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1

Quantitative fuel motion determination with the CABRI fast neutron hodoscope; Evaluation methods and results  

Microsoft Academic Search

The fast neutron hodoscope installed at the CABRI reactor in Cadarache, France, is employed to provide quantitative fuel motion data during experiments in which single liquid-metal fast breeder reactor test pins are subjected to simulated accident conditions. Instrument design and performance are reviewed, the methods for the quantitative evaluation are presented, and error sources are discussed. The most important findings

K. Baumung; G. Augier

1991-01-01

2

Quantitative method for evaluation of aesthetic results after laser treatment for birthmarks.  

PubMed

Subjective assessment of results after laser treatment for birthmarks does not provide a validated method for clinicians. Previous reports concerning objective evaluation using L*a*b color coordinates were only partially successful due to difficulties in standardizing and comparing colors from pre- and posttreatment photographs. The study aimed to present a reliable and clinically applicable method of aesthetic result assessment after laser treatment for birthmarks. All 48 patients, included in the study, were treated for birthmarks on the face or neck using laser. Each pre- and posttreatment photograph was subjected to triple objective comparative assessment of color fading with use of a computer program, as well as to subjective evaluation by three core physicians and three laypeople. Objective analysis was based on an innovative method using combined L*a*b and hue saturation value color coordinates. Accuracy was higher between objective assessment with the computer program and subjective evaluation by core physicians than by laypeople. Repeatability of results was higher with the use of the computer program than among core physicians or among laypeople. In conclusion, our method may be considered for objective assessment of the results after laser treatment of vascular and pigmented birthmarks. PMID:23388877

Szychta, Pawel; Al-Nakib, Khalil; Anderson, Will; Stewart, Ken; Quaba, Awf

2013-11-01

3

Quantitative Methods for Management.  

National Technical Information Service (NTIS)

An elementary treatment of some of the better known and widely used analytical methods in operations research/systems analysis. The material is presented in a manner which attempts to indicate why quantitative methods are useful in managerial decision-mak...

G. Suzuki

1967-01-01

4

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

5

Quantitative Methods of Edge Detection.  

National Technical Information Service (NTIS)

Most local operators used in edge detection can be modelled by one of two methods: edge enhancement/thresholding and edge fitting. This dissertation presents a quantitative design and performance evaluation of these methods. The design techniques are base...

I. E. Abdou

1978-01-01

6

A new method for quantitative ultrasound measurements at multiple skeletal sites: first results of precision and fracture discrimination.  

PubMed

We investigated a new multisite quantitative ultrasound device that measures the acoustic velocity in axial transmission mode along the cortex. Using a prototype of the Omnisense (Sunlight Ultrasound Technologies, Rehovot, Israel), we tested the performance of this instrument at four sites of the skeleton: radius, ulna, metacarpal, and phalanx. Intraobserver (interobserver) precision errors ranged from 0.2% to 0.3% (0.3% to 0.7%) for triplicate measurements with repositioning. Fracture discrimination was tested by comparing a group of 34 women who had previously suffered a fracture of the hip, spine, ankle, or forearm to a group of 28 healthy women who had not suffered a fracture. Age-adjusted standardized odds ratios ranged from 1.6 to 4.5. Except for the ulna the sites showed a significant fracture discrimination (p < 0.01). The areas under the receiver operating curves (ROC) curves were from 0.88 to 0.89 for radius, metacarpal, and phalanx. A combination of the results from the three sites showed a significant increase of the ROC area to 0.95 (p < 0. 05). Our results show promising performance of this new device. The ability to measure a large variety of sites and the potential to combine these measurements are promising with regard to optimizing fracture risk assessment. PMID:10745297

Barkmann, R; Kantorovich, E; Singal, C; Hans, D; Genant, H K; Heller, M; Glüer, C C

2000-01-01

7

Quantitating heart lipids: comparison of results obtained using the Iatroscan method with those from phosphorus and gas chromatographic techniques.  

PubMed

The precision and accuracy of the Iatroscan method was evaluated by comparing the results obtained with established phosphorus and gas chromatographic techniques. A complete lipid class analysis of rat heart lipids was chosen in order to evaluate the performance of the Iatroscan method for biological samples which contained both neutral lipids and phospholipids. A partial scan and repeat development with chloroform/methanol/water (68.5:29:2.5) was introduced to achieve consistently good separations of the phospholipids on the Chromarods in the Iatroscan method. The results showed that the precision of the Iatroscan method for some lipid classes was comparable to that of phosphorus or gas chromatographic techniques, while for other lipid classes it was lower. Compared to the data obtained using the phosphorus method, the Iatroscan data were generally similar, while the gas chromatographic method generally gave lower values. These findings, together with the advantages of time required for analysis, size of sample, and universality of detection, suggest that the Iatroscan is a valuable complementary method for complex lipid analyses. PMID:4033372

Kramer, J K; Farnworth, E R; Thompson, B K

1985-08-01

8

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...

9

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

PubMed

Enterococci target sequence density estimates from analyses of diluted river water DNA extracts by EPA Methods 1611 and 1609 and estimates with lower detection limits from undiluted DNA extracts by Method 1609 were indistinguishable. These methods should be equally suitable for comparison with U.S. EPA 2012 Recreational Water Quality Criteria values. PMID:24681207

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

2014-06-01

10

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

11

Quantitative Urine Culture by Surface Drop Method  

PubMed Central

A simple drop method for quantitative urine culture was developed and tested in comparison with standard methods for bacterial urinary counts. In a group of 452 urines all yielding Escherichia coli, 74 showed counts of more than 100,000 colonies, and 16 showed counts between 10,000 and 100,000 colonies per ml. Of these 90 urines, 3 of the 16 in the doubtful group were false negative with the drop method. Another 7 urines in the total number of 452 showed discrepancies, but, because all would have been repeated, the second urine sample would have corrected the primary result. The ease and cleanliness of the method render it a suitable technique for screening normal and patient populations. The method was applied on a population sample of 1,330 persons from whom unwashed mid-stream urine was collected and yielded figures comparable with results published in the literature. The method discriminates between steps of 10-fold difference, whereas more accurate count methods show a standard error of ±25% and are reliable in a double dilution series. Images

Lorrier, Johanna C.; Valkenburg, Hans A.

1969-01-01

12

Methods in quantitative image analysis.  

PubMed

The main steps of image analysis are image capturing, image storage (compression), correcting imaging defects (e.g. non-uniform illumination, electronic-noise, glare effect), image enhancement, segmentation of objects in the image and image measurements. Digitisation is made by a camera. The most modern types include a frame-grabber, converting the analog-to-digital signal into digital (numerical) information. The numerical information consists of the grey values describing the brightness of every point within the image, named a pixel. The information is stored in bits. Eight bits are summarised in one byte. Therefore, grey values can have a value between 0 and 256 (2(8)). The human eye seems to be quite content with a display of 5-bit images (corresponding to 64 different grey values). In a digitised image, the pixel grey values can vary within regions that are uniform in the original scene: the image is noisy. The noise is mainly manifested in the background of the image. For an optimal discrimination between different objects or features in an image, uniformity of illumination in the whole image is required. These defects can be minimised by shading correction [subtraction of a background (white) image from the original image, pixel per pixel, or division of the original image by the background image]. The brightness of an image represented by its grey values can be analysed for every single pixel or for a group of pixels. The most frequently used pixel-based image descriptors are optical density, integrated optical density, the histogram of the grey values, mean grey value and entropy. The distribution of the grey values existing within an image is one of the most important characteristics of the image. However, the histogram gives no information about the texture of the image. The simplest way to improve the contrast of an image is to expand the brightness scale by spreading the histogram out to the full available range. Rules for transforming the grey value histogram of an existing image (input image) into a new grey value histogram (output image) are most quickly handled by a look-up table (LUT). The histogram of an image can be influenced by gain, offset and gamma of the camera. Gain defines the voltage range, offset defines the reference voltage and gamma the slope of the regression line between the light intensity and the voltage of the camera. A very important descriptor of neighbourhood relations in an image is the co-occurrence matrix. The distance between the pixels (original pixel and its neighbouring pixel) can influence the various parameters calculated from the co-occurrence matrix. The main goals of image enhancement are elimination of surface roughness in an image (smoothing), correction of defects (e.g. noise), extraction of edges, identification of points, strengthening texture elements and improving contrast. In enhancement, two types of operations can be distinguished: pixel-based (point operations) and neighbourhood-based (matrix operations). The most important pixel-based operations are linear stretching of grey values, application of pre-stored LUTs and histogram equalisation. The neighbourhood-based operations work with so-called filters. These are organising elements with an original or initial point in their centre. Filters can be used to accentuate or to suppress specific structures within the image. Filters can work either in the spatial or in the frequency domain. The method used for analysing alterations of grey value intensities in the frequency domain is the Hartley transform. Filter operations in the spatial domain can be based on averaging or ranking the grey values occurring in the organising element. The most important filters, which are usually applied, are the Gaussian filter and the Laplace filter (both averaging filters), and the median filter, the top hat filter and the range operator (all ranking filters). Segmentation of objects is traditionally based on threshold grey values. (AB PMID:8781988

Oberholzer, M; Ostreicher, M; Christen, H; Brühlmann, M

1996-05-01

13

Photographic colorimetry as a quantitative cytochemical method  

Microsoft Academic Search

A method for quantitative cytophotometry based on the photographic method of Ornstein is described. Taking special precautions, photographic negatives are made of microscopic objects with light from the appropriate part of the spectrum. Enlarged prints, developed in a blue colour, are made from these negatives. Stirring with a stream of nitrogen was applied in this procedure.

E. M. DEN TONKELAAR; P. Duijn

1964-01-01

14

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

15

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) [Ames, IA; Gjerde, Douglas T. (Ames, IA) [Ames, IA; Schmuckler, Gabriella (Haifa, IL) [Haifa, IL

1981-06-09

16

Quantitative methods of evaluating image segmentation  

Microsoft Academic Search

Two sets of measures are proposed in this paper for quantitatively evaluating segmentation results. The first set is designed for the situation where ground truth is available; while the second for the situation where ground truth is not available. Based on a test bank of more than 50 images for which ground truth is available, we computed both sets of

Qian Huang; Byron Dom

1995-01-01

17

A quantitation method for mass spectrometry imaging.  

PubMed

A new quantitation method for mass spectrometry imaging (MSI) with matrix-assisted laser desorption/ionization (MALDI) has been developed. In this method, drug concentrations were determined by tissue homogenization of five 10 µm tissue sections adjacent to those analyzed by MSI. Drug levels in tissue extracts were measured by liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS). The integrated MSI response was correlated to the LC/MS/MS drug concentrations to determine the amount of drug detected per MSI ion count. The study reported here evaluates olanzapine in liver tissue. Tissue samples containing a range of concentrations were created from liver harvested from rats administered a single dose of olanzapine at 0, 1, 4, 8, 16, 30, or 100 mg/kg. The liver samples were then analyzed by MALDI-MSI and LC/MS/MS. The MALDI-MSI and LC/MS/MS correlation was determined for tissue concentrations of ~300 to 60,000 ng/g and yielded a linear relationship over two orders of magnitude (R(2) = 0.9792). From this correlation, a conversion factor of 6.3 ± 0.23 fg/ion count was used to quantitate MSI responses at the pixel level (100 µm). The details of the method, its importance in pharmaceutical analysis, and the considerations necessary when implementing it are presented. PMID:21259359

Koeniger, Stormy L; Talaty, Nari; Luo, Yanping; Ready, Damien; Voorbach, Martin; Seifert, Terese; Cepa, Steve; Fagerland, Jane A; Bouska, Jennifer; Buck, Wayne; Johnson, Robert W; Spanton, Stephen

2011-02-28

18

Evaluation of an automated liquid hybridization method for DNA quantitation.  

PubMed

The AluQuant (Promega Corporation) liquid hybridization DNA quantitation method was evaluated on an automated robotic platform (Biomek 2000, Beckman Coulter, Fullerton, CA) for use in forensic PCR-STR systems. DNA from bloodstains and buccal swabs was extracted by three different methods: Chelex, Qiagen and DNA IQ (Promega). Samples were quantitated using both the Quantiblot and the AluQuant systems. Concordance between methods was determined by comparing the average AluQuant DNA concentrations for samples having matching (binned) Quantiblot values. Studies testing the "accuracy" (STR analysis), precision, sensitivity, and specifies specificity of the AluQuant method were also conducted. The effect of inhibitors (carpet, denim, and suede) was evaluated. The results indicate that the AluQuant quantitation system equals the Quantiblot system in "accuracy", sensitivity, precision, and primate-specificity. While extracts from denim and suede affected (inhibited) both systems minimally, the carpet extracts produced a sharp increase in DNA quantitation values in the AluQuant but not the Quantiblot system. The speed and user-friendliness of the AluQuant system on a robotic platform offer specific advantages to the forensic community. PMID:14979349

Hayn, Sandra; Wallace, Margaret M; Prinz, Mechthild; Shaler, Robert C

2004-01-01

19

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

20

Quantitative Methods for Evaluating Hospital Designs.  

National Technical Information Service (NTIS)

The study provides an integrated quantitative-qualitative basis for decisions involving the relative locations of functions, and hence facilities, within the individual short-term, general, voluntary hospital. The approach used in attacking the problem wa...

G. L. Delon H. E. Smalley

1970-01-01

21

Quantitative Immunochromatographic Strip Assay Method and Apparatus.  

National Technical Information Service (NTIS)

This patent application discloses an immunochromatographic assay for quantitation of a biological substrate such as hepatitis B antibody in which strips of nitrocellulose acetate filter paper are uniformly coated with a specific binding material for the s...

J. E. Hamont, J. W. Vincent, M. G. Pappas, R. Hajkowski

1985-01-01

22

Method of quantitating dsDNA  

DOEpatents

A method for quantitating dsDNA in an aqueous sample solution containing an unknown amount of dsDNA. A first aqueous test solution containing a known amount of a fluorescent dye-dsDNA complex and at least one fluorescence-attenutating contaminant is prepared. The fluorescence intensity of the test solution is measured. The first test solution is diluted by a known amount to provide a second test solution having a known concentration of dsDNA. The fluorescence intensity of the second test solution is measured. Additional diluted test solutions are similarly prepared until a sufficiently dilute test solution having a known amount of dsDNA is prepared that has a fluorescence intensity that is not attenuated upon further dilution. The value of the maximum absorbance of this solution between 200-900 nanometers (nm), referred to herein as the threshold absorbance, is measured. A sample solution having an unknown amount of dsDNA and an absorbance identical to that of the sufficiently dilute test solution at the same chosen wavelength is prepared. Dye is then added to the sample solution to form the fluorescent dye-dsDNA-complex, after which the fluorescence intensity of the sample solution is measured and the quantity of dsDNA in the sample solution is determined. Once the threshold absorbance of a sample solution obtained from a particular environment has been determined, any similarly prepared sample solution taken from a similar environment and having the same value for the threshold absorbance can be quantified for dsDNA by adding a large excess of dye to the sample solution and measuring its fluorescence intensity.

Stark, Peter C. (Los Alamos, NM); Kuske, Cheryl R. (Los Alamos, NM); Mullen, Kenneth I. (Los Alamos, NM)

2002-01-01

23

Validation of a quantitative method for real time PCR kinetics  

Microsoft Academic Search

Real time RT-PCR is the most sensitive method for quantitation of gene expression levels. The accuracy can be dependent on the mathematical model on which the quantitative methods are based. The generally accepted mathematical model assumes that amplification efficiencies are equal at the exponential phase of the reactions for the same amplicon. However, no methods are available to test the

Weihong Liu; David A. Saint

2002-01-01

24

Meaning in Method: The Rhetoric of Quantitative and Qualitative Research  

Microsoft Academic Search

The current debate about quantitative and qualitative methods focuses on whether there is a necessary connection between method-type and research paradigm that makes the different approaches incompatible. This paper argues that part of the connection is rhetorical. Quantitative methods express the assumptions of a positvisit paradigm which holds that behavior can be explained through objective facts. Design and instrumentation persuade

WILLIAM A. FIRESTONE

1987-01-01

25

Quantitative methods for ecological network analysi  

Microsoft Academic Search

The analysis of networks of ecological trophic transfers is a useful complement to simulation modeling in the quest for understanding whole-ecosystem dynamics. Trophic networks can be studied in quantitative and systematic fashion at several levels. Indirect relationships between any two individual taxa in an ecosystem, which often differ in either nature or magnitude from their direct influences, can be assayed

Robert E. Ulanowicz

2004-01-01

26

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

27

Mapcurves: a quantitative method for comparing categorical maps  

Microsoft Academic Search

We present Mapcurves, a quantitative goodness-of-fit (GOF) method that unambiguously shows the degree of spatial concordance between two or more categorical maps. Mapcurves graphically and quantitatively evaluate the degree of fit among any number of maps and quantify a GOF for each polygon, as well as the entire map. The Mapcurve method indicates a perfect fit even if all polygons

William W. Hargrove; Forrest M. Hoffman; Paul F. Hessburg

2006-01-01

28

Mapcurves: a quantitative method for comparing categorical maps  

Microsoft Academic Search

? Springer-Verlag 2006 Abstract We present Mapcurves, a quantitative goodness-of-fit (GOF) method that unambiguously shows the degree of spatial concordance between two or more categorical maps. Mapcurves graphically and quantitatively evaluate the degree of fit among any number of maps and quantify a GOF for each polygon, as well as the entire map. The Mapcurve method indicates a perfect fit

William Walter Hargrove; Forrest M. Hoffman; Paul F. Hessburg

2006-01-01

29

Quantitative comparison of spot detection methods in fluorescence microscopy.  

PubMed

Quantitative analysis of biological image data generally involves the detection of many subresolution spots. Especially in live cell imaging, for which fluorescence microscopy is often used, the signal-to-noise ratio (SNR) can be extremely low, making automated spot detection a very challenging task. In the past, many methods have been proposed to perform this task, but a thorough quantitative evaluation and comparison of these methods is lacking in the literature. In this paper, we evaluate the performance of the most frequently used detection methods for this purpose. These include seven unsupervised and two supervised methods. We perform experiments on synthetic images of three different types, for which the ground truth was available, as well as on real image data sets acquired for two different biological studies, for which we obtained expert manual annotations to compare with. The results from both types of experiments suggest that for very low SNRs ( approximately 2), the supervised (machine learning) methods perform best overall. Of the unsupervised methods, the detectors based on the so-called h -dome transform from mathematical morphology or the multiscale variance-stabilizing transform perform comparably, and have the advantage that they do not require a cumbersome learning stage. At high SNRs ( > 5), the difference in performance of all considered detectors becomes negligible. PMID:19556194

Smal, Ihor; Loog, Marco; Niessen, Wiro; Meijering, Erik

2010-02-01

30

Evaluation of Four Quantitative Laboratory Fume Hood Performance Test Methods.  

National Technical Information Service (NTIS)

Four quantitative laboratory fume hood performance test methods were evaluated, including: EPA uranine dye; ASHRAE Freon; EPA SF sub 6 ; and modified EPA SF sub 6 . Each of these methods were evaluated, based on: variability and reproducibility; practical...

L. M. Woodrow

1987-01-01

31

A rapid chemiluminescent method for quantitation of human DNA.  

PubMed Central

A sensitive and simple method for the quantitation of human DNA is described. This method is based on probe hybridization to a human alpha satellite locus, D17Z1. The biotinylated probe is hybridized to sample DNA immobilized on nylon membrane. The subsequent binding of streptavidin-horseradish peroxidase to the bound probe allows for chemiluminescent detection using a luminol-based reagent and X-ray film. Less than 150 pg of human DNA can easily be detected with a 15 minute exposure. The entire procedure can be performed in 1.5 hours. Microgram quantities of nonhuman DNA have been tested and the results indicate very high specificity for human DNA. The data on film can be scanned into a computer and a commercially available program can be used to create a standard curve where DNA quantity is plotted against the mean density of each slot blot signal. The methods described can also be applied to the very sensitive determination of quantity and quality (size) of DNA on Southern blots. The high sensitivity of this quantitation method requires the consumption of only a fraction of sample for analysis. Determination of DNA quantity is necessary for RFLP and many PCR-based tests where optimal results are obtained only with a relatively narrow range of DNA quantities. The specificity of this quantitation method for human DNA will be useful for the analysis of samples that may also contain bacterial or other non-human DNA, for example forensic evidence samples, ancient DNA samples, or clinical samples. Images

Walsh, P S; Varlaro, J; Reynolds, R

1992-01-01

32

Photographic colorimetry as a quantitative cytochemical method  

Microsoft Academic Search

The amount of absorbance in a number of Feulgen-stained chicken erythrocytes and bull spermatozoa was measured by two independent methods, namely photographic colorimetry and scanning cytophotometry. With both methods the amount of DNA was found to be highly constant in these objects. Both methods revealed a highly significant variation between nuclei of about 5 per cent. At this level however

E. M. Tonkelaar; P. VAN DUIJN

1964-01-01

33

Integrating Interpretive and Quantitative Methods in Socialization Research.  

ERIC Educational Resources Information Center

Examines the strengths and weaknesses of interpretive and quantitative research methods in comparative developmental research. Cites three recent studies of the Yupno, Fiji, and Mayan peoples to show how the interpretive approach contributes to the understanding of the meaning of behavior in context whereas the quantitative approach contributes a…

Gaskins, Suzanne

1994-01-01

34

An Uneasy Alliance: Combining Qualitative and Quantitative Research Methods  

Microsoft Academic Search

The paper describes the difficulties encountered in trying to combine qualitative and quantitative research methods in a study of the relationship between moral reasoning and teenage drug use. Four problems that arose in the attempt to reduce qualitative data to a quantitative format are described. These problems are: (1) making analytic sense of singular responses; (2) a mistaken logical inference

David R. Buchanan

1992-01-01

35

Quantitative infrared analysis of borophosphosilicate films using multivariate statistical methods  

SciTech Connect

Infrared (IR) spectroscopy can serve as a rapid method for the quantitative analysis of borophosphosilicate glass (BPSG) films on Si wafers for the microelectronics industry. The advantages of using statistically designed calibration sets are emphasized. Classical least-squares (CLS), partial least-squares (PLS), and principal component regression (PCR) methods are all found to provide improved precision over traditional peak-height measurements. The quantitative results from spectral measurements taken in transmission mode at both 0/sup 0/ and 60/sup 0/ incident angles were also compared. PLS and PCR methods yielded results that were comparable within the sampling error, and each exhibited a better analysis precision than that obtained from the CLS analysis. Both PLS and PCR methods yielded the best results when applied to the original 60/sup 0/ incident angle data, which was not corrected for film thickness. PLS and PCR analyses each gave a standard error of prediction (SEP) for boron of approx. = 0.1 wt% and approx. = 0.2 wt % for phosphorus for a set of 44 calibration samples which spanned a range of concentrations from 1 to 5 wt % B and 2 to 6 wt % P. The PLS and PCR methods applied to the IR spectra were also capable of monitoring film thickness with a SEP of 14 nm for films that varied in thickness from 430 to 1000 nm. The importance of using these full-spectrum multivariate methods for outlier sample detection is presented, and the ability to extract qualitative spectral information from the CLS and PLS calibrations is demonstrated.

Haaland, D.M.

1988-06-01

36

Quantitative Hydrocarbon Energies from the PMO Method.  

ERIC Educational Resources Information Center

Details a procedure for accurately calculating the quantum mechanical energies of hydrocarbons using the perturbational molecular orbital (PMO) method, which does not require the use of a computer. (BT)

Cooper, Charles F.

1979-01-01

37

Indirect scaling methods for testing quantitative emotion theories.  

PubMed

Two studies investigated the utility of indirect scaling methods, based on graded pair comparisons, for the testing of quantitative emotion theories. In Study 1, we measured the intensity of relief and disappointment caused by lottery outcomes, and in Study 2, the intensity of disgust evoked by pictures, using both direct intensity ratings and graded pair comparisons. The stimuli were systematically constructed to reflect variables expected to influence the intensity of the emotions according to theoretical models of relief/disappointment and disgust, respectively. Two probabilistic scaling methods were used to estimate scale values from the pair comparison judgements: Additive functional measurement (AFM) and maximum likelihood difference scaling (MLDS). The emotion models were fitted to the direct and indirect intensity measurements using nonlinear regression (Study 1) and analysis of variance (Study 2). Both studies found substantially improved fits of the emotion models for the indirectly determined emotion intensities, with their advantage being evident particularly at the level of individual participants. The results suggest that indirect scaling methods yield more precise measurements of emotion intensity than rating scales and thereby provide stronger tests of emotion theories in general and quantitative emotion theories in particular. PMID:23650936

Junge, Martin; Reisenzein, Rainer

2013-01-01

38

Quantitative Methods for Software Selection and Evaluation.  

National Technical Information Service (NTIS)

When performing a buy analysis and selecting a product as part of a software acquisition strategy, most organizations will consider primarily the requirements (the ability of the product to meet the need) and the cost. The method used for the analysis and...

M. S. Bandor

2006-01-01

39

Fluorometric method of quantitative cell mutagenesis  

SciTech Connect

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, F.A.

1982-08-17

40

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, F.A.

1980-12-12

41

A CT assisted method for absolute quantitation of internal radioactivity.  

PubMed

A method is described for the determination of radioactivity (microCi or MBq) at an organ site within an object or patient. Using both anatomic image data (CT or MRI scans) and planar gamma camera images, activity at depth is determined using a matrix inversion method based on least squares. The result of the inversion analysis was the unknown set of n linear (uniform) activity densities representative of each organ within the phantom or patient. The problem was overdetermined since the number of unknown activity densities (microCi/cm) was much less than the number of analysis points (N) within the nuclear image. This method, defined as the CT assisted matrix inversion (CAMI) technique, was accurate to within 15% for a three "organ" plastic phantom, wherein the organs were right circular cylinders having activities of 74 to 508 microCi (or 2.74 MBq to 18.8 MBq). This accuracy included image quantitation effects, particularly assumptions concerning attenuation correction. The average absolute percent error of the estimated activity in four distinct radioactive volumes in the phantom was 9.8%. It was found that the background activity within the phantom was estimated to be too high if sampling regions near strong sources were used in the analysis (scatter effect). This was minimized by going at least 2 cm away from such sources. By applying the method to a monoclonal antibody clinical study, activities within the patient's major organs such as liver, spleen, and kidney could be estimated, even in cases where the organ could not be visualized. Here, the CAMI algorithm gave internally consistent results for the patient's left and right lung linear activity concentrations. The CAMI technique resolves the problem of tissue superimposition using depth information from 3-D CT and is applicable in cases where a number of organs overlap in the gamma camera image. Thus, the method should be generally useful to nuclear image quantitation and the estimation of absorbed radiation doses in patients. One particular application is the estimation of radiation doses in radioimmunotherapy (RIT). PMID:8947907

Liu, A; Williams, L E; Raubitschek, A A

1996-11-01

42

A simple HPLC method for quantitation of enalaprilat  

Microsoft Academic Search

A reversed-phase high performance liquid chromatography (HPLC) method with UV-detection has been developed for the determination of enalaprilat. The method produced linear response over the wide concentration range of 1–200 ?g\\/ml, with an average accuracy of 97.35±4.93%, as well as average intra- and iter-day variations of 3.72 and 5.18%, respectively. The limits of detection and quantitation of the method were

Hosnieh Tajerzadeh; Mehrdad Hamidi

2001-01-01

43

An Approach to the Integration of Qualitative and Quantitative Research Methods in Software Engineering Research  

Microsoft Academic Search

Two distinct research methods coexist in SE: quantitative methods, which seek to measure and analyze causal relationships between variables in a framework with free values, and qualitative methods, which examine the proc- ess of creating meanings from which new or improved theorems are generated. Applying these two methods separately to SE research, it becomes clear that the results obtained are

María Lázaro; Esperanza Marcos

2006-01-01

44

Result-driven strategies for protein identification and quantitation--a way to optimize experimental design and derive reliable results.  

PubMed

Uni- or multidimensional microcapillary liquid chromatography (microLC) matrix-assisted laser desorption/ionization (MALDI) tandem mass spectrometry (MS/MS) approaches have gained significant attention for quantifying and identifying proteins in complex biological samples. The off-line coupling of microLC with MS quantitation and MS/MS identification methods makes new result-dependent workflows possible. A relational database is used to store the results from multiple high performance liquid chromatography runs, including information about MALDI plate positions, and both peptide and protein quantitations, and identifications. Unlike electrospray methodology, where all the decisions about which peptide to fragment, must be made during peptide fractionations, in the MALDI experiments the samples are effectively "frozen in time". Therefore, additional MS and MS/MS spectra can be acquired, to promote more accurate quantitation or additional identifications until reliable results are derived that meet experimental design criteria. In the case of what can be designated the expression-dependent workflow, quantitation can be detached from identification and only peak pairs with biological relevant expression changes can be selected for further MS/MS analyses. Alternatively, additional MS/MS data can be acquired to confirm tentative peptide mass fingerprint hits in what is designated a search result-dependent workflow. In the MS data-dependent workflow, the goal is to collect as many meaningful spectra as possible by judiciously adjusting the acquisition parameters based on characteristics of the parent masses. This level of sophistication requires the development of innovative algorithms for these three result-dependent workflows that make MS and MS/MS analysis more efficient and also add confidence to experimental results. PMID:14760720

Graber, Armin; Juhasz, Peter S; Khainovski, Nikita; Parker, Kenneth C; Patterson, Dale H; Martin, Stephen A

2004-02-01

45

A quantitative assessment method for Ascaris eggs on hands.  

PubMed

The importance of hands in the transmission of soil transmitted helminths, especially Ascaris and Trichuris infections, is under-researched. This is partly because of the absence of a reliable method to quantify the number of eggs on hands. Therefore, the aim of this study was to develop a method to assess the number of Ascaris eggs on hands and determine the egg recovery rate of the method. Under laboratory conditions, hands were seeded with a known number of Ascaris eggs, air dried and washed in a plastic bag retaining the washing water, in order to determine recovery rates of eggs for four different detergents (cationic [benzethonium chloride 0.1% and cetylpyridinium chloride CPC 0.1%], anionic [7X 1% - quadrafos, glycol ether, and dioctyl sulfoccinate sodium salt] and non-ionic [Tween80 0.1% -polyethylene glycol sorbitan monooleate]) and two egg detection methods (McMaster technique and FLOTAC). A modified concentration McMaster technique showed the highest egg recovery rate from bags. Two of the four diluted detergents (benzethonium chloride 0.1% and 7X 1%) also showed a higher egg recovery rate and were then compared with de-ionized water for recovery of helminth eggs from hands. The highest recovery rate (95.6%) was achieved with a hand rinse performed with 7X 1%. Washing hands with de-ionized water resulted in an egg recovery rate of 82.7%. This washing method performed with a low concentration of detergent offers potential for quantitative investigation of contamination of hands with Ascaris eggs and of their role in human infection. Follow-up studies are needed that validate the hand washing method under field conditions, e.g. including people of different age, lower levels of contamination and various levels of hand cleanliness. PMID:24802859

Jeandron, Aurelie; Ensink, Jeroen H J; Thamsborg, Stig M; Dalsgaard, Anders; Sengupta, Mita E

2014-01-01

46

A Quantitative Assessment Method for Ascaris Eggs on Hands  

PubMed Central

The importance of hands in the transmission of soil transmitted helminths, especially Ascaris and Trichuris infections, is under-researched. This is partly because of the absence of a reliable method to quantify the number of eggs on hands. Therefore, the aim of this study was to develop a method to assess the number of Ascaris eggs on hands and determine the egg recovery rate of the method. Under laboratory conditions, hands were seeded with a known number of Ascaris eggs, air dried and washed in a plastic bag retaining the washing water, in order to determine recovery rates of eggs for four different detergents (cationic [benzethonium chloride 0.1% and cetylpyridinium chloride CPC 0.1%], anionic [7X 1% - quadrafos, glycol ether, and dioctyl sulfoccinate sodium salt] and non-ionic [Tween80 0.1% -polyethylene glycol sorbitan monooleate]) and two egg detection methods (McMaster technique and FLOTAC). A modified concentration McMaster technique showed the highest egg recovery rate from bags. Two of the four diluted detergents (benzethonium chloride 0.1% and 7X 1%) also showed a higher egg recovery rate and were then compared with de-ionized water for recovery of helminth eggs from hands. The highest recovery rate (95.6%) was achieved with a hand rinse performed with 7X 1%. Washing hands with de-ionized water resulted in an egg recovery rate of 82.7%. This washing method performed with a low concentration of detergent offers potential for quantitative investigation of contamination of hands with Ascaris eggs and of their role in human infection. Follow-up studies are needed that validate the hand washing method under field conditions, e.g. including people of different age, lower levels of contamination and various levels of hand cleanliness.

Jeandron, Aurelie; Ensink, Jeroen H. J.; Thamsborg, Stig M.; Dalsgaard, Anders; Sengupta, Mita E.

2014-01-01

47

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

48

Quantitative Research Methods in the Social Sciences (15 credits)  

Microsoft Academic Search

This module will run in the Epiphany term and is of ten weeks' duration with weekly two hour evening sessions. It provides a contextualised introduction to the main quantitative methods employed in social science and builds on the preliminary discussion of these topics in 'Perspectives on Social Research'. The module is concerned with the business of measuring the world as

David Byrne

49

Quantitative assessment of single-cell RNA-sequencing methods  

PubMed Central

Interest in single-cell whole-transcriptome analysis is growing rapidly, especially for profiling rare or heterogeneous populations of cells. We compared commercially available single-cell RNA amplification methods with both microliter and nanoliter volumes, using sequence from bulk total RNA and multiplexed quantitative PCR as benchmarks to systematically evaluate the sensitivity and accuracy of various single-cell RNA-seq approaches. We show that single-cell RNA-seq can be used to perform accurate quantitative transcriptome measurement in individual cells with a relatively small number of sequencing reads and that sequencing large numbers of single cells can recapitulate bulk transcriptome complexity.

Wu, Angela R; Neff, Norma F; Kalisky, Tomer; Dalerba, Piero; Treutlein, Barbara; Rothenberg, Michael E; Mburu, Francis M; Mantalas, Gary L; Sim, Sopheak; Clarke, Michael F; Quake, Stephen R

2014-01-01

50

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.

2011-01-01

51

Validation of a DNA quantitation method on the Biomek® 3000.  

PubMed

Laboratory automation has the ability to increase the throughput and efficiency of laboratory processes to keep pace with current backlogs and requests for analysis. This paper addresses the specific studies employed to properly evaluate an automated method for DNA quantitation setup using Applied Biosystems Quantifiler™ Human DNA Quantification kit on a Biomek® 3000. The calibration of robotic pipetting as well as comparison with manually performed steps confirmed the accuracy of the automated methods used. Reproducibility studies evaluated differences between robotic and manually prepared human DNA standard curves. Additional studies examined DNA samples of known quantities, extract storage formats, sensitivity, and an assessment of contamination. The Biomek® 3000 not only demonstrated reproducibility and accuracy that equaled or surpassed the manual method but also revealed a contamination-free method to replace the multiple pipetting steps required during quantitation setup. PMID:20707832

Myers, Jarrah R

2010-11-01

52

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.

53

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

54

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

55

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.

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

2013-01-01

56

Comparison of multivariate calibration methods for quantitative spectral analysis  

SciTech Connect

The quantitative prediction abilities of four multivariate calibration methods for spectral analyses are compared by using extensive Monte Carlo simulations. The calibration methods compared include inverse least-squares (ILS), classical least-squares (CLS), partial least-squares (PLS), and principal component regression (PCR) methods. ILS is a frequency-limited method while the latter three are capable of full-spectrum calibration. The simulations were performed assuming Beer's law holds and that spectral measurement errors and concentration errors associated with the reference method are normally distributed. Eight different factors that could affect the relative performance of the calibration methods were varied in a two-level, eight-factor experimental design in order to evaluate their effect on the prediction abilities of the four methods. It is found that each of the three full-spectrum methods has its range of superior performance. The frequency-limited ILS method was never the best method, although in the presence of relatively large concentration errors it sometimes yields comparable analysis precision to the full-spectrum methods for the major spectral component. The importance of each factor in the absolute and relative performances of the four methods is compared.

Thomas, E.V.; Haaland, D.M. (Sandia National Laboratories, Albuquerque, NM (USA))

1990-05-15

57

Analytical methods for quantitation of prenylated flavonoids from hops  

PubMed Central

The female flowers of hops (Humulus lupulus L.) are used as a flavoring agent in the brewing industry. There is growing interest in possible health benefits of hops, particularly as estrogenic and chemopreventive agents. Among the possible active constituents, most of the attention has focused on prenylated flavonoids, which can chemically be classified as prenylated chalcones and prenylated flavanones. Among chalcones, xanthohumol (XN) and desmethylxanthohumol (DMX) have been the most studied, while among flavanones, 8-prenylnaringenin (8-PN) and 6-prenylnaringenin (6-PN) have received the most attention. Because of the interest in medicinal properties of prenylated flavonoids, there is demand for accurate, reproducible and sensitive analytical methods to quantify these compounds in various matrices. Such methods are needed, for example, for quality control and standardization of hop extracts, measurement of the content of prenylated flavonoids in beer, and to determine pharmacokinetic properties of prenylated flavonoids in animals and humans. This review summarizes currently available analytical methods for quantitative analysis of the major prenylated flavonoids, with an emphasis on the LC-MS and LC-MS-MS methods and their recent applications to biomedical research on hops. This review covers all methods in which prenylated flavonoids have been measured, either as the primary analytes or as a part of a larger group of analytes. The review also discusses methodological issues relating to the quantitative analysis of these compounds regardless of the chosen analytical approach.

Nikolic, Dejan; van Breemen, Richard B.

