Sample records for validation studies conducted

  1. Conducting ecologically valid prevention research: recruiting and retaining a "whole village" in multimethod, multiagent studies.

    PubMed

    Capaldi, D M; Chamberlain, P; Fetrow, R A; Wilson, J E

    1997-08-01

    Many prevention studies are now designed with complementary interventions in different settings. Evaluations of these interventions require assessing the child's behavior in each of these settings. Conducting these studies, therefore, may involve recruiting school districts, principals, classroom teachers, peers, parents, siblings, and in later years, employers and intimate partners. These participants may be considered natural raters or satellite subjects, depending on their degree of involvement. Issues of recruitment and retention thus are magnified in multimethod, multiagent studies. To illustrate these issues, findings are presented for three studies conducted with risk populations in the past decade at the Oregon Social Learning Center: a passive longitudinal study, a selected prevention study, and an indicated prevention study. Findings indicate that achieving high recruitment and retention rates for at-risk and high-risk subjects in multisetting studies is possible, and that a developmental approach should be taken to recruiting risk populations. PMID:9338955

  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. Global 3-D EM inversion of Sq variations based on simultaneous source and conductivity determination: concept validation and resolution studies

    NASA Astrophysics Data System (ADS)

    Koch, Stephan; Kuvshinov, Alexey

    2013-10-01

    We present a novel global 3-D electromagnetic (EM) inverse solution that allows to work in a unified and consistent manner with frequency-domain data that originate from ionospheric and magnetospheric sources irrespective of their spatial complexity. The main idea behind the approach is simultaneous determination of the source and conductivity distribution in the Earth. Such a determination is implemented in our solution as a looped sequential procedure that involves two steps: (1) determination of the source using a fixed 3-D conductivity model and (2) recovery of a 3-D conductivity model using a fixed source. We focus in this paper on analysis of Sq data and numerically verify each step separately and combined using data synthesized from 3-D models of the Earth induced by a realistic Sq source. To determine the source we implement an approach that makes use of a known conductivity structure of the Earth with non-uniform oceans. Based on model studies we show that this approach outperforms the conventional potential method. As for recovery of 3-D conductivity in the mantle, our inverse scheme relies on a regularized least-square formulation, exploits a limited-memory quasi-Newton optimization method and makes use of the adjoint source approach to calculate efficiently the misfit gradient. We perform resolution studies with checkerboard conductivity structures at depths between 10 and 1600 km for different inverse setups and conclude from these studies that: (1) inverting Z component gives much better results than inverting all (X, Y and Z) components; (2) data from the Sq source allows for resolving 3-D structures in depth range between 100 and 520 km; (3) the best resolution is achieved in the depth range of 100-250 km.

  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. 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.

  7. Developing and validating the Youth Conduct Problems Scale-Rwanda: a mixed methods approach.

    PubMed

    Ng, Lauren C; Kanyanganzi, Frederick; Munyanah, Morris; Mushashi, Christine; Betancourt, Theresa S

    2014-01-01

    This study developed and validated the Youth Conduct Problems Scale-Rwanda (YCPS-R). Qualitative free listing (n?=?74) and key informant interviews (n?=?47) identified local conduct problems, which were compared to existing standardized conduct problem scales and used to develop the YCPS-R. The YCPS-R was cognitive tested by 12 youth and caregiver participants, and assessed for test-retest and inter-rater reliability in a sample of 64 youth. Finally, a purposive sample of 389 youth and their caregivers were enrolled in a validity study. Validity was assessed by comparing YCPS-R scores to conduct disorder, which was diagnosed with the Mini International Neuropsychiatric Interview for Children, and functional impairment scores on the World Health Organization Disability Assessment Schedule Child Version. ROC analyses assessed the YCPS-R's ability to discriminate between youth with and without conduct disorder. Qualitative data identified a local presentation of youth conduct problems that did not match previously standardized measures. Therefore, the YCPS-R was developed solely from local conduct problems. Cognitive testing indicated that the YCPS-R was understandable and required little modification. The YCPS-R demonstrated good reliability, construct, criterion, and discriminant validity, and fair classification accuracy. The YCPS-R is a locally-derived measure of Rwandan youth conduct problems that demonstrated good psychometric properties and could be used for further research. PMID:24949628

  8. 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.

  9. Critical validation studies of neurofeedback.

    PubMed

    Gruzelier, John; Egner, Tobias

    2005-01-01

    The field of neurofeedback training has proceeded largely without validation. In this article the authors review studies directed at validating sensory motor rhythm, beta and alpha-theta protocols for improving attention, memory, and music performance in healthy participants. Importantly, benefits were demonstrable with cognitive and neurophysiologic measures that were predicted on the basis of regression models of learning to enhance sensory motor rhythm and beta activity. The first evidence of operant control over the alpha-theta ratio is provided, together with remarkable improvements in artistic aspects of music performance equivalent to two class grades in conservatory students. These are initial steps in providing a much needed scientific basis to neurofeedback. PMID:15564053

  10. 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

  11. FDDS: A Cross Validation Study.

    ERIC Educational Resources Information Center

    Sawyer, Judy Parsons

    The Family Drawing Depression Scale (FDDS) was created by Wright and McIntyre to provide a clear and reliable scoring method for the Kinetic Family Drawing as a procedure for detecting depression. A study was conducted to confirm the value of the FDDS as a systematic tool for interpreting family drawings with populations of depressed individuals.…

  12. 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…

  13. Validation of a mouse conductance system to determine LV volume: comparison to echocardiography and crystals.

    PubMed

    Feldman, M D; Erikson, J M; Mao, Y; Korcarz, C E; Lang, R M; Freeman, G L

    2000-10-01

    The application of left ventricular pressure-volume analysis to transgenic mice to characterize the cardiac phenotype has been problematic due to the small size of the mouse heart and the rapid heartbeat. Conductance technology has been miniaturized for the mouse and can solve this problem. However, there has been no validation of this technique. Accordingly, we performed echocardiography followed by simultaneous ultrasonic crystals, flow probe, and conductance studies in 18 CD-1 mice. Raw conductance volumes were corrected for an inhomogenous electrical field (alpha) and parallel conductance (G(pi)) yielding a stroke volume of 14.1 +/- 3.7 microliter/beat, end-diastolic volume of 20.8 +/- 6.5 microliter, and end-systolic volume of 9.0 +/- 5.8 microliter. The mean conductance volumes were no different from those derived by flow probe and echocardiography but did differ from ultrasonic crystals. G(pi) was determined to be 14.9 +/- 8.7 microliter. However, hypertonic saline altered dimension and pressure in the mouse left ventricle. Although G(pi) can be determined by the hypertonic saline method, saline altered hemodynamics, questioning its validity in the mouse. Although mean measures of absolute volume may be similar among different techniques, individual values did not correlate. PMID:11009457

  14. 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.

  15. Test of Creative Imagination: Validity and Reliability Study

    ERIC Educational Resources Information Center

    Gundogan, Aysun; Ari, Meziyet; Gonen, Mubeccel

    2013-01-01

    The purpose of this study was to investigate validity and reliability of the test of creative imagination. This study was conducted with the participation of 1000 children, aged between 9-14 and were studying in six primary schools in the city center of Denizli Province, chosen by cluster ratio sampling. In the study, it was revealed that the…

  16. Validation of non-Darcian flow effects in slug tests conducted in fractured rock boreholes

    NASA Astrophysics Data System (ADS)

    Quinn, Patryk M.; Parker, Beth L.; Cherry, John A.

    2013-04-01

    SummaryA series of rising and falling head slug tests with different initial applied head differentials (?Ho) were conducted in open fractured dolostone and sandstone boreholes using straddle packers isolating specific depth intervals (1.5 m length) to examine the influence of non-Darcian flow. The open holes were developed and inspected using video and acoustic televiewing (ATV) to ensure that evidence of skin effects due to drilling were absent. The transmissivity (T) values obtained from both the rising and falling head slug tests were very similar at low initial applied head; however, the T values were progressively smaller at larger ?Ho, suggesting error due to non-Darcian flow. Non-Darcian flow behavior was confirmed by constant head step tests conducted in the same test intervals where the injection rate (Q) vs. applied head (dH) relationship became non-linear at relatively low injection rates, and the non-Darcian data also resulted in lower T values. For a series of slug tests conducted at different ?Ho, non-Darcian flow effects gradually increased as ?Ho increased, consistent with the trends for constant head step tests conducted in the same test intervals. To maintain Darcian flow conditions in the fractured dolostone and sandstone tested in this study, ?Ho must be kept small, generally less than 0.2 m. This study demonstrates that by conducting both "stepped" slug tests and constant head step tests, the Darcian flow assumption for both types of tests can be rigorously validated. However, when only slug tests are conducted, it is necessary to conduct a series of "stepped" slug tests, including tests with small applied head differentials, to avoid errors due to non-Darcian flow.

  17. 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,…

  18. 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.

  19. A Validation Study of Maslow's Hierarchy of Needs Theory.

    ERIC Educational Resources Information Center

    Clay, Rex J.

    A study was conducted to expand the body of research that tests the validity of Abraham Maslow's hierarchy of needs theory in a work context where it often serves as a guide for the supervisor's relationships with his subordinates. Data was gathered by questionnaire which tested for a hierarchy of needs among instructors at four community colleges…

  20. Physical Activity Questionnaires (PAQ) Validation Studies - References

    Cancer.gov

    Wareham NJ, Jakes RW, Rennie KL et al. Validity and repeatability of a simple index derived from the short physical activity questionnaire used in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

  1. Thermographic validation of a novel, laminate body, analytical heat conduction model

    NASA Astrophysics Data System (ADS)

    Desgrosseilliers, Louis; Groulx, Dominic; White, Mary Anne

    2014-07-01

    The two-region fin model captures the heat spreading behaviour in multilayered composite bodies (i.e., laminates), heated only over a small part of their domains (finite heat source), where there is an inner layer that has a substantial capacity for heat conduction parallel to the heat exchange surface (convection cooling). This resulting heat conduction behaviour improves the overall heat transfer process when compared to heat conduction in homogeneous bodies. Long-term heat storage using supercooling salt hydrate phase change materials, stovetop cookware, and electronics cooling applications could all benefit from this kind of heat-spreading in laminates. Experiments using laminate films reclaimed from post-consumer Tetra Brik cartons were conducted with thin rectangular and circular heaters to confirm the laminate body, steady-state, heat conduction behaviour predicted by the two-region fin model. Medium to high accuracy experimental validation of the two-region fin model was achieved in Cartesian and cylindrical coordinates for forced external convection and natural convection, the latter for Cartesian only. These were conducted using constant heat flux finite heat source temperature profiles that were measured by infrared thermography. This validation is also deemed valid for constant temperature heat sources.

  2. 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.

  3. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the removal process, remedial investigation/ feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response...

  4. Critical validation studies of neurofeedback

    Microsoft Academic Search

    John Gruzelier; Tobias Egner

    2005-01-01

    In the pediatric field, the most widespread application of electroencephalo- graphic (EEG) biofeedback (neurofeedback) is for the treatment of attention deficit hyperactivity disorder (ADHD). Work began with the pioneering studies of Lubar et al (1-3) with the hypothesis that voluntary production of the sensory motor rhythm (SMR) required a child to stabilize or suppress motor activity while remaining attentive. The

  5. Clinical nerve conduction and needle electromyography studies.

    PubMed

    Lee, Donald H; Claussen, Gwendolyn C; Oh, Shin

    2004-01-01

    The electrodiagnostic study, consisting of nerve conduction studies and needle electromyography, is a useful adjunct to the clinical examination of the peripheral nervous system. The three types of nerve conduction study are motor, sensory, and mixed, of which motor is the least sensitive. Electromyography records the intrinsic electrical activity of muscle fibers, thus providing the physiologic status of muscle function. To interpret the electrodiagnostic study results, the clinician must understand the anatomic and physiologic basis of the studies. Peripheral nerve entrapment initially results in focal demyelination; thus, nerve conduction velocity slows across the site. However, with radiculopathy and nerve root compression, the nerve conduction study may be normal. Both nerve trauma and polyneuropathy show marked differences in their effect on the results of electrodiagnostic studies. PMID:15473679

  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. The Validity of Comparative Educational Studies.

    ERIC Educational Resources Information Center

    Bechger, Timo M.; van den Wittenboer, Godfried; Hox, Joop J.; De Glopper, C.

    1999-01-01

    Provides an explanation of the conditions required for valid comparison of educational achievement among existing groups, using the reading literacy study of the International Association for the Evaluation of Educational Achievement as an example. Discusses the meaningfulness and appropriateness of comparisons. (SLD)

  8. 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.

  9. Nerve conduction studies in early tuberculoid leprosy

    PubMed Central

    Vashisht, Deepak; Das, Arjun Lal; Vaishampayan, Sanjeev S; Vashisht, Surbhi; Joshi, Rajneesh

    2014-01-01

    Context: Hansen's disease is a chronic illness; besides involving skin and peripheral nerves, it affects multiple organs. Nerve involvement is always present in leprosy, and it may be present much before the patient manifests clinically. Aims: To assess nerve conduction parameters in thickened and contralateral non-thickened nerves in early tuberculoid leprosy Materials and Methods: Fifty new untreated male patients with tuberculoid and borderline tuberculoid leprosy in the age group of 15-50 years with thickened peripheral nerves on one side were included in the study. Nerve conduction studies consisting of sensory and motor velocity (NCV), distal latencies, and amplitude were carried out on thickened ulnar, common peroneal, and posterior tibial nerves and contralateral normal nerves. Statistical Analysis Used: Mean values along with coefficient of variation were obtained for various parameters. These were compared with normal values of the control population. P value was used to verify statistical significance. Results: Nerve conduction parameters were deranged in most of the thickened nerves. Sensory parameters were affected early in the disease process. Conclusion: Additional parameters are required to assess nerve damage in early cases, where it is more in slow conducting fibers (average velocity fibers). Change in conduction velocity may not be marked; this calls for the measurement of fast fibers separately because potentials recorded are mainly from myelinated fibers. PMID:25593812

  10. Conductivity study of chitosan based nanocomposites

    NASA Astrophysics Data System (ADS)

    Mohan, C. Raja; Murugan, S.; Jayakumar, K.

