The Experts below are selected from a list of 27 Experts worldwide ranked by ideXlab platform
Steven Luhn - One of the best experts on this subject based on the ideXlab platform.
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the discrimination of automotive clear coats by pyrolysis gas chromatography mass spectrometry and comparison of samples by a chromatogram library software
Forensic Science International, 2008Co-Authors: Bernd Plage, Annadolores Berg, Steven LuhnAbstract:The differentiation of 25 automotive clear coats was evaluated using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The samples were selected from eight different groups of samples which slightly differ in their infrared spectra. Most of the samples could be differentiated by visual inspection of the pyrograms. As an objective mean for evaluation a new software based on the comparison of chromatograms was tested for automatic classification considering retention times as well as mass spectra. The database was formed by the triplicate results of the set of the 25 samples. Normally a Replicate Measurement of a sample yields the best fit by library search. In addition, for most groups classification with moderate fits are obtained for samples belonging to the same group. Some samples are completely rearranged forming a new group of similar samples containing five samples from three different IR groups and four samples of three other groups, respectively. Furthermore detailed visual recognition of individual pyrolysis products allows subgrouping. Therefore, most samples can be differentiated from each other by Py-GC/MS. The exception were three sample groups containing two samples each, which could not be differentiated from each other neither by library search nor by recognition of minor individual pyrolysis products.
Maria Laura Patat - One of the best experts on this subject based on the ideXlab platform.
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estimation in comparative calibration models with Replicate Measurement
Statistics & Probability Letters, 2005Co-Authors: Patricia Gimenez, Maria Laura PatatAbstract:This paper considers consistent estimation in functional comparative calibration models with replication. Two consistent and asymptotically normal estimators based on the corrected score approach for Measurement error models are proposed. Asymptotic distributions and results of a small-scale simulation study comparing the estimators are reported.
Gary A Chase - One of the best experts on this subject based on the ideXlab platform.
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should echocardiography be performed to assess effects of antihypertensive therapy test retest reliability of echocardiography for Measurement of left ventricular mass and function
Journal of the American College of Cardiology, 1995Co-Authors: John S Gottdiener, Sue V Livengood, Patricia S Meyer, Gary A ChaseAbstract:Objectives. The purpose of this study was to determine the test-retest stability of echocardiography for the Measurement of left ventricular mass and function in patients with hypertension. Background. Determination of changes in left ventricular mass may be impaired by study variability. The amount by which variables of mass and left ventricular function must change in an individual patient to exceed temporal variability has not been determined in a multicenter trial. Methods. Ninety-six patients with hypertension had two-demensional targeted, M-mode Doppler echocardiography repeated at 6 ± 8 days by the same technician utilizing the same machine. Left ventricular mass and variables of systolic and diastolic function were measured. Test-retest reliability and the width of the 95% confidence intervals of variable change, as well as the contributions of age, study quality and body size to Measurement reliability, were determined. Results. Despite excellent reliability (intraclass coefficient of correlation 0.86), the 95% confidence interval width of a single Replicate Measurement of left ventricular mass was 59 g, exceeding usual decreases in mass during treatment. Study quality, which was dependent on age and weight, influenced test reliability. Although the confidence interval width for ejection fraction was narrow (5 U), those for peak early (E) and late (A) diastolic velocities were wide, resulting in a confidence interval width for the E/A ratio of 1.5. Conclusions. The temporal variability, particularly in obese or elderly patients, or both, of echocardiography for Measurement of left ventricular mass precludes its use to measure changes in mass of the magnitude likely to occur with therapy. Measurement stability is affected by study quality, and age and body weight both influence study quality. Although ejection fraction shows little temporal variability, the large width of the confidence interval of the Doppler E/A ratio impairs its use to serially measure diastolic function.
Bernd Plage - One of the best experts on this subject based on the ideXlab platform.
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the discrimination of automotive clear coats by pyrolysis gas chromatography mass spectrometry and comparison of samples by a chromatogram library software
Forensic Science International, 2008Co-Authors: Bernd Plage, Annadolores Berg, Steven LuhnAbstract:The differentiation of 25 automotive clear coats was evaluated using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The samples were selected from eight different groups of samples which slightly differ in their infrared spectra. Most of the samples could be differentiated by visual inspection of the pyrograms. As an objective mean for evaluation a new software based on the comparison of chromatograms was tested for automatic classification considering retention times as well as mass spectra. The database was formed by the triplicate results of the set of the 25 samples. Normally a Replicate Measurement of a sample yields the best fit by library search. In addition, for most groups classification with moderate fits are obtained for samples belonging to the same group. Some samples are completely rearranged forming a new group of similar samples containing five samples from three different IR groups and four samples of three other groups, respectively. Furthermore detailed visual recognition of individual pyrolysis products allows subgrouping. Therefore, most samples can be differentiated from each other by Py-GC/MS. The exception were three sample groups containing two samples each, which could not be differentiated from each other neither by library search nor by recognition of minor individual pyrolysis products.
Patricia Gimenez - One of the best experts on this subject based on the ideXlab platform.
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estimation in comparative calibration models with Replicate Measurement
Statistics & Probability Letters, 2005Co-Authors: Patricia Gimenez, Maria Laura PatatAbstract:This paper considers consistent estimation in functional comparative calibration models with replication. Two consistent and asymptotically normal estimators based on the corrected score approach for Measurement error models are proposed. Asymptotic distributions and results of a small-scale simulation study comparing the estimators are reported.