2013-01-01

58

[A new method of calibration and positioning in quantitative analysis of multicomponents by single marker].  

PubMed

This paper aims to establish a new method of calibration and positioning in quantitative analysis of multicomponents by single marker (QAMS), using Shuanghuanglian oral liquid as the research object. Establishing relative correction factors with reference chlorogenic acid to other 11 active components (neochlorogenic acid, cryptochlorogenic acid, cafferic acid, forsythoside A, scutellarin, isochlorogenic acid B, isochlorogenic acid A, isochlorogenic acid C, baicalin and phillyrin wogonoside) in Shuanghuanglian oral liquid by 3 correction methods (multipoint correction, slope correction and quantitative factor correction). At the same time chromatographic peak was positioned by linear regression method. Only one standard uas used to determine the content of 12 components in Shuanghuanglian oral liquid, in stead of needing too many reference substance in quality control. The results showed that within the linear ranges, no significant differences were found in the quantitative results of 12 active constituents in 3 batches of Shuanghuanglian oral liquid determined by 3 correction methods and external standard method (ESM) or standard curve method (SCM). And this method is simpler and quicker than literature methods. The results were accurate and reliable, and had good reproducibility. While the positioning chromatographic peaks by linear regression method was more accurate than relative retention time in literature. The slope and the quantitative factor correction controlling the quality of Chinese traditional medicine is feasible and accurate. PMID:23460972

He, Bing; Yang, Shi-Yan; Zhang, Yan

2012-12-01

59

Quantitative Gene Expression of Somatostatin Receptors and Noradrenaline Transporter Underlying Scintigraphic Results in Patients with Neuroendocrine Tumors  

Microsoft Academic Search

Aim: To measure, by a quantitative approach, the gene expression underlying the results of somatostatin receptor (sst) scintigraphy (111In-DTPA-octreotide) and noradrenaline transporter (NAT) scintigraphy (123I-MIBG) in patients with neuroendocrine (NE) tumors. Methods: The gene expression of somatostatin receptors 1–5 (sst) and NAT was measured quantitatively by real-time PCR in a group of patients with NE tumors (n = 14) and

Tina Binderup; Ulrich Knigge; Anne Mellon Mogensen; Carsten Palnaes Hansen; Andreas Kjaer

2008-01-01

60

Quantitative results of stellar evolution and pulsation theories.  

NASA Technical Reports Server (NTRS)

The discrepancy between the masses of Cepheid variables deduced from evolution theory and pulsation theory is examined. The effect of input physics on evolutionary tracks is first discussed; in particular, changes in the opacity are considered. The sensitivity of pulsation masses to opacity changes and to the ascribed values of luminosity and effective temperature are then analyzed. The Cepheid mass discrepancy is discussed in the light of the results already obtained. Other astronomical evidence, including the mass-luminosity relation for main sequence stars, the solar neutrino flux, and cluster ages are also considered in an attempt to determine the most likely source of error in the event that substantial mass loss has not occurred.

Fricke, K.; Stobie, R. S.; Strittmatter, P. A.

1971-01-01

61

Thermography as a quantitative imaging method for assessing postoperative inflammation  

PubMed Central

Objective To assess differences in skin temperature between the operated and control side of the face after mandibular third molar surgery using thermography. Methods 127 patients had 1 mandibular third molar removed. Before the surgery, standardized thermograms were taken of both sides of the patient's face using a Flir ThermaCam™ E320 (Precisions Teknik AB, Halmstad, Sweden). The imaging procedure was repeated 2 days and 7 days after surgery. A region of interest including the third molar region was marked on each image. The mean temperature within each region of interest was calculated. The difference between sides and over time were assessed using paired t-tests. Results No significant difference was found between the operated side and the control side either before or 7 days after surgery (p > 0.3). The temperature of the operated side (mean: 32.39 °C, range: 28.9–35.3 °C) was higher than that of the control side (mean: 32.06 °C, range: 28.5–35.0 °C) 2 days after surgery [0.33 °C, 95% confidence interval (CI): 0.22–0.44 °C, p < 0.001]. No significant difference was found between the pre-operative and the 7-day post-operative temperature (p > 0.1). After 2 days, the operated side was not significantly different from the temperature pre-operatively (p = 0.12), whereas the control side had a lower temperature (0.57 °C, 95% CI: 0.29–0.86 °C, p < 0.001). Conclusions Thermography seems useful for quantitative assessment of inflammation between the intervention side and the control side after surgical removal of mandibular third molars. However, thermography cannot be used to assess absolute temperature changes due to normal variations in skin temperature over time.

Christensen, J; Matzen, LH; Vaeth, M; Schou, S; Wenzel, A

2012-01-01

62

Mapcurves: a quantitative method for comparing categorical maps  

NASA Astrophysics Data System (ADS)

We present Mapcurves, a quantitative goodness-of-fit (GOF) method that unambiguously shows the degree of spatial concordance between two or more categorical maps. Mapcurves graphically and quantitatively evaluate the degree of fit among any number of maps and quantify a GOF for each polygon, as well as the entire map. The Mapcurve method indicates a perfect fit even if all polygons in one map are comprised of unique sets of the polygons in another map, if the coincidence among map categories is absolute. It is not necessary to interpret (or even know) legend descriptors for the categories in the maps to be compared, since the degree of fit in the spatial overlay alone forms the basis for the comparison. This feature makes Mapcurves ideal for comparing maps derived from remotely sensed images. A translation table is provided for the categories in each map as an output. Since the comparison is category-based rather than cell-based, the GOF is resolution-independent. Mapcurves can be applied either to entire map categories or to individual raster patches or vector polygons. Mapcurves also have applications for quantifying the spatial uncertainty of particular map features.

Hargrove, William W.; Hoffman, Forrest M.; Hessburg, Paul F.

2006-07-01

63

Quantitative methods to direct exploration based on hydrogeologic information  

USGS Publications Warehouse

Quantitatively Directed Exploration (QDE) approaches based on information such as model sensitivity, input data covariance and model output covariance are presented. Seven approaches for directing exploration are developed, applied, and evaluated on a synthetic hydrogeologic site. The QDE approaches evaluate input information uncertainty, subsurface model sensitivity and, most importantly, output covariance to identify the next location to sample. Spatial input parameter values and covariances are calculated with the multivariate conditional probability calculation from a limited number of samples. A variogram structure is used during data extrapolation to describe the spatial continuity, or correlation, of subsurface information. Model sensitivity can be determined by perturbing input data and evaluating output response or, as in this work, sensitivities can be programmed directly into an analysis model. Output covariance is calculated by the First-Order Second Moment (FOSM) method, which combines the covariance of input information with model sensitivity. A groundwater flow example, modeled in MODFLOW-2000, is chosen to demonstrate the seven QDE approaches. MODFLOW-2000 is used to obtain the piezometric head and the model sensitivity simultaneously. The seven QDE approaches are evaluated based on the accuracy of the modeled piezometric head after information from a QDE sample is added. For the synthetic site used in this study, the QDE approach that identifies the location of hydraulic conductivity that contributes the most to the overall piezometric head variance proved to be the best method to quantitatively direct exploration. ?? IWA Publishing 2006.

Graettinger, A. J.; Lee, J.; Reeves, H. W.; Dethan, D.

2006-01-01

64

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

PubMed

Few studies have addressed the efficacy of composite sampling for measuring indicator bacteria by quantitative PCR (qPCR). We compared results from composited samples with multiple-sample means for culture- and qPCR-based water quality monitoring. Results from composited samples for both methods were similarly correlated to multiple-sample means and predicted criteria exceedances equally. PMID:22865067

Converse, Reagan R; Wymer, Larry J; Dufour, Alfred P; Wade, Timothy J

2012-10-01

65

A quantitative method for clustering size distributions of elements  

NASA Astrophysics Data System (ADS)

A quantitative method was developed to group similarly shaped size distributions of particle-phase elements in order to ascertain sources of the elements. This method was developed and applied using data from two sites in Houston, TX; one site surrounded by refineries, chemical plants and vehicular and commercial shipping traffic, and the other site, 25 miles inland surrounded by residences, light industrial facilities and vehicular traffic. Twenty-four hour size-segregated (0.056< Dp (particle diameter)<1.8 ?m) particulate matter samples were collected during five days in August 2000. ICP-MS was used to quantify 32 elements with concentrations as low as a few picograms per cubic meter. Concentrations of particulate matter mass, sulfate and organic carbon at the two sites were often not significantly different from each other and had smooth unimodal size distributions indicating the regional nature of these species. Element concentrations varied widely across events and sites and often showed sharp peaks at particle diameters between 0.1 and 0.3 ?m and in the ultrafine mode ( Dp<0.1 ?m), which suggested that the sources of these elements were local, high-temperature processes. Elements were quantitatively grouped together in each event using Ward's Method to cluster normalized size distributions of all elements. Cluster analysis provided groups of elements with similar size distributions that were attributed to sources such as automobile catalysts, fluid catalytic cracking unit catalysts, fuel oil burning, a coal-fired power plant, and high-temperature metal working. The clustered elements were generally attributed to different sources at the two sites during each sampling day indicating the diversity of local sources that impact heavy metals concentrations in the region.

Dillner, Ann M.; Schauer, James J.; Christensen, William F.; Cass, Glen R.

66

Rapid quantitative method for total brominated vegetable oil in soft drinks using ion chromatography  

Microsoft Academic Search

A simple, quantitative and rapid method for total brominated vegetable oil (BVO) using ion chromatography (IC) with suppressed conductivity detection was developed and successfully applied to soft drinks with results expressed as inorganic bromide anion. The procedure involves extraction of BVO with diethyl ether and treatment with zinc dust in a solution of acetic acid, giving recoveries ranging between 92.5

Ashraf A. Yousef; Alaa B. Abbas; Bassam Sh. Badawi; Wafaa Y. Al-Jowhar; Esam A. Zain; Seham A. El-Mufti

2012-01-01

67

A General Quantitative Method for Evaluating the Visual Significance of Reflected Glare, Utilizing Visual Performance Data.  

ERIC Educational Resources Information Center

The results of all basic measurements and calculations of reflected glare for different lighting materials and conditions are presented in a series of tables and charts. All basic concepts of a quantitative method for evaluating the visual significance of reflected glare are identified in relationship to different types of visual performance. The…

Blackwell, H. Richard

1963-01-01

68

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

69

Quantitative polymerase chain reaction using the comparative C q method.  

PubMed

Quantitative PCR (qPCR) is considered the gold standard for molecular DNA quantification and can be used for a wide range of techniques from comparing gene expression levels to quantifying DNA copy number variation. The strengths of this assay include sensitivity to a wide range of expression levels, low starting template requirement, which is important when samples are scarce, and quick turnaround time. However, there are many variables to consider when performing qPCR: including (1) starting materials (e.g., tissues, cells, or genomic DNA), (2) fluorescent detection (e.g., SYBR green dye, fluorescent probes, or multiplexed assays), and (3) analysis methods (e.g., simple equations with single reference genes or complex algorithms with multiple reference genes). This chapter will introduce the process of designing an experiment while avoiding common mistakes and present tools for performing qPCR in a practical, simple, and efficient manner. PMID:21204034

Yeatts, Kimberly

2011-01-01

70

A quantitative evaluation of various deconvolution methods and their applications in the deconvolution of plasma spectra  

NASA Astrophysics Data System (ADS)

A quantitative evaluation of various deconvolution methods and their applications in processing plasma emitted spectra was performed. The iterative deconvolution algorithms evaluated here include Jansson's method, Richardson-Lucy's method, the maximum a posteriori method and Gold's method. The evaluation criteria include minimization of the sum of squared errors and the sum of squared relative error of parameters, and their rate of convergence. After comparing deconvolved results using these methods, it was concluded that Jansson's and Gold's methods were able to provide good profiles that are visually close to the original spectra. Additionally, Gold's method generally gives the best results when considering all the criteria above. The applications to the actual plasma spectra obtained from the EAST tokamak with these methods are also presented in this paper. The deconvolution results with Gold's and Jansson's methods show that the effects of instruments can be satisfactorily eliminated and clear spectra are recovered.

Xiong, Yanwei; Shi, Yuejiang; Li, Yingying; Fu, Jia; Lu, Bo; Zhang, Hongming; Wang, Xiaoguang; Wang, Fudi; Shen, Yongcai

2013-06-01

71

A Method for Quantitative Determination of Biofilm Viability  

PubMed Central

In this study we present a scheme for quantitative determination of biofilm viability offering significant improvement over existing methods with metabolic assays. Existing metabolic assays for quantifying viable bacteria in biofilms usually utilize calibration curves derived from planktonic bacteria, which can introduce large errors due to significant differences in the metabolic and/or growth rates of biofilm bacteria in the assay media compared to their planktonic counterparts. In the presented method we derive the specific growth rate of Streptococcus mutans bacteria biofilm from a series of metabolic assays using the pH indicator phenol red, and show that this information could be used to more accurately quantify the relative number of viable bacteria in a biofilm. We found that the specific growth rate of S. mutans in biofilm mode of growth was 0.70 h?1, compared to 1.09 h?1 in planktonic growth. This method should be applicable to other bacteria types, as well as other metabolic assays, and, for example, to quantify the effect of antibacterial treatments or the performance of bactericidal implant surfaces.

Welch, Ken; Cai, Yanling; Str?mme, Maria

2012-01-01

72

A quantitative method for measuring innate phagocytosis by human monocytes using real-time flow cytometry.  

PubMed

Phagocytosis is central to immunity however a rapid and standardized method is much needed for quantitative assessment of the phagocytic process. We describe a real-time flow cytometric method to quantitate the phagocytosis of fluorescent latex beads by human monocytes in serum-free conditions. Effects of buffer composition, temperature, pH, and bead surface on phagocytic rate are described. The innate phagocytic ability of human monocytes from single subjects measured by this method was relatively stable over many months although phagocytosis rate varied as much as two-fold between individuals. Comparable results were obtained with a simplified method using several mL of whole blood which is suitable for routine clinical application. This method also allows two-color flow cytometric measurement of cytosolic calcium levels during the phagocytic uptake of fluorescent beads. PMID:24132941

Gu, Ben J; Sun, Chun; Fuller, Stephen; Skarratt, Kristen K; Petrou, Steven; Wiley, James S

2014-04-01

73

Establishment and evaluation of event-specific quantitative PCR method for genetically modified soybean MON89788.  

PubMed

A novel real-time PCR-based analytical method was established for the event-specific quantification of a GM soybean event MON89788. The conversion factor (C(f)) which is required to calculate the GMO amount was experimentally determined. The quantitative method was evaluated by a single-laboratory analysis and a blind test in a multi-laboratory trial. The limit of quantitation for the method was estimated to be 0.1% or lower. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)), and the determined bias and RSD(R) values for the method were both less than 20%. These results suggest that the established method would be suitable for practical detection and quantification of MON89788. PMID:21071908

Takabatake, Reona; Onishi, Mari; Koiwa, Tomohiro; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Furui, Satoshi; Kitta, Kazumi

2010-01-01

74

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

75

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

76

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

77

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

78

Drama counts: uncovering Channel 4's history with quantitative research methods  

Microsoft Academic Search

Quantitative research methods have largely been used in sociological approaches of television studies, but less so to uncover institutional or textual histories. This paper attempts to extend the use of quantitative research methods for television studies by introducing readers to a database collected about television drama shown on British terrestrial television between 1970 and 2000. It argues that quantitative research

Elke Weissmann

2009-01-01

79

Quantitative measurement of ?140mm F/2 parabolic surface with Ronchi grating test method  

NASA Astrophysics Data System (ADS)

Ronchi grating test has been used widely to test optical surfaces in a qualitative way since it was contrived, while rarely to test the parabolic surface in a quantitative way. This paper discusses the application of Ronchi grating test to optical aspheric surfaces in a quantitative way on the base of self-made software which includes Ronchi null grating design, collection of Ronchi graph, data procession and so on. The whole system has been used to test a concave parabolic mirror with diameter 140mm and F number 2, and the result is approximately the same as that of the outcome of interferometer. The analysis software and test method establish a good foundation for the coming of quantitative measurement of big error of large-aperture aspheric surfaces.

Lei, Bai-Ping; Wu, Fan; Zhou, Chen-Bo

2009-05-01

80

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

81

[Quantitative methods of cancer risk assessment in exposure to chemicals].  

PubMed

This is a methodology paper--it contains a review of different quantitative risk assessment methods and their comparison. There are two aspects of cancer risk modeling discussed here: 1. When there is one effective dose only. There were compared two models in this evaluation: one proposed by the Dutch Expert Committee on Occupational Standards and the other--a classical two-stage model. It was taken into account that in both models the animals were exposed for less than two years. An exposure period and a study period of animals were considered in the Dutch methodology. If we use as an exposure measure average lifespan dose estimated with different coefficients of exposure time in an experiment, we get two different dose-response models. And each of them will create different human risk models. There is no criterion that would let us assess which of them is better. 2. There are many models used in the BenchMark Dose (BMD) method. But there is no criterion that allows us to choose the best model objectively. In this paper a two-stage classical model and three BMD models (two-stage, Weibull and linear) were fit for particular data. Very small differences between all the models were noticed. The differences were insignificant because of uncertainties in the risk modeling. The possibility of choice of one model from a bigger set of models is the greatest benefit of this comparison. If the examined chemical is a genotoxic carcinogen, nothing more is needed than to estimate the threshold value. PMID:19746890

Szymczak, Wies?aw

2009-01-01

82

A method to assess search engine results  

Microsoft Academic Search

Purpose – The aim of this paper is to develop a methodology for assessing search results retrieved from different sources. Design\\/methodology\\/approach – This is a two phase method, where in the first stage users select and rank the ten best search results from a randomly ordered set. In the second stage they are asked to choose the best pre-ranked result

Judit Bar-Ilan; Mark Levene

2011-01-01

83

Joint Multipoint Linkage Analysis of Multivariate Qualitative and Quantitative Traits. I. Likelihood Formulation and Simulation Results  

PubMed Central

Summary We describe a variance-components method for multipoint linkage analysis that allows joint consideration of a discrete trait and a correlated continuous biological marker (e.g., a disease precursor or associated risk factor) in pedigrees of arbitrary size and complexity. The continuous trait is assumed to be multivariate normally distributed within pedigrees, and the discrete trait is modeled by a threshold process acting on an underlying multivariate normal liability distribution. The liability is allowed to be correlated with the quantitative trait, and the liability and quantitative phenotype may each include covariate effects. Bivariate discrete-continuous observations will be common, but the method easily accommodates qualitative and quantitative phenotypes that are themselves multivariate. Formal likelihood-based tests are described for coincident linkage (i.e., linkage of the traits to distinct quantitative-trait loci [QTLs] that happen to be linked) and pleiotropy (i.e., the same QTL influences both discrete-trait status and the correlated continuous phenotype). The properties of the method are demonstrated by use of simulated data from Genetic Analysis Workshop 10. In a companion paper, the method is applied to data from the Collaborative Study on the Genetics of Alcoholism, in a bivariate linkage analysis of alcoholism diagnoses and P300 amplitude of event-related brain potentials.

Williams, Jeff T.; Van Eerdewegh, Paul; Almasy, Laura; Blangero, John

1999-01-01

84

Quantitative Methods for the Allocation of DOD Exploratory Development Resources.  

National Technical Information Service (NTIS)

Methodologies are studied for the selection of tasks in the Exploratory Development category of Department of Defense Research and Development Program. Emphasis is placed on quantitative methodologies, those in which an objective scoring procedure is esta...

C. L. Trozzo V. J. Berinati W. S. Payne

1972-01-01

85

The distinction between qualitative and quantitative research methods is problematic  

Microsoft Academic Search

The distinction between qualitative and quantitative research is abstract, very general and its value is usually taken for\\u000a granted. In contrast, this article attempts to show that the distinction between qualitative and quantitative research is\\u000a unclear, poor and therefore of limited value and that its popularity risks leading to unfortunate consequences. Various arguments\\u000a are presented for this conclusion. For example,

Carl Martin Allwood

2012-01-01

86

Development and validation of event-specific quantitative PCR method for genetically modified maize MIR604.  

PubMed

A GM maize event, MIR604, has been widely distributed and an analytical method to quantify its content is required to monitor the validity of food labeling. Here we report a novel real-time PCR-based quantitation method for MIR604 maize. We developed real-time PCR assays specific for MIR604 using event-specific primers designed by the trait developer, and for maize endogenous starch synthase IIb gene (SSIIb). Then, we determined the conversion factor, which is required to calculate the weight-based GM maize content from the copy number ratio of MIR604-specific DNA to the endogenous reference DNA. Finally, to validate the developed method, an interlaboratory collaborative trial according to the internationally harmonized guidelines was performed with blind samples containing MIR604 at the mixing levels of 0, 0.5, 1.0, 5.0 and 10.0%. The reproducibility (RSDr) of the developed method was evaluated to be less than 25%. The limit of quantitation of the method was estimated to be 0.5% based on the ISO 24276 guideline. These results suggested that the developed method would be suitable for practical quantitative analyses of MIR604 maize. PMID:23132355

Mano, Junichi; Furui, Satoshi; Takashima, Kaori; Koiwa, Tomohiro; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Takabatake, Reona; Kitta, Kazumi

2012-01-01

87

Qualitative and quantitative PCR methods for detection of three lines of genetically modified potatoes.  

PubMed

Qualitative and quantitative polymerase chain reaction (PCR) methods have been developed for the detection of genetically modified (GM) potatoes. The combination of specific primers for amplification of the promoter region of Cry3A gene, potato leafroll virus replicase gene, and potato virus Y coat protein gene allows to identify each line of NewLeaf, NewLeaf Y, and NewLeaf Plus GM potatoes. Multiplex PCR method was also established for the simple and rapid detection of the three lines of GM potato in a mixture sample. For further quantitative detection, the realtime PCR method has been developed. This method features the use of a standard plasmid as a reference molecule. Standard plasmid contains both a specific region of the transgene Cry3A and an endogenous UDP-glucose pyrophosphorylase gene of the potato. The test samples containing 0.5, 1, 3, and 5% GM potatoes were quantified by this method. At the 3.0% level of each line of GM potato, the relative standard deviations ranged from 6.0 to 19.6%. This result shows that the above PCR methods are applicable to detect GM potatoes quantitatively as well as qualitatively. PMID:15161181

Rho, Jae Kyun; Lee, Theresa; Jung, Soon-Il; Kim, Tae-San; Park, Yong-Hwan; Kim, Young-Mi

2004-06-01

88

Evaluation of the quantitative performances of supercritical fluid chromatography: From method development to validation.  

PubMed

Recently, the number of papers about SFC increased drastically but scientists did not truly focus their work on quantitative performances of this technique. In order to prove the potential of UHPSFC, the present work discussed about the different steps of the analytical life cycle of a method: from development to validation and application. Moreover, the UHPSFC quantitative performances were evaluated in comparison with UHPLC, which is the main technique used for quality control in the pharmaceutical industry and then could be considered as a reference. The methods were developed using Design Space strategy, leading to the optimization of robust method. In this context, when the Design Space optimization shows guarantee of quality, no more robustness study is required prior to the validation. Then, the methods were geometrically transferred in order to reduce the analysis time. The UHPSFC and UHPLC methods were validated based on the total error approach using accuracy profile. Even if UHPLC showed better precision and sensitivity, UHPSFC method is able to give accurate results in a dosing range larger than the 80-120% range required by the European Medicines Agency. Consequently, UHPSFC results are valid and could be used for the control of active substance in a finished pharmaceutical product. Finally, UHPSFC validated method was used to analyse real samples and gave similar results than the reference method (UHPLC). PMID:24513349

Dispas, Amandine; Lebrun, Pierre; Ziemons, Eric; Marini, Roland; Rozet, Eric; Hubert, Philippe

2014-08-01

89

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

90

Advanced quantitative magnetic nondestructive evaluation methods - Theory and experiment  

NASA Technical Reports Server (NTRS)

The paper reviews the scale of fatigue crack phenomena in relation to the size detection capabilities of nondestructive evaluation methods. An assessment of several features of fatigue in relation to the inspection of ball and roller bearings suggested the use of magnetic methods; magnetic domain phenomena including the interaction of domains and inclusions, and the influence of stress and magnetic field on domains are discussed. Experimental results indicate that simplified calculations can be used to predict many features of these results; the data predicted by analytic models which use finite element computer analysis predictions do not agree with respect to certain features. Experimental analyses obtained on rod-type fatigue specimens which show experimental magnetic measurements in relation to the crack opening displacement and volume and crack depth should provide methods for improved crack characterization in relation to fracture mechanics and life prediction.

Barton, J. R.; Kusenberger, F. N.; Beissner, R. E.; Matzkanin, G. A.

1979-01-01

91

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.

Yuan, Zhen; Jiang, Huabei

2012-01-01

92

What counts as “good” quantitative research and what can we say about when to use quantitative and\\/or qualitative methods?  

Microsoft Academic Search

In response to points raised by Dawson, Fischer, and Stein; Stam; and Stiles, the author delineates what counts as “good” quantitative research according to his proposal for explicitly interpretive quantitative methods. The key points concern how to employ these methods, not which quantitative methods we should use—“strong” rather than “soft” or vice versa. The author discusses ways in which what

Michael A. Westerman

2006-01-01

93

Iterative optimization method for design of quantitative magnetization transfer imaging experiments.  

PubMed

Quantitative magnetization transfer imaging (QMTI) using spoiled gradient echo sequences with pulsed off-resonance saturation can be a time-consuming technique. A method is presented for selection of an optimum experimental design for quantitative magnetization transfer imaging based on the iterative reduction of a discrete sampling of the Z-spectrum. The applicability of the technique is demonstrated for human brain white matter imaging at 1.5 T and 3 T, and optimal designs are produced to target specific model parameters. The optimal number of measurements and the signal-to-noise ratio required for stable parameter estimation are also investigated. In vivo imaging results demonstrate that this optimal design approach substantially improves parameter map quality. The iterative method presented here provides an advantage over free form optimal design methods, in that pragmatic design constraints are readily incorporated. In particular, the presented method avoids clustering and repeated measures in the final experimental design, an attractive feature for the purpose of magnetization transfer model validation. The iterative optimal design technique is general and can be applied to any method of quantitative magnetization transfer imaging. PMID:21748796

Levesque, Ives R; Sled, John G; Pike, G Bruce

2011-09-01

94

Quantitation Method for Hourly Organic Speciation of Atmospheric Urban Aerosols  

NASA Astrophysics Data System (ADS)

Organic speciation is critical to illucidating the origin and fate of a major component of atmospheric aerosols. Currently a gap exists in atmospheric sampling methods that provide both high-time resolution and compound specific information. The current standard for molecular level carbonaceous aerosol analysis is GC-MS analyses on filter samples with inherent time-resolution limitations. Single-particle mass spectrometer based instruments offer a huge advance by providing high time resolution data but fall short of providing molecular level information. The Thermal desorption Aerosol GC-MS/FID (TAG) instrument recently introduced (Williams et al., 2006) provides unique information about organic aerosols on the time-scale of an hour that serves to bridge this gap between filter and single-particle instruments. This presentation will focus on extending TAG measurements into the quantitative realm though a systematic field calibration scheme that corrects for slowly changing system response attributed to the quadrupole mass spectrometer. To illustrate the calibration approach, two classes of compounds are considered that are regularly generated by primary emission sources, n-alkanes and polyaromatic hydrocarbons. Being low- polarity compounds these two classes pose less difficulty for reproducible chromatography, thus simplifiying field data calibration. A sample collection and analysis cell with an integrated injection port allows for the in- situ calibration of the instrument using mulitple authentic standards. To obtain the calibrated response a single mixture containing multiple compound classes is regularly injected that substitutes for an internal standard. The technique is applied to data acquired during a four-week field campaign in Riverside, CA during the fall of 2005. A calibrated time series of organic compounds, positively identified through standard GC-MS methods, are shown to have very distinct diurnal patterns that could not be captured by integrated filter samples. Reference Williams, B.J., Goldstein, A.H., Kreisberg, N.M. and Hering, S.V., An In-Situ Instrument for Speciated Organic Composition of Atmospheric Aerosols: Thermal Desorption Aerosol GC/MS-FID (TAG), Aerosol Science and Technology 40:627-638, 2006.

Kreisberg, N. M.; Hering, S. V.; Williams, B. J.; Goldstein, A. H.

2006-12-01

95

Quantitative Three-Dimensional Imaging by Thermal Tomography Method  

NASA Astrophysics Data System (ADS)

Pulsed thermal imaging has been widely used for nondestructive evaluation of engineering materials. Development of advanced data processing methods has improved the capabilities of this technology. However, many limitations still present. Current data-processing methods intended for property measurement are mostly based on mathematical models that are only related to gross material properties such as thickness-averaged thermal diffusivity or sample thickness (or defect depth). These models cannot account for material property variations within the sample volume. On the other hand, data-processing methods intended for internal-flaw detection are usually not suitable for inspection of complex material systems. In addition to these fundamental issues, a prior knowledge for some parameters of the tested material is normally required in order to perform data processing with an appropriate model or to interpret result. These problems can all be addressed by a recently-developed thermal tomography method. It utilizes the one-sided flash thermal-imaging data to construct three-dimensional data of material's thermal effusivity in the entire sample volume. This paper discusses the theories and presents typical results obtained by this method.

Sun, J. G.

2011-06-01

96

Comparison of Transcription-Mediated Amplification and Growth-Based Methods for the Quantitation of Enterococcus Bacteria in Environmental Waters?  

PubMed Central

An assay based on transcription-mediated amplification (TMA) technology was used to quantitate Enterococcus fecal indicator bacteria in environmental water samples. The results generated by this and two growth-based methods relative to the 104 most-probable-number or CFU-per-100-ml threshold show that the three methods are in good qualitative agreement when tested against a range of water samples taken from different locations. The results demonstrate sensitive and rapid detection (approximately 4 h from sample collection to result) and quantitation of Enterococcus bacteria compared to the results with the growth-based methods.

Morris, Ceri A.; Blackwood, A. Denene; Kirs, Marek; Buttigieg, Neil D.; Morgan, Rhian R.; Hogan, James J.; Weeks, Ian; Noble, Rachel T.

2008-01-01

97

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

Microsoft Academic Search

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

Z. Y. Han; W. G. Weng

2011-01-01

98

Nuclear medicine and quantitative imaging research (instrumentation and quantitative methods of evaluation). Progress report, January 15-September 1, 1990.  

National Technical Information Service (NTIS)

This report summarizes goals and accomplishments of the research program supported under DOE Grant No. FG02-86ER60418 entitled Instrumentation and Quantitative Methods of Evaluation, with R. Beck, P. I. and M. Cooper, Co-P.I. during the period January 15,...

R. N. Beck M. D. Cooper

1990-01-01

99

The ROI of systems engineering: Some quantitative results for software-intensive systems  

Microsoft Academic Search

This paper presents quantitative results on the return on investment of systems engineering (SE-ROI) from an analysis of the 161 software projects in the COCOMO II database. The analysis shows that, after normalizing for the effects of other cost drivers, the cost difference between projects doing a minimal job of software systems engineering—as measured by the thorough- ness of its

Barry Boehm; Ricardo Valerdi; Eric Honour

2008-01-01

100

A new quantitative method for gunshot residue analysis by ion beam analysis.  

PubMed

Imaging and analyzing gunshot residue (GSR) particles using the scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDS) is a standard technique that can provide important forensic evidence, but the discrimination power of this technique is limited due to low sensitivity to trace elements and difficulties in obtaining quantitative results from small particles. A new, faster method using a scanning proton microbeam and Particle Induced X-ray Emission (?-PIXE), together with Elastic Backscattering Spectrometry (EBS) is presented for the non-destructive, quantitative analysis of the elemental composition of single GSR particles. In this study, the GSR particles were all Pb, Ba, Sb. The precision of the method is assessed. The grouping behaviour of different makes of ammunition is determined using multivariate analysis. The protocol correctly groups the cartridges studied here, with a confidence >99%, irrespective of the firearm or population of particles selected. PMID:23775063

Christopher, Matthew E; Warmenhoeven, John-William; Romolo, Francesco S; Donghi, Matteo; Webb, Roger P; Jeynes, Christopher; Ward, Neil I; Kirkby, Karen J; Bailey, Melanie J

2013-08-21

101

Health Professional’s Perceptions and Practices in Relation to Functional Capacity Evaluations: Results of a Quantitative Survey  

Microsoft Academic Search

Introduction This study investigated the perceptions and practices of Australian health professionals in relation to the use of functional\\u000a capacity evaluations (FCE’s). Methods A quantitative cross-sectional study design was used to survey health professionals who conduct FCE’s and who were working\\u000a for one of 219 rehabilitation providers in NSW, Australia. Seventy seven returned surveys were eligible for inclusion. Results Eleven

Carole James; Lynette Mackenzie

2009-01-01

102

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

103

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

104

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

105

Quantitative Methods in Computer-Directed Teaching Systems.  

National Technical Information Service (NTIS)

The report formulates in quantitative terms the decision problem associated with the design of a computer-directed teaching system. This formulation is then used to direct a theoretical inquiry into some of the aspects of this problem that are relevant to...

R. D. Smallwood I. J. Weinstein J. E. Eckles

1967-01-01

106

Quantitative methods to characterize morphological properties of cell lines.  

PubMed

Descriptive terms are often used to characterize cells in culture, but the use of nonquantitative and poorly defined terms can lead to ambiguities when comparing data from different laboratories. Although recently there has been a good deal of interest in unambiguous identification of cell lines via their genetic markers, it is also critical to have definitive, quantitative metrics to describe cell phenotypic characteristics. Quantitative metrics of cell phenotype will aid the comparison of data from experiments performed at different times and in different laboratories where influences such as the age of the population and differences in culture conditions or protocols can potentially affect cellular metabolic state and gene expression in the absence of changes in the genetic profile. Here, we present examples of robust methodologies for quantitatively assessing characteristics of cell morphology and cell-cell interactions, and of growth rates of cells within the population. We performed these analyses with endothelial cell lines derived from dolphin, bovine and human, and with a mouse fibroblast cell line. These metrics quantify some characteristics of these cells lines that clearly distinguish them from one another, and provide quantitative information on phenotypic changes in one of the cell lines over large number of passages. PMID:22619183

Mancia, Annalaura; Elliott, John T; Halter, Michael; Bhadriraju, Kiran; Tona, Alessandro; Spurlin, Tighe A; Middlebrooks, Bobby L; Baatz, John E; Warr, Gregory W; Plant, Anne L

2012-07-01

107

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.

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

2013-01-01

108

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

109

Heat transfer quantitative characterization: Passive and active methods  

NASA Astrophysics Data System (ADS)

Two ways of determining the convective fluxes from the nonsteady temperatures are discussed: the passive method of classical thermography, in which the heating due to convection alone is used; and the active method of stimulated thermography in which the heat transfer coefficients are found directly from the heating due to a source of radiation, which is added to the convection for very brief intervals. The various algorithms used for identification of the heat transfer coefficient are presented together with some experimental results. For heat transfer identification, monodimensional models are used in both the passive and active modes. Moreover, considering the fact that supersonic or hypersonic flows are being dealt with, it is assumed that the linearized transfer coefficient corresponding to the radiative transfers between the model and the wind tunnel wall is negligible compared with the convective transfer coefficient.

Balageas, D. L.

110

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

111

Multipoint methods for linkage analysis of quantitative trait loci in sib pairs  

SciTech Connect

The sib-pair method of Haseman and Elston is widely used for linkage analysis of quantitative traits. The method requires no assumptions concerning the mode of transmission of the trait, it is robust with respect to genetic heterogeneity, and it is computationally efficient. However, the practical usefulness of the method is limited by its statistical power, requiring large numbers of sib paris and highly informative markers to detect genetic loci of only moderate effect size. We have developed a family of interval mapping procedures which dramatically increase the statistical power of the classical sib-pair approach. The methods make use of information from pairs of markers which flank a putative quantitative trait locus (QTL) in order to estimate the location and effect size of the QTL. Here we describe an extension of the interval mapping procedure which takes into account all available marker information on a chromosome simultaneously, rather than just pairs of markers. The method provides a computationally fast approximation to full multipoint analysis of sib-pair data using a modified Haserman-Elston approach. It gives very similar results to the earlier interval mapping procedure when marker information is relatively uniform and a coarse map is used. However, there is a substantial improvement over the original method when markers differ in information content and when a dense map is employed. The method is illustrated using real and simulated sib-pair data.

Cardon, L.R. [Stanford Univ., CA (United States)]|[SRI International, Stanford, CA (United States); Cherny, S.S.; Fulker, D.W. [Univ. of Colorado, Boulder, CO (United States)

1994-09-01

112

Application of new least-squares methods for the quantitative infrared analysis of multicomponent samples  

SciTech Connect

Improvements have been made in previous least-squares regression analyses of infrared spectra for the quantitative estimation of concentrations of multicomponent mixtures. Spectral baselines are fitted by least-squares methods, and overlapping spectral features are accounted for in the fitting procedure. Selection of peaks above a threshold value reduces computation time and data storage requirements. Four weighted least-squares methods incorporating different baseline assumptions were investigated using FT-IR spectra of the three pure xylene isomers and their mixtures. By fitting only regions of the spectra that follow Beer's Law, accurate results can be obtained using three of the fitting methods even when baselines are not corrected to zero. Accurate results can also be obtained using one of the fits even in the presence of Beer's Law deviations. This is a consequence of pooling the weighted results for each spectral peak such that the greatest weighting is automatically given to those peaks that adhere to Beer's Law. It has been shown with the xylene spectra that semiquantitative results can be obtained even when all the major components are not known or when expected components are not present. This improvement over previous methods greatly expands the utility of quantitative least-squares analyses.

Haaland, D.M.; Easterling, R.G.