    2012-06-01

    Bio polymer like chitosan is dissolved in acids like formic and acetic acid and CdS nano particle prepared by chemical methods has been embedded in the salts of chitosan matrix. The viscous solution is cast into film on the glass substrate using spin coating method and their ionic conductivity has been studied for various frequencies and temperatures.

  11. 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.

  12. 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

  13. How was the APECC study conducted?

    Cancer.gov

    This population-based SEER study was conducted in collaboration with researchers at the Northern California Cancer Center. The Greater Bay Area Cancer Registry provided the sampling frame. Data were collected between April 2003 and November 2004 through a cross-sectional survey mailed to a representative sample of leukemia, colorectal, and bladder cancer survivors who were diagnosed 2-5 years before the study (diagnosis dates ranged from June 1, 1999 to May 31st, 2001).

  14. CFD Validation Studies for Hypersonic Flow Prediction

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.

    2001-01-01

    A series of experiments to measure pressure and heating for code validation involving hypersonic, laminar, separated flows was conducted at the Calspan-University at Buffalo Research Center (CUBRC) in the Large Energy National Shock (LENS) tunnel. The experimental data serves as a focus for a code validation session but are not available to the authors until the conclusion of this session. The first set of experiments considered here involve Mach 9.5 and Mach 11.3 N, flow over a hollow cylinder-flare with 30 deg flare angle at several Reynolds numbers sustaining laminar, separated flow. Truncated and extended flare configurations are considered. The second set of experiments, at similar conditions, involves flow over a sharp, double cone with fore-cone angle of 25 deg and aft-cone angle of 55 deg. Both sets of experiments involve 30 deg compressions. Location of the separation point in the numerical simulation is extremely sensitive to the level of grid refinement in the numerical predictions. The numerical simulations also show a significant influence of Reynolds number on extent of separation. Flow unsteadiness was easily introduced into the double cone simulations using aggressive relaxation parameters that normally promote convergence.

  15. CFD Validation Studies for Hypersonic Flow Prediction

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.

    2001-01-01

    A series of experiments to measure pressure and heating for code validation involving hypersonic, laminar, separated flows was conducted at the Calspan-University at Buffalo Research Center (CUBRC) in the Large Energy National Shock (LENS) tunnel. The experimental data serves as a focus for a code validation session but are not available to the authors until the conclusion of this session. The first set of experiments considered here involve Mach 9.5 and Mach 11.3 N2 flow over a hollow cylinder-flare with 30 degree flare angle at several Reynolds numbers sustaining laminar, separated flow. Truncated and extended flare configurations are considered. The second set of experiments, at similar conditions, involves flow over a sharp, double cone with fore-cone angle of 25 degrees and aft-cone angle of 55 degrees. Both sets of experiments involve 30 degree compressions. Location of the separation point in the numerical simulation is extremely sensitive to the level of grid refinement in the numerical predictions. The numerical simulations also show a significant influence of Reynolds number on extent of separation. Flow unsteadiness was easily introduced into the double cone simulations using aggressive relaxation parameters that normally promote convergence.

  16. Peripheral and central conduction studies in neurolathyrism.

    PubMed Central

    Misra, U K; Sharma, V P

    1994-01-01

    To study the involvement of motor and sensory pathways in neurolathyrism, 19 patients with lathyrism from Unnao, India, where lathyrism is endemic, were studied. The mean age of the patients at the time of the onset of illness was 35.8 (range 18-70) years. The mean duration of illness was 15.6 (range 2-30) years. The clinical picture comprised walking difficulty due to stiffness and mild weakness in all 19 patients, cramps in the legs in five, frequency or urgency of micturition in five, and flexor spasms in three. There was pronounced leg spasticity with a mean Ashworth score of 4.1 (range 2.9-5). Central motor conduction to the tibialis anterior muscle (CMCT-TA) was slow in 14 of the 17 patients (21 sides). Slowing of peripheral motor nerve conduction, although less pronounced, was significant in the upper limb in four and the lower limb in seven sides. The tibial somatosensory evoked potentials were normal and peroneal nerve conduction was marginally impaired. Values for CMCT-TA correlated with the degree of spasticity (p < 0.02) whereas weakness, crossed adductor reflexes, and clonus did not. The wide variability of CMCT-TA in lathyrism may be due to involvement of different types of fibres. Large diameter fibre involvement may cause pronounced slowing. Small diameter fibre involvement could produce appreciable spasticity and mild weakness but a lesser degree of slowing or even normal conduction. Images PMID:8201326

  17. Reliable Digit Span: A Systematic Review and Cross-Validation Study

    ERIC Educational Resources Information Center

    Schroeder, Ryan W.; Twumasi-Ankrah, Philip; Baade, Lyle E.; Marshall, Paul S.

    2012-01-01

    Reliable Digit Span (RDS) is a heavily researched symptom validity test with a recent literature review yielding more than 20 studies ranging in dates from 1994 to 2011. Unfortunately, limitations within some of the research minimize clinical generalizability. This systematic review and cross-validation study was conducted to address these…

  18. 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

  19. Organizational Systems Questionnaire (OSQ) Validity Study.

    PubMed

    Billings, James C; Kimball, Thomas G; Shumway, Sterling T; Korinek, Alan W

    2007-04-01

    Marriage and family therapists (MFTs), who are trained in systems theory and consult with complex and difficult systems (e.g., couples and families), are uniquely suited to both assess and intervene in broader organizational systems. However, MFTs are in need of more systemically designed assessment tools to guide and inform their interventions with organizational systems. This study examined the construct and concurrent validity of the Organizational Systems Questionnaire (OSQ). The OSQ is designed to use a systemic framework to measure the construct of organizational functioning. Participants were simultaneously administered the Abridged Job Description Index, Organizational Commitment Questionnaire, Stress in General, and Communication Satisfaction Questionnaire scales along with the OSQ. The OSQ demonstrated good construct validity, factor analysis indicates it is measuring one global factor of organizational functioning, reliability was strong (alpha = .91), and it showed high levels of internal consistency. The OSQ also demonstrated positive concurrent validity with acceptable levels of correlation with the other organizational measures. Overall, the OSQ was found to be a useful and psychometrically sound single-factor measure of organizational functioning. PMID:17437456

  20. Two phase detonation studies conducted in 1971

    NASA Technical Reports Server (NTRS)

    Nicholls, J. A.

    1972-01-01

    A report is presented describing the research conducted on five phases: (1) ignition of fuel drops by a shock wave and passage of a shock wave over a burning drop, (2) the energy release pattern of a two-phase detonation with controlled drop sizes, (3) the attenuation of shock and detonation waves passing over an acoustic liner, (4) experimental and theoretical studies of film detonations, and (5) a simplified analytical model of a rotating two-phase detonation wave in a rocket motor.

  1. Reliability and Validity of a Point-of-Care Sural Nerve Conduction Device for Identification of Diabetic Neuropathy

    PubMed Central

    Lee, Justin A.; Halpern, Elise M.; Lovblom, Leif E.; Yeung, Emily; Bril, Vera; Perkins, Bruce A.

    2014-01-01

    Background Confirmation of diabetic sensorimotor polyneuropathy (DSP) relies on standard nerve conduction studies (NCS) performed in specialized clinics. We explored the utility of a point-of-care device (POCD) for DSP detection by nontechnical personnel and a validation of diagnostic thresholds with those observed in a normative database. Research Design and Methods 44 subjects with type 1 and type 2 diabetes underwent standard NCS (reference method). Two nontechnical examiners measured sural nerve amplitude potential (SNAP) and conduction velocity (SNCV) using the POCD. Reliability was determined by intraclass correlation coefficients (ICC [2], [1]). Validity was determined by Bland-Altman analysis and receiver operating characteristic curves. Results The 44 subjects (50% female) with mean age 56±18 years had mean SNAP and SNCV of 8.0±8.6 µV and 41.5±8.2 m/s using standard NCS and 8.0±8.2 µV and 49.9±11.1 m/s using the POCD. Intrarater reproducibility ICC values were 0.97 for SNAP and 0.94 for SNCV while interrater reproducibility values were 0.83 and 0.79, respectively. Mean bias of the POCD was ?0.1±3.6 µV for SNAP and +8.4±6.4 m/s for SNCV. A SNAP of ?6 µV had 88% sensitivity and 94% specificity for identifying age-and height-standardized reference NCS values, while a SNCV of ?48 m/s had 94% specificity and 82% sensitivity. Abnormality in one or more of these thresholds was associated with 95% sensitivity and 71% specificity for identification of DSP according to electrophysiological criteria. Conclusions The POCD demonstrated excellent reliability and acceptable accuracy. Threshold values for DSP identification validated those of published POCD normative values. We emphasize the presence of measurement bias – particularly for SNCV – that requires adjustment of threshold values to reflect those of standard NCS. PMID:24466129

  2. Conducting a multi family member interview study.

    PubMed

    Reczek, Corinne

    2014-06-01

    Family researchers have long recognized the utility of incorporating interview data from multiple family members. Yet, relatively few contemporary scholars utilize such an approach due to methodological underdevelopment. This article contributes to family scholarship by providing a roadmap for developing and executing in-depth interview studies that include more than one family member. Specifically, it outlines the epistemological frames that most commonly underlie this approach, illustrates thematic research questions that it best addresses, and critically reviews the best methodological practices of conducting research with this approach. The three most common approaches are addressed in depth: separate interviews with each family member, dyadic or group interviews with multiple family members, and a combined approach that uses separate and dyadic or group interviews. This article speaks to family scholars who are at the beginning stages of their research project but are unsure of the best qualitative approach to answer a given research question. PMID:24410452

  3. An Experimental Study on Validation Problems with Existing HTML Webpages

    E-print Network

    Shen, Vincent Yun

    An Experimental Study on Validation Problems with Existing HTML Webpages Shan Chen Dan Hong Vincent the results of an experimental study on the validation problem of existing HTML pages in the World Wide Web. We have found that only about 5% of webpages are "valid" according to the HTML standard. An "invalid

  4. Proving external validity of ergonomics and quality relationship through review of real-world case studies

    Microsoft Academic Search

    O?uzhan Erdinç; Paul H. P. Yeow

    2011-01-01

    Prior lab experiment and simulated environment ergonomics studies revealed the cause-and-effect relationship between ergonomics and quality with high internal validity. However, the external validity, i.e. the generalisability of this relationship to field settings (manufacturing plants) cannot be ascertained unless field experiment studies are conducted. Therefore, the current study aims to review five field experiment ergonomics studies to strengthen the external

  5. Study on thermally conductive ESBR vulcanizates

    Microsoft Academic Search

    Zhiguo LiHong; Hong Chen; Zhenhua Zhu; Yong Zhang

    The thermal conductivities of emulsion polymerized styrene-butadiene rubber (ESBR) vulcanizates filled with alumina (Al2O3), zinc oxide (ZnO), carbon nanotubes (CNTs), silicon carbide (SiC), are measured by steady-state method. The effects of types\\u000a and loadings of the fillers and their mixture on thermal conductivities of the ESBR vulcanizates are investigated. The results\\u000a show that the thermal conductivity of ESBR vulcanizates filled

  6. Testing a better method of predicting postsurgery soft tissue response in Class II patients: A prospective study and validity assessment.

    PubMed

    Yoon, Kyoung-Sik; Lee, Ho-Jin; Lee, Shin-Jae; Donatelli, Richard E

    2014-10-01

    Objective: (1) To perform a prospective study using a new set of data to test the validity of a new soft tissue prediction method developed for Class II surgery patients and (2) to propose a better validation method that can be applied to a validation study. Materials and Methods: Subjects were composed of two subgroups: training subjects and validation subjects. Eighty Class II surgery patients provided the training data set that was used to build the prediction algorithm. The validation data set of 34 new patients was used for evaluating the prospective performance of the prediction algorithm. The validation was conducted using four validation methods: (1) simple validation and (2) fivefold, (3) 10-fold, and (4) leave-one-out cross-validation (LOO). Results: The characteristics between the training and validation subjects did not differ. The multivariate partial least squares regression returned more accurate prediction results than the conventional method did. During the prospective validation, all of the cross-validation methods (fivefold, 10-fold, and LOO) demonstrated fewer prediction errors and more stable results than the simple validation method did. No significant difference was noted among the three cross-validation methods themselves. Conclusion: After conducting a prospective study using a new data set, this new prediction method again performed well. In addition, a cross-validation technique may be considered a better option than simple validation when constructing a prediction algorithm. PMID:25275546

  7. Nerve conduction studies in hand surgery

    Microsoft Academic Search

    David J Slutsky

    2003-01-01

    The treatment of nerve disorders of the upper extremity has become a highly specialized area. There has been an evolution in the electrodiagnostic approach for evaluating patients with these disorders. Portable automated nerve conduction testing systems are becoming popular for limited nerve conduction testing in the office. Differential latency testing can aid in the diagnosis of dynamic nerve entrapment disorders

  8. 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…

  9. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Conducting the comparison study. 761.326 Section 761.326...Waste Samples § 761.326 Conducting the comparison study. Extract or analyze the comparison study samples using the alternative...

  10. Conduction Velocity of the Uterine Contraction in Serial Magnetomyogram (MMG) Data: Event Based Simulation and Validation

    PubMed Central

    Preissl, Hubert; Lowery, Curtis L.; Eswaran, Hari; Govindan, Rathinaswamy B.

