Sample records for validation studies conducted

  1. The Validity of Graduate Management Admission Test Scores: A Summary of Studies Conducted from 1997 to 2004

    ERIC Educational Resources Information Center

    Talento-Miller, Eileen; Rudner, Lawrence M.

    2008-01-01

    The validity of Graduate Management Admission Test (GMAT) scores is examined by summarizing 273 studies conducted between 1997 and 2004. Each of the studies was conducted through the Validity Study Service of the test sponsor and contained identical variables and statistical methods. Validity coefficients from each of the studies were corrected…

  2. The Conduct of Socially Valid Investigation by Culturally Diverse Researchers: A Delphi Study

    ERIC Educational Resources Information Center

    Dutta, Alo; Kundu, Madan; Chan, Fong

    2010-01-01

    Minority researchers have traditionally exhibited a need for and interest in investigating non-mainstream issues involving diverse communities. Since faculty at colleges and universities within the United States are largely Caucasian, research on issues relevant to marginalized groups is lacking. This three-stage Delphi study was designed to…

  3. Conducting and permeable states of cell membrane submitted to high voltage pulses: mathematical and numerical studies validated by the experiments.

    PubMed

    Leguèbe, M; Silve, A; Mir, L M; Poignard, C

    2014-11-01

    The aim of this paper is to present a new model of in vitro cell electropermeabilization, which describes separately the conducting state and the permeable state of the membrane submitted to high voltage pulses. We first derive the model based on the experimental observations and we present the numerical methods to solve the non-linear partial differential equations. We then present numerical simulations that corroborate qualitatively the experimental data dealing with the uptake of propidium iodide (PI) after millipulses. This tends to justify the validity of our modeling. Forthcoming work will be to calibrate the parameters of the model for quantitative description of the uptake. PMID:25010659

  4. Development and Validation of the Conduct Disorder Rating Scale

    ERIC Educational Resources Information Center

    Waschbusch, Daniel A.; Elgar, Frank J.

    2007-01-01

    Several rating scales for measuring externalizing problems in children are inconsistent with widely used diagnostic criteria for conduct disorder (CD). The Conduct Disorder Rating Scale (CDRS) was developed to provide valid measures of CD in children age 5 to 12 years. In Study 1, the CDRS was evaluated in a community sample of 1,554 children.…

  5. Simulators' validation study: Problem solution logic

    NASA Technical Reports Server (NTRS)

    Schoultz, M. B.

    1974-01-01

    A study was conducted to validate the ground based simulators used for aircraft environment in ride-quality research. The logic to the approach for solving this problem is developed. The overall problem solution flow chart is presented. The factors which could influence the human response to the environment on board the aircraft are analyzed. The mathematical models used in the study are explained. The steps which were followed in conducting the validation tests are outlined.

  6. Validation of a two-step quality control approach for a large-scale human urine metabolomic study conducted in seven experimental batches with LC/QTOF-MS.

    PubMed

    Demetrowitsch, Tobias J; Petersen, Beate; Keppler, Julia K; Koch, Andreas; Schreiber, Stefan; Laudes, Matthias; Schwarz, Karin

    2015-01-01

    After his study of food science at the Rheinische Friedrich-Wilhelms University of Bonn, Tobias J Demetrowitsch obtained his doctoral degree in the research field of metabolomics at the Christian-Albrechts-University of Kiel. The present paper is part of his doctoral thesis and describes an extended strategy to evaluate and verify complex or large-scale experiments and data sets. Large-scale studies result in high sample numbers, requiring the analysis of samples in different batches. So far, the verification of such LC-MS-based metabolomics studies is difficult. Common approaches have not provided a reliable validation procedure to date. This article shows a novel verification process for a large-scale human urine study (analyzed by a LC/QToF-MS system) using a two-step validation procedure. The first step comprises a targeted approach that aims to examine and exclude statistical outliers. The second step consists of a principle component analysis, with the aim of a tight cluster of all quality controls and a second for all volunteer samples. The applied study design provides a reliable two-step validation procedure for large-scale studies and additionally contains an inhouse verification procedure. PMID:25558939

  7. Carbon Fibers Conductivity Studies

    NASA Technical Reports Server (NTRS)

    Yang, C. Y.; Butkus, A. M.

    1980-01-01

    In an attempt to understand the process of electrical conduction in polyacrylonitrile (PAN)-based carbon fibers, calculations were carried out on cluster models of the fiber consisting of carbon, nitrogen, and hydrogen atoms using the modified intermediate neglect of differential overlap (MINDO) molecular orbital (MO) method. The models were developed based on the assumption that PAN carbon fibers obtained with heat treatment temperatures (HTT) below 1000 C retain nitrogen in a graphite-like lattice. For clusters modeling an edge nitrogen site, analysis of the occupied MO's indicated an electron distribution similar to that of graphite. A similar analysis for the somewhat less stable interior nitrogen site revealed a partially localized II electron distribution around the nitrogen atom. The differences in bonding trends and structural stability between edge and interior nitrogen clusters led to a two-step process proposed for nitrogen evolution with increasing HTT.

  8. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Use of other validity studies. 1607.7 Section 1607.7 Labor...General Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user....

  9. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Use of other validity studies. 1607.7 Section 1607.7 Labor...General Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user....

  10. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Use of other validity studies. 1607.7 Section 1607.7 Labor...General Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user....

  11. A validation study of polygraph examiner judgments

    Microsoft Academic Search

    Philip J. Bersh

    1969-01-01

    Validated the lie detection judgments in criminal investigations conducted by the military services against unanimous guilt-innocence decisions by a panel of 4 Judge Advocate General (JAG) attorneys. Since the study did not permit isolation of the role played by the polygraph record itself, the examiner's judgment was considered the end product of his complete interrogation of a suspect. Each JAG

  12. 49 CFR 40.91 - What validity tests must laboratories conduct on primary specimens?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false What validity tests must laboratories conduct on primary specimens? 40...ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.91 What validity tests must laboratories conduct on primary specimens?...

  13. 49 CFR 40.91 - What validity tests must laboratories conduct on primary specimens?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false What validity tests must laboratories conduct on primary specimens? 40...ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.91 What validity tests must laboratories conduct on primary specimens?...

  14. 49 CFR 40.91 - What validity tests must laboratories conduct on primary specimens?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false What validity tests must laboratories conduct on primary specimens? 40...ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.91 What validity tests must laboratories conduct on primary specimens?...

  15. 49 CFR 40.91 - What validity tests must laboratories conduct on primary specimens?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false What validity tests must laboratories conduct on primary specimens? 40...ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.91 What validity tests must laboratories conduct on primary specimens?...

  16. 49 CFR 40.91 - What validity tests must laboratories conduct on primary specimens?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false What validity tests must laboratories conduct on primary specimens? 40...ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.91 What validity tests must laboratories conduct on primary specimens?...

  17. Validation studies and proficiency testing.

    PubMed

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

    2002-01-01

    Genetically modified organisms (GMOs) entered the European food market in 1996. Current legislation demands the labeling of food products if they contain <1% GMO, as assessed for each ingredient of the product. To create confidence in the testing methods and to complement enforcement requirements, there is an urgent need for internationally validated methods, which could serve as reference methods. To date, several methods have been submitted to validation trials at an international level; approaches now exist that can be used in different circumstances and for different food matrixes. Moreover, the requirement for the formal validation of methods is clearly accepted; several national and international bodies are active in organizing studies. Further validation studies, especially on the quantitative polymerase chain reaction methods, need to be performed to cover the rising demand for new extraction methods and other background matrixes, as well as for novel GMO constructs. PMID:12083280

  18. PSI-Center Validation Studies

    NASA Astrophysics Data System (ADS)

    Nelson, B. A.; Akcay, C.; Glasser, A. H.; Hansen, C. J.; Jarboe, T. R.; Marklin, G. J.; Milroy, R. D.; Morgan, K. D.; Norgaard, P. C.; Shumlak, U.; Sutherland, D. A.; Victor, B. S.; Sovinec, C. R.; O'Bryan, J. B.; Held, E. D.; Ji, J.-Y.; Lukin, V. S.

    2014-10-01

    The Plasma Science and Innovation Center (PSI-Center - http://www.psicenter.org) supports collaborating validation platform experiments with 3D extended MHD simulations using the NIMROD, HiFi, and PSI-TET codes. Collaborators include the Bellan Plasma Group (Caltech), CTH (Auburn U), HBT-EP (Columbia), HIT-SI (U Wash-UW), LTX (PPPL), MAST (Culham), Pegasus (U Wisc-Madison), SSX (Swarthmore College), TCSU (UW), and ZaP/ZaP-HD (UW). The PSI-Center is exploring application of validation metrics between experimental data and simulations results. Biorthogonal decomposition (BOD) is used to compare experiments with simulations. BOD separates data sets into spatial and temporal structures, giving greater weight to dominant structures. Several BOD metrics are being formulated with the goal of quantitive validation. Results from these simulation and validation studies, as well as an overview of the PSI-Center status will be presented.

  19. 49 CFR 40.89 - What is validity testing, and are laboratories required to conduct it?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false What is validity testing, and are laboratories required to conduct it...PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.89 What is validity...

  20. Local lymph node assay — validation, conduct and use in practice

    Microsoft Academic Search

    D. A. Basketter; P. Evans; R. J. Fielder; G. F. Gerberick; R. J. Dearman; I. Kimber

    2002-01-01

    The validation of alternative methods is a relatively new activity in toxicology. The local lymph node assay (LLNA), a novel method for the identification of chemicals that have the potential to cause skin sensitization, was the first test to pass through the formal regulatory validation process established in the USA under the auspices of ICCVAM, the Interagency Coordinating Committee on

  1. Bioconversion study conducted by JPL

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J.

    1978-01-01

    The Jet Propulsion Laboratory (JPL) of Caltech conducted a study of bioconversion as a means of identifying the role of biomass for meeting the national energy fuel and chemical requirements and the role and means for JPL-Caltech involvement in bioconversion. The bioconversion study included the following categories; biomass sources, chemicals from biomass, thermochemical conversion of biomass to fuels, biological conversion of biomass to fuels and chemicals, and basic bioconversion sciences. A detailed review is included of the bioconversion fields cited with specific conclusions and recommendations given for future research and development and overall biomass system engineering and economic studies.

  2. Vascular elastography: a validation study.

    PubMed

    Lopata, Richard G P; Peters, Mathijs F J; Nijs, Jan; Oomens, Cees W J; Rutten, Marcel C M; van de Vosse, Frans N

    2014-08-01

    Vascular elastography techniques are promising tools for mechanical characterization of diseased arteries. These techniques are usually validated with simulations or phantoms or by comparing results with histology or other imaging modalities. In the study described here, vascular elastography was applied to porcine aortas in vitro during inflation testing (n = 10) and results were compared with those of standard bi-axial tensile testing, a technique that directly measures the force applied to the tissue. A neo-Hookean model was fit to the stress-strain data, valid for large deformations. Results indicated good correspondence between the two techniques, with GUS = 110 ± 11 kPa and GTT = 108 ± 10 kPa for ultrasound and tensile testing, respectively. Bland-Altman analysis revealed little bias (GUS-GTT = 2 ± 20 kPa). The next step will be the application of a non-linear material model that is also adaptable for in vivo measurements. PMID:24798385

  3. Nerve conduction and electromyography studies.

    PubMed

    Kane, N M; Oware, A

    2012-07-01

    Nerve conduction studies (NCS) and electromyography (EMG), often shortened to 'EMGs', are a useful adjunct to clinical examination of the peripheral nervous system and striated skeletal muscle. NCS provide an efficient and rapid method of quantifying nerve conduction velocity (CV) and the amplitude of both sensory nerve action potentials (SNAPs) and compound motor action potentials (cMAPs). The CV reflects speed of propagation of action potentials, by saltatory conduction, along large myelinated axons in a peripheral nerve. The amplitude of SNAPs is in part determined by the number of axons in a sensory nerve, whilst amplitude of cMAPs reflects integrated function of the motor axons, neuromuscular junction and striated muscle. Repetitive nerve stimulation (RNS) can identify defects of neuromuscular junction (NMJ) transmission, pre- or post-synaptic. Needle EMG examination can detect myopathic changes in muscle and signs of denervation. Combinations of these procedures can establish if motor and/or sensory nerve cell bodies or peripheral nerves are damaged (e.g. motor neuronopathy, sensory ganglionopathy or neuropathy), and also indicate if the primary target is the axon or the myelin sheath (i.e. axonal or demyelinating neuropathies). The distribution of nerve damage can be determined as either generalised, multifocal (mononeuropathy multiplex) or focal. The latter often due to compression at the common entrapment sites (such as the carpal tunnel, Guyon's canal, cubital tunnel, radial groove, fibular head and tarsal tunnel, to name but a few of the reported hundred or so 'entrapment neuropathies'). PMID:22614870

  4. RTEMS Validation and Testing Study

    NASA Astrophysics Data System (ADS)

    Ivraeus, U.; Alexandersson, J.; Brady, S.; Zulianello, M.; Rytter Nielsen, M.

    2007-08-01

    RTEMS stands for "Real Time Executive for Multiprocessor Systems". The operating system was developed by OAR Corp. on behalf of the US DoD and is licensed under a GPL variant. The focus of the study was to validate the RTEMS parts specific for the ERC32 target. Most findings during the study were of a non-critical kind and the conclusion is that the ERC32-version of the operating system works well. However, some issues were encountered and these are described in this paper.

  5. CANFOR Portuguese version: validation study

    PubMed Central

    2013-01-01

    Background The increase in prisoner population is a troublesome reality in several regions of the world. Along with this growth there is increasing evidence that prisoners have a higher proportion of mental illnesses and suicide than the general population. In order to implement strategies that address criminal recidivism and the health and social status of prisoners, particularly in mental disordered offenders, it is necessary to assess their care needs in a comprehensive, but individual perspective. This assessment must include potential harmful areas like comorbid personality disorder, substance misuse and offending behaviours. The Camberwell Assessment of Need – Forensic Version (CANFOR) has proved to be a reliable tool designed to accomplish such aims. The present study aimed to validate the CANFOR Portuguese version. Methods The translation, adaptation to the Portuguese context, back-translation and revision followed the usual procedures. The sample comprised all detainees receiving psychiatric care in four forensic facilities, over a one year period. A total of 143 subjects, and respective case manager, were selected. The forensic facilities were chosen by convenience: one prison hospital psychiatric ward (n=68; 47.6%), one male (n=24; 16.8%) and one female (n=22; 15.4%) psychiatric clinic and one civil security ward (n=29; 20.3%), all located nearby Lisbon. Basic descriptive statistics and Kappa weighted coefficients were calculated for the inter-rater and the test-retest reliability studies. The convergent validity was evaluated using the Global Assessment of Functioning and the Brief Psychiatric Rating Scale scores. Results The majority of the participants were male and single, with short school attendance, and accused of a crime involving violence against persons. The most frequent diagnosis was major depression (56.1%) and almost half presented positive suicide risk. The reliability study showed average Kappa weighted coefficients of 0.884 and 0.445 for inter-rater and test-retest agreement, respectively. The convergent validity study presented highly significant correlations between unmet needs scores, GAF and BPRS scores. Conclusions The CANFOR Portuguese version revealed similar psychometric properties to the original English version. Moreover, the results of the reliability and validity studies indicate that the tool is appropriate for individual care needs assessment and as a guide for the mental health and social interventions in forensic psychiatric services. PMID:23721105

  6. Predictive Validity of DSM-IV Oppositional Defiant and Conduct Disorders in Clinically Referred Preschoolers

    ERIC Educational Resources Information Center

    Keenan, Kate; Boeldt, Debra; Chen, Diane; Coyne, Claire; Donald, Radiah; Duax, Jeanne; Hart, Katherine; Perrott, Jennifer; Strickland, Jennifer; Danis, Barbara; Hill, Carri; Davis, Shante; Kampani, Smita; Humphries, Marisha

    2011-01-01

    Background: Diagnostic validity of oppositional defiant and conduct disorders (ODD and CD) for preschoolers has been questioned based on concerns regarding the ability to differentiate normative, transient disruptive behavior from clinical symptoms. Data on concurrent validity have accumulated, but predictive validity is limited. Predictive…

  7. MHD validation studies for RFPs

    NASA Astrophysics Data System (ADS)

    McCollam, K. J.; den Hartog, D. J.; Reusch, J. A.; Sarff, J. S.; Sauppe, J. P.; Schnack, D. D.; Sovinec, C. R.; Masamune, S.

    2013-10-01

    The reversed-field pinch (RFP) provides a nonlinear dynamical system suitable for validation studies of extended MHD, wherein laboratory measurements and resistive-MHD code results are compared so as to quantitatively evaluate the physical applicability of the mathematical model expressed in the code. We present plans for validation of the DEBS and NIMROD codes using the MST and RELAX RFP experiments, along with updates of results to date. MST operates in the full range of Lundquist number S accessible to the codes, and we identify metrics to be used for comparisons of sawtooth relaxation cycles at different S values. Previous work with the cylindrical, single-fluid DEBS code showed some quantitative agreement between code and experiment but disagreement for magnetic-fluctuation amplitudes (Reusch et al., PRL, 2011). Cylindrical NIMROD simulations with two-fluid effects gave closer agreement for the amplitudes (King et al., POP, 2012), but the two code studies were done using different fluid viscosities, which may also contribute to the different results. RELAX has a low aspect ratio of 2, which motivates comparisons to NIMROD runs in both cylindrical and toroidal geometry. The reversed-field pinch (RFP) provides a nonlinear dynamical system suitable for validation studies of extended MHD, wherein laboratory measurements and resistive-MHD code results are compared so as to quantitatively evaluate the physical applicability of the mathematical model expressed in the code. We present plans for validation of the DEBS and NIMROD codes using the MST and RELAX RFP experiments, along with updates of results to date. MST operates in the full range of Lundquist number S accessible to the codes, and we identify metrics to be used for comparisons of sawtooth relaxation cycles at different S values. Previous work with the cylindrical, single-fluid DEBS code showed some quantitative agreement between code and experiment but disagreement for magnetic-fluctuation amplitudes (Reusch et al., PRL, 2011). Cylindrical NIMROD simulations with two-fluid effects gave closer agreement for the amplitudes (King et al., POP, 2012), but the two code studies were done using different fluid viscosities, which may also contribute to the different results. RELAX has a low aspect ratio of 2, which motivates comparisons to NIMROD runs in both cylindrical and toroidal geometry. This work is supported by the USDOE and the NSF.

  8. The Self-Consciousness Scale: A Discriminant Validity Study

    ERIC Educational Resources Information Center

    Carver, Charles S.; Glass, David C.

    1976-01-01

    A validity study is conducted of the Self-Consciousness Scale components with male undergraduates. The components, Private and Public Self Consciousness and Social Anxiety did not correlate with any other measures used to establish their validity and thus seem to be independent of other measures tested. (Author/DEP)

  9. VALIDATION OF A THERMAL CONDUCTIVITY MEASUREMENT SYSTEM FOR FUEL COMPACTS

    SciTech Connect

    Jeff Phillips; Colby Jensen; Changhu Xing; Heng Ban

    2011-03-01

    A high temperature guarded-comparative-longitudinal heat flow measurement system has been built to measure the thermal conductivity of a composite nuclear fuel compact. It is a steady-state measurement device designed to operate over a temperature range of 300 K to 1200 K. No existing apparatus is currently available for obtaining the thermal conductivity of the composite fuel in a non-destructive manner due to the compact’s unique geometry and composite nature. The current system design has been adapted from ASTM E 1225. As a way to simplify the design and operation of the system, it uses a unique radiative heat sink to conduct heat away from the sample column. A finite element analysis was performed on the measurement system to analyze the associated error for various operating conditions. Optimal operational conditions have been discovered through this analysis and results are presented. Several materials have been measured by the system and results are presented for stainless steel 304, inconel 625, and 99.95% pure iron covering a range of thermal conductivities of 10 W/m*K to 70 W/m*K. A comparison of the results has been made to data from existing literature.

  10. 40 CFR 761.386 - Required experimental conditions for the validation study and subsequent use during decontamination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Required experimental conditions for the validation study and subsequent use during decontamination...Required experimental conditions for the validation study and subsequent use during decontamination...Temperature and pressure. Conduct the validation study and perform decontamination at...

  11. 40 CFR 761.386 - Required experimental conditions for the validation study and subsequent use during decontamination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Required experimental conditions for the validation study and subsequent use during decontamination...Required experimental conditions for the validation study and subsequent use during decontamination...Temperature and pressure. Conduct the validation study and perform decontamination at...

  12. 40 CFR 761.386 - Required experimental conditions for the validation study and subsequent use during decontamination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Required experimental conditions for the validation study and subsequent use during decontamination...Required experimental conditions for the validation study and subsequent use during decontamination...Temperature and pressure. Conduct the validation study and perform decontamination at...

  13. 40 CFR 761.386 - Required experimental conditions for the validation study and subsequent use during decontamination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Required experimental conditions for the validation study and subsequent use during decontamination...Required experimental conditions for the validation study and subsequent use during decontamination...Temperature and pressure. Conduct the validation study and perform decontamination at...

  14. 40 CFR 761.386 - Required experimental conditions for the validation study and subsequent use during decontamination.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Required experimental conditions for the validation study and subsequent use during decontamination...Required experimental conditions for the validation study and subsequent use during decontamination...Temperature and pressure. Conduct the validation study and perform decontamination at...

  15. Conducting and Reporting Case Studies.

    ERIC Educational Resources Information Center

    Lichtman, Merilyn; Taylor, Satomi Izumi

    Issues and elements of case study research are explored and illustrated with the example of a case study of a kindergarten in a suburb of Tokyo (Japan). Case study research is a type of qualitative research that concentrates on a single unit or entity, with boundaries established by the researcher. The case is an example drawn from a larger class,…

  16. Validation of the SSRS-T, Preschool Level as a Measure of Positive Social Behavior and Conduct Problems

    ERIC Educational Resources Information Center

    Rich, Erika Carpenter; Shepherd, Elizabeth J.; Nangle, Douglas W.

    2008-01-01

    Evidence for the validity of the Social Skills Rating System for Teachers, Preschool Level (SSRS-T) as a measure of positive social skills and conduct problems was examined in a sample of Head Start preschoolers. One feature of the study was the comparative analysis of the original published factor structure of the Social Skills Scale (i.e.,…

  17. Validity of diagnostic computer-based air and forehead bone conduction audiometry.

    PubMed

    Swanepoel, De Wet; Biagio, Leigh

    2011-04-01

    Computer-based audiometry allows for novel applications, including remote testing and automation, that may improve the accessibility and efficiency of hearing assessment in various clinical and occupational health settings. This study describes the validity of computer-based, diagnostic air and forehead bone conduction audiometry when compared wtih conventional industry standard audiometry in a sound booth environment. A sample of 30 subjects (19 to 77 years of age) was assessed with computer-based (KUDUwave 5000) and industry standard conventional audiometers (GSI 61) to compare air and bone conduction thresholds and test-retest reliability. Air conduction thresholds for the two audiometers corresponded within 5 dB or less in more than 90% of instances, with an average absolute difference of 3.5 dB (3.8 SD) and a 95% confidence interval of 2.6 to 4.5 dB. Bone conduction thresholds for the two audiometers corresponded within 10 dB or less in 92% of instances, with an average absolute difference of 4.9 dB (4.9 SD) and a 95% confidence interval of 3.6 to 6.1 dB. The average absolute test-retest threshold difference for bone conduction on the industry standard audiometer was 5.1 dB (5.3 SD) and for the computer-based audiometer 7.1 dB (6.4 SD). Computer-based audiometry provided air and bone conduction thresholds within the test-retest reliability limits of industry standard audiometry. PMID:21391065

  18. A Re-analysis of Published Differential Validity Studies.

    ERIC Educational Resources Information Center

    Ruch, William W.

    A survey of recent literature was undertaken to locate validity studies of paper-and-pencil tests which met the following criteria: (1) Studies were conducted in a business or industrial (i.e. non-education, non-military) setting; (2) Separate statistics were available for blacks and whites; (3) Race was not confounded with some outside variable…

  19. Interpretation of Validation Studies | Dietary Assessment Primer

    Cancer.gov

    Often, validation coefficients in the range of 0.4-0.6 are presented as evidence that an instrument is valid. In reality, however, such findings should not be used to answer a "yes" or "no" question with respect to whether or not an instrument is "valid". Further, the study design and whether an unbiased or imperfect reference measure was used to evaluate the instrument should be borne in mind.

  20. Conducting a wind sensing study

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1985-01-01

    Signal-to-noise requirements, and how signal-to-noise determines wind velocity measurement accuracy were studied. A Nd:YAG-based system was found to be competitive with a CO2-based system. Hardware was developed for a coherent Nd:YAG LIDAR system, and is being integrated into a functioning system. A diode-pumped monolithic rod laser to be used as a reference oscillator, a high-power, single-mode ring laser, for use as a master oscillator, and a high-gain, multipass amplifier were constructed.

  1. Nerve Conduction Studies in Multiple System Atrophy

    Microsoft Academic Search

    Michael Abele; Jörg B. Schulz; Katrin Bürk; Helge Topka; Johannes Dichgans; Thomas Klockgether

    2000-01-01

    To study the frequency and severity of peripheral neuropathy in multiple system atrophy (MSA), we performed nerve conduction studies in 42 MSA patients suffering from either cerebellar MSA (MSA-C) or parkinsonian MSA (MSA-P). Abnormal nerve conduction was present in 24% of the patients. Abnormalities were significantly more frequent in MSA-P (43%) compared to MSA-C (14%). Motor nerve conduction velocities were

  2. Transient hydraulic tomography in a sandbox with deterministic heterogeneity: Validation of hydraulic conductivity and specific storage tomograms

    NASA Astrophysics Data System (ADS)

    Liu, X.; Illman, W. A.; Craig, A. J.

    2005-12-01

    Hydraulic tomography is a method that images the hydraulic heterogeneity of the subsurface through the inversion of multiple pumping test data. Transient hydraulic tomography differentiates itself from steady-state tomography in that it not only estimates hydraulic conductivity but also provides an estimate of specific storage. Since it adopts transient pumping test data, it utilizes more data from each pumping test than steady-state tomography. Here, we investigate the information content of transient drawdown data through the analysis of synthetic and laboratory pumping test data in a 2-dimensional sandbox. In a synthetic study, pumping tests are performed on a computer model and the data generated is then used in the inversion. For the laboratory sandbox studies, pumping tests are performed on a physical sandbox model with deterministic heterogeneity. The data generated from these "real" tests are then used for transient inversions. To validate the tomograms, we utilize other hydraulic tests conducted at multiple scales in the sandbox such as permeameter tests on extracted cores, slug tests, single-hole tests, cross-hole tests and large-scale pumping tests. Validation consists of: 1) comparing local hydraulic conductivity and specific storage values from independent hydraulic tests to local values from transient hydraulic tomography; and 2) comparing the statistical moments of hydraulic conductivity and specific storage from the inverse model to those from other measurements. After validation of the results, we examine the information content of transient drawdown data by comparing the early, intermediate and late stages of drawdown data and the corresponding tomograms resulting from these data. We also compare the transient results with the hydraulic conductivity distribution from previously conducted steady-state hydraulic tomography to examine whether transient pumping data can improve the quality of the hydraulic conductivity tomograms. Finally, we use the hydraulic conductivity and specific storage tomograms from transient hydraulic tomography to predict the drawdown curves of other pumping tests that we did not use in the inversion.

  3. FETAX interlaboratory validation study: Phase 2 testing

    SciTech Connect

    Bantle, J.A. (Oklahoma State Univ., Stillwater, OK (United States). Dept. of Zoology); Burton, D.T. (WYE Research and Educational Center, Queenstown, MD (United States)); Dawson, D.A. (Ashland Univ., OH (United States). Dept. of Biology and Toxicology) (and others)

    1994-10-01

    The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a 96-h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that helps in embryo staging and identifying malformations. As part of the ASTM process, an interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FETAX. Six different laboratories participated in the study. Each laboratory utilized one technician with the exception of one laboratory, which utilized two independent technicians. In Phase 1, FETAX proved to be more repeatable and reliable than many other bioassays. However, some excessive variation was observed in a few laboratories. Some of this variation may have been due to an initial lack of experience with the assay by some technicians. Phase 2, which is reported here, showed far less intralaboratory and interlaboratory variability than did Phase 1. Nonteratogens such as saccharin and sodium cyclamate showed the most consistent results, whereas more variability was observed for the teratogens caffeine and 5-fluorouracil. Interlaboratory coefficient of variation values for all FETAX end points ranged from 7.3 to 54.7%. The minimum concentration to inhibit growth proved to be the most variable end point for three of the four test chemicals, whereas the LC50 and EC50 (malformation) proved to be less variable.

  4. Courseware Validation: A Case Study.

    ERIC Educational Resources Information Center

    Persico, D.

    1996-01-01

    Discusses summative and formative evaluation methods used and problems encountered in the study of LOGICLANDIA, a courseware package for the teaching and learning of predicate logic in Italian secondary schools. The evaluation process had three phases: subjective, in-house prototypes, and field testing. Results produced revisions in courseware…

  5. Code Validation Study for Base Flows

    NASA Technical Reports Server (NTRS)

    Ascoli, Edward P.; Heiba, Adel H.; Lagnado, Ronald R.; Ungewitter, Ronald J.; Williams, Morgan

    1993-01-01

    New and old rocket launch concepts recommend the clustering of motors for improved lift capability. The flowfield of the base region of the rocket is very complex and can contain high temperature plume gases. These hot gases can cause catastrophic problems if not adequately designed for. To assess the base region characteristics, advanced computational fluid dynamics (CFD) is being used. As a precursor to these calculations the CFD code requires validation on base flows. The primary objective of this code validation study was to establish a high level of confidence in predicting base flows with the USA CFD code. USA has been extensively validated for fundamental flows and other applications. However, base heating flows have a number of unique characteristics so it was necessary to extend the existing validation for this class of problems. In preparation for the planned NLS 1.5 Stage base heating analysis, six case sets were studied to extend the USA code validation data base. This presentation gives a cursive review of three of these cases. The cases presented include a 2D axi-symmetric study, a 3D real nozzle study, and a 3D multi-species study. The results of all the studies show good general agreement with data with no adjustments to the base numerical algorithms or physical models in the code. The study proved the capability of the USA code for modeling base flows within the accuracy of available data.

  6. Role of chaos for the validity of statistical mechanics laws: diffusion and conduction

    E-print Network

    Massimo Cencini; Fabio Cecconi; Massimo Falcioni; Angelo Vulpiani

    2008-04-04

    Several years after the pioneering work by Fermi Pasta and Ulam, fundamental questions about the link between dynamical and statistical properties remain still open in modern statistical mechanics. Particularly controversial is the role of deterministic chaos for the validity and consistency of statistical approaches. This contribution reexamines such a debated issue taking inspiration from the problem of diffusion and heat conduction in deterministic systems. Is microscopic chaos a necessary ingredient to observe such macroscopic phenomena?

  7. Proton Conductivity Studies on Biopolymer Electrolytes

    NASA Astrophysics Data System (ADS)

    Harun, N. I.; Sabri, N. S.; Rosli, N. H. A.; Taib, M. F. M.; Saaid, S. I. Y.; Kudin, T. I. T.; Ali, A. M. M.; Yahya, M. Z. A.

    2010-07-01

    Proton conducting solid biopolymer electrolyte membranes consisting of methyl cellulose (MC) and different wt.% of ammonium nitrate (NH4NO3) were prepared by solution cast technique. Impedance spectroscopy was carried out to study electrical characteristics of bulk materials. The ionic conductivity of the prepared samples was calculated using the bulk resistance (Rb) obtained from impedance spectroscopy plot. The highest ionic conductivity obtained was 1.17×10-4 Scm-1 for the sample with composition ratio of MC(50): NH4NO3(50). To enhance the ionic conductivity, propylene carbonate (PC) and ethylene carbonate (EC) plasticizers were introduced. It was found that the ionic conductivity of polymer electrolyte membranes increased with the increase in plasticizers concentration. The ionic conductivities of solid polymer electrolytes based on MC-NH4NO3-PC was enhanced up to 4.91×10-3 Scm-1 while for the MC-NH4NO3-EC system, the highest conductivity was 1.74×10-2 Scm-1. The addition of more plasticizer however decreases in mechanical stability of the membranes.

  8. Proton Conductivity Studies on Biopolymer Electrolytes

    SciTech Connect

    Harun, N. I.; Sabri, N. S.; Rosli, N. H. A.; Taib, M. F. M.; Saaid, S. I. Y.; Kudin, T. I. T. [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Ali, A. M. M.; Yahya, M. Z. A. [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2010-07-07

    Proton conducting solid biopolymer electrolyte membranes consisting of methyl cellulose (MC) and different wt.% of ammonium nitrate (NH{sub 4}NO{sub 3}) were prepared by solution cast technique. Impedance spectroscopy was carried out to study electrical characteristics of bulk materials. The ionic conductivity of the prepared samples was calculated using the bulk resistance (R{sub b}) obtained from impedance spectroscopy plot. The highest ionic conductivity obtained was 1.17x10{sup -4} Scm{sup -1} for the sample with composition ratio of MC(50): NH{sub 4}NO{sub 3}(50). To enhance the ionic conductivity, propylene carbonate (PC) and ethylene carbonate (EC) plasticizers were introduced. It was found that the ionic conductivity of polymer electrolyte membranes increased with the increase in plasticizers concentration. The ionic conductivities of solid polymer electrolytes based on MC-NH{sub 4}NO{sub 3}-PC was enhanced up to 4.91x10{sup -3} Scm{sup -1} while for the MC-NH{sub 4}NO{sub 3}-EC system, the highest conductivity was 1.74x10{sup -2} Scm{sup -1}. The addition of more plasticizer however decreases in mechanical stability of the membranes.

  9. Gas release and conductivity modification studies

    NASA Technical Reports Server (NTRS)

    Linson, L. M.; Baxter, D. C.

    1979-01-01

    The behavior of gas clouds produced by releases from orbital velocity in either a point release or venting mode is described by the modification of snowplow equations valid in an intermediate altitude regime. Quantitative estimates are produced for the time dependence of the radius of the cloud, the average internal energy, the translational velocity, and the distance traveled. The dependence of these quantities on the assumed density profile, the internal energy of the gas, and the ratio of specific heats is examined. The new feature is the inclusion of the effect of the large orbital velocity. The resulting gas cloud models are used to calculate the characteristics of the field line integrated Pedersen conductivity enhancements that would be produced by the release of barium thermite at orbital velocity in either the point release or venting modes as a function of release altitude and chemical payload weight.

  10. How to Conduct an Energy Efficiency Study

    E-print Network

    Biles, J. E.

    1979-01-01

    This paper describes how to organize a team of specialists in order to conduct an energy efficiency study in a totally unfamiliar plant. In-plant data gathering techniques are presented as well as methods for obtaining ideas and information from...

  11. Framework for planning and conducting pilot studies.

    PubMed

    Smith, Lisa Janette; Harrison, Margaret B

    2009-12-01

    Researchers working with partners in home care to plan a pragmatic multicenter community-based, randomized, controlled trial for leg ulcer compression treatment realized a smaller pilot study would be necessary. Because no framework for conducting pilot studies could be found, the authors developed a framework for pilot study methodology to inform the planning of such research. To this end, an integrative literature review was conducted, guided by an explicit search strategy, retrieval procedures, and appraisal process, to identify recognized pilot study aims, processes, and methodologies used in previously reported community pilot studies. Factors influencing study inclusion were recognized pilot study aims and purposes and a concise working definition of pilot study. Methodologies used in previously conducted community pilot studies were reviewed. Although relevant published research was limited, 11 pilot studies met the inclusion criteria for this review and contained suggestions to further develop or improve plans for larger definitive trials to enable a better fit of protocols within the delivery systems and scopes of practice. Pilot research processes could be divided into two stages: early planning and pilot trial. Direction for procedures and methods was gained relative to planning for an effective pilot study regarding eligibility, recruitment and data collection, management, and analysis. The results were used to develop an organizing framework for the authors' pilot study and named the Pilot Research Process (PReP) Framework. The process was instrumental in working with the authors' research team and clinical partners in the planning of their leg ulcer treatment pilot study. This framework may provide a foundation for others to analyze or develop a pilot study methodology in planning a large-scale study. PMID:20038790

  12. Evaluating the Construct Validity of Psychopathy in Black and White Male Inmates: Three Preliminary Studies

    Microsoft Academic Search

    David S. Kosson; Stevens S. Smith; Joseph P. Newman

    1990-01-01

    Although Black inmates represent almost half the population of United States prisons and have been included in several studies of psychopathy, there appear to be no published studies to date addressing the validity of the psychopathy construct in Black inmates. Three studies were conducted to assess the validity of the construct in Black male inmates using Hare's Psychopathy Checklist (PCL).

  13. Effective electrical conductivity of carbon nanotube-polymer composites: a simplified model and its validation

    NASA Astrophysics Data System (ADS)

    Jang, Sung-Hwan; Yin, Huiming

    2015-04-01

    A simplified model is presented to predict the effective electrical conductivity of carbon nanotube(CNT)-polymer composite with different material proportions, which is validated by the experiments of multi-walled CNT/polydimethylsiloxane (PDMS) composites. CNTs are well dispersed in a PDMS matrix, and the mixture is then cured and cast into thin films for electrical characterization. The CNTs are assumed to be statistically uniformly distributed in the PDMS matrix with the three-dimensional (3D) waviness. As the proportion of CNTs increases to a certain level, namely the percolation threshold, the discrete CNTs start to connect with each other, forming a 3D network which exhibits a significant increase of effective electrical conductivity. The eight-chain model has been used to predict the effective electrical conductivity of the composite, in which the contact resistance between CNTs has been considered through the Simmons’ equation. The eight-chain network features can be significantly changed with the modification to mixing process, CNT length and diameter, and CNT clustering and curling. A Gaussian statistics-based formulation is used to calculate the effective length of a single CNT well dispersed in the matrix. The modeling results of effective electrical conductivity agree with the experiments very well, which are highly dependent on a contact resistance between CNTs and the waviness of the CNTs. The effect of inner-nanotube distance and diameter of CNTs on the effective electrical conductivity of the CNT/PDMS composite is also discussed.

  14. A scattering model for perfectly conducting random surfaces. I - Model development. II - Range of validity

    NASA Technical Reports Server (NTRS)

    Fung, A. K.; Pan, G. W.

    1987-01-01

    The surface current on a perfectly conducting randomly rough surface is estimated by solving iteratively a standard integral equation, and the estimate is then used to compute the far-zone scattered fields and the backscattering coefficients for vertical, horizontal and cross polarizations. The model developed here yields a simple backscattering coefficient expression in terms of the surface parameters. The expression reduces analytically to the Kirchhoff and the first-order small-perturbation model in the high- and low-frequency regions, respectively. The range of validity of the model is determined.

  15. Validity

    NSDL National Science Digital Library

    Edwin P. Christmann

    2008-11-01

    In this chapter, the authors will describe the four types of validity: construct validity, content validity, concurrent validity, and predictive validity. Depending on the test and the rationale or purpose for its administration, and understanding of the

  16. Statistical power in criterion-related validation studies

    Microsoft Academic Search

    Frank L. Schmidt; John E. Hunter; Vern W. Urry

    1976-01-01

    Examined systematically the sample sizes necessary to provide adequate power in validation studies under various conditions of range restriction and criterion unreliability. For purposes of brevity, the examination was restricted to the validity parameter values (i.e., true validities) of .35 and .50. Results demonstrate that sample sizes required to produce adequate power in empirical validation studies are substantially larger than

  17. A validation study of the Siriraj Stroke Score.

    PubMed

    Kan, C H; Lee, S K; Low, C S; Velusamy, S S; Cheong, I

    2000-12-01

    A cross-sectional study was conducted on 160 Malaysian patients to validate the usefulness of the Siriraj Stroke Score (SSS) for differentiating intracerebral haemorrhage and infarction following acute strokes. Our results indicate that the score lacks sensitivity and specificity. It should thus not be used in epidemiological studies to determine stroke types in a community. More importantly, in the absence of information from neuroimaging of the brain, it cannot be used safely by physicians to assess the need or otherwise of thrombolytic and/or anticoagulant therapy after an acute stroke. PMID:11221275

  18. Conduction studies of the normal sural nerve.

    PubMed

    Horowitz, S H; Krarup, C

    1992-03-01

    The sural nerve was studied orthodromically using the near-nerve technique in 273 normal subjects (155 females, 118 males) aged 5 to 90 years. The sensory action potential (SAP), evoked at the dorsum of the foot, was recorded at the lateral malleolus and midcalf, and at the midcalf when evoked at the lateral malleolus. In addition, the SAP was recorded at intermediate distal sites and at proximal sites at the popliteal fossa, the gluteal fold, and the S-1 root. The amplitude of the SAP recorded at midcalf was 32% higher in females than in males. This was probably due to volume-conduction properties, as differences between genders were less noticeable at more distal recording sites. The amplitude decreased steeply and exponentially with age. Conduction distance had a strong influence on the amplitude of the SAP, which decreased with increasing distance following a power relationship with an exponent of 1.4 to 1.7. This decrease was due to temporal dispersion with decreased summation and increased phase cancellation. The conduction velocity was slightly lower along the very distal course of the nerve than along more proximal segments. PMID:1557087

  19. HREELS and Auger studies of conducting polymers

    SciTech Connect

    Jennings, W.D.; Chottiner, G.S.; Natarajan, C.; Melo, A.V.; Hoffman, R.W.; O'Grady, W.E.; Lundstrom, I.; Salaneck, W.R.

    1984-08-01

    High Resolution Electron Energy Loss Spectroscopy (HREELS) and Auger Spectroscopy have been used to examine the surface of conducting polymer samples. The samples were 100 nm thick films of polypyrrole doped with either BF/sub 4/ or ClO/sub 4/ negative ions. The films were made in Sweden and shipped to the USA for study. HREELS spectra could be obtained without difficulty in the samples' as is condition. These spectra showed broad bands corresponding to known polypyrrole vibrational modes. Exposure of the polymer to oxygen had no effect, but water could be adsorbed on the samples at 130 K. In addition to vibrational excitations, broader electronic transitions were also identified. Auger studies were performed in an effort to characterize the surface. These studies indicate that considerable non-stoichiometry exists in the surface region. There were, as expected, problems due to questionable sample cleanliness, sample charging, and electron beam damage. 21 references, 6 figures, 3 tables.

  20. Sampling theory methodology applicable to data validation studies

    SciTech Connect

    Chernick, M.R.

    1980-01-01

    In data validation studies, surveys are conducted to obtain information about the data collection process and the uses of the data. In many cases standard sampling techniques can be used. Two methods, stratified random sampling and cluster sampling, were used for surveys in the Form 4 data validation study. Form 4 is a data collection system on monthly generation and consumption of fuels by electric power plants. A description of those applications is given. Sometimes time and cost constraints make more sophisticated controlled sampling approaches necessary. One such approach using balanced incomplete block designs is described; an appendix surveys the existence results for these designs. Sequential methods which may prove to be more cost effective are discussed, as are sequential approaches to the problem of determining the size of a population. Problems requiring further research are also discussed. Some preliminary results on the problem of stratification with respect to more than one variable are included. The results were obtained for the Form 4 respondent population. The Form 4 study indicated that standard statistical sampling methods could be useful in data validation surveys. For example, at least 30 percent of the respondents do not report net generation as the instructions define it, and only 25 percent of the state regulatory agencies use the Form 4 data. Such inferences were possible only because statistical sampling procedures were used. 3 tables.

  1. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false A validation study. 761.395 Section 761...761.79(d)(4) § 761.395 A validation study. (a) Decontaminate the...Q of this part. (2) Report all validation study surface sample...

  2. 40 CFR 761.392 - Preparing validation study samples.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Preparing validation study samples. 761.392 Section...d)(4) § 761.392 Preparing validation study samples. (a)(1) To...spike) the surface to be used in the validation study as follows: (i) Use a...

  3. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false A validation study. 761.395 Section 761...761.79(d)(4) § 761.395 A validation study. (a) Decontaminate the...Q of this part. (2) Report all validation study surface sample...

  4. 40 CFR 761.392 - Preparing validation study samples.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Preparing validation study samples. 761.392 Section...d)(4) § 761.392 Preparing validation study samples. (a)(1) To...spike) the surface to be used in the validation study as follows: (i) Use a...

  5. 40 CFR 761.392 - Preparing validation study samples.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Preparing validation study samples. 761.392 Section...d)(4) § 761.392 Preparing validation study samples. (a)(1) To...spike) the surface to be used in the validation study as follows: (i) Use a...

  6. 40 CFR 761.392 - Preparing validation study samples.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Preparing validation study samples. 761.392 Section...d)(4) § 761.392 Preparing validation study samples. (a)(1) To...spike) the surface to be used in the validation study as follows: (i) Use a...

  7. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false A validation study. 761.395 Section 761...761.79(d)(4) § 761.395 A validation study. (a) Decontaminate the...Q of this part. (2) Report all validation study surface sample...

  8. 40 CFR 761.392 - Preparing validation study samples.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Preparing validation study samples. 761.392 Section...d)(4) § 761.392 Preparing validation study samples. (a)(1) To...spike) the surface to be used in the validation study as follows: (i) Use a...

  9. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false A validation study. 761.395 Section 761...761.79(d)(4) § 761.395 A validation study. (a) Decontaminate the...Q of this part. (2) Report all validation study surface sample...

  10. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false A validation study. 761.395 Section 761...761.79(d)(4) § 761.395 A validation study. (a) Decontaminate the...Q of this part. (2) Report all validation study surface sample...

  11. O`ahu Grid Study: Validation of Grid Models

    E-print Network

    O`ahu Grid Study: Validation of Grid Models Prepared for the U.S. Department of Energy Office............................................................................................................. 1 2 Model Validation .................................................................................................... 1 2.1 Production Cost Modeling (GE MAPSTM Analysis) ......................................... 2 2

  12. Structural and Electrical Study of Conducting Polymers

    NASA Astrophysics Data System (ADS)

    Shaktawat, Vinodini; Dixit, Manasvi; Saxena, N. S.; Sharma, Kananbala

    2010-06-01

    Pure and oxalic acid doped conducting polymers (polyaniline and polypyrrole) were chemically synthesized using ammonium persulfate (APS) as an oxidant. These samples were characterized through Scanning Electron Microscopy (SEM), which provides information about the surface topography of polymers. I-V characteristics have been recorded at room temperature as well as in the temperature range from 313 K to 463 K. So obtained characteristic curves were found to be linear. Temperature dependence of conductivity suggests a semiconducting nature in polyaniline samples with increase in temperature, whereas oxalic acid doped polypyrrole sample suggests a transition from semiconducting to metallic nature with the increase of temperature.

  13. Neuroscience Investigations: An Overview of Studies Conducted

    NASA Technical Reports Server (NTRS)

    Reschke, Millard F.

    1999-01-01

    The neural processes that mediate human spatial orientation and adaptive changes occurring in response to the sensory rearrangement encountered during orbital flight are primarily studied through second and third order responses. In the Extended Duration Orbiter Medical Project (EDOMP) neuroscience investigations, the following were measured: (1) eye movements during acquisition of either static or moving visual targets, (2) postural and locomotor responses provoked by unexpected movement of the support surface, changes in the interaction of visual, proprioceptive, and vestibular information, changes in the major postural muscles via descending pathways, or changes in locomotor pathways, and (3) verbal reports of perceived self-orientation and self-motion which enhance and complement conclusions drawn from the analysis of oculomotor, postural, and locomotor responses. In spaceflight operations, spatial orientation can be defined as situational awareness, where crew member perception of attitude, position, or motion of the spacecraft or other objects in three-dimensional space, including orientation of one's own body, is congruent with actual physical events. Perception of spatial orientation is determined by integrating information from several sensory modalities. This involves higher levels of processing within the central nervous system that control eye movements, locomotion, and stable posture. Spaceflight operational problems occur when responses to the incorrectly perceived spatial orientation are compensatory in nature. Neuroscience investigations were conducted in conjunction with U. S. Space Shuttle flights to evaluate possible changes in the ability of an astronaut to land the Shuttle or effectively perform an emergency post-landing egress following microgravity adaptation during space flights of variable length. While the results of various sensory motor and spatial orientation tests could have an impact on future space flights, our knowledge of sensorimotor adaptation to spaceflight is limited, and the future application of effective countermeasures depends, in large part, on the results from appropriate neuroscience investigations. Therefore, the objective of the neuroscience investigations could have a negative effect on mission success. The Neuroscience Laboratory, Johnson Space Center (JSC), implemented three integrated Detailed Supplementary Objectives (DSO) designed to investigate spatial orientation and the associated compensatory responses as a part of the EDOMP. The four primary goals were (1) to establish a normative database of vestibular and associated sensory changes in response to spaceflight, (2) to determine the underlying etiology of neurovestibular and sensory motor changes associated with exposure to microgravity and the subsequent return to Earth, (3) to provide immediate feedback to spaceflight crews regarding potential countermeasures that could improve performance and safety during and after flight, and (4) to take under consideration appropriate designs for preflight, in-flight, and postflight countermeasures that could be implemented for future flights.

  14. Global Electrical Conductivity Magnetic Satellite Induction Studies

    E-print Network

    Constable, Steve

    km. Skin depth can be a very useful indicator of energy penetration, but be careful! 2nd induction to measure Earth conductivity: · Magnetotelluric (MT) method Measure electric and magnetic fields · Geomagnetic depth sounding (GDS) method Measure horizontal and vertical magnetic fields 2nd

  15. Summary of Validity Data from the Admissions Testing Program Validity Study Service.

    ERIC Educational Resources Information Center

    Ford, Susan F.; Campos, Sandy

    Validity data (prediction of first-year grade point average) for colleges participating in the Admissions Testing Program Validity Study Service (VSS) and based on students entering college in 1964 through 1974 are summarized for the following predictors: Scholastic Aptitude Test (SAT)--verbal score, SAT--mathematical score, high school record,…

  16. An Agenda for NAEP Validity Research: NAEP Validity Studies. Working Paper Series.

    ERIC Educational Resources Information Center

    Stancavage, Frances B.

    The National Assessment of Educational Progress (NAEP) Validity Studies Panel undertook a systematic analysis to consider the domain of validity threats to NAEP and to identify the most urgent research priorities. A framework of six broad categories was developed: (1) the constructs measured within each of NAEP's subject domains; (2) the manner in…

  17. Study of Electrohydrodynamic Micropumping Through Conduction Phenomenon

    Microsoft Academic Search

    Seyed Reza Mahmoudi; Kazimierz Adamiak; G. S. Peter Castle; Mehdi Ashjaee

    2011-01-01

    In the present paper, a single-stage axisymmetric conduction micropump in the vertical configuration has been proposed. This micropump consists of four components: high- voltage ring electrode, grounded disk-shaped electrode, insula- tor spacer, and inlet\\/outlet ports. The high-voltage electrode and grounded electrode of the device were patterned on the two sep- arate commercial LCP substrates with 30 ?m copper cladding using

  18. Electrochemical corrosion studies in low conductivity propellants

    NASA Technical Reports Server (NTRS)

    Blue, G. D.; Moran, C. M.; Distefano, S.

    1986-01-01

    The Jet Propulsion Laboratory is investigating the possibility of developing advanced electrochemical techniques as accelerated compatibility tests for metal/propellant systems which overcome the problems associated with the low conductivity of the liquid propellants (e.g., hydrazines, nitrogen tetroxide). Both DC techniques and AC electrochemical impedance spectroscopy are being evaluated. Progress has been made in experiments involving stainless steel with hydrazine and nitrogen tetroxide propellants.

  19. Expert system verification and validation study

    NASA Technical Reports Server (NTRS)

    French, Scott W.; Hamilton, David

    1992-01-01

    Five workshops on verification and validation (V&V) of expert systems (ES) where taught during this recent period of performance. Two key activities, previously performed under this contract, supported these recent workshops (1) Survey of state-of-the-practice of V&V of ES and (2) Development of workshop material and first class. The first activity involved performing an extensive survey of ES developers in order to answer several questions regarding the state-of-the-practice in V&V of ES. These questions related to the amount and type of V&V done and the successfulness of this V&V. The next key activity involved developing an intensive hands-on workshop in V&V of ES. This activity involved surveying a large number of V&V techniques, conventional as well as ES specific ones. In addition to explaining the techniques, we showed how each technique could be applied on a sample problem. References were included in the workshop material, and cross referenced to techniques, so that students would know where to go to find additional information about each technique. In addition to teaching specific techniques, we included an extensive amount of material on V&V concepts and how to develop a V&V plan for an ES project. We felt this material was necessary so that developers would be prepared to develop an orderly and structured approach to V&V. That is, they would have a process that supported the use of the specific techniques. Finally, to provide hands-on experience, we developed a set of case study exercises. These exercises were to provide an opportunity for the students to apply all the material (concepts, techniques, and planning material) to a realistic problem.

  20. Idaho NTE Core Battery Validation: Study Report.

    ERIC Educational Resources Information Center

    Zetler, Alan G.

    The content validity of the National Teacher Examinations (NTE) Core Battery tests of communications skills, general knowledge, and professional knowledge was examined to determine whether this commercially available test was suitable for initial teacher certification in Idaho. Focus was on recommending adoption scores (cut scores) to the State…

  1. Practical challenges in conducting respiratory studies

    PubMed Central

    Hake, Sanjay D.; Patil, Mahesh L.; Shah, Tapankumar M.; Gokhale, Partha M.; Suvarna, Viraj

    2015-01-01

    Respiratory studies are complex on account of specific therapeutic knowledge that is needed and various instruments that are used for the management of this condition. Monitoring a respiratory study requires knowledge of the specific disease and associated guidelines. The intent of this article is to help clinical research professionals understand the technicalities, challenges, and the nuances of performing respiratory studies. PMID:25657898

  2. Conducting feasibility studies for knowledge based systems

    Microsoft Academic Search

    John Kingston

    2004-01-01

    This paper describes how to carry out a feasibility study for a potential knowledge based system application. It discusses factors to be considered under three headings: the business case, the technical feasibility, and stakeholder issues. It concludes with a case study of a feasibility study for a KBS to guide surgeons in diagnosis and treatment of thyroid conditions. q 2004

  3. Reliability and Validity of the School Health Policies and Programs Study 2000 Questionnaires.

    ERIC Educational Resources Information Center

    Brener, Nancy D.; Kann, Laura; Smith, Timothy K.