1982-11-01

113

Good results with the Ponseti method  

PubMed Central

Background and purpose In 2002–2003, several hospitals in Norway introduced the Ponseti method for treating clubfoot. The present multicenter study was conducted to evaluate the initial results of this method, and to compare them to the good results reported in the literature. Patients and methods 116 children with 162 congenital idiopathic clubfeet who were born between 2004 and 2006 were treated with the Ponseti method at 8 hospitals in Norway. All children were prospectively registered at birth, and 116 feet were assessed according to Pirani before treatment was started. 63% used a standard bilateral foot abduction brace, and 32% used a unilateral above-the-knee brace. One of the authors examined all feet at a mean age of 4 years. At follow-up, all feet were assessed by Pirani’s scoring system, and range of motion of the foot and ankle was measured. Results At follow-up, 77% of the feet had a Pirani score of 0.5 or better, good dorsiflexion and external rotation, and no forefoot adduction. An Achilles tenotomy had been performed in 79% of the feet. Compliance to any brace was good; only 7% were defined as non-compliant. Extensive soft tissue release had been performed in 3% of the feet. We found no statistically significant differences between the two braces, except a tendency of better Pirani score in the group using the bilateral foot abduction brace, and a tendency of better compliance in patients using the unilateral brace. Better Pirani scores were found in children who were treated at the largest hospitals. Interpretation After introducing the Ponseti method in Norway, the clinical outcome was good and in accordance with the reports from single centers. Only 5 feet needed extensive surgery during the first 4 years of life.

2012-01-01

114

An integrated quantitative risk analysis method for natural gas pipeline network  

Microsoft Academic Search

Natural gas industry is developing rapidly, and its accidents are threatening the urban safety. Risk management through quantitative assessment has become an important way to improve the safety performance of the natural gas supply system. In this paper, an integrated quantitative risk analysis method for natural gas pipeline network is proposed. This method is composed of the probability assessment of

Z. Y. Han; W. G. Weng

2010-01-01

115

Facile colorimetric methods for the quantitative determination of tetramisole hydrochloride.  

PubMed

A facile, rapid and sensitive methods for the determination of tetramisole hydrochloride in pure and in dosage forms are described. The procedures are based on the formation of coloured products with the chromogenic reagents alizarin blue BB (I), alizarin red S (II), alizarin violet 3R (III) and alizarin yellow G (IV). The coloured products showed absorption maxima at 605, 468, 631 and 388 nm for I-IV, respectively. The colours obtained were stable for 24 h. The colour system obeyed Beer's law in the concentration range 1.0-36, 0.8-32, 1.2-42 and 0.8-30 microg ml(-1) respectively. The results obtained showed good recoveries with relative standard deviations of 1.27, 0.96, 1.13 and 1.35%, respectively. The detection and determination limits were found to be 1.0 and 3.8, 1.2 and 4.2, 1.0 and 3.9 and finally 1.4 and 4.8 ng ml(-1) for I-IV complexes, respectively. Applications of the method to representative pharmaceutical formulations are represented and the validity assessed by applying the standard addition technique, which is comparable with that obtained using the official method. PMID:12396035

Amin, A S; Dessouki, H A

2002-10-01

116

Facile colorimetric methods for the quantitative determination of tetramisole hydrochloride  

NASA Astrophysics Data System (ADS)

A facile, rapid and sensitive methods for the determination of tetramisole hydrochloride in pure and in dosage forms are described. The procedures are based on the formation of coloured products with the chromogenic reagents alizarin blue BB (I), alizarin red S (II), alizarin violet 3R (III) and alizarin yellow G (IV). The coloured products showed absorption maxima at 605, 468, 631 and 388 nm for I-IV, respectively. The colours obtained were stable for 24 h. The colour system obeyed Beer's law in the concentration range 1.0-36, 0.8-32, 1.2-42 and 0.8-30 ?g ml -1, respectively. The results obtained showed good recoveries with relative standard deviations of 1.27, 0.96, 1.13 and 1.35%, respectively. The detection and determination limits were found to be 1.0 and 3.8, 1.2 and 4.2, 1.0 and 3.9 and finally 1.4 and 4.8 ng ml -1 for I-IV complexes, respectively. Applications of the method to representative pharmaceutical formulations are represented and the validity assessed by applying the standard addition technique, which is comparable with that obtained using the official method.

Amin, A. S.; Dessouki, H. A.

2002-10-01

117

A simplified method for quantitative assessment of the relative health and safety risk of environmental management activities  

SciTech Connect

This report presents a simplified method to assess the health and safety risk of Environmental Management activities of the US Department of Energy (DOE). The method applies to all types of Environmental Management activities including waste management, environmental restoration, and decontamination and decommissioning. The method is particularly useful for planning or tradeoff studies involving multiple conceptual options because it combines rapid evaluation with a quantitative approach. The method is also potentially applicable to risk assessments of activities other than DOE Environmental Management activities if rapid quantitative results are desired.

Eide, S.A.; Smith, T.H.; Peatross, R.G.; Stepan, I.E.

1996-09-01

118

Development and evaluation of an improved quantitative 90Y bremsstrahlung SPECT method  

PubMed Central

Purpose: Yttrium-90 (90Y) is one of the most commonly used radionuclides in targeted radionuclide therapy (TRT). Since it decays with essentially no gamma photon emissions, surrogate radionuclides (e.g., 111In) or imaging agents (e.g., 99mTc MAA) are typically used for treatment planning. It would, however, be useful to image 90Y directly in order to confirm that the distributions measured with these other radionuclides or agents are the same as for the 90Y labeled agents. As a result, there has been a great deal of interest in quantitative imaging of 90Y bremsstrahlung photons using single photon emission computed tomography (SPECT) imaging. The continuous and broad energy distribution of bremsstrahlung photons, however, imposes substantial challenges on accurate quantification of the activity distribution. The aim of this work was to develop and evaluate an improved quantitative 90Y bremsstrahlung SPECT reconstruction method appropriate for these imaging applications. Methods: Accurate modeling of image degrading factors such as object attenuation and scatter and the collimator-detector response is essential to obtain quantitatively accurate images. All of the image degrading factors are energy dependent. Thus, the authors separated the modeling of the bremsstrahlung photons into multiple categories and energy ranges. To improve the accuracy, the authors used a bremsstrahlung energy spectrum previously estimated from experimental measurements and incorporated a model of the distance between 90Y decay location and bremsstrahlung emission location into the SIMIND code used to generate the response functions and kernels used in the model. This improved Monte Carlo bremsstrahlung simulation was validated by comparison to experimentally measured projection data of a 90Y line source. The authors validated the accuracy of the forward projection model for photons in the various categories and energy ranges using the validated Monte Carlo (MC) simulation method. The forward projection model was incorporated into an iterative ordered subsets-expectation maximization (OS-EM) reconstruction code to allow for quantitative SPECT reconstruction. The resulting code was validated using both a physical phantom experiment with spherical objects in a warm background and a realistic anatomical phantom simulation. In the physical phantom study, the authors evaluated the method in terms of quantitative accuracy of activity estimates in the spheres; in the simulation study, the authors evaluated the accuracy and precision of activity estimates from various organs and compared them to results from a previously proposed method. Results: The authors demonstrated excellent agreement between the experimental measurement and Monte Carlo simulation. In the XCAT phantom simulation, the proposed method achieved much better accuracy in the modeling (error in photon counts was ?1.1?%) compared to a previously proposed method (errors were more than 20??%); the quantitative accuracy of activity estimates was excellent for all organs (errors were from ?1.6?% to 11.9?%) and comparable to previously published results for 131I using the same collimator. Conclusions: The proposed 90Y bremsstrahlung SPECT reconstruction method provided very accurate estimates of organ activities, with accuracies approaching those previously observed for 131I. The method may be useful in verifying organ doses for targeted radionuclide therapy using 90Y.

Rong, Xing; Du, Yong; Ljungberg, Michael; Rault, Erwann; Vandenberghe, Stefaan; Frey, Eric C.

2012-01-01

119

Development of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.  

PubMed

A duplex real-time PCR method was developed for quantitative screening analysis of GM maize. The duplex real-time PCR simultaneously detected two GM-specific segments, namely the cauliflower mosaic virus (CaMV) 35S promoter (P35S) segment and an event-specific segment for GA21 maize which does not contain P35S. Calibration was performed with a plasmid calibrant specially designed for the duplex PCR. The result of an in-house evaluation suggested that the analytical precision of the developed method was almost equivalent to those of simplex real-time PCR methods, which have been adopted as ISO standard methods for the analysis of GMOs in foodstuffs and have also been employed for the analysis of GMOs in Japan. In addition, this method will reduce both the cost and time requirement of routine GMO analysis by half. The high analytical performance demonstrated in the current study would be useful for the quantitative screening analysis of GM maize. We believe the developed method will be useful for practical screening analysis of GM maize, although interlaboratory collaborative studies should be conducted to confirm this. PMID:19602858

Oguchi, Taichi; Onishi, Mari; Minegishi, Yasutaka; Kurosawa, Yasunori; Kasahara, Masaki; Akiyama, Hiroshi; Teshima, Reiko; Futo, Satoshi; Furui, Satoshi; Hino, Akihiro; Kitta, Kazumi

2009-06-01

120

An Augmented Classical Least Squares Method for Quantitative Raman Spectral Analysis against Component Information Loss  

PubMed Central

We propose an augmented classical least squares (ACLS) calibration method for quantitative Raman spectral analysis against component information loss. The Raman spectral signals with low analyte concentration correlations were selected and used as the substitutes for unknown quantitative component information during the CLS calibration procedure. The number of selected signals was determined by using the leave-one-out root-mean-square error of cross-validation (RMSECV) curve. An ACLS model was built based on the augmented concentration matrix and the reference spectral signal matrix. The proposed method was compared with partial least squares (PLS) and principal component regression (PCR) using one example: a data set recorded from an experiment of analyte concentration determination using Raman spectroscopy. A 2-fold cross-validation with Venetian blinds strategy was exploited to evaluate the predictive power of the proposed method. The one-way variance analysis (ANOVA) was used to access the predictive power difference between the proposed method and existing methods. Results indicated that the proposed method is effective at increasing the robust predictive power of traditional CLS model against component information loss and its predictive power is comparable to that of PLS or PCR.

Zhou, Yan; Cao, Hui

2013-01-01

121

Reliability and Feasibility of Methods to Quantitatively Assess Peripheral Edema  

PubMed Central

Objective: To evaluate methods to assess peripheral edema for reliability, feasibility and correlation with the classic clinical assessment of pitting edema. Design: Cross-sectional observational study. Setting: Large primary care clinic in Marshfield, Wisconsin, USA. Participants: Convenience sample of 20 patients with type 2 diabetes and a range of edema severity, including patients without edema. Methods: Eight methods of edema assessment were evaluated: (1) clinical assessment of pit depth and recovery at three locations, (2) patient questionnaire, (3) ankle circumference, (4) figure-of-eight (ankle circumference using eight ankle/foot landmarks), (5) edema tester (plastic card with holes of varying size pressed to the ankle with a blood pressure cuff), (6) modified edema tester (edema tester with bumps), (7) indirect leg volume (by series of ankle/leg circumferences), and (8) foot/ankle volumetry by water displacement. Patients were evaluated independently by three nurse examiners. Results: Water displacement and ankle circumference had high inter-examiner agreement (intraclass correlation coefficient 0.93, 0.96 right; 0.97, 0.97 left). Agreement was inconsistent for figure-of-eight (0.64, 0.86), moderate for indirect leg volume (0.53, 0.66), and low for clinical assessments at all locations. Agreement was low for the edema testers but varied by the pressure administered. Correlation with the classic, subjective clinical assessment was good for the nurse-performed assessments and patient questionnaire. Ankle circumference and patient questionnaires each took 1 minute to complete. Other tools took >5 minutes to complete. Conclusions: Water displacement and ankle circumference showed excellent reliability; however, water displacement is a time-consuming measure and may pose implementation challenges in the clinical and clinical trial environments. Patient-reported level and frequency of edema, based on an unvalidated questionnaire, was generally well correlated with the physician assessment of edema severity and may prove to be another reliable and accurate method of assessing edema. Additional study is needed to evaluate the validity and responsiveness of these methods.

Brodovicz, Kimberly G.; McNaughton, Kristin; Uemura, Naoto; Meininger, Gary; Girman, Cynthia J.; Yale, Steven H.

2009-01-01

122

Novel quantitative test method of laser range finder for range measurement: computerized instrument test method  

NASA Astrophysics Data System (ADS)

The maximum rang finding ability of laser range finder (LRF) is greatly influenced by various factors under field conditions, and these factors are changing constantly. In this paper, the advantages and shortcomings of traditional test method 'dissipated light power ratio method' through field object target are analyzed. A computerized instrument is developed, this instrument has no influence with field environment and characteristics of targets, it is simple, effective, accurate and quantitative to test comprehensive ability of range measurement which LRF system itself has. This paper introduces optimal formulas by use of computerized instrument to estimate the measuring rang of LRF, studied the theory of equations of measuring range by laser, and made a breakthrough of test method at program control of time-delay simulating space range and transmission and receiving of LRF under field conditions. This computerized test instrument has highly practical application and theoretical guiding meaning in demarcating checking and accepting of product produced by factories.

Chen, Zhibin

1996-10-01

123

Static headspace gas chromatographic method for quantitative determination of residual solvents in pharmaceutical drug substances according to european pharmacopoeia requirements.  

PubMed

A static headspace (HS) gas chromatographic method for quantitative determination of residual solvents in a drug substance has been developed according to European Pharmacopoeia general procedure. A water-dimethylformamide mixture is proposed as sample solvent to obtain good sensitivity and recovery. The standard addition technique with internal standard quantitation was used for ethanol, tetrahydrofuran and toluene determination. Validation was performed within the requirements of ICH validation guidelines Q2A and Q2B. Selectivity was tested for 36 solvents, and system suitability requirements described in the European Pharmacopoeia were checked. Limits of detection and quantitation, precision, linearity, accuracy, intermediate precision and robustness were determined, and excellent results were obtained. PMID:15584239

Otero, Raquel; Carrera, Guillem; Dulsat, Joan Francesc; Fábregas, José Luís; Claramunt, Juan

2004-11-19

124

Intra-laboratory validation of chronic bee paralysis virus quantitation using an accredited standardised real-time quantitative RT-PCR method.  

PubMed

Chronic bee paralysis virus (CBPV) is responsible for chronic bee paralysis, an infectious and contagious disease in adult honey bees (Apis mellifera L.). A real-time RT-PCR assay to quantitate the CBPV load is now available. To propose this assay as a reference method, it was characterised further in an intra-laboratory study during which the reliability and the repeatability of results and the performance of the assay were confirmed. The qPCR assay alone and the whole quantitation method (from sample RNA extraction to analysis) were both assessed following the ISO/IEC 17025 standard and the recent XP U47-600 standard issued by the French Standards Institute. The performance of the qPCR assay and of the overall CBPV quantitation method were validated over a 6 log range from 10(2) to 10(8) with a detection limit of 50 and 100 CBPV RNA copies, respectively, and the protocol of the real-time RT-qPCR assay for CBPV quantitation was approved by the French Accreditation Committee. PMID:22207079

Blanchard, Philippe; Regnault, Julie; Schurr, Frank; Dubois, Eric; Ribière, Magali

2012-03-01

125

Quantitative thin-layer chromatographic method for determination of amantadine hydrochloride.  

PubMed

A simple and accurate thin-layer chromatographic (TLC) method for quantitative determination of amantadine hydrochloride (AMD) was developed and validated. The method employed TLC aluminum plates pre-coated with silica gel 60F-254 as a stationary phase. The solvent system used for development consisted of n-hexane-methanol-diethylamine (80: 40: 5, v/v/v). The separated spots were visualized as brown spots after spraying with modified Dragendorff's reagent solution. Amantadine hydrochloride was subjected to accelerated stress conditions: boiling, acid and alkaline hydrolysis, oxidation, and irradiation with ultraviolet light. The drug was found to be stable under all the investigated stress conditions. The method was validated for linearity, limits of detection (LOD) and quantitation (LOQ), precision, robustness, selectivity and accuracy. The optical densities of the separated spots were found to be linear with the amount of AMD in the range of 5-40 µg/spot with good correlation coefficient (r=0.9994). The LOD and LOQ values were 0.72 and 2.38 µg/spot, respectively. Statistical analysis proved that the method is repeatable and accurate for the determination of AMD. The method, in terms of its sensitivity, accuracy, precision, and robustness met the International Conference of Harmonization/Federal Drug Administration regulatory requirements. The proposed TLC method was successfully applied for the determination of AMD in bulk and capsules with good accuracy and precision; the label claim percentages were 99.0 ± 1.0%. The results obtained by the proposed TLC method were comparable with those obtained by the official method. The proposed method is more advantageous than the previously published chromatographic methods as it involved the most simple chromatographic technique; TLC. In addition, method relies on the use of inexpensive equipment, a scanner and software, and not critical derivatizing reagent, thus maximizing the ability of laboratories worldwide to analyze samples of AMD. PMID:23675083

Askal, Hassan F; Khedr, Alaa S; Darwish, Ibrahim A; Mahmoud, Ramadan M

2008-06-01

126

Quantitative Thin-Layer Chromatographic Method for Determination of Amantadine Hydrochloride  

PubMed Central

A simple and accurate thin-layer chromatographic (TLC) method for quantitative determination of amantadine hydrochloride (AMD) was developed and validated. The method employed TLC aluminum plates pre-coated with silica gel 60F-254 as a stationary phase. The solvent system used for development consisted of n-hexane-methanol-diethylamine (80: 40: 5, v/v/v). The separated spots were visualized as brown spots after spraying with modified Dragendorff’s reagent solution. Amantadine hydrochloride was subjected to accelerated stress conditions: boiling, acid and alkaline hydrolysis, oxidation, and irradiation with ultraviolet light. The drug was found to be stable under all the investigated stress conditions. The method was validated for linearity, limits of detection (LOD) and quantitation (LOQ), precision, robustness, selectivity and accuracy. The optical densities of the separated spots were found to be linear with the amount of AMD in the range of 5-40 µg/spot with good correlation coefficient (r=0.9994). The LOD and LOQ values were 0.72 and 2.38 µg/spot, respectively. Statistical analysis proved that the method is repeatable and accurate for the determination of AMD. The method, in terms of its sensitivity, accuracy, precision, and robustness met the International Conference of Harmonization/Federal Drug Administration regulatory requirements. The proposed TLC method was successfully applied for the determination of AMD in bulk and capsules with good accuracy and precision; the label claim percentages were 99.0 ± 1.0%. The results obtained by the proposed TLC method were comparable with those obtained by the official method. The proposed method is more advantageous than the previously published chromatographic methods as it involved the most simple chromatographic technique; TLC. In addition, method relies on the use of inexpensive equipment, a scanner and software, and not critical derivatizing reagent, thus maximizing the ability of laboratories worldwide to analyze samples of AMD.

Askal, Hassan F.; Khedr, Alaa S.; Darwish, Ibrahim A.; Mahmoud, Ramadan M.

2008-01-01

127

Chemical comparison of Tripterygium wilfordii and Tripterygium hypoglaucum based on quantitative analysis and chemometrics methods.  

PubMed

Tripterygium wilfordii (T. wilfordii) and Tripterygium hypoglaucum (T. hypoglaucum), two commonly used Chinese herbal medicines derived from Tripterygium genus, have been widely used for the treatment of rheumatoid arthritis and other related inflammatory diseases in clinical therapy. In the present study, a rapid resolution liquid chromatography/electrospray ionization tandem mass spectrometry (RRLC-ESI-MS(n)) method has been developed and validated for simultaneous determination of 19 bioactive compounds including four catechins, three sesquiterpene alkaloids, four diterpenoids, and eight triterpenoids in these two similar herbs. The method validation results indicated that the developed method had desirable specificity, linearity, precision and accuracy. Quantitative analysis results showed that there were significant differences in the content of different types of compounds in T. wilfordii and T. hypoglaucum. Moreover, chemometrics methods such as one-way ANOVA, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the two Tripterygium herbs based on the quantitative data of analytes, and it was proven straightforward and reliable to differentiate T. wilfordii and T. hypoglaucum samples from different origins. In conclusion, simultaneous quantification of multiple-active component by RRLC-ESI-MS(n) coupled with chemometrics analysis could be a well-acceptable strategy to compare and evaluate the quality of T. wilfordii and T. hypoglaucum. PMID:24694566

Guo, Long; Duan, Li; Liu, Ke; Liu, E-Hu; Li, Ping

2014-07-01

128

An improved method for retrospective motion correction in quantitative T2* mapping.  

PubMed

A new method for motion correction of T2*-weighted data and resulting quantitative T2* maps is presented. For this method, additional data sets with a reduced number of phase encoding steps covering the k-space centre are acquired. Motion correction is based on a 3-step procedure: (1) calculation of improved input data sets with reduced artefact levels from the original data, (2) creation of a target data set free of movement artefacts on the basis of the improved input data sets, and (3) fitting of original data to the target data set, yielding an optimum combination of acquired k-space data which suppresses lines affected by movement. The method was tested on healthy subjects performing pre-trained movement. Motion correction was successful unless the same k-space line was affected by movement in all data sets acquired on a specific subject. The method was applied to patients suffering from subarachnoid haemorrhage (group 1) or tumours (group 2) with accompanying edema in the brain. Motion correction improved the interpretability of T2*-weighted patient data and resulting quantitative T2* maps considerably by allowing a clear delineation between ventricle and edema and a clear localisation of haemorrhage (group 1) or a clear delineation of tumour accompanying edema (group 2) which was not possible in data affected by movement. PMID:24508652

Nöth, Ulrike; Volz, Steffen; Hattingen, Elke; Deichmann, Ralf

2014-05-15

129

An ECL-PCR method for quantitative detection of point mutation  

NASA Astrophysics Data System (ADS)

A new method for identification of point mutations was proposed. Polymerase chain reaction (PCR) amplification of a sequence from genomic DNA was followed by digestion with a kind of restriction enzyme, which only cut the wild-type amplicon containing its recognition site. Reaction products were detected by electrochemiluminescence (ECL) assay after adsorption of the resulting DNA duplexes to the solid phase. One strand of PCR products carries biotin to be bound on a streptavidin-coated microbead for sample selection. Another strand carries Ru(bpy)32+ (TBR) to react with tripropylamine (TPA) to emit light for ECL detection. The method was applied to detect a specific point mutation in H-ras oncogene in T24 cell line. The results show that the detection limit for H-ras amplicon is 100 fmol and the linear range is more than 3 orders of magnitude, thus, make quantitative analysis possible. The genotype can be clearly discriminated. Results of the study suggest that ECL-PCR is a feasible quantitative method for safe, sensitive and rapid detection of point mutation in human genes.

Zhu, Debin; Xing, Da; Shen, Xingyan; Chen, Qun; Liu, Jinfeng

2005-04-01

130

[Method of quantitative determination of androgens and their metabolites].  

PubMed

Simple and rapid procedure is developed for quantitative estimation of 3H-androgen metabolites, which is carried out without extraction of labelled steroids from tissue homogenates after incubation with a substrate. After incubation the samples were liophylized and the labelled metabolites were separated using thin-layer chromatography on Silufol plates. The zones, corresponding to labelled metabolites, were scratched out with silica gelsheet and radioactivity was estimated. The procedure excluded practically a loss of labelled steroids in the samples. The procedure was used for estimation of 3H-androgen metabolites in vitro--3H-testosterone, 3H1 dihydrotestosterone and 3H-5 alpha-androsterone-3 beta, 17 beta-diol in homogenates of hypophyses and hypothalamuses from rat males (intact and castrated) and in adenoma of human prostatic gland. PMID:7157716

Degtiar', V G; Miloserdov, Iu V; Kushlinski?, N E

1982-01-01

131

Quantitative estimation of poikilocytosis by the coherent optical method  

NASA Astrophysics Data System (ADS)

The investigation upon the necessity and the reliability required of the determination of the poikilocytosis in hematology has shown that existing techniques suffer from grave shortcomings. To determine a deviation of the erythrocytes' form from the normal (rounded) one in blood smears it is expedient to use an integrative estimate. The algorithm which is based on the correlation between erythrocyte morphological parameters with properties of the spatial-frequency spectrum of blood smear is suggested. During analytical and experimental research an integrative form parameter (IFP) which characterizes the increase of the relative concentration of cells with the changed form over 5% and the predominating type of poikilocytes was suggested. An algorithm of statistically reliable estimation of the IFP on the standard stained blood smears has been developed. To provide the quantitative characterization of the morphological features of cells a form vector has been proposed, and its validity for poikilocytes differentiation was shown.

Safonova, Larisa P.; Samorodov, Andrey V.; Spiridonov, Igor N.

2000-05-01

132

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

133

Comparison of quantitative analytical methods in headspace gas chroamtography of residual solvents  

Microsoft Academic Search

Summary  The aim of this work was to compare quantitative methods used for headspace gas chromatographic analysis of residual solvents\\u000a in standard aqueous solutions and to apply the methods to the analysis of medicines. We found that all three quantitative\\u000a methods (external standard, ESTD; internal standard, ISTD; and standard addition, ASTD) enable determination of the total\\u000a amount of solute in the

A. Naddaf; J. Balla

2000-01-01

134

Demystifying Quantitative Methods in Comparative Housing Research: Dispelling the Myth of Black Magic  

Microsoft Academic Search

With the quantitative–qualitative debate as a basis, this paper considers the relative merits and limitations of applying quantitative methods to comparative housing research. Although the initial discussion takes place in general terms, the example of the impact of an increase in real house prices on real consumers’ expenditure is employed to illustrate the issues that a housing researcher faces when

Nick Horsewood

2011-01-01

135

Evaluation of limb compartments with increased interstitial pressure. An improved noninvasive method for determining quantitative hardness  

Microsoft Academic Search

The purpose of this project was to study a noninvasive method of evaluating limbs at risk of compartment syndrome. Untreated limb compartment syndrome may lead to irreversible dysfunction, chronic pain and contracture. An improved means of obtaining quantitative hardness measurements is reported. The handheld noninvasive compartment syndrome evaluator (NCSE) device formulates a quantitative hardness curve of force verse depth of

Bruce D. Steinberg

2005-01-01

136

Correlated one-particle method: Numerical results  

NASA Astrophysics Data System (ADS)

In a previous paper a correlated one-particle method was formulated, where the effective Hamiltonian was composed of the Fock operator and a correlation potential. The objective was to define a correlated one-particle theory that would give all properties that can be obtained from a one-particle theory. The Fock-space coupled-cluster method was used to construct the infinite-order correlation potential, which yields correct ionization potentials (IP's) and electron affinities (EA's) as the negative of the eigenvalues. The model, however, was largely independent of orbital choice. To exploit the degree of freedom of improving the orbitals, the Brillouin-Brueckner condition is imposed, which leads to an effective Brueckner Hamiltonian. To assess its numerical properties, the effective Brueckner Hamiltonian is approximated through second order in perturbation. Its eigenvalues are the negative of IP's and EA's correct through second order, and its eigenfunctions are second-order Brueckner orbitals. We also give expressions for its energy and density matrix. Different partitioning schemes of the Hamiltonian are used and the intruder state problem is discussed. The results for ionization potentials, electron affinities, dipole moments, energies, and potential curves are given for some sample molecules.

Beste, Ariana; Bartlett, Rodney J.

2005-10-01

137

The {ROSAT} RESULTS ARCHIVE: Tools and Methods  

NASA Astrophysics Data System (ADS)

The ROSAT Results Archive ({RRA}) is a publicly accessible collection of source lists, images, spectra, lightcurves and counting rates derived from pointed-phase observations of the ROSAT X-ray satellite observatory. The {RRA} contains X-ray source data from both the ROSAT Position Sensitive Proportional Counter (PSPC) and the ROSAT High Resolution Imager (HRI) instruments, using only data processed with the current (REV2) version of the processing system to ensure data uniformity and accuracy. Each detected source is visually inspected and possible problems are flagged. In this paper we describe the methods used to screen the data products and the GUI-based tools used to screen and access the data.

Corcoran, M. F.; Harris, D. E.; Brunner, H. E.; Englhauser, J. K.; Voges, W. H.; Boller, T. H.; Watson, M. G.; Pye, J. P.

138

Active thermography as a quantitative method for non-destructive evaluation of porous carbon fiber reinforced polymers  

Microsoft Academic Search

In this work active thermography was successfully applied as a quantitative method for the non-destructive evaluation of porosity in carbon fiber reinforced polymers. Results showed that not only the level of porosity, but also the shape of the pores strongly influences the active thermography results, in particular the measured thermal diffusivity. In an experiment the shape of the pores was

G. Mayr; B. Plank; J. Sekelja; G. Hendorfer

2011-01-01

139

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

140

Quantitative Diagnostic Method for Biceps Long Head Tendinitis by Using Ultrasound  

PubMed Central

Objective. To investigate the feasibility of grayscale quantitative diagnostic method for biceps tendinitis and determine the cut-off points of a quantitative biceps ultrasound (US) method to diagnose biceps tendinitis. Design. Prospective cross-sectional case controlled study. Setting. Outpatient rehabilitation service. Methods. A total of 336 shoulder pain patients with suspected biceps tendinitis were recruited in this prospective observational study. The grayscale pixel data of the range of interest (ROI) were obtained for both the transverse and longitudinal views of the biceps US. Results. A total of 136 patients were classified with biceps tendinitis, and 200 patients were classified as not having biceps tendinitis based on the diagnostic criteria. Based on the Youden index, the cut-off points were determined as 26.85 for the transverse view and 21.25 for the longitudinal view of the standard deviation (StdDev) of the ROI values, respectively. When the ROI evaluation of the US surpassed the cut-off point, the sensitivity was 68% and the specificity was 90% in the StdDev of the transverse view, and the sensitivity was 81% and the specificity was 73% in the StdDev of the longitudinal view to diagnose biceps tendinitis. Conclusion. For equivocal cases or inexperienced sonographers, our study provides a more objective method for diagnosing biceps tendinitis in shoulder pain patients.

Huang, Shih-Wei; Wang, Wei-Te

2013-01-01

141

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

142

A quantitative immunopolymerase chain reaction method for detection of vegetative insecticidal protein in genetically modified crops.  

PubMed

Vegetative insecticidal protein (Vip) is being employed for transgenic expression in selected crops such as cotton, brinjal, and corn. For regulatory compliance, there is a need for a sensitive and reliable detection method, which can distinguish between approved and nonapproved genetically modified (GM) events and quantify GM contents as well. A quantitative immunopolymerase chain reaction (IPCR) method has been developed for the detection and quantification of Vip protein in GM crops. The developed assay displayed a detection limit of 1 ng/mL (1 ppb) and linear quantification range between 10 and 1000 ng/mL of Vip-S protein. The sensitivity of the assay was found to be 10 times higher than an analogous enzyme-linked immunosorbent assay for Vip-S protein. The results suggest that IPCR has the potential to become a standard method to quantify GM proteins. PMID:21899299

Kumar, Rajesh

2011-10-12

143

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

144

Catenation: Quantitative methods for the definition of coenoclines  

Microsoft Academic Search

Summary  Catenation is defined as the ordering of elements in continuous sequences that best accounts for local similarities without\\u000a assuming linear relations. It is thus a non-linear relative of ordination. When applied to phytosociological data it is equivalent\\u000a to the detection and definition of coenoclines.\\u000a \\u000a Several mathematical methods of catenation are available and potentially useful in phytosociology. One such method, continuity

Imanuel Noy-Meir

1974-01-01

145

A New Method for Quantitative Real-Time Polymerase Chain Reaction Data Analysis  

PubMed Central

Abstract Quantitative real-time polymerase chain reaction (qPCR) is a sensitive gene quantification method that has been extensively used in biological and biomedical fields. The currently used methods for PCR data analysis, including the threshold cycle method and linear and nonlinear model-fitting methods, all require subtracting background fluorescence. However, the removal of background fluorescence can hardly be accurate and therefore can distort results. We propose a new method, the taking-difference linear regression method, to overcome this limitation. Briefly, for each two consecutive PCR cycles, we subtract the fluorescence in the former cycle from that in the latter cycle, transforming the n cycle raw data into n?1 cycle data. Then, linear regression is applied to the natural logarithm of the transformed data. Finally, PCR amplification efficiencies and the initial DNA molecular numbers are calculated for each reaction. This taking-difference method avoids the error in subtracting an unknown background, and thus it is more accurate and reliable. This method is easy to perform, and this strategy can be extended to all current methods for PCR data analysis.

Rao, Xiayu; Lai, Dejian

2013-01-01

146

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

147

QUANTITATIVE CANCER RISK ASSESSMENT METHODOLOGY USING SHORT-TERM GENETIC BIOASSAYS: THE COMPARATIVE POTENCY METHOD  

EPA Science Inventory

Quantitative risk assessment is fraught with many uncertainties. The validity of the assumptions underlying the methods employed are often difficult to test or validate. Cancer risk assessment has generally employed either human epidemiological data from relatively high occupatio...

148

Compatibility of Qualitative and Quantitative Methods: Studying Child Sexual Abuse in America.  

ERIC Educational Resources Information Center

Illustrates how the combined use of qualitative and quantitative methods were necessary in obtaining a clearer understanding of the process of incest in American society. Argues that the exclusive use of one methodology would have obscured important information. (FMW)

Phelan, Patricia

1987-01-01

149

Characterization of working iron Fischer-Tropsch catalysts using quantitative diffraction methods  

NASA Astrophysics Data System (ADS)

This study presents the results of the ex-situ characterization of working iron Fischer-Tropsch synthesis (F-TS) catalysts, reacted hundreds of hours at elevated pressures, using a new quantitative x-ray diffraction analytical methodology. Compositions, iron phase structures, and phase particle morphologies were determined and correlated with the observed reaction kinetics. Conclusions were drawn about the character of each catalyst in its most and least active state. The identity of the active phase(s) in the Fe F-TS catalyst has been vigorously debated for more than 45 years. The highly-reduced catalyst, used to convert coal-derived syngas to hydrocarbon products, is thought to form a mixture of oxides, metal, and carbides upon pretreatment and reaction. Commonly, Soxhlet extraction is used to effect catalyst-product slurry separation; however, the extraction process could be producing irreversible changes in the catalyst, contributing to the conflicting results in the literature. X-ray diffraction doesn't require analyte-matrix separation before analysis, and can detect trace phases down to 300 ppm/2 nm; thus, working catalyst slurries could be characterized as-sampled. Data were quantitatively interpreted employing first principles methods, including the Rietveld polycrystalline structure method. Pretreated catalysts and pure phases were examined experimentally and modeled to explore specific behavior under x-rays. Then, the working catalyst slurries were quantitatively characterized. Empirical quantitation factors were calculated from experimental data or single crystal parameters, then validated using the Rietveld method results. In the most active form, after pretreatment in H 2 or in CO at Pambient, well-preserved working catalysts contained significant amounts of Fe7C3 with trace alpha-Fe, once reaction had commenced at elevated pressure. Amounts of Fe3O 4 were constant and small, with carbide dpavg < 15 nm. Small amounts of Fe7C3 were found in unreacted catalyst pretreated in CO at elevated pressures. In the least active form, well-preserved working catalysts contained Fe5C2 amounts >65 wt%, regardless of pretreatment gas and pressure, with all dpavg 18 nm. epsilon '-Fe2.2C carbide was found to probably consist of an {Fe5C2/FexO/epsilon-Fe3C} mixture. Fe5C2 carbide exhibited wide variations in diffraction pattern which could be correlated with sample handling events, changes in process conditions, or dpavg.

Mansker, Linda Denise

150

A bead-based method for multiplexed identification and quantitation of DNA sequences using flow cytometry.  

PubMed

A new multiplexed, bead-based method which utilizes nucleic acid hybridizations on the surface of microscopic polystyrene spheres to identify specific sequences in heterogeneous mixtures of DNA sequences is described. The method consists of three elements: beads (5.6-microm diameter) with oligomer capture probes attached to the surface, three fluorophores for multiplexed detection, and flow cytometry instrumentation. Two fluorophores are impregnated within each bead in varying amounts to create different bead types, each associated with a unique probe. The third fluorophore is a reporter. Following capture of fluorescent cDNA sequences from environmental samples, the beads are analyzed by flow cytometric techniques which yield a signal intensity for each capture probe proportional to the amount of target sequences in the analyte. In this study, a direct hybrid capture assay was developed and evaluated with regard to sequence discrimination and quantitation of abundances. The target sequences (628 to 728 bp in length) were obtained from the 16S/23S intergenic spacer region of microorganisms collected from polluted groundwater at the nuclear waste site in Hanford, Wash. A fluorescence standard consisting of beads with a known number of fluorescent DNA molecules on the surface was developed, and the resolution, sensitivity, and lower detection limit for measuring abundances were determined. The results were compared with those of a DNA microarray using the same sequences. The bead method exhibited far superior sequence discrimination and possesses features which facilitate accurate quantitation. PMID:11010868

Spiro, A; Lowe, M; Brown, D

2000-10-01

151

Composition and quantitation of microalgal lipids by ERETIC ¹H NMR method.  

