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1

Quantitative Methods II Winter 2012  

E-print Network

1 of 3 Quantitative Methods II Winter 2012 Meets: Thursdays 9am ­ 11:50am Professor: Jonathan.northwestern.edu This course is intended to be a continuation of the quantitative methods sequence that began with Quantitative assumptions are violated. We will then discuss various methods researchers use to overcome these obstacles

Bustamante, Fabián E.

2

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; Gler, C C

2000-01-01

3

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

Microsoft Academic Search

The precision and accuracy of the Iatroscan method was evaluated by comparing the results obtained with established phosphorus\\u000a and gas chromatographic techniques. A complete lipid class analysis of rat heart lipids was chosen in order to evaluate the\\u000a performance of the Iatroscan method for biological samples which contained both neutral lipids and phospholipids. A partial\\u000a scan and repeat development with

J. K. G. Kramer; E. R. Farnworth; B. K. Thompson

1985-01-01

4

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

5

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

6

Quantitative Statistical Methods for Image Quality Assessment  

PubMed Central

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

Dutta, Joyita; Ahn, Sangtae; Li, Quanzheng

2013-01-01

7

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; Brhlmann, M

1996-05-01

8

Method and apparatus for chromatographic quantitative analysis  

DOEpatents

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

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

1981-06-09

9

Quantitative evaluation of color image segmentation results  

Microsoft Academic Search

In this paper we consider the problem of the automatic evaluation of the results of color image segmentation. Liu and Yang (1994) have proposed an evaluation function, inspired by the qualitative criteria for good image segmentation established by Haralick and Shapiro (1985), that does not require that the user set any parameter or threshold value. We identify some limitations in

M. Borsotti; Paola Campadelli; Raimondo Schettini

1998-01-01

10

An improved method for quantitative culture of Malassezia furfur.  

PubMed

Quantitative culture of Malassezia furfur from clinically healthy skin in 25 individuals was performed with two different methods using contact plates. The best results were obtained when a glucose peptone yeast extract medium, with the addition of milk, Tween-60, glycerol and glycerol monostearate was used. Different techniques for incubation and the reproducibility of this method were evaluated. Incubation can be done in a plastic bag at 32 or 37 degrees C. This new method is simple, the colonies are easy to identify and the counts are high and reliable. PMID:1488557

Bergbrant, I M; Igerud, A; Nordin, P

1992-09-01

11

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

12

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

13

Qualitative versus Quantitative Results: An Experimental Introduction to Data Interpretation.  

ERIC Educational Resources Information Center

Described is an experiment in which the student can ascertain the meaning of a negative result from a qualitative test by performing a more sensitive quantitative test on the same sample. Methodology for testing urinary glucose with a spectrophotometer at 630 nm and with commercial assaying glucose strips is presented. (MVL)

Johnson, Eric R.; Alter, Paula

1989-01-01

14

A Quantitative Study of Small Disjuncts: Experiments and Results  

E-print Network

A Quantitative Study of Small Disjuncts: Experiments and Results Gary M. Weiss and Haym Hirsh and are interesting to machine learning researchers because they have a much higher error rate than large disjuncts. Previous research has investigated this phenomenon by performing ad hoc analyses of a small number

Weiss, Gary

15

Quantitative STEM: Experimental Methods and Applications  

NASA Astrophysics Data System (ADS)

High-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy (STEM) is highly sensitive to both the atomic number and the Debye-Waller factor of the atom columns. We will discuss the experimental requirements for a quantitative understanding of STEM image contrast, in particular the determination of the precise specimen thickness. We show that near perfect agreement can be achieved between theory and experiment and demonstrate that quantitative STEM allows for column-by-column counting of all the atoms in an arbitrarily shaped specimen.

LeBeau, J. M.; Findlay, S. D.; Allen, L. J.; Stemmer, S.

2012-07-01

16

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 meanSD and CV% of positive, and negative quality controls were equal to 126.49.6 and 7.6%, 10.41.25 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

17

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

18

An Improved Quantitative Analysis Method for Plant Cortical Microtubules  

PubMed Central

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

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

2014-01-01

19

A quantitative method for measuring the quality of history matches  

SciTech Connect

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

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

1997-08-01

20

Bioinformatics tools for the functional interpretation of quantitative proteomics results.  

PubMed

Proteins are the principal mediators of the functions in the cell; therefore, any abnormal variations on their abundance levels may reflect the presence of pathological processes. In this sense, many researchers rely on the functional interpretation of protein lists generated by quantitative proteomics experiments to analyze, for instance, these variations in the context of diseases' molecular basis and drug discovery. Since no analytical strategy or bioinformatics tool by itself is capable of extract all the information covered by a single experiment; herein we seek to provide the biologists with four groups of different but complementary bioinformatics tools for the functional interpretation of quantitative proteomics results. To this end we will review the basic concepts of a set of different bioinformatics approaches and we will give examples of freely available tools for each one of these approaches. PMID:24304321

Villavicencio-Diaz, Teresa Nunez; Rodriguez-Ulloa, Arielis; Guirola-Cruz, Osmany; Perez-Riverol, Yasset

2014-01-01

21

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

22

Review of Quantitative Software Reliability Methods  

SciTech Connect

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

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

2010-09-17

23

Methods of quantitative fire hazard analysis  

SciTech Connect

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

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

1992-05-01

24

Fluorometric method of quantitative cell mutagenesis  

DOEpatents

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

Dolbeare, Frank A. (Livermore, CA)

1982-01-01

25

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

26

Forwardbackward splitting method for quantitative photoacoustic tomography  

NASA Astrophysics Data System (ADS)

Quantitative photoacoustic tomography (PAT) reconstructs optical maps using ultrasonic measurements, with improved resolution from conventional optical imaging due to significantly smaller acoustic scattering than optical scattering for detecting signals in depth. In this work, formulating quantitative PAT as a nonlinear least-squares problem with l1-norm sparsity regularization, we develop an efficient gradient-based reconstruction algorithm using a forwardbackward splitting method, and prove its convergence for such a nonconvex problem.

Zhang, Xue; Zhou, Weifeng; Zhang, Xiaoqun; Gao, Hao

2014-12-01

27

A new method to perform quantitative measurement of bronchoscopic images  

Microsoft Academic Search

A new method to perform quantitative measurement of bronchoscopic images. P.K. McFawn, L. Forkert, J.T. Fisher. #ERS Journals Ltd 2001. ABSTRACT: Bronchoscopy is a commonly used clinical tool that provides a direct image of the bronchial lumen. However, bronchoscopy has seen little use as a quantitative measurement tool, mainly because of the wide-angle lens which distorts the image. The present

P. K. McFawn; L. Forkert; J. T. Fisher

2001-01-01

28

Optimization of a quantitative method for muscle histology assessment.  

PubMed

Optical microscopy offers the simplest way to obtain magnified images of biological tissues. The assessment of the muscle destructuration level can be performed by a method called Meat Destruction Indicator (MDI), which combines optical microscopy and image analysis. MDI can be used for evaluation of food quality and for considering mechanically separated meat (meat raw material with an MDI value above 58.1% contained muscle fibres sufficiently destructured). This paper is particularly focused on the metrological optimization of a quantitative image analysis method around the example of MDI measurement by microscopy, especially on the digital acquisition calibration focusing and analysis work-flow. Ten different samples (45 sections) were examined with variable settings of microscope and camera to define the optimal configuration. The tests were performed with different observers to define rules and criteria for results validation. Based on the obtained results, we suggest choosing objective rules to set the light and colour of the camera and the microscope focus. To control the results of the automatic segmentation emerged also as a key step, and objective rules for observers to select or discard wrong segmented images should be defined. The adjusted MDI measurement by microscope can be used as a reliable method with good repeatability, thanks to this metrological assessment, which could and should be applied to all image analysis applications whatever the application. PMID:23410149

Sifre, L; Coton, J P; Andr, B; Rez?ov-Lukkov, Z

2013-04-01

29

Wave propagation models for quantitative defect detection by ultrasonic methods  

NASA Astrophysics Data System (ADS)

Ultrasonic guided wave testing necessitates of quantitative, rather than qualitative, information on flaw size, shape and position. This quantitative diagnosis ability can be used to provide meaningful data to a prognosis algorithm for remaining life prediction, or simply to generate data sets for a statistical defect classification algorithm. Quantitative diagnostics needs models able to represent the interaction of guided waves with various defect scenarios. One such model is the Global-Local (GL) method, which uses a full finite element discretization of the region around a flaw to properly represent wave diffraction, and a suitable set of wave functions to simulate regions away from the flaw. Displacement and stress continuity conditions are imposed at the boundary between the global and the local regions. In this paper the GL method is expanded to take advantage of the Semi-Analytical Finite Element (SAFE) method in the global portion of the waveguide. The SAFE method is efficient because it only requires the discretization of the cross-section of the waveguide to obtain the wave dispersion solutions and it can handle complex structures such as multilayered sandwich panels. The GL method is applied to predicting quantitatively the interaction of guided waves with defects in aluminum and composites structural components.

Srivastava, Ankit; Bartoli, Ivan; Coccia, Stefano; Lanza di Scalea, Francesco

2008-03-01

30

Quantitative methods for somatosensory evaluation in atypical odontalgia.  

PubMed

A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO) patients. The computerized search included the main databases (MEDLINE, EMBASE, and Cochrane Library). The studies included used the following quantitative sensory testing (QST) methods: mechanical detection threshold (MDT), mechanical pain threshold (MPT) (pinprick), pressure pain threshold (PPT), dynamic mechanical allodynia with a cotton swab (DMA1) or a brush (DMA2), warm detection threshold (WDT), cold detection threshold (CDT), heat pain threshold (HPT), cold pain detection (CPT), and/or wind-up ratio (WUR). The publications meeting the inclusion criteria revealed that only mechanical allodynia tests (DMA1, DMA2, and WUR) were significantly higher and pain threshold tests to heat stimulation (HPT) were significantly lower in the affected side, compared with the contralateral side, in AO patients; however, for MDT, MPT, PPT, CDT, and WDT, the results were not significant. These data support the presence of central sensitization features, such as allodynia and temporal summation. In contrast, considerable inconsistencies between studies were found when AO patients were compared with healthy subjects. In clinical settings, the most reliable evaluation method for AO in patients with persistent idiopathic facial pain would be intraindividual assessments using HPT or mechanical allodynia tests. PMID:25627886

Porporatti, Andr Lus; Costa, Yuri Martins; Stuginski-Barbosa, Juliana; Bonjardim, Leonardo Rigoldi; Conti, Paulo Csar Rodrigues; Svensson, Peter

2015-01-01

31

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. PMID:24802859

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

2014-01-01

32

Quantitative Imaging of Corrosion in Plates by Eddy Current Methods  

E-print Network

Quantitative Imaging of Corrosion in Plates by Eddy Current Methods Bruno Luong \\Lambda and Fadil the problem of determining material loss due to cor­ rosion in a plate. Eddy current data are collected on one the relationship between eddy current loop impedance change with the loss profile. In this context, we show

Santosa, Fadil

33

Spy quantitative inspection with a machine vision light sectioning method  

NASA Astrophysics Data System (ADS)

Machine vision light sectioning sensing is developed and expanded to the range of spy quantitative inspection for hole-like work pieces in this paper. A light beam from a semiconductor laser diode is converged into a line-shape by a cylindrical lens. A special compact reflecting-refracting prism group is designed to ensure that such a sectioning light is projected axially onto the inner surface, and to make the deformed line be imaged onto a CCD sensitive area. The image is digitized and captured into a computer by a 512512 pixel card, and machine vision image processing methods such as thresholding, line centre detect and the least-squares method are developed for contour feature extraction and description. Two other important problems in such an inspection system are how to orientate the deep-going optical probe and how to bring the projected line into focus. A focusing criterion based on image position deviation and a four-step orientating procedure are put forward, and analysed to be feasible respectively. The experimental results show that the principle is correct and the techniques are realizable, and a good future for application in industry is possible.

Tu, Da-Wei; Lin, Cai-Xing

2000-08-01

34

A novel targeted learning method for quantitative trait Loci mapping.  

PubMed

We present a novel semiparametric method for quantitative trait loci (QTL) mapping in experimental crosses. Conventional genetic mapping methods typically assume parametric models with Gaussian errors and obtain parameter estimates through maximum-likelihood estimation. In contrast with univariate regression and interval-mapping methods, our model requires fewer assumptions and also accommodates various machine-learning algorithms. Estimation is performed with targeted maximum-likelihood learning methods. We demonstrate our semiparametric targeted learning approach in a simulation study and a well-studied barley data set. PMID:25258376

Wang, Hui; Zhang, Zhongyang; Rose, Sherri; van der Laan, Mark

2014-12-01

35

Methods for applying the quantitative structure-activity relationship paradigm.  

PubMed

There are several Quantitative Structure-Activity Relationship (QSAR) methods to assist in the design of compounds for medicinal use. Owing to the different QSAR methodologies, deciding which QSAR method to use depends on the composition of system of interest and the desired results. The relationship between a compound's binding affinity/activity to its structural properties was first noted in the 1930s by Hammett and later refined by Hansch and Fujita in the mid-1960s. In 1988 Cramer and coworkers created Comparative Molecular Field Analysis (CoMFA) incorporating the three-dimensional (3D) aspects of the compounds, specifically the electrostatic fields of the compound, into the QSAR model. Hopfinger and coworkers included an additional dimension to 3D-QSAR methodology in 1997 that eliminated the question of "Which conformation to use in a QSAR study?", creating 4D-QSAR. In 1999 Chemical Computing Group Inc. (CCG) developed the Binary-QSAR methodology and added novel 3D-QSAR descriptors to the traditional QSAR model allowing the 3D properties of compounds to be incorporated into the traditional QSAR model. Recently CCG released Probabilistic Receptor Potentials to calculate the substrate's atomic preferences in the active site. These potentials are constructed by fitting analytical functions to experimental properties of the substrates using knowledge-based methods. An overview of these and other QSAR methods will be discussed along with an in-depth examination of the methodologies used to construct QSAR models. Also, included in this chapter is a case study of molecules used to create QSAR models utilizing different methodologies and QSAR programs. PMID:15141113

Esposito, Emilio Xavier; Hopfinger, Anton J; Madura, Jeffry D

2004-01-01

36

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

PubMed Central

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

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

2011-01-01

37

A review of methods for quantitative evaluation of axial vertebral rotation  

PubMed Central

Quantitative evaluation of axial vertebral rotation is essential for the determination of reference values in normal and pathological conditions and for understanding the mechanisms of the progression of spinal deformities. However, routine quantitative evaluation of axial vertebral rotation is difficult and error-prone due to the limitations of the observer, characteristics of the observed vertebral anatomy and specific imaging properties. The scope of this paper is to review the existing methods for quantitative evaluation of axial vertebral rotation from medical images along with all relevant publications, which may provide a valuable resource for studying the existing methods or developing new methods and evaluation strategies. The reviewed methods are divided into the methods for evaluation of axial vertebral rotation in 2D images and the methods for evaluation of axial vertebral rotation in 3D images. Key evaluation issues and future considerations, supported by the results of the overview, are also discussed. PMID:19242736

Pernu, Franjo; Likar, Botjan

2009-01-01

38

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

NASA Astrophysics Data System (ADS)

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

Michalska, J.; Chmiela, B.

2014-03-01

39

Methods for linkage analysis of quantitative trait loci in humans.  

PubMed

This paper reviews linkage analysis methods for detecting loci associated with quantitative traits in humans. All such methods are based on the underlying principle that family members who have similar trait values should have higher than expected levels of sharing of genetic material (identity by descent) near the genes that influence those traits. A number of different statistical methods for testing that association between shared trait values and shared identity by descent have been developed over the past 30 or more years. These different types of tests are reviewed here, with emphasis on their theory and derivations. Robustness and power are also discussed. PMID:11855951

Feingold, E

2001-11-01

40

Derivatization methods for quantitative bioanalysis by LC-MS/MS.  

PubMed

LC with atmospheric pressure ionization MS is essential to a large number of quantitative bioanalyses for a variety of compounds, especially nonvolatile or highly polar compounds. However, in many instances, weak ionization, poor LC retention and instability of certain analytes hinder the development of the LC-MS/MS method. Chemical derivatization has been used for different classes of analytes to improve their ionization efficiency, chromatographic separation and chemical stability. This work presents an overview of chemical derivatization methods that have been applied to the quantitative LC-MS/MS analyses of nine classes of molecules, including aldehydes, amino acids, bisphosphonate drugs, carbohydrates, carboxylic acids, nucleosides and their associated analogs, steroids, thiol-containing compounds and vitamin D metabolites, in biological matrices. PMID:22191594

Deng, Pan; Zhan, Yan; Chen, Xiaoyan; Zhong, Dafang

2012-01-01

41

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. PMID:24077106

Nikoli?, Dejan; van Breemen, Richard B.

2013-01-01

42

A Quantitative Method To Evaluate Neutralizer Toxicity againstAcanthamoeba castellanii  

Microsoft Academic Search

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

SALLY L. BUCK; ANDRUTH A. ROSENTHAL

1996-01-01

43

A comparison of three methods for quantitation of variant hemoglobin fractions.  

PubMed

Three methods, cellulose acetate electrophoresis-densitometry (CAE-D), cellulose acetate electrophoresis-elution (CAE-E), and microchromatography (MGC), were evaluated to determine the best method for quantitating variant hemoglobins. Evaluations were performed in two phases. In Phase I samples of known hemoglobins were obtained and Hb S and/or Hb C were quantitated by the three methods to evaluate agreement of results. In Phase II reference samples were prepared. The Hb S concentrations from each method were compared to the reference value to determine the effect of varying concentrations of Hb S on the methods. Cellulose acetate electrophoresis-densitometry proved to be the best method for quantitating variant hemoglobins in which the concentration was greater than 35 percent. Microchromatography was shown to be the best method when Hb S was approximately 30 percent. Either the microchromatography or the cellulose acetate electrophoresis-elution method proved to be a good method for quantitating approximately 25 percent Hb S. PMID:7211934

Pearce, C J

1980-10-01

44

Quantitative PCR method to measure the fungal endophyte in locoweeds.  

PubMed

A fungal endophyte ( Undifilum oxytropis ) has been implicated in the synthesis of swainsonine in Oxytropis and Astragalus species, commonly known as locoweeds. A quantitative PCR method has been developed to measure the amount of endophyte in Oxytropis and Astragalus species. The limit of quantitation was estimated to be 0.2 pg of endophyte/ng of total DNA. This method of analysis was used to quantify the amount of endophyte in 10 plants each of Oxytropis sericea (white point locoweed), Astragalus mollissimus (wooly locoweed), and Astragalus lentiginosus (spotted locoweed). A significant amount of individual plant variability was observed in endophyte content among individuals in all three species. In one O. sericea and one A. lentiginosus plant swainsonine concentrations were near or below the limit of detection. These plants also had the lowest amounts of endophyte when compared to the other specimens. This method will be a useful tool in further investigating the role the endophyte plays in swainsonine production in various locoweed species. PMID:19545150

Cook, Daniel; Gardner, Dale R; Welch, Kevin D; Roper, Jessie M; Ralphs, Michael H; Green, Benedict T

2009-07-22

45

Implementation of a quantitative Foucault knife-edge method by means of isophotometry  

NASA Astrophysics Data System (ADS)

Detailed description of stages of computer processing of the shadowgrams during implementation of a modern quantitative Foucault knife-edge method is presented. The map of wave-front aberrations introduced by errors of an optical surface or a system, along with the results of calculation of the set of required characteristics of image quality, are shown.

Zhevlakov, A. P.; Zatsepina, M. E.; Kirillovskii, V. K.

2014-06-01

46

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

47

The ACCE method: an approach for obtaining quantitative or qualitative estimates of residual confounding  

PubMed Central

Background: Nonrandomized studies typically cannot account for confounding from unmeasured factors. Method: A method is presented that exploits the recently-identified phenomenon of confounding amplification to produce, in principle, a quantitative estimate of total residual confounding resulting from both measured and unmeasured factors. Two nested propensity score models are constructed that differ only in the deliberate introduction of an additional variable(s) that substantially predicts treatment exposure. Residual confounding is then estimated by dividing the change in treatment effect estimate between models by the degree of confounding amplification estimated to occur, adjusting for any association between the additional variable(s) and outcome. Results: A hypothetical example is provided to illustrate how the method produces a quantitative estimate of residual confounding if the methods requirements and assumptions are met. Previously published data is used to illustrate that, whether or not the method routinely provides precise quantitative estimates of residual confounding, the method appears to produce a valuable qualitative estimate of the likely direction and general size of residual confounding. Limitations: Uncertainties exist, including identifying the best approaches for: 1) predicting the amount of confounding amplification, 2) minimizing changes between the nested models unrelated to confounding amplification, 3) assessing the association of the introduced variable(s) with outcome, and 4) deriving confidence intervals for the methods estimates (although bootstrapping is one plausible approach). Conclusions: To this authors knowledge, it has not been previously suggested that the phenomenon of confounding amplification, if such amplification is as predictable as suggested by a recent simulation, provides a logical basis for estimating total residual confounding. The method's basic approach is straightforward. The method's routine usefulness, however, has not yet been established, nor has the method been fully validated. Rapid further investigation of this novel method is clearly indicated, given the potential value of its quantitative or qualitative output.

Smith, Eric G.

2014-01-01

48

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.

49

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

50

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.

51

Quantitative mass spectrometric analysis of glycoproteins combined with enrichment methods.  

PubMed

Mass spectrometry (MS) has been a core technology for high sensitive and high-throughput analysis of the enriched glycoproteome in aspects of quantitative assays as well as qualitative profiling of glycoproteins. Because it has been widely recognized that aberrant glycosylation in a glycoprotein may involve in progression of a certain disease, the development of efficient analysis tool for the aberrant glycoproteins is very important for deep understanding about pathological function of the glycoprotein and new biomarker development. This review first describes the protein glycosylation-targeting enrichment technologies mainly employing solid-phase extraction methods such as hydrizide-capturing, lectin-specific capturing, and affinity separation techniques based on porous graphitized carbon, hydrophilic interaction chromatography, or immobilized boronic acid. Second, MS-based quantitative analysis strategies coupled with the protein glycosylation-targeting enrichment technologies, by using a label-free MS, stable isotope-labeling, or targeted multiple reaction monitoring (MRM) MS, are summarized with recent published studies. 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Rapid Commun. Mass Spec Rev 34:148-165, 2015. PMID:24889823

Ahn, Yeong Hee; Kim, Jin Young; Yoo, Jong Shin

2015-04-01

52

A method for the extraction and quantitation of phycoerythrin from algae  

NASA Technical Reports Server (NTRS)

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

Stewart, D. E.

1982-01-01

53

Detection and quantitation of equid gammaherpesviruses (EHV-2, EHV-5) in nasal swabs using an accredited standardised quantitative PCR method.  

PubMed

Equid gammaherpesviruses-2 and -5 are involved in respiratory problems, with potential clinical manifestations such as nasal discharge, pharyngitis and swollen lymph nodes. These viruses are sometimes associated with a poor-performance syndrome, which may result in a significant and negative economic impact for the horse industry. The aim of the present study was to develop and validate quantitative PCR methods for the detection and quantitation of EHV-2 and EHV-5 in equine respiratory fluids. Two distinct tests were characterised: (a) for the qPCR alone and (b) for the whole method (extraction and qPCR) according to the standard model AFNOR XP U47-600-2 (viz., specificity, quantifiable sensibility, linearity, accuracy, range of application, trueness, precision, repeatability and precision of reproducibility). EHV-2 and EHV-5 detection were performed on nasal swabs collected from 172 horses, all of which exhibited clinical signs of respiratory disease. The data revealed a high rate of EHV-2/EHV-5 co-detection that was correlated significantly with age. Viral load of EHV-2 was significantly higher in young horses whereas viral load of EHV-5 was not significantly different with age. PMID:24370678

Hue, Erika S; Fortier, Guillaume D; Fortier, Christine I; Leon, Albertine M; Richard, Eric A; Legrand, Loc J; Pronost, Stphane L

2014-03-01

54

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

55

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

56

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

57

Quantitative cell imaging using single beam phase retrieval method  

Microsoft Academic Search

Quantitative three-dimensional imaging of cells can provide important information about their morphology as well as their dynamics, which will be useful in studying their behavior under various conditions. There are several microscopic techniques to image unstained, semi-transparent specimens, by converting the phase information into intensity information. But most of the quantitative phase contrast imaging techniques is realized either by using

Arun Anand; Vani Chhaniwal; Bahram Javidi

2011-01-01

58

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

59

Quantitative Methods for Comparing Different Polyline Stream Network Models  

SciTech Connect

Two techniques for exploring relative horizontal accuracy of complex linear spatial features are described and sample source code (pseudo code) is presented for this purpose. The first technique, relative sinuosity, is presented as a measure of the complexity or detail of a polyline network in comparison to a reference network. We term the second technique longitudinal root mean squared error (LRMSE) and present it as a means for quantitatively assessing the horizontal variance between two polyline data sets representing digitized (reference) and derived stream and river networks. Both relative sinuosity and LRMSE are shown to be suitable measures of horizontal stream network accuracy for assessing quality and variation in linear features. Both techniques have been used in two recent investigations involving extracting of hydrographic features from LiDAR elevation data. One confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes yielded better stream network delineations, based on sinuosity and LRMSE, when using LiDAR-derived DEMs. The other demonstrated a new method of delineating stream channels directly from LiDAR point clouds, without the intermediate step of deriving a DEM, showing that the direct delineation from LiDAR point clouds yielded an excellent and much better match, as indicated by the LRMSE.

Danny L. Anderson; Daniel P. Ames; Ping Yang

2014-04-01

60

Comparison of different surface quantitative analysis methods: Application to corium  

NASA Astrophysics Data System (ADS)

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

Guilbaud, Nathalie; Blin, Delphine; Prodeaud, Phllippe; Dugne, Olivier; Guneau, Christine

2000-07-01

61

Quantitative Methods for Evaluating the Efficacy of Thalamic Deep Brain Stimulation in Patients with Essential Tremor  

PubMed Central

Background Deep brain stimulation (DBS) of the thalamus is a safe and efficient method for treatment of disabling tremor in patient with essential tremor (ET). However, successful tremor suppression after surgery requires careful selection of stimulus parameters. Our aim was to examine the possible use of certain quantitative methods for evaluating the efficacy of thalamic DBS in ET patients in clinical practice, and to compare these methods with traditional clinical tests. Methods We examined 22 patients using the Essential Tremor Rating Scale (ETRS) and quantitative assessment of tremor with the stimulator both activated and deactivated. We used an accelerometer (CATSYS tremor Pen) for quantitative measurement of postural tremor, and a eurythmokinesimeter (EKM) to evaluate kinetic tremor in a rapid pointing task. Results The efficacy of DBS on tremor suppression was prominent irrespective of the method used. The agreement between clinical rating of postural tremor and tremor intensity as measured by the CATSYS tremor pen was relatively high (rs?=?0.74). The agreement between kinetic tremor as assessed by the ETRS and the main outcome variable from the EKM test was low (rs?=?0.34). The lack of agreement indicates that the EKM test is not comparable with the clinical test. Discussion Quantitative methods, such as the CATSYS tremor pen, could be a useful complement to clinical tremor assessment in evaluating the efficacy of DBS in clinical practice. Future studies should evaluate the precision of these methods and long-term impact on tremor suppression, activities of daily living (ADL) function and quality of life. PMID:24255800

Wastensson, Gunilla; Holmberg, Bjrn; Johnels, Bo; Barregard, Lars

2013-01-01

62

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

63

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

PubMed

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

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

2013-01-01

64

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

PubMed

Metabolite concentration measurements in in vivo NMR are generally performed under partially saturated conditions, with correction for partial saturation performed after data collection using a measured saturation factor. Here, we present an experimental test of the hypothesis that quantitation errors can occur due to application of such saturation factor corrections in changing systems. Thus, this extends our previous theoretical work on quantitation errors due to varying saturation factors. We obtained results for two systems frequently studied by 31P NMR, the ischemic rat heart and the electrically stimulated rat gastrocnemius muscle. The results are interpreted in light of previous theoretical work which defined the degree of saturation occurring in a one-pulse experiment for a system with given spin-lattice relaxation times, T(1)s, equilibrium magnetizations, M(0)s, and reaction rates. We found that (i) the assumption of constancy of saturation factors leads to quantitation errors on the order of 40% in inorganic phosphate; (ii) the dominant contributor to the quantitation errors in inorganic phosphate is most likely changes in T(1); (iii) T(1) and M(0) changes between control and intervention periods, and chemical exchange contribute to different extents to quantitation errors in phosphocreatine and gamma-ATP; (iv) relatively small increases in interpulse delay substantially decreased quantitation errors for metabolites in ischemic rat hearts; (v) random error due to finite SNR led to approximately 4% error in quantitation, and hence was a substantially smaller contributor than were changes in saturation factors. PMID:12713964

Galbn, Craig J; Ellis, Scott J; Spencer, Richard G S

2003-04-01

65

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

NASA Astrophysics Data System (ADS)

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

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

2003-04-01

66

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

E-print Network

4th Colloquium on Textile Reinforced Structures (CTRS4) 1 Quantitative methods used to characterize level of the yarn / matrix interface, in the case of Textile Reinforced Concrete (TRC). These methods interface made by scanning electronic microscopy. As a result, it is shown how the two methods described

Paris-Sud XI, Université de

67

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

68

Determination of accuracy of quantitative immunohistochemical results with an antigen-immobilized filter model system.  

PubMed

To determine accuracy of quantitative immunohistochemical results, serially diluted liver cell lysates from methylcholanthrene (MC)-treated rats containing cytochrome P-450 (P-450) 1A were immobilized on nitrocellulose (NC) filters and stained by the indirect immunoperoxidase method under saturation conditions. The stained filters were processed for image analysis and the relationship between the resulting immunostaining intensity due to P-450 1A and the antigen amount immobilized on the filters was examined. The relationship examined in the filters fitted with an exponential curve. Thus, the intensity due to P-450 1A is not simply proportional to the antigen amount. Subsequently, immunostaining intensity due to P-450 1A was measured in sections from control and methylcholanthrene (MC)-treated rats by image analysis with an image processor, and the antigen content in cell lysates from control and MC-treated animals was measured immunochemically by quantitative single radial immunodiffusion. Although immunochemically measured P-450 1A content in the lysates increased markedly (26 times), average staining intensity in sections increased slightly (2-3 times) after MC injection. However, when the exponential curve obtained from the filter binding assay was used as a standard curve to convert staining intensity in sections to molar content of P-450 1A, the resulting content was compatible with the immunochemical content. The divergence between the increase in immunochemically measured P-450 1A content and that in immunostaining intensity in sections after MC injection is therefore attributed primarily to the curvilinear relationship between the intensity and the content. PMID:9538619

Watanabe, J; Mino, K; Tanaka, T; Kanamura, S

1998-02-01

69

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

70

A novel method for quantitative geosteering using azimuthal gamma-ray logging.  

PubMed

A novel method for quantitative geosteering by using azimuthal gamma-ray logging is proposed. Real-time up and bottom gamma-ray logs when a logging tool travels through a boundary surface with different relative dip angles are simulated with the Monte Carlo method. Study results show that response points of up and bottom gamma-ray logs when the logging tool moves towards a highly radioactive formation can be used to predict the relative dip angle, and then the distance from the drilling bit to the boundary surface is calculated. PMID:25479436

Yuan, Chao; Zhou, Cancan; Zhang, Feng; Hu, Song; Li, Chaoliu

2015-02-01

71

Methods and Challenges in Quantitative Imaging Biomarker Development.  

PubMed

Academic radiology is poised to play an important role in the development and implementation of quantitative imaging (QI) tools. This article, drafted by the Association of University Radiologists Radiology Research Alliance Quantitative Imaging Task Force, reviews current issues in QI biomarker research. We discuss motivations for advancing QI, define key terms, present a framework for QI biomarker research, and outline challenges in QI biomarker development. We conclude by describing where QI research and development is currently taking place and discussing the paramount role of academic radiology in this rapidly evolving field. PMID:25481515

Abramson, Richard G; Burton, Kirsteen R; Yu, John-Paul J; Scalzetti, Ernest M; Yankeelov, Thomas E; Rosenkrantz, Andrew B; Mendiratta-Lala, Mishal; Bartholmai, Brian J; Ganeshan, Dhakshinamoorthy; Lenchik, Leon; Subramaniam, Rathan M

2015-01-01

72

A quantitative method for visual phantom image quality evaluation  

Microsoft Academic Search

This work presents an image quality evaluation technique for uniform-background target-object phantom images. The Degradation-Comparison-Threshold (DCT) method involves degrading the image quality of a target-containing region with a blocking processing and comparing the resulting image to a similarly degraded target-free region. The threshold degradation needed for 92% correct detection of the target region is the image quality measure of the

Dev P. Chakraborty; Xiong Liu; Michael O'Shea; Lawrence C. Toto

2000-01-01

73

An Uneasy Alliance: Combining Qualitative and Quantitative Research Methods.  

ERIC Educational Resources Information Center

In a study of the relationship between moral reasoning and teenage drug use, problems arose in an attempt to reduce qualitative data to a quantitative format: (1) making analytic sense of singular and universal responses; (2) the mistaken logical inference that each pattern of judgment should have behavioral indicators; and (3) construction and

Buchanan, David R.

1992-01-01

74

Anesthesia of Artemia Larvae: Method for Quantitative Study  

Microsoft Academic Search

Potency of anesthetics is quantitatively measured with laboratory-hatched larvae of the brine shrimp Artemia salina. Statistical fluctuations are minimized in that 100,000 animals are used to determine a single median anesthetic dose value. The technique was developed to study molecular mechanisms of general anesthesia.

Arthur B. Robinson; Kenneth F. Manly; Michael P. Anthony; John F. Catchpool; Linus Pauling

1965-01-01

75

Corridor4DM: the Michigan method for quantitative nuclear cardiology.  

