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1

Quantitative molecular methods in virology  

Microsoft Academic Search

Summary During the past few years, significant technical effort was made to develop molecular methods for the absolute quantitation of nucleic acids in biological samples. In virology, semi-quantitative and quantitative techniques of different principle, complexity, and reliability were designed, optimized, and applied in basic and clinical researches. The principal data obtained in successful pilot applications in vivo are reported in

M. Clementi; S. Menzo; A. Manzin; P. Bagnarelli

1995-01-01

2

Rigor in Traditional Quantitative Methods.  

ERIC Educational Resources Information Center

This paper offers reasons for using traditional quantitative research methods and illustrates some of the considerations demanding rigor in a study on gender discrimination in school-administrator salaries. Traditional quantitative methods provide a meaningful language based on numbers and objectivity, and they are less time-consuming and complex…

Pounder, Diana G.

3

Comparison of instrument-read dipsticks for albumin and creatinine in urine with visual results and quantitative methods.  

PubMed

Three hospital sites evaluated the Bayer two-pad urine dipstick as a screening test for microalbuminuria. One pad estimates albumin concentrations between 10 and 150 mg/L, and the second estimates creatinine values between 300 and 3,000 mg/L. The Boehringer Mannheim (BMD) Micral dipstick was also compared and evaluated. The accuracy of the dipsticks was judged by comparison with cuvet-based immunonephelometry for albumin and to standard rate-Jaffe methods for creatinine; these assays were well standardized and controlled and were assumed to give accurate values. Precision of these methods and that of the dipsticks was determined by multiple assays of control materials. Visual or instrument (Clinitek 50 or 100) evaluation of the Bayer or visual checks of the BMD albumin dipstick pad with patients' urines gave clinically acceptable accuracy. The albumin/creatinine ratio from the Bayer dipsticks gave better accuracy for albumin excretion than the albumin pads alone from either manufacturer. This ratio should permit making a good estimate of the 24-hr albumin excretion in a randomly collected urine. PMID:9773958

Pugia, M J; Lott, J A; Luke, K E; Shihabi, Z K; Wians, F H; Phillips, L

1998-01-01

4

Comparison of Enterococcus quantitative polymerase chain reaction analysis results from midwest U.S. river samples using EPA Method 1611 and Method 1609 PCR reagents  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) has provided recommended beach advisory values in its 2012 recreational water quality criteria (RWQC) for states wishing to use quantitative polymerase chain reaction (qPCR) for the monitoring of Enterococcus fecal indicator bacteria...

5

Quantitative results from the focusing schlieren technique  

NASA Technical Reports Server (NTRS)

An iterative theoretical approach to obtain quantitative density data from the focusing schlieren technique is proposed. The approach is based on an approximate modeling of the focusing action in a focusing schlieren system, and an estimation of an appropriate focal plane thickness. The theoretical approach is incorporated in a computer program, and results obtained from a supersonic wind tunnel experiment evaluated by comparison with CFD data. The density distributions compared favorably with CFD predictions. However, improvements to the system are required in order to reduce noise in the data, to improve specifications of a depth of focus, and to refine the modeling of the focusing action.

Cook, S. P.; Chokani, Ndaona

1993-01-01

6

Quantitative methods in psychology: inevitable and useless.  

PubMed

Science begins with the question, what do I want to know? Science becomes science, however, only when this question is justified and the appropriate methodology is chosen for answering the research question. Research question should precede the other questions; methods should be chosen according to the research question and not vice versa. Modern quantitative psychology has accepted method as primary; research questions are adjusted to the methods. For understanding thinking in modern quantitative psychology, two epistemologies should be distinguished: structural-systemic that is based on Aristotelian thinking, and associative-quantitative that is based on Cartesian-Humean thinking. The first aims at understanding the structure that underlies the studied processes; the second looks for identification of cause-effect relationships between the events with no possible access to the understanding of the structures that underlie the processes. Quantitative methodology in particular as well as mathematical psychology in general, is useless for answering questions about structures and processes that underlie observed behaviors. Nevertheless, quantitative science is almost inevitable in a situation where the systemic-structural basis of behavior is not well understood; all sorts of applied decisions can be made on the basis of quantitative studies. In order to proceed, psychology should study structures; methodologically, constructive experiments should be added to observations and analytic experiments. PMID:21833199

Toomela, Aaro

2010-01-01

7

Quantitative method of medication system interface evaluation.  

PubMed

The objective of this study was to develop a quantitative method of evaluating the user interface for medication system software. A detailed task analysis provided a description of user goals and essential activity. A structural fault analysis was used to develop a detailed description of the system interface. Nurses experienced with use of the system under evaluation provided estimates of failure rates for each point in this simplified fault tree. Means of estimated failure rates provided quantitative data for fault analysis. Authors note that, although failures of steps in the program were frequent, participants reported numerous methods of working around these failures so that overall system failure was rare. However, frequent process failure can affect the time required for processing medications, making a system inefficient. This method of interface analysis, called Software Efficiency Evaluation and Fault Identification Method, provides quantitative information with which prototypes can be compared and problems within an interface identified. PMID:17625402

Pingenot, Alleene Anne; Shanteau, James; Pingenot, James D F

2007-01-01

8

Quantitative Statistical Methods for Image Quality Assessment  

PubMed Central

Quantitative measures of image quality and reliability are critical for both qualitative interpretation and quantitative analysis of medical images. While, in theory, it is possible to analyze reconstructed images by means of Monte Carlo simulations using a large number of noise realizations, the associated computational burden makes this approach impractical. Additionally, this approach is less meaningful in clinical scenarios, where multiple noise realizations are generally unavailable. The practical alternative is to compute closed-form analytical expressions for image quality measures. The objective of this paper is to review statistical analysis techniques that enable us to compute two key metrics: resolution (determined from the local impulse response) and covariance. The underlying methods include fixed-point approaches, which compute these metrics at a fixed point (the unique and stable solution) independent of the iterative algorithm employed, and iteration-based approaches, which yield results that are dependent on the algorithm, initialization, and number of iterations. We also explore extensions of some of these methods to a range of special contexts, including dynamic and motion-compensated image reconstruction. While most of the discussed techniques were developed for emission tomography, the general methods are extensible to other imaging modalities as well. In addition to enabling image characterization, these analysis techniques allow us to control and enhance imaging system performance. We review practical applications where performance improvement is achieved by applying these ideas to the contexts of both hardware (optimizing scanner design) and image reconstruction (designing regularization functions that produce uniform resolution or maximize task-specific figures of merit). PMID:24312148

Dutta, Joyita; Ahn, Sangtae; Li, Quanzheng

2013-01-01

9

Getting Started with Quantitative Methods in Physics Education Research  

NSDL National Science Digital Library

In this article we provide a brief overview of three groups of quantitative research methods commonly used in physics education research (PER): descriptive statistics, inferential statistics, and measurement instrument development and validation. These quantitative research methods are used respectively in three major types of PER, namely survey research, experimental/quasi-experimental studies, and measurement and evaluation studies. In order to highlight the importance of the close alignment between research questions and selected quantitative research methods, we review these quantitative techniques within each research type from three perspectives: data collection, data analysis, and result interpretation. We discuss the purpose, key aspects and potential issues of each quantitative technique, and where possible, specific PER studies are included as examples to illustrate how these methods fulfill specific research goals.

Ding, Lin; Liu, Xiufeng

2013-01-25

10

QUANTITATIVE METHODS IN PSYCHOLOGY A Power Primer  

E-print Network

of the Journal of Abnormal and Social Psychology, which found the mean power to detect medium effect sizes) reported a power reviewof the 1984 volumeof the Journal of Abnormal Psychology (some 24 years after mineQUANTITATIVE METHODS IN PSYCHOLOGY A Power Primer Jacob Cohen New \\brk University One possible

11

Method and apparatus for chromatographic quantitative analysis  

DOEpatents

An improved apparatus and method for the quantitative analysis of a solution containing a plurality of anion species by ion exchange chromatography which utilizes a single eluent and a single ion exchange bed which does not require periodic regeneration. The solution containing the anions is added to an anion exchange resin bed which is a low capacity macroreticular polystyrene-divinylbenzene resin containing quarternary ammonium functional groups, and is eluted therefrom with a dilute solution of a low electrical conductance organic acid salt. As each anion species is eluted from the bed, it is quantitatively sensed by conventional detection means such as a conductivity cell.

Fritz, James S. (Ames, IA); Gjerde, Douglas T. (Ames, IA); Schmuckler, Gabriella (Haifa, IL)

1981-06-09

12

Quantitative Method of Measuring Metastatic Activity  

NASA Technical Reports Server (NTRS)

The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated uroldnase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

Morrison, Dennis R. (Inventor)

1999-01-01

13

Quantitative laser-induced breakdown spectroscopy data using peak area step-wise regression analysis: an alternative method for interpretation of Mars science laboratory results  

SciTech Connect

The ChemCam instrument on the Mars Science Laboratory (MSL) will include a laser-induced breakdown spectrometer (LIBS) to quantify major and minor elemental compositions. The traditional analytical chemistry approach to calibration curves for these data regresses a single diagnostic peak area against concentration for each element. This approach contrasts with a new multivariate method in which elemental concentrations are predicted by step-wise multiple regression analysis based on areas of a specific set of diagnostic peaks for each element. The method is tested on LIBS data from igneous and metamorphosed rocks. Between 4 and 13 partial regression coefficients are needed to describe each elemental abundance accurately (i.e., with a regression line of R{sup 2} > 0.9995 for the relationship between predicted and measured elemental concentration) for all major and minor elements studied. Validation plots suggest that the method is limited at present by the small data set, and will work best for prediction of concentration when a wide variety of compositions and rock types has been analyzed.

Clegg, Samuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Dyar, Melinda D [MT HOLYOKE COLLEGE; Schafer, Martha W [LSU; Tucker, Jonathan M [MT HOLYOKE COLLEGE

2008-01-01

14

Quantitative Cerebral MR Perfusion Imaging: Preliminary Results in Stroke  

PubMed Central

Purpose To evaluate quantitative cerebral blood flow (qCBF) with traditional time-based measurements or metrics of cerebral perfusion: time to peak (Tmax) and mean transit time (MTT) in stroke patients. Materials and Methods Nine ischemic stroke patients (4 Male, 5 Female, 63±16 years old) were included in the study which was HIPAA compliant and institutional review board approved. Cerebral perfusion was quantified using the Bookend method. Mean values of qCBF, Tmax, and MTT were determined in regions of interest (ROIs). ROIs were drawn on diffusion weighted images in diffusion positive, critically ischemic (CI), in ipsilateral normal region immediately surrounding the critically ischemic region, the presumed penumbra (PP), and in contralateral diffusion negative control, presumed normal region (PN) of gray and white matter separately (GM and WM). Results In both GM and WM, qCBF measures distinguished the studied brain regions with the most markedly reduced values in regions corresponding to extent of likely ischemic injury. In planned comparisons, only qCBF measurements differed significantly between CI and PP tissues. ROC analysis supported the utility of qCBF for discriminating brain regions differing in the likely extent of ischemic injury (CI and PN regions – qCBF: AUC=0.96, Tmax: AUC=0.96, MTT: AUC=0.72). Importantly, qCBF afforded the best discrimination of CI and PP regions (qCBF: AUC=0.82, Tmax: AUC=0.65, MTT: AUC=0.52). Conclusions This initial evaluation indicates that quantitative MRI perfusion is feasible in ischemic stroke patients. qCBF derived with this strategy provide enhanced discrimination of CI and PP compared to time-based imaging metrics. This approach merits investigation in larger clinical studies. PMID:20882609

Shah, Maulin K.; Shin, Wanyong; Parikh, Vishal S.; Ragin, Ann; Mouannes, Jessy; Bernstein, Richard A.; Walker, Matthew T.; Bhatt, Hem; Carroll, Timothy J.

2010-01-01

15

Interlaboratory Comparison of Quantitative PCR Test Results for Dehalococcoides  

EPA Science Inventory

Quantitative PCR (qPCR) techniques have been widely used to measure Dehalococcoides (Dhc) DNA in the groundwater at field sites for several years. Interpretation of these data may be complicated when different laboratories using alternate methods conduct the analysis. An...

16

A quantitative method for evaluating alternatives. [aid to decision making  

NASA Technical Reports Server (NTRS)

When faced with choosing between alternatives, people tend to use a number of criteria (often subjective, rather than objective) to decide which is the best alternative for them given their unique situation. The subjectivity inherent in the decision-making process can be reduced by the definition and use of a quantitative method for evaluating alternatives. This type of method can help decision makers achieve degree of uniformity and completeness in the evaluation process, as well as an increased sensitivity to the factors involved. Additional side-effects are better documentation and visibility of the rationale behind the resulting decisions. General guidelines for defining a quantitative method are presented and a particular method (called 'hierarchical weighted average') is defined and applied to the evaluation of design alternatives for a hypothetical computer system capability.

Forthofer, M. J.

1981-01-01

17

Quantitative EDXS analysis of organic materials using the ?-factor method.  

PubMed

In this study we successfully applied the ?-factor method to perform quantitative X-ray analysis of organic thin films consisting of light elements. With its ability to intrinsically correct for X-ray absorption, this method significantly improved the quality of the quantification as well as the accuracy of the results compared to conventional techniques in particular regarding the quantification of light elements. We describe in detail the process of determining sensitivity factors (?-factors) using a single standard specimen and the involved parameter optimization for the estimation of ?-factors for elements not contained in the standard. The ?-factor method was then applied to perform quantitative analysis of organic semiconducting materials frequently used in organic electronics. Finally, the results were verified and discussed concerning validity and accuracy. PMID:24012932

Fladischer, Stefanie; Grogger, Werner

2014-01-01

18

Simple laboratory methods for quantitative IR measurements of CW agents  

Microsoft Academic Search

A simple method is presented for quantitatively measuring the absorbance of chemical warfare (CW) agents and their simulants in the vapour phase. The technique is based on a standard lab-bench FTIR spectrometer, 10-cm gas cell, a high accuracy Baratron pressure manometer, vacuum pump and simple stainless-steel hardware components. The results of this measurement technique are demonstrated for sarin (GB) and

Eldon Puckrin; Jean-Marc Thériault; Hugo Lavoie; Denis Dubé; Carmela J. Lepage; Michael Petryk

2005-01-01

19

Novel method for ANA quantitation using IIF imaging system.  

PubMed

A variety of antinuclear antibodies (ANAs) are found in the serum of patients with autoimmune diseases. The detection of abnormal ANA titers is a critical criterion for diagnosis of systemic lupus erythematosus (SLE) and other connective tissue diseases. Indirect immunofluorescence assay (IIF) on HEp-2 cells is the gold standard method to determine the presence of ANA and therefore provides information about the localization of autoantigens that are useful for diagnosis. However, its utility was limited in prognosing and monitoring of disease activity due to the lack of standardization in performing the technique, subjectivity in interpreting the results and the fact that it is only semi-quantitative. On the other hand, ELISA for the detection of ANA can quantitate ANA but could not provide further information about the localization of the autoantigens. It would be ideal to integrate both of the quantitative and qualitative methods. To address this issue, this study was conducted to quantitatively detect ANAs by using IIF imaging analysis system. Serum samples from patients with ANA positive (including speckled, homogeneous, nuclear mixture and cytoplasmic mixture patterns) and negative were detected for ANA titers by the classical IIF and analyzed by an image system, the image of each sample was acquired by the digital imaging system and the green fluorescence intensity was quantified by the Image-Pro plus software. A good correlation was found in between two methods and the correlation coefficients (R(2)) of various ANA patterns were 0.942 (speckled), 0.942 (homogeneous), 0.923 (nuclear mixture) and 0.760 (cytoplasmic mixture), respectively. The fluorescence density was linearly correlated with the log of ANA titers in various ANA patterns (R(2)>0.95). Moreover, the novel ANA quantitation method showed good reproducibility (F=0.091, p>0.05) with mean±SD and CV% of positive, and negative quality controls were equal to 126.4±9.6 and 7.6%, 10.4±1.25 and 12.0%, respectively. In conclusion, our novel ANA quantitation method can provide both of the fluorescence density, which could precisely reflect the fluctuate of ANAs level in patient's serum and the useful information about the localization of the autoantigens for clinician in diagnosing and monitoring diseases. PMID:24370749

Peng, Xiaodong; Tang, Jiangtao; Wu, Yongkang; Yang, Bin; Hu, Jing

2014-02-01

20

Informatics Methods to Enable Sharing of Quantitative Imaging Research Data  

PubMed Central

Introduction The National Cancer Institute (NCI) Quantitative Research Network (QIN) is a collaborative research network whose goal is to share data, algorithms and research tools to accelerate quantitative imaging research. A challenge is the variability in tools and analysis platforms used in quantitative imaging. Our goal was to understand the extent of this variation and to develop an approach to enable sharing data and to promote reuse of quantitative imaging data in the community. Methods We performed a survey of the current tools in use by the QIN member sites for representation and storage of their QIN research data including images, image meta-data and clinical data. We identified existing systems and standards for data sharing and their gaps for the QIN use case. We then proposed a system architecture to enable data sharing and collaborative experimentation within the QIN. Results There area variety of tools currently used by each QIN institution. We developed a general information system architecture to support the QIN goals. We also describe the remaining architecture gaps we are developing to enable members to share research images and image meta-data across the network. Conclusions As a research network, the QIN will stimulate quantitative imaging research by pooling data, algorithms and research tools. However, there are gaps in current functional requirements that will need to be met by future informatics development. Special attention must be given to the technical requirements needed to translate these methods into the clinical research workflow to enable validation and qualification of these novel imaging biomarkers. PMID:22770688

Levy, Mia A.; Freymann, John B.; Kirby, Justin S.; Fedorov, Andriy; Fennessy, Fiona M.; Eschrich, Steven A.; Berglund, Anders E.; Fenstermacher, David A.; Tan, Yongqiang; Guo, Xiaotao; Casavant, Thomas L.; Brown, Bartley J.; Braun, Terry A.; Dekker, Andre; Roelofs, Erik; Mountz, James M.; Boada, Fernando; Laymon, Charles; Oborski, Matt; Rubin, Daniel L

2012-01-01

21

Blending Qualitative & Quantitative Research Methods in Theses and Dissertations.  

ERIC Educational Resources Information Center

This guide discusses combining qualitative and quantitative research methods in theses and dissertations. It covers a wide array of methods, the strengths and limitations of each, and how they can be effectively interwoven into various research designs. The first chapter is "The Qualitative and the Quantitative." Part 1, "A Catalogue of…

Thomas, R. Murray

22

An improved quantitative analysis method for plant cortical microtubules.  

PubMed

The arrangement of plant cortical microtubules can reflect the physiological state of cells. However, little attention has been paid to the image quantitative analysis of plant cortical microtubules so far. In this paper, Bidimensional Empirical Mode Decomposition (BEMD) algorithm was applied in the image preprocessing of the original microtubule image. And then Intrinsic Mode Function 1 (IMF1) image obtained by decomposition was selected to do the texture analysis based on Grey-Level Cooccurrence Matrix (GLCM) algorithm. Meanwhile, in order to further verify its reliability, the proposed texture analysis method was utilized to distinguish different images of Arabidopsis microtubules. The results showed that the effect of BEMD algorithm on edge preserving accompanied with noise reduction was positive, and the geometrical characteristic of the texture was obvious. Four texture parameters extracted by GLCM perfectly reflected the different arrangements between the two images of cortical microtubules. In summary, the results indicate that this method is feasible and effective for the image quantitative analysis of plant cortical microtubules. It not only provides a new quantitative approach for the comprehensive study of the role played by microtubules in cell life activities but also supplies references for other similar studies. PMID:24744684

Lu, Yi; Huang, Chenyang; Wang, Jia; Shang, Peng

2014-01-01

23

A quantitative method for measuring the quality of history matches  

SciTech Connect

History matching can be an efficient tool for reservoir characterization. A {open_quotes}good{close_quotes} history matching job can generate reliable reservoir parameters. However, reservoir engineers are often frustrated when they try to select a {open_quotes}better{close_quotes} match from a series of history matching runs. Without a quantitative measurement, it is always difficult to tell the difference between a {open_quotes}good{close_quotes} and a {open_quotes}better{close_quotes} matches. For this reason, we need a quantitative method for testing the quality of matches. This paper presents a method for such a purpose. The method uses three statistical indices to (1) test shape conformity, (2) examine bias errors, and (3) measure magnitude of deviation. The shape conformity test insures that the shape of a simulated curve matches that of a historical curve. Examining bias errors assures that model reservoir parameters have been calibrated to that of a real reservoir. Measuring the magnitude of deviation assures that the difference between the model and the real reservoir parameters is minimized. The method was first tested on a hypothetical model and then applied to published field studies. The results showed that the method can efficiently measure the quality of matches. It also showed that the method can serve as a diagnostic tool for calibrating reservoir parameters during history matching.

Shaw, T.S. [Kerr-McGee Corp., Oklahoma City, OK (United States); Knapp, R.M. [Univ. of Oklahoma, Norman, OK (United States)

1997-08-01

24

ADVANCING THE STUDY OF VIOLENCE AGAINST WOMEN USING MIXED METHODS: INTEGRATING QUALITATIVE METHODS INTO A QUANTITATIVE RESEARCH PROGRAM  

PubMed Central

A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032

Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol

2011-01-01

25

Advanced Quantitative Methods in Counseling Psychology: Synthesis.  

ERIC Educational Resources Information Center

The individual best qualified to design an empirical study is one who is most familiar with the nature of the phenomenon and research area; most familiar with the possible alternative methods for designing and analyzing the study; and most capable of evaluating the potential advantages and disadvantages of the alternatives. (Author)

Ellis, Michael V.; Chartrand, Judy M.

1999-01-01

26

Review of Quantitative Software Reliability Methods  

SciTech Connect

The current U.S. Nuclear Regulatory Commission (NRC) licensing process for digital systems rests on deterministic engineering criteria. In its 1995 probabilistic risk assessment (PRA) policy statement, the Commission encouraged the use of PRA technology in all regulatory matters to the extent supported by the state-of-the-art in PRA methods and data. Although many activities have been completed in the area of risk-informed regulation, the risk-informed analysis process for digital systems has not yet been satisfactorily developed. Since digital instrumentation and control (I&C) systems are expected to play an increasingly important role in nuclear power plant (NPP) safety, the NRC established a digital system research plan that defines a coherent set of research programs to support its regulatory needs. One of the research programs included in the NRC's digital system research plan addresses risk assessment methods and data for digital systems. Digital I&C systems have some unique characteristics, such as using software, and may have different failure causes and/or modes than analog I&C systems; hence, their incorporation into NPP PRAs entails special challenges. The objective of the NRC's digital system risk research is to identify and develop methods, analytical tools, and regulatory guidance for (1) including models of digital systems into NPP PRAs, and (2) using information on the risks of digital systems to support the NRC's risk-informed licensing and oversight activities. For several years, Brookhaven National Laboratory (BNL) has worked on NRC projects to investigate methods and tools for the probabilistic modeling of digital systems, as documented mainly in NUREG/CR-6962 and NUREG/CR-6997. However, the scope of this research principally focused on hardware failures, with limited reviews of software failure experience and software reliability methods. NRC also sponsored research at the Ohio State University investigating the modeling of digital systems using dynamic PRA methods. These efforts, documented in NUREG/CR-6901, NUREG/CR-6942, and NUREG/CR-6985, included a functional representation of the system's software but did not explicitly address failure modes caused by software defects or by inadequate design requirements. An important identified research need is to establish a commonly accepted basis for incorporating the behavior of software into digital I&C system reliability models for use in PRAs. To address this need, BNL is exploring the inclusion of software failures into the reliability models of digital I&C systems, such that their contribution to the risk of the associated NPP can be assessed.

Chu, T.L.; Yue, M.; Martinez-Guridi, M.; Lehner, J.

2010-09-17

27

Methods of quantitative fire hazard analysis  

SciTech Connect

Simplified fire hazard analysis methods have been developed as part of the FIVE risk-based fire induced vulnerability evaluation methodology for nuclear power plants. These fire hazard analyses are intended to permit plant fire protection personnel to conservatively evaluate the potential for credible exposure fires to cause critical damage to essential safe-shutdown equipment and thereby screen from further analysis spaces where a significant fire hazard clearly does not exist. This document addresses the technical bases for the fire hazard analysis methods. A separate user's guide addresses the implementation of the fire screening methodology, which has been implemented with three worksheets and a number of look-up tables. The worksheets address different locations of targets relative to exposure fire sources. The look-up tables address fire-induced conditions in enclosures in terms of three stages: a fire plume/ceiling jet period, an unventilated enclosure smoke filling period and a ventilated quasi-steady period.

Mowrer, F.W. (Mowrer (Frederick W.), Adelphi, MD (United States))

1992-05-01

28

Fluorometric method of quantitative cell mutagenesis  

DOEpatents

A method for assaying a cell culture for mutagenesis is described. A cell culture is stained first with a histochemical stain, and then a fluorescent stain. Normal cells in the culture are stained by both the histochemical and fluorescent stains, while abnormal cells are stained only by the fluorescent stain. The two stains are chosen so that the histochemical stain absorbs the wavelengths that the fluorescent stain emits. After the counterstained culture is subjected to exciting light, the fluorescence from the abnormal cells is detected.

Dolbeare, Frank A. (Livermore, CA)

1982-01-01

29

Methods and algorithms for quantitative proteomics by mass spectrometry.  

PubMed

Protein quantitation by mass spectrometry (MS) is attractive since it is possible to obtain both identification and quantitative values of proteins and their posttranslational modifications in a single experiment. In contrast, protein arrays only provide quantitative values of targeted proteins and their modifications. There are an overwhelming number of quantitative MS methods for protein and peptide quantitation. The aim here is to provide an overview of the most common MS methods and algorithms used in quantitative proteomics and discuss the computational algorithms needed to reliably quantitate proteins, peptides, and their posttranslational modifications. One of the main challenges in data analysis of many experimental projects is to pipe together a number of software solutions that are either commercial or freely available. The aim of this chapter is to provide a good set of algorithms, ideas, and resources that can easily be implemented in scripting language like R, Python, or Perl. By understanding the algorithmic ideas presented here, data from any instrument or modified experimental protocol can be analyzed and is therefore in the authors' opinion more valuable than a black box concept. PMID:23666727

Matthiesen, Rune; Carvalho, Ana Sofia

2013-01-01

30

Quantitative method to assess economic output of climate change  

NASA Astrophysics Data System (ADS)

In this paper, economic output of climate change is picked from the historical data, and a methodology of quantitative predicted economic output of climate change is provided by an economic-climatic model (C-D-C model). A historical reciprocating examination is engaged, using the data of outputs of various crops and total outputs of grain in 8 agricultural areas of China from 1981 to 2000, as well as the meteorological data of 160 observatory stations in China in the same time interval. The results show the methods are reasonable in certain extent and good in application. Finally, meaningful summery is concluded. The authors try to give a way for studying the effect of the future climatic change on economy. The results in economic research are introduced to the global climatic change study.

jieming, C.

2013-12-01

31

Food safety regulation, economic impact assessment and quantitative methods  

Microsoft Academic Search

Together with a call for more efficient regulations in the EU, there is a growing demand for transparency in the evaluation techniques to assess and predict their effects. This article explores the potential impacts of food safety regulations and discusses the quantitative methods used in the policy evaluation literature. Along with the strengths and limitations of each method, this review

Maddalena Ragona; Mario Mazzocchi

2008-01-01

32

Comparison of urine dipsticks with quantitative methods for microalbuminuria.  

PubMed

We describe a new dip- and read dipstick that detects urine albumin at concentrations of 10 mg/l and above and urine creatinine at concentrations of 300 mg/l and above. The albumin assay is based on a high-affinity, dye-binding technique while the creatinine assay is based on the peroxidase-like activity of copper creatinine complexes. With these two-test dipsticks, urines from normal adults supplemented with albumin and creatinine were correctly identified to within +/- 15% of the expected value for both analytes; the between-day coefficients of variation ranged from 7.1% to 16.1%. We tested 275 patients' unmodified urines by the Bayer and Boehringer Mannheim Micral-Test albumin dipsticks and for albumin with the Beckman Array on the same specimens. We also analyzed 42 selected urines from the group of 275 for albumin by another quantitative immunochemical method and by electrophoresis plus a total protein method to estimate the albumin concentration. The quantitative immunochemical methods appear to underestimate the urine albumin concentrations; in these 42 urines measured as negative, i.e., < ca. 16-20 mg/l, by one of the quantitative method but positive by the Bayer dipstick, 33 of these were positive by the electrophoresis/total protein assay combination. The Bayer albumin dipstick correctly identified urines as having < 16 mg/l or > or = 16 mg/l at an 80% rate. At a cutoff of 20 mg/l, the rate increased to 87%. We also determined the urinary albumin/creatinine ratios on the 275 patients using the Bayer two-pad dipstick and found agreement 84% of the time with the same ratio obtained from a quantitative immunochemical method for albumin and a rate-Jaffe method for creatinine; an albumin/creatinine ratio (mg/g) of 30 was used as the discrimination point. Albumin stability studies performed on the Beckman Array patients with six fresh urines showed small but consistent decreases at -20 degrees C but not at 4 degrees C after one month of storage. The albumin in contrived urines, as estimated by electrophoreses/total protein and by the dipsticks did not change at these storage conditions. Boric acid at 1 g/l as a urine preservative had no effect on the measurement of albumin by any of the methods described here nor of the assay of creatinine. Other urinary proteins present at abnormal excretion rates did not interfere with the Bayer albumin dipstick. Abnormal concentrations of bilirubin, citrate, creatine, ascorbic acid, albumin, hemoglobin and myoglobin in urine did not interfere with the creatinine dipstick measurements. The first four of the above did not affect the Bayer dipstick results for albumin. PMID:9352232

Pugia, M J; Lott, J A; Clark, L W; Parker, D R; Wallace, J F; Willis, T W

1997-09-01

33

Rapid quantitative monitoring method for the fish spoilage bacteria Pseudomonas.  

PubMed

Pseudomonas spp. is a group of microorganisms commonly found in fish and other fresh foods and is involved in their spoilage process. The aim of this study was to develop a rapid and accurate quantitative assay for Pseudomonas spp. in fish using real-time PCR. The assay targets the carbamoyl phosphate synthase gene (carA) with SYBR green based real-time PCR. The selectivity of the assay was confirmed using 24 Pseudomonas strains and 55 non-pseudomonad strains. A linear quantification was established over seven orders of magnitude, from 40 - 4(7) copies reaction(-1). The assay was validated on cod samples collected during two shelf life trials and showed a high degree of correlation to the plate count method (rP = 0.891) where the difference between the methods was 0.04 log(10) CFU g(-1) on average. The study shows that it is possible to quantify accurately the specific spoilage organisms belonging to the genus Pseudomonas in fish using real-time PCR. The method takes less than 5 h from sampling to results. The short detection time of the method can provide the fish industry with an important tool for quality control and processing management. PMID:18974905

Reynisson, Eyjólfur; Lauzon, Hélène Liette; Magnusson, Hannes; Hreggvidsson, Guethmundur Oli; Marteinsson, Viggó Thor

2008-11-01

34

A quantitative dimming method for LED based on PWM  

NASA Astrophysics Data System (ADS)

Traditional light sources were required to provide stable and uniform illumination for a living or working environment considering performance of visual function of human being. The requirement was always reasonable until non-visual functions of the ganglion cells in the retina photosensitive layer were found. New generation of lighting technology, however, is emerging based on novel lighting materials such as LED and photobiological effects on human physiology and behavior. To realize dynamic lighting of LED whose intensity and color were adjustable to the need of photobiological effects, a quantitative dimming method based on Pulse Width Modulation (PWM) and light-mixing technology was presented. Beginning with two channels' PWM, this paper demonstrated the determinacy and limitation of PWM dimming for realizing Expected Photometric and Colorimetric Quantities (EPCQ), in accordance with the analysis on geometrical, photometric, colorimetric and electrodynamic constraints. A quantitative model which mapped the EPCQ into duty cycles was finally established. The deduced model suggested that the determinacy was a unique individuality only for two channels' and three channels' PWM, but the limitation was an inevitable commonness for multiple channels'. To examine the model, a light-mixing experiment with two kinds of white LED simulated variations of illuminance and Correlation Color Temperature (CCT) from dawn to midday. Mean deviations between theoretical values and measured values were obtained, which were 15lx and 23K respectively. Result shows that this method can effectively realize the light spectrum which has a specific requirement of EPCQ, and provides a theoretical basis and a practical way for dynamic lighting of LED.

Wang, Jiyong; Mou, Tongsheng; Wang, Jianping; Tian, Xiaoqing

2012-10-01

35

Simple laboratory methods for quantitative IR measurements of CW agents  

NASA Astrophysics Data System (ADS)

A simple method is presented for quantitatively measuring the absorbance of chemical warfare (CW) agents and their simulants in the vapour phase. The technique is based on a standard lab-bench FTIR spectrometer, 10-cm gas cell, a high accuracy Baratron pressure manometer, vacuum pump and simple stainless-steel hardware components. The results of this measurement technique are demonstrated for sarin (GB) and soman (GD). A second technique is also introduced for the passive IR detection of CW agents in an open- air path located in a fumehood. Using a modified open-cell with a pathlength of 45 cm, open-air passive infrared measurements have been obtained for simulants and several classical CW agents. Detection, identification and quantification results based on passive infrared measurements are presented for GB and the CW agent simulant, DMMP, using the CATSI sensor which has been developed by DRDC Valcartier. The open-cell technique represents a relatively simple and feasible method for examining the detection capability of passive sensors, such as CATSI, for CW agents.

Puckrin, Eldon; Thériault, Jean-Marc; Lavoie, Hugo; Dubé, Denis; Lepage, Carmela J.; Petryk, Michael

2005-11-01

36

A quantitative cytochemical method for phosphofructokinase in plant tissues  

Microsoft Academic Search

A quantitative cytochemical method for the demonstration of phosphofructokinase has been successfully applied to a range of plant tissues. The findings indicate that this enzyme system may be assayed as in indicator of glycolytic activity in plant cells, and furthermore that the very high endogenous phosphoenolpyruvate concentrations may not be rate limiting in vivo.

P. B. Gahan; L. M. Bellani; M. A. Rana; B. D. Lake

1983-01-01

37

Research Design and Methods of Quantitative Synthesis of Medical Evidence  

Microsoft Academic Search

Objective: To review the scientific principles, strengths, and limitations of research designs and methods of quantitative synthesis of medical evidence.Data Sources: We used MEDLINE to perform a systematic search for literature using the keywords research design, epidemiology, and biometry. Journals searched included six major journals in obstetrics and gynecology and three in general medicine. These sources were supplemented with texts

Jeffrey F Peipert; Deidre S Gifford; Lori A Boardman

1997-01-01

38

A Mixed Quantitative/Qualitative Method Evaluating Compromise Solutions  

E-print Network

have devised for use in such design advice tools. 2 Conflict in collaborative design It is a wiseA Mixed Quantitative/Qualitative Method for Evaluating Compromise Solutions to Conflicts in Collaborative Design Dennis Bahler Dept. of Computer Science North Carolina State University Raleigh, NC 27695

Bahler, Dennis R.

39

A new mapping method for quantitative trait loci of silkworm  

PubMed Central

Background Silkworm is the basis of sericultural industry and the model organism in insect genetics study. Mapping quantitative trait loci (QTLs) underlying economically important traits of silkworm is of high significance for promoting the silkworm molecular breeding and advancing our knowledge on genetic architecture of the Lepidoptera. Yet, the currently used mapping methods are not well suitable for silkworm, because of ignoring the recombination difference in meiosis between two sexes. Results A mixed linear model including QTL main effects, epistatic effects, and QTL × sex interaction effects was proposed for mapping QTLs in an F2 population of silkworm. The number and positions of QTLs were determined by F-test and model selection. The Markov chain Monte Carlo (MCMC) algorithm was employed to estimate and test genetic effects of QTLs and QTL × sex interaction effects. The effectiveness of the model and statistical method was validated by a series of simulations. The results indicate that when markers are distributed sparsely on chromosomes, our method will substantially improve estimation accuracy as compared to the normal chiasmate F2 model. We also found that a sample size of hundreds was sufficiently large to unbiasedly estimate all the four types of epistases (i.e., additive-additive, additive-dominance, dominance-additive, and dominance-dominance) when the paired QTLs reside on different chromosomes in silkworm. Conclusion The proposed method could accurately estimate not only the additive, dominance and digenic epistatic effects but also their interaction effects with sex, correcting the potential bias and precision loss in the current QTL mapping practice of silkworm and thus representing an important addition to the arsenal of QTL mapping tools. PMID:21276233

2011-01-01

40

Correlation of quantitative risk results for high hazard processes.  

PubMed

A quantitative risk analysis was conducted to evaluate the design of the VX neutralization subsystem and related support facilities of the U.S. Army Newport Chemical Agent Disposal Facility. Three major incidents including agent release, personnel injury, and system loss were studied using fault tree analysis methodology. Each incident was assigned a risk assessment code based on the severity level and probability of occurrence of the incident. Safety mitigations or design changes were recommended to bring the "undesired" risk level (typical agent release events) to be "acceptable with controls" or "acceptable." PMID:12969409

Wang, Yanjun; West, Harry H; Teague, Tom L; Hasan, Najmul; Mannan, M Sam

2003-10-01

41

Development of a robust method for the quantitative determination of disaccharides in honey by gas chromatography  

Microsoft Academic Search

An iterative method for the GC quantitative determination of TMS-oxime disaccharides in honey has been developed. This approach takes into account possible positive systematic errors caused by unidentified compounds which overlap with the expected disaccharides. The results of its application to the determination of 15 disaccharides in simulated honey samples indicate that the iterative method is more robust that methods

E. de la Fuente; M. L. Sanz; I. Martínez-Castro; J. Sanz

2006-01-01

42

Albuminuria and proteinuria in hospitalized patients as measured by quantitative and dipstick methods.  

PubMed

We tested patients' urines for albumin, protein, and creatinine by quantitative and dipstick methods. The concentrations of these analytes were established by quantitative, cuvet-based chemistry methods that we assumed gave the "correct" values. There was good to excellent agreement of the dipstick results with the quantitative methods for the above three analytes. We found many patients who excreted pathological amounts of albumin and/or protein who did not have a diagnosis of kidney disease or other likely causes of proteinuria, suggesting that albuminuria and/or proteinuria were underdiagnosed in our group of patients. Those with cardiovascular disease, kidney disease, or diabetes showed the greatest predictive value of a positive test for albumin or protein by dipstick. Dipstick testing for albumin, protein, and creatinine had good or excellent agreement with quantitative methods. The dipstick tests were easy to use, simple, and low in cost, and can serve well for point-of-care testing. PMID:11574957

Pugia, M J; Wallace, J F; Lott, J A; Sommer, R; Luke, K E; Shihabi, Z K; Sheehan, M; Bucksa, J M

2001-01-01

43

Method for depth-resolved quantitation of optical properties in layered media using spatially modulated quantitative spectroscopy  

PubMed Central

We have demonstrated that spatially modulated quantitative spectroscopy (SMoQS) is capable of extracting absolute optical properties from homogeneous tissue simulating phantoms that span both the visible and near-infrared wavelength regimes. However, biological tissue, such as skin, is highly structured, presenting challenges to quantitative spectroscopic techniques based on homogeneous models. In order to more accurately address the challenges associated with skin, we present a method for depth-resolved optical property quantitation based on a two layer model. Layered Monte Carlo simulations and layered tissue simulating phantoms are used to determine the efficacy and accuracy of SMoQS to quantify layer specific optical properties of layered media. Initial results from both the simulation and experiment show that this empirical method is capable of determining top layer thickness within tens of microns across a physiological range for skin. Layer specific chromophore concentration can be determined to <±10% the actual values, on average, whereas bulk quantitation in either visible or near infrared spectroscopic regimes significantly underestimates the layer specific chromophore concentration and can be confounded by top layer thickness. PMID:21806282

Saager, Rolf B.; Truong, Alex; Cuccia, David J.; Durkin, Anthony J.

2011-01-01

44

A new method of high resolution, quantitative phase scanning microscopy  

NASA Astrophysics Data System (ADS)

Coherent Diffractive Imaging (CDI) is a method of lensless imaging that reconstructs a target object from recordings of the diffraction pattern it generates when illuminated by a coherent source. A new method of scanning CDI, 'Ptychography,' was introduced recently and has been successfully demonstrated as a method of lensless microscopy at optical and x-ray wavelengths. Here we show how it can be applied to visible light microscopy to produce high resolution quantitative phase images of low-contrast objects, such as unstained cells.

Maiden, A. M.; Rodenburg, J. M.; Humphry, M. J.

2010-06-01

45

Testing of flat optical surfaces by the quantitative Foucault method.  

PubMed

The complete theory of measurement of optical flat mirrors of circular or elliptical shape using the quantitative Foucault method is described here. It has been used in Córdoba since 1939 in a partially intuitive but correct form. The surface, not yet flat and, at times, astigmatic, is assimilated to the sum of a spherical plus a cylindrical dome. The errors of the three possible ways of reckoning are calculated. PMID:20174365

Simon, M C; Simon, J M

1978-01-01

46

Quantitative method of measuring cancer cell urokinase and metastatic potential  

NASA Technical Reports Server (NTRS)

The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated urokinase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

Morrison, Dennis R. (inventor)

1993-01-01

47

Analysis of 129I in Groundwater Samples: Direct and Quantitative Results below the Drinking Water Standard  

SciTech Connect

Due to its long half-life (15.7 million years) and relatively unencumbered migration in subsurface environments, 129I has been recognized as a contaminant of concern at numerous federal, private, and international facilities. In order to understand the long-term risk associated with 129I at these locations, quantitative analysis of groundwater samples must be performed. However, the ability to quantitatively assess the 129I content in groundwater samples requires specialized extraction and sophisticated analytical techniques, which are complicated and not always available to the general scientific community. This paper highlights an analytical method capable of directly quantifying 129I in groundwater samples at concentrations below the MCL without the need for sample pre-concentration. Samples were analyzed on a Perkin Elmer ELAN DRC II ICP-MS after minimal dilution using O2 as the reaction gas. Analysis of continuing calibration verification standards indicated that the DRC mode could be used for quantitative analysis of 129I in samples below the drinking water standard (0.0057 ng/ml or 1 pCi/L). The low analytical detection limit of 129I analysis in the DRC mode coupled with minimal sample dilution (1.02x) resulted in a final sample limit of quantification of 0.0051 ng/ml. Subsequent analysis of three groundwater samples containing 129I resulted in fully quantitative results in the DRC mode, and spike recovery analyses performed on all three samples confirmed that the groundwater matrix did not adversely impact the analysis of 129I in the DRC mode. This analytical approach has been proven to be a cost-effective, high-throughput technique for the direct, quantitative analysis of 129I in groundwater samples at concentrations below the current MCL.

Brown, Christopher F.; Geiszler, Keith N.; Lindberg, Michael J.

2007-03-03

48

Phase analysis in duplex stainless steel: comparison of EBSD and quantitative metallography methods  

NASA Astrophysics Data System (ADS)

The purpose of the research was to work out the qualitative and quantitative analysis of phases in DSS in as-received state and after thermal aging. For quantitative purposes, SEM observations, EDS analyses and electron backscattered diffraction (EBSD) methods were employed. Qualitative analysis of phases was performed by two methods: EBSD and classical quantitative metallography. A juxtaposition of different etchants for the revealing of microstructure and brief review of sample preparation methods for EBSD studies were presented. Different ways of sample preparation were tested and based on these results a detailed methodology of DSS phase analysis was developed including: surface finishing, selective etching methods and image acquisition. The advantages and disadvantages of applied methods were pointed out and compared the accuracy of the analysis phase performed by both methods.

Michalska, J.; Chmiela, B.

2014-03-01

49

Quantitative magnetisation transfer imaging in glioma: preliminary results.  

PubMed

Quantitative magnetisation transfer imaging (qMTI) is an extension of conventional MT techniques and allows the measurement of parameters that reflect tissue ultrastructure through the properties of macromolecule-bound protons; these include the bound proton fraction and the relaxation times of free and bound proton pools. It has been used in multiple sclerosis and Alzheimer's disease, and has shown changes in some of the parameters, particularly the bound proton fraction. The purpose of this pilot study was to assess whether qMTI could distinguish between gliomas and normal brain tissue, and provide proof of principle for its use in tumour characterisation. Eight subjects [three men, five women; mean age, 44 years; range, 27-66 years; seven World Health Organization (WHO) Grade II, one Grade III] with biopsy-proven glioma were imaged with a structural MRI protocol that included three-dimensional qMTI. qMTI parameters were extracted from regions of interest selected from different tumour components visible on conventional MR sequences, normal-appearing peritumoral tissue and distant normal-appearing white matter. All patients gave informed consent and the study was approved by the Local Research Ethics Committee. Almost all of the qMTI parameters detected abnormalities in both glioma and the peritumoral region relative to the distant white matter. In particular, the bound proton fraction was reduced significantly from 6.0 percentage units (pu) [standard deviation (SD), 0.5 pu] in normal-appearing white matter to 1.7 pu (SD?=?0.5 pu) in solid tumour and 2.2 pu (SD?=?0.5 pu) in peritumoral areas. This work shows that qMTI reveals abnormalities, not only in glioma, but also in the apparently normal tissue surrounding the conventionally defined tumour. Thus, qMTI shows promise for tumour characterisation and for studying tumour boundaries. These preliminary data justify larger studies in a range of different tumour types and grades. PMID:20960580

Tozer, Daniel J; Rees, Jeremy H; Benton, Christopher E; Waldman, Adam D; Jäger, H Rolf; Tofts, Paul S

2011-06-01

50

Quantitative comparison of analysis methods for spectroscopic optical coherence tomography  

PubMed Central

Spectroscopic optical coherence tomography (sOCT) enables the mapping of chromophore concentrations and image contrast enhancement in tissue. Acquisition of depth resolved spectra by sOCT requires analysis methods with optimal spectral/spatial resolution and spectral recovery. In this article, we quantitatively compare the available methods, i.e. the short time Fourier transform (STFT), wavelet transforms, the Wigner-Ville distribution and the dual window method through simulations in tissue-like media. We conclude that all methods suffer from the trade-off in spectral/spatial resolution, and that the STFT is the optimal method for the specific application of the localized quantification of hemoglobin concentration and oxygen saturation. PMID:24298417

Bosschaart, Nienke; van Leeuwen, Ton G.; Aalders, Maurice C. G.; Faber, Dirk J.

2013-01-01

51

Evaluating Polling Methods and Results  

NSDL National Science Digital Library

What basic skills are needed to read a poll? How are scientifically sound polls conducted? How can one gauge the reliability of poll data? In this lesson, students learn terms associated with polling as well as how to read and evaluate poll methodologies and results. They then practice administering and interpreting polls.

Network, The N.

52

A method for quantitative wet chemical analysis of urinary calculi.  

PubMed

We describe a simple method for quantitative chemical analysis of urinary calculi requiring no specialized equipment. Pulverized calculi are dried over silica gel at room temperature and dissolved in nitric acid, which was the only effective agent for complete dissolution. Calcium, magnesium, ammonium, and phosphate are then determined by conventional methods. Oxalate is determined by a method based on the quenching action of oxalate on the fluorescence of a zirconium-flavonol complex. Uric acid, when treated with nitric acid, is stoichiometrically converted to alloxan, which is determined fluorimetrically with 1,2-phenylenediamine. Similarly, cystine is oxidized by nitric acid to sulfate, which is determined turbidimetrically as barium sulfate. Protein is determined spectrophotometrically as xanthoprotein. The total mass recovery of authentic calculi was 92.2 +/- 6.7 (SD) per cent. The method permits analysis of calculi as small as 1.0 mg. Internal quality control is performed with specially designed control samples. PMID:6086179

Larsson, L; Sörbo, B; Tiselius, H G; Ohman, S

1984-06-27

53

Qualitative versus Quantitative Methods: Understanding Why Qualitative Methods are Superior for Criminology and Criminal Justice  

Microsoft Academic Search

The development of knowledge is important for criminology and criminal justice. Two predominant types of methods are available for criminologists' to use--quantitative and qualitative methods. The value, appropriateness and necessity of using qualitative methods is discussed. Because of the unique contributions - depth of understandings being primary -- that qualitative methods can provide it is argued that such approaches should

Richard Tewksbury

54

Knowledge Mining: A Quantitative Synthesis of Research Results and Findings  

Microsoft Academic Search

Knowledge mining emerged as a rapidly growing interdisciplinary field that merges together databases, statistics, machine\\u000a learning and related areas in order to extract valuable information and knowledge in large volumes of data. In this paper\\u000a we present the key finding of the results achieved during the NEMIS Conference on “Knowledge Mining”.

Penelope Markellou; Maria Rigou; Spiros Sirmakessis

55

A Quantitative Method To Evaluate Neutralizer Toxicity againstAcanthamoeba castellanii  

Microsoft Academic Search

A standard methodology for quantitatively evaluating neutralizer toxicity against Acanthamoeba castellanii does not exist. The objective of this study was to provide a quantitative method for evaluating neutralizer toxicity againstA. castellanii. Two methods were evaluated. A quantitative microtiter method for enumerating A. castellaniiwas evaluated by a 50% lethal dose endpoint method. The microtiter method was compared with the hemacytometer count

SALLY L. BUCK; ANDRUTH A. ROSENTHAL

1996-01-01

56

Gap analysis: Concepts, methods, and recent results  

USGS Publications Warehouse

Rapid progress is being made in the conceptual, technical, and organizational requirements for generating synoptic multi-scale views of the earth's surface and its biological content. Using the spatially comprehensive data that are now available, researchers, land managers, and land-use planners can, for the first time, quantitatively place landscape units - from general categories such as 'Forests' or 'Cold-Deciduous Shrubland Formation' to more categories such as 'Picea glauca-Abies balsamea-Populus spp. Forest Alliance' - in their large-area contexts. The National Gap Analysis Program (GAP) has developed the technical and organizational capabilities necessary for the regular production and analysis of such information. This paper provides a brief overview of concepts and methods as well as some recent results from the GAP projects. Clearly, new frameworks for biogeographic information and organizational cooperation are needed if we are to have any hope of documenting the full range of species occurrences and ecological processes in ways meaningful to their management. The GAP experience provides one model for achieving these new frameworks.