PubMed

Accurate characterization of biomass constituents is a crucial aspect of research in the biotechnological application of natural products. Here we report an efficient, fast and reproducible method for the identification and quantitation of fatty acids and complex lipids (triacylglycerols, glycolipids, phospholipids) in microalgae under investigation for the development of functional health products (probiotics, food ingredients, drugs, etc.) or third generation biofuels. The procedure consists of extraction of the biological matrix by modified Folch method and direct analysis of the resulting material by proton nuclear magnetic resonance (¹H NMR). The protocol uses a reference electronic signal as external standard (ERETIC method) and allows assessment of total lipid content, saturation degree and class distribution in both high throughput screening of algal collection and metabolic analysis during genetic or culturing studies. As proof of concept, the methodology was applied to the analysis of three microalgal species (Thalassiosira weissflogii, Cyclotella cryptica and Nannochloropsis salina) which drastically differ for the qualitative and quantitative composition of their fatty acid-based lipids. PMID:24084790

Nuzzo, Genoveffa; Gallo, Carmela; d'Ippolito, Giuliana; Cutignano, Adele; Sardo, Angela; Fontana, Angelo

2013-01-01

152

A Novel Feature-Tracking Echocardiographic Method for the Quantitation of Regional Myocardial Function  

PubMed Central

Objectives The aim of this study was to validate a novel, angle-independent, feature-tracking method for the echocardiographic quantitation of regional function. Background A new echocardiographic method, Velocity Vector Imaging (VVI) (syngo Velocity Vector Imaging technology, Siemens Medical Solutions, Ultrasound Division, Mountain View, California), has been introduced, based on feature tracking—incorporating speckle and endocardial border tracking, that allows the quantitation of endocardial strain, strain rate (SR), and velocity. Methods Seven dogs were studied during baseline, and various interventions causing alterations in regional function: dobutamine, 5-min coronary occlusion with reperfusion up to 1 h, followed by dobutamine and esmolol infusions. Echocardiographic images were acquired from short- and long-axis views of the left ventricle. Segment-length sonomicrometry crystals were used as the reference method. Results Changes in systolic strain in ischemic segments were tracked well with VVI during the different states of regional function. There was a good correlation between circumferential and longitudinal systolic strain by VVI and sonomicrometry (r = 0.88 and r = 0.83, respectively, p < 0.001). Strain measurements in the nonischemic basal segments also demonstrated a significant correlation between the 2 methods (r = 0.65, p < 0.001). Similarly, a significant relation was observed for circumferential and longitudinal SR between the 2 methods (r = 0.94, p < 0.001 and r = 0.90, p < 0.001, respectively). The endocardial velocity relation to changes in strain by sonomicrometry was weaker owing to significant cardiac translation. Conclusions Velocity Vector Imaging, a new feature-tracking method, can accurately assess regional myocardial function at the endocardial level and is a promising clinical tool for the simultaneous quantification of regional and global myocardial function.

Pirat, Bahar; Khoury, Dirar S.; Hartley, Craig J.; Tiller, Les; Rao, Liyun; Schulz, Daryl G.; Nagueh, Sherif F.; Zoghbi, William A.

2012-01-01

153

Comparative evaluation of two quantitative precipitation estimation methods in Korea  

NASA Astrophysics Data System (ADS)

The spatial distribution and intensity of rainfall is necessary for hydrological model, particularly, grid based distributed model. The weather radar is much higher spatial resolution (1kmx1km) than rain gauges (~13km) although radar is indirect measurement of rainfall and rain gauges are directly observed it. And also, radar is provided areal and gridded rainfall information while rain gauges are provided point data. Therefore, radar rainfall data can be useful for input data on the hydrological model. In this study, we compared two QPE schemes to produce radar rainfall for hydrological utilization. The two methods are 1) spatial adjustment and 2) real-time Z-R relationship adjustment (hereafter RAR; Radar-Aws Rain rate). We computed and analyzed the statistics such as ME (Mean Error), RMSE (Root mean square Error), and correlation using cross-validation method (here, leave-one-out method).

Ko, H.; Nam, K.; Jung, H.

2013-12-01

154

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

155

Quantitative void fraction measurement method by neutron radiography and applications to two-phase flow researches  

Microsoft Academic Search

Quantitative void fraction measurement method by neutron radiography was developed using a neutron absorber grid based on an umbra method. The cross-sectionally averaged void fraction for various flow patterns in air–water two-phase flow in a tube was measured quantitatively. Uncertainty analyses were carried out for the measured values and the accuracy of the measurement was discussed for each flow pattern.

N. Takenaka; H. Asano

2005-01-01

156

Experimental Methods for Quantitative Analysis of Thermally Driven Flows  

Microsoft Academic Search

Properly designed validation experiments are necessary to establish a satisfac- tory level of confidence in simulation algorithms. In this review recent achievements in the measurement techniques used for monitoring macroscopic flow field features are pre- sented. In particular, optical and electro-optical methods, for example thermography, tomography or particle image velocimetry, are reviewed and their application to simple solidification experiments demonstrated.

Tomasz A. Kowalewski

157

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

158

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

159

Quantitative Evaluation and Comparison of Lung Contour Extraction Methods  

Microsoft Academic Search

Pulmonary contours in chest CT images are closed curves that may, in some cases, exhibit multiple concave and convex irregularities. In this paper we assess the quality of pulmonary contours obtained by several fully automated methods. A comparison among these contours and corresponding manually drawn reference contours was performed and several figures of merit were assigned to each one of

José Silvestre Silva; Augusto Silva; Beatriz Sousa Santos

160

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.

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

2014-01-01

161

Functionally oriented and clinically feasible quantitative gait analysis method  

Microsoft Academic Search

A protocol for clinical gait analysis is described, and data from 30 normal adult female subjects are presented. Extensive\\u000a application to pathologic subjects has proven to be feasible and sufficiently accurate. The method is based on a particular\\u000a location and attachment of retro-reflective markers on the body and on a particular arrangement of four TV cameras. A motion\\u000a analyser measures

C. Frigo; M. Rabuffetti; D. C. Kerrigan; L. C. Deming; A. Pedotti

1998-01-01

162

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.

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

2014-01-01

163

Improved Quantitative Mass Spectrometry Methods for Characterizing Complex Ubiquitin Signals  

PubMed Central

Ubiquitinated substrates can be recruited to macromolecular complexes through interactions between their covalently bound ubiquitin (Ub) signals and Ub receptor proteins. To develop a functional understanding of the Ub system in vivo, methods are needed to determine the composition of Ub signals on individual substrates and in protein mixtures. Mass spectrometry has emerged as an important tool for characterizing the various forms of Ub. In the Ubiquitin-AQUA approach, synthetic isotopically labeled internal standard peptides are used to quantify unbranched peptides and the branched -GG signature peptides generated by trypsin digestion of Ub signals. Here we have built upon existing methods and established a comprehensive platform for the characterization of Ub signals. Digested peptides and isotopically labeled standards are analyzed either by selected reaction monitoring on a QTRAP mass spectrometer or by narrow window extracted ion chromatograms on a high resolution LTQ-Orbitrap. Additional peptides are now monitored to account for the N terminus of ubiquitin, linear polyUb chains, the peptides surrounding K33 and K48, and incomplete digestion products. Using this expanded battery of peptides, the total amount of Ub in a sample can be determined from multiple loci within the protein, minimizing possible confounding effects of complex Ub signals, digestion abnormalities, or use of mutant Ub in experiments. These methods have been useful for the characterization of in vitro, multistage ubiquitination and have now been extended to reactions catalyzed by multiple E2 enzymes. One question arising from in vitro studies is whether individual protein substrates in cells may be modified by multiple forms of polyUb. Here we have taken advantage of recently developed polyubiquitin linkage-specific antibodies recognizing K48- and K63-linked polyUb chains, coupled with these mass spectrometry methods, to further evaluate the abundance of mixed linkage Ub substrates in cultured mammalian cells. By combining these two powerful tools, we show that polyubiquitinated substrates purified from cells can be modified by mixtures of K48, K63, and K11 linkages.

Phu, Lilian; Izrael-Tomasevic, Anita; Matsumoto, Marissa L.; Bustos, Daisy; Dynek, Jasmin N.; Fedorova, Anna V.; Bakalarski, Corey E.; Arnott, David; Deshayes, Kurt; Dixit, Vishva M.; Kelley, Robert F.; Vucic, Domagoj; Kirkpatrick, Donald S.

2011-01-01

164

Time oriented score system (TOSS): A method for direct and quantitative assessment of nursing workload for ICU patients  

Microsoft Academic Search

A method for direct quantitation of nurses' workload required by ICU patients is described. Each nursing activity has been timed in 14 different ICUs participating in the multicentre study, and the results averaged. Nursing acts were grouped in different homology lists, complied according to operative similarities. Some lists include general nursing acts, which are common to all patients admitted to

G. Iapichino

1991-01-01

165

Quantitative determination of pneumococcal capsular polysaccharide serotype 14 using a modification of phenol–sulfuric acid method  

Microsoft Academic Search

The capsular polysaccharide of Streptococcus pneumoniae, serotype 14, is part of every pneumococcal vaccine presently in the market or under development. A strategy for the quantitative determination of this polysaccharide by the phenol–sulfuric acid method is described. The modality of acid addition is shown to be the critical step for obtaining reproducible test results between different technicians. Raising the incubation

Gabriela Cuesta; Norma Suarez; Maria I Bessio; Fernando Ferreira; Hugo Massaldi

2003-01-01

166

RE-EXAMINATION OF THE STATISTICAL METHODS USED TO DETERMINE THE NUMBER OF POINT COUNTS NEEDED FOR MICROPALEONTOLOGICAL QUANTITATIVE RESEARCH  

Microsoft Academic Search

Currently some controversy exists in the micropaleontological community concerning the statistically correct number of counts required for quantitative examinations, particularly with respect to the effect of variations in the number ofspedes between samples and the significance of varying fractional abundances on the reliability of results, This analysis of the various statistical methods used to determine the number of required counts

R. TIMOTHY PATTERSON; EVAN FISHBEIN

1989-01-01

167

A Novel Generalized Ridge Regression Method for Quantitative Genetics  

PubMed Central

As the molecular marker density grows, there is a strong need in both genome-wide association studies and genomic selection to fit models with a large number of parameters. Here we present a computationally efficient generalized ridge regression (RR) algorithm for situations in which the number of parameters largely exceeds the number of observations. The computationally demanding parts of the method depend mainly on the number of observations and not the number of parameters. The algorithm was implemented in the R package bigRR based on the previously developed package hglm. Using such an approach, a heteroscedastic effects model (HEM) was also developed, implemented, and tested. The efficiency for different data sizes were evaluated via simulation. The method was tested for a bacteria-hypersensitive trait in a publicly available Arabidopsis data set including 84 inbred lines and 216,130 SNPs. The computation of all the SNP effects required <10 sec using a single 2.7-GHz core. The advantage in run time makes permutation test feasible for such a whole-genome model, so that a genome-wide significance threshold can be obtained. HEM was found to be more robust than ordinary RR (a.k.a. SNP-best linear unbiased prediction) in terms of QTL mapping, because SNP-specific shrinkage was applied instead of a common shrinkage. The proposed algorithm was also assessed for genomic evaluation and was shown to give better predictions than ordinary RR.

Shen, Xia; Alam, Moudud; Fikse, Freddy; Ronnegard, Lars

2013-01-01

168

Intentional Movement Performance Ability (IMPA): a method for robot-aided quantitative assessment of motor function.  

PubMed

The purpose of this paper is to propose a new assessment method for evaluating motor function of the patients who are suffering from physical weakness after stroke, incomplete spinal cord injury (iSCI) or other diseases. In this work, we use a robotic device to obtain the information of interaction occur between patient and robot, and use it as a measure for assessing the patients. The Intentional Movement Performance Ability (IMPA) is defined by the root mean square of the interactive torque, while the subject performs given periodic movement with the robot. IMPA is proposed to quantitatively determine the level of subject's impaired motor function. The method is indirectly tested by asking the healthy subjects to lift a barbell to disturb their motor function. The experimental result shows that the IMPA has a potential for providing a proper information of the subject's motor function level. PMID:24187313

Shin, Sung Yul; Kim, Jung Yoon; Lee, Sanghyeop; Lee, Junwon; Kim, Seung-Jong; Kim, ChangHwan

2013-06-01

169

Quantitative methods of measuring the sensitivity of the mouse sperm morphology assay  

SciTech Connect

In this study murine sperm were subjected to graded doses of X irradiation (0 to 120 rad) to determine whether quantitative measurements made on enlarged photographs of the sperm heads are related to radiation dose. We found that the Mahalanobis distance statistic, when used to measure distance in a multivariate space from a control group of measurements, could be used to classify sperm as normal or abnormal. The percent classified as abnormal by this method was found to be linearly related to dose. The results suggest that sensitivity of the murine sperm assay can be improved by selecting an optimal set of measurements. This improvement can reduce the doubling dose from approximately 70 rad to 10 to 15 rad while keeping the percentage of abnormal sperm in control mice at 3%, equal to the current visual method.

Moore, D.H.; Bennett, D.E.; Kranzler, D.; Wyrobek, A.J.

1982-09-01

170

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

171

A simple regression method for mapping quantitative trait loci in line crosses using flanking markers  

Microsoft Academic Search

The use of flanking marker methods has proved to be a powerful tool for the mapping of quantitative trait loci (QTL) in the segregating generations derived from crosses between inbred lines. Methods to analyse these data, based on maximum-likelihood, have been developed and provide good estimates of QTL effects in some situations. Maximum-likelihood methods are, however, relatively complex and can

C. S. HALEY; S. A. KNOTI

1992-01-01

172

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

173

Quantitative Ray Methods for Scattering of Sound by Spherical Shells.  

NASA Astrophysics Data System (ADS)

The application of ray methods to the scattering of high-frequency plane waves from evacuated elastic spherical shells is investigated. The investigation of ray methods for spherical shells is a precursor to the application of such methods to shells having more complicated shapes. The scattered pressure in the farfield of the shell is p _{sc} = p_{i}(a/2r)f( theta)exp(ikr) where p_{i } is the plane wave amplitude. The outer radius of the shell is a, h = a - b is the shell's thickness, and r is the distance to an observation point. Ray models are developed to synthesize the form function f( theta,ka) where k is the wavenumber of the incident wave and theta is the scattering angle. The forward scattering amplitude, f(theta = 0), is related to the extinction cross section, sigma_{e}, by the optical theorem. If the absorption by the scatterer is negligible, then sigma_{rm e} is equal to the scattering cross section sigma_{t}. A ray synthesis partitions f(theta = 0) into a component for ordinary forward diffraction about the shell, f_{FD}, and contributions from surface guided elastic waves. For high -frequency scattering, the relevant surface guided elastic waves are leaky Lamb waves. A similar ray synthesis of the backscattering amplitude f(theta=pi) contains a specular reflection component, f _{^}(theta=pi), and leaky Lamb wave contributions. A generalization of the geometrical theory of diffraction is employed to synthesize f_{l}(theta=0, {ka }) and f_{l}(theta= pi, {ka}) for the lth leaky Lamb wave contribution. The syntheses for forward and backwards scattering correctly describe the leaky Lamb wave contributions and are expressible in a Fabry-Perot resonator form. While the ray description of backscattering ordinarily accurately reproduces exact computations and experiments with tone burst, certain anomalies are discussed. A ray synthesis of f_{^} demonstrates a significant longitudinal resonance effect when k _{L}h = npi,n = 1, 2,..., where k_ {L} = omega/c _{L} is the longitudinal wavenumber within the shell. The analysis of f_{^ } is for an elastic material with vanishing shear velocity. The relevant range of ka is 7 <=q ka <=q 100. The shell is surrounded by water and is composed of 440c stainless steel with inner-to-outer radii ratio b/a = 0.838.

Kargl, Steven Gregory

1990-01-01

174

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.

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

2014-01-01

175

Biodistribution Studies of Nanoparticles Using Fluorescence Imaging: A Qualitative or Quantitative Method?  

PubMed Central

Purpose The biodistribution of Lipid/Calcium/Phosphate (LCP) nanoparticles (NPs) in tumor-bearing mice was investigated using fluorescence imaging. A quantitative validation of this method was done by 3H and 111In labeling of the nanoparticles. Methods The biodistribution of LCP NPs containing oligonucleotides was investigated using three different probes: Texas-Red labeled oligonucleotides, 3H-labeled oligonucleotides, and 111In-labled calcium phosphate. Results A discrepancy was found between the radioactivity and the fluorescence signals. Signals from 3H and 111In exhibited very similar distribution patterns, suggesting that liver and spleen were the major accumulation sites. However, fluorescence imaging indicated that tumor accumulation was predominant. We further confirmed that the fluorescence signals in both liver and spleen were greatly attenuated compared with those in the tumor due to the intrinsic tissue absorption and scattering. Near-infrared (NIR) dye Cy5.5 also suffered from the same problem, in that the quantitative data from whole organs was dramatically affected by absorption and scattering properties of the tissue. Conclusions Careful attention must be paid to the quantification and interpretation of fluorescence imaging measurements when comparing different tissues.

Liu, Yang; Tseng, Yu-cheng

2013-01-01

176

An immunochemical method for quantitation of Epinotia aporema granulovirus (EpapGV).  

PubMed

Epinotia aporema granulovirus (EpapGV) is a baculovirus that affects E. aporema larvae and has proven to be a good candidate for the biocontrol of this important pest in South America. As part of the quality control of the production of a bioinsecticide based on EpapGV, a sensitive method was developed for the detection and quantitation of the virus. To this end, we used the major occlusion body (OB) protein (granulin) to generate polyclonal antibodies in rabbits. Purified IgG fractions from hyperimmune sera were labeled with biotin and used as detecting antibodies in a double antibody sandwich enzyme linked immunosorbent assays (ELISA). No cross-reactivity was detected with any of the nucleopolyhedroviruses (NPV) tested in this study, while a minor degree of reactivity was observed with the closely related Cydia pomonella granulovirus (CpGV). The performance of the ELISA was satisfactory in terms of sensitivity, detecting as little as 0.53 ng/ml of EpapGV granulin in suspensions of purified virus OB. This represented 2.0x10(4) OB/ml. Granulin was also detected in complex and highly diluted bioinsecticidal formulate mixtures. In time course experiments, the virus was detected as early as 24 h post infection (p.i.). The results of the studies demonstrate that this method is a convenient, rapid and inexpensive alternative for routine detection and quantitation of EpapGV. PMID:12951208

Parola, Alejandro Daniel; Sciocco-Cap, Alicia; Glikmann, Graciela; Romanowski, Víctor

2003-09-01

177

Radioisotopic neutron transmission spectrometry: Quantitative analysis by using partial least-squares method.  

PubMed

Neutron spectrometry, based on the scattering of high energy fast neutrons from a radioisotope and slowing-down by the light hydrogen atoms, is a useful technique for non-destructive, quantitative measurement of hydrogen content because it has a large measuring volume, and is not affected by temperature, pressure, pH value and color. The most common choice for radioisotope neutron source is (252)Cf or (241)Am-Be. In this study, (252)Cf with a neutron flux of 6.3x10(6)n/s has been used as an attractive neutron source because of its high flux neutron and weak radioactivity. Pulse-height neutron spectra have been obtained by using in-house built radioisotopic neutron spectrometric system equipped with (3)He detector and multi-channel analyzer, including a neutron shield. As a preliminary study, polyethylene block (density of approximately 0.947g/cc and area of 40cmx25cm) was used for the determination of hydrogen content by using multivariate calibration models, depending on the thickness of the block. Compared with the results obtained from a simple linear calibration model, partial least-squares regression (PLSR) method offered a better performance in a quantitative data analysis. It also revealed that the PLSR method in a neutron spectrometric system can be promising in the real-time, online monitoring of the powder process to determine the content of any type of molecules containing hydrogen nuclei. PMID:19285419

Kim, Jong-Yun; Choi, Yong Suk; Park, Yong Joon; Jung, Sung-Hee

2009-01-01

178

Two quantitative methods for rib seriation in human skeletal remains.  

PubMed

Accurate rib sequencing is of importance to both forensic anthropologists and human osteologists, but until recently there have been few traits used to aid in the seriation of ribs within a human burial. This study examines two measurements (head to tubercle length and superior costotransverse ligament crest height) for the purpose of aiding rib identification and seriation in human skeletal remains. A sample of 344 ribs from 43 individuals from the 19th century Anglican Church cemetery of St. Thomas in Belleville, Ontario were used for the current study. While the head to tubercle length appeared unreliable for rib seriation, the superior costotransverse ligament crest height may provide an alternative technique for assessing rib sequence. More importantly though, the method provides a basis on which the identification of the central ribs can be made. PMID:9456539

Hoppa, R; Saunders, S

1998-01-01

179

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

180

Robust methods in bioequivalence assay; Preliminary results  

Microsoft Academic Search

Summary  The aim of this study is to compare four statistical methods for outlier identification in Bioequivalence tests.\\u000a \\u000a The methods are based in four confidence intervals, ‘parametric’, ‘non- parametric’, ‘robust with the asymptotic distribution\\u000a of the M-estimator’ and ‘robust with the bootstrap distribution’.\\u000a \\u000a \\u000a \\u000a The drug we used was Diltiazen, in a two sequence randomized crossover study design.\\u000a \\u000a \\u000a The pharmacokinetic parameters measured

A. V. Niselman; M. Garcia Ben; M. C. Rubio

1998-01-01

181

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

182

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

183

Fast and ultrasensitive method for quantitating prion infectivity titer  

PubMed Central

Bioassay by end-point dilution has been employed for decades for routine determination of prion infectivity titer. Here we show that the new Protein Misfolding Cyclic Amplification with Teflon beads (PMCAb) can be used to estimate titers of the misfolded version of the prion protein (PrPSc) with a higher level of precision and in 3 to 6 days as opposed to two years, when compared with bioassay. For two hamster strains 263K and SSLOW, median infective doses (ID50) determined by PCMAb (PMCAb50) were found to be 1012.8 and 1012.2 per gram of brain tissue, which are 160- and 4,000-fold higher than the corresponding ID50 values measured by bioassay. These 102-103-fold differences could be attributed to a large excess of PMCAb-reactive prion protein seeds with little or no infectivity. Alternatively, the differences between ID50 and PMCAb50 could be due to higher rate of clearance of PrPSc seeds in animals versus PMCAb reactions. A well calibrated PMCAb reaction can be an efficient and cost effective method for the estimation of PrPSc titer.

Makarava, Natallia; Savtchenko, Regina; Alexeeva, Irina; Rohwer, Robert G.; Baskakov, Ilia V.

2012-01-01

184

Fast and ultrasensitive method for quantitating prion infectivity titre.  

PubMed

Bioassay by end-point dilution has been used for decades for routine determination of prion infectivity titre. Here we show that the new protein misfolding cyclic amplification with beads (PMCAb) technique can be used to estimate titres of the infection-specific forms of the prion protein with a higher level of precision and in 3-6 days as opposed to 2 years, when compared with the bioassay. For two hamster strains, 263?K and SSLOW, the median reactive doses determined by PCMAb (PMCAb(50)) were found to be 10(12.8) and 10(12.2) per gram of brain tissue, which are 160- and 4,000-fold higher than the corresponding median infectious dose (ID(50)) values measured by bioassay. The 10(2)- to 10(3)-fold differences between ID(50) and PMCAb(50) values could be due to a large excess of PMCAb-reactive prion protein seeds with little or no infectivity. Alternatively, the differences between ID(50) and PMCAb(50) could be due to higher rate of clearance of infection-specific prion protein seeds in animals versus PMCAb reactions. A well-calibrated PMCAb reaction can be an efficient and cost-effective method for the estimation of infection-specific prion protein titre. PMID:22415832

Makarava, Natallia; Savtchenko, Regina; Alexeeva, Irina; Rohwer, Robert G; Baskakov, Ilia V

2012-01-01

185

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

186

Development of a new quantitative gas permeability method for dental implant-abutment connection tightness assessment  

PubMed Central

Background Most dental implant systems are presently made of two pieces: the implant itself and the abutment. The connection tightness between those two pieces is a key point to prevent bacterial proliferation, tissue inflammation and bone loss. The leak has been previously estimated by microbial, color tracer and endotoxin percolation. Methods A new nitrogen flow technique was developed for implant-abutment connection leakage measurement, adapted from a recent, sensitive, reproducible and quantitative method used to assess endodontic sealing. Results The results show very significant differences between various sealing and screwing conditions. The remaining flow was lower after key screwing compared to hand screwing (p = 0.03) and remained different from the negative test (p = 0.0004). The method reproducibility was very good, with a coefficient of variation of 1.29%. Conclusions Therefore, the presented new gas flow method appears to be a simple and robust method to compare different implant systems. It allows successive measures without disconnecting the abutment from the implant and should in particular be used to assess the behavior of the connection before and after mechanical stress.

2011-01-01

187

A penalized likelihood method for mapping epistatic quantitative trait Loci with one-dimensional genome searches.  

PubMed Central

Epistasis is a common and important phenomenon, as indicated by results from a number of recent experiments. Unfortunately, the discovery of epistatic quantitative trait loci (QTL) is difficult since one must search for multiple QTL simultaneously in two or more dimensions. Such a multidimensional search necessitates many statistical tests, and a high statistical threshold must be adopted to avoid false positives. Furthermore, the large number of (interaction) parameters in comparison with the number of observations results in a serious danger of overfitting and overinterpretation of the data. In this article we present a new statistical framework for mapping epistasis in inbred line crosses. It is based on reducing the high dimensionality of the problem in two ways. First, epistatic QTL are mapped in a one-dimensional genome scan for high interactions between QTL and the genetic background. Second, the dimension of the search is bounded by penalized likelihood methods. We use simulated backcross data to illustrate the new approach.

Boer, Martin P; Ter Braak, Cajo J F; Jansen, Ritsert C

2002-01-01

188

Method for resolving the consistency problem between rule-based and quantitative models using fuzzy simulation  

NASA Astrophysics Data System (ADS)

Given a physical system, there are experts who have knowledge about how this system operates. In some cases, there exits quantitative knowledge in the form of deep models. One of the main issues dealing with these different types of knowledge is 'how does one address the difference between the two model types, each of which represents a different level of knowledge about the system?' We have devised a method that starts with (1) the expert's knowledge about the system, and (2) a quantitative model that can represent all or some of the behavior of the system. This method then adjusts the knowledge in either the rule-based system or the quantitative system to achieve some degree of consistency between the two representations. Through checking and resolving the inconsistencies, we provide a way to obtain better models in general about systems by exploiting knowledge at all levels, whether qualitative or quantitative.

Kim, Gyooseok; Fishwick, Paul A.

1997-06-01

189

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

NASA Astrophysics Data System (ADS)

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 measurements of a two-dimensional benchmark flow (a Prandtl-Meyer expansion fan) are compared with the theoretical density field and with the density inferred from PIV velocity measurements. The method's performance is also evaluated a priori from an experiment ray-tracing simulation. The density measurements show good agreement with theory. Moreover, CCS and BOS return comparable results with respect to each other and with respect to the PIV measurements. BOS proves to be very sensitive to displacements of the wind tunnel during the experiment and requires a correction for it, making it necessary to apply extra boundary conditions in the integration procedure. Furthermore, spatial resolution can be a limiting factor for accurate measurements using BOS. CCS suffers from relatively high noise in the density gradient measurement due to camera noise and has a smaller dynamic range when compared to BOS. Finally the application of the two schlieren methods to a separated wake flow is demonstrated. Flow features such as shear layers and expansion and recompression waves are measured with both methods.

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

190

How to use linear regression and correlation in quantitative method comparison studies.  

PubMed

Linear regression methods try to determine the best linear relationship between data points while correlation coefficients assess the association (as opposed to agreement) between the two methods. Linear regression and correlation play an important part in the interpretation of quantitative method comparison studies. Their major strength is that they are widely known and as a result both are employed in the vast majority of method comparison studies. While previously performed by hand, the availability of statistical packages means that regression analysis is usually performed by software packages including MS Excel, with or without the software programe Analyze-it as well as by other software packages. Such techniques need to be employed in a way that compares the agreement between the two methods examined and more importantly, because we are dealing with individual patients, whether the degree of agreement is clinically acceptable. Despite their use for many years, there is a lot of ignorance about the validity as well as the pros and cons of linear regression and correlation techniques. This review article describes the types of linear regression and regression (parametric and non-parametric methods) and the necessary general and specific requirements. The selection of the type of regression depends on where one has been trained, the tradition of the laboratory and the availability of adequate software. PMID:18324950

Twomey, P J; Kroll, M H

2008-04-01

191

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

192

The use of electromagnetic induction methods for establishing quantitative permafrost models in West Greenland  

NASA Astrophysics Data System (ADS)

The sedimentary settings at West Greenlandic town and infrastructural development sites are dominated by fine-grained marine deposits of late to post glacial origin. Prior to permafrost formation, these materials were leached by percolating precipitation, resulting in depletion of salts. Present day permafrost in these deposits is therefore very ice-rich with ice contents approaching 50-70% vol. in some areas. Such formations are of great concern in building and construction projects in Greenland, as they loose strength and bearing capacity upon thaw. It is therefore of both technical and economical interest to develop methods to precisely investigate and determine parameters such as ice-content and depth to bedrock in these areas. In terms of geophysical methods for near surface investigations, traditional methods such as Electrical Resistivity Tomography (ERT) and Refraction Seismics (RS) have generally been applied with success. The Georadar method usually fails due to very limited penetration depth in the fine-grained materials, and Electromagnetic Induction (EMI) methods are seldom applicable for quantitative interpretation due to the very high resistivities causing low induced currents and thus small secondary fields. Nevertheless, in some areas of Greenland the marine sequence was exposed relatively late, and as a result the sediments may not be completely leached of salts. In such cases, layers with pore water salinity approaching that of sea water, may be present below an upper layer of very ice rich permafrost. The saline pore water causes a freezing-point depression which results in technically unfrozen sediments at permafrost temperatures around -3 °C. Traditional ERT and VES measurements are severely affected by equivalency problems in these settings, practically prohibiting reasonable quantitative interpretation without constraining information. Such prior information may be obtained of course from boreholes, but equipment capable of drilling permafrozen sediments is generally not available in Greenland, and mobilization costs are therefore considerable thus limiting the use of geotechnical borings to larger infrastructure and construction projects. To overcome these problems, we have tested the use of shallow Transient ElectroMagnetic (TEM) measurements, to provide constraints in terms of depth to and resistivity of the conductive saline layer. We have tested such a setup at two field sites in the Ilulissat area (mid-west Greenland), one with available borehole information (site A), the second without (site C). VES and TEM soundings were collected at each site and the respective data sets subsequently inverted using a mutually constrained inversion scheme. At site A, the TEM measurements (20x20m square loop, in-loop configuration) show substantial and repeatable negative amplitude segments, and therefore it has not presently been possible to provide a quantitative interpretation for this location. Negative segments are typically a sign of Induced Polarization or cultural effects. Forward modeling based on inversion of the VES data constrained with borehole information has indicated that IP effects could indeed be the cause of the observed anomaly, although such effects are not normally expected in permafrost or saline deposits. Data from site C has shown that jointly inverting the TEM and VES measurements does provide well determined estimates for all layer parameters except the thickness of the active layer and resistivity of the bedrock. The active layer thickness may be easily probed to provide prior information on this parameter, and the bedrock resistivity is of limited interest in technical applications. Although no confirming borehole information is available at this site, these results indicate that joint or mutually constrained inversion of TEM and VES data is feasible and that this setup may provide a fast and cost effective method for establishing quantitative interpretations of permafrost structure in partly saline conditions.

Ingeman-Nielsen, Thomas; Brandt, Inooraq

2010-05-01

193

New method for quantitative analysis of multiple scelerosis using MR images  

NASA Astrophysics Data System (ADS)

A method for quantitative analysis of multiple sclerosis (MS) was presented. An automatic self-adaptive image segmentation algorithm was first employed to classify voxels in multi- spectral magnetic resonance (MR) images. The segmentation results from multi-spectral MR images were then combined to obtain reliable results. The volumes of brain tissues and cerebral spinal fluid (CSF) were finally extracted. Since it is fully automated, the results of the segmentation algorithm are completely reproducible. The repeatability of the presented method was evaluated on volunteer data sets. The variation is less than 0.2% for the intra-cranial volume, the whole brain volume, the central CSF, the white matter (WM) and the gray matter (GM). The variation of 3% for the entire CSF is mainly due to the peripheral CSF part, which has more partial volume effect and is less important than the central one. Methods for minimizing this variation are under investigation. These measurements demonstrate the potential for study on whole brain atrophy and cerebral atrophy. Feasibility studies on 14 MS patients were performed. The results are promising.

Chen, Dongqing; Huang, Wei; Christodoulou, C.; Li, Lihong; Qian, Huayuan; Krupp, Lauren; Liang, Zhengrong

2001-05-01

194

Smaller, Scale-Free Gene Networks Increase Quantitative Trait Heritability and Result in Faster Population Recovery  

PubMed Central

One of the goals of biology is to bridge levels of organization. Recent technological advances are enabling us to span from genetic sequence to traits, and then from traits to ecological dynamics. The quantitative genetics parameter heritability describes how quickly a trait can evolve, and in turn describes how quickly a population can recover from an environmental change. Here I propose that we can link the details of the genetic architecture of a quantitative trait—i.e., the number of underlying genes and their relationships in a network—to population recovery rates by way of heritability. I test this hypothesis using a set of agent-based models in which individuals possess one of two network topologies or a linear genotype-phenotype map, 16–256 genes underlying the trait, and a variety of mutation and recombination rates and degrees of environmental change. I find that the network architectures introduce extensive directional epistasis that systematically hides and reveals additive genetic variance and affects heritability: network size, topology, and recombination explain 81% of the variance in average heritability in a stable environment. Network size and topology, the width of the fitness function, pre-change additive variance, and certain interactions account for ?75% of the variance in population recovery times after a sudden environmental change. These results suggest that not only the amount of additive variance, but importantly the number of loci across which it is distributed, is important in regulating the rate at which a trait can evolve and populations can recover. Taken in conjunction with previous research focused on differences in degree of network connectivity, these results provide a set of theoretical expectations and testable hypotheses for biologists working to span levels of organization from the genotype to the phenotype, and from the phenotype to the environment.

Malcom, Jacob W.

2011-01-01

195

Quantitative assessment of trabecular bone micro-architecture of the wrist via 7 Tesla MRI: preliminary results  

PubMed Central

Object The goal of this study was to determine the feasibility of performing quantitative 7T magnetic resonance imaging (MRI) assessment of trabecular bone micro-architecture of the wrist, a common fracture site. Materials and methods The wrists of 4 healthy subjects (1 woman, 3 men, 28±8.9 years) were scanned on a 7T whole body MR scanner using a 3D fast low-angle shot (FLASH) sequence (TR/TE = 20/4.5ms, 0.169 × 0.169 × 0.5mm). Trabecular bone was segmented and divided into 4 or 8 angular subregions. Total bone volume (TBV), bone volume fraction (BVF), surface-curve ratio (SC), and erosion index (EI) were computed. Subjects were scanned twice to assess measurement reproducibility. Results Group mean subregional values for TBV, BVF, SC, and EI (8 subregion analysis) were as follows: 8489 ± 3686, 0.27 ± 0.045, 9.61 ± 6.52; and 1.43 ± 1.25. Within each individual, there was subregional variation in TBV, SC, and EI (>5%), but not BVF (<5%). Intersubject variation (?12%) existed for all parameters. Within-subject coefficients of variation were ?10%. Conclusion This is the first study to perform quantitative 7T MRI assessment of trabecular bone micro-architecture of the wrist. This method could be utilized to study perturbations in bone structure in subjects with osteoporosis or other bone disorders.

Wang, Ligong; Liang, Guoyuan; Babb, James S.; Wiggins, Graham C.; Saha, Punam K.; Regatte, Ravinder R.

2013-01-01

196

Comparison of Transcription-Mediated Amplification and Growth-Based Methods for the Quantitation of Enterococcus Bacteria in Environmental Waters  

Microsoft Academic Search

An assay based on transcription-mediated amplification (TMA) technology was used to quantitate Entero- coccus fecal indicator bacteria in environmental water samples. The results generated by this and two growth- based methods relative to the 104 most-probable-number or CFU-per-100-ml threshold show that the three methods are in good qualitative agreement when tested against a range of water samples taken from different

Ceri A. Morris; A. Denene Blackwood; Marek Kirs; Neil D. Buttigieg; Rhian R. Morgan; James J. Hogan; Rachel T. Noble

2008-01-01

197

An evaluation of four quantitative laboratory fume hood performance test methods  

SciTech Connect

Four quantitative laboratory fume hood performance test methods were evaluated, including: EPA uranine dye; ASHRAE Freon; EPA SF/sub 6/; and modified EPA SF/sub 6/. Each of these methods were evaluated, based on: variability and reproducibility; practical applications for field use; and the amount of leakage detected at the hood face. Testing was done on a hood in both the bypass and auxiliary-air supplied modes, and at five average face velocities - 60, 80, 100, 125, and 150 fpm. The ASHRAE Freon method was most sensitive for the bypass hood. Statistical analysis of the variability and reproducibility of the methods showed the repeat calibrations of the ITI Leakmeter to be the only factor which was significantly different. Each of the methods had problems which limited their field applicability. The results indicated that leakage from the hood face did not change significantly with the range of face velocities tested for either the bypass or auxiliary hood. 47 refs., 16 figs., 6 tabs.

Woodrow, L.M.

1987-11-01

198

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

199

Application of quality control planning methods for the improvement of a quantitative molecular assay.  

PubMed

Hepatitis B virus (HBV) DNA measurement has an important role in the diagnosis and management of patients with chronic HBV infection. In cases of chronic hepatitis B, clinical decision is based on either the absolute amount of HBV DNA level, or else the relative change in HBV DNA level. To produce high quality and comparable results, assay performance characteristics must be verified and statistical quality control methods must be planned. In this study, systematic and random error values in an assay of plasma HBV DNA were determined. Performance of the method was examined by employing a normalized operational process specifications (OPSpecs) chart. The systematic error at low and high control levels were 0.33 and 0.22 log(IU/mL) respectively. At both levels, the standard deviations (SD) of the assay were 0.17 log(IU/mL). In addition, a single rule of 12.5SD with 2 control measurements was selected as a candidate quality control method. The assay performed well and was acceptable for clinical use. Further improvement may be attained by switching to automated purification methods. In this study, the well-established discipline of statistical quality control was applied to a real-time quantitative PCR. It was concluded that by employing statistical quality control (QC) methods, which utilize long-term controls, critical changes in the measurement system could be detected. PMID:23933079

Shahsiah, Reza; Nili, Fatemeh; Ardalan, Farid Azmoudeh; Pourgholi, Fatemeh; Borumand, Mohammad Ali

2013-11-01

200

Quantitative and Qualitative Approaches to Knowledge: Proposing a Method of Functional Integration for the Relationship between Empirical Methods.  