PubMed

Quantitative software for the analysis and review of myocardial perfusion emission computed tomography images is an indispensable tool in the nuclear physician's evaluation of patients with known or suspected heart disease. The Corridor4DM (4DM) application (formerly known as 4DM-SPECT), developed at the University of Michigan Medical Center, is a quantitative software application providing automated processing, analysis, and reporting of myocardial perfusion and function from cardiac emission computed tomography studies in a tightly integrated, user-centered environment. With health care placing increased emphasis on higher quality and efficiency in diagnostic imaging, quantitative analysis and review software applications need to provide a comprehensive environment supporting correlative review of multimodality images, integrated report generation, and remote review capabilities. The current and future design capabilities of the 4DM software application are discussed with respect to the changing landscape of imaging, where cardiac computed tomography, positron emission tomography, structured reporting, and remote review are expanding the base requirement specifications for quantitative software. PMID:17679053

Ficaro, Edward P; Lee, Benjamin C; Kritzman, James N; Corbett, James R

2007-07-01

76

METHOD OF QUANTITATIVE BACTERIAL COUNT IN BURN WOUND  

Microsoft Academic Search

Objective: To describe a technique for conducting Quantitative bacteriology in burn wounds, which is a very important tool in the management of burn wound sepsis. Methodology: Technique was used in 21 patients with burn wound injury. Biopsy for the bacteriology was taken with the help of punch forceps. Then it was directly put into sterilized pre weighed homogenizer bag containing

Mohammad Ashraf Ganatra; Hammad Ashraf Ganatra

77

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

E-print Network

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

Torgersen, Christian

78

Methods for quantitative image quality evaluation of MRI parallel reconstructions: detection and perceptual difference model  

Microsoft Academic Search

Many reconstruction algorithms are being proposed for parallel magnetic resonance imaging (MRI), which uses multiple coils and subsampled k-space data, and a quantitative method for comparison of algorithms is sorely needed. On such images, we compared three methods for quantitative image quality evaluation: human detection, computer detection model and a computer perceptual difference model (PDM). One-quarter sampling and three different

Yuhao Jiang; Donglai Huo; David L. Wilson

2007-01-01

79

Development and evaluation of a model-based downscatter compensation method for quantitative I-131 SPECT  

PubMed Central

Purpose: The radionuclide 131I has found widespread use in targeted radionuclide therapy (TRT), partly due to the fact that it emits photons that can be imaged to perform treatment planning or posttherapy dose verification as well as beta rays that are suitable for therapy. In both the treatment planning and dose verification applications, it is necessary to estimate the activity distribution in organs or tumors at several time points. In vivo estimates of the 131I activity distribution at each time point can be obtained from quantitative single-photon emission computed tomography (QSPECT) images and organ activity estimates can be obtained either from QSPECT images or quantification of planar projection data. However, in addition to the photon used for imaging, 131I decay results in emission of a number of other higher-energy photons with significant abundances. These higher-energy photons can scatter in the body, collimator, or detector and be counted in the 364 keV photopeak energy window, resulting in reduced image contrast and degraded quantitative accuracy; these photons are referred to as downscatter. The goal of this study was to develop and evaluate a model-based downscatter compensation method specifically designed for the compensation of high-energy photons emitted by 131I and detected in the imaging energy window. Methods: In the evaluation study, we used a Monte Carlo simulation (MCS) code that had previously been validated for other radionuclides. Thus, in preparation for the evaluation study, we first validated the code for 131I imaging simulation by comparison with experimental data. Next, we assessed the accuracy of the downscatter model by comparing downscatter estimates with MCS results. Finally, we combined the downscatter model with iterative reconstruction-based compensation for attenuation (A) and scatter (S) and the full (D) collimator-detector response of the 364 keV photons to form a comprehensive compensation method. We evaluated this combined method in terms of quantitative accuracy using the realistic 3D NCAT phantom and an activity distribution obtained from patient studies. We compared the accuracy of organ activity estimates in images reconstructed with and without addition of downscatter compensation from projections with and without downscatter contamination. Results: We observed that the proposed method provided substantial improvements in accuracy compared to no downscatter compensation and had accuracies comparable to reconstructions from projections without downscatter contamination. Conclusions: The results demonstrate that the proposed model-based downscatter compensation method is effective and may have a role in quantitative 131I imaging. PMID:21815394

Song, Na; Du, Yong; He, Bin; Frey, Eric C.

2011-01-01

80

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

PubMed Central

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 a more focused set of phenotypes within a clear biological context than conventional eQTL mapping. Results Applying this method to a study of endometrial cancer revealed regulatory mechanisms supported by the literature: a creQTL between a locus upstream of STARD13/DLC2 and a group of seven IFN?-induced genes. This suggests that the Rho-GTPase encoded by STARD13 regulates IFN?-induced genes and the DNA damage response. Conclusions Because of the importance of IFN? in cancer, our results suggest that creQTL may provide a finer picture of gene regulation and may reveal additional molecular targets for intervention. An open source R implementation of the method is available at http://sites.google.com/site/kenkompass/. PMID:21226949

2011-01-01

81

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. PMID:22559605

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

2012-01-01

82

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

83

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

84

Quantitative Analysis and Validation of Method Using HPTLC  

NASA Astrophysics Data System (ADS)

High performance thin layer chromatography is an emerging alternative analytical technique in comparison with conventional column chromatography because of its simplicity, rapidity, accuracy, robustness, and cost effectiveness. Choice of vast array of supporting matrices and solvent systems resulted in separation of almost all types of analytes except volatiles. First step of a robust method development for routine quantification is to check the stability of analyte during various steps of chromatographic development followed by preparation of calibration curves. Thereafter, various validation aspects of analysis namely peak purity, linearity and range, precision, limit of detection, limit of quantification, robustness, and accuracy have to be measured.

Dhandhukia, Pinakin C.; Thakker, Janki N.

85

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; Ribire, Magali

2012-03-01

86

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

PubMed Central

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

Rong, Xing; Frey, Eric C.

2013-01-01

87

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

88

Full quantitative phase analysis of hydrated lime using the Rietveld method  

SciTech Connect

Full quantitative phase analysis (FQPA) using X-ray powder diffraction and Rietveld refinements is a well-established method for the characterization of various hydraulic binders such as Portland cement and hydraulic limes. In this paper, the Rietveld method is applied to hydrated lime, a non-hydraulic traditional binder. The potential presence of an amorphous phase in this material is generally ignored. Both synchrotron radiation and a conventional X-ray source were used for data collection. The applicability of the developed control file for the Rietveld refinements was investigated using samples spiked with glass. The results were cross-checked by other independent methods such as thermal and chemical analyses. The sample microstructure was observed by transmission electron microscopy. It was found that the consistency between the different methods was satisfactory, supporting the validity of FQPA for this material. For the samples studied in this work, the amount of amorphous material was in the range 2-15 wt.%.

Lassinantti Gualtieri, Magdalena, E-mail: magdalena.gualtieri@unimore.it [Dipartimento Ingegneria dei Materiali e dell'Ambiente, Universita Degli Studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41100 Modena (Italy); Romagnoli, Marcello; Miselli, Paola; Cannio, Maria [Dipartimento Ingegneria dei Materiali e dell'Ambiente, Universita Degli Studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41100 Modena (Italy)] [Dipartimento Ingegneria dei Materiali e dell'Ambiente, Universita Degli Studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41100 Modena (Italy); Gualtieri, Alessandro F. [Dipartimento di Scienze della Terra, Universita Degli Studi di Modena e Reggio Emilia, I-41100 Modena (Italy)] [Dipartimento di Scienze della Terra, Universita Degli Studi di Modena e Reggio Emilia, I-41100 Modena (Italy)

2012-09-15

89

Derivative method for phase retrieval in off-axis quantitative phase imaging.  

PubMed

We present a method for phase retrieval in off-axis interferometric systems. By numerically calculating the transverse 1st and 2nd order derivatives of the interferogram, we show that one can directly retrieve the quantitative phase image, without the need for Fourier or Hilbert transformations. Because of this, the method is significantly faster than the current approaches. We illustrate our method using biological specimen data from three different off-axis quantitative phase imaging techniques. PMID:22660056

Bhaduri, Basanta; Popescu, Gabriel

2012-06-01

90

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

91

Determination of haem derivatives in the cerebrospinal fluid--a semi-quantitative method.  

PubMed Central

A spectrophotometric method for semi-quantitative determination of oxyhaemoglobin, methaemoglobin and bilirubin in the cerebrospinal fluid is described and evaluated. The method involves correction for CSF protein. It is based on absorbance registrations on three wavelengths; 400, 420 and 470 nm. Reference values for a healthy control group and a hyperbilirubinaemic group are presented. Evaluation of the method shows that it is well suited to semi-quantitative determination of haem derivatives in the CSF. PMID:6886704

Wahlgren, N G; Bergstrm, K

1983-01-01

92

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

93

Methods for quantitative health impact assessment of an airport and waste incinerator: two case studies  

Microsoft Academic Search

Findings from epidemiological studies can be used to make quantitative predictions of health impacts of new developments in a land-use planning context. In UK practice, exposures that may impact on health are described in environmental statements, but the health outcomes are rarely assessed explicitly. Methods for quantitative health impact assessments (HIA) are demonstrated in two case studies: proposals to extend

Caroline Phillips; Mark McCarthy; Roger Barrowcliffe

2010-01-01

94

Methods for quantitative determination of drug localized in the skin.  

PubMed

The quantification of drugs within the skin is essential for topical and transdermal delivery research. Over the last two decades, horizontal sectioning, consisting of both tape stripping and parallel slicing through the deeper tissues has constituted the traditional investigative technique. In recent years, this methodology has been augmented by such procedures as heat separation, qualitative autoradiography, isolation of the pilosebaceous units and the use of induced follicle-free skin. The development of skin quantitative autoradiography represents an entirely novel approach which permits quantification and visualization of the penetrant throughout a vertical cross-section of skin. Noninvasive strategies involve the application of optical measuring systems such as attenuated total reflectance Fourier transform infrared, fluorescence, remittance or photothermal spectroscopies. PMID:9801425

Touitou, E; Meidan, V M; Horwitz, E

1998-12-01

95

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

PubMed

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

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

2014-10-01

96

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

97

A novel real-time quantitative PCR method using attached universal template probe  

PubMed Central

A novel real-time quantitative polymerase chain reaction (PCR) method using an attached universal template (UT) probe is described. The UT is an approximately 20 base attachment to the 5? end of a PCR primer, and it can hybridize with a complementary TaqMan probe. One of the advantages of this method is that different target DNA sequences can be detected employing the same UT probe, which substantially reduces the cost of real-time PCR set-up. In addition, this method could be used for simultaneous detection using a 6-carboxy-fluorescein-labeled UT probe for the target gene and a 5-hexachloro-fluorescein-labeled UT probe for the reference gene in a multiplex reaction. Moreover, the requirement of target DNA length for UTPCR analysis is relatively flexible, and it could be as short as 56 bp in this report, suggesting the possibility of detecting target DNA from partially degraded samples. The UTPCR system with degenerate primers could also be designed to screen homologous genes. Taken together, our results suggest that the UTPCR technique is efficient, reliable, inexpensive and less labor-intensive for quantitative PCR analysis. PMID:14530456

Zhang, Yuanli; Zhang, Dabing; Li, Wenquan; Chen, Jianqun; Peng, Yufa; Cao, Wei

2003-01-01

98

Multiplexed method to calibrate and quantitate fluorescence signal for allergen-specific IgE.  

PubMed

Using a microarray platform for allergy diagnosis allows for testing of specific IgE sensitivity to a multitude of allergens, while requiring only small volumes of serum. However, variation of probe immobilization on microarrays hinders the ability to make quantitative, assertive, and statistically relevant conclusions necessary in immunodiagnostics. To address this problem, we have developed a calibrated, inexpensive, multiplexed, and rapid protein microarray method that directly correlates surface probe density to captured labeled secondary antibody in clinical samples. We have identified three major technological advantages of our calibrated fluorescence enhancement (CaFE) technique: (i) a significant increase in fluorescence emission over a broad range of fluorophores on a layered substrate optimized specifically for fluorescence; (ii) a method to perform label-free quantification of the probes in each spot while maintaining fluorescence enhancement for a particular fluorophore; and (iii) a calibrated, quantitative technique that combines fluorescence and label-free modalities to accurately measure probe density and bound target for a variety of antibody-antigen pairs. In this paper, we establish the effectiveness of the CaFE method by presenting the strong linear dependence of the amount of bound protein to the resulting fluorescence signal of secondary antibody for IgG, ?-lactoglobulin, and allergen-specific IgEs to Ara h 1 (peanut major allergen) and Phl p 1 (timothy grass major allergen) in human serum. PMID:22060132

Monroe, Margo R; Reddington, Alexander P; Collins, Austin D; LaBoda, Craig; Cretich, Marina; Chiari, Marcella; Little, Frdric F; Unl, M Selim

2011-12-15

99

A quantitative assessment of nuclear weapons proliferation risk utilizing probabilistic methods  

E-print Network

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

Sentell, Dennis Shannon, 1971-

2002-01-01

100

Quantitative Methods for Strategic and Investment Planning in the Oil-Refining  

E-print Network

Quantitative Methods for Strategic and Investment Planning in the Oil-Refining Brenno C by one refinery Refinery Opera*onal Planning - Simulate the Refining Scenarios Supply Chain Investments Planning - Test the refinery best scenarios

Grossmann, Ignacio E.

101

A Quantitative Diagnostic Method Based on Bayesian Networks in Traditional Chinese Medicine  

Microsoft Academic Search

\\u000a Traditional Chinese Medicine (TCM) is one of the most important complementary and alternative medicines. Due to the subjectivity\\u000a and fuzziness of diagnosis in TCM, quantitative model or methods are needed to facilitate the popularization of TCM. In this\\u000a article, a novel quantitative method for syndrome differentiation based on BNs is proposed. First the symptoms are selected\\u000a by a novel mutual

Huiyan Wang; Jie Wang

2006-01-01

102

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

ERIC Educational Resources Information Center

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

Danjuma, Ibrahim Mohammed

2011-01-01

103

Evaluating Attitudes, Skill, and Performance in a Learning-Enhanced Quantitative Methods Course: A Structural Modeling Approach.  

ERIC Educational Resources Information Center

Used a structural modeling approach to evaluate relations among attitudes, initial skills, and performance in a Quantitative Methods course that involved students in active learning. Results largely confirmed hypotheses offering support for educational reform efforts that propose actively involving students in the learning process, especially in

Harlow, Lisa L.; Burkholder, Gary J.; Morrow, Jennifer A.

2002-01-01

104

Disseminated Toxoplasmosis, Resulting from Infection of Allograft, after Orthotopic Liver Transplantation: Usefulness of Quantitative PCR  

PubMed Central

Disseminated toxoplasmosis is a life-threatening disease in liver transplant recipients that can result from an organ-transmitted infection. We report here a case of fatal disseminated toxoplasmosis after orthotopic liver transplantation from a seropositive donor (immunoglobulin G [IgG]+ and IgM?) in a patient who was nonimmune for toxoplasmosis prior to transplantation. Quantitative PCR analyses of various clinical specimens, including serum samples, appeared retrospectively to be a valuable diagnostic tool that might guide therapeutic attitudes. PMID:11980935

Botterel, F.; Ichai, P.; Feray, C.; Bouree, P.; Saliba, F.; Tur Raspa, R.; Samuel, D.; Romand, S.

2002-01-01

105

The need for quantitative methods in syntax and semantics research  

E-print Network

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

Gibson, Edward A.

106

Low level drug product API form analysis - Avalide tablet NIR quantitative method development and robustness challenges.  

PubMed

Avalide(@), a medication used for the treatment of hypertension, is a combination of Irbesartan, and Hydrochlorothiazide. Irbesartan, one of the active pharmaceutical ingredients (API) in Avalide products, exists in two neat crystalline forms: Form A and Form B. Irbesartan Form A is the API form used in a wet granulation for the preparation of Avalide tablets. The presence of the less soluble Irbesartan Form B in Avalide tablets may result in the slower dissolution. In this paper, we have presented our work on the method development, verification and challenges of quantitatively detecting, via NIR and ssNMR, very small amounts of Irbesartan Form B in Avalide tablets. As part of the NIR method development and qualification, limit of detection, linearity and accuracy were examined. In addition, a limited study of the robustness of the method was conducted and a bias in the level of Form B was correlated to the ambient humidity. ssNMR, a primary method for the determination of polymorphic composition, was successfully used as an orthogonal technique to verify the accuracy of the NIR method and added to the confidence in the NIR method. The speed and efficiency of the NIR method make it a suitable and convenient tool for routine analysis of Avalide tablets for Form B in a QC environment. PMID:24316453

Pan, Duohai; Crull, George; Yin, Shawn; Grosso, John

2014-02-01

107

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

PubMed

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

Demeke, Tigst; Ratnayaka, Indira; Phan, Anh

2009-01-01

108

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

109

A quantitative evaluation of two methods for preserving hair samples  

USGS Publications Warehouse

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

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

2003-01-01

110

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

111

The Ten Beads Method: A Novel Way to Collect Quantitative Data in Rural Uganda  

PubMed Central

This paper illustrates how locally appropriate methods can be used to collect quantitative data from illiterate respondents. This method uses local beads to represent quantities, which is a novel yet potentially valuable methodological improvement over standard Western survey methods. PMID:25170477

Bwambale, Francis Mulekya; Moyer, Cheryl A.; Komakech, Innocent; -Mangen, Fred-Wabwire; Lori, Jody R

2013-01-01

112

A new method for fast quantitative mapping of absolute water content in vivo.  

PubMed

The presence of brain edema, in its various forms, is an accompanying feature of many diseased states. Although the localized occurrence of brain edema may be demonstrated with MRI, the quantitative determination of absolute water content, an aspect that could play an important role in the objective evaluation of the dynamics of brain edema and the monitoring of the efficiency of treatment, is much more demanding. We present a method for the localized and quantitative measurement of absolute water content based on the combination of two fast multi-slice and multi-time point sequences QUTE and TAPIR for mapping the T(2)* and T(1) relaxation times, respectively. Incorporation of corrections for local B(1) field miscalibrations, temperature differences between the subject and a reference probe placed in the FOV, receiver profile inhomogeneities and T(1) saturation effects are included and allow the determination of water content with anatomical resolution and a precision >98%. The method was validated in phantom studies and was applied to the localized in vivo measurement of water content in a group of normal individuals and a patient with brain tumor. The results demonstrate that in vivo measurement of regional absolute water content is possible in clinically relevant measurement times with a statistical and systematic measurement error of <2%. PMID:16650780

Neeb, H; Zilles, K; Shah, N J

2006-07-01

113

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

114

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

PubMed Central

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

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

2014-01-01

115

Optogalvanic intracavity quantitative detector and method for its use  

DOEpatents

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

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

1983-01-01

116

QUANTITATIVE METHODS FOR CROSS-SPECIES MAPPING (CSM)  

EPA Science Inventory

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

117

The need for quantitative methods in syntax and semantics research  

Microsoft Academic Search

The prevalent method in syntax and semantics research involves obtaining a judgement of the acceptability of a sentence\\/meaning pair, typically by just the author of the paper, sometimes with feedback from colleagues. This methodology does not allow proper testing of scientific hypotheses because of (a) the small number of experimental participants (typically one); (b) the small number of experimental stimuli

Edward Gibson; Evelina Fedorenko

2010-01-01

118

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

119

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

120

Results of a Formal Methods Demonstration Project  

NASA Technical Reports Server (NTRS)

This paper describes the results of a cooperative study conducted by a team of researchers in formal methods at three NASA Centers to demonstrate FM techniques and to tailor them to critical NASA software systems. This pilot project applied FM to an existing critical software subsystem, the Shuttle's Jet Select subsystem (Phase I of an ongoing study). The present study shows that FM can be used successfully to uncover hidden issues in a highly critical and mature Functional Subsystem Software Requirements (FSSR) specification which are very difficult to discover by traditional means.

Kelly, J.; Covington, R.; Hamilton, D.

1994-01-01

121

Interferences of suspended clay fraction in protein quantitation by several determination methods  

Microsoft Academic Search

Seven current methods of protein quantitation, Bradford (standard, micro, and 590\\/450nm ratio), Lowry, bicinchoninic acid (BCA), UV spectrophotometry at 280nm, and Quant-iT fluorescence-based determination, were compared with regard to their susceptibility to interferences due to the presence of suspended and not easily detectable clay particles. Bovine serum albumin (BSA) and Na-Wyoming montmorillonite were selected as model protein and reference clay,

I. Lozzi; A. Pucci; O. L. Pantani; L. P. DAcqui; L. Calamai

2008-01-01

122

A Simple Quantitative Method for Assessing Pulmonary Damage after  

E-print Network

Pulmonary damage after radiotherapy is typically characterized by an initial alveolar inflammation (pneumonitis) followed by chronic fibrosis. In the present study, changes in lung architecture were measured in the pneumonitis phase after whole-body low-dose X irradiation of C57BL/6 mice. Radiation damage was evaluated at 24 h and 18 weeks postirradiation. Three distinct scoring systems were used: (1) manually evaluating alveolar distortion and infiltration of inflammatory cells into the alveolar space using a continuous numerical scale across an entire lung section, (2) physically measuring the average thickness of the alveolar septa from multiple representative microscope fields, and (3) a new rapid automated mathematical algorithm based on image segmentation of alveolar space across an entire section. Each scoring method detected significant changes in alveolar architecture at the

X Irradiation; L. Downing; A K. E. Sawarynski; B J. Li; C M. Mcgonagle; D M. D. Sims A; B. Marples A

123

Quantitative Trait Locus Mapping Methods for Diversity Outbred Mice  

PubMed Central

Genetic mapping studies in the mouse and other model organisms are used to search for genes underlying complex phenotypes. Traditional genetic mapping studies that employ single-generation crosses have poor mapping resolution and limit discovery to loci that are polymorphic between the two parental strains. Multiparent outbreeding populations address these shortcomings by increasing the density of recombination events and introducing allelic variants from multiple founder strains. However, multiparent crosses present new analytical challenges and require specialized software to take full advantage of these benefits. Each animal in an outbreeding population is genetically unique and must be genotyped using a high-density marker set; regression models for mapping must accommodate multiple founder alleles, and complex breeding designs give rise to polygenic covariance among related animals that must be accounted for in mapping analysis. The Diversity Outbred (DO) mice combine the genetic diversity of eight founder strains in a multigenerational breeding design that has been maintained for >16 generations. The large population size and randomized mating ensure the long-term genetic stability of this population. We present a complete analytical pipeline for genetic mapping in DO mice, including algorithms for probabilistic reconstruction of founder haplotypes from genotyping array intensity data, and mapping methods that accommodate multiple founder haplotypes and account for relatedness among animals. Power analysis suggests that studies with as few as 200 DO mice can detect loci with large effects, but loci that account for <5% of trait variance may require a sample size of up to 1000 animals. The methods described here are implemented in the freely available R package DOQTL. PMID:25237114

Gatti, Daniel M.; Svenson, Karen L.; Shabalin, Andrey; Wu, Long-Yang; Valdar, William; Simecek, Petr; Goodwin, Neal; Cheng, Riyan; Pomp, Daniel; Palmer, Abraham; Chesler, Elissa J.; Broman, Karl W.; Churchill, Gary A.

2014-01-01

124

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

125

Quantitative interferometric microscopic flow cytometer with expanded principal component analysis method  

NASA Astrophysics Data System (ADS)

Quantitative interferometric microscopy is used in biological and medical fields and a wealth of applications are proposed in order to detect different kinds of biological samples. Here, we develop a phase detecting cytometer based on quantitative interferometric microscopy with expanded principal component analysis phase retrieval method to obtain phase distributions of red blood cells with a spatial resolution ~1.5 ?m. Since expanded principal component analysis method is a time-domain phase retrieval algorithm, it could avoid disadvantages of traditional frequency-domain algorithms. Additionally, the phase retrieval method realizes high-speed phase imaging from multiple microscopic interferograms captured by CCD camera when the biological cells are scanned in the field of view. We believe this method can be a powerful tool to quantitatively measure the phase distributions of different biological samples in biological and medical fields.

Wang, Shouyu; Jin, Ying; Yan, Keding; Xue, Liang; Liu, Fei; Li, Zhenhua

2014-11-01

126

An improved transmutation method for quantitative determination of the components in multicomponent overlapping chromatograms.  

PubMed

An improved method is proposed for the quantitative determination of multicomponent overlapping chromatograms based on a known transmutation method. To overcome the main limitation of the transmutation method caused by the oscillation generated in the transmutation process, two techniques--wavelet transform smoothing and the cubic spline interpolation for reducing data points--were adopted, and a new criterion was also developed. By using the proposed algorithm, the oscillation can be suppressed effectively, and quantitative determination of the components in both the simulated and experimental overlapping chromatograms is successfully obtained. PMID:15164155

Shao, Xueguang; Yu, Zhengliang; Ma, Chaoxiong

2004-06-01

127

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

128

Statistical methods for quantitative mass spectrometry proteomic experiments with labeling.  

PubMed

Mass Spectrometry utilizing labeling allows multiple specimens to be subjected to mass spectrometry simultaneously. As a result, between-experiment variability is reduced. Here we describe use of fundamental concepts of statistical experimental design in the labeling framework in order to minimize variability and avoid biases. We demonstrate how to export data in the format that is most efficient for statistical analysis. We demonstrate how to assess the need for normalization, perform normalization, and check whether it worked. We describe how to build a model explaining the observed values and test for differential protein abundance along with descriptive statistics and measures of reliability of the findings. Concepts are illustrated through the use of three case studies utilizing the iTRAQ 4-plex labeling protocol. PMID:23176383

Oberg, Ann L; Mahoney, Douglas W

2012-01-01

129

Statistical methods for quantitative mass spectrometry proteomic experiments with labeling  

PubMed Central

Mass Spectrometry utilizing labeling allows multiple specimens to be subjected to mass spectrometry simultaneously. As a result, between-experiment variability is reduced. Here we describe use of fundamental concepts of statistical experimental design in the labeling framework in order to minimize variability and avoid biases. We demonstrate how to export data in the format that is most efficient for statistical analysis. We demonstrate how to assess the need for normalization, perform normalization, and check whether it worked. We describe how to build a model explaining the observed values and test for differential protein abundance along with descriptive statistics and measures of reliability of the findings. Concepts are illustrated through the use of three case studies utilizing the iTRAQ 4-plex labeling protocol. PMID:23176383

2012-01-01

130

Comparison of Overlap Methods for Quantitatively Synthesizing Single-Subject Data  

ERIC Educational Resources Information Center

Four overlap methods for quantitatively synthesizing single-subject data were compared to visual analysts' judgments. The overlap methods were percentage of nonoverlapping data, pairwise data overlap squared, percentage of data exceeding the median, and percentage of data exceeding a median trend. Visual analysts made judgments about 160 A-B data

Wolery, Mark; Busick, Matthew; Reichow, Brian; Barton, Erin E.

2010-01-01

131

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 matesthe quantitative genetic metric for assortative matingfor phenological traits. The

ARTHUR E. WEIS; TANYA M. KOSSLER

2004-01-01

132

Quantitative oximetry of breast tumors: a near-infrared method that identifies two optimal wavelengths  

E-print Network

Quantitative oximetry of breast tumors: a near-infrared method that identifies two optimal.7050, 300.1030. 1. Introduction Breast cancer is the most common cancer diagnosed and the second leading cause of cancer death among women in the United States.1 The current method for screening is x

Fantini, Sergio

133

IT: An Effective Pedagogic Tool in the Teaching of Quantitative Methods in Management.  

ERIC Educational Resources Information Center

Examines the possibility of supplementing conventional pedagogic methods with information technology-based teaching aids in the instruction of quantitative methods to undergraduate students. Considers the case for a problem-based learning approach, and discusses the role of information technology. (Author/LRW)

Nadkami, Sanjay M.

1998-01-01

134

A simple method for quantitative imaging of 2D acoustic fields using refracto-vibrometry  

NASA Astrophysics Data System (ADS)

This paper presents a simple 2D method for rapid time resolved quantitative imaging of acoustic waves using refracto-vibrometry. We present the theoretical background, the experimental method and reconstructions of acoustic reflection and interference. We investigate the applicability of the method, in particular the effect of sound radiator geometry. Finite element and experimental reconstructions of the sound fields are analysed. The spatial limitations and accuracy of the method are presented and discussed.

Malkin, Robert; Todd, Thomas; Robert, Daniel

2014-09-01

135

Comparison of Quantitative Sweat Chloride Methods after Positive Newborn Screen for Cystic Fibrosis  

PubMed Central

Summary Objectives Rapid and reliable confirmatory sweat testing following a positive newborn screen (NBS) for cystic fibrosis (CF) is preferred to allow for early diagnosis and to decrease parental anxiety. The Cystic Fibrosis Foundation (CFF) recently recommended a quantity not sufficient (QNS) rate of ? 10% in infants < 3 months of age referred for quantitative sweat chloride analysis. Two CFF-approved methods are available by which to quantitatively measure chloride concentration in sweat. Our objective was to compare the performance of the Macroduct sweat collection system (MSCS) with the Gibson and Cooke technique (GCT) in the acquisition of samples for the determination of sweat chloride concentration in infants with a positive Minnesota State NBS for cystic fibrosis. Methods A retrospective database review of infants referred to the core Minnesota CF Center or its affiliate site for confirmatory sweat testing was performed to compare the QNS rates for the two techniques. Associations between birthweight, age at test, race and QNS rates were examined. Results 568 infants were referred for 616 sweat tests from March 2006January 2010. The mean age was 32.8 days at the initial sweat test. The GCT had a significantly higher QNS rate compared to the MSCS (15.4% vs. 2.1%, p<0.0001). There was no association between age and the probability of QNS. The probability of QNS decreased as birthweight increased (p=0.02). After adjusting for age, the odds of QNS using the GCT remained 8.34 (95% CI: 3.7218.71) times that of the MSCS. Non-white infants had a significantly higher likelihood of QNS compared to non-Hispanic white infants (p = 0.0025). Conclusions Given the performance of the MSCS, the Minnesota CF Center has implemented the MSCS as its method of choice for diagnostic sweat testing in infants following a positive state NBS. PMID:22786625

Laguna, Theresa A.; Lin, Nan; Wang, Qi; Holme, Bonnie; McNamara, John; Regelmann, Warren E.

2013-01-01

136

A quantitative method to measure telomerase activity by bioluminescence connected with telomeric repeat amplification protocol.  

PubMed

Telomerase is expected to be a new biomarker for cancer diagnosis. The telomeric repeat amplification protocol (TRAP) is a sensitive method to detect telomerase activity. However, TRAP and its modified protocols are not always suitable for measuring telomerase activity of a large number of clinical samples to diagnosis cancer because these methods generally require a time-consuming detection step such as gel electrophoresis. To improve the procedure for mass diagnosis, we applied bioluminescence to replace the detection step. Telomerase activity is measured by evaluating the amount of inorganic pyrophosphate generated in PCR amplification of telomerase elongation product, with use of the sensitive enzymatic luminometric inorganic pyrophosphate detection assay (ELIDA). TRAP connected with ELIDA (TRAP-ELIDA) can quantitatively detect telomerase activity within linearity from 2 to 1000 cell equivalents. The ELIDA signals accorded with results of TRAP-SYBR green staining, and the results of ELIDA were significantly correlated to those of TRAP connected with an enzyme-linked immunosorbent assay (TRAP-ELISA) (r(2) = 0.992, P < 0.001). TRAP-ELIDA is a simple and sensitive method to quantify telomerase activity without time-consuming gel electrophoresis. Because TRAP-ELIDA measures telomerase activity with a luminometer, it could be applied to a large number of clinical samples at the same time. PMID:11730342

Xu, S; He, M; Yu, H; Cai, X; Tan, X; Lu, B; Shu, B

2001-12-15

137

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 512512-pixels image was 1.57 sec; each acquired image was averaged four frames to improve the signal-to-noise ratio. Our results indicated that collagen presence as determined by counting the ratio of the SHG pixels over the whole pixels for normal and cancerous thyroid tissues were 0.48+/-0.05, 0.33+/-0.06 respectively. In addition, to quantitatively assess collagen-related changes, we employed GLCM texture analysis to the SHG images. Corresponding results showed that the correlation both fell off with distance in normal and cancerous group. Calculated value of Corr50 (the distance where the correlation crossed 50% of the initial correlation) indicated significant difference. This study demonstrates that SHG method can be used as a complementary tool in thyroid histopathology.

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

2012-03-01

138

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 512512-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

139

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

140

Intracranial aneurysm segmentation in 3D CT angiography: method and quantitative validation  

NASA Astrophysics Data System (ADS)

Accurately quantifying aneurysm shape parameters is of clinical importance, as it is an important factor in choosing the right treatment modality (i.e. coiling or clipping), in predicting rupture risk and operative risk and for pre-surgical planning. The first step in aneurysm quantification is to segment it from other structures that are present in the image. As manual segmentation is a tedious procedure and prone to inter- and intra-observer variability, there is a need for an automated method which is accurate and reproducible. In this paper a novel semi-automated method for segmenting aneurysms in Computed Tomography Angiography (CTA) data based on Geodesic Active Contours is presented and quantitatively evaluated. Three different image features are used to steer the level set to the boundary of the aneurysm, namely intensity, gradient magnitude and variance in intensity. The method requires minimum user interaction, i.e. clicking a single seed point inside the aneurysm which is used to estimate the vessel intensity distribution and to initialize the level set. The results show that the developed method is reproducible, and performs in the range of interobserver variability in terms of accuracy.

Firouzian, Azadeh; Manniesing, R.; Flach, Z. H.; Risselada, R.; van Kooten, F.; Sturkenboom, M. C. J. M.; van der Lugt, A.; Niessen, W. J.

2010-03-01

141

accurate, meaningful and useful. DBA6000: Quantitative Business Research Methods 2  

E-print Network

Give only as many decimal places as are accurate, meaningful and useful. Make sure decimal points are aligned. DBA6000: Quantitative Business Research Methods 2 Numerical tables Give only as many decimal places as are accurate, meaningful and useful. Make sure decimal points are aligned. Use horizontal or vertical lines to help the reader make the desired comparisons. DBA6000: Quantitative Business Research Methods 2 Numerical tables Give only as many decimal places as are accurate, meaningful and useful. Make sure decimal points are aligned. Use horizontal or vertical lines to help the reader make the desired comparisons.

unknown authors

142

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

PubMed Central

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

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

2014-01-01

143

A rapid, sensitive, and selective method for quantitation of lamprey migratory pheromones in river water.  

PubMed

The methodology of using fish pheromones, or chemical signatures, as a tool to monitor or manage species of fish is rapidly gaining popularity. Unequivocal detection and accurate quantitation of extremely low concentrations of these chemicals in natural waters is paramount to using this technique as a management tool. Various species of lamprey are known to produce a mixture of three important migratory pheromones; petromyzonol sulfate (PS), petromyzonamine disulfate (PADS), and petromyzosterol disulfate (PSDS), but presently there are no established robust methods for quantitation of all three pheromones. In this study, we report a new, highly sensitive and selective method for the rapid identification and quantitation of these pheromones in river water samples. The procedure is based on pre-concentration, followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. The method is fast, with unambiguous pheromone determination. Practical quantitation limits of 0.25ng/l were achieved for PS and PADS and 2.5ng/l for PSDS in river water, using a 200-fold pre-concentration, However, lower quantitation limits can be achieved with greater pre-concentration. The methodology can be modified easily to include other chemicals of interest. Furthermore, the pre-concentration step can be applied easily in the field, circumventing potential stability issues of these chemicals. PMID:22076684

Stewart, Michael; Baker, Cindy F; Cooney, Terry

2011-11-01

144

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

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

2012-01-01

145

Patient satisfaction with teledermatology: quantitative and qualitative results from a randomized controlled trial.  