    2012-01-01

    We propose a novel approach to calculate the conduction velocity (CV) of the uterine contraction bursts in magnetomyogram (MMG) signals measured using a multichannel SQUID array. For this purpose, we partition the sensor coordinates into four different quadrants and identify the contractile bursts using a previously proposed Hilbert-wavelet transform approach. If contractile burst is identified in more than one quadrant, we calculate the center of gravity (CoG) in each quadrant for each time point as the sum of the product of the sensor coordinates with the Hilbert amplitude of the MMG signals normalized by the sum of the Hilbert amplitude of the signals over all sensors. Following this we compute the delay between the CoGs of all (six) possible quadrant pairs combinations. As a first step, we validate this approach by simulating a stochastic model based on independent second-order autoregressive processes (AR2) and we divide them into 30 second disjoint windows and insert burst activity at specific time instances in preselected sensors. Also we introduce a lag of 5 ± 1 seconds between different quadrants. Using our approach we calculate the CoG of the signals in a quadrant. To this end, we compute the delay between CoGs obtained from different quadrants and show that our approach is able to reliably capture the delay incorporated in the model. We apply the proposed approach to 19 serial MMG data obtained from two subjects and show an increase in the CV as the subjects approached labor. PMID:22255713

  11. Conductivity

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students make a simple conductivity tester using a battery and light bulb. They learn the difference between conductors and insulators of electrical energy as they test a variety of materials for their ability to conduct electricity.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Mössbauer study of conductive oxide glass

    SciTech Connect

    Matsuda, Koken; Kubuki, Shiro [Tokyo Metropolitan University, Hachi-Oji, Tokyo 192-0397 (Japan); Nishida, Tetsuaki, E-mail: nishida@fuk.kindai.ac.jp [Kinki University, Iizuka, Fukuoka 820-8555 (Japan)

    2014-10-27

    Heat treatment of barium iron vanadate glass, BaO?Fe{sub 2}O{sub 3}?V{sub 2}O{sub 5}, at temperatures higher than crystallization temperature causes a marked decrease in resistivity (?) from several M?cm to several ?cm. {sup 57}Fe Mössbauer spectrum of heat-treated vanadate glass shows a marked decrease in quadrupole splitting (?) of Fe{sup III}, reflecting a structural relaxation, i.e., an increased symmetry of 'distorted' FeO{sub 4} and VO{sub 4} tetrahedra which are connected to each other by sharing corner oxygen atoms. Structural relaxation of 3D-network of vanadate glass accompanies a decrease in the activation energy for the conduction, reflecting a decreased energy gap between the donor level and conduction band. A marked increase in the conductivity was observed in CuO- or Cu{sub 2}O-containing barium iron vanadate glass after heat treatment at 450 °C for 30 min or more. 'n-type semiconductor model combined with small polaron hopping theory' was proposed in order to explain the high conductivity.

  17. Mössbauer study of conductive oxide glass

    NASA Astrophysics Data System (ADS)

    Matsuda, Koken; Kubuki, Shiro; Nishida, Tetsuaki

    2014-10-01

    Heat treatment of barium iron vanadate glass, BaO - Fe2O3- V2O5, at temperatures higher than crystallization temperature causes a marked decrease in resistivity (?) from several M?cm to several ?cm. 57Fe Mössbauer spectrum of heat-treated vanadate glass shows a marked decrease in quadrupole splitting (?) of FeIII, reflecting a structural relaxation, i.e., an increased symmetry of "distorted" FeO4 and VO4 tetrahedra which are connected to each other by sharing corner oxygen atoms. Structural relaxation of 3D-network of vanadate glass accompanies a decrease in the activation energy for the conduction, reflecting a decreased energy gap between the donor level and conduction band. A marked increase in the conductivity was observed in CuO- or Cu2O -containing barium iron vanadate glass after heat treatment at 450 °C for 30 min or more. "n-type semiconductor model combined with small polaron hopping theory" was proposed in order to explain the high conductivity.

  18. Construct Validation Theory Applied to the Study of Personality Dysfunction

    PubMed Central

    Zapolski, Tamika C. B.; Guller, Leila; Smith, Gregory T.

    2013-01-01

    The authors review theory validation and construct validation principles as related to the study of personality dysfunction. Historically, personality disorders have been understood to be syndromes of heterogeneous symptoms. The authors argue that the syndrome approach to description results in diagnoses of unclear meaning and constrained validity. The alternative approach of describing personality dysfunction in terms of homogeneous dimensions of functioning avoids the problems of the syndromal approach and has been shown to provide more valid description and diagnosis. The authors further argue that description based on homogeneous dimensions of personality function/dysfunction is more useful, because it provides direct connections to validated treatments. PMID:22321263

  19. Numerical Study of the Metamodel Validation Process

    Microsoft Academic Search

    Bertrand IOOSS

    2009-01-01

    Complex computer codes are often too time expensive to be directly used to perform uncertainty, sensitivity, optimization and robustness analyses. A widely accepted method to circumvent this problem consists in replacing cpu time expensive computer models by cpu inexpensive mathematical functions, called metamodels. In this paper, we focus on the essential step of the metamodel validation phase which consists in

  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. Thermal and electrical contact conductance studies

    NASA Technical Reports Server (NTRS)

    Vansciver, S. W.; Nilles, M.

    1985-01-01

    Prediction of electrical and thermal contact resistance for pressed, nominally flat contacts is complicated by the large number of variables which influence contact formation. This is reflected in experimental results as a wide variation in contact resistances, spanning up to six orders of magnitude. A series of experiments were performed to observe the effects of oxidation and surface roughness on contact resistance. Electrical contact resistance and thermal contact conductance from 4 to 290 K on OFHC Cu contacts are reported. Electrical contact resistance was measured with a 4-wire DC technique. Thermal contact conductance was determined by steady-state longitudinal heat flow. Corrections for the bulk contribution ot the overall measured resistance were made, with the remaining resistance due solely to the presence of the contact.

  2. 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.

  3. Causation and effectuation processes: A validation study

    Microsoft Academic Search

    Gaylen N. Chandler; Dawn R. DeTienne; Alexander McKelvie; Troy V. Mumford

    2011-01-01

    We develop and validate measures of causation and effectuation approaches to new venture creation and test our measures with two samples of entrepreneurs in young firms. Our measure of causation is a well-defined and coherent uni-dimensional construct. We propose that effectuation is a formative, multidimensional construct with three associated sub-dimensions (experimentation, affordable loss, and flexibility) and one dimension shared with

  4. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...completion of the validation study, measurements from the contaminated surfaces must have an arithmetic mean of ?10 µg/100 cm2 . If the arithmetic mean is >10 µg/100 cm2 , then the validation study failed and the solvent may not be...

  5. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...completion of the validation study, measurements from the contaminated surfaces must have an arithmetic mean of ?10 µg/100 cm2 . If the arithmetic mean is >10 µg/100 cm2 , then the validation study failed and the solvent may not be...

  6. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...completion of the validation study, measurements from the contaminated surfaces must have an arithmetic mean of ?10 µg/100 cm2 . If the arithmetic mean is >10 µg/100 cm2 , then the validation study failed and the solvent may not be...

  7. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...completion of the validation study, measurements from the contaminated surfaces must have an arithmetic mean of ?10 µg/100 cm2 . If the arithmetic mean is >10 µg/100 cm2 , then the validation study failed and the solvent may not be...

  8. 40 CFR 761.395 - A validation study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...completion of the validation study, measurements from the contaminated surfaces must have an arithmetic mean of ?10 µg/100 cm2 . If the arithmetic mean is >10 µg/100 cm2 , then the validation study failed and the solvent may not be...

  9. Vision Test Validation Study for the Health Examination Survey Among Youths 12-17 years.

    ERIC Educational Resources Information Center

    Roberts, Jean

    A validation study of the vision test battery used in the Health Examination Survey of 1966-1970 was conducted among 210 youths 12-17 years-old who had been part of the larger survey. The study was designed to discover the degree of correspondence between survey test results and clinical examination by an opthalmologist in determining the…

  10. 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

  11. Assessing Attachment in Young Adulthood: A Validational Study.

    ERIC Educational Resources Information Center

    Moses, Lizbeth A.; And Others

    A sample of college students (N=170) was used to replicate and extend recent investigations that had conceptualized adults' close relationships within an early attachment framework. Analyses were conducted to support the validity of Hazan and Shaver's (1987) attachment measures, which were designed to assess the three major styles of attachment:…

  12. FETAX interlaboratory validation study: Phase 2 testing

    Microsoft Academic Search

    John A. Bantle; Dennis T. Burton; Douglas A. Dawson; James N. Dumont; Robert A. Finch; Douglas J. Fort; Greg Linder; James R. Rayburn; David Buchwalter; Angela M. Gaudet-Hull; Margaret A. Maurice; Steven D. Turley

    1994-01-01

    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

  13. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study § 792...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

  14. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study § 792...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

  15. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

  16. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

  17. Rocky Flats 1990--91 winter validation tracer study: Volume 1

    SciTech Connect

    Brown, K.J. [North American Weather Consultants, Salt Lake City, UT (United States)

    1991-10-01

    During the winter of 1990--91, North American Weather Consultants (NAWC) and its subcontractor, ABB Environmental Services (ABBES), conducted a Winter Validation Study (WVS) for EG&G Rocky Flats involving 12 separate tracer experiments conducted between February 3 and February 19, 1991. Six experiments were conducted during nighttime hours and four experiments were conducted during daytime hours. In addition, there was one day/night and one night/day transitional experiment conducted. The primary purpose of the WVS was to gather data to further the approval process for the Terrain Responsive Atmospheric Code (TRAC). TRAC is an atmospheric dispersion model developed and operated at the Department of Energy`s (DOE`s) Rocky Flats Plant (RFP) north of Denver, Colorado. A secondary objective was to gather data that will serve to validate the TRAC model physics.

  18. The ECVAM International Validation Study on In Vitro Tests for Skin Corrosivity. 1. Selection and Distribution of the Test Chemicals

    Microsoft Academic Search

    M. D. Barratt; P. G. Brantom; J. H. Fentem; I. Gerner; A. P. Walker; A. P. Worth

    1998-01-01

    An international validation study on in vitro tests for skin corrosivity was conducted during 1996 and 1997 under the auspices of the European Centre for the Validation of Alternative Methods (ECVAM). The main objectives of the study were to assess the performances of selected in vitro tests in discriminating between: (a) corrosives (C) and non-corrosives (NC), for selected groups of

  19. How to Conduct an Energy Efficiency Study

    E-print Network

    Biles, J. E.

    1979-01-01

    ; is the foundation of the study. i 2. Plant Energy Balance. This is a flow sheet indicating all energy interchanges for the exist ; ing plant at the specified production rate (Figure 2). Note that the concept is for easy reading. The boilers are shown at the top.... It discusses how the energy study was started and establishes a perspective for the reader at the beginning of the report. Section 2. Plant Energy Balance This is the first document published for the study. It is important that all energy inter changes...

  20. Numerical predictions of two-dimensional conduction, convection, and radiation heat transfer. II. Validation

    Microsoft Academic Search

    Daniel R. Rousse; Guillaume Gautier; Jean-Francois Sacadura

    2000-01-01

    This paper presents several test problems that were used to validate the formulation and implementation of a CVFEM for combined-mode heat transfer in participating media. The objective here is to demonstrate that the proposed CVFEM can be used to solve combined modes of heat transfer in media that emit, absorb, and scatter radiant energy in regularly- and irregularly-shaped geometries. The

  1. Validation study on avermectine residues in foodstuffs.

    PubMed

    Giannetti, L; Giorgi, A; Necci, F; Ferretti, G; Buiarelli, F; Neri, B

    2011-08-26

    Avermectines are antiparasitic agents widely used as veterinary drugs for food producing animals. The European Community, due to their side effects, limited the use of these molecules establishing maximum residue limits (MRLs) in some foods. A validated qualitative and quantitative high performance liquid chromatography method with fluorescence detection (HPLC-FL) is presented for the simultaneous determination of ivermectin (IVM), abemectin (ABA), moxidectin (MOX), eprinomectin (EPR), doramectin (DOR) and emamectin (EMA) in foodstuffs (muscle, eggs and milk). Samples were extracted with acetonitrile, purified with liquid-liquid extraction (LLE), and analysed by HLPC-FL previous derivatization with trifluoroacetic anhydride (TFAA) in presence of 1-methyl-imidazole (MI) and acetic acid. To date, the presented method is the first validated for the matrix eggs, and in accordance with the requirements set by Commission Decision 2002/657/EC. Recoveries of the methods, calculated spiking the samples in the range 5.0-100.0 ?g kg(-1), were 64-83% for muscle, 65-89% for milk and 63-84% for eggs. The precision (CV) ranged between 9.2 and 17.1% for muscle, 9.9 and 16.6% for milk and from 9.4 to 17.4% for eggs. Linearity for the six analytes was calculated from 5.0 to 200.0 ?g kg(-1). The main advantages of the presented method are its rapidity, the specificity, the good precision and recovery that make it very suitable to the detection and determination of avermectines. PMID:21742111

  2. 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.…

  3. An Empirical Study of Reporting Practices Concerning Measurement Validity

    ERIC Educational Resources Information Center

    Hogan, Thomas P.; Agnello, Jessica

    2004-01-01

    This study investigates the current research practice concerning reporting measurement validity evidence based on a sample of 696 research reports listed in the American Psychological Association's Directory of Unpublished Experimental Mental Measures. Only 55% of the reports included any type of validity evidence. This was a substantially lower…

  4. Validation Study of the Malay Version of the Work-Family Conflict Questionnaire

    PubMed Central

    SANAZ, Aazami; SYAQIRAH, Akmal; KHADIJAH, Shamsuddin

    2014-01-01

    Background: Work-family conflict has received increasing attention in recent decades in the area of workplace stressors, which can affect employees’ health. However, the dimensionality of the work–family conflict construct among the Malay-speaking population has not been clarified. In order to do so, it is crucial to use an instrument that is appropriate and valid for the Malay-speaking population. As such, the goal of this study was to validate and test the dimensionality of the Malay version of the Work-Family Conflict Questionnaire. Methods: The present study conducted exploratory factor analysis, confirmatory factor analysis, discriminant validity, convergent validity, and internal consistency, using Cronbach’s alpha, of the work–family conflict construct among 332 working women in Malaysia. Results: The results supported the existence of four dimensions in the Work-Family Conflict Questionnaire that distinguish between time based and strain-based work-family conflict and family-work conflict. The discriminant validity, convergent validity, and internal consistency of this construct are adequately supported. Conclusion: The findings of this study supported the existence of discriminant and convergent validity, as well as adequate reliability, for the construct. Thus, the Work–Family Conflict Questionnaire is a valid and reliable instrument among Malay-speaking working women. PMID:24639612