Jennings, M.D.

2000-01-01

57

[Quantitative and qualitative research methods, can they coexist yet?].  

PubMed

Qualitative design is gaining ground in Nursing research. In spite of a relative progress however, the evidence based practice movement continues to dominate and to underline the exclusive value of quantitative design (particularly that of randomized clinical trials) for clinical decision making. In the actual context convenient to those in power making utilitarian decisions on one hand, and facing nursing criticism of the establishment in favor of qualitative research on the other hand, it is difficult to chose a practical and ethical path that values the nursing role within the health care system, keeping us committed to quality care and maintaining researcher's integrity. Both qualitative and quantitative methods have advantages and disadvantages, and clearly, none of them can, by itself, capture, describe and explain reality adequately. Therefore, a balance between the two methods is needed. Researchers bare responsibility to society and science, and they should opt for the appropriate design susceptible to answering the research question, not promote the design favored by the research funding distributors. PMID:21800639

Hunt, Elena; Lavoie, Anne-Marise

2011-06-01

58

Quantitative results on heating events in the quiet corona Arnold O. Benz and Sm Krucker  

E-print Network

Quantitative results on heating events in the quiet corona Arnold O. Benz and Säm Krucker Citation;Quantitative Results on Heating Events in the Quiet Corona Arnold O. Benz 1 and Krucker2 1Institute constitute a major energy input into the corona, suggesting that the lower corona is not just heated

59

Quantitative Methods in Archaeology: A Review of Recent Trends and Developments  

Microsoft Academic Search

This paper reviews recent developments in the application of quantitative methods to archaeological research and focuses upon three major themes: the development of so-called designer methods, which are quantitative methods created to solve specific problems; the resurgence of whole-society modeling through a variety of formal and mathematical approaches; and trends in the the teaching of quantitative methods at the undergraduate

Mark Aldenderfer

1998-01-01

60

Quantitative Methods in the Study of Local History  

ERIC Educational Resources Information Center

The author suggests how the quantitative analysis of data from census records, assessment roles, and newspapers may be integrated into the classroom. Suggestions for obtaining quantitative data are provided. (DE)

Davey, Pene

1974-01-01

61

Methods for Quantitative Interpretation of Retarding Field Analyzer Data  

SciTech Connect

Over the course of the CesrTA program at Cornell, over 30 Retarding Field Analyzers (RFAs) have been installed in the CESR storage ring, and a great deal of data has been taken with them. These devices measure the local electron cloud density and energy distribution, and can be used to evaluate the efficacy of different cloud mitigation techniques. Obtaining a quantitative understanding of RFA data requires use of cloud simulation programs, as well as a detailed model of the detector itself. In a drift region, the RFA can be modeled by postprocessing the output of a simulation code, and one can obtain best fit values for important simulation parameters with a chi-square minimization method.

Calvey, J.R.; Crittenden, J.A.; Dugan, G.F.; Palmer, M.A.; Furman, M.; Harkay, K.

2011-03-28

62

Quantitative characterization of an image brightness subtraction method for motion determination  

NASA Astrophysics Data System (ADS)

We present a method for estimating the average frame-to- frame motion of a videotaped textured surface undergoing deformations. The method is based on subtracting successive frames from the video sequence and generates an approximation to the spatial average of the square of the surface's displacement field between the two frames. The method is computationally much faster than a full optical flow analysis, but is not always quantitatively accurate. We identify the parameters governing the errors, identify the regime in which the method is quantitatively accurate, and demonstrate that the accuracy can be assessed using only information internal to the algorithm. Finally, we apply both our method and a correspondence-based optical flow method to video sequences of spontaneously beating tissue cultures of embryonic chick cardiomyocytes. We show that the extent of the agreement between the two sets of results matches the predicted values.

Koss, Jordan Miles

63

Nuclear medicine and imaging research (instrumentation and quantitative methods of evaluation)  

SciTech Connect

This document is the annual progress report for project entitled 'Instrumentation and Quantitative Methods of Evaluation.' Progress is reported in separate sections individually abstracted and indexed for the database. Subject areas reported include theoretical studies of imaging systems and methods, hardware developments, quantitative methods of evaluation, and knowledge transfer: education in quantitative nuclear medicine imaging.

Beck, R.N.; Cooper, M.; Chen, C.T.

1992-07-01

64

University Students' Research Orientations: Do negative attitudes exist toward quantitative methods?  

Microsoft Academic Search

This paper examines university social science and education students' views of research methodology, especially asking whether a negative research orientation towards quantitative methods exists. Finnish (n?=?196) and US (n?=?122) students answered a questionnaire concerning their views on quantitative, qualitative, empirical, and theoretical methods, their readiness to use quantitative and qualitative methods in their own research, and the difficulties they experienced

Mari Murtonen

2005-01-01

65

Rapid quantitative pharmacodynamic imaging by a novel method: theory, simulation testing and proof of principle  

PubMed Central

Pharmacological challenge imaging has mapped, but rarely quantified, the sensitivity of a biological system to a given drug. We describe a novel method called rapid quantitative pharmacodynamic imaging. This method combines pharmacokinetic-pharmacodynamic modeling, repeated small doses of a challenge drug over a short time scale, and functional imaging to rapidly provide quantitative estimates of drug sensitivity including EC50 (the concentration of drug that produces half the maximum possible effect). We first test the method with simulated data, assuming a typical sigmoidal dose-response curve and assuming imperfect imaging that includes artifactual baseline signal drift and random error. With these few assumptions, rapid quantitative pharmacodynamic imaging reliably estimates EC50 from the simulated data, except when noise overwhelms the drug effect or when the effect occurs only at high doses. In preliminary fMRI studies of primate brain using a dopamine agonist, the observed noise level is modest compared with observed drug effects, and a quantitative EC50 can be obtained from some regional time-signal curves. Taken together, these results suggest that research and clinical applications for rapid quantitative pharmacodynamic imaging are realistic. PMID:23940831

Koller, Jonathan M.; Miller, Brad D.

2013-01-01

66

Understanding youth: using qualitative methods to verify quantitative community indicators.  

PubMed

Community- and individual-level data were collected from interviews with 1,294 boys and girls, 13 to 19 years old, in three impoverished urban communities of Beirut. Univariate analyses of variables provide quantitative indicators of adolescents' lives and communities. Researchers including the authors, interested in using these indicators to plan for community interventions with youth in the Palestinian refugee camp, discuss the pertinent results with youth from the camp in six focus groups. The authors find that many indicators misrepresent the situation of youth in the camp. For example, adolescents may have underreported cigarette and argileh (water pipe) smoking (8.3% and 22.4%, respectively) because of the lack of social desirability of these behaviors; other questions may have been misunderstood, such as perceived health and health compared to others. Also, important issues for them such as drug abuse, violence, and school problems were not asked. Implications for intervention research are discussed. PMID:17971480

Makhoul, Jihad; Nakkash, Rima

2009-01-01

67

Modeling conflict : research methods, quantitative modeling, and lessons learned.  

SciTech Connect

This study investigates the factors that lead countries into conflict. Specifically, political, social and economic factors may offer insight as to how prone a country (or set of countries) may be for inter-country or intra-country conflict. Largely methodological in scope, this study examines the literature for quantitative models that address or attempt to model conflict both in the past, and for future insight. The analysis concentrates specifically on the system dynamics paradigm, not the political science mainstream approaches of econometrics and game theory. The application of this paradigm builds upon the most sophisticated attempt at modeling conflict as a result of system level interactions. This study presents the modeling efforts built on limited data and working literature paradigms, and recommendations for future attempts at modeling conflict.

Rexroth, Paul E.; Malczynski, Leonard A.; Hendrickson, Gerald A.; Kobos, Peter Holmes; McNamara, Laura A.

2004-09-01

68

A fully automated method for quantitative cerebral hemodynamic analysis using DSC-MRI  

PubMed Central

Dynamic susceptibility contrast (DSC)-based perfusion analysis from MR images has become an established method for analysis of cerebral blood volume (CBV) in glioma patients. To date, little emphasis has, however, been placed on quantitative perfusion analysis of these patients, mainly due to the associated increased technical complexity and lack of sufficient stability in a clinical setting. The aim of our study was to develop a fully automated analysis framework for quantitative DSC-based perfusion analysis. The method presented here generates quantitative hemodynamic maps without user interaction, combined with automatic segmentation of normal-appearing cerebral tissue. Validation of 101 patients with confirmed glioma after surgery gave mean values for CBF, CBV, and MTT, extracted automatically from normal-appearing whole-brain white and gray matter, in good agreement with literature values. The measured age- and gender-related variations in the same parameters were also in agreement with those in the literature. Several established analysis methods were compared and the resulting perfusion metrics depended significantly on method and parameter choice. In conclusion, we present an accurate, fast, and automatic quantitative perfusion analysis method where all analysis steps are based on raw DSC data only. PMID:20087370

Bj?rnerud, Atle; Emblem, Kyrre E

2010-01-01

69

Quantitative methods for developing C2 system requirement  

SciTech Connect

The US Army established the Army Tactical Command and Control System (ATCCS) Experimentation Site (AES) to provide a place where material and combat developers could experiment with command and control systems. The AES conducts fundamental and applied research involving command and control issues using a number of research methods, ranging from large force-level experiments, to controlled laboratory experiments, to studies and analyses. The work summarized in this paper was done by Pacific Northwest Laboratory under task order from the Army Tactical Command and Control System Experimentation Site. The purpose of the task was to develop the functional requirements for army engineer automation and support software, including MCS-ENG. A client, such as an army engineer, has certain needs and requirements of his or her software; these needs must be presented in ways that are readily understandable to the software developer. A requirements analysis then, such as the one described in this paper, is simply the means of communication between those who would use a piece of software and those who would develop it. The analysis from which this paper was derived attempted to bridge the communications gap'' between army combat engineers and software engineers. It sought to derive and state the software needs of army engineers in ways that are meaningful to software engineers. In doing this, it followed a natural sequence of investigation: (1) what does an army engineer do, (2) with which tasks can software help, (3) how much will it cost, and (4) where is the highest payoff This paper demonstrates how each of these questions was addressed during an analysis of the functional requirements of engineer support software. Systems engineering methods are used in a task analysis and a quantitative scoring method was developed to score responses regarding the feasibility of task automation. The paper discusses the methods used to perform utility and cost-benefits estimates.

Tyler, K.K.

1992-06-01

70

Quantitative methods for developing C2 system requirement  

SciTech Connect

The US Army established the Army Tactical Command and Control System (ATCCS) Experimentation Site (AES) to provide a place where material and combat developers could experiment with command and control systems. The AES conducts fundamental and applied research involving command and control issues using a number of research methods, ranging from large force-level experiments, to controlled laboratory experiments, to studies and analyses. The work summarized in this paper was done by Pacific Northwest Laboratory under task order from the Army Tactical Command and Control System Experimentation Site. The purpose of the task was to develop the functional requirements for army engineer automation and support software, including MCS-ENG. A client, such as an army engineer, has certain needs and requirements of his or her software; these needs must be presented in ways that are readily understandable to the software developer. A requirements analysis then, such as the one described in this paper, is simply the means of communication between those who would use a piece of software and those who would develop it. The analysis from which this paper was derived attempted to bridge the ``communications gap`` between army combat engineers and software engineers. It sought to derive and state the software needs of army engineers in ways that are meaningful to software engineers. In doing this, it followed a natural sequence of investigation: (1) what does an army engineer do, (2) with which tasks can software help, (3) how much will it cost, and (4) where is the highest payoff? This paper demonstrates how each of these questions was addressed during an analysis of the functional requirements of engineer support software. Systems engineering methods are used in a task analysis and a quantitative scoring method was developed to score responses regarding the feasibility of task automation. The paper discusses the methods used to perform utility and cost-benefits estimates.

Tyler, K.K.

1992-06-01

71

Comparing Isotope Dilution Methods to Label Free Quantitation Methods For The Analysis of Vaccine Standards and Products  

PubMed Central

Determining protein content in biologics is an important part of the production process. An example of interest to public health is the influenza vaccine, where the amount of the major antigenic protein hemagglutinin and the amount of egg proteins from the expression system are regulated. Mass spectrometry has advantages of higher specificity, speed and permits other proteins to be analyzed simultaneously. Here, we present the use of a MRM method for quantitation of hemagglutinin and other vaccine proteins developed in our laboratory and compare this approach to a label free method (MSE) for simultaneous identification and absolute quantitation of virus and egg proteins. Influenza vaccine samples were tryptically digested using a protocol developed in our laboratory to ensure consistent and reproducible results. Traditional IDMS measurements were made on ThermoFisher Scientific TSQ quantum triple quadrupole platform. Label free methods (LC-MSE) were performed on a Waters qTOF Premier platform and the PLGS software. Both instruments were coupled to an Identical Agilent 1200 LC platform to insure an accurate comparison. The results of the study illustrated that IDMS remains the gold standard for absolute protein quantitation via mass spectrometry. MSE performed with comparable precision and accuracy in cases where the sample was less complex (monovalent pandemic vaccines vs. seasonal trivalent vaccines). In addition the choice of peptides made by the MSE algorithm and the choice of influenza proteins used in the database also affected the precision and accuracy of the MSE absolute quantitation results.

Winne, Emily; Santana, Wanda I.; Williams, Tracie L.; Barr, John R.; Bundy, Jonathan

2013-01-01

72

A method for the extraction and quantitation of phycoerythrin from algae  

NASA Technical Reports Server (NTRS)

A summary of a new technique for the extraction and quantitation of phycoerythrin (PHE) from algal samples is described. Results of analysis of four extracts representing three PHE types from algae including cryptomonad and cyanophyte types are presented. The method of extraction and an equation for quantitation are given. A graph showing the relationship of concentration and fluorescence units that may be used with samples fluorescing around 575-580 nm (probably dominated by cryptophytes in estuarine waters) and 560 nm (dominated by cyanophytes characteristics of the open ocean) is provided.

Stewart, D. E.

1982-01-01

73

Variable selection method for quantitative trait analysis based on parallel genetic algorithm  

PubMed Central

Summary Selection of important genetic and environmental factors is of strong interest in quantitative trait analyses. In this study, we use parallel genetic algorithm (PGA) to identify genetic and environmental factors in genetic association studies of complex human diseases. Our method can take account of both multiple markers across the genome and environmental factors, and also can be used to do fine mappings based on the results of haplotype analysis to select the markers that are associated with the quantitative traits. Using both simulated and real examples, we show that PGA is able to choose the variables correctly and is also an easy-to-use variable selection tool. PMID:19799600

Mukhopadhyay, Siuli; George, Varghese; Xu, Hongyan

2009-01-01

74

Experimental demonstration of quantitation errors in MR spectroscopy resulting from saturation corrections under changing conditions  

NASA Astrophysics Data System (ADS)

Metabolite concentration measurements in in vivo NMR are generally performed under partially saturated conditions, with correction for partial saturation performed after data collection using a measured saturation factor. Here, we present an experimental test of the hypothesis that quantitation errors can occur due to application of such saturation factor corrections in changing systems. Thus, this extends our previous theoretical work on quantitation errors due to varying saturation factors. We obtained results for two systems frequently studied by 31P NMR, the ischemic rat heart and the electrically stimulated rat gastrocnemius muscle. The results are interpreted in light of previous theoretical work which defined the degree of saturation occurring in a one-pulse experiment for a system with given spin-lattice relaxation times, T1s, equilibrium magnetizations, M0s, and reaction rates. We found that (i) the assumption of constancy of saturation factors leads to quantitation errors on the order of 40% in inorganic phosphate; (ii) the dominant contributor to the quantitation errors in inorganic phosphate is most likely changes in T1; (iii) T1 and M0 changes between control and intervention periods, and chemical exchange contribute to different extents to quantitation errors in phosphocreatine and ?-ATP; (iv) relatively small increases in interpulse delay substantially decreased quantitation errors for metabolites in ischemic rat hearts; (v) random error due to finite SNR led to approximately 4% error in quantitation, and hence was a substantially smaller contributor than were changes in saturation factors.

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

2003-04-01

75

Comparison of different surface quantitative analysis methods: Application to corium  

NASA Astrophysics Data System (ADS)

In the case of a severe hypothetical accident in a pressurized water reactor, the reactor assembly melts partially or completely. The formed material, named "corium," flows out and spreads at the bottom of the reactor. In order to limit and control the consequences of such an accident, it is necessary to know precisely the specifications of the O-U-Zr basic system. These specifications should lead to the understanding of physico-chemical phenomenon happening at very high temperatures, from the study at room temperature of solidified structures. Toward that goal, a corium mix was processed by a melting by electron bombing at very high temperature (3000 K), followed by a quenching of the ingot in an Isabell[1] evaporator, Metallographical analyses were then necessary in order to validate thermodynamic databases set by the Thermo-Calc software.[2,3] The study consists of setting a global quantitative analysis method of the surface that would be fast and reliable, in order to determine a global composition of corium.

Guilbaud, Nathalie; Blin, Delphine; Pérodeaud, Phllippe; Dugne, Olivier; Guéneau, Christine

2000-07-01

76

A new method for the quantitative analysis of endodontic microleakage.  

PubMed

The aim of this in vitro study was to evaluate the apical seal obtained with three commonly used root canal sealing cements: Sealapex, AH Plus or Topseal, and Sealite, using a new method based on the quantitative analysis of 125I-radiolabeled lysozyme penetration. One hundred thirteen teeth with straight single root canals were instrumented to master apical point #25/30. These were divided into three groups: (i) negative control (4 roots) covered with two layers of nail polish, (ii) test group (105 roots) obturated by laterally condensed guttapercha with the three cements; and (iii) positive control (4 roots) obturated without cement. The groups were then immersed in 125I lysozyme solution for a period of 1, 7, 14, or 28 days. After removal, six sections of 0.8 mm length each were made of each root with a fine diamond wire. Each section was analyzed for activity by a gamma counter, corrected for decay, and used to quantify protein penetration. Leakage was high in the positive control and almost negligible in the negative control. AH Plus (Topseal) and Sealapex showed similar leakage behavior over time, with AH Plus (Topseal) performing better. Sealite showed acceptable leakage up until day 14, after which a large increase occurred, presumably due to three-dimensional instability. PMID:10321181

Haïkel, Y; Wittenmeyer, W; Bateman, G; Bentaleb, A; Allemann, C

1999-03-01

77

A new method of phase derivative extracting for off-axis quantitative phase imaging  

NASA Astrophysics Data System (ADS)

We present a new derivative method for phase information extraction in off-axis quantitative phase imaging (QPI). Similar to other rapid derivative method, this method only uses the interference term, the 1st and 2nd order derivatives of a single interferogram in QPI, but the assumption in our method is different from that of other derivative method. And this method can be used to optimize small spatial frequency processing capability in slightly off-axis QPI. We illustrate the proposed method with theory and simulation experiment of a ball, and prove our method by comparing our simulation results with the experimental results of the red blood cell and the skin cancer cell, respectively.

Xu, Yuanyuan; Wang, Yawei; Jin, Weifeng; Lv, Cuihong; Wu, Hui

2013-09-01

78

Evaluation of ROI methods for quantitative FDOPA PET images  

SciTech Connect

Issues about the accuracy of region of interest (ROI) definition methods for FDOPA PET studies were investigated. An MRI-based ROI method and manually defined ROI method were compared using a computer simulated brain phantom and four real PET studies. The results indicate the error or discrepancy between MRI-based ROI and manually defined ROI is small ({le} 5%) at different head orientations and different noise levels. The VOI is not sensitive to the orientation, but the mid-plane ROI is also fairly reliable.

Yu, D.C.; Lin, K.P.; Yang, J.; Huang, S.C. [UCLA School of Medicine, Los Angeles, CA (United States). Div. of Nuclear Medicine and Biophysics

1995-12-31

79

Quantitative methods in archaeology: A review of recent trends and developments  

Microsoft Academic Search

This paper reviews recent developments in the application of quantitative methods to archaeological research and focuses upon\\u000a three major themes: the development of so-called designer methods, which are quantitative methods created to solve specific\\u000a problems; the resurgence of whole-society modeling through a variety of formal and mathematical approaches; and trends in\\u000a the the teaching of quantitative methods at the undergraduate

Mark Aldenderfer

1998-01-01

80

A Framework for Mixing Methods in Quantitative Measurement Development, Validation, and Revision: A Case Study  

ERIC Educational Resources Information Center

A framework for quantitative measurement development, validation, and revision that incorporates both qualitative and quantitative methods is introduced. It extends and adapts Adcock and Collier's work, and thus, facilitates understanding of quantitative measurement development, validation, and revision as an integrated and cyclical set of…

Luyt, Russell

2012-01-01

81

A calibration-free, one-step method for quantitative photoacoustic tomography  

PubMed Central

Purpose: Recently reported quantitative photoacoustic tomography (PAT) has significantly expanded the utilities of PAT because it allows for recovery of tissue optical absorption coefficient which directly correlates with tissue physiological information. However, the recovery of optical absorption coefficient by the existing quantitative PAT approaches strongly depends on the accuracy of absorbed energy density distribution, and on the knowledge of accurate strength and distribution of incident light source. The purpose of this study is to develop a new algorithm for the reconstruction of optical absorption coefficient that does not depend on these initial parameters. Methods: Here the authors propose a novel one-step reconstruction approach that can directly recover optical absorption coefficient from photoacoustic measurements along boundary domain. The authors validate the method using simulation and phantom experiments. Results: The authors have demonstrated experimental evidence that it is possible to directly recover optical absorption coefficient maps using boundary photoacoustic measurements coupled with the photon diffusion equation in just one step. The authors found that the method described is able to quantitatively reconstruct absorbing objects with different sizes and optical contrast levels. Conclusions: Compared to the authors’ previous two-step methods, the reconstruction results obtained here show that the one-step scheme can significantly improve the accuracy of absorption coefficient recovery. PMID:23127082

Yuan, Zhen; Jiang, Huabei

2012-01-01

82

[Development and validation of event-specific quantitative PCR method for genetically modified maize LY038].  

PubMed

In this article, we report a novel real-time PCR-based analytical method for quantitation of the GM maize event LY038. We designed LY038-specific and maize endogenous reference DNA-specific PCR amplifications. After confirming the specificity and linearity of the LY038-specific PCR amplification, we determined the conversion factor required to calculate the weight-based content of GM organism (GMO) in a multilaboratory evaluation. Finally, in order to validate the developed method, an interlaboratory collaborative trial according to the internationally harmonized guidelines was performed with blind DNA samples containing LY038 at the mixing levels of 0, 0.5, 1.0, 5.0 and 10.0%. The precision of the method was evaluated as the RSD of reproducibility (RSDR), and the values obtained were all less than 25%. The limit of quantitation of the method was judged to be 0.5% based on the definition of ISO 24276 guideline. The results from the collaborative trial suggested that the developed quantitative method would be suitable for practical testing of LY038 maize. PMID:23470871

Mano, Junichi; Masubuchi, Tomoko; Hatano, Shuko; Futo, Satoshi; Koiwa, Tomohiro; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Takabatake, Reona; Kitta, Kazumi

2013-01-01

83

Quantitation of Endogenous Peptides using Mass Spectrometry Based Methods  

PubMed Central

The mass spectrometry-based “omics” sub-discipline that focuses on comprehensive, often exploratory, analyses of endogenous peptides involved in cell-to-cell communication is oftentimes referred to as peptidomics. While the progress in bioanalytical technology development for peptide discovery has been tremendous, perhaps the largest advances have involved robust quantitative mass spectrometric approaches and data mining algorithms. These efforts have accelerated the discovery and validation of biomarkers, functionally important posttranslational modifications, and unexpected molecular interactions, information that aids drug development. In this article we outline the current approaches used in quantitative peptidomics and the technical challenges that stimulate new advances in the field, while also reviewing the newest literature on functional characterizations of endogenous peptides using quantitative mass spectrometry. PMID:23790312

Romanova, Elena V.; Dowd, Sarah E.; Sweedler, Jonathan V.

2013-01-01

84

GINI COEFFICIENTS, SOCIAL NETWORK ANALYSIS, AND MARKOV CHAINS: QUANTITATIVE METHODS FOR ANA-  

E-print Network

GINI COEFFICIENTS, SOCIAL NETWORK ANALYSIS, AND MARKOV CHAINS: QUANTITATIVE METHODS FOR ANA- LYZING Management Project No.: 538 Title of Project: Gini Coefficients, social network analysis and Markov Chains

85

11.220 Quantitative Reasoning and Statistical Method for Planning I, Spring 2006  

E-print Network

This course develops logical, empirically based arguments using statistical techniques and analytic methods. It covers elementary statistics, probability, and other types of quantitative reasoning useful for description, ...

Zegras, P. Christopher

86

Conversion of cDNA differential display results (DDRT-PCR) into quantitative transcription profiles  

PubMed Central

Background Gene expression studies on non-model organisms require open-end strategies for transcription profiling. Gel-based analysis of cDNA fragments allows to detect alterations in gene expression for genes which have neither been sequenced yet nor are available in cDNA libraries. Commonly used protocols for gel-based transcript profiling are cDNA differential display (DDRT-PCR) and cDNA-AFLP. Both methods have been used merely as qualitative gene discovery tools so far. Results We developed procedures for the conversion of cDNA Differential Display data into quantitative transcription profiles. Amplified cDNA fragments are separated on a DNA sequencer and detector signals are converted into virtual gel images suitable for semi-automatic analysis. Data processing consists of four steps: (i) cDNA bands in lanes corresponding to samples treated with the same primer combination are matched in order to identify fragments originating from the same transcript, (ii) intensity of bands is determined by densitometry, (iii) densitometric values are normalized, and (iv) intensity ratio is calculated for each pair of corresponding bands. Transcription profiles are represented by sets of intensity ratios (control vs. treatment) for cDNA fragments defined by primer combination and DNA mobility. We demonstrated the procedure by analyzing DDRT-PCR data on the effect of secondary metabolites of oilseed rape Brassica napus on the transcriptome of the pathogenic fungus Leptosphaeria maculans. Conclusion We developed a data processing procedure for the quantitative analysis of amplified cDNA fragments separated by electrophoresis. The system utilizes common software and provides an open-end alternative to DNA microarray analysis of the transcriptome. It is expected to work equally well with DDRT-PCR and cDNA-AFLP data and be useful particularly in reseach on organisms for which microarray analysis is not available or economical. PMID:15807902

Venkatesh, Balakrishnan; Hettwer, Ursula; Koopmann, Birger; Karlovsky, Petr

2005-01-01

87

Quantitative Measurement Method for Possible Rib Fractures in Chest Radiographs  

PubMed Central

Objectives This paper proposes a measurement method to quantify the abnormal characteristics of the broken parts of ribs using local texture and shape features in chest radiographs. Methods Our measurement method comprises two steps: a measurement area assignment and sampling step using a spline curve and sampling lines orthogonal to the spline curve, and a fracture-ness measurement step with three measures, asymmetry and gray-level co-occurrence matrix based measures (contrast and homogeneity). They were designed to quantify the regional shape and texture features of ribs along the centerline. The discriminating ability of our method was evaluated through region of interest (ROI) analysis and rib fracture classification test using support vector machine. Results The statistically significant difference was found between the measured values from fracture and normal ROIs; asymmetry (p < 0.0001), contrast (p < 0.001), and homogeneity (p = 0.022). The rib fracture classifier, trained with the measured values in ROI analysis, detected every rib fracture from chest radiographs used for ROI analysis, but it also classified some unbroken parts of ribs as abnormal parts (8 to 17 line sets; length of each line set, 2.998 ± 2.652 mm; length of centerlines, 131.067 ± 29.460 mm). Conclusions Our measurement method, which includes a flexible measurement technique for the curved shape of ribs and the proposed shape and texture measures, could discriminate the suspicious regions of ribs for possible rib fractures in chest radiographs. PMID:24175118

Kim, Jaeil; Kim, Sungjun; Kim, Young Jae

2013-01-01

88

Analyzing the Students' Academic Integrity using Quantitative Methods  

ERIC Educational Resources Information Center

The transition period in Romania has generated a series of important changes, including the reforming of the Romanian tertiary education. This process has been accelerated after the signing of the Bologna treaty. Important changes were recorded in many of the quantitative aspects (such as number of student enrolled, pupil-student ratio etc) as…

Teodorescu, Daniel; Andrei, Tudorel; Tusa, Erika; Herteliu, Claudiu; Stancu, Stelian

2007-01-01

89

Issues Related to Data Analysis and Quantitative Methods in PER  

NSDL National Science Digital Library

This paper, presented at the 2002 Physics Education Research Conference, offers authors' discussion of some issues that always arise, implicitly or explicitly, when conducting quantitative research and carrying out data analysis in Physics Education Research. (Most are relevant for qualitative research as well.)

Meltzer, David (David Elliott)

2010-07-22

90

Issues Related to Data Analysis and Quantitative Methods in PER  

NSDL National Science Digital Library

This paper, presented at the 2002 Physics Education Research Conference, offers authors' discussion of some issues that always arise, implicitly or explicitly, when conducting quantitative research and carrying out data analysis in Physics Education Research. (Most are relevant for qualitative research as well.)

Meltzer, David E.

2006-12-06

91

Quantitative Methods for Administrative Decision Making in Junior Colleges.  

ERIC Educational Resources Information Center

With the rapid increase in number and size of junior colleges, administrators must take advantage of the decision-making tools already used in business and industry. This study investigated how these quantitative techniques could be applied to junior college problems. A survey of 195 California junior college administrators found that the problems…

Gold, Benjamin Knox

92

Machine learning methods for quantitative analysis of Raman spectroscopy data  

NASA Astrophysics Data System (ADS)

The automated identification and quantification of illicit materials using Raman spectroscopy is of significant importance for law enforcement agencies. This paper explores the use of Machine Learning (ML) methods in comparison with standard statistical regression techniques for developing automated identification methods. In this work, the ML task is broken into two sub-tasks, data reduction and prediction. In well-conditioned data, the number of samples should be much larger than the number of attributes per sample, to limit the degrees of freedom in predictive models. In this spectroscopy data, the opposite is normally true. Predictive models based on such data have a high number of degrees of freedom, which increases the risk of models over-fitting to the sample data and having poor predictive power. In the work described here, an approach to data reduction based on Genetic Algorithms is described. For the prediction sub-task, the objective is to estimate the concentration of a component in a mixture, based on its Raman spectrum and the known concentrations of previously seen mixtures. Here, Neural Networks and k-Nearest Neighbours are used for prediction. Preliminary results are presented for the problem of estimating the concentration of cocaine in solid mixtures, and compared with previously published results in which statistical analysis of the same dataset was performed. Finally, this paper demonstrates how more accurate results may be achieved by using an ensemble of prediction techniques.

Madden, Michael G.; Ryder, Alan G.

2003-03-01

93

Quantitative sacroiliac scintigraphy. The effect of method of selection of region of interest  

SciTech Connect

Various authors have advocated quantitative methods of evaluating bone scintigrams to detect sacroiliitis, while others have not found them useful. Many explanations for this disagreement have been offered, including differences in the method of case selection, ethnicity, gender, and previous drug therapy. It would appear that one of the most important impediments to consistent results is the variability of selecting sacroiliac joint and reference regions of interest (ROIs). The effect of ROI selection would seem particularly important because of the normal variability of radioactivity within the reference regions that have been used (sacrum, spine, iliac wing) and the inhomogeneity of activity in the SI joints. We have investigated the effect of ROI selection, using five different methods representative of, though not necessarily identical to, those found in the literature. Each method produced unique mean indices that were different for patients with ankylosing spondylitis (AS) and controls. The method of Ayres (19) proved superior (largest mean difference, smallest variance), but none worked well as a diagnostic tool because of substantial overlap of the distributions of indices of patient and control groups. We conclude that ROI selection is important in determining results, and quantitative scintigraphic methods in general are not effective tools for diagnosing AS. Among the possible factors limiting success, difficulty in selecting a stable reference area seems of particular importance.

Davis, M.C.; Turner, D.A.; Charters, J.R.; Golden, H.E.; Ali, A.; Fordham, E.W.

1984-06-01

94

Bird community as an indicator of biodiversity: results from quantitative surveys in Brazil  

Microsoft Academic Search

This short review presents the results obtained in several localities of Brazil on the composition of forest bird communities. Data were collected since the late 80's, after we introduced a new methodology of quantitative survey, based on acoustic identification and unlimited-radius point census. Although these data are still scattered, they show uniquely precise and coherently comparative patterns of composition of

JACQUES M. E. VIELLIARD

2000-01-01

95

A new method for quantitating total lesion glucose metabolic changes in serial tumor FDG PET studies  

SciTech Connect

Accurate quantitative FDG PET studies have the potential for important applications in clinical oncology for monitoring therapy induced changes in tumor glycolytic rates. Due to a number of technical problems that complicate the use of quantitative PET tumor imaging, methods which can maximize the accuracy and precision of such measurements are advantageous. In this study, we developed and evaluated a method for reducing the errors caused by the conventional single plane, single ROI analysis in parametric images generated from pixel by pixel Patlak graphic analysis (PGA) in FDG PET studies of melanoma patients. We compared this new method to the conventional ROI method. The new processing method involves (1) generating the correlation coefficient (r) constrained Patlak parametric images from dynamic PET data; (2) summing up all the planes which cover the lesion; (3) defining a single ROI which covers the whole lesion in the summing image and determining the total lesion glucose metabolic index (K{sub T}, ml/min/lesion). Although only a single ROI was defined on the summing image, the glucose metabolic index obtained showed negligible difference (<1%) compared to those obtained from multiple ROIs on multiple planes of unconstrained parametric images. When the dynamic PET images were rotated and translated to simulate different patient positionings between scans at different times, the results obtained from the new method showed negligible difference (<2%). In summary, we present a simple but reliable method to quantitatively monitor the total lesion glucose metabolic changes during tumor growth. The method has several advantages over the conventional single ROI, single plane evaluation: (1) less sensitive to the ROI definition; (2) smaller intra- and inter-observer variations and (3) not requiring image registrations of serial scan data.

Wu, H.M.; Hoh, C.K.; Huang, S.C.; Phelps, M.E. [UCLA School of Medicine, Los Angeles, CA (United States)] [and others

1994-05-01

96

A Method for Quantitative Mapping of Thick Oil Spills Using Imaging Spectroscopy  

E-print Network

A Method for Quantitative Mapping of Thick Oil Spills Using Imaging Spectroscopy By Roger N. Clark (AVIRIS) Team, 2010, A method for quantitative mapping of thick oil spills using imaging spectroscopy: U ....................................................................................................................................................14 Figures 1. Image of oil emulsion from the Deepwater Horizon oil spill in the Gulf of Mexico off

Torgersen, Christian

97

Chromatospectrophotometric method for the quantitative determination of pectolinarigenin in Linaria vulgaris and L. kurdica  

Microsoft Academic Search

A chromatospectrophotometric method for the quantitative determination of pectolinarigenin in the epigeal parts ofLinaria vulgaris andL. kurdica is proposed. The relative error of the method is ±2.89%.

V. V. Stetskov; B. A. Krivut

1982-01-01

98

A collimator optimization method for quantitative imaging: Application to Y-90 bremsstrahlung SPECT  

PubMed Central

Purpose: Post-therapy quantitative 90Y bremsstrahlung single photon emission computed tomography (SPECT) has shown great potential to provide reliable activity estimates, which are essential for dose verification. Typically 90Y imaging is performed with high- or medium-energy collimators. However, the energy spectrum of 90Y bremsstrahlung photons is substantially different than typical for these collimators. In addition, dosimetry requires quantitative images, and collimators are not typically optimized for such tasks. Optimizing a collimator for 90Y imaging is both novel and potentially important. Conventional optimization methods are not appropriate for 90Y bremsstrahlung photons, which have a continuous and broad energy distribution. In this work, the authors developed a parallel-hole collimator optimization method for quantitative tasks that is particularly applicable to radionuclides with complex emission energy spectra. The authors applied the proposed method to develop an optimal collimator for quantitative 90Y bremsstrahlung SPECT in the context of microsphere radioembolization. Methods: To account for the effects of the collimator on both the bias and the variance of the activity estimates, the authors used the root mean squared error (RMSE) of the volume of interest activity estimates as the figure of merit (FOM). In the FOM, the bias due to the null space of the image formation process was taken in account. The RMSE was weighted by the inverse mass to reflect the application to dosimetry; for a different application, more relevant weighting could easily be adopted. The authors proposed a parameterization for the collimator that facilitates the incorporation of the important factors (geometric sensitivity, geometric resolution, and septal penetration fraction) determining collimator performance, while keeping the number of free parameters describing the collimator small (i.e., two parameters). To make the optimization results for quantitative 90Y bremsstrahlung SPECT more general, the authors simulated multiple tumors of various sizes in the liver. The authors realistically simulated human anatomy using a digital phantom and the image formation process using a previously validated and computationally efficient method for modeling the image-degrading effects including object scatter, attenuation, and the full collimator-detector response (CDR). The scatter kernels and CDR function tables used in the modeling method were generated using a previously validated Monte Carlo simulation code. Results: The hole length, hole diameter, and septal thickness of the obtained optimal collimator were 84, 3.5, and 1.4 mm, respectively. Compared to a commercial high-energy general-purpose collimator, the optimal collimator improved the resolution and FOM by 27% and 18%, respectively. Conclusions: The proposed collimator optimization method may be useful for improving quantitative SPECT imaging for radionuclides with complex energy spectra. The obtained optimal collimator provided a substantial improvement in quantitative performance for the microsphere radioembolization task considered. PMID:23927349

Rong, Xing; Frey, Eric C.

2013-01-01

99

Quantitative investigation into methods for evaluating neocortical slice viability  

PubMed Central

Background In cortical and hippocampal brain slice experiments, the viability of processed tissue is usually judged by the amplitude of extracellularly-recorded seizure-like event (SLE) activity. Surprisingly, the suitability of this approach for evaluating slice quality has not been objectively studied. Furthermore, a method for gauging the viability of quiescent tissue, in which SLE activity is intentionally suppressed, has not been documented. In this study we undertook to address both of these matters using the zero-magnesium SLE model in neocortical slices. Methods Using zero-magnesium SLE activity as the output parameter, we investigated: 1) changes in the pattern (amplitude, frequency and length) of SLE activity as slice health either deteriorated; or was compromised by altering the preparation methodology and; 2) in quiescent tissue, whether the triggering of high frequency field activity following electrode insertion predicted subsequent development of SLE activity — and hence slice viability. Results SLE amplitude was the single most important variable correlating with slice viability, with a value less than 50 ?V indicative of tissue unlikely to be able to sustain population activity for more than 30–60 minutes. In quiescent slices, an increase in high frequency field activity immediately after electrode insertion predicted the development of SLE activity in 100% of cases. Furthermore, the magnitude of the increase in spectral power correlated with the amplitude of succeeding SLE activity (R2 40.9%, p?

2013-01-01

100

Link-based quantitative methods to identify differentially coexpressed genes and gene Pairs  

PubMed Central

Background Differential coexpression analysis (DCEA) is increasingly used for investigating the global transcriptional mechanisms underlying phenotypic changes. Current DCEA methods mostly adopt a gene connectivity-based strategy to estimate differential coexpression, which is characterized by comparing the numbers of gene neighbors in different coexpression networks. Although it simplifies the calculation, this strategy mixes up the identities of different coexpression neighbors of a gene, and fails to differentiate significant differential coexpression changes from those trivial ones. Especially, the correlation-reversal is easily missed although it probably indicates remarkable biological significance. Results We developed two link-based quantitative methods, DCp and DCe, to identify differentially coexpressed genes and gene pairs (links). Bearing the uniqueness of exploiting the quantitative coexpression change of each gene pair in the coexpression networks, both methods proved to be superior to currently popular methods in simulation studies. Re-mining of a publicly available type 2 diabetes (T2D) expression dataset from the perspective of differential coexpression analysis led to additional discoveries than those from differential expression analysis. Conclusions This work pointed out the critical weakness of current popular DCEA methods, and proposed two link-based DCEA algorithms that will make contribution to the development of DCEA and help extend it to a broader spectrum. PMID:21806838

2011-01-01

101

Quantitative three dimensional nonlinear inverse scattering and reflection breast imaging: Initial clinical results.  

PubMed

Water bath breast scanners utilize either ray based or inverse scattering techniques for the quantitative images. The 3D inverse scattering approach we use requires a 3D forward and back-propagation problem to be solved, resulting in ~1.2 mm resolution images. The resulting speed of sound map is then used in a 3D inhomogeneous, eikonal equation based reflection algorithm to account for refraction effects, and yield a 3D co-registered speckle free 360 degree compounded B-scan like volume. There is no harmful ionizing radiation, no compression, and no required contrast agents for proper utilization of our device. The quantitative transmission ultrasound (QTUS) images are independent of operator skill. The patient lies prone on a full length table with the breast pendant in the water bath. The breast is gently immobilized with the use of a breast retention pad that magnetically "attaches" to a magnetic retention rod for imaging of the breast. Scan time for each breast is approximately 10 min. We will show full 3D quantitative images obtained from consented, anonymous patients from several academic collaborating institutions. We will compare our QTUS images with mammographic, MRI, and hand held US images, and correlate biopsy results where appropriate. PMID:25235046

Wiskin, James; Borup, David; Iuanow, Elaine; Klock, John; Lenox, Mark

2014-04-01

102

Co-regulatory expression quantitative trait loci mapping: method and application to endometrial cancer  

Microsoft Academic Search

BACKGROUND: Expression quantitative trait loci (eQTL) studies have helped identify the genetic determinants of gene expression. Understanding the potential interacting mechanisms underlying such findings, however, is challenging. METHODS: We describe a method to identify the trans-acting drivers of multiple gene co-expression, which reflects the action of regulatory molecules. This method-termed co-regulatory expression quantitative trait locus (creQTL) mapping-allows for evaluation of

Kenneth S Kompass; John S Witte

2011-01-01

103

Limitations of the ferrozine method for quantitative assay of mineral systems for ferrous and total iron  

NASA Astrophysics Data System (ADS)

The quantitative assay of clay minerals, soils, and sediments for Fe(II) and total Fe is fundamental to understanding biogeochemical cycles occurring therein. The commonly used ferrozine method was originally designed to assay extracted forms of Fe(II) from non-silicate aqueous systems. It is becoming, however, increasingly the method of choice to report the total reduced state of Fe in soils and sediments. Because Fe in soils and sediments commonly exists in the structural framework of silicates, extraction by HCl, as used in the ferrozine method, fails to dissolve all of the Fe. The phenanthroline (phen) method, on the other hand, was designed to assay silicate minerals for Fe(II) and total Fe and has been proven to be highly reliable. In the present study potential sources of error in the ferrozine method were evaluated by comparing its results to those obtained by the phen method. Both methods were used to analyze clay mineral and soil samples for Fe(II) and total Fe. Results revealed that the conventional ferrozine method under reports total Fe in samples containing Fe in silicates and gives erratic results for Fe(II). The sources of error in the ferrozine method are: (1) HCl fails to dissolve silicates and (2) if the analyte solution contains Fe 3+, the analysis for Fe 2+ will be photosensitive, and reported Fe(II) values will likely be greater than the actual amount in solution. Another difficulty with the ferrozine method is that it is tedious and much more labor intensive than the phen method. For these reasons, the phen method is preferred and recommended. Its procedure is simpler, takes less time, and avoids the errors found in the ferrozine method.

Anastácio, Alexandre S.; Harris, Brittany; Yoo, Hae-In; Fabris, José Domingos; Stucki, Joseph W.

2008-10-01

104

A SVM-based quantitative fMRI method for resting-state functional network detection.  

PubMed

Resting-state functional magnetic resonance imaging (fMRI) aims to measure baseline neuronal connectivity independent of specific functional tasks and to capture changes in the connectivity due to neurological diseases. Most existing network detection methods rely on a fixed threshold to identify functionally connected voxels under the resting state. Due to fMRI non-stationarity, the threshold cannot adapt to variation of data characteristics across sessions and subjects, and generates unreliable mapping results. In this study, a new method is presented for resting-state fMRI data analysis. Specifically, the resting-state network mapping is formulated as an outlier detection process that is implemented using one-class support vector machine (SVM). The results are refined by using a spatial-feature domain prototype selection method and two-class SVM reclassification. The final decision on each voxel is made by comparing its probabilities of functionally connected and unconnected instead of a threshold. Multiple features for resting-state analysis were extracted and examined using an SVM-based feature selection method, and the most representative features were identified. The proposed method was evaluated using synthetic and experimental fMRI data. A comparison study was also performed with independent component analysis (ICA) and correlation analysis. The experimental results show that the proposed method can provide comparable or better network detection performance than ICA and correlation analysis. The method is potentially applicable to various resting-state quantitative fMRI studies. PMID:24928301

Song, Xiaomu; Chen, Nan-kuei

2014-09-01

105

The need for quantitative methods in syntax and semantics research  

E-print Network

The prevalent method in syntax and semantics research involves obtaining a judgement of the acceptability of a sentence/meaning pair, typically by just the author of the paper, sometimes with feedback from colleagues. This ...

Gibson, Edward A.

106

A method and fortran program for quantitative sampling in paleontology  

USGS Publications Warehouse

The Unit Sampling Method is a binomial sampling method applicable to the study of fauna preserved in rocks too well cemented to be disaggregated. Preliminary estimates of the probability of detecting each group in a single sampling unit can be converted to estimates of the group's volumetric abundance by means of correction curves obtained by a computer simulation technique. This paper describes the technique and gives the FORTRAN program. ?? 1976.

Tipper, J.C.

1976-01-01

107

Quantitative method for in vitro matrigel invasiveness measurement through image analysis software.  

PubMed

The determination of cell invasion by matrigel assay is usually evaluated by counting cells able to pass through a porous membrane and attach themselves to the other side, or by an indirect quantification of eluted specific cell staining dye by means of optical density measurement. This paper describes a quantitative analytical imaging approach for determining the invasiveness of tumor cells using a simple method, based on images processing with the public domain software, ImageJ. Images obtained by direct capture are split into the red channel, and the generated image is used to measure the area that cells cover in the picture. To overcome the several disadvantages that classical cell invasion determinations present, we propose this method because it generates more accurate and sensitive determinations, and it could be a reasonable option for improving the quality of the results. The cost-effective alternative method proposed is based on this simple and robust software that is worldwide affordable. PMID:24990701

Gallo-Oller, Gabriel; Rey, Juan A; Dotor, Javier; Castresana, Javier S

2014-10-01

108

Comparison of Enterococcus quantitative polymerase chain reaction analysis results from fresh and marine waters on two real-time instruments.  

PubMed

The U.S. Environmental Protection Agency will be recommending a quantitative polymerase chain reaction (qPCR) method targeting Enterococcus spp. as an option for monitoring recreational beach water quality. A practical consideration for implementation of this and other qPCR methods is whether the results are comparable on different PCR instruments. In this study, quantitative estimates of Enterococcus densities from marine and freshwater samples were determined by the qPCR method from cycle threshold (Ct) measurements obtained on Applied Biosystems StepOnePlus and Cepheid SmartCycler instruments. Three variations of a comparative Ct model, differing in their sources of calibration data, were used in the estimations. Both traditional and Bayesian statistical modeling approaches were examined in the instrument comparisons. The traditional analysis of variance (ANOVA) approach indicated no significant differences (p>0.05) between mean density estimates from the instruments in two of the three model variations. The Bayesian approach indicated that the 95% Bayesian credible intervals of density estimates from the instruments overlapped in all models; however, the uncertainty of the estimates varied depending on the model. These results support the interchangeable use of the two instruments in the method and also illustrate the importance of defining the source of calibration data used in the comparative Ct model. PMID:22863982

Sivaganensan, Mano; Varma, Manju; Haugland, Richard A

2012-11-01

109

A quantitative evaluation of two methods for preserving hair samples  

USGS Publications Warehouse

Hair samples are an increasingly important DNA source for wildlife studies, yet optimal storage methods and DNA degradation rates have not been rigorously evaluated. We tested amplification success rates over a one-year storage period for DNA extracted from brown bear (Ursus arctos) hair samples preserved using silica desiccation and -20 ??C freezing. For three nuclear DNA microsatellites, success rates decreased significantly after a six-month time point, regardless of storage method. For a 1000 bp mitochondrial fragment, a similar decrease occurred after a two-week time point. Minimizing delays between collection and DNA extraction will maximize success rates for hair-based noninvasive genetic sampling projects.

Roon, D. A.; Waits, L. P.; Kendall, K. C.

2003-01-01

110

Methods for Acquisition of Quantitative Data from Confocal Images of Gene Expression in situ  

PubMed Central

In this review, we summarize original methods for the extraction of quantitative information from confocal images of gene-expression patterns. These methods include image segmentation, the extraction of quantitative numerical data on gene expression, and the removal of background signal and spatial registration. Finally, it is possible to construct a spatiotemporal atlas of gene expression from individual images recorded at each developmental stage. Initially all methods were developed to extract quantitative numerical information from confocal images of segmentation gene expression in Drosophila melanogaster. The application of these methods to Drosophila images makes it possible to reveal new mechanisms in the formation of segmentation gene expression domains, as well as to construct a quantitative atlas of segmentation gene expression. Most image processing procedures can be easily adapted to process a wide range of biological images. PMID:19343098

Surkova, S. Yu.; Myasnikova, E. M.; Kozlov, K. N.; Samsonova, A. A.; Reinitz, J.; Samsonova, M. G.

