma and space environment parameters relevant to Low Earth Orbits (LEO) spacecraft-plasma interaction modeling. Magnetic fields are obtained from the International Geophysical Reference Field (IGRF) and plasma parameters are obtained from the International Reference Ionosphere (IRI) model. All parameters are computed in the spacecraft frame of reference as a function of its six Keplerian elements. They are presented in a format that can be used directly in most spacecraft-plasma interaction models. Catalogue identifier: AENY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 270308 No. of bytes in distributed program, including test data, etc.: 2323222 Distribution format: tar.gz Programming language: FORTRAN 90. Computer: Non specific. Operating system: Non specific. RAM: 7.1 MB Classification: 19, 4.14. External routines: IRI, IGRF (included in the package). Nature of problem: Compute magnetic field components, direction of the sun, sun visibility factor and approximate plasma parameters in the reference frame of a Low Earth Orbit satellite. Solution method: Orbit integration, calls to IGRF and IRI libraries and transformation of coordinates from geocentric to spacecraft frame reference. Restrictions: Low Earth orbits, altitudes between 150 and 2000 km. Running time: Approximately two seconds to parameterize a full orbit with 1000 points.

A Comparative Study of the Applied Methods for Estimating Deflection of the Vertical in Terrestrial Geodetic Measurements

PubMed Central

Vittuari, Luca; Tini, Maria Alessandra; Sarti, Pierguido; Serantoni, Eugenio; Borghi, Alessandra; Negusini, Monia; Guillaume, Sébastien

2016-01-01

This paper compares three different methods capable of estimating the deflection of the vertical (DoV): one is based on the joint use of high precision spirit leveling and Global Navigation Satellite Systems (GNSS), a second uses astro-geodetic measurements and the third gravimetric geoid models. The working data sets refer to the geodetic International Terrestrial Reference Frame (ITRF) co-location sites of Medicina (Northern, Italy) and Noto (Sicily), these latter being excellent test beds for our investigations. The measurements were planned and realized to estimate the DoV with a level of precision comparable to the angular accuracy achievable in high precision network measured by modern high-end total stations. The three methods are in excellent agreement, with an operational supremacy of the astro-geodetic method, being faster and more precise than the others. The method that combines leveling and GNSS has slightly larger standard deviations; although well within the 1 arcsec level, which was assumed as threshold. Finally, the geoid model based method, whose 2.5 arcsec standard deviations exceed this threshold, is also statistically consistent with the others and should be used to determine the DoV components where local ad hoc measurements are lacking. PMID:27104544

Evaluation of a Method for Rapid Detection of Listeria monocytogenes in Dry-Cured Ham Based on Impedanciometry Combined with Chromogenic Agar.

PubMed

Labrador, Mirian; Rota, María C; Pérez, Consuelo; Herrera, Antonio; Bayarri, Susana

2018-05-01

The food industry is in need of rapid, reliable methodologies for the detection of Listeria monocytogenes in ready-to-eat products, as an alternative to the International Organization of Standardization (ISO) 11290-1 reference method. The aim of this study was to evaluate impedanciometry combined with chromogenic agar culture for the detection of L. monocytogenes in dry-cured ham. The experimental setup consisted in assaying four strains of L. monocytogenes and two strains of Listeria innocua in pure culture. The method was evaluated according to the ISO 16140:2003 standard through a comparative study with the ISO reference method with 119 samples of dry-cured ham. Significant determination coefficients ( R 2 of up to 0.99) for all strains assayed in pure culture were obtained. The comparative study results had 100% accuracy, 100% specificity, and 100% sensitivity. Impedanciometry followed by chromogenic agar culture was capable of detecting 1 CFU/25 g of food. L. monocytogenes was not detected in the 65 commercial samples tested. The method evaluated herein represents a promising alternative for the food industry in its efforts to control L. monocytogenes. Overall analysis time is shorter and the method permits a straightforward analysis of a large number of samples with reliable results.

Laser based water equilibration method for d18O determination of water samples

NASA Astrophysics Data System (ADS)

Mandic, Magda; Smajgl, Danijela; Stoebener, Nils

2017-04-01

Determination of d18O with water equilibration method using mass spectrometers equipped with equilibration unit or Gas Bench is known already for many years. Now, with development of laser spectrometers this extends methods and possibilities to apply different technologies in laboratory but also in the field. The Thermo Scientific™ Delta Ray™ Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect and Teledyne Cetac ASX-7100 offers high precision and throughput of samples. It employs optical spectroscopy for continuous measurement of isotope ratio values and concentration of carbon dioxide in ambient air, and also for analysis of discrete samples from vials, syringes, bags, or other user-provided sample containers. Test measurements and conformation of precision and accuracy of method determination d18O in water samples were done in Thermo Fisher application laboratory with three lab standards, namely ANST, Ocean II and HBW. All laboratory standards were previously calibrated with international reference material VSMOW2 and SLAP2 to assure accuracy of the isotopic values of the water. With method that we present in this work achieved repeatability and accuracy are 0.16‰ and 0.71‰, respectively, which fulfill requirements of regulatory method for wine and must after equilibration with CO2.

Estimating Contraceptive Prevalence Using Logistics Data for Short-Acting Methods: Analysis Across 30 Countries

PubMed Central

Cunningham, Marc; Brown, Niquelle; Sacher, Suzy; Hatch, Benjamin; Inglis, Andrew; Aronovich, Dana

2015-01-01

Background: Contraceptive prevalence rate (CPR) is a vital indicator used by country governments, international donors, and other stakeholders for measuring progress in family planning programs against country targets and global initiatives as well as for estimating health outcomes. Because of the need for more frequent CPR estimates than population-based surveys currently provide, alternative approaches for estimating CPRs are being explored, including using contraceptive logistics data. Methods: Using data from the Demographic and Health Surveys (DHS) in 30 countries, population data from the United States Census Bureau International Database, and logistics data from the Procurement Planning and Monitoring Report (PPMR) and the Pipeline Monitoring and Procurement Planning System (PipeLine), we developed and evaluated 3 models to generate country-level, public-sector contraceptive prevalence estimates for injectable contraceptives, oral contraceptives, and male condoms. Models included: direct estimation through existing couple-years of protection (CYP) conversion factors, bivariate linear regression, and multivariate linear regression. Model evaluation consisted of comparing the referent DHS prevalence rates for each short-acting method with the model-generated prevalence rate using multiple metrics, including mean absolute error and proportion of countries where the modeled prevalence rate for each method was within 1, 2, or 5 percentage points of the DHS referent value. Results: For the methods studied, family planning use estimates from public-sector logistics data were correlated with those from the DHS, validating the quality and accuracy of current public-sector logistics data. Logistics data for oral and injectable contraceptives were significantly associated (P<.05) with the referent DHS values for both bivariate and multivariate models. For condoms, however, that association was only significant for the bivariate model. With the exception of the CYP-based model for condoms, models were able to estimate public-sector prevalence rates for each short-acting method to within 2 percentage points in at least 85% of countries. Conclusions: Public-sector contraceptive logistics data are strongly correlated with public-sector prevalence rates for short-acting methods, demonstrating the quality of current logistics data and their ability to provide relatively accurate prevalence estimates. The models provide a starting point for generating interim estimates of contraceptive use when timely survey data are unavailable. All models except the condoms CYP model performed well; the regression models were most accurate but the CYP model offers the simplest calculation method. Future work extending the research to other modern methods, relating subnational logistics data with prevalence rates, and tracking that relationship over time is needed. PMID:26374805

Comparison of the performance of IFA, CFA, and ELISA assays for the serodiagnosis of acute Q fever by quality assessment.

PubMed

Herremans, Tineke; Hogema, Boris M; Nabuurs, Marrigje; Peeters, Marcel; Wegdam-Blans, Marjolijn; Schneeberger, Peter; Nijhuis, Carla; Notermans, Daan W; Galama, Joep; Horrevorts, Anton; van Loo, Inge H M; Vlaminckx, Bart; Zaaijer, Hans L; Koopmans, Marion P; Berkhout, Hanneke; Socolovschi, Cristina; Raoult, Didier; Stenos, John; Nicholson, William; Bijlmer, Henk

2013-01-01

The indirect immunofluorescence assay (IFA) is considered the reference method for diagnosing Q fever, but serology is also performed by complement fixation assay (CFA) or enzyme-linked immunosorbent assay (ELISA). However, comparability between these assays is not clear, and therefore a quality assessment was performed. A total of 25 serum samples from negative controls, Q fever patients, and a serial diluted high-positive sample were analyzed in 10 Dutch laboratories. Six laboratories performed CFA, 5 performed IFA, and 5 performed ELISAs. Three international reference laboratories from Australia, France, and the USA also participated in this study. Qualitative values between laboratories using the same methods were within close range, and all 3 methods correctly identified acute Q fever patients. The IFA, ELISA, and CFA are all suitable serodiagnostic assays to diagnose acute Q fever, but the IFA remains an important tool in the follow-up of patients and in identifying patients at risk for developing chronic Q fever. Copyright © 2013 Elsevier Inc. All rights reserved.

The Need to Communicate: Fighting Human Trafficking in Vietnam

DTIC Science & Technology

2014-06-01

traffic in women and girls for purposes of prostitution , between what countries the traffic is being carried on, the methods used in procuring and...The details behind these cases are horrific, such as an increasing trend of foreigners visiting Vietnam for what UNIAP refers to as “ child sex...10 Ibid, 30-32. 11 Ibid., 30, 32. 12 Ibid, 31. 13 Children’s Care International. " Child Labour." Accessed 31 October 2013. http://aipe

SRS 2010 Vegetation Inventory GeoStatistical Mapping Results for Custom Reaction Intensity and Total Dead Fuels.

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

Edwards, Lloyd A.; Paresol, Bernard

This report of the geostatistical analysis results of the fire fuels response variables, custom reaction intensity and total dead fuels is but a part of an SRS 2010 vegetation inventory project. For detailed description of project, theory and background including sample design, methods, and results please refer to USDA Forest Service Savannah River Site internal report “SRS 2010 Vegetation Inventory GeoStatistical Mapping Report”, (Edwards & Parresol 2013).

LOW LEVEL COUNTING TECHNIQUES WITH SPECIAL REFERENCE TO BIOMEDICAL TRACER PROBLEMS

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

Hosain, F.; Nag, B.D.

1959-12-01

Low-level counting techniques in tracer experiments are discussed with emphasis on the measurement of beta and gamma radiations with Geiger and scintillation counting methods. The basic principles of low-level counting are outlined. Screen-wall counters, internal gas counters, low-level beta counters, scintillation spectrometers, liquid scintillators, and big scintillation installations are described. Biomedical tracer investigations are discussed. Applications of low-level techniques in archaeological dating, biology, and other problems are listed. (M.C.G.)

Accuracy of a Flash Glucose Monitoring System in Diabetic Dogs.

PubMed

Corradini, S; Pilosio, B; Dondi, F; Linari, G; Testa, S; Brugnoli, F; Gianella, P; Pietra, M; Fracassi, F

2016-07-01

A novel flash glucose monitoring system (FGMS) (FreeStyle Libre, Abbott, UK) was recently developed for humans. It continuously measures the interstitial glucose (IG) concentrations for 14 days. To assess the clinical and analytical accuracy of the FGMS in diabetic dogs. Ten client-owned diabetic dogs on insulin treatment. Prospective and observational study. The FGMS was placed on the neck for up to 14 days. During the 1st-2nd, 6-7th, and 13-14th days from application, the IG measurements were compared with the plasma (EDTA) glucose (PG) concentrations analyzed by a reference hexokinase based method. The application and the use of the FGMS were apparently painless, easy, and well tolerated by all dogs. Mild erythema at the site of the application was found in 5/10 dogs at the end of the wearing period. A good correlation between IG and PG concentrations (rho = 0.94; P < .001) was found. The FGMS was 93, 99, and 99% accurate at low, normal, and high blood glucose concentrations. Mean ± standard deviation difference from the reference method was 2.3 ± 46.8 mg/dL. The FGMS is easy to use and is accurate for IG glucose measurement in diabetic dogs. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Flammability of gas mixtures. Part 1: fire potential.