  5. Signal-averaged P wave analysis for delineation of interatrial conduction – Further validation of the method

    PubMed Central

    Holmqvist, Fredrik; Platonov, Pyotr G; Havmöller, Rasmus; Carlson, Jonas

    2007-01-01

    Background The study was designed to investigate the effect of different measuring methodologies on the estimation of P wave duration. The recording length required to ensure reproducibility in unfiltered, signal-averaged P wave analysis was also investigated. An algorithm for automated classification was designed and its reproducibility of manual P wave morphology classification investigated. Methods Twelve-lead ECG recordings (1 kHz sampling frequency, 0.625 ?V resolution) from 131 healthy subjects were used. Orthogonal leads were derived using the inverse Dower transform. Magnification (100 times), baseline filtering (0.5 Hz high-pass and 50 Hz bandstop filters), signal averaging (10 seconds) and bandpass filtering (40–250 Hz) were used to investigate the effect of methodology on the estimated P wave duration. Unfiltered, signal averaged P wave analysis was performed to determine the required recording length (6 minutes to 10 s) and the reproducibility of the P wave morphology classification procedure. Manual classification was carried out by two experts on two separate occasions each. The performance of the automated classification algorithm was evaluated using the joint decision of the two experts (i.e., the consensus of the two experts). Results The estimate of the P wave duration increased in each step as a result of magnification, baseline filtering and averaging (100 ± 18 vs. 131 ± 12 ms; P < 0.0001). The estimate of the duration of the bandpass-filtered P wave was dependent on the noise cut-off value: 119 ± 15 ms (0.2 ?V), 138 ± 13 ms (0.1 ?V) and 143 ± 18 ms (0.05 ?V). (P = 0.01 for all comparisons). The mean errors associated with the P wave morphology parameters were comparable in all segments analysed regardless of recording length (95% limits of agreement within 0 ± 20% (mean ± SD)). The results of the 6-min analyses were comparable to those obtained at the other recording lengths (6 min to 10 s). The intra-rater classification reproducibility was 96%, while the interrater reproducibility was 94%. The automated classification algorithm agreed with the manual classification in 90% of the cases. Conclusion The methodology used has profound effects on the estimation of P wave duration, and the method used must therefore be validated before any inferences can be made about P wave duration. This has implications in the interpretation of multiple studies where P wave duration is assessed, and conclusions with respect to normal values are drawn. P wave morphology and duration assessed using unfiltered, signal-averaged P wave analysis have high reproducibility, which is unaffected by the length of the recording. In the present study, the performance of the proposed automated classification algorithm, providing total reproducibility, showed excellent agreement with manually defined P wave morphologies. PMID:17925022

  6. Validation study of the USDA’s data quality evaluation system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Nutrient Data Laboratory (NDL) of USDA conducted a validation study of the USDA Data Quality Evaluation System (DQES). The system evaluates the quality of analytical data by rating important documentation concerning the analytical method, analytical quality control, number of samples, sampling ...

  7. Lessons Learned Conducting User Studies in a Dialysis Ward

    E-print Network

    Connelly, Kay

    Lessons Learned Conducting User Studies in a Dialysis Ward Abstract In this paper, we describe lessons learned while conducting user studies in a dialysis ward. We learned that we must be more aware ward to develop DIMA and lessons learned along the way. We begin with a description of the user study

  8. 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.

  9. Method validation study of hypoglycin A determination in ackee fruit.

    PubMed

    Ware, George M

    2002-01-01

    A study was conducted to validate the performance characteristics of a published method entitled "Reversed-Phase Liquid Chromatographic Detection of Hypoglycin A in Canned Ackee Fruit Sample." Hypoglycin A (HG-A) was extracted from ackee fruit with 80% ethanol-water, centrifuged, and filtered; the sample extract then was reacted with phenylisothiocyanate. HG-A was separated by reversed-phase chromatography as the phenylthiocarbamyl derivative and detected at the low nanogram level using a UV detector at 254 nm. A study was conducted to determine recovery of HG-A added to a control ackee fruit sample. A control sample containing a low level of HG-A was spiked with 403.2, 201.6, 96.8, and 48.4 microg HG-A/g ackee fruit, respectively. Twelve replicates were analyzed for each spike level. The mean percent recovery +/- standard deviation for spike levels 403.2, 201.6, 96.8, and 48.4 microg HG-A/g were 94.37 +/- 1.27, 99.12 +/- 2.09, 107.95 +/- 5.42, and 129.18 +/- 15.32%, respectively. The percent coefficient of variation (%CV) for spike levels 403.2, 201.6, 96.8, and 48.4 microg HG-A/g were 1.35, 2.11, 5.02, and 11.86%, respectively. The recovery data indicate that HG-A can be recovered from ackee fruit with excellent accuracy and precision. Precision data obtained from replicate assays of ackee fruit naturally contaminated with low, medium, and high HG-A levels is presented. PMID:12180690

  10. Hyper-X Stage Separation Trajectory Validation Studies

    NASA Technical Reports Server (NTRS)

    Tartabini, Paul V.; Bose, David M.; McMinn, John D.; Martin, John G.; Strovers, Brian K.

    2003-01-01

    An independent twelve degree-of-freedom simulation of the X-43A separation trajectory was created with the Program to Optimize Simulated trajectories (POST II). This simulation modeled the multi-body dynamics of the X-43A and its booster and included the effect of two pyrotechnically actuated pistons used to push the vehicles apart as well as aerodynamic interaction forces and moments between the two vehicles. The simulation was developed to validate trajectory studies conducted with a 14 degree-of-freedom simulation created early in the program using the Automatic Dynamic Analysis of Mechanics Systems (ADAMS) simulation software. The POST simulation was less detailed than the official ADAMS-based simulation used by the Project, but was simpler, more concise and ran faster, while providing similar results. The increase in speed provided by the POST simulation provided the Project with an alternate analysis tool. This tool was ideal for performing separation control logic trade studies that required the running of numerous Monte Carlo trajectories.

  11. Conduct Prior to Study Abroad Conduct prior to study is not screened when applying for an ISU study abroad program if you are

    E-print Network

    Hu, Hui

    Conduct Conduct Prior to Study Abroad Conduct prior to study is not screened when applying for an ISU study abroad program if you are a currently enrolled student at ISU. If you have a conduct charge may need to provide documentation to a host institution or consulate. Conduct During Study Abroad

  12. High pressure electrical conductivity studies of acid doped polybenzimidazole

    Microsoft Academic Search

    J. J Fontanella; M. C Wintersgill; J. S Wainright; R. F Savinell; M Litt

    1998-01-01

    Electrical conductivity studies of acid doped poplybenzimidazole (PBI) and 85% phosphoric acid have been carried out. The PBI contained about 600mol% of 85% phosphoric acid and the electrical conductivity was deduced from complex impedance studies which were made at frequencies from 10 to 107Hz. Measurements were made at pressures up to 0.25 GPa and temperatures of about 25, 50 and

  13. FACES IV & the Circumplex Model: Validation Study

    Microsoft Academic Search

    David H. Olson

    2010-01-01

    FACES IV was developed to tap the full continuum of the cohesion and flexibility dimensions from the Circumplex Model of Marital and Family Systems. Six scales were developed, with two balanced scales and four unbalanced scales designed to tap low & high cohesion (disengaged and enmeshed) and flexibility (rigid and chaotic). This study provides initial evidence the six scales in

  14. Proximal nerve conduction studies in chronic inflammatory demyelinating polyneuropathy

    Microsoft Academic Search

    Yusuf A. Rajabally; Saiju Jacob

    2006-01-01

    ObjectiveThe purpose of this study was to evaluate the sensitivity and specificity of proximal upper limb motor nerve conduction study abnormalities in chronic inflammatory demyelinating polyneuropathy (CIDP), using standard percutaneous stimulations up to Erb’s point.

  15. Assessing Interpersonal Aspects of Schizoid Personality Disorder: Preliminary Validation Studies

    Microsoft Academic Search

    David S. Kosson; Ronald Blackburn; Katherine A. Byrnes; Sohee Park; Caroline Logan; John P. Donnelly

    2008-01-01

    In 2 studies, we examined the reliability and validity of an interpersonal measure of schizoid personality disorder (SZPD) based on nonverbal behaviors and interpersonal interactions occurring during interviews. A total of 556 male jail inmates in the United States participated in Study 1; 175 mentally disordered offenders in maximum security hospitals in the United Kingdom participated in Study 2. Across

  16. Validation of GC and HPLC systems for residue studies

    SciTech Connect

    Williams, M. [Horizon Labs., Inc., Columbia, MO (United States)

    1995-12-01

    For residue studies, GC and HPLC system performance must be validated prior to and during use. One excellent measure of system performance is the standard curve and associated chromatograms used to construct that curve. The standard curve is a model of system response to an analyte over a specific time period, and is prima facia evidence of system performance beginning at the auto sampler and proceeding through the injector, column, detector, electronics, data-capture device, and printer/plotter. This tool measures the performance of the entire chromatographic system; its power negates most of the benefits associated with costly and time-consuming validation of individual system components. Other measures of instrument and method validation will be discussed, including quality control charts and experimental designs for method validation.

  17. Experimental Study on Aero Conductivity of Porous Media

    Microsoft Academic Search

    Jiajun Chen; Guanguang Yang; Yunwu Liu; Bing Zheng; Jian Yang

    2006-01-01

    To study the variation pattern of aero conductivity of different porous media under low pressure conditions, three kinds of media are selected. These include sandy clay loam, fine sand, and medium sand, and air as fluid to conduct soil column ventilation tests. Pressure at both ends of the columns is measured under different ventilation flow rates during testing. The test

  18. A Combined Conductivity and XAS Study of Plastically Crystalline Electrolytes

    NASA Astrophysics Data System (ADS)

    Chadwick, A. V.; Berko, A.; Blacklocks, A. N.; Edwards, W.

    2010-11-01

    We report a study of the conductivity of LiBr and copper salt doped succinonitrile along with X-ray absorption measurements for the bromide and copper ions. The work shows that the ions are in well-ordered sites for most of the plastic phase and relatively high conductivity is due to a small fraction of the ions which are mobile.

  19. Experimental study on the instability of conductive droplets

    Microsoft Academic Search

    H. A. Elghazaly; G. S. P. Castle

    1990-01-01

    In previous studies, the authors introduced an analytical model to predict the final state for both single sibling and multi-sibling breakups. In order to verify the validity of this model, charged droplets of water were formed at the tip of capillary tube raised to high potential and subjected to external electric fields. The nozzle characteristics were tested to identify the

  20. California Diploma Project Technical Report III: Validity Study--Validity Study of the Health Sciences and Medical Technology Standards

    ERIC Educational Resources Information Center

    McGaughy, Charis; Bryck, Rick; de Gonzalez, Alicia

    2012-01-01

    This study is a validity study of the recently revised version of the Health Science Standards. The purpose of this study is to understand how the Health Science Standards relate to college and career readiness, as represented by survey ratings submitted by entry-level college instructors of health science courses and industry representatives. For…

  1. A Validation Study of the Adolescent Dissociative Experiences Scale

    ERIC Educational Resources Information Center

    Keck Seeley, Susan. M.; Perosa, Sandra, L.; Perosa, Linda, M.

    2004-01-01

    Objective: The purpose of this study was to further the validation process of the Adolescent Dissociative Experiences Scale (A-DES). In this study, a 6-item Likert response format with descriptors was used when responding to the A-DES rather than the 11-item response format used in the original A-DES. Method: The internal reliability and construct…

  2. Sources of Self-Efficacy in Mathematics: A Validation Study

    ERIC Educational Resources Information Center

    Usher, Ellen L.; Pajares, Frank

    2009-01-01

    The purpose of this study was to develop and validate items with which to assess A. Bandura's (1997) theorized sources of self-efficacy among middle school mathematics students. Results from Phase 1 (N=1111) were used to develop and refine items for subsequent use. In Phase 2 of the study (N=824), a 39-item, four-factor exploratory model fit best.…

  3. The Jackson Career Explorer: Two Further Validity Studies

    ERIC Educational Resources Information Center

    Schermer, Julie Aitken

    2012-01-01

    The present report consists of two further validity studies using the Jackson Career Explorer (JCE), a short form and continuous version of the Jackson Vocational Interest Survey, measuring 34 interests. The first study examined the relationships between the JCE and five personality factors, from a sample of 528 individuals. The correlations found…

  4. 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.

  5. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    NASA Astrophysics Data System (ADS)

    Nagendra, K.; Babu, G. Satish; Reddy, C. Narayana; Gowda, Veeranna

    2011-07-01

    Glasses in the system xLi2SO4-20Li2O-(80-x) [80P2O5-20V2O5] (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 Li2SO4 concentration. The ac conductivities have been fitted to the Almond-West type single power law equation ?(?) = ?(0)+A?s where `s' is the power law exponent. The ac conductivity found to increase with increase of Li2SO4 concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

  6. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...proposal to modify an ongoing study pursuant to paragraphs...appropriate to the facts of the case, a demonstration that: (1) Approved studies were not conducted as...appropriate to the facts of the case, a statement explaining...objectives of any approved study could not be met...

  7. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...proposal to modify an ongoing study pursuant to paragraphs...appropriate to the facts of the case, a demonstration that: (1) Approved studies were not conducted as...appropriate to the facts of the case, a statement explaining...objectives of any approved study could not be met...

  8. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...proposal to modify an ongoing study pursuant to paragraphs...appropriate to the facts of the case, a demonstration that: (1) Approved studies were not conducted as...appropriate to the facts of the case, a statement explaining...objectives of any approved study could not be met...

  9. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...proposal to modify an ongoing study pursuant to paragraphs...appropriate to the facts of the case, a demonstration that: (1) Approved studies were not conducted as...appropriate to the facts of the case, a statement explaining...objectives of any approved study could not be met...

  10. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    NASA Astrophysics Data System (ADS)

    Shukur, M. F.; Yusof, Y. M.; Zawawi, S. M. M.; Illias, H. A.; Kadir, M. F. Z.

    2013-11-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH4SCN). The sample containing 40 wt% NH4SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10-4 S cm-1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10-3 S cm-1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (Ea) was calculated for both systems and it is found that the sample with 40 wt% NH4SCN in the salted system obtained an Ea value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH4SCN salt. Changes in the C-O stretching vibration band intensity are observed at 1067 cm-1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems.

  11. 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.

  12. A Cross-Validation Study of the Posttraumatic Growth Inventory

    ERIC Educational Resources Information Center

    Sheikh, Alia I.; Marotta, Sylvia A.