2009-01-01

111

A quantitative assessment of nuclear weapons proliferation risk utilizing probabilistic methods  

E-print Network

A comparative quantitative assessment is made of the nuclear weapons proliferation risk between various nuclear reactor/fuel cycle concepts using a probabilistic method. The work presented details quantified proliferation ...

Sentell, Dennis Shannon, 1971-

2002-01-01

112

Optogalvanic intracavity quantitative detector and method for its use  

DOEpatents

The disclosure relates to an optogalvanic intracavity detector and method for its use. Measurement is made of the amount of light absorbed by atoms, small molecules and ions in a laser cavity utilizing laser-produced changes in plasmas containing the same atoms, molecules, or ions. 6 figs.

Zalewski, E.F.; Keller, R.A.; Apel, C.T.

1983-09-06

113

Optogalvanic intracavity quantitative detector and method for its use  

DOEpatents

The disclosure relates to an optogalvanic intracavity detector and method for its use. Measurement is made of the amount of light absorbed by atoms, small molecules and ions in a laser cavity utilizing laser-produced changes in plasmas containing the same atoms, molecules, or ions.

Zalewski, Edward F. (Gaithersburg, MD); Keller, Richard A. (Los Alamos, NM); Apel, Charles T. (Los Alamos, NM)

1983-01-01

114

Optogalvanic intracavity quantitative detector and method for its use  

DOEpatents

The disclosure relates to an optogalvanic intracavity detector and method for its use. Measurement is made of the amount of light absorbed by atoms, small molecules and ions in a laser cavity utilizing laser-produced changes in plasmas containing the same atoms, molecules or ions.

Zalewski, E.F.; Keller, R.A.; Apel, C.T.

1981-02-25

115

Bioanalytical methods for quantitation of levamisole, a widespread cocaine adulterant.  

PubMed

Abstract Levamisole is an anthelminthic that was first used as a de-worming agent in humans and animals. It has also been used to treat inflammatory conditions as well as certain types of cancer. Levamisole was discontinued for human use in the early 21st century due to toxic side effects including agranulocytosis and vasculitis. Recently, levamisole was discovered as a cocaine adulterant after reports emerged of drug users with the above disorders. As the prevalence of cocaine usage has grown in the last 15 years, measurement of levamisole in human samples has become increasingly important. This review focuses on the various bioanalytical methods available for the determination of levamisole in human plasma and urine. Earlier methods employed gas chromatography coupled with nitrogen-selective thermionic specific detection and nitrogen-phosphorus detection, as well as high performance liquid chromatography coupled with ultraviolet detection. In addition, gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) have also been described. Currently, GC-MS appears to be the method of choice however recent developments in the area of LC-MS/MS make this technology an attractive alternative. The merits of both GC-MS and LC-MS/MS for the determination of levamisole are evaluated on the basis of sample preparation, chromatographic separation conditions, run time, and analytical performance. In addition, emerging methods in this area are also reviewed. PMID:23152411

Shea, Jennifer L

2013-01-01

116

QUANTITATIVE METHODS FOR CROSS-SPECIES MAPPING (CSM)  

EPA Science Inventory

Cross species extrapolation will be defined as prediction from one species to another without empirical verification. ross species mapping (CSM) is the same except empirical verification is performed. SM may be viewed as validation of methods for extrapolation. Algorithms for CSM...

117

Development of air and dust sampling methods for quantitative measurements of polybromated diphenyl ethers (PBDEs) in offices  

E-print Network

Development of air and dust sampling methods for quantitative measurements of polybromated diphenyl to PBDEs measurements in indoor air and dust (development of quantitative sampling methods and field of the development of quantitative sampling methods and their use during a field campaign in 24 offices. 2 MATERIALS/METHODS

Paris-Sud XI, Université de

118

Quantitative HPLC-UV method for the determination of firocoxib from horse and dog plasma  

Microsoft Academic Search

A sensitive reversed-phase HPLC-UV method was developed for the determination of firocoxib, a novel and highly selective COX-2 inhibitor, in plasma. A 1.0mL dog or horse plasma sample is mixed with water and passed through a hydrophobic–lipophilic copolymer solid-phase extraction column to isolate firocoxib. Quantitation is based on an external standard curve. The method has a validated limit of quantitation

Valerie Kvaternick; Thomas Malinski; Jill Wortmann; James Fischer

2007-01-01

119

Application of quantitative salt iodine analysis compared with the standard method.  

PubMed

Laboratory investigation of 50 iodated salt samples (from producers, households, markets etc) were studied at the Research Nuclear Medicine Building, Siriraj Hospital. Two methods for the determination of iodine in salt are herein described. The standard method as recommended by The Programme Against Micronutrient Malnutrition (PAMM) / The Micronutrient Initiative (MI)/ The International Council for Control of Iodine Deficiency Disorders (ICCIDD) was the iodometric titration method. The starch-KI salt iodine quantitative method was developed in our laboratory for validation purposes. This method is high in precision, accuracy, sensitivity as well as specificity. The coefficient of variation (%CV) for intra and inter assay was below 10. Iodine contents as low as 10 ppm, could be detected. The proposed starch-KI method offered some advantages: e.g. not complicated, easier to learn and easier to perform competently, could be applied for spot qualitative test and readily performed outside the laboratory. The results obtained by the starch-KI method correlated well with the standard method (y = 0.98x - 3.22, r = 0.99). PMID:11556468

Chongchirasiri, S; Pattanachak, S; Putrasreni, N; Suwanik, R; Pattanachak, H; Tojinda, N; Pleehachinda, R

2001-06-01

120

Relative Quantification of Costal Cordillera (Ecuador) Uplift : Preliminary Results from Quantitative Geomorphology  

NASA Astrophysics Data System (ADS)

The coastal cordillera of Ecuador (culminating point around 800 m) includes on its littoral margins uplifted marine terraces (maximum known 360 m). The coastal cordillera constitutes an important barrier of drainage and on nearly 600 km the drainage resulting from the Andes is diverted towards Río Guayas in the South and Río Esmeraldas in North. What is the uplifting mode of the coastal cordillera? For how long it has constituted a barrier of drainage? Does the coastal cordillera rising be linked with the littoral margin rising? Does the cordillera have raised in a homogeneous or segmented way? What is the geodynamic process of the uplift of the cordillera? Can this uplift be related with the subduction of the Carnegie ridge? The first objective of this work is to analyze the morphology of the coastal cordillera with helps of quantitative geomorphology using digital techniques such as DEM (realized with a resolution of 30 m by Marc Souris, IRD), to specify the evolution of the coastal cordillera uplift. This study was carried out starting combining analysis of morphology, maps derived from the slopes and anomalies of the drainage of the hydrographic network. In the second time, three methods were applied to DEM data using the ArcGIS software: 1) the digitalization and the interpolation of basal surface of the last marine formation of regional distribution (the Borbón formation on the geological map of Ecuador) to determine paleo-horizontal and to see its deformation; 2) the extraction of 109 profiles of rivers which allow us to calculate for each river the vertical, horizontal, and total deviation compared to the theoretical profile of the river and the associated SL index; 3) the measurement of the relief incision (depth + half width of the valley, on the whole 7500 measurements) according to the method of Bonnet et al. (1998). We adapted this method to be able to represent the state of incision in any point, correcting from the influence of the lithology and the influence of altitude. The analysis of the profiles of the rivers and incision combined with the morpho-structural analysis show that the coastal cordillera is segmented in blocks that have each one their own period of rising and their own rate of uplift. Six blocks are individualized. The results on the profiles of river show that the coastal area of the cordillera in as a whole in uplift. The results on the incisions show that the uplift is relatively more important in the northern part of the coastal cordillera. Two fault systems have guided the evolution of the coastal cordillera, the Jipijapa system and the Jama system that is prolonged in the East of Río Esmeraldas. The two systems seem to control the exhumation of the peninsula of Manta, whereas the system of Jama controls the rising of a North-west block. The coastal cordillera starts rising in its central part. The beginning of rising probably happens at the end of Pliocene. Rising continues then to the South-west and finally develops in the North and in the peninsula of Manta. The highest rates of relative uplift are seen in blocks of the North of the coastal cordillera that is not located in front of the Carnegie ridge.

Reyes, Pedro; Dauteuil, Olivier; Michaud, François

2010-05-01

121

Serum inorganic sulphate: quantitation by a new radiochemical method.  

PubMed

A new procedure for serum inorganic sulphate determination is described. The method is simple, accurate and highly reproducible. It is based on radioisotopic dilution of 35S-sulphate by protein-free, phosphate-free serum. The decrease in initial 35S-sulphate specific activity (corresponding to added serum sulphate) is determined in the supernatant after partial precipitation of sulphate by barium ion. Serum sulphate is computed thereafter from a standard curve. Recovery of added sulphate from dialysed or undialysed serum was 100%. The intra- and interassay coefficients of variation were 3.5% and 4.1%, respectively. The serum sulphate concentration measured by this method in 93 normal subjects was 400 +/- 90 mumol/l (mean +/- SD), which agreed with the values reported in the literature. Serum sulphate did not correlate with sex (p greater than 0.40, n = 93), but a significant correlation with age was observed (r = 0.25, p less than 0.02, n = 93). PMID:3546585

Soliman, H; Callebert, J; Tabuteau, F; Mutel, V; Dreux, C

1986-12-01

122

A Comparative Study on Tobacco Cessation Methods: A Quantitative Systematic Review  

PubMed Central

Background: During recent years, there have been many advances in different types of pharmacological and non-pharmacological tobacco control treatments. In this study, we aimed to identify the most effective smoking cessation methods used in quit based upon a review of the literature. Methods: We did a search of PubMed, limited to English publications from 2000 to 2012. Two trained reviewers independently assessed titles, abstracts and full texts of articles after a pilot inter-rater reliability assessment which was conducted by the author (GH). The total number of papers and their conclusions including recommendation of that method (positive) or not supporting (negative) was computed for each method. The number of negative papers was subtracted from the number of positive ones for each method. In cases of inconsistency between the two reviewers, these were adjudicated by author. Results: Of the 932 articles that were critically assessed, 780 studies supported quit smoking methods. In 90 studies, the methods were not supported or rejected and in 62 cases the methods were not supported. Nicotine replacement therapy (NRT), Champix and Zyban with 352, 117 and 71 studies respectively were the most supported methods and e-cigarettes and non-Nicotine medications with one case were the least supported methods. Finally, NRT with 39 and Champix and education with 36 scores were the most supported methods. Conclusions: Results of this review indicate that the scientific papers in the most recent decade recommend the use of NRT and Champix in combination with educational interventions. Additional research is needed to compare qualitative and quantitative studies for smoking cessation. PMID:25013685

Heydari, Gholamreza; Masjedi, Mohammadreza; Ahmady, Arezoo Ebn; Leischow, Scott J.; Lando, Harry A.; Shadmehr, Mohammad Behgam; Fadaizadeh, Lida

2014-01-01

123

Methods Used by Pre-Service Nigeria Certificate in Education Teachers in Solving Quantitative Problems in Chemistry  

ERIC Educational Resources Information Center

This paper reports part of the results of research on chemical problem solving behavior of pre-service teachers in Plateau and Northeastern states of Nigeria. Specifically, it examines and describes the methods used by 204 pre-service teachers in solving quantitative problems from four topics in chemistry. Namely, gas laws; electrolysis;…

Danjuma, Ibrahim Mohammed

2011-01-01

124

Spatial access priority mapping (SAPM) with fishers: a quantitative GIS method for participatory planning.  

PubMed

Spatial management tools, such as marine spatial planning and marine protected areas, are playing an increasingly important role in attempts to improve marine management and accommodate conflicting needs. Robust data are needed to inform decisions among different planning options, and early inclusion of stakeholder involvement is widely regarded as vital for success. One of the biggest stakeholder groups, and the most likely to be adversely impacted by spatial restrictions, is the fishing community. In order to take their priorities into account, planners need to understand spatial variation in their perceived value of the sea. Here a readily accessible, novel method for quantitatively mapping fishers' spatial access priorities is presented. Spatial access priority mapping, or SAPM, uses only basic functions of standard spreadsheet and GIS software. Unlike the use of remote-sensing data, SAPM actively engages fishers in participatory mapping, documenting rather than inferring their priorities. By so doing, SAPM also facilitates the gathering of other useful data, such as local ecological knowledge. The method was tested and validated in Northern Ireland, where over 100 fishers participated in a semi-structured questionnaire and mapping exercise. The response rate was excellent, 97%, demonstrating fishers' willingness to be involved. The resultant maps are easily accessible and instantly informative, providing a very clear visual indication of which areas are most important for the fishers. The maps also provide quantitative data, which can be used to analyse the relative impact of different management options on the fishing industry and can be incorporated into planning software, such as MARXAN, to ensure that conservation goals can be met at minimum negative impact to the industry. This research shows how spatial access priority mapping can facilitate the early engagement of fishers and the ready incorporation of their priorities into the decision-making process in a transparent, quantitative way. PMID:23874623

Yates, Katherine L; Schoeman, David S

2013-01-01

125

Mixing Qualitative and Quantitative Methods: Insights into Design and Analysis Issues  

ERIC Educational Resources Information Center

This article describes and discusses issues related to research design and data analysis in the mixing of qualitative and quantitative methods. It is increasingly desirable to use multiple methods in research, but questions arise as to how best to design and analyze the data generated by mixed methods projects. I offer a conceptualization for such…

Lieber, Eli

2009-01-01

126

The development of processing methods for a quantitative histological investigation of rat hearts  

E-print Network

and created a method to perform the quantitative histological investigation of the rat hearts in a way that is both timely and cost effective. We developed a processing method that preserves the orientation of the fiber and sheet angles. This method...

Jetton, Emily Hope

2004-11-15

127

Method for Quantitatively Evaluating the Lateralization of Linguistic Function Using Functional MR Imaging  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Various methods for evaluating the lateralization of lin- guistic function using functional MR imaging have been proposed. However, the optimal meth- od remains controversial. The purpose of this study was not only to establish a method for quantitatively evaluating the lateralization of linguistic function but also to evaluate its optimality. METHODS: Internal speech tasks were measured by

Shun-ichi Nagata; Koichi Uchimura; Wataru Hirakawa; Jun-ichi Kuratsu

2001-01-01

128

Combining qualitative and quantitative methods in research practice: purposes and advantages  

Microsoft Academic Search

Despite ongoing ‘paradigm wars’ between the methodological traditions of qualitative and quantitative research, ‘mixed methods’ represents nowadays a rapidly developing field of social science methodology. In such discussions it is often emphasized that the use of methods should be predominantly influenced by substantive research questions, and not only by methodological and epistemological considerations. As all methods have specific limitations as

Udo Kelle

2006-01-01

129

Assessment and application of quantitative schlieren methods: Calibrated color schlieren and background oriented schlieren  

Microsoft Academic Search

Two quantitative schlieren methods are assessed and compared: calibrated color schlieren (CCS) and background oriented schlieren (BOS). Both methods are capable of measuring the light deflection angle in two spatial directions, and hence the projected density gradient vector field. Spatial integration using the conjugate gradient method returns the projected density field. To assess the performance of CCS and BOS, density

G. E. Elsinga; B. W. van Oudheusden; F. Scarano; D. W. Watt

2004-01-01

130

Dynamic and quantitative method of analyzing service consistency evolution based on extended hierarchical finite state automata.  

PubMed

This paper is concerned with the dynamic evolution analysis and quantitative measurement of primary factors that cause service inconsistency in service-oriented distributed simulation applications (SODSA). Traditional methods are mostly qualitative and empirical, and they do not consider the dynamic disturbances among factors in service's evolution behaviors such as producing, publishing, calling, and maintenance. Moreover, SODSA are rapidly evolving in terms of large-scale, reusable, compositional, pervasive, and flexible features, which presents difficulties in the usage of traditional analysis methods. To resolve these problems, a novel dynamic evolution model extended hierarchical service-finite state automata (EHS-FSA) is constructed based on finite state automata (FSA), which formally depict overall changing processes of service consistency states. And also the service consistency evolution algorithms (SCEAs) based on EHS-FSA are developed to quantitatively assess these impact factors. Experimental results show that the bad reusability (17.93% on average) is the biggest influential factor, the noncomposition of atomic services (13.12%) is the second biggest one, and the service version's confusion (1.2%) is the smallest one. Compared with previous qualitative analysis, SCEAs present good effectiveness and feasibility. This research can guide the engineers of service consistency technologies toward obtaining a higher level of consistency in SODSA. PMID:24772033

Fan, Linjun; Tang, Jun; Ling, Yunxiang; Li, Benxian

2014-01-01

131

Dynamic and Quantitative Method of Analyzing Service Consistency Evolution Based on Extended Hierarchical Finite State Automata  

PubMed Central

This paper is concerned with the dynamic evolution analysis and quantitative measurement of primary factors that cause service inconsistency in service-oriented distributed simulation applications (SODSA). Traditional methods are mostly qualitative and empirical, and they do not consider the dynamic disturbances among factors in service's evolution behaviors such as producing, publishing, calling, and maintenance. Moreover, SODSA are rapidly evolving in terms of large-scale, reusable, compositional, pervasive, and flexible features, which presents difficulties in the usage of traditional analysis methods. To resolve these problems, a novel dynamic evolution model extended hierarchical service-finite state automata (EHS-FSA) is constructed based on finite state automata (FSA), which formally depict overall changing processes of service consistency states. And also the service consistency evolution algorithms (SCEAs) based on EHS-FSA are developed to quantitatively assess these impact factors. Experimental results show that the bad reusability (17.93% on average) is the biggest influential factor, the noncomposition of atomic services (13.12%) is the second biggest one, and the service version's confusion (1.2%) is the smallest one. Compared with previous qualitative analysis, SCEAs present good effectiveness and feasibility. This research can guide the engineers of service consistency technologies toward obtaining a higher level of consistency in SODSA. PMID:24772033

Fan, Linjun; Tang, Jun; Ling, Yunxiang; Li, Benxian

2014-01-01

132

An Improved Flow Cytometry Method For Precise Quantitation Of Natural-Killer Cell Activity  

NASA Technical Reports Server (NTRS)

The ability to assess NK cell cytotoxicity using flow cytometry has been previously described and can serve as a powerful tool to evaluate effector immune function in the clinical setting. Previous methods used membrane permeable dyes to identify target cells. The use of these dyes requires great care to achieve optimal staining and results in a broad spectral emission that can make multicolor cytometry difficult. Previous methods have also used negative staining (the elimination of target cells) to identify effector cells. This makes a precise quantitation of effector NK cells impossible due to the interfering presence of T and B lymphocytes, and the data highly subjective to the variable levels of NK cells normally found in human peripheral blood. In this study an improved version of the standard flow cytometry assay for NK activity is described that has several advantages of previous methods. Fluorescent antibody staining (CD45FITC) is used to positively identify target cells in place of membranepermeable dyes. Fluorescent antibody staining of target cells is less labor intensive and more easily reproducible than membrane dyes. NK cells (true effector lymphocytes) are also positively identified by fluorescent antibody staining (CD56PE) allowing a simultaneous absolute count assessment of both NK cells and target cells. Dead cells are identified by membrane disruption using the DNA intercalating dye PI. Using this method, an exact NK:target ratio may be determined for each assessment, including quantitation of NK target complexes. Backimmunoscatter gating may be used to track live vs. dead Target cells via scatter properties. If desired, NK activity may then be normalized to standardized ratios for clinical comparisons between patients, making the determination of PBMC counts or NK cell percentages prior to testing unnecessary. This method provides an exact cytometric determination of NK activity that highly reproducible and may be suitable for routine use in the clinical setting.

Crucian, Brian; Nehlsen-Cannarella, Sandra; Sams, Clarence

2006-01-01

133

Immunochemical methods for quantitation of vitamin B6. Technical report  

SciTech Connect

A procedure is described which proposes schemes for determining the total of all B6 vitamins in acid-hydrolyzed samples utilizing a radio-immunoassay (RIA) or an enzyme-immunoassay (EIA). Sample preparation is similar for both RIA and EIA. Two specific antibodies (antipyridoxine and antipyridoxamine) are employed to determine pyridoxamine, a portion of the sample is reduced with sodium borohydride. Pyridoxal is determined by difference between pyridoxine before and after reduction. The results indicate that two procedures have been developed which are selective for pyridoxamine (the fluorescent enzyme immunoassay and the spin immunoassay) and one assay which is equally sensitive to pyridoxine and pyridoxamine (the radio-immunoassay).

Brandon, D.L.; Corse, J.W.

1981-09-30

134

A simple recoverable titration method for quantitative characterization of amine-functionalized carbon nanotubes  

NASA Astrophysics Data System (ADS)

A simple recoverable titration method is described for quantitative characterization of amine functions attached to the carbon nanotubes (CNTs). This titration is a two-step method, originated from the alkaline nature of amine functions. The amount of amine functions on CNTs determinate by titration method showed a good quantitative agreement with those of thermogravimetric analysis. Interestingly, the titrated samples could be easily recovered to their original activities, with a simple base treatment. Based on simplicity and minimum spent time, this method is suggested for characterization of amine functionalities attached on carbon nanotubes as well as all graphitic nanostructures.

Moaseri, Ehsan; Baniadam, Majid; Maghrebi, Morteza; Karimi, Majid

2013-01-01

135

Nuclear medicine and imaging research (instrumentation and quantitative methods of evaluation). Progress report, January 15, 1992--January 14, 1993  

SciTech Connect

This document is the annual progress report for project entitled ``Instrumentation and Quantitative Methods of Evaluation.`` Progress is reported in separate sections individually abstracted and indexed for the database. Subject areas reported include theoretical studies of imaging systems and methods, hardware developments, quantitative methods of evaluation, and knowledge transfer: education in quantitative nuclear medicine imaging.

Beck, R.N.; Cooper, M.; Chen, C.T.

1992-07-01

136

A practical and sensitive method of quantitating lymphangiogenesis in vivo.  

PubMed

To address the inadequacy of current assays, we developed a directed in vivo lymphangiogenesis assay (DIVLA) by modifying an established directed in vivo angiogenesis assay. Silicon tubes (angioreactors) were implanted in the dorsal flanks of nude mice. Tubes contained either growth factor-reduced basement membrane extract (BME)-alone (negative control) or BME-containing vascular endothelial growth factor (VEGF)-D (positive control for lymphangiogenesis) or FGF-2/VEGF-A (positive control for angiogenesis) or a high VEGF-D-expressing breast cancer cell line MDA-MD-468LN (468-LN), or VEGF-D-silenced 468LN. Lymphangiogenesis was detected superficially with Evans Blue dye tracing and measured in the cellular contents of angioreactors by multiple approaches: lymphatic vessel endothelial hyaluronan receptor-1 (Lyve1) protein (immunofluorescence) and mRNA (qPCR) expression and a visual scoring of lymphatic vs blood capillaries with dual Lyve1 (or PROX-11 or Podoplanin)/Cd31 immunostaining in cryosections. Lymphangiogenesis was absent with BME, high with VEGF-D or VEGF-D-producing 468LN cells and low with VEGF-D-silenced 468LN. Angiogenesis was absent with BME, high with FGF-2/VEGF-A, moderate with 468LN or VEGF-D and low with VEGF-D-silenced 468LN. The method was reproduced in a syngeneic murine C3L5 tumor model in C3H/HeJ mice with dual Lyve1/Cd31 immunostaining. Thus, DIVLA presents a practical and sensitive assay of lymphangiogenesis, validated with multiple approaches and markers. It is highly suited to identifying pro- and anti-lymphangiogenic agents, as well as shared or distinct mechanisms regulating lymphangiogenesis vs angiogenesis, and is widely applicable to research in vascular/tumor biology. PMID:23711825

Majumder, Mousumi; Xin, Xiping; Lala, Peeyush K

2013-07-01

137

A quantitative method for photovoltaic encapsulation system optimization  

NASA Technical Reports Server (NTRS)

It is pointed out that the design of encapsulation systems for flat plate photovoltaic modules requires the fulfillment of conflicting design requirements. An investigation was conducted with the objective to find an approach which will make it possible to determine a system with optimum characteristics. The results of the thermal, optical, structural, and electrical isolation analyses performed in the investigation indicate the major factors in the design of terrestrial photovoltaic modules. For defect-free materials, minimum encapsulation thicknesses are determined primarily by structural considerations. Cell temperature is not strongly affected by encapsulant thickness or thermal conductivity. The emissivity of module surfaces exerts a significant influence on cell temperature. Encapsulants should be elastomeric, and ribs are required on substrate modules. Aluminum is unsuitable as a substrate material. Antireflection coating is required on cell surfaces.

Garcia, A., III; Minning, C. P.; Cuddihy, E. F.

1981-01-01

138

Effects of DNA extraction and purification methods on real-time quantitative PCR analysis of Roundup Ready soybean.  

PubMed

The quality of DNA affects the accuracy and repeatability of quantitative PCR results. Different DNA extraction and purification methods were compared for quantification of Roundup Ready (RR) soybean (event 40-3-2) by real-time PCR. DNA was extracted using cetylmethylammonium bromide (CTAB), DNeasy Plant Mini Kit, and Wizard Magnetic DNA purification system for food. CTAB-extracted DNA was also purified using the Zymo (DNA Clean & Concentrator 25 kit), Qtip 100 (Qiagen Genomic-Tip 100/G), and QIAEX II Gel Extraction Kit. The CTAB extraction method provided the largest amount of DNA, and the Zymo purification kit resulted in the highest percentage of DNA recovery. The Abs260/280 and Abs260/230 ratios were less than the expected values for some of the DNA extraction and purification methods used, indicating the presence of substances that could inhibit PCR reactions. Real-time quantitative PCR results were affected by the DNA extraction and purification methods used. Further purification or dilution of the CTAB DNA was required for successful quantification of RR soybean. Less variability of quantitative PCR results was observed among experiments and replications for DNA extracted and/or purified by CTAB, CTAB+Zymo, CTAB+Qtip 100, and DNeasy methods. Correct and repeatable results for real-time PCR quantification of RR soybean were achieved using CTAB DNA purified with Zymo and Qtip 100 methods. PMID:19714982

Demeke, Tigst; Ratnayaka, Indira; Phan, Anh

2009-01-01

139

MODIS Radiometric Calibration Program, Methods and Results  

NASA Technical Reports Server (NTRS)

As a key instrument for NASA s Earth Observing System (EOS), the Moderate Resolution Imaging Spectroradiometer (MODIS) has made significant contributions to the remote sensing community with its unprecedented amount of data products continuously generated from its observations and freely distributed to users worldwide. MODIS observations, covering spectral regions from visible (VIS) to long-wave infrared (LWIR), have enabled a broad range of research activities and applications for studies of the earth s interactive system of land, oceans, and atmosphere. In addition to extensive pre-launch measurements, developed to characterize sensor performance, MODIS carries a set of on-board calibrators (OBC) that can be used to track on-orbit changes of various sensor characteristics. Most importantly, dedicated and continuous calibration efforts have been made to maintain sensor data quality. This paper provides an overview of the MODIS calibration program, on-orbit calibration activities, methods, and performance. Key calibration results and lessons learned from the MODIS calibration effort are also presented in this paper.

Xiong, Xiaoxiong; Guenther, Bruce; Angal, Amit; Barnes, William; Salomonson, Vincent; Sun, Junqiang; Wenny, Brian

2012-01-01

140

Validation of PCR methods for quantitation of genetically modified plants in food.  

PubMed

For enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients, quantitative detection methods such as quantitative competitive (QC-PCR) and real-time PCR are applied by official food control laboratories. The experiences of 3 European food control laboratories in validating such methods were compared to describe realistic performance characteristics of quantitative PCR detection methods. The limit of quantitation (LOQ) of GMO-specific, real-time PCR was experimentally determined to reach 30-50 target molecules, which is close to theoretical prediction. Starting PCR with 200 ng genomic plant DNA, the LOQ depends primarily on the genome size of the target plant and ranges from 0.02% for rice to 0.7% for wheat. The precision of quantitative PCR detection methods, expressed as relative standard deviation (RSD), varied from 10 to 30%. Using Bt176 corn containing test samples and applying Bt176 specific QC-PCR, mean values deviated from true values by -7to 18%, with an average of 2+/-10%. Ruggedness of real-time PCR detection methods was assessed in an interlaboratory study analyzing commercial, homogeneous food samples. Roundup Ready soybean DNA contents were determined in the range of 0.3 to 36%, relative to soybean DNA, with RSDs of about 25%. Taking the precision of quantitative PCR detection methods into account, suitable sample plans and sample sizes for GMO analysis are suggested. Because quantitative GMO detection methods measure GMO contents of samples in relation to reference material (calibrants), high priority must be given to international agreements and standardization on certified reference materials. PMID:11767156

Hübner, P; Waiblinger, H U; Pietsch, K; Brodmann, P

2001-01-01

141

Mixing Methods for Full-Strength Results: Two Welfare Studies  

ERIC Educational Resources Information Center

This article discusses the practical application of mixed quantitative and qualitative designs. Mixed methods designs can be especially powerful in illuminating policy solutions and directions for social action, thus supporting the social justice goals of social work and other helping professions. However, the decision to combine methods must be…

Sosulski, Marya R.; Lawrence, Catherine

2008-01-01

142

Comparison study on qualitative and quantitative risk assessment methods for urban natural gas pipeline network.  

PubMed

In this paper, a qualitative and a quantitative risk assessment methods for urban natural gas pipeline network are proposed. The qualitative method is comprised of an index system, which includes a causation index, an inherent risk index, a consequence index and their corresponding weights. The quantitative method consists of a probability assessment, a consequences analysis and a risk evaluation. The outcome of the qualitative method is a qualitative risk value, and for quantitative method the outcomes are individual risk and social risk. In comparison with previous research, the qualitative method proposed in this paper is particularly suitable for urban natural gas pipeline network, and the quantitative method takes different consequences of accidents into consideration, such as toxic gas diffusion, jet flame, fire ball combustion and UVCE. Two sample urban natural gas pipeline networks are used to demonstrate these two methods. It is indicated that both of the two methods can be applied to practical application, and the choice of the methods depends on the actual basic data of the gas pipelines and the precision requirements of risk assessment. PMID:21402442

Han, Z Y; Weng, W G

2011-05-15

143

Improved gas chromatographic–mass spectrometric method for the quantitative determination of vinpocetine in human plasma  

Microsoft Academic Search

An improved and validated method for the determination of vinpocetine in human plasma using a combination of a solid-phase extraction as a cleaning step followed by gas chromatography–mass spectrometry (GC–MS) has been presented. Quantitation has been carried out with apovincaminic acid methyl ester as internal standard. A limit of detection of 0.01 ng\\/ml, limit of quantitation of 0.10 ng\\/ml, as

M Vatsova; S Tzvetanov; A Drenska; J Goranscheva; N Tyutyulkova

1997-01-01

144

Novel competitive PCR methods for quantitation of T-cell receptor delta (TCRD) gene rearrangements.  

PubMed

Since the invention of the polymerase chain reaction (PCR) several quantitative PCR-based approaches have been described. Recently, the real-time PCR method became a standard in quantitative PCR, although high costs of the necessary equipment and reagents make it unaffordable for many laboratories. In this paper we describe two novel competitive PCR techniques, which were used to determine the frequency of T-cell receptor delta gene (TCRD) rearrangements in peripheral blood leukocytes. In the reference gene competitive PCR (rgc-PCR) the rearranged TCRD gene competes with the reference gene (RAG1) for common reagents (dNTPs and Taq polymerase). The intensity ratio of amplification products, TCRD/RAG1, corresponds to the portion of cells containing a rearrangement. A series of reactions was performed, in which RAG1 primers were added to the PCR after different numbers of cycles. On the basis of the number of cycles needed to obtain equal band intensity, the frequency of cells containing a rearrangement was calculated. In the common primer competitive PCR (cpc-PCR), two gene rearrangements, Vdelta1-Jdelta1 and Vdelta2-Jdelta1, compete for the common Jdelta1 primer. The competing genes are amplified from the same genomic DNA template; therefore unlike in the method using the internal competitor, the results are not affected by the quantity or quality of the analysed sample. We showed that the rgc-PCR and cpc-PCR are reliable and give reproducible results. The methods do not require any expensive equipment or reagents, and can be used to determine the frequency of gene rearrangements. PMID:12080179

Masternak, Micha? M; Przybylski, Grzegorz K; Smoczkiewicz, Pawe?; P?otek, W?odzimierz; Kowalczyk, Dariusz W; Nowak, Jerzy S

2002-01-01

145

Different methods for reproducing time, different results  

PubMed Central

One of the most widely used tasks for investigating psychological time, time reproduction, requires from participants the reproduction of the duration of a previously presented stimulus. Although prior studies have investigated the effects of different cognitive processes on time reproduction performance, no studies have looked into the effects of different reproduction methods on these performances. In the present study, participants were randomly assigned to one of three reproduction methods, which included (a) just pressing at the end of the interval, (b) pressing to start and stop the interval, and (c) maintaining continuous pressing during the interval. The study revealed that the three reproduction methods were not equivalent, with the method involving keypresses to start and stop the reproduction showing the highest accuracy, and the method of continuous press generating less variability. PMID:24470257

Stablum, Franca; McClintock, Shawn M.; Grondin, Simon

2014-01-01

146

Critical appraisal of quantitative PCR results in colorectal cancer research: can we rely on published qPCR results?  

PubMed

The use of real-time quantitative polymerase chain reaction (qPCR) in cancer research has become ubiquitous. The relative simplicity of qPCR experiments, which deliver fast and cost-effective results, means that each year an increasing number of papers utilizing this technique are being published. But how reliable are the published results? Since the validity of gene expression data is greatly dependent on appropriate normalisation to compensate for sample-to-sample and run-to-run variation, we have evaluated the adequacy of normalisation procedures in qPCR-based experiments. Consequently, we assessed all colorectal cancer publications that made use of qPCR from 2006 until August 2013 for the number of reference genes used and whether they had been validated. Using even these minimal evaluation criteria, the validity of only three percent (6/179) of the publications can be adequately assessed. We describe common errors, and conclude that the current state of reporting on qPCR in colorectal cancer research is disquieting. Extrapolated to the study of cancer in general, it is clear that the majority of studies using qPCR cannot be reliably assessed and that at best, the results of these studies may or may not be valid and at worst, pervasive incorrect normalisation is resulting in the wholesale publication of incorrect conclusions. This survey demonstrates that the existence of guidelines, such as MIQE, is necessary but not sufficient to address this problem and suggests that the scientific community should examine its responsibility and be aware of the implications of these findings for current and future research. PMID:24423493

Dijkstra, J R; van Kempen, L C; Nagtegaal, I D; Bustin, S A

2014-06-01

147

[Comparison of methods estimating a quantitative parameter: evaluation of the agreement].  

PubMed

Many quantitative clinical, biological and radiological parameters are useful in medicine for guiding diagnosis and therapy. The nephrologists use such parameters on a daily basis, particularly to assess renal function. In order to use the measurement methods of these parameters in clinical practice, it is mandatory to establish the agreement of the values provided, comparatively to the value obtained by using the reference measurement method of this parameter. This review details the methodology for the validation of methods for estimating quantitative parameters. PMID:23415929

Rognant, Nicolas; Bacchetta, Justine; Juillard, Laurent

2013-04-01

148

Background estimation methods for quantitative x-ray fluorescence analysis of gold nanoparticles in biomedical applications  

NASA Astrophysics Data System (ADS)

Accurate background estimation to isolate the fluorescence signals is an important issue for quantitative X-ray fluorescence (XRF) analysis of gold nanoparticles (GNPs). Though a good estimation can be obtained experimentally through acquiring the background spectrum of water solution, it inevitably leads to unnecessary second exposure in reality. Thus, several numerical methods such as trapezoidal shape estimation, interpolation by polynomial fitting and SNIP (Statistics sensitive Nonlinear Iterative Peak-Clipping) algorithm are proposed to achieve this goal. This paper aims to evaluate the estimation results calculated by these numerical methods through comparing with that acquired using the experimental way, in term of mean squared error (MSE). Four GNP/water solutions with various concentrations from 0.0% to 1.0% by weight are prepared. Then, ten spectra are acquired for each solution for further analysis, under the identical condition of using pencil beam x-ray and single spectrometer. Finally, the experimental and numerical methods are performed on these spectra within the optimally determined energy window and their statistical characteristics are analyzed and compared. These numerical background estimation methods as well as the evaluation methods can be easily extended to analyze the fluorescence signals of other nanoparticle biomarkers such as gadolinium, platinum and Barium in multiple biomedical applications.

Ren, Liqiang; Wu, Di; Li, Yuhua; Chen, Wei R.; Liu, Hong

2014-02-01

149

Result Demonstration: A Method That Works  

E-print Network

: A Method That Works Chris Boleman, Assistant Professor and Extension Specialist and Darrell A. Dromgoole, District Extension Administrator The Texas A&M University System O ne of the most effective educational tools for transferring research...: A Method That Works Chris Boleman, Assistant Professor and Extension Specialist and Darrell A. Dromgoole, District Extension Administrator The Texas A&M University System O ne of the most effective educational tools for transferring research...

Boleman, Chris; Dromgoole, Darrell A.

2007-05-24

150

A Simple Method for the Quantitative Determination of N-Acetyl-p-Aminophenol (APAP) in Urine  

Microsoft Academic Search

A simple method is describedfor the rapid quantitative analysisof N-acetyl-p-amino- phenol (APAP) in urine. APAP and its conjugates present in the urine following the ingestion of acetophenetidin, APAP or acetanilid, are hydrolyzed with acid to p. aminophenol. This compoundis coupledwith phenolin the presenceof hypobromiteto form an indophenol dye whose concentration is determined spectrophotometrically. Application of this method to a study

Richard M. Welch; A. H. Conney

151

A distillation method for the quantitative determination of malonaldehyde in rancid foods  

Microsoft Academic Search

Summary  An improved distillation method is described for the quantitative determination of malonaldehyde in foods containing oxidized\\u000a fats. The procedure is compared with other methods in current use for the determination of malonaldehyde. A high correlation\\u000a of TBA numbers with rancid odor in cooked meats was established.

Basil G. Tarladgis; Betty M. Watts; Margaret T. Younathan; Leroy Dugan

1960-01-01

152

A quantitative schlieren method for the investigation of axisymmetrical shock waves  

Microsoft Academic Search

Schlieren methods are well established to visualize acoustical, thermodynamic, and other phenomena, which influence the refractive index distribution in transparent media. We propose a quantitative schlieren method for the investigation of an ultrasonic field distribution generated by an electromagnetic (EM) shock wave source. In our schlieren system we have used a shiftable slit with variable width for sampling the angular

Andrzej Cwik; Helmut Ermert

1993-01-01

153

A method for the quantitative determination of crystalline phases by X-ray  

NASA Technical Reports Server (NTRS)

A mineral analysis method is described for rapid quantitative determination of crystalline substances in those cases in which the sample is present in pure form or in a mixture of known composition. With this method there is no need for prior chemical analysis.

Petzenhauser, I.; Jaeger, P.

1988-01-01

154

Integrating Qualitative Methods in a Predominantly Quantitative Evaluation: A Case Study and Some Reflections.  

ERIC Educational Resources Information Center

A review of qualitative methods used in a predominantly quantitative evaluation indicates a variety of roles for such a mixing of methods, including framing and revising research questions, assessing the validity of measures and adaptations to program implementation, and gauging the degree of uncertainty and generalizability of conclusions.…

Mark, Melvin M.; Feller, Irwin; Button, Scott B.

1997-01-01

155

Combining qualitative and quantitative research within mixed method research designs: A methodological review  

Microsoft Academic Search

ObjectivesIt has been argued that mixed methods research can be useful in nursing and health science because of the complexity of the phenomena studied. However, the integration of qualitative and quantitative approaches continues to be one of much debate and there is a need for a rigorous framework for designing and interpreting mixed methods research. This paper explores the analytical

Ulrika Östlund; Lisa Kidd; Yvonne Wengström; Neneh Rowa-Dewar

2011-01-01

156

A simple quantitative method to determine short chain fatty acid levels in biological fluids.  

PubMed

A simple method has been developed for quantitative acetic, propionic, isobutyric, butyric, isovaleric, valeric, isocaproic, and caproic acids in intestinal fluids, feces and blood. The method utilizes extraction with ether and gas chromatography. It is accurate over a wide range of SCFA concentrations and appears to be applicable to any biological fluid. PMID:975584

Whitehead, J S; Kim, Y S; Prizont, R

1976-11-01

157

Genetic variation in flowering time induces phenological assortative mating: quantitative genetic methods applied to Brassica rapa  

Microsoft Academic Search

It has been argued from first principles that plants mate assortatively by flowering time. However, there have been very few studies of phenological assortative mating, perhaps because current methods to infer paternal phenotype are difficult to apply to natural populations. Two methods are presented to estimate the phenotypic correlation between mates—the quantitative genetic metric for assortative mating—for phenological traits. The

ARTHUR E. WEIS; TANYA M. KOSSLER

2004-01-01

158

American Historical Archeology: Methods and Results  

Microsoft Academic Search

For historical archeology to be effective, research methods must be employed that ensure that both archeological and historical data be synthesized in a constructive manner. An example from Flowerdew Hundred, a Virginia plantation, illustrates such an approach. Collections from eighteen sites (1619 to 1720) were studied and dated by the inside bore diameters of pipestem fragments from clay smoking pipes.

James Deetz

1988-01-01

159

Quantitative analysis of collagen change between normal and cancerous thyroid tissues based on SHG method  

NASA Astrophysics Data System (ADS)

Second-harmonic generation (SHG) is proved to be a high spatial resolution, large penetration depth and non-photobleaching method. In our study, SHG method was used to investigate the normal and cancerous thyroid tissue. For SHG imaging performance, system parameters were adjusted for high-contrast images acquisition. Each x-y image was recorded in pseudo-color, which matches the wavelength range in the visible spectrum. The acquisition time for a 512×512-pixels image was 1.57 sec; each acquired image was averaged four frames to improve the signal-to-noise ratio. Our results indicated that collagen presence as determined by counting the ratio of the SHG pixels over the whole pixels for normal and cancerous thyroid tissues were 0.48+/-0.05, 0.33+/-0.06 respectively. In addition, to quantitatively assess collagen-related changes, we employed GLCM texture analysis to the SHG images. Corresponding results showed that the correlation both fell off with distance in normal and cancerous group. Calculated value of Corr50 (the distance where the correlation crossed 50% of the initial correlation) indicated significant difference. This study demonstrates that SHG method can be used as a complementary tool in thyroid histopathology.

Chen, Xiwen; Huang, Zufang; Xi, Gangqin; Chen, Yongjian; Lin, Duo; Wang, Jing; Li, Zuanfang; Sun, Liqing; Chen, Jianxin; Chen, Rong

2011-11-01

160

Quantitative analysis of collagen change between normal and cancerous thyroid tissues based on SHG method  

NASA Astrophysics Data System (ADS)

Second-harmonic generation (SHG) is proved to be a high spatial resolution, large penetration depth and non-photobleaching method. In our study, SHG method was used to investigate the normal and cancerous thyroid tissue. For SHG imaging performance, system parameters were adjusted for high-contrast images acquisition. Each x-y image was recorded in pseudo-color, which matches the wavelength range in the visible spectrum. The acquisition time for a 512×512-pixels image was 1.57 sec; each acquired image was averaged four frames to improve the signal-to-noise ratio. Our results indicated that collagen presence as determined by counting the ratio of the SHG pixels over the whole pixels for normal and cancerous thyroid tissues were 0.48+/-0.05, 0.33+/-0.06 respectively. In addition, to quantitatively assess collagen-related changes, we employed GLCM texture analysis to the SHG images. Corresponding results showed that the correlation both fell off with distance in normal and cancerous group. Calculated value of Corr50 (the distance where the correlation crossed 50% of the initial correlation) indicated significant difference. This study demonstrates that SHG method can be used as a complementary tool in thyroid histopathology.

Chen, Xiwen; Huang, Zufang; Xi, Gangqin; Chen, Yongjian; Lin, Duo; Wang, Jing; Li, Zuanfang; Sun, Liqing; Chen, Jianxin; Chen, Rong

2012-03-01

161

Comparative assessment of fluorescent transgene methods for quantitative imaging in human cells.  

PubMed

Fluorescence tagging of proteins is a widely used tool to study protein function and dynamics in live cells. However, the extent to which different mammalian transgene methods faithfully report on the properties of endogenous proteins has not been studied comparatively. Here we use quantitative live-cell imaging and single-molecule spectroscopy to analyze how different transgene systems affect imaging of the functional properties of the mitotic kinase Aurora B. We show that the transgene method fundamentally influences level and variability of expression and can severely compromise the ability to report on endogenous binding and localization parameters, providing a guide for quantitative imaging studies in mammalian cells. PMID:25232003

Mahen, Robert; Koch, Birgit; Wachsmuth, Malte; Politi, Antonio Z; Perez-Gonzalez, Alexis; Mergenthaler, Julia; Cai, Yin; Ellenberg, Jan

2014-11-01

162

Quantitative Estimation Method for Liver Fibrosis Based on Combination of Rayleigh Distributions  

NASA Astrophysics Data System (ADS)

Since the clinical diagnosis based on ultrasonic B-mode images is dependent on the skill of the doctor, the realization of a quantitative diagnostic method using ultrasound echo signals is highly required. We have been investigating the quantitative diagnostic technique mainly on hepatic diseases. In this paper, we present a new analysis method using echo signals for the quantitative estimation of liver fibrosis. To quantitatively determine the stage of liver fibrosis, we propose a model in which the probability density function of echo amplitude is expressed as a combination of two Rayleigh distributions. These two Rayleigh distributions correspond to the echo components from the normal and diseased tissues. In addition, using this amplitude distribution model of echo amplitude, we present the estimation method to obtain the amount of fibrous tissue and stage of fibrotic degeneration of the liver from moments about mean of the echo amplitude. Basic examination using clinical images suggest that the quantitative estimation of liver fibrosis based on a combination of Rayleigh distributions is valid.

Igarashi, Yu; Ezuka, Hiroshi; Yamaguchi, Tadashi; Hachiya, Hiroyuki

2010-07-01

163

Simple but novel test method for quantitatively comparing robot mapping algorithms using SLAM and dead reckoning  

NASA Astrophysics Data System (ADS)

This article presents a comparative study between a well-known SLAM (Simultaneous Localization and Mapping) algorithm, called Gmapping, and a standard Dead-Reckoning algorithm; the study is based on experimental results of both approaches by using a commercial skid-based turning robot, P3DX. Five main base-case scenarios are conducted to evaluate and test the effectiveness of both algorithms. The results show that SLAM outperformed the Dead Reckoning in terms of map-making accuracy in all scenarios but one, since SLAM did not work well in a rapidly changing environment. Although the main conclusion about the excellence of SLAM is not surprising, the presented test method is valuable to professionals working in this area of mobile robots, as it is highly practical, and provides solid and valuable results. The novelty of this study lies in its simplicity. The simple but novel test method for quantitatively comparing robot mapping algorithms using SLAM and Dead Reckoning and some applications using autonomous robots are being patented by the authors in U.S. Patent Application Nos. 13/400,726 and 13/584,862.

Davey, Neil S.; Godil, Haris

2013-05-01

164

A quantitative study of motion estimation methods on 4D cardiac gated SPECT reconstruction  

PubMed Central

Purpose: Motion-compensated temporal processing can have a major impact on improving the image quality in gated cardiac single photon emission computed tomography (SPECT). In this work, we investigate the effect of different optical flow estimation methods for motion-compensated temporal processing in gated SPECT. In particular, we explore whether better motion estimation can substantially improve reconstructed image quality, and how the estimated motion would compare to the ideal case of known motion in terms of reconstruction. Methods: We consider the following three methods for obtaining the image motion in 4D reconstruction: (1) the Horn–Schunck optical flow equation (OFE) method, (2) a recently developed periodic OFE method, and (3) known cardiac motion derived from the NURBS-based cardiac-torso (NCAT) phantom. The periodic OFE method is used to exploit the inherent periodic nature in cardiac gated images. In this method, the optical flow in a sequence is modeled by a Fourier harmonic representation, which is then estimated from the image data. We study the impact of temporal processing on 4D reconstructions when the image motion is obtained with the different methods above. For quantitative evaluation, we use simulated imaging with multiple noise realizations from the NCAT phantom, where different patient geometry and lesion sizes are also considered. To quantify the reconstruction results, we use the following measures of reconstruction accuracy and defect detection in the myocardium: (1) overall error level in the myocardium, (2) regional accuracy of the left ventricle (LV) wall, (3) accuracy of regional time activity curves of the LV, and (4) perfusion defect detectability with a channelized Hotelling observer (CHO). In addition, we also examine the effect of noise on the distortion in the reconstructed LV wall shape by detecting its contours. As a preliminary demonstration, these methods are also tested on two sets of clinical acquisitions. Results: For the different quantitative measures considered, the periodic OFE further improved the reconstruction accuracy of the myocardium compared to OFE in 4D reconstruction; its improvement in reconstruction almost matched that of the known motion. Specifically, the overall mean-squared error in the myocardium was reduced by over 20% with periodic OFE; with noise level fixed at 10%, the regional bias on the LV was reduced from 20% (OFE) to 14% (periodic OFE), compared to 11% by the known motion. In addition, the CHO results show that there was also improvement in lesion detectability with the periodic OFE. The regional time activity curves obtained with the periodic OFE were also observed to be more consistent with the reference; in addition, the contours of the reconstructed LV wall with the periodic OFE were demonstrated to show less degree of variations among different noise realizations. Such improvements were also consistent with the results obtained from the clinical acquisitions. Conclusions: Use of improved optical flow estimation can further improve the accuracy of reconstructed images in 4D. The periodic OFE method not only can achieve improvements over the traditional OFE, but also can almost match that of the known motion in terms of the several quality measures considered. PMID:22894443

Qi, Wenyuan; Yang, Yongyi; Niu, Xiaofeng; King, Michael A.