PubMed

Schröder, Volkmar; Molnarne, Maria

2005-05-20

International and European dangerous substances and dangerous goods regulations refer to the standard ISO 10156 (1996). This standard includes a test method and a calculation procedure for the determination of the flammability of gases and gas mixtures in air. The substance indices for the calculation, the so called "Tci values", which characterise the fire potential, are provided as well. These ISO Tci values are derived from explosion diagrams of older literature sources which do not take into account the test method and the test apparatus. However, since the explosion limits are influenced by apparatus parameters, the Tci values and lower explosion limits, given by the ISO tables, are inconsistent with those measured according to the test method of the same standard. In consequence, applying the ISO Tci values can result in wrong classifications. In this paper internationally accepted explosion limit test methods were evaluated and Tci values were derived from explosion diagrams. Therefore, an "open vessel" method with flame propagation criterion was favoured. These values were compared with the Tci values listed in ISO 10156. In most cases, significant deviations were found. A detailed study about the influence of inert gases on flammability is the objective of Part 2.

Working towards accreditation by the International Standards Organization 15189 Standard: how to validate an in-house developed method an example of lead determination in whole blood by electrothermal atomic absorption spectrometry.

PubMed

Garcia Hejl, Carine; Ramirez, Jose Manuel; Vest, Philippe; Chianea, Denis; Renard, Christophe

2014-09-01

Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.

International Society of Human and Animal Mycology (ISHAM)-ITS reference DNA barcoding database--the quality controlled standard tool for routine identification of human and animal pathogenic fungi.

PubMed

Irinyi, Laszlo; Serena, Carolina; Garcia-Hermoso, Dea; Arabatzis, Michael; Desnos-Ollivier, Marie; Vu, Duong; Cardinali, Gianluigi; Arthur, Ian; Normand, Anne-Cécile; Giraldo, Alejandra; da Cunha, Keith Cassia; Sandoval-Denis, Marcelo; Hendrickx, Marijke; Nishikaku, Angela Satie; de Azevedo Melo, Analy Salles; Merseguel, Karina Bellinghausen; Khan, Aziza; Parente Rocha, Juliana Alves; Sampaio, Paula; da Silva Briones, Marcelo Ribeiro; e Ferreira, Renata Carmona; de Medeiros Muniz, Mauro; Castañón-Olivares, Laura Rosio; Estrada-Barcenas, Daniel; Cassagne, Carole; Mary, Charles; Duan, Shu Yao; Kong, Fanrong; Sun, Annie Ying; Zeng, Xianyu; Zhao, Zuotao; Gantois, Nausicaa; Botterel, Françoise; Robbertse, Barbara; Schoch, Conrad; Gams, Walter; Ellis, David; Halliday, Catriona; Chen, Sharon; Sorrell, Tania C; Piarroux, Renaud; Colombo, Arnaldo L; Pais, Célia; de Hoog, Sybren; Zancopé-Oliveira, Rosely Maria; Taylor, Maria Lucia; Toriello, Conchita; de Almeida Soares, Célia Maria; Delhaes, Laurence; Stubbe, Dirk; Dromer, Françoise; Ranque, Stéphane; Guarro, Josep; Cano-Lira, Jose F; Robert, Vincent; Velegraki, Aristea; Meyer, Wieland

2015-05-01

Human and animal fungal pathogens are a growing threat worldwide leading to emerging infections and creating new risks for established ones. There is a growing need for a rapid and accurate identification of pathogens to enable early diagnosis and targeted antifungal therapy. Morphological and biochemical identification methods are time-consuming and require trained experts. Alternatively, molecular methods, such as DNA barcoding, a powerful and easy tool for rapid monophasic identification, offer a practical approach for species identification and less demanding in terms of taxonomical expertise. However, its wide-spread use is still limited by a lack of quality-controlled reference databases and the evolving recognition and definition of new fungal species/complexes. An international consortium of medical mycology laboratories was formed aiming to establish a quality controlled ITS database under the umbrella of the ISHAM working group on "DNA barcoding of human and animal pathogenic fungi." A new database, containing 2800 ITS sequences representing 421 fungal species, providing the medical community with a freely accessible tool at http://www.isham.org/ and http://its.mycologylab.org/ to rapidly and reliably identify most agents of mycoses, was established. The generated sequences included in the new database were used to evaluate the variation and overall utility of the ITS region for the identification of pathogenic fungi at intra-and interspecies level. The average intraspecies variation ranged from 0 to 2.25%. This highlighted selected pathogenic fungal species, such as the dermatophytes and emerging yeast, for which additional molecular methods/genetic markers are required for their reliable identification from clinical and veterinary specimens. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

CON4EI: Selection of the reference chemicals for hazard identification and labelling of eye irritating chemicals.

PubMed

Adriaens, E; Alépée, N; Kandarova, H; Drzewieckac, A; Gruszka, K; Guest, R; Willoughby, J A; Verstraelen, S; Van Rompay, A R

2017-10-01

Assessment of the acute eye irritation potential is part of the international regulatory requirements for testing of chemicals. In the past, several prospective and retrospective validation studies have taken place in the area of serious eye damage/eye irritation testing. Success in terms of complete replacement of the regulatory in vivo Draize rabbit eye test has not yet been achieved. A very important aspect to ensure development of successful alternative test methods and/or strategies for serious eye damage/eye irritation testing is the selection of appropriate reference chemicals. A set of 80 reference chemicals was selected for the CEFIC-LRI-AIMT6-VITO CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project, in collaboration with Cosmetics Europe, from the Draize Reference Database published by Cosmetics Europe based on key criteria that were set in their paper (e.g. balanced by important driver of classification and physical state). The most important goals of the CON4EI project were to identify the performance of eight in vitro alternative tests in terms of driver of classification and to identify similarities/differences between the methods in order the build a successful testing strategy that can discriminate between all UN GHS categories. This paper provides background on selection of the test chemicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reprint of "CON4EI: Selection of the reference chemicals for hazard identification and labelling of eye irritating chemicals".

PubMed

Adriaens, E; Alépée, N; Kandarova, H; Drzewieckac, A; Gruszka, K; Guest, R; Willoughby, J A; Verstraelen, S; Van Rompay, A R

2018-06-01

Assessment of the acute eye irritation potential is part of the international regulatory requirements for testing of chemicals. In the past, several prospective and retrospective validation studies have taken place in the area of serious eye damage/eye irritation testing. Success in terms of complete replacement of the regulatory in vivo Draize rabbit eye test has not yet been achieved. A very important aspect to ensure development of successful alternative test methods and/or strategies for serious eye damage/eye irritation testing is the selection of appropriate reference chemicals. A set of 80 reference chemicals was selected for the CEFIC-LRI-AIMT6-VITO CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project, in collaboration with Cosmetics Europe, from the Draize Reference Database published by Cosmetics Europe based on key criteria that were set in their paper (e.g. balanced by important driver of classification and physical state). The most important goals of the CON4EI project were to identify the performance of eight in vitro alternative tests in terms of driver of classification and to identify similarities/differences between the methods in order the build a successful testing strategy that can discriminate between all UN GHS categories. This paper provides background on selection of the test chemicals. Copyright © 2018. Published by Elsevier Ltd.

When Students Doubt Their Teachers' Diagnostic Competence: Moderation in the Internal/External Frame of Reference Model

ERIC Educational Resources Information Center

Zimmermann, Friederike; Möller, Jens; Köller, Olaf

2018-01-01

The internal/external frame of reference model (I/E model) posits that individuals' achievement-related self-concepts are formed through social comparisons (e.g., self vs. peers) within academic domains and dimensional comparisons (e.g., math vs. verbal) between distinct domains. A large body of research has supported the theorized pattern of…

Antecedents of Academic Emotions: Testing the Internal/External Frame of Reference Model for Academic Enjoyment

ERIC Educational Resources Information Center

Goetz, Thomas; Frenzel, Anne C.; Hall, Nathan C.; Pekrun, Reinhard

2008-01-01

The present study focused on students' academic enjoyment as predicted by achievement in multiple academic domains. Assumptions were based on Marsh's internal/external (I/E) frame of reference model and Pekrun's control-value theory of achievement emotions, and were tested in a sample of 1380 German students from grades 5 to 10. Students' academic…

Charting Teacher Education Policy in the Republic of Ireland with Particular Reference to the Impact of Economic Recession

ERIC Educational Resources Information Center

Clarke, Marie; Killeavy, Maureen

2012-01-01

Background: Teacher education is an area of concern both in the policy and practice domains in both international and national contexts. Internationally, there are a wide range teacher education programmes and there is also considerable diversity with reference to policy approaches that operationalise such provision. Purpose: This paper focuses on…

33 CFR 157.02 - Incorporation by reference: Where can I get a copy of the publications mentioned in this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Resolution A.393(X), adopted on 14 November 1977, Recommendation on International Performance and Test...), Guidelines on the Enhanced Programme of Inspections During Surveys of Bulk Carriers and Oil Tankers, Annex B... reference approved for § 157.445. (c) Oil Companies International Marine Forum (OCIMF) 27 Queen Anne's Gate...

The Reciprocal Internal/External Frame of Reference Model Using Grades and Test Scores

ERIC Educational Resources Information Center

Möller, Jens; Zimmermann, Friederike; Köller, Olaf

2014-01-01

Background: The reciprocal I/E model (RI/EM) combines the internal/external frame of reference model (I/EM) with the reciprocal effects model (REM). The RI/EM extends the I/EM longitudinally and the REM across domains. The model predicts that, within domains, mathematics and verbal achievement (VACH) and academic self-concept have positive effects…

Quantity quotient reporting. A proposal for a standardized presentation of laboratory results.

PubMed

Haeckel, Rainer; Wosniok, Werner

2009-01-01

Laboratory results are reported in different units (despite international recommendations for SI units) together with different reference limits, of which several exist for many quantities. It is proposed to adopt the concept of the intelligence quotient and to report quantitative results as a quantity quotient (QQ) in laboratory medicine. This quotient is essentially the difference (measured result minus mean or mode value of the reference interval) divided by the observed biological variation CV(o). Thus, all quantities are reported in the same unit system with the same reference limits (for convenience shifted to e.g., 80-120). The critical difference can also be included in this standardization concept. In this way the information of reference intervals and the original result are integrated into one combined value, which has the same format for all quantities suited for quotient reporting (QR). The proposal of QR does not interfere with neither the current concepts of traceability, SI units or method standardization. This proposal represents a further step towards harmonization of reporting. It provides simple values which can be interpreted easily by physicians and their patients.

Statistical tools for transgene copy number estimation based on real-time PCR.