    2005-01-01

    This article is a cross-validation of R. G. Tedeschi and L. G. Calhoun's (1996) original study of the development of the Posttraumatic Growth Inventory (PTGI). It describes several psychometric properties of scores on the PTGI in a sample of middle- to old-aged adults with a history of cardiovascular disease. The results did not support the…

  13. Homework Purpose Scale for Middle School Students: A Validation Study

    ERIC Educational Resources Information Center

    Xu, Jianzhong

    2011-01-01

    The purpose of the present study is to test the validity of scores on the Homework Purpose Scale (HPS) for middle school students. The participants were 1,181 eighth graders in the southeastern United States, including (a) 699 students in urban school districts and (b) 482 students in rural school districts. First, confirmatory factor analysis was…

  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. Understanding Foreign Language Learning Strategies: A Validation Study

    ERIC Educational Resources Information Center

    Tragant, Elsa; Thompson, Marilyn S.; Victori, Mia

    2013-01-01

    The present work aims to contribute to our understanding of the underlying dimensions of language learning strategies in foreign language contexts. The study analyzes alternative factor structures underlying a recently developed instrument (Tragant and Victori, 2012) and it includes the age factor in the examination of its construct validity. The…

  16. A quantitative approach to perceived health status: a validation study

    Microsoft Academic Search

    S M Hunt; S P McKenna; J McEwen; E M Backett; J Williams; E Papp

    1980-01-01

    The current recognition of the importance of perceived health status as a predictor of need for, and utilisation of, health services has led to attempts to produce indicators which assess subjective rather than objective health problems. The development of the Nottingham Health Profile is described, together with a study which tested the validity of the instrument on four groups of

  17. 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,

  18. 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…

  19. Reflective Thinking Scale: A Validity and Reliability Study

    ERIC Educational Resources Information Center

    Basol, Gulsah; Evin Gencel, Ilke

    2013-01-01

    The purpose of this study was to adapt Reflective Thinking Scale to Turkish and investigate its validity and reliability over a Turkish university students' sample. Reflective Thinking Scale (RTS) is a 5 point Likert scale (ranging from 1 corresponding Agree Completely, 3 to Neutral, and 5 to Not Agree Completely), purposed to measure…

  20. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    Microsoft Academic Search

    K. Nagendra; G. Satish Babu; C. Narayana Reddy; Veeranna Gowda

    2011-01-01

    Glasses in the system xLi2SO4–20Li2O–(80?x)[80P2O5–20V2O5] (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 Li2SO4 concentration. The ac conductivities have been fitted to the Almond-West type single power

  1. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    Microsoft Academic Search

    K. Nagendra; G. Satish Babu; C. Narayana Reddy; Veeranna Gowda

    2011-01-01

    Glasses in the system xLi2SO4-20Li2O-(80-x) [80P2O5-20V2O5] (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 Li2SO4 concentration. The ac conductivities have been fitted to the Almond-West type single

  2. 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

  3. Sexual behavioral abstine HIV/AIDS questionnaire: Validation study of an Iranian questionnaire

    PubMed Central

    Najarkolaei, Fatemeh Rahmati; Niknami, Shamsaddin; Shokravi, Farkhondeh Amin; Tavafian, Sedigheh Sadat; Fesharaki, Mohammad Gholami; Jafari, Mohammad Reza

    2014-01-01

    Background: This study was designed to assess the validity and reliability of the designed sexual, behavioral abstinence, and avoidance of high-risk situation questionnaire (SBAHAQ), with an aim to construct an appropriate development tool in the Iranian population. Materials and Methods: A descriptive–analytic study was conducted among female undergraduate students of Tehran University, who were selected through cluster random sampling. After reviewing the questionnaires and investigating face and content validity, internal consistency of the questionnaire was assessed by Cronbach's alpha. Explanatory and confirmatory factor analysis was conducted using SPSS and AMOS 16 Software, respectively. Results: The sample consisted of 348 female university students with a mean age of 20.69 ± 1.63 years. The content validity ratio (CVR) coefficient was 0.85 and the reliability of each section of the questionnaire was as follows: Perceived benefit (PB; 0.87), behavioral intention (BI; 0.77), and self-efficacy (SE; 0.85) (Cronbach's alpha totally was 0.83). Explanatory factor analysis showed three factors, including SE, PB, and BI, with the total variance of 61% and Kaiser–Meyer–Olkin (KMO) index of 88%. These factors were also confirmed by confirmatory factor analysis [adjusted goodness of fitness index (AGFI) = 0.939, root mean square error of approximation (RMSEA) = 0.039]. Conclusion: This study showed the designed questionnaire provided adequate construct validity and reliability, and could be adequately used to measure sexual abstinence and avoidance of high-risk situations among female students. PMID:24741650

  4. Electrical studies on silver based fast ion conducting glassy materials

    NASA Astrophysics Data System (ADS)

    Rao, B. Appa; Kumar, E. Ramesh; Kumari, K. Rajani; Bhikshamaiah, G.

    2014-04-01

    Among all the available fast ion conductors, silver based glasses exhibit high conductivity. Further, glasses containing silver iodide enhances fast ion conducting behavior at room temperature. Glasses of various compositions of silver based fast ion conductors in the AgI-Ag2O-[(1-x)B2O3-xTeO2] (x=0 to1 mol% in steps of 0.2) glassy system have been prepared by melt quenching method. The glassy nature of the compounds has been confirmed by X-ray diffraction. The electrical conductivity (AC) measurements have been carried out in the frequency range of 1 KHz-3MHz by Impedance Analyzer in the temperature range 303-423K. The DC conductivity measurements were also carried out in the temperature range 300-523K. From both AC and DC conductivity studies, it is found that the conductivity increases and activation energy decreases with increasing the concentration of TeO2 as well as with temperature. The conductivity of the present glass system is found to be of the order of 10-2 S/cm at room temperature. The ionic transport number of these glasses is found to be 0.999 indicating that these glasses can be used as electrolyte in batteries.

  5. Electrical studies on silver based fast ion conducting glassy materials

    SciTech Connect

    Rao, B. Appa, E-mail: apparao.bojja@gmail.com; Kumar, E. Ramesh, E-mail: apparao.bojja@gmail.com; Kumari, K. Rajani, E-mail: apparao.bojja@gmail.com; Bhikshamaiah, G., E-mail: apparao.bojja@gmail.com [Department of Physics, Osmania University, Hyderabad-500007 (India)

    2014-04-24

    Among all the available fast ion conductors, silver based glasses exhibit high conductivity. Further, glasses containing silver iodide enhances fast ion conducting behavior at room temperature. Glasses of various compositions of silver based fast ion conductors in the AgI?Ag{sub 2}O?[(1?x)B{sub 2}O{sub 3}?xTeO{sub 2}] (x=0 to1 mol% in steps of 0.2) glassy system have been prepared by melt quenching method. The glassy nature of the compounds has been confirmed by X-ray diffraction. The electrical conductivity (AC) measurements have been carried out in the frequency range of 1 KHz–3MHz by Impedance Analyzer in the temperature range 303–423K. The DC conductivity measurements were also carried out in the temperature range 300–523K. From both AC and DC conductivity studies, it is found that the conductivity increases and activation energy decreases with increasing the concentration of TeO{sub 2} as well as with temperature. The conductivity of the present glass system is found to be of the order of 10{sup ?2} S/cm at room temperature. The ionic transport number of these glasses is found to be 0.999 indicating that these glasses can be used as electrolyte in batteries.

  6. Conductance resonance studies of gold cluster-assembled nanofilms

    NASA Astrophysics Data System (ADS)

    Wang, Guang-hou

    1997-06-01

    STM/STS are used to study single electron tunneling effect of gold clusters deposited on H-terminated Si crystal substrate. We find that the gold clusters are randomly stacking up on the surface of the substrate and sharp conductance resonance peaks appear when the tip of STM is positioned right above the top of one of the Au clusters while they disappear when the tip approaches towards the boundaries between the clusters on the nanofilm. Furthermore, the conductance peaks are not equidistant with fine structures and negative differential resistances (NDR) are observed at bias voltage higher than 0.3 V. By the generalized Breit-Wigner formula in a tight-binding approximation we find that in the conductance resonance the multi-peak structure may come from the interaction between Au clusters of the cluster-assembled nanofilm and the different arrangement of Au clusters may cause difference of the conductance resonance.

  7. Spiritual Histories and Native Americans: A Mixed Method Validation Study

    Microsoft Academic Search

    David R. Hodge; Gordon E. Limb

    2009-01-01

    Although spirituality plays a central role in health and wellness for many Native Americans, surprisingly few spiritual assessment tools have been validated with this population. This mixed-method study modifies an existing spiritual assessment tool—spiritual histories—that may be particularly congruent with Native American culture. Using a sample of recognized experts in Native culture (N = 50), the study identifies: (a) the

  8. Experimental study on the instability of conductive droplets

    NASA Astrophysics Data System (ADS)

    Elghazaly, H. A.; Castle, G. S. P.

    1990-01-01

    In previous studies, the authors introduced an analytical model to predict the final state for both single sibling and multi-sibling breakups. In order to verify the validity of this model, charged droplets of water were formed at the tip of capillary tube raised to high potential and subjected to external electric fields. The nozzle characteristics were tested to identify the different ejection modes. Under some conditions of electric field at the nozzle tip, breakup of the ejected droplets resulted. These droplets were collected on water sensitive paper and then examined to estimate the droplets size. The results showed good agreement with the analytical predictions and also supported the validity of the concept of treelike secondary breakups introduced in the model.

  9. Design, development, testing and validation of a Photonics Virtual Laboratory for the study of LEDs

    NASA Astrophysics Data System (ADS)

    Naranjo, Francisco L.; Martínez, Guadalupe; Pérez, Ángel L.; Pardo, Pedro J.

    2014-07-01

    This work presents the design, development, testing and validation of a Photonic Virtual Laboratory, highlighting the study of LEDs. The study was conducted from a conceptual, experimental and didactic standpoint, using e-learning and m-learning platforms. Specifically, teaching tools that help ensure that our students perform significant learning have been developed. It has been brought together the scientific aspect, such as the study of LEDs, with techniques of generation and transfer of knowledge through the selection, hierarchization and structuring of information using concept maps. For the validation of the didactic materials developed, it has been used procedures with various assessment tools for the collection and processing of data, applied in the context of an experimental design. Additionally, it was performed a statistical analysis to determine the validity of the materials developed. The assessment has been designed to validate the contributions of the new materials developed over the traditional method of teaching, and to quantify the learning achieved by students, in order to draw conclusions that serve as a reference for its application in the teaching and learning processes, and comprehensively validate the work carried out.

  10. 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

  11. [Study of Beck's hopelessness scale. Validation and factor analysis].

    PubMed

    Bouvard, M; Charles, S; Guérin, J; Aimard, G; Cottraux, J

    1992-01-01

    The validation study and factorial analysis of the Beck's hopelessness scale is presented. Two groups were compared including patients suffering from depression (n = 100) and a control group (n = 93). Age and sex were comparable in the two groups. The hopelessness scale is valid, and differentiates depressive patients from control subjects. The scale has a good reliability (test-retest, r = .81) and a good internal consistency (alpha = .97) for depressive subjects and alpha = .79 for control subjects). It also shows a good concurrent validity with other scales assessing depressive cognitions, the automatic thoughts questionnaire, the dysfunctional attitudes scale (form A) and a scale assessing the suicidal risk (ERSD). No concurrent validity is found with scales assessing the intensity of depression, the Beck depression inventory and the Hamilton scale. The factorial analysis elicits a general factor, accounting for 38.15% of the variance, and reflecting negative feelings about the future. The study of all the factorial analysis shows the stability of the factorial structure. PMID:1299593

  12. GEOSTATIONARY SATELLITE BASED RAINFALL ESTIMATION AND VALIDATION: A CASE STUDY OF JAVA ISLAND, INDONESIA

    NASA Astrophysics Data System (ADS)

    Suseno, Dwi Prabowo Yuga; Yamada, Tomohito J.

    Near real time rainfall information is necessary for early warning of rainfall triggered hazard such as floods and landslides. Remote sensing based rainfall estimation has been considered to be used to fulfill that purpose. This research is addressed to use geostationary based rainfall estimation by using Multi Transport Satellite (MTSAT) data which is blended with Tropical Rainfall Measuring Mission (TRMM) 2A12 datasets in order to provide near real time rainfall information, especially for hazard study purposes over Java Island, Indonesia. Comparison to TRMM Multi Precipitation Analysis (TMPA) datasets is performed. Spatial and temporal validation of those rainfall estimations is conducted by validating them with available rain gauge data during a rainy season in December 2007. Temporal validation result shows that TMPA demonstrated better statistical performance than MTSAT blended. However for the spatial correlation, MTSAT blended shows relatively better performance than TMPA.

  13. Nerve conduction studies of lower extremities in pes planus subjects.

    PubMed

    Budak, F; Bamaç, B; Ozbek, A; Kutluay, P; Komsuo?lu, S

    2001-01-01

    Pes planus is a condition in which the medial longitudinal arch is depressed. Pedoscop, eyeball visualization, ink mat and roentgenography were used in clinical evaluation. We performed nerve conduction studies on both feet of 28 pes planus subjects. Our results demonstrated mild prolongation distal latency of the medial and lateral plantar sensory nerves, and delayed sensory conduction velocity of the medial plantar sensory nerve. The presence of electrodiagnostic abnormalities in this study population helps to substantiate the presence of compression neuropathy of the medial or lateral plantar nerve in pes planus subjects. PMID:11721301

  14. 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.