    2003-01-01

    Conducted a data quality substudy in conjunction with the School Health Policies and Programs Study (SHPPS) 2000 to assess the quality of study questionnaires. Validity of state and district level questionnaires was examined via telephone interviews with original respondents. A test-retest reliability of the school and classroom level…

  4. SAMICS Validation. SAMICS Support Study, Phase 3

    NASA Technical Reports Server (NTRS)

    1979-01-01

    SAMICS provides a consistent basis for estimating array costs and compares production technology costs. A review and a validation of the SAMICS model are reported. The review had the following purposes: (1) to test the computational validity of the computer model by comparison with preliminary hand calculations based on conventional cost estimating techniques; (2) to review and improve the accuracy of the cost relationships being used by the model: and (3) to provide an independent verification to users of the model's value in decision making for allocation of research and developement funds and for investment in manufacturing capacity. It is concluded that the SAMICS model is a flexible, accurate, and useful tool for managerial decision making.

  5. Measurement of Thermal Conductivity Using Steady-State Isothermal Conditions and Validation by Comparison with Thermoelectric Device Performance

    NASA Astrophysics Data System (ADS)

    Taylor, Patrick J.; Maddux, Jay R.; Uppal, Parvez N.

    2012-09-01

    A new technique for measuring thermal conductivity with significantly improved accuracy is presented. By using the Peltier effect to counterbalance an imposed temperature difference, a completely isothermal, steady-state condition can be obtained across a sample. In this condition, extraneous parasitic heat flows that would otherwise cause error can be eliminated entirely. The technique is used to determine the thermal conductivity of p-type and n-type samples of (Bi,Sb)2(Te,Se)3 materials, and thermal conductivity values of 1.47 W/m K and 1.48 W/m K are obtained respectively. To validate this technique, those samples were assembled into a Peltier cooling device. The agreement between the Seebeck coefficient measured individually and from the assembled device were within 0.5%, and the corresponding thermal conductivity was consistent with the individual measurements with less than 2% error.

  6. Electrical conductivity studies of poly(ethyleneoxide)-poly(vinylalcohol) blends

    Microsoft Academic Search

    Rachna Mishra; K. J Rao

    1998-01-01

    The electrical conductivity studies have been conducted over the entire range of composition in poly(ethyleneoxide)-poly(vinylalcohol) blends over a wide frequency regime. The conductivity variation has been investigated using the modified Almond-West formulation of ?(w)=A1ws1+A2ws2 for different compositions and is found to fit the ac conductivity data better at all temperatures. The dielectric data were analysed using complex dielectric constant ?*,

  7. Charge transport studies of proton and ion conducting materials

    NASA Astrophysics Data System (ADS)

    Versek, Craig Wm

    The development of a high-throughput impedance spectroscopy instrumentation platform for conductivity characterization of ion transport materials is outlined. Collaborative studies using this system are summarized. Charge conduction mechanisms and conductivity data for small molecule proton conducting liquids, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, and select mixtures of these compounds are documented. Furthermore, proton diffusivity measurements using a Pulse Field Gradient Nuclear Magnetic Resonance (PFG NMR) technique for imidazole and 1,2,3-triazole binary mixtures are compared. Studies of azole functionalized discotic and linear mesogens with conductivity, structural, and thermal characterizations are detailed.

  8. The Graduate Record Examinations Validity Study Service: Yesterday and Tomorrow.

    ERIC Educational Resources Information Center

    Kingston, Neal M.; And Others

    The Graduate Record Examinations (GRE) Validity Study Service (VSS) was developed by the Educational Testing Service at the request of the GRE Board to help graduate departments investigate the validity of their student selection procedures. The GRE VSS reports are aimed primarily at graduate department chairpersons and faculty members--those who…

  9. Measuring Long-Distance Romantic Relationships: A Validity Study

    ERIC Educational Resources Information Center

    Pistole, M. Carole; Roberts, Amber

    2011-01-01

    This study investigated aspects of construct validity for the scores of a new long-distance romantic relationship measure. A single-factor structure of the long-distance romantic relationship index emerged, with convergent and discriminant evidence of external validity, high internal consistency reliability, and applied utility of the scores.…

  10. An overview of the landscape valuation studies conducted in

    E-print Network

    Paris-Sud XI, Université de

    EA 4272 An overview of the landscape valuation studies conducted in France economy Pierre,version1-17Feb2012 #12;1 AN OVERVIEW OF THE LANDSCAPE VALUATION STUDIES CONDUCTED IN FRANCE Abstract: This article presents an overview of the landscape valuation studies carried out in France. The reported

  11. Coding Conversation between Intimates: A Validation Study of the Intimate Negotiation Coding System (INCS).

    ERIC Educational Resources Information Center

    Ting-Toomey, Stella

    A study was conducted to test the reliability and validity of the Intimate Coding System (INCS)--an instrument designed to code verbal conversation in intimate relationships. Subjects, 34 married couples, completed Spanier's Dyadic Adjustment Scale, which elicited information about relational adjustment and satisfaction in intimate couples in…

  12. A Validity Study of Two Forms of the Self-Esteem Rating Scale

    ERIC Educational Resources Information Center

    Nugent, William R.

    2004-01-01

    A study was conducted to assess the equivalence of validity and reliability of two forms of the Self-Esteem Rating Scale. A total of 228 responses were obtained from a purposive sample. Several data analysis methods were used to test specific hypotheses, and two methods of equating observed scores on the two forms were used. The results were…

  13. Validation Study of the NTE for Certification of Entry Level Teachers in the State of Mississippi.

    ERIC Educational Resources Information Center

    Hankins, Brenda J.; Hancock, James J.

    A content validity study of the National Teacher Examination (NTE) was conducted by Educational Testing Service for the Mississippi State Board of Education. Its purposes were: (1) to assess the NTE's appropriateness as a measure of knowledge acquired through teacher preparation programs and required as a qualification to teach in Mississippi; and…

  14. Symptom validity testing and its underlying psychophysiological response pattern: a preliminary study.

    PubMed

    Vilar-López, R; Pérez-García, M; Sánchez-Barrera, M B; Rodríguez-Fernández, A; Gómez-Río, M

    2011-03-01

    Very little is known about the autonomic psychophysiological responses while individuals are executing a Symptom Validity Test. Therefore, the aim of this study is to analyze the peripheral psychophysiological correlates (electrodermal conductance and heart rate) during the performance of the Victoria Symptom Validity Test (VSVT). The sample of this study was composed of 30 participants who underwent the VSVT under two conditions: Exaggeration of cognitive deficits (ECD) and normal effort. Our results showed differences on skin conductance between correct answers and errors limited to the decision-making phase of the ECD condition. Those differences found in the maximum conductance value when participants decide to simulate their deficits could be related to emotional activation. No differences were found on the variable heart rate between the two conditions of the study. Implications of these results are discussed. PMID:21169274

  15. Design and Implementation Content Validity Study: Development of an instrument for measuring Patient-Centered Communication

    PubMed Central

    Zamanzadeh, Vahid; Ghahramanian, Akram; Rassouli, Maryam; Abbaszadeh, Abbas; Alavi-Majd, Hamid; Nikanfar, Ali-Reza

    2015-01-01

    Introduction: The importance of content validity in the instrument psychometric and its relevance with reliability, have made it an essential step in the instrument development. This article attempts to give an overview of the content validity process and to explain the complexity of this process by introducing an example. Methods: We carried out a methodological study conducted to examine the content validity of the patient-centered communication instrument through a two-step process (development and judgment). At the first step, domain determination, sampling (item generation) and instrument formation and at the second step, content validity ratio, content validity index and modified kappa statistic was performed. Suggestions of expert panel and item impact scores are used to examine the instrument face validity. Results: From a set of 188 items, content validity process identified seven dimensions includes trust building (eight items), informational support (seven items), emotional support (five items), problem solving (seven items), patient activation (10 items), intimacy/friendship (six items) and spirituality strengthening (14 items). Content validity study revealed that this instrument enjoys an appropriate level of content validity. The overall content validity index of the instrument using universal agreement approach was low; however, it can be advocated with respect to the high number of content experts that makes consensus difficult and high value of the S-CVI with the average approach, which was equal to 0.93. Conclusion: This article illustrates acceptable quantities indices for content validity a new instrument and outlines them during design and psychometrics of patient-centered communication measuring instrument.

  16. Sensor data validation and reconstruction. Phase 1: System architecture study

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The sensor validation and data reconstruction task reviewed relevant literature and selected applicable validation and reconstruction techniques for further study; analyzed the selected techniques and emphasized those which could be used for both validation and reconstruction; analyzed Space Shuttle Main Engine (SSME) hot fire test data to determine statistical and physical relationships between various parameters; developed statistical and empirical correlations between parameters to perform validation and reconstruction tasks, using a computer aided engineering (CAE) package; and conceptually designed an expert system based knowledge fusion tool, which allows the user to relate diverse types of information when validating sensor data. The host hardware for the system is intended to be a Sun SPARCstation, but could be any RISC workstation with a UNIX operating system and a windowing/graphics system such as Motif or Dataviews. The information fusion tool is intended to be developed using the NEXPERT Object expert system shell, and the C programming language.

  17. Experimental validation of an extended Kalman smoothing technique for solving nonlinear inverse heat conduction problems

    Microsoft Academic Search

    N. Daouas; M.-S. Radhouani

    2007-01-01

    A new approach combining the use of the Kalman filter with an extended version of a smoothing technique and introducing the use of future time measurements is developed in order to improve the solution of a nonlinear Inverse Heat Conduction Problem (IHCP). The behaviour of the proposed algorithm is analysed in presence of a real set of experimental noisy temperature

  18. Lightning return stroke current radiation in presence of a conducting ground: 2. Validity assessment of simplified approaches

    NASA Astrophysics Data System (ADS)

    Delfino, Federico; Procopio, Renato; Rossi, Mansueto; Rachidi, Farhad; Nucci, Carlo Alberto

    2008-03-01

    In this paper, the developed formulation, which we shall call the "reference" one, is used to assess the validity of the most popular simplified approach for the calculation of the lightning electromagnetic field over a conducting earth, namely, the Cooray-Rubinstein (CR) approximation. This formula provides a simple method to evaluate the radial component of the electric field which is the component most affected by the finite ground conductivity and which plays an important role within the Agrawal et al. (1980) field-to-transmission line-coupling model. Several configurations are examined, with different values for the ground conductivity and different field observation points. A thorough analysis of all the simulated field components is carried out and comparisons are also made with the "ideal" field, namely, the field that would be present under the assumption of perfectly conducting ground. It is shown that for channel base current typical of subsequent strokes and for very low conductivities, the CR formula exhibits some deviations from the reference one but it still represents a conservative estimation of the radial field component, since it behaves as un upper bound for the exact curve. The developed algorithm is characterized by fast performances in terms of CPU time, lending itself to be used for several applications, including a coupling code for lightning induced overvoltages calculations.

  19. A framework for evaluating and conducting prognostic studies: an application to cirrhosis of the liver.

    PubMed

    Infante-Rivard, C; Villeneuve, J P; Esnaola, S

    1989-01-01

    A framework for evaluating and conducting prognostic studies is proposed. Recently published studies on prognosis of cirrhosis of the liver are evaluated according to the proposed framework. It was found that appropriate statistical techniques were often used to analyze the results of prognostic studies of cirrhosis of the liver. On the other hand, the studies performed poorly with regards to study design, the determination of the usefulness of the data, the validity of the collected information, and the analytic strategy. It is hoped that the criteria suggested in this paper will improve the planning and the reporting of prognostic studies. PMID:2668451

  20. Molecular dynamics study of heat conduction in silicon nanowires

    NASA Astrophysics Data System (ADS)

    Volz, Sebastian; Chen, Gang

    1998-03-01

    With the advancement of nanofabrication technologies, nanowires may be produced for both fundamental studies and practical applications. While many former works have been carried out to characterize the electronic and optical properties of nanowires, little attention has been paid to the heat conduction mechanisms occurring in these structures. However, a fundamental understanding of heat conduction in these nanodevices is important for a number of technological areas such as electronics and thermoelectrics. In this works, we performed numerical studies based on molecular dynamics technique to simulate heat conduction in silicon nanowires lying in the vacuum. The device cells are arranged according to a diamond single crystal structure and interatomic forces are derived from the Stillinger-Weber potential currently assumed in solid silicon. By computing the time dependent heat flux and temperature field, the effective thermal conductivity of the wire was derived. The dependence of thermal conductivity on transverse dimensions and temperature is also probed.

  1. Experimental Study of Acid Fracture Conductivity of Austin Chalk Formation 

    E-print Network

    Nino Penaloza, Andrea

    2013-05-01

    to those in actual acid fracture treatments. After acid etching, fracture conductivity is measured at different closure stresses. This research work presents a systematic study to investigate the effect of temperature, rock-acid contact time and initial...

  2. Ride qualities criteria validation/pilot performance study: Flight test results

    NASA Technical Reports Server (NTRS)

    Nardi, L. U.; Kawana, H. Y.; Greek, D. C.

    1979-01-01

    Pilot performance during a terrain following flight was studied for ride quality criteria validation. Data from manual and automatic terrain following operations conducted during low level penetrations were analyzed to determine the effect of ride qualities on crew performance. The conditions analyzed included varying levels of turbulence, terrain roughness, and mission duration with a ride smoothing system on and off. Limited validation of the B-1 ride quality criteria and some of the first order interactions between ride qualities and pilot/vehicle performance are highlighted. An earlier B-1 flight simulation program correlated well with the flight test results.

  3. Validity in Action: Lessons from Studies of Data Use

    ERIC Educational Resources Information Center

    Moss, Pamela A.

    2013-01-01

    Studies of data use illuminate ways in which education professionals have used test scores and other evidence relevant to students' learning--in action in their own contexts of work--to make decisions about their practice. These studies raise instructive challenges for a validity theory that focuses on intended interpretations and uses of test…

  4. Verification, Validation and Sensitivity Studies in Computational Biomechanics

    PubMed Central

    Anderson, Andrew E.; Ellis, Benjamin J.; Weiss, Jeffrey A.

    2012-01-01

    Computational techniques and software for the analysis of problems in mechanics have naturally moved from their origins in the traditional engineering disciplines to the study of cell, tissue and organ biomechanics. Increasingly complex models have been developed to describe and predict the mechanical behavior of such biological systems. While the availability of advanced computational tools has led to exciting research advances in the field, the utility of these models is often the subject of criticism due to inadequate model verification and validation. The objective of this review is to present the concepts of verification, validation and sensitivity studies with regard to the construction, analysis and interpretation of models in computational biomechanics. Specific examples from the field are discussed. It is hoped that this review will serve as a guide to the use of verification and validation principles in the field of computational biomechanics, thereby improving the peer acceptance of studies that use computational modeling techniques. PMID:17558646

  5. Open-source MFIX-DEM software for gas-solids flows: Part II Validation studies

    SciTech Connect

    Li, Tingwen [National Energy Technology Laboratory (NETL); Garg, Rahul [National Energy Technology Laboratory (NETL); Galvin, Janine [National Energy Technology Laboratory (NETL); Pannala, Sreekanth [ORNL

    2012-01-01

    With rapid advancements in computer hardware and numerical algorithms, computational fluid dynamics (CFD) has been increasingly employed as a useful tool for investigating the complex hydrodynamics inherent in multiphase flows. An important step during the development of a CFD model and prior to its application is conducting careful and comprehensive verification and validation studies. Accordingly, efforts to verify and validate the open-source MFIX-DEM software, which can be used for simulating the gas solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles, have been made at the National Energy Technology Laboratory (NETL). In part I of this paper, extensive verification studies were presented and in this part, detailed validation studies of MFIX-DEM are presented. A series of test cases covering a range of gas solids flow applications were conducted. In particular the numerical results for the random packing of a binary particle mixture, the repose angle of a sandpile formed during a side charge process, velocity, granular temperature, and voidage profiles from a bounded granular shear flow, lateral voidage and velocity profiles from a monodisperse bubbling fluidized bed, lateral velocity profiles from a spouted bed, and the dynamics of segregation of a binary mixture in a bubbling bed were compared with available experimental data, and in some instances with empirical correlations. In addition, sensitivity studies were conducted for various parameters to quantify the error in the numerical simulation.

  6. Open-Source MFIX-DEM Software for Gas-Solids Flows: Part II - Validation Studies

    SciTech Connect

    Li, Tingwen

    2012-04-01

    With rapid advancements in computer hardware and numerical algorithms, computational fluid dynamics (CFD) has been increasingly employed as a useful tool for investigating the complex hydrodynamics inherent in multiphase flows. An important step during the development of a CFD model and prior to its application is conducting careful and comprehensive verification and validation studies. Accordingly, efforts to verify and validate the open-source MFIX-DEM software, which can be used for simulating the gas–solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles, have been made at the National Energy Technology Laboratory (NETL). In part I of this paper, extensive verification studies were presented and in this part, detailed validation studies of MFIX-DEM are presented. A series of test cases covering a range of gas–solids flow applications were conducted. In particular the numerical results for the random packing of a binary particle mixture, the repose angle of a sandpile formed during a side charge process, velocity, granular temperature, and voidage profiles from a bounded granular shear flow, lateral voidage and velocity profiles from a monodisperse bubbling fluidized bed, lateral velocity profiles from a spouted bed, and the dynamics of segregation of a binary mixture in a bubbling bed were compared with available experimental data, and in some instances with empirical correlations. In addition, sensitivity studies were conducted for various parameters to quantify the error in the numerical simulation.

  7. Conducting Internet Research With the Transgender Population: Reaching Broad Samples and Collecting Valid Data

    PubMed Central

    Miner, Michael H.; Bockting, Walter O.; Romine, Rebecca Swinburne; Raman, Sivakumaran

    2013-01-01

    Health research on transgender people has been hampered by the challenges inherent in studying a hard-to-reach, relatively small, and geographically dispersed population. The Internet has the potential to facilitate access to transgender samples large enough to permit examination of the diversity and syndemic health disparities found among this population. In this article, we describe the experiences of a team of investigators using the Internet to study HIV risk behaviors of transgender people in the United States. We developed an online instrument, recruited participants exclusively via websites frequented by members of the target population, and collected data using online quantitative survey and qualitative synchronous and asynchronous interview methods. Our experiences indicate that the Internet environment presents the investigator with some unique challenges and that commonly expressed criticisms about Internet research (e.g., lack of generalizable samples, invalid study participants, and multiple participation by the same subject) can be overcome with careful method design, usability testing, and pilot testing. The importance of both usability and pilot testing are described with respect to participant engagement and retention and the quality of data obtained online. PMID:24031157

  8. Computational study of NMDA conductance and cortical oscillations in schizophrenia

    PubMed Central

    Kirli, Kübra Komek; Ermentrout, G. B.; Cho, Raymond Y.

    2014-01-01

    N-methyl-D-aspartate (NMDA) receptor hypofunction has been implicated in the pathophysiology of schizophrenia. The illness is also characterized by gamma oscillatory disturbances, which can be evaluated with precise frequency specificity employing auditory cortical entrainment paradigms. This computational study investigates how synaptic NMDA hypofunction may give rise to network level oscillatory deficits as indexed by entrainment paradigms. We developed a computational model of a local cortical circuit with pyramidal cells and fast-spiking interneurons (FSI), incorporating NMDA, ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic (AMPA), and ?-aminobutyric acid (GABA) synaptic kinetics. We evaluated the effects of varying NMDA conductance on FSIs and pyramidal cells, as well as AMPA to NMDA ratio. We also examined the differential effects across a broad range of entrainment frequencies as a function of NMDA conductance. Varying NMDA conductance onto FSIs revealed an inverted-U relation with network gamma whereas NMDA conductance onto the pyramidal cells had a more monotonic relationship. Varying NMDA vs. AMPA conductance onto FSIs demonstrated the necessity of AMPA in the generation of gamma while NMDA receptors had a modulatory role. Finally, reducing NMDA conductance onto FSI and varying the stimulus input frequency reproduced the specific reductions in gamma range (~40 Hz) as observed in schizophrenia studies. Our computational study showed that reductions in NMDA conductance onto FSIs can reproduce similar disturbances in entrainment to periodic stimuli within the gamma range as reported in schizophrenia studies. These findings provide a mechanistic account of how specific cellular level disturbances can give rise to circuitry level pathophysiologic disturbance in schizophrenia. PMID:25368573

  9. Science Sampler: Validating assessment--Teacher study groups

    NSDL National Science Digital Library

    Erin Peters

    2008-01-01

    Teacher study groups are a valuable method of examining the validity of classroom assessments and determining how well the assessments align with student learning goals. The implementation of teacher study groups is based on a model from the Schools Around the World Academy for Teaching Excellence (Council for Basic Education 2000). The teacher study groups are composed of four to six teachers. Often a teacher solicits group members by sending out flyers to the faculty to find interested volunteers.

  10. Questionnaire techniques in assessing acne handicap: Reliability and validity study

    Microsoft Academic Search

    M. S. Salek; G. K. Khan; A. Y. Finlay

    1996-01-01

    The purpose of this study was to examine and compare the reliability and validity of two acne-specific measures, the Cardiff Acne Disability Index (CADI), the Acne Disability Index (ADI) and a general health status instrument, the United Kingdom Sickness Impact Profile (UKSIP). The test-retest reliability was carried out for the UKSIP, ADI and CADI with an interval of 10 days

  11. Teachers' Engagement at Work: An International Validation Study

    ERIC Educational Resources Information Center

    Klassen, Robert M.; Aldhafri, Said; Mansfield, Caroline F.; Purwanto, Edy; Siu, Angela F. Y.; Wong, Marina W.; Woods-McConney, Amanda

    2012-01-01

    This study explored the validity of the Utrecht Work Engagement Scale in a sample of 853 practicing teachers from Australia, Canada, China (Hong Kong), Indonesia, and Oman. The authors used multigroup confirmatory factor analysis to test the factor structure and measurement invariance across settings, after which they examined the relationships…

  12. Emotional Abilities in Couples: A Construct Validation Study

    Microsoft Academic Search

    Heather M. Foran; K. Daniel O’Leary; Mathew C. Williams

    2012-01-01

    Extensive research has evaluated emotional abilities measures among individuals, but the validity of these constructs in a couples context has yet to be examined despite theoretical perspectives often highlighting the detrimental effects of poor emotional abilities on interpersonal functioning. The current study evaluates four measures of emotional abilities in a sample of 104 couples (emotional intelligence, self-rated alexithymia, partner-rated alexithymia,

  13. A Validation Study of Early Adolescents' Pubertal Self-Assessments

    ERIC Educational Resources Information Center

    Schmitz, Katharine E.; Hovell, Melbourne F.; Nichols, Jeanne F.; Irvin, Veronica L.; Keating, Kristen; Simon, Gayle M.; Gehrman, Christine; Jones, Kenneth Lee

    2004-01-01

    This study aimed to determine whether self-assessed puberty is sufficiently reliable and valid to substitute for physician examination when feasibility of physician examination is low (e.g., behavioral research). Adolescents (convenience sample N = 178 endocrinology patients and N = 125 from educational trial; mean age 12.7 and 11.3 years,…

  14. Rap-Music Attitude and Perception Scale: A Validation Study

    ERIC Educational Resources Information Center

    Tyson, Edgar H.

    2006-01-01

    Objective: This study tests the validity of the Rap-music Attitude and Perception (RAP) Scale, a 1-page, 24-item measure of a person's thoughts and feelings surrounding the effects and content of rap music. The RAP was designed as a rapid assessment instrument for youth programs and practitioners using rap music and hip hop culture in their work…

  15. Internal Validity Studies of a Telephone Preemployment Measure.

    ERIC Educational Resources Information Center

    Gerstein, Lawrence H.; And Others

    1989-01-01

    Data are presented on the validity and reliability of a new form of employee honesty testing: "The Integrity Interview." Results indicated that this instrument was a reliable alternative to commonly used written measures, although further study is needed to establish normative data across different employee populations and settings. (Author/TE)

  16. A Validity Study of the Self-Esteem Inventory.

    ERIC Educational Resources Information Center

    Landis, H. John

    Results of this validation study of a slightly modified version of the Coppersmith Self-Esteem Inventory substantiate its use with seventh graders to assess Goal I (concerning self-understanding and appreciation of self-worth) of the Educational Quality Assessment Program in Pennsylvania. Appendixes include the definition and rationale for Goal I,…

  17. A Validation Study of the Existential Anxiety Scale.

    ERIC Educational Resources Information Center

    Hullett, Michael A.

    Logotherapy is a meaning-centered psychotherapy which focuses on both the meaning of human existence and the personal search for meaning. If the will to search for meaning is frustrated, "existential frustration" may result. This study validates the Existential Anxiety Scale (EAS) developed by Good and Good (1974). Basic principles of logotherapy…

  18. Instruments for the assessment of social anxiety disorder: Validation studies

    PubMed Central

    Osório, Flávia de Lima; Crippa, José Alexandre de Souza; Loureiro, Sonia Regina

    2012-01-01

    Great progress has been observed in the literature over the last decade regarding the validation of instruments for the assessment of Social Anxiety Disorder in the Brazilian context. Particularly outstanding in this respect is the production of a group of Brazilian investigators regarding the psychometric study of the following instruments: Liebowitz Social Anxiety Scale, Social Phobia Inventory, Brief Social Phobia Scale, Disability Profile, Liebowitz Self-Rated Disability Scale, Social Phobia Safety Behaviors Scale and Self-Statements During Public Speaking Scale, which have proved to be appropriate and valid for use in the adult Brazilian population, representing resources for the assessment of social anxiety in clinical and experimental situations. PMID:24175172

  19. Instruments for the assessment of social anxiety disorder: Validation studies.

    PubMed

    Osório, Flávia de Lima; Crippa, José Alexandre de Souza; Loureiro, Sonia Regina

    2012-10-22

    Great progress has been observed in the literature over the last decade regarding the validation of instruments for the assessment of Social Anxiety Disorder in the Brazilian context. Particularly outstanding in this respect is the production of a group of Brazilian investigators regarding the psychometric study of the following instruments: Liebowitz Social Anxiety Scale, Social Phobia Inventory, Brief Social Phobia Scale, Disability Profile, Liebowitz Self-Rated Disability Scale, Social Phobia Safety Behaviors Scale and Self-Statements During Public Speaking Scale, which have proved to be appropriate and valid for use in the adult Brazilian population, representing resources for the assessment of social anxiety in clinical and experimental situations. PMID:24175172

  20. Greek version of the Internet Addiction Test: a validation study.

    PubMed

    Tsimtsiou, Zoi; Haidich, Anna-Bettina; Kokkali, Stamatia; Dardavesis, Theodoros; Young, Kimberly S; Arvanitidou, Malamatenia

    2014-06-01

    The aim of this project was to translate, culturally adapt and validate the Internet Addiction Test (IAT) in Greek adults. Twenty-one post-graduate medical students participated in the cultural adaptation procedure and 151 both post- and under-graduate medical students in the validation process. The internal consistency shown by a Cronbach's alpha was 0.91. Two-week test-retest reliability was rtt = 0.84, p < 0.001. Face validity was affirmed by 83.6 % of the students. In terms of convergent validity, the hours of daily internet use were positively correlated with IAT score (rho = 0.48, p < 0.001). Moreover, IAT scores were higher in students that reported use of online gambling (40.5 vs 29.2, p = 0.004), pornographic sites (36.5 vs 28.0, p = 0.003) and online games (35.6 vs 28.2, p = 0.009). Exploratory factor analysis revealed three interpretable factors for the IAT, "Psychological/Emotional Conflict", "Time Management" and "Neglect Work", that showed good internal consistency and concurrent validity, explaining 55.3 % of the variance. The Greek version of IAT has shown good psychometric properties, comparable with the original IAT and the previously published translated versions, and can be a useful tool in future studies on internet addiction. PMID:24307176

  1. Low thermal conductivity of graphyne nanotubes from molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Hu, Ming; Jing, Yuhang; Zhang, Xiaoliang

    2015-04-01

    It is well known that carbon nanotubes (CNTs) possess ultrahigh thermal conductivity that is comparable to bulk diamond. However, no research has studied the possible low thermal conductivity of different CNTs so far. By performing nonequilibrium molecular dynamic simulations, we reveal that the perfect graphyne nanotube (GNT) exhibits an unprecedentedly low thermal conductivity (below 10 W/mK at room temperature), which is generally two orders of magnitude lower than that of ordinary CNTs and even lower than the values reported for defected, doped, and chemically functionalized CNTs. By performing phonon polarization and spectral energy density analysis, we observe that the ultralow thermal conductivity stems from the unique atomic structure of the GNT, consisting of the weak acetylenic linkage (s p C-C bonds) and the strong hexagonal ring (s p2 C-C bonds), which results in a large vibrational mismatch between these two components, and thus induces significantly inefficient heat transfer. Moreover, the thermal transport in GNT with a large number of acetylenic linkages is dominated by the low frequency longitudinal modes in the linkage. Such strong confinement of the low frequency thermal energy results in the extremely low thermal conductivity due to the flattened phonon dispersion curves (low phonon group velocities). The exploration of the abnormal thermal transport of GNTs paves the way for design and application of the relevant devices that could benefit from the ultralow thermal conductivity, such as thermoelectrics for energy conversion.

  2. Use and validity of principles of extremum of entropy production in the study of complex systems

    SciTech Connect

    Heitor Reis, A., E-mail: ahr@uevora.pt

    2014-07-15

    It is shown how both the principles of extremum of entropy production, which are often used in the study of complex systems, follow from the maximization of overall system conductivities, under appropriate constraints. In this way, the maximum rate of entropy production (MEP) occurs when all the forces in the system are kept constant. On the other hand, the minimum rate of entropy production (mEP) occurs when all the currents that cross the system are kept constant. A brief discussion on the validity of the application of the mEP and MEP principles in several cases, and in particular to the Earth’s climate is also presented. -- Highlights: •The principles of extremum of entropy production are not first principles. •They result from the maximization of conductivities under appropriate constraints. •The conditions of their validity are set explicitly. •Some long-standing controversies are discussed and clarified.

  3. A reliability and validity study of the Palliative Performance Scale

    Microsoft Academic Search

    Francis Ho; Francis Lau; Michael G Downing; Mary Lesperance

    2008-01-01

    BACKGROUND: The Palliative Performance Scale (PPS) was first introduced in1996 as a new tool for measurement of performance status in palliative care. PPS has been used in many countries and has been translated into other languages. METHODS: This study evaluated the reliability and validity of PPS. A web-based, case scenarios study with a test-retest format was used to determine reliability.

  4. Evaluating the quality of dietary intake validation studies.

    PubMed

    Serra-Majem, Lluis; Frost Andersen, Lene; Henríque-Sánchez, Patricia; Doreste-Alonso, Jorge; Sánchez-Villegas, Almudena; Ortiz-Andrelluchi, Adriana; Negri, Eva; La Vecchia, Carlo

    2009-12-01

    Within the EURopean micronutrient RECommendations Aligned Network of Excellence (EURRECA), a scoring system was developed to assess the quality of dietary intake validation studies. The scoring system included three steps. The first step was to give each study a quality score, which included five components: sample size, statistics used, data collection procedure, consideration of seasonality and supplement use. Scores ranged from 0 to 7, and validation studies classified as very good ( > or = 5), good (5-3.5), acceptable/reasonable (3.5-2.5) and poor ( < 2.5). The second and third steps included an adjustment/weighting of the correlation coefficient according to the quality score and moreover a rating of the adjusted/weighted correlation. The scoring system was tested in 124 validation studies that included at least one vitamin. Only 5.6 % of the 124 studies were judged to be of very good quality according to the quality score, 41.9 % of good quality and 16.9 % had a poor rating. When adjusting for the study quality scores, crude and adjusted mean correlations of vitamins A, C, D and E intakes were similar, but the percentage of correlation values classified as poor or very good was higher after adjustment. These results show the importance of considering the quality of studies validating dietary assessment methods and the correlations obtained for the micronutrient of interest when interpreting effects observed in epidemiological studies using dietary assessment methods. Without a doubt, this subject constitutes a key topic for research in nutritional epidemiology. PMID:20100366

  5. Exploratory Study of Conductivity in Detonation Waves D. R. Wilson,

    E-print Network

    Texas at Arlington, University of

    from those early investigations are not directly pertinent to combustion applications at higher use of a facility used previously to study the conductivity of high-enthalpy, seeded air plasmas.7 of detonation were achieved. This detonated gas passed through a test section that enabled the average conduc

  6. Paraphasias in Multilingual Conduction Aphasia: A Single Case Study

    ERIC Educational Resources Information Center

    Hegde, Medha; Bhat, Sapna

    2007-01-01

    Conduction aphasia is a type of fluent aphasia, which is caused due to the damage to the supramarginal gyrus and arcuate fasciculus resulting in repetition disturbance. It has been speculated that linguistic system in bilingual aphasics can breakdown in different ways across languages. There is a lack of detailed linguistic studies in specific…

  7. Genome-wide association study of conduct disorder symptomatology

    Microsoft Academic Search

    D M Dick; F Aliev; R F Krueger; A Edwards; A Agrawal; M Lynskey; P Lin; M Schuckit; V Hesselbrock; J Nurnberger; L Almasy; B Porjesz; H J Edenberg; K Bucholz; J Kramer; S Kuperman; L Bierut

    2011-01-01

    Conduct disorder (CD) is one of the most prevalent childhood psychiatric conditions, and is associated with a number of serious concomitant and future problems. CD symptomatology is known to have a considerable genetic component, with heritability estimates in the range of 50%. Despite this, there is a relative paucity of studies aimed at identifying genes involved in the susceptibility to

  8. FIBULAR MOTOR NERVE CONDUCTION STUDIES AND ANKLE SENSORIMOTOR CAPACITIES*

    PubMed Central

    Richardson, James K.; Allet, Lara; Kim, Hogene; Ashton-Miller, James A.

    2012-01-01

    Introduction Nerve conduction studies provide information regarding the status of the peripheral nerve, but relationships with sensorimotor capacities that influence mobility have not been defined. Methods A secondary analysis was conducted of data from 41 older subjects (20 women, age 69.1 ± 8.3 years), 25 with diabetic neuropathy of varying severity, and 16 without diabetes or neuropathy. Measurements included routine fibular motor nerve conduction studies and laboratory-based determination of ankle inversion/eversion proprioceptive thresholds and ankle inversion/eversion motor function. Results Independent of age, fibular amplitude correlated robustly with ankle inversion/eversion proprioceptive thresholds (R2 = .591, p < .001), moderately with ankle inversion and eversion rates of torque generation (R2 = .216; p = .004 and R2 = .200; p = .006, respectively), and more strongly when fibular motor amplitude was normalized for body mass index (R2 = .350; p < .001 and R2 = .275; p = .001). Discussion Fibular motor amplitude was strongly associated with ankle sensorimotor capacities that influence lateral balance and recovery from perturbations during gait. The results suggest that nerve conduction study measures have potential for an expanded clinical role in evaluating mobility function in the population studied. PMID:23225524

  9. Studying the coefficient of thermal conductivity for liquid metals

    Microsoft Academic Search

    A. I. Veinik; G. V. Markov; é. B. Matulis

    1989-01-01

    We discuss a method for an experimental study of the coefficient of thermal conductivity, specific heat capacity, and the specific electrical resistance of metals in the solid and liquid states, as well as the data that we have obtained with respect to the indicated properties of Bi, In, Cd, and Pb.

  10. Ab-initio study of napthelene based conducting polymer

    SciTech Connect

    Ruhela, Ankur [Advanced Materials Research Group, Computational Nanoscience and Technology Lab (CNTL), ABV-Indian Institute of Information Technology and Management, Gwalior -474010, India and Amity Institute of Nanotechnology, Amity University, Noida-201303 (India); Kanchan, Reena, E-mail: reena.kanchan1977@gmail.com [Department of Chemistry, Jiwaji University, Gwalior-474001 (India); Srivastava, Anurag [Advanced Materials Research Group, Computational Nanoscience and Technology Lab (CNTL), ABV-Indian Institute of Information Technology and Management, Gwalior -474010 (India); Sinha, O. P. [Amity Institute of Nanotechnology, Amity University, Noida-201303 (India)

    2014-04-24

    In this paper, we have identified structural and electronic properties of conducting polymers by using DFT based ATK-VNL ab-initio tool. Naphthalene derivative structures were stabilized by varying the bond length between two atoms of the molecule C-N and C-C. We have also studied the molecular energy spectrum of naphthalene derivatives and found the HOMOLUMO for the same. A comparison of structural and electronic properties of naphthalene derivatives by attaching the functional group of amine, have been performed and found that they show good semi conducting properties.

  11. Assessment of Fatigue in Cancer Patients and Community Dwellers: Validation Study of the Filipino Version of the Brief Fatigue Inventory

    Microsoft Academic Search

    Tito R. Mendoza; Adriano V. Laudico; Xin Shelley Wang; Hong Guo; Maria Lourdes Matsuda; Victor D. Yosuico; Edilberto P. Fragante; Charles S. Cleeland

    2010-01-01

    Objective: Clinical trials that might identify effective therapies for cancer-related fatigue, one of the most distressing symptoms experienced by patients, require a validated fatigue assessment tool. We developed and validated a Filipino language version of the Brief Fatigue Inventory (BFI-F) for describing the prevalence and severity of fatigue among Filipino patients with cancer. Methods: We conducted a cross-sectional study in

  12. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    SciTech Connect

    Nagendra, K. [Government First Grade College, Bhatkal, Karawar District-581 320 (India); Babu, G. Satish; Gowda, Veeranna [Government College for Women, Chintamani-563125, Karnataka (India); Reddy, C. Narayana [Maharani Science College for Women, Bangalore-560 001 (India)

    2011-07-15

    Glasses in the system xLi{sub 2}SO{sub 4}-20Li{sub 2}O-(80-x) [80P{sub 2}O{sub 5}-20V{sub 2}O{sub 5}](5{>=}x{>=}20 mol%) has been prepared by melt quenching method. Dc and ac conductivity has been studied over a wide range of frequency (10 Hz to 10 MHz) and temperature (298 K-523 K). The dc conductivity found to increase with increase of Li{sub 2}SO{sub 4} concentration. The ac conductivities have been fitted to the Almond-West type single power law equation {sigma}({omega}) = {sigma}(0)+A{omega}{sup s} where 's' is the power law exponent. The ac conductivity found to increase with increase of Li{sub 2}SO{sub 4} concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

  13. An experimental study of degradation of anisotropic conductive adhesive joints

    Microsoft Academic Search

    Y. C. Lin; Xu Chen; Z. P. Wang

    2006-01-01

    The epoxy-based anisotropic conductive film (ACF) joints have the potential of being exposed to a hygrothermal environment and susceptible to moisture sorption. The long-term hygrothermal aging will induce the irreversible damages of epoxy resins system due to susceptibility of the polymer to hydrolysis, oxidation, etc. In this study, the hygrothermal environment test (85degC\\/85%RH) was used as an accelerator for the

  14. Cross-cultural adaptation, evaluation and validation of the Spouse Response Inventory: a study protocol

    PubMed Central

    Kaiser, Ulrike; Steinmetz, Dorit; Scharnagel, Rüdiger; Jensen, Mark P; Balck, Friedrich; Sabatowski, Rainer

    2014-01-01

    Introduction Since the response of spouses has been proven to be an important reinforcement of pain behaviour and disability it has been addressed in research and therapy. Fordyce suggested pain behaviour and well behaviour be considered in explaining suffering in chronic pain patients. Among existing instruments concerning spouse's responses the aspect of well behaviour has not been examined so far. The SRI (Spouse Response Inventory) tries to consider pain behaviour and well behaviour and appears to be acceptable because of its brevity and close proximity to daily language. The aim of the study is the translation into German, followed by evaluation and validation, of the SRI on a German sample of patients with chronic pain. Methods and analyses The study is comprehensively designed: initially, the focus will lie on the translation of the instrument following the guidelines for cross-cultural translation and adaptation and evaluation of the German version according to the source study. Subsequently, a validation referring to predictive, incremental and construct validation will be conducted using instruments based on similar or close but different constructs. Evaluation of the resulting SRI-G (SRI-German) will be conducted on a sample of at least 30 patients with chronic pain attending a comprehensive pain centre. For validation at least 120 patients with chronic headache, back pain, cancer related pain and somatoform pain disorder shall be included, for a total of 480 patients. Separate analyses according to specific pain diagnoses will be performed to ensure psychometric property, interpretability and control of diagnosis of specific limitations. Analyses will include comprehensive investigation of psychometric property of the scale by hierarchical regression analyses, correlation analyses, multivariate analysis of variance and exploratory factor analyses (SPSS). Ethics The study protocol was approved by the Ethics Committee of the University of Dresden (EK 335 122008) based on the Helsinki declaration. PMID:25763793

  15. Recruiting Hispanic Women for a Population-based Study: Validity of Surname Search and Characteristics of Nonparticipants

    Microsoft Academic Search

    Carol Sweeney; Sandra L. Edwards; Kathy B. Baumgartner; Jennifer S. Herrick; Leslie E. Palmer; Maureen A. Murtaugh; Antoinette Stroup; Martha L. Slattery

    Conducting research on the health of Hispanic populations in the United States entails challenges of identifying individuals who are Hispanic and obtaining good study participation. In this report, identification of Hispanics using a surname search and ethnicity information collected by cancer registries was validated, compared with self-report, for breast cancer cases and controls in Utah and New Mexico. Factors influencing

  16. ACCURACY OF DIETARY RECALL USING THE USDA 5-STEP MULTIPLE PASS METHOD IN MEN: AN OBSERVATIONAL VALIDATION STUDY.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This observational validation study was conducted under controlled conditions to test the accuracy of dietary recall in normal weight, overweight, and obese men using the USDA 5-Step Multiple-Pass Method for dietary recall. This was a Cross-sectional analysis of actual and recalled intake of food du...

  17. Steady-state hydraulic tomography in a laboratory aquifer with deterministic heterogeneity: Multi-method and multiscale validation of hydraulic conductivity tomograms

    Microsoft Academic Search

    Walter A. Illman; Xiaoyi Liu; Andrew Craig

    2007-01-01

    Hydraulic tomography potentially is a viable technology that facilitates subsurface imaging of hydraulic heterogeneity. To date, a comprehensive validation of hydraulic tomography has not been done either at the laboratory or field scales. The main objective of this paper is to examine the accuracy of hydraulic conductivity (K) tomograms obtained from the steady-state hydraulic tomography algorithm of [Yeh, T.-C. J.,

  18. Measuring Small-Group Environments: A Validity Study of Scores from the Salter Environmental Type Assessment and the Group Environment Scale

    ERIC Educational Resources Information Center

    Salter, Daniel W.; Junco, Reynol

    2007-01-01

    This concurrent validity study of Salter Environmental Type Assessment scores was conducted with the Group Environment Scale. A principal components factor analysis with varimax rotation of 191 college students' responses suggested two factors that accounted for 51% of the variance. The factor-analytic results and concurrent validity coefficients…

  19. Obtaining Valid Laboratory Data in Clinical Trials Conducted in Resource Diverse Settings: Lessons Learned from a Microbicide Phase III Clinical Trial

    PubMed Central

    Crucitti, Tania; Fransen, Katrien; Maharaj, Rashika; Tenywa, Tom; Massinga Loembé, Marguerite; Murugavel, Kailapuri Gangatharan; Mendonca, Kevin; Abdellati, Said; Beelaert, Greet; Van Damme, Lut

    2010-01-01

    Background Over the last decade several phase III microbicides trials have been conducted in developing countries. However, laboratories in resource constrained settings do not always have the experience, infrastructure, and the capacity to deliver laboratory data meeting the high standards of clinical trials. This paper describes the design and outcomes of a laboratory quality assurance program which was implemented during a phase III clinical trial evaluating the efficacy of the candidate microbicide Cellulose Sulfate 6% (CS) [1]. Methodology In order to assess the effectiveness of CS for HIV and STI prevention, a phase III clinical trial was conducted in 5 sites: 3 in Africa and 2 in India. The trial sponsor identified an International Central Reference Laboratory (ICRL), responsible for the design and management of a quality assurance program, which would guarantee the reliability of laboratory data. The ICRL provided advice on the tests, assessed local laboratories, organized trainings, conducted supervision visits, performed re-tests, and prepared control panels. Local laboratories were provided with control panels for HIV rapid tests and Chlamydia trachomatis/Neisseria gonorrhoeae (CT/NG) amplification technique. Aliquots from respective control panels were tested by local laboratories and were compared with results obtained at the ICRL. Results Overall, good results were observed. However, discordances between the ICRL and site laboratories were identified for HIV and CT/NG results. One particular site experienced difficulties with HIV rapid testing shortly after study initiation. At all sites, DNA contamination was identified as a cause of invalid CT/NG results. Both problems were timely detected and solved. Through immediate feedback, guidance and repeated training of laboratory staff, additional inaccuracies were prevented. Conclusions Quality control guidelines when applied in field laboratories ensured the reliability and validity of final study data. It is essential that sponsors provide adequate resources for implementation of such comprehensive technical assessment and monitoring systems. Trial Registration ClinicalTrials.gov NCT00153777 and Current Controlled Trials ISRCTN95638385 PMID:21048963

  20. ICESat Calibration-Validation and Mass Balance Studies in Antarctica

    NASA Astrophysics Data System (ADS)

    Csatho, B.; Schenk, T.; Huh, K.; van der Veen, C.; Lee, I.; Spikes, V. B.; Krabill, W.

    2003-12-01

    To map mass balance changes of major drainage basins over a relatively short period, ICESat is designed to measure surface elevation changes with an accuracy of 1.5 cm/year for spatial averages of measurements over areas of 100 km2. To achieve this accuracy different post-launch calibration-validation (CV) approaches are used to identify and to remove the non-geophysical artifacts from the data products. As part of the CV effort detailed surface topography was mapped by NASA's Airborne Topographic Mapper (ATM) scanning laser over sites in Greenland, western US and the Dry Valleys in Antarctica. Ice sheet surface elevations mapped by airborne laser altimetry surveys also serve as baselines for the ICESat mission. Here we present results from two different projects in the Antarctica. Detailed surface topography, derived from ATM data, is used to verify the ICESat products over the Dry Valleys. Surface elevations, mapped by the University of Texas airborne system (former Support Office of Airborne Geophysics), serves as baselines to map changes over the West Antarctic Ice Sheet ice streams. ATM surveys were conducted over the Dry Valleys in December 2001 in collaboration with NSF and USGS. In addition to survey candidate calibration/validation sites for the ICESat mission, the campaign was going to support NSF projects and to provide data to evaluate the potential of the use of laser altimetry in the Antarctica. The survey resulted blanket coverage over several sites. We have developed a procedure using robust estimation techniques to remove the outlier observations and to interpolate the data into regular grids (DEMs). The ICESat elevation and waveform products were verified by comparing them with the DEMs and with simulated waveforms. Surface reflectivity, necessary for the waveform simulation, was derived from satellite imagery. The stable terrain of the site makes it ideal for serving as benchmark surface throughout the ICESat mission. Precise repeat laser altimetry surveys were conducted with the SOAR system in 1997/98 and 1999/2000 over portions of the Whillans ice stream and ice streams C and E, West Antarctica. It is well known that these ice streams are undergoing substantial changes in length, width, thickness and speed at decadal and shorter changes. We determined elevation changes during the last 5 years by comparing elevations measured by ICESat over the 8-day repeat orbits with the results of the SOAR surveys. We plan to use the 91-day repeat ICESat data to investigate the details of the surface change pattern.

  1. Conducting Simulation Studies in the R Programming Environment

    PubMed Central

    Hallgren, Kevin A.

    2014-01-01

    Simulation studies allow researchers to answer specific questions about data analysis, statistical power, and best-practices for obtaining accurate results in empirical research. Despite the benefits that simulation research can provide, many researchers are unfamiliar with available tools for conducting their own simulation studies. The use of simulation studies need not be restricted to researchers with advanced skills in statistics and computer programming, and such methods can be implemented by researchers with a variety of abilities and interests. The present paper provides an introduction to methods used for running simulation studies using the R statistical programming environment and is written for individuals with minimal experience running simulation studies or using R. The paper describes the rationale and benefits of using simulations and introduces R functions relevant for many simulation studies. Three examples illustrate different applications for simulation studies, including (a) the use of simulations to answer a novel question about statistical analysis, (b) the use of simulations to estimate statistical power, and (c) the use of simulations to obtain confidence intervals of parameter estimates through bootstrapping. Results and fully annotated syntax from these examples are provided. PMID:25067989

  2. Use of wearable technology for performance assessment: A validation study.

    PubMed

    Papi, Enrica; Osei-Kuffour, Denise; Chen, Yen-Ming A; McGregor, Alison H

    2015-07-01

    The prevalence of osteoarthritis is increasing globally but current compliance with rehabilitation remains poor. This study explores whether wearable sensors can be used to provide objective measures of performance with a view to using them as motivators to aid compliance to osteoarthritis rehabilitation. More specifically, the use of a novel attachable wearable sensor integrated into clothing and inertial measurement units located in two different positions, at the waist and thigh pocket, was investigated. Fourteen healthy volunteers were asked to complete exercises adapted from a knee osteoarthritis rehabilitation programme whilst wearing the three sensors including five times sit-to-stand test, treadmill walking at slow, preferred and fast speeds. The performances of the three sensors were validated against a motion capture system and an instrumented treadmill. The systems showed a high correlation (r(2) > 0.7) and agreement (mean difference range: -0.02-0.03 m, 0.005-0.68 s) with gold standards. The novel attachable wearable sensor was able to monitor exercise tasks as well as the inertial measurement units (ICC > 0.95). Results also suggested that a functional placement (e.g., situated in a pocket) is a valid position for performance monitoring. This study shows the potential use of wearable technologies for assessing subject performance during exercise and suggests functional solutions to enhance acceptance. PMID:25937613

  3. The family of origin scale: A construct validation study

    Microsoft Academic Search

    Bruce A. Ryan; George F. Kawash; Marshall Fine; Blaine Powel

    1994-01-01

    Data from 69 women and 63 men along with ratings from a panel of expert judges were used to assess the construct validity of the Family Of Origin Scale as a measure of family health. Loevinger's conception of construct validity, focusing on the substantive, structural, and external components of validity, was employed to organize the research procedures followed and the

  4. Development, validation and stability study of pediatric atenolol syrup.

    PubMed

    Foppa, T; Murakami, F S; Silva, M A S

    2007-07-01

    Atenolol [4-(2-hydroxy-isopropylaminopropoxy)-phenylacetamide], is a cardioselective beta1-adrenergic receptor blocking agent prescribed for treatment of hypertension, angina pectoris and cardiac arrhythmias. However, most of these medicines are not formulated for easy or accurate administration to children. Atenolol is unstable in solutions and therefore the development of a liquid dosage form is a significant challenge. Studies showed that the degradation rate of atenolol is dependent on the temperature, indicating higher stability at 4 degrees C. Atenolol syrup is stable for 9 days, with acceptable apearance. A second order model adequately described atenolol decomposition when stored as syrup. A stability-indicating method was developed and validated in order to evaluate these studies. PMID:17718193

  5. The diagnostic value of clinical examination after falanga--a pilot validation study.

    PubMed

    Amris, Kirstine; Rasmussen, Ole Vedel; Baykal, Turkcan; Lök, Veli

    2009-01-01

    Medico-legal documentation of alleged exposure to falanga torture warrants a high diagnostic accuracy of the applied clinical tests. The objective of this study was to establish data on the validity of palpatory examination of the footpads and the plantar fascia and to assess the distribution of observations among selected cases and non-cases in a small study sample. Calculated estimates of sensitivity and specificity of the individual diagnostic tests are reported and, in general, did not meet the authority-based criteria of an 80% cut-off point. The observed total number of true tests in this study was 65 %. It is concluded that future studies of the reliability of clinical examination and assessment of the variability of observations among unselected cases and non-cases should be conducted in a larger cross-sectional study population. PMID:19491481

  6. Skin conductance fear conditioning impairments and aggression: a longitudinal study.

    PubMed

    Gao, Yu; Tuvblad, Catherine; Schell, Anne; Baker, Laura; Raine, Adrian

    2015-02-01

    Autonomic fear conditioning deficits have been linked to child aggression and adult criminal behavior. However, it is unknown if fear conditioning deficits are specific to certain subtypes of aggression, and longitudinal research is rare. In the current study, reactive and proactive aggression were assessed in a sample of males and females when aged 10, 12, 15, and 18 years old. Skin conductance fear conditioning data were collected when they were 18 years old. Individuals who were persistently high on proactive aggression measures had significantly poorer conditioned responses at 18 years old when compared to others. This association was not found for reactive aggression. Consistent with prior literature, findings suggest that persistent antisocial individuals have unique neurobiological characteristics and that poor autonomic fear conditioning is associated with the presence of increased instrumental aggressive behavior. PMID:25174802

  7. A validation study of a stochastic model of human interaction

    NASA Astrophysics Data System (ADS)

    Burchfield, Mitchel Talmadge

    The purpose of this dissertation is to validate a stochastic model of human interactions which is part of a developmentalism paradigm. Incorporating elements of ancient and contemporary philosophy and science, developmentalism defines human development as a progression of increasing competence and utilizes compatible theories of developmental psychology, cognitive psychology, educational psychology, social psychology, curriculum development, neurology, psychophysics, and physics. To validate a stochastic model of human interactions, the study addressed four research questions: (a) Does attitude vary over time? (b) What are the distributional assumptions underlying attitudes? (c) Does the stochastic model, {-}N{intlimitssbsp{-infty}{infty}}varphi(chi,tau)\\ Psi(tau)dtau, have utility for the study of attitudinal distributions and dynamics? (d) Are the Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein theories applicable to human groups? Approximately 25,000 attitude observations were made using the Semantic Differential Scale. Positions of individuals varied over time and the logistic model predicted observed distributions with correlations between 0.98 and 1.0, with estimated standard errors significantly less than the magnitudes of the parameters. The results bring into question the applicability of Fisherian research designs (Fisher, 1922, 1928, 1938) for behavioral research based on the apparent failure of two fundamental assumptions-the noninteractive nature of the objects being studied and normal distribution of attributes. The findings indicate that individual belief structures are representable in terms of a psychological space which has the same or similar properties as physical space. The psychological space not only has dimension, but individuals interact by force equations similar to those described in theoretical physics models. Nonlinear regression techniques were used to estimate Fermi-Dirac parameters from the data. The model explained a high degree of the variance in each probability distribution. The correlation between predicted and observed probabilities ranged from a low of 0.955 to a high value of 0.998, indicating that humans behave in psychological space as Fermions behave in momentum space.