PubMed

Yuan, Joshua S; Burris, Jason; Stewart, Nathan R; Mentewab, Ayalew; Stewart, C Neal

2007-11-01

As compared with traditional transgene copy number detection technologies such as Southern blot analysis, real-time PCR provides a fast, inexpensive and high-throughput alternative. However, the real-time PCR based transgene copy number estimation tends to be ambiguous and subjective stemming from the lack of proper statistical analysis and data quality control to render a reliable estimation of copy number with a prediction value. Despite the recent progresses in statistical analysis of real-time PCR, few publications have integrated these advancements in real-time PCR based transgene copy number determination. Three experimental designs and four data quality control integrated statistical models are presented. For the first method, external calibration curves are established for the transgene based on serially-diluted templates. The Ct number from a control transgenic event and putative transgenic event are compared to derive the transgene copy number or zygosity estimation. Simple linear regression and two group T-test procedures were combined to model the data from this design. For the second experimental design, standard curves were generated for both an internal reference gene and the transgene, and the copy number of transgene was compared with that of internal reference gene. Multiple regression models and ANOVA models can be employed to analyze the data and perform quality control for this approach. In the third experimental design, transgene copy number is compared with reference gene without a standard curve, but rather, is based directly on fluorescence data. Two different multiple regression models were proposed to analyze the data based on two different approaches of amplification efficiency integration. Our results highlight the importance of proper statistical treatment and quality control integration in real-time PCR-based transgene copy number determination. These statistical methods allow the real-time PCR-based transgene copy number estimation to be more reliable and precise with a proper statistical estimation. Proper confidence intervals are necessary for unambiguous prediction of trangene copy number. The four different statistical methods are compared for their advantages and disadvantages. Moreover, the statistical methods can also be applied for other real-time PCR-based quantification assays including transfection efficiency analysis and pathogen quantification.

Identification of internal control genes for quantitative expression analysis by real-time PCR in bovine peripheral lymphocytes.

PubMed

Spalenza, Veronica; Girolami, Flavia; Bevilacqua, Claudia; Riondato, Fulvio; Rasero, Roberto; Nebbia, Carlo; Sacchi, Paola; Martin, Patrice

2011-09-01

Gene expression studies in blood cells, particularly lymphocytes, are useful for monitoring potential exposure to toxicants or environmental pollutants in humans and livestock species. Quantitative PCR is the method of choice for obtaining accurate quantification of mRNA transcripts although variations in the amount of starting material, enzymatic efficiency, and the presence of inhibitors can lead to evaluation errors. As a result, normalization of data is of crucial importance. The most common approach is the use of endogenous reference genes as an internal control, whose expression should ideally not vary among individuals and under different experimental conditions. The accurate selection of reference genes is therefore an important step in interpreting quantitative PCR studies. Since no systematic investigation in bovine lymphocytes has been performed, the aim of the present study was to assess the expression stability of seven candidate reference genes in circulating lymphocytes collected from 15 dairy cows. Following the characterization by flow cytometric analysis of the cell populations obtained from blood through a density gradient procedure, three popular softwares were used to evaluate the gene expression data. The results showed that two genes are sufficient for normalization of quantitative PCR studies in cattle lymphocytes and that YWAHZ, S24 and PPIA are the most stable genes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Establishment of hepatitis A vaccine (inactivated, non-adsorbed) BRP batches 2 and 3.

PubMed

Morgeaux, S; Manniam, I; Variot, P; Buchheit, K H; Daas, A; Wierer, M; Costanzo, A

2015-01-01

The current hepatitis A vaccine (HAV), inactivated, non-adsorbed, European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) is used for the in vitro potency assay of HAV as prescribed by the Ph. Eur. general chapter 2.7.14 Assay of hepatitis A vaccine. This reference preparation was calibrated in 2008 through an international collaborative study and was assigned a potency of 12 IU/mL. During use of this BRP it appeared to be inapplicable in certain cases due to a low nominal antigen content. Consequently, the European Directorate for the Quality of Medicines and HealthCare (EDQM) established replacement batches for this BRP, calibrated against the 1(st) WHO International Standard (IS) for HAV (inactivated), using the standard in vitro ELISA (enzyme-linked immunosorbent assay) method validated previously. The results of the study showed that the candidate BRPs were suitable for the intended purpose, and following completion of the study, they were adopted in November 2014 by the Ph. Eur. Commission as HAV (inactivated, non-adsorbed) BRP batches 2 and 3, with an assigned potency of 1350 IU/mL, for in vitro antigen content determination by ELISA. As the amount of material in each vial largely exceeds the amount required for the performance of a single assay, the BRPs are to be aliquoted by users as single-use aliquots and refrozen below -50 °C prior to their use as reference preparations.

The theory of reference values: an unfinished symphony.

PubMed

Siest, Gerard; Henny, Joseph; Gräsbeck, Ralph; Wilding, Peter; Petitclerc, Claude; Queraltó, Josep M; Hyltoft Petersen, Peter

2013-01-01

The history of the theory of reference values can be written as an unfinished symphony. The first movement, allegro con fuoco, played from 1960 to 1980: a mix of themes devoted to the study of biological variability (intra-, inter-individual, short- and long-term), preanalytical conditions, standardization of analytical methods, quality control, statistical tools for deriving reference limits, all of them complex variations developed on a central melody: the new concept of reference values that would replace the notion of normality whose definition was unclear. Additional contributions (multivariate reference values, use of reference limits from broad sets of patient data, drug interferences) conclude the movement on the variability of laboratory tests. The second movement, adagio, from 1980 to 2000, slowly develops and implements initial works. International and national recommendations were published by the IFCC-LM (International Federation of Clinical Chemistry and Laboratory Medicine) and scientific societies [French (SFBC), Spanish (SEQC), Scandinavian societies…]. Reference values are now topics of many textbooks and of several congresses, workshops, and round tables that are organized all over the world. Nowadays, reference values are part of current practice in all clinical laboratories, but not without difficulties, particularly for some laboratories to produce their own reference values and the unsuitability of the concept with respect to new technologies such as HPLC, GCMS, and PCR assays. Clinicians through consensus groups and practice guidelines have introduced their own tools, the decision limits, likelihood ratios and Reference Change Value (RCV), creating confusion among laboratorians and clinicians in substituting reference values and decision limits in laboratory reports. The rapid development of personalized medicine will eventually call for the use of individual reference values. The beginning of the second millennium is played allegro ma non-troppo from 2000 to 2012: the theory of reference values is back into fashion. The need to revise the concept is emerging. The manufacturers make a friendly pressure to facilitate the integration of Reference Intervals (RIs) in their technical documentation. Laboratorians are anxiously awaiting the solutions for what to do. The IFCC-LM creates Reference Intervals and Decision Limits Committee (C-RIDL) in 2005. Simultaneously, a joint working group IFCC-CLSI is created on the same topic. In 2008 the initial recommendations of IFCC-LM are revised and new guidelines are published by the Clinical and Laboratory Standards Institute (CLSI C28-A3). Fundamentals of the theory of reference values are not changed, but new avenues are explored: RIs transference, multicenter reference intervals, and a robust method for deriving RIs from small number of subjects. Concomitantly, other statistical methods are published such as bootstraps calculation and partitioning procedures. An alternative to recruiting healthy subjects proposes the use of biobanks conditional to the availability of controlled preanalytical conditions and of bioclinical data. The scope is also widening to include veterinary biology! During the early 2000s, several groups proposed the concept of 'Universal RIs' or 'Global RIs'. Still controversial, their applications await further investigations. The fourth movement, finale: beyond the methodological issues (statistical and analytical essentially), important questions remain unanswered. Do RIs intervene appropriately in medical decision-making? Are RIs really useful to the clinicians? Are evidence-based decision limits more appropriate? It should be appreciated that many laboratory tests represent a continuum that weakens the relevance of RIs. In addition, the boundaries between healthy and pathological states are shady areas influenced by many biological factors. In such a case the use of a single threshold is questionable. Wherever it will apply, individual reference values and reference change values have their place. A variation on an old theme! It is strange that in the period of personalized medicine (that is more stratified medicine), the concept of reference values which is based on stratification of homogeneous subgroups of healthy people could not be discussed and developed in conjunction with the stratification of sick patients. That is our message for the celebration of the 50th anniversary of Clinical Chemistry and Laboratory Medicine. Prospects are broad, enthusiasm is not lacking: much remains to be done, good luck for the new generations!

3D measurements in conventional X-ray imaging with RGB-D sensors.

PubMed

Albiol, Francisco; Corbi, Alberto; Albiol, Alberto

2017-04-01

A method for deriving 3D internal information in conventional X-ray settings is presented. It is based on the combination of a pair of radiographs from a patient and it avoids the use of X-ray-opaque fiducials and external reference structures. To achieve this goal, we augment an ordinary X-ray device with a consumer RGB-D camera. The patient' s rotation around the craniocaudal axis is tracked relative to this camera thanks to the depth information provided and the application of a modern surface-mapping algorithm. The measured spatial information is then translated to the reference frame of the X-ray imaging system. By using the intrinsic parameters of the diagnostic equipment, epipolar geometry, and X-ray images of the patient at different angles, 3D internal positions can be obtained. Both the RGB-D and X-ray instruments are first geometrically calibrated to find their joint spatial transformation. The proposed method is applied to three rotating phantoms. The first two consist of an anthropomorphic head and a torso, which are filled with spherical lead bearings at precise locations. The third one is made of simple foam and has metal needles of several known lengths embedded in it. The results show that it is possible to resolve anatomical positions and lengths with a millimetric level of precision. With the proposed approach, internal 3D reconstructed coordinates and distances can be provided to the physician. It also contributes to reducing the invasiveness of ordinary X-ray environments and can replace other types of clinical explorations that are mainly aimed at measuring or geometrically relating elements that are present inside the patient's body. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Nuclear reference materials to meet the changing needs of the global nuclear community

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

Martin, H.R.; Gradle, C.G.; Narayanan, U.I.

New Brunswick Laboratory (NBL) serves as the U.S. Government`s certifying authority for nuclear reference materials and measurement calibration standards. In this role, NBL provides nuclear reference materials certified for chemical and/or isotopic compositions traceable to a nationally accepted, internationally compatible reference base. Emphasis is now changing as to the types of traceable nuclear reference materials needed as operations change within the Department of Energy complex and at nuclear facilities around the world. New challenges include: environmental and waste minimization issues, facilities and materials transitioning from processing to storage modes with corresponding changes in the types of measurements being performed, emphasismore » on requirements for characterization of waste materials, and difficulties in transporting nuclear materials and international factors, including IAEA influences. During these changing times, it is critical that traceable reference materials be provided for calibration or validation of the performance of measurement systems. This paper will describe actions taken and planned to meet the changing reference material needs of the global nuclear community.« less

Is food allergen analysis flawed? Health and supply chain risks and a proposed framework to address urgent analytical needs.

PubMed

Walker, M J; Burns, D T; Elliott, C T; Gowland, M H; Mills, E N Clare

2016-01-07

Food allergy is an increasing problem for those affected, their families or carers, the food industry and for regulators. The food supply chain is highly vulnerable to fraud involving food allergens, risking fatalities and severe reputational damage to the food industry. Many facets are being pursued to ameliorate the difficulties including better food labelling and the concept of thresholds of elicitation of allergy symptoms as risk management tools. These efforts depend to a high degree on the ability reliably to detect and quantify food allergens; yet all current analytical approaches exhibit severe deficiencies that jeopardise accurate results being produced particularly in terms of the risks of false positive and false negative reporting. If we fail to realise the promise of current risk assessment and risk management of food allergens through lack of the ability to measure food allergens reproducibly and with traceability to an international unit of measurement, the analytical community will have failed a significant societal challenge. Three distinct but interrelated areas of analytical work are urgently needed to address the substantial gaps identified: (a) a coordinated international programme for the production of properly characterised clinically relevant reference materials and calibrants for food allergen analysis; (b) an international programme to widen the scope of proteomics and genomics bioinformatics for the genera containing the major allergens to address problems in ELISA, MS and DNA methods; (c) the initiation of a coordinated international programme leading to reference methods for allergen proteins that provide results traceable to the SI. This article describes in more detail food allergy, the risks of inapplicable or flawed allergen analyses with examples and a proposed framework, including clinically relevant incurred allergen concentrations, to address the currently unmet and urgently required analytical requirements. Support for the above recommendations from food authorities, business organisations and National Measurement Institutes is important; however transparent international coordination is essential. Thus our recommendations are primarily addressed to the European Commission, the Health and Food Safety Directorate, DG Santé. A global multidisciplinary consortium is required to provide a curated suite of data including genomic and proteomic data on key allergenic food sources, made publically available on line.