  15. Hermeneutic Inquiry in the Study of Human Conduct

    Microsoft Academic Search

    Martin J. Packer

    1985-01-01

    Interest is growing in the hermeneutic or interpretive approach to the study of human conduct. This article draws upon the work of Martin Heidegger to compare hermeneutics with the other major paradigms of inquiry and explanation in psychology: rationalism (cognitivism and structuralism) and empiricism (experimentalism and behaviorism). The comparison is threefold: in terms of their view of the form and

  16. 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

  17. Background: AOML is conducting climate studies with global

    E-print Network

    and forecast long-term climate changes. By collecting long-term, excellent-quality observations in the ocean- 1 - Background: AOML is conducting climate studies with global scope to better understand currents including the Gulf Stream, Deep Western Boundary Current, North Brazil Current, tropical

  18. Infants - Background & Validation Studies - NCS Dietary Assessment Literature Review

    Cancer.gov

    The dynamic growth and development experienced in infancy is the most rapid of any age. The progression in feeding skills (Exhibit 3.1) marks important developmental milestones that support rapid changes in food habits and nutrient intakes. The frequency of dietary assessment during infancy is an important methodological issue in longitudinal studies, as is the selection of a method validated for the developmental stage of the infant and for the specific research questions.

  19. 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

  20. How was the ECHOS-NHL study conducted?

    Cancer.gov

    This population-based SEER study was conducted in collaboration with researchers at the University of Southern California and the Los Angeles County Cancer Surveillance Program's SEER registry, which provided the sampling frame. Data were collected through a cross-sectional survey mailed to eligible survivors of aggressive NHL who were diagnosed 2-5 years before the study (diagnosis dates ranged from June 1, 1998 to August 31, 2001).

  1. Pooled results from 5 validation studies of dietary self-report instruments using recovery biomarkers for energy and protein intake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 U.S. adult populations from...

  2. Validation studies of the DOE-2 Building Energy Simulation Program. Final Report

    SciTech Connect

    Sullivan, R.; Winkelmann, F.

    1998-06-01

    This report documents many of the validation studies (Table 1) of the DOE-2 building energy analysis simulation program that have taken place since 1981. Results for several versions of the program are presented with the most recent study conducted in 1996 on version DOE-2.1E and the most distant study conducted in 1981 on version DOE-1.3. This work is part of an effort related to continued development of DOE-2, particularly in its use as a simulation engine for new specialized versions of the program such as the recently released RESFEN 3.1. RESFEN 3.1 is a program specifically dealing with analyzing the energy performance of windows in residential buildings. The intent in providing the results of these validation studies is to give potential users of the program a high degree of confidence in the calculated results. Validation studies in which calculated simulation data is compared to measured data have been conducted throughout the development of the DOE-2 program. Discrepancies discovered during the course of such work has resulted in improvements in the simulation algorithms. Table 2 provides a listing of additions and modifications that have been made to various versions of the program since version DOE-2.1A. One of the most significant recent changes in the program occurred with version DOE-2.1E. An improved algorithm for calculating the outside surface film coefficient was implemented. In addition, integration of the WINDOW 4 program was accomplished resulting in improved ability in analyzing window energy performance. Validation and verification of a program as sophisticated as DOE-2 must necessarily be limited because of the approximations inherent in the program. For example, the most accurate model of the heat transfer processes in a building would include a three-dimensional analysis. To justify such detailed algorithmic procedures would correspondingly require detailed information describing the building and/or HVAC system and energy plant parameters. Until building simulation programs can get this data directly from CAD programs, such detail would negate the usefulness of the program for the practicing engineers and architects who currently use the program. In addition, the validation studies discussed herein indicate that such detail is really unnecessary. The comparison of calculated and measured quantities have resulted in a satisfactory level of confidence that is sufficient for continued use of the DOE-2 program. However, additional validation is warranted, particularly at the component level, to further improve the program.

  3. Dielectric, conduction and breakdown studies on europium fluoride thin films

    NASA Astrophysics Data System (ADS)

    Meena, P.; Balasubramanian, C.; Narayandass, Sa. K.; Mangalaraj, D.

    1994-11-01

    Thin film capacitors of AlEuF3-Al were formed onto well-cleaned glass slides by vacuum evaporation under a pressure of 2.66 times 10(exp -3) Pa. The structure of the europium fluoride film was found to be amorphous. From aging studies of the capacitor, it was found that the capacitance becomes almost constant after about 60 days. Two cycles of annealing at 353 K were required to stabilize the film. A large increase in capacitance was observed in the low frequency region, indicating the possibility of interfacial polarization. The frequency dependence of tan delta at various temperatures shows a loss minimum which shifts to higher frequencies with increasing temperature. The activation energy was calculated. The frequency dependence of conductivity and the low value of the activation energy suggest that the conduction mechanism is due to electronic hopping. D.C. conduction studies reveal a space charge conduction mechanism in europium fluoride films. The dependence of breakdown field on thickness and the temperatures show that this film obeys the Forlani-Minnaja theory.

  4. Nerve conduction studies of upper extremities in tennis players

    PubMed Central

    Colak, T; Bamac, B; Ozbek, A; Budak, F; Bamac, Y

    2004-01-01

    Objectives: The influence of regular and intense practice of an asymmetric sport such as tennis on nerves in the elbow region was examined. Methods: The study included 21 male elite tennis players with a mean (SD) age of 27.5 (1.7) years and 21 male non-active controls aged 26.4 (1.9) years. Anthropometric measurements (height, weight, limb length, and perimeters of arm and forearm) were determined for each subject, and range of motion assessment and radiographic examination carried out. Standard nerve conduction techniques using constant measured distances were applied to evaluate the median, ulnar, and radial nerves in the dominant and non-dominant limb of each individual. Results: The sensory and motor conduction velocities of the radial nerve and the sensory conduction velocity of the ulnar nerve were significantly delayed in the dominant arms of tennis players compared with their non-dominant arms and normal subjects. There were no statistical differences in the latencies, conduction velocities, or amplitudes of the median motor and sensory nerves between controls and tennis players in either the dominant or non-dominant arms. However, the range of motion of the upper extremity was significantly increased in tennis players when compared with control subjects. Tennis players were taller and heavier than control subjects and their dominant upper limb lengths were longer, and arm and forearm circumferences greater, than those of the control subjects. Conclusions: Many of the asymptomatic tennis players with abnormal nerve conduction tests in the present study may have presymptomatic or asymptomatic neuropathy similar to subclinical entrapment nerve neuropathy. PMID:15388554

  5. The Bronchiectasis Severity Index. An International Derivation and Validation Study

    PubMed Central

    Goeminne, Pieter; Aliberti, Stefano; McDonnell, Melissa J.; Lonni, Sara; Davidson, John; Poppelwell, Lucy; Salih, Waleed; Pesci, Alberto; Dupont, Lieven J.; Fardon, Thomas C.; De Soyza, Anthony; Hill, Adam T.

    2014-01-01

    Rationale: There are no risk stratification tools for morbidity and mortality in bronchiectasis. Identifying patients at risk of exacerbations, hospital admissions, and mortality is vital for future research. Objectives: This study describes the derivation and validation of the Bronchiectasis Severity Index (BSI). Methods: Derivation of the BSI used data from a prospective cohort study (Edinburgh, UK, 2008–2012) enrolling 608 patients. Cox proportional hazard regression was used to identify independent predictors of mortality and hospitalization over 4-year follow-up. The score was validated in independent cohorts from Dundee, UK (n = 218); Leuven, Belgium (n = 253); Monza, Italy (n = 105); and Newcastle, UK (n = 126). Measurements and Main Results: Independent predictors of future hospitalization were prior hospital admissions, Medical Research Council dyspnea score greater than or equal to 4, FEV1 < 30% predicted, Pseudomonas aeruginosa colonization, colonization with other pathogenic organisms, and three or more lobes involved on high-resolution computed tomography. Independent predictors of mortality were older age, low FEV1, lower body mass index, prior hospitalization, and three or more exacerbations in the year before the study. The derived BSI predicted mortality and hospitalization: area under the receiver operator characteristic curve (AUC) 0.80 (95% confidence interval, 0.74–0.86) for mortality and AUC 0.88 (95% confidence interval, 0.84–0.91) for hospitalization, respectively. There was a clear difference in exacerbation frequency and quality of life using the St. George’s Respiratory Questionnaire between patients classified as low, intermediate, and high risk by the score (P < 0.0001 for all comparisons). In the validation cohorts, the AUC for mortality ranged from 0.81 to 0.84 and for hospitalization from 0.80 to 0.88. Conclusions: The BSI is a useful clinical predictive tool that identifies patients at risk of future mortality, hospitalization, and exacerbations across healthcare systems. PMID:24328736

  6. Case study for model validation : assessing a model for thermal decomposition of polyurethane foam.

    SciTech Connect

    Dowding, Kevin J.; Leslie, Ian H. (New Mexico State University, Las Cruces, NM); Hobbs, Michael L.; Rutherford, Brian Milne; Hills, Richard Guy (New Mexico State University, Las Cruces, NM); Pilch, Martin M.

    2004-10-01

    A case study is reported to document the details of a validation process to assess the accuracy of a mathematical model to represent experiments involving thermal decomposition of polyurethane foam. The focus of the report is to work through a validation process. The process addresses the following activities. The intended application of mathematical model is discussed to better understand the pertinent parameter space. The parameter space of the validation experiments is mapped to the application parameter space. The mathematical models, computer code to solve the models and its (code) verification are presented. Experimental data from two activities are used to validate mathematical models. The first experiment assesses the chemistry model alone and the second experiment assesses the model of coupled chemistry, conduction, and enclosure radiation. The model results of both experimental activities are summarized and uncertainty of the model to represent each experimental activity is estimated. The comparison between the experiment data and model results is quantified with various metrics. After addressing these activities, an assessment of the process for the case study is given. Weaknesses in the process are discussed and lessons learned are summarized.

  7. 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.

  8. Optical study on conducting polymer-based field effect devices

    NASA Astrophysics Data System (ADS)

    Kim, Youngmin; Hsu, Fang-Chi; Chiou, Nan-Rong; Park, June Hyoung; Waldmann, Oliver; Prigodin, Vladimir; Epstein, Arthur J.

    2003-03-01

    ¡°Optical study on conducting polymer-based field effect devices ¡° Y.M. Kim, F.C. Hsu, N.R. Chiou, J.H. Park, O. Waldmann, V.N. Prigodin, A. J. Epstein, The Ohio State University Time variation of source-drain current with gate modulation of conducting polymer-based field effect devices was studied by in-situ mid-infrared(MIR) reflectance measurements. The transistor-like field effect devices were fabricated using aluminum gate which also works as an optically reflective layer, several different insulating polymers, and poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonic acid)(PEDOT/PSS) active layer. The MIR reflectance measurement of the response to application of a gate voltage shows reflectivity change proportional to the source-drain current variation, shift in interference pattern, and no significant change in phonon features. For the specular reflectance measurement, about 1cm x 1cm area, and 0.1 1 micron thick active layer was prepared, and the insulating layer thickness was also 0.1 1 micron. Because of the small thickness compared to the penetration depth of the PEDOT/PSS, there are the transmission dominant region and the reflectance dominant region, and the reflectivity was increased in the transmission dominant and decreased and in the reflectance dominant region. The results are compared with models for the field effect control of conductance of doped polymers. Supported by ONR Grant No. N00014-01-1-0427.

  9. Validation study of the Chinese Early Development Instrument (CEDI)

    PubMed Central

    2013-01-01

    Background The Early Development Instrument (EDI) is a comprehensive instrument used to assess school readiness in preschool children. This study was carried out to evaluate the psychometric properties of the Chinese version of the EDI (CEDI) in Hong Kong. Methods One hundred and sixty-seven children were purposefully sampled from kindergartens in two districts with very different socioeconomic statuses. The CEDI was assessed for concurrent validity, internal consistency and test-retest reliability. The developmental vulnerability identified using the CEDI scores was further examined in relation to the socioeconomic status of the district and family. Results The CEDI displayed adequate internal consistency, with Cronbach’s alphas ranging from 0.70 to 0.95 on its five domains. Concurrent validity was supported by moderate and significant correlations (0.25 to 0.49) on the relevant domains between the CEDI and a comparable measure. The level of test-retest reliability was good, with a kappa statistic of 0.89. In general, girls outperformed boys, particularly in the social, emotional and communication/general knowledge domains. After controlling for the uneven distribution of sex, children from socioeconomically disadvantaged districts and families were found to be at greater risk of developmental vulnerability than their more advantaged counterparts. Conclusion The evidence gathered in this study supports the CEDI’s use as a valid and reliable instrument in assessing school readiness and identifying developmentally vulnerable children in Chinese populations. Its preliminary findings on the socioeconomic gradients of child development suggest that the CEDI is a promising tool for leveraging evidence-based, context-sensitive policies and practices to foster the development of all children. PMID:24053538

  10. The development of a quantitative electroencephalographic scanning process for attention deficit-hyperactivity disorder: Reliability and validity studies

    Microsoft Academic Search

    Vincent J. Monastra; Joel F. Lubar; Michael Linden

    2001-01-01

    The development of a quantitative electroencephalographic (QEEG)-based procedure for use in the assessment of attention deficit-hyperactivity disorder (ADHD) was examined through a series of studies investigating test reliability and validation issues. This process, involving a spectral analysis of the electrophysiological power output from a single, midline, central location (the vertex), was conducted in 469 participants, 6 to 20 years of

  11. 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

  12. 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...