ERIC Educational Resources Information Center

Qualitative and quantitative social science research methods rather than representing opposing research methods instead are reinforcing research traditions. The ability of either research methodology to make lasting and important contributions requires the ability to synthesize and integrate with the other approach. While the assumptions of each…

Allen, Mike; Silver, Charles

201

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

202

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

203

Qualitative Methods Can Enrich Quantitative Research on Occupational Stress: An Example from One Occupational Group  

ERIC Educational Resources Information Center

The chapter examines the ways in which qualitative and quantitative methods support each other in research on occupational stress. Qualitative methods include eliciting from workers unconstrained descriptions of work experiences, careful first-hand observations of the workplace, and participant-observers describing "from the inside" a particular…

Schonfeld, Irvin Sam; Farrell, Edwin

2010-01-01

204

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

205

Optimization of the Weck-Cel Collection Method for Quantitation of Cytokines in Mucosal Secretions  

Microsoft Academic Search

Measurement of immune components in mucosal secretions is important for the evaluation of local immu- nity at the mucosal surfaces. The Weck-Cel ophthalmic sponge provides a method for the collection of these secretions. The sponge absorbs a relatively large volume of material, therefore allowing for quantitation of multiple immune components. Additionally, it provides a method in which the same device

LISA CENCIA ROHAN; ROBERT P. EDWARDS; LORI A. KELLY; KELLY A. COLENELLO; FREDERICK P. BOWMAN; PEGGY A. CROWLEY-NOWICK

2000-01-01

206

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

207

Clustering and training set selection methods for improving the accuracy of quantitative laser induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

We investigated five clustering and training set selection methods to improve the accuracy of quantitative chemical analysis of geologic samples by laser induced breakdown spectroscopy (LIBS) using partial least squares (PLS) regression. The LIBS spectra were previously acquired for 195 rock slabs and 31 pressed powder geostandards under 7 Torr CO2 at a stand-off distance of 7 m at 17 mJ per pulse to simulate the operational conditions of the ChemCam LIBS instrument on the Mars Science Laboratory Curiosity rover. The clustering and training set selection methods, which do not require prior knowledge of the chemical composition of the test-set samples, are based on grouping similar spectra and selecting appropriate training spectra for the partial least squares (PLS2) model. These methods were: (1) hierarchical clustering of the full set of training spectra and selection of a subset for use in training; (2) k-means clustering of all spectra and generation of PLS2 models based on the training samples within each cluster; (3) iterative use of PLS2 to predict sample composition and k-means clustering of the predicted compositions to subdivide the groups of spectra; (4) soft independent modeling of class analogy (SIMCA) classification of spectra, and generation of PLS2 models based on the training samples within each class; (5) use of Bayesian information criteria (BIC) to determine an optimal number of clusters and generation of PLS2 models based on the training samples within each cluster. The iterative method and the k-means method using 5 clusters showed the best performance, improving the absolute quadrature root mean squared error (RMSE) by ~ 3 wt.%. The statistical significance of these improvements was ~ 85%. Our results show that although clustering methods can modestly improve results, a large and diverse training set is the most reliable way to improve the accuracy of quantitative LIBS. In particular, additional sulfate standards and specifically fabricated analog samples with Mars-like compositions may improve the accuracy of ChemCam measurements on Mars. Refinement of the iterative method, modifications of the basic k-means clustering algorithm, and classification based on specifically selected S, C and Si emission lines may also prove beneficial and merit further study.

Anderson, Ryan B.; Bell, James F., III; Wiens, Roger C.; Morris, Richard V.; Clegg, Samuel M.

2012-04-01

208

Comparison of Six DNA Extraction Methods for Recovery of Fungal DNA as Assessed by Quantitative PCR  

PubMed Central

The detection of fungal pathogens in clinical samples by PCR requires the use of extraction methods that efficiently lyse fungal cells and recover DNA suitable for amplification. We used quantitative PCR assays to measure the recovery of DNA from two important fungal pathogens subjected to six DNA extraction methods. Aspergillus fumigatus conidia or Candida albicans yeast cells were added to bronchoalveolar lavage fluid and subjected to DNA extraction in order to assess the recovery of DNA from a defined number of fungal propagules. In order to simulate hyphal growth in tissue, Aspergillus fumigatus conidia were allowed to form mycelia in tissue culture media and then harvested for DNA extraction. Differences among the DNA yields from the six extraction methods were highly significant (P < 0.0001) in each of the three experimental systems. An extraction method based on enzymatic lysis of fungal cell walls (yeast cell lysis plus the use of GNOME kits) produced high levels of fungal DNA with Candida albicans but low levels of fungal DNA with Aspergillus fumigatus conidia or hyphae. Extraction methods employing mechanical agitation with beads produced the highest yields with Aspergillus hyphae. The MasterPure yeast method produced high levels of DNA from C. albicans but only moderate yields from A. fumigatus. A reagent from one extraction method was contaminated with fungal DNA, including DNA from Aspergillus and Candida species. In conclusion, the six extraction methods produce markedly differing yields of fungal DNA and thus can significantly affect the results of fungal PCR assays. No single extraction method was optimal for all organisms.

Fredricks, David N.; Smith, Caitlin; Meier, Amalia

2005-01-01

209

[Kidney spiral CT. Indication, method, results].  

PubMed

The introduction on spiral computed tomography (spiral CT) has vastly enriched the methodological diversity of computer-tomographic scans. It allows for the recording of different perfusion or excretion stages of the kidney parenchyma of the urine draining paths by carrying out long-distance, phase-identical multiple examinations of the retroperitoneum. The description of the findings which are characterized by their local and contrasts behavior is possible. The following report describes the indications and technological process of kidney spiral CT using kidney-typical intravenous contrast media. Special emphasis is put on the advantages and limits of multiple phase spiral CT. Decisive preconditions are: 1. specific clinical query, 2. selection of the corresponding phase contrasts of the kidneys and uretra or bladder, 3. exact technical and temporal adjustment of the acquisition parameters. Scanning times are in the range of seconds. The overall examination can be carried out quick and without any major strain on the part of the patient. A sound proof and a general differentiation of focal kidney lesions can be derived from the acquired data. This is also true for kidneys and ureters findings. Bladder findings can be localized and differentiated according to stage. More than two "spiral acquisitions" should be carried out with re-straint taking exposure to radiation into account. Due to the sound registration of focal lesions, its capability of reproduction and its short-time examination, the spiral CT of the kidneys can be said to be the most effective current scanning method of the retroperitoneum following clinical examinations and sonography. PMID:10384691

Braunschweig, R; Hundt, W; Breiteneder, T; Beilicke, M; Reiser, M

1999-05-01

210

Method for measuring transformation energy and quantitative characterization of transformation-induced plasticity  

Microsoft Academic Search

A method for measuring transformation energy (E\\u000a pt) of strain-induced martensite (SIM) and quantitative characterization of transformation-induced plasticity is developed using\\u000a characteristics of the tensile curve of three metastable austenitic stainless steels, 10Cr18.5Ni8.5Mnl.9Si0.9, 19Cr17.5Ni7.4Mn2.3Si1.0,\\u000a and 10Cr16.2Ni11.8Mn1.2Si0.7. The results show that the E\\u000a pt of tested materials at ?196 C is 11.3, 14.7, and 20.1106 J\\/m3, respectively; E\\u000a pt remains constant

W. F. Zhang; Y. M. Chen; J. H. Zhu

2002-01-01

211

Measuring access to medicines: a review of quantitative methods used in household surveys  

PubMed Central

Background Medicine access is an important goal of medicine policy; however the evaluation of medicine access is a subject under conceptual and methodological development. The aim of this study was to describe quantitative methodologies to measure medicine access on household level, access expressed as paid or unpaid medicine acquisition. Methods Searches were carried out in electronic databases and health institutional sites; within references from retrieved papers and by contacting authors. Results Nine papers were located. The methodologies of the studies presented differences in the recall period, recruitment of subjects and medicine access characterization. Conclusions The standardization of medicine access indicators and the definition of appropriate recall periods are required to evaluate different medicines and access dimensions, improving studies comparison. Besides, specific keywords must be established to allow future literature reviews about this topic.

2010-01-01

212

[Quantitative analysis method of natural gas combustion process combining wavelength selection and outlier spectra detection].  

PubMed

The present paper uses a combination method of wavelength selection and outlier spectra detection for quantitative analysis of nature gas combustion process based on its near infrared spectra. According to the statistical distribution of partial least squares (PLS) model coefficients and prediction errors, the method realized wavelength selection and outlier spectra detection, respectively. In contrast with PLS, PLS after leave-one-out for outlier detection (LOO-PLS), uninformative variable elimination by PLS (UVE-PLS) and UVE-PLS after leave-one-out for outlier detection (LOO-UVE-PLS), the root-mean-squared error of prediction (RMSEP) based on the method for CH4 prediction model is reduced by 14.33%, 14.33%, 10.96% and 12.21%; the RMSEP value for CO prediction model is reduced by 67.26%, 72.58%, 11.32% and 4.52%; the RMSEP value for CO2 prediction model is reduced by 5.95%, 19.7%, 36.71% and 4.04% respectively. Experimental results demonstrate that the method can significantly decrease the number of selected wavelengths, reduce model complexity and effectively detect outlier spectra. The established prediction model of analytes is more accurate as well as robust. PMID:23285890

Cao, Hui; Hu, Luo-Na; Zhou, Yan

2012-10-01

213

Quantitative analysis of eugenol in clove extract by a validated HPLC method.  

PubMed

Clove (Eugenia caryophyllata) is a well-known medicinal plant used for diarrhea, digestive disorders, or in antiseptics in Korea. Eugenol is the main active ingredient of clove and has been chosen as a marker compound for the chemical evaluation or QC of clove. This paper reports the development and validation of an HPLC-diode array detection (DAD) method for the determination of eugenol in clove. HPLC separation was accomplished on an XTerra RP18 column (250 x 4.6 mm id, 5 microm) with an isocratic mobile phase of 60% methanol and DAD at 280 nm. Calibration graphs were linear with very good correlation coefficients (r2 > 0.9999) from 12.5 to 1000 ng/mL. The LOD was 0.81 and the LOQ was 2.47 ng/mL. The method showed good intraday precision (%RSD 0.08-0.27%) and interday precision (%RSD 0.32-1.19%). The method was applied to the analysis of eugenol from clove cultivated in various countries (Indonesia, Singapore, and China). Quantitative analysis of the 15 clove samples showed that the content of eugenol varied significantly, ranging from 163 to 1049 ppb. The method of determination of eugenol by HPLC is accurate to evaluate the quality and safety assurance of clove, based on the results of this study. PMID:21313806

Yun, So-Mi; Lee, Myoung-Heon; Lee, Kwang-Jick; Ku, Hyun-Ok; Son, Seong-Wan; Joo, Yi-Seok

2010-01-01

214

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

215

Evaluation of quantitative methods for the determination of polyphenols in algal extracts.  

PubMed

Marine brown algae such as Ascophyllum nodosum and Fucus vesiculosus accumulate polyphenols composed of phloroglucinol units. These compounds are of ecological importance and, due to their antioxidative activity, of pharmacological value as well. In this study four methods for the quantitative determination of phlorotannins are compared: spectrophotometric determinations using Folin-Ciocalteu's phenol reagent or 2,4-dimethoxybenzaldehyde (DMBA), quantitative (1)H NMR spectroscopy (qHNMR), and gravimetrical measurements. On the basis of the relative standard deviation and the F-test, the determination using Folin-Ciocalteu's phenol reagent and qHNMR proved to be the most reliable and precise methods. PMID:18052031

Parys, Sabine; Rosenbaum, Anne; Kehraus, Stefan; Reher, Gerrit; Glombitza, Karl-Werner; König, Gabriele M

2007-12-01

216

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

217

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.

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

2012-01-01

218

Does contraceptive treatment in wildlife result in side effects? A review of quantitative and anecdotal evidence.  

PubMed

The efficacy of contraceptive treatments has been extensively tested, and several formulations are effective at reducing fertility in a range of species. However, these formulations should minimally impact the behavior of individuals and populations before a contraceptive is used for population manipulation, but these effects have received less attention. Potential side effects have been identified theoretically and we reviewed published studies that have investigated side effects on behavior and physiology of individuals or population-level effects, which provided mixed results. Physiological side effects were most prevalent. Most studies reported a lack of secondary effects, but were usually based on qualitative data or anecdotes. A meta-analysis on quantitative studies of side effects showed that secondary effects consistently occur across all categories and all contraceptive types. This contrasts with the qualitative studies, suggesting that anecdotal reports are insufficient to investigate secondary impacts of contraceptive treatment. We conclude that more research is needed to address fundamental questions about secondary effects of contraceptive treatment and experiments are fundamental to conclusions. In addition, researchers are missing a vital opportunity to use contraceptives as an experimental tool to test the influence of reproduction, sex and fertility on the behavior of wildlife species. PMID:19656957

Gray, Meeghan E; Cameron, Elissa Z

2010-01-01

219

Quantitative comparison of reconstruction methods for intra-voxel fiber recovery from diffusion MRI.  

PubMed

Validation is arguably the bottleneck in the diffusion magnetic resonance imaging (MRI) community. This paper evaluates and compares 20 algorithms for recovering the local intra-voxel fiber structure from diffusion MRI data and is based on the results of the "HARDI reconstruction challenge" organized in the context of the "ISBI 2012" conference. Evaluated methods encompass a mixture of classical techniques well known in the literature such as diffusion tensor, Q-Ball and diffusion spectrum imaging, algorithms inspired by the recent theory of compressed sensing and also brand new approaches proposed for the first time at this contest. To quantitatively compare the methods under controlled conditions, two datasets with known ground-truth were synthetically generated and two main criteria were used to evaluate the quality of the reconstructions in every voxel: correct assessment of the number of fiber populations and angular accuracy in their orientation. This comparative study investigates the behavior of every algorithm with varying experimental conditions and highlights strengths and weaknesses of each approach. This information can be useful not only for enhancing current algorithms and develop the next generation of reconstruction methods, but also to assist physicians in the choice of the most adequate technique for their studies. PMID:24132007

Daducci, Alessandro; Canales-Rodríguez, Erick Jorge; Descoteaux, Maxime; Garyfallidis, Eleftherios; Gur, Yaniv; Lin, Ying-Chia; Mani, Merry; Merlet, Sylvain; Paquette, Michael; Ramirez-Manzanares, Alonso; Reisert, Marco; Reis Rodrigues, Paulo; Sepehrband, Farshid; Caruyer, Emmanuel; Choupan, Jeiran; Deriche, Rachid; Jacob, Mathews; Menegaz, Gloria; Pr?kovska, Vesna; Rivera, Mariano; Wiaux, Yves; Thiran, Jean-Philippe

2014-02-01

220

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

NASA Astrophysics Data System (ADS)

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, and generalized synchronization) based on various simulation models. For this purpose, quantitative criteria are used: in addition to mean square error under null hypothesis (independence between two signals) and mean variance computed over all values of coupling degree in each model, we provide a criterion for comparing performances. Results show that the performances of the compared methods are highly dependavxx 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.

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

2006-09-01

221

Telomere length measurement by a novel monochrome multiplex quantitative PCR method  

PubMed Central

The current quantitative polymerase chain reaction (QPCR) assay of telomere length measures telomere (T) signals in experimental DNA samples in one set of reaction wells, and single copy gene (S) signals in separate wells, in comparison to a reference DNA, to yield relative T/S ratios that are proportional to average telomere length. Multiplexing this assay is desirable, because variation in the amount of DNA pipetted would no longer contribute to variation in T/S, since T and S would be collected within each reaction, from the same input DNA. Multiplexing also increases throughput and lowers costs, since half as many reactions are needed. Here, we present the first multiplexed QPCR method for telomere length measurement. Remarkably, a single fluorescent DNA-intercalating dye is sufficient in this system, because T signals can be collected in early cycles, before S signals rise above baseline, and S signals can be collected at a temperature that fully melts the telomere product, sending its signal to baseline. The correlation of T/S ratios with Terminal Restriction Fragment (TRF) lengths measured by Southern blot was stronger with this monochrome multiplex QPCR method (R2 = 0.844) than with our original singleplex method (R2 = 0.677). Multiplex T/S results from independent runs on different days were highly reproducible (R2 = 0.91).

Cawthon, Richard M.

2009-01-01

222

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

223

Development of a Relational Database to Capture and Merge Clinical History with the Quantitative Results of Radionuclide Renography  

PubMed Central

Our objective was to design and implement a clinical history database capable of linking to our database of quantitative results from 99mTc-mercaptoacetyltriglycine (MAG3) renal scans and export a data summary for physicians or our software decision support system. Methods For database development, we used a commercial program. Additional software was developed in Interactive Data Language. MAG3 studies were processed using an in-house enhancement of a commercial program. The relational database has 3 parts: a list of all renal scans (the RENAL database), a set of patients with quantitative processing results (the Q2 database), and a subset of patients from Q2 containing clinical data manually transcribed from the hospital information system (the CLINICAL database). To test interobserver variability, a second physician transcriber reviewed 50 randomly selected patients in the hospital information system and tabulated 2 clinical data items: hydronephrosis and presence of a current stent. The CLINICAL database was developed in stages and contains 342 fields comprising demographic information, clinical history, and findings from up to 11 radiologic procedures. A scripted algorithm is used to reliably match records present in both Q2 and CLINICAL. An Interactive Data Language program then combines data from the 2 databases into an XML (extensible markup language) file for use by the decision support system. A text file is constructed and saved for review by physicians. Results RENAL contains 2,222 records, Q2 contains 456 records, and CLINICAL contains 152 records. The interobserver variability testing found a 95% match between the 2 observers for presence or absence of ureteral stent (? = 0.52), a 75% match for hydronephrosis based on narrative summaries of hospitalizations and clinical visits (? = 0.41), and a 92% match for hydronephrosis based on the imaging report (? = 0.84). Conclusion We have developed a relational database system to integrate the quantitative results of MAG3 image processing with clinical records obtained from the hospital information system. We also have developed a methodology for formatting clinical history for review by physicians and export to a decision support system. We identified several pitfalls, including the fact that important textual information extracted from the hospital information system by knowledgeable transcribers can show substantial interobserver variation, particularly when record retrieval is based on the narrative clinical records.

Folks, Russell D.; Savir-Baruch, Bital; Garcia, Ernest V.; Verdes, Liudmila; Taylor, Andrew T.

2013-01-01

224

In vivo Repeatability and Reproducibility of the Quantitative Light-Induced Fluorescence Method  

Microsoft Academic Search

In vivo repeatability and reproducibility of the quantitative light-induced fluorescence (QLF) method were tested with respect to three variables: lesion area, and average and maximum changes in lesion fluorescence. To test the image-capturing stages, three analysts each captured images of 15 incipient smooth surface lesions in vivo, and the images were analysed by one of the analysts. To test the

Sofia Tranæus; Xie-Qi Shi; Lars-Erik Lindgren; Karin Trollsås; Birgit Angmar-Månsson

2002-01-01

225

Quantitative analysis of genetically modified organisms (GMO) in processed food by PCR-based methods  

Microsoft Academic Search

Two different PCR-based approaches for the quantitative analysis of genetically modified organism (GMO) – components in foods are presented using Soybean derived samples as an example. The first method – a double competitive PCR – is well suited to determine threshold levels of GMO content in food. The other – PCR on-line measurement – is suited to determine ratios of

A. Wurz; A. Bluth; P. Zeltz; C. Pfeifer; R. Willmund

1999-01-01

226

A quantitative method for zoning of protected areas and its spatial ecological implications  

Microsoft Academic Search

Zoning is a key prescriptive tool for administration and management of protected areas. However, the lack of zoning is common for most protected areas in developing countries and, as a consequence, many protected areas are not effective in achieving the goals for which they were created. In this work, we introduce a quantitative method to expeditiously zone protected areas and

María del Carmen Sabatini; Adriana Verdiell; Ricardo M. Rodríguez Iglesias; Marta Vidal

2007-01-01

227

Quantitative Evaluation of Three Calibration Methods for 3-D Freehand Ultrasound  

Microsoft Academic Search

In this paper, three different calibration methods for three-dimensional (3-D) freehand ultrasound (US) are evaluated. Calibration is the process of estimating the rigid transformation from US image coordinates to the coordinate system of the tracking sensor mounted onto the probe. Calibration accuracy has an important impact on quantitative studies. Geometrical precision can also be crucial in many interventions and surgery.

François Rousseau; Pierre Hellier; Marloes M. J. Letteboer; Wiro J. Niessen; Christian Barillot

2006-01-01

228

Quantitative Neutronographic Analysis of Fibre Texture of Zirconium by the Time-of-Flight Method.  

National Technical Information Service (NTIS)

Quantitative neutronographic analysis of fibre texture of zirconium has been done by the time-of-flight method. On the IBR-30 pulsed reactor 16 diffraction spectra are measured on each of three deformation states of the sample. Pole figures have been dete...

M. Betzl K. Walther W. Matz K. Feldmann

1980-01-01

229

Qualitative and Quantitative Research Methods: Old Wine in New Bottles? On Understanding and Interpreting Educational Phenomena  

ERIC Educational Resources Information Center

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…

Smeyers, Paul

2008-01-01

230

Developing a quantitative method to evaluate peach ( Prunus persica) flesh mealiness  

Microsoft Academic Search

A quantitative method to measure peach flesh mealiness based on free juice was developed. Free juice was measured by subjecting fruit tissue to a pressing force of 667 N for 1 min before centrifugation. After this extraction, the juice was collected and centrifuged at 6000g for 10 min. The supernatant was weighed and used to represent the free juice from

Carlos H. Crisosto; John M. Labavitch

2002-01-01

231

A method for accurate detection of genomic microdeletions using real-time quantitative PCR  

Microsoft Academic Search

BACKGROUND: Quantitative Polymerase Chain Reaction (qPCR) is a well-established method for quantifying levels of gene expression, but has not been routinely applied to the detection of constitutional copy number alterations of human genomic DNA. Microdeletions or microduplications of the human genome are associated with a variety of genetic disorders. Although, clinical laboratories routinely use fluorescence in situ hybridization (FISH) to

Rosanna Weksberg; Simon Hughes; Laura Moldovan; Anne S Bassett; Eva WC Chow; Jeremy A Squire

2005-01-01

232

The coexistence approach — a method for quantitative reconstructions of Tertiary terrestrial palaeoclimate data using plant fossils  

Microsoft Academic Search

The coexistence approach is introduced as a method for quantitative terrestrial palaeoclimate reconstructions in the Tertiary. It is based on the assumption that Tertiary plant taxa have similar climatic requirements to their nearest living relatives. The aim of the coexistence approach is to find for a given fossil flora and a given climate parameter the climatic interval in which all

Volker Mosbrugger; Torsten Utescher

1997-01-01

233

Statistical Methods for Expression Quantitative Trait Loci (eQTL) Mapping  

Microsoft Academic Search

Summary. Traditional genetic mapping has largely focused on the identification of loci affecting one, or at most a few, complex traits. Microarrays allow for measurement of thousands of gene expression abundances, themselves complex traits, and a number of recent investigations have considered these measurements as phenotypes in mapping studies. Combining traditional quantitative trait loci (QTL) mapping methods with microarray data

C. M. Kendziorski; M. Chen; M. Yuan; H. Lan; A. D. Attie

2005-01-01

234

An immunochemical method for quantitation of Epinotia aporema granulovirus (EpapGV)  

Microsoft Academic Search

Epinotia aporema granulovirus (EpapGV) is a baculovirus that affects E. aporema larvae and has proven to be a good candidate for the biocontrol of this important pest in South America. As part of the quality control of the production of a bioinsecticide based on EpapGV, a sensitive method was developed for the detection and quantitation of the virus. To this

Alejandro Daniel Parola; Alicia Sciocco-Cap; Graciela Glikmann; V??ctor Romanowski

2003-01-01

235

Paradigms Lost and Pragmatism Regained: Methodological Implications of Combining Qualitative and Quantitative Methods  

ERIC Educational Resources Information Center

This article examines several methodological issues associated with combining qualitative and quantitative methods by comparing the increasing interest in this topic with the earlier renewal of interest in qualitative research during the 1980s. The first section argues for the value of Kuhn's concept of paradigm shifts as a tool for examining…

Morgan, David L.

2007-01-01

236

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

237

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

238

Infectious titres of sheep scrapie and bovine spongiform encephalopathy agents cannot be accurately predicted from quantitative laboratory test results.  

PubMed

It is widely accepted that abnormal forms of the prion protein (PrP) are the best surrogate marker for the infectious agent of prion diseases and, in practice, the detection of such disease-associated (PrP(d)) and/or protease-resistant (PrP(res)) forms of PrP is the cornerstone of diagnosis and surveillance of the transmissible spongiform encephalopathies (TSEs). Nevertheless, some studies question the consistent association between infectivity and abnormal PrP detection. To address this discrepancy, 11 brain samples of sheep affected with natural scrapie or experimental bovine spongiform encephalopathy were selected on the basis of the magnitude and predominant types of PrP(d) accumulation, as shown by immunohistochemical (IHC) examination; contra-lateral hemi-brain samples were inoculated at three different dilutions into transgenic mice overexpressing ovine PrP and were also subjected to quantitative analysis by three biochemical tests (BCTs). Six samples gave 'low' infectious titres (10?·? to 10?·? LD?? g?¹) and five gave 'high titres' (10?·¹ to ? 10?·? LD?? g?¹) and, with the exception of the Western blot analysis, those two groups tended to correspond with samples with lower PrP(d)/PrP(res) results by IHC/BCTs. However, no statistical association could be confirmed due to high individual sample variability. It is concluded that although detection of abnormal forms of PrP by laboratory methods remains useful to confirm TSE infection, infectivity titres cannot be predicted from quantitative test results, at least for the TSE sources and host PRNP genotypes used in this study. Furthermore, the near inverse correlation between infectious titres and Western blot results (high protease pre-treatment) argues for a dissociation between infectivity and PrP(res). PMID:22915693

González, Lorenzo; Thorne, Leigh; Jeffrey, Martin; Martin, Stuart; Spiropoulos, John; Beck, Katy E; Lockey, Richard W; Vickery, Christopher M; Holder, Thomas; Terry, Linda

2012-11-01

239

Field Results of an In-Place, Quantitative Performance Test for Laboratory Fume Hoods  

Microsoft Academic Search

A new method for testing fume hood performance was developed and previously reported. It involves measurement of tracer chemical concentrations outside a hood that result from a steady release of sulfur hexafluoride tracer chemical inside the hood. The tracer chemical is released through a hollow rectangular diffuser that encloses the entire work area. Field surveys on 50 laboratory fume hoods

Louis J. Diberardinis; Melvin W. First; Raymond E. Ivany

1991-01-01

240

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.

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

2011-01-01

241

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

242

Quantitative methods for evaluating optical and frictional properties of cationic polymers.  

PubMed

This paper presents three quantitative methods to examine gloss, opacity, and friction of cationic polymers. The adsorption of cationic polymers onto hair and skin can be regarded as a thin film coating. Therefore, optical and frictional properties of polymer films are of significant relevance to the applications of cationic polymers in hair care products. Such properties reflect the desirable hair condition attributes consumers seek in shampoo and conditioner products. Using these test methods, polyquaternium-10 and cationic guar samples of varying molecular weight and cationic substitution were compared. The effect of an anionic surfactant, sodium dodecyl sulfate (SDS), on polymer film properties was also investigated. Neat guar hydroxypropyl trimonium chloride imparts less friction than polyquaternium-10 but dulls the substrate employed in this study. The optical data show that polyquaternium-10 provides greater film clarity and gloss than cationic guars. In the presence of SDS, polyquaternium-10 also displays similar or lower friction than cationic guar. The comparative optical and frictional results are in good agreement with the visual assessment of the cationic polymer films. These results clearly demonstrate that polyquaternium-10 exhibits superior film properties in the forms of both neat polymer and polymer/surfactant complex. In addition, microscopic techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM) provide powerful explanations for the differences noted between the two popular classes of cationic polymers. The test methods described in this paper can be utilized to differentiate the upper performance potential of cationic polymers. These objective and standardized test methods derived from the coatings industry are not affected by the variability of hair or the formulation complexity of end products. They can be useful tools in the product development process in quickly screening the relative performance of different polymers. PMID:11382843

Wu, W; Alkema, J; Shay, G D; Basset, D R

2001-01-01

243

Measuring microRNAs: Comparisons of microarray and quantitative PCR measurements, and of different total RNA prep methods  

Microsoft Academic Search

BACKGROUND: Determining the expression levels of microRNAs (miRNAs) is of great interest to researchers in many areas of biology, given the significant roles these molecules play in cellular regulation. Two common methods for measuring miRNAs in a total RNA sample are microarrays and quantitative RT-PCR (qPCR). To understand the results of studies that use these two different techniques to measure

Robert A Ach; Hui Wang; Bo Curry

2008-01-01

244

Quantitative quality-assessment techniques to compare fractionation and depletion methods in SELDI-TOF mass spectrometry experiments  

Microsoft Academic Search

Motivation: Mass-spectrometry (MS), such as the surface-enhanced laser desorption and ionization time-of-flight (SELDI-TOF) MS, pro- vides a potentially promising proteomic technology for biomarker discovery. An important matter for such a technology to be used routinely is its reproducibility. It is of significant interest to develop quantitative measures to evaluate the quality and reliability of different experimental methods. Results: We compare

Jaroslaw Harezlak; Mike Wang; David Christiani; Xihong Lin

2007-01-01

245

Bayesian data augmentation methods for the synthesis of qualitative and quantitative research findings  

PubMed Central

The possible utility of Bayesian methods for the synthesis of qualitative and quantitative research has been repeatedly suggested but insufficiently investigated. In this project, we developed and used a Bayesian method for synthesis, with the goal of identifying factors that influence adherence to HIV medication regimens. We investigated the effect of 10 factors on adherence. Recognizing that not all factors were examined in all studies, we considered standard methods for dealing with missing data and chose a Bayesian data augmentation method. We were able to summarize, rank, and compare the effects of each of the 10 factors on medication adherence. This is a promising methodological development in the synthesis of qualitative and quantitative research.

Crandell, Jamie L.; Voils, Corrine I.; Chang, YunKyung; Sandelowski, Margarete

2010-01-01

246

Development of a method for automated quantitative analysis of ores using LIBS  

Microsoft Academic Search

This paper reports the development of a method for real-time automated quantitative analysis of mineral ores using a commercial laser-induced breakdown spectroscopy instrument, TRACER™ 2100, fitted with a recently developed computer controlled auto-sampler. The auto-sampler permits the execution of methods for performing calibrations and analysis of multiple elements on multiple samples. Furthermore, the analysis is averaged over multiple locations on

S. Rosenwasser; G Asimellis; B Bromley; R Hazlett; J Martin; T Pearce; A Zigler

2001-01-01

247

Quantitative method of image analysis when drift is present in a scanning probe microscope  

Microsoft Academic Search

We present a quantitative method of image analysis that automatically corrects for system drift in comparisons of images before and after an event under study. The method utilizes 2-dimensional correlations followed by automatic z-scaling, shifting, and the calculation of a difference image from the before and after images. Optical reflectance near-field scanning optical microscope (NSOM) images that show the effects

S. H. Huerth; H. D. Hallen

2003-01-01

248

An Efficient Method for Quantitative Association Rules to Raise Reliance of Data  

Microsoft Academic Search

\\u000a This paper suggests an efficient method to raise reliance of Large Interval Itemsets to convert quantitative item into binary\\u000a item. The suggested method does not leave behind meaningful items. And can create more quantity of minute Large Interval Itemsets\\u000a and can minimize the loss of attribution of original data because it generate merged interval which is close to the figure

Hye-jung Lee; Won-hwan Park; Doo-soon Park

2004-01-01

249

Bayesian data augmentation methods for the synthesis of qualitative and quantitative research findings  

Microsoft Academic Search

The possible utility of Bayesian methods for the synthesis of qualitative and quantitative research has been repeatedly suggested\\u000a but insufficiently investigated. In this project, we developed and used a Bayesian method for synthesis, with the goal of\\u000a identifying factors that influence adherence to HIV medication regimens. We investigated the effect of 10 factors on adherence.\\u000a Recognizing that not all factors

Jamie L. Crandell; Corrine I. Voils; YunKyung Chang; Margarete Sandelowski

2011-01-01

250

Analysis of quantitative methods for rib seriation using the Spitalfields documented skeletal collection.  

PubMed

Accurate rib seriation is essential in forensic anthropology and bioarchaeology for determination of minimum numbers of individuals, sequencing trauma patterns to the chest, and identification of central ribs for use in age estimation. We investigate quantitative methods for rib seriation based on three metric variables: superior (anterior) costo-transverse crest height (SCTCH), articular facet of the tubercle-to-angle length (AFTAL), and head-to-articular facet length (HAFL). The sample consists of complete but unseriated sets of ribs from 133 individuals from the documented (known age and sex) and undocumented skeletal collections of Christ Church Spitalfields, London. This research confirms the results of an earlier study (Hoppa and Saunders [1998] J. Forensic. Sci. 43:174-177) and extends it with the application of two new metric traits and further analyses of sex differences. Analyses of variance showed that SCTCH and AFTAL are significantly associated (P < 0.001) with rib number. Tukey tests of pairwise rib comparisons revealed that for two dimensions (SCTCH and AFTAL), the central ribs (3rd-6th) are significantly distinct from each other (P < 0.05). Using simple ranking of either the SCTCH or AFTAL traits, the proportion of correctly identified ribs within +/-1 position was 80%, compared to initial seriation using morphological methods (Dudar [1993] J. Forensic. Sci. 28:788-797; Mann [1993] J. Forensic. Sci. 28:151-155). Significant sex dimorphism was also identified for these two traits. Analysis of the HAFL trait produced somewhat equivocal results, suggesting that this variable is not reliable for rib seriation. The variable SCTCH proves to be the most useful dimension for seriation, and shows that all but the 7th-9th ribs can be distinguished from others in the sequence, with important results for the 4th rib, where ranking allowed identification in 86% of cases, consistent with morphological methods for intact ribs. PMID:15503341

Owers, Sonya K; Pastor, Robert F

2005-06-01

251

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

252

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.

Good, W V

2001-01-01

253

Method for Estimating Total Attenuation from a Spatial Map of Attenuation Slope for Quantitative Ultrasound Imaging  

PubMed Central

Estimating total ultrasound attenuation from backscatter data is essential in the field of quantitative ultrasound (QUS) because of the need to compensate for attenuation when estimating the backscatter coefficient and QUS parameters. This work uses a reference phantom method of attenuation estimation to create a spatial map of attenuation slope (AS) from backscatter radio-frequency (RF) data of three phantoms and a rat mammary adenocarcinoma tumor (MAT). The attenuation maps show changes in attenuation between different regions of the phantoms and the MAT tumor. Analyses of the attenuation maps of the phantoms suggest that the AS estimates are in good quantitative agreement with the known values for the phantoms. Furthermore, estimates of total attenuation from the attenuation maps are likewise in good quantitative agreement with known values.

Pawlicki, Alexander D.; O'Brien, William D.

2013-01-01

254

An Evaluation of Quantitative Methods of Determining the Degree of Melting Experienced by a Chondrule  

NASA Technical Reports Server (NTRS)

Many workers have considered the degree to which partial melting occurred in chondrules they have studied, and this has led to attempts to find reliable methods of determining the degree of melting. At least two quantitative methods have been used in the literature: a convolution index (CVI), which is a ratio of the perimeter of the chondrule as seen in thin section divided by the perimeter of a circle with the same area as the chondrule, and nominal grain size (NGS), which is the inverse square root of the number density of olivines and pyroxenes in a chondrule (again, as seen in thin section). We have evaluated both nominal grain size and convolution index as melting indicators. Nominal grain size was measured on the results of a set of dynamic crystallization experiments previously described, where aliquots of LEW97008(L3.4) were heated to peak temperatures of 1250, 1350, 1370, and 1450 C, representing varying degrees of partial melting of the starting material. Nominal grain size numbers should correlate with peak temperature (and therefore degree of partial melting) if it is a good melting indicator. The convolution index is not directly testable with these experiments because the experiments do not actually create chondrules (and therefore they have no outline on which to measure a CVI). Thus we had no means to directly test how well the CVI predicted different degrees of melting. Therefore, we discuss the use of the CVI measurement and support the discussion with X-ray Computed Tomography (CT) data.

Nettles, J. W.; Lofgren, G. E.; Carlson, W. D.; McSween, H. Y., Jr.

2004-01-01

255

Quantitative analysis of oxidized guanine, 8-oxoguanine, in mitochondrial DNA by immunofluorescence method.  