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

International comparison of activity measurements of a solution of 75Se

NASA Astrophysics Data System (ADS)

Ratel, Guy

2002-04-01

Activity measurements of a solution of 75Se, supplied by the BIPM, have been carried out by 21 laboratories within the framework of an international comparison. Seven different methods were used. Details on source preparation, experimental facilities and counting data are reported. The measured activity-concentration values show a total spread of 6.62% before correction and 6.02% after correction for delayed events, with standard deviations of the unweighted means of 0.45% and 0.36%, respectively. The correction for delayed events was measured directly by four laboratories. Unfortunately no consensus on the activity value could be deduced from their results. The results of the comparison have been entered in the tables of the International Reference System (SIR) for γ-ray emitting radionuclides. The half-life of the metastable state was also determined by two laboratories and found to be in good agreement with the values found in the literature.

Visualization of the IMIA Yearbook of Medical Informatics Publications over the Last 25 Years

PubMed Central

Tam-Tham, H.; Minty, E. P.

2016-01-01

Summary Background The last 25 years have been a period of innovation in the area of medical informatics. The International Medical Informatics Association (IMIA) has published, every year for the last quarter century, the Yearbook of Medical Informatics, collating selected papers from various journals in an attempt to provide a summary of the academic medical informatics literature. The objective of this paper is to visualize the evolution of the medical informatics field over the last 25 years according to the frequency of word occurrences in the papers published in the IMIA Yearbook of Medical Informatics. Methods A literature review was conducted examining the IMIA Yearbook of Medical Informatics between 1992 and 2015. These references were collated into a reference manager application to examine the literature using keyword searches, word clouds, and topic clustering. The data was considered in its entirety, as well as segregated into 3 time periods to examine the evolution of main trends over time. Several methods were used, including word clouds, cluster maps, and custom developed web-based information dashboards. Results The literature search resulted in a total of 1210 references published in the Yearbook, of which 213 references were excluded, resulting in 997 references for visualization. Overall, we found that publications were more technical and methods-oriented between 1992 and 1999; more clinically and patient-oriented between 2000 and 2009; and noted the emergence of “big data”, decision support, and global health in the past decade between 2010 and 2015. Dashboards were additionally created to show individual reference data, as well as, aggregated information. Conclusion Medical informatics is a vast and expanding area with new methods and technologies being researched, implemented, and evaluated. Determining visualization approaches that enhance our understanding of literature is an active area of research, and like medical informatics, is constantly evolving as new software and algorithms are developed. This paper examined several approaches for visualizing the medical informatics literature to show historical trends, associations, and aggregated summarized information to illustrate the state and changes in the IMIA Yearbook publications over the last quarter century. PMID:27362591

Data Assimilation as a Tool for Developing a Mars International Reference Atmosphere

NASA Technical Reports Server (NTRS)

Houben, Howard

2005-01-01

A new paradigm for a Mars International Reference Atmosphere is proposed. In general, as is certainly now the case for Mars, there are sufficient observational data to specify what the full atmospheric state was under a variety of circumstances (season, dustiness, etc.). There are also general circulation models capable of deter- mining the evolution of these states. If these capabilities are combined-using data assimilation techniques-the resulting analyzed states can be probed to answer a wide variety of questions, whether posed by scientists, mission planners, or others. This system would fulfill all the purposes of an international reference atmosphere and would make the scientific results of exploration missions readily available to the community. Preliminary work on a website that would incorporate this functionality has begun.

Trace element reference values in tissues from inhabitants of the EU. XII. Development of BioReVa program for statistical treatment.

PubMed

Iversen, B S; Sabbioni, E; Fortaner, S; Pietra, R; Nicolotti, A

2003-01-20

Statistical data treatment is a key point in the assessment of trace element reference values being the conclusive stage of a comprehensive and organized evaluation process of metal concentration in human body fluids. The EURO TERVIHT project (Trace Elements Reference Values in Human Tissues) was started for evaluating, checking and suggesting harmonized procedures for the establishment of trace element reference intervals in body fluids and tissues. Unfortunately, different statistical approaches are being used in this research field making data comparison difficult and in some cases impossible. Although international organizations such as International Federation of Clinical Chemistry (IFCC) or International Union of Pure and Applied Chemistry (IUPAC) have issued recommended guidelines for reference values assessment, including the statistical data treatment, a unique format and a standardized data layout is still missing. The aim of the present study is to present a software (BioReVa) running under Microsoft Windows platform suitable for calculating the reference intervals of trace elements in body matrices. The main scope for creating an ease-of-use application was to control the data distribution, to establish the reference intervals according to the accepted recommendation, on the base of the simple statistic, to get a standard presentation of experimental data and to have an application to which further need could be integrated in future. BioReVa calculates the IFCC reference intervals as well as the coverage intervals recommended by IUPAC as a supplement to the IFCC intervals. Examples of reference values and reference intervals calculated with BioReVa software concern Pb and Se in blood; Cd, In and Cr in urine, Hg and Mo in hair of different general European populations. University of Michigan

[Information flow between medical and social sciences].

PubMed

Schubert, András; Somogyi, Anikó

2014-12-28

In order to reveal impacts of natural and social sciences on each other, the authors examined connections between fields of medical and social sciences using a search for references and citations of scientific publication. 1. The largest affinity between the medical and social sciences was found between neurosciences and psychology, but there was a significant affinity between clinical sciences and general social sciences, as well. 2. The example of General & Internal Medicine papers in the topics of "diabetes" suggests that in the period 2001-2010 the share of references to social sciences was significantly increased. In the meantime, social science papers in the same topics contained references to Clinical Medicine papers in a constantly high percentage. 3. In the sample under study, the age distribution of social science papers in the references did not differ significantly from that of the other sources. 4. Share of references to social science papers was found to be extremely high among Hungarian General & Internal Medicine papers in the topics of "diabetes". This finding still requires clarification, nevertheless, since e.g. it was not supported by an institutional comparison including the largest Hungarian medical research university. 5. The intensity of the reference/citation mediated information flows between the Hungarian Medical Journal, Orvosi Hetilap and social sciences appears to be in accordance with the current international trends.

Age-dependent biochemical quantities: an approach for calculating reference intervals.

PubMed

Bjerner, J

2007-01-01

A parametric method is often preferred when calculating reference intervals for biochemical quantities, as non-parametric methods are less efficient and require more observations/study subjects. Parametric methods are complicated, however, because of three commonly encountered features. First, biochemical quantities seldom display a Gaussian distribution, and there must either be a transformation procedure to obtain such a distribution or a more complex distribution has to be used. Second, biochemical quantities are often dependent on a continuous covariate, exemplified by rising serum concentrations of MUC1 (episialin, CA15.3) with increasing age. Third, outliers often exert substantial influence on parametric estimations and therefore need to be excluded before calculations are made. The International Federation of Clinical Chemistry (IFCC) currently recommends that confidence intervals be calculated for the reference centiles obtained. However, common statistical packages allowing for the adjustment of a continuous covariate do not make this calculation. In the method described in the current study, Tukey's fence is used to eliminate outliers and two-stage transformations (modulus-exponential-normal) in order to render Gaussian distributions. Fractional polynomials are employed to model functions for mean and standard deviations dependent on a covariate, and the model is selected by maximum likelihood. Confidence intervals are calculated for the fitted centiles by combining parameter estimation and sampling uncertainties. Finally, the elimination of outliers was made dependent on covariates by reiteration. Though a good knowledge of statistical theory is needed when performing the analysis, the current method is rewarding because the results are of practical use in patient care.

Towards absolute quantification of allergenic proteins in food--lysozyme in wine as a model system for metrologically traceable mass spectrometric methods and certified reference materials.

PubMed

Cryar, Adam; Pritchard, Caroline; Burkitt, William; Walker, Michael; O'Connor, Gavin; Burns, Duncan Thorburn; Quaglia, Milena

2013-01-01

Current routine food allergen quantification methods, which are based on immunochemistry, offer high sensitivity but can suffer from issues of specificity and significant variability of results. MS approaches have been developed, but currently lack metrological traceability. A feasibility study on the application of metrologically traceable MS-based reference procedures was undertaken. A proof of concept involving proteolytic digestion and isotope dilution MS for quantification of protein allergens in a food matrix was undertaken using lysozyme in wine as a model system. A concentration of lysozyme in wine of 0.95 +/- 0.03 microg/g was calculated based on the concentrations of two peptides, confirming that this type of analysis is viable at allergenically meaningful concentrations. The challenges associated with this promising method were explored; these included peptide stability, chemical modification, enzymatic digestion, and sample cleanup. The method is suitable for the production of allergen in food certified reference materials, which together with the achieved understanding of the effects of sample preparation and of the matrix on the final results, will assist in addressing the bias of the techniques routinely used and improve measurement confidence. Confirmation of the feasibility of MS methods for absolute quantification of an allergenic protein in a food matrix with results traceable to the International System of Units is a step towards meaningful comparison of results for allergen proteins among laboratories. This approach will also underpin risk assessment and risk management of allergens in the food industry, and regulatory compliance of the use of thresholds or action levels when adopted.

Project Management for International Development.

ERIC Educational Resources Information Center

Axelrod, Valija M.; Magisos, Joel H.

A project developed a content model for international project management training. It also compiled a bibliography of project management references, identified specific project management training needs based upon a survey of international sponsors and contractor personnel, and documented the training needs of international project managers. Data…

A Jeziorski-Monkhorst fully uncontracted multi-reference perturbative treatment. I. Principles, second-order versions, and tests on ground state potential energy curves

NASA Astrophysics Data System (ADS)

Giner, Emmanuel; Angeli, Celestino; Garniron, Yann; Scemama, Anthony; Malrieu, Jean-Paul

2017-06-01

The present paper introduces a new multi-reference perturbation approach developed at second order, based on a Jeziorski-Mokhorst expansion using individual Slater determinants as perturbers. Thanks to this choice of perturbers, an effective Hamiltonian may be built, allowing for the dressing of the Hamiltonian matrix within the reference space, assumed here to be a CAS-CI. Such a formulation accounts then for the coupling between the static and dynamic correlation effects. With our new definition of zeroth-order energies, these two approaches are strictly size-extensive provided that local orbitals are used, as numerically illustrated here and formally demonstrated in the Appendix. Also, the present formalism allows for the factorization of all double excitation operators, just as in internally contracted approaches, strongly reducing the computational cost of these two approaches with respect to other determinant-based perturbation theories. The accuracy of these methods has been investigated on ground-state potential curves up to full dissociation limits for a set of six molecules involving single, double, and triple bond breaking together with an excited state calculation. The spectroscopic constants obtained with the present methods are found to be in very good agreement with the full configuration interaction results. As the present formalism does not use any parameter or numerically unstable operation, the curves obtained with the two methods are smooth all along the dissociation path.