  8. An international validation study of two achievement goal measures in a pharmacy education context

    PubMed Central

    Alrakaf, Saleh; Abdelmageed, Ahmed; Kiersma, Mary; Coulman, Sion A; John, Dai N; Tordoff, June; Anderson, Claire; Noreddin, Ayman; Sainsbury, Erica; Rose, Grenville; Smith, Lorraine

    2014-01-01

    Background Achievement goal theory helps us understand what motivates students to participate in educational activities. However, measuring achievement goals in a precise manner is problematic. Elliot and McGregor’s Achievement Goal Questionnaire (AGQ) and Elliot and Murayama’s revised Achievement Goal Questionnaire (AGQ-R) are widely used to assess students’ achievement goals. Both instruments were developed and validated using undergraduate psychology students in the USA. Methods In this study, our aims were to first of all, assess the construct validity of both questionnaires using a cohort of Australian pharmacy students and, subsequently, to test the generalizability and replicability of these tools more widely in schools of pharmacy in other English-speaking countries. The AGQ and the AGQ-R were administered during tutorial class time. Confirmatory factor analysis procedures, using AMOS 19 software, were performed to determine model fit. Results In contrast to the scale developers’ findings, confirmatory factor analysis supported a superior model fit for the AGQ compared with the AGQ-R, in all countries under study. Conclusion Validating measures of achievement goal motivation for use in pharmacy education is necessary and has implications for future research. Based on these results, the AGQ will be used to conduct future cross-sectional and longitudinal analyses of the achievement goals of undergraduate pharmacy students from these countries. PMID:25298743

  9. Cyber victim and bullying scale: A study of validity and reliability

    Microsoft Academic Search

    Bayram Çetin; Erkan Yaman; Adem Peker

    2011-01-01

    The purpose of this study is to develop a reliable and valid scale, which determines cyber victimization and bullying behaviors of high school students. Research group consisted of 404 students (250 male, 154 male) in Sakarya, in 2009–2010 academic years. In the study sample, mean age is 16.68. Content validity and face validity of the scale was provided via field

  10. The motivations-attributes-skills-knowledge competency cluster validation model an empirical study 

    E-print Network

    Stevens, Jeffery Allen

    2004-09-30

    -Attributes-Skills-Knowledge Inverted Funnel Validation (MIFV) competency cluster model. The second purpose of this empirical research study was to introduce a new competency cluster validation model (MIFV). This model, if properly developed, should serve as a strong workforce...

  11. A Construct Validation Study of Test Anxiety: A Discriminant Validation of Fear of Failure, Worry, and Emotionality.

    ERIC Educational Resources Information Center

    Hagtvet, Knut A.

    The study tested a hypothesized three-dimensional structure of test anxiety involving the constructs of fear of failure, emotionality, and worry. The discriminant validity of these three constructs was studied. Uninformed students were told about a mathematics test in a lesson just prior to administration. They were compared to informed students…

  12. [Studies of peripheral nerve conduction velocities in vibrating tool operators].

    PubMed

    Hisanaga, H

    1982-05-01

    Vibrating tools such as chain-saws, rock-drills, grinders and tie-tampers have been widely used in many kinds of industries in Japan, causing vibration syndrome among the operators. As is well-known, the syndrome includes disorders of the peripheral circulation in the hands, e.g. Raynaud's phenomenon, and of the peripheral and central nervous systems. As the result of preventive countermeasures to the syndrome during the last decade, the picture of the syndrome has been partly changing especially for the patients among the state forestry workers; for example, the prevalence of the peripheral nerve disorders has been relatively increasing compared with that of Raynaud's phenomenon. Peripheral nerve disorders such as numbness, paresthesia and hypesthesia in the upper limbs tend to be usually cumulative and irreversible. The disorders are very important problem of vibration syndrome from the standpoint of treatment and prevention, though there are only a few reports of the study on the disorders using electrophysiological methods. In order to make objectively clear the peripheral nerve disorders, 236 male vibrating tool operators (= Group V) were examined. The following nerve conduction velocities were measured: (1) Maximal motor nerve conduction velocities (MCV) of the median and ulnar nerves in the forearm. (2) Sensory nerve conduction velocities (SCV) of the median and ulnar nerves in the forearm and palm. (3) Residual latency (RL) of the median and ulnar nerves. Besides, working conditions and complaints relevant to vibration syndrome were examined by using questionnaires. MCVs, SCVs and RLs that were outside of mean +/- 2 S.D. of the control group (= Group C), consisting of 30 healthy men, were evaluated as abnormal. The obtained results led to the following conclusions: (1) All MCVs, SCVs and RLs of Group V were significantly less than those of the control group. In Group V, prevalence of the abnormality in each of forearm SCVs was higher than that in each of MCVs of the corresponding nerves. (2) The difference between the median and ulnar SCV in the palm and the respective SCV in the forearm of each subject was significantly greater for Group V than Group C. (Palm-forearm difference) (3) The difference between the forearm and palmar SCV of the ulnar nerve and the respective velocities of the median nerve was statistically greater for Group V than for Group C. (Ulnar-median difference) (4) Ulnar SCV in the palm of Group V was significantly related to the total operating hours of vibrating tools. (5) There was no significant relation between all the nerve conduction velocities and the white finger attack. But a significant relation was noticed between the prevalence of the abnormal values of ulnar SCV in the palm and the peripheral circulatory function score computed from the data of nail press test and cold immersion test. PMID:6292556

  13. A validation study of elementary science ISTEP+ scores

    NASA Astrophysics Data System (ADS)

    Simonelli, Glenn

    The Indiana Statewide Testing for Educational Progress-Plus (ISTEP+) was designed to assess student mastery of key educational goals. The 5th grade ISTEP+ Science Test (5-GIST) is part of the ISTEP+ testing regime. The Indiana Academic Standards were developed to guide instruction in the state, and questions on the ISTEP+ were aligned with these standards. Since its inception, the use of the ISTEP+ exam has been changed to comply with the dictates of both Indiana Public Law 221 and the national No Child Left Behind act. With these modifications, the purpose of the tests has shifted from assessment of individual student academic progress to evaluation of the quality of the educational institution administering the tests. The validity of this use has never been established. The purpose of this study is to assess the validity of the 5-GIST as an instrument for assessing and forming judgments about the quality of science instruction in a particular school. ISTEP+ scores of 2 cohorts of students in a Midwestern school district were converted into Z-scores and tracked from 3rd to 5th grade. A regression line was established to account for the general aptitude and the socio-economic status (SES) of the students. Examining the residuals of the 5-GIST scores revealed that between 57% and 60% of the variance in the scores can be attributed to the general aptitude and SES of the students, leaving between 40% and 43% that can be interpreted as reflecting the effect of the school on student learning.

  14. Psychometric instrumentation: reliability and validity of instruments used for clinical practice, evidence-based practice projects and research studies.

    PubMed

    Mayo, Ann M

    2015-01-01

    It is important for CNSs and other APNs to consider the reliability and validity of instruments chosen for clinical practice, evidence-based practice projects, or research studies. Psychometric testing uses specific research methods to evaluate the amount of error associated with any particular instrument. Reliability estimates explain more about how well the instrument is designed, whereas validity estimates explain more about scores that are produced by the instrument. An instrument may be architecturally sound overall (reliable), but the same instrument may not be valid. For example, if a specific group does not understand certain well-constructed items, then the instrument does not produce valid scores when used with that group. Many instrument developers may conduct reliability testing only once, yet continue validity testing in different populations over many years. All CNSs should be advocating for the use of reliable instruments that produce valid results. Clinical nurse specialists may find themselves in situations where reliability and validity estimates for some instruments that are being utilized are unknown. In such cases, CNSs should engage key stakeholders to sponsor nursing researchers to pursue this most important work. PMID:25856028

  15. Portuguese validation of the Internet Addiction Test: An empirical study

    PubMed Central

    PONTES, HALLEY M.; PATRÃO, IVONE M.; GRIFFITHS, MARK D.

    2014-01-01

    Background and aims: Research into Internet addiction (IA) has increased greatly over the last decade. Despite its various definitions and general lack of consensus regarding its conceptualisation amongst researchers, instruments for measuring this phenomenon have proliferated in a number of countries. There has been little research on IA in Portugal and this may be partly due to the absence of standardised measurement tools for assessing IA. Methods: This study attempted to address this issue by adapting a Portuguese version of the Internet Addiction Test (IAT) via a translation-back translation process and Confirmatory Factor Analysis in a sample of 593 Portuguese students that completed a Portuguese version of the IAT along with questions related to socio-demographic variables. Results: The findings suggested that the IAT appears to be a valid and reliable instrument for measuring IA among Portuguese young adults as demonstrated by its satisfactory psychometric properties. However, the present findings also suggest the need to reword and update some of the IAT’s items. Prevalence of IA found in the sample was 1.2% and is discussed alongside findings relating to socio-demographic correlates. Limitations and implications of the present study are also discussed. Conclusions: The present study calls for a reflection of the IAT while also contributing to a better understanding of the basic aspects of IA in the Portuguese community since many health practitioners are starting to realise that Internet use may pose a risk for some individuals. PMID:25215221

  16. Failure mechanism study of anisotropic conductive film (ACF) packages

    Microsoft Academic Search

    Lei L. Mercado; Jerry White; Vijay Sarihan; Tien-Yu Tom Lee

    2003-01-01

    Anisotropic conductive film (ACF) consists of an adhesive polymer matrix with dispersed conductive particles. In flip-chip technology, ACF has been used in place of solder and underfill for chip attachment to glass or organic substrates. The filler particles establish the electrical contacts between the interconnecting areas. ACF flip-chip bonding provides finer pitch, higher package density, reduced package size and improved

  17. Validity Shrinkage in Ridge Regression: A Simulation Study.

    ERIC Educational Resources Information Center

    Faden, Vivian; Bobko, Philip

    1982-01-01

    Ridge regression offers advantages over ordinary least squares estimation when a validity shrinkage criterion is considered. Comparisons of cross-validated multiple correlations indicate that ridge estimation is superior when the predictors are multicollinear, the number of predictors is large relative to sample size, and the population multiple…

  18. Verification and Validation Studies for the LAVA CFD Solver

    NASA Technical Reports Server (NTRS)

    Moini-Yekta, Shayan; Barad, Michael F; Sozer, Emre; Brehm, Christoph; Housman, Jeffrey A.; Kiris, Cetin C.

    2013-01-01

    The verification and validation of the Launch Ascent and Vehicle Aerodynamics (LAVA) computational fluid dynamics (CFD) solver is presented. A modern strategy for verification and validation is described incorporating verification tests, validation benchmarks, continuous integration and version control methods for automated testing in a collaborative development environment. The purpose of the approach is to integrate the verification and validation process into the development of the solver and improve productivity. This paper uses the Method of Manufactured Solutions (MMS) for the verification of 2D Euler equations, 3D Navier-Stokes equations as well as turbulence models. A method for systematic refinement of unstructured grids is also presented. Verification using inviscid vortex propagation and flow over a flat plate is highlighted. Simulation results using laminar and turbulent flow past a NACA 0012 airfoil and ONERA M6 wing are validated against experimental and numerical data.

  19. Turkish validity and reliability study of the Weiss Functional Impairment Rating Scale-Parent Report.

    PubMed

    Tarakç?o?lu, Mahmut C; Çak?n Memik, Nursu; Olgun, Nesligül N; Aydemir, Ömer; Weiss, Margaret D

    2015-06-01

    Attention deficit hyperactivity disorder (ADHD) is seen frequently in childhood and leads to marked impairment in functioning. There is no scale in Turkey with documented validity and reliability that assesses ADHD-specific functional impairment (FI). This study aimed at adapting the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P), which assesses ADHD-related FI, for use in Turkey, and examining psychometric aspects of the scale. The study included 250 children diagnosed with ADHD and 250 healthy children and their parents. Internal consistency and test-retest methods were used to test the reliability of the scale. Validity was tested with exploratory and confirmatory factor analyses and convergent and discriminant validity analyses. Since all six questions of the WFIRS-P were scored 0, analyses were conducted for the original scale questionnaire consisting of 50 items and the questionnaire consisting of 44 items where the six questions scored 0 were not included. The Cronbach's alpha coefficient was 0.93 for the whole scale. The Spearman's correlation coefficient was 0.93 for test-retest reliability. The exploratory factor analysis run on the 44-item questionnaire showed that the scale items were best represented in a 7-factor structure, but some items were placed in different subdomains than those of the original scale. In the confirmatory factor analysis, the root mean square error of approximation was 0.061, and the comparative fit index was 0.95 for the whole model. Therefore, the Turkish WFIRS-P is valid and reliable in testing functional impairment in children with ADHD. PMID:25428590

  20. Perovskite transparent conducting oxides: an ab initio study

    NASA Astrophysics Data System (ADS)

    Dabaghmanesh, S.; Saniz, R.; Amini, M. N.; Lamoen, D.; Partoens, B.

    2013-10-01

    We present an ab initio study of the electronic structure and of the formation energies of various point defects in BaSnO3 and SrGeO3. We show that La and Y impurities substituting Ba or Sr are shallow donors with a preferred 1 + charge state. These defects have a low formation energy within all the suitable equilibrium growth conditions considered. Oxygen vacancies behave as shallow donors as well, preferring the 2 + charge state. Their formation energies, however, are higher in most growth conditions, indicating a limited contribution to conductivity. The calculated electron effective mass in BaSnO3, with a value of 0.21 me, and the very high mobility reported recently in La-doped BaSnO3 single-crystals, suggest that remarkably low scattering rates can be achieved in the latter. In the case of SrGeO3, our results point to carrier density and mobility values in the low range for typical polycrystalline TCOs, in line with experiment.

  1. Perovskite transparent conducting oxides: an ab initio study.

    PubMed

    Dabaghmanesh, S; Saniz, R; Amini, M N; Lamoen, D; Partoens, B

    2013-10-16

    We present an ab initio study of the electronic structure and of the formation energies of various point defects in BaSnO3 and SrGeO3. We show that La and Y impurities substituting Ba or Sr are shallow donors with a preferred 1 + charge state. These defects have a low formation energy within all the suitable equilibrium growth conditions considered. Oxygen vacancies behave as shallow donors as well, preferring the 2 + charge state. Their formation energies, however, are higher in most growth conditions, indicating a limited contribution to conductivity. The calculated electron effective mass in BaSnO3, with a value of 0.21 m(e), and the very high mobility reported recently in La-doped BaSnO3 single-crystals, suggest that remarkably low scattering rates can be achieved in the latter. In the case of SrGeO3, our results point to carrier density and mobility values in the low range for typical polycrystalline TCOs, in line with experiment. PMID:24060940

  2. Studying conduction-electron/interface interactions using transverse electron focusing

    NASA Astrophysics Data System (ADS)

    Tsoi, V. S.; Bass, J.; Wyder, P.

    1999-10-01

    Understanding the microscopic processes by which the electrons within conductors are scattered at surfaces and interfaces is important for both fundamental physics and technology. The authors review what has been learned so far about scattering of electrons at a variety of surfaces and interfaces using a technique, transverse electron focusing (TEF), that involves two point contacts in a uniform magnetic field. Transverse electron focusing is a sort of ?-ray spectrometer in a metal, except that, whereas the ?-ray spectrometer requires a narrow beam because the energy and momentum of a free electron can be arbitrary, in TEF the electrons of interest all have the Fermi energy and momentum, so focusing occurs even for electrons injected isotropically in angle. Transverse electron focusing is unique in its ability to probe localized and selectable portions of the interface from inside the conductor, using conduction electrons on only small parts of the Fermi surface. The authors first briefly review the essential features of TEF and of ideal and rough surfaces and describe the three techniques now used for injecting and detecting electrons: needle contacts, lithographically fabricated contacts, and light-induced injection. They then turn to measurements in metals and semimetals of the probability of specular reflection q from a given interface for electrons at the Fermi energy impinging at perpendicular incidence. They examine how q varies over different crystal faces for different electron orbits on the Fermi surfaces of a variety of conductors and how it is affected by changes in the de Broglie wavelength ?dB, by chemical etching, ion etching, or physical damage, by a molecular overlayer condensed from the surrounding atmosphere, and, for semimetals, by surface band bending (surface charge). The authors also explain how to measure the dependence of q upon the angle of incidence q(?), which gives information about surface structure. Transverse electron focusing studies of a variety of quasiparticle effects arising because the electrons are in a solid are described. These include (a) scattering of excitations moving on ``holelike'' orbits-q can depend upon the sign of the particle charge; (b) scattering involving a surface reciprocal-lattice vector G?, including surface resonances induced by an artificial grating etched onto a Bi surface; and (c) scattering between different parts of the Fermi surface-intervalley scattering (IVS)-including scattering in which the sign of the quasiparticle charge changes. The authors review studies of scattering of electrons from a normal-metal (or semimetal)/superconductor interface, which involves an unusual phenomenon called Andreev reflection, in which the signs of both the charge and mass change. Also described are TEF studies of scattering of light-excited electrons from an intercrystalline boundary and recent TEF measurements of q for scattering from the boundary of the two-dimensional electron gas. The authors conclude with a list of future TEF studies of conduction-electron/interface interactions that they believe to be interesting and important.

  3. Moral judgment reloaded: a moral dilemma validation study

    PubMed Central

    Christensen, Julia F.; Flexas, Albert; Calabrese, Margareta; Gut, Nadine K.; Gomila, Antoni

    2014-01-01

    We propose a revised set of moral dilemmas for studies on moral judgment. We selected a total of 46 moral dilemmas available in the literature and fine-tuned them in terms of four conceptual factors (Personal Force, Benefit Recipient, Evitability, and Intention) and methodological aspects of the dilemma formulation (word count, expression style, question formats) that have been shown to influence moral judgment. Second, we obtained normative codings of arousal and valence for each dilemma showing that emotional arousal in response to moral dilemmas depends crucially on the factors Personal Force, Benefit Recipient, and Intentionality. Third, we validated the dilemma set confirming that people's moral judgment is sensitive to all four conceptual factors, and to their interactions. Results are discussed in the context of this field of research, outlining also the relevance of our RT effects for the Dual Process account of moral judgment. Finally, we suggest tentative theoretical avenues for future testing, particularly stressing the importance of the factor Intentionality in moral judgment. Additionally, due to the importance of cross-cultural studies in the quest for universals in human moral cognition, we provide the new set dilemmas in six languages (English, French, German, Spanish, Catalan, and Danish). The norming values provided here refer to the Spanish dilemma set. PMID:25071621

  4. Expectations of Students in Biomedical Graduate Studies I. Student Conduct

    E-print Network

    Plotkin, Joshua B.

    of the Office of Student Conduct. These include, but are not limited to, policies on sexual harassment, acquaintance rape and sexual violence, appropriate use of electronic resources, open expression, and drug

  5. A benchmark study on the thermal conductivity of nanofluids

    E-print Network

    Buongiorno, Jacopo

    This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was ...

  6. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs...Chemical Analysis Procedures for Non-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison...

  7. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs...Chemical Analysis Procedures for Non-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison...

  8. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs...Chemical Analysis Procedures for Non-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison...

  9. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs...Chemical Analysis Procedures for Non-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison...

  10. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs...Chemical Analysis Procedures for Non-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison...

  11. Study on the Validity and Reliability of Melbourne Decision Making Scale in Turkey

    ERIC Educational Resources Information Center

    Çolakkadioglu, Oguzhan; Deniz, M. Engin

    2015-01-01

    This study is to analyze the validity and reliability of Melbourne Decision Making Questionnaire (MDMQ). The sample consisted of 650 university students. The structural validity of the MDMQ, as well as correlations among its sub-scales, measure-bound validity, internal consistency, item total correlations and test-retest reliability coefficients…

  12. [Educational game of medication administration: a validation study].

    PubMed

    Moreira, Amanda Portugal de Andrade; Sabóia, Vera Maria; Camacho, Alessandra Conceição Leite Funchal; Daher, Donizete Vago; Teixeira, Elizabeth

    2014-07-01

    This is a methodological research, which aimed to determine the validity of an educational technology (ET) in the form of educational game of medicine administration, according to the judges and audience, using the theoretical stage of Pasquali model. Data were collected between September 2011 and May 2012 in two stages: 1) application and validation of TE by forty students of the 4th period of Nursing, at the Fluminense Federal University (target audience); 2) observation and validation of TE by 8 teachers (judges). The questionnaires were organized in Likert scale, with items distributed in blocks and analyzed quantitatively. The game was validated, since it has over 80% approval by the two groups, and may therefore be used as a TE in the discipline of Fundamentals of Nursing. The results were positive, demonstrating that students and teachers are more interested in content taught when most dynamic technologies are used in the classroom. PMID:25271575

  13. Measurement of Pancreatic Volume by Abdominal MRI: A Validation Study

    PubMed Central

    Szczepaniak, Edward W.; Malliaras, Konstantinos; Nelson, Michael D.; Szczepaniak, Lidia S.

    2013-01-01

    Objective To develop abdominal magnetic resonance imaging (MRI) protocol to measure pancreatic volume in humans and to validate it in large animals. Materials and Methods We performed abdominal MRI in eight mini-pigs using a clinical 3T MRI system. We used consecutive parallel abdominal slices, covering the entire pancreas to calculate pancreatic volume. Following MRI, animals were sacrificed, the pancreas was removed, and the volume of the pancreas was measured by water displacement. We used the same MRI protocol to measure pancreatic volume in 21 humans. To assess reproducibility of in vivo measurement we repeated MRI pancreas volume evaluation within 24 hours in additional five humans. Results In mini-pigs the measurements of pancreatic volume by MRI and by water displacement were almost identical (R2?=?0.9867; p<0.0001). In humans the average pancreas volume was 72.7+/?4.5 ml, range from 35.0 to 105.5 ml. This result is in strong agreement with results of previous large postmortem and computed tomography (CT) studies. Repeated measurements of pancreatic volume in humans were highly reproducible. Pancreatic volume measured in vivo was negatively correlated with age, body fat mass, pancreatic TG levels, and visceral fat mass. Conclusions These initial results are highly encouraging and our protocol for pancreatic volume estimation in vivo may prove useful in obesity research to follow in vivo changes of pancreatic volume and structure during time course of obesity and type 2 diabetes development. PMID:23418491

  14. The Psychiatric Care Satisfaction Questionnaire: a reliability and validity study

    Microsoft Academic Search

    D. A. Barker; M. W. Orrell

    1999-01-01

    Patient satisfaction can be a useful marker in evaluating the quality of psychiatric care. However, this form of measurement\\u000a has been hampered by the lack of attention paid to the psychometric properties of instruments devised. The Psychiatric Care\\u000a Satisfaction Questionnaire (PCSQ) was developed and tests of acceptability, validity and reliability were undertaken using\\u000a 52 inpatients. Content validity was assessed by

  15. Rediscovery rate estimation for assessing the validation of significant findings in high-throughput studies.

    PubMed

    Ganna, Andrea; Lee, Donghwan; Ingelsson, Erik; Pawitan, Yudi

    2015-08-01

    It is common and advised practice in biomedical research to validate experimental or observational findings in a population different from the one where the findings were initially assessed. This practice increases the generalizability of the results and decreases the likelihood of reporting false-positive findings. Validation becomes critical when dealing with high-throughput experiments, where the large number of tests increases the chance to observe false-positive results. In this article, we review common approaches to determine statistical thresholds for validation and describe the factors influencing the proportion of significant findings from a 'training' sample that are replicated in a 'validation' sample. We refer to this proportion as rediscovery rate (RDR). In high-throughput studies, the RDR is a function of false-positive rate and power in both the training and validation samples. We illustrate the application of the RDR using simulated data and real data examples from metabolomics experiments. We further describe an online tool to calculate the RDR using t-statistics. We foresee two main applications. First, if the validation study has not yet been collected, the RDR can be used to decide the optimal combination between the proportion of findings taken to validation and the size of the validation study. Secondly, if a validation study has already been done, the RDR estimated using the training data can be compared with the observed RDR from the validation data; hence, the success of the validation study can be assessed. PMID:25256289

  16. Electrokinetic experimental study on saturated rock samples: zeta potential and surface conductance

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Hu, Hengshan; Guan, Wei; Li, Hui

    2015-05-01

    It is important to know the electrokinetic properties of crustal rocks for interpreting the conductivity mechanisms and seismoelectric phenomena during earthquakes and seismoelectric well logging. In this study, electrokinetic experiments are conducted using a special core-holder by employing an AC lock-in technique. A series of experiments are conducted on 10 sandstone samples to measure the streaming potentials and streaming currents, and the experiments on each sample are done at six different salinities. The streaming potential coefficient and streaming current coefficient are calculated from the measured streaming potentials and streaming currents. The experimental results show that streaming potential coefficient and streaming current coefficient decrease as the salinity increases. The dependence of these two coefficients on permeability and pore radius are analysed and compared with previous works. At low salinities, the streaming potential coefficient and streaming current coefficient increase with the increasing permeability and pore radius. At high salinities, the streaming potential coefficient (streaming current coefficient) almost share a same value for 10 different samples. This conclusion indicates that the differences of rock parameters can only be well recognized at lower salinities, and the electrokinetic signals are invalid at high salinities, which offers a restrictive condition for using the amplitude of electrokinetic signals to estimate rock parameters. The zeta-potential have also been estimated through combined measurements of streaming potential and streaming current. The surface conductivity and its contribution to electrokinetic effects are determined from a comparison of zeta-potentials by two different methods, and then the validation of the Helmholz-Smoluchowski equation for a capillary tube is tested in rocks. We also compare our date with theoretical and experimental works, and set up an expression about the relationship between zeta potential and salinity, which fits the experimental data well.

  17. Validation of reference genes for RT-qPCR studies of gene expression in banana fruit under different experimental conditions

    Microsoft Academic Search

    Lei ChenHai-ying; Hai-ying Zhong; Jian-fei Kuang; Jian-guo Li; Wang-jin Lu; Jian-ye Chen

    Reverse transcription quantitative real-time PCR (RT-qPCR) is a sensitive technique for quantifying gene expression, but its\\u000a success depends on the stability of the reference gene(s) used for data normalization. Only a few studies on validation of\\u000a reference genes have been conducted in fruit trees and none in banana yet. In the present work, 20 candidate reference genes\\u000a were selected, and

  18. Systematic validation of disease models for pharmacoeconomic evaluations. Swiss HIV Cohort Study.

    PubMed

    Sendi, P P; Craig, B A; Pfluger, D; Gafni, A; Bucher, H C

    1999-08-01

    Pharmacoeconomic evaluations are often based on computer models which simulate the course of disease with and without medical interventions. The purpose of this study is to propose and illustrate a rigorous approach for validating such disease models. For illustrative purposes, we applied this approach to a computer-based model we developed to mimic the history of HIV-infected subjects at the greatest risk for Mycobacterium avium complex (MAC) infection in Switzerland. The drugs included as a prophylactic intervention against MAC infection were azithromycin and clarithromycin. We used a homogenous Markov chain to describe the progression of an HIV-infected patient through six MAC-free states, one MAC state, and death. Probability estimates were extracted from the Swiss HIV Cohort Study database (1993-95) and randomized controlled trials. The model was validated testing for (1) technical validity (2) predictive validity (3) face validity and (4) modelling process validity. Sensitivity analysis and independent model implementation in DATA (PPS) and self-written Fortran 90 code (BAC) assured technical validity. Agreement between modelled and observed MAC incidence confirmed predictive validity. Modelled MAC prophylaxis at different starting conditions affirmed face validity. Published articles by other authors supported modelling process validity. The proposed validation procedure is a useful approach to improve the validity of the model. PMID:10461580

  19. Alaska North Slope Tundra Travel Model and Validation Study

    SciTech Connect

    Harry R. Bader; Jacynthe Guimond

    2006-03-01

    The Alaska Department of Natural Resources (DNR), Division of Mining, Land, and Water manages cross-country travel, typically associated with hydrocarbon exploration and development, on Alaska's arctic North Slope. This project is intended to provide natural resource managers with objective, quantitative data to assist decision making regarding opening of the tundra to cross-country travel. DNR designed standardized, controlled field trials, with baseline data, to investigate the relationships present between winter exploration vehicle treatments and the independent variables of ground hardness, snow depth, and snow slab thickness, as they relate to the dependent variables of active layer depth, soil moisture, and photosynthetically active radiation (a proxy for plant disturbance). Changes in the dependent variables were used as indicators of tundra disturbance. Two main tundra community types were studied: Coastal Plain (wet graminoid/moist sedge shrub) and Foothills (tussock). DNR constructed four models to address physical soil properties: two models for each main community type, one predicting change in depth of active layer and a second predicting change in soil moisture. DNR also investigated the limited potential management utility in using soil temperature, the amount of photosynthetically active radiation (PAR) absorbed by plants, and changes in microphotography as tools for the identification of disturbance in the field. DNR operated under the assumption that changes in the abiotic factors of active layer depth and soil moisture drive alteration in tundra vegetation structure and composition. Statistically significant differences in depth of active layer, soil moisture at a 15 cm depth, soil temperature at a 15 cm depth, and the absorption of photosynthetically active radiation were found among treatment cells and among treatment types. The models were unable to thoroughly investigate the interacting role between snow depth and disturbance due to a lack of variability in snow depth cover throughout the period of field experimentation. The amount of change in disturbance indicators was greater in the tundra communities of the Foothills than in those of the Coastal Plain. However the overall level of change in both community types was less than expected. In Coastal Plain communities, ground hardness and snow slab thickness were found to play an important role in change in active layer depth and soil moisture as a result of treatment. In the Foothills communities, snow cover had the most influence on active layer depth and soil moisture as a result of treatment. Once certain minimum thresholds for ground hardness, snow slab thickness, and snow depth were attained, it appeared that little or no additive effect was realized regarding increased resistance to disturbance in the tundra communities studied. DNR used the results of this modeling project to set a standard for maximum permissible disturbance of cross-country tundra travel, with the threshold set below the widely accepted standard of Low Disturbance levels (as determined by the U.S. Fish and Wildlife Service). DNR followed the modeling project with a validation study, which seemed to support the field trial conclusions and indicated that the standard set for maximum permissible disturbance exhibits a conservative bias in favor of environmental protection. Finally DNR established a quick and efficient tool for visual estimations of disturbance to determine when investment in field measurements is warranted. This Visual Assessment System (VAS) seemed to support the plot disturbance measurements taking during the modeling and validation phases of this project.

  20. Teacher Evaluation Project. The Beginning Teacher Program, Intellectual Skills Development, Validity Studies of the Evaluation System, Special Instrument Development. Report for 1984-1985.

    ERIC Educational Resources Information Center

    Florida Coalition for the Development of a Performance Measurement System, Tallahassee.

    Reports, summaries, and recommendations are presented on the following research studies: (1) Beginning Teacher Studies; (2) Instructional Skills for Teaching Higher Order Thinking; (3) Development of the Conferential Observation Instrument; (4) Predictive Validity Studies Conducted to Test the Relationship Between Teacher Performance as Measured…

  1. Validity of The Health Improvement Network (THIN) for the study of psoriasis

    PubMed Central

    Seminara, N.M.; Abuabara, K.; Shin, D.B.; Langan, S.M.; Kimmel, S.E.; Margolis, D.; Troxel, A.B.; Gelfand, J.M.

    2010-01-01

    Background Psoriasis is a common disease frequently studied in large databases. To date the validity of psoriasis information has not been established in The Health Improvement Network (THIN). Objectives To investigate the validity of THIN for identifying psoriasis patients and to determine if the database can be used to determine the natural history of disease. Patients/Methods First we conducted a cross sectional study to determine if psoriasis prevalence in THIN is similar to expected. Second we created a cohort of 4900 patients, aged 45–65, with a psoriasis diagnostic Read Code and surveyed their GPs to confirm the diagnosis clinically. Third we created models to determine if psoriasis descriptors (extent, severity, duration, and dermatologist confirmation) could be accurately captured from database records. Results Psoriasis prevalence was 1.9%, and showed the characteristic age distribution expected. GP questionnaires were received for 4,634 of 4,900 cohort patients (95% response rate), and psoriasis diagnoses were confirmed in 90% of patients. Duration of disease in the database showed substantial agreement with physician query (kappa = 0.69). GPs confirmed that the psoriasis diagnosis was corroborated by a dermatologist in 91% of patients whose database records contained a dermatology referral code associated with a psoriasis code. We achieved good discrimination between patients with and without extensive disease based on the number of psoriasis codes received per year (Area Under Curve, AUC = 0.8). Conclusions THIN is a valid data resource for studying psoriasis and can be used to identify characteristics of the disease such as duration and confirmation by a dermatologist. PMID:21073449

  2. Asymptotic Studies of Closely Spaced, Highly Conducting Cylinders

    Microsoft Academic Search

    R. C. McPhedran; L. Poladian; G. W. Milton

    1988-01-01

    We consider the solution of the scalar transport problem for a pair of nearly touching cylinders of high conductivity. We obtain an expression for the set of multipole moments of the potential distribution for this problem in terms of the hypergeometric function. We apply this expression in the estimation of truncation errors occurring in the matrix solution of the corresponding

  3. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  4. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  5. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  6. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  7. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...HEALTH AND HUMAN SERVICES GENERAL GOOD LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a...

  8. Interlaboratory validation of the in vitro eye irritation tests for cosmetic ingredients. (1) Overview of the validation study and Draize scores for the evaluation of the tests

    Microsoft Academic Search

    Y Ohno; T Kaneko; T Inoue; Y Morikawa; T Yoshida; A Fujii; M Masuda; T Ohno; M Hayashi; J Momma; T Uchiyama; K Chiba; N Ikeda; Y Imanishi; H Itakagaki; H Kakishima; Y Kasai; A Kurishita; H Kojima; K Matsukawa; T Nakamura; K Ohkoshi; H Okumura; K Saijo; K Sakamoto; T Suzuki; K Takano; H Tatsumi; N Tani; M Usami; R Watanabe

    1999-01-01

    A three-step interlaboratory validation of alternative methods to the Draize eye irritation test (Draize test) was conducted by the co-operation of 27 organizations including national research institutes, universities, cosmetic industries, kit suppliers and others. Twelve alternative methods were evaluated using 38 cosmetic ingredients and isotonic sodium chloride solution. Draize tests were conducted according to the OECD guidelines using the same

  9. External Validity of Conduct and Oppositional Defiant Disorders Determined by the NIMH Diagnostic Interview Schedule for Children

    Microsoft Academic Search

    Patrick C. Friman; Michael L. Handwerk; Gail L. Smith; Robert E. Larzelere; Christopher P. Lucas; David M. Shaffer

    2000-01-01

    We administered the Diagnostic Interview Schedule for Children (DISC) two times to a group of youth (222 boys, 147 girls) entering residential care, once at their time of entry and once 1 year later. We then compared their DISC outcomes on Conduct Disorder (CD) and Oppositional Defiant Disorder (ODD) against changes in independent direct observations of diagnostically relevant behavior obtained

  10. Commitment in different relationships statuses: validation study of the personal commitment scale.

    PubMed

    Monteiro, Ana Pego; Costa-Ramalho, Susana; Ribeiro, Maria Teresa; Pinto, Alexandra Marques

    2015-01-01

    This study presents the validation process of the Portuguese version of the short-form Dedication Scale (Rhoades, Stanley, & Markman, 2006; Stanley, 1986), with a sample of 924 participants in different relationship statutes. With 14 items, this short version is recommended by the authors for its simple use, when wanting to measure commitment in romantic relationships. Confirmatory factor analysis showed that the instrument did not have a totally acceptable fit with the data so an exploratory factor analysis was conducted. This revealed a one-dimensional structure of the scale, and led to the exclusion of two items, which relate to a distinct meta-commitment dimension. In sum, the Portuguese version (ECP - Personal Commitment Scale) has 12 items, with good internal consistency (? = .82), correlations item-total between .36 and .60, and good criteria validity (p < .001). Its use for research is therefore appropriate. In a second study, significant differences were found between the participants' four relationship statuses (dating non-cohabiting and cohabiting relationships, formal unions and marriage) (p < .001; ?2 p = .03). Results showed that married participants were more committed than those in a formal union, even when controlling for several relational and socio-demographic variables. No differences were found between cohabiting and non-cohabiting dating participants. Men reported higher levels of commitment than women (p < .001; ?2 p = .02). Implications and suggestions for future research are discussed. PMID:26037376

  11. A Validation Study of Merging and Spacing Techniques in a NAS-Wide Simulation

    NASA Technical Reports Server (NTRS)

    Glaab, Patricia C.

    2011-01-01

    In November 2010, Intelligent Automation, Inc. (IAI) delivered an M&S software tool to that allows system level studies of the complex terminal airspace with the ACES simulation. The software was evaluated against current day arrivals in the Atlanta TRACON using Atlanta's Hartsfield-Jackson International Airport (KATL) arrival schedules. Results of this validation effort are presented describing data sets, traffic flow assumptions and techniques, and arrival rate comparisons between reported landings at Atlanta versus simulated arrivals using the same traffic sets in ACES equipped with M&S. Initial results showed the simulated system capacity to be significantly below arrival capacity seen at KATL. Data was gathered for Atlanta using commercial airport and flight tracking websites (like FlightAware.com), and analyzed to insure compatible techniques were used for result reporting and comparison. TFM operators for Atlanta were consulted for tuning final simulation parameters and for guidance in flow management techniques during high volume operations. Using these modified parameters and incorporating TFM guidance for efficiencies in flowing aircraft, arrival capacity for KATL was matched for the simulation. Following this validation effort, a sensitivity study was conducted to measure the impact of variations in system parameters on the Atlanta airport arrival capacity.

  12. Predicting NCLEX-RN success with the HESI Exit Exam: eighth validity study.

    PubMed

    Langford, Rae; Young, Anne

    2013-01-01

    Increasingly, Elsevier's HESI Exit Exam (E(2)) is being used to assess students' readiness for the National Council Licensure Examination for Registered Nurses (NCLEX-RN). Seven previously conducted validity studies indicate that the E(2) is 96.36%-99.16% accurate in predicting NCLEX-RN success. Findings of this eighth validity study, which also investigated the predictive accuracy of repeat testing with parallel versions of the E(2), indicated that the E(2) is highly accurate (94.93%-98.32%) in predicting NCLEX-RN success for the initial testing and 2 retests. Of the 66 participating nursing programs, deans and directors from 43 (65.15%) of the programs reported implementing a policy that used E(2) scores as a benchmark for remediation. A score of 850 was the most common E(2) benchmark designated by faculties, and students who failed to achieve the faculty-designated E(2) benchmark score were required to retest with a parallel version of the E(2). Remediation resources used to assist students in achieving faculty-designated E(2) benchmark scores varied widely, with many programs employing multiple remediation methods. PMID:23566508

  13. Nuclear Spin Lattice Relaxation and Conductivity Studies of the Non-Arrhenius Conductivity Behavior in Lithium Fast Ion Conducting Sulfide Glasses

    SciTech Connect

    Benjamin Michael Meyer

    2003-05-31

    As time progresses, the world is using up more of the planet's natural resources. Without technological advances, the day will eventually arrive when these natural resources will no longer be sufficient to supply all of the energy needs. As a result, society is seeing a push for the development of alternative fuel sources such as wind power, solar power, fuel cells, and etc. These pursuits are even occurring in the state of Iowa with increasing social pressure to incorporate larger percentages of ethanol in gasoline. Consumers are increasingly demanding that energy sources be more powerful, more durable, and, ultimately, more cost efficient. Fast Ionic Conducting (FIC) glasses are a material that offers great potential for the development of new batteries and/or fuel cells to help inspire the energy density of battery power supplies. This dissertation probes the mechanisms by which ions conduct in these glasses. A variety of different experimental techniques give a better understanding of the interesting materials science taking place within these systems. This dissertation discusses Nuclear Magnetic Resonance (NMR) techniques performed on FIC glasses over the past few years. These NMR results have been complimented with other measurement techniques, primarily impedance spectroscopy, to develop models that describe the mechanisms by which ionic conduction takes place and the dependence of the ion dynamics on the local structure of the glass. The aim of these measurements was to probe the cause of a non-Arrhenius behavior of the conductivity which has been seen at high temperatures in the silver thio-borosilicate glasses. One aspect that will be addressed is if this behavior is unique to silver containing fast ion conducting glasses. more specifically, this study will determine if a non-Arrhenius correlation time, {tau}, can be observed in the Nuclear Spin Lattice Relaxation (NSLR) measurements. If so, then can this behavior be modeled with a new single distribution of activation energies (DAE) to calculate the corresponding conductivity and relaxation rates as a function of temperature and frequency?

  14. 40 CFR 152.93 - Citation of a previously submitted valid study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...is not the original data submitter, the applicant may cite the study only in...authorization of original data submitter. The applicant may cite any valid study for...compensation to the original data submitter . The applicant may cite any valid study...

  15. A Reliability and Validity Study of the Cornell Scale among Elderly Inpatients, Using Various Clinical Criteria

    Microsoft Academic Search

    Maria Lage Barca; Knut Engedal; Geir Selbæk

    2010-01-01

    Background: The validity of the Cornell Scale for Depression in Dementia is seldom studied in institutions. Method: Two reliability studies, with 103 and 32 patients, and a validity study with 231 patients in nursing homes and in hospital were performed. They were assessed by the Cornell Scale, Clinical Dementia Rating scale and Self-Maintenance scale. A psychiatrist ‘blind’ to the Cornell

  16. Conducting atomic force microscopy study of silicon dioxide breakdown

    Microsoft Academic Search

    R. M. Atta; M. P. Murrell; M. E. Welland

    1995-01-01

    A summary is given of an experimental method used to obtain the local dielectric strength of thin insulators using atomic force microscopy with conducting tips. This technique is applied to 7-15 nm thick SiOâ films grown on either crystalline silicon or polysilicon substrates. The dielectric breakdown of the oxides over small areas (â¼5X10⁻¹⁶ m²) follows that observed in the intrinsic

  17. An Experimental Study of Characteristic Combustion-Driven Flow for CFD Validation

    NASA Technical Reports Server (NTRS)

    Santoro, Robert J.

    1997-01-01

    A series of uni-element rocket injector studies were completed to provide benchmark quality data needed to validate computational fluid dynamic models. A shear coaxial injector geometry was selected as the primary injector for study using gaseous hydrogen/oxygen and gaseous hydrogen/liquid oxygen propellants. Emphasis was placed on the use of nonintrusive diagnostic techniques to characterize the flowfields inside an optically-accessible rocket chamber. Measurements of the velocity and species fields were obtained using laser velocimetry and Raman spectroscopy, respectively. Qualitative flame shape information was also obtained using laser-induced fluorescence excited from OH radicals and laser light scattering studies of aluminum oxide particle seeded combusting flows. The gaseous hydrogen/liquid oxygen propellant studies for the shear coaxial injector focused on breakup mechanisms associated with the liquid oxygen jet under subcritical pressure conditions. Laser sheet illumination techniques were used to visualize the core region of the jet and a Phase Doppler Particle Analyzer was utilized for drop velocity, size and size distribution characterization. The results of these studies indicated that the shear coaxial geometry configuration was a relatively poor injector in terms of mixing. The oxygen core was observed to extend well downstream of the injector and a significant fraction of the mixing occurred in the near nozzle region where measurements were not possible to obtain. Detailed velocity and species measurements were obtained to allow CFD model validation and this set of benchmark data represents the most comprehensive data set available to date. As an extension of the investigation, a series of gas/gas injector studies were conducted in support of the X-33 Reusable Launch Vehicle program. A Gas/Gas Injector Technology team was formed consisting of the Marshall Space Flight Center, the NASA Lewis Research Center, Rocketdyne and Penn State. Injector geometries studied under this task included shear and swirl coaxial configurations as well as an impinging jet injector.

  18. The Conduct of Drug Metabolism Studies Considered Good Practice (II): In Vitro Experiments

    PubMed Central

    Jia, Lee; Liu, Xiaodong

    2009-01-01

    In vitro drug metabolism studies, which are inexpensive and readily carried out, serve as an adequate screening mechanism to characterize drug metabolites, elucidate their pathways, and make suggestions for further in vivo testing. This publication is a sequel to part I in a series and aims at providing a general framework to guide designs and protocols of the in vitro drug metabolism studies considered good practice in an efficient manner such that it would help researchers avoid common pitfalls and misleading results. The in vitro models include hepatic and non-hepatic microsomes, cDNA-expressed recombinant human CYPs expressed in insect cells or human B lymphoblastoid, chemical P450 inhibitors, S9 fraction, hepatocytes and liver slices. Important conditions for conducting the in vitro drug metabolism studies using these models are stated, including relevant concentrations of enzymes, co-factors, inhibitors and test drugs; time of incubation and sampling in order to establish kinetics of reactions; appropriate control settings, buffer selection and method validation. Separate in vitro data should be logically integrated to explain results from animal and human studies and to provide insights into the nature and consequences of in vivo drug metabolism. This article offers technical information and data and addresses scientific rationales and practical skills related to in vitro evaluation of drug metabolism to meet regulatory requirements for drug development. PMID:18220563

  19. How Useful are Work Samples in Validational Studies?

    Microsoft Academic Search

    Douglas N. Jackson; William G. Harris; Michael C. Ashton; Julie M. McCarthey; Paul F. Tremblay

    2000-01-01

    Some job tasks do not lend themselves to formal on-the-job assessment because they do not occur with sufficient regularity to permit the standardized measurement required in validational research. The preparation of incident reports by police and security officers is such a job task. The production of accurate, literate incident reports is important because these reports are often required in legal

  20. A Validity Study of Two Projective Object Representations Measures.

    ERIC Educational Resources Information Center

    Hibbard, Stephen; And Others

    1995-01-01

    Two projective measures of object representations, the Concept of the Object on the Rorschach and the Social Cognition and Object Relations Scales, were compared with each other and measures of intelligence and pathology with 15 children and 94 adult patients. Results support the construct validity of object representations. (SLD)

  1. A Validity Study of the Salter Environmental Type Assessment.

    ERIC Educational Resources Information Center

    Salter, Daniel W.

    2002-01-01

    Correlational analyses of data from 202 students on the Work Environment Scale and Salter Environmental Type Assessment (SETA) supported concurrent validity. Factor analysis identified three factors accounting for 70% of variance: positive work settings, structure, and work pressure/task orientation. SETA appears useful as a commensurate Myers…

  2. The Caregiver Role Identity Scale: A Validation Study

    ERIC Educational Resources Information Center

    Siebert, Darcy Clay; Siebert, Carl F.

    2005-01-01

    Objective: This article reports the validation of the Caregiver Role Identity Scale, designed to measure the prominence of helping professionals' identity as personal and professional caregivers. The authors developed the measure to test its application to burnout, depression, and professional impairment among social workers. Method: Data from a…

  3. Guidelines for the Design and Conduct of Clinical Studies in Knee Articular Cartilage Repair

    PubMed Central

    Mithoefer, Kai; Saris, Daniel B.F.; Farr, Jack; Kon, Elizaveta; Zaslav, Kenneth; Cole, Brian J.; Ranstam, Jonas; Yao, Jian; Shive, Matthew; Levine, David; Dalemans, Wilfried; Brittberg, Mats

    2011-01-01

    Objective: To summarize current clinical research practice and develop methodological standards for objective scientific evaluation of knee cartilage repair procedures and products. Design: A comprehensive literature review was performed of high-level original studies providing information relevant for the design of clinical studies on articular cartilage repair in the knee. Analysis of cartilage repair publications and synopses of ongoing trials were used to identify important criteria for the design, reporting, and interpretation of studies in this field. Results: Current literature reflects the methodological limitations of the scientific evidence available for articular cartilage repair. However, clinical trial databases of ongoing trials document a trend suggesting improved study designs and clinical evaluation methodology. Based on the current scientific information and standards of clinical care, detailed methodological recommendations were developed for the statistical study design, patient recruitment, control group considerations, study endpoint definition, documentation of results, use of validated patient-reported outcome instruments, and inclusion and exclusion criteria for the design and conduct of scientifically sound cartilage repair study protocols. A consensus statement among the International Cartilage Repair Society (ICRS) and contributing authors experienced in clinical trial design and implementation was achieved. Conclusions: High-quality clinical research methodology is critical for the optimal evaluation of current and new cartilage repair technologies. In addition to generally applicable principles for orthopedic study design, specific criteria and considerations apply to cartilage repair studies. Systematic application of these criteria and considerations can facilitate study designs that are scientifically rigorous, ethical, practical, and appropriate for the question(s) being addressed in any given cartilage repair research project.

  4. Generalization of GRE General Test Validity across Departments.

    ERIC Educational Resources Information Center

    Boldt, Robert F.

    This study of the validity of the Graduate Record Examinations (GRE) General Test used data from predictive validity studies that were conducted by the GRE Validity Study Service (VSS) in 79 graduate departments. The performance criterion was first-year grades in graduate school. Observed validities were computed, and for each graduate department…

  5. Validity of Internet-Based Longitudinal Study Data: The Elephant in the Virtual Room

    PubMed Central

    Summers, Kim M; Bronsvoort, B Mark C; Handel, Ian G; Clements, Dylan N

    2015-01-01

    Background Internet-based data collection relies on well-designed and validated questionnaires. The theory behind designing and validating questionnaires is well described, but few practical examples of how to approach validation are available in the literature. Objective We aimed to validate data collected in an ongoing Internet-based longitudinal health study through direct visits to participants and recall of their health records. We demonstrate that despite extensive pre-planning, social desirability can still affect data in unexpected ways and that anticipation of poor quality data may be confounded by positive validation. Methods Dogslife is a large-scale, Web-based longitudinal study of canine health, in which owners of Labrador Retrievers were recruited and questioned at regular intervals about the lifestyle and health of their dogs using an Internet-based questionnaire. The Dogslife questionnaire predominantly consists of closed-answer questions. In our work, two separate validation methodologies were used: (1) direct interviews with 43 participants during visits to their households and (2) comparison of owner-entered health reports with 139 historical health records. Results Our results indicate that user-derived measures should not be regarded as a single category; instead, each measurement should be considered separately as each presents its own challenge to participants. We recommend trying to ascertain the extent of recall decay within a study and, if necessary, using this to guide data collection timepoints and analyses. Finally, we recommend that multiple methods of communication facilitate validation studies and aid cohort engagement. Conclusions Our study highlighted how the theory underpinning online questionnaire design and validation translates into practical data issues when applied to Internet-based studies. Validation should be regarded as an extension of questionnaire design, and that validation work should commence as soon as sufficient data are available. We believe that validation is a crucial step and hope our suggested guidelines will help facilitate validation of other Internet-based cohort studies. PMID:25887101

  6. Scanning Ion Conductance Microscopy for Studying Biological Samples

    PubMed Central

    Happel, Patrick; Thatenhorst, Denis; Dietzel, Irmgard D.

    2012-01-01

    Scanning ion conductance microscopy (SICM) is a scanning probe technique that utilizes the increase in access resistance that occurs if an electrolyte filled glass micro-pipette is approached towards a poorly conducting surface. Since an increase in resistance can be monitored before the physical contact between scanning probe tip and sample, this technique is particularly useful to investigate the topography of delicate samples such as living cells. SICM has shown its potential in various applications such as high resolution and long-time imaging of living cells or the determination of local changes in cellular volume. Furthermore, SICM has been combined with various techniques such as fluorescence microscopy or patch clamping to reveal localized information about proteins or protein functions. This review details the various advantages and pitfalls of SICM and provides an overview of the recent developments and applications of SICM in biological imaging. Furthermore, we show that in principle, a combination of SICM and ion selective micro-electrodes enables one to monitor the local ion activity surrounding a living cell. PMID:23202197

  7. Comparison of Driving Errors Between On-the-Road and Simulated Driving Assessment: A Validation Study

    Microsoft Academic Search

    Orit Shechtman; Sherrilene Classen; Kezia Awadzi; William Mann

    2009-01-01

    Objective: Driving simulation provides a convenient and safe method for assessing driving behaviors. Many authors, however, agree that validation is a key component of any study that utilizes simulators to assess driving performance. The purpose of this study was to test driver response validity by discerning whether behavioral responses of drivers, as expressed by type and number of errors, are

  8. Electrical Conductivity, Near-Infrared Absorption, and Thermal Lens Spectroscopic Studies of Percolation of Microemulsions

    E-print Network

    Reid, Scott A.