PubMed

As part of a randomized controlled trial involving 208 dermatology patients, a quantitative and qualitative study was undertaken to explore patients' satisfaction with a specialist dermatological opinion and further management obtained through either a traditional outpatient consultation (control group) or an asynchronous teleconsultation (telemedicine group). There was a response rate of 71% to the quantitative patient satisfaction survey (148 replies from 208 distributed questionnaires). The responders comprised 80 of the 111 telemedicine patients (72%) and 68 of the 97 control patients (70%). Overall levels of patient satisfaction were high in both groups, and there was no significant difference between them. Ninety per cent of patients in the control group were satisfied with their overall care, compared with 81% in the telemedicine group, and 87% of patients in the control group were satisfied with their overall management, compared with 84% in the telemedicine group. Follow-up qualitative interviews with 30 of the participants also suggested that patients were generally positive about their care and management, regardless of group, age or gender. Receiving a diagnosis, treatment and cure, receiving adequate information and explanations, the need to be taken seriously, the need for individualized personal care, and the importance of a short waiting time for an appointment and treatment were all aspects of care and management most likely to result in patient satisfaction, regardless of modality. PMID:15006213

Collins, Karen; Walters, Stephen; Bowns, Ian

2004-01-01

146

Quantifying disability: data, methods and results.  

PubMed Central

Conventional methods for collecting, analysing and disseminating data and information on disability in populations have relied on cross-sectional censuses and surveys which measure prevalence in a given period. While this may be relevant for defining the extent and demographic pattern of disabilities in a population, and thus indicating the need for rehabilitative services, prevention requires detailed information on the underlying diseases and injuries that cause disabilities. The Global Burden of Disease methodology described in this paper provides a mechanism for quantifying the health consequences of the years of life lived with disabilities by first estimating the age-sex-specific incidence rates of underlying conditions, and then mapping these to a single disability index which collectively reflects the probability of progressing to a disability, the duration of life lived with the disability, and the approximate severity of the disability in terms of activity restriction. Detailed estimates of the number of disability-adjusted life years (DALYs) lived are provided in this paper, for eight geographical regions. The results should be useful to those concerned with planning health services for the disabled and, more particularly, with determining policies to prevent the underlying conditions which give rise to serious disabling sequelae. PMID:8062403

Murray, C. J.; Lopez, A. D.

1994-01-01

147

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

148

Quantitative structure-activity relationships of imidazole-containing farnesyltransferase inhibitors using different chemometric methods.  

PubMed

Farnesyltranseferase inhibitors (FTIs) are one of the most promising classes of anticancer agents, but though some compounds in this category are in clinical trials there are no marketed drugs in this class yet. Quantitative structure activity relationship (QSAR) models can be used for predicting the activity of FTI candidates in early stages of drug discovery. In this study 192 imidazole-containing FTIs were obtained from the literature, structures of the molecules were optimized using Hyperchem software, and molecular descriptors were calculated using Dragon software. The most suitable descriptors were selected using genetic algorithms-partial least squares (GA-PLS) and stepwise regression, and indicated that the volume, shape and polarity of the FTIs are important for their activities. 2D-QSAR models were prepared using both linear methods, i.e., multiple linear regression (MLR), and non-linear methods, i.e., artificial neural networks (ANN) and support vector machines (SVM). The proposed QSAR models were validated using internal and external validation methods. The results show that the proposed 2D-QSAR models are valid and that they can be applied to predict the activities of imidazole-containing FTIs. The prediction capability of the 2D-QSAR (linear and non-linear) models is comparable to and somewhat better than that of previous 3D-QSAR models and the non-linear models are more accurate than the linear models. PMID:22920090

Shayanfar, Ali; Ghasemi, Saeed; Soltani, Somaieh; Asadpour-Zeynali, Karim; Doerksen, Robert J; Jouyban, Abolghasem

2013-05-01

149

Development of an Alu-based, Real-Time PCR Method for Quantitation of Human DNA in Forensic Samples  

Microsoft Academic Search

Running header: Human Real-Time PCR Quantitation ABSTRACT: Determining the amount of human DNA extracted from a crime scene sample is an important step in DNA profiling. The forensic community relies almost entirely upon a technique (slot blot) to quantitate human DNA that is imprecise, time consuming and labor intensive. We have previously described a method for quantitation of human DNA

Janice A. Nicklas; Eric Buel

150

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

151

COMPARISON OF TWO METHODS FOR THE QUANTITATION OF BETA-GLUCANS FROM SHIITAKE MUSHROOMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fungal polysaccharides and glucans, including lentinan from shiitakes, have been identified as promoting human health, and consequently, the sale of mushroom-based health products has increased significantly in recent years. Reliable methods for the quantitation of lentinan must be available if shi...

152

The Use of Quantitative Methods as an Aid to Decision Making in Educational Administration.  

ERIC Educational Resources Information Center

Three quantitative methods are outlined, with suggestions for application to particular problem areas of educational administration: (1) The Leontief input-output analysis, incorporating a "transaction table" for displaying relationships between economic outputs and inputs, mainly applicable to budget analysis and planning; (2) linear programing,

Alkin, Marvin C.

153

A simple method for quantitative diagnosis of small hive beetles, Aethina tumida, in the field  

Technology Transfer Automated Retrieval System (TEKTRAN)

Here we present a simple and fast method for quantitative diagnosis of small hive beetles (= SHB) in honeybee field colonies using corrugated plastic diagnostic-strips. In Australia, we evaluated its efficacy by comparing the number of lured SHB with the total number of beetles in the hives. The d...

154

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

E-print Network

GINI COEFFICIENTS, SOCIAL NETWORK ANALYSIS, AND MARKOV CHAINS: QUANTITATIVE METHODS FOR ANA- LYZING Carolina, 1994 Research Project Submitted in Partial Fulfillment of the Requirements for the Degree Faculty of Environment Project No. 538 © Gregory Kelly 2012 SIMON FRASER UNIVERSITY Summer 2012 All rights

155

An Elephant in the Room: Bias in Evaluating a Required Quantitative Methods Course  

ERIC Educational Resources Information Center

Undergraduate Political Science programs often require students to take a quantitative research methods course. Such courses are typically among the most poorly rated. This can be due, in part, to the way in which courses are evaluated. Students are generally asked to provide an overall rating, which, in turn, is widely used by students, faculty,

Fletcher, Joseph F.; Painter-Main, Michael A.

2014-01-01

156

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

Microsoft Academic Search

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

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

1984-01-01

157

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

158

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

ERIC Educational Resources Information Center

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

Bernstein, Jeffrey L.; Allen, Brooke Thomas

2013-01-01

159

Weaving Versus Blending: a quantitative assessment of the information carrying capacities of two alternative methods for  

E-print Network

Weaving Versus Blending: a quantitative assessment of the information carrying capacities of two of the information-carrying capacities of two alternative methods for encoding multivariate information using color colors subtended only 3 minutes of visual angle in the texture. However, the information-carrying

Healey, Christopher G.

160

Improved GC/MS method for quantitation of n-Alkanes in plant and fecal material  

Technology Transfer Automated Retrieval System (TEKTRAN)

A gas chromatography-mass spectrometry (GC/MS) method for the quantitation of n-alkanes (carbon backbones ranging from 21 to 36 carbon atoms) in forage and fecal samples has been developed. Automated solid-liquid extraction using elevated temperature and pressure minimized extraction time to 30 min...

161

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

162

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

163

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

PubMed Central

A simple, precise, and accurate HPLC method has been developed and validated for the quantitative analysis of Dronedarone Hydrochloride in tablet form. An isocratic separation was achieved using a Waters Symmetry C8 (100 4.6 mm), 5 ?m particle size column with a flow rate of 1 ml/min and UV detector at 290 nm. The mobile phase consisted of buffer: methanol (40:60 v/v) (buffer: 50 mM KH2PO4 + 1 ml triethylamine in 1 liter water, pH=2.5 adjusted with ortho-phosphoric acid). The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The specificity of the method was determined by assessing interference from the placebo and by stress testing the drug (forced degradation). The method was linear over the concentration range 2080 ?g/ml (r2 = 0.999) with a Limit of Detection (LOD) and Limit of Quantitation (LOQ) of 0.1 and 0.3 ?g/ml respectively. The accuracy of the method was between 99.2100.5%. The method was found to be robust and suitable for the quantitative analysis of Dronedarone Hydrochloride in a tablet formulation. Degradation products resulting from the stress studies did not interfere with the detection of Dronedarone Hydrochloride so the assay is thus stability-indicating. PMID:23641332

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

2013-01-01

164

COMPARISON OF TWO ORTHOGONAL LIQUID CHROMATOGRAPHIC METHODS FOR QUANTITATION OF SUGARS IN FOOD  

Microsoft Academic Search

For analysis of seven sugars in various food samples, high-performance thin-layer chromatography ultraviolet detection (HPTLC-UV) was compared with high-performance liquid chromatography evaporative light scattering detection (HPLC-ELSD). The methods were orthogonal to each other with regard to separation and detection. The benchmarking of both methods showed HPTLC as highly suited or even better, if compared to HPLC, for quantitation of sugars

Gertrud E. Morlock; Gulnar Sabir

2011-01-01

165

Research methods in sport and exercise psychology: quantitative and qualitative issues  

Microsoft Academic Search

Contemporary aspects of research methods in sport and exercise psychology are discussed in this wide-ranging review. After an introduction centred on trends in sport and exercise psychology methods, the review is organized around the major themes of quantitative and qualitative research. Our aim is to highlight areas that may be problematic or controversial (e.g. stepwise statistical procedures), underused (e.g. discriminant

Stuart J. H. Biddle; David Markland; David Gilbourne; Nikos L. D. Chatzisarantis; Andrew C. Sparkes

2001-01-01

166

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

167

Raman spectroscopy provides a rapid, non-invasive method for quantitation of starch in live, unicellular microalgae.  

PubMed

Conventional methods for quantitation of starch content in cells generally involve starch extraction steps and are usually labor intensive, thus a rapid and non-invasive method will be valuable. Using the starch-producing unicellular microalga Chlamydomonas reinhardtii as a model, we employed a customized Raman spectrometer to capture the Raman spectra of individual single cells under distinct culture conditions and along various growth stages. The results revealed a nearly linear correlation (R(2) = 0.9893) between the signal intensity at 478 cm(-1) and the starch content of the cells. We validated the specific correlation by showing that the starch-associated Raman peaks were eliminated in a mutant strain where the AGPase (ADP-glucose pyrophosphorylase) gene was disrupted and consequentially the biosynthesis of starch blocked. Furthermore, the method was validated in an industrial algal strain of Chlorella pyrenoidosa. This is the first demonstration of starch quantitation in individual live cells. Compared to existing cellular starch quantitation methods, this single-cell Raman spectra-based approach is rapid, label-free, non-invasive, culture-independent, low-cost, and potentially able to simultaneously track multiple metabolites in individual live cells, therefore should enable many new applications. PMID:24906189

Ji, Yuetong; He, Yuehui; Cui, Yanbin; Wang, Tingting; Wang, Yun; Li, Yuanguang; Huang, Wei E; Xu, Jian

2014-12-01

168

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

NASA Astrophysics Data System (ADS)

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 each sample, thus compensating for heterogeneous morphology. The results for phosphate ore are reported here, but similar methods are being developed for a range of ores and minerals. Methods were developed to automatically perform metallic element calibrations for supplied phosphate ore samples containing known concentrations of the following minerals: P 2O 5, CaO, MgO, SiO 2 and Al 2O 3. A spectral line for each desired element was selected with respect to the best combination of peak intensity and minimum interferences from other lines. This is a key step, because of the observed matrix dependence of the technique. The optimum combination of the time interval between the laser firing (plasma formation), signal detection, and the duration of the optical detection was then determined for each element, to optimize spectral line intensity and resolution. The instrument was capable of analyzing the required elements in the phosphate ore samples supplied with 2-4% relative standard deviations for most elements. Calibrations were achieved for P, Ca, Mg, Al and Si with linear regression coefficients of 0.985, 0.980, 0.993, 0.987 and 0.985, respectively. Preparation and analysis time for each sample was less than 5 min.

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

2001-06-01

169

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 2.1 ng/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

170

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

PubMed Central

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

Szalai, Bence; Hoffmann, Pter; Prokop, Susanne; Erdlyi, Lszl; Vrnai, Pter; Hunyady, Lszl

2014-01-01

171

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

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Organic fluorescent material-assembled nanoparticles for IHC were prepared. Black-Right-Pointing-Pointer New nanoparticle fluorescent intensity was 10.2-fold greater than Qdot655. Black-Right-Pointing-Pointer Nanoparticle staining analyzed a wide range of ER expression levels in tissue. Black-Right-Pointing-Pointer Nanoparticle staining enhanced the quantitative sensitivity for ER diagnosis. -- Abstract: The detection of estrogen receptors (ERs) by immunohistochemistry (IHC) using 3,3 Prime -diaminobenzidine (DAB) is slightly weak as a prognostic marker, but it is essential to the application of endocrine therapy, such as antiestrogen tamoxifen-based therapy. IHC using DAB is a poor quantitative method because horseradish peroxidase (HRP) activity depends on reaction time, temperature and substrate concentration. However, IHC using fluorescent material provides an effective method to quantitatively use IHC because the signal intensity is proportional to the intensity of the photon excitation energy. However, the high level of autofluorescence has impeded the development of quantitative IHC using fluorescence. We developed organic fluorescent material (tetramethylrhodamine)-assembled nanoparticles for IHC. Tissue autofluorescence is comparable to the fluorescence intensity of quantum dots, which are the most representative fluorescent nanoparticles. The fluorescent intensity of our novel nanoparticles was 10.2-fold greater than quantum dots, and they did not bind non-specifically to breast cancer tissues due to the polyethylene glycol chain that coated their surfaces. Therefore, the fluorescent intensity of our nanoparticles significantly exceeded autofluorescence, which produced a significantly higher signal-to-noise ratio on IHC-imaged cancer tissues than previous methods. Moreover, immunostaining data from our nanoparticle fluorescent IHC and IHC with DAB were compared in the same region of adjacent tissues sections to quantitatively examine the two methods. The results demonstrated that our nanoparticle staining analyzed a wide range of ER expression levels with higher accuracy and quantitative sensitivity than DAB staining. This enhancement in the diagnostic accuracy and sensitivity for ERs using our immunostaining method will improve the prediction of responses to therapies that target ERs and progesterone receptors that are induced by a downstream ER signal.

Gonda, Kohsuke, E-mail: gonda@med.tohoku.ac.jp [Department of Nano-Medical Science, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan)] [Department of Nano-Medical Science, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Miyashita, Minoru [Department of Surgical Oncology, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan)] [Department of Surgical Oncology, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan); Watanabe, Mika; Takahashi, Yayoi [Department of Pathology, Tohoku University Hospital, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan)] [Department of Pathology, Tohoku University Hospital, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan); Goda, Hideki; Okada, Hisatake; Nakano, Yasushi [Optical and Biological R and D Center, Konica Minolta Technology Center, Inc., No. 1 Sakuramachi, Hino-shi, Tokyo 191-8511 (Japan)] [Optical and Biological R and D Center, Konica Minolta Technology Center, Inc., No. 1 Sakuramachi, Hino-shi, Tokyo 191-8511 (Japan); Tada, Hiroshi [Department of Surgical Oncology, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan)] [Department of Surgical Oncology, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan); Amari, Masakazu [Department of Nano-Medical Science, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan)] [Department of Nano-Medical Science, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Ohuchi, Noriaki [Department of Nano-Medical Science, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan) [Department of Nano-Medical Science, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Department of Surgical Oncology, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8574 (Japan)

2012-09-28

172

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

173

Studies of crack dynamics in clay soil I. Experimental methods, results, and morphological quantification  

E-print Network

Studies of crack dynamics in clay soil I. Experimental methods, results, and morphological geometric measures which provide a quantitative description of crack patterns at the soil surface including Minkowski functions. Additionally, we measured the distribution of angles within the crack network

Hoffmann, Heiko

174

Interferences of suspended clay fraction in protein quantitation by several determination methods.  

PubMed

Seven current methods of protein quantitation, Bradford (standard, micro, and 590/450 nm ratio), Lowry, bicinchoninic acid (BCA), UV spectrophotometry at 280 nm, and Quant-iT fluorescence-based determination, were compared with regard to their susceptibility to interferences due to the presence of suspended and not easily detectable clay particles. Bovine serum albumin (BSA) and Na-Wyoming montmorillonite were selected as model protein and reference clay, respectively. Protein-clay suspension mixtures were freshly prepared for each assay to simulate supernatants not completely centrifuged in batch sorption/kinetic experiments. Seven fixed increasing levels of clay (0.0, 0.00725, 0.0145, 0.029, 0.058, 0.145, 0.435 mg ml(-1)) were mixed with different levels of BSA in an appropriate range for each assay. To ascertain the interfering effect of different levels of clay, the theoretical concentrations of BSA were plotted against the estimated BSA concentrations of the samples, as obtained from the calibration curve of each method. A correct quantitation of the BSA concentration not influenced by clay would be described by a regression line with slope (b) not significantly different from 1 and an intercept (a) not significantly different from zero. At the lowest clay levels (0.00725 mg ml(-1)) a significant interference was evident for Bradford micro, Bradford 590/450, UV, and fluorescence. The three methods (Bradford standard, Lowry, and BCA) that seemed to show the better performances in the presence of clay after this first screening step also underwent an ANCOVA analysis, with the measured BSA concentrations as dependent variable and the clay concentrations as covariate. The Bradford standard and BCA methods were affected by a clay-dependent interference on BSA quantitation. The Lowry assay was the only method that gave correct estimates of BSA concentrations in the presence of any of the clay levels tested. PMID:18314004

Lozzi, I; Pucci, A; Pantani, O L; D'Acqui, L P; Calamai, L

2008-05-01

175

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

176

Quantitative Proteomic Analysis of Serum Proteins from Oral Cancer Patients: Comparison of Two Analytical Methods  

PubMed Central

Serum proteomic analysis can be a valuable approach for the discovery of protein biomarkers for early detection or monitoring of a disease. In this study, two analytical methods were compared for quantification of serum proteins in patients with oral cancer. In the first approach, we quantified serum proteins between oral squamous cell carcinoma (OSCC) and healthy control subjects by performing in-solution digestion of serum proteins, isobaric tags for relative and absolute quantification (iTRAQ) labeling of the resulting peptides, strong cation exchange (SCX) fractionation of labeled peptides and finally capillary liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis of the peptides. In the second approach, we first separated serum proteins with SDS-PAGE. The gel-separated proteins were then digested with trypsin and the resulting peptides were labeled with iTRAQ and analyzed with LC-MS/MS for protein quantification. A total of 319 serum proteins were quantified with the first proteomic approach whereas a total of 281 proteins were quantified by the second proteomic approach. Most of the proteins were identified and quantified by both approaches, suggesting that these methods are similarly effective for serum proteome analysis. This study provides compelling evidence that quantitative serum proteomic analysis of OSCC is a valuable approach for identifying differentially expressed proteins in cancer patients circulation systems that may be used as potential biomarkers for disease detection. Further validation in large oral cancer patient populations may lead to a simple and low invasive clinical tool for OSCC diagnosis or monitoring. PMID:25196439

Yang, Yan; Huang, Junwei; Rabii, Bahareh; Rabii, Ramin; Hu, Shen

2014-01-01

177

a Study of the Synchrotron Laue Method for Quantitative Crystal Structure Analysis.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. Quantitative crystal structure analyses have been carried out on small molecule crystals using synchrotron radiation and the Laue method. A variety of single crystal structure determinations and associated refinements are used and compared with the monochromatic analyses. The new molecular structure of 7-amino-5-bromo -4-methyl-2-oxo-1,2,3,4-tetrahidro-1, 6 -naphthyridine-8-carbonitrile (C_{10 }H_9ON_4 Br.H_2O) has been determined, first using monochromatic Mo Kalpha radiation and a four-circle diffractometer, then using synchrotron Laue diffraction photography. The structure refinements showed a R-factor of 4.97 and 14.0% for the Mo Kalpha and Laue data respectively. The molecular structure of (S)-2-chloro-2-fluoro-N-((S)-1-phenylethyl) ethanamide, (C_{10}H _{11}ClFNO), has been determined using the same crystal throughout for X-ray monochromatic analyses (Mo Kalpha and Cu K alpha) followed by synchrotron Laue data collection. The Laue and monochromatic data compare favourably. The R -factors (on F) were 6.23, 6.45 and 8.19% for the Mo K alpha, Cu Kalpha and Laue data sets respectively. The molecular structure of 3-(5-hydroxy-3-methyl-1-phenylpyrazol-4-yl)-1,3-diphenyl -prop- 2-en-1-one, (C_{25 }H_{20}N _2O_2) has been determined using the synchrotron Laue method. The results compare very well with Mo Kalpha monochromatic data. The R-factors (on F) were 4.60 and 5.29% for Mo Kalpha and Laue analysis respectively. The Laue method is assessed in locating the 20 hydrogen atoms in this structure. The structure analysis of the benzil compound ((C_6H_5 O.CO_2)) is carried out using the synchrotron Laue method firstly at room temperature and secondly at low temperature -114 ^circC. The structure shows an R-factor (on F) of 13.06% and 6.85% for each data set respectively. The synchrotron Laue method was used to collect data for ergocalciferol (Vitamin D_2). The same crystal was also used to record oscillation data with the synchrotron radiation monochromatic beam. A new molecular structure of (Dinitrato-(N,N ^'-dimethylethylene-diamine)copper(II)) has been determined using Mo Kalpha radiation on a four circle diffractometer. The refinement resulted in an R-factor (on F) of 4.06%.

Gomez de Anderez, Dora M.

1990-01-01

178

A Study of the Synchrotron Laue Method for Quantitative Crystal Structure Analysis  

NASA Astrophysics Data System (ADS)

Quantitative crystal structure analyses have been carried out on small molecule crystals using synchrotron radiation and the Laue method. A variety of single crystal structure determinations and associated refinements are used and compared with the monochromatic analyses. The new molecular structure of 7-amino-5-bromo -4-methyl-2-oxo-1,2,3,4 -tetrahidro-1,6 -naphthyridine-8-carbonitrile (C_{10 }H_9ON_4 BrcdotH_2O) has been determined, first using monochromatic Mo K alpha radiation and a four-circle diffractometer, then using synchrotron Laue diffraction photography. The structure refinements showed an R-factor of 4.97 and 14.0% for the Mo Kalpha and Laue data respectively. The molecular structure of (S)-2-chloro-2-fluoro-N-((S)-1-phenylethyl) ethanamide, (C_{10}H _{11}ClFNO), has been determined using the same crystal throughout for X-ray monochromatic analyses (Mo Kalpha and Cu K alpha) followed by synchrotron Laue data collection. The Laue and monochromatic data compare favourably. The R -factors (on F) were 6.23, 6.45 and 8.19% for the Mo K alpha, Cu Kalpha and Laue data sets respectively. The molecular structure of 3-(5-hydroxy-3-methyl-1-phenylpyrazol-4-yl)-1,3-diphenyl -prop-2-en-1-one, (C_{25}H _{20}N_2 O_2) has been determined using the synchrotron Laue method. The results compare very well with Mo Kalpha monochromatic data. The R-factors (on F) were 4.60 and 5.29% for Mo Kalpha and Laue analyses respectively. The Laue method is assessed in locating the 20 hydrogen atoms in this structure. The structure analyses of the benzil compound ((C_6H_5 OcdotCO_2)) is carried out using the synchrotron Laue method firstly at room temperature and secondly at low temperature. The structure shows an R-factor (on F) of 13.06% and 6.85% for each data set respectively. The synchrotron Laue method was used to collect data for ergocalciferol (Vitamin D_2). The same crystal was also used to record oscillation data with the synchrotron radiation monochromatic beam. A new molecular structure of (Dinitrato-(N,N ^'-dimethylethylene-diamine)copper(II)) has been determined using Mo Kalpha radiation on a four circle diffractometer. The refinement resulted in an R-factor (on F) of 4.06%.

Gomez de Anderez, Dora M.

1990-01-01

179

[Quantitative image analysis as a scanning method in histopathological routine diagnostics applied for instance to chronical liver diseases (author's transl)].  

PubMed

A method is given by means of which histological image contents can quantitatively be determined with the help of electronic image analysis. A case of a chronical liver disease is quoted as instance for the application of the method in routine diagnosis. A possibility is shown to open quantitative and reproducible computation to descriptive histopathology. PMID:1107750

Schwalbach, G

1975-11-01

180

Result Demonstration: A Method That Works  

E-print Network

the effectiveness of result demonstration. Step 1: When identifying the problem, you will need to ana- lyze the current situation. You will need to collect information that will help you accurately describe the issues facing the local pro- ducers and to develop... basis. For example, a producer pro- vides a small acreage area in which to test a new seed. If the seed grows well in the trial, the producer may plant it more extensively on the farm during the next growing season. Observability is the degree...

Boleman, Chris; Dromgoole, Darrell A.

2007-05-24

181

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

SciTech Connect

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

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

1990-09-01

182

Integrated multiplatform method for in vitro quantitative assessment of cellular uptake for fluorescent polymer nanoparticles  

NASA Astrophysics Data System (ADS)

Studies of cellular internalization of nanoparticles (NPs) play a paramount role for the design of efficient drug delivery systems, but so far they lack a robust experimental technique able to quantify the NP uptake in terms of number of NPs internalized in each cell. In this work we propose a novel method which provides a quantitative evaluation of fluorescent NP uptake by combining flow cytometry and plate fluorimetry with measurements of number of cells. Single cell fluorescence signals measured by flow cytometry were associated with the number of internalized NPs, exploiting the observed linearity between average flow cytometric fluorescence and overall plate fluorimeter measures, and previous calibration of the microplate reader with serial dilutions of NPs. This precise calibration has been made possible by using biocompatible fluorescent NPs in the range of 20-300 nm with a narrow particle size distribution, functionalized with a covalently bonded dye, Rhodamine B, and synthesized via emulsion free-radical polymerization. We report the absolute number of NPs internalized in mouse mammary tumor cells (4T1) as a function of time for different NP dimensions and surface charges and at several exposure concentrations. The obtained results indicate that 4T1 cells incorporated 103-104 polymer NPs in a short time, reaching an intracellular concentration 15 times higher than the external one.

Ferrari, Raffaele; Lupi, Monica; Falcetta, Francesca; Bigini, Paolo; Paolella, Katia; Fiordaliso, Fabio; Bisighini, Cinzia; Salmona, Mario; D'Incalci, Maurizio; Morbidelli, Massimo; Moscatelli, Davide; Ubezio, Paolo

2014-01-01

183

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

184

A quantitative (1)H nuclear magnetic resonance (qHNMR) method for assessing the purity of iridoids and secoiridoids.  

PubMed

This paper utilized a quantitative (1)H nuclear magnetic resonance (qHNMR) method for assessing the purity of iridoids and secoiridoids. The method was fully validated, including specificity, linearity, accuracy, precision, reproducibility, and robustness. For optimization of experimental conditions, several experimental parameters were investigated, including relaxation delay (D1), scan numbers (NS) and power length (PL1). The quantification was based on the area ratios of H-3 from analytes relative to aromatic protons from 1,4-dinitrobenzene (internal standard) with methanol-d4 as solvent. Five iridoids and secoiridoids (sweroside, swertiamarin, gentiopicroside, geniposide, genipin) were analyzed. Furthermore, the results were validated by the high performance liquid chromatography coupled with ultraviolet detection (HPLC-UV) method. It can be concluded that the qHNMR method was simple, rapid, and accurate, providing a reliable and superior method for assessing the purity of iridoids and secoiridoids. PMID:25510321

Li, Zeyun; Welbeck, Edward; Yang, Li; He, Chunyong; Hu, Haijun; Song, Ming; Bi, Kaishun; Wang, Zhengtao

2015-01-01

185

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

186

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. PMID:19555078

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

2009-01-01

187

A new semiautomatic method for quantitative static and dynamic bone histology  

Microsoft Academic Search

SummaryA new semiautomatic technique combining advantages of the manual and fully automatic methods is described for obtaining quantitative\\u000a static and dynamic histologic data of bone. The hardware consists of a photomicroscope, digitizing platen, digitizer, plotter\\/printer,\\u000a floppy disc drive, and computer. The microscope is equipped with a drawing tube through which the image of the digitizing\\u000a platen is projected over the

Hartmut H. Malluche; David Sherman; Wolfgang Meyer; Shaul G. Massry

1982-01-01

188

A quantitative method for predicting shelf life of soft drinks using a model system  

Microsoft Academic Search

Summary A quantitative method for the prediction of growth of the food spoilage yeastZygosaccharomyces bailii in a model fruit-drink system is described. A factorially designed experiment was employed to produce polynomial equations relating pH and sugar concentration (brix) to the lag period and doubling time of this yeast. Low pH values (40) show a strong synergistic action on the extension

M. B. Cole; M. H. J. Keenan

1987-01-01

189

Si NMR sensitivity enhancement methods for the quantitative study of organosilicate hydrolysis and condensation  

E-print Network

29 Si NMR sensitivity enhancement methods for the quantitative study of organosilicate hydrolysis condi- tions for efficient silica production [1­7]. The process involves the hydrolysis and subsequent­O­H ! Si­O­Si þ H2O ð2? and Si­O­H þ Si­O­R ! Si­O­Si þ ROH ð3? Thorough characterization of hydrolysis

Sahai, Nita

190

Undergraduate Quantitative  

E-print Network

Undergraduate Quantitative Research Methods with: Childhood Studies | Geography | Politics | Social.ac.uk/study The University of Bristol is introducing a new quantitative research methods pathway to a range of social science new courses, work placements and pathways to Why enhance your degree with quantitative research

Bristol, University of

191

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 doseresponse 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 expectationmaximization (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

192

Post-Reconstruction Non-Local Means Filtering Methods using CT Side Information for Quantitative SPECT  

PubMed Central

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.

2013-01-01

193

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

194

Improved methods for capture, extraction, and quantitative assay of environmental DNA from Asian bigheaded carp (Hypophthalmichthys spp.).  

PubMed

Indirect, non-invasive detection of rare aquatic macrofauna using aqueous environmental DNA (eDNA) is a relatively new approach to population and biodiversity monitoring. As such, the sensitivity of monitoring results to different methods of eDNA capture, extraction, and detection is being investigated in many ecosystems and species. One of the first and largest conservation programs with eDNA-based monitoring as a central instrument focuses on Asian bigheaded carp (Hypophthalmichthys spp.), an invasive fish spreading toward the Laurentian Great Lakes. However, the standard eDNA methods of this program have not advanced since their development in 2010. We developed new, quantitative, and more cost-effective methods and tested them against the standard protocols. In laboratory testing, our new quantitative PCR (qPCR) assay for bigheaded carp eDNA was one to two orders of magnitude more sensitive than the existing endpoint PCR assays. When applied to eDNA samples from an experimental pond containing bigheaded carp, the qPCR assay produced a detection probability of 94.8% compared to 4.2% for the endpoint PCR assays. Also, the eDNA capture and extraction method we adapted from aquatic microbiology yielded five times more bigheaded carp eDNA from the experimental pond than the standard method, at a per sample cost over forty times lower. Our new, more sensitive assay provides a quantitative tool for eDNA-based monitoring of bigheaded carp, and the higher-yielding eDNA capture and extraction method we describe can be used for eDNA-based monitoring of any aquatic species. PMID:25474207

Turner, Cameron R; Miller, Derryl J; Coyne, Kathryn J; Corush, Joel

2014-01-01

195

Improved Methods for Capture, Extraction, and Quantitative Assay of Environmental DNA from Asian Bigheaded Carp (Hypophthalmichthys spp.)  

PubMed Central

Indirect, non-invasive detection of rare aquatic macrofauna using aqueous environmental DNA (eDNA) is a relatively new approach to population and biodiversity monitoring. As such, the sensitivity of monitoring results to different methods of eDNA capture, extraction, and detection is being investigated in many ecosystems and species. One of the first and largest conservation programs with eDNA-based monitoring as a central instrument focuses on Asian bigheaded carp (Hypophthalmichthys spp.), an invasive fish spreading toward the Laurentian Great Lakes. However, the standard eDNA methods of this program have not advanced since their development in 2010. We developed new, quantitative, and more cost-effective methods and tested them against the standard protocols. In laboratory testing, our new quantitative PCR (qPCR) assay for bigheaded carp eDNA was one to two orders of magnitude more sensitive than the existing endpoint PCR assays. When applied to eDNA samples from an experimental pond containing bigheaded carp, the qPCR assay produced a detection probability of 94.8% compared to 4.2% for the endpoint PCR assays. Also, the eDNA capture and extraction method we adapted from aquatic microbiology yielded five times more bigheaded carp eDNA from the experimental pond than the standard method, at a per sample cost over forty times lower. Our new, more sensitive assay provides a quantitative tool for eDNA-based monitoring of bigheaded carp, and the higher-yielding eDNA capture and extraction method we describe can be used for eDNA-based monitoring of any aquatic species. PMID:25474207

Turner, Cameron R.; Miller, Derryl J.; Coyne, Kathryn J.; Corush, Joel

2014-01-01

196

An improvement of the 2(delta delta CT) method for quantitative real-time polymerase chain reaction data analysis  

PubMed Central

Background The 2-??CT method has been extensively used as a relative quantification strategy for quantitative real-time polymerase chain reaction (qPCR) data analysis. This method is a convenient way to calculate relative gene expression levels between different samples in that it directly uses the threshold cycles (CTs) generated by the qPCR system for calculation. However, this approach relies heavily on an invalid assumption of 100% PCR amplification efficiency across all samples. In addition, the 2-??CT method is applied to data with automatic removal of background fluorescence by the qPCR software. Since the background fluorescence is unknown, subtracting an inaccurate background can lead to distortion of the results. To address these problems, we present an improved method, the individual efficiency corrected calculation. Results Our method takes into account the PCR efficiency of each individual sample. In addition, it eliminates the need for background fluorescence estimation or subtraction because the background can be cancelled out using the differencing strategy. The DNA amount for a certain gene and the relative DNA amount among different samples estimated using our method were closer to the true values compared to the results of the 2-??CT method. Conclusions The improved method, the individual efficiency corrected calculation, produces more accurate estimates in relative gene expression than the 2-??CT method and is thus a better way to calculate relative gene expression.

Rao, Xiayu; Zhou, Zhicheng; Lin, Xin

2014-01-01

197

Quantitative analysis of sitagliptin using the (19)F-NMR method: a universal technique for fluorinated compound detection.  

PubMed

To expand the application scope of nuclear magnetic resonance (NMR) technology in quantitative analysis of pharmaceutical ingredients, (19)F nuclear magnetic resonance ((19)F-NMR) spectroscopy has been employed as a simple, rapid, and reproducible approach for the detection of a fluorine-containing model drug, sitagliptin phosphate monohydrate (STG). ciprofloxacin (Cipro) has been used as the internal standard (IS). Influential factors, including the relaxation delay time (d1) and pulse angle, impacting the accuracy and precision of spectral data are systematically optimized. Method validation has been carried out in terms of precision and intermediate precision, linearity, limit of detection (LOD) and limit of quantification (LOQ), robustness, and stability. To validate the reliability and feasibility of the (19)F-NMR technology in quantitative analysis of pharmaceutical analytes, the assay result has been compared with that of (1)H-NMR. The statistical F-test and student t-test at 95% confidence level indicate that there is no significant difference between these two methods. Due to the advantages of (19)F-NMR, such as higher resolution and suitability for biological samples, it can be used as a universal technology for the quantitative analysis of other fluorine-containing pharmaceuticals and analytes. PMID:25381991

Zhang, Fen-Fen; Jiang, Meng-Hong; Sun, Lin-Lin; Zheng, Feng; Dong, Lei; Shah, Vishva; Shen, Wen-Bin; Ding, Ya

2015-01-01

198

A method for quantitative analysis of aquatic humic substances in clear water based on carbon concentration.  