Pediatric Reference Intervals for Free Thyroxine and Free Triiodothyronine

PubMed Central

Jang, Megan; Guo, Tiedong; Soldin, Steven J.

2009-01-01

Background The clinical value of free thyroxine (FT4) and free triiodothyronine (FT3) analysis depends on the reference intervals with which they are compared. We determined age- and sex-specific reference intervals for neonates, infants, and children 0–18 years of age for FT4 and FT3 using tandem mass spectrometry. Methods Reference intervals were calculated for serum FT4 (n = 1426) and FT3 (n = 1107) obtained from healthy children between January 1, 2008, and June 30, 2008, from Children's National Medical Center and Georgetown University Medical Center Bioanalytical Core Laboratory, Washington, DC. Serum samples were analyzed using isotope dilution liquid chromatography tandem mass spectrometry (LC/MS/MS) with deuterium-labeled internal standards. Results FT4 reference intervals were very similar for males and females of all ages and ranged between 1.3 and 2.4 ng/dL for children 1 to 18 years old. FT4 reference intervals for 1- to 12-month-old infants were 1.3–2.8 ng/dL. These 2.5 to 97.5 percentile intervals were much tighter than reference intervals obtained using immunoassay platforms 0.48–2.78 ng/dL for males and 0.85–2.09 ng/dL for females. Similarly, FT3 intervals were consistent and similar for males and females and for all ages, ranging between 1.5 pg/mL and approximately 6.0 pg/mL for children 1 month of age to 18 years old. Conclusions This is the first study to provide pediatric reference intervals of FT4 and FT3 for children from birth to 18 years of age using LC/MS/MS. Analysis using LC/MS/MS provides more specific quantification of thyroid hormones. A comparison of the ultrafiltration tandem mass spectrometric method with equilibrium dialysis showed very good correlation. PMID:19583487

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.

International documentary standards and comparison of national physical measurement standards for the calibration of accelerometers

NASA Astrophysics Data System (ADS)

Evans, David J.

2002-11-01

The documentary standards defining internationally adopted methodologies and protocols for calibrating transducers used to measure vibration are currently developed under the International Organization for Standardization (ISO) Technical Committee 108 Sub Committee 3 (Use and calibration of vibration and shock measuring instruments). Recent revisions of the documentary standards on primary methods for the calibration of accelerometers used to measure rectilinear motion have been completed. These standards can be, and have been, used as references in the technical protocols of key international and regional comparisons between National Measurement Institutes (NMIs) on the calibration of accelerometers. These key comparisons are occurring in part as a result of the creation of the Mutual Recognition Arrangement between NMIs which has appendices that document the uncertainties, and the comparisons completed in support of the uncertainties, claimed by the National Laboratories that are signatories of the MRA. The measurements for the first international and the first Interamerican System of Metrology (SIM) regional key comparisons in vibration have been completed. These intercomparisons were promulgated via the relatively new Consultative Committee for Acoustics, Ultrasound and Vibration (CCAUV) of the International Committee for Weights and Measures (CIPM) and SIM Metrology Working Group (MWG) 9, respectively.

High-temperature potentiometric oxygen sensor with internal reference

DOEpatents

Routbort, Jules L [Hinsdale, IL; Singh, Dileep [Naperville, IL; Dutta, Prabir K [Worthington, OH; Ramasamy, Ramamoorthy [North Royalton, OH; Spirig, John V [Columbus, OH; Akbar, Sheikh [Hilliard, OH

2011-11-15

A compact oxygen sensor is provided, comprising a mixture of metal and metal oxide an enclosure containing said mixture, said enclosure capable of isolating said mixture from an environment external of said enclosure, and a first wire having a first end residing within the enclosure and having a second end exposed to the environment. Also provided is a method for the fabrication of an oxygen sensor, the method comprising confining a metal-metal oxide solid mixture to a container which consists of a single material permeable to oxygen ions, supplying an electrical conductor having a first end and a second end, whereby the first end resides inside the container as a reference (PO.sub.2).sup.ref, and the second end resides outside the container in the atmosphere where oxygen partial pressure (PO.sub.2).sup.ext is to be measured, and sealing the container with additional single material such that grain boundary sliding occurs between grains of the single material and grains of the additional single material.

LC-MS/MS-based approach for obtaining exposure estimates of metabolites in early clinical trials using radioactive metabolites as reference standards.

PubMed

Zhang, Donglu; Raghavan, Nirmala; Chando, Theodore; Gambardella, Janice; Fu, Yunlin; Zhang, Duxi; Unger, Steve E; Humphreys, W Griffith

2007-12-01

An LC-MS/MS-based approach that employs authentic radioactive metabolites as reference standards was developed to estimate metabolite exposures in early drug development studies. This method is useful to estimate metabolite levels in studies done with non-radiolabeled compounds where metabolite standards are not available to allow standard LC-MS/MS assay development. A metabolite mixture obtained from an in vivo source treated with a radiolabeled compound was partially purified, quantified, and spiked into human plasma to provide metabolite standard curves. Metabolites were analyzed by LC-MS/MS using the specific mass transitions and an internal standard. The metabolite concentrations determined by this approach were found to be comparable to those determined by valid LC-MS/MS assays. This approach does not requires synthesis of authentic metabolites or the knowledge of exact structures of metabolites, and therefore should provide a useful method to obtain early estimates of circulating metabolites in early clinical or toxicological studies.

Estimating Contraceptive Prevalence Using Logistics Data for Short-Acting Methods: Analysis Across 30 Countries.

PubMed

Cunningham, Marc; Bock, Ariella; Brown, Niquelle; Sacher, Suzy; Hatch, Benjamin; Inglis, Andrew; Aronovich, Dana

2015-09-01

Contraceptive prevalence rate (CPR) is a vital indicator used by country governments, international donors, and other stakeholders for measuring progress in family planning programs against country targets and global initiatives as well as for estimating health outcomes. Because of the need for more frequent CPR estimates than population-based surveys currently provide, alternative approaches for estimating CPRs are being explored, including using contraceptive logistics data. Using data from the Demographic and Health Surveys (DHS) in 30 countries, population data from the United States Census Bureau International Database, and logistics data from the Procurement Planning and Monitoring Report (PPMR) and the Pipeline Monitoring and Procurement Planning System (PipeLine), we developed and evaluated 3 models to generate country-level, public-sector contraceptive prevalence estimates for injectable contraceptives, oral contraceptives, and male condoms. Models included: direct estimation through existing couple-years of protection (CYP) conversion factors, bivariate linear regression, and multivariate linear regression. Model evaluation consisted of comparing the referent DHS prevalence rates for each short-acting method with the model-generated prevalence rate using multiple metrics, including mean absolute error and proportion of countries where the modeled prevalence rate for each method was within 1, 2, or 5 percentage points of the DHS referent value. For the methods studied, family planning use estimates from public-sector logistics data were correlated with those from the DHS, validating the quality and accuracy of current public-sector logistics data. Logistics data for oral and injectable contraceptives were significantly associated (P<.05) with the referent DHS values for both bivariate and multivariate models. For condoms, however, that association was only significant for the bivariate model. With the exception of the CYP-based model for condoms, models were able to estimate public-sector prevalence rates for each short-acting method to within 2 percentage points in at least 85% of countries. Public-sector contraceptive logistics data are strongly correlated with public-sector prevalence rates for short-acting methods, demonstrating the quality of current logistics data and their ability to provide relatively accurate prevalence estimates. The models provide a starting point for generating interim estimates of contraceptive use when timely survey data are unavailable. All models except the condoms CYP model performed well; the regression models were most accurate but the CYP model offers the simplest calculation method. Future work extending the research to other modern methods, relating subnational logistics data with prevalence rates, and tracking that relationship over time is needed. © Cunningham et al.

46 CFR 95.01-2 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... for the Installation of Sprinkler Systems, incorporation by reference approved for § 95.30-1. (2... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE... Specification for International Shore Connections for Marine Fire Applications, incorporation by reference...

46 CFR 193.01-3 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... for the Installation of Sprinkler Systems, incorporation by reference approved for § 193.30-1. (2... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE... Specification for International Shore Connections for Marine Fire Applications, incorporation by reference...

46 CFR 193.01-3 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... for the Installation of Sprinkler Systems, incorporation by reference approved for § 193.30-1. (2... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE... Specification for International Shore Connections for Marine Fire Applications, incorporation by reference...

46 CFR 95.01-2 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... for the Installation of Sprinkler Systems, incorporation by reference approved for § 95.30-1. (2... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE... Specification for International Shore Connections for Marine Fire Applications, incorporation by reference...

Evaluation of New Reference Genes in Papaya for Accurate Transcript Normalization under Different Experimental Conditions

PubMed Central

Chen, Weixin; Chen, Jianye; Lu, Wangjin; Chen, Lei; Fu, Danwen

2012-01-01

Real-time reverse transcription PCR (RT-qPCR) is a preferred method for rapid and accurate quantification of gene expression studies. Appropriate application of RT-qPCR requires accurate normalization though the use of reference genes. As no single reference gene is universally suitable for all experiments, thus reference gene(s) validation under different experimental conditions is crucial for RT-qPCR analysis. To date, only a few studies on reference genes have been done in other plants but none in papaya. In the present work, we selected 21 candidate reference genes, and evaluated their expression stability in 246 papaya fruit samples using three algorithms, geNorm, NormFinder and RefFinder. The samples consisted of 13 sets collected under different experimental conditions, including various tissues, different storage temperatures, different cultivars, developmental stages, postharvest ripening, modified atmosphere packaging, 1-methylcyclopropene (1-MCP) treatment, hot water treatment, biotic stress and hormone treatment. Our results demonstrated that expression stability varied greatly between reference genes and that different suitable reference gene(s) or combination of reference genes for normalization should be validated according to the experimental conditions. In general, the internal reference genes EIF (Eukaryotic initiation factor 4A), TBP1 (TATA binding protein 1) and TBP2 (TATA binding protein 2) genes had a good performance under most experimental conditions, whereas the most widely present used reference genes, ACTIN (Actin 2), 18S rRNA (18S ribosomal RNA) and GAPDH (Glyceraldehyde-3-phosphate dehydrogenase) were not suitable in many experimental conditions. In addition, two commonly used programs, geNorm and Normfinder, were proved sufficient for the validation. This work provides the first systematic analysis for the selection of superior reference genes for accurate transcript normalization in papaya under different experimental conditions. PMID:22952972

An International Strategy for Human Exploration of the Moon: The International Space Exploration Coordination Group (ISECG) Reference Architecture for Human Lunar Exploration

NASA Technical Reports Server (NTRS)

Laurini, Kathleen C.; Hufenbach, Bernhard; Junichiro, Kawaguchi; Piedboeuf, Jean-Claude; Schade, Britta; Lorenzoni, Andrea; Curtis, Jeremy; Hae-Dong, Kim

2010-01-01

The International Space Exploration Coordination Group (ISECG) was established in response to The Global Exploration Strategy: The Framework for Coordination developed by fourteen space agencies and released in May 2007. Several ISECG participating space agencies have been studying concepts for human exploration of the moon that allow individual and collective goals and objectives to be met. This 18 month study activity culminated with the development of the ISECG Reference Architecture for Human Lunar Exploration. The reference architecture is a series of elements delivered over time in a flexible and evolvable campaign. This paper will describe the reference architecture and how it will inform near-term and long-term programmatic planning within interested agencies. The reference architecture is intended to serve as a global point of departure conceptual architecture that enables individual agency investments in technology development and demonstration, International Space Station research and technology demonstration, terrestrial analog studies, and robotic precursor missions to contribute towards the eventual implementation of a human lunar exploration scenario which reflects the concepts and priorities established to date. It also serves to create opportunities for partnerships that will support evolution of this concept and its eventual realization. The ISECG Reference Architecture for Human Lunar Exploration (commonly referred to as the lunar gPoD) reflects the agency commitments to finding an effective balance between conducting important scientific investigations of and from the moon, as well as demonstrating and mastering the technologies and capabilities to send humans farther into the Solar System. The lunar gPoD begins with a robust robotic precursor phase that demonstrates technologies and capabilities considered important for the success of the campaign. Robotic missions will inform the human missions and buy down risks. Human exploration will start with a thorough scientific investigation of the polar region while allowing the ability to demonstrate and validate the systems needed to take humans on more ambitious lunar exploration excursions. The ISECG Reference Architecture for Human Lunar Exploration serves as a model for future cooperation and is documented in a summary report and a comprehensive document that also describes the collaborative international process that led to its development. ISECG plans to continue with architecture studies such as this to examine an open transportation architecture and other destinations, with expanded participation from ISECG agencies, as it works to inform international partnerships and advance the Global Exploration Strategy.