  13. Manual palpation of lumbo-pelvic landmarks: a validity study.

    PubMed

    Kilby, Julia; Heneghan, Nicola R; Maybury, Mark

    2012-06-01

    Manual palpation (MP) is commonly used for the assessment of patients with neuromusculoskeletal dysfunction. During assessment of lumbo-pelvic disorders in particular, it may be used not only to explore pain and resistance in the region, but also to evaluate the symmetry and movement quality of the area. Whilst reliability of MP has been extensively investigated, its validity remains relatively under researched. The aim of this study was to explore the accuracy of MP of lumbo-pelvic bony points. Ultrasound images of three bony landmarks [4th lumbar spinous process (L4), left and right posterior superior iliac spines (PSIS)] were acquired from models (n = 3) in the prone position and the points marked with an ultra-violet (UV) pen. Nine musculoskeletal physiotherapists were asked to identify the bony landmarks using MP. Measurements (mms) were taken between the UV marks and the palpators' marks. The mean error (standard deviation) (mm) for MP of L4, LPSIS, RPSIS were 15.63 (3.89), 20.07 (4.60), 20.59 (2.79) respectively. Bland and Altman analysis gave a mean value of 0.173, with 95% limits of agreement ranging from -27.8 to 26.3. This study suggests that MP of specific lumbo-pelvic bony points has limited validity. PMID:21945296

  14. Japanese version of the MD Anderson Symptom Inventory: a validation study.

    PubMed

    Okuyama, Toru; Wang, Xin Shelley; Akechi, Tatsuo; Mendoza, Tito R; Hosaka, Takashi; Cleeland, Charles S; Uchitomi, Yosuke

    2003-12-01

    Cancer patients frequently suffer from a myriad of symptoms. The development and application of comprehensive assessment tools is essential to the effective management of these symptoms. The M.D. Anderson Symptom Inventory (MDASI), developed in English, is a brief, self-rating multiple symptom assessment scale that consists of 13 symptom items and 6 interference items. We examined the validity and reliability of the Japanese version of this scale (MDASI-J) by evaluating 252 randomly selected cancer patients. They were asked to self-administer the MDASI-J and the European Organization for Research and Treatment of Cancer QLQ-C 30. Construct, criterion, convergent and discriminant validity, and reliability of the MDASI-J were evaluated and compared with corresponding data obtained in the previous study conducted in the United States. The results indicated that the MDASI-J is a valid and practical measure for assessing multiple symptoms in Japanese cancer patients. Both factor analysis and cluster analysis showed the consistency of the statistical structure of the English and Japanese versions, indicating the cross-cultural validity of the scale. PMID:14654261

  15. Pilot In-Trail Procedure Validation Simulation Study

    NASA Technical Reports Server (NTRS)

    Bussink, Frank J. L.; Murdoch, Jennifer L.; Chamberlain, James P.; Chartrand, Ryan; Jones, Kenneth M.

    2008-01-01

    A Human-In-The-Loop experiment was conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) to investigate the viability of the In-Trail Procedure (ITP) concept from a flight crew perspective, by placing participating airline pilots in a simulated oceanic flight environment. The test subject pilots used new onboard avionics equipment that provided improved information about nearby traffic and enabled them, when specific criteria were met, to request an ITP flight level change referencing one or two nearby aircraft that might otherwise block the flight level change. The subject pilots subjective assessments of ITP validity and acceptability were measured via questionnaires and discussions, and their objective performance in appropriately selecting, requesting, and performing ITP flight level changes was evaluated for each simulated flight scenario. Objective performance and subjective workload assessment data from the experiment s test conditions were analyzed for statistical and operational significance and are reported in the paper. Based on these results, suggestions are made to further improve the ITP.

  16. The Fast Scattering Code (FSC): Validation Studies and Program Guidelines

    NASA Technical Reports Server (NTRS)

    Tinetti, Ana F.; Dunn, Mark H.

    2011-01-01

    The Fast Scattering Code (FSC) is a frequency domain noise prediction program developed at the NASA Langley Research Center (LaRC) to simulate the acoustic field produced by the interaction of known, time harmonic incident sound with bodies of arbitrary shape and surface impedance immersed in a potential flow. The code uses the equivalent source method (ESM) to solve an exterior 3-D Helmholtz boundary value problem (BVP) by expanding the scattered acoustic pressure field into a series of point sources distributed on a fictitious surface placed inside the actual scatterer. This work provides additional code validation studies and illustrates the range of code parameters that produce accurate results with minimal computational costs. Systematic noise prediction studies are presented in which monopole generated incident sound is scattered by simple geometric shapes - spheres (acoustically hard and soft surfaces), oblate spheroids, flat disk, and flat plates with various edge topologies. Comparisons between FSC simulations and analytical results and experimental data are presented.

  17. The Cancer Message Literacy Tests: Psychometric Analyses and Validity Studies

    PubMed Central

    Mazor, Kathleen M.; Rogers, H. Jane; Williams, Andrew E.; Roblin, Douglas W.; Gaglio, Bridget; Field, Terry S.; Greene, Sarah M.; Han, Paul K. J.; Costanza, Mary E.

    2012-01-01

    Objectives To examine the psychometric properties of two new health literacy tests, and to evaluate score validity. Methods Adults aged 40 to 71 completed the Cancer Message Literacy Test-Listening (CMLT- Listening), the Cancer Message Literacy Test-Reading (CMLT-Reading), the REALM, the Lipkus numeracy test, a brief knowledge test (developed for this study) and five brief cognitive tests. Participants also self-reported educational achievement, current health, reading ability, ability to understand spoken information, and language spoken at home. Results Score reliabilities were good (CMLT-Listening: alpha = .84) to adequate (CMLT-Reading: alpha =.75). Scores on both CMLT tests were positively and significantly correlated with scores on the REALM, numeracy, cancer knowledge and the cognitive tests. Mean CMLT scores varied as predicted according to educational level, language spoken at home, self-rated health, self-reported reading, and self-rated ability to comprehend spoken information. Conclusions The psychometric findings for both tests are promising. Scores appear to be valid indicators of comprehension of spoken and written health messages about cancer prevention and screening. Practice Implications The CMLT-Listening will facilitate research into comprehension of spoken health messages, and together with the CMLT-Reading will allow researchers to examine the unique contributions of listening and reading comprehension to health-related decisions and behaviors. PMID:22789147

  18. Theoretical study of conductance, capacitance and transport properties of nanostructures

    NASA Astrophysics Data System (ADS)

    Pomorski, Pawel

    2003-10-01

    In the past two decades, significant progress in constructing physical systems of reduced dimensionality has been made. In these systems, quantum effects are observed in the electric current response to an applied bias voltage. Considerable theoretical effort has been made to understand conductance and capacitance which characterize this response. In addition to a fundamental science interest, there has been a significant technological need to build and understand small scale devices in order to maintain the current rate of progress in increasing computer performance. In this thesis, we theoretically investigated the conductance and capacitance of mesoscopic and molecular scale systems. Our approach incorporated Landauer-Buttiker transport theory. We developed a highly efficient method, based on the solution of the time-dependent Schrodinger equation incorporating a magnetic field, to solve the quantum scattering problem in mesoscopic nanostructures. We studied linear response capacitance in a two plate mesoscopic capacitor with one plate a quantum conductor in the ballistic scattering regime. By determining the scattering wavefunctions in the quantum plate, we were able to obtain relevant densities of states and use them to self-consistently calculate capacitance matrix coefficients for the system. We find the capacitance to be highly dependent on the external magnetic field and the number of probes attached to the quantum conductor. To study molecular scale systems, our approach was based on Density Functional Theory within Local Density Approximation and non-equilibrium Green's functions, implemented in the simulation package McDcal. For the work in this thesis, we modified McDcal to run on parallel computer architectures. We studied the current-voltage characteristics of silicon cage nanowires sandwiched between aluminum electrodes. We successfully analyzed our results using the complex band structure of the nanowire. Finally, we studied the capacitance properties of carbon nanotube junctions. In junctions with tubes so far apart that their wavefunctions do not overlap, we studied the variation in capacitance for different relative tube positions and radii. We also studied junctions where the nanotubes are in contact but in which there is no current due to a conductance gap. In this system we find an enhancement in the value of capacitance.

  19. Ulnar nerve at the elbow – normative nerve conduction study

    PubMed Central

    2013-01-01

    Introduction A goal of our work was to perform nerve conduction studies (NCSs) of the ulnar nerve focused on the nerve conduction across the elbow on a sufficiently large cohort of healthy subjects in order to generate reliable reference data. Methods We examined the ulnar nerve in a position with the elbow flexion of 90o from horizontal. Motor response was recorded from the abductor digiti minimi muscle (ADM) and the first dorsal interosseous muscle (FDI). Results In our sample of 227 healthy volunteers we have examined 380 upper arms with the following results: amplitude (Amp)-CMAP(wrist) for ADM 9.6 ± 2.3 mV, MNCV at the forearm 60.4 ± 5.2 m/s, MNCV across the elbow 57.1 ± 5.9 m/s. Discussion Our study showed that motor NCSs of the ulnar nerve above elbow (AE) and below elbow (BE) in a sufficiently large cohort using methodology recommended by AANEM gave results well comparable for registration from FDI and ADM. PMID:23398737

  20. Carpal tunnel syndrome with normal nerve conduction studies.

    PubMed

    Witt, John C; Hentz, Joseph G; Stevens, J Clarke

    2004-04-01

    The utility of electrodiagnostic testing in the evaluation of carpal tunnel syndrome (CTS) has been questioned. We studied patients who met the clinical criteria for CTS and compared patients who had normal nerve conduction studies (NCS) with patients who had abnormal NCS. We found that 25% of the CTS patients without confounding neurologic disorders had normal NCS with median palmar nerve stimulation. Patients with abnormal NCS were older and heavier and had more clinical features of CTS. NCS results could not be predicted accurately from clinical features by use of logistic regression models. This was especially true in clinically borderline cases. NCS did not predict the outcome of conservative management. We concluded that NCS provide independent information in the evaluation of suspected CTS, especially when fewer clinical criteria are present, but that NCS are not helpful in predicting the outcome of nonsurgical management. PMID:15052616

  1. New York State TrueAllele® Casework Validation Study*

    PubMed Central

    Perlin, Mark W; Belrose, Jamie L; Duceman, Barry W

    2013-01-01

    DNA evidence can pose interpretation challenges, particularly with low-level or mixed samples. It would be desirable to make full use of the quantitative data, consider every genotype possibility, and objectively produce accurate and reproducible DNA match results. Probabilistic genotype computing is designed to achieve these goals. This validation study assessed TrueAllele® probabilistic computer interpretation on 368 evidence items in 41 test cases and compared the results with human review of the same data. Whenever there was a human result, the computer's genotype was concordant. Further, the computer produced a match statistic on 81 mixture items (for 87 inferred matching genotypes) in the test cases, while human review reported a statistic on 25 of these items (30.9%). Using match statistics to quantify information, probabilistic genotyping was shown to be sensitive, specific, and reproducible. These results demonstrate that objective probabilistic genotyping of biological evidence can reliably preserve DNA identification information. PMID:23865896

  2. Thermal conductivity at the nanoscale: A molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Lyver, John W., IV

    With the growing use of nanotechnology and nanodevices in many fields of engineering and science, a need for understanding the thermal properties of such devices has increased. The ability for nanomaterials to conduct heat is highly dependent on the purity of the material, internal boundaries due to material changes and the structure of the material itself. Experimentally measuring the heat transport at the nanoscale is extremely difficult and can only be done as a macro output from the device. Computational methods such as various Monte Carlo (MC) and molecular dynamics (MD) techniques for studying the contribution of atomic vibrations associated with heat transport properties are very useful. The Green--Kubo method in conjunction with Fourier's law for calculating the thermal conductivity, kappa, has been used in this study and has shown promise as one approach well adapted for understanding nanosystems. Investigations were made of the thermal conductivity using noble gases, modeled with Lennard-Jones (LJ) interactions, in solid face-centered cubic (FCC) structures. MC and MD simulations were done to study homogeneous monatomic and binary materials as well as slabs of these materials possessing internal boundaries. Additionally, MD simulations were done on silicon carbide nanowires, nanotubes, and nanofilaments using a potential containing two-body and three-body terms. The results of the MC and MD simulations were matched against available experimental and other simulations and showed that both methods can accurately simulate real materials in a fraction of the time and effort. The results of the study show that in compositionally disordered materials the selection of atomic components by their mass, hard-core atomic diameter, well depth, and relative concentration can change the kappa by as much as an order of magnitude. It was found that a 60% increase in mass produces a 25% decrease in kappa. A 50% increase in interatomic strength produces a 25% increase in kappa, while as little as a 10% change in the hard core radius can almost totally suppress a materials ability to conduct heat. Additionally, for two LJ materials sharing an interface, the atomic vibrations altering the heat energy depend on the type of internal boundary in the material. Mass increases across the interfacial boundary enhance excitation of the very low frequency (ballistic) vibrational modes, while the opposite effect is seen as increases in hard core radius and interatomic strength enhance excitation of higher frequency vibrational modes. Additionally, it was found that this effect was diminished for higher temperatures around half the Debye temperatures. In nanodevices and nanomachines, there is an additional factor that degrades heat transport at the boundary. In fact, the interface induces a temperature jump consistent with a thermal resistance created by the boundary. It was found that the temperature jump, which is due to a boundary resistance, was significant in boundaries involving small mass changes, lesser in changes in hard core radii changes and even lesser for interatomic strength changes. The study of SiC nanowires and nanotubes showed that the structural changes produced vastly different kappa. The kappa in closely packed structures like nanowires and nanofilaments approximated that of the bulk SiC, yet were less sensitive to temperature than the 1/T relationship traditionally found in bulk systems. The more open nanostructures, like nanotubes, had vastly lower kappa values and are almost totally insensitive to temperature variation. The results of this study can be used in the design of nano-machines where heat generation and transport is a concern. Additionally, the design of nano-machines which transport heat like nano-refrigerators or nano-heaters may be possible due to a better selection of materials with the understanding of how the materials affect their nanothermal properties at the nano scale.

  3. A procedure for the measurement of infant skin conductance and its initial validation using clap induced startle

    PubMed Central

    Ham, Jacob; Tronick, Ed

    2008-01-01

    Studies examining psychophysiologic markers of infant emotional development abound. However, few studies have used skin conductance (SC), though it measures sympathetic activity, and none have measured SC on infants sitting up and actively engaged with another person, a significant challenge given the measures sensitivity to movement artifact. In this pilot/feasibility study, we present a procedure for measuring infant SC during active engagement with another person who executes a series of startling claps to elicit an SC response. We measured SC on the plantar surface of the foot of 17 five-month old infants. We found unconditioned SC responses that were related to the intensity of physical startle reactions for each clap trial. We also found anticipatory, conditioned SC responses that occurred within 5s before each clap that occurred when the researcher raised his clasped hands. These conditioned SC responses grew linearly in intensity over trials. We conclude that SC may be a useful addition to the infant researcher’s armamentarium and may indeed be used to measure physiologic reactivity in infants even when actively engaged with another person. Addition of SC measurement to research on infant emotion and emotional communication is likely to advance our understanding of the psychophysiologic foundations of infant emotional development. PMID:18683186

  4. 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

  5. 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

  6. External Validity of Studies on Aggressive Behavior in Patients with Schizophrenia: Systematic Review

    PubMed Central

    Steinert, Tilman; Hamann, Karen

    2012-01-01

    Studies on violence in schizophrenia use two different approaches: use of epidemiological data, and clinical studies recording direct patient data after gaining informed consent. With regard to informed consent requiring agreement and cooperation, the question arises as to what extent participants represent patients with schizophrenia and violent behaviour (external validity). We conducted a systematic literature research. In most of the studies, aggression or violence, respectively, were poorly defined. Only 5 (15.2%) studies used a cut-off score on an aggression scale. Only 6 studies (18.2%) reported the number of patients who refused to participate, and 16 (48.5%) reported the number of drop-outs. Only 3 studies (9.1%) reported a systematic comparison of participants and non-participants. We found that data which allow for the assessment of representativeness of the investigated samples are poorly reported. For most studies, doubts regarding external validity seem justified and generalisability is questionable due to possible selection bias. PMID:22934120

  7. 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

  8. 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.