PubMed

Aquatic humic substances (AHSs) are major constituents of dissolved organic matter (DOM) in freshwater, where they perform a number of important ecological and geochemical functions, yet no method exists for quantifying all AHSs. We have developed a method for the quantitative analysis of AHSs based on their carbon concentration. Our approach includes: (1) the development of techniques for clear-water samples with low AHS concentrations, which normally complicate quantification; (2) avoiding carbon contamination in the laboratory; and (3) optimizing the AHS adsorption conditions. PMID:23060000

Tsuda, Kumiko; Takata, Akihiro; Shirai, Hidekado; Kozaki, Katsutoshi; Fujitake, Nobuhide

2012-01-01

199

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

NASA Astrophysics Data System (ADS)

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

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

1997-09-01

200

Selective and quantitative cell detection based both on aptamers and the conventional cell-staining methods.  

PubMed

Aptamer-based biochips for selective cell detection and quantitation in combination of the recent biochip technology and the conventional cell staining methods are described. Using a model system comprising HER2- or PSMA-positive cells as the analytes and single-stranded RNA aptamers specific for HER2 or PSMA as immobilized ligands on chips, we could demonstrate that aptamers were equivalent or superior to antibodies in terms of specificity and sensitivity, respectively. In particular, our PSMA-specific sensor was found to have the characteristics of good stability, reproducibility and reusability, with detection limit as low as 10(3) LNCaP cells. In conclusion, we could show the suitability of nucleic acid aptamers as low molecular weight receptors on biochips for sensitive and specific cell detection and quantitation for future diagnostics development. PMID:23357002

Kim, Jisu; Lee, Gwan-Ho; Jung, Woong; Hah, Sang Soo

2013-05-15

201

Quantitative measurement of analyte gases in a microwave spectrometer using a dynamic sampling method  

NASA Astrophysics Data System (ADS)

This article reports quantitative measurement of concentrations of water vapor (absorption line at 22.235 GHz) and ethylene oxide (absorption line at 23.123 GHz) in different gas mixtures by means of a microwave spectrometer. The problem of absorption line broadening and the gas memory problem inherent in the quantitative analysis of gases using microwave molecular rotational spectroscopy have been solved. The line broadening problem was minimized by gas dilution with nitrogen and the gas memory problem was effectively reduced by means of a dynamic sampling method. Calibration of ethylene oxide with a dilution factor of 5 has demonstrated that the standard deviations of the calibration data were less than 4.2%. A typical ethylene oxide sterilization production cycle was chosen to monitor chamber ethylene oxide concentrations in the gas dwell phase and the repeatability of these real time measurements was 2.7%.

Zhu, Z.; Matthews, I. P.; Samuel, A. H.

1996-07-01

202

Development and evaluation of event-specific quantitative PCR method for genetically modified soybean A2704-12.  

PubMed

A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) soybean event; A2704-12. During the plant transformation, DNA fragments derived from pUC19 plasmid were integrated in A2704-12, and the region was found to be A2704-12 specific. The pUC19-derived DNA sequences were used as primers for the specific detection of A2704-12. We first tried to construct a standard plasmid for A2704-12 quantification using pUC19. However, non-specific signals appeared with both qualitative and quantitative PCR analyses using the specific primers with pUC19 as a template, and we then constructed a plasmid using pBR322. The conversion factor (C(f)), which is required to calculate the amount of the genetically modified organism (GMO), was experimentally determined with two real-time PCR instruments, the Applied Biosystems 7900HT and the Applied Biosystems 7500. The determined C(f) values were both 0.98. The quantitative method was evaluated by means of blind tests in multi-laboratory trials using the two real-time PCR instruments. The limit of quantitation for the method was estimated to be 0.1%. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSD(R)), and the determined bias and RSD(R) values for the method were each less than 20%. These results suggest that the developed method would be suitable for practical analyses for the detection and quantification of A2704-12. PMID:21515963

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

2011-01-01

203

Quantitative carbide analysis using the Rietveld method for 2.25Cr-1Mo-0.25V steel  

SciTech Connect

It is usually difficult to quantitatively determine the mass fraction of each type of precipitates in steels using transmission electron microscopy and traditional X-ray powder diffraction analysis methods. In this paper the Rietveld full-pattern fitting algorithm was employed to calculate the relative mass fractions of the precipitates in 2.25Cr-1Mo-0.25V steel. The results suggest that the fractions of MC, M{sub 7}C{sub 3} and M{sub 23}C{sub 6} carbides were evaluated precisely and relatively quickly. In addition, it was found that the fine MC phase dissolved into the matrix with prolonged tempering.

Zhang Yongtao [School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); Han Haibo [Instrumental analysis center, Shanghai Jiaotong University, Shanghai 200240 (China); Miao Lede [Research Institute, Baoshan Iron and Steel Co., Ltd., Shanghai 201900 (China); Zhang Hanqian, E-mail: hqzhang1964@126.com [School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China) and Research Institute, Baoshan Iron and Steel Co., Ltd., Shanghai 201900 (China); Li Jinfu [School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

2009-09-15

204

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. PMID:24859343

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

2014-01-01

205

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

206

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

PubMed

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

Ou, Yinglei

2014-10-10

207

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

208

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

209

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

SciTech Connect

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

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

1997-01-10

210

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

SciTech Connect

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

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

1997-01-01

211

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

212

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

PubMed Central

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

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

2012-01-01

213

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

214

A quantitative method of evaluation of gait under the influence of electrical stimulation in hemiparetic patients.  

PubMed

To improve the procedure of selecting stimulation parameters for the best functional movement, quantitative gait evaluation was investigated. Based on the information obtained by force measuring shoes and a goniometric system, the method consists of computing average values and standard deviations of ground reaction and its point of action, goniometric functions, as well as the ankle joint torque in the sagittal and frontal plane, and their graphic representation. Deviation of the measured variables with respect to the normal gait pattern is the measure of the gait quality. Stimulation parameters were adjusted so that the patient's gait pattern approached normal. PMID:3165202

Kljaji?, M; Krajnik, J; Stanic, U

1988-01-01

215

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

216

Apparatus and method for quantitative determination of materials contained in fluids  

DOEpatents

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

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

1982-09-07

217

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

NASA Astrophysics Data System (ADS)

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

Gupta, Lokesh Kumar

2012-11-01

218

Three-dimensional quantitative analysis of adhesive remnants and enamel loss resulting from debonding orthodontic molar tubes  

PubMed Central

Aims Presenting a new method for direct, quantitative analysis of enamel surface. Measurement of adhesive remnants and enamel loss resulting from debonding molar tubes. Material and methods Buccal surfaces of fifteen extracted human molars were directly scanned with an optic blue-light 3D scanner to the nearest 2?m. After 20s etching molar tubes were bonded and after 24h storing in 0.9% saline - debonded. Then 3D scanning was repeated. Superimposition and comparison were proceeded and shape alterations of the entire objects were analyzed using specialized computer software. Residual adhesive heights as well as enamel loss depths have been obtained for the entire buccal surfaces. Residual adhesive volume and enamel loss volume have been calculated for every tooth. Results The maximum height of adhesive remaining on enamel surface was 0.76mm and the volume on particular teeth ranged from 0.047mm3 to 4.16mm3. The median adhesive remnant volume was 0.988mm3. Mean depths of enamel loss for particular teeth ranged from 0.0076mm to 0.0416mm. Highest maximum depth of enamel loss was 0.207mm. Median volume of enamel loss was 0.104mm3 and maximum volume was 1.484mm3. Conclusions Blue-light 3D scanning is able to provide direct precise scans of the enamel surface, which can be superimposed in order to calculate shape alterations. Debonding molar tubes leaves a certain amount of adhesive remnants on the enamel, however the interface fracture pattern varies for particular teeth and areas of enamel loss are present as well. PMID:25208969

2014-01-01

219

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

PubMed Central

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

Slatkin, Montgomery

2013-01-01

220

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

PubMed

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

Slatkin, Montgomery

2013-11-01

221

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

PurposeTo develop an absolute quantification method for membrane proteins, and to construct a quantitative atlas of membrane transporter\\u000a proteins in the bloodbrain barrier, liver and kidney of mouse.\\u000a \\u000a \\u000a \\u000a MethodsMouse 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 chromatographytandem mass spectrometer (LC\\/MS\\/MS).\\u000a \\u000a \\u000a \\u000a ResultsThe target

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

2008-01-01

222

Assessment of Riboflavin as a Tracer Substance: Comparison of a Qualitative to a Quantitative Method of Riboflavin Measurement  

PubMed Central

Background Noncompliance with medications may have major impacts on outcomes measured in research, potentially distorting the validity of controlled clinical trials. Riboflavin is frequently used in trials as a marker of adherence. It can be combined with study medication and is excreted in urine where it fluoresces under UV light. This study compares qualitative visual inspection of fluorescence to quantitative fluorometric analysis of riboflavin concentration in its ability to detect the presence of riboflavin in urine. Methods Twenty-four volunteers received 0 mg, 25 mg, and 50 mg doses of riboflavin under single-blind conditions, with 20 also receiving a 100 mg dose. Five serial urine samples were collected over the following 36 hours. Quantitative measurement of riboflavin by fluorometric analysis and qualitative assessment of each sample using visual inspection were performed. Results The overall false positive rate for qualitative assessment was 53%. For quantitative assessment, a riboflavin concentration of 900 ng/mL was established to classify positive samples. More than 80% of samples were positive 2 to 24 hours following ingestion of 25 mg and 50 mg, and less than 80% were positive at 36 hours. At least 95% of observations for the 100 mg dose were above 900 ng/mL at all timepoints. Conclusions Quantitative fluorometric assessment is superior to qualitative visual inspection alone in determining medication adherence. The combination of 2550 mg of daily riboflavin and a cut-off level of 900 ng/mL allows for the acceptable sensitivity of missing detection of non-compliant participants while preserving a high level of power to detect all cases of medication compliance. PMID:22921475

Herron, Abigail J.; Mariani, John J.; Pavlicova, Martina; Parinello, Christina M.; Bold, Krysten W.; Levin, Frances R.; Nunes, Edward V.; Sullivan, Maria A.; Raby, Wilfred N.; Bisaga, Adam

2013-01-01

223

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

224

The Quantitative Ideas and Methods in Assessment of Four Properties of Chinese Medicinal Herbs.  

PubMed

The purpose of this review is to summarize and reflect on the current status and problems of the research on the properties of Chinese medicinal herbs. Hot, warm, cold, and cool are the four properties/natures of Chinese medicinal herbs. They are defined based on the interaction between the herbs with human body. How to quantitatively assess the therapeutic effect of Chinese medicinal herbs based on the theoretical system of Traditional Chinese medicine (TCM) remains to be a challenge. Previous studies on the topic from several perspectives have been presented. Results and problems were discussed. New ideas based on the technology of biophoton radiation detection are proposed. With the development of biophoton detection technology, detection and characterization of human biophoton emission has led to its potential applications in TCM. The possibility of using the biophoton analysis system to study the interaction of Chinese medicinal herbs with human body and to quantitatively determine the effect of the Chinese medicinal herbal is entirely consistent with the holistic concept of TCM theory. The statistical entropy of electromagnetic radiations from the biological systems can characterize the four properties of Chinese medicinal herbs, and the spectrum can characterize the meridian tropism of it. Therefore, we hypothesize that by the use of biophoton analysis system, the four properties and meridian tropism of Chinese medicinal herbs can be quantitatively expressed. PMID:25395193

Fu, Jialei; Pang, Jingxiang; Zhao, Xiaolei; Han, Jinxiang

2014-11-14

225

Development and validation of a LC-MS method for quantitation of ergot alkaloids in lateral saphenous vein tissue  

Technology Transfer Automated Retrieval System (TEKTRAN)

A liquid chromatography-mass spectrometry (LC/MS) method for simultaneous quantitation of seven ergot alkaloids (lysergic acid, ergonovine, ergovaline, ergocornine, ergotamine, ergocryptine and ergocrystine) in vascular tissue was developed and validated. Reverse-phase chromatography, coupled to an...

226

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

PubMed

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. PMID:24711712

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

2014-01-01

227

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 1215 months for glioblastomas and 25 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. PMID:24711712

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

2014-01-01

228

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. PMID:23807616

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

229

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

NASA Astrophysics Data System (ADS)

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

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

2004-05-01

230

A systematic study on the influencing parameters and improvement of quantitative analysis of multi-component with single marker method using notoginseng as research subject.  

PubMed

A new quantitative analysis of multi-component with single marker (QAMS) method for 11 saponins (ginsenosides Rg1, Rb1, Rg2, Rh1, Rf, Re and Rd; notoginsenosides R1, R4, Fa and K) in notoginseng was established, when 6 of these saponins were individually used as internal referring substances to investigate the influences of chemical structure, concentrations of quantitative components, and purities of the standard substances on the accuracy of the QAMS method. The results showed that the concentration of the analyte in sample solution was the major influencing parameter, whereas the other parameters had minimal influence on the accuracy of the QAMS method. A new method for calculating the relative correction factors by linear regression was established (linear regression method), which demonstrated to decrease standard method differences of the QAMS method from 1.20%0.02% - 23.29%3.23% to 0.10%0.09% - 8.84%2.85% in comparison with the previous method. And the differences between external standard method and the QAMS method using relative correction factors calculated by linear regression method were below 5% in the quantitative determination of Rg1, Re, R1, Rd and Fa in 24 notoginseng samples and Rb1 in 21 notoginseng samples. And the differences were mostly below 10% in the quantitative determination of Rf, Rg2, R4 and N-K (the differences of these 4 constituents bigger because their contents lower) in all the 24 notoginseng samples. The results indicated that the contents assayed by the new QAMS method could be considered as accurate as those assayed by external standard method. In addition, a method for determining applicable concentration ranges of the quantitative components assayed by QAMS method was established for the first time, which could ensure its high accuracy and could be applied to QAMS methods of other TCMs. The present study demonstrated the practicability of the application of the QAMS method for the quantitative analysis of multi-component and the quality control of TCMs and TCM prescriptions. PMID:25618711

Wang, Chao-Qun; Jia, Xiu-Hong; Zhu, Shu; Komatsu, Katsuko; Wang, Xuan; Cai, Shao-Qing

2015-03-01

231

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

232

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

233

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

PubMed

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 [SN (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 SN (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 SN (RER). These results indicate that rat cerebellar basket cells endure important age-related changes. The significant decrease in the SN (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. PMID:11465864

Henrique, R M; Rocha, E; Reis, A; Marcos, R; Oliveira, M H; Silva, M W; Monteiro, R A

2001-06-01

234

CREST (Climate REconstruction SofTware): a probability density function (PDF)-based quantitative climate reconstruction method  

NASA Astrophysics Data System (ADS)

Several methods currently exist to quantitatively reconstruct palaeoclimatic variables from fossil botanical data. Of these, probability density function (PDF)-based methods have proven valuable as they can be applied to a wide range of plant assemblages. Most commonly applied to fossil pollen data, their performance, however, can be limited by the taxonomic resolution of the pollen data, as many species may belong to a given pollen type. Consequently, the climate information associated with different species cannot always be precisely identified, resulting in less-accurate reconstructions. This can become particularly problematic in regions of high biodiversity. In this paper, we propose a novel PDF-based method that takes into account the different climatic requirements of each species constituting the broader pollen type. PDFs are fitted in two successive steps, with parametric PDFs fitted first for each species and then a combination of those individual species PDFs into a broader single PDF to represent the pollen type as a unit. A climate value for the pollen assemblage is estimated from the likelihood function obtained after the multiplication of the pollen-type PDFs, with each being weighted according to its pollen percentage. To test its performance, we have applied the method to southern Africa as a regional case study and reconstructed a suite of climatic variables (e.g. winter and summer temperature and precipitation, mean annual aridity, rainfall seasonality). The reconstructions are shown to be accurate for both temperature and precipitation. Predictable exceptions were areas that experience conditions at the extremes of the regional climatic spectra. Importantly, the accuracy of the reconstructed values is independent of the vegetation type where the method is applied or the number of species used. The method used in this study is publicly available in a software package entitled CREST (Climate REconstruction SofTware) and will provide the opportunity to reconstruct quantitative estimates of climatic variables even in areas with high geographical and botanical diversity.

Chevalier, M.; Cheddadi, R.; Chase, B. M.

2014-11-01

235

Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry  

E-print Network

1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

American Society for Testing and Materials. Philadelphia

1994-01-01

236

RAPID RP HPLC METHOD FOR QUANTITATIVE DETERMINATION OF LORNOXICAM IN TABLETS  

PubMed Central

The objective of the study was to develop a simple, rapid, specific and precise reverse phase high performance liquid chromatographic method for the determination of lornoxicam in bulk and pharmaceutical preparations. Chromatographic separation of the drug was performed on a eclipse C18 column (150 mm 4.6 mm, 5 ?m) as stationary phase and mobile phase used is methanol: 0.1% formic acid in water (80:20 v/v), with a flow rate of 0.8 mL min-1 and UV detection at 381 nm. The proposed method was validated for linearity, accuracy, precision, limit of detection (LOD) and limit of quantitation (LOQ). Linearity, accuracy and precision were found to be acceptable over the ranges of 0.5-20 ?g/ml. It can be conveniently adopted for routine quality control analysis of lornoxicam. PMID:24825976

Attimarad, Mahesh

2010-01-01

237

The Use of Multiple Markers in a Bayesian Method for Mapping Quantitative Trait Loci  

PubMed Central

Information on multiple linked genetic markers was used in a Bayesian method for the statistical mapping of quantitative trait loci (QTL). Bayesian parameter estimation and hypothesis testing were implemented via Markov chain Monte Carlo algorithms. Variables sampled were the augmented data (marker-QTL genotypes, polygenic effects), an indicator variable for linkage or nonlinkage, and the parameters. The parameter vector included allele frequencies at the markers and the QTL, map distances of the markers and the QTL, QTL substitution effect, and polygenic and residual variances. The criterion for QTL detection was the marginal posterior probability of a QTL being located on the chromosome carrying the markers. The method was evaluated empirically by analyzing simulated granddaughter designs consisting of 2000 sons, 20 related sires, and their ancestors. PMID:8844168

Uimari, P.; Thaller, G.; Hoeschele, I.

1996-01-01

238

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

239

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. PMID:22492459

Bodenhausen, Natacha; Zeyer, Josef; Brgmann, Helmut

2012-01-01

240

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

USGS Publications Warehouse

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

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

1993-01-01

241

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 , 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 25C. 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. PMID:23781483

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

2012-01-01

242

From "weight of evidence" to quantitative data integration using multicriteria decision analysis and Bayesian methods.  

PubMed

"Weighing" available evidence in the process of decision-making is unavoidable, yet it is one step that routinely raises suspicions: what evidence should be used, how much does it weigh, and whose thumb may be tipping the scales? This commentary aims to evaluate the current state and future roles of various types of evidence for hazard assessment as it applies to environmental health. In its recent evaluation of the US Environmental Protection Agency's Integrated Risk Information System assessment process, the National Research Council committee singled out the term "weight of evidence" (WoE) for critique, deeming the process too vague and detractive to the practice of evaluating human health risks of chemicals. Moving the methodology away from qualitative, vague and controversial methods towards generalizable, quantitative and transparent methods for appropriately managing diverse lines of evidence is paramount for both regulatory and public acceptance of the hazard assessments. The choice of terminology notwithstanding, a number of recent Bayesian WoE-based methods, the emergence of multi criteria decision analysis for WoE applications, as well as the general principles behind the foundational concepts of WoE, show promise in how to move forward and regain trust in the data integration step of the assessments. We offer our thoughts on the current state of WoE as a whole and while we acknowledge that many WoE applications have been largely qualitative and subjective in nature, we see this as an opportunity to turn WoE towards a quantitative direction that includes Bayesian and multi criteria decision analysis. PMID:25592482

Linkov, Igor; Massey, Olivia; Keisler, Jeff; Rusyn, Ivan; Hartung, Thomas

2015-01-01

243

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

PubMed Central

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

Stofanko, Martin; Gonalves-Dornelas, Higgor; Cunha, Pricila Silva; Pena, Helosa B.; Vianna-Morgante, Angela M.; Pena, Srgio Danilo Junho

2013-01-01

244

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

SciTech Connect

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

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

1997-01-10

245

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 N.; Whitman, Richard L.; Vesper, Stephen J.

2003-01-01

246

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

247

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

PubMed Central

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

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

2014-01-01

248

Validated HPTLC method for simultaneous quantitation of paracetamol, diclofenac potassium, and famotidine in tablet formulation.  

PubMed

A sensitive, simple, selective, precise, and accurate HPTLC method of analysis for paracetamol, diclofenac potassium, and famotidine both as a bulk drug and in tablet formulation was developed and validated. The method used HPTLC aluminum plates precoated with silica gel 60F254 as the stationary phase, and the mobile phase consisted of toluene-acetone-methanol-formic acid (5 + 2 + 2 + 0.01, v/v/v/v). Densitometric evaluation of the separated zones was performed at 274 nm. This system was found to give compact spots for paracetamol (Rf value = 0.62 +/- 0.03), diclofenac potassium (0.75 +/- 0.02), and famotidine (0.17 +/- 0.03). The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 1625-9750 ng/spot for paracetamol, 250-1500 ng/spot for diclofenac potassium, and 100-600 ng/spot for famotidine. The method was validated for precision, robustness, and recovery according to International Conference on Harmonization guidelines. No chromatographic interference from the tablet excipients was found. Statistical analysis showed that the method was repeatable and selective for the simultaneous quantitation of the three drugs in tablet formulation and for routine quality control of raw materials of the drugs. PMID:20629373

Khatal, Laxman D; Kamble, Asmita Y; Mahadik, Mahadeo V; Dhaneshwar, Sunil R

2010-01-01

249

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

PubMed Central

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

Han, Joan C.; Elsea, Sarah H.; Pena, Helosa B.; Pena, Srgio Danilo Junho

2013-01-01

250

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, J.N., Jr.

1954-01-01

251

Methods for quantitative evaluation of dynamics of repair proteins within irradiated cells  

NASA Astrophysics Data System (ADS)

Living HeLa cells are irradiated well directed with single 100 MeV oxygen ions by the superconducting ion microprobe SNAKE, the Superconducting Nanoscope for Applied Nuclear (= Kern-) Physics Experiments, at the Munich 14 MV tandem accelerator. Various proteins, which are involved directly or indirectly in repair processes, accumulate as clusters (so called foci) at DNA-double strand breaks (DSBs) induced by the ions. The spatiotemporal dynamics of these foci built by the phosphorylated histone ?-H2AX are studied. For this purpose cells are irradiated in line patterns. The ?-H2AX is made visible under the fluorescence microscope using immunofluorescence techniques. Quantitative analysis methods are developed to evaluate the data of the microscopic images in order to analyze movement of the foci and their changing size.

Hable, V.; Dollinger, G.; Greubel, C.; Hauptner, A.; Krcken, R.; Dietzel, S.; Cremer, T.; Drexler, G. A.; Friedl, A. A.; Lwe, R.

2006-04-01

252

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

253

[Method of quantitative analysis of beta2-microglobulin in human blood].  

PubMed

A simple and economic method of radial immunodiffusion is developed for diagnostic measurements of beta 2-microglobulin in human serum. Human serum and plasma concentrations of beta 2-microglobulin can be measured sufficiently accurately; the results are reproducible. The reproducibility and addictiveness of the method were evaluated. The error of the method is no more than 15% (3-36 mg/liter), which is permissible for methods of this type. PMID:12085710

Shabunina, I V; Afanas'eva, O I; Pokrovski?, S N

2002-05-01

254

Initial results and mixed directions for Research Methods Tutor 1  

E-print Network

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

Wiemer-Hastings, Peter

255

Quantitative computed tomography of vertebral spongiosa: a sensitive method for detecting early bone loss after oophorectomy  

SciTech Connect

The bone mineral loss was assessed serially in 37 premenopausal women for 24 months after oophorectomy and the dose-response for conjugated estrogen therapy in preventing this loss was determined. Spinal cancellous bone was measured by quantitative computed tomography and measurement of appendicular cortical bone by radial photon absorptiometry and metacarpal radiogrammetry. For the placebo and low-dose treatment groups, the mean annual bone mineral losses were 7% to 9% from the vertebral spongiosum and 1% to 3% from the peripheral cortex. The correlation between axial and appendicular loss was weak, precluding a reliable estimate of spinal loss from peripheral measurements. For the maximal-dose group (0.6 mg/d), the mean annual bone mineral losses were less than 0.5% from the axial and appendicular sites, and were not significant. The results indicate that spinal quantitative computed tomography provides a highly sensitive measurement of bone mineral loss after oophorectomy, that bone mineral loss is five- to sevenfold greater from the spinal spongiosum than from the appendicular cortex, and that conjugated estrogen in doses of less than 0.6 mg/d are inadequate to prevent the vertebral mineral loss.

Genant, H.K.; Cann, C.E.; Ettinger, B.; Gordan, G.S.

1982-11-01

256

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

Microsoft Academic Search

ObjectThe goal of this study was to determine the feasibility of performing quantitative 7T magnetic resonance imaging (MRI) assessment\\u000a of trabecular bone micro-architecture of the wrist, a common fracture site.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methodsThe wrists of 4 healthy subjects (1 woman, 3 men, 288.9years) were scanned on a 7T whole body MR scanner using a 3D fast\\u000a low-angle shot (FLASH) sequence

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

2011-01-01

257

Maguelone plaster braces for the reduction of scoliotic curves: methods and results.  

PubMed

The authors discuss the basic principles in the reduction of scoliotic curves using the Maguelone method devised by Perdriolle and Vidal. The mechanical concepts of this method derive from corrective forces characteristic of the E.D.F. method but are used differently in terms of direction and quantitative relationships, namely derotation-de-flexion-kyphotisation replaces the elongation-de-flexion-derotation which characterizes the E.D.F. method. This modification is based on the assumption that in the pathogenesis of scoliosis the stages involve rotation, flexion and lordosis in that order. The method is discussed in detail as are the principles on which it is based. Finally, a group of cases are presented demonstrating the percentage gain after reduction, expressed in Cobb angles and degrees of torsion. The results appear to provide significant support for the effectiveness of the method. PMID:2380053

Becchetti, S; Senes, F M; Pinelli, G

1990-03-01

258

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

259

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...

260

A rapid gas chromatography method for quantitation of free fatty acids, monoacyl-, diacyl-, and triacylglycerols without derivatization  

Microsoft Academic Search

Quantitative analysis of mixtures of free fatty acids, monoacyl-, diacyl-, and triacylglycerols by a simple and rapid gas chromatography method has been developed. The analysis was carried out on a short capillary column without derivatization. When the triacontane was used as an internal standard, we obtained relative response factors for each lipid class with reproducibility and accuracy. This method could

Seok Joon Kwonl; Seoung Yong Lee; Sang Woo Cho; Joon Shick Rheel

1993-01-01

261

Evaluation of rapid DNA extraction methods for the quantitative detection of fungi using real-time PCR analysis  

Microsoft Academic Search

Three comparatively rapid methods for the extraction of DNA from fungal conidia and yeast cells in environmental (air, water and dust) samples were evaluated for use in real-time PCR (TaqMan) analyses. A simple bead milling method was developed to provide sensitive, accurate and precise quantification of target organisms in air and water (tap and surface) samples. However, quantitative analysis of

Richard A. Haugland; Nichole Brinkman; Stephen J. Vesper

2002-01-01

262

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

263

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

E-print Network

to PBDEs measurements in indoor air and dust (development of quantitative sampling methods and field) in settled dust ranged between 12-193 or 8-201 pg/cm2 according to the used method. Indoor air PBDEs consumption is undoubtedly important, several studies highlight the role of indoor dust in PBDE exposure

Paris-Sud XI, Université de

264

c 1997 by Jay H. Lee, Jin Hoon Choi, and Kwang Soon Lee 1.5 QUANTITIVE PID TUNING METHODS  

E-print Network

c 1997 by Jay H. Lee, Jin Hoon Choi, and Kwang Soon Lee 1.5 QUANTITIVE PID TUNING METHODS Tuning PID parameters is not a trivial task in general. Various tuning methods have been proposed for di Lee Kc Ku Kc = Ku Kc Ku step 4 Calculateand implementPID parametersusing the the Ziegler

Hong, Deog Ki

265

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

266

A simple and rapid method to identify and quantitatively analyze triterpenoid saponins in Ardisia crenata using ultrafast liquid chromatography coupled with electrospray ionization quadrupole mass spectrometry.  

PubMed

Ardisia plant species have been used in traditional medicines, and their bioactive constituents of 13,28-epoxy triterpenoid saponins have excellent biological activities for new drug development. In this study, a fast and simple method based on ultrafast liquid chromatography coupled to electrospray ionization mass spectrometry (UFLC-MS) was developed to simultaneously identify and quantitatively analyze triterpenoid saponins in Ardisia crenata extracts. In total, 22 triterpenoid saponins, including two new compounds, were identified from A. crenata. The method exhibited good linearity, precision and recovery for the quantitative analysis of eight marker saponins. A relative quantitative method was also developed using one major saponin (ardisiacrispin B) as the standard to break through the choke-point of the lack of standards in phytochemical analysis. The method was successfully applied to quantitatively analyze saponins in commercially available plant samples. This study describes the first systematic analysis of 13,28-epoxy-oleanane-type triterpenoid saponins in the genus Ardisia using LC-ESI-MS. The results can provide the chemical support for further biological studies, phytochemotaxonomical studies and quality control of triterpenoid saponins in medicinal plants of the genus Ardisia. PMID:25459939

Ma, Ling; Li, Wei; Wang, Hanqing; Kuang, Xinzhu; Li, Qin; Wang, Yinghua; Xie, Peng; Koike, Kazuo

2015-01-01

267

A new sample preparation method for the absolute quantitation of a target proteome using (18)O labeling combined with multiple reaction monitoring mass spectrometry.  

PubMed

A key step in the workflow of bottom-up proteomics is the proteolysis of proteins into peptides with trypsin. In addition, enzyme-catalytic (18)O labeled peptides as internal standards coupled with multiple reaction monitoring mass spectrometry (MRM MS) for the absolute quantitation of the target proteome is commonly used for its convenient operation and low cost. However, long digestion and labeling times, incomplete digestion and (18)O to (16)O back exchange limit its application, therefore, we developed a rapid and efficient digestion method based on a high ratio of trypsin to protein. In addition, after separation of the digested samples using pipette tips packed with reversed-phase packing materials in house, the trypsin can be separated, collected and reused at least four times. Based on this approach, a novel protein quantification method using (18)O-labeled QconCAT peptides as internal standards combined with MRM MS for the absolute quantitation of a target proteome is established. Experimental results showed that the novel method had high digestion and (18)O labeling efficiencies, and no (18)O to (16)O back-exchange occurred. A linear range covering 2 orders of magnitude and a limit of quantification (LOQ) as low as 5 fmol were achieved with an RSD below 10%. Then, the quantitative method is used for the absolute quantitation of drug metabolizing enzymes in human liver microsomes. The results are in good agreement with the previously reported data, which demonstrates that the novel method can be used for absolute quantitative analyses of target proteomes in complex biological samples. PMID:25568899

Li, Jiabin; Zhou, Lianqi; Wang, Huanhuan; Yan, Hui; Li, Nannan; Zhai, Rui; Jiao, Fenglong; Hao, Feiran; Jin, Zuyao; Tian, Fang; Peng, Bo; Zhang, Yangjun; Qian, Xiaohong

2015-02-01

268

Quantitative chromosome map of Coix lacryma-jobi L. by imaging methods.  

PubMed

Prometaphase chromosomes of Coix lacryma-jobi L. were quantitatively analyzed based on their distribution patterns of DAPI signals. The DAPI signals showed prominent uneven distribution along the chromosomes. Based on the DAPI signal patterns, a quantitative chromosome map was constructed for the first time in C. lacryma-jobi. The quantitative chromosome map will offer the foundation for genome analysis of C. lacryma-jobi. PMID:14986433

Han, Yong-Hua; Qi, Cui-Ying; Liu, Li-Hua; Song, Yun-Chun

2003-12-01

269

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; Jurez, Krutzkaya; Zuluaga, Magda; Bye, Robert; Mata, Rachel

2012-01-01

270

A rapid method for the quantitative determination of short-chain free volatile fatty acids from cheese.  

PubMed

The determination of free volatile fatty acids (FVFA) is of interest in the analysis of cheeses. As these compounds are components of taste and flavor, they give indications on metabolic reactions taking place during cheese ripening and can provide an evaluation of cheese defects and their causes. One of the most widely used methods for the determination of FVFA in cheese involves preliminary recovery from the matrix by steam distillation, followed by gas chromatography separation. Relatively high distillate volumes must be collected to achieve a quantitative yield of all the compounds of interest, so that, as a result, the solution is too diluted to achieve good instrumental sensitivity. In this paper, an alternative method for the determination of C2-C6 free carboxylic acids in cheeses involving the use of a Nukol capillary column and crotonic acid as internal standard is described. This method is quick and cheap, as the sample preparation is a simple extraction with water. The underivatized FVFA are then directly separated by gas chromatography. Using this method, all FVFA in cheeses can be quantified with good repeatability and excellent recovery. PMID:10956109

Innocente, N; Moret, S; Corradini, C; Conte, L S

2000-08-01

271

A novel preclinical method to quantitatively evaluate early-stage metastatic events at the murine blood-brain barrier.  