    Electrical Conductivity, Near-Infrared Absorption, and Thermal Lens Spectroscopic Studies studied below and above the percolation thresholds by electrical conductivity, near-infrared absorption quenching, neutron and light scattering, and electrical conductivity.1,2 However, in spite of these numerous

  9. Conducting systematic reviews of diagnostic studies: didactic guidelines

    PubMed Central

    Devillé, Walter L; Buntinx, Frank; Bouter, Lex M; Montori, Victor M; de Vet, Henrica CW; van der Windt, Danielle AWM; Bezemer, P Dick

    2002-01-01

    Background Although guidelines for critical appraisal of diagnostic research and meta-analyses have already been published, these may be difficult to understand for clinical researchers or do not provide enough detailed information. Methods Development of guidelines based on a systematic review of the evidence in reports of systematic searches of the literature for diagnostic research, of methodological criteria to evaluate diagnostic research, of methods for statistical pooling of data on diagnostic accuracy, and of methods for exploring heterogeneity. Results Guidelines for conducting diagnostic systematic reviews are presented in a stepwise fashion and are followed by comments providing further information. Examples are given using the results of two systematic reviews on the accuracy of the urine dipstick in the diagnosis of urinary tract infections, and on the accuracy of the straight-leg-raising test in the diagnosis of intervertebral disc hernia. PMID:12097142

  10. Steady-state hydraulic tomography in a laboratory aquifer with deterministic heterogeneity: Multi-method and multiscale validation of hydraulic conductivity tomograms

    NASA Astrophysics Data System (ADS)

    Illman, Walter A.; Liu, Xiaoyi; Craig, Andrew

    2007-08-01

    SummaryHydraulic tomography potentially is a viable technology that facilitates subsurface imaging of hydraulic heterogeneity. To date, a comprehensive validation of hydraulic tomography has not been done either at the laboratory or field scales. The main objective of this paper is to examine the accuracy of hydraulic conductivity ( K) tomograms obtained from the steady-state hydraulic tomography algorithm of [Yeh, T.-C. J., Liu, S., 2000. Hydraulic tomography: development of a new aquifer test method. Water Resources Research 36, 2095-2105]. We first obtain a reference K tomogram through the inversion of synthetic cross-hole test data generated through numerical simulations. The purpose of reference K tomogram generation is to examine the ability of the algorithm to image the heterogeneity pattern under optimal conditions without experimental errors and with full control of forcing functions (initial and boundary conditions as well as source/sink terms). Parallel to the generation of synthetic data, we conduct hydraulic tests at multiple scales in a laboratory aquifer with deterministic heterogeneity to generate data that are used to validate K tomograms from hydraulic tomography. Measurements include multiple K estimates from core, slug, single-hole and cross-hole tests as well as several unidirectional, flow-through experiments conducted on the sandbox under steady-state conditions. Validation of K tomograms involved a multi-method and multiscale approach proposed herein which include: (1) visual comparisons of K tomograms to the true sand distributions and the reference K tomogram; (2) testing the ability of the K tomogram to predict the hydraulic head distribution of an independent cross-hole test not used in the computation of the K tomogram; (3) comparison of the conditional mean and variance of local K from the K tomograms to the sample mean and variance of results from other measurements; (4) comparison of local K values from K tomograms to those from the reference K tomogram; and (5) comparison of local K values from K tomograms to those obtained from cores and single-hole tests. The multi-method and multiscale validation approach proposed herein further illustrates the robustness of steady-state hydraulic tomography in subsurface heterogeneity delineation.

  11. Studies of non-diffusive heat conduction through spatially periodic and time-harmonic thermal excitations

    E-print Network

    Collins, Kimberlee C. (Kimberlee Chiyoko)

    2015-01-01

    Studies of non-diffusive heat conduction provide insight into the fundamentals of heat transport in condensed matter. The mean free paths (MFPs) of phonons that are most important for conducting heat are well represented ...

  12. Conducting influenza virus pathogenesis studies in avian species.

    PubMed

    Cardona, Carol J; Halvorson, David A; Brown, Justin D; Pantin-Jackwood, Mary J

    2014-01-01

    Avian infection studies with influenza A virus are an important means of assessing host susceptibility, viral pathogenesis, host responses to infection, mechanisms of transmission, and viral pathotype. Complex systems and natural settings may also be explored with carefully designed infection studies. In this chapter, we explore the elements of infection studies, general guidelines for choosing a virus to use, host selection, and many aspects of study design. PMID:24899429

  13. A Contract Research Organization's Challenge: Validating Cutting-Edge Software for Imaging in Clinical Studies

    Microsoft Academic Search

    Brenda K. Young; Dena Flamini; James Gimpel

    2010-01-01

    Conducting imaging in clinical trials often involves the use of cutting-edge computer software. The computer systems featured in the medical imaging workstations used in clinical investigations must be validated prior to data collection in support of a regulatory submission. Good clinical practice (GCP) guidelines, derived from international standards adopted by the US FDA, are the benchmarks for drug and device

  14. The federal Post Conviction Risk Assessment (PCRA): a construction and validation study.

    PubMed

    Lowenkamp, Christopher T; Johnson, James L; Holsinger, Alexander M; Vanbenschoten, Scott W; Robinson, Charles R

    2013-02-01

    Offender assessment has been and remains the cornerstone of effective community supervision. This article presents the development of and tests the predictive validity of a 4th-generation risk assessment instrument designed for U.S. probation. A large administrative data set was used to create the assessment instrument and conduct an initial validation. Subsequent data generated from officer-completed assessments were used to conduct a prospective validation. Finally, data from case vignettes scored by trained officers were used to test the interrater agreement of the assessment instrument. Overall, analysis revealed that the assessment instrument predicted rearrest reliably when using the assessment results based on administrative data or officer-completed assessments. Analysis also revealed high rates of interrater agreement. Recommendations for future research and policy implications are presented. PMID:23148771

  15. Conducting atomic force microscopy study of silicon dioxide breakdown

    SciTech Connect

    O`Shea, S.J.; Atta, R.M.; Murrell, M.P.; Welland, M.E. [Cambridge Univ. (United Kingdom)] [Cambridge Univ. (United Kingdom)

    1995-09-01

    A summary is given of an experimental method used to obtain the local dielectric strength of thin insulators using atomic force microscopy with conducting tips. This technique is applied to 7-15 nm thick SiO{sub 2} films grown on either crystalline silicon or polysilicon substrates. The dielectric breakdown of the oxides over small areas ({approximately}5X10{sup -16} m{sup 2}) follows that observed in the intrinsic breakdown of conventional metal-oxide-semiconductor structures, with a maximum breakdown field of 13.2{+-}0.8 MV/cm. On the polycrystalline samples variation in dielectric strength between individual grains can be observed, with the oxide over some grains breaking down entirely. A difficulty when working in air is that sample or tip contamination and induced growth of material under the tip lead to changes in either the effective barrier height or local material thickness which are not related to the SiO{sub 2} film. These effects are discussed in detail. 20 refs., 8 figs., 1 tab.

  16. Conducting Event Studies on a Small Stock Exchange

    Microsoft Academic Search

    Jan Bartholdy; Dennis Olson; Paula Peare

    2007-01-01

    This paper analyses whether it is possible to perform an event study on a small stock exchange with thinly trade stocks. The main conclusion is that event studies can be performed provided that certain adjustments are made. First, a minimum of 25 events appears necessary to obtain acceptable size and power in statistical tests. Second, trade to trade returns should

  17. Conducting influenza virus pathogenesis studies in avian species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian infection studies with influenza A are an important means of assessing host susceptibility, viral pathogenesis, host responses to infection, mechanisms of transmission and viral pathotype. Complex systems and natural settings may also be explored with carefully designed infection studies. In ...

  18. Towards a standard procedure for validation of satellite-derived cloud liquid water path: a study with SEVIRI data

    Microsoft Academic Search

    W. Greuell; R. A. Roebeling

    2009-01-01

    Differences between satellite-derived and ground-based values of cloud liquid water path (LWPsat and LWPgr) in validation studies are partly caused by issues associated with the validation itself, in particular scale differences and the parallax. We have performed calculations aiming at establishing standards for validation procedures so that contributions to the differences by the validation issues are minimized. To study this

  19. Predicting NCLEX-RN Success: the Seventh Validity Study HESI Exit exam.

    PubMed

    Young, Anne; Willson, Pamela

    2012-01-01

    The findings of six previously conducted studies indicated that the HESI (E) was highly accurate in predicting NCLEX-RN success. The purpose of this study-the seventh study to investigate the validity of the E-was to examine the accuracy of three parallel versions of the Ein predicting licensure success and to describe program practices regarding E benchmark scores, remediation programs, and retesting policies. The findings of this study again indicated that the E was highly accurate in predicting NCLEX-RN success. Additionally, all three versions of the E were found to have a predictive accuracy above 90%. The most common E benchmark score designated by faculty at the participating schools was 850, and most schools required students to retest with different versions of the E until the faculty-designated E benchmark score was achieved. Remediation seemed to be effective in raising students' E scores, and it was recommended that future research investigate the effectiveness of specific remediation strategies. PMID:22024971

  20. Validation of Landslide Susceptibility Maps; Examples and Applications from a Case Study in Northern Spain

    Microsoft Academic Search

    Juan Remondo; Alberto González; José Ramón Díaz De Terán; Antonio Cendrero; Andrea Fabbri; Chang-Jo F. Chung

    2003-01-01

    A procedure for validating landslide susceptibility maps wasapplied in a study area in northern Spain and the results obtained compared. Validationwas used to carry out sensitivity analysis for individual variables and combinationsof variables. The validity of different map-making methods was tested, as well as theutility of different types of Favourability Functions. The results obtained show thatvalidation is essential to determine

  1. A Study of the Criterion Validity of the Mattis Dementia Rating Scale.

    ERIC Educational Resources Information Center

    Fernandez, Alberto Luis; Scheffel, Debora L.

    2003-01-01

    Evaluated the criterion validity of the Mattis Dementia Rating Scale (S. Mattis, 1988) with a concurrent study to obtain a cut-off score for an Argentinean population by administering a battery of tests to 60 memory disorder patients. Findings demonstrate high convergent validity with another measure and show an appropriate cut score for use with…

  2. Validation Study of a Gatekeeping Attitude Index for Social Work Education

    ERIC Educational Resources Information Center

    Tam, Dora M. Y.; Coleman, Heather

    2011-01-01

    This article reports on a study designed to validate the Gatekeeping Attitude Index, a 14-item Likert scaling index. The authors collected data from a convenience sample of social work field instructors (N = 188) with a response rate of 74.0%. Construct validation by exploratory factor analysis identified a 2-factor solution on the index after…

  3. Quality Rating and Improvement System (QRIS) Validation Study Designs. CEELO FastFacts

    ERIC Educational Resources Information Center

    Schilder, D.

    2013-01-01

    In this "Fast Facts," a state has received Race to the Top Early Learning Challenge funds and is seeking information to inform the design of the Quality Rating and Improvement System (QRIS) validation study. The Center on Enhancing Early Learning Outcomes (CEELO) responds that according to Resnick (2012), validation of a QRIS is an…

  4. Validating the Center for Epidemiological Studies Depression Scale for Children in Rwanda

    ERIC Educational Resources Information Center

    Betancourt, Theresa; Scorza, Pamela; Meyers-Ohki, Sarah; Mushashi, Christina; Kayiteshonga, Yvonne; Binagwaho, Agnes; Stulac, Sara; Beardslee, William R.

    2012-01-01

    Objective: We assessed the validity of the Center for Epidemiological Studies Depression Scale for Children (CES-DC) as a screen for depression in Rwandan children and adolescents. Although the CES-DC is widely used for depression screening in high-income countries, its validity in low-income and culturally diverse settings, including sub-Saharan…

  5. A case study of verification, validation, and accreditation for advanced distributed simulation

    Microsoft Academic Search

    Ernest H. Page; Bradford S. Canova; John A. Tufarolo

    1997-01-01

    The techniques and methodologies for verification and validation of software-based systems have arguably realized their greatest utility within the context of simulation. Advanced Distributed Simulation (ADS), a major initiative within the defense modeling and simulation community, presents a variety of challenges to the classical approaches. A case study of the development process and concomitant verification and validation activities for the

  6. Study on the hydraulic conductivity of Boom clay1 Yong-Feng Deng1, 2

    E-print Network

    Boyer, Edmond

    1 Study on the hydraulic conductivity of Boom clay1 2 Yong-Feng Deng1, 2 , Anh-Minh Tang2 , Yu Geotechnical Journal 48 (2011) 1461-1470" DOI : 10.1139/T11-048 #12;2 Abstract1 The hydraulic conductivity. Experimental results show that the hydraulic conductivity3 is mainly governed by the soil porosity

  7. Sympathetic Skin Response in Hemodialysis Patients: Correlation with Nerve Conduction Studies and Adequacy of Dialysis

    Microsoft Academic Search

    N. R. Robles; M. Solis; L. Albarran; J. F. Esparrago; F. Roncero; E. Sanchez-Casado

    1999-01-01

    A sympathetic skin response (SSR) test was performed in diabetic and nondiabetic patients undergoing regular hemodialysis and the results correlated with nerve conduction studies (NCS): sensory conduction velocity (SCV) and motor conduction velocity (MCV). Comparisons were made between diabetic and nondiabetic patients and between cuprophane and polyacrylonitrile membrane dialyzed patients. Six nondiabetic uremic patients (30%) and all diabetic patients had

  8. Use of Atomistic Phonon Dispersion and Boltzmann Transport Formalism to Study the Thermal Conductivity

    E-print Network

    in the presence of moderate boundary scattering. Index terms: silicon nanowires, thermal conductivity, modified The thermal conductivity of bulk Si has a relatively high value of ~140W/mK, and is dominated by phonon studies can be found in the literature regarding the thermal conductivity of Si NWs [4, 5, 6, 7, 8

  9. Studies on the electrical conduction in silver telluride thin films

    Microsoft Academic Search

    P. Gnanadurai; N. Soundararajan; C. E. Sooriamoorthi

    2003-01-01

    The temperature dependence of the electrical resistance of unannealed and annealed silver telluride thin films of different thickness between 30 and 110 nm, prepared by thermal evaporation at a pressure of 2 × 10-5 mbar, has been studied. The films are polycrystalline. It is found that metastable defects influence the phase transition in unannealed films. The annealed films undergo a

  10. Airport air quality. Results of recent model validation studies

    Microsoft Academic Search

    D. G. Smith; S. A. Bremer; D. W. Heinold; R. J. Yamartino

    1979-01-01

    Experimental data on CO and NO\\/sub x\\/ levels in the near-field of individual aircraft sources during taxiing and takeoff operations, respectively, obtained in a monitoring program at Dulles International Airport in Washington, D.C., conducted for the U.S. Federal Aviation Administration have been correlated by using the ensemble-fit method. The observed CO plume rise rate during taxiing is generally consistent with

  11. Field emission study of MWCNT/conducting polymer nanocomposite

    NASA Astrophysics Data System (ADS)

    Alvi, M. A.; Al-Ghamdi, A. A.; Husain, M.

    2014-12-01

    MWCNTs/Polypyrrole nanocomposites were synthesized by solution mixing method. These synthesized nanocomposites were studied carefully by Raman Spectroscopy and Scanning Electron Microscopy measurements. The field emission study of MWCNTs/Polypyrrole nanocomposites were performed in diode arrangement under vacuum of the order of 10-5 Torr. The emission current under exploration depends on applied voltage. The prepared nanocomposites depict low turn-on field at 1.4 V/?m that reaches to a maximum emission current density 0.020 mA/cm2 at 2.4 V/?m, which is calculated from the graph of current density (J) against the applied electric field (E) and from Fowler-Nordheim (F-N) plot.

  12. A NASA ER-2 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A specially equipped Dryden Flight Research Center ER-2 (a modified U-2) soars above Patrick Air Force Base enroute to a hurricane in the Atlantic. The plane is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. Soaring above 65,000 feet, the ER-2 will measure the structure of hurricanes and the surrounding atmosphere that steers the storm's movement. The hurricane study, which lasts through September 1998, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  13. A NASA ER-2 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The pilot of this high-altitude research plane, a specially equipped Dryden Flight Research Center ER-2 (a modified U-2), settles into the cockpit at Patrick Air Force Base before taking off into a hurricane. The plane is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. Soaring above 65,000 feet, the ER-2 will measure the structure of hurricanes and the surrounding atmosphere that steers the storm's movement. The hurricane study, which lasts through September 1998, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  14. A NASA ER-2 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A specially equipped Dryden Flight Research Center ER-2 (a modified U-2) takes off from Patrick Air Force Base enroute to a hurricane in the Atlantic. The plane is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. Soaring above 65,000 feet, the ER-2 will measure the structure of hurricanes and the surrounding atmosphere that steers the storm's movement. The hurricane study, which lasts through September 1998, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  15. A NASA ER-2 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This high-altitude research plane, a specially equipped Dryden Flight Research Center ER-2 (a modified U-2), is readied at Patrick Air Force Base for flight into a hurricane in the Atlantic. The plane is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. The ER-2, soaring above 65,000 feet, will measure the structure of hurricanes and the surrounding atmosphere that steers the storms' movement. The hurricane study, which lasts through September 1998, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  16. A NASA ER-2 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The pilot climbs into the cockpit of a high-altitude research plane, a specially equipped Dryden Flight Research Center ER-2 (a modified U-2), at Patrick Air Force Base. Soaring above 65,000 feet, the ER-2 will measure the structure of hurricanes and the surrounding atmosphere that steers the storm's movement. The plane is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. The hurricane study, which lasts through September 1998, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  17. A NASA DC-8 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This NASA Dryden Flight Research Center DC-8 takes off from Patrick Air Force Base to pursue its goal of collecting high- altitude information about Atlantic hurricanes and tropical storms. Flying at 35,000 to 40,000 feet, the plane is equipped with instruments to measure the storm's structure, environment and changes in intensity and tracking. The DC-8 is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. The hurricane study, which lasts through September, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  18. Quantum mechanics concept assessment: Development and validation study

    NASA Astrophysics Data System (ADS)

    Sadaghiani, Homeyra R.; Pollock, Steven J.

    2015-06-01

    As part of an ongoing investigation of students' learning in first semester upper-division quantum mechanics, we needed a high-quality conceptual assessment instrument for comparing outcomes of different curricular approaches. The process of developing such a tool started with converting a preliminary version of a 14-item open-ended quantum mechanics assessment tool (QMAT) to a multiple-choice (MC) format. Further question refinement, development of effective distractors, adding new questions, and robust statistical analysis has led to a 31-item quantum mechanics concept assessment (QMCA) test. The QMCA is used as post-test only to assess students' knowledge about five main topics of quantum measurement: the time-independent Schrödinger equation, wave functions and boundary conditions, time evolution, and probability density. During two years of testing and refinement, the QMCA has been given in alpha (N =61 ) and beta versions (N =263 ) to students in upper division quantum mechanics courses at 11 different institutions with an average post-test score of 54%. By allowing for comparisons of student learning across different populations and institutions, the QMCA provides instructors and researchers a more standard measure of effectiveness of different curricula or teaching strategies on student conceptual understanding of quantum mechanics. In this paper, we discuss the construction of effective distractors and the use of student interviews and expert feedback to revise and validate both questions and distractors. We include the results of common statistical tests of reliability and validity, which suggest the instrument is presently in a stable, usable, and promising form.

  19. Validity and Reliability Study of the Self-Efficacy Scale in Rendering Piano Education to Children of 6-12 Years

    ERIC Educational Resources Information Center

    Ekinci, Hatice

    2014-01-01

    This study was conducted in order to develop a valid and reliable scale that can be used in measuring self-efficacy of candidate music teachers in rendering piano education to children of 6-12 years. To this end, a pool of 51 items was created by using the literature, and taking the opinions of piano professors and piano instructors working with…

  20. A Collection of Studies Conducted in Education about "Global Warming" Problem

    ERIC Educational Resources Information Center

    Bozdogan, Aykut Emre

    2011-01-01

    The studies global warming problem conducted in education discipline in the world and in Turkey were analysed for this study. The literature was reviewed extensively especially through the articles in the indexed journals of Ebsco Host, Science Direct, Taylor and Francis and Web of Science databases and this study was conducted according to the…

  1. Reliability and validity of the Center for Epidemiological Studies Depression Scale in 2 special adult samples from rural China.

    PubMed

    Zhang, Jie; Sun, Weiwei; Kong, Yuanyuan; Wang, Cuntong

    2012-11-01

    Few studies on the validation of the Center for Epidemiological Studies Depression Scale (CES-D) in Chinese have been conducted in the samples from rural area, whereas the mental health problems among rural Chinese deserve more attention. For instance, the suicide rate in rural China is about 3 times that of the urban rate. This study aimed at assessing reliability and validity of the CES-D in 2 special adult samples in rural China, with data obtained by face-to-face interviews. One sample consisted of the proxy informants for subjects who committed suicide, and the other was of the proxy informants for living controls. For each person who committed suicide and each control, a family member and close friend served as informants. This study focused on informants themselves (not the persons who committed suicide or the living control himself/herself). Suicide informants (n = 781) who had experienced the suicide of a relative or close friend in the past 6 months were compared with the control informants (n = 832) who had no such experience. Internal reliability was satisfactory (Cronbach coefficients were .949 for suicide informants and .880 for control informants). Good concurrent validity and criterion validity were found by analyzing the relations to negative life events and the Scale for Suicide Ideation. Confirmatory factor analyses indicated that 3-factor structure (positive affect, interpersonal problems, depressive mood and somatic symptoms combined) had good fit in rural Chinese. These findings suggested that the CES-D had good reliability and validity when applied in these 2 adult samples in rural China. Factor structure analyses of the CES-D indicated that "somatization" process of expressing depressive symptoms still existed among rural Chinese. PMID:22520090

  2. Strategies to assess the validity of recommendations: a study protocol

    PubMed Central

    2013-01-01

    Background Clinical practice guidelines (CPGs) become quickly outdated and require a periodic reassessment of evidence research to maintain their validity. However, there is little research about this topic. Our project will provide evidence for some of the most pressing questions in this field: 1) what is the average time for recommendations to become out of date?; 2) what is the comparative performance of two restricted search strategies to evaluate the need to update recommendations?; and 3) what is the feasibility of a more regular monitoring and updating strategy compared to usual practice?. In this protocol we will focus on questions one and two. Methods The CPG Development Programme of the Spanish Ministry of Health developed 14 CPGs between 2008 and 2009. We will stratify guidelines by topic and by publication year, and include one CPG by strata. We will develop a strategy to assess the validity of CPG recommendations, which includes a baseline survey of clinical experts, an update of the original exhaustive literature searches, the identification of key references (reference that trigger a potential recommendation update), and the assessment of the potential changes in each recommendation. We will run two alternative search strategies to efficiently identify important new evidence: 1) PLUS search based in McMaster Premium LiteratUre Service (PLUS) database; and 2) a Restrictive Search (ReSe) based on the least number of MeSH terms and free text words needed to locate all the references of each original recommendation. We will perform a survival analysis of recommendations using the Kaplan-Meier method and we will use the log-rank test to analyse differences between survival curves according to the topic, the purpose, the strength of recommendations and the turnover. We will retrieve key references from the exhaustive search and evaluate their presence in the PLUS and ReSe search results. Discussion Our project, using a highly structured and transparent methodology, will provide guidance of when recommendations are likely to be at risk of being out of date. We will also assess two novel restrictive search strategies which could reduce the workload without compromising rigour when CPGs developers check for the need of updating. PMID:23967896

  3. Statistical study of UHF scintillations conducted between 1994 and 2013

    NASA Astrophysics Data System (ADS)

    Valladares, C. E.; Sheehan, R. E.

    2013-12-01

    A spaced-antenna scintillation system was installed at Ancon, Peru in May 1994 to measure amplitude fluctuations of 250-MHz signals from a geostationary satellite located 100° W using three antennas spaced in the magnetic east-west direction. The system also included a receiver of L-band signals from the GOES satellite and a second baseline was added in November 1996 consisting of 2 spaced-antennas receiving UHF signals from a satellite at 25° W. This system also called the MISETA scintillation system was designed and built under supervision of Dr. Santimay Basu. The MISETA measurements have provided the climatology of amplitude scintillation and zonal irregularity drifts during almost 2 solar cycles. In addition to these statistical results, The MISETA system has been used to study in detail scintillation onset, duration, recurrence, and S4 intensity during special atmospheric processes such as stratospheric sudden warming (SSW) events. It was found that during SSW events scintillations occurred less frequently and appeared at later local times. Our conclusions are also compared with measurements from other scintillation/equatorial spread F sensors that exist in the Peruvian region. Digisonde and VIPIR ionosondes, coherent radars, imagers, and GPS receivers from the LISN network in South America, provide additional information on the characteristics of the disturbed environment and endorse the UHF scintillation results.

  4. Validity of using Gaussian Schell model for extended beacon studies

    NASA Astrophysics Data System (ADS)

    Basu, Santasri; Cusumano, Salvatore J.; Hyde, Milo W.; Marciniak, Michael A.; Fiorino, Steven T.

    2012-06-01

    In many military applications that use Adaptive Optics (AO) a point source beacon is ideally required at the target to measure and to correct for the wavefront aberrations caused by propagation through the atmosphere. However, it is rarely possible to create a point source beacon at the target. The "extended beacons" that are created instead have intensity profiles with a finite spatial extent and exhibit varying degrees of spatial coherence. The Gaussian Schell model might be a convenient way to model these extended sources because of its analytical tractability. The present work examines the validity of using such a model by evaluating the scattered field from a rough surface target using a full wave electromagnetic solution (method of moments). The full wave electromagnetic calculation improves the fidelity of the analysis by capturing all aspects of laser-target interaction i.e. shadowing/ masking, multiple reflections etc. A variety of rough surface targets with different roughness statistics has been analyzed. This analysis will ultimately aid in understanding the key parameters of extended beacons and how they impact the Adaptive Optics (AO) system performance.

  5. Students' Perceptions of Characteristics of Effective College Teachers: A Validity Study of a Teaching Evaluation Form Using a Mixed-Methods Analysis

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.; Witcher, Ann E.; Collins, Kathleen M. T.; Filer, Janet D.; Wiedmaier, Cheryl D.; Moore, Chris W.

    2007-01-01

    This study used a multistage mixed-methods analysis to assess the content-related validity (i.e., item validity, sampling validity) and construct-related validity (i.e., substantive validity, structural validity, outcome validity, generalizability) of a teaching evaluation form (TEF) by examining students' perceptions of characteristics of…

  6. Validity Studies Using the Comprehensive Ability Battery (CAB): I. Academic Achievement Criteria

    ERIC Educational Resources Information Center

    Hakstian, A. Ralph; Bennet, Richard W.

    1977-01-01

    A new multiple abilities battery, the Comprehensive Ability Battery, is described, and the results of five criterion-related validity studies using eleven tests of the battery are reported. (Author/JKS)

  7. Plume trajectory validation study: Brown cloud support project overview

    SciTech Connect

    Brown-Strattan, M.A. (ed.); Smith, M.L.

    1991-09-30

    The brown cloud is an air pollution phenomenon of great concern to the Denver metropolitan area. Regulatory agencies, academia, and research organizations are involved in characterizing the development and transport of the brown cloud and identifying mitigation approaches. In support of this effort, NOAA conducted releases of small (one cubic meter) constant density balloons from sites in Denver and along the South Platte Valley. These balloons, called tetroons'' because of their tetrahedral shape, carried five-ounce transponders and were tracked by radar as they rose to predetermined altitudes and followed airflow patterns at those altitudes. The data gathered from these releases included the geographic position and altitude of each tetroon over time. These data will aid efforts to understand brown cloud development, structure, and transport.

  8. Plume trajectory validation study: Brown cloud support project overview

    SciTech Connect

    Brown-Strattan, M.A. [ed.; Smith, M.L.

    1991-09-30

    The brown cloud is an air pollution phenomenon of great concern to the Denver metropolitan area. Regulatory agencies, academia, and research organizations are involved in characterizing the development and transport of the brown cloud and identifying mitigation approaches. In support of this effort, NOAA conducted releases of small (one cubic meter) constant density balloons from sites in Denver and along the South Platte Valley. These balloons, called ``tetroons`` because of their tetrahedral shape, carried five-ounce transponders and were tracked by radar as they rose to predetermined altitudes and followed airflow patterns at those altitudes. The data gathered from these releases included the geographic position and altitude of each tetroon over time. These data will aid efforts to understand brown cloud development, structure, and transport.

  9. Using a 3D Virtual Supermarket to Measure Food Purchase Behavior: A Validation Study

    PubMed Central

    Jiang, Yannan; Steenhuis, Ingrid Hendrika Margaretha; Ni Mhurchu, Cliona

    2015-01-01

    Background There is increasing recognition that supermarkets are an important environment for health-promoting interventions such as fiscal food policies or front-of-pack nutrition labeling. However, due to the complexities of undertaking such research in the real world, well-designed randomized controlled trials on these kinds of interventions are lacking. The Virtual Supermarket is a 3-dimensional computerized research environment designed to enable experimental studies in a supermarket setting without the complexity or costs normally associated with undertaking such research. Objective The primary objective was to validate the Virtual Supermarket by comparing virtual and real-life food purchasing behavior. A secondary objective was to obtain participant feedback on perceived sense of “presence” (the subjective experience of being in one place or environment even if physically located in another) in the Virtual Supermarket. Methods Eligible main household shoppers (New Zealand adults aged ?18 years) were asked to conduct 3 shopping occasions in the Virtual Supermarket over 3 consecutive weeks, complete the validated Presence Questionnaire Items Stems, and collect their real supermarket grocery till receipts for that same period. Proportional expenditure (NZ$) and the proportion of products purchased over 18 major food groups were compared between the virtual and real supermarkets. Data were analyzed using repeated measures mixed models. Results A total of 123 participants consented to take part in the study. In total, 69.9% (86/123) completed 1 shop in the Virtual Supermarket, 64.2% (79/123) completed 2 shops, 60.2% (74/123) completed 3 shops, and 48.8% (60/123) returned their real supermarket till receipts. The 4 food groups with the highest relative expenditures were the same for the virtual and real supermarkets: fresh fruit and vegetables (virtual estimate: 14.3%; real: 17.4%), bread and bakery (virtual: 10.0%; real: 8.2%), dairy (virtual: 19.1%; real: 12.6%), and meat and fish (virtual: 16.5%; real: 16.8%). Significant differences in proportional expenditures were observed for 6 food groups, with largest differences (virtual – real) for dairy (in expenditure 6.5%, P<.001; in items 2.2%, P=.04) and fresh fruit and vegetables (in expenditure: –3.1%, P=.04; in items: 5.9%, P=.002). There was no trend of overspending in the Virtual Supermarket and participants experienced a medium-to-high presence (88%, 73/83 scored medium; 8%, 7/83 scored high). Conclusions Shopping patterns in the Virtual Supermarket were comparable to those in real life. Overall, the Virtual Supermarket is a valid tool to measure food purchasing behavior. Nevertheless, it is important to improve the functionality of some food categories, in particular fruit and vegetables and dairy. The results of this validation will assist in making further improvements to the software and with optimization of the internal and external validity of this innovative methodology. PMID:25921185

  10. Study of thermal conductivity in organic solid wastes before composting J. HUET, C. Druilhe, G. Debenest

    E-print Network

    Paris-Sud XI, Université de

    Study of thermal conductivity in organic solid wastes before composting J. HUET, C. Druilhe, G. Debenest ORBIT2012 1 STUDY OF THERMAL CONDUCTIVITY IN ORGANIC SOLID WASTES BEFORE COMPOSTING J. Huet and disposal. Composting can be defined as the process whereby aerobic micro-organisms convert organic

  11. Central motor conduction time by magnetic stimulation of the cortex and peripheral nerve conduction follow-up studies in Friedreich's ataxia

    Microsoft Academic Search

    A Cruz-Mart??nez; F Palau

    1997-01-01

    A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9–12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for

  12. In-Trail Procedure Air Traffic Control Procedures Validation Simulation Study

    NASA Technical Reports Server (NTRS)

    Chartrand, Ryan C.; Hewitt, Katrin P.; Sweeney, Peter B.; Graff, Thomas J.; Jones, Kenneth M.

    2012-01-01

    In August 2007, Airservices Australia (Airservices) and the United States National Aeronautics and Space Administration (NASA) conducted a validation experiment of the air traffic control (ATC) procedures associated with the Automatic Dependant Surveillance-Broadcast (ADS-B) In-Trail Procedure (ITP). ITP is an Airborne Traffic Situation Awareness (ATSA) application designed for near-term use in procedural airspace in which ADS-B data are used to facilitate climb and descent maneuvers. NASA and Airservices conducted the experiment in Airservices simulator in Melbourne, Australia. Twelve current operational air traffic controllers participated in the experiment, which identified aspects of the ITP that could be improved (mainly in the communication and controller approval process). Results showed that controllers viewed the ITP as valid and acceptable. This paper describes the experiment design and results.

  13. Developing Environmental Sensitivity for Children Scale: Reliability and Validity Studies

    Microsoft Academic Search

    Emin Atasoy

    This study a This study aims to develop an Environmental Sensitivity Scale for pupils aged between 9-15 who attend primary School. In an attempt to develop questionnaire items, the relevant literature has been reviewed, and the studies of the researchers of Environmental Science and Education have been investigated. In order to ensure the reliability of 90-item-Likert scale which has been

  14. The "RG Sausage's" Missing Ingredients: Investigating the Validity of Reliability Generalization Study Design.

    ERIC Educational Resources Information Center

    Romano, Jeanine; Kromrey, Jeffrey D.

    The purpose of this study was to examine the potential impact of selected methodological factors on the validity of conclusions from reliability generalization (RG) studies. The study focused on four factors; (1) missing data in the primary studies; (2) transformation of sample reliability estimates; (3) use of sample weights for estimating mean…

  15. Validity and reproducibility of the food frequency questionnaire used in the Shanghai Women's Health Study

    Microsoft Academic Search

    X O Shu; G Yang; F Jin; D Liu; L Kushi; W Wen; Y-T Gao; W Zheng

    2004-01-01

    To evaluate the validity and reliability of the food frequency questionnaire (FFQ) used in the Shanghai Women's Health Study (SWHS), 200 SWHS participants were recruited for a dietary calibration study. Study participants completed an FFQ at baseline and 24-h dietary recalls (24-HDR) twice per month consecutively for 12 months. At the end of the study, a second FFQ was administered.

  16. Reliability and validity of the tritrac-R3D accelerometer during backpacking: a case study.

    PubMed

    DeVoe, D; Dalleck, L

    2001-08-01

    This study investigated the utility of the Tritrac-R3D accelerometer as a reliable and valid instrument in the quantification of physical activity while backpacking in the field and to evaluate heart-rate responses and oxygen consumption to assess the feasibility of using the Tritrac-R3D to estimate caloric expenditure. Two 7-day backpacking expeditions were conducted in two consecutive years by a single subject at Grand Canyon National Park, Arizona. The average hiking heart rate ranged front 60% to 77% HRmax during the expeditions. The average rate of estimated caloric cost ranged from 6.8 to 11.7 kcals x min.(-1) (equivalent to 408 to 702 kcals x hr.(-1)), indicating a relatively moderate to high level of exertion. The Tritrac had adequate consistency and reliability in the field between the two expeditions in recorded activity counts. The Tritrac underestimated caloric expenditure during backpacking with changes in terrain, and hiking speed contributed to even greater disparity in accuracy. PMID:11693704

  17. Terrestrial gastropods (Helix spp) as sentinels of primary DNA damage for biomonitoring purposes: a validation study.

    PubMed

    Angeletti, Dario; Sebbio, Claudia; Carere, Claudio; Cimmaruta, Roberta; Nascetti, Giuseppe; Pepe, Gaetano; Mosesso, Pasquale

    2013-04-01

    We validated the alkaline comet assay in two species of land snail (Helix aspersa and Helix vermiculata) to test their suitability as sentinels for primary DNA damage in polluted environments. The study was conducted under the framework of a biomonitoring program for a power station in Central Italy that had recently been converted from oil to coal-fired plant. After optimizing test conditions, the comet assay was used to measure the % Tail DNA induced by in vitro exposure of hemocytes to different concentrations of a reactive oxygen species (H2 O2 ). The treatment induced significant increases in this parameter with a concentration effect, indicating the effectiveness of the assay in snail hemocytes. After evaluating possible differences between the two species, we sampled them in three field sites at different distances from the power station, and in two reference sites assumed to have low or no levels of pollution. No species differences emerged. Percent Tail DNA values in snails from the sites near the power station were higher than those from control sites. An inverse correlation emerged between % Tail DNA and distance from the power station, suggesting that the primary DNA damage decreased as distance increased away from the pollution source. Detection of a gradient of heavy metal concentration in snail tissues suggests that these pollutants are a potential cause of the observed pattern. The comet assay appears to be a suitable assay and Helix spp. populations suitable sentinels to detect the genotoxic impact of pollutants. PMID:23444166

  18. Mini-Mental Parkinson: first validation study of a new bedside test constructed for Parkinson's disease.

    PubMed

    Mahieux, F; Michelet, D; Manifacier, M J; Boller, F; Fermanian, J; Guillard, A

    1995-01-01

    We have developed a brief screening test aimed at identifying cognitive disorders in Parkinson's disease. The Mini-Mental Parkinson derives from the Mini-Mental State Examination of Folstein. It includes seven ordered subsections, with a total score of 32. A pilot study was conducted in 50 community-dwelling parkinsonian patients, in order to establish its metrological qualities. Comparisons were made with a neuropsychological battery including several tests widely used in the assessment of specific cognitive disorders in Parkinson's disease. The correlations between the Mini-Mental Parkinson and each component of this battery were substantial, especially for the performance subtests of the WAIS-R (r = 0.62 to 0.72), the Stroop test (r = 0.65) the 15-objects test (r = 0.64), the word fluency (r = 0.63) and the Odd Man Out test (r = 0.61). The validity of each subtest of the Mini-Mental Parkinson was adequate except for one, based on a word choice, which requires a modification in French before definitive use. The test-retest reliability was high (r = 0.84). There was a significant difference in the mean scores in cases with confusional event (22.4), even without current signs of dementia, compared with patients with no such history (27.2). In conclusion, this brief test is suitable for assessment of parkinsonian patients. PMID:24487398

  19. Note: optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems.

    PubMed

    Moscicki, J K; Sokolowska, D; Kwiatkowski, L; Dziob, D; Nowak, J

    2014-02-01

    A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time. PMID:24593402

  20. Note: Optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems

    SciTech Connect

    Moscicki, J. K.; Sokolowska, D.; Dziob, D.; Nowak, J. [Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)] [Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Kwiatkowski, L. [Department of Econometrics and Operations Research, Cracow University of Economics, Rakowicka 27, 31-510 Krakow (Poland)] [Department of Econometrics and Operations Research, Cracow University of Economics, Rakowicka 27, 31-510 Krakow (Poland)

    2014-02-15

    A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time.

  1. Thermal Conductivity in Zeolites Studied by Non-equilibrium Molecular Dynamics Simulations

    NASA Astrophysics Data System (ADS)

    Schnell, Sondre K.; Vlugt, Thijs J. H.

    2013-07-01

    The thermal conductivity of zeolites is an important material property. For example, this is the case for catalysis, where chemical reactions release heat either inside zeolites or at zeolite surfaces. At zeolite surfaces, heat is released during the adsorption of guest molecules. Unfortunately, it can be difficult to determine the thermal conductivity of zeolites from experiments or from equilibrium molecular dynamics simulations. Non-equilibrium molecular dynamics (NEMD) simulation is an interesting approach to determine thermal conductivities. Inducing a thermal gradient by moving kinetic energy between different parts of the simulation box, and then studying the resulting thermal gradient, will lead to direct access to the thermal conductivity of the zeolite. In this work, we have used NEMD simulations to determine the thermal conductivity of several pure silica zeolites. The zeolites are modeled using the Demontis force field, making it possible to screen many zeolite frameworks, and study finite-size effects. In addition, we have studied the influence of adsorbed guest molecules on the thermal conductivity. The thermal conductivity of zeolites is usually in order of 0.6 to almost 4 , with large differences between different crystallographic directions. We find that the loading of guest molecules adsorbed inside the zeolite has a minor influence on the thermal conductivity, and that in general the thermal conductivity increases with increasing framework density of the zeolite.

  2. Virtual Environment Interpersonal Trust Scale: Validity and Reliability Study

    ERIC Educational Resources Information Center

    Usta, Ertugrul

    2012-01-01

    The purpose of this study is in the process of interpersonal communication in virtual environments is available from the trust problem is to develop a measurement tool. Trust in the process of distance education today, and has been a factor to be investigated. People, who take distance education course, they could may remain within the process…

  3. Theoretical Evaluation Self-Test (Test): A Preliminary Validation Study

    ERIC Educational Resources Information Center

    Coleman, Daniel

    2004-01-01

    Over nearly 40 years, several scales have been developed to measure therapist theoretical orientation (Poznanski & McLennan, 1995). This study, unlike previous efforts, focuses on "community clinicians"--social workers and other mental health professionals (such as psychologists, counselors, psychiatrists, and psychiatric nurses) who work in…

  4. Rorschach measures of aggression: a laboratory-based validity study.

    PubMed

    Kivisto, Aaron J; Swan, Scott A

    2013-01-01

    This study sought to complement the archival research designs that have established the empirical foundations of Rorschach aggression scores, including Exner's ( 2003 ) Aggressive Movement (AG) score and Meloy and Gacono's ( 1992 ) Aggressive Content (AgC), Aggressive Past (AgPast), and Aggressive Potential (AgPot) variables. Utilizing a highly controlled laboratory-based aggression paradigm and self-report measures of violence history in a sample of 35 undergraduate males with an average age of 19.38 (SD = 2.11), this study found that only AgC was positively associated with in vivo aggression (r = .40, p = .02). None of the Rorschach measures of aggression were significantly associated with self-reported violence history, although there were several trends approaching significance. Theoretical and methodological implications are discussed. PMID:22906090

  5. Are All Clinical Studies Sponsored by Industry Not Valid?

    PubMed Central

    Heinemann, Lutz

    2008-01-01

    Industry-sponsored studies have such a bad reputation that some journals require an additional statistical analysis by an independent statistician. This commentary discusses some of the reasons why academic people tend to believe that “academic” science is better than industry-driven science. Most likely, when it comes to publications, the risk of fraud exists in both worlds as the pressure to publish “significant” data is prevalent in both worlds. In contrast to the academic world, the level of control by regulatory bodies for industry-sponsored studies is much higher. Therefore, the quality of industry-driven studies is high, at least when it comes to the quality of data. One of the main reasons why academic people are so skeptical about the pharmaceutical industry is a lack of knowledge about the work done in industry. It is as demanding and scientific as in other industries. In turn, many physicians working in the pharmaceutical industry have low self-esteem. Also, the pharmaceutical industry should improve its self-presentation adequately to get rid of its bad image. There is a clear need for more communication between both worlds in order to better understand the mutual difficulties and needs. PMID:19885307

  6. The adult antisocial syndrome with and without antecedent conduct disorder: Comparisons from an adoption study

    Microsoft Academic Search

    Douglas R. Langbehn; Remi J. Cadoret

    2001-01-01

    DSM antisocial personality disorder (ASPD) requires a retrospective diagnosis of conduct disorder—historical behavior not present in everyone with adult ASPD criteria. Using adoption study data, we examined the impact of this requirement on biological and environmental risk associations. We also compared clinical correlates of adult antisocial behavior with and without prior conduct disorder. We defined three subgroups: DSM-III ASPD (n

  7. Cesium-Filled Single Wall Carbon Nanotubes as Conducting Nanowires: Scanning Tunneling Spectroscopy Study

    Microsoft Academic Search

    S. H. Kim; W. I. Choi; G. Kim; Y. J. Song; G.-H. Jeong; R. Hatakeyama; J. Ihm; Y. Kuk

    2007-01-01

    Metal-filled single wall carbon nanotubes (SWCNTs) are examined for possible application to conducting wires in nanoelectronics architecture. The local electronic structure of SWCNTs partially filled with cesium atoms is studied with scanning tunneling spectroscopy. The conduction and valence bands are shifted downward with two localized states in the gap at the location where the Cs atoms are filled. From a

  8. Conductivity of blends of polyaniline with PMMA and cellulose acetate: aging studies

    Microsoft Academic Search

    J. Nizio?; J. Laska

    1999-01-01

    Effect of aging on the conductivity of polyaniline doped with phosphoric acid diesters, and its blends with nonconductive polymers is the subject of this study. Conductivity of polyaniline doped with bis(2-ethylhexyl) phosphate increases about one order of magnitude during first year of aging in ambient conditions, and then decreases one to two orders of magnitude after six years. Similarly, increase

  9. Study: Honeybees make ruthless relatives Many species of ants, wasps and bees conduct in cannibalism

    E-print Network

    Wenseleers, Tom

    Study: Honeybees make ruthless relatives Many species of ants, wasps and bees conduct. The same applies to wasps and ants. But many don't survive. In all of these cannibalistic acts, each eater to a new survey of more than 100 species of ants, bees and wasps conducted by Wenseleers and Francis

  10. Curriculum Design Orientations Preference Scale of Teachers: Validity and Reliability Study

    ERIC Educational Resources Information Center

    Bas, Gokhan

    2013-01-01

    The purpose of this study was to develop a valid and reliable scale for preferences of teachers in regard of their curriculum design orientations. Because there was no scale development study similar to this one in Turkey, it was considered as an urgent need to develop such a scale in the study. The sample of the research consisted of 300…

  11. Validity and feasibility of a digital diet estimation method for use with preschool children: a pilot study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of the study was to assess the validity and feasibility of a digital diet estimation method for use with preschool children in Head Start. Preschool children and their caregivers participated in validation (n=22) and feasibility (n=24) pilot studies. Validity was determined in the metabolic...

  12. Validity and reliability tests in case study research: a literature review with “hands-on” applications for each research phase

    Microsoft Academic Search

    Andreas M. Riege

    2003-01-01

    Despite the advantages of the case study method, its reliability and validity remain in doubt. Tests to establish the validity and reliability of qualitative data are important to determine the stability and quality of the data obtained. However, there is no single, coherent set of validity and reliability tests for each research phase in case study research available in the

  13. Validation of protein carbonyl measurement: A multi-centre study

    PubMed Central

    Augustyniak, Edyta; Adam, Aisha; Wojdyla, Katarzyna; Rogowska-Wrzesinska, Adelina; Willetts, Rachel; Korkmaz, Ayhan; Atalay, Mustafa; Weber, Daniela; Grune, Tilman; Borsa, Claudia; Gradinaru, Daniela; Chand Bollineni, Ravi; Fedorova, Maria; Griffiths, Helen R.

    2014-01-01

    Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial kits. We have further explored the potential causes of variance in carbonyl analysis in a ring study. A soluble protein fraction was prepared from rat liver and exposed to 0, 5 and 15 min of UV irradiation. Lyophilised preparations were distributed to six different laboratories that routinely undertook protein carbonyl analysis across Europe. ELISA and Western blotting techniques detected an increase in protein carbonyl formation between 0 and 5 min of UV irradiation irrespective of method used. After irradiation for 15 min, less oxidation was detected by half of the laboratories than after 5 min irradiation. Three of the four ELISA carbonyl results fell within 95% confidence intervals. Likely errors in calculating absolute carbonyl values may be attributed to differences in standardisation. Out of up to 88 proteins identified as containing carbonyl groups after tryptic cleavage of irradiated and control liver proteins, only seven were common in all three liver preparations. Lysine and arginine residues modified by carbonyls are likely to be resistant to tryptic proteolysis. Use of a cocktail of proteases may increase the recovery of oxidised peptides. In conclusion, standardisation is critical for carbonyl analysis and heavily oxidised proteins may not be effectively analysed by any existing technique. PMID:25560243

  14. Validation of Physical Activity Tracking via Android Smartphones Compared to ActiGraph Accelerometer: Laboratory-Based and Free-Living Validation Studies

    PubMed Central

    Buman, Matthew P; Grieco, Lauren; Rosenberger, Mary; Winter, Sandra J; Haskell, William; King, Abby C

    2015-01-01

    Background There is increasing interest in using smartphones as stand-alone physical activity monitors via their built-in accelerometers, but there is presently limited data on the validity of this approach. Objective The purpose of this work was to determine the validity and reliability of 3 Android smartphones for measuring physical activity among midlife and older adults. Methods A laboratory (study 1) and a free-living (study 2) protocol were conducted. In study 1, individuals engaged in prescribed activities including sedentary (eg, sitting), light (sweeping), moderate (eg, walking 3 mph on a treadmill), and vigorous (eg, jogging 5 mph on a treadmill) activity over a 2-hour period wearing both an ActiGraph and 3 Android smartphones (ie, HTC MyTouch, Google Nexus One, and Motorola Cliq). In the free-living study, individuals engaged in usual daily activities over 7 days while wearing an Android smartphone (Google Nexus One) and an ActiGraph. Results Study 1 included 15 participants (age: mean 55.5, SD 6.6 years; women: 56%, 8/15). Correlations between the ActiGraph and the 3 phones were strong to very strong (?=.77-.82). Further, after excluding bicycling and standing, cut-point derived classifications of activities yielded a high percentage of activities classified correctly according to intensity level (eg, 78%-91% by phone) that were similar to the ActiGraph’s percent correctly classified (ie, 91%). Study 2 included 23 participants (age: mean 57.0, SD 6.4 years; women: 74%, 17/23). Within the free-living context, results suggested a moderate correlation (ie, ?=.59, P<.001) between the raw ActiGraph counts/minute and the phone’s raw counts/minute and a strong correlation on minutes of moderate-to-vigorous physical activity (MVPA; ie, ?=.67, P<.001). Results from Bland-Altman plots suggested close mean absolute estimates of sedentary (mean difference=–26 min/day of sedentary behavior) and MVPA (mean difference=–1.3 min/day of MVPA) although there was large variation. Conclusions Overall, results suggest that an Android smartphone can provide comparable estimates of physical activity to an ActiGraph in both a laboratory-based and free-living context for estimating sedentary and MVPA and that different Android smartphones may reliably confer similar estimates. PMID:25881662

  15. VALUE - A Framework to Validate Downscaling Approaches for Climate Change Studies

    NASA Astrophysics Data System (ADS)

    Maraun, Douglas; Widmann, Martin; Gutiérrez, José M.; Kotlarski, Sven; Chandler, Richard E.; Hertig, Elke; Wibig, Joanna; Huth, Radan; Wilke, Renate A. I.

    2015-04-01

    VALUE is an open European network to validate and compare downscaling methods for climate change research. VALUE aims to foster collaboration and knowledge exchange between climatologists, impact modellers, statisticians, and stakeholders to establish an interdisciplinary downscaling community. A key deliverable of VALUE is the development of a systematic validation framework to enable the assessment and comparison of both dynamical and statistical downscaling methods. Here, we present the key ingredients of this framework. VALUE's main approach to validation is user-focused: starting from a specific user problem, a validation tree guides the selection of relevant validation indices and performance measures. Several experiments have been designed to isolate specific points in the downscaling procedure where problems may occur: what is the isolated downscaling skill? How do statistical and dynamical methods compare? How do methods perform at different spatial scales? Do methods fail in representing regional climate change? How is the overall representation of regional climate, including errors inherited from global climate models? The framework will be the basis for a comprehensive community-open downscaling intercomparison study, but is intended also to provide general guidance for other validation studies.

  16. Electrical conductivity and phase transition studies of TiO2-BaO system

    NASA Astrophysics Data System (ADS)

    Beg, Saba; Haneef, Sadaf

    2015-01-01

    The solid solution of BaTiO3 was prepared by conventional solid state reaction. The electrical conductivity of TiO2-BaO system has been studied at different temperatures for various molar ratios. The isothermal conductivity increases with BaO concentration due to the vacancy migration phenomenon. It has been found that the electrical conductivity after attaining a maximum value at 240°C decreases with increase in temperature due to the collapse of the fluorite framework. A second rise in conductivity in the temperature range 470-540°C indicates the phase transition of TiO2 from anatase to rutile. AC Impedance measurements proved that the oxide ion conductivity predominantly arises from the grain contribution. The sample characterization and the study of phase transition changes were done by using XRD, FT-IR and DSC measurements. On increasing the concentration of BaO the transition temperature shifts towards higher side.

  17. Concept study and validation of Antarctic telescope tower

    NASA Astrophysics Data System (ADS)

    Lanford, Ephraim; Swain, Mark; Meyers, Catherine; Muramatsu, Tamao; Nielson, Greg; Olson, Valerie; Ronsse, Sebastien; Vinding Nyden, Emily; Hammerschlag, Robert; Little, Patrick

    2006-06-01

    Studies by Mark Swain and a colleague at the Max Planck Institut fur Astronomie, coupled with results from past and ongoing projects at Harvey Mudd College, strongly suggest that it may be possible to achieve imaging performance comparable to the Hubble Space Telescope at relatively low cost using available, commercial products. This is achievable by placing a 2.4 m telescope, with readily available adaptive optics, on a 30 m tower located at a high-elevation geological "dome" in Antarctica. An initial project surveyed relevant tower design approaches, then generated and evaluated six concept designs for telescope towers. Using data for typical and extreme wind at Dome C to generate wind loads, finite element analysis yielded lateral deflections at the top of 0.3 mm for typical winds and 12.1 mm for extreme gusts, with the lowest resonant frequency at 0.7 Hz; some tower concepts are innovative and allow for easy shipment, setup, and relocation. A subsequent project analyzed a tower designed by Hammerschlag and found fundamental resonance frequencies at 4.3 Hz for bending and 5.9 Hz for torsion; this project also designed and simulated an active telescope control system that maintained 17 milliarcsecond pointing error for the telescope atop the tower during typical wind conditions.