The Internal/External Frame of Reference Model of Self-Concept and Achievement Relations: Age-Cohort and Cross-Cultural Differences

ERIC Educational Resources Information Center

Marsh, Herbert W.; Abduljabbar, Adel Salah; Parker, Philip D.; Morin, Alexandre J. S.; Abdelfattah, Faisal; Nagengast, Benjamin; Möller, Jens; Abu-Hilal, Maher M.

2015-01-01

The internal/external frame of reference (I/E) model and dimensional comparison theory posit paradoxical relations between achievement (ACH) and self-concept (SC) in mathematics (M) and verbal (V) domains; ACH in each domain positively affects SC in the matching domain (e.g., MACH to MSC) but negatively in the nonmatching domain (e.g., MACH to…

Verbal and Math Self-Concepts: An Extension of the Internal/External Frame of Reference Model.

ERIC Educational Resources Information Center

Marsh, Herbert W.; Byrne, Barbara M.

The internal/external (I/E) frame of reference model describes relations among Verbal self-concept (VSC), Math self-concept (MSC), and corresponding achievement scores (VACH, MACH). In support of the model Marsh (1986) found that: (1) VSC and MSC were nearly uncorrelated; (2) the effect of VACH on VSC, and of MACH on MSC, were positive; but (3)…

Initiating and Managing University-Based International Research and Development Activities.

ERIC Educational Resources Information Center

Peterson, Marla P.

1987-01-01

Initiating and managing international research and development are discussed, including: basic principles for participation in international development activities; AID and World Bank project cycles; AID and World Bank contracting modes and instruments; and international contract negotiations. Some reference sources are appended. (MLW)

Validation of endogenous reference genes for qRT-PCR analysis of human visceral adipose samples

PubMed Central

2010-01-01

Background Given the epidemic proportions of obesity worldwide and the concurrent prevalence of metabolic syndrome, there is an urgent need for better understanding the underlying mechanisms of metabolic syndrome, in particular, the gene expression differences which may participate in obesity, insulin resistance and the associated series of chronic liver conditions. Real-time PCR (qRT-PCR) is the standard method for studying changes in relative gene expression in different tissues and experimental conditions. However, variations in amount of starting material, enzymatic efficiency and presence of inhibitors can lead to quantification errors. Hence the need for accurate data normalization is vital. Among several known strategies for data normalization, the use of reference genes as an internal control is the most common approach. Recent studies have shown that both obesity and presence of insulin resistance influence an expression of commonly used reference genes in omental fat. In this study we validated candidate reference genes suitable for qRT-PCR profiling experiments using visceral adipose samples from obese and lean individuals. Results Cross-validation of expression stability of eight selected reference genes using three popular algorithms, GeNorm, NormFinder and BestKeeper found ACTB and RPII as most stable reference genes. Conclusions We recommend ACTB and RPII as stable reference genes most suitable for gene expression studies of human visceral adipose tissue. The use of these genes as a reference pair may further enhance the robustness of qRT-PCR in this model system. PMID:20492695

Validation of endogenous reference genes for qRT-PCR analysis of human visceral adipose samples.

PubMed

Mehta, Rohini; Birerdinc, Aybike; Hossain, Noreen; Afendy, Arian; Chandhoke, Vikas; Younossi, Zobair; Baranova, Ancha

2010-05-21

Given the epidemic proportions of obesity worldwide and the concurrent prevalence of metabolic syndrome, there is an urgent need for better understanding the underlying mechanisms of metabolic syndrome, in particular, the gene expression differences which may participate in obesity, insulin resistance and the associated series of chronic liver conditions. Real-time PCR (qRT-PCR) is the standard method for studying changes in relative gene expression in different tissues and experimental conditions. However, variations in amount of starting material, enzymatic efficiency and presence of inhibitors can lead to quantification errors. Hence the need for accurate data normalization is vital. Among several known strategies for data normalization, the use of reference genes as an internal control is the most common approach. Recent studies have shown that both obesity and presence of insulin resistance influence an expression of commonly used reference genes in omental fat. In this study we validated candidate reference genes suitable for qRT-PCR profiling experiments using visceral adipose samples from obese and lean individuals. Cross-validation of expression stability of eight selected reference genes using three popular algorithms, GeNorm, NormFinder and BestKeeper found ACTB and RPII as most stable reference genes. We recommend ACTB and RPII as stable reference genes most suitable for gene expression studies of human visceral adipose tissue. The use of these genes as a reference pair may further enhance the robustness of qRT-PCR in this model system.

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

PubMed

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

2017-01-01

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

"I Am Chelsea Manning": Comparison of Gendered Representation of Private Manning in U.S. and International News Media.

PubMed

Hackl, Andrea M; Becker, Amy B; Todd, Maureen E

2016-01-01

On August 22, 2013, Bradley Manning released a statement requesting to be referred to as female. In the following days, the news media discussed whether language should shift toward a female representation. Using quantitative content analysis and qualitative contextual analysis, this study analyzed whether U.S. and international newspapers (N = 197) acknowledged Manning's request to be referred to as "Chelsea" in the two weeks after the statement. Results suggest that the mainstream press was hesitant in shifting toward a female representation. A comparison of international and U.S. newspapers suggests that the U.S. press lagged behind international coverage using a female depiction.

Cont-Bouchaud Percolation Model Including Tobin Tax

NASA Astrophysics Data System (ADS)

Ehrenstein, Gudrun

The Tobin tax is an often discussed method to tame speculation and get a source of income. The discussion is especially heated when the financial markets are in crisis. In this article we refer to the foreign exchange markets. The Tobin tax should be a small international tax affecting all currency transactions and thus consequently reducing destabilizing speculations. In this way this tax should take over a control function. By including the Tobin tax in the microscopic model of Cont and Bouchaud one finds that this tax could be the right method to control foreign exchange operations and to get a good source of income.

Prediction of hydrocarbons in sedimentary basins

USGS Publications Warehouse

Harff, J.E.; Davis, J.C.; Eiserbeck, W.

1993-01-01

To estimate the undiscovered hydrocarbon potential of sedimentary basins, quantitative play assessments specific for each location in a region may be obtained using geostatistical methods combined with the theory of classification of geological objects, a methodology referred to as regionalization. The technique relies on process modeling and measured borehole data as well as probabilistic methods to exploit the relationship between geology (the "predictor") and known hydrocarbon productivity (the "target") to define prospective stratigraphic intervals within a basin. It is demonstrated in case studies from the oil-producing region of the western Kansas Pennsylvanian Shelf and the gas-bearing Rotliegend sediments of the Northeast German Basin. ?? 1993 International Association for Mathematical Geology.

Simultaneous analysis of tea catechins, caffeine, gallic acid, theanine and ascorbic acid by micellar electrokinetic capillary chromatography.

PubMed

Aucamp, J P; Hara, Y; Apostolides, Z

2000-04-21

A micellar electrokinetic capillary chromatography (MEKC) method for the simultaneous analysis of five tea catechins, theanine, caffeine, gallic acid and ascorbic acid has been developed. The catechins are (-)-epicatechin, (+)-catechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. p-Nitrophenol serves as both reference and internal standard. All the components are separated within 13 min with a 57 cm uncoated fused-silica column. On-column detection was carried out at 200 nm. This method has been used to measure these compounds in fresh tea leaves and tea liquor. The limit of detection for all analytes ranged from 1 to 20 microg/ml.

Psychometric testing of the short version of the world health organization quality of life (WHOQOL-BREF) questionnaire among pulmonary tuberculosis patients in Taiwan

PubMed Central

2012-01-01

Background Studies on the effects of tuberculosis on a patient’s quality of life (QOL) are scant. The objective of this study was to evaluate the psychometric properties of the Taiwan short version of the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire using patients with tuberculosis in Taiwan and healthy referents. Methods The Taiwanese short version of the WHOQOL-BREF was administered to patients with tuberculosis undergoing treatment and healthy referents from March 2007 to July 2007. Patients with tuberculosis (n = 140) and healthy referents (n = 130), matched by age, sex, and ethnicity, agreed to an interview. All participants lived in eastern Taiwan. Reliability assessments included internal consistency, whereas validity assessments included construct validity, convergent validity, and discriminant validity. Results More than half of these patients and referents were men (70.7% and 66.2%, respectively), and their average ages were 50.1 and 47.9 years, respectively. Approximately 60% of patients and referents were aboriginal Taiwanese (60.7% and 61.1%, respectively). The proportion with low socioeconomic status was greater for these patients. The internal consistency reliability coefficients were .92 and .93 for the patients and healthy referents, respectively. Exploratory factor analysis on the healthy referents displayed a 4-domain model, which was compatible with the original WHOQOL-BREF 4-domain model. However, for the TB patient group, after deleting 3 items, both exploratory and confirmatory factor analysis revealed a 6-domain model. Conclusion Psychometric evaluation of the Taiwan short version of the WHOQOL-BREF indicates that it has adequate reliability for use in research with TB patients in Taiwan. However, the factor structure generated from this TB patient sample differed from the WHO’s original 4-factor model, which raised a validity concern to apply the Taiwan short version of the WHOQOL-BREF to Taiwanese TB patients. Future research recruiting another sample to revisit this validity issue must be conducted to determine the validity of the WHOQOL-BREF TW in patients with TB. PMID:22877305

Avoiding pitfalls of internal controls: validation of reference genes for analysis by qRT-PCR and Western blot throughout rat retinal development.

PubMed

Rocha-Martins, Maurício; Njaine, Brian; Silveira, Mariana S

2012-01-01

Housekeeping genes have been commonly used as reference to normalize gene expression and protein content data because of its presumed constitutive expression. In this paper, we challenge the consensual idea that housekeeping genes are reliable controls for expression studies in the retina through the investigation of a panel of reference genes potentially suitable for analysis of different stages of retinal development. We applied statistical tools on combinations of retinal developmental stages to assess the most stable internal controls for quantitative RT-PCR (qRT-PCR). The stability of expression of seven putative reference genes (Actb, B2m, Gapdh, Hprt1, Mapk1, Ppia and Rn18s) was analyzed using geNorm, BestKeeper and Normfinder software. In addition, several housekeeping genes were tested as loading controls for Western blot in the same sample panel, using Image J. Overall, for qRT-PCR the combination of Gapdh and Mapk1 showed the highest stability for most experimental sets. Actb was downregulated in more mature stages, while Rn18s and Hprt1 showed the highest variability. We normalized the expression of cyclin D1 using various reference genes and demonstrated that spurious results may result from blind selection of internal controls. For Western blot significant variation could be seen among four putative internal controls (β-actin, cyclophilin b, α-tubulin and lamin A/C), while MAPK1 was stably expressed. Putative housekeeping genes exhibit significant variation in both mRNA and protein content during retinal development. Our results showed that distinct combinations of internal controls fit for each experimental set in the case of qRT-PCR and that MAPK1 is a reliable loading control for Western blot. The results indicate that biased study outcomes may follow the use of reference genes without prior validation for qRT-PCR and Western blot.