PubMed

The observation that approximately 15% of women with disseminated breast cancer will develop symptomatic brain metastases combined with treatment guidelines discouraging single-agent chemotherapeutic strategies facilitates the desire for novel strategies aimed at outright brain metastasis prevention. Effective and robust preclinical methods to evaluate early-stage metastatic processes, brain metastases burden, and overall mean survival are lacking. Here, we develop a novel method to quantitate early metastatic events (arresting and extravasation) in addition to traditional end time-point parameters such as tumor burden and survival in an experimental mouse model of brain metastases of breast cancer. Using this method, a reduced number of viable brain-seeking metastatic cells (from 3,331 263 cells/brain to 1,079 495 cells/brain) were arrested in brain one week postinjection after TGF? knockdown. Treatment with a TGF? receptor inhibitor, galunisertib, reduced the number of arrested cells in brain to 808 82 cells/brain. Furthermore, we observed a reduction in the percentage of extravasated cells (from 63% to 30%) compared with cells remaining intralumenal when TGF? is knocked down or inhibited with galunisertib (40%). The observed reduction of extravasated metastatic cells in brain translated to smaller and fewer brain metastases and resulted in prolonged mean survival (from 36 days to 62 days). This method opens up potentially new avenues of metastases prevention research by providing critical data important to early brain metastasis of breast cancer events. Cancer Prev Res; 8(1); 68-76. 2014 AACR. PMID:25348853

Adkins, Chris E; Nounou, Mohamed I; Mittapalli, Rajendar K; Terrell-Hall, Tori B; Mohammad, Afroz S; Jagannathan, Rajaganapathi; Lockman, Paul R

2015-01-01

272

New augmented classical least squares methods for improved quantitative spectral analyses  

Microsoft Academic Search

A series of new augmented classical least squares (ACLS) methods have been developed that show considerable promise for improving multivariate spectral calibrations. The normal limitations of classical least squares (CLS) methods are largely overcome by using information derived from the spectral residuals during the CLS calibration in the development of the new ACLS models. The resulting models are able to

David M Haaland; David K Melgaard

2002-01-01

273

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

SciTech Connect

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

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

1997-01-01

274

A method for accurate quantitative XPS analysis of multimetallic or multiphase catalysts on support particles  

SciTech Connect

A mathematical formalism for the quantitative analysis of X-ray photoelectron spectroscopy (XPS) intensities for supported, multiphase catalysts is presented. Such powdered catalysts are modeled as spherical support particles, covered in regions (islands) by different stratified layers of phases. It specifically considers the variation in photoelectron take-off angle over the surface of the particles, by integrating the signal over the particle`s volume. The evaluation of this integral can be done numerically, but for certain particle sizes it is simplified by a new approximation to the exponential integral function presented here, which introduces an error of {le}4%. The results show that the common assumption of normal emission usually leads to large errors (factors of 2-5). A simpler approximation to this new formalism, using the unweighted average take-off angle of photoelectrons from the local surface normal of 57.3{degrees}, introduces an error of {le}23% except for species whose main intensity arises from an underlayer that is buried by another phase of average depth greater than 1.3 {lambda}({lambda} is a photoelectron`s inelastic mean free path.) It is useful for the initial optimization of parameters when searching for structural models of catalysts that are consistent with their XPS spectra. These formalisms are also applicable in treating other shapes of catalysts than those treated explicitly here, provided the phase`s surface-to-volume ratio is the same as chosen in this model and that the BET surface area is less than about 35 m{sup 2}/g. More complex expressions which treat higher surface area samples are also presented. The formalisms can also be used in quantitative Auger electron spectroscopy (AES), if the XPS sensitivity factors are replaced by AES sensitivity factors. 17 refs., 8 figs.

Frydman, A.; Campbell, C.T.; Castner, D.G. [Univ. of Washington, Seattle, WA (United States)] [and others] [Univ. of Washington, Seattle, WA (United States); and others

1995-11-01

275

Analytic Study of the Tadoma Method: Background and Preliminary Results.  

ERIC Educational Resources Information Center

The paper reports the results of preliminary tests of the speechreading ability of a deaf blind adult who uses the Tadoma Method (speechreading based solely on vibrotactile information) for language acquisition and information. (Author/PHR)

Norton, Susan J.; And Others

1977-01-01

276

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

PubMed

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

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

2015-03-01

277

Quantitative sampling method for fungus gnat (Diptera: Sciaridae) eggs in soilless growing media.  

PubMed

A simple method is described for separating fungus gnat eggs from soilless growing media. The flotation/extraction method primarily involves the use of a MgSO4 solution (density 1.065 g cm(-3)) and a series of sieving procedures. Bradysia sp. nr. coprophila Lintner eggs were collected in an isolation chamber containing adult fungus gnats. Three soilless growing media were used: Metro-Mix 560 with Scott's Coir, Sunshine LC1 Mix, and Universal SB 300 Mix. Each growing medium was inoculated with 100 fungus gnat eggs. Growing medium samples were processed using separatory funnels and a MgSO4 solution. Eggs were washed through a 250-microm sieve and collected on a 53-microm sieve, and then the eggs were rinsed into glass petri dishes. The sieving process separated fungus gnat eggs from the larger growing medium particulates (perlite, bark, and peat), providing a sample consisting of water, eggs, and fine growing medium particulates (peat). Using a vortex for 60 s increased the number of fungus gnat eggs recovered (37.4 +/- 3.7-67.1 +/- 1.9 [mean +/- SEM]) for all three growing media. The mean number of fungus gnat eggs recovered from the three soilless growing media was significantly different, with the growing medium containing coir (Metro-Mix 560) having the highest recovery rate of 61.0 +/- 2.1. For all three growing media, there was > 50% recovery of fungus gnat eggs. In addition to fungus gnat eggs, this method also may prove useful for quantitative recovery of shore fly (Scatella sp.) eggs and the eggs of other arthropods from soilless growing media. PMID:16156596

Meers, Theresa L; Cloyd, Raymond A

2005-08-01

278

Method for quantitative sampling of fungus gnat larvae in soilless growing media.  

PubMed

A simple method is described for separating fungus gnat larvae from soilless growing media. Samples are first fractionated by water flotation with an inverted flask procedure and then the sediment is degassed under reduced air pressure and fractionated in magnesium sulfate (MgSO4) solution (density of 1.12 g cm(-3)). Fungus gnat larvae with only a small amount of contaminating debris are recovered from the surface of the MgSO4 solution for immediate counting or for preservation in alcohol. In evaluations of different commercial soilless growing media with a range of components, two repetitions of the water flotation step eliminated 20-40% of the dry weight of samples and virtually all of the perlite from further processing. Repeating both the water and MgSO4 flotations a third time only marginally improved the recovery of larval fungus gnats, Bradysia sp. nr. coprophila, added to pasteurized media. Extraction efficiency differed between instars and, to a lesser extent, between different types of media. Across three commercial soilless media tested, recovery was 24-33% for first, 68-85% for second, 85-95% for third, and 98-100% for fourth instars. Within combinations of media and instar, recovery was consistent. With this method, a 400-cm3 sample can be processed and be ready for counting in 1-1.5 h; samples can also be processed in batches or in assembly-line manner to process many samples per day. The method may also prove useful for quantitative recovery of shore fly larvae, thrips pupae, and other arthropods from soilless growing media. PMID:15154498

Zaborski, Edmond R; Cloyd, Raymond A

2004-04-01

279

Integrating Quantitative and Ethnographic Methods to Describe the Classroom. Report No. 5083.  

ERIC Educational Resources Information Center

The debate between proponents of ethnographic and quantitative methodology in classroom observation is reviewed, and the respective strengths and weaknesses of the two approaches are discussed. These methodologies are directly compared in a study that conducted simultaneous ethnographic and quantitative observations on nine classrooms. It is

Malitz, David; And Others

280

Application of stability-indicating HPTLC method for quantitative determination of metadoxine in pharmaceutical dosage form.  

PubMed

A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic method for analysis of metadoxine both as a bulk drug and in formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of acetone-chloroform-methanol-ammonia (7.0:4.0:3.0:1.2, v/v/v/v). Densitometric analysis of metadoxine was carried out in the absorbance mode at 315 nm. This system was found to give compact spots for metadoxine (Rf value of 0.45+/-0.02, for six replicates). Metadoxine was subjected to acid, alkali and neutral hydrolysis, oxidation, dry and wet heat treatment and photo and UV degradation. The drug undergoes degradation under all stress conditions. Also, the degraded products were well resolved from the pure drug with significantly different Rf values. The method was validated for linearity, precision, robustness, LOD, LOQ, specificity and accuracy. Linearity was found to be in the range of 100-1500 ng/spot with significantly high value of correlation coefficient r2=0.9997+/-1.02. The linear regression analysis data for the calibration plots showed good linear relationship with r2=0.9999+/-0.58 in the working concentration range of 200-700 ng/spot. The mean value of slope and intercept were 0.11+/-0.04 and 18.73+/-1.89, respectively. The limits of detection and quantitation were 50 and 100 ng/spot, respectively. Statistical analysis proves that the method is repeatable and specific for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one. Moreover, the proposed HPTLC method was utilized to investigate the kinetics of acid and base degradation process. Arrhenius plot was constructed and activation energy was calculated respectively for acid and base degradation process. PMID:15848212

Kaul, Neeraj; Agrawal, Himani; Patil, Bharat; Kakad, Abhijit; Dhaneshwar, S R

2005-04-01

281

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

NASA Astrophysics Data System (ADS)

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

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

1999-10-01

282

Quantitative determination of zopiclone and its impurity by four different spectrophotometric methods  

NASA Astrophysics Data System (ADS)

Four simple, sensitive and selective spectrophotometric methods are presented for determination of Zopiclone (ZPC) and its impurity, one of its degradation products, namely; 2-amino-5-chloropyridine (ACP). Method A is a dual wavelength spectrophotometry; where two wavelengths (252 and 301 nm for ZPC, and 238 and 261 nm for ACP) were selected for each component in such a way that difference in absorbance is zero for the second one. Method B is isoabsorptive ratio method by combining the isoabsorptive point (259.8 nm) in the ratio spectrum using ACP as a divisor and the ratio difference for a single step determination of both components. Method C is third derivative (D3) spectrophotometric method which allows determination of both ZPC at 283.6 nm and ACP at 251.6 nm without interference of each other. Method D is based on measuring the peak amplitude of the first derivative of the ratio spectra (DD1) at 263.2 nm for ZPC and 252 nm for ACP. The suggested methods were validated according to ICH guidelines and can be applied for routine analysis in quality control laboratories. Statistical analysis of the results obtained from the proposed methods and those obtained from the reported method has been carried out revealing high accuracy and good precision.

Abdelrahman, Maha M.; Naguib, Ibrahim A.; El Ghobashy, Mohamed R.; Ali, Nesma A.

2015-02-01

283

Quantitative determination of zopiclone and its impurity by four different spectrophotometric methods.  

PubMed

Four simple, sensitive and selective spectrophotometric methods are presented for determination of Zopiclone (ZPC) and its impurity, one of its degradation products, namely; 2-amino-5-chloropyridine (ACP). Method A is a dual wavelength spectrophotometry; where two wavelengths (252 and 301nm for ZPC, and 238 and 261nm for ACP) were selected for each component in such a way that difference in absorbance is zero for the second one. Method B is isoabsorptive ratio method by combining the isoabsorptive point (259.8nm) in the ratio spectrum using ACP as a divisor and the ratio difference for a single step determination of both components. Method C is third derivative (D(3)) spectrophotometric method which allows determination of both ZPC at 283.6nm and ACP at 251.6nm without interference of each other. Method D is based on measuring the peak amplitude of the first derivative of the ratio spectra (DD(1)) at 263.2nm for ZPC and 252nm for ACP. The suggested methods were validated according to ICH guidelines and can be applied for routine analysis in quality control laboratories. Statistical analysis of the results obtained from the proposed methods and those obtained from the reported method has been carried out revealing high accuracy and good precision. PMID:25244295

Abdelrahman, Maha M; Naguib, Ibrahim A; El Ghobashy, Mohamed R; Ali, Nesma A

2015-02-25

284

Quantitative method for measuring heat flux emitted from a cryogenic object  

DOEpatents

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

Duncan, Robert V. (Tijeras, NM)

1993-01-01

285

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

NASA Astrophysics Data System (ADS)

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

Lach, Denise

2014-01-01

286

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

PubMed Central

The growing interest in the role of Reactive Oxygen Species (ROS) and in the assessment of oxidative stress in health and disease clashes with the lack of consensus on reliable quantitative noninvasive methods applicable. The study aimed at demonstrating that a recently developed Electron Paramagnetic Resonance microinvasive method provides direct evidence of the instantaneous presence of ROS returning absolute concentration levels that correlate with a posteriori assays of ROS-induced damage by means of biomarkers. The reliability of the choice to measure ROS production rate in human capillary blood rather than in plasma was tested (step I). A significant (P < 0.01) linear relationship between EPR data collected on capillary blood versus venous blood (R2 = 0.95), plasma (R2 = 0.82), and erythrocytes (R2 = 0.73) was found. Then (step II) ROS production changes of various subjects' categories, young versus old and healthy versus pathological at rest condition, were found significantly different (range 0.00010.05 P level). The comparison of the results with antioxidant capacity and oxidative damage biomarkers concentrations showed that all changes indicating increased oxidative stress are directly related to ROS production increase. Therefore, the adopted method may be an automated technique for a lot of routine in clinical trials. PMID:25374651

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

2014-01-01

287

Development of a planar chromatographic method for quantitation of anthocyanes in pomace, feed, juice and wine.  

PubMed

An efficient HPTLC method was developed, which required minimal sample preparation for quantitation of the main anthocyanes in pomace, animal feed as well as various foods. The best separation of 11 anthocyanes was achieved on HPTLC plates silica gel 60 F254 with a mixture of ethyl acetate-2-butanone-formic acid-water for anthocyanins and ethyl acetate-toluene-formic acid-water for anthocyanidins. Due to the high flexibility of the HPTLC method, both anthocyane groups could be developed in a combined 2-step method. The second development was only necessary if anthocyanidins were detected in the samples. This normal phase separation was found superior to the best separation achieved on RP-18 phases with a mixture of water-n-propanol-formic acid. Absorbance measurement was performed using the multi-wavelength scan at 505 (or 510), 520, 530 and 555 nm. The correlation coefficients of the calibrations ranged between 0.9993 and 0.9999 for the 11 anthocyanes. LOQs were all ?90 ng/zone, most even ?30 ng/zone and for pn-3-glc and pg-3-glc even ?7 ng/zone. With regard to the analysis of mv-3-glc in grape seed/marc meal and supplemented animal feed samples, the mean repeatabilities were 1.4% (laboratory 1) and 1.8% (laboratory 2). The intermediate precisions within a laboratory over several months were ?6.7%. The ruggedness of the method was ?5.5%. The method was transferred to other sample types. Juice and wine samples, which were from the same plant source, showed a comparable anthocyanin pattern, whereas the pattern was characteristically different between plant sources. Unknown anthocyanin sample components were analyzed via HPTLC-ESI-MS by eluting the zones of interest with the TLC-MS Interface, which was helpful for further characterization of unknowns. An interesting tool was demonstrated by effect-directed analysis with regard to radical scavenging properties and general bioactivity based on detection with Vibrio fischeri bacteria. PMID:23570852

Krger, Stephanie; Urmann, Olessia; Morlock, Gertrud E

2013-05-10

288

On the discrepant results in synchrony judgment and temporal-order judgment tasks: a quantitative model.  

PubMed

Research on the perception of temporal order uses either temporal-order judgment (TOJ) tasks or synchrony judgment (SJ) tasks, in both of which two stimuli are presented with some temporal delay and observers must judge the order of presentation. Results generally differ across tasks, raising concerns about whether they measure the same processes. We present a model including sensory and decisional parameters that places these tasks in a common framework that allows studying their implications on observed performance. TOJ tasks imply specific decisional components that explain the discrepancy of results obtained with TOJ and SJ tasks. The model is also tested against published data on audiovisual temporal-order judgments, and the fit is satisfactory, although model parameters are more accurately estimated with SJ tasks. Measures of latent point of subjective simultaneity and latent sensitivity are defined that are invariant across tasks by isolating the sensory parameters governing observed performance, whereas decisional parameters vary across tasks and account for observed differences across them. Our analyses concur with other evidence advising against the use of TOJ tasks in research on perception of temporal order. PMID:22829342

Garca-Prez, Miguel A; Alcal-Quintana, Roco

2012-10-01

289

Functional MR imaging of the motor cortex in healthy volunteers and patients with brain tumours: qualitative and quantitative results.  

PubMed

The purpose of this study was to compare functional magnetic resonance (MR) imaging of the motor cortex in healthy volunteers and patients with brain tumours. Functional MR imaging was performed in 14 healthy volunteers and 14 patients with tumours in or near the primary motor cortex with groups being matched for age, sex, and handedness. Functional images were acquired during motion of the right and left hand. Time courses of signal intensity within the contralateral, ipsilateral, and supplementary motor cortex as well as z-maps were calculated, their quality being assessed visually. Mean signal increase between activation and rest were evaluated within the contralateral, ipsilateral, and supplementary motor cortex, the activated area in those regions of interest was measured using z-maps. The quality of functional MR experiments was generally lower in patients than in volunteers. The quantitative results showed a trend towards increased ipsilateral activation in volunteers during left hand compared to right hand motion and in patients during motion of the affected compared to the non-affected hand. Considering quantitative and qualitative results, significantly increased ipsilateral activation was found in patients compared to healthy volunteers. In conclusion, functional MR imaging quality was significantly reduced in patient studies compared to healthy volunteers, even if influences of age, sex, and handedness were excluded. Increased ipsilateral activation was found in patients with brain tumours which can be interpreted by an improved connectivity between both hemispheres. PMID:10321113

Fellner, C; Schlaier, J; Fellner, F; Held, P; Blank, M; Schwerdtner, J; Brawanski, A; Kalender, W A

1999-01-01

290

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

PubMed Central

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

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

2008-01-01

291

Quantitative evaluation of automatic methods for lesions detection in breast ultrasound images  

NASA Astrophysics Data System (ADS)

Ultrasound (US) is a useful diagnostic tool to distinguish benign from malignant breast masses, providing more detailed evaluation in dense breasts. Due to the subjectivity in the images interpretation, computer-aid diagnosis (CAD) schemes have been developed, increasing the mammography analysis process to include ultrasound images as complementary exams. As one of most important task in the evaluation of this kind of images is the mass detection and its contours interpretation, automated segmentation techniques have been investigated in order to determine a quite suitable procedure to perform such an analysis. Thus, the main goal in this work is investigating the effect of some processing techniques used to provide information on the determination of suspicious breast lesions as well as their accurate boundaries in ultrasound images. In tests, 80 phantom and 50 clinical ultrasound images were preprocessed, and 5 segmentation techniques were tested. By using quantitative evaluation metrics the results were compared to a reference image delineated by an experienced radiologist. A self-organizing map artificial neural network has provided the most relevant results, demonstrating high accuracy and low error rate in the lesions representation, corresponding hence to the segmentation process for US images in our CAD scheme under tests.

Marcomini, Karem D.; Schiabel, Homero; Carneiro, Antonio Adilton O.

2013-02-01

292

DEVELOPMENT OF A RAPID, QUANTITATIVE METHOD FOR THE DETECTION OF INFECTIVE COXSACKIE AND ECHO VIRUSES IN DRINKING WATER  

EPA Science Inventory

The objectives of this research are to improve on the current analytical methods for quantitative detection of infective coxsackie and echo viruses in drinking water. The specific objectives of this research are to: (1) Improve the sensitivity and specificity of IMS-PCR for in...

293

A New Method for Quantitative Marking of Deposited Lithium via Chemical Treatment on Graphite Anodes in Lithium-Ion Cells  

E-print Network

A New Method for Quantitative Marking of Deposited Lithium via Chemical Treatment on Graphite Anodes in Lithium-Ion Cells Yvonne Krämer*[a] , Claudia Birkenmaier[b] , Julian Feinauer[a,c] , Andreas*[e] and Thomas Schleid[f] Abstract: A novel approach for the marking of deposited lithium on graphite anodes from

Schmidt, Volker

294

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

Microsoft Academic Search

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

Isabel Taverniers; Erik Van Bockstaele; Marc De Loose

2004-01-01

295

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

Microsoft Academic Search

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

Kenneth J. Livak; Thomas D. Schmittgen

2001-01-01

296

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

ERIC Educational Resources Information Center

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

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

2007-01-01

297

Teaching Integrative Physiology Using the Quantitative Circulatory Physiology Model and Case Discussion Method: Evaluation of the Learning Experience  

ERIC Educational Resources Information Center

One of the problems that we have found when teaching human physiology in a Spanish medical school is that the degree of understanding by the students of the integration between organs and systems is rather poor. We attempted to remedy this problem by using a case discussion method together with the Quantitative Circulatory Physiology (QCP)

Rodriguez-Barbero, A.; Lopez-Novoa, J. M.

2008-01-01

298

Q-Squared in Policy: The Use of Qualitative and Quantitative Methods of Poverty Analysis in Decision-Making  

Microsoft Academic Search

This introductory essay for the journal Symposium presents an overview of issues related to Q-Squared in Policy: the use of qualitative and quantitative methods of poverty analysis in decision-making. We focus on issues raised on the supply side of data use, relating, inter alia to the informational content and policy usefulness of different types of data and analysis. These issues

Paul Shaffer; Ravi Kanbur; Nguyen Thu Hang; Ellen Bortei-Doku Aryeetey

2009-01-01

299

Differential Equations of Fractional Order: Methods, Results and Problems. II  

Microsoft Academic Search

The article, being a continuation of the first one [A.A. Kilbas and J.J. Trujillo (2001). Differential equations of fractional order. Methods, results and problems, I. Applicable Analysis , 78 (1-2), 153-192.], deals with the so-called differential equations of fractional order in which an unknown function is contained under the operation of a derivative of fractional order. The methods and the

A. A. Kilbas; J. J. Trujillo

2002-01-01

300

An experimental method for evaluating the contribution of deleterious mutations to quantitative trait variation  

E-print Network

that the contribution of rare, partially recessive alleles to quantitative trait variation can be assessed by comparing the relative magnitudes of two genetic variance components: the covariance of additive and homozygous dominance effects (Cad) and the additive genetic...

Kelly, John K.

1999-06-01

301

A review of methods for quantitative evaluation of axial vertebral rotation  

Microsoft Academic Search

Quantitative evaluation of axial vertebral rotation is essential for the determination of reference values in normal and pathological\\u000a conditions and for understanding the mechanisms of the progression of spinal deformities. However, routine quantitative evaluation\\u000a of axial vertebral rotation is difficult and error-prone due to the limitations of the observer, characteristics of the observed\\u000a vertebral anatomy and specific imaging properties. The

Toma Vrtovec; Franjo Pernu; Botjan Likar

2009-01-01

302

Measurement and Meaning: Combining Quantitative and Qualitative Methods for the Analysis of Poverty and Social Exclusion in Latin America. World Bank Technical Paper.  

ERIC Educational Resources Information Center

This report consists of a collection of case studies from Latin America combining qualitative and quantitative research methods for the analysis of poverty within a social exclusion framework. The first chapter provides an overview of the differences between quantitative and qualitative methods, and the gains from using both types of methods in

Gacitua-Mario, Estanislao, Ed.; Wodon, Quentin, Ed.

303

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

PubMed

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

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

2014-10-01

304

Initial Results of an MDO Method Evaluation Study  

NASA Technical Reports Server (NTRS)

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

Alexandrov, Natalia M.; Kodiyalam, Srinivas

1998-01-01

305

Fragmentation of DNA affects the accuracy of the DNA quantitation by the commonly used methods  

PubMed Central

Background Specific applications and modern technologies, like non-invasive prenatal testing, non-invasive cancer diagnostic and next generation sequencing, are currently in the focus of researchers worldwide. These have common characteristics in use of highly fragmented DNA molecules for analysis. Hence, for the performance of molecular methods, DNA concentration is a crucial parameter; we compared the influence of different levels of DNA fragmentation on the accuracy of DNA concentration measurements. Results In our comparison, the performance of the currently most commonly used methods for DNA concentration measurement (spectrophotometric, fluorometric and qPCR based) were tested on artificially fragmented DNA samples. In our comparison, unfragmented and three specifically fragmented DNA samples were used. According to our results, the level of fragmentation did not influence the accuracy of spectrophotometric measurements of DNA concentration, while other methods, fluorometric as well as qPCR-based, were significantly influenced and a decrease in measured concentration was observed with more intensive DNA fragmentation. Conclusions Our study has confirmed that the level of fragmentation of DNA has significant impact on accuracy of DNA concentration measurement with two of three mostly used methods (PicoGreen and qPCR). Only spectrophotometric measurement was not influenced by the level of fragmentation, but sensitivity of this method was lowest among the three tested. Therefore if it is possible the DNA quantification should be performed with use of equally fragmented control DNA. PMID:23406353

2013-01-01

306

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

307

A 3-Dimensional Absorbed Dose Calculation Method Based on Quantitative SPECT for Radionuclide Therapy: Evaluation for 131I Using Monte Carlo Simulation  

PubMed Central

A general method is presented for patient-specific 3-dimensional absorbed dose calculations based on quantitative SPECT activity measurements. Methods The computational scheme includes a method for registration of the CT image to the SPECT image and position-dependent compensation for attenuation, scatter, and collimator detector response performed as part of an iterative reconstruction method. A method for conversion of the measured activity distribution to a 3-dimensional absorbed dose distribution, based on the EGS4 (electron-gamma shower, version 4) Monte Carlo code, is also included. The accuracy of the activity quantification and the absorbed dose calculation is evaluated on the basis of realistic Monte Carlosimulated SPECT data, using the SIMIND (simulation of imaging nuclear detectors) program and a voxel-based computer phantom. CT images are obtained from the computer phantom, and realistic patient movements are added relative to the SPECT image. The SPECT-based activity concentration and absorbed dose distributions are compared with the true ones. Results Correction could be made for object scatter, photon attenuation, and scatter penetration in the collimator. However, inaccuracies were imposed by the limited spatial resolution of the SPECT system, for which the collimator response correction did not fully compensate. Conclusion The presented method includes compensation for most parameters degrading the quantitative image information. The compensation methods are based on physical models and therefore are generally applicable to other radionuclides. The proposed evaluation methodology may be used as a basis for future intercomparison of different methods. PMID:12163637

Ljungberg, Michael; Sjgreen, Katarina; Liu, Xiaowei; Frey, Eric; Dewaraja, Yuni; Strand, Sven-Erik

2009-01-01

308

Evaluation of a quantitative clinical method for assessment of sensory skin irritation.  

PubMed

Sensory skin irritation refers to the myriad of symptomatic complaints (e.g., sting and burn) frequently associated with inflammatory skin conditions or skin intolerance to various chemicals or finished products. Sensory irritation is an important factor in consumer acceptance of the products that they buy and use; however, from a safety testing and risk assessment standpoint, it has been difficult to evaluate. Recently, methods have been developed to more quantitatively assess sensory irritation using a semantically-labeled scale of sensation intensity, the labeled magnitude (LM) scale. Using this device, studies were conducted to determine if test subjects' perceptions of recalled or imagined sensory responses (from a series of survey questions) were related to their actual sensory reactivity to chemical challenge. Subjects were presented with 15 skin sensation scenarios of varying intensities and asked to record their self-perceived recalled or imagined responses using the LM scale. Individual and mean responses to each of the 15 survey questions were compared within and across studies. Considerable variation was seen between subjects' responses to the questions, particularly for questions pertaining to stronger stimuli (e.g., scalding water or skin lacerations). There was also little consistency seen in the pattern of individual responses across the questions. However, among 4 different study populations, the group mean scores for each of the 15 survey questions showed a high degree of consistency. Also, in spite of the variability in perceived responses to the recalled/imagined skin sensations, statistically significant dose-response and time-response patterns were observed in chemical (lactic acid and capsaicin) challenge studies. In one capsaicin study, a direct relationship was observed, among 83% of the study subjects, between the mean recall intensity scores and actual responses to subsequent capsaicin challenge. This pattern was not seen in a lactic acid challenge study. However, a similar relationship was seen in this study if only recall stimuli related to sting-type responses were included in the analysis. Hence, use of recall/imagined skin sensation perception data for prediction of actual reactivity to chemical probes may have screening utility depending on the survey questions used. On the whole, the LM scale is of practical use for quantifying subjective sensory irritation responses. Combined with evolving noninvasive instrumental and bioassay procedures for identifying biophysical or inflammatory markers of sensory irritation, better methods are on the horizon for improving our sensory skin irritation testing and risk assessment capabilities. PMID:11683830

Robinson, M K; Perkins, M A

2001-10-01

309

Reference Genes Selection for Quantitative Real-Time PCR Using RankAggreg Method in Different Tissues of Capra hircus  

PubMed Central

Identification of reference genes with stable levels of gene expression is an important prerequisite for obtaining reliable results in analysis of gene expression data using quantitative real time PCR (RT-qPCR). Since the underlying assumption of reference genes is that expressed at the exact same level in all sample types, in this study, we evaluated the expression stability of nine most commonly used endogenous controls (GAPDH, ACTB, 18S rRNA, RPS18, HSP-90, ALAS, HMBS, ACAC, and B2M) in four different tissues of the domestic goat, Capra hircus, including liver, visceral, subcutaneous fat and longissimus muscles, across different experimental treatments (a standard diet prepared using the NRC computer software as control and the same diet plus one mg chromium/day). We used six different software programs for ranking of reference genes and found that individual rankings of the genes differed among them. Additionally, there was a significant difference in ranking patterns of the studied genes among different tissues. A rank aggregation method was applied to combine the ranking lists of the six programs to a consensus ranking. Our results revealed that HSP-90 was nearly always among the two most stable genes in all studied tissues. Therefore, it is recommended for accurate normalization of RT-qPCR data in goats, while GAPDH, ACTB, and RPS18 showed the most varied expressions and should be avoided as reference genes. PMID:24358246

Najafpanah, Mohammad Javad; Sadeghi, Mostafa; Bakhtiarizadeh, Mohammad Reza

2013-01-01

310

Ultrahigh-performance liquid chromatographic-tandem mass spectrometric multimycotoxin method for quantitating 26 mycotoxins in maize silage.  

PubMed

A multianalyte method was developed to identify and quantitate 26 mycotoxins simultaneously in maize silage by means of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The extraction and cleanup procedure consists of two extraction steps followed by purification on a Waters Oasis HLB column. The method developed was validated with the requirements of Commission Decision 2002/657/EC taken into account. The limit of detection and quantitation ranges were 5-348 and 11-695 ng/g, respectively. Apparent recovery varied between 61 and 116%, whereas repeatability and reproducibility were within the ranges of 3-45 and 5-49%, respectively. The method developed was successfully applied for maize silage samples taken at the cutting surface and 1 m behind that surface. Mainly Fusarium toxins (beauvericin, deoxynivalenol, enniatins, fumonisins, fusaric acid, and zearalenone) were detected, but postharvest toxins such as mycophenolic acid and roquefortine C were identified as well. PMID:21888373

Van Pamel, Els; Verbeken, Annemieke; Vlaemynck, Geertrui; De Boever, Johan; Daeseleire, Els

2011-09-28

311

Quantitative magnetic resonance imaging of the fetal brain in utero: Methods and applications  

PubMed Central

Application of modern magnetic resonance imaging (MRI) techniques to the live fetus in utero is a relatively recent endeavor. The relative advantages and disadvantages of clinical MRI relative to the widely used and accepted ultrasonographic approach are the subject of a continuing debate; however the focus of this review is on the even younger field of quantitative MRI as applied to non-invasive studies of fetal brain development. The techniques covered under this header include structural MRI when followed by quantitative (e.g., volumetric) analysis, as well as quantitative analyses of diffusion weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI. The majority of the published work reviewed here reflects information gathered from normal fetuses scanned during the 3rd trimester, with relatively smaller number of studies of pathological samples including common congenital pathologies such as ventriculomegaly and viral infection. PMID:25170390

Biegon, Anat; Hoffmann, Chen

2014-01-01

312

A Method to Quantitatively Apportion Pollutants at High Spatial and Temporal Resolution: The Stochastic Lagrangian Apportionment Method (SLAM).  

PubMed

We introduce a method to quantify upwind contributions to concentrations of atmospheric pollutants. The Stochastic Lagrangian Apportionment Method (SLAM) carries out the following: (1) account for chemical transformations and depositional losses; (2) incorporate the effects of turbulent dispersion; (3) simulate the locations of the sources with high spatial and temporal resolution; and (4) minimize the impact from numerical diffusion. SLAM accomplishes these four features by using a time-reversed Lagrangian particle dispersion model and then simulating chemical changes forward in time, while tagging and keeping track of different sources. As an example of SLAM's application, we show its use in apportioning sources contributing to ammonia (NH3) and ammonium particulates (p-NH4(+)) at a site in southern Ontario, Canada. Agricultural emissions are seen to dominate contributions to NH3 and p-NH4(+) at the site. The source region of NH3 was significantly smaller than that of p-NH4(+), which covered numerous states of the American Midwest. The source apportionment results from SLAM were compared against those from zeroing-out individual sources ("brute force method"; BFM). The comparisons show SLAM to produce almost identical results as BFM for NH3, but higher concentrations of p-NH4(+), likely due to indirect effects that affect BFM. Finally, uncertainties in the SLAM approach and ways to address such shortcomings by combining SLAM with inverse methods are discussed. PMID:25437345

Lin, John C; Wen, Deyong

2015-01-01

313

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

EPA Science Inventory

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

314

Quantitative Pleistocene calcareous nannofossil biostratigraphy: preliminary results from the IODP Site U1385 (Exp 339), the Shackleton Site  

NASA Astrophysics Data System (ADS)

In order to explore the effects of Mediterranean Outflow Water (MOW) on North Atlantic circulation and climate, Integrated Ocean Drilling Program (IODP) Expedition 339 (Mediterranean Outflow) cored a series of sites in the Gulf of Cadiz slope and off West Iberia (North East Atlantic). Site U1385 (3748'N, 1010?W, 3146 m water depth) was selected and drilled in the lower slope of the Portuguese margin, at a location close to the so-called Shackleton Site MD95-2042 (in honor of the late Sir Nicholas Shackleton), to provide a marine reference section of Pleistocene millennial-scale climate variability. Three holes were cored at Site U1385 using the Advanced Piston Corer (APC) to a depth of ~151 meters below seafloor in order to recover a continuous stratigraphic record covering the past 1.4 Ma. Here we present preliminary results of the succession of standard and alternative calcareous nannofossil events. Our quantitative study based on calcareous nannofossils shows well-preserved and abundant assemblages throughout the core. Most conventional Pleistocene events were recognized. Moreover, our quantitative investigations provide further data on the stratigraphic distribution of some species and groups, such as the large Emiliania huxleyi (>4 ?m), the small Gephyrocapsa group, and Reticulofenestra cisnerosii. A preliminary calibration of the calcareous nannofossil events with the paleomagnetic and astronomical signal, estimated by comparison with geophysical and logging parameters is also presented. *IODP Expedition 339 Scientists: Bahr, A., Ducassou. E., Flood, R., Furota, S., Jimenez-Espejo, F., Kim, J. K., Krissek, L., Kuroda, J., Llave, E., Lofi, J., Lourens, L., Miller, M., Nanayama, F., Nishida, N., Roque, C., Sloss, C., Takashimizu, Y., Tzanova, A., Williams, T.

Balestra, B.; Flores, J. A.; Acton, G.; Alvarez Zarikian, C. A.; Grunert, P.; Hernandez-Molina, F. J.; Hodell, D. A.; Li, B.; Richter, C.; Sanchez Goni, M.; Sierro, F. J.; Singh, A.; Stow, D. A.; Voelker, A.; Xuan, C.

2013-12-01

315

Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples. [Patent application  

DOEpatents

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

Caldwell, J.T.; Kunz, W.E.; Cates, M.R.; Franks, L.A.

1982-07-07

316

Energy and environmental research emphasizing low-rank coal--Task 4.4: Development of supercritical fluid extraction methods for the quantitation of sulfur forms in coal  

SciTech Connect

Current analytical methods are inadequate for accurately measuring sulfur forms in coal. This task was concerned with developing methods to quantitate and identify major sulfur forms in coal based on direct measurement (as opposed to present techniques based on indirect measurement and difference values). The focus was on the forms that were least understood and for which the analytical methods have been the poorest, i.e., organic and elemental sulfur. Improved measurement techniques for sulfatic and pyritic sulfur also need to be developed. A secondary goal was to understand the interconversion of sulfur forms in coal during thermal processing. This task had as its focus the development of selective extraction methods that will allow the direct measurement of sulfur content in each form. Therefore, selective extraction methods were needed for the major sulfur forms in coal, including elemental, pyritic, sulfatic, and organic sulfur. This study was a continuation of that of previous analytical method development for sulfur forms in coal which resulted in the successful isolation and quantitation of elemental and sulfatic sulfur. Super- and subcritical extractions with methanol or water with and without additives were investigated in an attempt to develop methods for pyritic and organic sulfur forms analysis in coal. Based on these studies, a sequential extraction scheme that is capable of selectively determining elemental, sulfatic, pyritic and two forms of organic sulfur is presented here.