2012-01-01

165

VENEREAL DISEASE CONTROL: METHODS, OBSTACLES AND RESULTS  

PubMed Central

This is really a report of progress. Co-operation of the Government with state health departments has produced such results that the backward step of discontinuance can never be taken. The problem of preventing venereal disease has become one of the principal phases of preventive medicine and physicians and health officers can not possibly longer remain indifferent. PMID:18010246

Pierce, C. C.

1920-01-01

166

Use of fundamental parameters method for quantitative analysis of spectra acquired on spectrometer with Kumakhov lens  

NASA Astrophysics Data System (ADS)

A method has been developed for reconstructing continuous x-ray spectrum based on processing spectrometry information obtained as a result of x-rays scattering on light targets. The reconstruction model takes into account coherent and Compton components of scattered radiation, detector resolution and efficacy. The suggested method is universal: it permits to reconstruct the actual shape of spectrum falling onto the x-ray sample. It should be noted that the initial shape of x-ray spectrum as emitted by the anode of x-ray tube is significantly distorted due to various filters, collimators, including x-ray lenses, scattering processes in the media between the anode and sample. A number of examples is given, where x-ray spectra were reconstructed for different configurations of spectrometry tracts. Thus reconstructed x-ray spectra are further used (as input) for quantitative XRF analysis of samples by the method of fundamental parameters (MFP). The developed calculation code implements the MFP version in the original Sherman interpretation6. As input, both the absolute values of intensities for the base lines of characteristic radiation (in case of 1 00% rating), and relative values of intensities rated by the value of the base lines of a "pure element" are used. The procedure of calculating intensities of the "pure element" base lines based on the analysis of samples with known chemical composition is given. Intensities of the base lines of characteristic radiation are determined through application of the deconvolution procedure by the least-squares method. As basic functions, the following is used: Gauss distributions for characteristic radiation lines and piecewise-linear approximation for the background. The efficiency and universal nature of the above comprehensive method is supported by the results of qualitative RFA obtained for a number of samples with known chemical composition using different types of spectrometers.

Afanasiev, I. B.; Danichev, V. V.; Ivanov, V. F.; Kondratenko, R. I.; Mikhin, V. A.

2005-07-01

167

Development of a quantitative diagnostic method of estrogen receptor expression levels by immunohistochemistry using organic fluorescent material-assembled nanoparticles.  

PubMed

The detection of estrogen receptors (ERs) by immunohistochemistry (IHC) using 3,3'-diaminobenzidine (DAB) is slightly weak as a prognostic marker, but it is essential to the application of endocrine therapy, such as antiestrogen tamoxifen-based therapy. IHC using DAB is a poor quantitative method because horseradish peroxidase (HRP) activity depends on reaction time, temperature and substrate concentration. However, IHC using fluorescent material provides an effective method to quantitatively use IHC because the signal intensity is proportional to the intensity of the photon excitation energy. However, the high level of autofluorescence has impeded the development of quantitative IHC using fluorescence. We developed organic fluorescent material (tetramethylrhodamine)-assembled nanoparticles for IHC. Tissue autofluorescence is comparable to the fluorescence intensity of quantum dots, which are the most representative fluorescent nanoparticles. The fluorescent intensity of our novel nanoparticles was 10.2-fold greater than quantum dots, and they did not bind non-specifically to breast cancer tissues due to the polyethylene glycol chain that coated their surfaces. Therefore, the fluorescent intensity of our nanoparticles significantly exceeded autofluorescence, which produced a significantly higher signal-to-noise ratio on IHC-imaged cancer tissues than previous methods. Moreover, immunostaining data from our nanoparticle fluorescent IHC and IHC with DAB were compared in the same region of adjacent tissues sections to quantitatively examine the two methods. The results demonstrated that our nanoparticle staining analyzed a wide range of ER expression levels with higher accuracy and quantitative sensitivity than DAB staining. This enhancement in the diagnostic accuracy and sensitivity for ERs using our immunostaining method will improve the prediction of responses to therapies that target ERs and progesterone receptors that are induced by a downstream ER signal. PMID:22959769

Gonda, Kohsuke; Miyashita, Minoru; Watanabe, Mika; Takahashi, Yayoi; Goda, Hideki; Okada, Hisatake; Nakano, Yasushi; Tada, Hiroshi; Amari, Masakazu; Ohuchi, Noriaki

2012-09-28

168

Quantitative evaluation of linear and nonlinear methods characterizing interdependencies between brain signals  

PubMed Central

Brain functional connectivity can be characterized by the temporal evolution of correlation between signals recorded from spatially-distributed regions. It is aimed at explaining how different brain areas interact within networks involved during normal (as in cognitive tasks) or pathological (as in epilepsy) situations. Numerous techniques were introduced for assessing this connectivity. Recently, some efforts were made to compare methods performances but mainly qualitatively and for a special application. In this paper, we go further and propose a comprehensive comparison of different classes of methods (linear and nonlinear regressions, phase synchronization (PS), and generalized synchronization (GS)) based on various simulation models. For this purpose, quantitative criteria are used: in addition to mean square error (MSE) under null hypothesis (independence between two signals) and mean variance (MV) computed over all values of coupling degree in each model, we introduce a new criterion for comparing performances. Results show that the performances of the compared methods are highly depending on the hypothesis regarding the underlying model for the generation of the signals. Moreover, none of them outperforms the others in all cases and the performance hierarchy is model-dependent. PMID:17025676

Ansari-Asl, Karim; Senhadji, Lotfi; Bellanger, Jean-Jacques; Wendling, Fabrice

2006-01-01

169

Comparing the soil quality changes of different land uses determined by two quantitative methods.  

PubMed

Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices. A study was initiated in Wolong Nature Reserve, Sichuan Province, China to elucidate the soil quality changes of natural secondary succession, forest planting and agricultural practices after deforestation in the humid mountainous region. The soil qualities of six land use types (natural forestland, grassland, shrub land, secondary forestland, cultivated land and reforested land) were compared using two quantitative methods: the integrated soil quality index (QI) and soil deterioration index (DI). The QI values of natural forestland, grassland, shrub land, secondary forestland, cultivated land, reforested land were 0.8039, 0.3277, 0.9127, 0.6881, 0.0285 and 0.3183, respectively. The DI values were 0%, -14%, 12%, 1%, -26% and -18% respectively. Both indexes suggested that shrub land can restore soil properties. To compare the two methods more directly, a deduced index QI' based on QI value was developed. The results showed that DI and QI' had a very high linear correlation coefficient (r = 0.9775) despite the values were different. Both methods were efficient in evaluating the soil quality levels and DI was a more simple way in soil quality assessment, while QI could show more ecological meanings. PMID:12765257

Fu, Bo-jie; Liu, Shi-liang; Lu, Yi-he; Chen, Li-ding; Ma, Ke-ming; Liu, Guo-hua

2003-03-01

170

Quantitative evaluation of besifloxacin ophthalmic suspension by HPLC, application to bioassay method and cytotoxicity studies.  

PubMed

Besifloxacin (BSF) is a synthetic chiral fluoroquinolone developed for the topical treatment of ophthalmic infections. The present study reports the development and validation of a microbiological assay, applying the cylinder-plate method, for determination of BSF in ophthalmic suspension. To assess this methodology, the development and validation of the method was performed for the quantification of BSF by high performance liquid chromatography (HPLC). The HPLC method showed specificity, linearity in the range of 20-80 µg mL(-1) (r=0.9998), precision, accuracy and robustness. The microbiological method is based on the inhibitory effect of BSF upon the strain of Staphylococcus epidermidis ATCC 12228 used as a test microorganism. The bioassay validation method yielded excellent results and included linearity, precision, accuracy, robustness and selectivity. The assay results were treated statistically by analysis of variance (ANOVA) and were found to be linear (r=0.9974) in the range of 0.5-2.0 µg mL(-1), precise (inter-assay: RSD=0.84), accurate (101.4%), specific and robust. The bioassay and the previously validated high performance liquid chromatographic (HPLC) method were compared using Student's t test, which indicated that there was no statistically significant difference between these two methods. These results confirm that the proposed microbiological method can be used as routine analysis for the quantitative determination of BSF in an ophthalmic suspension. A preliminary stability study during the HPLC validation was performed and demonstrated that BSF is unstable under UV conditions. The photodegradation kinetics of BSF in water showed a first-order reaction for the drug product (ophthalmic suspension) and a second-order reaction for the reference standard (RS) under UVA light. UVA degraded samples of BSF were also studied in order to determine the preliminary in vitro cytotoxicity against mononuclear cells. The results indicated that BSF does not alter the cell membrane and has been considered non-toxic to human mononuclear cells in the experimental conditions tested. PMID:24401427

Costa, Márcia C N; Barden, Amanda T; Andrade, Juliana M M; Oppe, Tércio P; Schapoval, Elfrides E S

2014-02-01

171

Effect of platform, reference material, and quantification model on enumeration of Enterococcus by quantitative PCR methods.  

PubMed

Quantitative polymerase chain reaction (qPCR) is increasingly being used for the quantitative detection of fecal indicator bacteria in beach water. QPCR allows for same-day health warnings, and its application is being considered as an option for recreational water quality testing in the United States (USEPA, 2011. EPA-OW-2011-0466, FRL-9609-3, Notice of Availability of Draft Recreational Water Quality Criteria and Request for Scientific Views). However, transition of qPCR from a research tool to routine water quality testing requires information on how various method variations affect target enumeration. Here we compared qPCR performance and enumeration of enterococci in spiked and environmental water samples using three qPCR platforms (Applied Biosystem StepOnePlus™, the BioRad iQ™5 and the Cepheid SmartCycler(®) II), two reference materials (lyophilized cells and frozen cells on filters) and two comparative CT quantification models (?CT and ??CT). Reference materials exerted the biggest influence, consistently affecting results by approximately 0.5 log(10) unit. Platform had the smallest effect, generally exerting <0.1 log(10) unit difference in final results. Quantification model led to small differences (0.04-0.2 log(10) unit) in this study with relatively uninhibited samples, but has the potential to cause as much as 8-fold (0.9 log(10) unit) difference in potentially inhibitory samples. Our findings indicate the need for a certified and centralized source of reference materials and additional studies to assess applicability of the quantification models in analyses of PCR inhibitory samples. PMID:23123048

Cao, Yiping; Sivaganesan, Mano; Kinzelman, Julie; Blackwood, A Denene; Noble, Rachel T; Haugland, Richard A; Griffith, John F; Weisberg, Stephen B

2013-01-01

172

A novel volumetric method for quantitation of titanium dioxide in cosmetics.  

PubMed

Nowadays there are many sun-protection cosmetics incorporating organic or inorganic UV filters as active ingredients. Chemically stable inorganic sunscreen agents, usually metal oxides, are widely employed in high-SPF (sun protection factor) products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as a pigment for a long period of cosmetic history. With the development of micronization techniques, it has become possible to incorporate titanium dioxide in sunscreen formulations without the previous whitening effect, and hence its use in cosmetics has become an important research topic. However, there are very few works related to quantitation of titanium dioxide in sunscreen products. In this research, we analyzed the amounts of titanium dioxide in sunscreen cosmetics by adapting redox titration, reduction of Ti(IV) to Ti(III), and reoxidation to Ti(IV). After calcification of other organic ingredients of cosmetics, titanium dioxide is dissolved by hot sulfuric acid. The dissolved Ti(IV) is reduced to Ti(III) by adding metallic aluminum. The reduced Ti(III) is titrated against a standard oxidizing agent, Fe(III) (ammonium iron(III) sulfate), with potassium thiocyanate as an indicator. In order to test the accuracy and applicability of the proposed method, we analyzed the amounts of titanium dioxide in four types of sunscreen cosmetics, namely cream, make-up base, foundation, and powder, after adding known amounts of titanium dioxide (1 approximately 25 w/w%). The percentages of titanium dioxide recovered in the four types of formulations were in the range between 96% and 105%. We also analyzed seven commercial cosmetic products labeled with titanium dioxide as an ingredient and compared the results with those obtained from ICP-AES (inductively coupled plasma-atomic emission spectrometry), one of the most powerful atomic analysis techniques. The results showed that the titrated amounts were well in accord with the analyzed amounts of titanium dioxide by ICP-AES. Although instrument-based analytical methods, namely ICP-MS (inductively coupled plasma-mass spectrometry) and ICP-AES, are best for the analysis of titanium, it is difficult for small cosmetic companies to install such instruments because of their high cost. It was found that the volumetric method presented here gives quantitatively accurate and reliable results with routine lab-ware and chemicals. PMID:17111072

Kim, Young So; Kim, Boo-Min; Park, Sang-Chul; Jeong, Hye-Jin; Chang, Ih Seop

2006-01-01

173

Macromol. Chem. Phys. 2001, 202, 6172 61 A Method for the Quantitation of Charge by Size  

E-print Network

Macromol. Chem. Phys. 2001, 202, 61­72 61 A Method for the Quantitation of Charge by Size Exclusion by the hydrodynamic effects of the solute, i.e. the viscosity radius (Rg). However, many researchers have also used and charge, taking advantage of the influence of ionic strength on elution. We subse- quently applied

Dubin, Paul D.

174

Overcoming Methods Anxiety: Qualitative First, Quantitative Next, Frequent Feedback along the Way  

ERIC Educational Resources Information Center

Political Science research methods courses face two problems. First is what to cover, as there are too many techniques to explore in any one course. Second is dealing with student anxiety around quantitative material. We explore a novel way to approach these issues. Our students began by writing a qualitative paper. They followed with a term…

Bernstein, Jeffrey L.; Allen, Brooke Thomas

2013-01-01

175

Method for the quantitative determination of adlumine in Corydalis sempervirens and as the isolated substance  

Microsoft Academic Search

A chromato-spectrometric method has been developed for the quantitative determination of the biologically active alkaloid adlumine of pale corydalis which permits the determination of adlumine in the plant material with an accuracy of ±3.62% and of the isolated substance with an accuracy of ±0.79%.

B. A. Krivut; N. A. Fedyunina; N. N. Margvelashvili; L. M. Molodozhnikova

1984-01-01

176

Media and Communication Research Methods: An Introduction to Qualitative and Quantitative Approaches.  

ERIC Educational Resources Information Center

Examining both qualitative and quantitative approaches, this introductory text addresses media and communication research methods. Written for beginning research students at both the undergraduate and graduate levels, the book is clear, concise, and accompanied by many detailed examples. Attention-grabbing dialogue begins each chapter and gives…

Berger, Arthur Asa

177

Examining Stress in Graduate Assistants: Combining Qualitative and Quantitative Survey Methods  

ERIC Educational Resources Information Center

The aim of this study was to employ qualitative and quantitative survey methods in a concurrent mixed model design to assess stressors and strains in graduate assistants. The stressors most frequently reported qualitatively were work overload, interpersonal conflict, and organizational constraints; the most frequently reported psychological…

Mazzola, Joseph J.; Walker, Erin J.; Shockley, Kristen M.; Spector, Paul E.

2011-01-01

178

Novel competitive PCR methods for quantitation of T-cell receptor delta (TCRD) gene rearrangements  

Microsoft Academic Search

Since the invention of the polymerase chain reaction (PCR) several quantita- tive PCR-based approaches have been described. Recently, the real-time PCR method became a standard in quantitative PCR, although high costs of the necessary equipment and reagents make it unaffordable for many laboratories. In this paper we describe two novel competitive PCR techniques, which were used to determine the frequency

Grzegorz K. PRZYBYLSKI; Dariusz W. KOWALCZYK; Jerzy S. NOWAK

2002-01-01

179

Qualitative and quantitative research methods: old wine in new bottles? On understanding and interpreting educational phenomena  

Microsoft Academic Search

Generally educational research is grounded in the empirical traditions of the social sciences (commonly called quantitative and qualitative methods) and is as such distinguished from other forms of scholarship such as theoretical, conceptual or methodological essays, critiques of research traditions and practices and those studies grounded in the humanities (e.g. history, philosophy, literary analysis, arts?based inquiry). Since the early twentieth

Paul Smeyers

2008-01-01

180

IMPROVED QUANTITATIVE METHODS FOR MULTIPLE NEUROPHARMACOLOGICAL NON-INVASIVE BRAIN PET STUDIES  

E-print Network

i IMPROVED QUANTITATIVE METHODS FOR MULTIPLE NEUROPHARMACOLOGICAL NON-INVASIVE BRAIN PET STUDIES.2.2 Multiple Neuropharmacological Measures from a single PET scan ................. 4 1.2.2.1 Dual ...................................................................................... 5 1.2.3 Reduction of inter-scanner PET image variability

Fessler, Jeffrey A.

181

Reconciling incongruous qualitative and quantitative findings in mixed methods research: exemplars from research with drug using populations  

PubMed Central

Mixed methods research is increasingly being promoted in the health sciences as a way to gain more comprehensive understandings of how social processes and individual behaviours shape human health. Mixed methods research most commonly combines qualitative and quantitative data collection and analysis strategies. Often, integrating findings from multiple methods is assumed to confirm or validate the findings from one method with the findings from another, seeking convergence or agreement between methods. Cases in which findings from different methods are congruous are generally thought of as ideal, while conflicting findings may, at first glance, appear problematic. However, the latter situation provides the opportunity for a process through which apparently discordant results are reconciled, potentially leading to new emergent understandings of complex social phenomena. This paper presents three case studies drawn from the authors’ research on HIV risk among injection drug users in which mixed methods studies yielded apparently discrepant results. We use these case studies (involving injection drug users [IDUs] using a needle/syringe exchange program in Los Angeles, California, USA; IDUs seeking to purchase needle/syringes at pharmacies in Tijuana, Mexico; and young street-based IDUs in San Francisco, CA, USA) to identify challenges associated with integrating findings from mixed methods projects, summarize lessons learned, and make recommendations for how to more successfully anticipate and manage the integration of findings. Despite the challenges inherent in reconciling apparently conflicting findings from qualitative and quantitative approaches, in keeping with others who have argued in favour of integrating mixed methods findings, we contend that such an undertaking has the potential to yield benefits that emerge only through the struggle to reconcile discrepant results and may provide a sum that is greater than the individual qualitative and quantitative parts. PMID:21680168

Wagner, Karla D.; Davidson, Peter J.; Pollini, Robin A.; Strathdee, Steffanie A.; Washburn, Rachel; Palinkas, Lawrence A.

2011-01-01

182

Quantitative methods for analysing cumulative effects on fish migration success: a review.  

PubMed

It is often recognized, but seldom addressed, that a quantitative assessment of the cumulative effects, both additive and non-additive, of multiple stressors on fish survival would provide a more realistic representation of the factors that influence fish migration. This review presents a compilation of analytical methods applied to a well-studied fish migration, a more general review of quantitative multivariable methods, and a synthesis on how to apply new analytical techniques in fish migration studies. A compilation of adult migration papers from Fraser River sockeye salmon Oncorhynchus nerka revealed a limited number of multivariable methods being applied and the sub-optimal reliance on univariable methods for multivariable problems. The literature review of fisheries science, general biology and medicine identified a large number of alternative methods for dealing with cumulative effects, with a limited number of techniques being used in fish migration studies. An evaluation of the different methods revealed that certain classes of multivariable analyses will probably prove useful in future assessments of cumulative effects on fish migration. This overview and evaluation of quantitative methods gathered from the disparate fields should serve as a primer for anyone seeking to quantify cumulative effects on fish migration survival. PMID:22803726

Johnson, J E; Patterson, D A; Martins, E G; Cooke, S J; Hinch, S G

2012-07-01

183

[Research on rapid and quantitative detection method for organophosphorus pesticide residue].  

PubMed

The methods of physical-chemical inspection is adopted in the traditional pesticide residue detection, which require a lot of pretreatment processes, are time-consuming and complicated. In the present study, the authors take chlorpyrifos applied widely in the present agricultural field as the research object and propose a rapid and quantitative detection method for organophosphorus pesticide residues. At first, according to the chemical characteristics of chlorpyrifos and comprehensive chromogenic effect of several colorimetric reagents and secondary pollution, the pretreatment of the scheme of chromogenic reaction of chlorpyrifos with resorcin in a weak alkaline environment was determined. Secondly, by analyzing Uv-Vis spectrum data of chlorpyrifos samples whose content were between 0. 5 and 400 mg kg-1, it was confirmed that the characteristic information after the color reaction mainly was concentrated among 360 approximately 400 nm. Thirdly, the full spectrum forecasting model was established based on the partial least squares, whose correlation coefficient of calibration was 0. 999 6, correlation coefficient of prediction reached 0. 995 6, standard deviation of calibration (RMSEC) was 2. 814 7 mg kg-1, and standard deviation of verification (RMSEP) was 8. 012 4 mg kg-1. Fourthly, the wavelengths whose center wavelength is 400 nm was extracted as characteristic region to build a forecasting model, whose correlation coefficient of calibration was 0. 999 6, correlation coefficient of prediction reached 0. 999 3, standard deviation of calibration (RMSEC) was 2. 566 7 mg kg-1 , standard deviation of verification (RMSEP) was 4. 886 6 mg kg-1, respectively. At last, by analyzing the near infrared spectrum data of chlorpyrifos samples with contents between 0. 5 and 16 mg kg-1, the authors found that although the characteristics of the chromogenic functional group are not obvious, the change of absorption peaks of resorcin itself in the neighborhood of 5 200 cm-' happens. The above-mentioned experimental results show that the proposed method is effective and feasible for rapid and quantitative detection prediction for organophosphorus pesticide residues. In the method, the information in full spectrum especially UV-Vis spectrum is strengthened by chromogenic reaction of a colorimetric reagent, which provides a new way of rapid detection of pesticide residues for agricultural products in the future. PMID:25095434

Sun, Yuan-Xin; Chen, Bing-Tai; Yi, Sen; Sun, Ming

2014-05-01

184

Accuracy, Precision, and Method Detection Limits of Quantitative PCR for Airborne Bacteria and Fungi ?  

PubMed Central

Real-time quantitative PCR (qPCR) for rapid and specific enumeration of microbial agents is finding increased use in aerosol science. The goal of this study was to determine qPCR accuracy, precision, and method detection limits (MDLs) within the context of indoor and ambient aerosol samples. Escherichia coli and Bacillus atrophaeus vegetative bacterial cells and Aspergillus fumigatus fungal spores loaded onto aerosol filters were considered. Efficiencies associated with recovery of DNA from aerosol filters were low, and excluding these efficiencies in quantitative analysis led to underestimating the true aerosol concentration by 10 to 24 times. Precision near detection limits ranged from a 28% to 79% coefficient of variation (COV) for the three test organisms, and the majority of this variation was due to instrument repeatability. Depending on the organism and sampling filter material, precision results suggest that qPCR is useful for determining dissimilarity between two samples only if the true differences are greater than 1.3 to 3.2 times (95% confidence level at n = 7 replicates). For MDLs, qPCR was able to produce a positive response with 99% confidence from the DNA of five B. atrophaeus cells and less than one A. fumigatus spore. Overall MDL values that included sample processing efficiencies ranged from 2,000 to 3,000 B. atrophaeus cells per filter and 10 to 25 A. fumigatus spores per filter. Applying the concepts of accuracy, precision, and MDL to qPCR aerosol measurements demonstrates that sample processing efficiencies must be accounted for in order to accurately estimate bioaerosol exposure, provides guidance on the necessary statistical rigor required to understand significant differences among separate aerosol samples, and prevents undetected (i.e., nonquantifiable) values for true aerosol concentrations that may be significant. PMID:20817798

Hospodsky, Denina; Yamamoto, Naomichi; Peccia, Jordan

2010-01-01

185

Development of a quantitative method to measure vision in children with chronic cortical visual impairment.  

PubMed Central

PURPOSE: Cortical visual impairment (CVI) is the most common cause of bilateral vision impairment in children in Western countries. Better quantitative tools for measuring vision are needed to assess these children, to allow measurement of their visual deficit, and to monitor their response to treatment and rehabilitation. The author performed a series of experiments to assess the use of the sweep visual evoked potential (VEP) as a quantitative tool for measuring vision in CVI. METHODS: The first experiment was a reliability measure (test/retest) of VEP grating acuity thresholds of 23 children with CVI. To validate the VEP procedure, VEP grating acuity was compared to a clinical measure of vision, the Huo scale, and to a psychophysical measure of vision, the Teller Acuity Card procedure. Finally, the sweep VEP was tested as a tool for defining optimal luminance conditions for grating acuity in 13 children with CVI, by measuring grating thresholds under 2 different luminance conditions: 50 and 100 candela per square meter (cd/m2). RESULTS: Retest thresholds were similar to original thresholds (r2 = 0.662; P = .003, 1-tailed t test). Grating VEP measures correlate significantly with the clinical index (r2 = 0.63; P = .00004). Teller acuity measurements are also similar to VEP measures in children (r2 = 0.64; P = .0005) but show lower acuities compared to the VEP for children with particularly low vision. Finally, 3 of 13 children tested under 2 background luminance conditions showed paradoxical improvement in grating threshold with dimmer luminance. CONCLUSIONS: The sweep VEP tool is a reliable and valid means for measuring grating acuity in children with CVI. The tool also shows promise as a means of determining the optimal visual environment for children with CVI. PMID:11797314

Good, W V

2001-01-01

186

Accuracy, precision, and method detection limits of quantitative PCR for airborne bacteria and fungi.  

PubMed

Real-time quantitative PCR (qPCR) for rapid and specific enumeration of microbial agents is finding increased use in aerosol science. The goal of this study was to determine qPCR accuracy, precision, and method detection limits (MDLs) within the context of indoor and ambient aerosol samples. Escherichia coli and Bacillus atrophaeus vegetative bacterial cells and Aspergillus fumigatus fungal spores loaded onto aerosol filters were considered. Efficiencies associated with recovery of DNA from aerosol filters were low, and excluding these efficiencies in quantitative analysis led to underestimating the true aerosol concentration by 10 to 24 times. Precision near detection limits ranged from a 28% to 79% coefficient of variation (COV) for the three test organisms, and the majority of this variation was due to instrument repeatability. Depending on the organism and sampling filter material, precision results suggest that qPCR is useful for determining dissimilarity between two samples only if the true differences are greater than 1.3 to 3.2 times (95% confidence level at n = 7 replicates). For MDLs, qPCR was able to produce a positive response with 99% confidence from the DNA of five B. atrophaeus cells and less than one A. fumigatus spore. Overall MDL values that included sample processing efficiencies ranged from 2,000 to 3,000 B. atrophaeus cells per filter and 10 to 25 A. fumigatus spores per filter. Applying the concepts of accuracy, precision, and MDL to qPCR aerosol measurements demonstrates that sample processing efficiencies must be accounted for in order to accurately estimate bioaerosol exposure, provides guidance on the necessary statistical rigor required to understand significant differences among separate aerosol samples, and prevents undetected (i.e., nonquantifiable) values for true aerosol concentrations that may be significant. PMID:20817798

Hospodsky, Denina; Yamamoto, Naomichi; Peccia, Jordan

2010-11-01

187

Quantitative planar thallium-201 stress scintigraphy: A critical evaluation of the method  

SciTech Connect

The results of quantitative analysis of planar thallium-/sup 201/ stress scintigraphy are superior to those of visual analysis. The increased sensitivity for detection of coronary artery disease is associated with maintenance of specificity. Consequently, the authors believe that quantitative analysis is the state-of-the-art for planar /sup 201/Tl stress scintigraphy. They emphasize that for reliable and reproducible results, rigorous quality control and strict adherence to a standardized imaging protocol are necessary. An important feature is clarity of display of computer data. In this experience, the most important feature for making quantitative analysis reliable and accessible for a broader user market is simultaneous display of the lower limits of normal with processed patient data. This provides a simple visual impression of the degree and extent of abnormal /sup 201/Tl distribution and kinetics relative to the lower limit of normal.

Wackers, F.J.; Fetterman, R.C.; Mattera, J.A.; Clements, J.P.

1985-01-01

188

Quantitative evaluation of registration methods for atlas-based diffuse optical tomography  

NASA Astrophysics Data System (ADS)

In Diffuse Optical Tomography (DOT), an atlas-based model can be used as an alternative to a subject-specific anatomical model for recovery of brain activity. The main step of the generation of atlas-based subject model is the registration of atlas model to the subject head. The accuracy of the DOT then relies on the accuracy of registration method. In this work, 11 registration methods are quantitatively evaluated. The registration method with EEG 10/20 systems with 19 landmarks and non-iterative point to point algorithm provides approximately 1.4 mm surface error and is considered as the most efficient registration method.

Wu, Xue; Eggebrecht, Adam T.; Culver, Joseph P.; Zhan, Yuxuan; Basevi, Hector; Dehghani, Hamid

2013-06-01

189

A Quantitative Method for Assessment of Prescribing Patterns Using Electronic Health Records  

PubMed Central

Background Most available quality indicators for hospitals are represented by simple ratios or proportions, and are limited to specific events. A generalized method that can be applied to diverse clinical events has not been developed. The aim of this study was to develop a simple method of evaluating physicians' prescription patterns for diverse events and their level of awareness of clinical practice guidelines. Methods and Findings We developed a quantitative method called Prescription pattern Around Clinical Event (PACE), which is applicable to electronic health records (EHRs). Three discrete prescription patterns (intervention, maintenance, and discontinuation) were determined based on the prescription change index (PCI), which was calculated by means of the increase or decrease in the prescription rate after a clinical event. Hyperkalemia and Clostridium difficile-associated diarrhea (CDAD) were used as example cases. We calculated the PCIs of 10 drugs related to hyperkalemia, categorized them into prescription patterns, and then compared the resulting prescription patterns with the known standards for hyperkalemia treatment. The hyperkalemia knowledge of physicians was estimated using a questionnaire and compared to the prescription pattern. Prescriptions for CDAD were also determined and compared to clinical knowledge. Clinical data of 1698, 348, and 1288 patients were collected from EHR data. The physicians prescribing behaviors for hyperkalemia and CDAD were concordant with the standard knowledge. Prescription patterns were well correlated with individual physicians' knowledge of hyperkalemia (??=?0.714). Prescribing behaviors according to event severity or clinical condition were plotted as a simple summary graph. Conclusion The algorithm successfully assessed the prescribing patterns from the EHR data. The prescription patterns were well correlated with physicians' knowledge. We expect that this algorithm will enable quantification of prescribers' adherence to clinical guidelines and be used to facilitate improved prescribing practices. PMID:24130689

Schuemie, Martijn J.; Park, Man Young; Kim, Ju Han; Park, Rae Woong

2013-01-01

190

Method Development and Validation of a Stability-Indicating RP-HPLC Method for the Quantitative Analysis of Dronedarone Hydrochloride in Pharmaceutical Tablets.  

PubMed

A simple, precise, and accurate HPLC method has been developed and validated for the quantitative analysis of Dronedarone Hydrochloride in tablet form. An isocratic separation was achieved using a Waters Symmetry C8 (100 × 4.6 mm), 5 ?m particle size column with a flow rate of 1 ml/min and UV detector at 290 nm. The mobile phase consisted of buffer: methanol (40:60 v/v) (buffer: 50 mM KH2PO4 + 1 ml triethylamine in 1 liter water, pH=2.5 adjusted with ortho-phosphoric acid). The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The specificity of the method was determined by assessing interference from the placebo and by stress testing the drug (forced degradation). The method was linear over the concentration range 20-80 ?g/ml (r(2) = 0.999) with a Limit of Detection (LOD) and Limit of Quantitation (LOQ) of 0.1 and 0.3 ?g/ml respectively. The accuracy of the method was between 99.2-100.5%. The method was found to be robust and suitable for the quantitative analysis of Dronedarone Hydrochloride in a tablet formulation. Degradation products resulting from the stress studies did not interfere with the detection of Dronedarone Hydrochloride so the assay is thus stability-indicating. PMID:23641332

Dabhi, Batuk; Jadeja, Yashwantsinh; Patel, Madhavi; Jebaliya, Hetal; Karia, Denish; Shah, Anamik

2013-03-01

191

Method Development and Validation of a Stability-Indicating RP-HPLC Method for the Quantitative Analysis of Dronedarone Hydrochloride in Pharmaceutical Tablets  

PubMed Central

A simple, precise, and accurate HPLC method has been developed and validated for the quantitative analysis of Dronedarone Hydrochloride in tablet form. An isocratic separation was achieved using a Waters Symmetry C8 (100 × 4.6 mm), 5 ?m particle size column with a flow rate of 1 ml/min and UV detector at 290 nm. The mobile phase consisted of buffer: methanol (40:60 v/v) (buffer: 50 mM KH2PO4 + 1 ml triethylamine in 1 liter water, pH=2.5 adjusted with ortho-phosphoric acid). The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The specificity of the method was determined by assessing interference from the placebo and by stress testing the drug (forced degradation). The method was linear over the concentration range 20–80 ?g/ml (r2 = 0.999) with a Limit of Detection (LOD) and Limit of Quantitation (LOQ) of 0.1 and 0.3 ?g/ml respectively. The accuracy of the method was between 99.2–100.5%. The method was found to be robust and suitable for the quantitative analysis of Dronedarone Hydrochloride in a tablet formulation. Degradation products resulting from the stress studies did not interfere with the detection of Dronedarone Hydrochloride so the assay is thus stability-indicating. PMID:23641332

Dabhi, Batuk; Jadeja, Yashwantsinh; Patel, Madhavi; Jebaliya, Hetal; Karia, Denish; Shah, Anamik

2013-01-01

192

Qualitative and quantitative event-specific PCR detection methods for oxy-235 canola based on the 3' integration flanking sequence.  

PubMed

As more genetically modified plant events are approved for commercialization worldwide, the event-specific PCR method has become the key method for genetically modified organism (GMO) identification and quantification. This study reveals the 3' flanking sequence of the exogenous integration of Oxy-235 canola employing thermal asymmetric interlaced PCR (TAIL-PCR). On the basis of the revealed 3' flanking sequence, PCR primers and TaqMan probe were designed and qualitative and quantitative PCR assays were established for Oxy-235 canola. The specificity and limits of detection (LOD) and quantification (LOQ) of these two PCR assays were validated to as low as 0.1% for the relative LOD of qualitative PCR assay; the absolute LOD and LOQ were low to 10 and 20 copies of canola genomic DNA in quantitative PCR assay, respectively. Furthermore, ideal quantified results were obtained in the practical canola sample detection. All of the results indicate that the developed qualitative and quantitative PCR methods based on the revealed 3' integration flanking sequence are suitable for GM canola Oxy-235 identification and quantification. PMID:18298073

Yang, Litao; Guo, Jinchao; Zhang, Haibo; Liu, Jia; Zhang, Dabing

2008-03-26

193

Improved Methodical Approach for Quantitative BRET Analysis of G Protein Coupled Receptor Dimerization  

PubMed Central

G Protein Coupled Receptors (GPCR) can form dimers or higher ordered oligomers, the process of which can remarkably influence the physiological and pharmacological function of these receptors. Quantitative Bioluminescence Resonance Energy Transfer (qBRET) measurements are the gold standards to prove the direct physical interaction between the protomers of presumed GPCR dimers. For the correct interpretation of these experiments, the expression of the energy donor Renilla luciferase labeled receptor has to be maintained constant, which is hard to achieve in expression systems. To analyze the effects of non-constant donor expression on qBRET curves, we performed Monte Carlo simulations. Our results show that the decrease of donor expression can lead to saturation qBRET curves even if the interaction between donor and acceptor labeled receptors is non-specific leading to false interpretation of the dimerization state. We suggest here a new approach to the analysis of qBRET data, when the BRET ratio is plotted as a function of the acceptor labeled receptor expression at various donor receptor expression levels. With this method, we were able to distinguish between dimerization and non-specific interaction when the results of classical qBRET experiments were ambiguous. The simulation results were confirmed experimentally using rapamycin inducible heterodimerization system. We used this new method to investigate the dimerization of various GPCRs, and our data have confirmed the homodimerization of V2 vasopressin and CaSR calcium sensing receptors, whereas our data argue against the heterodimerization of these receptors with other studied GPCRs, including type I and II angiotensin, ?2 adrenergic and CB1 cannabinoid receptors. PMID:25329164

Szalai, Bence; Hoffmann, Peter; Prokop, Susanne; Erdelyi, Laszlo; Varnai, Peter; Hunyady, Laszlo

2014-01-01

194

Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples  

DOEpatents

Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for .sup.239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

Caldwell, John T. (Los Alamos, NM); Kunz, Walter E. (Santa Fe, NM); Cates, Michael R. (Oak Ridge, TN); Franks, Larry A. (Santa Barbara, CA)

1985-01-01

195

Evaluation of the 3D visualization of quantitative stereoelectroencephalographic information. New results.  

E-print Network

or interpretation procedures), however only a few studies have been dedicated to the evaluation of the visualization of the values. Our study is devoted to the evaluation of the quantitative visualization of these signals in a particular medical application, the clinical epilepsy studies. In this medical field, 3D representations

Paris-Sud XI, Université de

196

Quantitative evaluation of periprosthetic infection by real-time polymerase chain reaction: a comparison with conventional methods.  

PubMed

Several recent studies have demonstrated the limited accuracy of conventional culture methods for diagnosing periprosthetic infections. We have applied real-time polymerase chain reaction (PCR) assays for the rapid identification of bacteria around implants and reported its utility. However, the capability of quantification is also a useful feature of this type of assay. The aim of our study was to validate the usefulness of quantitative analyses using real-time PCR of cases with clinical periprosthetic infections in comparison with more established tests, such as C-reactive protein (CRP) levels, microbiologic cultures, and histopathology. Fifty-six joints with suspected infections were reviewed retrospectively. A universal PCR assay was used to perform the quantitative analyses. The differences in the threshold cycles between clinical samples and a negative control (?Ct) in each case were calculated. The results of the quantitative PCR assay were compared with CRP levels, microbiologic cultures, and histopathology. There was a significant correlation found between the CRP and ?Ct values. There were also significant differences found in the ?Ct values according to CRP levels, with higher CRP levels showing higher ?Ct values. Similarly, there were significant differences in the ?Ct measurements in our culture results and among our pathologic evaluations. We confirmed that quantification by universal PCR based on the ?Ct correlated with preoperative CRP levels and was associated with the microbiologic culture results and pathologic severity. This quantification method may be valuable for assessing infection severity. PMID:22832168

Miyamae, Yushi; Inaba, Yutaka; Kobayashi, Naomi; Choe, Hyonmin; Ike, Hiroyuki; Momose, Takako; Fujiwara, Shusuke; Saito, Tomoyuki

2012-10-01

197

A method for operative quantitative interpretation of multispectral images of biological tissues  

NASA Astrophysics Data System (ADS)

A method for operative retrieval of spatial distributions of biophysical parameters of a biological tissue by using a multispectral image of it has been developed. The method is based on multiple regressions between linearly independent components of the diffuse reflection spectrum of the tissue and unknown parameters. Possibilities of the method are illustrated by an example of determining biophysical parameters of the skin (concentrations of melanin, hemoglobin and bilirubin, blood oxygenation, and scattering coefficient of the tissue). Examples of quantitative interpretation of the experimental data are presented.

Lisenko, S. A.; Kugeiko, M. M.

2013-10-01

198

Task 4.4 - development of supercritical fluid extraction methods for the quantitation of sulfur forms in coal  

SciTech Connect

Development of advanced fuel forms depends on having reliable quantitative methods for their analysis. Determination of the true chemical forms of sulfur in coal is necessary to develop more effective methods to reduce sulfur content. Past work at the Energy & Environmental Research Center (EERC) indicates that sulfur chemistry has broad implications in combustion, gasification, pyrolysis, liquefaction, and coal-cleaning processes. Current analytical methods are inadequate for accurately measuring sulfur forms in coal. This task was concerned with developing methods to quantitate and identify major sulfur forms in coal based on direct measurement (as opposed to present techniques based on indirect measurement and difference values). The focus was on the forms that were least understood and for which the analytical methods have been the poorest, i.e., organic and elemental sulfur. Improved measurement techniques for sulfatic and pyritic sulfur also need to be developed. A secondary goal was to understand the interconversion of sulfur forms in coal during thermal processing. EERC has developed the first reliable analytical method for extracting and quantitating elemental sulfur from coal (1). This method has demonstrated that elemental sulfur can account for very little or as much as one-third of the so-called organic sulfur fraction. This method has disproved the generally accepted idea that elemental sulfur is associated with the organic fraction. A paper reporting the results obtained on this subject entitled {open_quote}Determination of Elemental Sulfur in Coal by Supercritical Fluid Extraction and Gas Chromatography with Atomic Emission Detection{close_quote} was published in Fuel (A).

Timpe, R.C.

1995-04-01

199

Localization and quantitation of chloroplast enzymes and light-harvesting components using immunocytochemical methods  

SciTech Connect

Seven chloroplast proteins were localized in Porphyridium cruentum (ATCC 50161) by immunolabeling with colloidal gold on electron microscope sections of log phase cells grown under red, green, and white light. Ribulose bisphosphate carboxylase labeling occurred almost exclusively in the pyrenoid. The major apoproteins of photosystem I (56-64 kD) occurred mostly over the stromal thylakoid region and also appeared over the thylakoids passing through the pyrenoid. Labeling for photosystem II core components (D2 and a 45 kD Chl-binding protein), for phycobilisomes (allophycocyanin, and a 91 kD L{sub CM} linker) and for ATP synthase ({beta} subunit) were predominantly present in the thylakoid region but not in the pyrenoid region of the chloroplast. Red light cells had increased labeling per thylakoid length for polypeptides of photosystem II and of phycobilisomes, while photosystem I density decreased, compared to white light cells. Conversely, green light cells had a decreased density of photosystem II and phycobilisome polypeptides, while photosystem I density changed little compared with white light cells. A comparison of the immunogold labeling results with data from spectroscopic methods and from rocket immunoelectrophoresis indicates that it can provide a quantitative measure of the relative amounts of protein components as well as their localization in specific organeller compartments.

Mustardy, L.; Cunningham, F.X Jr.; Gantt, E. (Univ. of Maryland, College Park (USA))

1990-09-01

200

Quantitative method for measuring heat flux emitted from a cryogenic object  

Microsoft Academic Search

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until

Robert V

1993-01-01

201

Mathematical Model and Quantitative Research Method on the Variability of Task Execution-time  

Microsoft Academic Search

The task execution-time is unpredictability on the modern complex digital signal processing platform. This paper proposed the mathematical model and the quantitative research method on the variability of task execution-time. On the modern complex digital signal processing platform, the task execution-time probability density can be approximated as normal distribution. This paper proposed the reliability of execution-time as an indicator to

Liu Ming; Yan Chao

2012-01-01

202

Quantitative magnetic resonance imaging of the knee: a method of measuring response to intra-articular treatments  

PubMed Central

OBJECTIVES—To investigate the potential of quantitative magnetic resonance imaging (MRI) to differentiate between therapeutically induced changes in inflammation and synovial proliferation in rheumatoid arthritis (RA) of the knee.?METHODS—MRI of the knee was performed on patients with RA before and one week after injection with corticosteroid (triamcinolone acetonide, TA group, n=9) and before, four, and 12 weeks after injection with yttrium-90 plus TA (TA+Y group, n=7). MRI scans were analysed by subjective visual grading by a trained observer and by computer aided quantitation for three features: synovial fluid volume, synovial pannus volume, and synovial enhancement after intravenous contrast agent.?RESULTS—All TA subjects improved clinically at one week but the effects of TA+Y were more variable. TA significantly reduced synovial enhancement and effusion volume, whereas TA+Y at 12 weeks tended to increase synovial enhancement and decrease pannus volume. Quantitative MRI values agreed well with subjective assessment of scans. Comparison of calculated change on MRI scan before and immediately after aspiration with actual volume aspirated showed high correlation (r=0.96).?CONCLUSIONS—Quantitative MRI correlates with subjective visual assessment and, at least for synovial fluid, is accurate. MRI can differentiate actions of two therapeutic modalities on various pathological processes and is sensitive enough to detect change after one week. With the additional advantage of lack of observer bias, it will probably become a useful tool in the development and assessment of existing and novel treatments.?? PMID:9227168

Creamer, P; Keen, M; Zananiri, F; Waterton, J; Maciewicz, R; Oliver, C; Dieppe, P; Watt, I

1997-01-01

203

A method of quantitative risk assessment for transmission pipeline carrying natural gas.  

PubMed

Regulatory authorities in many countries are moving away from prescriptive approaches for keeping natural gas pipelines safe. As an alternative, risk management based on a quantitative assessment is being considered to improve the level of safety. This paper focuses on the development of a simplified method for the quantitative risk assessment for natural gas pipelines and introduces parameters of fatal length and cumulative fatal length. The fatal length is defined as the integrated fatality along the pipeline associated with hypothetical accidents. The cumulative fatal length is defined as the section of pipeline in which an accident leads to N or more fatalities. These parameters can be estimated easily by using the information of pipeline geometry and population density of a Geographic Information Systems (GIS). To demonstrate the proposed method, individual and societal risks for a sample pipeline have been estimated from the historical data of European Gas Pipeline Incident Data Group and BG Transco. With currently acceptable criteria taken into account for individual risk, the minimum proximity of the pipeline to occupied buildings is approximately proportional to the square root of the operating pressure of the pipeline. The proposed method of quantitative risk assessment may be useful for risk management during the planning and building stages of a new pipeline, and modification of a buried pipeline. PMID:15913887

Jo, Young-Do; Ahn, Bum Jong

2005-08-31

204

Quantitative HPLC-UV method for the determination of firocoxib from horse and dog plasma.  

PubMed

A sensitive reversed-phase HPLC-UV method was developed for the determination of firocoxib, a novel and highly selective COX-2 inhibitor, in plasma. A 1.0 mL dog or horse plasma sample is mixed with water and passed through a hydrophobic-lipophilic copolymer solid-phase extraction column to isolate firocoxib. Quantitation is based on an external standard curve. The method has a validated limit of quantitation of 25 ng/mL and a limit of detection of 10 ng/mL. The validated upper limit of quantitation was 2500 ng/mL for horses and 10,000 ng/mL for dogs. The average recoveries ranged from 88-93% for horse plasma and 96-103% for dog plasma. The coefficient of variation in all cases was less than 10%. This method is suitable for the analysis of clinical samples from pharmacokinetic and bioequivalence studies and drug monitoring. PMID:17537684

Kvaternick, Valerie; Malinski, Thomas; Wortmann, Jill; Fischer, James

2007-07-01

205

CTSI Quantitative Methods Pilot Program The Design, Biostatistics and Epidemiology (DBE) Core, the Pilot Core, and the Novel  

E-print Network

1 CTSI Quantitative Methods Pilot Program The Design, Biostatistics and Epidemiology (DBE) Core, a quantitative methods researcher is an investigator with a background in statistics, biostatistics, epidemiology the career development of junior investigators in the fields of statistics, biostatistics, and epidemiology

Sibille, Etienne

206

Using quantitative and qualitative data in health services research – what happens when mixed method findings conflict? [ISRCTN61522618  

Microsoft Academic Search

BACKGROUND: In this methodological paper we document the interpretation of a mixed methods study and outline an approach to dealing with apparent discrepancies between qualitative and quantitative research data in a pilot study evaluating whether welfare rights advice has an impact on health and social outcomes among a population aged 60 and over. METHODS: Quantitative and qualitative data were collected

Suzanne Moffatt; Martin White; Joan Mackintosh; Denise Howel

2006-01-01

207

The Use of Quantitative and Qualitative Methods in the Analysis of Academic Achievement among Undergraduates in Jamaica  

ERIC Educational Resources Information Center

This paper describes a study which uses quantitative and qualitative methods in determining the relationship between academic, institutional and psychological variables and degree performance for a sample of Jamaican undergraduate students. Quantitative methods, traditionally associated with the positivist paradigm, and involving the counting and…

McLaren, Ingrid Ann Marie

2012-01-01

208

Quantitative and chemical fingerprint analysis for quality control of Rhizoma Coptidischinensis based on UPLC-PAD combined with chemometrics methods  

Microsoft Academic Search

To control the quality of Rhizoma Coptidis, a method based on ultra performance liquid chromatography with photodiode array detector (UPLC-PAD) was developed for quantitative analysis of five active alkaloids and chemical fingerprint analysis. In quantitative analysis, the five alkaloids showed good regression (R > 0.999 2) within test ranges and the recovery of the method was in the range of

Wei-Jun Kong; Yan-Ling Zhao; Xiao-He Xiao; Cheng Jin; Zu-Lun Li

2009-01-01

209

Quantitative analysis of rib movement based on dynamic chest bone images: preliminary results  

NASA Astrophysics Data System (ADS)

Rib movement during respiration is one of the diagnostic criteria in pulmonary impairments. In general, the rib movement is assessed in fluoroscopy. However, the shadows of lung vessels and bronchi overlapping ribs prevent accurate quantitative analysis of rib movement. Recently, an image-processing technique for separating bones from soft tissue in static chest radiographs, called "bone suppression technique", has been developed. Our purpose in this study was to evaluate the usefulness of dynamic bone images created by the bone suppression technique in quantitative analysis of rib movement. Dynamic chest radiographs of 10 patients were obtained using a dynamic flat-panel detector (FPD). Bone suppression technique based on a massive-training artificial neural network (MTANN) was applied to the dynamic chest images to create bone images. Velocity vectors were measured in local areas on the dynamic bone images, which formed a map. The velocity maps obtained with bone and original images for scoliosis and normal cases were compared to assess the advantages of bone images. With dynamic bone images, we were able to quantify and distinguish movements of ribs from those of other lung structures accurately. Limited rib movements of scoliosis patients appeared as reduced rib velocity vectors. Vector maps in all normal cases exhibited left-right symmetric distributions, whereas those in abnormal cases showed nonuniform distributions. In conclusion, dynamic bone images were useful for accurate quantitative analysis of rib movements: Limited rib movements were indicated as a reduction of rib movement and left-right asymmetric distribution on vector maps. Thus, dynamic bone images can be a new diagnostic tool for quantitative analysis of rib movements without additional radiation dose.