  18. Validation study on the Ocular Irritection assay for eye irritation testing.

    PubMed

    Eskes, Chantra; Hoffmann, Sebastian; Facchini, Davide; Ulmer, Rich; Wang, Amy; Flego, Manuela; Vassallo, Marco; Bufo, Monica; van Vliet, Erwin; d'Abrosca, Federica; Wilt, Nathan

    2014-08-01

    Both a prospective and a retrospective validation study were undertaken to assess the suitability of the Ocular Irritection assay to discriminate ocular hazards as defined by the OECD and UN Globally Harmonized System (UN GHS) for classification. The primary focus of the study was to evaluate the usefulness of the Ocular Irritection assay to reliably discriminate chemicals not requiring classification (UN GHS non-classified), from classified chemicals (UN GHS Categories 1 and 2). Furthermore a post-hoc evaluation was carried out to evaluate the usefulness of the assay to discriminate chemicals inducing serious eye damage (UN GHS Category 1) from other classes. The prospective validation study was conducted between 2009 and 2012 following internationally agreed principles. A set of 56 coded test chemicals for which quality and/or peer-reviewed in vivo data were available were used to obtain prospective data on the assay's reliability (reproducibility within and between laboratories) and relevance (predictive capacity). The assay showed good within-laboratory variability, transferability including to a naïve laboratory, and between-laboratory concordance of classifications (82% for the discrimination of non-classified from classified chemicals, and 83% for the discrimination of Category 1 from other classes). The obtained prospective data were then combined with existing data on the Ocular Irritection collected from various sources, totaling 88 chemicals with parallel in vivo and in vitro data to obtain a comprehensive assessment of the test method performances. The enlarged dataset comprised 43 non-classified, 25 Category 2 and 20 Category 1 chemicals according to the UN GHS classification. When used for the identification of UN GHS non-classified versus classified materials (based on the existing cut-off of 12.5) the Ocular Irritection assay showed an overall a sensitivity of 93% and a specificity of 58%. An evaluation on possible reasons for misclassification identified some organic functional groups (acrylate, carboxamide and cycloalkene) to correlate with the observed mispredictions. If these functional groups were excluded from the Ocular Irritection applicability domain, the obtained dataset (n=79 chemicals distributed as 41 UN GHS Classified and 38 Non-Classified chemicals) had an overall sensitivity of 98%, and specificity of 63%, which is in line with currently adopted test methods. When used for the identification of UN GHS Category 1 versus other categories (based on the existing cut-off of 30.0) the Ocular Irritection assay showed an overall specificity of 81% and a sensitivity of 50% which is again in line with currently adopted test methods. The Ocular Irritection assay appeared therefore as a useful test method to predict chemicals not requiring classification for eye hazards according to the UN GHS classification system. Furthermore the method was found suitable to identify serious/irreversible eye damage (UN GHS Category 1). The detailed documentation and results of the study have been submitted to an internationally recognized validation centre for peer-review. PMID:24637247

  19. Treatment Integrity: A Review of Intervention Studies Conducted with Children with Autism

    ERIC Educational Resources Information Center

    Wheeler, John J.; Baggett, Bob A.; Fox, James; Blevins, Leia

    2006-01-01

    The purpose of this study was to assess the degree to which behavioral intervention studies conducted with children diagnosed with autism operationally defined the independent variables (IVs) and evaluated treatment integrity (TI). The study replicated the criteria from Gresham, Gansle, and Noell (1993) and focused exclusively on research studies…

  20. Mixed ionic and electronic conducting electrode studies for an alkali metal thermal to electric converter

    Microsoft Academic Search

    Yuyan Guo

    2006-01-01

    This research focuses on preparation, kinetics, and performance studies of mixed ionic and electronic conducting electrodes (MIEE) applied in an alkali metal thermal to electric converter (AMTEC). Two types of MIEE, metal\\/sodium titanate and metal\\/beta\\

  1. Conductive olfactory losses in chronic rhinosinusitis? – A computational fluid dynamics study of 29 patients

    PubMed Central

    Zhao, Kai; Jiang, Jianbo; Pribitkin, Edmund A.; Dalton, Pamela; Rosen, David; Lyman, Brian; Yee, Karen K.; Rawson, Nancy E.; Cowart, Beverly J.

    2014-01-01

    Objective Besides sensorineural factors, conductive impediments likely contribute to olfactory losses in chronic rhinosinusitis (CRS) patients, yet no conclusive evidence exists. We aimed to examine possible conductive factors using computational fluid dynamics (CFD) models. Methods 29 CRS patients were assessed via odorant detection thresholds (ODTs), rhinomanometry (nasal resistance: NR), acoustic rhinometry (minimum-cross-sectional area: MCA) and CT staging. CFD simulations of nasal airflow and odorant absorption to olfactory region were carried out based on individual CTs. Biopsies of olfactory epithelium (OE) were collected, cryo-sectioned, stained and scored for erosion. Results Significant correlations to ODTs were found for three variables: odor absorption in the olfactory region (r=?0.60, p<0.01), MCA (r=?0.40, p<0.05) and CT staging (r=0.42, p<0.05). However, significant findings were limited to ODTs of the highly soluble l-carvone. Multiple regression analysis revealed that these variables combined, with the addition of NR, can account for 65% of the total variance in ODTs. CT staging correlated significantly with OE erosion (r=0.77, p<0.01) and can replace the latter in the regression with comparable outcomes. Partial correlations suggest the contributions of both conductive and sensorineural variables are more prominent if adjusted for the effects of the other. Olfactory loss and inflammatory factors have strong bilateral involvement, while conductive factors are independent between sides. As validation, CFD-simulated NRs significantly correlated with rhinomanometrically assessed ones (r=0.60, p<0.01). Conclusion Both conductive and sensorineural mechanisms can contribute to olfactory losses in CRS. CFD modeling provides critical guidance in understanding the role of conductive impediments in olfactory dysfunction in CRS. PMID:24449655

  2. An optimal guarding scheme for thermal conductivity measurement using a guarded cut-bar technique, part 1 experimental study

    SciTech Connect

    Xing, Changhu [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Jensen, Colby [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Folsom, Charles [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Ban, Heng [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Marshall, Douglas W. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-01-01

    In the guarded cut-bar technique, a guard surrounding the measured sample and reference (meter) bars is temperature controlled to carefully regulate heat losses from the sample and reference bars. Guarding is typically carried out by matching the temperature profiles between the guard and the test stack of sample and meter bars. Problems arise in matching the profiles, especially when the thermal conductivitiesof the meter bars and of the sample differ, as is usually the case. In a previous numerical study, the applied guarding condition (guard temperature profile) was found to be an important factor in measurement accuracy. Different from the linear-matched or isothermal schemes recommended in literature, the optimal guarding condition is dependent on the system geometry and thermal conductivity ratio of sample to meter bar. To validate the numerical results, an experimental study was performed to investigate the resulting error under different guarding conditions using stainless steel 304 as both the sample and meter bars. The optimal guarding condition was further verified on a certified reference material, pyroceram 9606, and 99.95% pure iron whose thermal conductivities are much smaller and much larger, respectively, than that of the stainless steel meter bars. Additionally, measurements are performed using three different inert gases to show the effect of the insulation effective thermal conductivity on measurement error, revealing low conductivity, argon gas, gives the lowest error sensitivity when deviating from the optimal condition. The result of this study provides a general guideline for the specific measurement method and for methods requiring optimal guarding or insulation.

  3. Preliminary study on improvement of cementitious grout thermal conductivity for geothermal heat pump applications

    SciTech Connect

    Allan, M.L.

    1996-06-01

    Preliminary studies were preformed to determine whether thermal conductivity of cementitious grouts used to backfill heat exchanger loops for geothermal heat pumps could be improved, thus improving efficiency. Grouts containing selected additives were compares with conventional bentonite and cement grouts. Significant enhancement of grout alumina grit, steel fibers, and silicon carbide increased the thermal conductivity when compared to unfilled, high solids bentonite grouts and conventional cement grouts. Furthermore, the developed grouts retained high thermal conductivity in the dry state, where as conventional bentonite and cement grouts tend to act as insulators if moisture is lost. The cementitious grouts studied can be mixed and placed using conventional grouting equipment.

  4. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Ta?demir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. PMID:25342307

  5. Case study of verification, validation, and testing in the Automated Data Processing (ADP) system development life cycle

    SciTech Connect

    Riemer, C.A.

    1990-05-01

    Staff of the Environmental Assessment and Information Sciences Division of Argonne National Laboratory (ANL) studies the role played by the organizational participants in the Department of Veterans Affairs (VA) that conduct verification, validation, and testing (VV T) activities at various stages in the automated data processing (ADP) system development life cycle (SDLC). A case-study methodology was used to assess the effectiveness of VV T activities (tasks) and products (inputs and outputs). The case selected for the study was a project designed to interface the compensation and pension (C P) benefits systems with the centralized accounts receivable system (CARS). Argonne developed an organizational SDLC VV T model and checklists to help collect information from C P/CARS participants on VV T procedures and activities, and these were then evaluated against VV T standards.

  6. Sources of Validity Evidence for Educational and Psychological Tests: A Follow-Up Study

    ERIC Educational Resources Information Center

    Cizek, Gregory J.; Bowen, Daniel; Church, Keri

    2010-01-01

    This study followed up on previous work that examined the incidence of reporting evidence based on test consequences in "Mental Measurements Yearbook". In the present study, additional possible outlets for what has been called "consequential validity" evidence were investigated, including all articles published in the past 10 years in several…

  7. Compassion Fatigue and Psychological Distress Among Social Workers: A Validation Study

    Microsoft Academic Search

    Richard E. Adams; Joseph A. Boscarino; Charles R. Figley

    2006-01-01

    Few studies have focused on caring professionals and their emotional exhaustion from working with traumatized clients, referred to as compassion fatigue (CF). The present study had 2 goals: (a) to assess the psychometric properties of a CF scale, and (b) to examine the scale's predictive validity in a multivariate model. The data came from a survey of social workers living

  8. Toward the validation of Tinto's model of college student attrition: A review of recent studies

    Microsoft Academic Search

    Patrick T. Terenzini; Ernest T. Pascarella

    1980-01-01

    This paper describes the salient findings of six studies undertaken to assess the construct validity of Tinto's model of college student attrition. The studies are based on three independent data collections over a three-year period and indicate that students' informal contacts with faculty members are consistently related to subsequent persistence\\/withdrawal decisions. Background characteristics appear not to be reliably related to

  9. An Attitude Scale for Smart Board Use in Education: Validity and Reliability Studies

    ERIC Educational Resources Information Center

    Sad, Suleyman Nihat

    2012-01-01

    The main purpose of this study was to develop an instrument to measure the attitudes of elementary students towards smart board (SB) use in education. A sequential exploratory mixed method was used. So the study started with a qualitative approach to establish the content and face validity of the scale, followed by a quantitative approach to test…

  10. The Construct and Criterion Validity of Emotional Intelligence and Its Potential Utility for Management Studies

    Microsoft Academic Search

    Kenneth S. Law; Chi-Sum Wong; Lynda J. Song

    2004-01-01

    In this study, the authors reviewed the definition of emotional intelligence (EI) and argued that EI is conceptually distinct from personality. In Study 1, the authors showed that EI was related to yet distinct from personality dimensions and that it had incremental predictive power on life satisfaction. The authors examined the construct validity of self-reports and others' ratings of EI

  11. A Validity and Reliability Study on the Development of the Values Scale in Turkey

    ERIC Educational Resources Information Center

    Dilmac, Bulent; Aricak, Osman Tolga; Cesur, Sevim

    2014-01-01

    The purpose of the present study is to examine the initial psychometric properties of the Values Scale for adults. While developing the first stage of the Values Scale, open-ended data on the values held by 216 university students were obtained. During the second stage, the validity and reliability studies of the 60-item Values Scale obtained by…

  12. A Validity and Reliability Study of the Motivated Strategies for Learning Questionnaire

    ERIC Educational Resources Information Center

    Erturan Ilker, Gökçe; Arslan, Yunus; Demirhan, Giyasettin

    2014-01-01

    The aim of this study is to determine the validity and reliability of the Motivated Strategies for Learning Questionnaire (MSLQ) for high school students. In total, 1605 students (829 girls, 776 boys, average age = 15.67 ± 1.19) from three different high schools in the central district of Ankara voluntarily participated in the study. The MSLQ was…

  13. The Depression Anxiety and Stress Scale (DASS): The Study of Validity and Reliability

    ERIC Educational Resources Information Center

    Akin, Ahmet; Cetin, Bayram

    2007-01-01

    This study investigated the validity and reliability of the Turkish version of the Depression Anxiety Stress Scale (DASS). The sample of the study consisted of 590 university students, 121 English teachers and 136 emotionally disturbed individuals who sought treatment in various clinics and counseling centers. Factor loadings of the scale ranged…

  14. Water Awareness Scale for Pre-Service Science Teachers: Validity and Reliability Study

    ERIC Educational Resources Information Center

    Filik Iscen, Cansu

    2015-01-01

    The role of teachers in the formation of environmentally sensitive behaviors in students is quite high. Thus, the water awareness of teachers, who represent role models for students, is rather important. The main purpose of this study is to identify the reliability and validity study outcomes of the Water Awareness Scale, which was developed to…

  15. The Scales of Psychological Well-Being: A Study of Validity and Reliability

    ERIC Educational Resources Information Center

    Akin, Ahmet

    2008-01-01

    This study investigated the validity and reliability of the Turkish version of the Scales of Psychological Well-being (Ryff, 1989a). The sample of the study consists of 1214 university students. Results of language equivalency showed that correlations between the Turkish and English forms were 0.94 for autonomy, 0.97 for environmental mastery,…

  16. Development and Validation of the Short Use of Creative Cognition Scale in Studying

    ERIC Educational Resources Information Center

    Rogaten, Jekaterina; Moneta, Giovanni B.

    2015-01-01

    This paper reports the development and validation of a short Use of Creative Cognition Scale in Studying (UCCS) that was inspired by the Cognitive Processes Associated with Creativity (CPAC) scale. In Study 1, items from two of the six subscales of the CPAC were excluded due to conceptual and psychometric issues to create a 21-item CPAC scale,…

  17. Developing a Scale for Innovation Management at Schools: A Study of Validity and Reliability

    ERIC Educational Resources Information Center

    Bulbul, Tuncer

    2012-01-01

    The purpose of this study is to develop a valid and reliable assessment tool for use in determining the competency beliefs of school administrators about innovation management. The scale applied to a study group of 216 school administrators, after work Centered on assessing intelligibility and specialized opinion. Exploratory and confirmatory…

  18. Communication: Minimum in the thermal conductivity of supercooled water: A computer simulation study

    SciTech Connect

    Bresme, F., E-mail: f.bresme@imperial.ac.uk [Chemical Physics Section, Department of Chemistry, Imperial College, London SW7 2AZ, United Kingdom and Department of Chemistry, Norwegian University of Science and Technology, Trondheim 7491 (Norway); Biddle, J. W.; Sengers, J. V.; Anisimov, M. A. [Institute for Physical Science and Technology, and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)] [Institute for Physical Science and Technology, and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28

    We report the results of a computer simulation study of the thermodynamic properties and the thermal conductivity of supercooled water as a function of pressure and temperature using the TIP4P-2005 water model. The thermodynamic properties can be represented by a two-structure equation of state consistent with the presence of a liquid-liquid critical point in the supercooled region. Our simulations confirm the presence of a minimum in the thermal conductivity, not only at atmospheric pressure, as previously found for the TIP5P water model, but also at elevated pressures. This anomalous behavior of the thermal conductivity of supercooled water appears to be related to the maximum of the isothermal compressibility or the minimum of the speed of sound. However, the magnitudes of the simulated thermal conductivities are sensitive to the water model adopted and appear to be significantly larger than the experimental thermal conductivities of real water at low temperatures.

  19. Communication: minimum in the thermal conductivity of supercooled water: a computer simulation study.

    PubMed

    Bresme, F; Biddle, J W; Sengers, J V; Anisimov, M A

    2014-04-28

    We report the results of a computer simulation study of the thermodynamic properties and the thermal conductivity of supercooled water as a function of pressure and temperature using the TIP4P-2005 water model. The thermodynamic properties can be represented by a two-structure equation of state consistent with the presence of a liquid-liquid critical point in the supercooled region. Our simulations confirm the presence of a minimum in the thermal conductivity, not only at atmospheric pressure, as previously found for the TIP5P water model, but also at elevated pressures. This anomalous behavior of the thermal conductivity of supercooled water appears to be related to the maximum of the isothermal compressibility or the minimum of the speed of sound. However, the magnitudes of the simulated thermal conductivities are sensitive to the water model adopted and appear to be significantly larger than the experimental thermal conductivities of real water at low temperatures. PMID:24784243

  20. Study of Impurity Distributions (Mainly Lithium in Silicon) Using ac Hopping Conduction

    Microsoft Academic Search

    M. Pollak; D. H. Watt

    1965-01-01

    The results of previous studies on ac impurity conduction are applied in an attempt to study the distribution of impurities when this is not random. The present study applies mostly to the distribution of lithium in silicon, but a few other situations are also examined. A possibility is presented, on a theoretical basis, to determine experimentally the complete distribution function

  1. An Assessment of Treatment Integrity in Behavioral Intervention Studies Conducted with Persons with Mental Retardation

    ERIC Educational Resources Information Center

    Wheeler, John J.; Mayton, Michael R.; Carter, Stacy L.; Chitiyo, Morgan; Menendez, Anthony L.; Huang, Ann

    2009-01-01

    The purpose of this study was to assess the degree to which behavioral intervention studies conducted with persons with mental retardation operationally defined the independent variables and evaluated and reported measures of treatment integrity. The study expands the previous work in this area reported by Gresham, Gansle, and Noell (1993) and…

  2. A Proposed Design for Conducting Target Animal Safety Studies for Developing New Veterinary Pharmaceuticals

    Microsoft Academic Search

    Michael C. Carakostas; James J. Colaianne

    1996-01-01

    Target animal safety studies are required for the regulatory approval of any new veterinary pharmaceutical registered almost anywhere in the world. Both the United States and Europe have extensive guidelines for conducting these studies. Due to new veterinary drug labeling requirements in the United States, changes in the overall design of target animal safety studies will be required for the

  3. An Innovative Approach for Reviewing Case Studies Conducted at a Taiwan University - Information Management Perspectives

    Microsoft Academic Search

    Pei-Hsuan Hsieh

    This research proposes an innovative approach for r eviewing 52 case studies conducted at a Taiwan univ ersity. The roles played by the cases are first clarified, followed by a discussion of the formation of the ca ses by the study methods. Then, by applying the perspectives from th e information management (IM) field, three study met hod types: algorithm

  4. Validation of the Center for Epidemiologic Studies Depression Scale in Black Single Mothers

    PubMed Central

    Atkins, Rahshida

    2015-01-01

    Background and Purpose The purpose of this study was to investigate the factor structure of the Center for Epidemiologic Studies Depression (CES-D) scale in a community sample of Black single mothers and to evaluate the scale’s construct validity. Methods Principal components and exploratory factor analysis were used. The participants responded to the CES-D scale and Spielberger’s State-Trait Anger Expression Inventory. Results The final sample consisted of 208 Black single mothers aged 18–45 years. A 2-factor structure was accepted. Construct validity was confirmed via significant correlations with the anger scales. A method artifact for the 2-factor solution was ruled out. Conclusion The CES-D scale is valid for use with Black single mothers. Additional psychometric evidence for the CES-D for Black single mothers is warranted. PMID:25608436

  5. The Iranian version of the Premenstrual Symptoms Screening Tool (PSST): a validation study.

    PubMed

    Hariri, Fatemeh Zahra; Moghaddam-Banaem, Lida; Siah Bazi, Shiva; Saki Malehi, Amal; Montazeri, Ali

    2013-12-01

    The objective of the current study was to translate and test psychometric properties of the Premenstrual Symptoms Screening Tool (PSST) in Iran. Using a standard "forward-backward" procedure, the English version of PSST was translated into Persian. A random sample of university students aged 18 years and over completed the questionnaire in Tehran, Iran. Psychometric properties of the Iranian version of PSST were assessed by performing reliability (internal consistency) and validity analyses [Content Validity Ratio (CVR) and Content Validity Index (CVI)]. In all, 925 female students took part in the study. Of these, 284 (30.7 %) had premenstrual syndrome (PMS) and 119 (12.9 %) had premenstrual dysphoric disorder (PMDD). Reliability of the PSST as measured by internal consistency was found to be satisfactory (Cronbach's alpha coefficient, 0.93). The content validity as assessed by CVR and CVI were desirable (0.7 and 0.8, respectively). The Iranian version of PSST seems to be a reliable and valid measure of detecting PMS and PMDD in Iranian young female populations. PMID:23974654

  6. The Application of Spatial Signature Analysis to Electrical Test Data: Validation Study

    SciTech Connect

    Gleason, S.S.; Karnowski, T.P.; Lakhani, F.; Tobin, K.W.

    1999-03-15

    This paper presents the results of the Spatial Signature Analysis (SSA) Electrical-test (e-test) validation study that was conducted between February and June, 1998. SSA is an automated procedure developed by researchers at the Oak Ridge National Laboratory to address the issue of intelligent data reduction while providing feedback on current manufacturing processes. SSA was initially developed to automate the analysis of optical defect data. Optical defects can form groups, or clusters, which may have a distinct shape. These patterns can reveal information about the manufacturing process. Optical defect SSA uses image processing algorithms and a classifier system to interpret and identify these patterns, or signatures. SSA has been extended to analyze and interpret electrical test data. The algorithms used for optical defect SSA have been adapted and applied to e-test binmaps. An image of the binmap is created, and features such as geometric and invariant moments are extracted and presented to a pair-wise, fuzzy, k-NN classifier. The classifier itself was prepared by manually training, which consists of storing example signatures of interest in a library, then executing an automated process which treats the examples as prototype signatures. The training process includes a procedure for automatically determining which features are most relevant to each class. The evaluation was performed by installing the SSA software as a batch process at three SEMATECH member company sites. Feedback from member company representatives was incorporated and classifiers were built to automatically assign labels to the binmap signatures. The three sites produced memory devices (DRAM) and microprocessors in a mature process fabrication environment. For all of these products, 5,620 signatures that encompassed approximately 552 wafers were human-classified and analyzed. The performance of the SSA E-test system indicates that the approach was successful in reliably classifying binmap signatures in a manner similar to the human expert.

  7. Molecular dynamics study on interfacial thermal conductance of unirradiated and irradiated SiC/C

    NASA Astrophysics Data System (ADS)

    Wang, Qingyu; Wang, Chenglong; Zhang, Yue; Li, Taosheng

    2014-06-01

    SiCf/SiC composite materials have been considered as candidate structural materials for several types of advanced nuclear reactors. Both experimental and computer simulations studies have revealed the degradation of thermal conductivity for this material after irradiation. The objective of this study is to investigate the effect of SiC/graphite interface structure and irradiation on the interfacial thermal conductance by using molecular dynamics simulation. Five SiC/graphite composite models were created with different interface structures, and irradiation was introduced near the interfaces. Thermal conductance was calculated by means of reverse-NEMD method. Results show that there is a positive correlation between the interfacial energy and interfacial C-Si bond quantity, and irradiated models showed higher interfacial energy compared with their unirradiated counterparts. Except the model with graphite atom plane parallel to the interface, the interfacial thermal conductance of unirradiated and irradiated (1000 eV) models, increases as the increase of interfacial energy, respectively. For all irradiated models, lattice defects are of importance in impacting the interfacial thermal conductance depending on the interface structure. For the model with graphite layer parallel to the interface, the interfacial thermal conductance increased after irradiation, for the other models the interfacial thermal conductance decreased. The vibrational density of states of atoms in the interfacial region was calculated to analyze the phonon mismatch at the interface.

  8. Conductivity studies of Chitosan doped with different ammonium salts: Effect of ion size

    NASA Astrophysics Data System (ADS)

    Mohan, C. Raja; Senthilkumar, M.; Jayakumar, K.

    2015-06-01

    In the present investigation influence of ion size on the electrical properties of various ammonium salts of various concentrations doped with Chitosan liquid electrolyte has been studied. The attachment of ammonium salts with Chitosan has been confirmed through FTIR Spectrum. Polarizability is calculated from the refractive index data. Addition of ammonium salts increases the conductivity. It is also observed that increase in ion size, increases the ionic conductivity due to increase in amorphous nature of the material. Increase in concentration leads to increase in conductivity due to the presence of more number of free ions.

  9. "Conducting Is Everywhere!" A Case Study of the Development of Preservice Music Teacher Occupational Identity in a Beginning Conducting Course

    ERIC Educational Resources Information Center

    Johnson, Erik

    2014-01-01

    Research on pre-service music teacher occupational identity often highlights two competing identities: performer and teacher (L'Roy, 1983; Roberts, 1991; Pellegrino, 2009). Of the many factors that contribute to the occupational identity of the pre-service music teacher (Woodford, 2002), conducting has the potential to integrate performer and…

  10. Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study

    USGS Publications Warehouse

    Illman, W.A.; Zhu, J.; Craig, A.J.; Yin, D.

    2010-01-01

    Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number of characterization approaches to obtain K at various scales and in varying degrees of detail, but there is a paucity of information in terms of which characterization approach best predicts flow through aquifers or drawdowns caused by some drawdown inducing events. The main objective of this paper is to assess K estimates obtained by various approaches by predicting drawdowns from independent cross-hole pumping tests and total flow rates through a synthetic heterogeneous aquifer from flow-through tests. Specifically, we (1) characterize a synthetic heterogeneous aquifer built in the sandbox through various techniques (permeameter analyses of core samples, single-hole, cross-hole, and flow-through testing), (2) obtain mean K fields through traditional analysis of test data by treating the medium to be homogeneous, (3) obtain heterogeneous K fields through kriging and steady state hydraulic tomography, and (4) conduct forward simulations of 16 independent pumping tests and six flowthrough tests using these homogeneous and heterogeneous K fields and comparing them to actual data. Results show that the mean K and heterogeneous K fields estimated through kriging of small-scale K data (core and single-hole tests) yield biased predictions of drawdowns and flow rates in this synthetic heterogeneous aquifer. In contrast, the heterogeneous K distribution or ?K tomogram? estimated via steady state hydraulic tomography yields excellent predictions of drawdowns of pumping tests not used in the construction of the tomogram and very good estimates of total flow rates from the flowthrough tests. These results suggest that steady state groundwater model validation is possible in this laboratory sandbox aquifer if the heterogeneous K distribution and forcing functions (boundary conditions and source/sink terms) are characterized sufficiently. ?? 2010 by the American Geophysical Union.

  11. Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study

    NASA Astrophysics Data System (ADS)

    Illman, Walter A.; Zhu, Junfeng; Craig, Andrew J.; Yin, Danting

    2010-04-01

    Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number of characterization approaches to obtain K at various scales and in varying degrees of detail, but there is a paucity of information in terms of which characterization approach best predicts flow through aquifers or drawdowns caused by some drawdown inducing events. The main objective of this paper is to assess K estimates obtained by various approaches by predicting drawdowns from independent cross-hole pumping tests and total flow rates through a synthetic heterogeneous aquifer from flow-through tests. Specifically, we (1) characterize a synthetic heterogeneous aquifer built in the sandbox through various techniques (permeameter analyses of core samples, single-hole, cross-hole, and flow-through testing), (2) obtain mean K fields through traditional analysis of test data by treating the medium to be homogeneous, (3) obtain heterogeneous K fields through kriging and steady state hydraulic tomography, and (4) conduct forward simulations of 16 independent pumping tests and six flow-through tests using these homogeneous and heterogeneous K fields and comparing them to actual data. Results show that the mean K and heterogeneous K fields estimated through kriging of small-scale K data (core and single-hole tests) yield biased predictions of drawdowns and flow rates in this synthetic heterogeneous aquifer. In contrast, the heterogeneous K distribution or "K tomogram" estimated via steady state hydraulic tomography yields excellent predictions of drawdowns of pumping tests not used in the construction of the tomogram and very good estimates of total flow rates from the flow-through tests. These results suggest that steady state groundwater model validation is possible in this laboratory sandbox aquifer if the heterogeneous K distribution and forcing functions (boundary conditions and source/sink terms) are characterized sufficiently.

  12. Nerve conduction velocity study of the upper limb in Raynaud's phenomenon

    Microsoft Academic Search

    M. Mondelli; C. Romano; R. De Stefano; R. Cioni

    2000-01-01

    A prospective study of upper limb nerve conduction velocity was performed in 39 subjects (9 males, 30 females, mean age 46.8?years)\\u000a with idiopathic Raynaud's phenomenon (RP) and 18 patients (3 males, 15 females, mean age 49.9?years) with RP secondary to\\u000a systemic sclerosis (SS). Five subjects with idiopathic RP (13%) showed slowing of sensory conduction velocity (SCV) of the\\u000a distal median

  13. A Community Based Study to Test the Reliability and Validity of Physical Activity Measurement Techniques

    PubMed Central

    Misra, Puneet; Upadhyay, Ravi Prakash; Krishnan, Anand; Sharma, Neelam; Kapoor, Suresh K.

    2014-01-01

    Introduction: Physical activity (PA) is protective against non-communicable diseases and it can reduce premature mortality. However, it is difficult to assess the frequency, duration, type and intensity of PA. The global physical activity questionnaire (GPAQ) has been developed by World Health Organization with the aim of having valid and reliable estimates of PA. The primary aim of this study is to assess the repeatability of the GPAQ instrument and the secondary aim is to validate it against International Physical Activity Questionnaire (IPAQ) and against an objective measure of PA (i.e., using pedometers) in both rural and peri-urban areas of North India. Methods: A total of 262 subjects were recruited by random selection from Ballabgarh Block of Haryana State in India. For test retest repeatability of GPAQ and IPAQ, the instruments were administered on two occasions separated by at least 3 days. For concurrent validity, both questionnaires were administered in random order and for criterion validity step counters were used. Spearman's correlation coefficient, intra-class correlation (ICC) and Cohen's kappa was used in the analysis. Results: For GPAQ validity, the spearman's Rho ranged from 0.40 to 0.59 and ICC ranged from 0.43 to 0.81 while for IPAQ validity, spearman correlation coefficient ranged from 0.42 to 0.43 and ICC ranged from 0.56 to 0.68. The observed concurrent validity coefficients suggested that both the questionnaires had reasonable agreement (Spearman Rho of >0.90; P < 0.0001; ICC: 0.76-0.91, P < 0.05). Conclusions: GPAQ is similar to IPAQ in measuring PA and can be used for measurement of PA in community settings. PMID:25489442

  14. A study on the validity of the point-particle model for particle-turbulence interaction

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongzhen; Prosperetti, Andrea

    2002-11-01

    The point-particle model, widely used in simulations of particle-turbulence interaction, is justified when the particle size is smaller than or comparable to the Kolmogorov scale. The precise limits of validity of the approximation and the manner in which errors accrue when the particle size increases are not well known. In the present work, direct simulations are conducted for a single finite-size particle suspended in a decaying homogeneous turbulent flow generated with a spectral code as an intial condition. The simulations are conducted by means of the PHYSALIS method. The trajectories of finite-size and point particles are compared as the particle radius is increased above the Kolmogorov scale for different Stokes numbers.

  15. Fruit and Vegetable Intake Assessed by Food Frequency Questionnaire and Plasma Carotenoids: A Validation Study in Adults

    PubMed Central

    Burrows, Tracy L.; Hutchesson, Melinda J.; Rollo, Megan E.; Boggess, May M.; Guest, Maya; Collins, Clare E.

    2015-01-01

    Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (?- and ?-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for ?-carotene, ?-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of ?-carotene, ?-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence. PMID:25954899

  16. Fruit and vegetable intake assessed by food frequency questionnaire and plasma carotenoids: a validation study in adults.

    PubMed

    Burrows, Tracy L; Hutchesson, Melinda J; Rollo, Megan E; Boggess, May M; Guest, Maya; Collins, Clare E

    2015-01-01

    Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (?- and ?-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for ?-carotene, ?-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of ?-carotene, ?-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence. PMID:25954899

  17. Impact of Event Scale: A cross-validation study and some empirical evidence supporting a conceptual model of stress response syndromes

    Microsoft Academic Search

    Nathan J. Zilberg; Daniel S. Weiss; Mardi J. Horowitz

    1982-01-01

    Conducted a cross-validational study on the Impact of Event Scale (IES), a self-report instrument assessing the essential characteristics associated with stress disorders. 35 bereaved outpatients completed the IES before entering time-limited dynamic psychotherapy and at 4 and 12 mo following termination. A further 28 Ss, not participating in therapy, completed the measure at similar intervals. Results confirm the scale's relevance,

  18. Border College Consortium Descriptive Test of English Skills and Verbal Aptitude Test: Norming and Validation Study.

    ERIC Educational Resources Information Center

    Karathanos, Demetrius

    1991-01-01

    The background and rationale for the 2 tests are described and results of a norming and validation study involving 804 Mexican-American college freshmen in 5 border community colleges are reported. The results provide evidence that the DTES and VAT are reliable and effective for Mexican-American students, having overcome inadequacies of other…

  19. Understanding and Measuring Evaluation Capacity: A Model and Instrument Validation Study

    ERIC Educational Resources Information Center

    Taylor-Ritzler, Tina; Suarez-Balcazar, Yolanda; Garcia-Iriarte, Edurne; Henry, David B.; Balcazar, Fabricio E.

    2013-01-01

    This study describes the development and validation of the Evaluation Capacity Assessment Instrument (ECAI), a measure designed to assess evaluation capacity among staff of nonprofit organizations that is based on a synthesis model of evaluation capacity. One hundred and sixty-nine staff of nonprofit organizations completed the ECAI. The 68-item…

  20. Incremental Validity of Thinking Styles in Predicting Academic Achievements: An Experimental Study in Hypermedia Learning Environments

    ERIC Educational Resources Information Center

    Fan, Weiqiao; Zhang, Li-Fang; Watkins, David

    2010-01-01

    The study examined the incremental validity of thinking styles in predicting academic achievement after controlling for personality and achievement motivation in the hypermedia-based learning environment. Seventy-two Chinese college students from Shanghai, the People's Republic of China, took part in this instructional experiment. The…

  1. A Construct Validation Study of Phonological Awareness for Children Entering Prekindergarten

    ERIC Educational Resources Information Center

    Webb, Mi-Young Lee; Schwanenflugel, Paula J.; Kim, Seock-Ho

    2004-01-01

    The purpose of this study was to determine the psychometric characteristics of a phonological awareness assessment for prekindergarten children using Messick's (1989) framework for unitary construct validity. Upon entry into prekindergarten, children were given rhyme discrimination, syllable segmentation, initial phoneme isolation, and phoneme…

  2. A Study of the Validity and Reliability of a Mathematics Lesson Attitude Scale and Student Attitudes

    ERIC Educational Resources Information Center

    Tezer, Murat; Ozcan, Deniz

    2015-01-01

    Attitudes of the students towards mathematics lessons are very important in terms of their success and motivation. The purpose of this study is to develop a scale for the assessment of primary school students' attitudes towards mathematics courses in the 2nd and 3rd grades, to analyse its validity-reliability structure and to determine the…

  3. Cross-validation and calibration of Jackson-Pollock equations with DXA: the TIGER study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Jackson-Pollock (J&P) body composition equations were developed primarily from data on white men and women using hydrostatically determined body density (BD) as the criterion measure. This study cross-validated the J&P equations with ethnically diverse subjects and percent fat (%fat) determined ...

  4. A validation study of existing neutronics tools against ZPPR-21 and ZPPR-15 critical experiments

    Microsoft Academic Search

    W. S. Yang; S. J. Kim

    2007-01-01

    A study was performed to validate the existing tools for fast reactor neutronics analysis against previous critical experiments. The six benchmark problems for the ZPPR-21 critical experiments phases A through F specified in the Handbook of Evaluated Criticality Safety Benchmark Experiments were analyzed. Analysis was also performed for three loading configurations of the ZPPR-15 Phase A experiments. As-built core models

  5. The Dimensions of Learning Organization Questionnaire (DLOQ): A Validation Study in a Korean Context

    ERIC Educational Resources Information Center

    Song, Ji Hoon; Joo, Baek-Kyoo; Chermack, Thomas J.

    2009-01-01

    The purpose of this study is to assess the validity and reliability of the measurement scores of the learning organization culture, the Dimensions of Learning Organization Questionnaire (DLOQ), in a Korean context. A total of 1,529 cases from 11 firms in two major Korean conglomerates were analyzed. Rigorous translation procedures, including both…

  6. Development and Validation of Information Technology Mentor Teacher Attitude Scale: A Pilot Study

    ERIC Educational Resources Information Center

    Saltan, Fatih

    2015-01-01

    The aim of this study development and validation of a teacher attitude scale toward Information Technology Mentor Teachers (ITMT). ITMTs give technological support to other teachers for integration of technology in their lessons. In the literature, many instruments have been developed to measure teachers' attitudes towards the technological tools…

  7. Tools for studying animal behaviour: validation of dive profiles relayed via the Argos satellite system

    E-print Network

    Hays, Graeme

    Tools for studying animal behaviour: validation of dive profiles relayed via the Argos satellite satellite system (http://www.argosinc.com). Behavioural data relayed remotely via the Argos satellite system of their time submerged, further limiting the time available for communication with satel- lites. The problem

  8. The 1983 National Teacher Examinations Core Battery Louisiana Validation Study: Final Report. (Revised).

    ERIC Educational Resources Information Center

    Garvue, Robert; And Others

    The purpose of this study was to determine the validity of the National Teacher Examinations (NTE) Core Battery for use in teacher certification in Louisiana. This information was produced to assist in the recommendation and establishment of a required score on the NTE. The jury judgment approach was used. Panels of faculty members were drawn from…

  9. Validating the Interpretations of PISA and TIMSS Tasks: A Rating Study

    ERIC Educational Resources Information Center

    Rindermann, Heiner; Baumeister, Antonia E. E.

    2015-01-01

    Scholastic tests regard cognitive abilities to be domain-specific competences. However, high correlations between competences indicate either high task similarity or a dependence on common factors. The present rating study examined the validity of 12 Programme for International Student Assessment (PISA) and Third or Trends in International…

  10. The Family-Centered Behavior Scales: A Report on the Validation Study.

    ERIC Educational Resources Information Center

    Allen, Reva I.

    This conference paper discusses the results of a study that investigated the validity of the Family-Centered Behavior Scale (FCBS) and its companion tool, the FCBS-Importance. On the FCBS, parents of children with special needs rate how often a professional with whom they work performs certain family-centered behaviors. On the FCBS-Importance,…

  11. MSc in Computer Science and Engineering Study Lines Rules Valid until 1 September 2012

    E-print Network

    Mosegaard, Klaus

    -implantable medical devices. The design process of digital systems must therefore address a number of different1/12 MSc in Computer Science and Engineering ­ Study Lines ­ Rules Valid until 1 September 2012, system integration, distributed and embedded systems, networks, software engineering, algorithms

  12. A Construct Validity Study of the Myers-Briggs Type Indicator

    Microsoft Academic Search

    David Cohen; Marilye Cohen; Herbert Cross

    1981-01-01

    This study assessed the construct validity of the Myers-Briggs Type Indicator, MBTI (Myers, 1976). The rationale was that friends or relatives can make judgments about an individual which will be associated with his\\/her predominant personality type. Forty-eight subjects rated themselves on two seven-point Likert scales designed to assess behavioral styles. These inventories (designated, \\

  13. Digital Professional Portfolios of Preservice Teaching: An Initial Study of Score Reliability and Validity

    ERIC Educational Resources Information Center

    Derham, Carol; DiPerna, James

    2007-01-01

    The purpose of this study was to investigate initial evidence regarding the reliability and validity of scores from a digital professional portfolio (DPP) designed to assess the instructional competencies of preservice teachers. Data were collected from 30 preservice teachers during their intern teaching experience. Data were analyzed using a…

  14. Validity Study of the Autism Spectrum Disorders-Diagnostic for Children (ASD-DC)

    ERIC Educational Resources Information Center

    Matson, Johnny L.; Gonzalez, Melissa; Wilkins, Jonathan

    2009-01-01

    The Autism Spectrum Disorders-Diagnostic for Children (ASD-DC) is a 40-item Likert format scale designed to serve in the diagnosis of children and adolescents from 2 to 16 years of age. The reliability and factor structure of the scale have been established in previous research. Studies 1 and 2 were designed to evaluate the validity of the measure…

  15. Slicing the Attitude Pie: A Validity and Reliability Study of a New Attitude Assessment Technique.

    ERIC Educational Resources Information Center

    Lull, James T.; Cappella, Joseph N.

    This paper introduces a new measure of attitude, the "attitude pie," which attempts to separate true neutrality from degree of indifference while providing an evaluation score on the issue being judged. A large reliability-validity study involving ten attitude traits, four different methods, and over one hundred subjects at three different times…

  16. Stages of Change in Physical Activity: A Validation Study in Late Adolescence

    ERIC Educational Resources Information Center

    Parker, Philip D.; Martin, Andrew J.; Martinez, Carissa; Marsh, Herbert W.; Jackson, Susan A.

    2010-01-01

    The present study explores the validity of a recent stages of change (SoC) measure and algorithm among a sample of late adolescents. MANOVA and structural equation modeling are used to assess the relationship between five SoC groups (precontemplation, contemplation, preparation, action, and maintenance) and a set of dependent measures including…

  17. Epithelial Gaps in a Rodent Model of Inflammatory Bowel Disease: A Quantitative Validation Study

    E-print Network

    Alberta, University of

    Epithelial Gaps in a Rodent Model of Inflammatory Bowel Disease: A Quantitative Validation Study with accuracy comparable to CM and light microscopy. In a mouse model of inflammatory bowel disease online 9 June 2011 Subject Category: inflammatory bowel disease INTRODUCTION Epithelial cell shedding

  18. The Arabic Version of the Mayo-Portland Adaptability Inventory 4: A Validation Study

    ERIC Educational Resources Information Center

    Hamed, Razan; Tariah, Hashem Abu; Malkawi, Somaya; Holm, Margo B.

    2012-01-01

    The Mayo-Portland Adaptability Inventory 4 (MPAI-4) is a valid and reliable assessment tool to detect clinical impairments in patients with acquired brain injury. The tool is widely used by rehabilitation therapists worldwide, given its good psychometric properties and its availability in several languages. The purpose of this study was to…

  19. Developing a Science Process Skills Test for Secondary Students: Validity and Reliability Study

    ERIC Educational Resources Information Center

    Feyzioglu, Burak; Demirdag, Baris; Akyildiz, Murat; Altun, Eralp

    2012-01-01

    Science process skills are claimed to enable an individual to improve their own life visions and give a scientific view/literacy as a standard of their understanding about the nature of science. The main purpose of this study was to develop a test for measuring a valid, reliable and practical test for Science Process Skills (SPS) in secondary…

  20. Review of Studies of the Concurrent and Predictive Validity of the National Teacher Examinations

    ERIC Educational Resources Information Center

    Quirk, Thomas J.; And Others

    1973-01-01

    Background and purposes of the National Teacher Examinations (NTE) and the hazards of combining data on these tests in research studies are discussed; the predictive validity of the NTE with in-service teachers is analyzed. Suggestions are made for closer correlation between rating scales and what the standardized tests themselves attempt to…

  1. A Construct Validity Study of Clinical Competence: A Multitrait Multimethod Matrix Approach

    ERIC Educational Resources Information Center

    Baig, Lubna; Violato, Claudio; Crutcher, Rodney

    2010-01-01

    Introduction: The purpose of the study was to adduce evidence for estimating the construct validity of clinical competence measured through assessment instruments used for high-stakes examinations. Methods: Thirty-nine international physicians (mean age = 41 + 6.5 y) participated in high-stakes examination and 3-month supervised clinical practice…

  2. CFD validation studies for a high-speed foil-assisted semi-planing catamaran

    Microsoft Academic Search

    Manivannan Kandasamy; Seng Keat Ooi; Pablo Carrica; Frederick Stern; Emilio F. Campana; Daniele Peri; Philip Osborne; Jessica Cote; Neil Macdonald; Nic de Waal

    2011-01-01

    This paper details the CFD validation studies carried out as a prerequisite for multi-fidelity CFD-based design optimization\\u000a of high-speed passenger-only ferries aimed at reducing far-field wake energy that causes beach erosion. A potential flow program\\u000a (WARP) and a URANS program (CFDSHIP) were validated using full-scale measurements of resistance, sinkage, trim, and far-field\\u000a wake train obtained over a wide range of

  3. ORGANOTIN TOXICITY STUDIES CONDUCTED WITH SELECTED MARINE ORGANISMS AT EPA'S ENVIRONMENTAL RESEARCH LABORATORY, GULF BREEZE, FLORIDA

    EPA Science Inventory

    Studies on effect of bis(tri-n-butyltin)oxide (TBTO) and other organotins on marine species have been conducted at the U.S. Environmental Protection Agency's laboratory at Gulf Breeze, Florida, since 1983. First studies were done on two species of algae, Skeletonema costatum and ...

  4. Obstacles to Conducting Curriculum Research in Bilingual Education: A Case Study.

    ERIC Educational Resources Information Center

    Schon, Isabel; Hopkins, Kenneth D.

    The obstacles associated with conducting curricular research in school settings are discussed. A study of bilingual students in the Phoenix area demonstrated the difficulties associated with high absenteeism and drop out rates. In a study of Spanish reading materials, it proved difficult to identify schools where administrators would be willing to…

  5. Do you have depression? Stanford University is conducting a research study on the

    E-print Network

    Sonnenburg, Justin L.

    Do you have depression? Stanford University is conducting a research study on the interaction between depression and pre-diabetes. Study participants receive a comprehensive assessment on behavior and role in brain function in men and women with depression. Who can participate? The researchers

  6. Methodological, Theoretical, Infrastructural, and Design Issues in Conducting Good Outcome Studies

    ERIC Educational Resources Information Center

    Kelly, Michael P.; Moore, Tessa A.

    2011-01-01

    This article outlines a set of methodological, theoretical, and other issues relating to the conduct of good outcome studies. The article begins by considering the contribution of evidence-based medicine to the methodology of outcome research. The lessons which can be applied in outcome studies in nonmedical settings are described. The article…

  7. Peripheral motor and sensory nerve conduction studies in normal infants and children

    Microsoft Academic Search

    Antonio Garc??a; Jesús Calleja; Francisco M. Antol??n; José Berciano

    2000-01-01

    Objective: There are few data on electrophysiological data of motor and sensory fibres during nerve maturation. The aim of this study is to investigate the evolution of nerve conduction in the upper and lower limbs during the first years of life.Methods: The study comprised 92 normal infants and children aged from 1 week to 6 years. Using surface electrodes, the

  8. Conduction Velocity Distribution Estimation using the Collision Technique Theory and Simulation Study

    E-print Network

    Gonzalez Cueto, Jose

    Engineering Dalhousie University, Halifax, NS, Canada Abstract: Current nerve conduction studies (NCS estimates with a percent mean square error (PMSE) lower than 1.1% for all CTS cases studied and lower than 2 detect the severity of CTS in a patient more accurately than current NCS. * Corresponding Author

  9. Study of the Kinetics of an S[subscript N]1 Reaction by Conductivity Measurement

    ERIC Educational Resources Information Center

    Marzluff, Elaine M.; Crawford, Mary A.; Reynolds, Helen

    2011-01-01

    Substitution reactions, a central part of organic chemistry, provide a model system in physical chemistry to study reaction rates and mechanisms. Here, the use of inexpensive and readily available commercial conductivity probes coupled with computer data acquisition for the study of the temperature and solvent dependence of the solvolysis of…

  10. Three School Based Models for Conducting Follow-up Studies of Teacher Education and Training.

    ERIC Educational Resources Information Center

    Borich, Gary D.

    The rise of interest in the evaluation of teacher education and training during the decade 1967-1977 is charted; a review of related concepts and studies is presented; and three evaluation models for conducting follow-up studies on training effectiveness are examined. Three issues arising to prominence in the last decade are identified and…

  11. Guidelines for conducting and reporting case study research in software engineering

    Microsoft Academic Search

    Per Runeson; Martin Höst

    2009-01-01

    Abstract,Case study is a suitable research methodology,for software engineering,research since it studies contemporary phenomena in its natural context. However, the understanding of what constitutes a case study varies, and hence the quality of the resulting studies. This paper aims,at providing,an introduction to case study methodology,and,guidelines for researchers,conducting,case studies and,readers studying,reports of such,studies. The content is based on the authors’ own,experience

  12. Exposure Measurement Error in PM2.5 Health Effects Studies: A Pooled Analysis of Eight Personal Exposure Validation Studies

    EPA Science Inventory

    Background: Exposure measurement error is a concern in long-term PM2.5 health studies using ambient concentrations as exposures. We assessed error magnitude by estimating calibration coefficients as the association between personal PM2.5 exposures from validation studies and typ...

  13. A numerical study of the influence of interconnected conductive paths in electrically resistive rocks

    NASA Astrophysics Data System (ADS)

    Mandolesi, E.; Moorkamp, M.; Jones, A. G.

    2013-12-01

    Several electromagnetic (EM) geophysical methods focus on the EM properties of rocks and sediments to determine a reliable image of the subsurface, while the same electromagnetic properties are measured in the laboratory with a wide range of instruments and techniques. None of these measurements return an unequivocal result. The hypothesis related to the presence of interconnected pathways of electrically conductive materials in resistive hosts has been studied with increasing interest in recent years, and the comprehension of phenomena that scale from the microstructures of the rocks up to field electrical conductivity measurements represents the boundary that prevents the direct comparison between laboratory data and field data. In recent years some numerical approaches have been investigated to understand the effects of interconnected pathways of conductors on field measurements, usually restricting the studies to direct current (DC) sources. Bearing in mind the time-variating nature of natural electromagnetic sources that take a role in field measurements, we numerically simulated the effects of such EM sources on the conductivity measured on the surface of a three-dimensional realistic body embedded in an uniform host by using electromagnetic induction equations. Since most real rocks are poor conductors, we modeled a two-phase mixture of rock and interconnected conductive elements (representing melts, saline fluids, sulphidic, carbonitic, or metallic sediments, etc.), randomly generated within the background host. We compared the electrical conductivity measured from a sample of randomly generated models with the electrical conductivity limits predicted by Hashin-Shtrikman bounds.

  14. Electrical conductivity and stimulated thermocurrent studies of the dicalcium strontium propionate single crystal

    NASA Astrophysics Data System (ADS)

    Madhusudan, V.; Sathyanarayan, S. G.; Sivarama Sastry, G.

    1982-11-01

    Electrical conductivity and stimulated thermocurrent studies of dicalcium strontium propionate (DSP) in pure, Fe 3+ and acetate-doped single crystals have been performed in the temperature range 303-503 K. Conductivity measurements of pure and doped crystals indicate that propionate anions are responsible for the transition occurring at 400 K. Thermoelectric power measurements in the range 340-500 K of DSP (pure indicate that the transport charge carriers are electrons. A model for the conduction mechanism is proposed on the basis of ? or resonating electrons of the carboxyl groups moving via tunnelling involving metal ions (Sr 2+ and Ca 2+). From activation energies estimated from conductivity and STC measurements the STC peak in DSP (Fe 3+) occurring at 511 K is attributed to an impurity-vacancy jump mechanism.

  15. Thermal conductivity studies of metal dispersed multiwalled carbon nanotubes in water and ethylene glycol based nanofluids

    SciTech Connect

    Jha, Neetu; Ramaprabhu, S. [Department of Physics, Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Indian Institute of Technology Madras, Chennai 600036 (India)

    2009-10-15

    High thermal conducting metal nanoparticles have been dispersed on the multiwalled carbon nanotubes (MWNTs) outer surface. Structural and morphological characterizations of metal dispersed MWNTs have been carried out using x-ray diffraction analysis, high resolution transmission electron microscopy, energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy. Nanofluids have been synthesized using metal-MWNTs in de-ionized water (DI water) and ethylene glycol (EG) base fluids. It has been observed that nanofluids maintain the same sequence of thermal conductivity as that of metal nanoparticles Ag-MWNTs>Au-MWNTs>Pd-MWNTs. A maximum enhancement of 37.3% and 11.3% in thermal conductivity has been obtained in Ag-MWNTs nanofluid with DI water and EG as base fluids, respectively, at a volume fraction of 0.03%. Temperature dependence study also shows enhancement of thermal conductivity with temperature.

  16. Conductance of ferro- and antiferro-magnetic single-atom contacts: A first-principles study

    SciTech Connect

    Tan, Zhi-Yun [School of Physics and Mechanical and Electrical Engineering, Zunyi Normal College, Zunyi (China)] [School of Physics and Mechanical and Electrical Engineering, Zunyi Normal College, Zunyi (China); Zheng, Xiao-long; Ye, Xiang; Xie, Yi-qun [Department of Physics, Shanghai Normal University, 100 Guilin Road, Shanghai 200232 (China)] [Department of Physics, Shanghai Normal University, 100 Guilin Road, Shanghai 200232 (China); Ke, San-Huang [Department of Physics, Key Laboratory of Advanced Microstructured Materials, MOE, Tongji University, 1239 Siping Road, Shanghai 200092 (China)] [Department of Physics, Key Laboratory of Advanced Microstructured Materials, MOE, Tongji University, 1239 Siping Road, Shanghai 200092 (China)

    2013-08-14

    We present a first-principles study on the spin dependent conductance of five single-atom magnetic junctions consisting of a magnetic tip and an adatom adsorbed on a magnetic surface, i.e., the Co-Co/Co(001) and Ni-X/Ni(001) (X = Fe, Co, Ni, Cu) junctions. When their spin configuration changes from ferromagnetism to anti-ferromagnetism, the spin-up conductance increases while the spin-down one decreases. For the junctions with a magnetic adatom, there is nearly no spin valve effect as the decreased spin-down conductance counteracts the increased spin-up one. For the junction with a nonmagnetic adatom (Ni-Cu/Ni(001)), a spin valve effect is obtained with a variation of 22% in the total conductance. In addition, the change in spin configuration enhances the spin filter effect for the Ni-Fe/Ni(001) junction but suppresses it for the other junctions.