PubMed

8-Oxoguanine (8-oxoG), an oxidized form of guanine, is one of the major mutagenic lesions generated under oxidative stress. Oxidative damage in mitochondrial DNA has been implicated as a causative factor for a wide variety of degenerative diseases as well as for cancer during aging. We established a quantitative method for in situ detection of 8-oxoG in mitochondrial DNA in a single-cell level using a monoclonal antibody. Specific detection of 8-oxoG in mitochondrial DNA was confirmed by pre-treatment of samples with DNase I or MutM, the latter excising 8-oxoG opposite C in DNA. We then analyzed 8-oxoG dynamics in mitochondrial DNA of the wild-type and 8-oxoG DNA glycosylase (OGG1)-deficient mouse cells after exposure to hydrogen peroxide. Intensities for the 8-oxoG immunoreactivity in mitochondrial DNA were increased immediately after the exposure to hydrogen peroxide in both types of cells. The increased intensities returned to basal levels within a few hours only in wild-type cells, but not in OGG1-deficient cells which exhibited the increased intensities even 24 h after the exposure. These results indicate that OGG1 is a major enzyme for excision repair of 8-oxoG in mitochondrial DNA in mouse cells, and that our method described here is appropriate to study 8-oxoG dynamics in mitochondrial DNA. PMID:19513676

Ohno, Mizuki; Oka, Sugako; Nakabeppu, Yusaku

2009-01-01

256

Sequential follow-up results of catheter invention for coronary artery lesions after Kawasaki disease: quantitative coronary artery. Angiography and intravascular ultrasound imaging  

Microsoft Academic Search

Background—The purpose of this study was to assess the sequential follow-up results of catheter intervention in Kawasaki disease by use of quantitative coronary angiography (QCA) and intravascular ultrasound imaging. Methods and Results—Catheter intervention was performed on 23 stenotic lesions in 22 patients (aged 2 to 24 years). Percutaneous balloon angioplasty (PBA) was performed in 4 patients, stent implantation in 7,

Masahiro Ishii; Takafumi Ueno; Hisao Ikeda

2003-01-01

257

Quantitative Evaluation of Experimental Results an the Heterogeneous Freezing Nucleation of Supercooled Liquids  

Microsoft Academic Search

Freezing experiments using large numbers of small drops are frequently used for the study of both homogeneous and heterogeneous nucleation of water and of other substances. For heterogeneous nucleation, the spread in the observed freezing temperatures of drops has been shown to arise from the presence of nuclei of different activities in the sample. In the past no quantitative assessment

Gabor Vali

1971-01-01

258

Quantitative determination of creatine kinase isoenzyme catalytic concentrations in serum using immunological methods.  

PubMed

For the determination of creatine kinase isoenzyme catalytic concentrations in serum two methods based on immunological reactions are presented: One method uses inhibiting antibodies, which selectively block the activity of creatine kinase M subunits ("Inhibition Test"). This test is used for routine measurements of creatine kinase MB catalytic concentration; Another method uses precipitating antibodies, which allows a quantitative differentiation of creatine kinase isoenzymes MM, MB and BB ("Precipitation Test"). This test is used as a control for the Inhibition Test for the possible presence of creatine kinase BB activities in doubtful cases. Procedures, specificity, correlation and application of these methods are discussed. PMID:859004

Würzburg, U; Hennrich, N; Orth, H D; Lang, H; Prellwitz, W; Neumeier, D; Knedel, M; Rick, W

1977-03-01

259

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

260

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.

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

2013-01-01

261

Laboratory and field validation of a Cry1Ab protein quantitation method for water.  

PubMed

The widespread planting of crops expressing insecticidal proteins derived from the soil bacterium Bacillus thuringiensis (Bt) has given rise to concerns regarding potential exposure to non-target species. These proteins are released from the plant throughout the growing season into soil and surface runoff and may enter adjacent waterways as runoff, erosion, aerial deposition of particulates, or plant debris. It is crucial to be able to accurately quantify Bt protein concentrations in the environment to aid in risk analyses and decision making. Enzyme-linked immunosorbent assay (ELISA) is commonly used for quantitation of Bt proteins in the environment; however, there are no published methods detailing and validating the extraction and quantitation of Bt proteins in water. The objective of the current study was to optimize the extraction of a Bt protein, Cry1Ab, from three water matrices and validate the ELISA method for specificity, precision, accuracy, stability, and sensitivity. Recovery of the Cry1Ab protein was matrix-dependent and ranged from 40 to 88% in the validated matrices, with an overall method detection limit of 2.1ng/L. Precision among two plates and within a single plate was confirmed with a coefficient of variation less than 20%. The ELISA method was verified in field and laboratory samples, demonstrating the utility of the validated method. The implementation of a validated extraction and quantitation protocol adds consistency and reliability to field-collected data regarding transgenic products. PMID:25059137

Strain, Katherine E; Whiting, Sara A; Lydy, Michael J

2014-10-01

262

Convergence results for general linear methods on singular perturbation problems  

Microsoft Academic Search

Many numerical methods used to solve Ordinary Differential Equations, or Differential Algebraic Equations can be written as general linear methods. The B-convergence results for general linear methods are for algebraically stable methods, and therefore useless for nearly A-stable methods. The purpose of this paper is to show convergence for singular perturbation problems for the class of general linear methods without

Stefan Schneider

1993-01-01

263

Quantitative proteomics: assessing the spectrum of in-gel protein detection methods  

PubMed Central

Proteomics research relies heavily on visualization methods for detection of proteins separated by polyacrylamide gel electrophoresis. Commonly used staining approaches involve colorimetric dyes such as Coomassie Brilliant Blue, fluorescent dyes including Sypro Ruby, newly developed reactive fluorophores, as well as a plethora of others. The most desired characteristic in selecting one stain over another is sensitivity, but this is far from the only important parameter. This review evaluates protein detection methods in terms of their quantitative attributes, including limit of detection (i.e., sensitivity), linear dynamic range, inter-protein variability, capacity for spot detection after 2D gel electrophoresis, and compatibility with subsequent mass spectrometric analyses. Unfortunately, many of these quantitative criteria are not routinely or consistently addressed by most of the studies published to date. We would urge more rigorous routine characterization of stains and detection methodologies as a critical approach to systematically improving these critically important tools for quantitative proteomics. In addition, substantial improvements in detection technology, particularly over the last decade or so, emphasize the need to consider renewed characterization of existing stains; the quantitative stains we need, or at least the chemistries required for their future development, may well already exist.

Gauci, Victoria J.; Wright, Elise P.

2010-01-01

264

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

265

[Comparative study of the quantitative determination of kanamycin sulfate in ophthalmic films with a collagen base by microbiological and chemical methods].  

PubMed

The results of the comparative study on microbiological and chemical quantitative determination of kanamycin sulfate in the ophthalmic films with the collagen base are presented. The intraocular films prepared with the use of 1 per cent collagen solution contain dexamethasone and kanamycin. The agar diffusion method with Bacillus pumilus NCTC 8241 as the test microbe and the photocolorimetric method based on estimation of the optical density of the colored compound formed after acid hydrolysis of kanamycin with orcinol and ferric chloride were used for the quantitative determination of kanamycin. The results of the quantitative determinations of kanamycin in the films with the two methods did not differ significantly. However, the error of the microbiological method was +/- 3,75 per cent, whereas that of the chemical method was +/- 1.23 per cent or approximately 3 times lower. The time of the analysis decreased from 24 to 1.5-2 h. Moreover, the chemical method is simple and readily reproducible. PMID:6524895

Ivanova, L A; Abramova, T A; Levkovich, N M; Okhotnikova, V F; Kartashov, V S

1984-12-01

266

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

267

Multi-Window Classical Least Squares Multivariate Calibration Methods for Quantitative ICP-AES Analyses  

SciTech Connect

The advent of inductively coupled plasma-atomic emission spectrometers (ICP-AES) equipped with charge-coupled-device (CCD) detector arrays allows the application of multivariate calibration methods to the quantitative analysis of spectral data. We have applied classical least squares (CLS) methods to the analysis of a variety of samples containing up to 12 elements plus an internal standard. The elements included in the calibration models were Ag, Al, As, Au, Cd, Cr, Cu, Fe, Ni, Pb, Pd, and Se. By performing the CLS analysis separately in each of 46 spectral windows and by pooling the CLS concentration results for each element in all windows in a statistically efficient manner, we have been able to significantly improve the accuracy and precision of the ICP-AES analyses relative to the univariate and single-window multivariate methods supplied with the spectrometer. This new multi-window CLS (MWCLS) approach simplifies the analyses by providing a single concentration determination for each element from all spectral windows. Thus, the analyst does not have to perform the tedious task of reviewing the results from each window in an attempt to decide the correct value among discrepant analyses in one or more windows for each element. Furthermore, it is not necessary to construct a spectral correction model for each window prior to calibration and analysis: When one or more interfering elements was present, the new MWCLS method was able to reduce prediction errors for a selected analyte by more than 2 orders of magnitude compared to the worst case single-window multivariate and univariate predictions. The MWCLS detection limits in the presence of multiple interferences are 15 rig/g (i.e., 15 ppb) or better for each element. In addition, errors with the new method are only slightly inflated when only a single target element is included in the calibration (i.e., knowledge of all other elements is excluded during calibration). The MWCLS method is found to be vastly superior to partial least squares (PLS) in this case of limited numbers of calibration samples.

CHAMBERS,WILLIAM B.; HAALAND,DAVID M.; KEENAN,MICHAEL R.; MELGAARD,DAVID K.

1999-10-01

268

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

269

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

270

Quantitative phase detection with expanded principal component analysis method on interferometric microscopic cytometer  

NASA Astrophysics Data System (ADS)

Based on interferometric microscopy, we develop a quantitative interferometric microscopic cytometer with expanded principal component analysis (PCA) phase retrieval method to obtain phase distributions of numerous biological samples with spatial resolution ~1.5 ?m. The expanded PCA method realizes high-speed phase imaging from multiple microscopic interferograms captured by CCD camera when the biological samples are scanned in the field of view. This method is a time-domain algorithm which calculates faster than traditional frequency-domain algorithms and overcomes drawbacks induced by fast Fourier transform. The potential of this phase detecting system for studying biological systems is demonstrated with simulations and phase measurement of red blood cells in experiments.

Wang, Shouyu; Xue, Liang; Li, Hailong; Lai, Jiancheng; Song, Yang; Li, Zhenhua

2014-07-01

271

Sensitive method for quantitation of angiotensin-converting enzyme (ACE) activity in tissue.  

PubMed

A novel sensitive and specific method for the measurement of tissue angiotensin-converting enzyme (ACE) activity utilizing HPLC is described. ACE activity was determined in detergent-extracted canine hearts utilizing the synthetic ACE-specific substrate hippuryl histidyl leucine (HHL), both in the presence and the absence of the site-specific inhibitor captopril. Tissue ACE activity was quantitated from the moles of hippuric acid (HA) formed, in time-fixed assays, utilizing HPLC separation of HA from HHL and UV-spectrophotometry for quantitation of HA as in the standard Cushman and Cheung assay (Cushman DW and Cheung HS, Biochem Pharmacol 20: 1637-1648, 1971). Separation of HA from HHL was performed by reverse phase HPLC on a phenyl silica gel column with an eluent consisting of 20% acetonitrile in 0.1 M aqueous ammonium phosphate buffer, pH 6.8. After the standard liquid/liquid extraction procedure with ethyl acetate, HPLC analysis revealed the presence of unreacted substrate, HHL, in amounts comparable to the product of interest, HA, in the final assay; moreover, the amount of HA formed did not fall completely to zero in the presence of captopril. Regional studies of canine cardiac ACE activity utilizing the HPLC-based assay and the standard assay method showed a significantly higher ACE activity in the right ventricle compared with the left ventricle (2.37 +/- 0.7 vs 1.24 +/- 0.18 mU/g, P < 0.05 [N = 6], respectively) in the HPLC-based assay, but no difference in right and left ventricular ACE activities by the standard assay (0.25 +/- 0.08 vs 0.31 +/- 0.09 mU/g [N = 6], respectively). Kinetic studies utilizing the HPLC-based assay coupled with the use of captopril showed Km (1.34 +/- 0.08 mM) and Vmax (36.8 +/- 11.5 x 10(-10) M/min) values in agreement with those in the literature. Our results demonstrate that the application of HPLC to the standard Cushman and Cheung assay improves the sensitivity and specificity of the standard assay and enables the use of much smaller amounts (approximately 4 vs approximately 400 mg for the Cushman and Cheung assay) of tissue for ACE activity assay. PMID:7503795

Meng, Q C; Balcells, E; Dell'Italia, L; Durand, J; Oparil, S

1995-10-26

272

Quantitative determination of sibutramine in adulterated herbal slimming formulations by TLC-image analysis method.  

PubMed

A simple thin layer chromatographic (TLC)-image analysis method was developed for rapid determination and quantitation of sibutramine hydrochloride (SH) adulterated in herbal slimming products. Chromatographic separation of SH was achieved on a silica gel 60 F(254) TLC plate, using toluene-n-hexane-diethylamine (9:1:0.3, v/v/v) as the mobile phase and Dragendorff reagent as spot detection. Image analysis of the scanned TLC plate was performed to quantify the amount of SH. The polynomial regression data for the calibration plots showed good linear relationship in the concentration range of 1-6 ?g/spot. The limits of detection and quantitation were 190 and 634 ng/spot, respectively. The method gave satisfactory specificity, precision, accuracy, robustness and was applied for determination of SH in herbal formulations. The contents of SH in adulterated samples determined by the TLC-image analysis and TLC-densitometry were also compared. PMID:22227151

Phattanawasin, Panadda; Sotanaphun, Uthai; Sukwattanasinit, Tasamaporn; Akkarawaranthorn, Jariya; Kitchaiya, Sarunyaporn

2012-06-10

273

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

274

Quantitative assessment of tear production: A review of methods and utility in dry eye drug discovery  

Microsoft Academic Search

The successful development of a therapeutic agent targeting treatment of dry eye syndrome necessitates the demonstration of\\u000a drug efficacy for both sign and symptom endpoints. As numerous therapeutic strategies incorporate a secretagogue function\\u000a into their overall mechanism of action, the quantitative assessment of tear production serves as a logical endpoint to anchor\\u000a “sign” efficacy. Although several methods including the Schirmer,

Michelle Senchyna; Martin B Wax

2008-01-01

275

RP-HPLC Method for the Quantitation of Glabridin in Yashti-madhu ( Glycyrrhiza glabra )  

Microsoft Academic Search

A reverse phase high performance liquid chromatographic method is developed for the quantitation of glabridin in Glycyrrhiza glabra, using C18 column with acetonitrile-water containing 2% AcOH (70:30) as an eluent. Glabridin is detected by UV absorption at 280 nm\\u000a after separation by the chromatographic system. Good linearity was obtained in the working range of the concentration (0.01–0.1 mg mL?1), with correlation coefficients 0.999.

K. Shanker; A. Fatima; A. S. Negi; V. K. Gupta; M. P. Darokar; M. M. Gupta; S. P. S. Khanuja

2007-01-01

276

Models and methods for quantitative analysis of surface-enhanced Raman spectra.  

PubMed

The quantitative analysis of surface-enhanced Raman spectra using scattering nanoparticles has shown the potential and promising applications in in vivo molecular imaging. The diverse approaches have been used for quantitative analysis of Raman pectra information, which can be categorized as direct classical least squares models, full spectrum multivariate calibration models, selected multivariate calibration models, and latent variable regression (LVR) models. However, the working principle of these methods in the Raman spectra application remains poorly understood and a clear picture of the overall performance of each model is missing. Based on the characteristics of the Raman spectra, in this paper, we first provide the theoretical foundation of the aforementioned commonly used models and show why the LVR models are more suitable for quantitative analysis of the Raman spectra. Then, we demonstrate the fundamental connections and differences between different LVR methods, such as principal component regression, reduced-rank regression, partial least square regression (PLSR), canonical correlation regression, and robust canonical analysis, by comparing their objective functions and constraints.We further prove that PLSR is literally a blend of multivariate calibration and feature extraction model that relates concentrations of nanotags to spectrum intensity. These features (a.k.a. latent variables) satisfy two purposes: the best representation of the predictor matrix and correlation with the response matrix. These illustrations give a new understanding of the traditional PLSR and explain why PLSR exceeds other methods in quantitative analysis of the Raman spectra problem. In the end, all the methods are tested on the Raman spectra datasets with different evaluation criteria to evaluate their performance. PMID:24058035

Li, Shuo; Nyagilo, James O; Dave, Digant P; Gao, Jean

2014-03-01

277

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

278

Quantitative methods for genome-scale analysis of in situ hybridization and correlation with microarray data  

PubMed Central

With the emergence of genome-wide colorimetric in situ hybridization (ISH) data sets such as the Allen Brain Atlas, it is important to understand the relationship between this gene expression modality and those derived from more quantitative based technologies. This study introduces a novel method for standardized relative quantification of colorimetric ISH signal that enables a large-scale cross-platform expression level comparison of ISH with two publicly available microarray brain data sources.

Lee, Chang-Kyu; Sunkin, Susan M; Kuan, Chihchau; Thompson, Carol L; Pathak, Sayan; Ng, Lydia; Lau, Chris; Fischer, Shanna; Mortrud, Marty; Slaughterbeck, Cliff; Jones, Allan; Lein, Ed; Hawrylycz, Michael

2008-01-01

279

A quantitative and standardized robotic method for the evaluation of arm proprioception after stroke.  

PubMed

Stroke often results in both motor and sensory deficits, which may interact in the manifested functional impairment. Proprioception is known to play important roles in the planning and control of limb posture and movement; however, the impact of proprioceptive deficits on motor function has been difficult to elucidate due in part to the qualitative nature of available clinical tests. We present a quantitative and standardized method for evaluating proprioception in tasks directly relevant to those used to assess motor function. Using a robotic manipulandum that exerted controlled displacements of the hand, stroke participants were evaluated, and compared with a control group, in their ability to detect such displacements in a 2-alternative, forced-choice paradigm. A psychometric function parameterized the decision process underlying the detection of the hand displacements. The shape of this function was determined by a signal detection threshold and by the variability of the response about this threshold. Our automatic procedure differentiates between participants with and without proprioceptive deficits and quantifies functional proprioceptive sensation on a magnitude scale that is meaningful for ongoing studies of degraded motor function in comparable horizontal movements. PMID:22256252

Simo, Lucia S; Ghez, Claude; Botzer, Lior; Scheidt, Robert A

2011-01-01

280

Variety of geologic silhouette shapes distinguishable by multiple rotations method of quantitative shape analysis text  

SciTech Connect

Silhouette shapes are two-dimensional projections of three-dimensional objects such as sand grains, gravel, and fossils. Within-the-margin markings such as chamber boundaries, sutures, or ribs are ignored. Comparisons between populations of objects from similar and differential origins (i.e., environments, species or genera, growth series, etc) is aided by quantifying the shapes. The Multiple Rotations Method (MRM) uses a variation of ''eigenshapes'', which is capable of distinguishing most of the subtle variations that the ''trained eye'' can detect. With a video-digitizer and microcomputer, MRM is fast, more accurate, and more objective than the human eye. The resulting shape descriptors comprise 5 or 6 numbers per object that can be stored and retrieved to compare with similar descriptions of other objects. The original-shape outlines can be reconstituted sufficiently for gross recognition from these few numerical descriptors. Thus, a semi-automated data-retrieval system becomes feasible, with silhouette-shape descriptions as one of several recognition criteria. MRM consists of four ''rotations'': rotation about a center to a comparable orientation; a principal-components rotation to reduce the many original shape descriptors to a few; a VARIMAX orthogonal-factor rotation to achieve simple structure; and a rotation to achieve factor scores on individual objects. A variety of subtly different shapes includes sand grains from several locations, ages, and environments, and fossils of several types. This variety illustrates the feasibility of quantitative comparisons by MRM.

Collins, D.G.; Parks, J.M.

1984-04-01

281

A Quantitative and Standardized Robotic Method for the Evaluation of Arm Proprioception after Stroke  

PubMed Central

Stroke often results in both motor and sensory deficits, which may interact in the manifested functional impairment. Proprioception is known to play important roles in the planning and control of limb posture and movement; however, the impact of proprioceptive deficits on motor function has been difficult to elucidate due in part to the qualitative nature of available clinical tests. We present a quantitative and standardized method for evaluating proprioception in tasks directly relevant to those used to assess motor function. Using a robotic manipulandum that exerted controlled displacements of the hand, stroke participants were evaluated, and compared with a control group, in their ability to detect such displacements in a 2-alternative, forced-choice paradigm. A psychometric function parameterized the decision process underlying the detection of the hand displacements. The shape of this function was determined by a signal detection threshold and by the variability of the response about this threshold. Our automatic procedure differentiates between participants with and without proprioceptive deficits and quantifies functional proprioceptive sensation on a magnitude scale that is meaningful for ongoing studies of degraded motor function in comparable horizontal movements.

Simo, Lucia S.; Ghez, Claude; Botzer, Lior; Scheidt, Robert A.

2014-01-01

282

A New Quantitative Method for the Non-Invasive Documentation of Morphological Damage in Paintings Using RTI Surface Normals.  

PubMed

In this paper we propose a reliable surface imaging method for the non-invasive detection of morphological changes in paintings. Usually, the evaluation and quantification of changes and defects results mostly from an optical and subjective assessment, through the comparison of the previous and subsequent state of conservation and by means of condition reports. Using quantitative Reflectance Transformation Imaging (RTI) we obtain detailed information on the geometry and morphology of the painting surface with a fast, precise and non-invasive method. Accurate and quantitative measurements of deterioration were acquired after the painting experienced artificial damage. Morphological changes were documented using normal vector images while the intensity map succeeded in highlighting, quantifying and describing the physical changes. We estimate that the technique can detect a morphological damage slightly smaller than 0.3 mm, which would be difficult to detect with the eye, considering the painting size. This non-invasive tool could be very useful, for example, to examine paintings and artwork before they travel on loan or during a restoration. The method lends itself to automated analysis of large images and datasets. Quantitative RTI thus eases the transition of extending human vision into the realm of measuring change over time. PMID:25010699

Manfredi, Marcello; Bearman, Greg; Williamson, Greg; Kronkright, Dale; Doehne, Eric; Jacobs, Megan; Marengo, Emilio

2014-01-01

283

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

284

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

285

Test Characteristics of Urinary Biomarkers Depend on Quantitation Method in Acute Kidney Injury  

PubMed Central

The concentration of urine influences the concentration of urinary biomarkers of AKI. Whether normalization to urinary creatinine concentration, as commonly performed to quantitate albuminuria, is the best method to account for variations in urinary biomarker concentration among patients in the intensive care unit is unknown. Here, we compared the diagnostic and prognostic performance of three methods of biomarker quantitation: absolute concentration, biomarker normalized to urinary creatinine concentration, and biomarker excretion rate. We measured urinary concentrations of alkaline phosphatase, ?-glutamyl transpeptidase, cystatin C, neutrophil gelatinase–associated lipocalin, kidney injury molecule–1, and IL-18 in 528 patients on admission and after 12 and 24 hours. Absolute concentration best diagnosed AKI on admission, but normalized concentrations best predicted death, dialysis, or subsequent development of AKI. Excretion rate on admission did not diagnose or predict outcomes better than either absolute or normalized concentration. Estimated 24-hour biomarker excretion associated with AKI severity, and for neutrophil gelatinase–associated lipocalin and cystatin C, with poorer survival. In summary, normalization to urinary creatinine concentration improves the prediction of incipient AKI and outcome but provides no advantage in diagnosing established AKI. The ideal method for quantitating biomarkers of urinary AKI depends on the outcome of interest.

Md Ralib, Azrina; Pickering, John W.; Shaw, Geoffrey M.; Devarajan, Prasad; Edelstein, Charles L.; Bonventre, Joseph V.

2012-01-01

286

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

287

A field- and laboratory-based quantitative analysis of alluvium: Relating analytical results to TIMS data  

NASA Technical Reports Server (NTRS)

Thermal Infrared Multispectral Scanner (TIMS) data were acquired over the McDowell Mountains northeast of Scottsdale, Arizona during August 1994. The raw data were processed to emphasize lithologic differences using a decorrelation stretch and assigning bands 5, 3, and 1 to red, green, and blue, respectively. Processed data of alluvium flanking the mountains exhibit moderate color variation. The objective of this study was to determine, using a quantitative approach, what environmental variable(s), in the absence of bedrock, is/are responsible for influencing the spectral properties of the desert alluvial surface.

Wenrich, Melissa L.; Hamilton, Victoria E.; Christensen, Philip R.

1995-01-01

288

[Quantitative identification Qijudihuang pill by integrating overall information method based on parallel five wavelength high performance liquid chromatographic fingerprints].  

PubMed

Parallel five wavelength high performance liquid chromatographic (PFW-HPLC) fingerprints of Qijudihuang Pill (QJDHP) were established. The quality of QJDHP was identified based on systematically quantified fingerprint method (SQFM) by the integrating overall information method (IOIM). The chromatographic fingerprints (CFPs) were developed by reversed-phase (RP) HPLC, in which 51, 49, 52, 49 and 47 co-existing peaks were marked at 203, 228, 265, 280 and 326 nm, respectively, by choosing paeonol (POL) peak as the reference peak. The natural weighted method (NWM), average method (AM) and project parameter method (PPM) were separately used to integrate the different chemical qualitative and quantitative information from different PFW-HPLC fingerprints. By using the IOIM based on SQFM, the qualities of DMS2, DMS4, DMS5 and DMS6 (2 grade) were identified as very good; DMS1, DMS3 and DMS10, DMS11 (3 grade) as good; DMS9 (4 grade) as fine; DMS7 (6 grade) as common, in which DMS8 was regarded as moderate (5 grade) by the AM and as common (6 grade) by PPM. The qualities of 11 batches of QJDHP were identified, in which 8 batches were above the good level, 1 batch was fine level and two batches were common level. Therefore AM was the most accurate and simple method to integrate all the information. The experimental results indicated that the IOIM based on the PFW-HPLC can be effectively used to identify qualitatively and quantitatively the quality of Chinese traditional medicine from overall information, which is a reliable method and also can quantitatively simplify the bountiful information of HPLC-DAD (diode array detection) fingerprints. In fact, the comprehensive identification ability of IOIM is the most reliable and effective one. PMID:21171286

Sun, Guoxiang; Wu, Bo; Bi, Kaishun

2010-09-01

289

Researchers' views on return of incidental genomic research results: qualitative and quantitative findings  

PubMed Central

Purpose Comprehensive genomic analysis including exome and genome sequencing is increasingly being utilized in research studies, leading to the generation of incidental genetic findings. It is unclear how researchers plan to deal with incidental genetic findings. Methods We conducted a survey of the practices and attitudes of 234 members of the US genetic research community and performed qualitative semistructured interviews with 28 genomic researchers to understand their views and experiences with incidental genetic research findings. Results We found that 12% of the researchers had returned incidental genetic findings, and an additional 28% planned to do so. A large majority of researchers (95%) believe that incidental findings for highly penetrant disorders with immediate medical implications should be offered to research participants. However, there was no consensus on returning incidental results for other conditions varying in penetrance and medical actionability. Researchers raised concerns that the return of incidental findings would impose significant burdens on research and could potentially have deleterious effects on research participants if not performed well. Researchers identified assistance needed to enable effective, accurate return of incidental findings. Conclusion The majority of the researchers believe that research participants should have the option to receive at least some incidental genetic research results.

Klitzman, Robert; Appelbaum, Paul S.; Fyer, Abby; Martinez, Josue; Buquez, Brigitte; Wynn, Julia; Waldman, Cameron R.; Phelan, Jo; Parens, Erik; Chung, Wendy K.

2013-01-01

290

Post-reconstruction non-local means filtering methods using CT side information for quantitative SPECT.  

PubMed

Quantitative SPECT techniques are important for many applications including internal emitter therapy dosimetry where accurate estimation of total target activity and activity distribution within targets are both potentially important for dose–response evaluations. We investigated non-local means (NLM) post-reconstruction filtering for accurate I-131 SPECT estimation of both total target activity and the 3D activity distribution. We first investigated activity estimation versus number of ordered-subsets expectation–maximization (OSEM) iterations. We performed simulations using the XCAT phantom with tumors containing a uniform and a non-uniform activity distribution, and measured the recovery coefficient (RC) and the root mean squared error (RMSE) to quantify total target activity and activity distribution, respectively. We observed that using more OSEM iterations is essential for accurate estimation of RC, but may or may not improve RMSE. We then investigated various post-reconstruction filtering methods to suppress noise at high iteration while preserving image details so that both RC and RMSE can be improved. Recently, NLM filtering methods have shown promising results for noise reduction. Moreover, NLM methods using high-quality side information can improve image quality further. We investigated several NLM methods with and without CT side information for I-131 SPECT imaging and compared them to conventional Gaussian filtering and to unfiltered methods. We studied four different ways of incorporating CT information in the NLM methods: two known (NLM CT-B and NLM CT-M) and two newly considered (NLM CT-S and NLM CT-H). We also evaluated the robustness of NLM filtering using CT information to erroneous CT. NLM CT-S and NLM CT-H yielded comparable RC values to unfiltered images while substantially reducing RMSE. NLM CT-S achieved ?2.7 to 2.6% increase of RC compared to no filtering and NLM CT-H yielded up to 6% decrease in RC while other methods yielded lower RCs than them: Gaussian filtering (up to 11.8% decrease in RC), NLM method without CT (up to 9.5% decrease in RC), and NLM CT-M and NLM CT-B (up to 19.4% decrease in RC). NLM CT-S and NLM CT-H achieved 8.2 to 33.9% and ?0.9 to 36% decreased RMSE on tumors compared to no filtering respectively while other methods yielded less reduced or increased RMSE: Gaussian filtering (up to 7.9% increase in RMSE), NLM method without CT (up to 18.3% increase in RMSE), and NLM CT-M and NLM CT-B (up to 31.5% increase in RMSE). NLM CT-S and NLM CT-H also yielded images with tumor shapes that better-matched the true shapes than other methods. All NLM methods using CT information were robust to small misregistration between SPECT and CT, but NLM CT-S and NLM CT-H were more sensitive than NLM CT-M and NLM CT-B to missing CT information. PMID:23956327

Chun, Se Young; Fessler, Jeffrey A; Dewaraja, Yuni K

2013-09-01

291

Post-reconstruction non-local means filtering methods using CT side information for quantitative SPECT  

NASA Astrophysics Data System (ADS)

Quantitative SPECT techniques are important for many applications including internal emitter therapy dosimetry where accurate estimation of total target activity and activity distribution within targets are both potentially important for dose-response evaluations. We investigated non-local means (NLM) post-reconstruction filtering for accurate I-131 SPECT estimation of both total target activity and the 3D activity distribution. We first investigated activity estimation versus number of ordered-subsets expectation-maximization (OSEM) iterations. We performed simulations using the XCAT phantom with tumors containing a uniform and a non-uniform activity distribution, and measured the recovery coefficient (RC) and the root mean squared error (RMSE) to quantify total target activity and activity distribution, respectively. We observed that using more OSEM iterations is essential for accurate estimation of RC, but may or may not improve RMSE. We then investigated various post-reconstruction filtering methods to suppress noise at high iteration while preserving image details so that both RC and RMSE can be improved. Recently, NLM filtering methods have shown promising results for noise reduction. Moreover, NLM methods using high-quality side information can improve image quality further. We investigated several NLM methods with and without CT side information for I-131 SPECT imaging and compared them to conventional Gaussian filtering and to unfiltered methods. We studied four different ways of incorporating CT information in the NLM methods: two known (NLM CT-B and NLM CT-M) and two newly considered (NLM CT-S and NLM CT-H). We also evaluated the robustness of NLM filtering using CT information to erroneous CT. NLM CT-S and NLM CT-H yielded comparable RC values to unfiltered images while substantially reducing RMSE. NLM CT-S achieved -2.7 to 2.6% increase of RC compared to no filtering and NLM CT-H yielded up to 6% decrease in RC while other methods yielded lower RCs than them: Gaussian filtering (up to 11.8% decrease in RC), NLM method without CT (up to 9.5% decrease in RC), and NLM CT-M and NLM CT-B (up to 19.4% decrease in RC). NLM CT-S and NLM CT-H achieved 8.2 to 33.9% and -0.9 to 36% decreased RMSE on tumors compared to no filtering respectively while other methods yielded less reduced or increased RMSE: Gaussian filtering (up to 7.9% increase in RMSE), NLM method without CT (up to 18.3% increase in RMSE), and NLM CT-M and NLM CT-B (up to 31.5% increase in RMSE). NLM CT-S and NLM CT-H also yielded images with tumor shapes that better-matched the true shapes than other methods. All NLM methods using CT information were robust to small misregistration between SPECT and CT, but NLM CT-S and NLM CT-H were more sensitive than NLM CT-M and NLM CT-B to missing CT information.

Chun, Se Young; Fessler, Jeffrey A.; Dewaraja, Yuni K.

2013-09-01

292

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

PubMed Central

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 with a minimized 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 the bacteria Shewanella oneidensis, and mouse plasma, as well as 18O labeling of such complex protein mixtures, which validated the application of this method for differential proteomic measurements. This approach is simple, reproducible, cost effective, rapid, and thus well-suited for automation.

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

2009-01-01

293

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

294

Methods for Peptide and Protein Quantitation by Liquid Chromatography-Multiple Reaction Monitoring Mass Spectrometry*  

PubMed Central

Liquid chromatography-multiple reaction monitoring mass spectrometry of peptides using stable isotope dilution (SID) provides a powerful tool for targeted protein quantitation. However, the high cost of labeled peptide standards for SID poses an obstacle to multiple reaction monitoring studies. We compared SID to a labeled reference peptide (LRP) method, which uses a single labeled peptide as a reference standard for all measured peptides, and a label-free (LF) approach, in which quantitation is based on analysis of un-normalized peak areas for detected MRM transitions. We analyzed peptides from the Escherichia coli proteins alkaline phosphatase and ?-galactosidase spiked into lysates from human colon adenocarcinoma RKO cells. We also analyzed liquid chromatography-multiple reaction monitoring mass spectrometry data from a recently published interlaboratory study by the National Cancer Institute Clinical Proteomic Technology Assessment for Cancer network (Addona et al. (2009) Nat. Biotechnol. 27: 633–641), in which unlabeled and isotopically labeled synthetic peptides or their corresponding proteins were spiked into human plasma. SID displayed the highest correlation coefficients and lowest coefficient of variation in regression analyses of both peptide and protein spike studies. In protein spike experiments, median coefficient of variation values were about 10% for SID and 20–30% for LRP and LF methods. Power calculations indicated that differences in measurement error between the methods have much less impact on measured protein expression differences than biological variation. All three methods detected significant (p < 0.05) differential expression of three endogenous proteins in a test set of 10 pairs of human lung tumor and control tissues. Further, the LRP and LF methods both detected significant differences (p < 0.05) in levels of seven biomarker candidates between tumors and controls in the same set of lung tissue samples. The data indicate that the LRP and LF methods provide cost-effective alternatives to SID for many quantitative liquid chromatography-multiple reaction monitoring mass spectrometry applications.

Zhang, Haixia; Liu, Qinfeng; Zimmerman, Lisa J.; Ham, Amy-Joan L.; Slebos, Robbert J. C.; Rahman, Jamshedur; Kikuchi, Takefume; Massion, Pierre P.; Carbone, David P.; Billheimer, Dean; Liebler, Daniel C.

2011-01-01

295

Nuclear Medicine and Imaging Research. Instrumentation and Quantitative Methods of Evaluation. Progress Report, January 15, 1984-January 14, 1985.  

National Technical Information Service (NTIS)

This program addresses problems involving the basic science and technology of radioactive tracer methods as they relate to nuclear medicine and imaging. The broad goal is to develop new instruments and methods for image formation, processing, quantitation...

R. N. Beck M. D. Cooper

1984-01-01

296

Detection of human herpesvirus 8 by quantitative polymerase chain reaction: development and standardisation of methods  

PubMed Central

Background Human herpesvirus 8 (HHV-8), the aetiological agent of Kaposi’s sarcoma (KS), multicentric Castleman’s disease (MCD), and primary effusion lymphoma (PEL) is rare in Australia, but endemic in Sub-Saharan Africa, parts of South-east Asia and Oceania. While the treatment of external KS lesions can be monitored by clinical observation, the internal lesions of KS, MCD and PEL require extensive and expensive internal imaging, or autopsy. In patients with MCD and PEL, if HHV-8 viraemia is not reduced quickly, ~50% die within 24?months. HHV-8 qPCR is a valuable tool for monitoring HHV-8 viraemia, but is not available in many parts of the world, including those with high prevalence of KS and HHV-8. Methods A new molecular facility with stringent three-phase workflow was established, adhering to NPAAC and CLSI guidelines. Three fully validated quantitative assays were developed: two for detection and quantification of HHV-8; one for GAPDH, necessary for normalisation of viral loads in tissue and peripheral blood. Results The HHV-8 ORF73 and ORF26 qPCR assays were 100% specific. All qPCR assays, displayed a broad dynamic range (102 to 1010 copies/?L TE Buffer) with a limit of detection of 4.85x103, 5.61x102, and 2.59x102 copies/?L TE Buffer and a limit of quantification of 4.85x103, 3.01x102, and 1.38x102 copies/?L TE Buffer for HHV-8 ORF73, HHV-8 ORF26, and GAPDH respectively. The assays were tested on a panel of 35 KS biopsies from Queensland. All were HHV-8 qPCR positive with average viral load of 2.96x105 HHV-8 copies/?L DNA extract (range: 4.37x103 to 1.47x106 copies/?L DNA extract): When normalised these equate to an average viral load of 2.44x104 HHV-8 copies/103 cells (range: 2.20x102 to 7.38x105 HHV-8 copies/103 cells). Conclusions These are the first fully optimised, validated and MIQE compliant HHV-8 qPCR assays established in Australia. They worked well for qualitative detection of HHV-8 in archival tissue, and are well-suited for quantitative detection in whole blood. They are now available for research, for clinical diagnosis of HHV-8 infection, and for monitoring treatment efficacy.