Timpe, R.C.

1995-04-01

317

An Adapted Mindfulness-Based Stress Reduction Program for Elders in a Continuing Care Retirement Community: Quantitative and Qualitative Results From a Pilot Randomized Controlled Trial.  

PubMed

The purpose of this study was to test the feasibility and effectiveness of an adapted 8-week Mindfulness-Based Stress Reduction (MBSR) program for elders in a continuing care community. This mixed-methods study used both quantitative and qualitative measures. A randomized waitlist control design was used for the quantitative aspect of the study. Thirty-nine elderly were randomized to MBSR (n = 20) or a waitlist control group (n = 19), mean age was 82 years. Both groups completed pre-post measures of health-related quality of life, acceptance and psychological flexibility, facets of mindfulness, self-compassion, and psychological distress. A subset of MBSR participants completed qualitative interviews. MBSR participants showed significantly greater improvement in acceptance and psychological flexibility and in role limitations due to physical health. In the qualitative interviews, MBSR participants reported increased awareness, less judgment, and greater self-compassion. Study results demonstrate the feasibility and potential effectiveness of an adapted MBSR program in promoting mind-body health for elders. PMID:25492049

Moss, Aleez S; Reibel, Diane K; Greeson, Jeffrey M; Thapar, Anjali; Bubb, Rebecca; Salmon, Jacqueline; Newberg, Andrew B

2014-12-01

318

Simplified and rapid method for extraction of ergosterol from natural samples and detection with quantitative and semi-quantitative methods using thin-layer chromatography  

Microsoft Academic Search

A new and simplified method for extraction of ergosterol (ergosta-5,7,22-trien-3?-ol) from fungi in soil and litter was developed using pre-soaking extraction and paraffin oil for recovery. Recoveries of ergosterol were in the range of 94100% depending on the solvent to oil ratio. Extraction efficiencies equal to heat-assisted extraction treatments were obtained with pre-soaking extraction. Ergosterol was detected with thin-layer chromatography

Thomas Larsen; Jrgen Axelsen; Helle Weber Ravn

2004-01-01

319

Rapid assessment of rivers using macroinvertebrates: the role of experience, and comparisons with quantitative methods  

Microsoft Academic Search

We assessed rapid biological assessment (RBA) of macroinvertebrate communities in comparison with quantitative sampling at 18 pairs of river sites in south-eastern Australia. One member of each pair served as a reference site and the other was affected by mild to moderate human disturbance from a point or diffuse source (fish farm effluents, small municipal sewage discharges, a dam, agriculture

Leon Metzeling; Bruce Chessman; Rodney Hardwick; Vera Wong

2003-01-01

320

A general Monte Carlo method for mapping multiple quantitative trait loci  

Microsoft Academic Search

In this paper we address the mapping of multiple quantitative trait loci (QTLs) in line crosses for which the genetic data are highly incomplete. Such complicated situations occur, for instance, when dominant markers are used or when unequally informative markers are used in experiments with outbred populations. We describe a general and flexible Monte Carlo expectation-maximization (Monte Carlo EM) algorithm

Ritsert C. Jansen

1996-01-01

321

Simple, fast and cheap cleanup method for quantitation of aflatoxins in important agricultural products by HPLC  

Technology Transfer Automated Retrieval System (TEKTRAN)

A simple, fast and cheap chemical cleanup procedure for low-level quantitative determination of aflatoxins in major economically important agricultural commodities using HPLC has been developed. Aflatoxins were extracted from a ground sample with methanol-water (80:20, v/v), and after a cleanup step...

322

Quantitative electroencephalography: A method to assess cerebral injury after hypothermic circulatory arrest  

Microsoft Academic Search

Although hypothermic circulatory arrest and low-flow cardiopulmonary bypass are routinely used for surgical correction of congenital cardiac anomalies, use of long durations of arrest, often required for more complex repairs, raises serious concerns about cerebral safety. Searching for an intraoperative assessment that can reliably predict cerebral injury, we have found an excellent correlation between changes in quantitative electroencephalography intraoperatively and

Craig K. Mezrow; Peter S. Midulla; Ali M. Sadeghi; Alejandro Gandsas; Weijia Wang; Howard H. Shiang; Carol Bodian; Otto E. Dapunt; Rosario Zappulla; Randall B. Griepp

1995-01-01

323

Berberine sulphate binding to mast cell polyanions: A cytofluorometric method for the quantitation of heparin  

Microsoft Academic Search

A cytofluorometric study on the binding of the fluorescent cationic dye Berberine sulphate to some tissue anions is reported. Measurements were performed on peritoneal cells and on models containing heparin or DNA. The dye was found to be suitable for cytofluorometric quantitation of heparin. At pH 4 a staining equilibrium was established when the dye apparently binds selectively to phosphate

Lennart Enerbck

1974-01-01

324

Simple and validated quantitative H NMR method for the determination of methylation, acetylation, and feruloylation degree of pectin.  

PubMed

The knowledge of pectin esterification degree is of primary importance to predict gelling and other properties of pectin from different sources. This paper reports the development of a simple and rapid (1)H NMR-based method for the simultaneous quantitative determination of methylation, acetylation, and feruloylation degree of pectin isolated from various food sources. Pectin esters are hydrolyzed in NaOH/D2O, and the obtained methanol, acetic acid, and ferulic acid are directly measured by (1)H NMR. High accuracy, repeatability, and reproducibility of the method were obtained, and the analysis time is reduced as compared to conventional chromatography- or titration-based methods. PMID:25137229

Mller-Maatsch, Judith; Caligiani, Augusta; Tedeschi, Tullia; Elst, Kathy; Sforza, Stefano

2014-09-17

325

Qualitative and quantitative approaches to health impact assessment: An analysis of the political and philosophical milieu of the multi-method approach  

Microsoft Academic Search

Health Impact Assessment (HIA) is a relatively new, but increasingly important, contributor to both local and national decision-making processes. Adopting a multi-method approach, it incorporates qualitative and quantitative analyses to determine the various health impacts of policies and projects. HIA thus reflects recent developments in sociological theory, which have promoted qualitative techniques and challenged the dominance of quantitative methods. HIA

Kevin Love; Catherine Pritchard; Kevin Maguire; Ann Mccarthy; Paul Paddock

2005-01-01

326

New method to quantitate platelets adhered on biomaterials using monoclonal antibodies to human platelet membrane glycoprotein SZ-21  

SciTech Connect

This study developed a new technique to quantitate platelets adhered on biomaterials surfaces in vitro, based on a surface phased radioimmunoassay using a monoclonal antibody SZ-21, directed specifically against the membrane glycoprotein complex IIIa of human platelets. In vitro perfusion is performed in system which consists of testing tubes and infusion pump. After 5 minutes perfusion with fresh ACD anticoagulated human whole blood at 2,000s-1 platelets deposition on surface precoated with proteins determined using anti-human platelet antibody (125 I-SZ-21) are 4,173 +/- 932 (Albumin), 59,032 +/- 25,554 (Fibrinogen), and 71,253 +/- 11,484 (Collagen). Meanwhile, platelets adhered on surfaces of four polymers were determined (platelet/mm2): 19,493 +/- 2,050 (Silicone), 48,193 +/- 4,055 (Polytetrafluoroethylene), 50,375 +/- 8,675 (Polyvinyl chloride) and 101,906 +/- 5,916 (Polyethylene). These results were confirmed by SEM. This method is not only applied for evaluating rapidly and reliably blood compatibility of biomaterials in vitro, but will be used at basic study for interaction of blood materials.

Xi, T.F.; Zhang, J.C.; Tian, W.H.; Wang, C.R.; Lei, X.H.; Wai, H.Y.; Ruan, C.G. (National Institute for Control of Pharmaceutical and Biological Products, Beijing (China))

1990-01-01

327

Quantitative Evaluation of E1 Endoglucanase Recovery from Tobacco Leaves Using the Vacuum Infiltration-Centrifugation Method  

PubMed Central

As a production platform for recombinant proteins, plant leaf tissue has many advantages, but commercialization of this technology has been hindered by high recovery and purification costs. Vacuum infiltration-centrifugation (VI-C) is a technique to obtain extracellularly-targeted products from the apoplast wash fluid (AWF). Because of its selective recovery of secreted proteins without homogenizing the whole tissue, VI-C can potentially reduce downstream production costs. Lab scale experiments were conducted to quantitatively evaluate the VI-C method and compared to homogenization techniques in terms of product purity, concentration, and other desirable characteristics. From agroinfiltrated Nicotiana benthamiana leaves, up to 81% of a truncated version of E1 endoglucanase from Acidothermus cellulolyticus was recovered with VI-C versus homogenate extraction, and average purity and concentration increases of 4.2-fold and 3.1-fold, respectively, were observed. Formulas were developed to predict recovery yields of secreted protein obtained by performing multiple rounds of VI-C on the same leaf tissue. From this, it was determined that three rounds of VI-C recovered 97% of the total active recombinant protein accessible to the VI-C procedure. The results suggest that AWF recovery is an efficient process that could reduce downstream processing steps and costs for plant-made recombinant proteins. PMID:24971334

Kingsbury, Nathaniel J.; McDonald, Karen A.

2014-01-01

328

Analysis of strength and failure pattern of human proximal femur using quantitative computed tomography (QCT)-based finite element method.  

PubMed

This paper presents a novel method for fast and reliable prediction of the failure strength of human proximal femur, using the quantitative computed tomography (QCT)-based linear finite element analysis (FEA). Ten fresh frozen human femora (age: 3416) were QCT-scanned and the pertinent 3D voxel-based finite element models were constructed. A specially-designed holding frame was used to define and maintain a unique geometrical reference system for both FEA and in-vitro mechanical testing. The analyses and tests were carried out at 8 different loading orientations. A new scheme was developed for assortment of the element risk factor (defined as the ratio of the strain energy density to the yield strain energy for each element) and implemented for the prediction of the failure strength. The predicted and observed failure patterns were in correspondence, and the FEA predictions of the failure loads were in very good agreement with the experimental results (R2=0.86, slope=0.96, p<0.01). The average computational time was 5 min (on a regular desktop personal computer) for an average element number of 197,000. Noting that the run-time for a similar nonlinear model is about 8h, it was concluded that the proposed linear scheme is overwhelmingly efficient in terms of computational costs. Thus, it can efficiently be used to predict the femoral failure strength with the same accuracy of similar nonlinear models. PMID:24735974

Mirzaei, Majid; Keshavarzian, Maziyar; Naeini, Vahid

2014-07-01

329

Searching for seafloor massive sulfides: a quantitative review of high-resolution methods in deep sea sonar bathymetry for mining applications  

NASA Astrophysics Data System (ADS)

Seafloor massive sulphides are deep sea mineral deposits currently being examined as a potential mining resource. Conventional sonar bathymetry products gathered by sea surface platforms do not achieve adequate spatial resolution to detect these resources. High-resolution beamforming methods (such as multiple signal classification and estimation of signal parameters via rotational invariance techniques) improve the resolution of sonar bathymetry. We perform a quantitative review of these high-resolution methods using a novel simulator, showing results in the absence of platform motion for a single ping cycle. It was found that high-resolution methods achieved greater bathymetric accuracy and higher resolution than conventional beamforming and that these methods may be adequate for this style of marine exploration. These methods were also robust in the presence of unwanted persistent signals and low signal to noise ratios.

Mitchley, Michael; Sears, Michael

2014-06-01

330

[Quantitative determination of trans-fatty acids in oils and fats by capillary gas chromatography: results of a JOCS collaborative study].  

PubMed

Excessive intake of trans-fatty acids increases the risk of cardiovascular disease. Much attention is drawn to the consumption of trans-fatty acids worldwide, and regulations for trans-fatty acids are instituted in several countries. Precise and convenient methods for determination of trans-fatty acid level are required, but there is no standard method using capillary Gas Chromatography in Japan. Therefore, for the new standard method, collaborative studies were carried out. The results were as follows: 1) Heptadecanoate (C17:0 free fatty acid) was chosen for internal standard substance. 2) Two Gas Chromatography columns, SP2560 (100 m) column (100% cyanopropyl polysiloxane liquid phase) and TC-70 (60 m) column (70% cyanopropyl polysilphenylene-siloxane liquid phase), were examined in the collaborative studies. We measured the edible oil samples containing 2-45 g/100 g of trans-fatty acids, and trans-fatty acid contents were quantitatively the same with both columns. The range of reproducibility coefficient of variation were below 10%. 3) Fats and oils sampled were soybean, rapeseed, palm, palm kernel, beef tallow, pork fat and their hydrogenated forms, for which good peak resolution was achieved. From the above results, the technique evaluated in the present study was considered to be suitable for determination of the content of trans-fatty acids in fats and oils exclusive of fish oil and milk fat. PMID:17898507

Shirasawa, Seiichi; Shiota, Makoto; Arakawa, Hiroshi; Shigematsu, Yasuhiko; Yokomizo, Kazuhisa; Shionoya, Noriko; Okamoto, Takahisa; Miyazaki, Yousuke; Takahashi, Shigeyuki; Himata, Katsuichi

2007-01-01

331

DEVELOPMENT OF A VALIDATED STABILITY INDICATING LC METHOD FOR QUANTITATIVE DETERMINATION OF AN ANTISPASMODIC DRUG AND ITS RELATED SUBSTANCES  

Microsoft Academic Search

Present article describes development and validation of stability indicating liquid chromatographic method for quantitative determination of ?-cyclohexyl-?-hydroxy-benzeneacetic acid-4-(diethylamino)-2-butynyl ester hydrochloride a potential antispasmodic and anticholinergic drug and its four impurities (related substances) using a Zorbax SB-Cyano column and mobile phase consisting of aqueous buffer (0.20% triethylamine) and acetonitrile in the ratio 49:51 and with a pH 6.3. The developed LC

Nandini R. Pai; Deepnandan S. Dubhashi

2010-01-01

332

A quantitative application of the thermoelectric method for measuring water uptake by cotton plants  

E-print Network

they measured sap veloc- ties in intact plants with a minimum of injury (8). Dixon (9) measured flow rates in a branch of a young ash tree by using a thermocouple arrangement for detecting heat f'low. His results indicated mass flow in the stem both upward... oxy- gen and carbon dioxide levels within the soil could be detected. The thermoelectric method is based on the assumption that since Personal Communication. most of the water absorbed by plants is transpired, the rate of sap flow in the stem is a...

Naghshineh-Pour, Bahman

2012-06-07

333

Optimization and qualification of a quantitative reversed-phase HPLC method for hemagglutinin in influenza preparations and its comparative evaluation with biochemical assays.  

PubMed

A previously described reversed-phase HPLC (RP-HPLC) method based on fast separations on a non-porous silica stationary phase [1] was optimized and qualified for the quantitative determination of hemagglutinin (HA) in influenza vaccine preparations. Optimization of the gradient elution conditions led to improved separation of the HA1 subunit from other vaccine constituents. The sensitivity of the method was significantly increased by using native fluorescence detection, resulting in an approximately 10-fold increase as compared to UV-vis detection. This enabled the elimination of the concentration step described in the original method and allowed direct analysis of vaccine preparations. The method was qualified for linearity, range, limit of detection, limit of quantitation and precision. Overall, it was found to be linear over the range of 2.5-100 ?g HA/mL for all subtypes examined. This range covered 50-150% of the concentration found for individual strains in seasonal influenza vaccines and in the pandemic H1N1 vaccine. The limit of detection and limit of quantitation for each subtype were found to be suitable for the method's intended purpose and compared well to values found by the single radial immunodiffusion (SRID). The repeatability of the method gave RSD values below 5% for both retention time and peak areas. As expected for intermediate precision, larger RSD values for peak area were obtained but were below 10% and deemed acceptable. The RP-HPLC results were compared to Western blot analysis using a HA universal antibody for a set of 15 monovalent A/California H1N1 preparations and showed good correlation. Similarly, the quantitative nature of the RP-HPLC method was assessed in relation to the SRID assay currently used for the determination of the HA content in bulk antigen and final vaccine preparations. Thus, for a series of 23 monovalent A/Brisbane/59/2007 H1N1 bulks, ranging between 12.7 and 15.9 ?g HA/mL by SRID, the RP-HPLC values were found to be in very good agreement, ranging between 11.9 and 14.1 ?g HA/mL (n=5) for five determinations carried out on 5 different days. During the 2009-10 H1N1 influenza pandemic the quantitative RP-HPLC method was used alongside several other test methods for the analysis of pandemic H1N1 vaccine preparations that included bulk antigen and final vaccines. The HA content of vaccines formulated at 15 or 30 ?g/mL was measured by RP-HPLC and SRID and results showed that the HA content determined by RP-HPLC correlated well to that determined by SRID and to values determined by Western blot. Overall, the results provided further evidence of the usefulness of RP-HPLC for the detection and quantitation of the HA content once a reference standard has been established. PMID:21397719

Lorbetskie, Barry; Wang, Jun; Gravel, Caroline; Allen, Cynthia; Walsh, Mike; Rinfret, Aline; Li, Xuguang; Girard, Michel

2011-04-18

334

Quantitative methods for three-dimensional comparison and petrographic description of chondrites  

SciTech Connect

X-ray computed tomography can be used to generate three-dimensional (3D) volumetric representations of chondritic meteorites. One of the challenges of using collected X-ray tomographic data is the extraction of useful data for 3D petrographic analysis or description. Here, I examine computer-aided quantitative 3D texture metrics that can be used for the classification of chondritic meteorites. These quantitative techniques are extremely useful for discriminating between chondritic materials, but yield little information on the 3D morphology of chondrite components. To investigate the morphology of chondrite minerals such as Fe(Ni) metal and related sulfides, the homology descriptors known as Betti numbers, are examined. Both methodologies are illustrated with theoretical discussion and examples. Betti numbers may be valuable for examining the nature of metal-silicate structural changes within chondrites with increasing degrees of metamorphism.

Friedrich, J.M. (Fordham)

2008-10-20

335

Methods and preliminary measurement results of liquid Li wettability  

SciTech Connect

A test of lithium wettability was performed in high vacuum (< 3 10{sup ?4} Pa). High magnification images of Li droplets on stainless steel substrates were produced and processed using the MATLAB{sup } program to obtain clear image edge points. In contrast to the more standard ?/2 or polynomial fitting methods, ellipse fitting of the complete Li droplet shape resulted in reliable contact angle measurements over a wide range of contact angles. Using the ellipse fitting method, it was observed that the contact angle of a liquid Li droplet on a stainless steel substrate gradually decreased with increasing substrate temperature. The critical wetting temperature of liquid Li on stainless steel was observed to be about 290?C.

Zuo, G. Z., E-mail: zuoguizh@ipp.ac.cn; Hu, J. S.; Ren, J.; Sun, Z.; Yang, Q. X.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zakharov, L. E.; Mansfield, D. K. [Princeton Plasma Physics Laboratory, MS-27 P.O. Box 451, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, MS-27 P.O. Box 451, Princeton, New Jersey 08543 (United States)

2014-02-15

336

A processing method and results of meteor shower radar observations  

NASA Technical Reports Server (NTRS)

Studies of meteor showers permit the solving of some principal problems of meteor astronomy: to obtain the structure of a stream in cross section and along its orbits; to retrace the evolution of particle orbits of the stream taking into account gravitational and nongravitational forces and to discover the orbital elements of its parent body; to find out the total mass of solid particles ejected from the parent body taking into account physical and chemical evolution of meteor bodies; and to use meteor streams as natural probes for investigation of the average characteristics of the meteor complex in the solar system. A simple and effective method of determining the flux density and mass exponent parameter was worked out. This method and its results are discussed.

Belkovich, O. I.; Suleimanov, N. I.; Tokhtasjev, V. S.

1987-01-01

337

A Method for Accurate Quantitative XPS Analysis of Multimetallic or Multiphase Catalysts on Support Particles  

Microsoft Academic Search

A mathematical formalism for the quantitative analysis of X-ray photoelectron spectroscopy (XPS) intensities for supported, multiphase catalysts is presented. Such powdered catalysts are modeled as spherical support particles, covered in regions (islands) by different stratified layers of phases. It specifically considers the variation in photoelectron take-off angle over the surface of the particles, by integrating the signal over the particle?s

A. Frydman; D. G. Castner; M. Schmal; C. T. Campbell

1995-01-01

338

Developing methods for qualitative and quantitative analysis of Chelidonium majus herbs  

Microsoft Academic Search

A pure compound has been isolated and identified as coptisine on the basis of UV and NMR spectroscopy data using preparative\\u000a separation of the extract from greater celandine (Chelidonium majus L.) herbs by column chromatography over short columns of silica gel. Qualitative and quantitative estimation of the total\\u000a alkaloid contents in C. majus is performed using TLC analysis and spectrophotometry

E. S. Artamonova; V. A. Kurkin

2008-01-01

339

An efficient method-development strategy for quantitative chemical imaging using terahertz pulse spectroscopy  

Microsoft Academic Search

The purpose of our research was to investigate efficient procedures for generating multivariate prediction vectors for quantitative\\u000a chemical analysis of solid dosage forms using terahertz pulse imaging (TPI) reflection spectroscopy. A set of calibration\\u000a development and validation tablet samples was created following a ternary mixture of anhydrous theophylline, lactose monohydrate,\\u000a and microcrystalline cellulose (MCC). Spectral images of one side of

Robert P. Cogdill; Steven M. Short; Ryanne Forcht; Zhenqi Shi; Yaochun Shen; Philip F. Taday; Carl A. Anderson; James K. Drennen

2006-01-01

340

A scanning electron microscope method for automated, quantitative analysis of mineral matter in coal  

Microsoft Academic Search

Quantitative mineralogical analysis has been carried out on a series of nine coal samples from Australia, South Africa and China using a newly-developed automated image analysis system coupled to a scanning electron microscope. The image analysis system (QEM ? SEM) gathers X-ray spectra and backscattered electron data from a number of points on a conventional grain-mount polished section under the

Robert A. Creelman; Colin R. Ward

1996-01-01

341

Comparative Analysis of a Hierarchical Bayesian Method for Quantitative Trait Loci Analysis for the Arabidopsis Thaliana  

Microsoft Academic Search

This work performs an analysis on two, quite different, techniques for Quantitative Trait Loci (QTL) Analysis. Interval Mapping\\u000a (IM) as described by Karl Broman is compared to a Hierarchical Bayesian Model (HBM) technique that reduces the problem of\\u000a QTL analysis down to one of model selection. Simulations were generated for the flowering plant of the Arabidopsis thaliana for evaluation of

Caroline Pearson; Susan J. Simmons; Karl Ricanek Jr; Edward L. Boone

2007-01-01

342

A method for fully automated quantitative analysis of arterial flow using flow-sensitized MR images  

Microsoft Academic Search

While the recent developments in the velocity-sensitive MR imaging offer great potential for non-invasive assessment of blood flow in major blood vessels, the clinical applications of this technique have been hampered by tedious, human-assisted data processing techniques. In this paper, we describe a robust system for automated extraction of quantitative as well as qualitative flow information from velocity-sensitive, phase contrast

Michael P. Chwialkowski; Yaser M. Ibrahim; Hong F. Li; Ronald M. Peshock

1996-01-01

343

Simple method of open skin wound healing model in corticosteroid-treated and diabetic rats: standardization of semi-quantitative and quantitative histological assessments  

Microsoft Academic Search

The use of a simple and reproducible model is inevitable for objective statement of the effects of external factors on wound healing. Hence, present study was conducted to establish an excisional model of skin wound healing in corticosteroid treated, and streptozotocine induced diabetic rats as well as to standardized the semi-quantitative and quantitative evaluation of selected parameters. Round full thickness

P. Gal; R. Kilik; M. Mokry; B. Vidinsky; T. Vasilenko; S. Mozes; N. Bobrov; Z. Tomori; J. Bober; L. Lenhardt

344

[A new method for quantitative measurement of the cadmium absorbed by chick embryos].  

PubMed

We attempted to determine the quantity of cadmium incorporated in hens eggs after immersion in cadmium solutions, and the cadmium concentration measured in embryos. We discussed equipment allowing simultaneous treatment of up to 42 samples, and called it " digestor ". It consisted of two gas-heated sand baths, two stands for cooling down solutions and an evacuation system for toxic vapours. Our method was based on wet mineralisation. It consisted of desintegrating experimental chick embryos in a HNO3/H2O2 mixed solution. After heating and evaporating, the quantity of cadmium in the remnant was determined by atomic absorption spectrophotometry. The reliability of such a technique was tested by studying as controls controls 17 days-old chick embryos injected with a known quantity of Cd(NO3). It showed no loss of cadmium. We also compared our procedure with a dry ashing method. The latter showed unacceptable losses and insufficient precision for the problems we wanted to investigate. Our method gave us much more precise results. The equipment we developed has functioned wholly satisfactorily and allowed us to investigate for instance cadmium distribution and concentration in embryonic organs of 17 days-old chicks. It could also be useful for researches concerning other biological samples analyzed for different heavy metals. PMID:6724786

Gottofrey, J

1984-01-01

345

A field method for making a quantitative estimate of altered tuff in sandstone  

USGS Publications Warehouse

The use of benzidine to identify altered tuff in sandstone is practical for field or field laboratory studies associated with stratigraphic correlations, mineral deposit investigations, or paleogeographic interpretations. The method is based on the ability of saturated benzidine (C12H12N2) solution to produce a blue stain on montmorillonite-bearing tuff grains. The method is substantiated by the results of microscopic, X-ray spectrometer, and spectrographic tests which lead to the conclusion that: (1) the benzidine stain test differentiates grains of different composition, (2) the white or gray grains which are stained a uniform blue color are fragments of altered tuff, and (3) white or gray grains which stain in a few small spots are probably silicified tuff. The amount of sand grains taken from a hand specimen or an outcrop which will be held by a penny is spread out on a nonabsorbent white surface and soaked with benzidine for 5 minutes. The approximate number blue grains and the average grain size are used in a chart to determine a reference number which measures relative order of abundance. The chart, based on a volume relationship, corrects for the variation in the number of grains in the sample as the grain size varies. Practical use of the method depends on a knowledge of several precautionary measures as well as an understanding of the limitations of benzidine staining tests.

Cadigan, R.A.

1954-01-01

346

Seriate histomorphometry of whole rat stomach: an accurate and reliable method for quantitative analysis of mucosal damage.  

PubMed

The evaluation of mucosal damage in experimental models of gastric injury is commonly based on macroscopic detection of gross lesions and/or histological examination of tissue samples and is limited by the subjectivity of the examiner and by the paucity of nonrepresentative samples. This study proposes a novel method for the histomorphometric analysis of gastric damage, based on the examination of seriate parallel strips taken from whole rat stomachs. Strips were cut perpendicular to the lesser curvature, placed on a glass slide, with the side of each strip distal to the pylorus upward, and processed for routine histology. Sections were then observed by light microscopy: the length of damaged mucosa divided by the total length of mucosa, measured on a micrometric scale and expressed in percentage values, was indicated as the lesion index. Furthermore, to evaluate the severity of the damage, three types of lesions were discriminated depending on their depth: type I, lysis of luminal cells; type II, damage involving the cells lying on both surface mucosa and gastric pits; and type III, damage involving the lower part of the lamina propria with injury of glands associated with detachment of whole mucosal layers. Three models of acute gastric damage (ethanol, hemorrhagic shock, and indomethacin) were examined and treatment was also carried out with the antiulcer drugs omeprazole, ranitidine, and misoprostol, to show the advantages of this histomorphometric approach. The results indicate that this method allows an accurate quantitative analysis of gastric damage, and the effects of different antiulcer drugs can be better discriminated. PMID:11437645

Natale, G; Lazzeri, G; Blandizzi, C; Gherardi, G; Lenzi, P; Pellegrini, A; Del Tacca, M

2001-07-01

347

Optimization of an Optical Inspection System Based on the Taguchi Method for Quantitative Analysis of Point-of-Care Testing  

PubMed Central

This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP). PMID:25256108

Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng

2014-01-01

348

Acquisition and Retention of Quantitative Communication Skills in an Undergraduate Biology Curriculum: Long-Term Retention Results  

NSDL National Science Digital Library

The purpose of this study was to assess some of the effects of a nontraditional, experimental learning approach designed to improve rapid acquisition and long-term retention of quantitative communication skills (QCS) such as descriptive and inferential st

Chevalier, Cary D.; Ashley, David C.; Rushin, John W.

2010-05-01

349

[A quantitation method for andrographolide and dehydroandrographolide by X-ray powder diffraction Fourier fingerprint pattern technique].  

PubMed

The powder X-ray diffraction Fourier fingerprint pattern technique was used to develop a new quantitation method for the analysis of andrographolide and dehydroandrographolide. And the high performance liquid chromatography method was used to evaluate the quantity of andrographolide and dehydroandrographolide. The relationship of diffraction peak intensity and content of andrographolide and dehydroandrographolide was investigated. The powder X-ray diffraction Fourier fingerprint pattern analysis technique can be used to evaluate the quantity of andrographolide and dehydroandrographolide in the herb simultaneously. PMID:20931774

Gong, Ning-Bo; L, Li-Juan; Liu, Chao; Ma, Lin; Chen, Ruo-Yun; L, Yang

2010-05-01

350

Development of mass spectrometry selected reaction monitoring method for quantitation and pharmacokinetic study of stepharine in rabbit plasma.  

PubMed

Highly sensitive liquid chromatography mass spectrometry method on triple quadrupole (QQQ) mass spectrometer was successfully applied for pharmacokinetic study of stepharine in rabbit plasma. Specific ion transitions of stepharine protonated precursor ion were selected and recorded in the certain retention time employing dynamic selected reaction monitoring mode. The developed method facilitated quantitative measurements of stepharine in plasma samples in linear range of five orders of magnitude with high accuracy and low standard deviation coefficient and pharmacokinetics parameters were calculated. The apparent volume of stepharine distribution (estimated as ratio of clearance to elimination rate constant, data not shown) allows us to assume that stepharine was extensively distributed throughout the body. PMID:24696679

Kopylov, Arthur T; Kuznetsova, Ksenia G; Mikhailova, Olga M; Moshkin, Andrey G; Turkin, Vladimir V; Alimov, Andrei A

2014-01-01

351

Development of Mass Spectrometry Selected Reaction Monitoring Method for Quantitation and Pharmacokinetic Study of Stepharine in Rabbit Plasma  

PubMed Central

Highly sensitive liquid chromatography mass spectrometry method on triple quadrupole (QQQ) mass spectrometer was successfully applied for pharmacokinetic study of stepharine in rabbit plasma. Specific ion transitions of stepharine protonated precursor ion were selected and recorded in the certain retention time employing dynamic selected reaction monitoring mode. The developed method facilitated quantitative measurements of stepharine in plasma samples in linear range of five orders of magnitude with high accuracy and low standard deviation coefficient and pharmacokinetics parameters were calculated. The apparent volume of stepharine distribution (estimated as ratio of clearance to elimination rate constant, data not shown) allows us to assume that stepharine was extensively distributed throughout the body. PMID:24696679

Kopylov, Arthur T.; Kuznetsova, Ksenia G.; Mikhailova, Olga M.; Moshkin, Andrey G.; Turkin, Vladimir V.; Alimov, Andrei A.

2014-01-01

352

A simple method for using silicone elastomer masks for quantitative analysis of cell migration without cellular damage or substrate disruption  

PubMed Central

Cell migration is fundamental to many biological processes, including development, normal tissue remodeling, wound healing, and many pathologies. However, cell migration is a complex process, and understanding its regulation in health and disease requires the ability to manipulate and measure this process quantitatively under controlled conditions. This report describes a simple in vitro assay for quantitative analysis of cell migration in two-dimensional cultures that is an inexpensive alternative to the classic scratch assay. The method described utilizes flexible silicone masks fabricated in the lab according to the research demands of the specific experiment to create a cell-free area for cells to invade, followed by quantitative analysis based on widely available microscopic imaging tools. This experimental approach has the important advantage of visualizing cell migration in the absence of the cellular damage and disruption of the substrate that occurs when the wound is created in the scratch assay. This approach allows the researcher to study the intrinsic migratory characteristics of cells in the absence of potentially confounding contributions from cellular responses to injury and disruption of cellsubstrate interactions. This assay has been used with vascular smooth muscle cells, fibroblasts, and epithelial cell types, but should be applicable to the study of practically any type of cultured cell. Furthermore, this method can be easily adapted for use with fluorescence microscopy, molecular biological, or pharmacological manipulations to explore the molecular mechanisms of cell migration, live cell imaging, fluorescence microscopy, and correlative immunolabeling. PMID:24430202

Sherry, David M; Parks, Eileen E; Bullen, Elizabeth C; Updike, Dawn L; Howard, Eric W

2013-01-01

353

Current and emerging quantitative magnetic resonance imaging methods for assessing and predicting the response of breast cancer to neoadjuvant therapy  

PubMed Central

Reliable early assessment of breast cancer response to neoadjuvant therapy (NAT) would provide considerable benefit to patient care and ongoing research efforts, and demand for accurate and noninvasive early-response biomarkers is likely to increase. Response assessment techniques derived from quantitative magnetic resonance imaging (MRI) hold great potential for integration into treatment algorithms and clinical trials. Quantitative MRI techniques already available for assessing breast cancer response to neoadjuvant therapy include lesion size measurement, dynamic contrast-enhanced MRI, diffusion-weighted MRI, and proton magnetic resonance spectroscopy. Emerging yet promising techniques include magnetization transfer MRI, chemical exchange saturation transfer MRI, magnetic resonance elastography, and hyperpolarized MR. Translating and incorporating these techniques into the clinical setting will require close attention to statistical validation methods, standardization and reproducibility of technique, and scanning protocol design. PMID:23154619

Abramson, Richard G; Arlinghaus, Lori R; Weis, Jared A; Li, Xia; Dula, Adrienne N; Chekmenev, Eduard Y; Smith, Seth A; Miga, Michael I; Abramson, Vandana G; Yankeelov, Thomas E

2012-01-01

354

Mode-Stirred Method Implementation for HIRF Susceptibility Testing and Results Comparison with Anechoic Method  

NASA Technical Reports Server (NTRS)

This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that test method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identified and implemented.

Nguyen, Truong X.; Ely, Jay J.; Koppen, Sandra V.

2001-01-01

355

[A new quantitative method for quantifying left heart jets by Doppler color imaging].  