Sex-specific reference intervals of hematologic and biochemical analytes in Sprague-Dawley rats using the nonparametric rank percentile method.

PubMed

He, Qili; Su, Guoming; Liu, Keliang; Zhang, Fangcheng; Jiang, Yong; Gao, Jun; Liu, Lida; Jiang, Zhongren; Jin, Minwu; Xie, Huiping

2017-01-01

Hematologic and biochemical analytes of Sprague-Dawley rats are commonly used to determine effects that were induced by treatment and to evaluate organ dysfunction in toxicological safety assessments, but reference intervals have not been well established for these analytes. Reference intervals as presently defined for these analytes in Sprague-Dawley rats have not used internationally recommended statistical method nor stratified by sex. Thus, we aimed to establish sex-specific reference intervals for hematologic and biochemical parameters in Sprague-Dawley rats according to Clinical and Laboratory Standards Institute C28-A3 and American Society for Veterinary Clinical Pathology guideline. Hematology and biochemistry blood samples were collected from 500 healthy Sprague-Dawley rats (250 males and 250 females) in the control groups. We measured 24 hematologic analytes with the Sysmex XT-2100i analyzer, 9 biochemical analytes with the Olympus AU400 analyzer. We then determined statistically relevant sex partitions and calculated reference intervals, including corresponding 90% confidence intervals, using nonparametric rank percentile method. We observed that most hematologic and biochemical analytes of Sprague-Dawley rats were significantly influenced by sex. Males had higher hemoglobin, hematocrit, red blood cell count, red cell distribution width, mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, neutrophils, lymphocytes, monocytes, percentage of neutrophils, percentage of monocytes, alanine aminotransferase, aspartate aminotransferase, and triglycerides compared to females. Females had higher mean corpuscular hemoglobin concentration, plateletcrit, platelet count, eosinophils, percentage of lymphocytes, percentage of eosinophils, creatinine, glucose, total cholesterol and urea compared to males. Sex partition was required for most hematologic and biochemical analytes in Sprague-Dawley rats. We established sex-specific reference intervals, including corresponding 90% confidence intervals, for Sprague-Dawley rats. Understanding the significant discrepancies in hematologic and biochemical analytes between male and female Sprague-Dawley rats provides important insight into physiological effects in test rats. Establishment of locally sex-specific reference intervals allows a more precise evaluation of animal quality and experimental results of Sprague-Dawley rats in our toxicology safety assessment.

Efficient and accurate local single reference correlation methods for high-spin open-shell molecules using pair natural orbitals

NASA Astrophysics Data System (ADS)

Hansen, Andreas; Liakos, Dimitrios G.; Neese, Frank

2011-12-01

A production level implementation of the high-spin open-shell (spin unrestricted) single reference coupled pair, quadratic configuration interaction and coupled cluster methods with up to doubly excited determinants in the framework of the local pair natural orbital (LPNO) concept is reported. This work is an extension of the closed-shell LPNO methods developed earlier [F. Neese, F. Wennmohs, and A. Hansen, J. Chem. Phys. 130, 114108 (2009), 10.1063/1.3086717; F. Neese, A. Hansen, and D. G. Liakos, J. Chem. Phys. 131, 064103 (2009), 10.1063/1.3173827]. The internal space is spanned by localized orbitals, while the external space for each electron pair is represented by a truncated PNO expansion. The laborious integral transformation associated with the large number of PNOs becomes feasible through the extensive use of density fitting (resolution of the identity (RI)) techniques. Technical complications arising for the open-shell case and the use of quasi-restricted orbitals for the construction of the reference determinant are discussed in detail. As in the closed-shell case, only three cutoff parameters control the average number of PNOs per electron pair, the size of the significant pair list, and the number of contributing auxiliary basis functions per PNO. The chosen threshold default values ensure robustness and the results of the parent canonical methods are reproduced to high accuracy. Comprehensive numerical tests on absolute and relative energies as well as timings consistently show that the outstanding performance of the LPNO methods carries over to the open-shell case with minor modifications. Finally, hyperfine couplings calculated with the variational LPNO-CEPA/1 method, for which a well-defined expectation value type density exists, indicate the great potential of the LPNO approach for the efficient calculation of molecular properties.

Body fatness or anthropometry for assessment of unhealthy weight status? Comparison between methods in South African children and adolescents.

PubMed

Craig, Eva; Reilly, John; Bland, Ruth

2013-11-01

A variety of methods are available for defining undernutrition (thinness/underweight/under-fat) and overnutrition (overweight/obesity/over-fat). The extent to which these definitions agree is unclear. The present cross-sectional study aimed to assess agreement between widely used methods of assessing nutritional status in children and adolescents, and to examine the benefit of body composition estimates. The main objective of the cross-sectional study was to assess underweight, overweight and obesity using four methods: (i) BMI-for-age using WHO (2007) reference data; (ii) BMI-for-age using Cole et al. and International Obesity Taskforce cut-offs; (iii) weight-for-age using the National Centre for Health Statistics/WHO growth reference 1977; and (iv) body fat percentage estimated by bio-impedance (body fat reference curves for children of McCarthy et al., 2006). Comparisons were made between methods using weighted kappa analyses. Rural South Africa. Individuals (n 1519) in three age groups (school grade 1, mean age 7 years; grade 5, mean age 11 years; grade 9, mean age 15 years). In boys, prevalence of unhealthy weight status (both under- and overnutrition) was much higher at all ages with body fatness measures than with simple anthropometric proxies for body fatness; agreement between fatness and weight-based measures was fair or slight using Landis and Koch categories. In girls, prevalence of unhealthy weight status was also higher with body fatness than with proxies, although agreement between measures ranged from fair to substantial. Methods for defining under- and overnutrition should not be considered equivalent. Weight-based measures provide highly conservative estimates of unhealthy weight status, possibly more conservative in boys. Simple body composition measures may be more informative than anthropometry for nutritional surveillance of children and adolescents.

Bio-Inspired Metallo-Supramolecular Polymers for Combined Mechanical Properties

DTIC Science & Technology

2010-01-01

3 4 5 6 0 50 100 150 200 Temp (°C) H ea t F lo w (m W ) Figure 8. DSC trace of polymer 7. 1H NMR analysis indicated complete reaction of the...static and dynamic mechanical analysis methods. 11 5. References 1. Guan, Z. Polymer International 2007, 56, 467. 2. Oberhauser, A. F ...Hansma, P. K.; Carrion-Vazques, M.; Fernandez, J. M. Proc. Natl. Acad. Sci. USA 2001, 98, 468. 3. Reif, M. Gautel, M.; Oesterhelt, F .; Fernandez, J

Designing an effective office brochure.

PubMed

Metzger, Michael Z

2003-01-01

The office brochure is an effective and comparatively inexpensive method for both internal and external marketing of your practice. With the advent of desktop publishing, almost anyone with a computer and a few hours can design, write, and edit the brochure. However to be successful, certain concepts such as color, paper weight, font, and layout must be understood. Once printed, a well-planned program for the use of the brochure can effectively promote the practice to the present and future patients, referring physicians, and insurance companies.

Validation of Modifications to the ANSR for Listeria Method for Improved Internal Positive Control Performance.

PubMed

Alles, Susan; Meister, Evan; Hosking, Edan; Tovar, Eric; Shaulis, Rebecca; Schonfeld, Mark; Zhang, Lei; Li, Lin; Biswas, Preetha; Mozola, Mark; Donofrio, Robert; Chen, Yi

2018-03-01

A study was conducted to validate a minor reagent formulation change to the ANSR for Listeria method, Performance Tested MethodSM 101202. This change involves increasing the master mix volume prelyophilization by 40% and addition of salmon sperm DNA (nontarget DNA) to the master mix. These changes improve the robustness of the internal positive control response and reduce the possibility of obtaining invalid results due to weak-positive control curves. When three foods (hot dogs, Mexican-style cheese, and cantaloupe) and sponge samples taken from a stainless steel surface were tested, no significant differences in performance between the ANSR and U.S. Food and Drug Administration Bacteriological Analytical Manual or U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedures were observed for any of the matrixes as determined by probability of detection analysis. Inclusivity and exclusivity testing yielded 100% expected results for target and nontarget bacteria. Accelerated stability testing was carried out over a 7 week period and showed no decrease in assay performance over time.

A new strategy for in vivo spectral editing. Application to GABA editing using selective homonuclear polarization transfer spectroscopy

NASA Astrophysics Data System (ADS)

Shen, Jun; Yang, Jehoon; Choi, In-Young; Li, Shizhe Steve; Chen, Zhengguang

2004-10-01

A novel single-shot in vivo spectral editing method is proposed in which the signal to be detected, is regenerated anew from the thermal equilibrium magnetization of a source to which it is J-coupled. The thermal equilibrium magnetization of the signal to be detected together with those of overlapping signals are suppressed by single-shot gradient dephasing prior to the signal regeneration process. Application of this new strategy to in vivo GABA editing using selective homonuclear polarization transfer allows complete suppression of overlapping creatine and glutathione while detecting the GABA-4 methylene resonance at 3.02 ppm with an editing yield similar to that of conventional editing methods. The NAA methyl group at 2.02 ppm was simultaneously detected and can be used as an internal navigator echo for correcting the zero order phase and frequency shifts and as an internal reference for concentration. This new method has been demonstrated for robust in vivo GABA editing in the rat brain and for study of GABA synthesis after acute vigabatrin administration.

Jim Starnes' Contributions to Residual Strength Analysis Methods for Metallic Structures

NASA Technical Reports Server (NTRS)

Young, Richard D.; Rose, Cheryl A.; Harris, Charles E.

2005-01-01

A summary of advances in residual strength analyses methods for metallic structures that were realized under the leadership of Dr. James H. Starnes, Jr., is presented. The majority of research led by Dr. Starnes in this area was conducted in the 1990's under the NASA Airframe Structural Integrity Program (NASIP). Dr. Starnes, respectfully referred to herein as Jim, had a passion for studying complex response phenomena and dedicated a significant amount of research effort toward advancing damage tolerance and residual strength analysis methods for metallic structures. Jim's efforts were focused on understanding damage propagation in built-up fuselage structure with widespread fatigue damage, with the goal of ensuring safety in the aging international commercial transport fleet. Jim's major contributions in this research area were in identifying the effects of combined internal pressure and mechanical loads, and geometric nonlinearity, on the response of built-up structures with damage. Analytical and experimental technical results are presented to demonstrate the breadth and rigor of the research conducted in this technical area. Technical results presented herein are drawn exclusively from papers where Jim was a co-author.

Methods to improve routine bioassay monitoring for freshly separated, poorly transported plutonium

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

Bihl, D.E.; Lynch, T.P.; Carbaugh, E.H.