Tanaka, R.; Sanada, S.; Oda, M.; Mitsutaka, M.; Suzuki, K.; Sakuta, K.; Kawashima, H.

2014-03-01

210

Evaluation of a High Intensity Focused Ultrasound-Immobilized Trypsin Digestion and 18 O-Labeling Method for Quantitative Proteomics  

SciTech Connect

A new method that uses immobilized trypsin concomitant with ultrasonic irradiation results in ultra-rapid digestion and thorough 18O labeling for quantitative protein comparisons. The reproducible and highly efficient method provided effective digestions in <1 min and minimized the amount of enzyme required compared to traditional methods. This method was demonstrated for digestion of both simple and complex protein mixtures, including bovine serum albumin, a global proteome extract from bacteria Shewanella oneidensis, and mouse plasma, as well as for the labeling of complex protein mixtures, which validated the application of this method for differential proteomic measurements. This approach is simple, reproducible, cost effective, and rapid, and thus well-suited for automation.

Lopez-Ferrer, Daniel; Hixson, Kim K.; Smallwood, Heather S.; Squier, Thomas C.; Petritis, Konstantinos; Smith, Richard D.

2009-08-01

211

Quantitative study of reflection of sunlight by a glass curtain wall resulting in a visual masking effect.  

PubMed

Because of the complexity of the shapes of the structures of buildings, the glass curtain walls of such buildings have different geometries; some of these glass curtain walls have high reflectivity and can strongly focus incident solar light. Under ideal conditions, the solar radiation flux incident onto the glass curtain wall and the solar flux reflected from the glass curtain wall can be theoretically determined. When exposed to an intense light source, human eyes exhibit a visual masking effect when processing an image; the resulting noise level and signal-to-noise ratio in the image are studied. Using field measurements to measure the reflected sunlight of two types of glass curtain walls, the energy distributions of the light reflected from these two different glass curtain walls are determined. This paper focuses on analysis of the experimental results and the cause of the visual masking effect due to the reflection of sunlight from a glass curtain wall and on the method of quantitative calculation of the visual masking effect. PMID:25322397

Ou, Yinglei

2014-10-10

212

Quantitative Determination of Caffeine in Beverages Using a Combined SPME-GC/MS Method  

NASA Astrophysics Data System (ADS)

Solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS) has been applied to the analysis of various caffeinated beverages. Unlike the current methods, this technique is solvent free and requires no pH adjustments. The simplicity of the SPME-GC/MS method lends itself to a good undergraduate laboratory practice. This publication describes the analytical conditions and presents the data for determination of caffeine in coffee, tea, and coke. Quantitation by isotopic dilution is also illustrated.

Pawliszyn, Janusz; Yang, Min J.; Orton, Maureen L.

1997-09-01

213

[Application of MALT-CLS method to FTIR quantitative analysis of atmospheric trace gas].  

PubMed

The MALT-CLS method for quantitative analysis of atmosphere trace gas by FTIR spectrometry was studied. Some experiments are described, such as long-path White cell, and passive remote sensing of aircraft. The characteristic of this method is that the calibration spectra are calculated from a database of absorption line parameters HITRAN using MALT program, including environmental and instrumental effects in the calculation. It is particularly useful in long open-path and solar FTIR spectroscopy, or passive remote sensing by FTIR. PMID:17020024

Gao, Min-Guang; Liu, Wen-Qing; Zhang, Tian-Shu; Liu, Jian-Guo; Lu, Yi-Huai; Xu, Liang; Zhu, Jun

2006-07-01

214

Using quantitative and qualitative data in health services research - what happens when mixed method findings conflict? [ISRCTN61522618  

PubMed Central

Background In this methodological paper we document the interpretation of a mixed methods study and outline an approach to dealing with apparent discrepancies between qualitative and quantitative research data in a pilot study evaluating whether welfare rights advice has an impact on health and social outcomes among a population aged 60 and over. Methods Quantitative and qualitative data were collected contemporaneously. Quantitative data were collected from 126 men and women aged over 60 within a randomised controlled trial. Participants received a full welfare benefits assessment which successfully identified additional financial and non-financial resources for 60% of them. A range of demographic, health and social outcome measures were assessed at baseline, 6, 12 and 24 month follow up. Qualitative data were collected from a sub-sample of 25 participants purposively selected to take part in individual interviews to examine the perceived impact of welfare rights advice. Results Separate analysis of the quantitative and qualitative data revealed discrepant findings. The quantitative data showed little evidence of significant differences of a size that would be of practical or clinical interest, suggesting that the intervention had no impact on these outcome measures. The qualitative data suggested wide-ranging impacts, indicating that the intervention had a positive effect. Six ways of further exploring these data were considered: (i) treating the methods as fundamentally different; (ii) exploring the methodological rigour of each component; (iii) exploring dataset comparability; (iv) collecting further data and making further comparisons; (v) exploring the process of the intervention; and (vi) exploring whether the outcomes of the two components match. Conclusion The study demonstrates how using mixed methods can lead to different and sometimes conflicting accounts and, using this six step approach, how such discrepancies can be harnessed to interrogate each dataset more fully. Not only does this enhance the robustness of the study, it may lead to different conclusions from those that would have been drawn through relying on one method alone and demonstrates the value of collecting both types of data within a single study. More widespread use of mixed methods in trials of complex interventions is likely to enhance the overall quality of the evidence base. PMID:16524479

Moffatt, Suzanne; White, Martin; Mackintosh, Joan; Howel, Denise

2006-01-01

215

Quantitative methods for measuring DNA flexibility in vitro and in vivo  

PubMed Central

The double-helical DNA biopolymer is particularly resistant to bending and twisting deformations. This property has important implications for DNA folding in vitro and for the packaging and function of DNA in living cells. Among the outstanding questions in the field of DNA biophysics are the underlying origin of DNA stiffness, and the mechanisms by which DNA stiffness is overcome within cells. Exploring these questions requires experimental methods to quantitatively measure DNA bending and twisting stiffness both in vitro and in vivo. Here we discuss two classical approaches, T4 DNA ligase-mediated DNA cyclization kinetics, and lac repressor-mediated DNA looping in E. coli. We review the theoretical basis for these techniques and how each can be applied to quantitate biophysical parameters that describe the DNA polymer. We then show how we have modified these methods and applied them to quantitate how apparent DNA physical properties are altered in vitro and in vivo by sequence non-specific architectural DNA binding proteins such as the E. coli HU protein and eukaryotic HMGB proteins. PMID:21195233

Peters, Justin P.; Becker, Nicole A.; Rueter, Emily M.; Bajzer, Zeljko; Kahn, Jason D.; Maher, L. James

2014-01-01

216

Systemic Errors In Quantitative PCR Titration of Self-Complementary AAV Vectors and Improved Alternative Methods  

PubMed Central

Self-complementary AAV (scAAV) vector genomes contain a covalently closed hairpin derived from a mutated inverted terminal repeat which connects the two monomer single stranded genomes into a head-to-head or tail-to-tail dimer. We found that during quantitative PCR (qPCR) this structure inhibits the amplification of proximal amplicons and causes the systemic underreporting of copy number by as much as 10-fold. We show that cleavage of scAAV vector genomes with restriction endonuclease to liberate amplicons from the covalently closed terminal hairpin restores quantitative amplification, and we implement this procedure in a simple, modified qPCR titration method for scAAV vectors. Additionally, we developed and present an AAV genome titration procedure based on gel electrophoresis that requires minimal sample processing and has very low inter assay variability, and as such is well suited for the rigorous quality control demands of clinical vector production facilities. PMID:22428975

Fagone, Paolo; Wright, J. Fraser; Nathwani, Amit C.; Nienhuis, Arthur W.; Davidoff, Andrew M.; Gray, John T.

2013-01-01

217

A quantitative assessment of reliability of the TOPAZ-2 space NPS reactor unit based on ground development results  

SciTech Connect

The paper discusses life-limiting factors (parameters) and statistics of random sudden failures, revealed in the course of ground development, for 4 given subsystems of the TOPAZ-2 space NPS reactor unit. Results are presented of a quantitative assessment of the lower confidence limits of the probability of failure-free operation.

Ponomarev-Stepnoi, Nikolai N.; Nechaev, Yuri A.; Khazanovich, Igor M.; Samodelov, Victor N.; Zakharov, Sergei M. [RRC 'Kurchatov Institute' Moscow 123182 (Russian Federation)

1997-01-10

218

A quantitative assessment of reliability of the TOPAZ-2 space NPS reactor unit based on ground development results  

SciTech Connect

The paper discusses life-limiting factors (parameters) and statistics of random sudden failures, revealed in the course of ground development, for 4 given subsystems of the TOPAZ-2 space NPS reactor unit. Results are presented of a quantitative assessment of the lower confidence limits of the probability of failure-free operation. {copyright} {ital 1997 American Institute of Physics.}

Ponomarev-Stepnoi, N.N.; Nechaev, Y.A.; Khazanovich, I.M.; Samodelov, V.N.; Zakharov, S.M. [RRC Kurchatov Institute Moscow123182 (Russia)

1997-01-01

219

A Simple Regression-Based Method to Map Quantitative Trait Loci Underlying Function-Valued Phenotypes  

PubMed Central

Most statistical methods for quantitative trait loci (QTL) mapping focus on a single phenotype. However, multiple phenotypes are commonly measured, and recent technological advances have greatly simplified the automated acquisition of numerous phenotypes, including function-valued phenotypes, such as growth measured over time. While methods exist for QTL mapping with function-valued phenotypes, they are generally computationally intensive and focus on single-QTL models. We propose two simple, fast methods that maintain high power and precision and are amenable to extensions with multiple-QTL models using a penalized likelihood approach. After identifying multiple QTL by these approaches, we can view the function-valued QTL effects to provide a deeper understanding of the underlying processes. Our methods have been implemented as a package for R, funqtl. PMID:24931408

Kwak, Il-Youp; Moore, Candace R.; Spalding, Edgar P.; Broman, Karl W.

2014-01-01

220

Improved quantitative method for fludarabine in human plasma by liquid chromatography and tandem mass spectrometry.  

PubMed

An improved quantitative assay was developed and validated for fludarabine in human plasma. Fludarabine and its internal standard, cladribine, were separated on a C18 analytical column after sample purification by strong anion-exchange solid-phase extraction. Quantitation was performed by electrospray triple-quadrupole mass spectrometry in positive ionization mode using multiple-reaction monitoring. This assay had excellent inter- and intra-assay precisions within 8%, and accuracies ranging from 100 to 116%. The method was linear within the concentration range of 0.2-250ng/mL using 100?L of plasma with mean R(2)=0.9999. The extraction recoveries were 85% for fludarabine and 95% for the internal standard, which represent a significant improvement over the previously published methods. We utilized this method for pharmacokinetic (PK) investigations in 215 patients. Interference peaks constantly observed in each blank plasma sample were well resolved from fludarabine using our optimized LC-MS/MS conditions, demonstrating the reliability of this improved assay. The validated method will be further applied to PK studies within our bone marrow transplant program, which will allow for optimal dose and scheduling of fludarabine in these patients. PMID:23777614

Ng, Ella S M; Kangarloo, S Bill; Daly, Andrew

2013-07-15

221

[Adequate application of quantitative and qualitative statistic analytic methods in acupuncture clinical trials].  

PubMed

Recently, proper use of the statistical methods in traditional Chinese medicine (TCM) randomized controlled trials (RCTs) has received increased attention. Statistical inference based on hypothesis testing is the foundation of clinical trials and evidence-based medicine. In this article, the authors described the methodological differences between literature published in Chinese and Western journals in the design and analysis of acupuncture RCTs and the application of basic statistical principles. In China, qualitative analysis method has been widely used in acupuncture and TCM clinical trials, while the between-group quantitative analysis methods on clinical symptom scores are commonly used in the West. The evidence for and against these analytical differences were discussed based on the data of RCTs assessing acupuncture for pain relief. The authors concluded that although both methods have their unique advantages, quantitative analysis should be used as the primary analysis while qualitative analysis can be a secondary criterion for analysis. The purpose of this paper is to inspire further discussion of such special issues in clinical research design and thus contribute to the increased scientific rigor of TCM research. PMID:22883399

Tan, Ming T; Liu, Jian-ping; Lao, Lixing

2012-08-01

222

The quantitative and qualitative recovery of Campylobacter from raw poultry using USDA and Health Canada methods.  

PubMed

Harmonisation of methods between Canadian government agencies is essential to accurately assess and compare the prevalence and concentrations present on retail poultry intended for human consumption. The standard qualitative procedure used by Health Canada differs to that used by the USDA for both quantitative and qualitative methods. A comparison of three methods was performed on raw poultry samples obtained from an abattoir to determine if one method is superior to the others in isolating Campylobacter from chicken carcass rinses. The average percent of positive samples was 34.72% (95% CI, 29.2-40.2), 39.24% (95% CI, 33.6-44.9), 39.93% (95% CI, 34.3-45.6) for the direct plating US method and the US enrichment and Health Canada enrichment methods, respectively. Overall there were significant differences when comparing either of the enrichment methods to the direct plating method using the McNemars chi squared test. On comparison of weekly data (Fishers exact test) direct plating was only inferior to the enrichment methods on a single occasion. Direct plating is important for enumeration and establishing the concentration of Campylobacter present on raw poultry. However, enrichment methods are also vital to identify positive samples where concentrations are below the detection limit for direct plating. PMID:25084671

Sproston, E L; Carrillo, C D; Boulter-Bitzer, J

2014-12-01

223

Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors  

DOEpatents

A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify .sup.233 U, .sup.235 U and .sup.239 Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as .sup.240 Pu, .sup.244 Cm and .sup.252 Cf, and the spontaneous alpha particle emitter .sup.241 Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether "permanent" low-level burial is appropriate for the waste sample.

Caldwell, John T. (Los Alamos, NM); Kunz, Walter E. (Santa Fe, NM); Atencio, James D. (Los Alamos, NM)

1984-01-01

224

Exploring the use of storytelling in quantitative research fields using a multiple case study method  

NASA Astrophysics Data System (ADS)

The purpose of this study was to explore the emerging use of storytelling in quantitative research fields. The focus was not on examining storytelling in research, but rather how stories are used in various ways within the social context of quantitative research environments. In-depth interviews were conducted with seven professionals who had experience using storytelling in their work and my personal experience with the subject matter was also used as a source of data according to the notion of researcher-as-instrument. This study is qualitative in nature and is guided by two supporting theoretical frameworks, the sociological perspective and narrative inquiry. A multiple case study methodology was used to gain insight about why participants decided to use stories or storytelling in a quantitative research environment that may not be traditionally open to such methods. This study also attempted to identify how storytelling can strengthen or supplement existing research, as well as what value stories can provide to the practice of research in general. Five thematic findings emerged from the data and were grouped under two headings, "Experiencing Research" and "Story Work." The themes were found to be consistent with four main theoretical functions of storytelling identified in existing scholarly literature: (a) sense-making; (b) meaning-making; (c) culture; and (d) communal function. The five thematic themes that emerged from this study and were consistent with the existing literature include: (a) social context; (b) quantitative versus qualitative; (c) we think and learn in terms of stories; (d) stories tie experiences together; and (e) making sense and meaning. Recommendations are offered in the form of implications for various social contexts and topics for further research are presented as well.

Matthews, Lori N. Hamlet

225

Investigation of a diffuse optical measurements-assisted quantitative photoacoustic tomographic method in reflection geometry  

PubMed Central

Abstract. Photoacoustic tomography provides the distribution of absorbed optical energy density, which is the product of optical absorption coefficient and optical fluence distribution. We report the experimental investigation of a novel fitting procedure that quantitatively determines the optical absorption coefficient of chromophores. The experimental setup consisted of a hybrid system of a 64-channel photoacoustic imaging system with a frequency-domain diffused optical measurement system. The fitting procedure included a complete photoacoustic forward model and an analytical solution of a target chromophore using the diffusion approximation. The fitting procedure combines the information from the photoacoustic image and the background information from the diffuse optical measurements to minimize the photoacoustic measurements and forward model data and recover the target absorption coefficient quantitatively. 1-cm-cube phantom absorbers of high and low contrasts were imaged at depths of up to 3.0 cm. The fitted absorption coefficient results were at least 80% of their true values. The sensitivities of this fitting procedure to target location, target radius, and background optical properties were also investigated. We found that this fitting procedure was most sensitive to the accurate determination of the target radius and depth. Blood sample in a thin tube of radius 0.58 mm, simulating a blood vessel, was also studied. The photoacoustic images and fitted absorption coefficients are presented. These results demonstrate the clinical potential of this fitting procedure to quantitatively characterize small lesions in breast imaging. PMID:22734743

Xu, Chen; Kumavor, Patrick D.; Aguirre, Andres; Zhu, Quing

2012-01-01

226

Investigation of a diffuse optical measurements-assisted quantitative photoacoustic tomographic method in reflection geometry.  

PubMed

Photoacoustic tomography provides the distribution of absorbed optical energy density, which is the product of optical absorption coefficient and optical fluence distribution. We report the experimental investigation of a novel fitting procedure that quantitatively determines the optical absorption coefficient of chromophores. The experimental setup consisted of a hybrid system of a 64-channel photoacoustic imaging system with a frequency-domain diffused optical measurement system. The fitting procedure included a complete photoacoustic forward model and an analytical solution of a target chromophore using the diffusion approximation. The fitting procedure combines the information from the photoacoustic image and the background information from the diffuse optical measurements to minimize the photoacoustic measurements and forward model data and recover the target absorption coefficient quantitatively. 1-cm-cube phantom absorbers of high and low contrasts were imaged at depths of up to 3.0 cm. The fitted absorption coefficient results were at least 80% of their true values. The sensitivities of this fitting procedure to target location, target radius, and background optical properties were also investigated. We found that this fitting procedure was most sensitive to the accurate determination of the target radius and depth. Blood sample in a thin tube of radius 0.58 mm, simulating a blood vessel, was also studied. The photoacoustic images and fitted absorption coefficients are presented. These results demonstrate the clinical potential of this fitting procedure to quantitatively characterize small lesions in breast imaging. PMID:22734743

Xu, Chen; Kumavor, Patrick D; Aguirre, Andres; Zhu, Quing

2012-06-01

227

Quantitative 1H NMR. Development and potential of an analytical method: an update.  

PubMed

Covering the literature from mid-2004 until the end of 2011, this review continues a previous literature overview on quantitative (1)H NMR (qHNMR) methodology and its applications in the analysis of natural products. Among the foremost advantages of qHNMR is its accurate function with external calibration, the lack of any requirement for identical reference materials, a high precision and accuracy when properly validated, and an ability to quantitate multiple analytes simultaneously. As a result of the inclusion of over 170 new references, this updated review summarizes a wealth of detailed experiential evidence and newly developed methodology that supports qHNMR as a valuable and unbiased analytical tool for natural product and other areas of research. PMID:22482996

Pauli, Guido F; Gödecke, Tanja; Jaki, Birgit U; Lankin, David C

2012-04-27

228

Quantitative 1H NMR: Development and Potential of an Analytical Method - an Update  

PubMed Central

Covering the literature from mid-2004 until the end of 2011, this review continues a previous literature overview on quantitative 1H NMR (qHNMR) methodology and its applications in the analysis of natural products (NPs). Among the foremost advantages of qHNMR is its accurate function with external calibration, the lack of any requirement for identical reference materials, a high precision and accuracy when properly validated, and an ability to quantitate multiple analytes simultaneously. As a result of the inclusion of over 170 new references, this updated review summarizes a wealth of detailed experiential evidence and newly developed methodology that supports qHNMR as a valuable and unbiased analytical tool for natural product and other areas of research. PMID:22482996

Pauli, Guido F.; Godecke, Tanja; Jaki, Birgit U.; Lankin, David C.

2012-01-01

229

A Robust Method for Quantitative High-throughput Analysis of Proteomes by 18O Labeling*  

PubMed Central

MS-based quantitative proteomics plays an increasingly important role in biological and medical research and the development of these techniques remains one of the most important challenges in mass spectrometry. Numerous stable isotope labeling approaches have been proposed. However, and particularly in the case of 18O-labeling, a standard protocol of general applicability is still lacking, and statistical issues associated to these methods remain to be investigated. In this work we present an improved high-throughput quantitative proteomics method based on whole proteome concentration by SDS-PAGE, optimized in-gel digestion, peptide 18O-labeling, and separation by off-gel isoelectric focusing followed by liquid chromatography-LIT-MS. We demonstrate that the off-gel technique is fully compatible with 18O peptide labeling in any pH range. A recently developed statistical model indicated that partial digestions and methionine oxidation do not alter protein quantification and that variances at the scan, peptide, and protein levels are stable and reproducible in a variety of proteomes of different origin. We have also analyzed the dynamic range of quantification and demonstrated the practical utility of the method by detecting expression changes in a model of activation of Jurkat T-cells. Our protocol provides a general approach to perform quantitative proteomics by 18O-labeling in high-throughput studies, with the added value that it has a validated statistical model for the null hypothesis. To the best of our knowledge, this is the first report where a general protocol for stable isotope labeling is tested in practice using a collection of samples and analyzed at this degree of statistical detail. PMID:20807836

Bonzon-Kulichenko, Elena; Perez-Hernandez, Daniel; Nunez, Estefania; Martinez-Acedo, Pablo; Navarro, Pedro; Trevisan-Herraz, Marco; del Carmen Ramos, Maria; Sierra, Saleta; Martinez-Martinez, Sara; Ruiz-Meana, Marisol; Miro-Casas, Elizabeth; Garcia-Dorado, David; Redondo, Juan Miguel; Burgos, Javier S.; Vazquez, Jesus

2011-01-01

230

A Rapid, Quantitative Method to Characterize The Human Lymphocyte Concentration for Automated High-Throughput Radiation Biodosimetry  

PubMed Central

We have developed a Quantitative Light Absorption Analysis (QLAA) method to rapidly estimate human lymphocyte concentrations isolated from small volumes of whole blood. Measurements of the light absorption analysis were calibrated for lymphocyte concentration levels using a hemocytometer. To validate the QLAA system, blood samples were collected from 17 healthy donors and lymphocyte absorption measurements were directly compared with the manual microscope counting. The results showed that lymphocyte measurements obtained using the QLAA system were comparable with the manually scored lymphocyte counts but with measurements taken in seconds. PMID:23781493

Xu, Yanping; Turner, Helen C.; Garty, Guy; Brenner, David

2013-01-01

231

A Rapid, Quantitative Method to Characterize The Human Lymphocyte Concentration for Automated High-Throughput Radiation Biodosimetry.  

PubMed

We have developed a Quantitative Light Absorption Analysis (QLAA) method to rapidly estimate human lymphocyte concentrations isolated from small volumes of whole blood. Measurements of the light absorption analysis were calibrated for lymphocyte concentration levels using a hemocytometer. To validate the QLAA system, blood samples were collected from 17 healthy donors and lymphocyte absorption measurements were directly compared with the manual microscope counting. The results showed that lymphocyte measurements obtained using the QLAA system were comparable with the manually scored lymphocyte counts but with measurements taken in seconds. PMID:23781493

Xu, Yanping; Turner, Helen C; Garty, Guy; Brenner, David

2013-03-01

232

Establishment and evaluation of event-specific qualitative and quantitative PCR method for genetically modified soybean DP356043-5  

Microsoft Academic Search

With the increasing development of genetically modified organisms (GMOs), labeling regulations have been introduced, which\\u000a require appropriate detection methods. The polymerase chain reaction (PCR) technique has been the mainstay for GMO detection,\\u000a especially for event-specific qualitative and quantitative PCR detection methods, which have become the internationally agreed\\u000a state-of-art. This paper describes the character and event-specific quantitative detection method of DP-356043-5

Wen Tao Xu; Nan Zhang; Yun Bo Luo; Zhi Fang Zhai; Ying Shang; Xing Hua Yan; Juan Juan Zheng; Kun Lun Huang

233

Apparatus and method for quantitative determination of materials contained in fluids  

DOEpatents

Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids are described. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is shown. Significant shortening of analysis time is achieved from the usual chemical techniques of analysis.

Radziemski, L.J.; Cremers, D.A.

1982-09-07

234

Apparatus and method for quantitative determination of materials contained in fluids  

DOEpatents

Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is demonstrated. Significant shortening of analysis time is achieved from those of the usual chemical techniques of analysis.

Radziemski, Leon J. (Los Alamos, NM); Cremers, David A. (Los Alamos, NM)

1985-01-01

235

Quantitative and qualitative methods in medical education research: AMEE Guide No 90: Part I.  

PubMed

Medical educators need to understand and conduct medical education research in order to make informed decisions based on the best evidence, rather than rely on their own hunches. The purpose of this Guide is to provide medical educators, especially those who are new to medical education research, with a basic understanding of how quantitative and qualitative methods contribute to the medical education evidence base through their different inquiry approaches and also how to select the most appropriate inquiry approach to answer their research questions. PMID:24846122

Tavakol, Mohsen; Sandars, John

2014-09-01

236

Quantitative and qualitative methods in medical education research: AMEE Guide No 90: Part II.  

PubMed

Abstract Medical educators need to understand and conduct medical education research in order to make informed decisions based on the best evidence, rather than rely on their own hunches. The purpose of this Guide is to provide medical educators, especially those who are new to medical education research, with a basic understanding of how quantitative and qualitative methods contribute to the medical education evidence base through their different inquiry approaches and also how to select the most appropriate inquiry approach to answer their research questions. PMID:24845954

Tavakol, Mohsen; Sandars, John

2014-10-01

237

A simple method for the separation and quantitation of radiolabeled thyroid hormones in thyroxine clearance studies.  

PubMed

A method was developed to facilitate the separation and quantitation of radiolabeled thyroxine in plasma for thyroxine clearance studies. Following intravenous injection of radioactive thyroxine, the radiolabeled thyroid hormones were isolated from plasma protein and polar metabolites by solid phase extraction on a C18 sorbent bed. The individual thyroid hormones were then separated by ion-pair reversed phase chromatography and sequentially eluted through a UV detector and radiochromatographic detector. The radioactivity of individual radiolabeled thyroid hormones was corrected for recovery of carrier as determined from UV absorbance. The recoveries of thyroxine and 3,5,3'-triiodothyronine (T3) were 96% and 101%, respectively. PMID:2074718

Grossman, S J

1990-11-01

238

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

NASA Astrophysics Data System (ADS)

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.

Gupta, Lokesh Kumar

2012-11-01

239

A quantitative autoradiographic method for the measurement of local rates of brain protein synthesis  

SciTech Connect

We have developed a new method for measuring local rates of brain protein synthesis in vivo. It combines the intraperitoneal injection of a large dose of low specific activity amino acid with quantitative autoradiography. This method has several advantages: 1) It is ideally suited for young or small animals or where immobilizing an animal is undesirable. 2 The amino acid injection ''floods'' amino acid pools so that errors in estimating precursor specific activity, which is especially important in pathological conditions, are minimized. 3) The method provides for the use of a radioautographic internal standard in which valine incorporation is measured directly. Internal standards from experimental animals correct for tissue protein content and self-absorption of radiation in tissue sections which could vary under experimental conditions.

Dwyer, B.E.; Donatoni, P.; Wasterlain, C.G.

1982-05-01

240

A method for estimating the effective number of loci affecting a quantitative character.  

PubMed

A likelihood method is introduced that jointly estimates the number of loci and the additive effect of alleles that account for the genetic variance of a normally distributed quantitative character in a randomly mating population. The method assumes that measurements of the character are available from one or both parents and an arbitrary number of full siblings. The method uses the fact, first recognized by Karl Pearson in 1904, that the variance of a character among offspring depends on both the parental phenotypes and on the number of loci. Simulations show that the method performs well provided that data from a sufficient number of families (on the order of thousands) are available. This method assumes that the loci are in Hardy-Weinberg and linkage equilibrium but does not assume anything about the linkage relationships. It performs equally well if all loci are on the same non-recombining chromosome provided they are in linkage equilibrium. The method can be adapted to take account of loci already identified as being associated with the character of interest. In that case, the method estimates the number of loci not already known to affect the character. The method applied to measurements of crown-rump length in 281 family trios in a captive colony of African green monkeys (Chlorocebus aethiopus sabaeus) estimates the number of loci to be 112 and the additive effect to be 0.26 cm. A parametric bootstrap analysis shows that a rough confidence interval has a lower bound of 14 loci. PMID:23973416

Slatkin, Montgomery

2013-11-01

241

Methods for quantitative detection of antibody-induced complement activation on red blood cells.  

PubMed

Antibodies against red blood cells (RBCs) can lead to complement activation resulting in an accelerated clearance via complement receptors in the liver (extravascular hemolysis) or leading to intravascular lysis of RBCs. Alloantibodies (e.g. ABO) or autoantibodies to RBC antigens (as seen in autoimmune hemolytic anemia, AIHA) leading to complement activation are potentially harmful and can be - especially when leading to intravascular lysis - fatal(1). Currently, complement activation due to (auto)-antibodies on RBCs is assessed in vitro by using the Coombs test reflecting complement deposition on RBC or by a nonquantitative hemolytic assay reflecting RBC lysis(1-4). However, to assess the efficacy of complement inhibitors, it is mandatory to have quantitative techniques. Here we describe two such techniques. First, an assay to detect C3 and C4 deposition on red blood cells that is induced by antibodies in patient serum is presented. For this, FACS analysis is used with fluorescently labeled anti-C3 or anti-C4 antibodies. Next, a quantitative hemolytic assay is described. In this assay, complement-mediated hemolysis induced by patient serum is measured making use of spectrophotometric detection of the released hemoglobin. Both of these assays are very reproducible and quantitative, facilitating studies of antibody-induced complement activation. PMID:24514151

Meulenbroek, Elisabeth M; Wouters, Diana; Zeerleder, Sacha

2014-01-01

242

A quantitative method for measurement of HL-60 cell apoptosis based on diffraction imaging flow cytometry technique  

PubMed Central

A quantitative method for measurement of apoptosis in HL-60 cells based on polarization diffraction imaging flow cytometry technique is presented in this paper. Through comparative study with existing methods and the analysis of diffraction images by a gray level co-occurrence matrix algorithm (GLCM), we found 4 GLCM parameters of contrast (CON), cluster shade (CLS), correlation (COR) and dissimilarity (DIS) exhibit high sensitivities as the apoptotic rates. It was further demonstrated that the CLS parameter correlates significantly (R2 = 0.899) with the degree of nuclear fragmentation and other three parameters showed a very good correlations (R2 ranges from 0.69 to 0.90). These results demonstrated that the new method has the capability for rapid and accurate extraction of morphological features to quantify cellular apoptosis without the need for cell staining. PMID:25071957

Yang, Xu; Feng, Yuanming; Liu, Yahui; Zhang, Ning; Lin, Wang; Sa, Yu; Hu, Xin-Hua

2014-01-01

243

A quantitative method for measurement of HL-60 cell apoptosis based on diffraction imaging flow cytometry technique.  

PubMed

A quantitative method for measurement of apoptosis in HL-60 cells based on polarization diffraction imaging flow cytometry technique is presented in this paper. Through comparative study with existing methods and the analysis of diffraction images by a gray level co-occurrence matrix algorithm (GLCM), we found 4 GLCM parameters of contrast (CON), cluster shade (CLS), correlation (COR) and dissimilarity (DIS) exhibit high sensitivities as the apoptotic rates. It was further demonstrated that the CLS parameter correlates significantly (R(2) = 0.899) with the degree of nuclear fragmentation and other three parameters showed a very good correlations (R(2) ranges from 0.69 to 0.90). These results demonstrated that the new method has the capability for rapid and accurate extraction of morphological features to quantify cellular apoptosis without the need for cell staining. PMID:25071957

Yang, Xu; Feng, Yuanming; Liu, Yahui; Zhang, Ning; Lin, Wang; Sa, Yu; Hu, Xin-Hua

2014-07-01

244

Evaluation of quantitative recovery methods for Listeria monocytogenes applied to stainless steel.  

PubMed

The ability of Listeria monocytogenes to attach to various food contact surfaces, such as stainless steel, polypropylene, and rubber compounds, is well documented. The retention of these or other pathogenic bacteria on food contact surfaces increases the risk of transmission to food products. The objective of this study was to compare several methods for quantitative recovery of Listeria monocytogenes from stainless steel surfaces. A cocktail of 4 serotypes of Listeria monocytogenes mixed in equivalent concentrations was inoculated onto type 304 stainless steel coupons in a 2 x 2 cm area. After 1 h exposure, coupons were sampled by one of the following methods: (1) swabbing with a premoistened Dacron swab; (2) rinsing with phosphate-buffered saline; (3) direct contact onto tryptic soy agar containing 0.6% yeast extract (TSA + YE) plates for 10 s; (4) sonication in an ultrasonic water bath (40 kHz); (5) contact with the bristles of a sonicating brush head for 1 min; and (6) indirect contact (2-4 mm distance) with a sonicating brush head for 1 min. The 3 sonication methods yielded higher recovery than the other 3 methods (P < 0.05). Brushing the coupons with the sonicating brush head (contact or noncontact) yielded a recovery level of about 60%. The lowest cell recovery (about 20%) was observed with the swab and direct agar contact methods. After a 12 h exposure, recoveries ranged from 17.4 (brush contact method) to 2% (swab method). PMID:17580634

Kang, David; Eifert, Joseph D; Williams, Robert C; Pao, Steven

2007-01-01

245

Rapid method for glutathione quantitation using high-performance liquid chromatography with coulometric electrochemical detection.  

PubMed

A rapid, sensitive, and direct method (without derivatization) was developed for the detection of reduced glutathione (GSH) in cultured hepatocytes (HepG2 cells) using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The method was validated according to the guidelines of the U.S. Food and Drug Administration in terms of linearity, lower limit of quantitation (LOQ), lower limit of detection (LOD), precision, accuracy, recovery, and stabilities of GSH standards and quality control samples. The total analysis time was 5 min, and the retention time of GSH was 1.78 min. Separation was carried out isocratically using 50 mM sodium phosphate (pH 3.0) as a mobile phase with a fused-core column. The detector response was linear between 0.01 and 80 ?mol/L, and the regression coefficient (R(2)) was >0.99. The LOD for GSH was 15 fmol, and the intra- and interday recoveries ranged between 100.7 and 104.6%. This method also enabled the rapid detection (in 4 min) of other compounds involved in GSH metabolism such as uric acid, ascorbic acid, and glutathione disulfite. The optimized and validated HPLC-ECD method was successfully applied for the determination of GSH levels in HepG2 cells treated with buthionine sulfoximine (BSO), an inhibitor, and ?-lipoic acid (?-LA), an inducer of GSH synthesis. As expected, the amount of GSH concentration-dependently decreased with BSO and increased with ?-LA treatments in HepG2 cells. This method could also be useful for the quantitation of GSH, uric acid, ascorbic acid, and glutathione disulfide in other biological matrices such as tissue homogenates and blood. PMID:24328299

Bayram, Banu; Rimbach, Gerald; Frank, Jan; Esatbeyoglu, Tuba

2014-01-15

246

Toward Arabidopsis thaliana hydrophilic metabolome: assessment of extraction methods and quantitative 1H NMR.  

PubMed

Our goal was to establish the hydrophilic metabolome of heterotrophic Arabidopsis thaliana cells grown in suspension, a cellular model of plant sink tissues. Water-soluble metabolites were extracted using four protocols: perchloric acid, boiling ethanol, methanol and methanol/chloroform (M/Chl). They were detected and quantified using (1)H nuclear magnetic resonance (NMR) spectroscopy at 400 MHz. Extraction yields and reproducibility of the extraction methods were investigated. The effects of cell harvest protocol, cell grinding and lyophilization and storage conditions on the measured metabolic profiles were also studied. These quantitative studies demonstrated for the first time that the four extraction protocols commonly used do lead to quite similar molecular compositions as analyzed by (1)H NMR. The M/Chl method proved effective and reliable to prepare series of physiologically significant extracts from plant cells for (1)H NMR analysis. Reproducibility of the detected metabolome was assessed over long periods of time by analyzing a large number of separate extracts prepared from independent cultures. Larger variations in the NMR metabolite profiles could be correlated to changes in physiological parameters of the culture medium. Quantitative resolved (1)H NMR of cell extracts proved to be robust and reliable for routine metabolite profiling of plant cell cultures. PMID:20522173

Gromova, Marina; Roby, Claude

2010-10-01

247

Problems of a thermionic space NPS reactor unit quantitative reliability assessment on the basis of ground development results  

SciTech Connect

The paper sets forth major problems that arose in the course of a quantitative assessment of reliability of a TOPAZ-2 space NPS reactor unit performed on the basis of ground development results. Proposals are made on the possible ways to solve those problems through development and introduction of individual standards especially for the ground development stage, which would specify the assessment algorithm and censoring rules, and exclude a number of existing uncertainties when making a decision on going to flight testing.

Ponomarev-Stepnoi, Nikolai N.; Nechaev, Yuri A.; Khazanovich, Igor M.; Samodelov, Victor N.; Pavlov, Konstantin A. [RRC 'Kurchatov Institute' Moscow 123182 (Russian Federation); Russian Federation Ministry of Defense Central Scientific-Research Institute of Space Force Moscow K-160 (Russian Federation)

1997-01-10

248

Quantitation of X-Ray Radiographic Elemental Maps Using Factorial Analysis of Correspondence: Methods and Programs  

NASA Astrophysics Data System (ADS)

We examine the problem of building quantitative elemental maps from X-ray absorption images (radiography). As we suggested in a previous publication in Microbeam Analysis, factorial analysis of correspondence is shown to be an optimal method, in the least squares sense, for solving the multilinear equation system given by Beer's law: it relates to an efficient description of the problem in the concentration phase space. We explain how factorial analysis is related to singular value decomposition and we give a complete description of the algorithm. The method can be applied to any multilinear analytical technique as well. Programs are written in C and Mathematica® languages. Academic users may obtain the relevant software (source and code) as freeware directly from the authors.

Trebbia, P.; Ferrar, G.

1996-02-01

249

A QUANTITATIVE, THREE-DIMENSIONAL METHOD FOR ANALYZING ROTATIONAL MOVEMENT FROM SINGLE-VIEW MOVIES  

PubMed

The study of animal movement is an important aspect of functional morphological research. The three-dimensional movements of (parts of) animals are usually recorded on two-dimensional film frames. For a quantitative analysis, the real movements should be reconstructed from their projections. If movements occur in one plane, their projection is distorted only if this plane is not parallel to the film plane. Provided that the parallel orientation of the movement with respect to the film plane is checked accurately, a two-dimensional method of analysis (ignoring projection errors) can be justified for quantitative analysis of planar movements. Films of movements of skeletal elements of the fish head have generally been analyzed with the two-dimensional method (e.g. Sibbing, 1982; Hoogenboezem et al. 1990; Westneat, 1990; Claes and de Vree, 1991), which is justifiable for planar movements. Unfortunately, the movements of the head bones of fish are often strongly non-planar, e.g. the movement of the pharyngeal jaws and the gill arches. The two-dimensional method is inappropriate for studying such complex movements (Sibbing, 1982; Hoogenboezem et al. 1990). For a qualitative description of movement patterns, the conditions for the use of the two-dimensional method may be somewhat relaxed. When two (or more) views of a movement are recorded simultaneously, the three-dimensional movements can readily be reconstructed using two two-dimensional images (e.g. Zarnack, 1972; Nachtigall, 1983; van Leeuwen, 1984; Drost and van den Boogaart, 1986). However, because of technical (and budget) limitations, simultaneous views of a movement cannot always be shot. In this paper, a method is presented for reconstructing the three-dimensional orientation and rotational movement of structures using single-view films and for calculating rotation in an object-bound frame. Ellington (1984) presented a similar method for determining three-dimensional wing movements from single-view films of flying insects. Ellington's method is based upon the bilateral symmetry of the wing movements. The present method does not depend on symmetry and can be applied to a variety of kinematic investigations. It eliminates a systematic error: the projection error. The measuring error is not discussed; it is the same in the two-dimensional and three-dimensional method of analysis. PMID:9317811

Berg

1994-06-01

250

Diagnostic performance of different measurement methods for lung nodule enhancement at quantitative contrast-enhanced computed tomography  

NASA Astrophysics Data System (ADS)

Lack of angiogenesis virtually excludes malignancy of a pulmonary nodule; assessment with quantitative contrast-enhanced CT (QECT) requires a reliable enhancement measurement technique. Diagnostic performance of different measurement methods in the distinction between malignant and benign nodules was evaluated. QECT (unenhanced scan and 4 post-contrast scans) was performed in 48 pulmonary nodules (12 malignant, 12 benign, 24 indeterminate). Nodule enhancement was the difference between the highest nodule density at any post-contrast scan and the unenhanced scan. Enhancement was determined with: A) the standard 2D method; B) a 3D method consisting of segmentation, removal of peripheral structures and density averaging. Enhancement curves were evaluated for their plausibility using a predefined set of criteria. Sensitivity and specificity were 100% and 33% for the 2D method resp. 92% and 55% for the 3D method using a threshold of 20 HU. One malignant nodule did not show significant enhancement with method B due to adjacent atelectasis which disappeared within the few minutes of the QECT examination. Better discrimination between benign and malignant lesions was achieved with a slightly higher threshold than proposed in the literature. Application of plausibility criteria to the enhancement curves rendered less plausibility faults with the 3D method. A new 3D method for analysis of QECT scans yielded less artefacts and better specificity in the discrimination between benign and malignant pulmonary nodules when using an appropriate enhancement threshold. Nevertheless, QECT results must be interpreted with care.

Wormanns, Dag; Klotz, Ernst; Dregger, Uwe; Beyer, Florian; Heindel, Walter

2004-05-01

251

Methods of experimentation with models and utilization of results  

NASA Technical Reports Server (NTRS)

The present report treats the subject of testing small models in a wind tunnel and of the methods employed for rendering the results constant, accurate and comparable with one another. Detailed experimental results are given.

Robert,

1924-01-01

252

Simple absolute quantification method correcting for quantitative PCR efficiency variations for microbial community samples.  

PubMed

Real-time quantitative PCR (qPCR) is a widely used technique in microbial community analysis, allowing the quantification of the number of target genes in a community sample. Currently, the standard-curve (SC) method of absolute quantification is widely employed for these kinds of analysis. However, the SC method assumes that the amplification efficiency (E) is the same for both the standard and the sample target template. We analyzed 19 bacterial strains and nine environmental samples in qPCR assays, targeting the nifH and 16S rRNA genes. The E values of the qPCRs differed significantly, depending on the template. This has major implications for the quantification. If the sample and standard differ in their E values, quantification errors of up to orders of magnitude are possible. To address this problem, we propose and test the one-point calibration (OPC) method for absolute quantification. The OPC method corrects for differences in E and was derived from the ??C(T) method with correction for E, which is commonly used for relative quantification in gene expression studies. The SC and OPC methods were compared by quantifying artificial template mixtures from Geobacter sulfurreducens (DSM 12127) and Nostoc commune (Culture Collection of Algae and Protozoa [CCAP] 1453/33), which differ in their E values. While the SC method deviated from the expected nifH gene copy number by 3- to 5-fold, the OPC method quantified the template mixtures with high accuracy. Moreover, analyzing environmental samples, we show that even small differences in E between the standard and the sample can cause significant differences between the copy numbers calculated by the SC and the OPC methods. PMID:22492459

Brankatschk, Robert; Bodenhausen, Natacha; Zeyer, Josef; Bürgmann, Helmut

2012-06-01

253

Initial results and mixed directions for Research Methods Tutor 1  

E-print Network

Initial results and mixed directions for Research Methods Tutor 1 Peter Wiemer-Hastings a,2 and Information Systems b DePaul University Department of Psychology Abstract. RMT (Research Methods Tutor on research methods in psychology. RMT has a web-based interface and uses a talking head to to present its

Wiemer-Hastings, Peter

254

A small-scale method for quantitation of carotenoids in bacteria and yeasts.  

PubMed

Microbial carotenoids are difficult to extract because of their embedding into a compact matrix and prominent sensitivity to degradation. Especially for carotenoid analysis of bacteria and yeasts, there is lack of information about capability, precision and recovery of the method used. Accordingly, we investigated feasibility, throughput and validity of a new small-scale method using Micrococcus luteus and Rhodotorula glutinis for testing purposes. For disintegration and extraction, we combined primarily mild techniques: enzymatically we used combinations of lysozyme and lipase for bacteria as well as lyticase and lipase for yeasts. Additional mechanical treatment included sonication and freeze-thawing cycles. Chemical treatment with dimethylsulfoxide was applied for yeasts only. For extraction we used a methanol-chloroform mixture stabilized efficiently with butylated hydroxytoluene and alpha-tocopherol. Separation of compounds was achieved with HPLC, applying a binary methanol/tert-butyl methyl ether gradient on a polymer reversed C30 phase. Substances of interest were detected and identified applying a photodiode-array (PDA) and carotenoids quantitated as all-trans-beta-carotene equivalents. For evaluation of recovery and reproducibility of the extraction method, we used beta-8'-apo-carotenal as internal standard. The method provides a sensitive tool for the determination of carotenoids from bacteria and yeasts and also for small changes in carotenoid spectrum of a single species. Corequisite large experiments are facilitated by the high throughput of the method. PMID:17509707

Kaiser, Philipp; Surmann, Peter; Vallentin, Gerald; Fuhrmann, Herbert

2007-07-01

255

Recent Advances in Human Quantitative-Trait-Locus Mapping: Comparison of Methods for Selected Sibling Pairs  

PubMed Central

During the past few years, there has been a great deal of new work on methods for mapping quantitative-trait loci by use of sibling pairs and sibships. There are several new methods based on linear regression, as well as several more that are based on score statistics. In theory, most of the new methods should be relatively robust to violations of distributional assumptions and to selected sampling, but, in practice, there has been little evaluation of how the methods perform on selected samples. We survey most of the new regression-based statistics and score statistics and propose a few minor variations on the score statistics. We use simulation to evaluate the type I error and the power of all of the statistics, considering (a) population samples of sibling pairs and (b) sibling pairs ascertained on the basis of at least one sibling with a trait value in the top 10% of the distribution. Most of the statistics have correct type I error for selected samples. The statistics proposed by Xu et al. and by Sham and Purcell are generally the most powerful, along with one of our score statistic variants. Even among the methods that are most powerful for “nice” data, some are more robust than others to non-Gaussian trait models and/or misspecified trait parameters. PMID:12970847

T.Cuenco, Karen; Szatkiewicz, Jin P.; Feingold, Eleanor

2003-01-01

256

Simple, rapid and inexpensive quantitative fluorescent PCR method for detection of microdeletion and microduplication syndromes.  

PubMed

Because of economic limitations, the cost-effective diagnosis of patients affected with rare microdeletion or microduplication syndromes is a challenge in developing countries. Here we report a sensitive, rapid, and affordable detection method that we have called Microdeletion/Microduplication Quantitative Fluorescent PCR (MQF-PCR). Our procedure is based on the finding of genomic regions with high homology to segments of the critical microdeletion/microduplication region. PCR amplification of both using the same primer pair, establishes competitive kinetics and relative quantification of amplicons, as happens in microsatellite-based Quantitative Fluorescence PCR. We used patients with two common microdeletion syndromes, the Williams-Beuren syndrome (7q11.23 microdeletion) and the 22q11.2 microdeletion syndromes and discovered that MQF-PCR could detect both with 100% sensitivity and 100% specificity. Additionally, we demonstrated that the same principle could be reliably used for detection of microduplication syndromes, by using patients with the Lubs (MECP2 duplication) syndrome and the 17q11.2 microduplication involving the NF1 gene. We propose that MQF-PCR is a useful procedure for laboratory confirmation of the clinical diagnosis of microdeletion/microduplication syndromes, ideally suited for use in developing countries, but having general applicability as well. PMID:23620743

Stofanko, Martin; Gonçalves-Dornelas, Higgor; Cunha, Pricila Silva; Pena, Heloísa B; Vianna-Morgante, Angela M; Pena, Sérgio Danilo Junho

2013-01-01

257

Characterization of a method for quantitating food consumption for mutation assays in Drosophila  

SciTech Connect

Quantitation of food consumption is necessary when determining mutation responses to multiple chemical exposures in the sex-linked recessive lethal assay in Drosophila. One method proposed for quantitating food consumption by Drosophila is to measure the incorporation of 14C-leucine into the flies during the feeding period. Three sources of variation in the technique of Thompson and Reeder have been identified and characterized. First, the amount of food consumed by individual flies differed by almost 30% in a 24 hr feeding period. Second, the variability from vial to vial (each containing multiple flies) was around 15%. Finally, the amount of food consumed in identical feeding experiments performed over the course of 1 year varied nearly 2-fold. The use of chemical consumption values in place of exposure levels provided a better means of expressing the combined mutagenic response. In addition, the kinetics of food consumption over a 3 day feeding period for exposures to cyclophosphamide which produce lethality were compared to non-lethal exposures. Extensive characterization of lethality induced by exposures to cyclophosphamide demonstrate that the lethality is most likely due to starvation, not chemical toxicity.