  17. Experimental study of negative differential conductivity in GaAs:Cr

    NASA Astrophysics Data System (ADS)

    Rubinger, R. M.; de Oliveira, A. G.; Bezerra, J. C.; Ribeiro, G. M.; Rodrigues, W. N.; Moreira, M. V. B.

    2000-07-01

    We have studied the temperature and illumination dependencies of the current versus voltage characteristics I(V) of a Cr-doped GaAs sample. An S-shaped negative differential conductivity with a threshold at around 1 kV cm-1 was associated with a trap with activation energy of 90 meV. The low-conductivity state in I(V) characteristics is strongly influenced by illumination and temperature. We also present evidence that the electrical conduction above the threshold electric field occurs by a mechanism that involves free electrons despite the fact that the low-conductivity state is p type. This supports the assumption that the 90 meV trap is a donor.

  18. Conductance of ferro- and antiferro-magnetic single-atom contacts: A first-principles study

    NASA Astrophysics Data System (ADS)

    Tan, Zhi-Yun; Zheng, Xiao-long; Ye, Xiang; Xie, Yi-qun; Ke, San-Huang

    2013-08-01

    We present a first-principles study on the spin dependent conductance of five single-atom magnetic junctions consisting of a magnetic tip and an adatom adsorbed on a magnetic surface, i.e., the Co-Co/Co(001) and Ni-X/Ni(001) (X = Fe, Co, Ni, Cu) junctions. When their spin configuration changes from ferromagnetism to anti-ferromagnetism, the spin-up conductance increases while the spin-down one decreases. For the junctions with a magnetic adatom, there is nearly no spin valve effect as the decreased spin-down conductance counteracts the increased spin-up one. For the junction with a nonmagnetic adatom (Ni-Cu/Ni(001)), a spin valve effect is obtained with a variation of 22% in the total conductance. In addition, the change in spin configuration enhances the spin filter effect for the Ni-Fe/Ni(001) junction but suppresses it for the other junctions.

  19. The Drug Evaluation and Classification Program in the state of Texas: a validation study 

    E-print Network

    Walden, Troy Duane

    2005-08-29

    A retrospective research study was conducted to determine the effectiveness of the Drug Evaluation and Classification Program (DECP) procedures in order to identify subjects under the influence of specific drug categories. The investigator wanted...

  20. Solid-state ionics: Studies of lithium-conducting sulfide glasses and a superconducting oxide compound

    SciTech Connect

    Ahn, Byung Tae.

    1989-01-01

    The first part of this work studies lithium-conducting sulfide glasses for battery applications, while the second part studies the thermodynamic properties of a superconducting oxide compound by using an oxide electrolyte. Lithium conducting glasses based on the SiS{sub 2}-Li{sub 2}S system are possible solid electrolytes for high-energy-density lithium batteries. The foremost requirement for solid electrolytes is that they should have high ionic conductivities. Unfortunately, most crystalline lithium conductors have low ionic conductivities at room temperature. However, glass ionic conductors show higher ionic conductivities than do crystalline forms of the same material. In addition to higher ionic conductivities, glasses appear to have several advantages over crystalline materials. These advantages include isotropic conductivity, absence of grain boundary effects, ease of glass forming, and the potential for a wide range of stability to oxidizing and reducing conditions. Using pyrolitic graphite-coated quartz ampoules, new ternary compounds and glasses in the SiS{sub 2}-Li{sub 2}S system were prepared. Several techniques were used to characterize the materials: powder x-ray diffraction, differential thermal analysis, differential scanning calorimetry, and AC impedance spectroscopy. The measured lithium conductivity of the sulfide glasses was one of the highest among the known solid lithium conductors. Measuring the equilibrium open circuit voltages assisted in determining the electrochemical stabilities of the ternary compounds and glasses with respect to pure Li. A solid-state ionic technique called oxygen coulometric titration was used to measure the thermodynamic stability, the oxygen stoichiometry, and the effects of the oxygen stoichiometry, and the effects of the oxygen stoichiometry and the cooling rate on superconductivity of the YBa{sub 2}Cu{sub 3}O{sub 7-x} compound were investigated.

  1. Study of interfaces in zirconia using ionic conductivity measurements and stress-induced potentials

    NASA Astrophysics Data System (ADS)

    Pannikkat, Anilkumar Raman

    Interfaces in ceramics control their mechanical and electrical properties by affecting the concentration and mobility of the defects and other charge carriers in the material. The properties of interfaces such as the presence of an interface potential either created by the structure or by external forces control the creep and conductive properties in the material. Conductivity in zirconia is influenced by the grain size of the material. Small grain sizes increase their toughness, but degrade the conductivity. We have studied the ionic conductivity in zirconia using four probe DC measurements as a function of the grain size keeping all other variables constant. The conductivity decreased initially as we decreased the grain size and then increased below a critical size. We explain this by assuming anisotropy in conductivity perpendicular and parallel to the grain boundaries. Very reliable activation energy measurements have been made. At the same time we have also improved the ionic conductivity in fine grained zirconia to a level similar to those present in presently used oxygen sensors. Thus tougher sensors can be created. In the second part, for the first time, we have been able to measure a thermodynamic property of interfaces which had only been postulated earlier. A change in the chemical potential is induced at interfaces by normal tractions. In ionic electrolytes, this shows up as an electrical potential which can be measured by simple instrumentation. We applied normal stresses to ionic materials (zirconia) and measured the electrical potential between the stressed and unstressed surfaces. A detailed study of the kinetics showed that the diffusion at the electrode/zirconia interface was the controlling factor. The study has implications in electrochemical probes which are subject to stresses. It also led us to a way to use zirconia to measure stresses at high temperatures and as a shock sensor. We were also able to use the procedure to measure the charge of an oxygen ion on zirconia surfaces with different orientations.

  2. Agreement across self, peer, parent, and teacher versions of the MASP: a validation study 

    E-print Network

    King, Sonia Rachelle

    1993-01-01

    University Chair of Advisory Committee: Dr. Timothy A. Cavell The Measure of Adolescent Social Performance (MASP) is a self- report measure that assesses social performance in situations commonly experienced and problematic for adolescents. We ath...'mpted to further validate the MASP and its three subscales (Peer, Family, and School) by evaluating adolescents' self-report against peer, parent, and teacher reports. Forty-one ninth-grade students participated in this study. The first hypothesis of this study...

  3. Statistical power of tests of the situational specificity hypothesis in validity generalization studies: A cautionary note

    Microsoft Academic Search

    H. G. Osburn; John C. Callender; Jack M. Greener; Steven Ashworth

    1983-01-01

    Evaluated the statistical power of the Callender-Osburn method for testing the situational specificity hypothesis in validity generalization studies. The Schmidt-Hunter 75% rule for testing the situational specificity hypothesis was also studied with regard to its sensitivity for detecting both Type I and Type II errors. Results show that both the Callender-Osburn procedure and Schmidt-Hunter 75% rule lacked sufficient statistical power

  4. Validation of simulation models using measured performance data from the Los Alamos study center

    Microsoft Academic Search

    D. Curtis; T. Freeman; J. C. Hedstrom; T. Inooka; O. Jorgensen; M. Osumi; K. Hinotani; P. Lermusieau

    1981-01-01

    The results and conclusions of an International Energy Agency (IEA) solar heating and cooling program to validate computer simulation codes using measured performance data from the Los Alamos Study Center are discussed. The Study Center is a 6000-m² solar heated and cooled building located in Los Alamos, New Mexico. The building includes a 716-m² flat plate selective surface solar collector.

  5. CALPUFF and AERMOD Model Validation Study in the Near Field: Martins Creek Revisited

    Microsoft Academic Search

    Alan L. Dresser; Robert D. Huizer

    2011-01-01

    This paper describes a near-field validation study involving the steady-state, U.S. Environmental Protection Agency (EPA) guideline model AERMOD and the nonsteady-state puff model CALPUFF. Relative model performance is compared with field measurements collected near Martins Creek, PA—a rural, hilly area along the Pennsylvania-New Jersey border. The principal emission sources in the study were two coal-fired power plants with tall stacks

  6. A Technical Infrastructure to Conduct Randomized Database Studies Facilitated by a General Practice Research Database

    PubMed Central

    Mosis, Georgio; Vlug, Albert E.; Mosseveld, Mees; Dieleman, Jeanne P.; Stricker, Bruno C.; van der Lei, Johan; Sturkenboom, Miriam C.J.M.

    2005-01-01

    General practice research databases are increasingly used to study intended and unintended effects of treatments. However, confounding by indication remains a major problem. The randomized database study methodology has been proposed as a method to combine the strengths of observational database (generalizability) and the strength of the randomized clinical trial (RCT) design (randomization). We developed an infrastructure that enables the execution of randomized database studies with treatment randomization facilitated by a general practice research database. The requirements posed by the methodology of randomized database studies were facilitated by software components. Our assessment showed that it is technically possible to conduct randomized trials in general practice according to the randomized database design. The infrastructure facilitated the conduct of randomized database studies in general practice but some practical difficulties and methodological issues remain. The technical infrastructure seems to be both promising and potentially feasible to facilitate future randomized database studies, although the methodology needs to be evaluated in more detail. PMID:16049228

  7. The Patient-Doctor Relationship Questionnaire (PDRQ-9) in Primary Care: A Validity Study.

    PubMed

    Porcerelli, John H; Murdoch, William; Morris, Pierre; Fowler, Shannon

    2014-09-01

    This study assessed the validity of the Patient-Doctor Relationship Questionnaire-9 (PDRQ-9) in a primary care sample (N = 180). Convergent validity was assessed through a correlation between the patient-rated PDRQ-9 and the physician-rated Difficult Doctor Patient Relationship Questionnaire-10 (DDPRQ-10). Discriminant validity was assessed through correlations between the PDRQ-9 and patient age, patient- and physician-reported health and psychological distress. To determine if the PDRQ-9 could discriminate between groups, patient PDRQ-9 ratings were compared between patients who were treated by faculty physicians versus those who were treated by residents. An exploratory factor analysis confirmed that the PDRQ-9 was made up of a single factor. The PDRQ-9 scale was internally consistent (? = .96) and significantly and negatively correlated with the DDPRQ-10 (r = -.22, p = .003) and was not significantly correlated with patient age, health, or psychological distress. PDRQ-9 ratings were statistically greater in patients who were treated by faculty physicians than those who were treated by residents (p = .01). This study provides additional support for the reliability and validity of the PDRQ-9 as a measure of the doctor-patient relationship in a primary care sample. PMID:25106125

  8. CALPUFF and AERMOD model validation study in the near field: Martins Creek revisited.

    PubMed

    Dresser, Alan L; Huizer, Robert D

    2011-06-01

    This paper describes a near-field validation study involving the steady-state, U.S. Environmental Protection Agency (EPA) guideline model AERMOD and the nonsteady-state puff model CALPUFF. Relative model performance is compared with field measurements collected near Martins Creek, PA-a rural, hilly area along the Pennsylvania-New Jersey border. The principal emission sources in the study were two coal-fired power plants with tall stacks and buoyant plumes. Over 1 yr of sulfur dioxide measurements were collected at eight monitors located at or above the two power plants' stack tops. Concurrent meteorological data were available at two sites. Both sites collected data 10 m above the ground. One of the sites also collected sonic detection and ranging measurements up to 420 m above ground. The ability of the two models to predict monitored sulfur dioxide concentrations was assessed in a four-part model validation. Each part of the validation applied different criteria and statistics to provide a comprehensive evaluation of model performance. Because of their importance in regulatory applications, an emphasis was placed on statistics that demonstrate the model's ability to reproduce the upper end of the concentration distribution. On the basis of the combined results of the four-part validation (i.e., weight of evidence), the performance of CALPUFF was judged to be superior to that of AERMOD. PMID:21751581

  9. A semi-automatic method for left ventricle volume estimate: an in vivo validation study

    NASA Technical Reports Server (NTRS)

    Corsi, C.; Lamberti, C.; Sarti, A.; Saracino, G.; Shiota, T.; Thomas, J. D.

    2001-01-01

    This study aims to the validation of the left ventricular (LV) volume estimates obtained by processing volumetric data utilizing a segmentation model based on level set technique. The validation has been performed by comparing real-time volumetric echo data (RT3DE) and magnetic resonance (MRI) data. A validation protocol has been defined. The validation protocol was applied to twenty-four estimates (range 61-467 ml) obtained from normal and pathologic subjects, which underwent both RT3DE and MRI. A statistical analysis was performed on each estimate and on clinical parameters as stroke volume (SV) and ejection fraction (EF). Assuming MRI estimates (x) as a reference, an excellent correlation was found with volume measured by utilizing the segmentation procedure (y) (y=0.89x + 13.78, r=0.98). The mean error on SV was 8 ml and the mean error on EF was 2%. This study demonstrated that the segmentation technique is reliably applicable on human hearts in clinical practice.

  10. A study of rock matrix diffusion properties by electrical conductivity measurements

    SciTech Connect

    Ohlsson, Y.; Neretnieks, I.

    1999-07-01

    Traditional rock matrix diffusion experiments on crystalline rock are very time consuming due to the low porosity and extensive analysis requirements. Electrical conductivity measurements are, on the other hand, very fast and larger samples can be used than are practical in ordinary diffusion experiments. The effective diffusivity of a non-charged molecule is readily evaluated from the measurements, and influences from surface conductivity on diffusion of cations can be studied. A large number of samples of varying thickness can be measured within a short period, and the changes in transport properties with position in a rock core can be examined. In this study the formation factor of a large number of Aespoe diorite samples is determined by electrical conductivity measurements. The formation factor is a geometric factor defined as the ratio between the effective diffusivity of a non-charged molecule, to that of the same molecule in free liquid. The variation of this factor with position among a borecore and with sample length, and its coupling to the porosity of the sample is studied. Also the surface conductivity is studied. This was determined as the residual conductivity after leaching of the pore solution ions. The formation factor of most of the samples is in the range 1E-5 to 1E-4, with a mean value of about 5E-5. Even large samples (4--13 cm) give such values. The formation factor increases with increasing porosity and the change in both formation factor and porosity with position in the borecore can be large, even for samples close to each other. The surface conductivity increases with increasing formation factor for the various samples but the influence on the pore diffusion seems to be higher for samples of lower formation factor. This suggests that the relation between the pore surface area and the pore volume is larger for samples of low formation factor.

  11. Collection and validation of data in the United Kingdom Atomic Energy Authority mortality study.

    PubMed Central

    Fraser, P; Booth, M; Beral, V; Inskip, H; Firsht, S; Speak, S

    1985-01-01

    The United Kingdom Atomic Energy Authority mortality study investigated the relation between mortality and recorded exposure to ionising radiation among employees working at the authority's seven establishments between 1946 and 1979. This report examines the design of the study and methods of data collection and validation. The completeness of the study population was deemed to be unsatisfactory at two establishments, where records of employment before 1965 had been destroyed. Assessment of the magnitude of the deficit led to the conclusion that the data from these establishments were too incomplete for inclusion in the mortality analysis. At the other establishments validation showed that the data collected were accurate and unbiased. Certain characteristics of the 39 546 employees included in the mortality analysis were identified which were relevant in interpreting the findings. PMID:3926231

  12. Host genetic factors in American cutaneous leishmaniasis: a critical appraisal of studies conducted in an endemic area of Brazil

    PubMed Central

    Castellucci, Léa Cristina; de Almeida, Lucas Frederico; Jamieson, Sarra Elisabeth; Fakiola, Michaela; de Carvalho, Edgar Marcelino; Blackwell, Jenefer Mary

    2014-01-01

    American cutaneous leishmaniasis (ACL) is a vector-transmitted infectious disease with an estimated 1.5 million new cases per year. In Brazil, ACL represents a significant public health problem, with approximately 30,000 new reported cases annually, representing an incidence of 18.5 cases per 100,000 inhabitants. Corte de Pedra is in a region endemic for ACL in the state of Bahia (BA), northeastern Brazil, with 500-1,300 patients treated annually. Over the last decade, population and family-based candidate gene studies were conducted in Corte de Pedra, founded on previous knowledge from studies on mice and humans. Notwithstanding limitations related to sample size and power, these studies contribute important genetic biomarkers that identify novel pathways of disease pathogenesis and possible new therapeutic targets. The present paper is a narrative review about ACL immunogenetics in BA, highlighting in particular the interacting roles of the wound healing gene FLI1 with interleukin-6 and genes SMAD2 and SMAD3 of the transforming growth factor beta signalling pathway. This research highlights the need for well-powered genetic and functional studies on Leishmania braziliensis infection as essential to define and validate the role of host genes in determining resistance/susceptibility regarding this disease. PMID:24863979

  13. Reliability and validity study of Persian modified version of MUSIC (musculoskeletal intervention center) – Norrtalje questionnaire

    PubMed Central

    Alipour, Akbar; Ghaffari, Mostafa; Jensen, Irene; Shariati, Batoul; Vingard, Eva

    2007-01-01

    Background Musculoskeletal disorders (MSDs) are a major health problem in the world. Self-reported questionnaires are a known method for estimating the prevalence of MSDs among the population. One of the studies concerning MSDs and their relation to work-related physical and psychosocial factors, as well as non-work-related factors, is the MUSIC-Norrtalje study in Sweden. In this study, the research group developed a questionnaire, which has been validated during its development process and is now considered a well-known instrument. The aim of this study is to validate the Persian version of this questionnaire. Methods The first step was to establish two expert panel groups in Iran and Sweden. The Focus Group Discussion (FGD) method was used to detect questionnaire face and content validity. To detect questionnaire reliability, we used the test-retest method. Results Except for two items, all other questions that respondents had problems with in the focus group (20 of 297), had unclear translations; the ambiguity was related to the stem of the questions and the predicted answers were clear for the participants. The concepts of 'household/spare time' and 'physical activity in the workplace' were not understood by the participants of FGD; this has been solved by adding further descriptions to these phrases in the translation. In the test-retest study, the reliability coefficient was relatively high in most items (only 5 items out of 297 had an ICC or kappa below 0.7). Conclusion The findings from the present study provide evidence that the Persian version of the MUSIC questionnaire is a reliable and valid instrument. PMID:17764557

  14. A catch-up validation study of an in vitro skin irritation test method using reconstructed human epidermis LabCyte EPI-MODEL24.

    PubMed

    Kojima, Hajime; Katoh, Masakazu; Shinoda, Shinsuke; Hagiwara, Saori; Suzuki, Tamie; Izumi, Runa; Yamaguchi, Yoshihiro; Nakamura, Maki; Kasahawa, Toshihiko; Shibai, Aya

    2014-07-01

    Three validation studies were conducted by the Japanese Society for Alternatives to Animal Experiments in order to assess the performance of a skin irritation assay using reconstructed human epidermis (RhE) LabCyte EPI-MODEL24 (LabCyte EPI-MODEL24 SIT) developed by the Japan Tissue Engineering Co., Ltd. (J-TEC), and the results of these studies were submitted to the Organisation for Economic Co-operation and Development (OECD) for the creation of a Test Guideline (TG). In the summary review report from the OECD, the peer review panel indicated the need to resolve an issue regarding the misclassification of 1-bromohexane. To this end, a rinsing operation intended to remove exposed chemicals was reviewed and the standard operating procedure (SOP) revised by J-TEC. Thereafter, in order to confirm general versatility of the revised SOP, a new validation management team was organized by the Japanese Center for the Validation of Alternative Methods (JaCVAM) to undertake a catch-up validation study that would compare the revised assay with similar in vitro skin irritation assays, per OECD TG No. 439 (2010). The catch-up validation and supplementary studies for LabCyte EPI-MODEL24 SIT using the revised SOPs were conducted at three laboratories. These results showed that the revised SOP of LabCyte EPI-MODEL24 SIT conformed more accurately to the classifications for skin irritation under the United Nations Globally Harmonised System of Classification and Labelling of Chemicals (UN GHS), thereby highlighting the importance of an optimized rinsing operation for the removal of exposed chemicals in obtaining consistent results from in vitro skin irritation assays. PMID:24122860

  15. NERVE CONDUCTION STUDIES FOR CARPAL TUNNEL SYNDROME: ESSENTIAL PRELUDE TO SURGERY OR UNNECESSARY LUXURY?

    Microsoft Academic Search

    N. J SMITH

    2002-01-01

    Although carpal tunnel syndrome is a relatively trivial condition, controversy surrounds the use of nerve conduction studies, and whether they are essential to make the diagnosis, or as a prelude to surgery. This is partly due to the lack of a generally agreed definition of the condition, and failure to recognize that the patient's first priority is rapid relief of

  16. Molecular Dynamics Study of Gating in the Mechanosensitive Channel of Small Conductance MscS

    Microsoft Academic Search

    Marcos Sotomayor; Klaus Schulten

    2004-01-01

    Mechanosensitive channels are a class of ubiquitous membrane proteins gated by mechanical strain in the cellular membrane. MscS, the mechanosensitive channel of small conductance, is found in the inner membrane of Escherichia coli and its crystallographic structure in an open form has been recently solved. By means of molecular dynamics simulations we studied the stability of the channel conformation suggested

  17. USING CONTINUOUS MONITORS FOR CONDUCTING TRACER STUDIES IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The use of online monitors for conducting a distribution system tracer study is proving to be an essential tool to accurately understand the flow dynamics in a distribution system. In a series of field testing sponsored by U. S. Environmental Protection Agency (EPA) and Greater ...

  18. A Theoretical Study on Proton Conduction Mechanism in BaZrO3 Perovskite

    E-print Network

    Helgaker, Trygve

    Chapter 14 A Theoretical Study on Proton Conduction Mechanism in BaZrO3 Perovskite Taku Onishi mechanism in BaZrO3 perovskite, from the viewpoint of energetics and bonding. The calculated activation investigated hydrogen defect around zirconium vacancy. 14.1 Introduction The perovskite-type cubic BaZrO3 shows

  19. Fretting corrosion studies of an extrinsic conducting polymer and tin interface

    Microsoft Academic Search

    J. Swingler; J. W. McBride

    2001-01-01

    Novel contact connector materials such as conducting polymers are becoming available which improve performance and enable further miniaturisation. Studies of a polymer-tin interface have been carried out to characterise contact resistance performance under fretting conditions. Degradation mechanisms have been identified using contact resistance measurements and surface analysis tools. These mechanisms have been shown to be different to those found in

  20. Acoustical and thermal conductivity studies on CuO/DEA-benzene hybrid nanofluids

    NASA Astrophysics Data System (ADS)

    Rohini, B.; Gopalakrishnan, M.; Kiruba, R.; Mahalingam, T.; Kingson Solomon Jeevaraj, A.

    2013-02-01

    Binary organic liquid based copper oxide nanofluids of various concentrations have been prepared through ultrasonically assisted chemical solution method. Ultrasonic studies, refractive indices, densities are carried out for the nanofluids for various temperature where Thermal conductivity was also measured for the nanofluids at room temperature. The molecular interactions responsible for the changes in acoustical parameters with respect to concentration and temperature are discussed.

  1. The Connoisseurship of Conducting: A Qualitative Study of Exemplary Wind Band Conductors

    ERIC Educational Resources Information Center

    Barry, Nancy; Henry, Daniel

    2015-01-01

    This study aimed to gain an in-depth perspective through examining how the conducting pedagogy of three selected exemplary high school and college instrumental music conductors function within the context of an actual rehearsal. A typical rehearsal was video recorded, followed by a "think-aloud" session in which the conductor viewed the…

  2. Paychecks: A Guide to Conducting Salary-Equity Studies for Higher Education Faculty. Second Edition.

    ERIC Educational Resources Information Center

    Haignere, Lois

    This guidebook is designed as a resource for those in the higher education community who want to conduct analyses of bias in faculty salaries or to understand and interpret the results of studies presented to them. This edition will help readers detect gender and face bias in current rank, select a salary-equity consultant, understand different…

  3. The Use of Relational Databases as a Tool for Conducting Clinical Studies

    PubMed Central

    Miller, Randolph A.; Kapoor, Wishwa N.; Peterson, Jacqueline

    1983-01-01

    Many clinical investigators already have access to powerful university mainframe-based relational database management systems. Many of these programs, with minimal expense in time and money, can be employed to assist the investigator in conducting clinical trials. We describe our experience using one such general relational database system (System 1022) in completing several academic studies.

  4. Pressure ulcer prevention algorithm content validation: a mixed-methods, quantitative study.

    PubMed

    van Rijswijk, Lia; Beitz, Janice M

    2015-04-01

    Translating pressure ulcer prevention (PUP) evidence-based recommendations into practice remains challenging for a variety of reasons, including the perceived quality, validity, and usability of the research or the guideline itself. Following the development and face validation testing of an evidence-based PUP algorithm, additional stakeholder input and testing were needed. Using convenience sampling methods, wound care experts attending a national wound care conference and a regional wound ostomy continence nursing (WOCN) conference and/or graduates of a WOCN program were invited to participate in an Internal Review Board-approved, mixed-methods quantitative survey with qualitative components to examine algorithm content validity. After participants provided written informed consent, demographic variables were collected and participants were asked to comment on and rate the relevance and appropriateness of each of the 26 algorithm decision points/steps using standard content validation study procedures. All responses were anonymous. Descriptive summary statistics, mean relevance/appropriateness scores, and the content validity index (CVI) were calculated. Qualitative comments were transcribed and thematically analyzed. Of the 553 wound care experts invited, 79 (average age 52.9 years, SD 10.1; range 23-73) consented to participate and completed the study (a response rate of 14%). Most (67, 85%) were female, registered (49, 62%) or advanced practice (12, 15%) nurses, and had > 10 years of health care experience (88, 92%). Other health disciplines included medical doctors, physical therapists, nurse practitioners, and certified nurse specialists. Almost all had received formal wound care education (75, 95%). On a Likert-type scale of 1 (not relevant/appropriate) to 4 (very relevant and appropriate), the average score for the entire algorithm/all decision points (N = 1,912) was 3.72 with an overall CVI of 0.94 (out of 1). The only decision point/step recommendation with a CVI of ? 0.70 was the recommendation to provide medical-grade sheepskin for patients at high risk for friction/shear. Many positive and substantive suggestions for minor modifications including color, flow, and algorithm orientation were received. The high overall and individual item rating scores and CVI further support the validity and appropriateness of the PUP algorithm with the addition of the minor modifications. The generic recommendations facilitate individualization, and future research should focus on construct validation testing. PMID:25853377

  5. Results of a European interlaboratory method validation study for the quantitative determination of lipophilic marine biotoxins in raw and cooked shellfish based on high-performance liquid chromatography–tandem mass spectrometry. Part I: collaborative study

    Microsoft Academic Search

    Anja These; Christine Klemm; Ingo Nausch; Steffen Uhlig

    2011-01-01

    A European interlaboratory collaborative study was conducted to validate a method for the quantitative determination of lipophilic\\u000a marine biotoxins based on high-performance liquid chromatography–tandem mass spectrometry. During this study, the diarrhetic\\u000a shellfish poisoning toxins okadaic acid, dinophysis toxin1 and 2 including their esters, the azaspiracids 1-3, pectenotoxin2,\\u000a and the yessotoxins were investigated at concentration levels near the limit of quantification

  6. Lessons Learned During the Conduct of Clinical Studies in The Dental PBRN

    PubMed Central

    Gilbert, Gregg H.; Richman, Joshua S.; Gordan, Valeria V.; Rindal, D. Brad; Fellows, Jeffrey L.; Benjamin, Paul L.; Wallace-Dawson, Martha; Williams, O. Dale

    2012-01-01

    Effectively addressing challenges of conducting research in nonacademic settings is crucial to its success. A dental practice-based research network called The Dental Practice-Based Research Network (DPBRN) is comprised of practitioner-investigators in two health maintenance organizations, several universities, many U.S. states, and three Scandinavian countries. Our objective in this article is to describe lessons learned from conducting studies in this research context; the studies are conducted by clinicians in community settings who may be doing their first research study. To date, twenty-one studies have been completed or are in implementation. These include a broad range of topic areas, enrollment sizes, and study designs. A total of 1,126 practitioner-investigators have participated in at least one study. After excluding one study because it involved electronic records queries only, these studies included more than 70,000 patient/participant units. Because the DPBRN is committed to being both practitioner- and patient-driven, all studies must be approved by its Executive Committee and a formal study section of academic clinical scientists. As a result of interacting with a diverse range of institutional and regulatory entities, funding agencies, practitioners, clinic staff, patients, academic scientists, and geographic areas, twenty-three key lessons have been learned. Patients’ acceptance of these studies has been very high, judging from high participation rates and their completion of data forms. Early studies substantially informed later studies with regard to study design, practicality, forms design, informed consent process, and training and monitoring methods. Although time-intensive and complex, these solutions improved acceptability of practice-based research to patients, practitioners, and university researchers. PMID:21460266

  7. Lessons learned during the conduct of clinical studies in the dental PBRN.

    PubMed

    Gilbert, Gregg H; Richman, Joshua S; Gordan, Valeria V; Rindal, D Brad; Fellows, Jeffrey L; Benjamin, Paul L; Wallace-Dawson, Martha; Williams, O Dale

    2011-04-01

    Effectively addressing challenges of conducting research in nonacademic settings is crucial to its success. A dental practice-based research network called The Dental Practice-Based Research Network (DPBRN) is comprised of practitioner- investigators in two health maintenance organizations, several universities, many U.S. states, and three Scandinavian countries. Our objective in this article is to describe lessons learned from conducting studies in this research context; the studies are conducted by clinicians in community settings who may be doing their first research study. To date, twenty-one studies have been completed or are in implementation. These include a broad range of topic areas, enrollment sizes, and study designs. A total of 1,126 practitioner-investigators have participated in at least one study. After excluding one study because it involved electronic records queries only, these studies included more than 70,000 patient/participant units. Because the DPBRN is committed to being both practitioner- and patient-driven, all studies must be approved by its Executive Committee and a formal study section of academic clinical scientists. As a result of interacting with a diverse range of institutional and regulatory entities, funding agencies, practitioners, clinic staff, patients, academic scientists, and geographic areas, twenty-three key lessons have been learned. Patients' acceptance of these studies has been very high, judging from high participation rates and their completion of data forms. Early studies substantially informed later studies with regard to study design, practicality, forms design, informed consent process, and training and monitoring methods. Although time-intensive and complex, these solutions improved acceptability of practice-based research to patients, practitioners, and university researchers. PMID:21460266

  8. Picosecond pulse-conductivity technique applied to study excess-electron reactions in hydrocarbon mixtures

    SciTech Connect

    Bakale, G.; Beck, G.

    1983-01-01

    To measure electron reactions on a picosecond timescale the investigators developed a picosecond pulse-conductivity technique, which makes use of the electron fine-structure pulses of our LINAC (pulse width 25 vs FWHM) to produce excess electrons and now detects changes in sample conductance under optimum conditions with an instrumental response of 18 ps. This resolution is in agreement with a theoretical estimate. This technique has been successfully applied to study excess electron reactions in solvents covering a mobility range from 0.24 to 100 cm/sup 2/V/sup -1/s/sup -1/; extension to lower mobility liquids seem possible.

  9. Comparative study of electrically conductive thick films with and without glass

    Microsoft Academic Search

    Zongrong Liu; D. D. L. Chung

    2004-01-01

    An air-fireable, glass-free, electrically conductive thick-film material (96.6% Ag, 1.38% Cu, 0.28% Al, 0.35% Ti, and 1.39%\\u000a Sn by weight) and a conventional glass-containing, electrically conductive thick-film materials (96.6% Ag and 3.4% glass frit\\u000a by weight), both on alumina substrates, were studied by electrical, mechanical, thermal, and microscopic methods. The volume\\u000a electrical resistivity of the glass-free thick film (2.510?6 ?cm,

  10. Study of the solution thermal conductivity effect on nonlinear refraction of colloidal gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Sarkhosh, L.; Mansour, N.

    2015-06-01

    In nanoparticle colloidal systems, the thermal nonlinearity is affected by the thermal parameters of the surrounding solution. Having a low temperature gradient rate solution may be a key factor in producing high thermal nonlinear properties in colloids. In this manuscript, the effect of the thermal conductivity of the surrounding liquid environment on the thermal nonlinear refraction of gold nanoparticles (AuNPs) synthesized by laser ablation of a gold target in different solutions is investigated. Gold nanoparticles colloids have been fabricated by the nanosecond pulsed laser ablation of a pure gold plate in different liquid environments with a thermal conductivity range of 0.14–0.60?W?mK?1 including cyclohexanone, castor oil, dimethyl sulfoxide, ethylene glycol, glycerin and water. The AuNPs colloids exhibit a UV-Vis absorption spectrum with a surface plasmon absorption peak at about 540??±??20?nm. The thermal nonlinear optical responses of the gold colloids are measured using the Z-scan technique under low power CW laser irradiation at 532?nm near the surface plasmon peak of the nanoparticles. Our results show that the nonlinear refractive index of the nanoparticle colloids is considerably affected by the thermal conductivity of liquid medium. The largest nonlinear refractive index of??3.1??×??10–7?cm2?W?1 is obtained for AuNP in cyclohexanone with the lowest thermal conductivity of 0.14?W?mK?1 whereas the lowest one of??0.1??×??10?7?cm2?W?1 is obtained for AuNP in water with the highest thermal conductivity of 0.60?W?mK?1. This study shows that the nonlinear refractive index value of colloids can be controlled by the thermal conductivity of the used liquid’s environment. This allows us to design low threshold optical limiters by choosing a solution with low thermal conductivity for colloidal nanoparticles.

  11. Temporal changes of topsoil hydraulic conductivity studied by multiple-point tension disk infiltrometer

    NASA Astrophysics Data System (ADS)

    Klipa, Vladimir; Zumr, David; Snehota, Michal; Dohnal, Michal

    2015-04-01

    Hydraulic conductivity of cultivated soils is strongly affected by agrotechnical procedures, soil compaction, plant growth etc. This contribution is focused on series of measurement of topsoil unsaturated hydraulic conductivity using automated multipoint tension infiltrometer developed at CTU in Prague. The apparatus consists of two triplets of minidisk infiltrometers that are supported by a light aluminum frame. Therefore it allows simultaneous measurement of six tension infiltrations at two different pressure heads. Experiments were conducted at the experimental agricultural catchment Nu?ice (Central Bohemia, Czech Republic) as a part of the broader research of rainfall-runoff and soil erosion processes. The soil in the catchment is classified as Cambisol with texture that is ranging from loam to clay loam and is conservatively tilled. Series of ten infiltration campaigns (56 individual infiltration experiments) were carried out on a single experimental plot during period of two years. Dataset involves measurement under various agricultural activities and crop phenophases. The hydraulic conductivities were determined using extended semiempirical estimation procedure of Zhang. Additionally, large undisturbed soil samples were analyzed with use of X-ray computed tomography to assess the soil structure morphology in detail. Results show that unsaturated hydraulic conductivity was the lowest in early spring and did increase at beginning of summer. Unsaturated soil hydraulic conductivity was higher when the soil bulk density was high. During the summer and autumn the unsaturated hydraulic conductivity remained relatively unchanged. The impact of agricultural procedures was not apparent in the dataset.. The study has been supported by the Czech Science Foundation Project No. 13-20388P and by CTU in Prague funding via Student's Grant Competition SGS No. SGS14/131/OHK1/2T/11. The MultiDisk infiltrometer was developed within the framework of the project supported by the Technology Agency of the Czech Republic under No.: TA01021844.

  12. Development and validation of UV spectrophotometric method to study stress degradation behaviour of rizatriptan benzoate.

    PubMed

    Amolkumar, Kempwade; Ashok, Taranalli; Kiran, Jadhav

    2015-01-01

    Rizatriptan benzoate is a 5 HT 1B/1D receptor agonist which is prescribed for the treatment of migraine. In the present study new, simple, specific ultraviolet spectrophotometric method for rizatriptan benzoate was developed and validated. Forced degradation studies were carried out in acidic, alkaline and neutral pH conditions. The absorbance maxima peak was found to be 224 nm and linearity was observed in the concentration range of 0. 5-2. 5 µg . mL-1 with regression coefficient value of 0. 998 8. The method was validated and found to be precise. The percent recovery for rizatriptan benzoate was found to be 98. 576±0. 202. The bulk drug was found to be stable in neutral and acidic pH conditions but got degraded in 1 N NaOH solution. PMID:25993836

  13. Validation study of a Portuguese version of the Hospital Anxiety and Depression Scale.

    PubMed

    Pais-Ribeiro, J; Silva, I; Ferreira, T; Martins, A; Meneses, R; Baltar, M

    2007-03-01

    The study aims to develop and assess metric proprieties of the Portuguese version of the Hospital Anxiety and Depression Scale. A sequential sample includes 1322 participants diagnosed with cancer, stroke, epilepsy, coronary heart disease, diabetes, myotonic dystrophy, obstructive sleep apnoea, depression and a non-disease group, which completed the HADS. The first step includes translation, retroversion, inspection for lexical equivalence and content validity, and cognitive debriefing. Then we reproduce oblique exploratory factor analysis and use confirmatory factor analysis. We explore the sensibility of the questionnaire. The validation process of the Portuguese HADS version shows metric properties similar to those in international studies, suggesting that it measures the same constructs, in the same way, as the original HADS form. PMID:17365902

  14. WHO Study on the reliability and validity of the alcohol and drug use disorder instruments: overview of methods and results

    Microsoft Academic Search

    B Üstün; W Compton; D Mager; T Babor; O Baiyewu; S Chatterji; L Cottler; A Gö?ü?; V Mavreas; L Peters; C Pull; J Saunders; R Smeets; M.-R Stipec; R Vrasti; D Hasin; R Room; W Van den Brink; D Regier; J Blaine; B. F Grant; N Sartorius

    1997-01-01

    The WHO Study on the reliability and validity of the alcohol and drug use disorder instruments is an international study which has taken place in 12 centres in ten countries, aiming to test the reliability and validity of three diagnostic instruments for alcohol and drug use disorders: the Composite International Diagnostic Interview (CIDI), the Schedules for Clinical Assessment in Neuropsychiatry

  15. Summary and analysis of neutron measurements conducted during the Oak Ridge personnel dosimetry intercomparison studies

    Microsoft Academic Search

    Swaja

    1987-01-01

    Since 1974, neutron personnel dosimetry intercomparison studies (PDIS) have been conducted annually at the Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research Facility. During these studies, neutron dosimeters are mailed to ORNL, exposed to low-level (less than 15 mSv) dose equivalents in a variety of mixed-radiation fields produced using the Health Physics Research Reactor (HPRR), and then returned to the

  16. Dielectric Behavior and A. C. Conductivity Studies on Cobalt Nanoferrites Synthesized Using Combustion Method

    Microsoft Academic Search

    B. J. Madhu; S. Razikha Banu; M. Kavya; B. Shruthi; M. S. Vasanthkumar; T. V. Sannamma; M. Surendra

    2011-01-01

    Cobalt nanoferrite particles were prepared by combustion method. The structures of the samples were studied with X-ray diffraction (XRD) using Cu-K? radiation. The X-ray diffraction analysis revealed the nanocrystalline nature in the prepared ferrite samples. Dielectric and a. c. conductivity studies have been undertaken over a wide range of frequencies (100Hz-5MHz) at room temperature. The dielectric loss tangent (tan?) was

  17. Safety studies conducted on a proprietary high-purity aloe vera inner leaf fillet preparation, Qmatrix®

    Microsoft Academic Search

    Lonnie D. Williams; George A. Burdock; Eunju Shin; Seunghyun Kim; T. H. Jo; Kenneth N. Jones; Ray A. Matulka

    2010-01-01

    The aloe vera plant has a long history of safe use for oral and topical applications. This publication describes safety studies conducted on a proprietary high-purity aloe vera inner leaf fillet preparation, Qmatrix®. In a 13-week study in rats, Qmatrix® was administered via gavage at 0, 500, 1000 and 2000mg\\/kg body weight (bw)\\/day. There were no significant changes in food

  18. Capacitance and conductance studies on silicon solar cells subjected to 8 MeV electron irradiations

    NASA Astrophysics Data System (ADS)

    Sathyanarayana Bhat, P.; Rao, Asha; Sanjeev, Ganesh; Usha, G.; Priya, G. Krishna; Sankaran, M.; Puthanveettil, Suresh E.

    2015-06-01

    The space grade silicon solar cells were irradiated with 8 MeV electrons with doses ranging from 5-100 k Gy. Capacitance and conductance measurements were carried out in order to investigate the anomalous degradation of the cells in the radiation harsh environments and the results are presented in this paper. Detailed and systematic analysis of the frequency-dependent capacitance and conductance measurements were performed to extract the information about the interface trap states. The small increase in density of interface states was observed from the conductance-frequency measurements. The reduction in carrier concentration upon electron irradiation is due to the trapping of charge carriers by the radiation induced trap centres. The Drive Level Capacitance Profiling (DLCP) technique has been applied to study the properties of defects in silicon solar cells. A small variation in responding state densities with measuring frequency was observed and the defect densities are in the range 1015 -1016 cm-3.

  19. Temperature dependent ionic conductivity and mobility studies of hot-pressed solid polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Chandra, Angesh; Chandra, Archana; Bhatt, Alok

    2015-06-01

    Temperature dependent ionic conductivity (?), ionic mobility (µ), and mobile ion concentration (n) of the hot-pressed Solid Polymer Electrolytes (SPEs): (1-x) PEO: x NaBr, where 0 < x < 50 in wt. %, has been reported. SPE films have been casted using a hot-press technique in place of the traditional solution cast method. A conductivity enhancement of the two orders of magnitude was achieved in SPE film composition: (70PEO: 30NaBr) at room temperature and this has been referred to as Optimum Conducting Composition (OCC). To determine the activation energy (Ea), energy of migration (Em) and energy of formation (Ef) temperature dependent studies of SPE OCC have been carried out with the help of various experimental procedures.

  20. Strain effects on the ionic conductivity of Y-doped ceria: A simulation study

    E-print Network

    Burbano, Mario; Watson, Graeme W

    2013-01-01

    In this paper we report a computational study of the effects of strain on the conductivity of Y-doped ceria (YDC). This material was chosen as it is of technological interest in the field of Solid Oxide Fuel Cells (SOFCs). The simulations were performed under realistic operational temperatures and strain (\\epsilon) levels. For bulk and thin film YDC, the results show that tensile strain leads to conductivity enhancements of up to 3.5x and 1.44x, respectively. The magnitude of these enhancements is in agreement with recent experimental and computational evidence. In addition, the methods presented herein allowed us to identify enhanced ionic conductivity in the surface regions of YDC slabs and its anisotropic character.

  1. Ionic conductivity and FT-IR studies on plasticized PVC/PMMA blend polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Stephan, A. Manuel; Kumar, T. Prem; Renganathan, N. G.; Pitchumani, S.; Thirunakaran, R.; Muniyandi, N.

    Ionic conductivities of plasticized poly(vinylchoride) (PVC)/poly(methylmethacrylate) (PMMA) blend electrolyte films containing two different lithium salts, viz., lithium tetrafluroborate (LiBF 4) and lithium perchlorate (LiClO 4) are studied using the AC impedance technique at 25°C, 40°C, 50°C and 60°C. A mixture of ethylene carbonate (EC) and propylene carbonate (PC) is used as the plasticizer. Pure PMMA and PMMA-rich phases exhibited better conductivity. The variation of ionic conductivity for different plasticizer contents and for different lithium salts is reported. The variation in film morphology is examined by scanning electron microscopic examination. Finally, the existence of ion-ion pairs has been identified using Fourier Transform Infrared analysis (FT-IR) measurements.

  2. Comparing the Similarity of Responses Received from Studies in Amazon's Mechanical Turk to Studies Conducted Online and with Direct Recruitment.

    PubMed

    Bartneck, Christoph; Duenser, Andreas; Moltchanova, Elena; Zawieska, Karolina

    2015-01-01

    Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies. PMID:25876027

  3. Gene expression–based survival prediction in lung adenocarcinoma: a multi-site, blinded validation study

    Microsoft Academic Search

    Kerby Shedden; Jeremy M G Taylor; Steven A Enkemann; Ming-Sound Tsao; Timothy J Yeatman; William L Gerald; Steven Eschrich; Igor Jurisica; Thomas J Giordano; David E Misek; Andrew C Chang; Chang Qi Zhu; Daniel Strumpf; Samir Hanash; Frances A Shepherd; Keyue Ding; Lesley Seymour; Katsuhiko Naoki; Nathan Pennell; Barbara Weir; Roel Verhaak; Christine Ladd-Acosta; Todd Golub; Michael Gruidl; Anupama Sharma; Janos Szoke; Maureen Zakowski; Valerie Rusch; Mark Kris; Agnes Viale; Noriko Motoi; William Travis; Barbara Conley; Venkatraman E Seshan; Matthew Meyerson; Rork Kuick; Kevin K Dobbin; Tracy Lively; James W Jacobson; David G Beer

    2008-01-01

    Although prognostic gene expression signatures for survival in early-stage lung cancer have been proposed, for clinical application, it is critical to establish their performance across different subject populations and in different laboratories. Here we report a large, training–testing, multi-site, blinded validation study to characterize the performance of several prognostic models based on gene expression for 442 lung adenocarcinomas. The hypotheses

  4. Expert-System Scores for Complex Constructed-Response Quantitative Items: A Study of Convergent Validity

    Microsoft Academic Search

    Randy Elliot Bennett; Marc M. Sebrechts; Donald A. Rock

    1991-01-01

    This study investigated the convergent validity of expert-system scores for four mathematical constructed-response item formats. A five-factor model comprised of four constructed-response for mat factors and a Graduate Record Examination (GRE) General Test quantitative factor was posed. Confirmatory factor analysis was used to test the fit of this model and to compare it with several alter natives. The five-factor model

  5. The Menopause Rating Scale (MRS) as outcome measure for hormone treatment? A validation study

    Microsoft Academic Search

    Lothar AJ Heinemann; Thai DoMinh; Frank Strelow; Silvia Gerbsch; Jörg Schnitker; Hermann PG Schneider

    2004-01-01

    : BACKGROUND: The Menopause Rating Scale is a health-related Quality of Life scale developed in the early 1990s and step-by-step validated since then. No methodologically detailed work on the utility of the scale to assess health-related changes after treatment was published before. METHOD: We analysed an open, uncontrolled post-marketing study with over 9000 women with pre- and post-treatment data of

  6. The Bland-Altman Method Should Not Be Used in Regression Cross-Validation Studies

    ERIC Educational Resources Information Center

    O'Connor, Daniel P.; Mahar, Matthew T.; Laughlin, Mitzi S.; Jackson, Andrew S.

    2011-01-01

    The purpose of this study was to demonstrate the bias in the Bland-Altman (BA) limits of agreement method when it is used to validate regression models. Data from 1,158 men were used to develop three regression equations to estimate maximum oxygen uptake (R[superscript 2] = 0.40, 0.61, and 0.82, respectively). The equations were evaluated in a…

  7. Study of the Validity of K. Bane's Formulae for the CLIC Accelerator Structure

    E-print Network

    Zennaro, R

    2008-01-01

    The comprehension of short range wakefields is essential for the design of CLIC. Useful tools are the Karl Bane's formulae which provide geometrical parameterization of the short range wake for periodic rotational-symmetric structures. The comparison of 2D computations based on ABCI with predicted results and the study of the range of validity of these formulae are the subjects of this paper. An extended model for rounded iris structures is also proposed.

  8. Reliability and validity studies of the WHO-Composite International Diagnostic Interview (CIDI): A critical review

    Microsoft Academic Search

    Hans-Ulrich Wittchen

    1994-01-01

    Summary-This paper reviews rehahility and validity studies of the WHO Composite International Diagnostic Interview (CIDI). The CID1 is a comprehensive and fully standardized diagnostic interview designed for assessing mental disorders according to the definitions of the Diagnostic Criteria for Research of ICD-10 and DSM-III-R. The inslrument contains 276 symptom questions many of which are coupled with probe questions to evaluate

  9. Validation of New Measures of Disability and Functioning in the National Health and Aging Trends Study

    PubMed Central

    Kasper, Judith D.; Cornman, Jennifer C.; Agree, Emily M.; Bandeen-Roche, Karen; Mor, Vincent; Spillman, Brenda C.; Wallace, Robert; Wolf, Douglas A.

    2011-01-01

    Background. Measurement gaps continue to hamper fuller understanding of late-life disability trends and dynamics. This article reports findings that validate the self-reported components of the disability protocol to be used in the new National Health and Aging Trends Study. The protocol was designed to redress existing measures by attending to environmental aspects of disability, capturing a broader range of capacity to perform tasks and including participation restriction items. Methods. We undertook an in-person validation study to determine the reliability, validity, and initial measurement properties of the National Health and Aging Trends Study self-reported disability protocol (n = 326). A random subset (n = 111) was readministered the protocol within 2–4 weeks. The interview and reinterview included new self-reported measures of physical capacity, activity limitations, and participation restrictions, as well as established performance and cognitive tests. We calculated percent agreement and kappa between interviews for all self-reported items and summary measures. We also assessed the construct validity of summary measures through correlations with demographic characteristics, frailty, memory, and performance-based mobility and confirmed whether activity limitations and participation restrictions were distinct domains. Results. New items and derived summary measures demonstrate robustness over a short time period, with kappas for retained/recommended items in the .60–.80 range. The summary measures correlate as expected with age, sex, residential status, and established performance-based constructs. Two factors, representing activity limitations and participation restrictions, were confirmed. Conclusions. The National Health and Aging Trends Study protocol preserves the ability to examine more traditional measures of functioning while offering new insights into how activities are performed and preserving key conceptual distinctions. PMID:21715647

  10. Salem plant dynamic voltage study and validation of computer models by tests

    SciTech Connect

    Hajos, L.G. (Public Service Electric and Gas, Nuclear Dept., MCN 47, Hancocks Bridge, NJ (US)); Hannett, L.N. (Power Technologies, Inc., Schenectady, NY (US))

    1991-12-01

    A voltage profile study was performed for the power distribution system of the Salem Nuclear Generating Station to determine the cause of an apparent misoperation of undervoltage relays. A dynamic model of the distribution system was developed for simulation of the bus transfer from the generators auxiliary transformer to the station power transformer. This paper presents the work performed by the authors in validating the computer dynamic simulation model by a test.