PubMed

Quantification of valvular lesions by Color Doppler is based on jet measurements. The aim of this new method is to reduce some of the errors in these measurements: uncertainty in delimiting the colored areas of the jets; spontaneous beat-to-beat variations of the jets entailing interpretative difficulties. The first step was to determine the correlations between the colored areas and previously established single-gated Doppler criteria, retaining spectral criteria to define the borders of the jets, so overcoming some of the limitations of color Doppler. The association of these methods resulted in better discrimination between grades and a better correlation in 45 angiographically controlled mitral and aortic regurgitations than with color Doppler alone. In stenotic lesions, spectral criteria from single-gated associated exploration enabled localisation of the level for planimetry of the section of the jet at its origin visualised by color Doppler. Satisfactory correlations were obtained with the Gorlin surface area in a group of 43 patients with mitral and aortic stenosis. A coefficient of variation of 13 to 14 per cent was found with planimetry of the regurgitant jet in the upstream cardiac chamber. Uni-dimensional measurement decreased this variation to 6 to 11 per cent in the same patients. The largest decrease in variability (6 to 8 per cent) was observed in stenotic and regurgitant lesions with planimetry of the section of jet at its origin performed in held mid-expiration and so this would appear to be the best method. The guide lines and technological improvement associated with the physiopathological information provided by color Doppler should refine the quantification of valvular heart lesions. PMID:2514635

Veyrat, C; Legeais, S; Gourtchiglouian, C; Sainte Beuve, D; Abitbol, G; Kalmanson, D

1989-11-01

356

Bacterial interference in vitro. Comparison between a quantitative kinetic and a cocultivation blood agar test method.  

PubMed

The aim of the present study was to compare two methods for estimation of bacterial growth interference between various bacteria using a Bioscreen robot analyzer, allowing kinetic documentation, and a cocultivation test on blood agar plates. Six laboratory strains with different virulence and growth requirements were used: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus mitis, Staphylococcus aureus, and Staphylococcus epidermidis. The interference activity was correlated with a reference system of Streptococcus sanguis (strain alpha 89) and Streptococcus pyogenes (group A streptococci, GAS serotypes T 9 and T 22). The methods used and results obtained were as follows: 1. Estimation of synergistic and antagonistic bacterial interferences using a Bioscreen robot analyzer. Suspensions of viable bacteria were added to microtiter plates with different concentrations of UV light-killed bacteria in liquid media. The Bioscreen analyzer monitored bacterial growth every 10 min for 24 h giving kinetic data during the growth period. Synergisms as well as antagonisms were demonstrated between the tested bacterial strains which have not earlier been reported in the literature. However, the antagonistic effect observed between the six strains was less than that induced by the S. sanguis strain on the two strains of S. pyogenes. 2. Cocultivation of bacterial strains on blood agar surface with precultivated or simultaneously stamped interfering bacteria indicated no detectable interference between the six tested bacterial strains, while the S. sanguis strain inhibited the growth of S. pyogenes strains as well as the hemolysis around the colonies. The Bioscreen method was found more sensitive for testing bacterial interference compared to the commonly used blood agar test. PMID:7833000

Johansson, A; Bergenholtz, A; Holm, S E

1994-11-01

357

[Quantitative retrieval of chlorophyll a concentration in Taihu Lake using machine learning methods].  

PubMed

We evaluated the performance of two machine learning methods, artificial neural net (ANN) and support vector machine (SVM), for estimation of chlorophyll a in Taihu Lake from remote sensing data. The theoretical analysis has been done from basic theory and learning target of these two methods first. Then two empirical algorithms have been developed to relate reflectance of MODIS to in situ concentrations of chlorophyll a. The performance of ANN and SVM is comparatively analyzed in terms of validation, stability and robustness assessment and chlorophyll a distribution of Taihu Lake from two algorithms. The root of mean square deviation (RMSE) and average relative error (ARE) of validation data is only 5.85 and 26.5% of SVM retrieval model, however, RMSE and ARE of ANN model is 13.04 and 46.8%. Stability and robustness assessment suggest that SVM provides the better performance than ANN. And the retrieval results show that the chlorophyll a distribution of the whole lake from two algorithms is similar, however, the chlorophyll a concentration in the eastern region and central region of Taihu Lake is distorted by ANN model because of the limitations, such as learning target setting and over-learning in net construction. PMID:19558096

Zhang, Yu-Chao; Qian, Xin; Qian, Yu; Liu, Jian-Ping; Kong, Fan-Xiang

2009-05-15

358

Development and interlaboratory validation of quantitative polymerase chain reaction method for screening analysis of genetically modified soybeans.  

PubMed

A novel real-time polymerase chain reaction (PCR)-based quantitative screening method was developed for three genetically modified soybeans: RRS, A2704-12, and MON89788. The 35S promoter (P35S) of cauliflower mosaic virus is introduced into RRS and A2704-12 but not MON89788. We then designed a screening method comprised of the combination of the quantification of P35S and the event-specific quantification of MON89788. The conversion factor (Cf) required to convert the amount of a genetically modified organism (GMO) from a copy number ratio to a weight ratio was determined experimentally. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDR), respectively. The determined RSDR values for the method were less than 25% for both targets. We consider that the developed method would be suitable for the simple detection and approximate quantification of GMO. PMID:23302646

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

2013-01-01

359

A Colony Multiplex Quantitative PCR-Based 3S3DBC Method and Variations of It for Screening DNA Libraries  

PubMed Central

A DNA library is a collection of DNA fragments cloned into vectors and stored individually in host cells, and is a valuable resource for molecular cloning, gene physical mapping, and genome sequencing projects. To take the best advantage of a DNA library, a good screening method is needed. After describing pooling strategies and issues that should be considered in DNA library screening, here we report an efficient colony multiplex quantitative PCR-based 3-step, 3-dimension, and binary-code (3S3DBC) method we used to screen genes from a planarian genomic DNA fosmid library. This method requires only 3 rounds of PCR reactions and only around 6 hours to distinguish one or more desired clones from a large DNA library. According to the particular situations in different research labs, this method can be further modified and simplified to suit their requirements. PMID:25646755

An, Yang; Toyoda, Atsushi; Zhao, Chen; Fujiyama, Asao; Agata, Kiyokazu

2015-01-01

360

QUANTITATIVE METHODS FOR RESERVOIR CHARACTERIZATION AND IMPROVED RECOVERY: APPLICATION TO HEAVY OIL SANDS  

SciTech Connect

Improved prediction of interwell reservoir heterogeneity has the potential to increase productivity and to reduce recovery cost for California's heavy oil sands, which contain approximately 2.3 billion barrels of remaining reserves in the Temblor Formation and in other formations of the San Joaquin Valley. This investigation involves application of advanced analytical property-distribution methods conditioned to continuous outcrop control for improved reservoir characterization and simulation, particularly in heavy oil sands. The investigation was performed in collaboration with Chevron Production Company U.S.A. as an industrial partner, and incorporates data from the Temblor Formation in Chevron's West Coalinga Field. Observations of lateral variability and vertical sequences observed in Temblor Formation outcrops has led to a better understanding of reservoir geology in West Coalinga Field. Based on the characteristics of stratigraphic bounding surfaces in the outcrops, these surfaces were identified in the subsurface using cores and logs. The bounding surfaces were mapped and then used as reference horizons in the reservoir modeling. Facies groups and facies tracts were recognized from outcrops and cores of the Temblor Formation and were applied to defining the stratigraphic framework and facies architecture for building 3D geological models. The following facies tracts were recognized: incised valley, estuarine, tide- to wave-dominated shoreline, diatomite, and subtidal. A new minipermeameter probe, which has important advantages over previous methods of measuring outcrop permeability, was developed during this project. The device, which measures permeability at the distal end of a small drillhole, avoids surface weathering effects and provides a superior seal compared with previous methods for measuring outcrop permeability. The new probe was used successfully for obtaining a high-quality permeability data set from an outcrop in southern Utah. Results obtained from analyzing the fractal structure of permeability data collected from the southern Utah outcrop and from core permeability data provided by Chevron from West Coalinga Field were used in distributing permeability values in 3D reservoir models. Spectral analyses and the Double Trace Moment method (Lavallee et al., 1991) were used to analyze the scaling and multifractality of permeability data from cores from West Coalinga Field. T2VOC, which is a numerical flow simulator capable of modeling multiphase, multi-component, nonisothermal flow, was used to model steam injection and oil production for a portion of section 36D in West Coalinga Field. The layer structure and permeability distributions of different models, including facies group, facies tract, and fractal permeability models, were incorporated into the numerical flow simulator. The injection and production histories of wells in the study area were modeled, including shutdowns and the occasional conversion of production wells to steam injection wells. The framework provided by facies groups provides a more realistic representation of the reservoir conditions than facies tracts, which is revealed by a comparison of the history-matching for the oil production. Permeability distributions obtained using the fractal results predict the high degree of heterogeneity within the reservoir sands of West Coalinga Field. The modeling results indicate that predictions of oil production are strongly influenced by the geologic framework and by the boundary conditions. The permeability data collected from the southern Utah outcrop, support a new concept for representing natural heterogeneity, which is called the fractal/facies concept. This hypothesis is one of the few potentially simplifying concepts to emerge from recent studies of geological heterogeneity. Further investigation of this concept should be done to more fully apply fractal analysis to reservoir modeling and simulation. Additional outcrop permeability data sets and further analysis of the data from distinct facies will be needed in order to fully develop

James W. Castle; Fred J. Molz; Ronald W. Falta; Cynthia L. Dinwiddie; Scott E. Brame; Robert A. Bridges

2002-10-30

361

Comparison of Rapid Quantitative PCR-Based and Conventional Culture-Based Methods for Enumeration of Enterococcus spp. and Escherichia coli in Recreational Waters?  

PubMed Central

Recreational water quality is currently monitored using culture-based methods that require 18 to 96 h for results. Quantitative PCR (QPCR) methods that can be completed in less than 2 h have been developed, but they could yield different results than the conventional methods. We present two studies in which samples were processed simultaneously for Enterococcus spp. and Escherichia coli using two culture-based methods (EPA method 1600 and Enterolert/Colilert-18) and QPCR. The proprietary QPCR assays targeted the 23S rRNA (Enterococcus spp.) and uidA (E. coli) genes and were conducted using lyophilized beads containing all reagents. In the first study, the QPCR method developers processed 54 blind samples that were inoculated with sewage or pure cultures or were ambient beach samples. The second study involved 163 samples processed by water quality personnel. The correlation between results of QPCR and EPA 1600 during the first study (r2) was 0.69 for Enterococcus spp., which was less than that observed between the culture-based methods (r2, 0.87). During the second study, the correlations were similar. No false positives occurred in either study when QPCR-based assays were used with blank samples. Levels of reproducibility measured through coefficients of variation were similar for results by Enterococcus QPCR and culture-based methods during both studies but were higher for E. coli QPCR results in the first study. Regarding the concentration at which beach management decisions are issued in the State of California, the agreement between results of Enterococcus QPCR and EPA method 1600 was 88%, compared to 94% agreement between EPA method 1600 and Enterolert. The beach management decision agreement between E. coli QPCR and Colilert-18 was 94%. The samples showing disagreement suggested an underestimation bias for QPCR. PMID:20870786

Noble, Rachel T.; Blackwood, A. Denene; Griffith, John F.; McGee, Charles D.; Weisberg, Stephen B.

2010-01-01

362

Comparison of rapid quantitative PCR-based and conventional culture-based methods for enumeration of Enterococcus spp. and Escherichia coli in recreational waters.  

PubMed

Recreational water quality is currently monitored using culture-based methods that require 18 to 96 h for results. Quantitative PCR (QPCR) methods that can be completed in less than 2 h have been developed, but they could yield different results than the conventional methods. We present two studies in which samples were processed simultaneously for Enterococcus spp. and Escherichia coli using two culture-based methods (EPA method 1600 and Enterolert/Colilert-18) and QPCR. The proprietary QPCR assays targeted the 23S rRNA (Enterococcus spp.) and uidA (E. coli) genes and were conducted using lyophilized beads containing all reagents. In the first study, the QPCR method developers processed 54 blind samples that were inoculated with sewage or pure cultures or were ambient beach samples. The second study involved 163 samples processed by water quality personnel. The correlation between results of QPCR and EPA 1600 during the first study (r) was 0.69 for Enterococcus spp., which was less than that observed between the culture-based methods (r, 0.87). During the second study, the correlations were similar. No false positives occurred in either study when QPCR-based assays were used with blank samples. Levels of reproducibility measured through coefficients of variation were similar for results by Enterococcus QPCR and culture-based methods during both studies but were higher for E. coli QPCR results in the first study. Regarding the concentration at which beach management decisions are issued in the State of California, the agreement between results of Enterococcus QPCR and EPA method 1600 was 88%, compared to 94% agreement between EPA method 1600 and Enterolert. The beach management decision agreement between E. coli QPCR and Colilert-18 was 94%. The samples showing disagreement suggested an underestimation bias for QPCR. PMID:20870786

Noble, Rachel T; Blackwood, A Denene; Griffith, John F; McGee, Charles D; Weisberg, Stephen B

2010-11-01

363

A quantitative method for residues of macrolide antibiotics in porcine kidney by liquid chromatography/tandem mass spectrometry.  

PubMed

An LC/MS/MS-based multiresidue quantitative method was developed for the macrolides erythromycin A, neospiramycin I, oleandomycin, spiramycin I, tilmicosin, and tylosin A in porcine kidney tissues. The Canadian Food Inspection Agency (CFIA) had as part of its analytical scope an LC/UV method for quantification of residues of two macrolide antibiotics, tilmicosin and tylosin A, in the kidney, liver, and muscle of cattle, swine, and poultry. The method could not reliably detect concentrations below 10 microg/kg. To increase the scope of the CFIA's analytical capabilities, a sensitive multiresidue quantitative method for macrolide residues in food animal tissues was required. Porcine kidney samples were extracted with acetonitrile and alkaline buffer and cleaned-up using silica-based C18 SPE cartridges. Sample extracts were analyzed using LC/MS/MS with positive electrospray ionization. Fitness for purpose was verified in a single-laboratory validation study using a second analyst. The working analytical range was 5 to 50 microg/kg. LOD and LOQ were 0.5 to 0.6 microg/kg and 1.5 to 3.0 microg/kg, respectively. Limits of identification were 0.5 to 2.0 microg/kg. Relative intermediate precisions were 8 to 17%. Average absolute recoveries were 68 to 76%. PMID:22649946

Dickson, Leslie C; O'Byrne, Collin; Chan, Wayne

2012-01-01

364

Ten Years of LibQual: A Study of Qualitative and Quantitative Survey Results at the University of Mississippi 2001-2010  

ERIC Educational Resources Information Center

This article analyzes quantitative adequacy gap scores and coded qualitative comments from LibQual surveys at the University of Mississippi from 2001 to 2010, looking for relationships between library policy changes and LibQual results and any other trends that emerged. Analysis found no relationship between changes in policy and survey results

Greenwood, Judy T.; Watson, Alex P.; Dennis, Melissa

2011-01-01

365

Heterogeneous reaction rates in an ionic liquid: quantitative results from two-dimensional multiple population-period transient spectroscopy.  

PubMed

The hypotheses that ionic liquids are structurally heterogeneous at the molecular level and, even further, that this heterogeneity can transfer to the rates of reactions run in ionic liquids is being actively debated. Here, this hypothesis is tested using multiple population-period transient spectroscopy (MUPPETS), an emerging type of multidimensional measurement that resolves the kinetics of subensembles within a heterogeneous sample. A previous MUPPETS study of the excited-state twisting and electronic relaxation of auramine indicated that an ionic-liquid solvent induces rate dispersion due to a combination of heterogeneous and homogeneous processes, but those data could not quantitatively separate these contributions [Khurmi, C.; Berg, M. A. J. Phys. Chem. Lett.2010, 1, 161]. New MUPPETS data that include phase resolution and subtraction of thermal gratings are presented here and are successfully modeled. The total range of reaction rates (10--90%) is a factor of 70. If the solvent effect is viewed as a set of local viscosities, the viscosity distribution is broad and highly asymmetric. However, if the solvent is viewed as changing a reaction barrier, the data correspond to a Gaussian distribution of barrier heights. The relaxation of each subensemble is nonexponential with an initial induction period, but the shape of the decay is invariant across the rate distribution. A small (2%), long-lived component is identified as a part of the homogeneous kinetic scheme and thus as a secondary channel for excited-state relaxation, not as an impurity or alternative ground-state form of auramine. On the basis of these results, we suggest that the primary cause of rate heterogeneity is a long-lived local electric field acting on the charge redistribution during the reaction. PMID:21630702

Sahu, Kalyanasis; Kern, Sean J; Berg, Mark A

2011-07-14

366

Transcending the Quantitative-Qualitative Divide with Mixed Methods Research: A Multidimensional Framework for Understanding Congruence and Completeness in the Study of Values  

ERIC Educational Resources Information Center

Quantitative research dominates published literature in the helping professions. Mixed methods research, which integrates quantitative and qualitative methodologies, has received a lukewarm reception. The authors address the iterative separation that infuses theory, praxis, philosophy, methodology, training, and public perception and propose a

McLafferty, Charles L., Jr.; Slate, John R.; Onwuegbuzie, Anthony J.

2010-01-01

367

Flexible and Robust Methods for Rare-Variant Testing of Quantitative Traits in Trios and Nuclear Families  

PubMed Central

Most rare-variant association tests for complex traits are applicable only to population-based or case-control resequencing studies. There are fewer rare-variant association tests for family-based resequencing studies, which is unfortunate since pedigrees possess many attractive characteristics for such analyses. Family-based studies can be more powerful than their population-based counterparts due to increased genetic load and further enable the implementation of rare-variant association tests that, by design, are robust to confounding due to population stratification. With this in mind, we propose a rare-variant association test for quantitative traits in families; this test integrates the QTDT approach of Abecasis et al. [Abecasis, et al. 2000a] into the kernel-based SNP association test KMFAM of Schifano et al. [Schifano, et al. 2012]. The resulting within-family test enjoys the many benefits of the kernel framework for rare-variant association testing, including rapid evaluation of p-values and preservation of power when a region harbors rare causal variation that acts in different directions on phenotype. Additionally, by design, this within-family test is robust to confounding due to population stratification. While within-family association tests are generally less powerful than their counterparts that use all genetic information, we show that we can recover much of this power (while still ensuring robustness to population stratification) using a straightforward screening procedure. Our method accommodates covariates and allows for missing parental genotype data, and we have written software implementing the approach in R for public use. PMID:25044337

Jiang, Yunxuan; Conneely, Karen N.; Epstein, Michael P.

2014-01-01

368

Flexible and robust methods for rare-variant testing of quantitative traits in trios and nuclear families.  

PubMed

Most rare-variant association tests for complex traits are applicable only to population-based or case-control resequencing studies. There are fewer rare-variant association tests for family-based resequencing studies, which is unfortunate because pedigrees possess many attractive characteristics for such analyses. Family-based studies can be more powerful than their population-based counterparts due to increased genetic load and further enable the implementation of rare-variant association tests that, by design, are robust to confounding due to population stratification. With this in mind, we propose a rare-variant association test for quantitative traits in families; this test integrates the QTDT approach of Abecasis et al. [Abecasis etal., ] into the kernel-based SNP association test KMFAM of Schifano et al. [Schifano etal., ]. The resulting within-family test enjoys the many benefits of the kernel framework for rare-variant association testing, including rapid evaluation of P-values and preservation of power when a region harbors rare causal variation that acts in different directions on phenotype. Additionally, by design, this within-family test is robust to confounding due to population stratification. Although within-family association tests are generally less powerful than their counterparts that use all genetic information, we show that we can recover much of this power (although still ensuring robustness to population stratification) using a straightforward screening procedure. Our method accommodates covariates and allows for missing parental genotype data, and we have written software implementing the approach in R for public use. PMID:25044337

Jiang, Yunxuan; Conneely, Karen N; Epstein, Michael P

2014-09-01

369

Early assessment of breast cancer response to neoadjuvant chemotherapy by semi-quantitative analysis of high-temporal resolution DCE-MRI: Preliminary results  

PubMed Central

Purpose To evaluate whether semi-quantitative analysis of high temporal resolution dynamic contrast-enhanced MRI (DCE-MRI) acquired early in treatment can predict the response of locally advanced breast cancer (LABC) to neoadjuvant chemotherapy (NAC). Materials and Methods As part of an IRB-approved prospective study, 21 patients with LABC provided informed consent and underwent high temporal resolution 3 T DCE-MRI before and after 1 cycle of NAC. Using measurements performed by two radiologists, the following parameters were extracted for lesions at both examinations: lesion size (short and long axes, in both early and late phases of enhancement), radiologists subjective assessment of lesion enhancement, and percentages of voxels within the lesion demonstrating progressive, plateau, or washout kinetics. The latter data were calculated using two filters, one selecting for voxels enhancing ?50% over baseline and one for voxels enhancing ?100% over baseline. Pretreatment imaging parameters and parameter changes following cycle 1 of NAC were evaluated for their ability to discriminate patients with an eventual pathological complete response (pCR). Results All 21 patients completed NAC followed by surgery, with 9 patients achieving a pCR. No pretreatment imaging parameters were predictive of pCR. However, change after cycle 1 of NAC in percentage of voxels demonstrating washout kinetics with a 100% enhancement filter discriminated patients with an eventual pCR with an area under the receiver operating characteristic curve (AUC) of 0.77. Changes in other parameters, including lesion size, did not predict pCR. Conclusion Semi-quantitative analysis of high temporal resolution DCE-MRI in patients with LABC can discriminate patients with an eventual pCR after one cycle of NAC. PMID:23954320

Abramson, Richard G.; Li, Xia; Hoyt, Tamarya Lea; Su, Pei-Fang; Arlinghaus, Lori R.; Wilson, Kevin J.; Abramson, Vandana G.; Chakravarthy, A. Bapsi; Yankeelov, Thomas E.

2013-01-01

370

Analytic study of the Tadoma method: background and preliminary results.  

PubMed

Certain deaf-blind persons have been taught, through the Tadoma method of speechreading, to use vibrotactile cues from the face and neck to understand speech. This paper reports the results of preliminary tests of the speechreading ability of one adult Tadoma user. The tests were of four major types: (1) discrimination of speech stimuli; (2) recognition of words in isolation and in sentences; (3) interpretation of prosodic and syntactic features in sentences; and (4) comprehension of written (Braille) and oral speech. Words in highly contextual environments were much better perceived than were words in low-context environments. Many of the word errors involved phonemic substitutions which shared articulatory features with the target phonemes, with a higher error rate for vowels than consonants. Relative to performance on word-recognition tests, performance on some of the discrimination tests was worse than expected. Perception of sentences appeared to be mildly sensitive to rate of talking and to speaker differences. Results of the tests on perception of prosodic and syntactic features, while inconclusive, indicate that many of the features tested were not used in interpreting sentences. On an English comprehension test, a higher score was obtained for items administered in Braille than through oral presentation. PMID:904318

Norton, S J; Schultz, M C; Reed, C M; Braida, L D; Durlach, N I; Rabinowitz, W M; Chomsky, C

1977-09-01

371

A quantitative method for groundwater surveillance monitoring network design at the Hanford Site  

SciTech Connect

As part of the Environmental Surveillance Program at the Hanford Site, mandated by the US Department of Energy, hundreds of groundwater wells are sampled each year, with each sample typically analyzed for a variety of constituents. The groundwater sampling program must satisfy several broad objectives. These objectives include an integrated assessment of the condition of groundwater and the identification and quantification of existing, emerging, or potential groundwater problems. Several quantitative network desip objectives are proposed and a mathematical optimization model is developed from these objectives. The model attempts to find minimum cost network alternatives that maximize the amount of information generated by the network. Information is measured both by the rats of change with respect to time of the contaminant concentration and the uncertainty in contaminant concentration. In an application to tritium monitoring at the Hanford Site, both information measures were derived from historical data using time series analysis.

Meyer, P.D.

1993-12-01

372

Computerized method of lesion volume quantitation in multiple sclerosis: error of serial studies.  

PubMed

This study was designed to evaluate a potentially important source of error in T2-hyperintense lesion measurement unique to longitudinal multiple sclerosis treatment trials that would not be detected by the standard intraobserver and interobserver error analyses. The effect of this "error of serial studies" was tested by using the standard-of-reference manual-outlining approach and a modified bi-feature space (statistical) approach applied to a database of five consecutive patients. To simulate the conditions of a longitudinal treatment trial, each patient had immediate repeat MR studies of the brain with imperfect head repositioning. The study hypothesis was confirmed that with an improved quantitative methodology, the "error of serial studies" (interseries error) would exceed the intraobserver error. PMID:9090427

Simon, J H; Scherzinger, A; Raff, U; Li, X

1997-03-01

373

A method for fully automated quantitative analysis of arterial flow using flow-sensitized MR images.  

PubMed

While the recent developments in the velocity-sensitive MR imaging offer great potential for non-invasive assessment of blood flow in major blood vessels, the clinical applications of this technique have been hampered by tedious, human-assisted data processing techniques. In this paper, we describe a robust system for automated extraction of quantitative as well as qualitative flow information from velocity-sensitive, phase contrast MR images. The algorithm accomplishes reliable segmentation of blood vessels using multiresolution analysis based on wavelet transform, and employs a multivariate scoring criterion to minimize the impact of imaging artifacts such as partial volume averaging and flow turbulence, which normally cause incomplete or inaccurate detection of vascular boundaries. PMID:9007364

Chwialkowski, M P; Ibrahim, Y M; Li, H F; Peshock, R M

1996-01-01

374

Quantitative estimation of trace chemicals in industrial effluents with the Sticklet transform method  

NASA Astrophysics Data System (ADS)

Application of a novel transform operator, the Sticklet transform, to the quantitative estimation of trace chemicals in industrial effluent plumes is reported. The sticklet transform si a superset of the well-known derivative operator and the Haar wavelet, and is characterized by independently adjustable lobe width and separation. Computer simulations demonstrate that we can make accurate and robust concentration estimates of multiple chemical species in industrial effluent plumes in the presence of strong clutter background, interferent chemicals and random noise. In this paper we address the application of the sticklet transform in estimating chemical concentrations in the effluent plumes in the presence of atmospheric transmission effects. We show that this transform retains the ability to yield accurate estimates using on-plume / off-plume measurements that represenst atmospheric differentials up to 10% of the full atmospheric attenuation.

Mehta, Naresh C.; Scharlemann, Ernst T.; Stevens, Charles G.

2001-08-01

375

Quantitative Estimation of Trace Chemicals in Industrial Effluents with the Sticklet Transform Method  

SciTech Connect

Application of a novel transform operator, the Sticklet transform, to the quantitative estimation of trace chemicals in industrial effluent plumes is reported. The sticklet transform is a superset of the well-known derivative operator and the Haar wavelet, and is characterized by independently adjustable lobe width and separation. Computer simulations demonstrate that they can make accurate and robust concentration estimates of multiple chemical species in industrial effluent plumes in the presence of strong clutter background, interferent chemicals and random noise. In this paper they address the application of the sticklet transform in estimating chemical concentrations in effluent plumes in the presence of atmospheric transmission effects. They show that this transform retains the ability to yield accurate estimates using on-plume/off-plume measurements that represent atmospheric differentials up to 10% of the full atmospheric attenuation.

Mehta, N C; Scharlemann, E T; Stevens, C G

2001-04-02

376

A quantitative structure- property relationship of gas chromatographic/mass spectrometric retention data of 85 volatile organic compounds as air pollutant materials by multivariate methods  

PubMed Central

A quantitative structure-property relationship (QSPR) study is suggested for the prediction of retention times of volatile organic compounds. Various kinds of molecular descriptors were calculated to represent the molecular structure of compounds. Modeling of retention times of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR) and artificial neural network (ANN). The stepwise regression was used for the selection of the variables which gives the best-fitted models. After variable selection ANN, MLR methods were used with leave-one-out cross validation for building the regression models. The prediction results are in very good agreement with the experimental values. MLR as the linear regression method shows good ability in the prediction of the retention times of the prediction set. This provided a new and effective method for predicting the chromatography retention index for the volatile organic compounds. PMID:22594439

2012-01-01

377

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

PubMed

To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize. PMID:21873818

Takabatake, Reona; Koiwa, Tomohiro; Kasahara, Masaki; Takashima, Kaori; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Oguchi, Taichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

2011-01-01

378

Comparison of six methods of extracting Mycobacterium tuberculosis DNA from processed sputum for testing by quantitative real-time PCR.  

PubMed

Six methods of extracting Mycobacterium tuberculosis DNA from sputum for testing by quantitative PCR were compared: Tris-EDTA (TE) buffer, PrepMan Ultra, 2% sodium dodecyl sulfate (SDS)-10% Triton X with and without sonication, Infectio Diagnostics, Inc. (IDI) lysing tubes, and QIAGEN QIAamp DNA mini kit; all included a 15-min boiling step. Pooled digested and decontaminated sputum was spiked with M. tuberculosis ATCC 27294. Each extraction method was repeated eight times. Quantitative PCR was performed on the Smart Cycler and Rotor-Gene 3000 using primers targeting an 83-bp fragment of IS6110. An minor grove binding Eclipse probe with a fluorescent label was used for detection. An internal control was included to detect amplification inhibition. The limit of detection of M. tuberculosis DNA was 0.5 fg with both instruments. Calculated DNA concentrations (picograms) extracted using IDI, PrepMan, QIAGEN, and TE were 42.8, 30.4, 28.2, and 7.4, respectively, when run on the Smart Cycler, and 51.7, 20.1, 14.9, and 8.6, respectively, when run on Rotor-Gene. All extractions using SDS/Triton X with or without sonication were inhibited. Of the extraction methods evaluated, IDI lysis tubes provided the greatest yield of mycobacterial DNA, and the procedure can be completed in less than 1 h versus 2.5-3 h for the QIAGEN extraction. PMID:15872286

Aldous, Wade K; Pounder, June I; Cloud, Joann L; Woods, Gail L

2005-05-01

379

a New Quantitative Method for the Rapid Evaluation of Buildings against Earthquakes  

NASA Astrophysics Data System (ADS)

At the present time there exist numerous weak buildings which are not able to withstand earthquakes. At the same time, both private and public developers are trying to use scientific methods to prioritize and allocate budget in order to reinforce the above mentioned structures. This is because of the limited financial resources and time. In the recent years the procedure of seismic assessment before rehabilitation of vulnerable buildings has been implemented in many countries. Now, it seems logical to reinforce the existing procedures with the mass of available data about the effects caused by earthquakes on buildings. The main idea is driven from FMEA (Failure Mode and Effect Analysis) in quality management where the main procedure is to recognize the failure, the causes, and the priority of each cause and failure. Specifying the causes and effects which lead to a certain shortcoming in structural behavior during earthquakes, an inventory is developed and each building is rated through a yes-or-no procedure. In this way, the rating of the structure is based on some standard forms which along with relative weights are developed in this study. The resulted criteria by rapid assessment will indicate whether the structure is to be demolished, has a high, medium or low vulnerability or is invulnerable.

Mahmoodzadeh, Amir; Mazaheri, Mohammad Mehdi

2008-07-01

380

A new quantitative method for the rapid evaluation of buildings against earthquakes  

SciTech Connect

At the present time there exist numerous weak buildings which are not able to withstand earthquakes. At the same time, both private and public developers are trying to use scientific methods to prioritize and allocate budget in order to reinforce the above mentioned structures. This is because of the limited financial resources and time. In the recent years the procedure of seismic assessment before rehabilitation of vulnerable buildings has been implemented in many countries. Now, it seems logical to reinforce the existing procedures with the mass of available data about the effects caused by earthquakes on buildings. The main idea is driven from FMEA (Failure Mode and Effect Analysis) in quality management where the main procedure is to recognize the failure, the causes, and the priority of each cause and failure. Specifying the causes and effects which lead to a certain shortcoming in structural behavior during earthquakes, an inventory is developed and each building is rated through a yes-or-no procedure. In this way, the rating of the structure is based on some standard forms which along with relative weights are developed in this study. The resulted criteria by rapid assessment will indicate whether the structure is to be demolished, has a high, medium or low vulnerability or is invulnerable.

Mahmoodzadeh, Amir [Civil Engineering Dept., Islamic Azad University, Nagafabad (Iran, Islamic Republic of); Mazaheri, Mohammad Mehdi [Faculty member, Tehran University (Iran, Islamic Republic of)

2008-07-08

381

Morphologic change in coronary artery stenosis with the Medtronic Wiktor Stent: initial results from the core laboratory for quantitative angiography  

Microsoft Academic Search

The purpose of this study was to assess the early changes in stenosis geometry after implantation of the Medtronic Wiktor stent in human coronary arteries. Morphologic changes were evaluated by quantitative coronary angiography using automated edge detection. The hemodynamic significance of the morphologic changes were assessed by the calculation of the theoretical pressure drop across the dilated and stented stenosis

Patrick Serruys; Peter De Jaegere; Michel Bertrand; Gisbert Kober; Jean Francois Marquis; Jan Piessens; Rainer Uebis; Bernard Valeix; Volker Wiegand

1991-01-01

382

Quantitative analysis of flavonol glycosides in Ginkgo biloba: a comparison of two analytical methods.  

PubMed

A comparison of testing methods for constituents of Ginkgo biloba was performed as part of the process for determining which of the many available analytical methods was most appropriate for inclusion in the American Herbal Pharmacopoeia (AHP). Three primary methods were reviewed: those adopted by the European Pharmacopoeia, the National Science Foundation-Institute for Nutraceutical Advancement (NSF-INA) and the United States Pharmacopeia. Methods were compared by evaluating sample preparation and hydrolysis, precision and methods of total flavonol glycoside calculation by two independent laboratories. The AHP adopted the method of NSF-INA for inclusion in the AHP monograph owing to observed superiority of this method in terms of precision, glycoside calculation, ease of sample preparation and chromatographic parameters. PMID:16454477

Gray, D E; Upton, R; Chandra, A; Porter, A; Harris, R K

2006-01-01

383

Methods for the quantitative comparison of molecular estimates of clade age and the fossil record.  

PubMed

Approaches quantifying the relative congruence, or incongruence, of molecular divergence estimates and the fossil record have been limited. Previously proposed methods are largely node specific, assessing incongruence at particular nodes for which both fossil data and molecular divergence estimates are available. These existing metrics, and other methods that quantify incongruence across topologies including entirely extinct clades, have so far not taken into account uncertainty surrounding both the divergence estimates and the ages of fossils. They have also treated molecular divergence estimates younger than previously assessed fossil minimum estimates of clade age as if they were the same as cases in which they were older. However, these cases are not the same. Recovered divergence dates younger than compared oldest known occurrences require prior hypotheses regarding the phylogenetic position of the compared fossil record and standard assumptions about the relative timing of morphological and molecular change to be incorrect. Older molecular dates, by contrast, are consistent with an incomplete fossil record and do not require prior assessments of the fossil record to be unreliable in some way. Here, we compare previous approaches and introduce two new descriptive metrics. Both metrics explicitly incorporate information on uncertainty by utilizing the 95% confidence intervals on estimated divergence dates and data on stratigraphic uncertainty concerning the age of the compared fossils. Metric scores are maximized when these ranges are overlapping. MDI (minimum divergence incongruence) discriminates between situations where molecular estimates are younger or older than known fossils reporting both absolute fit values and a number score for incompatible nodes. DIG range (divergence implied gap range) allows quantification of the minimum increase in implied missing fossil record induced by enforcing a given set of molecular-based estimates. These metrics are used together to describe the relationship between time trees and a set of fossil data, which we recommend be phylogenetically vetted and referred on the basis of apomorphy. Differences from previously proposed metrics and the utility of MDI and DIG range are illustrated in three empirical case studies from angiosperms, ostracods, and birds. These case studies also illustrate the ways in which MDI and DIG range may be used to assess time trees resultant from analyses varying in calibration regime, divergence dating approach or molecular sequence data analyzed. PMID:25281846

Clarke, Julia A; Boyd, Clint A

2015-01-01

384

Cross-Proportions: A Conceptual Method for Developing Quantitative Problem-Solving Skills  

NASA Astrophysics Data System (ADS)

This paper focuses attention on the cross-proportion (C-P) method of mathematical problem solving, which was once widely used in chemical calculations. We propose that this method regain currency as an alternative to the dimensional analysis (DA) method, particularly in lower-level chemistry courses. In recent years, the DA method has emerged as the only problem solving mechanism offered to high-school and general chemistry students in contemporary textbooks, replacing more conceptual methods, C-P included. The C-P method emphasizes basic scientific principles through application during the process of solving numerical problems, which in turn promotes student understanding of these principles by constantly reinforcing basic concepts. We believe that appropriate teaching of chemistry needs to model its conceptual character as well as address students' different learning styles. Examples of C-P applications to molar mass and stoichiometry are given.