Thompson, E.D.; Reeder, B.A.; Bruce, R.D. (Miami Valley Laboratories, Procter Gamble Company, Cincinnati, OH (USA))

1991-01-01

258

Simple, Rapid and Inexpensive Quantitative Fluorescent PCR Method for Detection of Microdeletion and Microduplication Syndromes  

PubMed Central

Because of economic limitations, the cost-effective diagnosis of patients affected with rare microdeletion or microduplication syndromes is a challenge in developing countries. Here we report a sensitive, rapid, and affordable detection method that we have called Microdeletion/Microduplication Quantitative Fluorescent PCR (MQF-PCR). Our procedure is based on the finding of genomic regions with high homology to segments of the critical microdeletion/microduplication region. PCR amplification of both using the same primer pair, establishes competitive kinetics and relative quantification of amplicons, as happens in microsatellite-based Quantitative Fluorescence PCR. We used patients with two common microdeletion syndromes, the Williams-Beuren syndrome (7q11.23 microdeletion) and the 22q11.2 microdeletion syndromes and discovered that MQF-PCR could detect both with 100% sensitivity and 100% specificity. Additionally, we demonstrated that the same principle could be reliably used for detection of microduplication syndromes, by using patients with the Lubs (MECP2 duplication) syndrome and the 17q11.2 microduplication involving the NF1 gene. We propose that MQF-PCR is a useful procedure for laboratory confirmation of the clinical diagnosis of microdeletion/microduplication syndromes, ideally suited for use in developing countries, but having general applicability as well. PMID:23620743

Stofanko, Martin; Goncalves-Dornelas, Higgor; Cunha, Pricila Silva; Pena, Heloisa B.; Vianna-Morgante, Angela M.; Pena, Sergio Danilo Junho

2013-01-01

259

Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results  

E-print Network

PNNL-14537 Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results S.J. Smith E;PNNL-14537 Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results PNNL Research Report (Jan 2004) 2 ABSTRACT A global, self-consistent estimate of sulfur dioxide emissions over the last one

Hultman, Nathan E.

260

Depth determination for shallow teleseismic earthquakes Methods and results  

SciTech Connect

Contemporary methods used to determine depths of moderate-sized shallow teleseismic earthquakes are described. These include techniques based on surface wave spectra, and methods which estimate focal depth from the waveforms of body waves. The advantages of different methods and their limitations are discussed, and significant results for plate tectonics, obtained in the last five years by the application of these methods, are presented. 119 references.

Stein, S.; Wiens, D.A.

1986-11-01

261

Depth determination for shallow teleseismic earthquakes Methods and results  

NASA Technical Reports Server (NTRS)

Contemporary methods used to determine depths of moderate-sized shallow teleseismic earthquakes are described. These include techniques based on surface wave spectra, and methods which estimate focal depth from the waveforms of body waves. The advantages of different methods and their limitations are discussed, and significant results for plate tectonics, obtained in the last five years by the application of these methods, are presented.

Stein, Seth; Wiens, Douglas A.

1986-01-01

262

Biotechnol. Appl. Biochem. (2006) 44, 18 (Printed in Great Britain) doi:10.1042/BA20050218 1 Development of quantitative PCR methods to analyse neural  

E-print Network

and regeneration, and neural stem and progenitor cells have proven promising for neuroregeneration in numerous-lineage-specific markers. These methods provide more rapid and read- ily quantitative results when compared with immuno into many specialized cell types makes them highly promising for tissue engineering and regeneration efforts

Schaffer, David V.

263

A convenient method for the quantitative determination of elemental sulfur in coal by HPLC analysis of perchloroethylene extracts  

USGS Publications Warehouse

A convenient method for the quantitative determination of elemental sulfur in coal is described. Elemental sulfur is extracted from the coal with hot perchloroethylene (PCE) (tetrachloroethene, C2Cl4) and quantitatively determined by HPLC analysis on a C18 reverse-phase column using UV detection. Calibration solutions were prepared from sublimed sulfur. Results of quantitative HPLC analyses agreed with those of a chemical/spectroscopic analysis. The HPLC method was found to be linear over the concentration range of 6 ?? 10-4 to 2 ?? 10-2 g/L. The lower detection limit was 4 ?? 10-4 g/L, which for a coal sample of 20 g is equivalent to 0.0006% by weight of coal. Since elemental sulfur is known to react slowly with hydrocarbons at the temperature of boiling PCE, standard solutions of sulfur in PCE were heated with coals from the Argonne Premium Coal Sample program. Pseudo-first-order uptake of sulfur by the coals was observed over several weeks of heating. For the Illinois No. 6 premium coal, the rate constant for sulfur uptake was 9.7 ?? 10-7 s-1, too small for retrograde reactions between solubilized sulfur and coal to cause a significant loss in elemental sulfur isolated during the analytical extraction. No elemental sulfur was produced when the following pure compounds were heated to reflux in PCE for up to 1 week: benzyl sulfide, octyl sulfide, thiane, thiophene, benzothiophene, dibenzothiophene, sulfuric acid, or ferrous sulfate. A sluury of mineral pyrite in PCE contained elemental sulfur which increased in concentration with heating time. ?? 1993 American Chemical Society.

Buchanan, D.H.; Coombs, K.J.; Murphy, P.M.; Chaven, C.

1993-01-01

264

A Simple, Quantitative Method Using Alginate Gel to Determine Rat Colonic Tumor Volume In Vivo  

PubMed Central

Many studies of the response of colonic tumors to therapeutics use tumor multiplicity as the endpoint to determine the effectiveness of the agent. These studies can be greatly enhanced by accurate measurements of tumor volume. Here we present a quantitative method to easily and accurately determine colonic tumor volume. This approach uses a biocompatible alginate to create a negative mold of a tumor-bearing colon; this mold is then used to make positive casts of dental stone that replicate the shape of each original tumor. The weight of the dental stone cast correlates highly with the weight of the dissected tumors. After refinement of the technique, overall error in tumor volume was 16.9% ± 7.9% and includes error from both the alginate and dental stone procedures. Because this technique is limited to molding of tumors in the colon, we utilized the ApcPirc/+ rat, which has a propensity for developing colonic tumors that reflect the location of the majority of human intestinal tumors. We have successfully used the described method to determine tumor volumes ranging from 4 to 196 mm3. Alginate molding combined with dental stone casting is a facile method for determining tumor volume in vivo without costly equipment or knowledge of analytic software. This broadly accessible method creates the opportunity to objectively study colonic tumors over time in living animals in conjunction with other experiments and without transferring animals from the facility where they are maintained. PMID:24674588

Irving, Amy A; Young, Lindsay B; Pleiman, Jennifer K; Konrath, Michael J; Marzella, Blake; Nonte, Michael; Cacciatore, Justin; Ford, Madeline R; Clipson, Linda; Amos-Landgraf, James M; Dove, William F

2014-01-01

265

Application of quantitative 1H-NMR method to determination of gentiopicroside in Gentianae radix and Gentianae scabrae radix.  

PubMed

A quantitative (1)H-NMR method (qHNMR) was used to measure gentiopicroside content in Gentianae radix and Gentianae scabrae radix. Gentiopicroside is a major component of Gentianae radix and Gentianae scabrae radix. The purity of gentiopicroside was calculated from the ratio of the intensity of the H-3 signal at ? 7.44 ppm or the H-8 signal at ? 5.78 ppm in methanol-d 4 of gentiopicroside to that of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability by using potassium hydrogen phthalate of certified reference material (CRM) grade. As a result, the gentiopicroside content in two lots of Gentianae radix as determined by qHNMR was found to be 1.76 and 2.17 %, respectively. The gentiopicroside content in two lots of Gentianae scabrae radix was 2.73 and 3.99 %, respectively. We demonstrated that this method is useful for the quantitative analysis of crude drugs. PMID:24687868

Tanaka, Rie; Hasebe, Yuko; Nagatsu, Akito

2014-07-01

266

Rapid and Inexpensive Screening of Genomic Copy Number Variations Using a Novel Quantitative Fluorescent PCR Method  

PubMed Central

Detection of human microdeletion and microduplication syndromes poses significant burden on public healthcare systems in developing countries. With genome-wide diagnostic assays frequently inaccessible, targeted low-cost PCR-based approaches are preferred. However, their reproducibility depends on equally efficient amplification using a number of target and control primers. To address this, the recently described technique called Microdeletion/Microduplication Quantitative Fluorescent PCR (MQF-PCR) was shown to reliably detect four human syndromes by quantifying DNA amplification in an internally controlled PCR reaction. Here, we confirm its utility in the detection of eight human microdeletion syndromes, including the more common WAGR, Smith-Magenis, and Potocki-Lupski syndromes with 100% sensitivity and 100% specificity. We present selection, design, and performance evaluation of detection primers using variety of approaches. We conclude that MQF-PCR is an easily adaptable method for detection of human pathological chromosomal aberrations. PMID:24288428

Han, Joan C.; Elsea, Sarah H.; Pena, Heloisa B.; Pena, Sergio Danilo Junho

2013-01-01

267

Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip  

PubMed Central

It has been observed that microfluidic chips used for synthesizing 18F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e., electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, a calibration of Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles. PMID:19847018

Cho, Jennifer S; Taschereau, Richard; Olma, Sebastian; Liu, Kan; Chen, Yi-Chun; Shen, Clifton K-F; van Dam, R Michael; Chatziioannou, Arion F.

2009-01-01

268

Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip  

NASA Astrophysics Data System (ADS)

It has been observed that microfluidic chips used for synthesizing 18F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e. electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge-coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, the calibration of a Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles.

Cho, Jennifer S.; Taschereau, Richard; Olma, Sebastian; Liu, Kan; Chen, Yi-Chun; K-F Shen, Clifton; van Dam, R. Michael; Chatziioannou, Arion F.

2009-11-01

269

Rapid method for the quantitative determination of efavirenz in human plasma.  

PubMed

A pharmacokinetic interaction study between efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor used in the treatment of HIV-1 infection, and an African traditional medicine, African potato in human subjects was undertaken. This necessitated the development and validation of a quantitative method for the analysis of EFV in plasma. A simple mobile phase consisting of 0.1M formic acid, acetonitrile and methanol (43:52:5) was pumped at a low flow rate of 0.3 ml/min through a reverse phase Phenomenex Luna C(18) (2) (5 microm, 150 mm x 2.0mm i.d.) column maintained at 40 degrees C. Diclofenac sodium was used as an internal standard (IS) and EFV and IS were monitored at 247 nm and 275 nm, respectively. A simple and rapid sample preparation involved the addition of mobile phase to 100 microl of plasma to precipitate plasma proteins followed by direct injection of 10 microl of supernatant onto the column. The procedures were validated according to international standards with good reproducibility and linear response (r=0.9990). The intra- and inter-day accuracies were between 12.3 and 17.7% at the LLOQ and between -5.8 and 9.1% for the QC samples. The intra- and inter-day precision of EFV determinations were 5.1 or less and 7.2% RSD or less, respectively across the entire QC concentration range. Mean recovery based on high, medium and low quality control standards ranged between 92.7 and 94.1% with %RSD values better than 3%. Plasma samples were evaluated for short-term (ambient temperature for 6h) and long-term (-10+/-2 degrees C for 60 days) storage conditions and were found to be stable. The method described is cost-effective and has the necessary accuracy and precision for the rapid quantitative determination of EFV in human plasma. PMID:19375262

Mogatle, Seloi; Kanfer, Isadore

2009-07-12

270

Dans Revive the Past : Proceedings of the 39th Annual Conference of Computer Applications and Quantitative Methods in Archaeology (CAA), Beijing, China, 12-16  

E-print Network

and Quantitative Methods in Archaeology (CAA), Beijing, China, 12-16 April 2011 - Annual Conference of Computer Applications and Quantitative Methods in Archaeology (CAA 2011), Beijing : Chine (2011) - http://hal-paris1 manuscript, published in "Annual Conference of Computer Applications and Quantitative Methods in Archaeology

Paris-Sud XI, Université de

271

Arts therapies students’ scores in profession-related variables: Quantitative results of a longitudinal study  

Microsoft Academic Search

This longitudinal study investigated arts therapies students’ (N?=?51) scores in the following variables: career commitment, professional identity, need for occupational and training information, and perceived environmental and personal barriers to career decision-making. Key results suggest that students’ professional identity and career commitment significantly increased during training. Scores of dance movement therapy students, followed by art therapy students, were overall significantly

Hod Orkibi

2012-01-01

272

A quantitative real-time PCR method for monitoring Clostridium botulinum type A in rice samples.  

PubMed

A quantitative real-time PCR using SYBR Green dye was developed to target the neurotoxin type A (boNT/A) gene of Clostridium botulinum type A. Primer specificity was confirmed by analyzing 63 strains including 5 strains of C. botulinum type A and 11 of non-type A C. botulinum. The highly similar amplification efficiencies of the real-time PCR assay were observed for 5 strains of C. botulinum type A. The DNA extraction with NucliSENS miniMAG provided sufficient performance to obtain the purified DNA from steamed rice samples and to develop the standard curve for the enumeration of C. botulinum in steamed rice samples. The real-time PCR assay could detect 10 cells per milliliter of 10 x rice homogenate, thus indicating that more than 100 C. botulinum cells per g of rice sample was quantifiable by the real-time PCR assay. The inoculation of aseptic rice samples with low numbers of C. botulinum type A cells revealed that the fate of inoculated C. botulinum type A cells in rice samples could be monitored accurately by the real-time PCR assay. These results indicate that the real-time PCR assay developed in this study provides rapid, effective, and quantitative monitoring of C. botulinum in steamed rice samples. PMID:20377957

Takahashi, Hajime; Takakura, Chikako; Kimura, Bon

2010-04-01

273

Total reflection x-ray fluorescence spectroscopy (TXRF) a new high sensitivity (PPT) quantitative method for forensic and environmental samples  

SciTech Connect

Total Reflection X-Ray Fluorescence (TYRF) Spectroscopy instrumentation has recently become available on the U.S. commercial market. This x-ray excited method is touted for its sensitivity (parts per trillion), quantitative ability without the need for multi-element standards and lack of response change to matrix element differences. It has been promoted for use in forensic science and on environmental samples. This paper will discuss the results of a blind studies, wherein well characterized samples of forensic interest and environmental water proficiency tests were submitted for determination of elemental composition and concentration. The results indicate that this instrumentation should be considered by those laboratories analyzing materials at low (trace) concentrations or small (microscopical) size.

Kubic, T.A.; Amray, M.S. [ATOMIKA, Bedford, MA (United States); Reus, U. [ATOMKIA Instruments, Munich (Germany)] [and others

1995-12-31

274

Evaluation of a rapid, quantitative real-time PCR method for enumeration of pathogenic Candida cells in water  

USGS Publications Warehouse

Quantitative PCR (QPCR) technology, incorporating fluorigenic 5' nuclease (TaqMan) chemistry, was utilized for the specific detection and quantification of six pathogenic species of Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis, C. glabrata and C. lusitaniae) in water. Known numbers of target cells were added to distilled and tap water samples, filtered, and disrupted directly on the membranes for recovery of DNA for QPCR analysis. The assay's sensitivities were between one and three cells per filter. The accuracy of the cell estimates was between 50 and 200% of their true value (95% confidence level). In similar tests with surface water samples, the presence of PCR inhibitory compounds necessitated further purification and/or dilution of the DNA extracts, with resultant reductions in sensitivity but generally not in quantitative accuracy. Analyses of a series of freshwater samples collected from a recreational beach showed positive correlations between the QPCR results and colony counts of the corresponding target species. Positive correlations were also seen between the cell quantities of the target Candida species detected in these analyses and colony counts of Enterococcus organisms. With a combined sample processing and analysis time of less than 4 h, this method shows great promise as a tool for rapidly assessing potential exposures to waterborne pathogenic Candida species from drinking and recreational waters and may have applications in the detection of fecal pollution.

Brinkman, Nichole E.; Haugland, Richard A.; Wymer, Larry J.; Byappanahalli, Muruleedhara; Whitman, Richard L.; Vesper, Stephen J.

2003-01-01

275

Evaluation of a Rapid, Quantitative Real-Time PCR Method for Enumeration of Pathogenic Candida Cells in Water  

PubMed Central

Quantitative PCR (QPCR) technology, incorporating fluorigenic 5? nuclease (TaqMan) chemistry, was utilized for the specific detection and quantification of six pathogenic species of Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis, C. glabrata and C. lusitaniae) in water. Known numbers of target cells were added to distilled and tap water samples, filtered, and disrupted directly on the membranes for recovery of DNA for QPCR analysis. The assay's sensitivities were between one and three cells per filter. The accuracy of the cell estimates was between 50 and 200% of their true value (95% confidence level). In similar tests with surface water samples, the presence of PCR inhibitory compounds necessitated further purification and/or dilution of the DNA extracts, with resultant reductions in sensitivity but generally not in quantitative accuracy. Analyses of a series of freshwater samples collected from a recreational beach showed positive correlations between the QPCR results and colony counts of the corresponding target species. Positive correlations were also seen between the cell quantities of the target Candida species detected in these analyses and colony counts of Enterococcus organisms. With a combined sample processing and analysis time of less than 4 h, this method shows great promise as a tool for rapidly assessing potential exposures to waterborne pathogenic Candida species from drinking and recreational waters and may have applications in the detection of fecal pollution. PMID:12620869

Brinkman, Nichole E.; Haugland, Richard A.; Wymer, Larry J.; Byappanahalli, Muruleedhara; Whitman, Richard L.; Vesper, Stephen J.

2003-01-01

276

Recent Advances in Human Quantitative-Trait-Locus Mapping: Comparison of Methods for Discordant Sibling Pairs  

PubMed Central

Extreme discordant sibling pairs (EDSPs) are theoretically powerful for the mapping of quantitative-trait loci (QTLs) in humans. EDSPs have not been used much in practice, however, because of the need to screen very large populations to find enough pairs that are extreme and discordant. Given appropriate statistical methods, another alternative is to use moderately discordant sibling pairs (MDSPs)—pairs that are discordant but not at the far extremes of the distribution. Such pairs can be powerful yet far easier to collect than extreme discordant pairs. Recent work on statistical methods for QTL mapping in humans has included a number of methods that, though not developed specifically for discordant pairs, may well be powerful for MDSPs and possibly even EDSPs. In the present article, we survey the new statistics and discuss their applicability to discordant pairs. We then use simulation to study the type I error and the power of various statistics for EDSPs and for MDSPs. We conclude that the best statistic(s) for discordant pairs (moderate or extreme) is (are) to be found among the new statistics. We suggest that the new statistics are appropriate for many other designs as well—and that, in fact, they open the way for the exploration of entirely novel designs. PMID:12970846

Szatkiewicz, Jin P.; T.Cuenco, Karen; Feingold, Eleanor

2003-01-01

277

Quantitative analysis of the lamellarity of giant liposomes prepared by the inverted emulsion method.  

PubMed

The inverted emulsion method is used to prepare giant liposomes by pushing water-in-oil droplets through the oil/water interface into an aqueous medium. Due to the high encapsulation efficiency of proteins under physiological conditions and the simplicity of the protocol, it has been widely used to prepare various cell models. However, the lamellarity of liposomes prepared by this method has not been evaluated quantitatively. Here, we prepared liposomes that were partially stained with a fluorescent dye, and analyzed their fluorescence intensity under an epifluorescence microscope. The fluorescence intensities of the membranes of individual liposomes were plotted against their diameter. The plots showed discrete distributions, which were classified into several groups. The group with the lowest fluorescence intensity was determined to be unilamellar by monitoring the exchangeability of the inner and the outer solutions of the liposomes in the presence of the pore-forming toxin ?-hemolysin. Increasing the lipid concentration dissolved in oil increased the number of liposomes ?100 times. However, almost all the liposomes were unilamellar even at saturating lipid concentrations. We also investigated the effects of lipid composition and liposome content, such as highly concentrated actin filaments and Xenopus egg extracts, on the lamellarity of the liposomes. Remarkably, over 90% of the liposomes were unilamellar under all conditions examined. We conclude that the inverted emulsion method can be used to efficiently prepare giant unilamellar liposomes and is useful for designing cell models. PMID:25028876

Chiba, Masataka; Miyazaki, Makito; Ishiwata, Shin'ichi

2014-07-15

278

Quantitatively estimating defects in graphene devices using discharge current analysis method.  

PubMed

Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 10(14)/cm(2), which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication. PMID:24811431

Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

2014-01-01

279

Problems of a thermionic space NPS reactor unit quantitative reliability assessment on the basis of ground development results  

SciTech Connect

The paper sets forth major problems that arose in the course of a quantitative assessment of reliability of a TOPAZ-2 space NPS reactor unit performed on the basis of ground development results. Proposals are made on the possible ways to solve those problems through development and introduction of individual standards especially for the ground development stage, which would specify the assessment algorithm and censoring rules, and exclude a number of existing uncertainties when making a decision on going to flight testing. {copyright} {ital 1997 American Institute of Physics.}

Ponomarev-Stepnoi, N.N.; Nechaev, Y.A.; Khazanovich, I.M.; Samodelov, V.N. [RRC Kurchatov Institute Moscow123182 (Russia); Pavlov, K.A. [Russian Federation Ministry of Defense Central Scientific-Research Institute of Space Force MoscowK-160 (Russia)

1997-01-01

280

Quantifying social norms: by coupling the ecosystem management concept and semi-quantitative sociological methods  

NASA Astrophysics Data System (ADS)

Over recent decades, human-induced environmental changes have steadily and rapidly grown in intensity and impact to where they now often exceed natural impacts. As one of important components of human activities, social norms play key roles in environmental and natural resources management. But the lack of relevant quantitative data about social norms greatly limits our scientific understanding of the complex linkages between humans and nature, and hampers our solving of pressing environmental and social problems. In this study, we built a quantified method by coupling the ecosystem management concept, semi-quantitative sociological methods and mathematical statistics. We got the quantified value of social norms from two parts, whether the content of social norms coincide with the concept of ecosystem management (content value) and how about the performance after social norms were put into implementation (implementation value) . First, we separately identified 12 core elements of ecosystem management and 16 indexes of social norms, and then matched them one by one. According to their matched degree, we got the content value of social norms. Second, we selected 8 key factors that can represent the performance of social norms after they were put into implementation, and then we got the implementation value by Delph method. Adding these two parts values, we got the final value of each social norms. Third, we conducted a case study in Heihe river basin, the second largest inland river in China, by selecting 12 official edicts related to the river basin ecosystem management of Heihe River Basin. By doing so, we first got the qualified data of social norms which can be directly applied to the research that involved observational or experimental data collection of natural processes. Second, each value was supported by specific contents, so it can assist creating a clear road map for building or revising management and policy guidelines. For example, in this case study, the final quantified data of each social norm showed highly positive correlations with their content value rather than their implementation value, which implied the final value of social norms are mainly affected by the content of social norms. And the implementation of social norms had reached a relatively high degree compare to their theoretical maxvalue (from 71.29% to 80.25%) because of the compelling force of themselves, while the content value of social norms is so weak (from 16.69% to 30.62%) that urgently need to be improved. Third, the method can be extended to quantify the social norms of other ecosystems and further contributed to our understanding of the Coupled Human and Natural Systems and sustainability research.;

Zhang, D.; Xu, H.

2012-12-01

281

A novel method for quantitative determination of tea polysaccharide by resonance light scattering  

NASA Astrophysics Data System (ADS)

A new method for the determination of tea polysaccharide (TPS) in green tea ( Camellia sinensis) leaves has been developed. The method was based on the enhancement of resonance light scattering (RLS) of TPS in the presence of cetylpyridinium chloride (CPC)-NaOH system. Under the optimum conditions, the RLS intensity of CPC was greatly enhanced by adding TPS. The maximum peak of the enhanced RLS spectra was located at 484.02 nm. The enhanced RLS intensity was proportional to the concentration of TPS in the range of 2.0-20 ?g/ml. It showed that the new method and phenol-sulfuric acid method give some equivalent results by measuring the standard compounds. The recoveries of the two methods were 96.39-103.7% (novel method) and 100.15-103.65% (phenol-sulfuric acid method), respectively. However, it showed that the two methods were different to some extent. The new method offered a limit of detection (LOD) of 0.047 ?g/ml, whereas the phenol-sulfuric acid method gives a LOD of 1.54 ?g/ml. Interfered experiment demonstrated that the new method had highly selectivity, and was more suitable for the determination of TPS than phenol-sulfuric method. Stability test showed that new method had good stability. Moreover, the proposed method owns the advantages of easy operation, rapidity and practicability, which suggested that the proposed method could be satisfactorily applied to the determination of TPS in green tea.

Wei, Xinlin; Xi, Xionggang; Wu, Muxia; Wang, Yuanfeng

2011-09-01

282

Sensitive and selective gas chromatographic methods for the quantitation of camphor, menthol and methyl salicylate from human plasma  

Microsoft Academic Search

Analytical methods using gas chromatography–flame ionization detection (GC–FID) for the quantitation of camphor and menthol and GC–MS for the quantitation of methyl salicylate have been developed for measurement of low concentrations from human plasma. Anethole serves as the internal standard for camphor and menthol and ethyl salicylate serves as the internal standard for methyl salicylate. Plasma samples undergo multiple, sequential

Jennifer S Valdez; Debra K Martin; Michael Mayersohn

1999-01-01

283

Cloned plasmid DNA fragments as calibrators for controlling GMOs: different real-time duplex quantitative PCR methods.  

PubMed

Analytical real-time PCR technology is a powerful tool for implementation of the GMO labeling regulations enforced in the EU. The quality of analytical measurement data obtained by quantitative real-time PCR depends on the correct use of calibrator and reference materials (RMs). For GMO methods of analysis, the choice of appropriate RMs is currently under debate. So far, genomic DNA solutions from certified reference materials (CRMs) are most often used as calibrators for GMO quantification by means of real-time PCR. However, due to some intrinsic features of these CRMs, errors may be expected in the estimations of DNA sequence quantities. In this paper, two new real-time PCR methods are presented for Roundup Ready soybean, in which two types of plasmid DNA fragments are used as calibrators. Single-target plasmids (STPs) diluted in a background of genomic DNA were used in the first method. Multiple-target plasmids (MTPs) containing both sequences in one molecule were used as calibrators for the second method. Both methods simultaneously detect a promoter 35S sequence as GMO-specific target and a lectin gene sequence as endogenous reference target in a duplex PCR. For the estimation of relative GMO percentages both "delta C(T)" and "standard curve" approaches are tested. Delta C(T) methods are based on direct comparison of measured C(T) values of both the GMO-specific target and the endogenous target. Standard curve methods measure absolute amounts of target copies or haploid genome equivalents. A duplex delta C(T) method with STP calibrators performed at least as well as a similar method with genomic DNA calibrators from commercial CRMs. Besides this, high quality results were obtained with a standard curve method using MTP calibrators. This paper demonstrates that plasmid DNA molecules containing either one or multiple target sequences form perfect alternative calibrators for GMO quantification and are especially suitable for duplex PCR reactions. PMID:14689155

Taverniers, Isabel; Van Bockstaele, Erik; De Loose, Marc

2004-03-01

284

Methods for a longitudinal quantitative outcome with a multivariate Gaussian distribution multi-dimensionally censored by therapeutic intervention.  

PubMed

In longitudinal studies, a quantitative outcome (such as blood pressure) may be altered during follow-up by the administration of a non-randomized, non-trial intervention (such as anti-hypertensive medication) that may seriously bias the study results. Current methods mainly address this issue for cross-sectional studies. For longitudinal data, the current methods are either restricted to a specific longitudinal data structure or are valid only under special circumstances. We propose two new methods for estimation of covariate effects on the underlying (untreated) general longitudinal outcomes: a single imputation method employing a modified expectation-maximization (EM)-type algorithm and a multiple imputation (MI) method utilizing a modified Monte Carlo EM-MI algorithm. Each method can be implemented as one-step, two-step, and full-iteration algorithms. They combine the advantages of the current statistical methods while reducing their restrictive assumptions and generalizing them to realistic scenarios. The proposed methods replace intractable numerical integration of a multi-dimensionally censored MVN posterior distribution with a simplified, sufficiently accurate approximation. It is particularly attractive when outcomes reach a plateau after intervention due to various reasons. Methods are studied via simulation and applied to data from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study of treatment for type 1 diabetes. Methods proved to be robust to high dimensions, large amounts of censored data, low within-subject correlation, and when subjects receive non-trial intervention to treat the underlying condition only (with high Y), or for treatment in the majority of subjects (with high Y) in combination with prevention for a small fraction of subjects (with normal Y). PMID:24258796

Sun, Wanjie; Larsen, Michael D; Lachin, John M

2014-04-15

285

Application of X-ray absorption fine structure method for the quantitative analysis of hexavalent chromium in chromate conversion coating and plastic.  

PubMed

The X-ray absorption fine structure method was applied for the quantitative analysis of hexavalent Cr in electronic products. The pre-edge peak intensity of the Cr K-edge increased according to the hexavalent Cr amount, and the hexavalent Cr ratio was calculated quantitatively by using the intensity. By combining with inductively coupled plasma atomic emission spectroscopy measurement results that gave the total Cr amount, the absolute amount of hexavalent Cr in chromate conversion coating and plastic samples could be evaluated. The results obtained by this method were in good agreement with those obtained by the chemical analysis method. This method can be successfully applied for the determination of hexavalent Cr amount in electronic products such as chromate conversion coating and plastic. PMID:24694696

Oki, Mitsuhiro; Morimoto, Sayaka; Muramatsu, Miho; Yoshiki, Masahiko; Takenaka, Miyuki

2014-04-01

286

Multimodal quantitative neuroimaging databases and methods: the Cuban Human Brain Mapping Project.  

PubMed

This article reviews the contributions of the Cuban Neuroscience Center to the evolution of the statistical parametric mapping (SPM) of quantitative Multimodal Neuroimages (qMN), from its inception to more recent work. Attention is limited to methods that compare individual qMN to normative databases (n/qMN). This evolution is described in three successive stages: (a) the development of one variant of normative topographical quantitative EEG (n/qEEG-top) which carries out statistical comparison of individual EEG spectral topographies with regard to a normative database--as part of the now popular SPM of brain descriptive parameters; (b) the development of n/qEEG tomography (n/qEEG-TOM), which employs brain electrical tomography (BET) to calculate voxelwise SPM maps of source spectral features with respect to a norm; (c) the development of a more general n/qMN by substituting EEG parameters with other neuroimaging descriptive parameters to obtain SPM maps. The study also describes the creation of Cuban normative databases, starting with the Cuban EEG database obtained in the early 90s, and more recently, the Cuban Human Brain Mapping Project (CHBMP). This project has created a 240 subject database of the normal Cuban population, obtained from a population-based random sample, comprising clinical, neuropsychological, EEG, MRI and SPECT data for the same subjects. Examples of clinical studies using qMN are given and, more importantly, receiver operator characteristics (ROC) analyses of the different developments document a sustained effort to assess the clinical usefulness of the techniques. PMID:21870466

Hernandez-Gonzalez, Gertrudis; Bringas-Vega, Maria L; Galán-Garcia, Lidice; Bosch-Bayard, Jorge; Lorenzo-Ceballos, Yenisleidy; Melie-Garcia, Lester; Valdes-Urrutia, Lourdes; Cobas-Ruiz, Marcia; Valdes-Sosa, Pedro A

2011-07-01

287

Network 'Small-World-Ness': A Quantitative Method for Determining Canonical Network Equivalence  

PubMed Central

Background Many technological, biological, social, and information networks fall into the broad class of ‘small-world’ networks: they have tightly interconnected clusters of nodes, and a shortest mean path length that is similar to a matched random graph (same number of nodes and edges). This semi-quantitative definition leads to a categorical distinction (‘small/not-small’) rather than a quantitative, continuous grading of networks, and can lead to uncertainty about a network's small-world status. Moreover, systems described by small-world networks are often studied using an equivalent canonical network model – the Watts-Strogatz (WS) model. However, the process of establishing an equivalent WS model is imprecise and there is a pressing need to discover ways in which this equivalence may be quantified. Methodology/Principal Findings We defined a precise measure of ‘small-world-ness’ S based on the trade off between high local clustering and short path length. A network is now deemed a ‘small-world’ if S>1 - an assertion which may be tested statistically. We then examined the behavior of S on a large data-set of real-world systems. We found that all these systems were linked by a linear relationship between their S values and the network size n. Moreover, we show a method for assigning a unique Watts-Strogatz (WS) model to any real-world network, and show analytically that the WS models associated with our sample of networks also show linearity between S and n. Linearity between S and n is not, however, inevitable, and neither is S maximal for an arbitrary network of given size. Linearity may, however, be explained by a common limiting growth process. Conclusions/Significance We have shown how the notion of a small-world network may be quantified. Several key properties of the metric are described and the use of WS canonical models is placed on a more secure footing. PMID:18446219

Humphries, Mark D.; Gurney, Kevin

2008-01-01

288

mcrA-Targeted Real-Time Quantitative PCR Method To Examine Methanogen Communities?  

PubMed Central

Methanogens are of great importance in carbon cycling and alternative energy production, but quantitation with culture-based methods is time-consuming and biased against methanogen groups that are difficult to cultivate in a laboratory. For these reasons, methanogens are typically studied through culture-independent molecular techniques. We developed a SYBR green I quantitative PCR (qPCR) assay to quantify total numbers of methyl coenzyme M reductase ?-subunit (mcrA) genes. TaqMan probes were also designed to target nine different phylogenetic groups of methanogens in qPCR assays. Total mcrA and mcrA levels of different methanogen phylogenetic groups were determined from six samples: four samples from anaerobic digesters used to treat either primarily cow or pig manure and two aliquots from an acidic peat sample stored at 4°C or 20°C. Only members of the Methanosaetaceae, Methanosarcina, Methanobacteriaceae, and Methanocorpusculaceae and Fen cluster were detected in the environmental samples. The three samples obtained from cow manure digesters were dominated by members of the genus Methanosarcina, whereas the sample from the pig manure digester contained detectable levels of only members of the Methanobacteriaceae. The acidic peat samples were dominated by both Methanosarcina spp. and members of the Fen cluster. In two of the manure digester samples only one methanogen group was detected, but in both of the acidic peat samples and two of the manure digester samples, multiple methanogen groups were detected. The TaqMan qPCR assays were successfully able to determine the environmental abundance of different phylogenetic groups of methanogens, including several groups with few or no cultivated members. PMID:19447957

Steinberg, Lisa M.; Regan, John M.

2009-01-01

289

A Novel Method for Relative Quantitation of N-Glycans by Isotopic Labeling Using 18O-Water  

PubMed Central

Quantitation is an essential aspect of comprehensive glycomics study. Here, a novel isotopic-labeling method is described for N-glycan quantitation using 18O-water. The incorporation of the 18O-labeling into the reducing end of N-glycans is simply and efficiently achieved during peptide-N4-(N-acetyl-?-glucosaminyl) asparagine amidase F release. This process provides a 2-Da mass difference compared with the N-glycans released in 16O-water. A mathematical calculation method was also developed to determine the 18O/16O ratios from isotopic peaks. Application of this method to several standard glycoprotein mixtures and human serum demonstrated that this method can facilitate the relative quantitation of N-glycans over a linear dynamic range of two orders, with high accuracy and reproducibility.

Tao, Shujuan; Orlando, Ron

2014-01-01

290

A novel quantitative dual-isotope method for simultaneous ventilation and perfusion lung SPET.  

PubMed

A quantitative dual-isotope single-photon emission tomography (SPET) technique for the assessment of lung ventilation (V) and perfusion (Q) using, respectively, technetium-99m labelled Technegas (140 keV) and indium-113m labelled macro-aggregated albumin (392 keV), is presented, validated and clinically tested in a healthy volunteer. In order to assess V, Q and V/Q distributions in quantitative terms, algorithms which correct for down scattering, photon scattering and attenuation, as well as an organ outline algorithm, were implemented. Scatter and down-scatter correction were made in the spatial domain by pixel-wise image subtraction of projection-dependent global scattering factors obtained from the energy domain. The attenuation correction was based on an iterative projection/back-projection method. All studies were made on a three-headed SPET system (Trionix) with medium-energy parallel-hole collimators. The set of input data for quantification was based on SPET acquisition of emission data in four separate energy windows, the associated cumulative energy spectra and transmission data. The attenuation correction routine as well as the edge detection algorithm utilized data from (99m)Tc transmission tomography. Attenuation data for (113m)In were obtained by linear scaling of the (99m)Tc attenuation maps. The correction algorithms were experimentally validated with a stack phantom system and applied on a healthy volunteer. The mean difference between the corrected SPET data of the dense stack lung phantom and those obtained from the corresponding scatter- and attenuation-"free" version was only 1.9% for (99m)Tc and 0.9% for (113m)In. The estimated fractional V/Q distribution in the 3-D lung phantom volume had its peak at V/Q=1, with a width (FWHM) of 0.31 due to noise, particularly in the (113m)In images, and to partial volume effects. For a healthy volunteer, the corresponding values were 0.9 and 0.35, respectively. This method allows accurate assessment of radionuclide distribution on a regional basis. For basic lung physiology and clinical practice, the method allows assessment of the global frequency functions of the V, Q and V/Q distributions. PMID:12111126

Sánchez-Crespo, Alejandro; Petersson, Johan; Nyren, Sven; Mure, Margareta; Glenny, Robb W; Thorell, Jan-Olov; Jacobsson, Hans; Lindahl, Sten G E; Larsson, Stig A

2002-07-01

291

An optimized sensitive method for quantitation of DNA/RNA viruses in heparinized and cryopreserved plasma.  

PubMed

Sodium heparin, an anticoagulant used widely for blood collection, has been known to inhibit DNA polymerase activity in polymerase chain reaction (PCR) assays. However, all cryopreserved plasma samples collected in the 1980s and early 1990s at the Multicenter AIDS Cohort Study were from heparin-treated blood, which poses a problem in quantifying the target nucleic acids contained in those samples by PCR assay. In this study, a nucleic acid extraction procedure was optimized to remove the heparin from extracted nucleic acids. Using this optimized method, similar human immunodeficiency virus 1 (HIV-1) and cytomegalovirus (CMV) loads of these viruses that were added to normal donor blood from ethylenediaminetetraacetic acid (EDTA), acid citrate dextrose (ACD) or sodium heparin tubes were detected by reverse transcriptase (RT) real-time PCR and real-time PCR. Comparable HIV-1 and CMV loads were also detected in the blood of persons with active HIV-1 and CMV infections collected in EDTA-, ACD- or sodium heparin-treated tubes by RT real-time and real-time PCR. The findings showed that the optimized nucleic acid extraction procedure efficiently removes the heparin inhibition effect on the performance of real-time PCR. This method could be used to extract nucleic acids from archived, heparinized plasma for PCR based quantitation of target molecules. PMID:21645549

Ding, Ming; Bullotta, Arlene; Caruso, Lori; Gupta, Phalguni; Rinaldo, Charles R; Chen, Yue

2011-09-01

292

A rapid and direct method for the quantitative determination of tryptophan in the intact protein  

PubMed Central

1. A method is given for the quantitative determination of free tryptophan or tryptophan in the intact protein by treating with ninhydrin in a mixture of formic acid and hydrochloric acid (reagent b), for 10min at 100°C. Glycyltryptophan was used as a standard for the determination of tryptophan in the intact protein. The extinction at 390nm was linear in the range 0.05–0.5?mol for free tryptophan (?7120) and 0.05–0.30?mol for glycyltryptophan (?15400). 2. Free tryptophan in the presence of protein may be determined by treating with ninhydrin in a mixture of acetic acid and 0.6m-phosphoric acid (reagent a) for 10min at 100°C, the extinction being linear for tryptophan in the range 0.05–0.9?mol. N-Terminal tryptophan peptides also give the typical yellow product on treatment with reagent a. 3. Tryptophan content of several pure intact proteins when treated with the above method gave values in good agreement with those reported by others. A mean tryptophan content of 11.25 (s.e.m. ±0.08) ?mol/100mg of protein was found in rat brain during development from 1 to 82 days after birth. PMID:5451912

Gaitonde, M. K.; Dovey, T.

1970-01-01

293

Laboratory Evaluations of the Enterococcus qPCR Method for Recreational Water Quality Testing: Method Performance and Sources of Uncertainty in Quantitative Measurements  

EPA Science Inventory

The BEACH Act of 2000 directed the U.S. EPA to establish more expeditious methods for the detection of pathogen indicators in coastal waters, as well as new water quality criteria based on these methods. Progress has been made in developing a quantitative PCR (qPCR) method for en...

294

Development of a new quantitative X-ray microanalysis method for electron microscopy.  

PubMed

Quantitative X-ray microanalysis of thick samples is usually performed by measuring the characteristic X-ray intensities of each element in a sample and in corresponding standards. The ratio of the measured intensities from the unknown material to that from the standard is related to the concentration using the ZAF or ?(?z) equations. Under optimal conditions, accuracies approaching 1% are possible. However, all the experimental conditions must remain the same during the sample and standard measurements. This is not possible with cold field emission scanning electron microscopes (FE-SEMs) where beam current can fluctuate around 5% in its stable regime. Very little work has been done on variable beam current conditions (Griffin, B.J. & Nockolds, C.E., Scanning 13, 307-312, 1991), and none relating to cold FE-SEM applications. To address this issue, a new method was developed using a single spectral measurement. It is similar in approach to the Cliff-Lorimer method developed for the analytical transmission electron microscope. However, corrections are made for X rays generated from thick specimens using the ratio of the characteristic X-ray intensities of two elements in the same material. The proposed method utilizes the ratio of the intensity of a characteristic X-ray normalized by the sum of X-ray intensities of all the elements measured for the sample, which should also reduce the amplitude of error propagation. Uncertainties in the physical parameters of X-ray generation are corrected using a calibration factor that must be previously acquired or calculated. As an example, when this method was applied to the calculation of the composition of Au-Cu National Institute of Standards and Technology standards measured with a cold field emission source SEM, relative accuracies better than 5% were obtained. PMID:20961482

Horny, Paula; Lifshin, Eric; Campbell, Helen; Gauvin, Raynald

2010-12-01

295

Monochloramine disinfection kinetics of Nitrosomonas europaea by propidium monoazide quantitative PCR and Live/Dead BacLight Methods  

EPA Science Inventory

Monochloramine disinfection kinetics were determined for the pure culture ammonia-oxidizing bacterium Nitrosomonas europaea (ATCC 19718) by two culture independent methods: (1) LIVE/DEAD® BacLight? (LD) and (2) propidium monoazide quantitative PCR (PMA-qPCR). Both methods were f...

296

Determination of Calcium in Cereal with Flame Atomic Absorption Spectroscopy: An Experiment for a Quantitative Methods of Analysis Course  

ERIC Educational Resources Information Center

An experiment for determination of calcium in cereal using two-increment standard addition method in conjunction with flame atomic absorption spectroscopy (FAAS) is demonstrated. The experiment is intended to introduce students to the principles of atomic absorption spectroscopy giving them hands on experience using quantitative methods of…

Bazzi, Ali; Kreuz, Bette; Fischer, Jeffrey

2004-01-01

297

A Quantitative Study of a Software Tool that Supports a Part-Complete Solution Method on Learning Outcomes  

ERIC Educational Resources Information Center

This paper reports on the findings from a quantitative research study into the use of a software tool that was built to support a part-complete solution method (PCSM) for the learning of computer programming. The use of part-complete solutions to programming problems is one of the methods that can be used to reduce the cognitive load that students…

Garner, Stuart

2009-01-01

298

Understanding Variation in Treatment Effects in Education Impact Evaluations: An Overview of Quantitative Methods. NCEE 2014-4017  

ERIC Educational Resources Information Center

This report summarizes the complex research literature on quantitative methods for assessing how impacts of educational interventions on instructional practices and student learning differ across students, educators, and schools. It also provides technical guidance about the use and interpretation of these methods. The research topics addressed…

Schochet, Peter Z.; Puma, Mike; Deke, John

2014-01-01

299

Colloquium on Textile Reinforced Structures (CTRS4) 1 Quantitative methods used to characterize the impregnation of a  

E-print Network

4th Colloquium on Textile Reinforced Structures (CTRS4) 1 Quantitative methods used to characterize level of the yarn / matrix interface, in the case of Textile Reinforced Concrete (TRC). These methods strength (BENTUR AND MINDESS [3]). Textile reinforced concrete (TRC) is a fiber concrete composite material

Paris-Sud XI, Université de

300

Quantitative X-Ray Diffraction Analysis of Asbestos by the Silver Membrane Filter Method: Application to Chrysotile  

Microsoft Academic Search

A method is described for the quantitative analysis of microgram quantities of chrysotile. This method utilizes X-ray diffraction combined with an X-ray absorption correction procedure, based on the use of a silver membrane filter and includes a dispersion technique that eliminates the possibility of chrysotile fiber alterations. It also proposes an appropriate value for the deposition area of the sample

S. PULEDDA; A. MARCONI

1990-01-01

301

Research and Evaluation in Education and Psychology: Integrating Diversity with Quantitative, Qualitative, and Mixed Methods. Second Edition  

ERIC Educational Resources Information Center

In this new edition, the author explains quantitative, qualitative, and mixed methods, and incorporates the viewpoints of various research paradigms (postpositivist, constructivist, transformative, and pragmatic) into descriptions of these methods. Special emphasis is provided for conducting research in culturally complex communities. Each chapter…

Mertens, Donna M.

2004-01-01

302

A novel method for quantitative monitoring of transplanted islets of Langerhans by positive contrast magnetic resonance imaging  

PubMed Central

The Automatic Quantitative Ultrashort Echo Time imaging (AQUTE) protocol for serial MRI allows quantitative in-vivo monitoring of iron labeled pancreatic islets of Langerhans transplanted into the liver, quantifying graft implantation and persistence in a rodent model. Rats (n=14), transplanted with iron-oxide loaded cells (0–4000 islet equivalents, IEQ), were imaged using a 3D radial ultrashort echo time difference technique (dUTE) on a Siemens MAGNETOM 3T clinical scanner up to 5 months post-surgery. In-vivo 3D dUTE images gave positive contrast from labeled cells, suppressing liver signal and small vessels, allowing automatic quantification. Position of labeled islet clusters was consistent over time and quantification of hyperintense pixels correlated with the number of injected IEQs (R2= 0.898, p < 0.0001), and showed persistence over time (5 months post-transplantation). Automatic quantification was superior to standard imaging and manual counting methods, due to the uniform suppressed background and high contrast, resulting in significant timesavings, reproducibility and ease of quantification. 3D coverage of the whole liver in the absence of cardiac/respiratory artifact provided further improvement over conventional imaging. This imaging protocol reliably quantifies transplanted islet mass and has high translational potential to clinical studies of transplanted pancreatic islets. PMID:21564535

Crowe, Lindsey A; Ris, Frederic; Nielles-Vallespin, Sonia; Speier, Peter; Masson, Solange; Armanet, Mathieu; Morel, P; Toso, Christian; Bosco, Domenico; Berney, Thierry; Vallee, Jean-Paul

2011-01-01

303

A new quantitative screening method for removable prosthesis using pressure-indicating paste.  

PubMed

Aim of this study was to quantitatively evaluate the adaptation of the denture base to the mucosa using a non-setting pressure-indicating paste and to examine the relationship between quality of fit and the need for denture relining. A total of 123 dentures from 70 partially edentulous patients were studied. Examination paste extruded from the tip of the 18-G needle was applied to those denture surfaces contacting the alveolar crest. The denture was manually positioned with all clasps engaged on abutment teeth, and adaptation was assessed through paste distribution. Multiple logistic regression was used to analyse variables associated with diagnosing the need for a denture reline, producing odds ratios and 95% confidence intervals. The spread width was inversely proportional to the gap between the denture and mucosa. Regression analysis revealed statistically significant associations between the need for a denture reline and both the paste spread width and the duration of denture use. According to ROC curve analysis of the 'reline' and 'non-reline' groups, the need for a denture reline was indicated at a paste spread width of 2·0 mm or less. At this 2·0-mm threshold, the sensitivity was 85·1% and the specificity was 75·0%. The fit of removable denture bases was quantitatively evaluated by measuring the spread width of non-setting pressure-indicating paste extruded onto denture fit surfaces. The results suggest that the paste spread width is a useful parameter for discriminating the need for a denture reline. PMID:24894573

Sanagawa, T; Hara, T; Minagi, S

2014-10-01

304

Some results on numerical methods for hyperbolic conservation laws  

SciTech Connect

This dissertation contains some results on the numerical solutions of hyperbolic conservation laws. (1) The author introduced an artificial compression method as a correction to the basic ENO schemes. The method successfully prevents contact discontinuities from being smeared. This is achieved by increasing the slopes of the ENO reconstructions in such a way that the essentially non-oscillatory property of the schemes is kept. He analyzes the non-oscillatory property of the new artificial compression method by applying it to the UNO scheme which is a second order accurate ENO scheme, and proves that the resulting scheme is indeed non-oscillatory. Extensive 1-D numerical results and some preliminary 2-D ones are provided to show the strong performance of the method. (2) He combines the ENO schemes and the centered difference schemes into self-adjusting hybrid schemes which will be called the localized ENO schemes. At or near the jumps, he uses the ENO schemes with the field by field decompositions, otherwise he simply uses the centered difference schemes without the field by field decompositions. The method involves a new interpolation analysis. In the numerical experiments on several standard test problems, the quality of the numerical results of this method is close to that of the pure ENO results. The localized ENO schemes can be equipped with the above artificial compression method. In this way, he dramatically improves the resolutions of the contact discontinuities at very little additional costs. (3) He introduces a space-time mesh refinement method for time dependent problems.

Yang Huanan.