1988-09-01

Several human cases involving inhalation of plutonium oxide at Hanford have shown clearance half-times from the lung that are much longer than the 500-day half-time recommended for class Y plutonium in Publication 30 of the International Commission on Radiological Protection(ICRP). The more tenaciously retained material is referred to as super class Y plutonium. The ability to detect super class Y plutonium by current routine bioassay measurements is shown to be poor. Pacific Northwest Laboratory staff involved in the Hanford Internal Dosimetry Program investigated four methods to se if improvements in routine monitoring of workers for fresh super class Y plutoniummore » are feasible. The methods were lung counting, urine sampling, fecal sampling, and use of diethylenetriaminepentaacetate (DTPA) to enhance urinary excretion. Use of DTPA was determined to be not feasible. Routine fecal sampling was found to be feasible but not recommended. Recommendations were made to improve the detection level for routine annual urinalysis and routine annual lung counting. 12 refs., 9 figs., 7 tabs.« less

An Improved SoC Test Scheduling Method Based on Simulated Annealing Algorithm

NASA Astrophysics Data System (ADS)

Zheng, Jingjing; Shen, Zhihang; Gao, Huaien; Chen, Bianna; Zheng, Weida; Xiong, Xiaoming

2017-02-01

In this paper, we propose an improved SoC test scheduling method based on simulated annealing algorithm (SA). It is our first to disorganize IP core assignment for each TAM to produce a new solution for SA, allocate TAM width for each TAM using greedy algorithm and calculate corresponding testing time. And accepting the core assignment according to the principle of simulated annealing algorithm and finally attain the optimum solution. Simultaneously, we run the test scheduling experiment with the international reference circuits provided by International Test Conference 2002(ITC’02) and the result shows that our algorithm is superior to the conventional integer linear programming algorithm (ILP), simulated annealing algorithm (SA) and genetic algorithm(GA). When TAM width reaches to 48,56 and 64, the testing time based on our algorithm is lesser than the classic methods and the optimization rates are 30.74%, 3.32%, 16.13% respectively. Moreover, the testing time based on our algorithm is very close to that of improved genetic algorithm (IGA), which is state-of-the-art at present.

Gas chromatographic quantitation of underivatized amines in the determination of their octanol-0.1 M sodium hydroxide partition coefficients by the shake-flask method.

PubMed

Grunewald, G L; Pleiss, M A; Gatchell, C L; Pazhenchevsky, R; Rafferty, M F

1984-06-01

The use of gas chromatography (GC) for the determination of 0.1 M sodium hydroxide-octanol partition coefficients (log P) for a wide variety of ethylamines is demonstrated. The conventional shake-flask procedure (SFP) is utilized, with the addition of an internal reference, which is cleanly separated from the desired solute and solvents on a 10% Apiezon L, 2% potassium hydroxide on 80-100 mesh Chromosorb W AW column. The partitioned solute is extracted from the aqueous phase with chloroform and analyzed by GC. The method provides an accurate and highly reproducible means of determining log P values, as demonstrated by the low relative standard errors. The technique is both rapid and extremely versatile. The use of the internal standard method of analysis introduces consistency, since variables like the exact weight of solute are not necessary (unlike the traditional SFP) and the volume of sample injected is not critical. The technique is readily accessible to microgram quantities of solutes, making it ideal for a wide range of volatile, amine-bearing compounds.

Convergence studies in meshfree peridynamic simulations

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

Seleson, Pablo; Littlewood, David J.

2016-04-15

Meshfree methods are commonly applied to discretize peridynamic models, particularly in numerical simulations of engineering problems. Such methods discretize peridynamic bodies using a set of nodes with characteristic volume, leading to particle-based descriptions of systems. In this article, we perform convergence studies of static peridynamic problems. We show that commonly used meshfree methods in peridynamics suffer from accuracy and convergence issues, due to a rough approximation of the contribution to the internal force density of nodes near the boundary of the neighborhood of a given node. We propose two methods to improve meshfree peridynamic simulations. The first method uses accuratemore » computations of volumes of intersections between neighbor cells and the neighborhood of a given node, referred to as partial volumes. The second method employs smooth influence functions with a finite support within peridynamic kernels. Numerical results demonstrate great improvements in accuracy and convergence of peridynamic numerical solutions, when using the proposed methods.« less

EGR distribution and fluctuation probe based on CO.sub.2 measurements

DOEpatents

Parks, II, James E; Partridge, Jr., William P; Yoo, Ji Hyung

2015-04-07

A diagnostic system having a single-port EGR probe and a method for using the same. The system includes a light source, an EGR probe, a detector and a processor. The light source may provide a combined light beam composed of light from a mid-infrared signal source and a mid-infrared reference source. The signal source may be centered at 4.2 .mu.m and the reference source may be centered at 3.8 .mu.m. The EGR probe may be a single-port probe with internal optics and a sampling chamber with two flow cells arranged along the light path in series. The optics may include a lens for focusing the light beam and a mirror for reflecting the light beam received from a pitch optical cable to a catch optical cable. The signal and reference sources are modulated at different frequencies, thereby allowing them to be separated and the signal normalized by the processor.

Medición de posiciones astrométricas con CCD en la zona de Rup 21

NASA Astrophysics Data System (ADS)

Bustos Fierro, I. H.; Calderón, J. H.

It is shown the utilization of the block adjustment method for the measurement of astrometric positions from a mosaic of sixteen CCD images with partial overlap, which were taken with the Telescope Jorge Sahade of CASLEO. The observations cover an area of 25' x 25' around the open cluster Rup21. The source of reference positions was ACT Reference Catalog. The internal error of the measured positions is analyzed, and the external error is estimated from the comparison with the catalog USNO-A. In this comparison it is found that the direct CCD images taken with focal reducer could be distorted by severe field curvature. The effect of the distortion presumably introduced by the optics is eliminated with the suitable corrections of the stellar positions measured on every frame, but a new systematic effect on scales of the entire field is observed, which could be due to the distribution of the reference stars.

14 CFR 150.13 - Incorporations by reference.

Code of Federal Regulations, 2010 CFR

2010-01-01

... follows: International Electrotechnical Commission (IEC) Publication No. 179, entitled “Precision Sound Level Meters,” dated 1973. (d) Availability for purchase. Published material incorporated by reference...

14 CFR 150.13 - Incorporations by reference.

Code of Federal Regulations, 2011 CFR

2011-01-01

... follows: International Electrotechnical Commission (IEC) Publication No. 179, entitled “Precision Sound Level Meters,” dated 1973. (d) Availability for purchase. Published material incorporated by reference...

Evolution of activities in international biological standardization since the early days of the Health Organisation of the League of Nations.

PubMed

Sizaret, P

1988-01-01

The main activities in international biological standardization during the 18 years that followed the first international biological standardization meeting in London in 1921 were concerned with expressing the potencies of test preparations in comparison with reference materials. After the Second World War, however, it became clear that the testing of biological substances against international reference materials was only one among several measures for obtaining safe and potent products. The activities in international biological standardization were therefore widened so that, by the strict observance of specific manufacturing and control requirements, it was possible to gain further in safety and efficacy. At the end of 1987, 42 international requirements for biological substances were available and were being used as national requirements, sometimes after minor modification, by the majority of WHO's Member States. This is of utmost importance for the worldwide use of safe and potent biological products, including vaccines.

A candidate reference method using ICP-MS for sweat chloride quantification.

PubMed

Collie, Jake T; Massie, R John; Jones, Oliver A H; Morrison, Paul D; Greaves, Ronda F

2016-04-01

The aim of the study was to develop a method for sweat chloride (Cl) quantification using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to present to the Joint Committee for Traceability in Laboratory Medicine (JCTLM) as a candidate reference method for the diagnosis of cystic fibrosis (CF). Calibration standards were prepared from sodium chloride (NaCl) to cover the expected range of sweat Cl values. Germanium (Ge) and scandium (Sc) were selected as on-line (instrument based) internal standards (IS) and gallium (Ga) as the off-line (sample based) IS. The method was validated through linearity, accuracy and imprecision studies as well as enrolment into the Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) for sweat electrolyte testing. Two variations of the ICP-MS method were developed, an on-line and off-line IS, and compared. Linearity was determined up to 225 mmol/L with a limit of quantitation of 7.4 mmol/L. The off-line IS demonstrated increased accuracy through the RCPAQAP performance assessment (CV of 1.9%, bias of 1.5 mmol/L) in comparison to the on-line IS (CV of 8.0%, bias of 3.8 mmol/L). Paired t-tests confirmed no significant differences between sample means of the two IS methods (p=0.53) or from each method against the RCPAQAP target values (p=0.08 and p=0.29). Both on and off-line IS methods generated highly reproducible results and excellent linear comparison to the RCPAQAP target results. ICP-MS is a highly accurate method with a low limit of quantitation for sweat Cl analysis and should be recognised as a candidate reference method for the monitoring and diagnosis of CF. Laboratories that currently practice sweat Cl analysis using ICP-MS should include an off-line IS to help negate any pre-analytical errors.

Lower reference limits of quantitative cord glucose-6-phosphate dehydrogenase estimated from healthy term neonates according to the clinical and laboratory standards institute guidelines: a cross sectional retrospective study

PubMed Central

2013-01-01

Background Previous studies have reported the lower reference limit (LRL) of quantitative cord glucose-6-phosphate dehydrogenase (G6PD), but they have not used approved international statistical methodology. Using common standards is expecting to yield more true findings. Therefore, we aimed to estimate LRL of quantitative G6PD detection in healthy term neonates by using statistical analyses endorsed by the International Federation of Clinical Chemistry (IFCC) and the Clinical and Laboratory Standards Institute (CLSI) for reference interval estimation. Methods This cross sectional retrospective study was performed at King Abdulaziz Hospital, Saudi Arabia, between March 2010 and June 2012. The study monitored consecutive neonates born to mothers from one Arab Muslim tribe that was assumed to have a low prevalence of G6PD-deficiency. Neonates that satisfied the following criteria were included: full-term birth (37 weeks); no admission to the special care nursery; no phototherapy treatment; negative direct antiglobulin test; and fathers of female neonates were from the same mothers’ tribe. The G6PD activity (Units/gram Hemoglobin) was measured spectrophotometrically by an automated kit. This study used statistical analyses endorsed by IFCC and CLSI for reference interval estimation. The 2.5th percentiles and the corresponding 95% confidence intervals (CI) were estimated as LRLs, both in presence and absence of outliers. Results 207 males and 188 females term neonates who had cord blood quantitative G6PD testing met the inclusion criteria. Method of Horn detected 20 G6PD values as outliers (8 males and 12 females). Distributions of quantitative cord G6PD values exhibited a normal distribution in absence of the outliers only. The Harris-Boyd method and proportion criteria revealed that combined gender LRLs were reliable. The combined bootstrap LRL in presence of the outliers was 10.0 (95% CI: 7.5-10.7) and the combined parametric LRL in absence of the outliers was 11.0 (95% CI: 10.5-11.3). Conclusion These results contribute to the LRL of quantitative cord G6PD detection in full-term neonates. They are transferable to another laboratory when pre-analytical factors and testing methods are comparable and the IFCC-CLSI requirements of transference are satisfied. We are suggesting using estimated LRL in absence of the outliers as mislabeling G6PD-deficient neonates as normal is intolerable whereas mislabeling G6PD-normal neonates as deficient is tolerable. PMID:24016342

The Convergence of the Twain or Titanic Collision? BI and Reference in the 1990s' Sea of Change.

ERIC Educational Resources Information Center

Rettig, James

1995-01-01

The future role, scope, and nature of bibliographic instruction (BI) and reference services at academic libraries is unresolved. Both have felt internal pressures and challenges during the past decade. It is suggested that BI and reference share tasks and become a single service. (92 references) (Author/DGM)

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...

22 CFR 120.28 - Listing of forms referred to in this subchapter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Listing of forms referred to in this subchapter. 120.28 Section 120.28 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.28 Listing of forms referred to in this subchapter. The forms referred to in...