Cook, Elzbieta; Cook, Robert L.

2005-08-01

385

A quantitative immunostaining method for the measurement of UDP-galactose:lactosylceramide galactosyltransferase for the synthesis of globotriaosylceramide in rabbit small intestine and HeLa cells.  

PubMed

Galactosyltransferase is required for the addition of galactose to lactosylceramide (galactose beta 1-4 glucose beta 1-1 ceramide), resulting in the synthesis of globotriaosylceramide (Gb3). We describe a quantitative more sensitive and specific method for the measurement of UDP-galactose:lactosylceramide galactosyltransferase activities in rabbit small intestine and HeLa cell which utilizes the specific binding of Shiga toxin to the product, Gb3. Intestinal microsomal or HeLa cell sonicate preparations were incubated in the presence of lactosylceramide and [14C]UDP-galactose. The lipid reaction products were extracted on C18 Bond-Elut columns, separated by high-performance thin-layer chromatography and exposed to Shiga toxin followed by polyclonal rabbit anti-Shiga toxin antibody and goat anti-rabbit IgG alkaline phosphatase conjugate. Gb3 was visualized with NBT and BCIP and quantitated by densitometry. These data were compared with a standard assay in which, following incubation and lipid extraction, radioactivity was measured by scintillation counting of the isolated lipids. There was a 22-fold increase in enzyme activity by the immunostaining method compared to the usual scintillation counting technique. This is attributable to the exclusion of radioactive lipids other than Gb3 in calculating enzyme activity and the correction for endogenous UDP-galactose. Thus, the immunostaining method provides increased accuracy, sensitivity, and specificity in the assay of galactosyltransferase activity. PMID:8250238

Mobassaleh, M; Mishra, K; Keusch, G T

1993-10-01

386

A new quantitative evaluation method of spiral drawing for patients with Parkinsons disease based on a polar coordinate system with varying origin  

NASA Astrophysics Data System (ADS)

Parkinson's disease (PD) is a common disease of the central nervous system among the elderly, and its complex symptoms bring up challenges for the clinical diagnosis. In this paper, a new method based on a polar coordinate system with varying origin was proposed in order to quantitatively evaluate the performance in spiral drawing tasks for patients with Parkinson's disease, since this method can assess the movement ability of spiral drawing before and after deep brain stimulation (DBS) among the patients. In this paper, three normal subjects and twelve PD patients participated in spiral drawing experiment. The hand movements of patients, before and after DBS, were recorded by a digitized tablet respectively in this experiment. And the variation of origin, radius, degree and other characteristics of hand movements were evaluated by introducing a set of parameters for feature extraction. The result showed that the proposed polar coordinate system embraced good performance in the quantitative evaluation of spiral drawing. Therefore, the proposed method overcame the limitation of data processes with fixed origin for diagnosis and evaluation, and by combining with extraction and analysis of characteristic parameters it had clinical significance in measuring the effectiveness of operation or treatment for the PD patients.

Wang, Min; Wang, Bei; Zou, Junzhong; Nakamura, Masatoshi

2012-09-01

387

HUNTING THE COOLEST DWARFS: METHODS AND EARLY RESULTS  

SciTech Connect

We present the methods and first results of a survey of nearby high proper motion main-sequence stars to probe for cool companions with the Gemini camera at Lick Observatory. This survey uses a sample of old (age > 2 Gyr) stars as targets to probe for companions down to temperatures of 500 K. Multi-epoch observations allow us to discriminate comoving companions from background objects. So far, our survey has successfully rediscovered the wide T8.5 companion to GJ 1263 and has discovered a companion to the nearby M0V star GJ 660.1. The companion to GJ 660.1 (GJ 660.1B) is {approx}4 mag fainter than its host star in the J-band and is located at a projected separation of {approx}120 AU. Known trigonometric parallax and Two Micron All Sky Survey magnitudes for the GJ 660.1 system indicate a spectral type for the companion of M9 {+-} 2.

Schneider, A.; Song, Inseok [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States); Melis, Carl [Center for Astrophysics and Space Sciences, University of California, San Diego, CA 92093-0424 (United States); Zuckerman, B., E-mail: aschneid@physast.uga.edu, E-mail: song@physast.uga.edu, E-mail: cmelis@ucsd.edu, E-mail: ben@astro.ucla.edu [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States)

2011-12-20

388

A novel method for assessing elbow pain resulting from epicondylitis  

PubMed Central

Abstract Objective To describe a novel orthopedic test (Polk's test) which can assist the clinician in differentiating between me- dial and lateral epicondylitis, 2 of the most common causes of elbow pain. This test has not been previously described in the literature. Clinical Features The testing procedure described in this paper is easy to learn, simple to perform and may provide the clinician with a quick and effective method of differentiating between lateral and medial epicondylitis. The test also helps to elucidate normal activities of daily living that the patient may unknowingly be performing on a repetitive basis that are hindering recovery. The results of this simple test allow the clinician to make immediate lifestyle recommendations to the patient that should improve and hasten the response to subsequent treatment. It may be used in conjunction with other orthopedic testing procedures, as it correlates well with other clinical tests for assessing epicondylitis. Conclusion The use of Polk's Test may help the clinician to diagnostically differentiate between lateral and medial epicondylitis, as well as supply information relative to choosing proper instructions for the patient to follow as part of their treatment program. Further research, performed in an academic setting, should prove helpful in more thoroughly evaluating the merits of this test. In the meantime, clinical experience over the years suggests that the practicing physician should find a great deal of clinical utility in utilizing this simple, yet effective, diagnostic procedure. PMID:19674572

Polkinghorn, Bradley S.

2002-01-01

389

Quantitative assessment of the impact of biomedical image acquisition on the results obtained from image analysis and processing  

PubMed Central

Introduction Dedicated, automatic algorithms for image analysis and processing are becoming more and more common in medical diagnosis. When creating dedicated algorithms, many factors must be taken into consideration. They are associated with selecting the appropriate algorithm parameters and taking into account the impact of data acquisition on the results obtained. An important feature of algorithms is the possibility of their use in other medical units by other operators. This problem, namely operators (acquisition) impact on the results obtained from image analysis and processing, has been shown on a few examples. Material and method The analysed images were obtained from a variety of medical devices such as thermal imaging, tomography devices and those working in visible light. The objects of imaging were cellular elements, the anterior segment and fundus of the eye, postural defects and others. In total, almost 200'000 images coming from 8 different medical units were analysed. All image analysis algorithms were implemented in C and Matlab. Results For various algorithms and methods of medical imaging, the impact of image acquisition on the results obtained is different. There are different levels of algorithm sensitivity to changes in the parameters, for example: (1) for microscope settings and the brightness assessment of cellular elements there is a difference of 8%; (2) for the thyroid ultrasound images there is a difference in marking the thyroid lobe area which results in a brightness assessment difference of 2%. The method of image acquisition in image analysis and processing also affects: (3) the accuracy of determining the temperature in the characteristic areas on the patients back for the thermal method - error of 31%; (4) the accuracy of finding characteristic points in photogrammetric images when evaluating postural defects error of 11%; (5) the accuracy of performing ablative and non-ablative treatments in cosmetology - error of 18% for the nose, 10% for the cheeks, and 7% for the forehead. Similarly, when: (7) measuring the anterior eye chamber there is an error of 20%; (8) measuring the tooth enamel thickness - error of 15%; (9) evaluating the mechanical properties of the cornea during pressure measurement - error of 47%. Conclusions The paper presents vital, selected issues occurring when assessing the accuracy of designed automatic algorithms for image analysis and processing in bioengineering. The impact of acquisition of images on the problems arising in their analysis has been shown on selected examples. It has also been indicated to which elements of image analysis and processing special attention should be paid in their design. PMID:24997012

2014-01-01

390

Development of quantitative NMR method with internal standard for the standard solutions of paralytic shellfish toxins and characterisation of gonyautoxin-5 and gonyautoxin-6.  

PubMed

The chemical analysis of paralytic shellfish toxins (PSTs) requires standard solutions with accurate concentration. The mouse toxicity in each toxin is also essential knowledge for the introduction of chemical analysis as an alternative method to mouse bioassay (MBA) in routine monitoring of shellfish. In this study, we developed the quantitative analysis of PSTs by nuclear magnetic resonance (NMR), using tert-butanol as an internal standard. Only proton signals with longitudinal relaxation time (T(1)) of less than 2.5 s, including the internal standard, were used for quantitation of toxins. Our method showed good precision (<3%) and accuracy (slope: 1.0038, R(2): 1.0000). The limit of quantitation (LOQ) at 5% relative standard deviation (RSD) was calculated to be 0.16 mM, which corresponded to 67 microg/mL as Saxitoxin (STX) diacetate form, while the limit of detection (LOD) was 0.04 mM. Gonyautoxin-5 (GTX5) and gonyautoxin-6 (GTX6) isolated from mussels were quantified by our method, and the toxicities of GTX5 and GTX6 were obtained by the MBA in which mice were standardized by STX provided from FDA. The specific toxicities of GTX5 and GTX6 newly calculated by the MBA were 120 MU/micromol (29 microg STX equiv./micromol) and 105 MU/micromol (25 microg STX equiv./micromol), respectively. These results are useful to convert the amount of GTX5 and GTX6 into the mouse toxicity, especially in the areas where the dinoflagellate Gymnodinium catenatum predominantly produces both toxins. PMID:20538011

Watanabe, Ryuichi; Suzuki, Toshiyuki; Oshima, Yasukatsu

2010-09-15

391

Quantitative determination of mithramycin in human plasma by a novel, sensitive ultra-HPLC-MS/MS method for clinical pharmacokinetic application.  

PubMed

Mithramycin is a neoplastic antibiotic synthesized by various Streptomyces bacteria. It is under investigation as a chemotherapeutic treatment for a wide variety of cancers. Ongoing and forthcoming clinical trials will require pharmacokinetic analysis of mithramycin in humans, both to see if target concentrations are achieved and to optimize dosing and correlate outcomes (response/toxicity) with pharmacokinetics. Two published methods for mithramycin quantitation exist, but both are immunoassays that lack current bioanalytical standards of selectivity and sensitivity. To provide an upgraded and more widely applicable assay, a UPLC-MS/MS method for quantitation of mithramycin in human plasma was developed. Solid-phase extraction allowed for excellent recoveries (>90%) necessary for high throughput analyses on sensitive instrumentation. However, a ?55% reduction in analyte signal was observed as a result of plasma matrix effects. Mithramycin and the internal standard chromomycin were separated on a Waters Acquity BEH C18 column (2.150 mm, 1.7 ?m) and detected using electrospray ionization operated in the negative mode at mass transitions m/z 1083.5?268.9 and 1181.5?269.0, respectively, on an AB Sciex QTrap 5500. The assay range was 0.5-500 ng/mL and proved to be linear (r(2)>0.996), accurate (?10% deviation), and precise (CV<15%). Mithramycin was stable in plasma at room temperature for 24 h, as well as through three freeze-thaw cycles. This method was subsequently used to quantitate mithramycin plasma concentrations from patients enrolled on two clinical trials at the NCI. PMID:25247492

Roth, Jeffrey; Peer, Cody J; Widemann, Brigitte; Cole, Diane E; Ershler, Rachel; Helman, Lee; Schrump, David; Figg, William D

2014-11-01

392

A RAPID METHOD FOR THE EXTRACTION OF FUNGAL DNA FROM ENVIRONMENTAL SAMPLES: EVALUATION IN THE QUANTITATIVE ANALYSIS OF MEMNONIELLA ECHINATA CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS  

EPA Science Inventory

New technologies are creating the potential for using nucleic acid sequence detection to perform routine microbiological analyses of environmental samples. Our laboratory has recently reported on the development of a method for the quantitative detection of Stachybotrys chartarum...

393

QUANTITATIVE TOXICOLOGIC PATHOLOGY-METHODS AND INTERPRETATION' SESSION AT THE JOINT MEETING OF SOCIETY OF TOXICOLOGIC PATHOLOGISTS AND THE INTERNATIONAL FEDERATION OF SOCIETIES OF TOXICOLOGIC PATHOLOGISTS  

EPA Science Inventory

Report of the 'Quantitative Toxicologic Pathology - Methods and Interpretation' session at the Joint meeting of Society of Toxicologic Pathologists and the International Federation of Societies of Toxicologic Pathologists, Orlando, Florida, USA, June 24-28, 2001. Douglas C. Wolf,...

394

Qualitative and quantitative determination of human biomarkers by laser photoacoustic spectroscopy methods  

NASA Astrophysics Data System (ADS)

The hypothesis that blood, urine and other body fluids and tissues can be sampled and analyzed to produce clinical information for disease diagnosis or therapy monitoring is the basis of modern clinical diagnosis and medical practice. The analysis of breath air has major advantages because it is a non-invasive method, represents minimal risk to personnel collecting the samples and can be often sampled. Breath air samples from the human subjects were collected using aluminized bags from QuinTron and analyzed using the laser photoacoustic spectroscopy (LPAS) technique. LPAS is used to detect traces of ethylene in breath air resulting from lipid peroxidation in lung epithelium following the radiotherapy and also traces of ammonia from patients subjected to hemodialysis for treatment of renal failure. In the case of patients affected by cancer and treated by external radiotherapy, all measurements were done at 10P(14) CO2 laser line, where the ethylene absorption coefficient has the largest value (30.4 cm-1 atm-1), whereas for patients affected by renal failure and treated by standard dialysis, all measurements were performed at 9R(30) CO2 laser line, where the ammonia absorption coefficient has the maximum value of 57 cm-1 atm-1. The levels of ethylene and ammonia in exhaled air, from patients with cancer and renal failure, respectively, were measured and compared with breath air contents from healthy humans. Human gas biomarkers were measured at sub-ppb (parts per billion) concentration sensitivities. It has been demonstrated that LPAS technique will play an important role in the future of exhaled breath air analysis. The key attributes of this technique are sensitivity, selectivity, fast and real time response, as well as its simplicity.

Popa, C.; Bratu, A. M.; Matei, C.; Cernat, R.; Popescu, A.; Dumitras, D. C.

2011-07-01

395

Reservoir function of the stratum corneum: development of an in vivo method to quantitatively determine the stratum corneum reservoir for topically applied substances.  

PubMed

Investigations on the stratum corneum (SC) reservoir for topically applied substances are of importance in dermatologic science in order to assess the pharmacokinetics of these substances. In the present study, an in vivo method was developed to determine the SC reservoir quantitatively and to investigate the temporal behavior of this reservoir. Therefore, increasing amounts of an oil-in-water emulsion (o/w emulsion) containing 4% of a chemical UV filter were topically applied onto the flexor forearms of 5 healthy volunteers. The saturation of the SC reservoir was determined utilizing the tape stripping technique 1 and 6 h after application. The capacity of the SC reservoir for the o/w emulsion was found to be approximately 2.7 mg/cm(2). Furthermore, a correlation of the capacity of the SC with transepidermal water loss was observed. Extending the time between the topical application and SC removal did not affect the distribution or the recovery rate of the UV filter in the SC. The results indicate that the reservoir of the SC is limited. This is reflected by the saturation level, which depends on the individual volunteer and, presumably, the topically applied substances and formulations used. The results show that the method developed is suited to quantitatively determine in vivo the SC reservoir for topically applied substances. PMID:15767768

Teichmann, A; Jacobi, U; Weigmann, H-J; Sterry, W; Lademann, J

2005-01-01

396

d-Glucose, d-Galactose, and d-Lactose non-enzyme quantitative and qualitative analysis method based on Cu foam electrode.  

PubMed

Here, d-Glucose, d-Galactose, and d-Lactose non-enzyme quantitative and qualitative analysis method using Cu foam electrode had been investigated. Porous Cu foam material was prepared by electrodeposition strategy, and used as working electrode. Cyclic voltammetry (CV) explained sweetener electro-oxidation process occurring on Cu foam electrode. Amperometric i-t scanning results demonstrated that Cu foam electrode fast responded to d-Glucose, d-Galactose, and d-Lactose in linear concentration range between 0.18mM and 3.47mM with significant sensitivity of 1.79mAcm(-2)mM(-1), 0.57mAcm(-2)mM(-1), and 0.64mAcm(-2)mM(-1), respectively. Limit of detection (LOD) was 9.30?M, 29.40?M, and 26?M respectively (S/N=3). Sweetener species was decided by stochastic resonance (SR) signal-to-noise ratio (SNR) eigen peak located noise intensities. Interference experiment results demonstrated that Cu foam electrode selectively responded to sweeteners against interference chemicals. The proposed method provides a promising way for sweetener non-enzyme quantitative and qualitative analysis. PMID:25577110

Jiaojiao, Jin; Yangyang, Ge; Gangying, Zheng; Yanping, Cai; Wei, Liu; Guohua, Hui

2015-05-15

397

B1 Sequence-Based Real-Time Quantitative PCR: A Sensitive Method for Direct Measurement of Mouse Plasma DNA Levels After Gamma Irradiation  

SciTech Connect

Purpose: Current biodosimetric techniques for determining radiation exposure have inherent delays, as well as quantitation and interpretation limitations. We have identified a new technique with the advantage of directly measuring circulating DNA by amplifying inter-B1 regions in the mouse genome, providing a sensitive method for quantitating plasma DNA. Methods and Materials: Real-time quantitative polymerase chain reaction (PCR) was used to detect levels of DNA by amplifying inter-B1 genomic DNA in plasma samples collected at 0-48 h from mice receiving 0-10 Gy total- or partial-body irradiation ({sup 137}Cs {gamma}-ray source at {approx}1.86 Gy/min; homogeneity: {+-} 6.5%). Results: The correlation coefficient between DNA levels and the threshold cycle value (C{sub T}) was 0.996, and the average recoveries of DNA in the assay were 87%. This assay revealed that when BALB/c mice were exposed to 10 Gy total-body irradiation (TBI), plasma DNA levels gradually increased beginning at 3 h after irradiation, peaked at 9 h, and returned to baseline within 48 h. Increased plasma DNA levels were also detected following upper-torso or lower-torso partial-body irradiation; however, TBI approximately doubled those plasma DNA levels at the same radiation dose. This technique therefore reflects total body cell damage. The advantages of this assay are that DNA extraction is not required, the assay is highly sensitive (0.002 ng), and results can be obtained within 2.5 h after collection of plasma samples. Conclusions: A radiation dose-dependent increase of plasma DNA was observed in the dose range from 2 to 10 Gy, suggesting that plasma DNA may be a useful radiation biomarker and adjunct to existing cell-based assays.

Zhang Hengshan; Zhang, Steven B.; Sun Weimin; Yang Shanmin; Zhang Mei; Wang Wei; Liu Chaomei; Zhang Kunzhong; Swarts, Steven; Fenton, Bruce M.; Keng, Peter; Maguire, David [Department of Radiation Oncology, University of Rochester School of Medicine and Dentistry, Rochester, NY (United States); Okunieff, Paul [Department of Radiation Oncology, University of Rochester School of Medicine and Dentistry, Rochester, NY (United States)], E-mail: Paul_Okunieff@URMC.Rochester.edu; Zhang Lurong [Department of Radiation Oncology, University of Rochester School of Medicine and Dentistry, Rochester, NY (United States)

2009-08-01

398

The role of work experience and individual beliefs in police officers' perceptions of date rape: an integration of quantitative and qualitative methods.  

PubMed

Surveyed police officers from two police departments in the Midwest on their perceptions of date rape (N = 91). The aim of this research was to examine the influence of officers' work experiences and general beliefs about women on their perceptions of date rape. Two approaches were utilized. First, using quantitative structural-equation modeling, a model that integrated work experiences and individual beliefs was evaluated using LISREL VII. Results suggest a direct path from the work experience variables to perceptions of date rape: Officers with more experience with rape cases held more sympathetic beliefs about date rape and date rape victims. Officers who found their training on rape to be very helpful, and those who reported that their work environment was sexualized and sexual harassment was a problem, were also less victim blaming. An indirect influence of these variables was also supported. Officers with more experience, those who perceived their training as helpful, and those with heightened awareness of sexual harassment in the workplace also held more favorable attitudes toward women, which, in turn, predicted less victim-blaming perceptions of date rape. Second, qualitative methods were used to have the police define and describe in their own words what has shaped their beliefs about date rape. These narratives were content analyzed by two raters. The qualitative results validated the quantitative findings as the officers were most likely to mention professional experience with rape cases and departmental trainings as important factors that changed their opinions. Work climate and personal experiences were also cited as influential. Implications for integrating qualitative and quantitative methods in research, and training interventions with police are discussed. PMID:7572832

Campbell, R

1995-04-01

399

Quantitative determination of caffeine in carbonated beverages by an HPLC method  

Microsoft Academic Search

The purpose of this work was to adapt and use the HPLC method proposed by SR EN 12856\\/2001 standard for the determination of some artificial sweeteners (acesulfame-K, aspartame and saccharin) for the quantification, in a single run, of the caffeine too. The method was validated in terms of sensitivity, linearity range, reproducibility, repeatability, analytical recovery and robustness. In this paper

Nour Violeta; Ionica Mir

400

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

E-print Network

, it was quite extensive and costly. Costa et al. (1999) developed a method that was used to perform three-dimensional reconstruction as well. Their method, while less expensive and much less time consuming, required sheet assumptions and did not look directly...

Jetton, Emily Hope

2004-11-15

401

A quantitative high-performance liquid chromatographic method to analyse commercial saffron ( Crocus sativus L.) products  

Microsoft Academic Search

An HPLC method to check components and purity in commercial saffron by photodiode array detection has been developed. The method was suitable for the standard analysis of commercial saffron. Therefore, 10 saffron metabolites responsible for the taste, flavour and colour were identified and quantified with high selectivity, precision and accuracy. Also, some artificial colorants, which can be used as adulterants,

P Lozano; M. R Castellar; M. J Simancas; J. L Iborra

1999-01-01

402

Evaluation of methods for oligonucleotide array data via quantitative real-time PCR  

Microsoft Academic Search

BACKGROUND: There are currently many different methods for processing and summarizing probe-level data from Affymetrix oligonucleotide arrays. It is of great interest to validate these methods and identify those that are most effective. There is no single best way to do this validation, and a variety of approaches is needed. Moreover, gene expression data are collected to answer a variety

Li-xuan Qin; Richard P. Beyer; Francesca N. Hudson; Nancy J. Linford; Daryl E. Morris; Kathleen F. Kerr

2006-01-01

403

How does carbon dioxide permeate cell membranes? A discussion of concepts, results and methods  

PubMed Central

We review briefly how the thinking about the permeation of gases, especially CO2, across cell and artificial lipid membranes has evolved during the last 100 years. We then describe how the recent finding of a drastic effect of cholesterol on CO2 permeability of both biological and artificial membranes fundamentally alters the long-standing idea that CO2as well as other gasespermeates all membranes with great ease. This requires revision of the widely accepted paradigm that membranes never offer a serious diffusion resistance to CO2 or other gases. Earlier observations of CO2-impermeable membranes can now be explained by the high cholesterol content of some membranes. Thus, cholesterol is a membrane component that nature can use to adapt membrane CO2 permeability to the functional needs of the cell. Since cholesterol serves many other cellular functions, it cannot be reduced indefinitely. We show, however, that cells that possess a high metabolic rate and/or a high rate of O2 and CO2 exchange, do require very high CO2 permeabilities that may not be achievable merely by reduction of membrane cholesterol. The article then discusses the alternative possibility of raising the CO2 permeability of a membrane by incorporating protein CO2 channels. The highly controversial issue of gas and CO2 channels is systematically and critically reviewed. It is concluded that a majority of the results considered to be reliable, is in favor of the concept of existence and functional relevance of protein gas channels. The effect of intracellular carbonic anhydrase, which has recently been proposed as an alternative mechanism to a membrane CO2 channel, is analysed quantitatively and the idea considered untenable. After a brief review of the knowledge on permeation of O2 and NO through membranes, we present a summary of the 18O method used to measure the CO2 permeability of membranes and discuss quantitatively critical questions that may be addressed to this method. PMID:24409149

Endeward, Volker; Al-Samir, Samer; Itel, Fabian; Gros, Gerolf

2013-01-01

404

A novel non-invasive optical method for quantitative visualization of pH dynamics in the rhizosphere of plants.  

PubMed

A novel optical method for non-invasive, quantitative and high-resolution imaging of spatial and temporal pH dynamics in soils mediated by plant roots is introduced. This method overcomes present limitations of measurement of pH, mainly short-term and punctiform measurements, by recording long-term dynamics of the micro-pattern of pH in the root-soil interface without disturbance of the biological and physico-chemical conditions. Juncus effusus L., rooting in a permanently flooded rhizotron, was selected as the test organism for qualifying the technique. The measurements showed pronounced diurnal variations of pH along the roots, particularly along the elongation zone. Diurnal oscillation of pH caused by the roots reached up to 0.5 units. Long-term records at 4 s intervals over more than 8 weeks revealed considerable spatial and temporal patterns of pH dynamics in the rhizosphere of about 10% of the pH scale (pH 7.0-8.5). The measured data were validated by the use of pH electrodes. Concomitantly measured oxygen concentration showed hypoxic conditions around root tips (10-70 micromol O2 L-1) and almost anoxic conditions (0.9 micromol O2 L-1) in the bulk soil. The present study qualifies this novel pH-sensing technique as a powerful analytical tool for quantitative visualization of undisturbed bioprocess dynamics. PMID:17238909

Blossfeld, Stephan; Gansert, Dirk

2007-02-01

405

A high-throughput method for the quantitative analysis of indole-3-acetic acid and other auxins from plant tissue.  

PubMed

To investigate novel pathways involved in auxin biosynthesis, transport, metabolism, and response, we have developed a high-throughput screen for indole-3-acetic acid (IAA) levels. Historically, the quantitative analysis of IAA has been a cumbersome and time-consuming process that does not lend itself to the screening of large numbers of samples. The method described here can be performed with or without an automated liquid handler and involves purification solely by solid-phase extraction in a 96-well format, allowing the analysis of up to 96 samples per day. In preparation for quantitative analysis by selected ion monitoring-gas chromatography-mass spectrometry, the carboxylic acid moiety of IAA is derivatized by methylation. The derivatization of the IAA described here was also done in a 96-well format in which up to 96 samples can be methylated at once, minimizing the handling of the toxic reagent, diazomethane. To this end, we have designed a custom diazomethane generator that can safely withstand high flow and accommodate larger volumes. The method for IAA analysis is robust and accurate over a range of plant tissue weights and can be used to screen for and quantify other indolic auxins and compounds including indole-3-butyric acid, 4-chloro-indole-3-acetic acid, and indole-3-propionic acid. PMID:17889819

Barkawi, Lana S; Tam, Yuen-Yee; Tillman, Julie A; Pederson, Ben; Calio, Jessica; Al-Amier, Hussein; Emerick, Michael; Normanly, Jennifer; Cohen, Jerry D

2008-01-15

406

Validation of a novel method for retrospectively estimating nutrient intake during pregnancy using a semi-quantitative food frequency questionnaire  

PubMed Central

Objective Case control studies evaluating the relationship between dietary intake of specific nutrients and risk of congenital, neonatal or early childhood disease require the ability to rank relative maternal dietary intake during pregnancy. Such studies are limited by the lack of validated instruments for assessing gestational dietary intake several years post-partum. This study aims to validate a semi-quantitative interview-administered food frequency questionnaire (FFQ) for retrospectively estimating nutrient intake at two critical time points during pregnancy. Methods The FFQ was administered to women (N=84), who 4 to 6 years earlier had participated in a prospective study to evaluate dietary intake during pregnancy. The FFQ queried participants about intake during the previous month (FFQ-month). This was then used as a reference point to estimate consumption by trimester (FFQ-pregnancy). The resulting data were compared to data collected during the original study from two 24-hour recalls (24hr-original) using Spearman correlation and Wilcoxon sign-rank-test. Results Total energy intake as estimated by the retrospective and original instruments did not differ and was only weakly correlated in the trimesters (1st & 3rd) as a whole (r = 0.18-32), though more strongly correlated when restricted to the first half of the 1st trimester (r=0.32) and later half of the 3rd trimester (r=0.87). After energy adjustment, correlation between the 24hR-original and FFQ-pregnancy in the 3rd trimester were r=0.25 (p<0.05) for dietary intake of vitamin A, and r=0.26 (p<0.05) for folate, and r= 0.23-0.77 (p<0.005) for folate, and vitamins A, B6 and B12 in the 1st and 3rd trimester after including vitamin supplement intake. Conclusions The FFQ-pregnancy provides a consistent estimate of maternal intake of key micronutrients during pregnancy and permits accurate ranking of intake 4-6 years post-partum. PMID:22116778

Meja-Rodrguez, Fabiola; Orjuela, Manuela A.; Garca-Guerra, Armando; Quezada-Sanchez, Amado David; Neufeld, Lynnette M.

2011-01-01

407

NPEC Sourcebook on Assessment: Definitions and Assessment Methods for Communication, Leadership, Information Literacy, Quantitative Reasoning, and Quantitative Skills. NPEC 2005-0832  

ERIC Educational Resources Information Center

Faculty, instructional staff, and assessment professionals are interested in student outcomes assessment processes and tools that can be used to improve learning experiences and academic programs. How can students' skills be assessed effectively? What assessments measure skills in communication? Leadership? Information literacy? Quantitative

Jones, Elizabeth A.; RiCharde, Stephen

2005-01-01

408

Weiszfeld's Method: Old and New Results Shoham Sabach  

E-print Network

anchors. The problem is credited to the well known French mathematician Pierre de Fermat who the 16 years old Hungarian mathematician Endre Weiszfeld devised a method for solving the Fermat of convergence. 1 Introduction - The Method One of the most fundamental location problems is the so-called Fermat

Beck, Amir

409

Validation of a Reversed-Phase HPLC Method for Quantitative Amino Acid Analysis  

PubMed Central

A semi-automated method for amino acid derivatization and analysis has been validated for use in analysis of protein biopharmaceuticals. The method includes protein hydrolysis, o-phthalaldehyde derivatization, and reversed-phase high-performance liquid chromatography analysis in a general-purpose UV-visible high-performance liquid chromatography system. Amino-acid derivatization is performed automatically by the high-performance liquid chromatography autosampler right before injection. The required validation parameters, i.e., specificity, linearity, accuracy, precision, limit of detection, and limit of quantification, were studied for bovine serum albumin and for a recombinant human Fab fragment. The method can be employed as an absolute quantification method for determination of extinction coefficients of recombinant proteins. PMID:16741240

Bartolomeo, Maria Paola; Maisano, Federico

2006-01-01

410

A simple method for quantitating the propensity for calcium oxalate crystallization in urine  

NASA Technical Reports Server (NTRS)

To assess the propensity for spontaneous crystallization of calcium oxalate in urine, the permissible increment in oxalate is calculated. The previous method required visual observation of crystallization with the addition of oxalate, this warranted the need for a large volume of urine and a sacrifice in accuracy in defining differences between small incremental changes of added oxalate. Therefore, this method has been miniaturized and spontaneous crystallization is detected from the depletion of radioactive oxalate. The new "micro" method demonstrated a marked decrease (p < 0.001) in the permissible increment in oxalate in urine of stone formers versus normal subjects. Moreover, crystallization inhibitors added to urine, in vitro (heparin or diphosphonate) or in vivo (potassium citrate administration), substantially increased the permissible increment in oxalate. Thus, the "micro" method has proven reliable and accurate in discriminating stone forming from control urine and in distinguishing changes of inhibitory activity.

Wabner, C. L.; Pak, C. Y.

1991-01-01

411

Evolution of quantitative methods for the study and management of avian populations: on the importance of individual contributions  

USGS Publications Warehouse

Evolution of quantitative methods for the study and management of avian populations: on the importance of individual contributions.-The EURING meetings and the scientists who have attended them have contributed substantially to the growth of knowledge in the field of estimating parameters of animal populations. The contributions of David R. Anderson to process modeling, parameter estimation and decision analysis are briefly reviewed. Metrics are considered for assessing individual contributions to a field of inquiry, and it is concluded that Anderson's contributions have been substantial. Important characteristics of Anderson and his career are the ability to identify and focus on important topics, the premium placed on dissemination of new methods to prospective users, the ability to assemble teams of complementary researchers, and the innovation and vision that characterized so much of his work. The paper concludes with a list of interesting current research topics for consideration by EURING participants.

Nichols, J.D.

2004-01-01

412

Comparison of three rapid and easy bacterial DNA extraction methods for use with quantitative real-time PCR.  

PubMed

The development of fast and easy on-site molecular detection and quantification methods for hazardous microbes on solid surfaces is desirable for several applications where specialised laboratory facilities are absent. The quantification of bacterial contamination necessitates the assessment of the efficiency of the used methodology as a whole, including the preceding steps of sampling and sample processing. We used quantitative real-time polymerase chain reaction (qrtPCR) for Escherichia coli and Staphylococcus aureus to measure the recovery of DNA from defined numbers of bacterial cells that were subjected to three different DNA extraction methods: the QIAamp DNA Mini Kit, Reischl et al.'s method and FTA Elute. FTA Elute significantly showed the highest median DNA extraction efficiency of 76.9% for E. coli and 108.9% for S. aureus. The Reischl et al. method and QIAamp DNA Mini Kit inhibited the E. coli qrtPCR assay with a 10-fold decrease of detectable DNA. None of the methods inhibited the S. aureus qrtPCR assay. The FTA Elute applicability was demonstrated with swab samples taken from the International Space Station (ISS) interior. Overall, the FTA Elute method was found to be the most suitable to selected criteria in terms of rapidity, easiness of use, DNA extraction efficiency, toxicity, and transport and storage conditions. PMID:21311936

van Tongeren, S P; Degener, J E; Harmsen, H J M

2011-09-01

413

A quantitative comparison of the commonly used methods for extracting carotenoids from avian plasma  

Microsoft Academic Search

Interest in animal carotenoids, especially in birds, has exploded in recent years, and so too have the methods employed to\\u000a investigate the nature and function of these pigments. Perhaps the most easily and commonly performed procedure in this work\\u000a has been the determination of carotenoid concentration from avian plasma. Over the past 20years of research on avian car