1989-01-01

305

Implementation and quantitative evaluation of analytical methods for attenuation correction in SPECT: a phantom study  

NASA Astrophysics Data System (ADS)

Three differing exact methods of inverting the two-dimensional (2D) exponential Radon transform were implemented and evaluated quantitatively with a phantom study. The phantom had the shape of a pie-chart divided into six cavities, each 480 ml in volume and 10 cm in height, that were symmetrically positioned in a cylinder that was 20 cm in diameter and 10 cm in height. This phantom tests for linearity between true activity concentration and measured activity concentration, and it is denoted as a linearity phantom in the present study. Each cavity contained a different concentration of a homogeneous solution of 99mTc (74, 148, 222, 296, 370 and 444 kBq ml-1). Data acquisition was performed with two energy windows: a 20% photopeak energy window set symmetrically over the 140 keV of 99mTc and a secondary 5% energy window set over the 122 keV peak. We optimized a triple-energy window scatter correction method for a gamma camera-collimator system to obtain accurate scatter-corrected projections. A circular ROI 3 cm in diameter was identified over each cavity region, and count density (counts per pixel) was calculated. This value was converted to activity concentration (kBq ml-1) using a cross-calibration coefficient between SPECT counts and the gamma well counter. The relation between true activity (x) and measured activity concentration (y) was fitted to a line using the least-squares method. Regression lines were y = 0.63+1.0255x (R2 = 0.9987), y = -2.62+1.0278x (R2 = 0.9995), and y = 0.092+1.0241x (R2 = 0.9989) for the Bellini, Inouye and Metz-Pan methods respectively. In another phantom study using two different types of phantoms, contrast of a cold region in the two was 96% and 101% for all three methods. Combined optimized scatter correction and analytical attenuation correction methods achieve good accuracy in quantification of activity distribution with a uniform attenuating medium.

Shinohara, Hiroyuki; Yamamoto, Tomoaki; Kuniyasu, Yoshio; Hashimoto, Takeyuki; Yokoi, Takashi

1999-10-01

306

Quantitative analysis of ecological effects for land use planning based on ecological footprint method: a case research in Nanyang City  

NASA Astrophysics Data System (ADS)

The research of coordinated development between land use and ecological building is a new problem with the development of country economy, whose intention is to improve economy development and protect eco-environment in order to realize regional sustainable development. Evaluating human effects on the ecosystem by a comprehensive, scientific and quantitative method is a critical issue in the process of general land use planning. At present, ecological footprint methodology, as an excellent educational tool applicable to global issues, is essential for quantifying humanity's consumption of natural capital, for overall assessments of human impact on earth as well as for general land use planning. However, quantitative studies on the development trends of ecological footprint (EF) time series and biological capacity (BC) time series in a given region are still rare. Taking Nanyang City as a case study, this paper presents two quantitative estimate indices over time scale called the change rate and scissors difference to quantitatively analyze the trends of EF and BC over the planning period in general land use planning form 1997-2004 and to evaluate the ecological effects of the land use general planning form 1997 to.2010. The results showed that: 1 In Nanyang city, trends of the per capita EF and BC were on the way round, and the ecological deficit enhanced from 1997 to 2010. 2 The difference between the two development trends of per capita EF and BC had been increasing rapidly and the conflict between the EF and BC was aggravated from 1997 to 2010. 3 The general land use planning (1997 - 2010) of Nanyang city had produced some positive effects on the local ecosystem, but the expected biological capacity in 2010 can hardly be realized following this trend. Therefore, this paper introduces a "trinity" land use model in the guidelines of environment- friendly land use pattern and based on the actual situation of Nanyang city, with the systemic synthesis of land utilization of the cities, the village and the suburb as a principal part and the land development reorganization and the ecological environment construction as the key point.

Zhang, Jing; Liu, Yaolin; Chen, Xinming

2008-10-01

307

UV partial least-squares calibration and liquid chromatographic methods for direct quantitation of levofloxacin in urine.  

PubMed

Levofloxacin was determined in human urine samples by application of a spectrophotometric multivariate calibration partial least-squares (PLS-1) method. A calibration set consisting of standards was prepared by using a multilevel multifactor experimental design. In order to ensure accurate results, the calibration matrix included a urine sample free of levofloxacin (i.e., urine blank). The components of the calibration matrix were levofloxacin and urine. The concentration of levofloxacin ranged from 0.5 to 16.5 microg/mL. Different urine concentrations were used as the second component of the calibration matrix in order to include the information inherent in the changes in the UV spectrum for urine upon dilution. In addition, a high-performance liquid chromatographic method was proposed. In this method, a Shim-pack amino column was used at ambient temperature with a mobile phase of 25 mM potassium dihydrogen phosphate (pH adjusted to 3.1 with phosphoric acid)-acetonitrile (70 + 30, v/v), and the flow rate was 1 mL/min. UV detection at 293 nm was used for quantitation. The proposed methods were applied to the determination of the dissolution rate for tablets containing levofloxacin. The urinary excretion pattern for the cumulative amount of levoflacin excreted was also calculated. PMID:17955970

El-Gindy, Alaa; Emara, Samy; Mostafa, Ahmed

2007-01-01

308

Revisiting the Isobole and Related Quantitative Methods for Assessing Drug Synergism  

PubMed Central

The isobole is well established and commonly used in the quantitative study of agonist drug combinations. This article reviews the isobole, its derivation from the concept of dose equivalence, and its usefulness in providing the predicted effect of an agonist drug combination, a topic not discussed in pharmacology textbooks. This review addresses that topic and also shows that an alternate method, called “Bliss independence,” is inconsistent with the isobolar approach and also has a less clear conceptual basis. In its simplest application the isobole is the familiar linear plot in Cartesian coordinates with intercepts representing the individual drug potencies. It is also shown that the isobole can be nonlinear, a fact recognized by its founder (Loewe) but neglected or rejected by virtually all other users. Whether its shape is linear or nonlinear the isobole is equally useful in detecting synergism and antagonism for drug combinations, and its theoretical basis leads to calculations of the expected effect of a drug combination. Numerous applications of isoboles in preclinical testing have shown that synergism or antagonism is not only a property of the two agonist drugs; the dose ratio is also important, a fact of potential importance to the design and testing of drug combinations in clinical trials. PMID:22511201

2012-01-01

309

Quantitative assessment of MS plaques and brain atrophy in multiple sclerosis using semiautomatic segmentation method  

NASA Astrophysics Data System (ADS)

Quantitative magnetic resonance (MR) imaging of the brain is useful in multiple sclerosis (MS) in order to obtain reliable indices of disease progression. The goal of this project was to estimate the total volume of gliotic and non gliotic plaques in chronic progressive multiple sclerosis with the help of a semiautomatic segmentation method developed at the Ragnar Granit Institute. Youth developed program running on a PC based computer provides de displays of the segmented data, in addition to the volumetric analyses. The volumetric accuracy of the program was demonstrated by segmenting MR images of fluid filed syringes. An anatomical atlas is to be incorporated in the segmentation system to estimate the distribution of MS plaques in various neural pathways of the brain. A total package including MS plaque volume estimation, estimation of brain atrophy and ventricular enlargement, distribution of MS plaques in different neural segments of the brain has ben planned for the near future. Our study confirmed that total lesion volumes in chronic MS disease show a poor correlation to EDSS scores but show a positive correlation to neuropsychological scores. Therefore accurate total volume measurements of MS plaques using the developed semiautomatic segmentation technique helped us to evaluate the degree of neuropsychological impairment.

Heinonen, Tomi; Dastidar, Prasun; Ryymin, Pertti; Lahtinen, Antti J.; Eskola, Hannu; Malmivuo, Jaakko

1997-05-01

310

Quantitative method for measuring heat flux emitted from a cryogenic object  

DOEpatents

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infra-red sensing devices.

Duncan, Robert V. (Tijeras, NM)

1993-01-01

311

Quantitative method for measuring heat flux emitted from a cryogenic object  

DOEpatents

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

Duncan, R.V.

1993-03-16

312

Toward a quantitative account of pitch distribution in spontaneous narrative: method and validation.  

PubMed

Pitch is well-known both to animate human discourse and to convey meaning in communication. The study of the statistical population distributions of pitch in discourse will undoubtedly benefit from methodological improvements. The current investigation examines a method that parameterizes pitch in discourse as musical pitch interval H measured in units of cents and that disaggregates the sequence of peak word-pitches using tools employed in time-series analysis and digital signal processing. The investigators test the proposed methodology by its application to distributions in pitch interval of the peak word-pitch (collectively called the discourse gamut) that occur in simulated and actual spontaneous emotive narratives obtained from 17 middle-aged African-American adults. The analysis, in rigorous tests, not only faithfully reproduced simulated distributions imbedded in realistic time series that drift and include pitch breaks, but the protocol also reveals that the empirical distributions exhibit a common hidden structure when normalized to a slowly varying mode (called the gamut root) of their respective probability density functions. Quantitative differences between narratives reveal the speakers' relative propensity for the use of pitch levels corresponding to elevated degrees of a discourse gamut (the "e-la") superimposed upon a continuum that conforms systematically to an asymmetric Laplace distribution. PMID:23654400

Matteson, Samuel E; Olness, Gloria Streit; Caplow, Nancy J

2013-05-01

313

Challenges of Interdisciplinary Research: Reconciling Qualitative and Quantitative Methods for Understanding Human-Landscape Systems  

NASA Astrophysics Data System (ADS)

While interdisciplinary research is increasingly practiced as a way to transcend the limitations of individual disciplines, our concepts, and methods are primarily rooted in the disciplines that shape the way we think about the world and how we conduct research. While natural and social scientists may share a general understanding of how science is conducted, disciplinary differences in methodologies quickly emerge during interdisciplinary research efforts. This paper briefly introduces and reviews different philosophical underpinnings of quantitative and qualitative methodological approaches and introduces the idea that a pragmatic, realistic approach may allow natural and social scientists to work together productively. While realism assumes that there is a reality that exists independently of our perceptions, the work of scientists is to explore the mechanisms by which actions cause meaningful outcomes and the conditions under which the mechanisms can act. Our task as interdisciplinary researchers is to use the insights of our disciplines in the context of the problem to co-produce an explanation for the variables of interest. Research on qualities necessary for successful interdisciplinary researchers is also discussed along with recent efforts by funding agencies and academia to increase capacities for interdisciplinary research.

Lach, Denise

2014-01-01

314

Effect of esterification condensation on the Folin-Ciocalteu method for the quantitative measurement of total phenols.  

PubMed

The Folin-Ciocalteu method is widely applied for the determination of the total phenolic contents in natural products. This method is significantly affected by the addition of sodium carbonate. The currently applied Folin-Ciocalteu methods may have been modified without any validation in the quantitative standards and the order of processes. In this study, serial experiments were performed to investigate the effect of phenolic calibrations based on the classic Folin-Ciocalteu method. Esterification condensations were observed in the assays with prior basification for gallic acid and catechin used as quantitative standards. The phenolic contents obtained in the samples differed depending on when basification occurred compared with the gallic acid calibration. The bias of the classic Folin-Ciocalteu method derived from cross-linkage of molecules was first defined in this study. The performance of the Folin-Ciocalteu method is optimised and validated again. PMID:25306311

Chen, Liang-Yu; Cheng, Chien-Wei; Liang, Ji-Yuan

2015-03-01

315

Performance of a new quantitative method for assessing dural ectasia in patients with FBN1 mutations and clinical features of Marfan syndrome  

Microsoft Academic Search

Introduction  This study presents a comparison of established methods for measuring dural ectasia with a new quantitative method of assessing\\u000a this clinical feature.\\u000a \\u000a \\u000a \\u000a Methods  Seventeen patients with an identified mutation in FBN1 were examined for dural ectasia. The results were compared with 17 age- and sex-matched controls. Our images were also evaluated\\u000a using the two methods of quantifying dural ectasia, namely those

Bahar Söylen; Kerstin Hinz; Jana Prokein; Hartmut Becker; Jörg Schmidtke; Mine Arslan-Kirchner

2009-01-01

316

Quantitative ultrasound method to detect and monitor laser-induced cavitation bubbles  

PubMed Central

An ultrasound technique to measure the spatial and temporal behavior of the laser-induced cavitation bubble is introduced. The cavitation bubbles were formed in water and in gels using a nanosecond pulsed Nd:YAG laser operating at 532 nm. A focused, single-element, 25-MHz ultrasound transducer was employed both to detect the acoustic emission generated by plasma expansion and to acoustically probe the bubble at different stages of its evolution. The arrival time of the passive acoustic emission was used to estimate the location of the cavitation bubble’s origin and the time of flight of the ultrasound pulse-echo signal was used to define its spatial extent. The results of ultrasound estimations of the bubble size were compared and found to be in agreement with both the direct optical measurements of the stationary bubble and the theoretical estimates of bubble dynamics derived from the well-known Rayleigh model of a cavity collapse. The results of this study indicate that the proposed quantitative ultrasound technique, capable of detecting and accurately measuring laser-induced cavitation bubbles in water and in a tissue-like medium, could be used in various biomedical and clinical applications. PMID:18601556

Karpiouk, Andrei B.; Aglyamov, Salavat R.; Bourgeois, Frederic; Ben-Yakar, Adela; Emelianov, Stanislav Y.

2008-01-01

317

Initial Results of an MDO Method Evaluation Study  

NASA Technical Reports Server (NTRS)

The NASA Langley MDO method evaluation study seeks to arrive at a set of guidelines for using promising MDO methods by accumulating and analyzing computational data for such methods. The data are collected by conducting a series of re- producible experiments. In the first phase of the study, three MDO methods were implemented in the SIGHT: framework and used to solve a set of ten relatively simple problems. In this paper, we comment on the general considerations for conducting method evaluation studies and report some initial results obtained to date. In particular, although the results are not conclusive because of the small initial test set, other formulations, optimality conditions, and sensitivity of solutions to various perturbations. Optimization algorithms are used to solve a particular MDO formulation. It is then appropriate to speak of local convergence rates and of global convergence properties of an optimization algorithm applied to a specific formulation. An analogous distinction exists in the field of partial differential equations. On the one hand, equations are analyzed in terms of regularity, well-posedness, and the existence and unique- ness of solutions. On the other, one considers numerous algorithms for solving differential equations. The area of MDO methods studies MDO formulations combined with optimization algorithms, although at times the distinction is blurred. It is important to

Alexandrov, Natalia M.; Kodiyalam, Srinivas

1998-01-01

318

Aircraft Engine Gas Path Diagnostic Methods: Public Benchmarking Results  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of aircraft engine health management (EHM) technologies. To help address this issue, a gas path diagnostic benchmark problem has been created and made publicly available. This software tool, referred to as the Propulsion Diagnostic Method Evaluation Strategy (ProDiMES), has been constructed based on feedback provided by the aircraft EHM community. It provides a standard benchmark problem enabling users to develop, evaluate and compare diagnostic methods. This paper will present an overview of ProDiMES along with a description of four gas path diagnostic methods developed and applied to the problem. These methods, which include analytical and empirical diagnostic techniques, will be described and associated blind-test-case metric results will be presented and compared. Lessons learned along with recommendations for improving the public benchmarking processes will also be presented and discussed.

Simon, Donald L.; Borguet, Sebastien; Leonard, Olivier; Zhang, Xiaodong (Frank)

2013-01-01

319

Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.  

PubMed

Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system. PMID:12083257

Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

2002-01-01

320

Spin echo SPI methods for quantitative analysis of fluids in porous media.  

PubMed

Fluid density imaging is highly desirable in a wide variety of porous media measurements. The SPRITE class of MRI methods has proven to be robust and general in their ability to generate density images in porous media, however the short encoding times required, with correspondingly high magnetic field gradient strengths and filter widths, and low flip angle RF pulses, yield sub-optimal S/N images, especially at low static field strength. This paper explores two implementations of pure phase encode spin echo 1D imaging, with application to a proposed new petroleum reservoir core analysis measurement. In the first implementation of the pulse sequence, we modify the spin echo single point imaging (SE-SPI) technique to acquire the k-space origin data point, with a near zero evolution time, from the free induction decay (FID) following a 90 degrees excitation pulse. Subsequent k-space data points are acquired by separately phase encoding individual echoes in a multi-echo acquisition. T(2) attenuation of the echo train yields an image convolution which causes blurring. The T(2) blur effect is moderate for porous media with T(2) lifetime distributions longer than 5 ms. As a robust, high S/N, and fast 1D imaging method, this method will be highly complementary to SPRITE techniques for the quantitative analysis of fluid content in porous media. In the second implementation of the SE-SPI pulse sequence, modification of the basic measurement permits fast determination of spatially resolved T(2) distributions in porous media through separately phase encoding each echo in a multi-echo CPMG pulse train. An individual T(2) weighted image may be acquired from each echo. The echo time (TE) of each T(2) weighted image may be reduced to 500 micros or less. These profiles can be fit to extract a T(2) distribution from each pixel employing a variety of standard inverse Laplace transform methods. Fluid content 1D images are produced as an essential by product of determining the spatially resolved T(2) distribution. These 1D images do not suffer from a T(2) related blurring. The above SE-SPI measurements are combined to generate 1D images of the local saturation and T(2) distribution as a function of saturation, upon centrifugation of petroleum reservoir core samples. The logarithm mean T(2) is observed to shift linearly with water saturation. This new reservoir core analysis measurement may provide a valuable calibration of the Coates equation for irreducible water saturation, which has been widely implemented in NMR well logging measurements. PMID:19307140

Li, Linqing; Han, Hui; Balcom, Bruce J

2009-06-01

321

Spin echo SPI methods for quantitative analysis of fluids in porous media  

NASA Astrophysics Data System (ADS)

Fluid density imaging is highly desirable in a wide variety of porous media measurements. The SPRITE class of MRI methods has proven to be robust and general in their ability to generate density images in porous media, however the short encoding times required, with correspondingly high magnetic field gradient strengths and filter widths, and low flip angle RF pulses, yield sub-optimal S/ N images, especially at low static field strength. This paper explores two implementations of pure phase encode spin echo 1D imaging, with application to a proposed new petroleum reservoir core analysis measurement. In the first implementation of the pulse sequence, we modify the spin echo single point imaging (SE-SPI) technique to acquire the k-space origin data point, with a near zero evolution time, from the free induction decay (FID) following a 90° excitation pulse. Subsequent k-space data points are acquired by separately phase encoding individual echoes in a multi-echo acquisition. T2 attenuation of the echo train yields an image convolution which causes blurring. The T2 blur effect is moderate for porous media with T2 lifetime distributions longer than 5 ms. As a robust, high S/ N, and fast 1D imaging method, this method will be highly complementary to SPRITE techniques for the quantitative analysis of fluid content in porous media. In the second implementation of the SE-SPI pulse sequence, modification of the basic measurement permits fast determination of spatially resolved T2 distributions in porous media through separately phase encoding each echo in a multi-echo CPMG pulse train. An individual T2 weighted image may be acquired from each echo. The echo time (TE) of each T2 weighted image may be reduced to 500 ?s or less. These profiles can be fit to extract a T2 distribution from each pixel employing a variety of standard inverse Laplace transform methods. Fluid content 1D images are produced as an essential by product of determining the spatially resolved T2 distribution. These 1D images do not suffer from a T2 related blurring. The above SE-SPI measurements are combined to generate 1D images of the local saturation and T2 distribution as a function of saturation, upon centrifugation of petroleum reservoir core samples. The logarithm mean T2 is observed to shift linearly with water saturation. This new reservoir core analysis measurement may provide a valuable calibration of the Coates equation for irreducible water saturation, which has been widely implemented in NMR well logging measurements.

Li, Linqing; Han, Hui; Balcom, Bruce J.

2009-06-01

322

Quantitative Human Health Risk Assessment. Phase 1. Review of Methods and Framework Recommendation.  

National Technical Information Service (NTIS)

The purpose of the study was to initiate the process of developing provincial protocols for the application of quantitative human health risk assessment at contaminated sites. This was undertaken via the review of methodologies used by other jurisdictions...

1993-01-01

323

A Quantitative Method to Monitor Reactive Oxygen Species Production by Electron Paramagnetic Resonance in Physiological and Pathological Conditions  

PubMed Central

The growing interest in the role of Reactive Oxygen Species (ROS) and in the assessment of oxidative stress in health and disease clashes with the lack of consensus on reliable quantitative noninvasive methods applicable. The study aimed at demonstrating that a recently developed Electron Paramagnetic Resonance microinvasive method provides direct evidence of the “instantaneous” presence of ROS returning absolute concentration levels that correlate with “a posteriori” assays of ROS-induced damage by means of biomarkers. The reliability of the choice to measure ROS production rate in human capillary blood rather than in plasma was tested (step I). A significant (P < 0.01) linear relationship between EPR data collected on capillary blood versus venous blood (R2 = 0.95), plasma (R2 = 0.82), and erythrocytes (R2 = 0.73) was found. Then (step II) ROS production changes of various subjects' categories, young versus old and healthy versus pathological at rest condition, were found significantly different (range 0.0001–0.05 P level). The comparison of the results with antioxidant capacity and oxidative damage biomarkers concentrations showed that all changes indicating increased oxidative stress are directly related to ROS production increase. Therefore, the adopted method may be an automated technique for a lot of routine in clinical trials. PMID:25374651

Mrakic-Sposta, Simona; Gussoni, Maristella; Montorsi, Michela; Porcelli, Simone; Vezzoli, Alessandra

2014-01-01

324

A rapid method for semi-quantitative analysis of neurite outgrowth from chick DRG explants using image analysis.  

PubMed

Neurite outgrowth from dorsal root ganglion (DRG) explants is a method of evaluating neurotrophic activity of growth factors and neurotrophin mimetics. The drawbacks to this approach are the difficulties in quantifying the response. Neurite counts are time consuming and labour intensive, and the accuracy is often questionable due to branching and fasciculation of the neurites. We report here a method of semi-quantitative analysis of neurite outgrowth from chick DRG explants, using image analysis to quantify the area occupied by neurites emanating from the ganglion. This method is rapid, takes into account both the length and number of neurites, and is unaffected by neurite fasciculation or branching. Primary explants of chick DRGs were treated with the neurotrophins nerve growth factor (NGF) or neurotrophin-3 (NT-3) and with the compound K252a. K252b was tested for potentiation of the response to NT-3. The results show a dose dependent outgrowth of neurites from explants treated with NGF, NT-3 and K252a, and potentiation of the NT-3 response by K252b. These responses were quantified by neurite area quantification using image analysis. We conclude that neurite area measurement using image analysis provides a robust means of evaluating neurotrophic activity of growth factors and neurotrophin mimetics in vitro. PMID:10595705

Bilsland, J; Rigby, M; Young, L; Harper, S

1999-10-15

325

Qualitative and Quantitative Method Comparison in Animal-Assisted Therapy Research  

Microsoft Academic Search

While there have been many presentations and anecdotal evidence in support of AAT, quantitative empirically validated studies are very limited. Without quantitative empirical studies to support the effectiveness of AAT, it remains an unproven complement to traditional physical and psychotherapeutic practices (Kruger & Serpell,2010). The value and importance of non-empirical literature on AAT,including therapists’ observations, various author’s personal experiences, and

Laura Denenholz

2011-01-01

326

Comparison of the Multiple-sample means with composite sample results for fecal indicator bacteria by quantitative PCR and culture  

EPA Science Inventory

ABSTRACT: Few studies have addressed the efficacy of composite sampling for measurement of indicator bacteria by QPCR. In this study, composite results were compared to single sample results for culture- and QPCR-based water quality monitoring. Composite results for both methods ...

327

Binary neutron-star mergers with Whisky and SACRA: First quantitative comparison of results from independent general-relativistic hydrodynamics codes  

SciTech Connect

We present the first quantitative comparison of two independent general-relativistic hydrodynamics codes, the whisky code and the sacra code. We compare the output of simulations starting from the same initial data and carried out with the configuration (numerical methods, grid setup, resolution, gauges) which for each code has been found to give consistent and sufficiently accurate results, in particular, in terms of cleanness of gravitational waveforms. We focus on the quantities that should be conserved during the evolution (rest mass, total mass energy, and total angular momentum) and on the gravitational-wave amplitude and frequency. We find that the results produced by the two codes agree at a reasonable level, with variations in the different quantities but always at better than about 10%.

Baiotti, Luca [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502 (Japan); Institute of Laser Engineering, Osaka University, Suita, 565-0871 (Japan); Shibata, Masaru [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502 (Japan); Yamamoto, Tetsuro [Yugen Club, Toyama, Shinjuku, Tokyo, 162-0052 (Japan)

2010-09-15

328

Binary neutron-star mergers with Whisky and SACRA: First quantitative comparison of results from independent general-relativistic hydrodynamics codes  

NASA Astrophysics Data System (ADS)

We present the first quantitative comparison of two independent general-relativistic hydrodynamics codes, the whisky code and the sacra code. We compare the output of simulations starting from the same initial data and carried out with the configuration (numerical methods, grid setup, resolution, gauges) which for each code has been found to give consistent and sufficiently accurate results, in particular, in terms of cleanness of gravitational waveforms. We focus on the quantities that should be conserved during the evolution (rest mass, total mass energy, and total angular momentum) and on the gravitational-wave amplitude and frequency. We find that the results produced by the two codes agree at a reasonable level, with variations in the different quantities but always at better than about 10%.

Baiotti, Luca; Shibata, Masaru; Yamamoto, Tetsuro

2010-09-01

329

Cloned plasmid DNA fragments as calibrators for controlling GMOs: different real-time duplex quantitative PCR methods  

Microsoft Academic Search

Analytical real-time PCR technology is a powerful tool for implementation of the GMO labeling regulations enforced in the EU. The quality of analytical measurement data obtained by quantitative real-time PCR depends on the correct use of calibrator and reference materials (RMs). For GMO methods of analysis, the choice of appropriate RMs is currently under debate. So far, genomic DNA solutions

Isabel Taverniers; Erik Van Bockstaele; Marc De Loose

2004-01-01

330

Quantitative analysis of ecological effects for land use planning based on ecological footprint method: a case research in Nanyang City  

Microsoft Academic Search

The research of coordinated development between land use and ecological building is a new problem with the development of country economy, whose intention is to improve economy development and protect eco-environment in order to realize regional sustainable development. Evaluating human effects on the ecosystem by a comprehensive, scientific and quantitative method is a critical issue in the process of general

Jing Zhang; Yaolin Liu; Xinming Chen

2008-01-01

331

Quantitative X-RAy Diffraction Analysis of Four Types of Amphibolic Asbestos by the Silver Membrane Filter Method  

Microsoft Academic Search

In this paper, the method that utilizes the X-ray diffraction technique combined with a procedure for X-ray absorption correction, already applied to chrysotile, was extended to the quantitative determination of microgram quantities of four types of amphibolic asbestos. These are: crocidolite, amosite, tremolite and anthophyllite. The effectiveness of the absorption correction procedure, based on the use of a silver membrane

S. Puledda; A. Marconi

1989-01-01

332

"What about People Our Age?" Applying Qualitative and Quantitative Methods to Uncover How Political Ads Alienate College Students  

ERIC Educational Resources Information Center

This study uses a sequential transformative mixed methods research design to explain how political advertising fails to engage college students. Qualitative focus groups examined how college students interpret the value of political advertising to them, and a quantitative manifest content analysis concerning ad framing of more than 100 ads from…

Parmelee, John H.; Perkins, Stephynie C.; Sayre, Judith J.

2007-01-01

333

Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2 ??? C T Method  

Microsoft Academic Search

The two most commonly used methods to analyze data from real-time, quantitative PCR experiments are absolute quantification and relative quantification. Absolute quantification determines the input copy number, usually by relating the PCR signal to a standard curve. Relative quantification relates the PCR signal of the target transcript in a treatment group to that of another sample such as an untreated

Kenneth J. Livak; Thomas D. Schmittgen

2001-01-01

334

Gas chromatographic–mass spectrometric method for the qualitative and quantitative determination of disaccharides and trisaccharides in honey  

Microsoft Academic Search

An improved method has been developed to identify and quantify honey disaccharides and trisaccharides by gas chromatography and mass spectrometry. The procedure, based on mass spectral and retention data (“retention time windows”) determined on two capillary columns with different stationary phases allowed the identification and quantitation in honey of 16 disaccharides and 9 trisaccharides, some of which were not previously

M. L. Sanz; J. Sanz; I. Martínez-Castro

2004-01-01

335

Chromatography–tandem mass spectrometry method for the simultaneous quantitation of metoprolol succinate and simvastatin in human plasma  

Microsoft Academic Search

The liquid chromatographic–tandem mass spectrometry method was developed for the accurate quantitation of metoprolol succinate (MET) and simvastatin (SIM) in human plasma which were obtained from the pharmacokinetic (PK) study. The sample purification and pre-concentration was performed by protein precipitation technique using propranolol hydrochloride as working internal standard (WIS). The chromatographic separation was achieved using an isocratic mobile phase consisting

P. Senthamil Selvan; T. K. Pal

2009-01-01

336

Quantitative evaluation method of the bubble structure of sponge cake by using morphology image processing  

NASA Astrophysics Data System (ADS)

Now a day, many evaluation methods for the food industry by using image processing are proposed. These methods are becoming new evaluation method besides the sensory test and the solid-state measurement that are using for the quality evaluation. An advantage of the image processing is to be able to evaluate objectively. The goal of our research is structure evaluation of sponge cake by using image processing. In this paper, we propose a feature extraction method of the bobble structure in the sponge cake. Analysis of the bubble structure is one of the important properties to understand characteristics of the cake from the image. In order to take the cake image, first we cut cakes and measured that's surface by using the CIS scanner. Because the depth of field of this type scanner is very shallow, the bubble region of the surface has low gray scale values, and it has a feature that is blur. We extracted bubble regions from the surface images based on these features. First, input image is binarized, and the feature of bubble is extracted by the morphology analysis. In order to evaluate the result of feature extraction, we compared correlation with "Size of the bubble" of the sensory test result. From a result, the bubble extraction by using morphology analysis gives good correlation. It is shown that our method is as well as the subjectivity evaluation.

Tatebe, Hironobu; Kato, Kunihito; Yamamoto, Kazuhiko; Katsuta, Yukio; Nonaka, Masahiko

2005-12-01

337

Quantitative comparison of alternative methods for coarse-graining biological networks  

NASA Astrophysics Data System (ADS)

Markov models and master equations are a powerful means of modeling dynamic processes like protein conformational changes. However, these models are often difficult to understand because of the enormous number of components and connections between them. Therefore, a variety of methods have been developed to facilitate understanding by coarse-graining these complex models. Here, we employ Bayesian model comparison to determine which of these coarse-graining methods provides the models that are most faithful to the original set of states. We find that the Bayesian agglomerative clustering engine and the hierarchical Nyström expansion graph (HNEG) typically provide the best performance. Surprisingly, the original Perron cluster cluster analysis (PCCA) method often provides the next best results, outperforming the newer PCCA+ method and the most probable paths algorithm. We also show that the differences between the models are qualitatively significant, rather than being minor shifts in the boundaries between states. The performance of the methods correlates well with the entropy of the resulting coarse-grainings, suggesting that finding states with more similar populations (i.e., avoiding low population states that may just be noise) gives better results.

Bowman, Gregory R.; Meng, Luming; Huang, Xuhui

2013-09-01

338

Quantitative comparison of alternative methods for coarse-graining biological networks.  

PubMed

Markov models and master equations are a powerful means of modeling dynamic processes like protein conformational changes. However, these models are often difficult to understand because of the enormous number of components and connections between them. Therefore, a variety of methods have been developed to facilitate understanding by coarse-graining these complex models. Here, we employ Bayesian model comparison to determine which of these coarse-graining methods provides the models that are most faithful to the original set of states. We find that the Bayesian agglomerative clustering engine and the hierarchical Nyström expansion graph (HNEG) typically provide the best performance. Surprisingly, the original Perron cluster cluster analysis (PCCA) method often provides the next best results, outperforming the newer PCCA+ method and the most probable paths algorithm. We also show that the differences between the models are qualitatively significant, rather than being minor shifts in the boundaries between states. The performance of the methods correlates well with the entropy of the resulting coarse-grainings, suggesting that finding states with more similar populations (i.e., avoiding low population states that may just be noise) gives better results. PMID:24089717

Bowman, Gregory R; Meng, Luming; Huang, Xuhui

2013-09-28

339

An average enumeration method of hyperspectral imaging data for quantitative evaluation of medical device surface contamination  

PubMed Central

We propose a quantification method called Mapped Average Principal component analysis Score (MAPS) to enumerate the contamination coverage on common medical device surfaces. The method was adapted from conventional Principal Component Analysis (PCA) on non-overlapped regions of a full frame hyperspectral image to resolve the percentage of contamination from the substrate. The concept was proven by using a controlled contamination sample with artificial test soil and color simulating organic mixture, and was further validated using a bacterial system including biofilm on stainless steel surface. We also validate the results of MAPS with other statistical spectral analysis including Spectral Angle Mapper (SAM). The proposed method provides an alternative quantification method for hyperspectral imaging data, which can be easily implemented by basic PCA analysis. PMID:25360377

Le, Hanh N. D.; Kim, Moon S.; Hwang, Jeeseong; Yang, Yi; Thainual, Paweena U; Kang, Jin U.; Kim, Do-Hyun

2014-01-01

340

An average enumeration method of hyperspectral imaging data for quantitative evaluation of medical device surface contamination.  

PubMed

We propose a quantification method called Mapped Average Principal component analysis Score (MAPS) to enumerate the contamination coverage on common medical device surfaces. The method was adapted from conventional Principal Component Analysis (PCA) on non-overlapped regions of a full frame hyperspectral image to resolve the percentage of contamination from the substrate. The concept was proven by using a controlled contamination sample with artificial test soil and color simulating organic mixture, and was further validated using a bacterial system including biofilm on stainless steel surface. We also validate the results of MAPS with other statistical spectral analysis including Spectral Angle Mapper (SAM). The proposed method provides an alternative quantification method for hyperspectral imaging data, which can be easily implemented by basic PCA analysis. PMID:25360377

Le, Hanh N D; Kim, Moon S; Hwang, Jeeseong; Yang, Yi; Thainual, Paweena U; Kang, Jin U; Kim, Do-Hyun

2014-10-01

341

Method for processing wastes resulting from production of phosphorus  

SciTech Connect

The method comprises processing slime and off-gases resulting from the production of phosphorus with an aqueous solution of copper sulphate having a concentration of from 15 to 50% at a temperature within the range of from 20* to 80* C. As a result, two products are obtained, i.e., a liquid product and a solid one. The solid product containing mainly copper phosphide as well as fluorides and chlorides of alkali metals and silicon, and silicates of calcium and aluminum, is used as a modifying and refining agent for hypereutectic silumines and for the manufacture of a copper-phosphorus alloy. The liquid product containing phosphoric acid, sulphuric acid and copper sulphate is used as starting product for the preparation of a copper-containing fertilizer. The method according to the present invention makes it possible to modify the production of phosphorus so as to eliminate the formation of secondary wastes and improve the environmental control.

Alzhanov, T.M.; Bykov, V.I.; Chernogorenko, V.B.; Dmitrenko, V.V.; Ishkhanov, E.S.; Kipchakbaev, A.D.; Koverya, V.M.; Lynchak, K.A.; Markovsky, E.A.; Muchnik, S.V.; Pobortsev, M.E.; Sapian, V.G.; Sergienko, V.Y.; Vopilov, A.N.

1980-03-11

342

Test Results for Entry Guidance Methods for Space Vehicles  

NASA Technical Reports Server (NTRS)

There are a number of approaches to advanced guidance and control that have the potential for achieving the goals of significantly increasing reusable launch vehicle (or any space vehicle that enters an atmosphere) safety and reliability, and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies has recently completed a rigorous testing phase where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. Results show a significant improvement over previous guidance approaches. The two best-scoring algorithm approaches show roughly equivalent results and are ready to be applied to future vehicle concepts.

Hanson, John M.; Jones, Robert E.

2004-01-01

343

Quantitative analysis of a bacteria-derived antibiotic in nematode-infected insects using HPLC–UV and TLC–UV methods  

Microsoft Academic Search

3,5-Dihydroxy-4-isopropylstilbene (ST), an antibiotic produced by the bacterial symbiont Photorhabdus luminescens of the nematodes of the genus Heterorhabditis was determined quantitatively in nematode bacterium-infected insects using HPLC or TLC for separation and UV for quantification. Comparable and reproducible results were obtained with both HPLC–UV and TLC–UV methods. Several factors, including solvents for extraction of the antibiotic from the infected insects,

Kaiji Hu; Jianxiong Li; John M Webster

1997-01-01

344

Quantitation of the main constituents of vanilla by reverse phase HPLC and ultra-high-pressure-liquid-chromatography with UV detection: method validation and performance comparison.  

PubMed

Vanilla's main constituents, i. e., vanillin, para-hydroxybenzaldehyde, and their corresponding acids, can be easily quantified by RP LC with UV detection and external calibration. This paper describes two methods that were developed using HPLC and ultra-high-pressure LC (UHPLC), respectively, and validated according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). Both methods were highly specific, exhibited good linearities with high precision, and achieved good accuracies of quantitative results. The UHPLC method was more sensitive, five times shorter, and gave better peak resolutions than the HPLC alternative. PMID:19714659

Cicchetti, Esmeralda; Chaintreau, Alain

2009-09-01

345

Noninvasive Methods for Quantitating Blood Time Activity Curves from Mouse PET Images Obtained with Fluorine18Fluorodeoxyglucose  

Microsoft Academic Search

The mouse model is currently being explored for various applica tions with PET imaging. Low resolution of current animal scanners relative to mouse size leads to difficulty in quantitating data from mouse PET images. We have, therefore, investigated methods for determining blood time-activity curves (TACs) from mouse PET studies done with fluorine-18-fluorodeoxyglucose (FDG).Methods: Eight mice were fasted, the tail vein

Leeta A. Green; Sanjiv S. Gambhir; Ashok Srinivasan; Pranab K. Banerjee; Carl K. HÃ; Simon R. Cherry; Susan Sharfstein

346

Quantitative nondestructive in-service evaluation of stay cables of cable-stayed bridges: methods and practical experience  

NASA Astrophysics Data System (ADS)

Stay cables of cable-stayed bridges have corrosion protection systems that can be elaborate. For example, such a system may simply consist of one or several coats of paint, or--more complex--of plastic pipes that are wrapped with tape and filled with grout. Frequently, these corrosion protection systems prevent visual inspections. Therefore, alternative nondestructive examination methods are called for. For example, modern dual-function electromagnetic (EM) instruments allow the simultaneous detection of external and internal localized flaws (such as external and internal broken wires and corrosion piting) and the measurement of loss of metallic cross-sectional area (typically caused by external or internal corrosion or wear). Initially developed for mining and skiing applications, these instruments have been successfully used for the inspection of stays of cable-stayed bridges, and for the inspection of guys of smoke stacks, flare stacks, broadcast towers, suspended roofs, etc. As a rule, guys and bridge cables are not subjected to wear and bending stresses. However, their safety can be compromised by corrosion caused by the failure of corrosion protection systems. Furthermore, live loads and wind forces create intermittent tensile stresses that can cause fatigue breaks of wires. This paper discusses the use of dual-function EM instruments for the detection and the nondestructive quantitative evaluation of cable deterioration. It explains the underlying principles. Experiences with this method together with field inspection results will be presented.

Weischedel, Herbert R.; Hoehle, Hans-Werner

1995-05-01

347

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

PubMed

A high-performance liquid chromatography (HPLC) method for the qualitative and quantitative analysis of allantoin in silk and seed of Zea mays has been developed. Allantoin separation in crude extract was achieved using a C 18 column and phosphate buffer solution (pH 3.0) as a mobile phase at ambient temperature at a flow rate of 1.0 mL/min and detected at 210 nm. The results showed that the amount of allantoin in samples was between 14 and 271 mg/100 g of dry plant material. A comprehensive validation of the method including sensitivity, linearity, repeatability, and recovery was conducted. The calibration curve was linear over the range of 0.2-200 microg/mL with a correlation coefficient of r2>0.999. Limit of detection (LOD, S/N=3) and limit of quantification (LOQ) values of the allantoin were 0.05 and 0.2 microg/mL (1.0 and 4.0 ng) respectively. The relative standard deviation (RSD) value of the repeatability was reported within 1.2%. The average recovery of allantoin added to samples was 100.6% with RSD of 1.5%. PMID:18189357

Haghi, Ghasem; Arshi, Rohollah; Safaei, Alireza

2008-02-27

348

Statistical uncertainty and its propagation in the analysis of quantitative polymerase chain reaction data: Comparison of methods.  

PubMed

Most methods for analyzing real-time quantitative polymerase chain reaction (qPCR) data for single experiments estimate the hypothetical cycle 0 signal y0 by first estimating the quantification cycle (Cq) and amplification efficiency (E) from least-squares fits of fluorescence intensity data for cycles near the onset of the growth phase. The resulting y0 values are statistically equivalent to the corresponding Cq if and only if E is taken to be error free. But uncertainty in E usually dominates the total uncertainty in y0, making the latter much degraded in precision compared with Cq. Bias in E can be an even greater source of error in y0. So-called mechanistic models achieve higher precision in estimating y0 by tacitly assuming E=2 in the baseline region and so are subject to this bias error. When used in calibration, the mechanistic y0 is statistically comparable to Cq from the other methods. When a signal threshold yq is used to define Cq, best estimation precision is obtained by setting yq near the maximum signal in the range of fitted cycles, in conflict with common practice in the y0 estimation algorithms. PMID:24991688

Tellinghuisen, Joel; Spiess, Andrej-Nikolai

2014-11-01

349

Development and validation of an RP-HPLC method to quantitate acyclovir in cross-linked chitosan microspheres produced by spray drying.  

PubMed

An accurate, simple, reproducible, and sensitive liquid chromatographic method is developed and validated to quantitate acyclovir (ACV) in cross-linked chitosan microspheres produced by spray drying. The analysis is carried out using a reversed-phase C18 column with UV-vis detection at 254 nm. The mobile phase is diluted with pure water and acetonitrile (95:5 v/v) at a flow-rate of 0.8 mL/min. The parameters used in the validation process are: linearity, range, quantitation limit, detection limit, accuracy, specificity precision, and ruggedness. The retention time of acyclovir is approximately 3.5 min with symmetrical peaks. The linearity in the range of 1-10 microg/mL presents a correlation coefficient of 0.9999. The chitosan and the tripolyphosphate in the formulation do not interfere with the analysis, and the recovery is quantitative. Results are satisfactory, and the method proves to be suitable to quantitate ACV in cross-linked chitosan microspheres. PMID:18647469

Stulzer, Hellen K; Tagliari, Monika Piazzon; Murakami, Fábio S; Silva, Marcos A S; Laranjeira, Mauro C M

2008-07-01

350

The bright knots at the tops of soft X-ray flare loops: Quantitative results from Yohkoh  

NASA Technical Reports Server (NTRS)

Soft X-ray Telescope (SXT) observations from the Japanese Yohkoh spacecraft have shown that confined bright regions are common features at the tops of flare loops throughout most of the duration of the flares. In this paper we present quantitative results for these flare knots, in relation to other flare regions, for four relatively 'simple' flares. Emission measure distributions, electron temperatures, and electron densities are derived from SXT and Yohkoh Bragg Crystal Spectrometer (BCS) observations. The four flares selected are dominated by what appear to be single-loop structures, with bright knots at the loop tops. The flares are neither long-duration nor impulsive events. The spatial distributions of brightness and emission measure in the flares are found to be quite similar for all four events, even though there are significant differences in dynamical behavior between at least two of the events. Temperatures and densities calculated for these flares are consistent with previous results from many solar experiments. An investigation of intensity correlations between adjacent pixels at the tops of the loops suggests the existence of local disturbances in the magnetic loops that occur on spatial scales less than the radii of the loops.

Doschek, G. A.; Strong, K. T.; Tsuneta, S.

1995-01-01

351

Analysis of Perfluorinated Chemicals in Sludge: Method Development and Initial Results  

EPA Science Inventory

A fast, rigorous method was developed to maximize the extraction efficacy for ten perfluorocarboxylic acids and perfluorooctanesulfonate from wastewater-treatment sludge and to quantitate using liquid chromatography, tandem-mass spectrometry (LC/MS/MS). First, organic solvents w...

352

Trajectory planning method for reduced patient risk in image-guided neurosurgery: concept and preliminary results  

NASA Astrophysics Data System (ADS)

We present a new preoperative planning method to quantify and help reduce the risk associated with needle and tool insertion trajectories in image-guided keyhole neurosurgery. The goal is to quantify the risk of a proposed straight trajectory, and/or to find the trajectory with the lowest risk to nearby brain structures based on pre-operative CT/MRI images. The method automatically computes the risk associated with a given trajectory, or finds the trajectory with the lowest risk to nearby brain structures based on preoperative image segmentation and on a risk volume map. The surgeon can revise the suggested trajectory, add a new one using interactive 3D visualization, and obtain a quantitative risk measure. The trajectory risk is evaluated based on the tool placement uncertainty, on the proximity of critical brain structures, and on a predefined table of quantitative geometric risk measures. Our preliminary results on a clinical dataset with eight targets show a significant reduction in trajectory risk and a shortening of the preoperative planning time as compared to the conventional method.

Shamir, Reuben R.; Joskowicz, Leo; Antiga, Luca; Foroni, Roberto I.; Shoshan, Yigal

2010-02-01

353

Supersonic cruise research aircraft structural studies: Methods and results  

NASA Technical Reports Server (NTRS)

NASA Langley Research Center SCAR in-house structural studies are reviewed. In methods development, advances include a new system of integrated computer programs called ISSYS, progress in determining aerodynamic loads and aerodynamically induced structural loads (including those due to gusts), flutter optimization for composite and metal airframe configurations using refined and simplified mathematical models, and synthesis of active controls. Results given address several aspects of various SCR configurations. These results include flutter penalties on composite wing, flutter suppression using active controls, roll control effectiveness, wing tip ground clearance, tail size effect on flutter, engine weight and mass distribution influence on flutter, and strength and flutter optimization of new configurations. The ISSYS system of integrated programs performed well in all the applications illustrated by the results, the diversity of which attests to ISSYS' versatility.

Sobieszczanski-Sobieski, J.; Gross, D.; Kurtze, W.; Newsom, J.; Wrenn, G.; Greene, W.

1981-01-01

354

Methods and preliminary measurement results of liquid Li wettability.  

PubMed

A test of lithium wettability was performed in high vacuum (< 3 × 10(-4) Pa). High magnification images of Li droplets on stainless steel substrates were produced and processed using the MATLAB(®) program to obtain clear image edge points. In contrast to the more standard "?/2" or polynomial fitting methods, ellipse fitting of the complete Li droplet shape resulted in reliable contact angle measurements over a wide range of contact angles. Using the ellipse fitting method, it was observed that the contact angle of a liquid Li droplet on a stainless steel substrate gradually decreased with increasing substrate temperature. The critical wetting temperature of liquid Li on stainless steel was observed to be about 290?°C. PMID:24593360

Zuo, G Z; Hu, J S; Ren, J; Sun, Z; Yang, Q X; Li, J G; Zakharov, L E; Mansfield, D K

2014-02-01

355

Fundamentals of quantitative research  

Microsoft Academic Search

The main purpose of this article is to introduce some important fundamental concepts of quantitative research to readers especially novice researchers. It comprises types of research, definitions of quantitative research, different types and assumptions of quantitative research, when to use and not to use quantitative methods, advantages, common approaches and samples of quantitative research, and common misconceptions. Besides, a set

Suphat Sukamolson

356

Evaluating Learning Style Personalization in Adaptive Systems: Quantitative Methods and Approaches  

Microsoft Academic Search

It is a widely held assumption that learning style is a useful model for quantifying user characteristics for effective personalized learning. We set out to challenge this assumption by discussing the current state of the art, in relation to quantitative evaluations of such systems and also the methodologies that should be employed in such evaluations. We present two case studies

Elizabeth J. Brown; Timothy J. Brailsford; Tony Fisher; Adam Moore

2009-01-01

357

Evaluation of energy dependency of TDCS method for scattering correction in quantitative SPECT  

Microsoft Academic Search

The transmission-dependent convolution subtraction (TDCS) technique is a promising technique in quantitative SPECT to subtract the scatter components from emission images. Usually a 20% photo-peak energy window is used in SPECT acquisitions. So far no investigation has been done to investigate the effect of energy windows to subtract the scatter components from emission images with the TDCS technique. To evaluate

Hossian M Deloar; Hiroshi Watabe; Kyeong Min Kim; T. Aoi; H. Iida

2002-01-01

358

Mixed Method Designs: A Review of Strategies for Blending Quantitative and Qualitative Methodologies  

ERIC Educational Resources Information Center

The historical debate surrounding quantitative and qualitative research paradigms has been at times rather passionate. Arguments for and against methodologies often have centered on the philosophical differences regarding issues such as generalizability, epistemology, and authentic representation of the phenomena under research. More recently,…

Pole, Kathryn

2007-01-01

359

Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors  

Microsoft Academic Search

A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify .sup.233 U,

John T. Caldwell; Walter E. Kunz; James D. Atencio

1984-01-01

360

Methods for Evidence-Based Practice: Quantitative Synthesis of Single-Subject Designs  

ERIC Educational Resources Information Center

Good quantitative evidence does not require large, aggregate group designs. The authors describe ground-breaking work in managing the conceptual and practical demands in developing meta-analytic strategies for single subject designs in an effort to add to evidence-based practice. (Contains 2 figures.)

Shadish, William R.; Rindskopf, David M.

2007-01-01

361

Commutability of the Epstein-Barr Virus WHO International Standard across Two Quantitative PCR Methods.  