  11. Impaired small fiber conduction in patients with Fabry disease: a neurophysiological case–control study

    PubMed Central

    2013-01-01

    Background Fabry disease is an inborn lysosomal storage disorder which is associated with small fiber neuropathy. We set out to investigate small fiber conduction in Fabry patients using pain-related evoked potentials (PREP). Methods In this case–control study we prospectively studied 76 consecutive Fabry patients for electrical small fiber conduction in correlation with small fiber function and morphology. Data were compared with healthy controls using non-parametric statistical tests. All patients underwent neurological examination and were investigated with pain and depression questionnaires. Small fiber function (quantitative sensory testing, QST), morphology (skin punch biopsy), and electrical conduction (PREP) were assessed and correlated. Patients were stratified for gender and disease severity as reflected by renal function. Results All Fabry patients (31 men, 45 women) had small fiber neuropathy. Men with Fabry disease showed impaired cold (p?conduction with PREP, men but not women with Fabry disease had lower amplitudes upon stimulation at face (p?conduction is impaired in men with Fabry disease and worsens with advanced disease severity. PREP are well-suited to measure A-delta fiber conduction. PMID:23705943

  12. Is the Scale for Measuring Motivational Interviewing Skills a valid and reliable instrument for measuring the primary care professionals motivational skills?: EVEM study protocol

    PubMed Central

    2012-01-01

    Background Lifestyle is one of the main determinants of people’s health. It is essential to find the most effective prevention strategies to be used to encourage behavioral changes in their patients. Many theories are available that explain change or adherence to specific health behaviors in subjects. In this sense the named Motivational Interviewing has increasingly gained relevance. Few well-validated instruments are available for measuring doctors’ communication skills, and more specifically the Motivational Interviewing. Methods/Design The hypothesis of this study is that the Scale for Measuring Motivational Interviewing Skills (EVEM questionnaire) is a valid and reliable instrument for measuring the primary care professionals skills to get behavior change in patients. To test the hypothesis we have designed a prospective, observational, multi-center study to validate a measuring instrument. –Scope: Thirty-two primary care centers in Spain. -Sampling and Size: a) face and consensual validity: A group composed of 15 experts in Motivational Interviewing. b) Assessment of the psychometric properties of the scale; 50 physician- patient encounters will be videoed; a total of 162 interviews will be conducted with six standardized patients, and another 200 interviews will be conducted with 50 real patients (n=362). Four physicians will be specially trained to assess 30 interviews randomly selected to test the scale reproducibility. -Measurements for to test the hypothesis: a) Face validity: development of a draft questionnaire based on a theoretical model, by using Delphi-type methodology with experts. b) Scale psychometric properties: intraobservers will evaluate video recorded interviews: content-scalability validity (Exploratory Factor Analysis), internal consistency (Cronbach alpha), intra-/inter-observer reliability (Kappa index, intraclass correlation coefficient, Bland & Altman methodology), generalizability, construct validity and sensitivity to change (Pearson product–moment correlation coefficient). Discussion The verification of the hypothesis that EVEM is a valid and reliable tool for assessing motivational interviewing would be a major breakthrough in the current theoretical and practical knowledge, as it could be used to assess if the providers put into practice a patient centered communication style and can be used both for training or researching purposes. Trials registration Dislip-EM study NCT01282190 (ClinicalTrials.gov) PMID:23173902

  13. Toward a Standard Procedure for Validation of Satellite-Derived Cloud Liquid Water Path: A Study with SEVIRI Data

    Microsoft Academic Search

    W. Greuell; R. A. Roebeling

    2009-01-01

    Differences between satellite-derived and ground-based values of cloud liquid water path (LWPsat and LWPgr, respectively) in validation studies are partly associated with the validation itself, in particular with scale differences and parallax. This paper aims at establishing standards for validation procedures to minimize these contributions to the differences. To investigate this, LWP values were collected as computed from ground-based microwave

  14. Injection Drug User Quality of Life Scale (IDUQOL): Findings from a content validation study

    PubMed Central

    Hubley, Anita M; Palepu, Anita

    2007-01-01

    Background Quality of life studies among injection drug users have primarily focused on health-related measures. The chaotic life-style of many injection drug users (IDUs), however, extends far beyond their health, and impacts upon social relationships, employment opportunities, housing, and day to day survival. Most current quality of life instruments do not capture the realities of people living with addictions. The Injection Drug Users' Quality of Life Scale (IDUQOL) was developed to reflect the life areas of relevance to IDUs. The present study examined the content validity of the IDUQOL using judgmental methods based on subject matter experts' (SMEs) ratings of various elements of this measure (e.g., appropriateness of life areas or items, names and descriptions of life areas, instructions for administration and scoring). Methods Six SMEs were provided with a copy of the IDUQOL and its administration and scoring manual and a detailed content validation questionnaire. Two commonly used judgmental measures of inter-rater agreement, the Content Validity Index (CVI) and the Average Deviation Mean Index (ADM), were used to evaluate SMEs' agreement on ratings of IDUQOL elements. Results A total of 75 elements of the IDUQOL were examined. The CVI results showed that all elements were endorsed by the required number of SMEs or more. The ADM results showed that acceptable agreement (i.e., practical significance) was obtained for all elements but statistically significant agreement was missed for nine elements. For these elements, SMEs' feedback was examined for ways to improve the elements. Open-ended feedback also provided suggestions for other revisions to the IDUQOL. Conclusion The results of the study provided strong evidence in support of the content validity of the IDUQOL and direction for the revision of some IDUQOL elements. PMID:17663783

  15. The importance of choosing the appropriate matrix to validate a bioanalytical method according to the study needs.

    PubMed

    Lachance, Sylvain; Lévesque, Ann

    2014-12-01

    Sylvain Lachance is a Bioanalytical Scientific Expert in the Bioanalytical Division of inVentiv Health Clinical Quebec City's (Canada) site, a CRO offering clinical, commercial and consulting services to the healthcare industry. He is responsible for following up on the conduct of bioanalytical method development activities by enhancing the scientific and technical knowledge of the researchers, bioanalytical project coordinators and of the laboratory technicians. He assists bioanalytical project coordinators in investigations during bioanalyses and method validations. He has been working in the Bioanalytical Division of inVentiv Health Clinical for over 16 years, working as a Research Scientist, Chromatographic Specialist and Scientific Expert. He has worked on multiple method developments in HPLC and LC-MS/MS, specifically on troubleshooting. He has been involved in more than 70 posters and publications in the bioanalytical field for different scientific meetings. Ann Lévesque obtained her PhD in Biochemistry at the Université Laval in Québec City in 1994 studying the biological actions of peptide analogs of the gastrin releasing peptide in the growth inhibition of cancer cells. Prior to joining inVentiv Health Clinical, she held management positions at other Contract Research Organizations. Her publications include over 100 posters, 17 scientific articles and book chapters in the clinical biochemistry and bioanalytical fields. Within inVentiv Health, Dr. Lévesque is responsible for managing the R&D and sample analysis teams performing bioanalytical analysis of small molecules and peptides. She is also acting as the Biomedical Laboratory Director accountable for the oversight of all activities related to the safety testing of samples from subjects enrolled in early stage clinical trials. Since joining the Bioanalytical Division, Dr. Lévesque has been instrumental in the great success of the laboratory by developing a culture of quality, innovation and value. Validation guidelines from different agencies mainly recommend that matrix effect should be studied with hemolyzed and hyperlipidemic samples, while the European agency requires also to investigate matrix effect on special population. When studies are done in countries with different dietary habits, or when a medication is administered to decrease the concentration of the endogenous compounds, should the matrix effect in these conditions be evaluated? Herein, three case studies are described to show the importance of choosing the appropriate matrix for the bioanalytical method validations and for their use to analyze the study samples according to the conditions required by the clinical trials. The case studies presented are related to the use of the testosterone, Omega-3 and cortisol methods. PMID:25529879

  16. Validation of the Use of Nonnaive Surgically Catheterized Rats for Pharmacokinetics Studies

    PubMed Central

    Deshmukh, Sujal V; Durston, Jessica; Shomer, Nirah H

    2008-01-01

    Although large animals, such as dogs and nonhuman primates, often are used for more than 1 pharmacokinetics study, common practice is to use only naive rodents for pharmacokinetics studies. We undertook a series of studies to validate whether surgically cannulated nonnaive rats could be used again after a 7-d washout. When vascular catheters are cared for appropriately, we find that they remain patent for more than 2 wk, with negligible drug carryover. Hematocrit decreased approximately 11% after pharmacokinetics studies but rebounded to prestudy levels after a 7-d washout. We empirically tested whether drugs known to alter drug disposition (1-aminobenzotriazole and quinidine) had residual effects on drug disposition after a 7-d washout and found that they did not. This finding suggests that after a 7-d washout, nonnaive rats likely would produce pharmacokinetics data similar to those of naive rats. We also tested reference compounds in naive and nonnaive rats and found no difference in pharmacokinetics parameters. Using surgically cannulated rats for a second study was feasible because of the relatively noninvasive nature of pharmacokinetics sampling (unrestrained rats attached to automated blood samplers). In addition, reusing surgically altered animals yields considerable cost savings. Our studies indicate that pharmacokinetics parameters did not differ significantly between naive and nonnaive rats. Cost–benefit analysis, monetary considerations, and validation studies support using rats for a second study after a 7-d washout period. PMID:19049252

  17. An approach to model validation and model-based prediction -- polyurethane foam case study.

    SciTech Connect

    Dowding, Kevin J.; Rutherford, Brian Milne

    2003-07-01

    Enhanced software methodology and improved computing hardware have advanced the state of simulation technology to a point where large physics-based codes can be a major contributor in many systems analyses. This shift toward the use of computational methods has brought with it new research challenges in a number of areas including characterization of uncertainty, model validation, and the analysis of computer output. It is these challenges that have motivated the work described in this report. Approaches to and methods for model validation and (model-based) prediction have been developed recently in the engineering, mathematics and statistical literatures. In this report we have provided a fairly detailed account of one approach to model validation and prediction applied to an analysis investigating thermal decomposition of polyurethane foam. A model simulates the evolution of the foam in a high temperature environment as it transforms from a solid to a gas phase. The available modeling and experimental results serve as data for a case study focusing our model validation and prediction developmental efforts on this specific thermal application. We discuss several elements of the ''philosophy'' behind the validation and prediction approach: (1) We view the validation process as an activity applying to the use of a specific computational model for a specific application. We do acknowledge, however, that an important part of the overall development of a computational simulation initiative is the feedback provided to model developers and analysts associated with the application. (2) We utilize information obtained for the calibration of model parameters to estimate the parameters and quantify uncertainty in the estimates. We rely, however, on validation data (or data from similar analyses) to measure the variability that contributes to the uncertainty in predictions for specific systems or units (unit-to-unit variability). (3) We perform statistical analyses and hypothesis tests as a part of the validation step to provide feedback to analysts and modelers. Decisions on how to proceed in making model-based predictions are made based on these analyses together with the application requirements. Updating modifying and understanding the boundaries associated with the model are also assisted through this feedback. (4) We include a ''model supplement term'' when model problems are indicated. This term provides a (bias) correction to the model so that it will better match the experimental results and more accurately account for uncertainty. Presumably, as the models continue to develop and are used for future applications, the causes for these apparent biases will be identified and the need for this supplementary modeling will diminish. (5) We use a response-modeling approach for our predictions that allows for general types of prediction and for assessment of prediction uncertainty. This approach is demonstrated through a case study supporting the assessment of a weapons response when subjected to a hydrocarbon fuel fire. The foam decomposition model provides an important element of the response of a weapon system in this abnormal thermal environment. Rigid foam is used to encapsulate critical components in the weapon system providing the needed mechanical support as well as thermal isolation. Because the foam begins to decompose at temperatures above 250 C, modeling the decomposition is critical to assessing a weapons response. In the validation analysis it is indicated that the model tends to ''exaggerate'' the effect of temperature changes when compared to the experimental results. The data, however, are too few and to restricted in terms of experimental design to make confident statements regarding modeling problems. For illustration, we assume these indications are correct and compensate for this apparent bias by constructing a model supplement term for use in the model-based predictions. Several hypothetical prediction problems are created and addressed. Hypothetical problems are used because no guidance was provided concern

  18. Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure Validation Simulation Study

    NASA Technical Reports Server (NTRS)

    Murdoch, Jennifer L.; Bussink, Frank J. L.; Chamberlain, James P.; Chartrand, Ryan C.; Palmer, Michael T.; Palmer, Susan O.

    2008-01-01

    The Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure (ITP) Validation Simulation Study investigated the viability of an ITP designed to enable oceanic flight level changes that would not otherwise be possible. Twelve commercial airline pilots with current oceanic experience flew a series of simulated scenarios involving either standard or ITP flight level change maneuvers and provided subjective workload ratings, assessments of ITP validity and acceptability, and objective performance measures associated with the appropriate selection, request, and execution of ITP flight level change maneuvers. In the majority of scenarios, subject pilots correctly assessed the traffic situation, selected an appropriate response (i.e., either a standard flight level change request, an ITP request, or no request), and executed their selected flight level change procedure, if any, without error. Workload ratings for ITP maneuvers were acceptable and not substantially higher than for standard flight level change maneuvers, and, for the majority of scenarios and subject pilots, subjective acceptability ratings and comments for ITP were generally high and positive. Qualitatively, the ITP was found to be valid and acceptable. However, the error rates for ITP maneuvers were higher than for standard flight level changes, and these errors may have design implications for both the ITP and the study's prototype traffic display. These errors and their implications are discussed.

  19. Validity of self-reported history of endodontic treatment in the Baltimore Longitudinal Study of Aging

    PubMed Central

    Gomes, Maximiliano Schünke; Hugo, Fernando Neves; Hilgert, Juliana Balbinot; Padilha, Dalva Maria Pereira; Simonsick, Eleanor Marie; Ferrucci, Luigi; Reynolds, Mark Allan

    2012-01-01

    Introduction Self-reported history of endodontic treatment (SRHET) has been used as a simplified method to estimate history of endodontic disease and treatment. This study aimed to quantify the validity of SRHET, as reported in the Baltimore Longitudinal Study of Aging (BLSA), as a method to: 1- identify individuals who experienced endodontic treatment (ET); and 2- identify individuals who present with apical periodontitis (AP). Methods SRHET was collected through the BLSA questionnaire in 247 participants. Data on ET and AP were determined from panoramic radiographs. The total number of ET, AP and missing teeth were recorded for each individual. Validity of SRHET was determined based on ET and AP, separately. Accuracy, efficiency, sensitivity, specificity, positive and negative predictive values (+PV, ?PV) and positive and negative likelihood ratios (+LR, ?LR) were calculated according to standard methods. Results After exclusions, 229 participants were available for ET analysis and 129 for AP analysis. The SRHET validity values were: sensitivity (ET=0.915; AP=0.782), specificity (ET=0.891; AP=0.689), +PV (ET=0.824; AP=0.353), ?PV (ET=0.949; AP=0.936), +LR (ET=8.394; AP=2.514) and ?LR (ET=0.095; AP=0.316). Conclusions SRHET was found to be a highly accurate method to predict ET but a weak predictor of the presence of AP among participants in the BLSA. PMID:22515884

  20. Ride qualities criteria validation/pilot performance study: Flight simulator results

    NASA Technical Reports Server (NTRS)

    Nardi, L. U.; Kawana, H. Y.; Borland, C. J.; Lefritz, N. M.

    1976-01-01

    Pilot performance was studied during simulated manual terrain following flight for ride quality criteria validation. An existing B-1 simulation program provided the data for these investigations. The B-1 simulation program included terrain following flights under varying controlled conditions of turbulence, terrain, mission length, and system dynamics. The flight simulator consisted of a moving base cockpit which reproduced motions due to turbulence and control inputs. The B-1 aircraft dynamics were programmed with six-degrees-of-freedom equations of motion with three symmetric and two antisymmetric structural degrees of freedom. The results provided preliminary validation of existing ride quality criteria and identified several ride quality/handling quality parameters which may be of value in future ride quality/criteria development.

  1. Experimental and theoretical studies of nanofluid thermal conductivity enhancement: a review

    PubMed Central

    2011-01-01

    Nanofluids, i.e., well-dispersed (metallic) nanoparticles at low- volume fractions in liquids, may enhance the mixture's thermal conductivity, knf, over the base-fluid values. Thus, they are potentially useful for advanced cooling of micro-systems. Focusing mainly on dilute suspensions of well-dispersed spherical nanoparticles in water or ethylene glycol, recent experimental observations, associated measurement techniques, and new theories as well as useful correlations have been reviewed. It is evident that key questions still linger concerning the best nanoparticle-and-liquid pairing and conditioning, reliable measurements of achievable knf values, and easy-to-use, physically sound computer models which fully describe the particle dynamics and heat transfer of nanofluids. At present, experimental data and measurement methods are lacking consistency. In fact, debates on whether the anomalous enhancement is real or not endure, as well as discussions on what are repeatable correlations between knf and temperature, nanoparticle size/shape, and aggregation state. Clearly, benchmark experiments are needed, using the same nanofluids subject to different measurement methods. Such outcomes would validate new, minimally intrusive techniques and verify the reproducibility of experimental results. Dynamic knf models, assuming non-interacting metallic nano-spheres, postulate an enhancement above the classical Maxwell theory and thereby provide potentially additional physical insight. Clearly, it will be necessary to consider not only one possible mechanism but combine several mechanisms and compare predictive results to new benchmark experimental data sets. PMID:21711739

  2. Hydraulic conductivity study of compacted clay soils used as landfill liners for an acidic waste

    SciTech Connect

    Hamdi, Noureddine, E-mail: nouryhamdi@gmail.com [Centre National des Recherches en Science des Materiaux, Borj Cedria Techno-Park, B.P. 95-2050, Hammam Lif, Tunis (Tunisia); Srasra, Ezzeddine [Centre National des Recherches en Science des Materiaux, Borj Cedria Techno-Park, B.P. 95-2050, Hammam Lif, Tunis (Tunisia)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Examined the hydraulic conductivity evolution as function of dry density of Tunisian clay soil. Black-Right-Pointing-Pointer Follow the hydraulic conductivity evolution at long-term of three clay materials using the waste solution (pH=2.7). Black-Right-Pointing-Pointer Determined how compaction affects the hydraulic conductivity of clay soils. Black-Right-Pointing-Pointer Analyzed the concentration of F and P and examined the retention of each soil. - Abstract: Three natural clayey soils from Tunisia were studied to assess their suitability for use as a liner for an acid waste disposal site. An investigation of the effect of the mineral composition and mechanical compaction on the hydraulic conductivity and fluoride and phosphate removal of three different soils is presented. The hydraulic conductivity of these three natural soils are 8.5 Multiplication-Sign 10{sup -10}, 2.08 Multiplication-Sign 10{sup -9} and 6.8 Multiplication-Sign 10{sup -10} m/s for soil-1, soil-2 and soil-3, respectively. Soil specimens were compacted under various compaction strains in order to obtain three wet densities (1850, 1950 and 2050 kg/m{sup 3}). In this condition, the hydraulic conductivity (k) was reduced with increasing density of sample for all soils. The test results of hydraulic conductivity at long-term (>200 days) using acidic waste solution (pH = 2.7, charged with fluoride and phosphate ions) shows a decrease in k with time only for natural soil-1 and soil-2. However, the specimens of soil-2 compressed to the two highest densities (1950 and 2050 kg/m{sup 3}) are cracked after 60 and 20 days, respectively, of hydraulic conductivity testing. This damage is the result of a continued increase in the internal stress due to the swelling and to the effect of aggressive wastewater. The analysis of anions shows that the retention of fluoride is higher compared to phosphate and soil-1 has the highest sorption capacity.

  3. Thermal conductivity improvement in carbon nanoparticle doped PAO oil: An experimental study

    NASA Astrophysics Data System (ADS)

    Shaikh, S.; Lafdi, K.; Ponnappan, R.

    2007-03-01

    The present work involves a study on the thermal conductivity of nanoparticle-oil suspensions for three types of nanoparticles, namely, carbon nanotubes (CNTs), exfoliated graphite (EXG), and heat treated nanofibers (HTT) with PAO oil as the base fluid. To accomplish the above task, an experimental analysis is performed using a modern light flash technique (LFA 447) for measuring the thermal conductivity of the three types of nanofluids, for different loading of nanoparticles. The experimental results show a similar trend as observed in literature for nanofluids with a maximum enhancement of approximately 161% obtained for the CNT-PAO oil suspension. The overall percent enhancements for different volume fractions of the nanoparticles are highest for the CNT-based nanofluid, followed by the EXG and the HTT. The findings from this study for the three different types of carbon nanoparticles can have great potential in the field of thermal management.

  4. Conductance technique in MOSFETs: Study of interface trap properties in the depletion and weak inversion regimes

    NASA Astrophysics Data System (ADS)

    Haddara, Hisham S.; El-Sayed, Mohamed

    1988-08-01

    A new and accurate approach to a.c. conductance measurements on MOSFETs is presented. It is shown that the conductance technique can be used to study interface trap properties in most of the silicon band-gap by direct measurement on a single MOSFET. The equivalent circuit is analyzed and the influence of the channel length on the inversion layer response is discussed in detail. It is shown that the channel time constant is mainly determined by the channel length. For small channel lengths L < 5 studied in a similar way as those interacting with the majority carrier band in depletion.

  5. Feasibility study of a swept frequency electromagnetic probe (SWEEP) using inductive coupling for the determination of subsurface conductivity of the earth and water prospecting in arid regions

    NASA Technical Reports Server (NTRS)

    Latorraca, G. A.; Bannister, L. H.

    1974-01-01

    Techniques developed for electromagnetic probing of the lunar interior, and techniques developed for the generation of high power audio frequencies were combined to make practical a magnetic inductive coupling system for the rapid measurement of ground conductivity profiles which are helpful when prospecting for the presence and quality of subsurface water. A system which involves the measurement of the direction, intensity, and time phase of the magnetic field observed near the surface of the earth at a distance from a horizontal coil energized so as to create a field that penetrates the earth was designed and studied to deduce the conductivity and stratification of the subsurface. Theoretical studies and a rudimentary experiment in an arid region showed that the approach is conceptually valid and that this geophysical prospecting technique can be developed for the economical exploration of subterranean water resources.

  6. Validity of the self reporting questionnaire-20 in epidemiological studies with older adults

    Microsoft Academic Search

    Marcia Scazufca; Paulo R. Menezes; Homero Vallada; Ricardo Araya

    2009-01-01

    Background  This study examined the validity of the self-reporting questionnaire (SRQ-20) in a population-based survey with older adults\\u000a in Sao Paulo, Brazil.\\u000a \\u000a \\u000a \\u000a Method  The study sample consisted of 2,008 individuals aged 65 years or more who were living in an economically disadvantaged area\\u000a of the city. The geriatric mental state (GMS) was used as the gold standard for the assessment of common mental

  7. Azadirachtin biopesticide: A review of studies conducted on its analytical chemistry, environmental behaviour and biological effects

    Microsoft Academic Search

    Kanth M. S. Sundaram

    1996-01-01

    This paper provides a brief review of studies conducted in our laboratory on the analytical chemistry, environmental behaviour and biological effects of azadirachtin?A, a neem?based pesticide.Azadirachtin?A (AZ?A) was isolated from samples of neem seed kernels, leaves, bark, root and stem, obtained from Kanthayapalayam, South India. The extracts were subjected to column cleanup and AZ?A concentration was quantified by using a

  8. NMR, DSC and high pressure electrical conductivity studies of liquid and hybrid electrolytes

    Microsoft Academic Search

    P. E. Stallworth; J. J. Fontanella; M. C. Wintersgill; Christopher D. Scheidler; Jeffrey J. Immel; S. G. Greenbaum; A. S. Gozdz

    1999-01-01

    Electrical conductivity, differential scanning calorimetry (DSC) and 'Li nuclear magnetic resonance (NMR) studies have been carried out on liquid electrolytes such as ethylene carbonate:propylene carbonate (EC:PC) and ECdimethyl carbonate (DMC) containing LiPF, (and LiCFaSO, for NMR) and films plasticized using the same liquid electrolytes. The films are based on poly(vinylidene fluoride) (PVdF) copolymerized with hexafluoropropylene and contain fumed silica. All

  9. Study of insulating electrical conductivity in hydrogenated amorphous silicon–nickel alloys at very low temperature

    Microsoft Academic Search

    A. Narjis; A. El kaaouachi; L. Limouny; S. Dlimi; A. Sybous; J. Hemine; R. Abdia; G. Biskupski

    2011-01-01

    On the insulating side of the metal–insulator transition (MIT), the study of the effect of low temperatures T on the electrical transport in amorphous silicon–nickel alloys a-Si1?yNiy:H exhibits that the electrical conductivity follows, at the beginning, the Efros–Shklovskii Variable Range Hopping regime (ES VRH) with T?1\\/2. This behaviour showed that long range electron–electron interaction reduces the Density Of State of

  10. Sensory nerve conduction studies of the L-1\\/L-2 dorsal rami

    Microsoft Academic Search

    Amrit P. Singh; Hillel M. Sommer

    1996-01-01

    Objective: This report describes a technique for performing sensory nerve conduction studies of the lateral cutaneous branches of the dorsal rami of the L-1\\/L-2 nerve roots for use in the evaluation of unilateral low back pain without lower limb referral.Subjects: Eleven healthy adult volunteers (9 men and 2 women) ranging in age from 25 to 36 years with no current

  11. A Genome-Wide Association Study of Upper Aerodigestive Tract Cancers Conducted within the INHANCE Consortium

    Microsoft Academic Search

    James D. McKay; Therese Truong; Valerie Gaborieau; Amelie Chabrier; Shu-Chun Chuang; Graham Byrnes; David Zaridze; Oxana Shangina; Neonila Szeszenia-Dabrowska; Jolanta Lissowska; Peter Rudnai; Eleonora Fabianova; Alexandru Bucur; Vladimir Bencko; Ivana Holcatova; Vladimir Janout; Lenka Foretova; Pagona Lagiou; Dimitrios Trichopoulos; Simone Benhamou; Christine Bouchardy; Wolfgang Ahrens; Franco Merletti; Lorenzo Richiardi; Renato Talamini; Luigi Barzan; Kristina Kjaerheim; Gary J. Macfarlane; Tatiana V. Macfarlane; Lorenzo Simonato; Cristina Canova; Antonio Agudo; Xavier Castellsagué; Ray Lowry; David I. Conway; Patricia A. McKinney; Claire M. Healy; Mary E. Toner; Ariana Znaor; Maria Paula Curado; Sergio Koifman; Ana Menezes; Victor Wünsch-Filho; José Eluf Neto; Leticia Fernández Garrote; Stefania Boccia; Gabriella Cadoni; Dario Arzani; Andrew F. Olshan; Mark C. Weissler; William K. Funkhouser; Jingchun Luo; Jan Lubi?ski; Joanna Trubicka; Marcin Lener; Dorota Oszutowska; Stephen M. Schwartz; Chu Chen; Sherianne Fish; David R. Doody; Joshua E. Muscat; Philip Lazarus; Carla J. Gallagher; Shen-Chih Chang; Zuo-Feng Zhang; Qingyi Wei; Erich M. Sturgis; Li-E Wang; Silvia Franceschi; Rolando Herrero; Karl T. Kelsey; Michael D. McClean; Carmen J. Marsit; Heather H. Nelson; Marjorie Romkes; Shama Buch; Tomoko Nukui; Shilong Zhong; Martin Lacko; Johannes J. Manni; Wilbert H. M. Peters; Rayjean J. Hung; John McLaughlin; Lars Vatten; Inger Njølstad; Gary E. Goodman; John K. Field; Triantafillos Liloglou; Paolo Vineis; Francoise Clavel-Chapelon; Domenico Palli; Rosario Tumino; Vittorio Krogh; Salvatore Panico; Carlos A. González; J. Ramón Quirós; Carmen Martínez; Carmen Navarro; Eva Ardanaz; Nerea Larrañaga; Kay-Tee Khaw; Timothy Key; H. Bas Bueno-de-Mesquita; Petra H. M. Peeters; Antonia Trichopoulou; Jakob Linseisen; Heiner Boeing; Göran Hallmans; Kim Overvad; Anne Tjønneland; Merethe Kumle; Elio Riboli; Kristjan Välk; Tõnu Voodern; Andres Metspalu; Diana Zelenika; Anne Boland; Marc Delepine; Mario Foglio; Doris Lechner; Hélène Blanché; Ivo G. Gut; Pilar Galan; Simon Heath; Mia Hashibe; Richard B. Hayes; Paolo Boffetta; Mark Lathrop; Paul Brennan

    2011-01-01

    Genome-wide association studies (GWAS) have been successful in identifying common genetic variation involved in susceptibility to etiologically complex disease. We conducted a GWAS to identify common genetic variation involved in susceptibility to upper aero-digestive tract (UADT) cancers. Genome-wide genotyping was carried out using the Illumina HumanHap300 beadchips in 2,091 UADT cancer cases and 3,513 controls from two large European multi-centre

  12. Application of In-situ Lysimetric Studies for Determining Soil Hydraulic Conductivity

    Microsoft Academic Search

    B. Hanumantha Rao; V. Sridhar; R. R. Rakesh; D. N. Singh; P. K. Narayan; P. K. Wattal

    2009-01-01

    Several techniques such as laboratory column studies, under normal and accelerated gravity environments, numerical modeling\\u000a and pedo-transfer functions have been employed by previous researchers to determine hydraulic conductivity of soils. However,\\u000a these methods suffer with several limitations, particularly, as far as regeneration of in-situ soil conditions and boundary\\u000a conditions, in an exceptionally small model, are concerned. Under these circumstances, in-situ

  13. Safety studies conducted on high-purity trans-resveratrol in experimental animals

    Microsoft Academic Search

    Lonnie D. Williams; George A. Burdock; James A. Edwards; Mareike Beck; Jochen Bausch

    2009-01-01

    trans-Resveratrol is a naturally occurring polyphenolic compound found in a variety of foods, but predominantly in grapes. Safety studies were conducted on high-purity trans-resveratrol (Resvida™), including skin and eye irritation, dermal sensitization, subchronic and reproductive toxicity, genotoxicity, and absorption, metabolism and excretion. Resvida™ was non-irritating to skin and eyes and non-sensitizing. It was non-mutagenic in a bacterial reverse mutation assay

  14. Experimental study on subcooled flow boiling on heating surfaces with different thermal conductivities

    NASA Astrophysics Data System (ADS)

    Zou, Ling

    Subcooled flow boiling is generally characterized by high heat transfer capacity and low wall superheat, which is essential for cooling applications requiring high heat transfer rate, such as nuclear reactors and fossil boilers. In this study, subcooled flow boiling on copper and stainless steel heating surfaces was experimentally investigated from both macroscopic and microscopic points of view. Flow boiling heat flux and heat transfer coefficient were experimentally measured on both surfaces under different conditions, such as pressure, flow rate and inlet subcooling. Significant boiling heat transfer coefficient differences were found between the copper and the stainless steel heating surfaces. To explain the different flow boiling behaviors on these two heating surfaces, nucleation site density and bubble dynamics were visually observed and measured at different experimental conditions utilizing a high-speed digital video camera. These two parameters are believed to be keys in determining flow boiling heat flux. Wall superheat, critical cavity size and wall heat flux were used to correlate with nucleation site density data. Among them, wall heat flux shows the best correlation for eliminating both pressure and surface property effects. The observed nucleation site distribution shows a random distribution. When compared to the spatial Poisson distribution, similarity between them was found, while the measured nucleation site distribution is more uniform. From experimental observations, for the two surface materials investigated, which have similar surface wettability but sharply different thermal properties, bubble dynamics displayed fairly similar behavior. The obtained experimental results indicate that thermal conductivity of heating surface material plays an important role in boiling heat transfer. This is due to thermal conductivity having a significant impact on the lateral heat conduction at the heating surface and consequently temperature uniformity of the heating surface. A model was then developed and solved numerically for heat conduction at the heating surface when bubbles are present. Several key parameters which impact lateral heat conduction and surface temperature profile were studied. These parameters include material thermal conductivity, bubble size, heating surface thickness, etc. Numerical results show that, temperature profile on the heating surface tends to be more uniform and have a lower average value on a heating surface with higher thermal conductivity, which agrees well with the experimental observation.

  15. An experimental study on thermal conductivity and viscosity of nanofluids containing carbon nanotubes.

    PubMed

    Sadri, Rad; Ahmadi, Goodarz; Togun, Hussein; Dahari, Mahidzal; Kazi, Salim Newaz; Sadeghinezhad, Emad; Zubir, Nashrul

    2014-01-01

    Recently, there has been considerable interest in the use of nanofluids for enhancing thermal performance. It has been shown that carbon nanotubes (CNTs) are capable of enhancing the thermal performance of conventional working liquids. Although much work has been devoted on the impact of CNT concentrations on the thermo-physical properties of nanofluids, the effects of preparation methods on the stability, thermal conductivity and viscosity of CNT suspensions are not well understood. This study is focused on providing experimental data on the effects of ultrasonication, temperature and surfactant on the thermo-physical properties of multi-walled carbon nanotube (MWCNT) nanofluids. Three types of surfactants were used in the experiments, namely, gum arabic (GA), sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS). The thermal conductivity and viscosity of the nanofluid suspensions were measured at various temperatures. The results showed that the use of GA in the nanofluid leads to superior thermal conductivity compared to the use of SDBS and SDS. With distilled water as the base liquid, the samples were prepared with 0.5 wt.% MWCNTs and 0.25% GA and sonicated at various times. The results showed that the sonication time influences the thermal conductivity, viscosity and dispersion of nanofluids. The thermal conductivity of nanofluids was typically enhanced with an increase in temperature and sonication time. In the present study, the maximum thermal conductivity enhancement was found to be 22.31% (the ratio of 1.22) at temperature of 45°C and sonication time of 40 min. The viscosity of nanofluids exhibited non-Newtonian shear-thinning behaviour. It was found that the viscosity of MWCNT nanofluids increases to a maximum value at a sonication time of 7 min and subsequently decreases with a further increase in sonication time. The presented data clearly indicated that the viscosity and thermal conductivity of nanofluids are influenced by the sonication time. Image analysis was carried out using TEM in order to observe the dispersion characteristics of all samples. The findings revealed that the CNT agglomerates breakup with increasing sonication time. At high sonication times, all agglomerates disappear and the CNTs are fragmented and their mean length decreases. PMID:24678607

  16. Numerical study of conductive heat losses from a magmatic source at Phlegraean Fields

    NASA Astrophysics Data System (ADS)

    Di Maio, Rosa; Piegari, Ester; Mancini, Cecilia; Scandone, R.

    2015-01-01

    The thermal evolution of the Phlegraean magmatic system (southern Italy) is studied by analyzing the influence of the thermal property variations on the solution of the heat conduction equation. The aim of this paper is to verify if appropriate choices of thermal parameters can reproduce, at least to greater depths, the high temperatures measured in the geothermal wells, drilled inside the caldera, under the assumption of heat loss from a magma chamber by conduction. Since the main purpose is to verify the plausibility of such an assumption, rather simple models of the magmatic system are adopted and only major volcanic events (i.e., the Campanian Ignimbrite and the Neapolitan Yellow Tuff eruptions) are considered. The results of the simulated two-dimensional model scenarios show that by assuming an extended source region, whose emplacement time is longer than 40 ka, heat conduction mechanisms can provide temperatures as high as those measured at depths deeper than about 2000 m. On the other hand, the 1D simulations show that appropriate choices for the thermal conductivity depth profiles can reproduce the observed temperatures at depths deeper than about 1000 m. These findings question the apparent consensus that convection is the only dominant form of heat transfer at Phlegraean Fields and might motivate new research for reconstructing the thermal evolution of the Phlegraean magmatic system.

  17. Comparative study of thermal conductivity of graphite fiber organic matrix composites

    SciTech Connect

    Mirmira, S.R.; Fletcher, L.S.

    1999-07-01

    In recent years, there have been new fibers and matrices introduced into composite technology. Fiber reinforced composites are versatile materials are extensively used in aerospace, automobile, and electronic components. This paper discusses the various analytical models developed for the prediction of effective thermal conductivity of graphite fiber organic matrix composites, and makes a critical comparison among them. In order to determine the relative accuracy of the analytical prediction techniques, a series of experimental tests were conducted to provide a consistent set of data. Comparisons are made with the experimental data obtained by previous researchers and those obtained by the present investigation. A comparison of the experimental effective thermal conductivity data as a function of temperature are shown in the adjacent figure. The type of fiber and matrix, fiber volume fraction, interfacial thermal resistance between the fiber and the matrix, and fiber orientation and dimensions play important roles in the effective thermal conductivity. Based on this comparative study, there is a definite need for an analytical model that accounts for the aforementioned parameters to accurately determine the thermal characteristics of graphite fiber organic matrix composites.

  18. Current Practice Patterns Regarding the Conduct of Thyroidectomy and Parathyroidectomy amongst Surgeons - A Survey Study

    PubMed Central

    Henry, LR; Helou, LB; Solomon, NP; Chang, A; Libutti, SK; Stojadinovic, A

    2012-01-01

    Background: Heterogeneity of surgical care exists among surgeons regarding the conduct of thyroidectomy and parathyroidectomy. Aim: To identify the current patterns of technical conduct of operation amongst surgeons performing thyroidectomy or parathyroidectomy. Methods: A survey was designed and beta-tested on five surgical oncologists for face validity and usability. The final version of this survey was constructed and disseminated using the professional version of the internet-based survey mechanism Survey Monkey and consisted of two eligibility questions and 22 questions regarding thyroidectomy/parathyroidectomy treatment patterns. The survey was disseminated electronically to American Association of Endocrine Surgeons (AAES) and American College of Surgeons (ACS) members. Survey results were collected, tabulated and analyzed. Responses among groups were compared using two sample T- tests. Significant responses were subsequently analyzed in generalized linear models to ascertain if significance remained with control of covariates. Results: Of 420 initial web survey visits, 236 (56.2%) surveys were completed. The majority of respondents reported being 'fellowship trained', experienced and 'high-volume' surgeons. The most common fellowship trainings were endocrine (46%), oncology (22%), head & neck (13%), or combinations of the three fellowships (14%). Most surgeons reported that they dissect the course of the recurrent laryngeal nerve (RLN) without using neuromonitoring. Nearly a third of respondents reported routinely using the Harmonic scalpel during the conduct of the operations. Significant differences emerged regarding operative technique according to residency training type, fellowship training, surgeon volume, and practice setting, but only those associated with residency training type and annual surgeon surgical volume remained significant within generalized linear models. Conclusion: Most surgeons who responded to this survey do not routinely use RLN neuromonitoring and most dissect the RLN during thyroidectomy. There are multiple variations in technique according to surgical training, surgeon volume, experience, and practice setting; however, only differences by residency training type and surgeon volume remained correlated significantly to surgeons' approaches to thyroidectomy and parathyroidectomy in multivariate analysis. These data may be useful for surgeons reflecting upon their individual practice, as well as for further defining current standards of practice from a medico legal perspective. PMID:22606210

  19. Assessing influence of conductivity in heart modelling with the aim of studying cardiovascular diseases

    NASA Astrophysics Data System (ADS)

    Sebastian, Rafael; Ordas, Sebastian; Plank, Gernot; Rodriguez, Blanca; Vigmond, Edward J.; Frangi, Alejandro F.

    2008-03-01

    The bidomain/monodomain equations have been widely used to model electrical activity in cardiac tissue. Here we present a sensitivity study of a crucial parameter in the bidomain model, the tissue conductivity. This study is necessary since there is no general agreement on the actual values that should be employed, mainly due to inconsistencies between the few sources of empirical information existent in the literature. Furthermore, estimates of this parameter from either imaging techniques or from experiments on isolated cardiac tissue have been inconsistent. For this study, a 3D biventricular model built from Multi-Detector Computer Tomography was used with the most relevant electrical structures, such as myocardial fiber orientation and the Purkinje system, were included. Specific ionic models for normal myocardium and for the Purkinje system were taken into account. Finite Element methods were used to solve the monodomain equation for a number of different conductivity settings. Comparative results using isochronal maps are shown in combination with statistical tests to measure changes in the sequence of electrical activation in the myocardium, conduction velocities (CV), and local activation times (LAT).

  20. Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*

    PubMed Central

    Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

    2014-01-01

    In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies. PMID:24599687

  1. Guiding the Selection of Physical Experiments for the Validation of a Model Designed to Study Grounding in Dc Distribution Systems

    Microsoft Academic Search

    Diomar Infante

    2011-01-01

    The following work establishes a process for model validation and its application to the study of grounding in DC shipboard power systems. The aim of the thesis is to create a general procedure detailing how to appropriately select physical experiments that validate the simulation model under use. The procedure presented can be applied to any physical system. In the work

  2. Validation Study of a Method for Assessing Complex Ill-Structured Problem Solving by Using Causal Representations

    ERIC Educational Resources Information Center

    Eseryel, Deniz; Ifenthaler, Dirk; Ge, Xun

    2013-01-01

    The important but little understood problem that motivated this study was the lack of research on valid assessment methods to determine progress in higher-order learning in situations involving complex and ill-structured problems. Without a valid assessment method, little progress can occur in instructional design research with regard to designing…

  3. The Theory of Planned Behavior (TPB) and Pre-Service Teachers' Technology Acceptance: A Validation Study Using Structural Equation Modeling

    ERIC Educational Resources Information Center

    Teo, Timothy; Tan, Lynde

    2012-01-01

    This study applies the theory of planned behavior (TPB), a theory that is commonly used in commercial settings, to the educational context to explain pre-service teachers' technology acceptance. It is also interested in examining its validity when used for this purpose. It has found evidence that the TPB is a valid model to explain pre-service…

  4. Measuring Students' Writing Ability on a Computer-Analytic Developmental Scale: An Exploratory Validity Study

    ERIC Educational Resources Information Center

    Burdick, Hal; Swartz, Carl W.; Stenner, A. Jackson; Fitzgerald, Jill; Burdick, Don; Hanlon, Sean T.

    2013-01-01

    The purpose of the study was to explore the validity of a novel computer-analytic developmental scale, the Writing Ability Developmental Scale. On the whole, collective results supported the validity of the scale. It was sensitive to writing ability differences across grades and sensitive to within-grade variability as compared to human-rated…

  5. Validation study of an electronic method of condensed outcomes tools reporting in orthopaedics.

    PubMed

    Farr, Jack; Verma, Nikhil; Cole, Brian J

    2013-12-01

    Patient-reported outcomes (PRO) instruments are a vital source of data for evaluating the efficacy of medical treatments. Historically, outcomes instruments have been designed, validated, and implemented as paper-based questionnaires. The collection of paper-based outcomes information may result in patients becoming fatigued as they respond to redundant questions. This problem is exacerbated when multiple PRO measures are provided to a single patient. In addition, the management and analysis of data collected in paper format involves labor-intensive processes to score and render the data analyzable. Computer-based outcomes systems have the potential to mitigate these problems by reformatting multiple outcomes tools into a single, user-friendly tool.The study aimed to determine whether the electronic outcomes system presented produces results comparable with the test-retest correlations reported for the corresponding orthopedic paper-based outcomes instruments.The study is designed as a crossover study based on consecutive orthopaedic patients arriving at one of two designated orthopedic knee clinics.Patients were assigned to complete either a paper or a computer-administered questionnaire based on a similar set of questions (Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee form, 36-Item Short Form survey, version 1, Lysholm Knee Scoring Scale). Each patient completed the same surveys using the other instrument, so that all patients had completed both paper and electronic versions. Correlations between the results from the two modes were studied and compared with test-retest data from the original validation studies.The original validation studies established test-retest reliability by computing correlation coefficients for two administrations of the paper instrument. Those correlation coefficients were all in the range of 0.7 to 0.9, which was deemed satisfactory. The present study computed correlation coefficients between the paper and electronic modes of administration. These correlation coefficients demonstrated similar results with an overall value of 0.86.On the basis of the correlation coefficients, the electronic application of commonly used knee outcome scores compare variably to the traditional paper variants with a high rate of test-retest correlation. This equivalence supports the use of the condensed electronic outcomes system and validates comparison of scores between electronic and paper modes. PMID:23729311

  6. Electrochemical studies of thin films of conducting polymers and conducting polymer composites deposited on metal and semiconductor electrodes

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Di Stefano, S.; Moacanin, J.

    1987-01-01

    Electrochemical studies indicate that poly(Isothianaphthene) or PITN, can be p-doped only. Electrochemical properties of PITN and Nafion-PITN in acetonitrile solutions containing tetra-phenyl Phosphonium chloride as supporting electrolyte are compared. In both cases, the electrochemical behavior of thin films are different from that of thick films. In addition, Nafion does not seem to alter the electrochemical properties of PITN. Cyclic voltammetric and chronocoulometric measurements were made to compute the diffusion coefficient of the counter ions. Electrochemical behavior of both PITN and Nafion-PITN in acetonitrile solution containing different counter ions are described. PITN, when electrochemically deposited, apparently neither passivates surface states present nor forms ohmic contacts with p-Si or p(+)Si single-crystal electrodes.

  7. Model Reduction, Validation, and Calibration of Wind Power Plants for Dynamic Studies

    SciTech Connect

    Elizondo, Marcelo A.; Lu, Shuai; Zhou, Ning; Samaan, Nader A.

    2011-10-10

    Accurate representation of wind power plants (WPP) in both offline and online power system stability studies has gained importance because of the rapid increase in installation of wind generation around the world. On the other hand, reduced WPP representation is preferred due to computational efficiency. To improve the accuracy, other authors have proposed changes in structure of the reduced model for large WPPs. The use of model validation and calibration is an alternative to improve the accuracy of the reduced WPP model. In this paper, we compare accuracy improvements brought by changes in model structure with accuracy improvements brought by validation and calibration of the reduced WPP model with minimal changes in structure. We illustrate our findings using a 168-machine WPP connected to the IEEE-39-bus test system. The parameters of the reduced WPP model are either calculated with current equivalencing techniques or validated and calibrated against a more accurate model. The changes in structure of the reduced model are 1-machine or 2-machine reduced models connected with a 1-line or 2-line collector equivalents. We show that the most accurate response is obtained by calibrating the parameters of the reduced model with minimum changes in structure.

  8. Validation of a static Franz diffusion cell system for in vitro permeation studies.

    PubMed

    Ng, Shiow-Fern; Rouse, Jennifer J; Sanderson, Francis D; Meidan, Victor; Eccleston, Gillian M

    2010-09-01

    Over the years, in vitro Franz diffusion experiments have evolved into one of the most important methods for researching transdermal drug administration. Unfortunately, this type of testing often yields permeation data that suffer from poor reproducibility. Moreover, this feature frequently occurs when synthetic membranes are used as barriers, in which case biological tissue-associated variability has been removed as an artefact of total variation. The objective of the current study was to evaluate the influence of a full-validation protocol on the performance of a tailor-made array of Franz diffusion cells (GlaxoSmithKline, Harlow, UK) available in our laboratory. To this end, ibuprofen was used as a model hydrophobic drug while synthetic membranes were used as barriers. The parameters investigated included Franz cell dimensions, stirring conditions, membrane type, membrane treatment, temperature regulation and sampling frequency. It was determined that validation dramatically reduced derived data variability as the coefficient of variation for steady-state ibuprofen permeation from a gel formulation was reduced from 25.7% to 5.3% (n = 6). Thus, validation and refinement of the protocol combined with improved operator training can greatly enhance reproducibility in Franz cell experimentation. PMID:20842539

  9. The multi-dimensional measure of informed choice: a validation study.

    PubMed

    Michie, Susan; Dormandy, Elizabeth; Marteau, Theresa M

    2002-09-01

    The aim of this prospective study is to assess the reliability and validity of a multi-dimensional measure of informed choice (MMIC). Participants were 225 pregnant women in two general hospitals in the UK, women receiving low-risk results following serum screening for Down syndrome. The MMIC was administered before testing and the Ottawa Decisional Conflict Scale was administered 6 weeks later. The component scales of the MMIC, knowledge and attitude, were internally consistent (alpha values of 0.68 and 0.78, respectively). Those who made a choice categorised as informed using the MMIC rated their decision 6 weeks later as being more informed, better supported and of higher quality than women whose choice was categorised as uninformed. This provides evidence of predictive validity, whilst the lack of association between the MMIC and anxiety shows construct (discriminant) validity. Thus, the MMIC has been shown to be psychometrically robust in pregnant women offered the choice to undergo prenatal screening for Down syndrome and receiving a low-risk result. Replication of this finding in other groups, facing other decisions, with other outcomes, should be assessed in future research. PMID:12220754

  10. In silico oncology: exploiting clinical studies to clinically adapt and validate multiscale oncosimulators.

    PubMed

    Stamatakos, Georgios S; Kolokotroni, Eleni; Dionysiou, Dimitra; Veith, Christian; Kim, Yoo-Jin; Franz, Astrid; Marias, Kostas; Sabczynski, Joerg; Bohle, Rainer; Graf, Norbert

    2013-01-01

    This paper presents a brief outline of the notion and the system of oncosimulator in conjunction with a high level description of the basics of its core multiscale model simulating clinical tumor response to treatment. The exemplary case of lung cancer preoperatively treated with a combination of chemotherapeutic agents is considered. The core oncosimulator model is based on a primarily top-down, discrete entity - discrete event multiscale simulation approach. The critical process of clinical adaptation of the model by exploiting sets of multiscale data originating from clinical studies/trials is also outlined. Concrete clinical adaptation results are presented. The adaptation process also conveys important aspects of the planned clinical validation procedure since the same type of multiscale data - although not the same data itself- is to be used for clinical validation. By having exploited actual clinical data in conjunction with plausible literature-based values of certain model parameters, a realistic tumor dynamics behavior has been demonstrated. The latter supports the potential of the specific oncosimulator to serve as a personalized treatment optimizer following an eventually successful completion of the clinical adaptation and validation process. PMID:24110993

  11. Validation of Welding Curriculum Manual.

    ERIC Educational Resources Information Center

    Stone, Sheila D.

    A study was conducted to validate the welding curriculum materials developed and published by the Oklahoma State Department of Vocational and Technical Education. Twelve instructors collected achievement data (unit tests, assignment sheets, and evaluation forms) concerning the performance of 280 students on a total of 46 instructional units. Item…

  12. A GLOBAL TWO-TEMPERATURE CORONA AND INNER HELIOSPHERE MODEL: A COMPREHENSIVE VALIDATION STUDY

    SciTech Connect

    Jin, M.; Manchester, W. B.; Van der Holst, B.; Gruesbeck, J. R.; Frazin, R. A.; Landi, E.; Toth, G.; Gombosi, T. I. [Atmospheric Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Vasquez, A. M. [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA) and FCEN (UBA), CC 67, Suc 28, Ciudad de Buenos Aires (Argentina); Lamy, P. L.; Llebaria, A.; Fedorov, A., E-mail: jinmeng@umich.edu [Laboratoire d'Astrophysique de Marseille, Universite de Provence, Marseille (France)

    2012-01-20

    The recent solar minimum with very low activity provides us a unique opportunity for validating solar wind models. During CR2077 (2008 November 20 through December 17), the number of sunspots was near the absolute minimum of solar cycle 23. For this solar rotation, we perform a multi-spacecraft validation study for the recently developed three-dimensional, two-temperature, Alfven-wave-driven global solar wind model (a component within the Space Weather Modeling Framework). By using in situ observations from the Solar Terrestrial Relations Observatory (STEREO) A and B, Advanced Composition Explorer (ACE), and Venus Express, we compare the observed proton state (density, temperature, and velocity) and magnetic field of the heliosphere with that predicted by the model. Near the Sun, we validate the numerical model with the electron density obtained from the solar rotational tomography of Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph C2 data in the range of 2.4 to 6 solar radii. Electron temperature and density are determined from differential emission measure tomography (DEMT) of STEREO A and B Extreme Ultraviolet Imager data in the range of 1.035 to 1.225 solar radii. The electron density and temperature derived from the Hinode/Extreme Ultraviolet Imaging Spectrometer data are also used to compare with the DEMT as well as the model output. Moreover, for the first time, we compare ionic charge states of carbon, oxygen, silicon, and iron observed in situ with the ACE/Solar Wind Ion Composition Spectrometer with those predicted by our model. The validation results suggest that most of the model outputs for CR2077 can fit the observations very well. Based on this encouraging result, we therefore expect great improvement for the future modeling of coronal mass ejections (CMEs) and CME-driven shocks.

  13. Cross-cultural, age and gender validation of a computerised questionnaire measuring personal, social and environmental associations with children's physical activity: the European Youth Heart Study

    PubMed Central

    Ommundsen, Yngvar; Page, Angie; Ku, Po-Wen; Cooper, Ashley R

    2008-01-01

    Objective This study investigated the construct validity of a computerised self-assessment tool to measure psychological, social and environmental influences of young peoples' physical activity. First, analyses of the measure's factorial validity, invariance across, age, gender culture were conducted. Second, the ability of the derived subscales to discriminate between children representing different levels of self-reported and objectively measured physical activity behaviour was examined. Methods Participants were 1875 boys and 2078 girls (total = 3958) aged 9–10 years (n = 1955, mean age = 9.65 ± 0.42) and 15–16 years (n = 2003, mean age = 15.49 ± 0.50) from four European countries in Northern, Southern and Eastern Europe who took part in the European Youth Heart Study (EYHS). Children completed the computerised self-assessment tool with support from the researcher if requested. Self-reported exercise and an objective measure of physical activity (Actigraph model 7164) were used for additional construct validation purposes. Results Overall evidence of good fit indicating satisfactory factorial validity and cross-cultural, age and gender invariance for 3 of the 4 measurement models were obtained. The majority of measures were also significantly different for those with high versus low levels of physical activity. Conclusion Overall, the computerised questionnaire holds promise for use cross-culturally with male and female children and adolescents to measure perceived personal, social and environmental influences on physical activity. Further development of the measures pertaining to perceived environmental influences seems warranted. PMID:18489736

  14. Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

    PubMed Central

    2010-01-01

    Background The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas. PMID:20487532

  15. The personal style inventory: Preliminary validation studies of new measures of sociotropy and autonomy

    Microsoft Academic Search

    Clive J. Robins; Jon Ladd; Joan Welkowitz; Paul H. Blaney; Rolando Diaz; Gary Kutcher

    1994-01-01

    We conducted five studies with depressed patients, demographically matched controls, and college students to develop and psychometrically evaluate new measures of concerns about interpersonal relationships (sociotropy) and autonomous achievement (autonomy), constructs that have been proposed to confer vulnerability to depression. The final version of the Personal Style Inventory (PSI) Sociotropy and Autonomy scales showed a good factor structure, internal consistency

  16. Performance evaluation of AERMOD, CALPUFF, and legacy air dispersion models using the Winter Validation Tracer Study dataset

    NASA Astrophysics Data System (ADS)

    Rood, Arthur S.

    2014-06-01

    The performance of the steady-state air dispersion models AERMOD and Industrial Source Complex 2 (ISC2), and Lagrangian puff models CALPUFF and RATCHET were evaluated using the Winter Validation Tracer Study dataset. The Winter Validation Tracer Study was performed in February 1991 at the former Rocky Flats Environmental Technology Site near Denver, Colorado. Twelve, 11-h tests were conducted where a conservative tracer was released and measured hourly at 140 samplers in concentric rings 8 km and 16 km from the release point. Performance objectives were unpaired maximum one- and nine-hour average concentration, location of plume maximum, plume impact area, arc-integrated concentration, unpaired nine-hour average concentration, and paired ensemble means. Performance objectives were aimed at addressing regulatory compliance, and dose reconstruction assessment questions. The objective of regulatory compliance is not to underestimate maximum concentrations whereas for dose reconstruction, the objective is an unbiased estimate of concentration in space and time. Performance measures included the fractional bias, normalized mean square error, geometric mean, geometric mean variance, correlation coefficient, and fraction of observations within a factor of two. The Lagrangian puff models tended to exhibit the smallest variance, highest correlation, and highest number of predictions within a factor of two compared to the steady-state models at both the 8-km and 16-km distance. Maximum one- and nine-hour average concentrations were less likely to be under-predicted by the steady-state models compared to the Lagrangian puff models. The characteristic of the steady-state models not to under-predict maximum concentrations make them well suited for regulatory compliance demonstration, whereas the Lagrangian puff models are better suited for dose reconstruction and long range transport.