2012-01-01

297

QUANTITATIVE EVALUATION OF ASR DETERIORATION LEVEL BASED ON SURVEY RESULT OF EXISTING STRUCTURE  

NASA Astrophysics Data System (ADS)

The relationship between the crack density and compressive strength of the core cylinder, which drilled from actual structure damaged by ASR, was investigated. The results showed that even if the crack density increased about 1.0m/m2, the compressive strength decreased only 2N/mm2. Then, the new method for estimating future compressive strength using the accumulation crack density in the current is proposed. In addition, the declining tendency of compressive strength by the ASR expansion was early proportional to the expansion, and it was examined on the reason for becoming gentle curve afterwards. As a technique, the detailed observation of ASR crack which arose in the loading test for the plane was carried out, after cylindrical specimen for test was cut in longitudinal direction. As the result, It was proven that the proportion in which line of rupture overlaps with the ASR crack was low, and the load is resisted by interlocking between coarse aggregate and concrete in the crack plane.

Kawashima, Yasushi; Kosa, Kenji; Matsumoto, Shigeru; Miura, Masatsugu

298

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.

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

2013-01-01

299

University of Miami Neuro-Spinal Index (UMNI): a quantitative method for determining spinal cord function.  

PubMed

At the University of Miami we have developed a quantitative scale for assessing spinal cord function and have utilised this scale in evaluating acute spinal cord injury patients over the last year. The assessments are performed by specially trained physical therapists who see the patients within an hour of their arrival at the hospital emergency room. The University of Miami Neuro-Spinal Index (UMNI) utilises standard methods of spinal cord functional assessment to produce a numerical value which can be used to determine change in a patient's status, even when the change is minimal. The UMNI yields both a sensory and motor scale which can be dealt with individually or in combination. This scale permits one to compare across patients, quantitative changes in status regardless of the initial of injury. The UMNI is sensitive to small changes. We are in the process of determining the UMNI's potential as a predictor of outcome. PMID:7443286

Klose, K J; Green, B A; Smith, R S; Adkins, R H; MacDonald, A M

1980-10-01

300

Time to Update and Quantitative Changes in the Results of Cochrane Pregnancy and Childbirth Reviews  

PubMed Central

Background The recommended interval between updates for systematic reviews included in The Cochrane Library is 2 years. However, it is unclear whether this interval is always appropriate. Whereas excessive updating wastes time and resources, insufficient updating allows out-of-date or incomplete evidence to guide clinical decision-making. We set out to determine, for Cochrane pregnancy and childbirth reviews, the frequency of updates, factors associated with updating, and whether updating frequency was appropriate. Methodology/Principal Findings Cochrane pregnancy and childbirth reviews published in Issue 3, 2007 of the Cochrane Database of Systematic Reviews were retrieved, and data were collected from their original and updated versions. Quantitative changes were determined for one of the primary outcomes (mortality, or the outcome of greatest clinical significance). Potential factors associated with time to update were assessed using the Cox proportional hazard model. Among the 101 reviews in our final sample, the median time before the first update was 3.3 years (95% CI 2.7–3.8). Only 32.7% had been updated within the recommended interval of 2 years. In 75.3% (76/101), a median of 3 new trials with a median of 576 additional participants were included in the updated versions. There were quantitative changes in 71% of the reviews that included new trials (54/76): the median change in effect size was 18.2%, and the median change in 95% CI width was 30.8%. Statistical significance changed in 18.5% (10/54) of these reviews, but conclusions were revised in only 3.7% (2/54). A shorter time to update was associated with the same original review team at updating. Conclusions/Significance Most reviews were updated less frequently than recommended by Cochrane policy, but few updates had revised conclusions. Prescribed time to update should be reconsidered to support improved decision-making while making efficient use of limited resources.

Jaidee, Wanlop; Moher, David; Laopaiboon, Malinee

2010-01-01

301

Characterization of working iron Fischer-Tropsch catalysts using quantitative diffraction methods  

Microsoft Academic Search

This study presents the results of the ex-situ characterization of working iron Fischer-Tropsch synthesis (F-TS) catalysts, reacted hundreds of hours at elevated pressures, using a new quantitative x-ray diffraction analytical methodology. Compositions, iron phase structures, and phase particle morphologies were determined and correlated with the observed reaction kinetics. Conclusions were drawn about the character of each catalyst in its most

Linda Denise Mansker

1999-01-01

302

Development and Application of Quantitative Detection Method for Viral Hemorrhagic Septicemia Virus (VHSV) Genogroup IVa  

PubMed Central

Viral hemorrhagic septicemia virus (VHSV) is a problematic pathogen in olive flounder (Paralichthys olivaceus) aquaculture farms in Korea. Thus, it is necessary to develop a rapid and accurate diagnostic method to detect this virus. We developed a quantitative RT-PCR (qRT-PCR) method based on the nucleocapsid (N) gene sequence of Korean VHSV isolate (Genogroup IVa). The slope and R2 values of the primer set developed in this study were ?0.2928 (96% efficiency) and 0.9979, respectively. Its comparison with viral infectivity calculated by traditional quantifying method (TCID50) showed a similar pattern of kinetic changes in vitro and in vivo. The qRT-PCR method reduced detection time compared to that of TCID50, making it a very useful tool for VHSV diagnosis.

Kim, Jong-Oh; Kim, Wi-Sik; Kim, Si-Woo; Han, Hyun-Ja; Kim, Jin Woo; Park, Myoung Ae; Oh, Myung-Joo

2014-01-01

303

Quantitative determination of pertechnetate by electrochemical methods. Electrochemistry of technetium radiopharmaceutical analogs  

SciTech Connect

Electroanalytical methods are described for obtaining quantitative information about pertechnetate in various matrices and qualitative information about analogs to commercially used /sup 99m/Tc skeletal imaging agents. An anodic stripping voltammetry method for determining pertechnetate is described that addresses the problem of multiple asymmetrical stripping waves occurring at solid electrodes. Lower detection limits are needed however, for determining pertechnetate in two matrices of specific interest, i.e., /sup 99/Mo//sup 99m/Tc generator eluents and environmental samples. A detailed discussion of a search for a well behaved pertechnetate reduction wave is followed by a description of the liquid chromatography/reductive electrochemical detection (LCEC) method developed for determining pertechnetate. The development of electroanalytical methods suitable for characterizing technetium methylene diphosphonate and technetium hydroxyethylidene reaction mixtures prepared by reduction of pertechnetate with NaBH/sub 4/ is presented.

Lewis, J.Y.

1983-01-01

304

[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

305

A quantitative GC-MS method for three major polyamines in postmortem brain cortex.  

PubMed

A quantitative method for putrescine (PUT), spermidine (SPD) and spermine (SPM) in homogenized postmortem human brain tissue is described that employs a novel, simple and rapid extractive derivatization with ethylchloroformate and trifluoroacetylation. These amines are metabolites of ornithine and are metabolically interconvertible in mammals. The method was developed to support an ongoing epidemiological study correlating these amines with the frequency of suicide. The isolation methodology is robust and requires less work and time than many previous methods. Analysis is by conventional electron ionization GC-MS with selected ion monitoring using a stable isotope-labeled analog for PUT and a chemical analog for SPD and SPM as internal standards. The time required for chromatographic analysis, about 20 min, is determined by the wide range of the relative volatilities of the derivatized polyamines. The method allows the quantitation of PUT down to 10 ng/g and SPD and SPM down to 100 and 1000 ng/g, respectively of wet tissue. PMID:19514045

Chen, Gary G; Turecki, Gustavo; Mamer, Orval A

2009-08-01

306

A quantitative method for the evaluation of three-dimensional structure of temporal bone pneumatization  

PubMed Central

Temporal bone pneumatization has been included in lists of characters used in phylogenetic analyses of human evolution. While studies suggest that the extent of pneumatization has decreased over the course of human evolution, little is known about the processes underlying these changes or their significance. In short, reasons for the observed reduction and the potential reorganization within pneumatized spaces are unknown. Technological limitations have limited previous analyses of pneumatization in extant and fossil species to qualitative observations of the extent of temporal bone pneumatization. In this paper, we introduce a novel application of quantitative methods developed for the study of trabecular bone to the analysis of pneumatized spaces of the temporal bone. This method utilizes high-resolution X-ray computed tomography (HRXCT) images and quantitative software to estimate three-dimensional parameters (bone volume fractions, anisotropy, and trabecular thickness) of bone structure within defined units of pneumatized spaces. We apply this approach in an analysis of temporal bones of diverse but related primate species, Gorilla gorilla, Pan troglodytes, Homo sapiens, and Papio hamadryas anubis, to illustrate the potential of these methods. In demonstrating the utility of these methods, we show that there are interspecific differences in the bone structure of pneumatized spaces, perhaps reflecting changes in the localized growth dynamics, location of muscle attachments, encephalization, or basicranial flexion.

Hill, Cheryl A.; Richtsmeier, Joan T.

2010-01-01

307

QDMR: a quantitative method for identification of differentially methylated regions by entropy  

PubMed Central

DNA methylation plays critical roles in transcriptional regulation and chromatin remodeling. Differentially methylated regions (DMRs) have important implications for development, aging and diseases. Therefore, genome-wide mapping of DMRs across various temporal and spatial methylomes is important in revealing the impact of epigenetic modifications on heritable phenotypic variation. We present a quantitative approach, quantitative differentially methylated regions (QDMRs), to quantify methylation difference and identify DMRs from genome-wide methylation profiles by adapting Shannon entropy. QDMR was applied to synthetic methylation patterns and methylation profiles detected by methylated DNA immunoprecipitation microarray (MeDIP-chip) in human tissues/cells. This approach can give a reasonable quantitative measure of methylation difference across multiple samples. Then DMR threshold was determined from methylation probability model. Using this threshold, QDMR identified 10?651 tissue DMRs which are related to the genes enriched for cell differentiation, including 4740 DMRs not identified by the method developed by Rakyan et al. QDMR can also measure the sample specificity of each DMR. Finally, the application to methylation profiles detected by reduced representation bisulphite sequencing (RRBS) in mouse showed the platform-free and species-free nature of QDMR. This approach provides an effective tool for the high-throughput identification of potential functional regions involved in epigenetic regulation.

Zhang, Yan; Liu, Hongbo; Lv, Jie; Xiao, Xue; Zhu, Jiang; Liu, Xiaojuan; Su, Jianzhong; Li, Xia; Wu, Qiong; Wang, Fang; Cui, Ying

2011-01-01

308

Quantitative Community Fingerprinting Methods for Estimating the Abundance of Operational Taxonomic Units in Natural Microbial Communities?  

PubMed Central

Molecular fingerprinting techniques offer great promise for analyzing changes in microbial community structure, especially when dealing with large number of samples. However, a serious limitation has been the lack of quantification offered by such techniques since the relative abundances of the identified operational taxonomic units (OTUs) in the original samples are not measured. A quantitative fingerprinting approach designated “qfingerprinting” is proposed here. This method involves serial dilutions of the sample of interest and further systematic fingerprinting of all dilution series. Using the ultimate dilutions for which OTU are still PCR amplifiable and taking into account peak size inaccuracy and peak reproducibility, the relative abundance of each OTU is then simultaneously determined over a scale spanning several orders of magnitude. The approach was illustrated by using a quantitative version of automated ribosomal intergenic spacer analysis (ARISA), here called qARISA. After validating the concept with a synthetic mixture of known DNA targets, qfingerprinting was applied to well-studied marine sediment samples to examine specific changes in OTU abundance associated with sediment depth. The new strategy represents a major advance for the detailed quantitative description of specific OTUs within complex communities. Further ecological applications of the new strategy are also proposed.

Ramette, Alban

2009-01-01

309

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, J.T.; Kunz, W.E.; Atencio, J.D.

1982-03-31

310

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

311

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

312

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.

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

2012-01-01

313

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

PubMed

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 identified by GC. The reliability of the analytical results was considerably improved by the use of this procedure: several unidentified disaccharides and trisaccharides were detected, and their presence was taken into account in the quantification. PMID:15628134

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

2004-12-01

314

Comparison of different approaches for evaluation of the detection and quantitation limits of a purity method: a case study using a capillary isoelectrofocusing method for a monoclonal antibody.  

PubMed

Several different techniques suggested by the International Conference on Harmonization (ICH) Q2R1 guideline were used to assess the signal and concentration at the limit of detection (LOD) and limit of quantitation (LOQ) for a purity method. These approaches were exemplified with a capillary isoelectrofocusing (cIEF) method, which has been developed to quantify the distribution of the charge isoforms of a monoclonal antibody. The charge isoforms are the result of incomplete posttranslational processing of C-terminal lysine residues of the heavy chain by carboxypeptidase. Results showed no significant discrepancy between LOD/LOQ obtained by the different techniques. Validation experiments corroborated the calculated LOQ. The results indicate that any single technique can provide meaningful values for the LOD and LOQ. Finally, important points to consider when applying these techniques to purity methods are discussed. PMID:18996077

Apostol, Izydor; Miller, Karen J; Ratto, Joseph; Kelner, Drew N

2009-02-01

315

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

316

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

SciTech Connect

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.

Grossman, S.J. (Merck Sharp Dohme Research Laboratories, West Point, PA (USA))

1990-11-01

317

A quantitative solid-state Raman spectroscopic method for control of fungicides.  

PubMed

A new analytical procedure using solid-state Raman spectroscopy within the THz-region for the quantitative determination of mixtures of different conformations of trifloxystrobin (EE, EZ, ZE and ZZ), tebuconazole (1), and propiconazole (2) as an effective method for the fungicide product quality monitoring programmes and control has been developed and validated. The obtained quantities were controlled independently by the validated hybrid HPLC electrospray ionization (ESI) tandem mass spectrometric (MS) and matrix-assisted laser desorption/ionization (MALDI) MS methods in the condensed phase. The quantitative dependences were obtained on the twenty binary mixtures of the analytes and were further tested on the three trade fungicide products, containing mixtures of trifloxystrobin-tebuconazole and trifloxystrobin-propiconazole, as an emissive concentrate or water soluble granules of the active ingredients. The present methods provided sufficient sensitivity as reflected by the metrologic quantities, evaluating the concentration limit of detection (LOD) and quantification (LOQ), linear limit (LL), measurement accuracy and precision, true quantity value, trueness of measurement and more. PMID:22679621

Ivanova, Bojidarka; Spiteller, Michael

2012-07-21

318

A Comparison of Multivariate and Pre-Processing Methods for Quantitative Laser-Induced Breakdown Spectroscopy of Geologic Samples  

NASA Technical Reports Server (NTRS)

The ChemCam instrument selected for the Curiosity rover is capable of remote laser-induced breakdown spectroscopy (LIBS).[1] We used a remote LIBS instrument similar to ChemCam to analyze 197 geologic slab samples and 32 pressed-powder geostandards. The slab samples are well-characterized and have been used to validate the calibration of previous instruments on Mars missions, including CRISM [2], OMEGA [3], the MER Pancam [4], Mini-TES [5], and Moessbauer [6] instruments and the Phoenix SSI [7]. The resulting dataset was used to compare multivariate methods for quantitative LIBS and to determine the effect of grain size on calculations. Three multivariate methods - partial least squares (PLS), multilayer perceptron artificial neural networks (MLP ANNs) and cascade correlation (CC) ANNs - were used to generate models and extract the quantitative composition of unknown samples. PLS can be used to predict one element (PLS1) or multiple elements (PLS2) at a time, as can the neural network methods. Although MLP and CC ANNs were successful in some cases, PLS generally produced the most accurate and precise results.

Anderson, R. B.; Morris, R. V.; Clegg, S. M.; Bell, J. F., III; Humphries, S. D.; Wiens, R. C.

2011-01-01

319

Sample preparation methods for quantitative detection of DNA by molecular assays and marine biosensors.  

PubMed

The need for quantitative molecular methods is growing in environmental, food, and medical fields but is hindered by low and variable DNA extraction and by co-extraction of PCR inhibitors. DNA extracts from Enterococcus faecium, seawater, and seawater spiked with E. faecium and Vibrio parahaemolyticus were tested by qPCR for target recovery and inhibition. Conventional and novel methods were tested, including Synchronous Coefficient of Drag Alteration (SCODA) and lysis and purification systems used on an automated genetic sensor (the Environmental Sample Processor, ESP). Variable qPCR target recovery and inhibition were measured, significantly affecting target quantification. An aggressive lysis method that utilized chemical, enzymatic, and mechanical disruption enhanced target recovery compared to commercial kit protocols. SCODA purification did not show marked improvement over commercial spin columns. Overall, data suggested a general need to improve sample preparation and to accurately assess and account for DNA recovery and inhibition in qPCR applications. PMID:23790450

Cox, Annie M; Goodwin, Kelly D

2013-08-15

320

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

321

Quantitative comparison of CTIPe model results with ground and space-based observations  

NASA Astrophysics Data System (ADS)

Physical models are valuable tools in the task to understand and forecast complex non-linear systems. Their value has been demonstrated in the past by comparing the output of numerical simulations with reliable observations, analyzing the driving terms in the mathematical equations, and so determine the relative importance of the various physical processes. Over the past 40 years, this methodology has enabled great advances in the scientific knowledge of the complex Sun-Earth system. However, the validation of the dynamics of the best available physics-based models has been far from comprehensive, even though the pathways for atmospheric response to forcing are apparently well understood. Energy input drives temperature and density changes, which in turn drive winds, which in turn drive changes in composition, electrodynamics, and the ionosphere. There has to be consistency in all the basic state parameters, otherwise the foundation of our perception is unfounded. This study aims to quantitatively assess the capability as well as the limitations of the global, three-dimensional, time-dependent, non-linear coupled model of the thermosphere, ionosphere, plasmasphere, and electrodynamics (CTIPe) in specifying and predicting the upper atmosphere neutral and plasma response to changes in external drivers using a comprehensive observational data set from ground and space and, at the same time, advance the understanding of the T-I system dynamics on different spatial and temporal scales. Observations from CHAMP and TIMED-GUVI satellites, ionosondes and Fabry-Perot Interferometers are among the measurements used in these model/data comparisons.

Fedrizzi, M.; Olsen, J. R.; Fuller-Rowell, T. J.; Codrescu, M.

2012-12-01

322

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

323

Quantitative analysis of in situ hybridization methods for the detection of actin gene expression.  

PubMed Central

We have implemented an efficient, quantitative approach for the optimization of in situ hybridization using double-stranded recombinant DNA probes. The model system studied was actin mRNA expression in chicken embryonic muscle cultures. Actin and control (pBR322) probes were nick-translated with p32 labeled nucleotides, hybridized to cells grown on coverslips, and quantitated in a scintillation counter. Cellular RNA retention was monitored via the incorporation of H3-Uridine into RNA prior to cell fixation. Over a thousand samples were analyzed, and among the technical variables examined were the fixation protocol, proteolytic cell pretreatment, the time course of hybridization, saturation kinetics, hybridization efficiency, and effect of probe size on hybridization and network formation. Results have allowed us to develop a reproducible in situ hybridization methodology which is simpler and less destructive to cellular RNA and morphology than other protocols. Moreover, this technique is highly sensitive and efficient in detection of cellular RNAs. Lastly, the rapid quantitative approach used for this analysis is valuable in itself as a potential alternative to filter or solution hybridizations. Images

Lawrence, J B; Singer, R H

1985-01-01

324

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

325

Malignant gliomas: current perspectives in diagnosis, treatment, and early response assessment using advanced quantitative imaging methods  

PubMed Central

Malignant gliomas consist of glioblastomas, anaplastic astrocytomas, anaplastic oligodendrogliomas and anaplastic oligoastrocytomas, and some less common tumors such as anaplastic ependymomas and anaplastic gangliogliomas. Malignant gliomas have high morbidity and mortality. Even with optimal treatment, median survival is only 12–15 months for glioblastomas and 2–5 years for anaplastic gliomas. However, recent advances in imaging and quantitative analysis of image data have led to earlier diagnosis of tumors and tumor response to therapy, providing oncologists with a greater time window for therapy management. In addition, improved understanding of tumor biology, genetics, and resistance mechanisms has enhanced surgical techniques, chemotherapy methods, and radiotherapy administration. After proper diagnosis and institution of appropriate therapy, there is now a vital need for quantitative methods that can sensitively detect malignant glioma response to therapy at early follow-up times, when changes in management of nonresponders can have its greatest effect. Currently, response is largely evaluated by measuring magnetic resonance contrast and size change, but this approach does not take into account the key biologic steps that precede tumor size reduction. Molecular imaging is ideally suited to measuring early response by quantifying cellular metabolism, proliferation, and apoptosis, activities altered early in treatment. We expect that successful integration of quantitative imaging biomarker assessment into the early phase of clinical trials could provide a novel approach for testing new therapies, and importantly, for facilitating patient management, sparing patients from weeks or months of toxicity and ineffective treatment. This review will present an overview of epidemiology, molecular pathogenesis and current advances in diagnoses, and management of malignant gliomas.

Ahmed, Rafay; Oborski, Matthew J; Hwang, Misun; Lieberman, Frank S; Mountz, James M

2014-01-01

326

Quantitative immunoelectrophoretic methods as tools for a polyvalent approach to standardization in the immunochemistry of Candida albicans.  

PubMed

Quantitative immunoelectrophoresis allows a polyvalent approach to immuno-chemical problems, i.e., identification, quantitation, and thereby standardization of antigens and antibodies in complex mixtures, for example as in crude extracts of microorganisms and their corresponding antisera. This approach is a short cut to conventional standardization of single purified substances, since the polyvalent approach gives a precise quantitative impression as described in this investigation and therefore enables the immunochemist to precisely select the right substance(s) to be purified for further standardization and characterization. To secure the precision of the results, in complex systems it is a sine qua non to select a complex antibody standard, a complex antigen standard, and to describe the complex standard precipitate pattern which again allows a quantitative study of the reproducibility of methods and procedures. The present article describes how such a standardization was approached in this laboratory within the field of Candida albicans immunochemistry. By means of crossed immunoelectrophoresis, 78 water-soluble antigens were demonstrated and enumerated in an antigen standard prepared from one strain of C. albicans A (B 311 Hasenclever). The antibody standard consisted of purified and concentrated rabbit antibodies. The migration velocity of each antigen was indicated in relation to purified human albumin. Not all precipitates could be seen in one immunoplate; therefore a standardized procedure was worked out showing reproducibly 54 precipitates. The reproducibility of quantitation by the crossed-immunoelectrophoresis procedure was determined for each of 30 antigens by repeated measurements; the relative standard deviations ranged from 2.4 to 15.4% and were below 10% for 24 antigens. A simple standardized antigen production procedure was described in great detail, and by quantitative determinations on 30 antigens the procedure was found to be satisfactorily reproducible. By means of crossed-line immunoelectrophoresis in the modification called absorption of antibodies in situ, it was found that strain B 311 contained no specific antigens in comparison to eight other strains of C. albicans. Thirty antigens were quantitated in antigen preparations made by the standardized procedure from the eight strains, and each antigen concentration was expressed as a percentage of the antigen standard. For each antigen a significant inter-strain variation was observed. Of 30 antigens, fifteen were satisfactorily stable after storage at -20 C for 1(1/2) years. The laboratory methods and procedures described in this article thus work with high precision and allow a rapid collection of quantitative data concerning many individual antigens and their corresponding antibodies without purification of antigens. A new complex antigen standard can be made with satisfactory precision from strain B 311. The production of a similar complex antibody standard is a major problem; therefore the main problem in the intra-laboratory standardization seems to be the change from one complex standard to another. In inter-laboratory standardization on the complex level, there seems to be a minimum demand that the first laboratory distributes the antibody standard and that other laboratories use the methods and procedures of the first laboratory. PMID:4577419

Axelsen, N H

1973-06-01

327

Characterization of thermal desorption instrumentation with a direct liquid deposition calibration method for trace 2,4,6-trinitrotoluene quantitation.  

PubMed

The use of thermal desorption systems for the analysis of trace vapors typically requires establishing a calibration curve from vapors generated with a permeation tube. The slow equilibration time of permeation tubes causes such an approach to become laborious when covering a wide dynamic range. Furthermore, many analytes of interest, such as explosives, are not available as permeation tubes. A method for easily and effectively establishing calibration curves for explosive vapor samples via direct deposition of standard solutions on thermal desorption tubes was investigated. The various components of the thermal desorption system were compared to a standard split/splitless inlet. Calibration curves using the direct liquid deposition method with a thermal desorption unit coupled to a cryo-focusing inlet were compared to a standard split/splitless inlet, and a statistical difference was observed but does not eliminate or deter the use of the direct liquid deposition method for obtaining quantitative results for explosive vapors. PMID:22265176

Field, Christopher R; Giordano, Braden C; Rogers, Duane A; Lubrano, Adam L; Rose-Pehrsson, Susan L

2012-03-01

328

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.

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

2014-01-01

329

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

330

A quantitative method for estimation of volume changes in arachnoid foveae with age.  

PubMed

Age-related changes of arachnoid foveae have been described, but objective, quantitative analyses are lacking. A new quantitative method is presented for estimation of change in total volume of arachnoid foveae with age. The pilot sample consisted of nine skulls from the Palmer Anatomy Laboratory. Arachnoid foveae were filled with sand, which was extracted using a vacuum pump. Mass was determined with an analytical balance and converted to volume. A reliability analysis was performed using intraclass correlation coefficients. The method was found to be highly reliable (intraobserver ICC = 0.9935, interobserver ICC = 0.9878). The relationship between total volume and age was then examined in a sample of 63 males of accurately known age from the Hamann-Todd collection. Linear regression analysis revealed no statistically significant relationship between total volume and age, or foveae frequency and age (alpha = 0.05). Development of arachnoid foveae may be influenced by health factors, which could limit its usefulness in aging. PMID:16566755

Duray, Stephen M; Martel, Stacie S

2006-03-01

331

A quantitative method for comparing human dentition with tooth marks using three-dimensional technology and geometric morphometric analysis.  

PubMed

Abstract Objective. To develop a quantitative method to compare 3D overlays from dental casts with experimental bitemarks by using geometric morphometric analysis. Materials and methods. Thirteen upper and lower dental casts and corresponding simulated bitemarks were 3D-scanned to generate comparison overlays with DentalPrint software(©). This study considered the inter-canine distance and four incisal angles. A matrix was created to compare all possible combinations of matches and non-matches between models and bites, i.e. 169 combinations (13 models × 13 bites), of which 13 were true matches. For each combination, the percentage difference was calculated between the variables in the model and the same variables in the bitemark. Logistic regression was used to obtain a predictive model (algorithm) for a match, calculating the discriminative values (area under the ROC curve, sensitivity and specificity) for each measure and for the logistic model. Results. Statistically significant discriminative power was found for all single (angle or distance) and combined (logistic model) variables, with lower 95% CI limits > 0.50 for areas under the ROC curves and sensitivity/specificity values > 50% in both maxilla and mandible. Conclusions. This quantitative method has sufficient discriminative power to be utilized in forensic cases. PMID:23972203

Martin-de-Las-Heras, Stella; Tafur, Daniel; Bravo, Manuel

2014-07-01

332

Age-related changes in rat cerebellar basket cells: a quantitative study using unbiased stereological methods  

PubMed Central

Cortical cerebellar basket cells are stable postmitotic cells; hence, they are liable to endure age-related changes. Since the cerebellum is a vital organ for the postural control, equilibrium and motor coordination, we aimed to determine the quantitative morphological changes in those interneurons with the ageing process, using unbiased techniques. Material from the cerebellar cortex (Crus I and Crus II) was collected from female rats aged 2, 6, 9, 12, 15, 18, 21 and 24 mo (5 animals per each age group), fixed by intracardiac perfusion, and processed for transmission electron microscopy, using conventional techniques. Serial semithin sections were obtained (5 blocks from each rat), enabling the determination of the number-weighted mean nuclear volume (by the nucleator method). On ultrathin sections, 25 cell profiles from each animal were photographed. The volume density of the nucleus, ground substance, mitochondria, Golgi apparatus (Golgi) and dense bodies (DB), and the mean surface density of the rough endoplasmic reticulum (RER) were determined, by point counting, using a morphometric grid. The mean total volumes of the soma and organelles and the mean total surface area of the RER [s?N (RER)] were then calculated. The results were analysed with 1-way ANOVA; posthoc pairwise comparisons of group means were performed using the Newman-Keuls test. The relation between age and each of the parameters was studied by regression analysis. Significant age-related changes were observed for the mean volumes of the soma, ground substance, Golgi, DB, and s?N (RER). Positive linear trends were found for the mean volumes of the ground substance, Golgi, and DB; a negative linear trend was found for the s?N (RER). These results indicate that rat cerebellar basket cells endure important age-related changes. The significant decrease in the s?N (RER) may be responsible for a reduction in the rate of protein synthesis. Additionally, it may be implicated in a cascade of events leading to cell damage due to the excitotoxic activity of glutamate, which could interfere in the functioning of the complex cerebellar neuronal network.

HENRIQUE, RUI M. F.; ROCHA, EDUARDO; REIS, ALCINDA; MARCOS, RICARDO; OLIVEIRA, MARIA H.; SILVA, MARIA W.; MONTEIRO, ROGERIO A. F.

2001-01-01

333

Rapid quantitative analysis of magnesium stearate in pharmaceutical powders and solid dosage forms by atomic absorption: method development and application in product manufacturing.  

PubMed

The distribution of magnesium stearate (MgSt) in tablet granule has a significant impact on the compression process. A rapid quantitative method for evaluating magnesium stearate content by atomic absorption was established. The MgSt was extracted from the granule in 0.1 mol/L nitric acid and the resulting free magnesium ion quantitated by atomic absorption. The total analysis time was significantly shortened in comparison to the previously used sample ignition method. This newly established method was evaluated with several drug products and several types of blender. The analytical method was also applied to tablets with poor compression (rough tablet surface). The MgSt content in these rough surface tablets was significantly lower than in tablets with smooth surfaces from the same batch. From these results, this atomic absorption method is considered to be an accurate and useful method for evaluating MgSt distribution and can be applied to tablet manufacturing process validation. PMID:19195812

Sugisawa, Keiichi; Kaneko, Takashi; Sago, Tsuyoshi; Sato, Tomonobu

2009-04-01

334

Genetic programming:? a novel method for the quantitative analysis of pyrolysis mass spectral data.  

PubMed

A technique for the analysis of multivariate data by genetic programming (GP) is described, with particular reference to the quantitative analysis of orange juice adulteration data collected by pyrolysis mass spectrometry (PyMS). The dimensionality of the input space was reduced by ranking variables according to product moment correlation or mutual information with the outputs. The GP technique as described gives predictive errors equivalent to, if not better than, more widespread methods such as partial least squares and artificial neural networks but additionally can provide a means for easing the interpretation of the correlation between input and output variables. The described application demonstrates that by using the GP method for analyzing PyMS data the adulteration of orange juice with 10% sucrose solution can be quantified reliably over a 0-20% range with an RMS error in the estimate of ?1%. PMID:21639171

Gilbert, R J; Goodacre, R; Woodward, A M; Kell, D B

1997-11-01

335

Quantitative Atlas of Membrane Transporter Proteins: Development and Application of a Highly Sensitive Simultaneous LC\\/MS\\/MS Method Combined with Novel In-silico Peptide Selection Criteria  

Microsoft Academic Search

Purpose  To develop an absolute quantification method for membrane proteins, and to construct a quantitative atlas of membrane transporter\\u000a proteins in the blood–brain barrier, liver and kidney of mouse.\\u000a \\u000a \\u000a \\u000a Methods  Mouse tissues were digested with trypsin, and mixed with stable isotope labeled-peptide as a quantitative standard. The amounts\\u000a of transporter proteins were simultaneously determined by liquid chromatography–tandem mass spectrometer (LC\\/MS\\/MS).\\u000a \\u000a \\u000a \\u000a Results  The target

Junichi Kamiie; Sumio Ohtsuki; Ryo Iwase; Ken Ohmine; Yuki Katsukura; Kazunari Yanai; Yumi Sekine; Yasuo Uchida; Shingo Ito; Tetsuya Terasaki

2008-01-01

336

Development and validation of a modified ultrasound-assisted extraction method and a HPLC method for the quantitative determination of two triterpenic acids in Hedyotis diffusa.  

PubMed

In the present study, the oleanolic acid (OA) and ursolic acid (UA) contents ofHedyotis diffusa and H. corymbosa were determined by a rapid, selective and accurate method combining modified ultrasound-assisted extraction (MUAE) and HPLC. Compared with traditional extraction methods, MUAE reduced the extraction time, the extraction temperature and the solvent consumption and maximized the extraction yields of OA and UA. Furthermore, the combined MUAE-HPLC method was applied to quantitate OA and UA in plant samples and exhibited good repeatability, reproducibility and stability. The mean recovery studies (one extraction cycle) for OA and UA were between 91.3 and 91.7% with RSD values less than 4.5%. The pioneer method was further applied to quantitate OA and UA in six samples of H. diffusa and five samples of H. corymbosa. The results showed that the OA and UA content in the samples from different sources were significantly different. This report is valuable for the application of H. diffusa and H. corymbosa obtained from different regions in clinical research and pharmacology. PMID:24555272

Yang, Yu-Chiao; Wei, Ming-Chi; Chiu, Hui-Fen; Huang, Ting-Chia

2013-12-01

337

Uniform hp convergence results for the mortar finite element method  

Microsoft Academic Search

The mortar nite element is an example of a non-conforming method which can be used to decompose and re-compose a domain into sub- domains without requiring compatibility between the meshes on the separate components. We obtain stability and convergence results for this method that are uniform in terms of both the degree and the mesh used, without assum- ing quasiuniformity

Padmanabhan Seshaiyer; Manil Suri

2000-01-01

338

Simple Absolute Quantification Method Correcting for Quantitative PCR Efficiency Variations for Microbial Community Samples  

PubMed Central

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 ??CT 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.

Bodenhausen, Natacha; Zeyer, Josef; Burgmann, Helmut

2012-01-01

339

[Results of Keller/Brandes method of hallux valgus surgery].  

PubMed

In 1983 to 1987 we operated 216 Patients on hallux valgus. In most of them we made the method of Keller/Brandes. This is a report about the results of 165 patients with 238 operated hallucis. PMID:2248609

Leonhardt, K

1990-09-01

340

Influence of the depth effect on quantitative results in single photon emission tomography with attenuation correction  

SciTech Connect

A study has been carried out in order to assess the influence of the solid angle effect during the scintigraphic images acquisition (depth effect), on the transverse sections reconstructed with 9 different techniques of attenuation correction. A numerical phantom of the abdomen, generated with auto-attenuation and with or without depth effect has been used. This depth effect was simulated from experimental data. The results show that the depth effect, modifying the reconstruction results has to be taken into account for the evaluation of attenuation correction techniques.

Pergrale, J.; Berche, C.; Iachetti, D.; Jatteau, M.; Normand, G.

1984-02-01

341

[Methods for evaluating surgical treatment results of complete acromioclavicular dislocation].  

PubMed

Results of operative treatment for complete dislocation of acromioclavicular joint in 15 patients are presented. Joint reconstruction was performed according to Henry's modified method supplemented with supraclavicular deltoid and trapezius muscles suture. Three different scales were used for functional assessment of the shoulder girdle at the follow-up. Depending on evaluation method used, different results of treatment were achieved. The evaluation scale proposed by Taft et al is, in our opinion, the most useful one in clinical practice. PMID:9273258

Kacik, W; Frac, R

1997-01-01

342

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.

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

2013-01-01

343

Qualitative and quantitative characterization of protein-phosphoinositide interactions with liposome-based methods  

PubMed Central

We characterized phosphoinositide binding of the S. cerevisiae PROPPIN Hsv2 qualitatively with density flotation assays and quantitatively through isothermal titration calorimetry (ITC) measurements using liposomes. We discuss the design of these experiments and show with liposome flotation assays that Hsv2 binds with high specificity to both PtdIns3P and PtdIns(3,5)P2. We propose liposome flotation assays as a more accurate alternative to the commonly used PIP strips for the characterization of phosphoinositide-binding specificities of proteins. We further quantitatively characterized PtdIns3P binding of Hsv2 with ITC measurements and determined a dissociation constant of 0.67 µM and a stoichiometry of 2:1 for PtdIns3P binding to Hsv2. PtdIns3P is crucial for the biogenesis of autophagosomes and their precursors. Besides the PROPPINs there are other PtdIns3P binding proteins with a link to autophagy, which includes the FYVE-domain containing proteins ZFYVE1/DFCP1 and WDFY3/ALFY and the PX-domain containing proteins Atg20 and Snx4/Atg24. The methods described could be useful tools for the characterization of these and other phosphoinositide-binding proteins.

Busse, Ricarda A.; Scacioc, Andreea; Hernandez, Javier M.; Krick, Roswitha; Stephan, Milena; Janshoff, Andreas; Thumm, Michael; Kuhnel, Karin

2013-01-01

344

ADvanced IMage Algebra (ADIMA): a novel method for depicting multiple sclerosis lesion heterogeneity, as demonstrated by quantitative MRI  

PubMed Central

Background: There are modest correlations between multiple sclerosis (MS) disability and white matter lesion (WML) volumes, as measured by T2-weighted (T2w) magnetic resonance imaging (MRI) scans (T2-WML). This may partly reflect pathological heterogeneity in WMLs, which is not apparent on T2w scans. Objective: To determine if ADvanced IMage Algebra (ADIMA), a novel MRI post-processing method, can reveal WML heterogeneity from proton-density weighted (PDw) and T2w images. Methods: We obtained conventional PDw and T2w images from 10 patients with relapsing–remitting MS (RRMS) and ADIMA images were calculated from these. We classified all WML into bright (ADIMA-b) and dark (ADIMA-d) sub-regions, which were segmented. We obtained conventional T2-WML and T1-WML volumes for comparison, as well as the following quantitative magnetic resonance parameters: magnetisation transfer ratio (MTR), T1 and T2. Also, we assessed the reproducibility of the segmentation for ADIMA-b, ADIMA-d and T2-WML. Results: Our study’s ADIMA-derived volumes correlated with conventional lesion volumes (p < 0.05). ADIMA-b exhibited higher T1 and T2, and lower MTR than the T2-WML (p < 0.001). Despite the similarity in T1 values between ADIMA-b and T1-WML, these regions were only partly overlapping with each other. ADIMA-d exhibited quantitative characteristics similar to T2-WML; however, they were only partly overlapping. Mean intra- and inter-observer coefficients of variation for ADIMA-b, ADIMA-d and T2-WML volumes were all < 6 % and < 10 %, respectively. Conclusion: ADIMA enabled the simple classification of WML into two groups having different quantitative magnetic resonance properties, which can be reproducibly distinguished.