PubMed

The commutability of international reference standards is critical for ensuring quantitative agreement across different viral load assays. Here, we demonstrate the commutability of the Epstein-Barr virus (EBV) WHO international standard for the BamHI-W and artus EBV assays. PMID:25078918

Abeynayake, Janaki; Johnson, Ryan; Libiran, Paolo; Sahoo, Malaya K; Cao, Hongbin; Bowen, Raffick; Chan, K C Allen; Le, Quynh-Thu; Pinsky, Benjamin A

2014-10-01

362

Quantitative Analysis of Organic Compounds: A Simple and Rapid Method for Use in Schools  

ERIC Educational Resources Information Center

Describes the procedure for making a quantitative analysis of organic compounds suitable for secondary school chemistry classes. Using the Schoniger procedure, the organic compound, such as PVC, is decomposed in a conical flask with oxygen. The products are absorbed in a suitable liquid and analyzed by titration. (JR)

Schmidt, Hans-Jurgen

1973-01-01

363

A simple LIBS method for fast quantitative analysis of fly ashes  

Microsoft Academic Search

An evaluation of quantitative analysis of major elements (Ca, Al, Mg, Si and Fe) present in fly ashes was made using a simple and cost effective LIBS system. LIBS parameters were optimized to obtain best sensitivity and repeatability. In this purpose different binders were compared, leading to best sensitivity and mechanical stability when a binder containing silver and cellulose was

Alice Stankova; Nicole Gilon; Lionel Dutruch; Viktor Kanicky

2010-01-01

364

Reference Genes Selection for Quantitative Real-Time PCR Using RankAggreg Method in Different Tissues of Capra hircus  

PubMed Central

Identification of reference genes with stable levels of gene expression is an important prerequisite for obtaining reliable results in analysis of gene expression data using quantitative real time PCR (RT-qPCR). Since the underlying assumption of reference genes is that expressed at the exact same level in all sample types, in this study, we evaluated the expression stability of nine most commonly used endogenous controls (GAPDH, ACTB, 18S rRNA, RPS18, HSP-90, ALAS, HMBS, ACAC, and B2M) in four different tissues of the domestic goat, Capra hircus, including liver, visceral, subcutaneous fat and longissimus muscles, across different experimental treatments (a standard diet prepared using the NRC computer software as control and the same diet plus one mg chromium/day). We used six different software programs for ranking of reference genes and found that individual rankings of the genes differed among them. Additionally, there was a significant difference in ranking patterns of the studied genes among different tissues. A rank aggregation method was applied to combine the ranking lists of the six programs to a consensus ranking. Our results revealed that HSP-90 was nearly always among the two most stable genes in all studied tissues. Therefore, it is recommended for accurate normalization of RT-qPCR data in goats, while GAPDH, ACTB, and RPS18 showed the most varied expressions and should be avoided as reference genes. PMID:24358246

Najafpanah, Mohammad Javad; Sadeghi, Mostafa; Bakhtiarizadeh, Mohammad Reza

2013-01-01

365

Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy  

SciTech Connect

To evaluate, during cardiac catheterization, what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer-based quantitative analysis of coronary angiograms was performed on the angiograms of 31 patients with isolated disease of the proximal left anterior descending coronary artery. The angiographic severity of stenosis was compared with the transstenotic pressure gradient measured with the dilation catheter during angioplasty and with the results of exercise thallium scintigraphy. A curvilinear relationship was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal area of obstruction (after subtracting the area of the angioplasty catheter). This relationship was best fitted by the equation: normalized mean pressure gradient . a + b . log (obstruction area), r . .74. The measurements of the percent area of stenosis (cutoff 80%) and of the transstenotic pressure gradient (cutoff 0.30) obtained at rest correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients.

Wijns, W.; Serruys, P.W.; Reiber, J.H.; van den Brand, M.; Simoons, M.L.; Kooijman, C.J.; Balakumaran, K.; Hugenholtz, P.G.

1985-02-01

366

A quantitative interpretation of recent experimental results on stable carbon isotope fractionation by aerobic CH 4-oxidizing bacteria  

NASA Astrophysics Data System (ADS)

A quantitative model of recent laboratory experiments on carbon isotope fractionation by methane-oxidizing bacteria is proposed. The simulated experimental apparatus consists of a bacterial culture with a constant liquid volume, a gas headspace and a methane bubbling mechanism. The relative effects of bacterial growth and transport phenomena that do not depend on cell density are clarified. In all calculations, gas-liquid mass transfer is defined by unconstrained model parameters. Limited mass transfer from the culture into the headspace, rather than the incomplete dissolution of substrate-rich bubbles, seems to have caused an apparent decrease in the measured carbon isotope fractionation. The experimenters attributed this fractionation shift to a growing imbalance among kinetic rates as methane consumption by bacteria increases. Model predictions support this interpretation but also show that changes in carbon isotope fractionation in the course of the experiments cannot be unambiguously correlated with bacterial cell density unless gas-liquid mass transfer parameters are calibrated. Simulations of other laboratory experiments indicate that a reported change in carbon isotope fractionation could, in part at least, be the result of experimental conditions rather than the emergence of a different methane oxidation pathway postulated by the experimenters. A careful evaluation of mass transfer from the liquid culture into the gas headspace is warranted in this type of experiments since isotope fractionation factors are likely to be used in a wide variety of environmental contexts.

Nihous, Gérard C.

2008-09-01

367

A Practical Method of Monitoring the Results of Health Care  

PubMed Central

To meet our goal of improving health care through more productive use of the data we are collecting about the delivery of health care we need to define our concepts of health and quality. The WHO definition of health allows the design of useful functional outcome criteria which give us measurable standards for the outcome of the health care. By recording, retrieving, and reviewing pertinent information from the structure and the process of health care for a valid comparison with its outcome, the most effective and efficient health care is identified. A practical system is presented which identifies the better methods of management and produces the motivation for change that results in improved care. The successful use of this system in a private practice supports its universal adaptability for health care providers. The initial encouraging results suggest that future trials in other types of practices will be even more encouraging.

Daugharty, G. D.

1979-01-01

368

Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples. [Patent application  

DOEpatents

Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fission are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for /sup 239/Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

Caldwell, J.T.; Kunz, W.E.; Cates, M.R.; Franks, L.A.

1982-07-07

369

A 3-Dimensional Absorbed Dose Calculation Method Based on Quantitative SPECT for Radionuclide Therapy: Evaluation for 131I Using Monte Carlo Simulation  

PubMed Central

A general method is presented for patient-specific 3-dimensional absorbed dose calculations based on quantitative SPECT activity measurements. Methods The computational scheme includes a method for registration of the CT image to the SPECT image and position-dependent compensation for attenuation, scatter, and collimator detector response performed as part of an iterative reconstruction method. A method for conversion of the measured activity distribution to a 3-dimensional absorbed dose distribution, based on the EGS4 (electron-gamma shower, version 4) Monte Carlo code, is also included. The accuracy of the activity quantification and the absorbed dose calculation is evaluated on the basis of realistic Monte Carlo–simulated SPECT data, using the SIMIND (simulation of imaging nuclear detectors) program and a voxel-based computer phantom. CT images are obtained from the computer phantom, and realistic patient movements are added relative to the SPECT image. The SPECT-based activity concentration and absorbed dose distributions are compared with the true ones. Results Correction could be made for object scatter, photon attenuation, and scatter penetration in the collimator. However, inaccuracies were imposed by the limited spatial resolution of the SPECT system, for which the collimator response correction did not fully compensate. Conclusion The presented method includes compensation for most parameters degrading the quantitative image information. The compensation methods are based on physical models and therefore are generally applicable to other radionuclides. The proposed evaluation methodology may be used as a basis for future intercomparison of different methods. PMID:12163637

Ljungberg, Michael; Sjogreen, Katarina; Liu, Xiaowei; Frey, Eric; Dewaraja, Yuni; Strand, Sven-Erik

2009-01-01

370

Simple and validated quantitative (1)h NMR method for the determination of methylation, acetylation, and feruloylation degree of pectin.  

PubMed

The knowledge of pectin esterification degree is of primary importance to predict gelling and other properties of pectin from different sources. This paper reports the development of a simple and rapid (1)H NMR-based method for the simultaneous quantitative determination of methylation, acetylation, and feruloylation degree of pectin isolated from various food sources. Pectin esters are hydrolyzed in NaOH/D2O, and the obtained methanol, acetic acid, and ferulic acid are directly measured by (1)H NMR. High accuracy, repeatability, and reproducibility of the method were obtained, and the analysis time is reduced as compared to conventional chromatography- or titration-based methods. PMID:25137229

Müller-Maatsch, Judith; Caligiani, Augusta; Tedeschi, Tullia; Elst, Kathy; Sforza, Stefano

2014-09-17

371

A computational method for the semi-automated quantitative analysis of tympanic membrane perforations and tympanosclerosis.  

PubMed

Tympanic membrane pathological findings such as perforations and tympanosclerotic plaques (along with conductive hearing loss and purulent drainage) are the most typical trademarks of either active or burned-out chronic otitis media. These findings are normally evaluated by an expert using visual subjective analysis. In this work, we present a computational semi-automated method to quantify these pathologies. We also present a validation study of the method using a subset of 39 cases randomly extracted from a set of more than 2000 cases (perforations and tympanosclerosis) of the Hospital de Clínicas de Porto Alegre. The validation was performed using Ground Truth images, generated by experts, and has shown promising results. PMID:19643399

Comunello, Eros; Wangenheim, Aldo von; Junior, Vilson Heck; Dornelles, Cristina; Costa, Sady Selamen

2009-10-01

372

Quantitative real-time PCR method with internal amplification control to quantify cyclopiazonic acid producing molds in foods.  

PubMed

A quantitative TaqMan real-time PCR (qPCR) method that includes an internal amplification control (IAC) to quantify cyclopiazonic acid (CPA)-producing molds in foods has been developed. A specific primer pair (dmaTF/dmaTR) and a TaqMan probe (dmaTp) were designed on the basis of dmaT gene which encodes the enzyme dimethylallyl tryptophan synthase involved in the biosynthesis of CPA. The IAC consisted of a 105 bp chimeric DNA fragment containing a region of the hly gene of Listeria monocytogenes. Thirty-two mold reference strains representing CPA producers and non-producers of different mold species were used in this study. All strains were tested for CPA production by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The functionality of the designed qPCR method was demonstrated by the high linear relationship of the standard curves relating to the dmaT gene copy numbers and the Ct values obtained from the different CPA producers tested. The ability of the qPCR protocol to quantify CPA-producing molds was evaluated in different artificially inoculated foods. A good linear correlation was obtained over the range 1-4 log cfu/g in the different food matrices. The detection limit in all inoculated foods ranged from 1 to 2 log cfu/g. This qPCR protocol including an IAC showed good efficiency to quantify CPA-producing molds in naturally contaminated foods avoiding false negative results. This method could be used to monitor the CPA producers in the HACCP programs to prevent the risk of CPA formation throughout the food chain. PMID:22986206

Rodríguez, Alicia; Werning, María L; Rodríguez, Mar; Bermúdez, Elena; Córdoba, Juan J

2012-12-01

373

Quantitative methods for three-dimensional comparison and petrographic description of chondrites  

SciTech Connect

X-ray computed tomography can be used to generate three-dimensional (3D) volumetric representations of chondritic meteorites. One of the challenges of using collected X-ray tomographic data is the extraction of useful data for 3D petrographic analysis or description. Here, I examine computer-aided quantitative 3D texture metrics that can be used for the classification of chondritic meteorites. These quantitative techniques are extremely useful for discriminating between chondritic materials, but yield little information on the 3D morphology of chondrite components. To investigate the morphology of chondrite minerals such as Fe(Ni) metal and related sulfides, the homology descriptors known as Betti numbers, are examined. Both methodologies are illustrated with theoretical discussion and examples. Betti numbers may be valuable for examining the nature of metal-silicate structural changes within chondrites with increasing degrees of metamorphism.

Friedrich, J.M. (Fordham)

2008-10-20

374

Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volume  

SciTech Connect

Purpose: This study describes the design and characteristics of a highly accurate, precise, and automated single-energy method to quantify percent fibroglandular tissue volume (%FGV) and fibroglandular tissue volume (FGV) using digital screening mammography. Methods: The method uses a breast tissue-equivalent phantom in the unused portion of the mammogram as a reference to estimate breast composition. The phantom is used to calculate breast thickness and composition for each image regardless of x-ray technique or the presence of paddle tilt. The phantom adheres to the top of the mammographic compression paddle and stays in place for both craniocaudal and mediolateral oblique screening views. We describe the automated method to identify the phantom and paddle orientation with a three-dimensional reconstruction least-squares technique. A series of test phantoms, with a breast thickness range of 0.5-8 cm and a %FGV of 0%-100%, were made to test the accuracy and precision of the technique. Results: Using test phantoms, the estimated repeatability standard deviation equaled 2%, with a {+-}2% accuracy for the entire thickness and density ranges. Without correction, paddle tilt was found to create large errors in the measured density values of up to 7%/mm difference from actual breast thickness. This new density measurement is stable over time, with no significant drifts in calibration noted during a four-month period. Comparisons of %FGV to mammographic percent density and left to right breast %FGV were highly correlated (r=0.83 and 0.94, respectively). Conclusions: An automated method for quantifying fibroglandular tissue volume has been developed. It exhibited good accuracy and precision for a broad range of breast thicknesses, paddle tilt angles, and %FGV values. Clinical testing showed high correlation to mammographic density and between left and right breasts.

Malkov, Serghei; Wang, Jeff; Kerlikowske, Karla; Cummings, Steven R.; Shepherd, John A. [Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, California 94143 (United States); Departments of Medicine and Epidemiology and Biostatistics, University of California-San Francisco, San Francisco, California 94143 (United States); Research Institute, California Pacific Medical Center, San Francisco, California 94143 (United States); Department of Radiology and Biomedical Imaging, University of California--San Francisco, San Francisco, California 94143 (United States)

2009-12-15

375

Computerized method and system for teaching prose, document and quantitative literacy  

US Patent & Trademark Office Database

A multimedia computerized literacy system providing for and enhancing the teaching of Literacy Skills to enable people to function more effectively in schools, society, and the workplace. The design of the system is based on the identification and understanding of the structures, contents, and strategies which underlie prose, document, and quantitative literacy. In particular, the system's design is based, in part, on the Knowledge Model Procedure, which builds upon a unique taxonomy of document structures, contents, and strategies in a way that facilitates the transfer of Literacy Skills across the wide array of document types, as well as across quantitative and prose Literacy Skills. In accordance with the Knowledge Model Procedure, the computerized literacy system, through a series of structure and use lessons, provides students with the skills to perform document, prose, and quantitative tasks of increasing complexity. The system uses specially designed exercise and practice tasks to enhance students' abilities to perform literacy tasks commonly required of adolescents and adults in modern society.

1999-04-13

376

A Simple ERP Method for Quantitative Analysis of Cognitive Workload in Myoelectric Prosthesis Control and Human-Machine Interaction  

PubMed Central

Common goals in the development of human-machine interface (HMI) technology are to reduce cognitive workload and increase function. However, objective and quantitative outcome measures assessing cognitive workload have not been standardized for HMI research. The present study examines the efficacy of a simple event-related potential (ERP) measure of cortical effort during myoelectric control of a virtual limb for use as an outcome tool. Participants trained and tested on two methods of control, direct control (DC) and pattern recognition control (PRC), while electroencephalographic (EEG) activity was recorded. Eighteen healthy participants with intact limbs were tested using DC and PRC under three conditions: passive viewing, easy, and hard. Novel auditory probes were presented at random intervals during testing, and significant task-difficulty effects were observed in the P200, P300, and a late positive potential (LPP), supporting the efficacy of ERPs as a cognitive workload measure in HMI tasks. LPP amplitude distinguished DC from PRC in the hard condition with higher amplitude in PRC, consistent with lower cognitive workload in PRC relative to DC for complex movements. Participants completed trials faster in the easy condition using DC relative to PRC, but completed trials more slowly using DC relative to PRC in the hard condition. The results provide promising support for ERPs as an outcome measure for cognitive workload in HMI research such as prosthetics, exoskeletons, and other assistive devices, and can be used to evaluate and guide new technologies for more intuitive HMI control. PMID:25402345

Deeny, Sean; Chicoine, Caitlin; Hargrove, Levi; Parrish, Todd; Jayaraman, Arun

2014-01-01

377

Analysis of strength and failure pattern of human proximal femur using quantitative computed tomography (QCT)-based finite element method.  

PubMed

This paper presents a novel method for fast and reliable prediction of the failure strength of human proximal femur, using the quantitative computed tomography (QCT)-based linear finite element analysis (FEA). Ten fresh frozen human femora (age: 34±16) were QCT-scanned and the pertinent 3D voxel-based finite element models were constructed. A specially-designed holding frame was used to define and maintain a unique geometrical reference system for both FEA and in-vitro mechanical testing. The analyses and tests were carried out at 8 different loading orientations. A new scheme was developed for assortment of the element risk factor (defined as the ratio of the strain energy density to the yield strain energy for each element) and implemented for the prediction of the failure strength. The predicted and observed failure patterns were in correspondence, and the FEA predictions of the failure loads were in very good agreement with the experimental results (R2=0.86, slope=0.96, p<0.01). The average computational time was 5 min (on a regular desktop personal computer) for an average element number of 197,000. Noting that the run-time for a similar nonlinear model is about 8h, it was concluded that the proposed linear scheme is overwhelmingly efficient in terms of computational costs. Thus, it can efficiently be used to predict the femoral failure strength with the same accuracy of similar nonlinear models. PMID:24735974

Mirzaei, Majid; Keshavarzian, Maziyar; Naeini, Vahid

2014-07-01

378

Chiral selectors for enantioresolution and quantitation of the antidepressant drug fluoxetine in pharmaceutical formulations by (19)F NMR spectroscopic method.  

PubMed

(19)F NMR spectroscopy was applied to the quantitative determination of fluoxetine enantiomers using different chiral recognition agents in pharmaceutical formulations. Several parameters affecting the enantioresolution including the type and concentration of chiral selector, concentration of fluoxetine and temperature were studied. The chiral selectors investigated are the cyclic oligosaccharides alpha-, beta- and gamma-cyclodextrin and a diamino derivative of methylated alpha-cyclodextrin (DAM-alpha-CD), linear polysaccharides (maltodextrin with dextrose equivalents of 4.0-7.0, 13.0-17.0 and 16.5-19.5) and the macrocyclic antibiotic vancomycin. Among the chiral selectors used, DAM-alpha-CD turned out to give the best resolution of the (19)F NMR signals of (R)- and (S)-fluoxetine. The calibration curve was linear for (R)- and (S)-fluoxetine over the range 0.10-1.35 mgmL(-1), the detection limits (S/N=3) being 5.9 and 7.5 microgmL(-1) for the pure solutions of (R)- and (S)-fluoxetine, respectively. The recovery studies performed on pharmaceutical samples ranged from about 90 to 110% with relative standard deviations of <8%. The results showed that the proposed method is rapid, precise and accurate. Applying statistical Student's t-test revealed insignificant difference between the real and measured contents at the 95% confidence level. PMID:17904479

Shamsipur, Mojtaba; Dastjerdi, Leila Shafiee; Haghgoo, Soheila; Armspach, Dominique; Matt, Dominique; Aboul-Enein, Hassan Y

2007-10-01

379

Validation of Dynamic Contrast Enhanced Ultrasound in Rodent Kidneys as an Absolute Quantitative Method for Measuring Blood Perfusion  

PubMed Central

Contrast-enhanced ultrasound (CEUS) has demonstrated utility in the monitoring of blood flow in tissues, organs, and tumors. However, current CEUS methods typically provide only relative image-derived measurements, rather than quantitative values of blood flow in milliliters/minute per gram of tissue. In this study, CEUS derived parameters of blood flow are compared to absolute measurements of blood flow in rodent kidneys. Additionally, the effect of contrast agent infusion rate and transducer orientation on image-derived perfusion measurements are assessed. Both wash-in curve and time-to-refill algorithms are examined. Data illustrate that for all conditions, image-derived flow measurements were well-correlated with transit-time flow probe measurements (R > 0.9). However, we report differences in the sensitivity to flow across different transducer orientations as well as the contrast analysis algorithm utilized. Results also indicate that there exists a range of contrast agent flow rates for which image-derived estimates are consistent. PMID:21601135

Kogan, Paul; Johnson, Kennita A.; Feingold, Steven; Garrett, Nicholas; Guracar, Ismayil; Arendshorst, William J.; Dayton, Paul A.

2011-01-01

380

Qualitative and Quantitative PCR Methods for Event-specific Detection of Genetically Modified Cotton Mon1445 and Mon531  

Microsoft Academic Search

Based on the DNA sequences of the junctions between recombinant and cotton genomic DNA of the two genetically modified (GM)\\u000a cotton varieties, herbicide-tolerance Mon1445 and insect-resistant Mon531, event-specific primers and probes for qualitative\\u000a and quantitative PCR detection for both GM cotton varieties were designed, and corresponding detection methods were developed.\\u000a In qualitative PCR detection, the simplex and multiplex PCR detection

Litao Yang; Aihu Pan; Kewei Zhang; Changsong Yin; Bingjun Qian; Jianxiu Chen; Cheng Huang; Dabing Zhang

2005-01-01

381

Quantitative structure–activity relationship modeling of polycyclic aromatic hydrocarbon mutagenicity by classification methods based on holistic theoretical molecular descriptors  

Microsoft Academic Search

Various polycyclic aromatic hydrocarbons (PAHs), ubiquitous environmental pollutants, are recognized mutagens and carcinogens. A homogeneous set of mutagenicity data (TA98 and TA100,+S9) for 32 benzocyclopentaphenanthrenes\\/chrysenes was modeled by the quantitative structure–activity relationship classification methods k-nearest neighbor and classification and regression tree, using theoretical holistic molecular descriptors. Genetic algorithm provided the selection of the best subset of variables for modeling mutagenicity.

Paola Gramatica; Ester Papa; Assunta Marrocchi; Lucio Minuti; Aldo Taticchi

2007-01-01

382

DEVELOPMENT OF A VALIDATED STABILITY INDICATING LC METHOD FOR QUANTITATIVE DETERMINATION OF AN ANTISPASMODIC DRUG AND ITS RELATED SUBSTANCES  

Microsoft Academic Search

Present article describes development and validation of stability indicating liquid chromatographic method for quantitative determination of ?-cyclohexyl-?-hydroxy-benzeneacetic acid-4-(diethylamino)-2-butynyl ester hydrochloride a potential antispasmodic and anticholinergic drug and its four impurities (related substances) using a Zorbax SB-Cyano column and mobile phase consisting of aqueous buffer (0.20% triethylamine) and acetonitrile in the ratio 49:51 and with a pH 6.3. The developed LC

Nandini R. Pai; Deepnandan S. Dubhashi

2010-01-01

383

Novel atomic absorption spectrometric and rapid spectrophotometric methods for the quantitation of paracetamol in saliva: application to pharmacokinetic studies.  

PubMed

A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III) (method I); oxidation of p-aminophenol after the hydrolysis of paracetamol (method II). Iron (II) then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III) in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II) at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 mug/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 mug/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 mug/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%. PMID:20046743

Issa, M M; Nejem, R M; El-Abadla, N S; Al-Kholy, M; Saleh, Akila A

2008-01-01

384

Effect of test method on pop plot results  

NASA Astrophysics Data System (ADS)

CTH hydrocode simulations performed for this study demonstrate that test method can affect shock reactivity measurements as displayed on the POP plot. For run distances greater than about 7 mm and pressures lower than 50 kbar, the run distances produced with the use of a flyer plate were shorter than those produced by a plane wave lens system. In contrast, the run distances were similar for pressures above 50 kbar. The plane wave lens system simulated was based on a 4' PWL used at the Army Research Laboratory and a combination of buffer plates. The sample explosive was taken to be Composition C4. Other simulations showed that measuring an average velocity of the buffer plate outside the center of the buffer plate will result in lower input pressures being calculated from the Rankine-Hugoniot jump conditions than those that would be calculated if the corresponding peak initial velocity at the buffer plate center was used.

Sutherland, Gerrit

2012-03-01

385

Interferometric SAR phase difference calibration: Methods and results  

SciTech Connect

This paper addresses the steps necessary to determine and maintain the phase calibration of a two-channel interferometric synthetic aperture radar (IFSAR). The method, setup, and accuracy of four different calibration techniques are compared. The most novel technique involves pointing the interferometric baseline at nadir and imaging a lake surface. The other techniques include measuring various flat surfaces in traditional side-looking IFSAR maps, in-flight closed-loop calibration path measurements, and static laboratory measurements. Initial results indicate that, using combinations of these measurements, it is possible to maintain the interferometric phase calibration of Sandia National Laboratories` K{sub U} Band IFSAR to better than 3 degrees. The time variability of various parts of the calibration and requirements for recalibration are also discussed.

Bickel, D.L.; Hensley, W.H.

1993-12-31

386

Energy and environmental research emphasizing low-rank coal--Task 4.4: Development of supercritical fluid extraction methods for the quantitation of sulfur forms in coal  

SciTech Connect

Current analytical methods are inadequate for accurately measuring sulfur forms in coal. This task was concerned with developing methods to quantitate and identify major sulfur forms in coal based on direct measurement (as opposed to present techniques based on indirect measurement and difference values). The focus was on the forms that were least understood and for which the analytical methods have been the poorest, i.e., organic and elemental sulfur. Improved measurement techniques for sulfatic and pyritic sulfur also need to be developed. A secondary goal was to understand the interconversion of sulfur forms in coal during thermal processing. This task had as its focus the development of selective extraction methods that will allow the direct measurement of sulfur content in each form. Therefore, selective extraction methods were needed for the major sulfur forms in coal, including elemental, pyritic, sulfatic, and organic sulfur. This study was a continuation of that of previous analytical method development for sulfur forms in coal which resulted in the successful isolation and quantitation of elemental and sulfatic sulfur. Super- and subcritical extractions with methanol or water with and without additives were investigated in an attempt to develop methods for pyritic and organic sulfur forms analysis in coal. Based on these studies, a sequential extraction scheme that is capable of selectively determining elemental, sulfatic, pyritic and two forms of organic sulfur is presented here.

Timpe, R.C.

1995-04-01

387

Quantitation of Hsp70 levels in Pimephales promelas using a competitive enzyme-linked immunosorbent assay (ELISA) method  

SciTech Connect

In order to evaluate the expression of stress proteins as biomarkers of the effects of chemical exposure, studies were carried out with Pimephales promelas (fathead minnows). Experiments were designed in which 90 to 120 days old fathead minnows were stressed with varying concentrations (0.25 ppm to 4 ppM) of Cu{sup 2+}, for 4 hours. The levels of Hsp7O in muscle tissue were quantitated by using a competitive enzyme-linked immunosorbent assay (ELISA) method that is highly specific and accurately measures the total pool of Hsp7O in tissues. In previous studies, the concentrations of Hsp7O were quantitated using ELISA in bovine tissue. Hsp70 (for calibration purposes) and antibodies that are specific to constitutive and inducible forms of Hsp7O were purchased commercially. Using this assay method the authors were able to confirm quantitatively, that relative to laboratory controls, higher levels of the inducible form of Hsp70 exists in the tissue of fish that were stressed with Cu{sup 2+}. This method allows for the rapid detection of stress proteins which could be used for field applications.

Badami, C.; Dickson, K.L. [Univ. of North Texas, Denton, TX (United States). Inst. of Applied Sciences

1995-12-31

388

A field method for making a quantitative estimate of altered tuff in sandstone  

USGS Publications Warehouse

The use of benzidine to identify altered tuff in sandstone is practical for field or field laboratory studies associated with stratigraphic correlations, mineral deposit investigations, or paleogeographic interpretations. The method is based on the ability of saturated benzidine (C12H12N2) solution to produce a blue stain on montmorillonite-bearing tuff grains. The method is substantiated by the results of microscopic, X-ray spectrometer, and spectrographic tests which lead to the conclusion that: (1) the benzidine stain test differentiates grains of different composition, (2) the white or gray grains which are stained a uniform blue color are fragments of altered tuff, and (3) white or gray grains which stain in a few small spots are probably silicified tuff. The amount of sand grains taken from a hand specimen or an outcrop which will be held by a penny is spread out on a nonabsorbent white surface and soaked with benzidine for 5 minutes. The approximate number blue grains and the average grain size are used in a chart to determine a reference number which measures relative order of abundance. The chart, based on a volume relationship, corrects for the variation in the number of grains in the sample as the grain size varies. Practical use of the method depends on a knowledge of several precautionary measures as well as an understanding of the limitations of benzidine staining tests.

Cadigan, R.A.

1954-01-01

389

On Quantitizing  

PubMed Central

Quantitizing, commonly understood to refer to the numerical translation, transformation, or conversion of qualitative data, has become a staple of mixed methods research. Typically glossed are the foundational assumptions, judgments, and compromises involved in converting disparate data sets into each other and whether such conversions advance inquiry. Among these assumptions are that qualitative and quantitative data constitute two kinds of data, that quantitizing constitutes a unidirectional process essentially different from qualitizing, and that counting is an unambiguous process. Among the judgments are deciding what and how to count. Among the compromises are balancing numerical precision with narrative complexity. The standpoints of “conditional complementarity,” “critical remediation,” and “analytic alternation” clarify the added value of converting qualitative data into quantitative form. PMID:19865603

Sandelowski, Margarete; Voils, Corrine I.; Knafl, George

2009-01-01

390

Potential of multivariate quantitative methods for delineation and visualization of ecoregions.  

PubMed

Multivariate clustering based on fine spatial resolution maps of elevation, temperature, precipitation, soil characteristics, and solar inputs has been used at several specified levels of division to produce a spectrum of quantitative ecoregion maps for the conterminous United States. The coarse ecoregion divisions accurately capture intuitively-understood regional environmental differences, whereas the finer divisions highlight local condition gradients, ecotones, and clines. Such statistically generated ecoregions can be produced based on user-selected continuous variables, allowing customized regions to be delineated for any specific problem. By creating an objective ecoregion classification, the ecoregion concept is removed from the limitations of human subjectivity, making possible a new array of ecologically useful derivative products. A red-green-blue visualization based on principal components analysis of ecoregion centroids indicates with color the relative combination of environmental conditions found within each ecoregion. Multiple geographic areas can be classified into a single common set of quantitative ecoregions to provide a basis for comparison, or maps of a single area through time can be classified to portray climatic or environmental changes geographically in terms of current conditions. Quantified representativeness can characterize borders between ecoregions as gradual, sharp, or of changing character along their length. Similarity of any ecoregion to all other ecoregions can be quantified and displayed as a "representativeness" map. The representativeness of an existing spatial array of sample locations or study sites can be mapped relative to a set of quantitative ecoregions, suggesting locations for additional samples or sites. In addition, the shape of Hutchinsonian niches in environment space can be defined if a multivariate range map of species occurrence is available. PMID:15883870

Hargrove, William W; Hoffman, Forrest M

2004-01-01

391

Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing.  

PubMed

This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP). PMID:25256108

Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng

2014-01-01

392

Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing  

PubMed Central

This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP). PMID:25256108

Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng

2014-01-01

393

Quantitative naturalistic methods for detecting change points in psychotherapy research: an illustration with alliance ruptures.  

PubMed

Analysis of change points in psychotherapy process could increase our understanding of mechanisms of change. In particular, naturalistic change point detection methods that identify turning points or breakpoints in time series data could enhance our ability to identify and study alliance ruptures and resolutions. This paper presents four categories of statistical methods for detecting change points in psychotherapy process: criterion-based methods, control chart methods, partitioning methods, and regression methods. Each method's utility for identifying shifts in the alliance is illustrated using a case example from the Beth Israel Psychotherapy Research program. Advantages and disadvantages of the various methods are discussed. PMID:22708548

Eubanks-Carter, Catherine; Gorman, Bernard S; Muran, J Christopher

2012-01-01

394

Development and validation of stability indicating method for the quantitative determination of venlafaxine hydrochloride in extended release formulation using high performance liquid chromatography  

PubMed Central

Objective: Venlafaxine,hydrochloride is a structurally novel phenethyl bicyclic antidepressant, and is usually categorized as a serotonin–norepinephrine reuptake inhibitor (SNRI) but it has been referred to as a serotonin–norepinephrine–dopamine reuptake inhibitor. It inhibits the reuptake of dopamine. Venlafaxine HCL is widely prescribed in the form of sustained release formulations. In the current article we are reporting the development and validation of a fast and simple stability indicating, isocratic high performance liquid chromatographic (HPLC) method for the determination of venlafaxine hydrochloride in sustained release formulations. Materials and Methods: The quantitative determination of venlafaxine hydrochloride was performed on a Kromasil C18 analytical column (250 × 4.6 mm i.d., 5 ?m particle size) with 0.01 M phosphate buffer (pH 4.5): methanol (40: 60) as a mobile phase, at a flow rate of 1.0 ml/min. For HPLC methods, UV detection was made at 225 nm. Results: During method validation, parameters such as precision, linearity, accuracy, stability, limit of quantification and detection and specificity were evaluated, which remained within acceptable limits. Conclusions: The method has been successfully applied for the quantification and dissolution profiling of Venlafaxine HCL in sustained release formulation. The method presents a simple and reliable solution for the routine quantitative analysis of Venlafaxine HCL. PMID:21814426

Kaur, Jaspreet; Srinivasan, K. K.; Joseph, Alex; Gupta, Abhishek; Singh, Yogendra; Srinivas, Kona S.; Jain, Garima

2010-01-01

395

A simple method for using silicone elastomer masks for quantitative analysis of cell migration without cellular damage or substrate disruption.  

PubMed

Cell migration is fundamental to many biological processes, including development, normal tissue remodeling, wound healing, and many pathologies. However, cell migration is a complex process, and understanding its regulation in health and disease requires the ability to manipulate and measure this process quantitatively under controlled conditions. This report describes a simple in vitro assay for quantitative analysis of cell migration in two-dimensional cultures that is an inexpensive alternative to the classic "scratch" assay. The method described utilizes flexible silicone masks fabricated in the lab according to the research demands of the specific experiment to create a cell-free area for cells to invade, followed by quantitative analysis based on widely available microscopic imaging tools. This experimental approach has the important advantage of visualizing cell migration in the absence of the cellular damage and disruption of the substrate that occurs when the "wound" is created in the scratch assay. This approach allows the researcher to study the intrinsic migratory characteristics of cells in the absence of potentially confounding contributions from cellular responses to injury and disruption of cell-substrate interactions. This assay has been used with vascular smooth muscle cells, fibroblasts, and epithelial cell types, but should be applicable to the study of practically any type of cultured cell. Furthermore, this method can be easily adapted for use with fluorescence microscopy, molecular biological, or pharmacological manipulations to explore the molecular mechanisms of cell migration, live cell imaging, fluorescence microscopy, and correlative immunolabeling. PMID:24430202

Sherry, David M; Parks, Eileen E; Bullen, Elizabeth C; Updike, Dawn L; Howard, Eric W

2013-01-01

396

A simple method for using silicone elastomer masks for quantitative analysis of cell migration without cellular damage or substrate disruption  

PubMed Central

Cell migration is fundamental to many biological processes, including development, normal tissue remodeling, wound healing, and many pathologies. However, cell migration is a complex process, and understanding its regulation in health and disease requires the ability to manipulate and measure this process quantitatively under controlled conditions. This report describes a simple in vitro assay for quantitative analysis of cell migration in two-dimensional cultures that is an inexpensive alternative to the classic “scratch” assay. The method described utilizes flexible silicone masks fabricated in the lab according to the research demands of the specific experiment to create a cell-free area for cells to invade, followed by quantitative analysis based on widely available microscopic imaging tools. This experimental approach has the important advantage of visualizing cell migration in the absence of the cellular damage and disruption of the substrate that occurs when the “wound” is created in the scratch assay. This approach allows the researcher to study the intrinsic migratory characteristics of cells in the absence of potentially confounding contributions from cellular responses to injury and disruption of cell–substrate interactions. This assay has been used with vascular smooth muscle cells, fibroblasts, and epithelial cell types, but should be applicable to the study of practically any type of cultured cell. Furthermore, this method can be easily adapted for use with fluorescence microscopy, molecular biological, or pharmacological manipulations to explore the molecular mechanisms of cell migration, live cell imaging, fluorescence microscopy, and correlative immunolabeling. PMID:24430202

Sherry, David M; Parks, Eileen E; Bullen, Elizabeth C; Updike, Dawn L; Howard, Eric W

2013-01-01

397

Quantitative analysis of murine terminal erythroid differentiation in vivo: novel method to study normal and disordered erythropoiesis  

PubMed Central

Terminal erythroid differentiation is the process during which proerythroblasts differentiate to produce enucleated reticulocytes. Although it is well established that during murine erythropoiesis in vivo, 1 proerythroblast undergoes 3 mitosis to generate sequentially 2 basophilic, 4 polychromatic, and 8 orthochromatic erythroblasts, currently there is no method to quantitatively monitor this highly regulated process. Here we outline a method that distinguishes each distinct stage of erythroid differentiation in cells from mouse bone marrow and spleen based on expression levels of TER119, CD44, and cell size. Quantitative analysis revealed that the ratio of proerythroblasts:basophilic:polychromatic:orthromatic erythroblasts follows the expected 1:2:4:8 ratio, reflecting the physiologic progression of terminal erythroid differentiation in normal mice. Moreover, in 2 stress erythropoiesis mouse models, phlebotomy-induced acute anemia and chronic hemolytic anemia because of 4.1R deficiency, the ratio of these erythroblast populations remains the same as that of wild-type bone marrow. In contrast, in anemic ?-thalassemia intermedia mice, there is altered progression which is restored to normal by transferrin treatment which was previously shown to ameliorate the anemic phenotype. The means to quantitate in vivo murine erythropoiesis using our approach will probably have broad application in the study of altered erythropoiesis in various red cell disorders. PMID:23287863

Liu, Jing; Zhang, Jianhua; Ginzburg, Yelena; Li, Huihui; Xue, Fumin; De Franceschi, Lucia; Chasis, Joel Anne; Mohandas, Narla

2013-01-01

398

A Quantitative Method for the Characterization of Lytic Metastases of the Bone from Radiographic Images  

PubMed Central

The aim of our study was to assess the diagnostic usefulness of the gray level parameters to distinguish osteolytic lesions using radiological images. Materials and Methods. A retrospective study was carried out. A total of 76 skeletal radiographs of osteolytic metastases and 67 radiographs of multiple myeloma were used. The cases were classified into nonflat (MM1 and OL1) and flat bones (MM2 and OL2). These radiological images were analyzed by using a computerized method. The parameters calculated were mean, standard deviation, and coefficient of variation (MGL, SDGL, and CVGL) based on gray level histogram analysis of a region-of-interest. Diagnostic utility was quantified by measurement of parameters on osteolytic metastases and multiple myeloma, yielding quantification of area under the receiver operating characteristic (ROC) curve (AUC). Results. Flat bone groups (MM2 and OL2) showed significant differences in mean values of MGL (P = 0.048) and SDGL (P = 0.003). Their corresponding values of AUC were 0.758 for MGL and 0.883 for SDGL in flat bones. In nonflat bones these gray level parameters do not show diagnostic ability. Conclusion. The gray level parameters MGL and SDGL show a good discriminatory diagnostic ability to distinguish between multiple myeloma and lytic metastases in flat bones. PMID:25054170

2014-01-01

399

Results of Ocular Dominance Testing Depend on Assessment Method  

PubMed Central

Purpose We developed a near ocular dominance test modeled after the distance hole-in-the card test, and assessed both test-retest reliability of four tests of ocular dominance and agreement between tests. Methods 46 subjects ages 18 to 78 years with visual acuity 20/40 or better in each eye were enrolled from a primary care practice. All subjects had normal eye examinations, with the exception of refractive error, and were examined in their habitual correction. Subjects were tested twice each with the distance hole-in-the-card test, new near hole- in-the-card test, near convergence test, and the Pediatric Eye Disease Investigator Group (PEDIG) fixation preference test. Test-retest reliability and agreement between tests were evaluated with the Kappa statistic. Results There was substantial to almost perfect test-retest reliability for the distance hole-in-the-card test, new near hole-in-the-card test, convergence test, and PEDIG fixation preference test (Kappa, k=0.77, 0.62, 0.84, 0.77, respectively). In contrast, the agreement between the new near hole in the card test and the other three tests – distance hole in the card, near convergence, and PEDIG fixation preference– was moderate to slight (k=0.41, 0.19, 0.11, respectively). Agreement was moderate to fair (k=0.47, 0.32) between the distance hole in the card test and the near convergence test, and between the distance-hole-in-the-card test and the PEDIG fixation preference test. Agreement was fair (k=0.27) between the near convergence test and the PEDIG fixation preference test. Conclusions Although there was excellent test-retest reliability of each ocular dominance test, there was only moderate to slight agreement between tests. Results of ocular dominance tests seem to vary depending on both the testing distance and the specific activity performed as part of the testing procedure. PMID:18455935

Rice, Melissa L.; Leske, David A.; Smestad, Christina E.; Holmes, Jonathan M.

2008-01-01

400

A novel quantitative method for evaluating diffuse in-stent narrowing at follow-up angiography.  

PubMed

A new quantitative parameter, diffuse index (DI), was proposed to evaluate objectively whether in-stent restenosis is diffuse or focal in nature. A total of 343 patients (346 lesions) with Wiktor-GX, AVE MS-II, or JOMED stents were evaluated at follow-up angiography. According to the QCA-CMS definition, lesion length is derived from the 100% reference diameter function (RDF). By moving the RDF downward, the lesion length, LL(x), at each percentage x of the RDF can be calculated. We have defined the DI by the ratio of this calculated length LL(x) and the total stent length, SL, in other words, DI = [LL(x)/SL]. The percentage plaque area (% PA) was calculated by dividing the plaque area by the sum of the plaque area and luminal area within the stent. An excellent correlation was found between the DI at 88% RDF and the % PA in all three stents (r > 0.88). The individual correlation curves were nearly identical, independent of the type of stent. Furthermore, based on the overall data, the combination of a DI > 0.8 and % PA > 30% correlated with a high incidence of subsequent major adverse cardiac events (13/25 = 52%). From these data, it can be concluded that the diffuse index is a new objective quantitative parameter to describe whether in-stent restenosis is of focal or diffuse nature. PMID:11747154

Ishii, Y; van Weert, A W; Hekking, E; de Marie, K; ter Horst, J; Oemrawsingh, P V; Reiber, J H

2001-11-01

401

Ten Years of LibQual: A Study of Qualitative and Quantitative Survey Results at the University of Mississippi 2001-2010  

ERIC Educational Resources Information Center

This article analyzes quantitative adequacy gap scores and coded qualitative comments from LibQual surveys at the University of Mississippi from 2001 to 2010, looking for relationships between library policy changes and LibQual results and any other trends that emerged. Analysis found no relationship between changes in policy and survey results

Greenwood, Judy T.; Watson, Alex P.; Dennis, Melissa

2011-01-01

402

HUNTING THE COOLEST DWARFS: METHODS AND EARLY RESULTS  

SciTech Connect

We present the methods and first results of a survey of nearby high proper motion main-sequence stars to probe for cool companions with the Gemini camera at Lick Observatory. This survey uses a sample of old (age > 2 Gyr) stars as targets to probe for companions down to temperatures of 500 K. Multi-epoch observations allow us to discriminate comoving companions from background objects. So far, our survey has successfully rediscovered the wide T8.5 companion to GJ 1263 and has discovered a companion to the nearby M0V star GJ 660.1. The companion to GJ 660.1 (GJ 660.1B) is {approx}4 mag fainter than its host star in the J-band and is located at a projected separation of {approx}120 AU. Known trigonometric parallax and Two Micron All Sky Survey magnitudes for the GJ 660.1 system indicate a spectral type for the companion of M9 {+-} 2.

Schneider, A.; Song, Inseok [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States); Melis, Carl [Center for Astrophysics and Space Sciences, University of California, San Diego, CA 92093-0424 (United States); Zuckerman, B., E-mail: aschneid@physast.uga.edu, E-mail: song@physast.uga.edu, E-mail: cmelis@ucsd.edu, E-mail: ben@astro.ucla.edu [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States)

2011-12-20

403

Current and emerging quantitative magnetic resonance imaging methods for assessing and predicting the response of breast cancer to neoadjuvant therapy  

PubMed Central

Reliable early assessment of breast cancer response to neoadjuvant therapy (NAT) would provide considerable benefit to patient care and ongoing research efforts, and demand for accurate and noninvasive early-response biomarkers is likely to increase. Response assessment techniques derived from quantitative magnetic resonance imaging (MRI) hold great potential for integration into treatment algorithms and clinical trials. Quantitative MRI techniques already available for assessing breast cancer response to neoadjuvant therapy include lesion size measurement, dynamic contrast-enhanced MRI, diffusion-weighted MRI, and proton magnetic resonance spectroscopy. Emerging yet promising techniques include magnetization transfer MRI, chemical exchange saturation transfer MRI, magnetic resonance elastography, and hyperpolarized MR. Translating and incorporating these techniques into the clinical setting will require close attention to statistical validation methods, standardization and reproducibility of technique, and scanning protocol design. PMID:23154619

Abramson, Richard G; Arlinghaus, Lori R; Weis, Jared A; Li, Xia; Dula, Adrienne N; Chekmenev, Eduard Y; Smith, Seth A; Miga, Michael I; Abramson, Vandana G; Yankeelov, Thomas E

2012-01-01

404

QUANTITATIVE METHODS FOR RESERVOIR CHARACTERIZATION AND IMPROVED RECOVERY: APPLICATION TO HEAVY OIL SANDS  

SciTech Connect

Improved prediction of interwell reservoir heterogeneity has the potential to increase productivity and to reduce recovery cost for California's heavy oil sands, which contain approximately 2.3 billion barrels of remaining reserves in the Temblor Formation and in other formations of the San Joaquin Valley. This investigation involves application of advanced analytical property-distribution methods conditioned to continuous outcrop control for improved reservoir characterization and simulation, particularly in heavy oil sands. The investigation was performed in collaboration with Chevron Production Company U.S.A. as an industrial partner, and incorporates data from the Temblor Formation in Chevron's West Coalinga Field. Observations of lateral variability and vertical sequences observed in Temblor Formation outcrops has led to a better understanding of reservoir geology in West Coalinga Field. Based on the characteristics of stratigraphic bounding surfaces in the outcrops, these surfaces were identified in the subsurface using cores and logs. The bounding surfaces were mapped and then used as reference horizons in the reservoir modeling. Facies groups and facies tracts were recognized from outcrops and cores of the Temblor Formation and were applied to defining the stratigraphic framework and facies architecture for building 3D geological models. The following facies tracts were recognized: incised valley, estuarine, tide- to wave-dominated shoreline, diatomite, and subtidal. A new minipermeameter probe, which has important advantages over previous methods of measuring outcrop permeability, was developed during this project. The device, which measures permeability at the distal end of a small drillhole, avoids surface weathering effects and provides a superior seal compared with previous methods for measuring outcrop permeability. The new probe was used successfully for obtaining a high-quality permeability data set from an outcrop in southern Utah. Results obtained from analyzing the fractal structure of permeability data collected from the southern Utah outcrop and from core permeability data provided by Chevron from West Coalinga Field were used in distributing permeability values in 3D reservoir models. Spectral analyses and the Double Trace Moment method (Lavallee et al., 1991) were used to analyze the scaling and multifractality of permeability data from cores from West Coalinga Field. T2VOC, which is a numerical flow simulator capable of modeling multiphase, multi-component, nonisothermal flow, was used to model steam injection and oil production for a portion of section 36D in West Coalinga Field. The layer structure and permeability distributions of different models, including facies group, facies tract, and fractal permeability models, were incorporated into the numerical flow simulator. The injection and production histories of wells in the study area were modeled, including shutdowns and the occasional conversion of production wells to steam injection wells. The framework provided by facies groups provides a more realistic representation of the reservoir conditions than facies tracts, which is revealed by a comparison of the history-matching for the oil production. Permeability distributions obtained using the fractal results predict the high degree of heterogeneity within the reservoir sands of West Coalinga Field. The modeling results indicate that predictions of oil production are strongly influenced by the geologic framework and by the boundary conditions. The permeability data collected from the southern Utah outcrop, support a new concept for representing natural heterogeneity, which is called the fractal/facies concept. This hypothesis is one of the few potentially simplifying concepts to emerge from recent studies of geological heterogeneity. Further investigation of this concept should be done to more fully apply fractal analysis to reservoir modeling and simulation. Additional outcrop permeability data sets and further analysis of the data from distinct facies will be needed in order to fully develop

James W. Castle; Fred J. Molz; Ronald W. Falta; Cynthia L. Dinwiddie; Scott E. Brame; Robert A. Bridges

2002-10-30

405

Quantitative method for the assignment of hinge and shear mechanism in protein domain movements  

PubMed Central

Motivation: A popular method for classification of protein domain movements apportions them into two main types: those with a ‘hinge’ mechanism and those with a ‘shear’ mechanism. The intuitive assignment of domain movements to these classes has limited the number of domain movements that can be classified in this way. Furthermore, whether intended or not, the term ‘shear’ is often interpreted to mean a relative translation of the domains. Results: Numbers of occurrences of four different types of residue contact changes between domains were optimally combined by logistic regression using the training set of domain movements intuitively classified as hinge and shear to produce a predictor for hinge and shear. This predictor was applied to give a 10-fold increase in the number of examples over the number previously available with a high degree of precision. It is shown that overall a relative translation of domains is rare, and that there is no difference between hinge and shear mechanisms in this respect. However, the shear set contains significantly more examples of domains having a relative twisting movement than the hinge set. The angle of rotation is also shown to be a good discriminator between the two mechanisms. Availability and implementation: Results are free to browse at http://www.cmp.uea.ac.uk/dyndom/interface/. Contact: sjh@cmp.uea.ac.uk. Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25078396

Taylor, Daniel; Cawley, Gavin; Hayward, Steven

2014-01-01