  17. Scanning ion conductance microscopy: a nanotechnology for biological studies in live cells

    PubMed Central

    Liu, Bing-Chen; Lu, Xiao-Yu; Song, Xiang; Lei, Ke-Yu; Alli, Abdel A.; Bao, Hui-Fang; Eaton, Douglas C.; Ma, He-Ping

    2012-01-01

    Scanning ion-conductance microscope (SICM), which enables high-resolution imaging of cell surface topography, has been developed for over two decades. However, only recently, a unique scanning mode is increasingly used in biological studies to allow SICM to detect the surface of live cells. More recently, in combination with confocal microscopy and patch-clamp electrophysiological techniques, SICM allows investigators to localize proteins or ion channels in a specific nanostructure at the cell surface. This article will briefly review SICM nanotechnique and summarize the role of SICM in biological studies. PMID:23335899

  18. Thermal conductivity imaging at micrometre-scale resolution for combinatorial studies of materials

    NASA Astrophysics Data System (ADS)

    Huxtable, Scott; Cahill, David G.; Fauconnier, Vincent; White, Jeffrey O.; Zhao, Ji-Cheng

    2004-05-01

    Combinatorial methods offer an efficient approach for the development of new materials. Methods for generating combinatorial samples of materials, and methods for characterizing local composition and structure by electron microprobe analysis and electron-backscatter diffraction are relatively well developed. But a key component for combinatorial studies of materials is high-spatial-resolution measurements of the property of interest, for example, the magnetic, optical, electrical, mechanical or thermal properties of each phase, composition or processing condition. Advances in the experimental methods used for mapping these properties will have a significant impact on materials science and engineering. Here we show how time-domain thermoreflectance can be used to image the thermal conductivity of the cross-section of a Nb-Ti-Cr-Si diffusion multiple, and thereby demonstrate rapid and quantitative measurements of thermal transport properties for combinatorial studies of materials. The lateral spatial resolution of the technique is 3.4 ?m, and the time required to measure a 100 × 100 pixel image is ~ 1 h. The thermal conductivity of TiCr2 decreases by a factor of two in crossing from the near-stoichiometric side of the phase to the Ti-rich side; and the conductivity of (Ti,Nb)3Si shows a strong dependence on crystalline orientation.

  19. Monte Carlo studies of flow and transport in fractal conductivity fields: Comparison with stochastic perturbation theory

    NASA Astrophysics Data System (ADS)

    Hassan, Ahmed E.; Cushman, John H.; Delleur, Jacques W.

    1997-11-01

    A Monte Carlo simulation of flow and transport is employed to study tracer migration in porous media with evolving scales of heterogeneity (fractal media). Transport is studied with both conservative and reactive chemicals in media that possess physical as well as chemical heterogeneity. Linear kinetic equations are assumed to relate the sorbed phase and the aqueous phase concentrations. The fluctuating log conductivity possesses the power law spectrum of a fractional Brownian motion (fBm). Chemical heterogeneity is represented as spatially varying reaction rates that also are assumed to obey fBm statistics and may be correlated to the conductivity field. The model is based on a finite difference approximation to the flow problem and a random walk particle-tracking approach for solving the solute transport equation. The model is used to make comparisons with the nonlocal transport equations recently developed by Deng et al. [1993], and Hu et al. [1995, 1997]. The results presented herein support these nonlocal models for a wide range of heterogeneous systems. However, the infinite integral scale associated with the fractal conductivity has a significant effect on the prediction of the nonlocal theories. This suggests that integral scale should play a role in stochastic Eulerian perturbation theories. The importance of the local-scale dispersion depends to a great extent on the magnitude of the local dispersivities. The effect of neglecting local dispersion decreases with the decrease in local dispersivity.

  20. Synthesis and Electrical Conductivity Studies of Poly (methyl methacrylate) in Presence of Transition Metal Ions

    NASA Astrophysics Data System (ADS)

    Ramesan, M. T.; Pradyumnan, P. P.

    2011-10-01

    Metal complexes of polymer based on poly methyl methacrylate (PMMA) were prepared by the in situ bulk polymerization of methyl methacrylate with different molar concentrations of salts of iron II chloride and cobalt II nitrate. These complexes were characterized by FTIR and UV spectroscopic studies revealed that the metal is coordinated to carbonyl oxygen and methoxy oxygen of methacrylate moiety. The surface morphology of these composite was studied with scanning electron microscope (SEM), indicated that metal incorporated polymer exhibit well dispersed structures. The basic decomposition pattern and thermal stability of the samples were carried out using TGA. The incorporation of metal in main chain of PMMA enhances excellent thermal resistance. Lower concentration of metal incorporated PMMA has superior thermal stability than higher dosage of metals. The a.c. conductivity behavior was investigated in the frequency range of 102-106 at room temperature. The molar concentrations of metal particle in the polymer matrix have greater influence on the observed conductivity values. Nickel (II) complexes of poly (methyl methacrylate) have better conductivity, dielectric constant and loss factor than that of iron (II) introduced polymer matrix.

  1. A randomized study examining the effect of 3 SSRI on premature ejaculation using a validated questionnaire

    PubMed Central

    Arafa, Mohamed; Shamloul, Rany

    2007-01-01

    Aim This study reports the results of a large prospective single-blinded clinical trial of 3 SSRI (paroxetine, fluoxetine and escitalopram) in PE using a validated questionnaire. Methods A total of 100 normally potent men suffering from PE were enrolled in a randomized single-blinded comparative study of fluoxetine, paroxetine and escitalopram Patients were randomized into 3 treatment groups. Group 1 comprised 33 men who received fluoxetine 20 mg daily, group 2 comprised 37 men who received escitalopram 10 mg and group 3 comprised 30 men who received paroxetine 20 mg daily. All drug regimens were given in early morning dose and continued for 4 weeks. Results All 100 (100%) patients experienced a significant increase in their AIPE total score after drug treatment. There was no significant difference regarding any of the 7 items of the AIPE between the 3 treatment groups. All 3 drugs were generally well tolerated. Conclusions Our relatively large study, using a validated questionnaire confirmed similar useful effect of paroxetine, fluoxetine and escitalopram on ejaculation time. Further large cohort studies with long-term follow up are needed to evaluate the sustained effects of these drugs on ejaculation latency. PMID:18472973

  2. Core level photoemission studies on conducting polypyrrole polymer nanotubes showing switching transitions

    NASA Astrophysics Data System (ADS)

    Sarkar, I.; Sarma, A.; Sanyal, M. K.; Thieß, S.; Drube, W.

    2013-10-01

    Conducting polypyrrole (PPY) nanotubes is a classical model system for strongly correlated disordered materials showing intriguing switching transitions from low to high conductivity states at low temperature. This switching behaviour can be tuned by incorporating gold nanoclusters to form composite nanotubes (AuPPY). Here, we present core level electronic structure studies on PPY and AuPPY nanotubes with different diameters using hard X-ray photoemission spectroscopy at room temperature. The spectroscopic data provide information on the role of diameter as well as metal cluster incorporation for a modification of the electronic structure of this important class of nanotubes. Furthermore, electrical transport measurements were performed at low temperature to extract the change in localization length and doping level in these nanotubes. Based on these results, we explain the observed electrical transport behavior of these nanotubes as the interplay of disorder and carrier concentration.

  3. AC conductivity and electrochemical studies of PVA/PEG based polymer blend electrolyte films

    NASA Astrophysics Data System (ADS)

    Polu, Anji Reddy; Kumar, Ranveer; Dehariya, Harsha

    2012-06-01

    Polymer blend electrolyte films based on Polyvinyl alcohol(PVA)/Poly(ethylene glycol)(PEG) and magnesium nitrate (Mg(NO3)2) were prepared by solution casting technique. Conductivity in the temperature range 303-373 K and transference number measurements have been employed to investigate the charge transport in this polymer blend electrolyte system. The highest conductivity is found to be 9.63 × 10-5 S/cm at 30°C for sample with 30 weight percent of Mg(NO3)2 in PVA/PEG blend matrix. Transport number data shows that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this electrolyte, an electrochemical cell with configuration Mg/(PVA+PEG+Mg(NO3)2)/(I2+C+electrolyte) was fabricated and its discharge characteristics profile has been studied.

  4. Thermoelectric power and thermal conductivity study of the Y3Ba5Cu8Ox system

    NASA Astrophysics Data System (ADS)

    Aksan, M. A.; Kizilaslan, O.; Aksan, E. N.; Yakinci, M. E.

    2012-07-01

    In the present study, the effect of heat treatment conditions on the structural/microstructural, electrical and transport properties, such as thermoelectric power and thermal conductivity, of the Y-358 system was investigated. The Y-123 phase instead of Y-358 were obtained with heat treatments. XRD and SEM analyses showed that the best structural formation was obtained for the sample prepared at 900 °C for 24 h. All the samples exhibited the Tc value around 91 K. Positive S(T) value was obtained in all the samples. S(T) data was analyzed by “Two band model with linear T-term”. In thermal conductivity of the samples, small peak with broad maximum was found just below Tc, unlike that of the HTc cuprates.

  5. Study of dc Electrical Conductivity, Magnetic Susceptibility and Thermal Behavior of Pyrrole Aniline Copolymer

    NASA Astrophysics Data System (ADS)

    Wasnik, H. R.; Kelkar, D. S.

    2015-02-01

    Chemical copolymerization of pyrrole and aniline has been carried out by taking the monomers in equimolar proportion. The structural analysis of the copolymer was done with the help of FTIR, WAXD and SEM techniques, the results confirm the formation of new material involving both pyrrole and aniline units. The dc electrical conductivity of the copolymer has been recorded up to 673k using two probe method. The log ? Vs 1/T plot shows the transition of the sample from metallic to semi conducting behavior and vice versa, at a particular temperature. The magnetic susceptibility was recorded at magnetic field of 0.1KG in the temperature range 313-507 K by using Guoy's method. The Thermal behavior of the copolymer was studied using DTA-TGA revealing variation in the Tg of copolymer when compared to homopolymers.

  6. Improving the electrical conductivity of carbon nanotube networks: a first-principles study.

    PubMed

    Li, Elise Y; Marzari, Nicola

    2011-12-27

    We address the issue of the low electrical conductivity observed in carbon nanotube networks using first-principles calculations of the structure, stability, and ballistic transport of different nanotube junctions. We first study covalent linkers, using the nitrene-pyrazine case as a model for conductance-preserving [2 + 1] cycloadditions, and discuss the reasons for their poor performance. We then characterize the role of transition-metal adsorbates in improving mechanical coupling and electrical tunneling between the tubes. We show that the strong hybridization between the transition-metal d orbitals with the ? orbitals of the nanotube can provide an excellent electrical bridge for nanotube-nanotube junctions. This effect is maximized in the case of nitrogen-doped nanotubes, thanks to the strong mechanical coupling between the tubes mediated by a single transition metal adatom. Our results suggest effective strategies to optimize the performance of carbon nanotube networks. PMID:22059779

  7. Pooled Results From 5 Validation Studies of Dietary Self-Report Instruments Using Recovery Biomarkers for Energy and Protein Intake

    PubMed Central

    Freedman, Laurence S.; Commins, John M.; Moler, James E.; Arab, Lenore; Baer, David J.; Kipnis, Victor; Midthune, Douglas; Moshfegh, Alanna J.; Neuhouser, Marian L.; Prentice, Ross L.; Schatzkin, Arthur; Spiegelman, Donna; Subar, Amy F.; Tinker, Lesley F.; Willett, Walter

    2014-01-01

    We pooled data from 5 large validation studies of dietary self-report instruments that used recovery biomarkers as references to clarify the measurement properties of food frequency questionnaires (FFQs) and 24-hour recalls. The studies were conducted in widely differing US adult populations from 1999 to 2009. We report on total energy, protein, and protein density intakes. Results were similar across sexes, but there was heterogeneity across studies. Using a FFQ, the average correlation coefficients for reported versus true intakes for energy, protein, and protein density were 0.21, 0.29, and 0.41, respectively. Using a single 24-hour recall, the coefficients were 0.26, 0.40, and 0.36, respectively, for the same nutrients and rose to 0.31, 0.49, and 0.46 when three 24-hour recalls were averaged. The average rate of under-reporting of energy intake was 28% with a FFQ and 15% with a single 24-hour recall, but the percentages were lower for protein. Personal characteristics related to under-reporting were body mass index, educational level, and age. Calibration equations for true intake that included personal characteristics provided improved prediction. This project establishes that FFQs have stronger correlations with truth for protein density than for absolute protein intake, that the use of multiple 24-hour recalls substantially increases the correlations when compared with a single 24-hour recall, and that body mass index strongly predicts under-reporting of energy and protein intakes. PMID:24918187

  8. The OECD program to validate the rat uterotrophic bioassay. Phase 2: dose-response studies.

    PubMed Central

    Kanno, Jun; Onyon, Lesley; Peddada, Shyamal; Ashby, John; Jacob, Elard; Owens, William

    2003-01-01

    The Organisation for Economic Co-operation and Development has completed phase 2 of an international validation program for the rodent uterotrophic bioassay. The purpose of the validation program was to demonstrate the performance of two versions of the uterotrophic bioassay, the immature female rat and the adult ovariectomized rat, in four standardized protocols. This article reports the dose-response studies of the validation program; the coded single-dose studies are reported in an accompanying paper. The dose-response study design used five selected weak estrogen agonists, bisphenol A, genistein, methoxychlor, nonylphenol, and o,p -DDT. These weak agonists were administered in a prescribed series of doses to measure the performance and reproducibility of the protocols among the participating laboratories. All protocols successfully detected increases in uterine weights when the weak agonists were administered. Within each protocol, there was good agreement and reproducibility of the dose response among laboratories with each substance. Substance-specific variations were observed in the influence of the route of administration on the uterine response, the potency as related to the dose producing the first statistically significant increase in uterine weights, and the maximum increase in uterine weight. Substantive performance differences were not observed between the uterotrophic bioassay versions or among the standardized protocols, and these were judged to be qualitatively equivalent. It is noteworthy that these results were reproducible under a variety of different experimental conditions (e.g., animal strain, diet, housing, bedding, vehicle, animal age), indicating that the bioassay's performance as a screen is robust. In conclusion, both the intact, immature, and adult OVX versions, and all protocols appear to be reproducible and transferable across laboratories and are able to detect weak estrogen agonists. PMID:12948896

  9. Improvement and Validation of Pilot-Scale Emerging Pathogen Removal Studies: The Effects of Spiking Concentration and Sampling Method

    NASA Astrophysics Data System (ADS)

    Lau, B. L.; Harrington, G. W.; Hoffman, R. M.; Borchardt, M. A.

    2004-05-01

    The presence of waterborne enteric pathogens in domestic water supplies represents a potentially significant human health risk. To evaluate the removal of these pathogens in drinking water treatment processes, researchers have needed to spike raw water with at least 106 pathogens/L in order to reliably detect the pathogens in treated water. Unfortunately, occurrence surveys have shown that pathogen concentrations in raw waters are significantly smaller than 106 pathogens/L (LeChevallier and Norton, 1995; States et al., 1997). Since regulatory decisions are based on results from pilot-scale experiments, it is necessary to determine if it is appropriate to extrapolate removal capacities based on unrealistic spike doses. Recent advances have been made in sample concentration and pathogen detection that allows removal studies to be conducted at more realistic spike concentrations. The overall goal of this project is to use continuous separation channel centrifugation (CSCC) and flow cytometry with cell sorting (FCCS) to evaluate Cryptosporidium removals in water treatment processes at concentrations nearer to those found in the aquatic environment. This project evaluates Cryptosporidium removal with a unique combination of experimental, concentration, and analytical methods. In order to characterize the removal of Cryptosporidium, pilot-scale experiments will be conducted between March and April 2004 with different initial Cryptosporidium concentrations (range from 102 to 106 Cryptosporidium/L) and sampling methods (grab versus continuous). CSCC will be used for concentration of pathogens in samples collected from the pilot plant. FCCS capability will be used for Cryptosporidium detection. These methods will achieve significantly higher pathogen recoveries and more precise pathogen counts than the methods that have traditionally been used for pilot plant studies. This research will provide the water industry with a way of validating previous removal studies and insight into how pathogens log removal credits should be granted.

  10. Defini*on of pilot studies Reasons to conduct a pilot study

    E-print Network

    Sherman, S. Murray

    · Reviewer's checklist · Example · On using pilot data for sample size calcula as pilot studies and researchers claim there is no need for sample size jus · Only large effect sizes will be detected · Analysis of power and sample size

  11. Mixed ionic and electronic conducting electrode studies for an alkali metal thermal to electric converter

    NASA Astrophysics Data System (ADS)

    Guo, Yuyan

    This research focuses on preparation, kinetics, and performance studies of mixed ionic and electronic conducting electrodes (MIEE) applied in an alkali metal thermal to electric converter (AMTEC). Two types of MIEE, metal/sodium titanate and metal/beta?-alumina were investigated, using Ni, Cu, Co and W as the metal components. Pure metal electrodes (PME) were also studied, including Ta, Ni, Nb, Ir, W and MoRe electrodes. The stability of MIEE/beta?-alumina solid electrolyte (BASE) interface was studied in terms of the chemical potential of Na-Al-Ti-O system at 1100K (typical AMTEC operating temperature). Ni metal was compatible with sodium titanate and BASE and displayed the best initial performance among all tested PMEs. Ni/sodium titanate electrodes with 4/1 mass ratios of metal/ceramic performed best among all tested electrodes. Scanning Electron Microscope (SEM) observations showed that grain agglomeration, which is the main mechanism for electrode degradation, occurred in all tested electrodes. Ceramic components were able to effectively limit the growth of metal grains and resulted in a long lifetime for MIEEs. Ni particles in the MIEE formed a network microstructure that was close to the theoretical morphology of the ideal electrode. A model based on percolation theory was constructed to interpret and predict the performance of MIEEs. The electrode kinetics was studied and a theoretical expression for the interface impedance was derived for both PME and MIEE, using electrochemical impedance spectroscopy (EIS). The conductivity of the Na2Ti 3O7 and Na2Ti6O13 mixture was measured. The average activation energy for the bulk conductivity was 0.87ev. Finally, theoretical analysis clarified that the transfer coefficient alpha value change would cause at most a few percent change in the electrode performance parameter B.

  12. Improving the Validity of Competency-Based Assessment.

    ERIC Educational Resources Information Center

    Thomson, P.; Saunders, J.; Foyster, J.

    A study was conducted to review the concept of validity in the context of vocational education and training (VET) in Australia. The study included a review of literature, case studies, presentation of key findings, and recommendation of a tool to guide assessors. An eight-faceted approach to validity, based on Nitko, was developed, with each…

  13. Studies of liquid adsorption, condensation and surface conductivity in porous media

    NASA Astrophysics Data System (ADS)

    Qi, Hao

    In the petroleum industry, accurate estimates of hydrocarbon reserve and its producibility are without a doubt among the most important issues. Quantitative estimates require the knowledge of three basic parameters of the rock formation: the porosity ?, the water saturation S w and the permeability k. Electrical conductivity is one of the most commonly made measurements used to deduce these quantities. Some empirical relationships used to make such estimates are quite well established and understood, however, many still lack a sound scientific foundation. Systematic laboratory investigation and theoretical understanding of the underlying petrophysics are much needed. This dissertation consists of three projects aimed at understanding both the surface conductivity observed in shaly sandstone, and the related phenomena of molecular adsorption on heterogeneous surfaces. In the first project, we carried out nitrogen adsorption experiments on three shale samples whose fractal dimensions had been previously characterized by small angle scattering (SANS). We found that analyzing the adsorption isotherm data according to the available theoretical predictions always resulted in D values that are lower than those obtained by SANS. The second project, a numerical simulation of adsorption on fractal surfaces, was designed to understand the origin of discrepancies revealed in the first project. We found that the interplay between van der Waals adsorption and capillary condensation always leads to a crossover between the two theoretical limits. The simulated isotherms exhibit the same general features we observed in our experimental data. The third project was aimed at understanding the surface conduction in porous media. We isolated the surface conductivity by growing water layers on the surface with water adsorption isotherm technique. Some of our results indicate that AC impedance measurement could let us determine the surface conductivity and separate it from that of the bulk, thereby more accurate estimates of oil saturation can be achieved in using the empirical Archie's relation. Our studies shed more light on the various aspects of the surface ionic conduction, including Debye - Huckle length, CPA phenomenon, and effects of saturation, cation species, temperature, and substrate.

  14. Reliability of molecular breeding values for Warner-Bratzler shear force and carcass traits of beef cattle - an independent validation study.

    PubMed

    Akanno, E C; Plastow, G; Woodward, B W; Bauck, S; Okut, H; Wu, X-L; Sun, C; Aalhus, J L; Moore, S S; Miller, S P; Wang, Z; Basarab, J A

    2014-07-01

    Interest in genetic improvement of carcass and tenderness traits of beef cattle using genome-based selection (GS) and marker-assisted management programs is increasing. The success of such a program depends on the presence of linkage disequilibrium between the observed markers and the underlying QTL as well as on the relationship between the discovery, validation, and target populations. For molecular breeding values (MBV) predicted for a target population using SNP markers, reliabilities of these MBV can be obtained from validation analyses conducted in an independent population distinct from the discovery set. The objective of this study was to test MBV predicted for carcass and tenderness traits of beef cattle in a Canadian-based validation population that is largely independent of a United States-based discovery set. The discovery data set comprised of genotypes and phenotypes from >2,900 multibreed beef cattle while the validation population consisted of 802 crossbred feeder heifers and steers. A bivariate animal model that fitted actual phenotype and MBV was used for validation analyses. The reliability of MBV was defined as square of the genetic correlation (R(2) g) that represents the proportion of the additive genetic variance explained by the SNP markers. Several scenarios involving different starting marker panels (384, 3K, 7K, and 50K) and different sets of SNP selected to compute MBV (50, 100, 200, 375, 400, 600, and 800) were investigated. Validation results showed that the most reliable MBV (R(2) g) were 0.34 for HCW, 0.36 for back fat thickness, 0.28 for rib eye area, 0.30 for marbling score, 0.25 for yield grade, and 0.38 for Warner-Bratzler shear force across the different scenarios explored. The results indicate that smaller SNP panels can be developed for use in genetic improvement of beef carcass and tenderness traits to exploit GS benefits. PMID:24802042

  15. Comparative studies of the thermal conductivity of spinel oxides with orbital degrees of freedom

    NASA Astrophysics Data System (ADS)

    Ishitsuka, Y.; Ishikawa, T.; Koborinai, R.; Omura, T.; Katsufuji, T.

    2014-12-01

    We studied the thermal conductivity of various transition-metal oxides with the spinel structure (MnV2O4, FeV2O4, CoV2O4, and Mn3O4) upon varying the temperature and magnetic field. We found that for the spinel oxides having V3 + ions (two electrons in the t2 g states) at the octahedral site, the orbital ordering suppresses the thermal resistivity (inverse thermal conductivity) in contrast to purely magnetic ordering, indicating that the orbital fluctuation of the V t2 g states is the main factor affecting the thermal conductivity. On the other hand, for Mn3O4, which has Mn3 + ions (one electron in the eg states) at the octahedral site, the thermal resistivity is suppressed in association with the successive magnetic phase transitions with decreasing temperature and increasing magnetic field. This can be explained by the frustration of Mn3 + spins and the fluctuation of Mn3 + eg orbitals.

  16. Computational Study of Subdural Cortical Stimulation: Effects of Simulating Anisotropic Conductivity on Activation of Cortical Neurons

    PubMed Central

    Seo, Hyeon; Kim, Donghyeon; Jun, Sung Chan

    2015-01-01

    Subdural cortical stimulation (SuCS) is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5) that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry. The anisotropic information was acquired from diffusion tensor magnetic resonance imaging (DT-MRI) and then applied to the white matter at various ratios of anisotropic conductivity. First, we compared the isotropic and anisotropic models; compared to the isotropic model, the anisotropic model showed that neurons were activated in the deeper bank during cathodal stimulation and in the wider crown during anodal stimulation. Second, several popular anisotropic principles were adapted to investigate the effects of variations in anisotropic information. We observed that excitation thresholds varied with anisotropic principles, especially with anodal stimulation. Overall, incorporating anisotropic conductivity into the anatomically realistic head model is critical for accurate estimation of neuronal responses; however, caution should be used in the selection of anisotropic information. PMID:26057524

  17. Density Functional Theory Study of the Conductivity of Manganese Dioxide Nanowires during Li+ Insertion

    NASA Astrophysics Data System (ADS)

    Wu, Ruqian; Wang, Hui; Thai, May Le; Penner, Reginald M.

    2015-03-01

    Manganese oxide (?-MnO2) as a battery material has various advantages such as low cost, high earth abundance and environmentally safe, and it has large interlayer space for lithium ion insertion and migration. In this work, the system of 200 MnO2 nanowire array is used to study the electrochemical changes through in situ conductivity measurements during the lithium ion insertion process. The result indicates that the conductivity of each MnO2 nanowire array increases as the lithium ion concentrations increases corresponding to more negative insertion potential. We perform ab initio molecular dynamic (AIMD) simulations and density functional theory (DFT) calculations with the van der Waals (vdW) correction to understand the fundamental electrochemical and structural properties of ?-MnO2 nanowires. We find that water molecules are important for the expansion of the interlayer distance of ?-MnO2, and reveal that the variation of conductivity of ?-MnO2 nanowires with different Li+ concentrations stems from the Li-produced gap states. HW and RW were supported 1000 talent fund in Fudan U and by DOE-BES (Grant No. DE- FG02-05ER46237). MT and RP were supported by the U.S. DOE-EFRC (Award Number DESC0001160).

  18. Low frequency conductivity study of gallium-substituted magnesium-copper spinel ferrite

    NASA Astrophysics Data System (ADS)

    Kaiser, M.; Ata-Allah, S. S.

    2005-12-01

    Mixed ferrites with the chemical formula Mg0.5Cu0.5GaxFe2-xO4 (0.0 x 0.5) were prepared by a ceramic route. X-ray diffraction results confirmed the presence of single-phase spinel structure for these samples. Electrical properties of these ferrites at various compositions were investigated from room temperature up to 550 K in the frequency range 102-105 Hz. The obtained results revealed semiconductor behavior at high frequency and metallic behavior at low frequency in these materials. All studied compositions exhibit a transition with a change in the slope of the conductivity versus temperature curve. The obtained transition temperature TC is found to decrease linearly with increasing Ga concentration. As Ga substitutes Fe in these compounds the activation energy for electrical conduction in the ferrimagnetic region (Ef) has a small variation with frequency. In contrast, the activation energy in the paramagnetic region (Ep) shows undefined behavior reflecting the nature of this disordered state. The relation of the universal exponent s with temperature gives evidence for the presence of the large overlap polaron (LOP) hopping conduction mechanism in these compounds. The obtained results are explained in the light of the cation-anion-cation and cation-cation interactions present over the octahedral B-sites in the spinel structure.

  19. Numerical Studies and Metric Development for Validation of MHD Models on the HIT-SI Experiment

    NASA Astrophysics Data System (ADS)

    Hansen, Chris

    2014-10-01

    Biorthogonal Decomposition (BD) decomposes large data sets, as produced by distributed diagnostic arrays, into principal mode structures without assumptions on spatial or temporal structure. We present an application of the BD technique to define a few scalar metrics that capture the level of agreement between macroscopic dynamics in different data sets. These metrics have been applied to validation of the Hall-MHD model using experimental data from the Helicity Injected Torus with Steady Inductive helicity injection (HIT-SI) experiment. Each metric provides a measure of correlation between mode shapes extracted from experimental data and simulations for an array of 192 surface mounted magnetic probes. In collaboration with the Plasma Science and Innovation (PSI) Center, extensive simulations have been performed and compared to experimental data using BD and other metrics to determine validity of the Hall-MHD model in the parameter regime of HIT-SI operation (T ~ 10 's eV, n ~1019 m-3). Numerical validation studies have been performed using NIMROD, which models the injectors as boundary conditions on the flux conserver, and PSI-TET, which models the entire plasma volume. Results from these studies will be presented, illustrating application of the BD method. A simplified (constant, uniform density and temperature) Hall-MHD model has accurately modeled the current amplification achieved when the injectors are driven with a frequency of 14.5 kHz. However at higher frequencies (30 kHz < finj < 70 kHz) this simplified model does not reproduce the experimental current amplification. In addition, simulations have yet to accurately reproduce the internal q profile, an important factor in equilibrium stability, indicating additional physics may be required to achieve full agreement. Work supported by the US Department of Energy.

  20. Validity and responsiveness of the Clubfoot Assessment Protocol (CAP). A methodological study

    PubMed Central

    Andriesse, Hanneke; Roos, Ewa M; Hägglund, Gunnar; Jarnlo, Gun-Britt

    2006-01-01

    Background The Clubfoot Assessment Protocol (CAP) is a multi dimensional instrument designed for longitudinal follow up of the clubfoot deformity during growth. Item reliability has shown to be sufficient. In this article the CAP's validity and responsiveness is studied using the Dimeglio classification scoring as a gold standard. Methods Thirty-two children with 45 congenital clubfeet were assessed prospectively and consecutively at ages of new-born, one, two, four months and two years of age. For convergent/divergent construct validity the Spearman's correlation coefficients were calculated. Discriminate validity was evaluated by studying the scores in bilateral clubfeet. The floor-ceiling effects at baseline (untreated clubfeet) and at two years of age (treated clubfeet) were evaluated. Responsiveness was evaluated by using effect sizes (ES) and by calculating if significant changes (Wilcoxons signed test) had occurred between the different measurement occasions. Results High to moderate significant correlation were found between CAP mobility I and morphology and the Dimeglio scores (rs = 0.77 and 0.44 respectively). Low correlation was found between CAP muscle function, mobility II and motion quality and the Dimeglio scoring system (rs = 0.20, 0.09 and 0.06 respectively). Of 13 children with bilateral clubfeet, 11 showed different CAP mobility I scores between right and left foot at baseline (untreated) compared with 5 with the Dimeglio score. At the other assessment occasions the CAP mobility I continued to show higher discrimination ability than the Dimeglio. No floor effects and low ceiling effects were found in the untreated clubfeet for both instruments. High ceiling effects were found in the CAP for the treated children and low for the Dimeglio. Responsiveness was good. ES from untreated to treated ranged from 0.80 to 4.35 for the CAP subgroups and was 4.68 for the Dimeglio. The first four treatment months, the CAP mobility I had generally higher ES compared with the Dimeglio. Conclusion The Clubfoot Assessment Protocol shows in this study good validity and responsiveness. The CAP is more responsive when severity ranges between mild – moderate to severe, while the Dimeglio focuses more on the extremes. The ability to discriminate between different mobility status of the right and left foot in bilaterally affected children in this population was higher compared with the Dimeglio score implicating a better sensitivity for the CAP. PMID:16539716

  1. Validation of an image-based technique to assess the perceptual quality of clinical chest radiographs with an observer study

    NASA Astrophysics Data System (ADS)

    Lin, Yuan; Choudhury, Kingshuk R.; McAdams, H. Page; Foos, David H.; Samei, Ehsan

    2014-03-01

    We previously proposed a novel image-based quality assessment technique1 to assess the perceptual quality of clinical chest radiographs. In this paper, an observer study was designed and conducted to systematically validate this technique. Ten metrics were involved in the observer study, i.e., lung grey level, lung detail, lung noise, riblung contrast, rib sharpness, mediastinum detail, mediastinum noise, mediastinum alignment, subdiaphragm-lung contrast, and subdiaphragm area. For each metric, three tasks were successively presented to the observers. In each task, six ROI images were randomly presented in a row and observers were asked to rank the images only based on a designated quality and disregard the other qualities. A range slider on the top of the images was used for observers to indicate the acceptable range based on the corresponding perceptual attribute. Five boardcertificated radiologists from Duke participated in this observer study on a DICOM calibrated diagnostic display workstation and under low ambient lighting conditions. The observer data were analyzed in terms of the correlations between the observer ranking orders and the algorithmic ranking orders. Based on the collected acceptable ranges, quality consistency ranges were statistically derived. The observer study showed that, for each metric, the averaged ranking orders of the participated observers were strongly correlated with the algorithmic orders. For the lung grey level, the observer ranking orders completely accorded with the algorithmic ranking orders. The quality consistency ranges derived from this observer study were close to these derived from our previous study. The observer study indicates that the proposed image-based quality assessment technique provides a robust reflection of the perceptual image quality of the clinical chest radiographs. The derived quality consistency ranges can be used to automatically predict the acceptability of a clinical chest radiograph.

  2. A Study of the Construct Validity of the Interactive Computer Interview System (ICIS) using Student Evaluations as the Outcome Measure

    E-print Network

    Evans, Chad Gerhold

    2010-06-30

    The present study sought to investigate the concurrent validity of the ICIS employment interview tool as measured by student satisfaction by examining the correlation between the scores obtained through interviews of forty high school teachers...

  3. Assessment of the conclusion validity for empirical research studies published in the journal of speech, language, and hearing research 

    E-print Network

    Byrns, Glenda Elkins

    2009-05-15

    , and Hearing Research (JSLHR) published in 2004. This methodological research synthesis evaluated (a) the research designs used in the JSLHR studies, (b) information and rationale used to inform population validity assessment decisions, and (c) the extent...

  4. [Critical reading of articles about diagnostic tests (part I): Are the results of the study valid?].

    PubMed

    Arana, E

    2015-01-01

    In the era of evidence-based medicine, one of the most important skills a radiologist should have is the ability to analyze the diagnostic literature critically. This tutorial aims to present guidelines for determining whether primary diagnostic articles are valid for clinical practice. The following elements should be evaluated: whether the study can be applied to clinical practice, whether the technique was compared to the reference test, whether an appropriate spectrum of patients was included, whether expectation bias and verification bias were limited, the reproducibility of the study, the practical consequences of the study, the confidence intervals for the parameters analyzed, the normal range for continuous variables, and the placement of the test in the context of other diagnostic tests. We use elementary practical examples to illustrate how to select and interpret the literature on diagnostic imaging and specific references to provide more details. PMID:25443434

  5. Two-Year Predictive Validity of Conduct Disorder Subtypes in Early Adolescence: A Latent Class Analysis of a Canadian Longitudinal Sample

    ERIC Educational Resources Information Center

    Lacourse, Eric; Baillargeon, Raymond; Dupere, Veronique; Vitaro, Frank; Romano, Elisa; Tremblay, Richard

    2010-01-01

    Background: Investigating the latent structure of conduct disorder (CD) can help clarify how symptoms related to aggression, property destruction, theft, and serious violations of rules cluster in individuals with this disorder. Discovering homogeneous subtypes can be useful for etiologic, treatment, and prevention purposes depending on the…

  6. Enhanced ionic conductivity and optical studies of plasticized (PEO-KCl) solid polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Chapi, Sharanappa; H, Devendrappa

    2015-06-01

    Solid polymer electrolytes (SPEs) based on Polyethylene oxide (PEO) doped with potassium chloride (KCl) were prepared by the solution cast technique. The conductivity increases from 10-10 to 10-6 Scm-1 at 303K with dopant. Optical absorption study shows that the direct & indirect optical band gaps were found decreased from 5.45-4.46eV and 4.96-3.86eV respectively with increasing the KCl. The XRD patterns reveal increasing the amorphous with increasing the dopent. The obtained results suggest that, these polymer systems are suitable candidates for solid state battery, electro chromic devices & optoelectronics display etc.

  7. Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

    Microsoft Academic Search

    Martin Röösli; Patrizia Frei; John Bolte; Georg Neubauer; Elisabeth Cardis; Maria Feychting; Peter Gajsek; Sabine Heinrich; Wout Joseph; Simon Mann; Luc Martens; Evelyn Mohler; Roger C Parslow; Aslak Harbo Poulsen; Katja Radon; Joachim Schüz; György Thuroczy; Jean-François Viel; Martine Vrijheid

    2010-01-01

    BACKGROUND: The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result,

  8. Validation of mathematical models of complex endocrine-metabolic systems. A case study on a model of glucose regulation

    Microsoft Academic Search

    C. Cobelli; A. Mari

    1983-01-01

    The validation process is an essential component of the modelling ofin vivo endocrine and metabolic systems. In the paper a validation study of a comprehensive model of the glucose regulation system,\\u000a previously developed for intravenous testing, is performed on a new data set based on oral glucose tolerance studies. A novel\\u000a approach based on a ‘partition and input\\/output inversion’ technique

  9. Conduct disorder and ADHD : evaluation of conduct problems as a categorical and quantitative trait in the international multicentre ADHD genetics study

    Microsoft Academic Search

    Richard J. L. Anney; Jessica Lasky-Su; C. O'Dushlaine; Elaine Kenny; Benjamin M. Neale; Aisling Mulligan; Barbara Franke; Kaixin Zhou; Wai Chen; Hanna Christiansen; A. Arias-Vasquez; Tobias Banaschewski; Jan Buitelaar; Richard Ebstein; Ana Miranda; Fernando Mulas; Robert D. Oades; Herbert Roeyers; Aribert Rothenberger; Joseph Sergeant; Edmund Sonuga-Barke; Hans Steinhausen; Philip Asherson; Stephen V. Faraone; Michael Gill

    2008-01-01

    Attention-deficit\\/hyperactivity disorder (ADHD) is typically characterized by inattention, excessive motor activity, impulsivity, and distractibility. Individuals with ADHD have significant impairment in family and peer relations, academic functioning, and show high co-morbidity with a wide range of psychiatric disorders including oppositional defiant disorder (ODD), conduct disorder (CD), anxiety disorder, depression, substance abuse, and pervasive developmental disorder (PDD). Family studies suggest that

  10. Motor function and perception in children with neuropsychiatric and conduct problems: results from a population based twin study

    PubMed Central

    2014-01-01

    Background Children with early symptomatic psychiatric disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) have been found to have high rates of motor and/or perception difficulties. However, there have been few large-scale studies reporting on the association between Conduct Disorder (CD) and motor/perception functions. The aim of the present study was to investigate how motor function and perception relate to measures of ADHD, ASD, and CD. Methods Parents of 16,994 Swedish twins (ages nine and twelve years) were interviewed using the Autism-Tics, ADHD and other Comorbidities inventory (A-TAC), which has been validated as a screening instrument for early onset child psychiatric disorders and symptoms. Associations between categorical variables of scoring above previously validated cut-off values for diagnosing ADHD, ASD, and CD on the one hand and motor and/or perception problems on the other hand were analysed using cross-tabulations, and the Fisher exact test. Associations between the continuous scores for ADHD, ASD, CD, and the subdomains Concentration/Attention, Impulsiveness/Activity, Flexibility, Social Interaction and Language, and the categorical factors age and gender, on the one hand, and the dependent dichotomic variables Motor control and Perception problems, on the other hand, were analysed using binary logistic regression in general estimated equation models. Results Male gender was associated with increased risk of Motor control and/or Perception problems. Children scoring above the cut-off for ADHD, ASD, and/or CD, but not those who were ‘CD positive’ but ‘ADHD/ASD negative’, had more Motor control and/or Perception problems, compared with children who were screen-negative for all three diagnoses. In the multivariable model, CD and Impulsiveness/Activity had no positive associations with Motor control and/or Perception problems. Conclusions CD symptoms or problems with Impulsiveness/Activity were associated with Motor control or Perception problems only in the presence of ASD symptoms and/or symptoms of inattention. Our results indicate that children with CD but without ASD or inattention do not show a deviant development of motor and perceptual functions. Therefore, all children with CD should be examined concerning motor control and perception. If problems are present, a suspicion of ADHD and/or ASD should be raised. PMID:24872861

  11. Validity and reliability of portfolio assessment of student competence in two dental school populations: a four-year study.

    PubMed

    Gadbury-Amyot, Cynthia C; McCracken, Michael S; Woldt, Janet L; Brennan, Robert L

    2014-05-01

    The purpose of this study was to empirically investigate the validity and reliability of portfolio assessment in two U.S. dental schools using a unified framework for validity. In the process of validation, it is not the test that is validated but rather the claims (interpretations and uses) about test scores that are validated. Kane's argument-based validation framework provided the structure for reporting results where validity claims are followed by evidence to support the argument. This multivariate generalizability theory study found that the greatest source of variance was attributable to faculty raters, suggesting that portfolio assessment would benefit from two raters' evaluating each portfolio independently. The results are generally supportive of holistic scoring, but analytical scoring deserves further research. Correlational analyses between student portfolios and traditional measures of student competence and readiness for licensure resulted in significant correlations between portfolios and National Board Dental Examination Part I (r=0.323, p<0.01) and Part II scores (r=0.268, p<0.05) and small and non-significant correlations with grade point average and scores on the Western Regional Examining Board (WREB) exam. It is incumbent upon the users of portfolio assessment to determine if the claims and evidence arguments set forth in this study support the proposed claims for and decisions about portfolio assessment in their respective institutions. PMID:24789826

  12. How Well Do Discharge Diagnoses Identify Hospitalised Patients with Community-Acquired Infections? – A Validation Study

    PubMed Central

    Henriksen, Daniel Pilsgaard; Nielsen, Stig Lønberg; Laursen, Christian Borbjerg; Hallas, Jesper; Pedersen, Court; Lassen, Annmarie Touborg

    2014-01-01

    Background Credible measures of disease incidence, trends and mortality can be obtained through surveillance using manual chart review, but this is both time-consuming and expensive. ICD-10 discharge diagnoses are used as surrogate markers of infection, but knowledge on the validity of infections in general is sparse. The aim of the study was to determine how well ICD-10 discharge diagnoses identify patients with community-acquired infections in a medical emergency department (ED), overall and related to sites of infection and patient characteristics. Methods We manually reviewed 5977 patients admitted to a medical ED in a one-year period (September 2010-August 2011), to establish if they were hospitalised with community-acquired infection. Using the manual review as gold standard, we calculated the sensitivity, specificity, predictive values, and likelihood ratios of discharge diagnoses indicating infection. Results Two thousand five hundred eleven patients were identified with community-acquired infection according to chart review (42.0%, 95% confidence interval [95%CI]: 40.8–43.3%) compared to 2550 patients identified by ICD-10 diagnoses (42.8%, 95%CI: 41.6–44.1%). Sensitivity of the ICD-10 diagnoses was 79.9% (95%CI: 78.1–81.3%), specificity 83.9% (95%CI: 82.6–85.1%), positive likelihood ratio 4.95 (95%CI: 4.58–5.36) and negative likelihood ratio 0.24 (95%CI: 0.22–0.26). The two most common sites of infection, the lower respiratory tract and urinary tract, had positive likelihood ratios of 8.3 (95%CI: 7.5–9.2) and 11.3 (95%CI: 10.2–12.9) respectively. We identified significant variation in diagnostic validity related to age, comorbidity and disease severity. Conclusion ICD-10 discharge diagnoses identify specific sites of infection with a high degree of validity, but only a moderate degree when identifying infections in general. PMID:24663388

  13. Validation of FSP Reactor Design with Sensitivity Studies of Beryllium-Reflected Critical Assemblies

    SciTech Connect

    John D. Bess; Margaret A. Marshall

    2013-02-01

    The baseline design for space nuclear power is a fission surface power (FSP) system: sodium-potassium (NaK) cooled, fast spectrum reactor with highly-enriched-uranium (HEU)-O2 fuel, stainless steel (SS) cladding, and beryllium reflectors with B4C control drums. Previous studies were performed to evaluate modeling capabilities and quantify uncertainties and biases associated with analysis methods and nuclear data. Comparison of Zero Power Plutonium Reactor (ZPPR)-20 benchmark experiments with the FSP design indicated that further reduction of the total design model uncertainty requires the reduction in uncertainties pertaining to beryllium and uranium cross-section data. Further comparison with three beryllium-reflected HEU-metal benchmark experiments performed at the Oak Ridge Critical Experiments Facility (ORCEF) concluded the requirement that experimental validation data have similar cross section sensitivities to those found in the FSP design. A series of critical experiments was performed at ORCEF in the 1960s to support the Medium Power Reactor Experiment (MPRE) space reactor design. The small, compact critical assembly (SCCA) experiments were graphite- or beryllium-reflected assemblies of SS-clad, HEU-O2 fuel on a vertical lift machine. All five configurations were evaluated as benchmarks. Two of the five configurations were beryllium reflected, and further evaluated using the sensitivity and uncertainty analysis capabilities of SCALE 6.1. Validation of the example FSP design model was successful in reducing the primary uncertainty constituent, the Be(n,n) reaction, from 0.28 %dk/k to 0.0004 %dk/k. Further assessment of additional reactor physics measurements performed on the SCCA experiments may serve to further validate FSP design and operation.

  14. Active transmembrane drug transport in microgravity: a validation study using an ABC transporter model

    PubMed Central

    Vaquer, Sergi; Cuyàs, Elisabet; Rabadán, Arnau; González, Albert; Fenollosa, Felip; de la Torre, Rafael

    2014-01-01

    Microgravity has been shown to influence the expression of ABC (ATP-Binding Cassette) transporters in bacteria, fungi and mammals, but also to modify the activity of certain cellular components with structural and functional similarities to ABC transporters. Changes in activity of ABC transporters could lead to important metabolic disorders and undesired pharmacological effects during spaceflights. However, no current means exist to study the functionality of these transporters in microgravity. To this end, a Vesicular Transport Assay ® (Solvo Biotechnology, Hungary) was adapted to evaluate multi-drug resistance-associated protein 2 (MRP2) trans-membrane estradiol-17-?-glucuronide (E17?G) transport activity, when activated by adenosine-tri-phosphate (ATP) during parabolic flights. Simple diffusion, ATP-independent transport and benzbromarone inhibition were also evaluated. A high accuracy engineering system was designed to perform, monitor and synchronize all procedures. Samples were analysed using a validated high sensitivity drug detection protocol. Experiments were performed in microgravity during parabolic flights, and compared to 1g on ground results using identical equipment and procedures in all cases. Our results revealed that sufficient equipment accuracy and analytical sensitivity were reached to detect transport activity in both gravitational conditions. Additionally, transport activity levels of on ground samples were within commercial transport standards, proving the validity of the methods and equipment used. MRP2 net transport activity was significantly reduced in microgravity, so was signal detected in simple diffusion samples. Ultra-structural changes induced by gravitational stress upon vesicle membranes or transporters could explain the current results, although alternative explanations are possible. Further research is needed to provide a conclusive answer in this regard. Nevertheless, the present validated technology opens new and interesting research lines in biology and human physiology with the potential for significant benefits for both space and terrestrial medicine. PMID:25520779

  15. Active transmembrane drug transport in microgravity: a validation study using an ABC transporter model.

    PubMed

    Vaquer, Sergi; Cuyàs, Elisabet; Rabadán, Arnau; González, Albert; Fenollosa, Felip; de la Torre, Rafael

    2014-01-01

    Microgravity has been shown to influence the expression of ABC (ATP-Binding Cassette) transporters in bacteria, fungi and mammals, but also to modify the activity of certain cellular components with structural and functional similarities to ABC transporters. Changes in activity of ABC transporters could lead to important metabolic disorders and undesired pharmacological effects during spaceflights. However, no current means exist to study the functionality of these transporters in microgravity. To this end, a Vesicular Transport Assay (®) (Solvo Biotechnology, Hungary) was adapted to evaluate multi-drug resistance-associated protein 2 (MRP2) trans-membrane estradiol-17-?-glucuronide (E17?G) transport activity, when activated by adenosine-tri-phosphate (ATP) during parabolic flights. Simple diffusion, ATP-independent transport and benzbromarone inhibition were also evaluated. A high accuracy engineering system was designed to perform, monitor and synchronize all procedures. Samples were analysed using a validated high sensitivity drug detection protocol. Experiments were performed in microgravity during parabolic flights, and compared to 1g on ground results using identical equipment and procedures in all cases. Our results revealed that sufficient equipment accuracy and analytical sensitivity were reached to detect transport activity in both gravitational conditions. Additionally, transport activity levels of on ground samples were within commercial transport standards, proving the validity of the methods and equipment used. MRP2 net transport activity was significantly reduced in microgravity, so was signal detected in simple diffusion samples. Ultra-structural changes induced by gravitational stress upon vesicle membranes or transporters could explain the current results, although alternative explanations are possible. Further research is needed to provide a conclusive answer in this regard. Nevertheless, the present validated technology opens new and interesting research lines in biology and human physiology with the potential for significant benefits for both space and terrestrial medicine. PMID:25520779

  16. A Validation Study of the Interpersonal Circumplex Scales in the Italian Language

    Microsoft Academic Search

    Lisa Di Blas

    2000-01-01

    Eight interpersonal scales, developed within the Italian lexical context, were tested with respect to different kinds of validity. The observed continuum of interpersonal attributes corresponded to, in terms of content, Wiggins' circumplex (substantive validity). Several tests, performed across different subsamples, showed that the scales conformed to circumplex properties (structural integrity). Correlational and regression results indicated some concurrent validity with the

  17. The potential influence of Internet-based social networking on the conduct of clinical research studies.

    PubMed

    Glickman, Seth W; Galhenage, Sam; McNair, Lindsay; Barber, Zachry; Patel, Keyur; Schulman, Kevin A; McHutchison, John G

    2012-02-01

    The rapid growth of internet usage has led to an explosion of social networking sites for discussion of health issues. This provides a forum for subjects to communicate with one another during the course of the studies. Previous studies have raised concerns about the quality of health information on social networking sites, although none have evaluated content related to ongoing clinical trials. We reviewed material posted in virtual communities by self-identified clinical trial participants. We identified material posted in online health forums that could introduce bias into clinical research studies; we believe that this issue warrants further study and discussion. Physicians and others who conduct clinical trials should be aware of this issue. Study investigators and research teams should also talk to their study subjects about where and how they are obtaining information in order to prevent behaviors and correct misinformation that could put a subject's safety or the study objectives at risk. Given the rapid increase in Internet use for health care, a broader evaluation of both the benefits and potential risks of social networking among research participants during the course of a clinical trial appears warranted. PMID:22378136

  18. Low conductivity water loop heat pump study at Lawrence Livermore National Laboratory

    SciTech Connect

    Chen, C.C.; Onu, C. [Southern Univ., Baton Rouge, LA (United States). College of Engineering; Smith, T.; Holda, M. [Lawrence Livermore National Lab., CA (United States)

    1995-12-31

    Based on results of the new Water Source Heat Pump (WSHP) systems operating in the US, these highly efficient heat pumps provide energy saving that will make them economically feasible to replace the inefficient, conventional HVAC systems. Additionally, an option to replace a centrifugal-compressor CFC chiller with a non-CFC chiller can be to replace the system with a highly efficient Water-Loop Heat Pump (WSHP) system. This replacement can result in a reduction of 20 to 30% in heating and air-conditioning energy costs. Low Conductivity Water (LCW) is purified water used for cooling in experimental laboratory, process, and air-conditioning equipment. It is one of several lab-wide mechanical utilities systems provided at Lawrence Livermore National Laboratory (LNL). The system is designed to maintain a supply temperature between 65 F and 85 F, with 100 psi at the inlet of the user building, 50--55 psi minimum differential pressures in the building, 35 psi maximum return pressure, and 0.4 umho/cm conductivity. However, this study is to utilize the existing LCW water loop to achieve the energy-efficiency improvement in a water resource heat pump (WRHP) system. The study will also utilize the life cycle costs as a tool to as the general selected criteria.

  19. Mastoid triangle for sex determination in adult Nigerian population: a validation study.

    PubMed

    Jaja, Blessing N R; Ajua, Christiana O; Didia, Blessing C

    2013-11-01

    In the quest for a simple, reliable technique to estimate the sex of human remains several novel metric skeletal indices have been reported. Only a few have been examined for utility in populations different from those in which they were developed. In this study, the mastoid process was evaluated for sex determination using 102 lateral cephalograms of a Nigerian sample of known age and sex. The asterion-mastoidale distance and mastoid triangular area were sexually dimorphic with mean values higher in males compared with females (p = 0.02). On analysis of the discriminant function, overall accuracy for sex classification was 55%. On cross-validation, the triangular area accurately identified 80% of females and 48% of males. The asterion-mastoidale distance was slightly more accurate at sexing the sample. The practical utility of the mastoid triangle area technique to differentiate sex in Nigerian populations is not supported by the results of this study. PMID:24117960

  20. Correction for FDG PET dose extravasations: Monte Carlo validation and quantitative evaluation of patient studies

    SciTech Connect

    Silva-Rodríguez, Jesús, E-mail: jesus.silva.rodriguez@sergas.es; Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Santiago de Compostela, Galicia (Spain) [Fundación Ramón Domínguez, Santiago de Compostela, Galicia (Spain); Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Sánchez, Manuel; Mosquera, Javier; Luna-Vega, Víctor [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain)] [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Cortés, Julia; Garrido, Miguel [Servicio de Medicina Nuclear, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia, Spain and Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain)] [Servicio de Medicina Nuclear, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia, Spain and Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Pombar, Miguel [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia (Spain)] [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia (Spain); Ruibal, Álvaro [Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain) [Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Fundación Tejerina, 28003, Madrid (Spain)

    2014-05-15

    Purpose: Current procedure guidelines for whole body [18F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) state that studies with visible dose extravasations should be rejected for quantification protocols. Our work is focused on the development and validation of methods for estimating extravasated doses in order to correct standard uptake value (SUV) values for this effect in clinical routine. Methods: One thousand three hundred sixty-seven consecutive whole body FDG-PET studies were visually inspected looking for extravasation cases. Two methods for estimating the extravasated dose were proposed and validated in different scenarios using Monte Carlo simulations. All visible extravasations were retrospectively evaluated using a manual ROI based method. In addition, the 50 patients with higher extravasated doses were also evaluated using a threshold-based method. Results: Simulation studies showed that the proposed methods for estimating extravasated doses allow us to compensate the impact of extravasations on SUV values with an error below 5%. The quantitative evaluation of patient studies revealed that paravenous injection is a relatively frequent effect (18%) with a small fraction of patients presenting considerable extravasations ranging from 1% to a maximum of 22% of the injected dose. A criterion based on the extravasated volume and maximum concentration was established in order to identify this fraction of patients that might be corrected for paravenous injection effect. Conclusions: The authors propose the use of a manual ROI based method for estimating the effectively administered FDG dose and then correct SUV quantification in those patients fulfilling the proposed criterion.