Tozer, Daniel J; Schmierer, Klaus; Chard, Declan T; Anderson, Valerie M; Altmann, Daniel R; Miller, David H; Wheeler-Kingshott, Claudia AM

2013-01-01

345

Transconvolution and the virtual positron emission tomograph-A new method for cross calibration in quantitative PET/CT imaging  

SciTech Connect

Purpose: Positron emission tomography (PET)/computed tomography (CT) measurements on small lesions are impaired by the partial volume effect, which is intrinsically tied to the point spread function of the actual imaging system, including the reconstruction algorithms. The variability resulting from different point spread functions hinders the assessment of quantitative measurements in clinical routine and especially degrades comparability within multicenter trials. To improve quantitative comparability there is a need for methods to match different PET/CT systems through elimination of this systemic variability. Consequently, a new method was developed and tested that transforms the image of an object as produced by one tomograph to another image of the same object as it would have been seen by a different tomograph. The proposed new method, termed Transconvolution, compensates for differing imaging properties of different tomographs and particularly aims at quantitative comparability of PET/CT in the context of multicenter trials. Methods: To solve the problem of image normalization, the theory of Transconvolution was mathematically established together with new methods to handle point spread functions of different PET/CT systems. Knowing the point spread functions of two different imaging systems allows determining a Transconvolution function to convert one image into the other. This function is calculated by convolving one point spread function with the inverse of the other point spread function which, when adhering to certain boundary conditions such as the use of linear acquisition and image reconstruction methods, is a numerically accessible operation. For reliable measurement of such point spread functions characterizing different PET/CT systems, a dedicated solid-state phantom incorporating {sup 68}Ge/{sup 68}Ga filled spheres was developed. To iteratively determine and represent such point spread functions, exponential density functions in combination with a Gaussian distribution were introduced. Furthermore, simulation of a virtual PET system provided a standard imaging system with clearly defined properties to which the real PET systems were to be matched. A Hann window served as the modulation transfer function for the virtual PET. The Hann's apodization properties suppressed high spatial frequencies above a certain critical frequency, thereby fulfilling the above-mentioned boundary conditions. The determined point spread functions were subsequently used by the novel Transconvolution algorithm to match different PET/CT systems onto the virtual PET system. Finally, the theoretically elaborated Transconvolution method was validated transforming phantom images acquired on two different PET systems to nearly identical data sets, as they would be imaged by the virtual PET system. Results: The proposed Transconvolution method matched different PET/CT-systems for an improved and reproducible determination of a normalized activity concentration. The highest difference in measured activity concentration between the two different PET systems of 18.2% was found in spheres of 2 ml volume. Transconvolution reduced this difference down to 1.6%. In addition to reestablishing comparability the new method with its parameterization of point spread functions allowed a full characterization of imaging properties of the examined tomographs. Conclusions: By matching different tomographs to a virtual standardized imaging system, Transconvolution opens a new comprehensive method for cross calibration in quantitative PET imaging. The use of a virtual PET system restores comparability between data sets from different PET systems by exerting a common, reproducible, and defined partial volume effect.

Prenosil, George A.; Weitzel, Thilo; Hentschel, Michael; Klaeser, Bernd; Krause, Thomas [Department of Nuclear Medicine, Inselspital, Bern University Hospital and University of Bern, 3010 Bern (Switzerland)

2013-06-15

346

Quantitative secretin MRCP (MRCPQ): results in 215 patients with known or suspected pancreatic pathology  

Microsoft Academic Search

Secretin magnetic resonance cholangiopancreatography quantification (MRCPQ) of pancreatic exocrine function correlates well\\u000a with steatorrhoea and conventional, non-invasive function tests. We report MRCPQ results in a variety of pancreatic conditions.\\u000a A total of 215 patients [107 male, mean age 46 years (14–78)] were studied. A multi-slice MRCP sequence was performed before\\u000a and at 2-min intervals after 0.1 ml\\/kg IV secretin. Change in small

A. R. Gillams; W. R. Lees

2007-01-01

347

Application of quantitative (1)H-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

348

A validated RP-HPLC-UV method for quantitative determination of puerarin in Pueraria tuberosa DC tuber extract  

PubMed Central

Background: Pueraria tuberosa (Fabaceae) is a well-known medicinal herbs used in Indian traditional medicines. The puerarin is one of the most important bioactive constituent found in the tubers of this plant. Quantitative estimation of bioactive molecules is essential for the purpose of quality control and dose determination of herbal medicines. The study was designed to develop a validated reversed phase high-performance liquid chromatography (RP-HPLC) method for the quantification of puerarin in the tuber extract of P. tuberosa. Materials and Methods: The RP-HPLC system with Luna C18 (2) 100 Å, 250 × 4.6 mm column was used in this study. The analysis was performed using the mobile phase: 0.1% acetic acid in acetonitrile and 0.1% acetic acid in water (90:10, v/v) under column temperature 25°C. The detection wavelength was set at 254 nm with a flow rate of 1 ml/min. The method validation was performed according to the guidelines of International Conference on Harmonization. Results: The puerarin content of P. tuberosa extract was found to be 9.28 ±0.09%. The calibration curve showed good linearity relationship in the range of 200-1000?g/ml (r2>0.99). The LOD and LOQ were 57.12 and 181.26?g/ml, respectively and the average recovery of puerarin was 99.73% ±1.02%. The evaluation of system suitability, precision, robustness and ruggedness parameters were also found to produce satisfactory results. Conclusions: The developed method is very simple and rapid with excellent specificity, accuracy and precision which can be useful for the routine analysis and quantitative estimation of puerarin in plant extracts and formulations.

Maji, Amal K.; Maity, Niladri; Banerji, Pratim; Banerjee, Debdulal

2012-01-01

349

A simple, quantitative method using alginate gel to determine rat colonic tumor volume in vivo.  

PubMed

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 Apc(Pirc/+) 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

2014-04-01

350

Quantitative calcium resistivity based method for accurate and scalable water vapor transmission rate measurement.  

PubMed

The development of flexible organic light emitting diode displays and flexible thin film photovoltaic devices is dependent on the use of flexible, low-cost, optically transparent and durable barriers to moisture and/or oxygen. It is estimated that this will require high moisture barriers with water vapor transmission rates (WVTR) between 10(-4) and 10(-6) g/m(2)/day. Thus there is a need to develop a relatively fast, low-cost, and quantitative method to evaluate such low permeation rates. Here, we demonstrate a method where the resistance changes of patterned Ca films, upon reaction with moisture, enable one to calculate a WVTR between 10 and 10(-6) g/m(2)/day or better. Samples are configured with variable aperture size such that the sensitivity and/or measurement time of the experiment can be controlled. The samples are connected to a data acquisition system by means of individual signal cables permitting samples to be tested under a variety of conditions in multiple environmental chambers. An edge card connector is used to connect samples to the measurement wires enabling easy switching of samples in and out of test. This measurement method can be conducted with as little as 1 h of labor time per sample. Furthermore, multiple samples can be measured in parallel, making this an inexpensive and high volume method for measuring high moisture barriers. PMID:21895269

Reese, Matthew O; Dameron, Arrelaine A; Kempe, Michael D

2011-08-01

351

Quantitative calcium resistivity based method for accurate and scalable water vapor transmission rate measurement  

NASA Astrophysics Data System (ADS)

The development of flexible organic light emitting diode displays and flexible thin film photovoltaic devices is dependent on the use of flexible, low-cost, optically transparent and durable barriers to moisture and/or oxygen. It is estimated that this will require high moisture barriers with water vapor transmission rates (WVTR) between 10-4 and 10-6 g/m2/day. Thus there is a need to develop a relatively fast, low-cost, and quantitative method to evaluate such low permeation rates. Here, we demonstrate a method where the resistance changes of patterned Ca films, upon reaction with moisture, enable one to calculate a WVTR between 10 and 10-6 g/m2/day or better. Samples are configured with variable aperture size such that the sensitivity and/or measurement time of the experiment can be controlled. The samples are connected to a data acquisition system by means of individual signal cables permitting samples to be tested under a variety of conditions in multiple environmental chambers. An edge card connector is used to connect samples to the measurement wires enabling easy switching of samples in and out of test. This measurement method can be conducted with as little as 1 h of labor time per sample. Furthermore, multiple samples can be measured in parallel, making this an inexpensive and high volume method for measuring high moisture barriers.

Reese, Matthew O.; Dameron, Arrelaine A.; Kempe, Michael D.

2011-08-01

352

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.

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

2013-01-01

353

Rapid and inexpensive screening of genomic copy number variations using a novel quantitative fluorescent PCR method.  

PubMed

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

Stofanko, Martin; Han, Joan C; Elsea, Sarah H; Pena, Heloísa B; Gonçalves-Dornelas, Higgor; Pena, Sérgio Danilo Junho

2013-01-01

354

Estimation methods for monthly humidity from dynamical downscaling data for quantitative assessments of climate change impacts  

NASA Astrophysics Data System (ADS)

Methods are proposed to estimate the monthly relative humidity and wet bulb temperature based on observations from a dynamical downscaling coupled general circulation model with a regional climate model (RCM) for a quantitative assessment of climate change impacts. The water vapor pressure estimation model developed was a regression model with a monthly saturated water vapor pressure that used minimum air temperature as a variable. The monthly minimum air temperature correction model for RCM bias was developed by stepwise multiple regression analysis using the difference in monthly minimum air temperatures between observations and RCM output as a dependent variable and geographic factors as independent variables. The wet bulb temperature was estimated using the estimated water vapor pressure, air temperature, and atmospheric pressure at ground level both corrected for RCM bias. Root mean square errors of the data decreased considerably in August.

Ueyama, Hideki

2012-07-01

355

Methods and apparatuses for quantitatively determining the likelihood of a disease  

US Patent & Trademark Office Database

The invention described provides a method of quantitatively evaluating one or more of the likelihood. severity and progression of a disease from medical images comprising processing medical images of a test subject to derive one or more feature space values characteristic of a disease-dependent image attributes, comparing the feature space values to those of a previously established database from medical images of known health} and known diseased subjects, wherein the comparing is based on feature space values that best discriminate between health and diseased subjects, summing a weighted distance of discriminant feature space values of the test subject to those of at least one of the mean feature space value of the healthy subjects and the mean feature space value of the diseased subjects, and providing from the summing a single number which is indicative of at least one of disease likelihood. severity and progression.

2014-04-15

356

Quantitative test method for evaluation of anti-fingerprint property of coated surfaces  

NASA Astrophysics Data System (ADS)

An artificial fingerprint liquid is formulated from artificial sweat, hydroxyl-terminated polydimethylsiloxane and a solvent for direct determination of anti-fingerprint property of a coated surface. A range of smooth and rough surfaces with different anti-fingerprint (AF) properties were fabricated by sol-gel technology, on which the AF liquid contact angles, artificial fingerprint and real human fingerprints (HF) were verified and correlated. It is proved that a surface with AF contact angle above 87° is fingerprint free. This provides an objective and quantitative test method to determine anti-fingerprint property of coated surfaces. It is also concluded that AF property can be achieved on smooth and optically clear surfaces. Deep porous structures are more favorable than bumpy structure for oleophobic and AF properties.

Wu, Linda Y. L.; Ngian, S. K.; Chen, Z.; Xuan, D. T. T.

2011-01-01

357

Quantitative radiochemical method for determination of major sources of natural radioactivity in ores and minerals  

USGS Publications Warehouse

When an ore sample contains radioactivity other than that attributable to the uranium series in equilibrium, a quantitative analysis of the other emitters must be made in order to determine the source of this activity. Thorium-232, radon-222, and lead-210 have been determined by isolation and subsequent activity analysis of some of their short-lived daughter products. The sulfides of bismuth and polonium are precipitated out of solutions of thorium or uranium ores, and the ??-particle activity of polonium-214, polonium-212, and polonium-210 is determined by scintillation-counting techniques. Polonium-214 activity is used to determine radon-222, polonium-212 activity for thorium-232, and polonium-210 for lead-210. The development of these methods of radiochemical analysis will facilitate the rapid determination of some of the major sources of natural radioactivity.

Rosholt, Jr. , J. N.

1954-01-01

358

A quantitative and qualitative method to control chemotherapeutic preparations by Fourier transform infrared-ultraviolet spectrophotometry.  

PubMed

Chemotherapy products in hospitals include a reconstitution step of manufactured drugs providing an adapted dosage to each patient. The administration of highly iatrogenic drugs raises the question of patients' safety and treatment efficiency. In order to reduce administration errors due to faulty preparations, we introduced a new qualitative and quantitative routine control based on Fourier Transform Infrared (FTIR) and UV-Visible spectrophotometry. This automated method enabled fast and specific control for 14 anticancer drugs. A 1.2 mL sample was used to assay and identify each preparation in less than 90 sec. Over a two-year period, 9370 controlled infusion bags showed a 1.49% nonconformity rate, under 15% tolerance from the theoretical concentration and 96% minimum identification matching factor. This study evaluated the reliability of the control process, as well as its accordance to chemotherapy deliverance requirements. Thus, corrective measures were defined to improve the control process. PMID:23014899

Dziopa, Florian; Galy, Guillaume; Bauler, Stephanie; Vincent, Benoit; Crochon, Sarah; Tall, Mamadou Lamine; Pirot, Fabrice; Pivot, Christine

2013-06-01

359

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.

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

360

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

PubMed

It has been observed that microfluidic chips used for synthesizing (18)F-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 (18)F 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 (18)F 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 (18)F 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 (18)F 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. 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

2009-11-21

361

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

362

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.

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

2003-01-01

363

Histo-cytometry: a method for highly multiplex quantitative tissue imaging analysis applied to dendritic cell subset microanatomy in lymph nodes.  

PubMed

Flow cytometry allows highly quantitative analysis of complex dissociated populations at the cost of neglecting their tissue localization. In contrast, conventional microscopy methods provide spatial information, but visualization and quantification of cellular subsets defined by complex phenotypic marker combinations is challenging. Here, we describe an analytical microscopy method, "histo-cytometry," for visualizing and quantifying phenotypically complex cell populations directly in tissue sections. This technology is based on multiplexed antibody staining, tiled high-resolution confocal microscopy, voxel gating, volumetric cell rendering, and quantitative analysis. We have tested this technology on various innate and adaptive immune populations in murine lymph nodes (LNs) and were able to identify complex cellular subsets and phenotypes, achieving quantitatively similar results to flow cytometry, while also gathering cellular positional information. Here, we employ histo-cytometry to describe the spatial segregation of resident and migratory dendritic cell subsets into specialized microanatomical domains, suggesting an unexpected LN demarcation into discrete functional compartments. PMID:22863836

Gerner, Michael Y; Kastenmuller, Wolfgang; Ifrim, Ina; Kabat, Juraj; Germain, Ronald N

2012-08-24

364

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

365

A Novel Method for Instantaneous, Quantitative Measurement of Molecular Mixing in Gaseous Flows  

NASA Astrophysics Data System (ADS)

Various techniques have been developed in the past for obtaining a resolution-free estimate of the extent of molecular mixing in non-reacting gas flows. These techniques often use two tracers, one of which has a large fluorescence quenching rate in the presense of a quencher, and the other does not. Other two-tracer approaches based on sensitized phosphorescence have also been developed. In these methods, two detectors and one or two laser sources are needed. We describe a novel method where a single tracer, laser and dual-frame detector are used to obtain quantitative measurements of the extent of molecular mixing. This method takes advantage of the effective oxygen quenching of phosphorescence of tracers such as acetone and biacetyl that are often used in laser induced fluorscence studies. In this work the details of the technique are described along with its application in an excited nitrogen jet discharging into air. The instantaneous planar distributions of molecularly mixed fluid and mixing efficiency are presented.

Hu, Hui; Koochesfahani, Manoochehr

2001-11-01

366

Technical note: development of a quantitative PCR method for monitoring strain dynamics during yogurt manufacture.  

PubMed

Yogurt starter cultures may consist of multiple strains of Lactobacillus delbrueckii ssp. bulgaricus (LB) and Streptococcus thermophilus (ST). Conventional plating methods for monitoring LB and ST levels during yogurt manufacture do not allow for quantification of individual strains. The objective of the present work was to develop a quantitative PCR method for quantification of individual strains in a commercial yogurt starter culture. Strain-specific primers were designed for 2 ST strains (ST DGCC7796 and ST DGCC7710), 1 LB strain (DGCC4078), and 1 Lactobacillus delbrueckii ssp. lactis strain (LL; DGCC4550). Primers for the individual ST and LB strains were designed to target unique DNA sequences in clustered regularly interspersed short palindromic repeats. Primers for LL were designed to target a putative mannitol-specific IIbC component of the phosphotransferase system. Following evaluation of primer specificity, standard curves relating cell number to cycle threshold were prepared for each strain individually and in combination in yogurt mix, and no significant differences in the slopes were observed. Strain balance data was collected for yogurt prepared at 41 and 43°C to demonstrate the potential application of this method. PMID:22916891

Miller, D M; Dudley, E G; Roberts, R F

2012-09-01

367

Quantitatively estimating defects in graphene devices using discharge current analysis method  

PubMed Central

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 1014/cm2, 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.

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

368

Quantitatively estimating defects in graphene devices using discharge current analysis method  

NASA Astrophysics Data System (ADS)

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 1014/cm2, 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.

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

2014-05-01

369

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

370

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

371

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

372

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

PubMed

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. PMID:21571584

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

2011-09-01

373

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

374

[A new qualitative and quantitative analytical method of chromatographic fingerprints: total quantum statistical moment].  

PubMed

A new qualitative and quantitative analytical method of the chromatographic fingerprints: the Total Quantum Statistical Moment (TQSM) has been eluciated and established according to statistical moment principle. The study was carried out with model drugs as the alcohol extracted liquid for Radix et Rhizoma Rhei (AELRR) by HPLC under the chromatographic conditions that the column was C18, 4.6 mm x 250 mm, 5 microm; the detection of wavelengths was set at 254 nm; a solution of acetonitrile: 1% acetic acid water (from 0:100 to 100:0) was carried with gradient elution as the mobile phase; the ratio of flow was 1 mL min(-1); the temperature was 40 degrees C. The coefficients were dealt with Excel document. It has been established the expressions that consists of four main parameters: 1) total quantum zero moment as AUC(T), area under curve; 2) total quantum respondent ratio as AUCPW(T), area under curve per weight; 3) total quantum center moment as MCRT(T), mean chromatographic retention time of total quantum, expressed by lambda(T); 4) total quantum variance as VCRT(T), variance of mean chromatographic retention time of total quantum, expressed by sigma2(T), by which we have obtained. The TQSM's parameters of the AELRR, such as AUC(T) as 3.273 x 10(8) microV s, AUCPW(T) as 2.286 x 10(6) microV s mg (-1), MCRT(T) as 33.50 min, VCRT(T) as 484.4 min2, and total quantum concentration as 143.2 mg mL(-1). The total quantum statistic moment can be characterized the curve of chromatographic fingerprints with expressive parameters above, also used to quantitative analyses by AUC(T), to qualitative analyses by AUCPW(T), MCR(T), and VCRT(T). PMID:18507349

He, Fu-Yuan; Zhou, Hong-Hao; Deng, Kai-Wen; Liu, Weng-Long; Liu, Ping-An

2008-02-01

375

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.

Steinberg, Lisa M.; Regan, John M.

2009-01-01

376

Fast and accurate method for quantitating E. coli host-cell DNA contamination in plasmid DNA preparations.  

PubMed

Plasmid DNA is being used successfully as a gene delivery vector in a variety of clinical applications. Similar to other pharmaceutical products for clinical use, the plasmid vectors must meet rigorous purity standards. One important contaminant is the DNA of the host cell used to produce the plasmids. We have developed a new method to accurately quantitate E. coli host-cell DNA in plasmid preparations. This method is based on kinetic PCR using the ABI PRISM 7700 with 23S rDNA as a target. This precise assay is significantly faster and has a lower limit of quantitation than the currently used Southern-based methods. PMID:10090994

Smith, G J; Helf, M; Nesbet, C; Betita, H A; Meek, J; Ferre, F

1999-03-01

377

A novel standard sample powder preparation method for quantitative analysis of polymorphs.  

PubMed

The purpose of this study was to improve the sensitivity and accuracy of the quantitative analysis of polymorphic mixtures. Calibration curve reliability has been improved through the advancement of standard mixture preparation techniques whereby samples at scales of several grams are homogeneously and accurately prepared without decrease in crystallinity. Crystalline powders are first micronized to anisotropic, nearly equal-sized (<10 microm) particles of almost random orientation in an air jet mill. These powders are then mixed in a vibration mill that includes rubber balls as mixing media. Using this technique, alpha and gamma forms of indomethacin (IMC) were prepared in various proportions from 0.5% to 50% alpha content and subjected to X-ray powder diffraction analysis. The validation data showed that these precisely prepared standard mixtures resulted in superior analytical sensitivity and accuracy compared to those prepared by agate mortar. PMID:15793799

Okumura, Takehiro; Otsuka, Makoto

2005-05-01

378

A validated micellar electrokinetic chromatography method for the quantitation of dexamethasone, ondansetron and aprepitant, antiemetic drugs, in organogel.  

PubMed

A micellar electrokinetic chromatography (MEKC) method was developed for the determination of three anti-vomiting drugs (aprepitant, dexamethasone and ondansetron) in pharmaceutical formulations. The method was optimized using a central composite design (CCD). Four main factors (borate buffer concentration, pH, methanol content and sodium dodecyl sulfate concentration) were optimized in order to obtain best resolutions and peak efficiencies in a minimum runtime. The separation was performed in a fused-silica capillary. After optimization, the background electrolyte consisted of a borate buffer (62.5mM, pH 8.75) containing sodium dodecyl sulfate (77.5mM) and methanol (3.75%). Under these conditions, a complete separation of each antiemetic drug and its respective internal standards was achieved in 38min. The method was validated with trueness values from 94.9 to 107.2% and precision results (repeatability and intermediate precision) lower than 5.9%. MEKC-UV was the first method allowing the separation of aprepitant, dexamethasone and ondansetron and was suitable for the quantitation of these three antiemetic drugs in organogel formulations. The rapid sample preparation coupled with an automated separation technique make this method convenient for quality control of extemporaneous magistral ready-to-use formulation. PMID:23978340

Bourdon, Florence; Lecoeur, Marie; Duhaut, Marion; Odou, Pascal; Vaccher, Claude; Foulon, Catherine

2013-12-01

379

Qualitative and quantitative PCR methods for event-specific detection of genetically modified cotton Mon1445 and Mon531.  

PubMed

Based on the DNA sequences of the junctions between recombinant and cotton genomic DNA of the two genetically modified (GM) cotton varieties, herbicide-tolerance Mon1445 and insect-resistant Mon531, event-specific primers and probes for qualitative and quantitative PCR detection for both GM cotton varieties were designed, and corresponding detection methods were developed. In qualitative PCR detection, the simplex and multiplex PCR detection systems were established and employed to identify Mon1445 and Mon531 from other GM cottons and crops. The limits of detection (LODs) of the simplex PCR were 0.05% for both Mon1445 and Mon531 using 100 ng DNA templates in one reaction, and the LOD of multiplex PCR analysis was 0.1%. For further quantitative detection using TaqMan real-time PCR systems for Mon1445 and Mon531, one plasmid pMD-ECS, used as reference molecule was constructed, which contained the quantitative amplified fragments of Mon1445, Mon531, and cotton endogenous reference gene. The limits of quantification (LOQs) of Mon1445 and Mon531 event-specific PCR systems using plasmid pMD-ECS as reference molecule were 10 copies, and the quantification range was from 0.03 to 100% in 100 ng of the DNA template for one reaction. Thereafter, five mixed cotton samples containing 0, 0.5, 0.9, 3 and 5% Mon1445 or Mon531 were quantified using established real-time PCR systems to evaluate the accuracy and precision of the developed real-time PCR detection systems. The accuracy expressed as bias varied from 1.33 to 8.89% for tested Mon1445 cotton samples, and from 2.67 to 6.80% for Mon531. The precision expressed as relative standard deviations (RSD) were different from 1.13 to 30.00% for Mon1445 cotton, and from 1.27 to 24.68% for Mon531. The range of RSD was similar to other laboratory results (25%). Concluded from above results, we believed that the established event-specific qualitative and quantitative PCR systems for Mon1445 and Mon531 in this study are acceptable and suitable for GM cotton identification and quantification. PMID:16315089

Yang, Litao; Pan, Aihu; Zhang, Kewei; Yin, Changsong; Qian, Bingjun; Chen, Jianxiu; Huang, Cheng; Zhang, Dabing

2005-12-01

380

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

381

Evaluating Multiple Prevention Programs: Methods, Results, and Lessons Learned  

ERIC Educational Resources Information Center

Extension faculty and agents/educators are increasingly collaborating with local and state agencies to provide and evaluate multiple, distinct programs, yet there is limited information about measuring outcomes and combining results across similar program types. This article explicates the methods and outcomes of a state-level evaluation of…

Adler-Baeder, Francesca; Kerpelman, Jennifer; Griffin, Melody M.; Schramm, David G.

2010-01-01

382

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

383

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

384

Development and validation of chromatographic methods for the identification and quantitation of organic compounds leached from a laminated polyolefin material.  

PubMed

Chromatographic methods for the identification of organic compounds leached from a plastic material used in solution containers in the pharmaceutical industry are described. Based on a set of compounds identified in extracts of a multilayered polyolefin film, targeted leachables are delineated for accumulation assessments, and methods to perform target quantitation are developed and validated. PMID:15355580

Jenke, Dennis; Poss, Mitchell; Story, James; Odufu, Alex; Zietlow, David; Tsilipetros, Tom

2004-08-01

385

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...

386

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

387

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

388

Electron Paramagnetic Resonance Oximetry as a Quantitative Method to Measure Cellular Respiration: A Consideration of Oxygen Diffusion Interference  

PubMed Central

Electron paramagnetic resonance (EPR) oximetry is being widely used to measure the oxygen consumption of cells, mitochondria, and submitochondrial particles. However, further improvement of this technique, in terms of data analysis, is required to use it as a quantitative tool. Here, we present a new approach for quantitative analysis of cellular respiration using EPR oximetry. The course of oxygen consumption by cells in suspension has been observed to have three distinct zones: pO2-independent respiration at higher pO2 ranges, pO2-dependent respiration at low pO2 ranges, and a static equilibrium with no change in pO2 at very low pO2 values. The approach here enables one to comprehensively analyze all of the three zones together—where the progression of O2 diffusion zones around each cell, their overlap within time, and their potential impact on the measured pO2 data are considered. The obtained results agree with previously established methods such as high-resolution respirometry measurements. Additionally, it is also demonstrated how the diffusion limitations can depend on cell density and consumption rate. In conclusion, the new approach establishes a more accurate and meaningful model to evaluate the EPR oximetry data on cellular respiration to quantify related parameters using EPR oximetry.

Presley, Tennille; Kuppusamy, Periannan; Zweier, Jay L.; Ilangovan, Govindasamy

2006-01-01

389

Evaluation of the ERETIC Method as an Improved Quantitative Reference for 1H HR-MAS Spectroscopy of Prostate Tissue  

PubMed Central

The Electronic REference To access In vivo Concentrations (ERETIC) method was applied to 1H HR-MAS spectroscopy. The accuracy, precision, and stability of ERETIC as a quantitative reference were evaluated in solution and human prostate tissue samples. For comparison, the reliability of 3-(trimethylsilyl)propionic-2,2,3,3-d4 acid (TSP) as a quantitation reference was also evaluated. The ERETIC and TSP peak areas were found to be stable in solution over the short-term and long-term, with long-term relative standard deviations (RSDs) of 4.10% and 2.60%, respectively. Quantification of TSP in solution using the ERETIC peak as a reference and a calibrated, rotor-dependent conversion factor yielded results with a precision ?2.9% and an accuracy error ?4.2% when compared with the expected values. The ERETIC peak area reproducibility was superior to TSP’s reproducibility, corrected for mass, in both prostate surgical and biopsy samples (4.53% vs. 21.2% and 3.34% vs. 31.8%, respectively). Furthermore, the tissue TSP peaks exhibited only 27.5% of the expected area, which would cause an overestimation of metabolite concentrations if used as a reference. The improved quantification accuracy and precision provided by ERETIC may enable the detection of smaller metabolic differences that may exist between individual tissue samples and disease states.

Albers, Mark J.; Butler, Thomas N.; Rahwa, Iman; Bao, Nguyen; Keshari, Kayvan R.; Swanson, Mark G.; Kurhanewicz, John

2010-01-01

390

Evaluation of the ERETIC method as an improved quantitative reference for 1H HR-MAS spectroscopy of prostate tissue.  

PubMed

The Electronic REference To access In vivo Concentrations (ERETIC) method was applied to (1)H HR-MAS spectroscopy. The accuracy, precision, and stability of ERETIC as a quantitative reference were evaluated in solution and human prostate tissue samples. For comparison, the reliability of 3-(trimethylsilyl)propionic-2,2,3,3-d(4) acid (TSP) as a quantitation reference was also evaluated. The ERETIC and TSP peak areas were found to be stable in solution over the short-term and long-term, with long-term relative standard deviations (RSDs) of 4.10% and 2.60%, respectively. Quantification of TSP in solution using the ERETIC peak as a reference and a calibrated, rotor-dependent conversion factor yielded results with a precision < or =2.9% and an accuracy error < or =4.2% when compared with the expected values. The ERETIC peak area reproducibility was superior to TSP's reproducibility, corrected for mass, in both prostate surgical and biopsy samples (4.53% vs. 21.2% and 3.34% vs. 31.8%, respectively). Furthermore, the tissue TSP peaks exhibited only 27.5% of the expected area, which would cause an overestimation of metabolite concentrations if used as a reference. The improved quantification accuracy and precision provided by ERETIC may enable the detection of smaller metabolic differences that may exist between individual tissue samples and disease states. PMID:19235261

Albers, Mark J; Butler, Thomas N; Rahwa, Iman; Bao, Nguyen; Keshari, Kayvan R; Swanson, Mark G; Kurhanewicz, John

2009-03-01

391

Quantitative methods to analyze subnuclear protein organization in cell populations with varying degrees of protein expression  

PubMed Central

The control of gene transcription is dependent on DNA-binding and coregulatory proteins that assemble in distinct regions of the cell nucleus. We use multispectral wide-field microscopy of cells expressing transcriptional coregulators labeled with fluorescent proteins (FP) to study the subnuclear localization and function of these factors in living cells. In coexpression studies, the glucocorticoid receptor interacting protein (GRIP) coactivator protein and the silencing mediator of retinoid and thyroid (SMRT) corepressor protein form spherical subnuclear focal bodies that are spatially distinct, suggesting that specific protein interactions concentrate these divergent proteins in separate subnuclear regions. However, the variability of these subnuclear bodies between cells within the population makes analysis based on “representative images” difficult, if not impossible. To address this issue, we develop a protocol for unbiased selection of cells from the population, followed by the automated quantification of the subnuclear organization of the labeled proteins. Statistical methods identify a significant linear correlation between the FP-coregulator expression level and subnuclear focal body formation for both FP-GRIP and FP-SMRT. Importantly, we confirm that these changes in subnuclear organization could be statistically normalized for differences in coregulator expression level. This integrated quantitative image analysis method will allow the rigorous comparison of different experimental cell populations that express variable levels of FP fusion proteins.

Voss, Ty C.; Demarco, Ignacio A.; Booker, Cynthia F.; Day, Richard N.

2005-01-01

392

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

393

Quantitative HPLC method for determining two of the major active phthalides from Ligusticum porteri roots.  

PubMed

Z-Ligustilide (1) and Z-6,6',7,3'-alpha-diligustilide (2), two of the major active phthalides of the medicinal plant Ligusticum porteri (osha), were chosen for the development and validation of an HPLC-diode array detection method suitable for QC of the crude drug. The method used gradient elution to achieve separation on a Hibar RT LiChrospher 100 C18 column. The LOD values were 29 and 45 microg/mL, and the LOQs were 89 and 125 microg/mL, respectively. The method showed good intraday precision (%RSD: 0.7 for 1 and 3.1 for 2) and interday precision (%RSD: 1.2 for 1 and 1.8 for 2). The method was used for the analysis of 1 and 2 in crude drug samples and several herbal preparations from Mexico and the United States. Quantitative analysis showed that the content of the two phthalides varied significantly among the samples. All the samples contained higher concentrations of 1 (0.15-2.5%) than 2 (0.002-1.0%). The profiles of volatile compounds in the essential oil obtained by hydrodistillation and solid-phase microextraction of L. porteri roots were analyzed by GC-MS. Thirty one chemical constituents (> 99.7% of the total content) were identified in the essential oil, which was characterized by the presence of a high percentage of phthalides (44.61%) and sesquiterpenes (10.69%). The major light volatile components extracted by solid-phase microextraction were monoterpenes. PMID:22468345

Rivero, Isabel; Juárez, Krutzkaya; Zuluaga, Magda; Bye, Robert; Mata, Rachel

2012-01-01

394

[Development of a method for the quantitative evaluation of the regional kinetics of the left ventricle].  

PubMed

Segmental wall motion abnormalities of the left ventricle frequently occur in ischemic heart disease. An objective, quantitative method is required to ensure the reproducibility of the assessment of left ventricular regional function, especially in evaluating the changes induced by diagnostic and therapeutic interventions. In 32 normal subjects we obtained 30 degrees right anterior oblique left ventriculograms and developed a method based on the following observations. The method should reflect the symmetric uniform motion of the left ventricular silhouette. Only actual contractile motion should be taken into account; therefore, rotatory and translational motion should be compensated for. Passive systolic movement of aortic and mitral valves accounts for the contraction of neighbouring myocardial segments. Left ventricular wall excursion is most often measured by a coordinate system: since the cavity of the left ventricle becomes relatively longer during systole, left ventricular walls contract neither toward a single central point nor toward the long axis; therefore the appropriate origin of the coordinate system will be a segment. Furthermore, as more elongated left ventricular end-diastolic silhouettes appear to show a greater extent of systolic lengthening (we show evidence of this), the length of the segment must be related to the end-diastolic shape. The basic steps of the method are: 1) identification of a symmetry line, from the aortic mid-point to the apex, by connecting the mid-point of 19 diameters perpendicular to the long axis; 2) roto-translation of the end-systolic silhouette so that the end-systolic apex and aortic mid-point lie on the symmetry line.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6735016

Rubartelli, P; Miccoli, F; Della Rovere, F; Mazzantini, S; Vischi, M; Zucchi, E; Pilot, A

1984-04-01

395

Infrared Fluorescence for Vascular Barrier Breach In Vivo - A Novel Method for Quantitation of Albumin Efflux  

PubMed Central

Summary Vascular hyperpermeability contributes to morbidity in inflammation. Current methodologies for in vivo assessment of permeability based on extravasation of Evans Blue (EB)-bound albumin are cumbersome and often lack sensitivity. We developed a novel infrared fluorescence (IRF) methodology for measurement of EB-albumin extravasation to quantify vascular permeability in murine models. Vascular permeability induced by endotoxemia was examined for all solid organs, brain, skin and peritoneum by IRF and the traditional absorbance-based measurement of EB in tissue extracts. Organ IRF increased linearly with increasing concentrations of i.v. EB (2.5-25 mg/kg). Tissue IRF was more sensitive for EB accumulation compared to the absorbance-based method. Accordingly, differences in vascular permeability and organ EB accumulation between lipopolysaccharide-treated and saline-treated mice were often significant when analyzed by IRF-based detection but not by absorbance-based detection. EB was detected in all 353 organs analyzed with IRF but only in 67% (239/353) of organs analyzed by absorbance-based methodology, demonstrating improved sensitivity of EB detection in organs with IRF. In contrast, EB in plasma after EB administration was readily measured by both methods with high correlation between the two methods (n=116, r2=0.86). Quantitation of organ-specific EB-IRF differences due to endotoxin was optimal when IRF was compared between mice matched for weight, gender, and age, and with appropriate corrections for organ weight and EB plasma concentrations. Notably, EB-IRF methodology leaves organs intact for subsequent histopathology. In summary, EB-IRF is a novel, highly sensitive, rapid, and convenient method for the relative quantification of EB in intact organs of treatment versus control mice.

von Drygalski, Annette; Furla-Freguia, Christian; Mosnier, Laurent O.; Yegneswaran, Subramanian; Ruf, Wolfram; Griffin, John H.

2013-01-01

396

Quantitative schlieren method for studying the wavefront reconstructed from a hologram  

SciTech Connect

A schlieren method is proposed for visualizing the deflection angles of the light beams reconstructed from a phase object hologram. The method is based on employing a stationary visualizing slit and selecting the image of a slit light source by a movable slit. This light source comprises several equidistant slit sources. Compensation for the aberrations of the hologram-recording system is considered. Experimental results of the evaluation tests showing the performance of the method developed are presented. 15 refs., 4 figs.

Lyalikov, A.M. [Kupala Grodno State Univ. (Belarus)

1995-03-01