  9. A Protocol for Conducting Rainfall Simulation to Study Soil Runoff

    PubMed Central

    Kibet, Leonard C.; Saporito, Louis S.; Allen, Arthur L.; May, Eric B.; Kleinman, Peter J. A.; Hashem, Fawzy M.; Bryant, Ray B.

    2014-01-01

    Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff. PMID:24748061

  10. A protocol for conducting rainfall simulation to study soil runoff.

    PubMed

    Kibet, Leonard C; Saporito, Louis S; Allen, Arthur L; May, Eric B; Kleinman, Peter J A; Hashem, Fawzy M; Bryant, Ray B

    2014-01-01

    Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff. PMID:24748061

  11. Photoluminescence and conductivity studies of anthracene-functionalized ruthenium nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Pradhan, Sulolit; Chen, Shaowei

    2011-05-01

    Carbene-stabilized ruthenium nanoparticles were functionalized with anthryl moieties by olefin metathesis reactions with 9-vinylanthracene, at a surface concentration of about 19.7%, as estimated by 1H NMR spectroscopic measurements. Because of the conjugated metal-ligand interfacial bonding interactions, UV-vis measurements of the resulting nanoparticles showed a new broad absorption band centered at 612 nm, in addition to the peaks observed with monomeric vinylanthracene. FTIR measurements depicted apparent red-shifts of the aromatic vibrational stretches as compared to those of the monomeric vinylanthracene, suggestive of decreasing bonding order of the aromatic moieties as a result of extended conjugation between the particle-bound anthracene groups. Photoluminescence measurements confirmed the notion that effective intraparticle charge delocalization occurred by virtue of the conjugated metal-ligand interfacial bonding interactions, with apparent red-shifts of the excitation peaks and blue-shifts of the emission features, as compared to those of the monomeric vinylanthracene. The diminishment of the Stokes shift was, at least in part, attributed to the different chemical environments surrounding the anthryl moieties on the nanoparticle surface. Electronic conductivity measurements showed that because of the conjugated Ru z.dbd C ? bonds, the activation energy for interparticle charge transport was about one order of magnitude lower than that observed with particles passivated by alkanethiolates. Additionally, whereas the original carbene-stabilized nanoparticles exhibited a semiconductor-metal transition within the temperature range of 100 to 320 K, anthracene-functionalized nanoparticles displayed apparent semiconducting behaviors with the ensemble conductivity increasing monotonically with temperature, most likely due to the disordering within the nanoparticle solids that arose from the different structures of the carbene ligands and anthryl moieties. These studies indicate that anthracene functionalization may be exploited as an effective route towards the manipulation of nanoparticle optoelectronic properties.Carbene-stabilized ruthenium nanoparticles were functionalized with anthryl moieties by olefin metathesis reactions with 9-vinylanthracene, at a surface concentration of about 19.7%, as estimated by 1H NMR spectroscopic measurements. Because of the conjugated metal-ligand interfacial bonding interactions, UV-vis measurements of the resulting nanoparticles showed a new broad absorption band centered at 612 nm, in addition to the peaks observed with monomeric vinylanthracene. FTIR measurements depicted apparent red-shifts of the aromatic vibrational stretches as compared to those of the monomeric vinylanthracene, suggestive of decreasing bonding order of the aromatic moieties as a result of extended conjugation between the particle-bound anthracene groups. Photoluminescence measurements confirmed the notion that effective intraparticle charge delocalization occurred by virtue of the conjugated metal-ligand interfacial bonding interactions, with apparent red-shifts of the excitation peaks and blue-shifts of the emission features, as compared to those of the monomeric vinylanthracene. The diminishment of the Stokes shift was, at least in part, attributed to the different chemical environments surrounding the anthryl moieties on the nanoparticle surface. Electronic conductivity measurements showed that because of the conjugated Ru z.dbd C ? bonds, the activation energy for interparticle charge transport was about one order of magnitude lower than that observed with particles passivated by alkanethiolates. Additionally, whereas the original carbene-stabilized nanoparticles exhibited a semiconductor-metal transition within the temperature range of 100 to 320 K, anthracene-functionalized nanoparticles displayed apparent semiconducting behaviors with the ensemble conductivity increasing monotonically with temperature, most likely due to the disordering within the nanoparticle solids that arose from the different s

  12. A Validation Study of the Dutch Childhood Trauma Questionnaire-Short Form: Factor Structure, Reliability, and Known-Groups Validity

    ERIC Educational Resources Information Center

    Thombs, Brett D.; Bernstein, David P.; Lobbestael, Jill; Arntz, Arnoud

    2009-01-01

    Objective: The 28-item Childhood Trauma Questionnaire-Short Form (CTQ-SF) has been translated into at least 10 different languages. The validity of translated versions of the CTQ-SF, however, has generally not been examined. The objective of this study was to investigate the factor structure, internal consistency reliability, and known-groups…

  13. 29 CFR 1607.14 - Technical standards for validity studies.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...practices which are demonstrated by facts other than past failure to conform with requirements for validation of selection procedures...procedures which purport to measure traits or constructs, such as intelligence, aptitude, personality, commonsense, judgment,...

  14. A study on sinoatrial conduction in the aged.

    PubMed

    Ueda, K; Kamata, C; Matsuo, H; Ohkawa, S; Okimoto, T

    1977-03-01

    Sinus node response to premature atrial stimulation (PAS) was studied in 30 aged patients (group I:21 cases without sinus node dysfunction, group II:9 cases with sick sinus syndrome). Sinoatrial conduction time (SACT) was calculated according to the method reported by Strauss et al. As coupling interval of PAS decreased, there noted 5 patterns of sinus node response. In Type A, return cycle length (RC) initially increased (fully compensatory pause) and then became constant; RC progressively increased either along the compensatory reference line (Type B1) or along the less-than-compensatory line (Type B2) without being constant. In 2 other cases, RC showed similar pattern as in Type A up to 32-37% of sinus cycle length where they showed abrupt prolongation below or above the compensatory reference line (Types C and D, respectively). The incidence of abnormal response (Types B1, B2, C, and D) was high both in group I (38.0%) and group II (33.3%). The calculated SACT in group I showed a high correlation with basic sinus cycle length, while no correlation was observed in group II. The possible factors influencing return cycle length and significance of frequent observation of abnormal sinus nodal responses in the aged subjects were discussed. PMID:870724

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

    PubMed

    Barker, D A; Orrell, M W

    1999-02-01

    Patient satisfaction can be a useful marker in evaluating the quality of psychiatric care. However, this form of measurement has been hampered by the lack of attention paid to the psychometric properties of instruments devised. The Psychiatric Care Satisfaction Questionnaire (PCSQ) was developed and tests of acceptability, validity and reliability were undertaken using 52 inpatients. Content validity was assessed by surveying psychiatrists, other mental health professionals, MIND workers and patient groups. Thirty-six (67.9%) of all mental health professionals felt that the questionnaire was a useful measure of patients' satisfaction with their care, and many comments also suggested high consensual validity. In terms of content validity, responses from patient groups indicated that the majority (63.6%) felt it to be a useful measure of patient satisfaction and 70.5% felt all the areas covered were important. Concurrent and criterion validity were also good, with high correlations with existing scales and with those on a section being significantly less satisfied on the PCSQ (F = 13.3, P = 0.0004). Test-retest reliability was adequate (Cohen's kappa 0.48-0.80) and the internal consistency of the PCSQ was good, at 0.82 (Cronbach's alpha). The PCSQ performed well in all aspects of validity and reliability, indicating that it has good psychometric properties and can be a useful tool for measuring patient satisfaction. However, there remains the need to analyse more closely the concept of satisfaction and its determinants. PMID:10189818

  16. Virtual Faces Expressing Emotions: An Initial Concomitant and Construct Validity Study

    PubMed Central

    Joyal, Christian C.; Jacob, Laurence; Cigna, Marie-Hélène; Guay, Jean-Pierre; Renaud, Patrice

    2014-01-01

    Background: Facial expressions of emotions represent classic stimuli for the study of social cognition. Developing virtual dynamic facial expressions of emotions, however, would open-up possibilities, both for fundamental and clinical research. For instance, virtual faces allow real-time Human–Computer retroactions between physiological measures and the virtual agent. Objectives: The goal of this study was to initially assess concomitants and construct validity of a newly developed set of virtual faces expressing six fundamental emotions (happiness, surprise, anger, sadness, fear, and disgust). Recognition rates, facial electromyography (zygomatic major and corrugator supercilii muscles), and regional gaze fixation latencies (eyes and mouth regions) were compared in 41 adult volunteers (20 ?, 21 ?) during the presentation of video clips depicting real vs. virtual adults expressing emotions. Results: Emotions expressed by each set of stimuli were similarly recognized, both by men and women. Accordingly, both sets of stimuli elicited similar activation of facial muscles and similar ocular fixation times in eye regions from man and woman participants. Conclusion: Further validation studies can be performed with these virtual faces among clinical populations known to present social cognition difficulties. Brain–Computer Interface studies with feedback–feedforward interactions based on facial emotion expressions can also be conducted with these stimuli. PMID:25324768

  17. 'Schizoid' personality and antisocial conduct: a retrospective case not study.

    PubMed

    Wolff, S; Cull, A

    1986-08-01

    A retrospective case not analysis for 30 boys diagnosed as having a 'schizoid' personality disorder (Asperger's syndrome) in childhood, and for 30 matched clinic attenders (with systematic follow-up data for 19 matched pairs), showed the incidence of antisocial conduct to be the same in the two groups. However, the 'schizoid' boys stole less often and had fewer alcohol problems. In this group antisocial conduct was less related to family disruption and social disadvantage, and more to an unusual fantasy life. Clinical descriptions of a series of 'schizoid' boys and girls with conspicuous antisocial conduct follow. They suggest that characteristic patterns of antisocial conduct in such children are persistent expressions of hostility and, especially in girls, pathological lying, for which environmental circumstances provide no explanation. PMID:3763781

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

    E-print Network

    Nino Penaloza, Andrea

    2013-05-01

    Acid fracture conductivity and the effect of key variables in the etching process during acid fracturing can be assessed at the laboratory scale. This is accomplished by using an experimental apparatus that simulates acid injection fluxes comparable...

  19. Molecular Dynamics study of the mixed oxide fuel thermal conductivity

    NASA Astrophysics Data System (ADS)

    Nichenko, S.; Staicu, D.

    2013-08-01

    There is still no clear understanding of the plutonium content influence on the thermal conductivity behaviour of the (U,Pu) O2 MOX fuels. In this work Classical Molecular Dynamics (MD) was used to investigate the (U,Pu) O2 thermal conductivity in the whole concentration range and in the temperature range from 400 K to 1600 K. The Green-Kubo approach was used for the thermal conductivity calculation and an algorithm was proposed to improve the accuracy of the calculation. The obtained results are in good agreement with the literature experimental data and results of modelling of other authors. On the basis of the obtained results we give recommendations for the MOX thermal conductivity evaluation in the concentration range from pure UO2 up to pure PuO2.

  20. A controlled study of Tourette syndrome. II. Conduct.

    PubMed Central

    Comings, D E; Comings, B G

    1987-01-01

    To assess conduct in Tourette syndrome (TS), 47 controls, 246 TS patients, 17 attention-deficit-disorder (ADD), and 15 ADD patients with minor tics or a family history of TS (ADD 2(0) TS) were compared for the following behaviors: running away from home, lying, stealing, starting fires, vandalism, being in trouble with the law, fighting, shouting at parents or peers, attacking others, lack of respect for adults, short temper, hurting animals, feeling full of hate, being unable to stop fighting, and problems with drugs and alcohol. With the exception of running away from home and being in trouble with the law, TS patients were significantly different from controls in all other behaviors. When the components were combined for a total conduct score, only one (2.1%) of the controls had a score greater than 13, and he had TS. By contrast, 35% of the TS patients had scores greater than 13 (P less than .0005). The correlation coefficient between the total conduct score and ADD score was .48. Although the presence of ADD was an important factor in determining conduct in TS, other factors such as depression and compulsive behavior also played a contributing role. There was little correlation between the total conduct score and the number of tics. It is estimated that among non-economically disadvantaged children, 10%-30% of conduct disorder may be due to the presence of a TS gene. PMID:3479013

  1. [Study on the conductivity properties of lightning channel by spectroscopy].

    PubMed

    Wang, Xue-Juan; Yuan, Ping; Cen, Jian-Yong; Wang, Jie; Zhang, Ting-Long

    2013-12-01

    Combining the spectra of cloud-to-ground lightning return obtained by a slit-less spectrograph with the transport theory of air plasma, the electrical conductivity in one discharge channel was calculated with different methods. The results show that the conductivity of the lightning channel core is of the order of 10(4) S m-1; the conductivity goes down with the increase in the channel height in the same channel; the contributions of the collisions between electron and first or second degree ionized atoms, and electron-electron as well as ion-ion collisions to the electrical conductivity of the lightning channel core can not be neglected; the collision integrals method is more reasonable for calculating the conductivity of the lightning channel core. Based on the conductivity, the discharge current was estimated and compared with the peak current of every return stroke, and the results are in the reasonable range, further, the correlation between the channel temperature and the discharge characteristics is discussed, which provides a practical way for this aspect. PMID:24611368

  2. 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.

  3. A comprehensive study on maxillofacial trauma conducted in Yamunanagar, India

    PubMed Central

    Bali, Rishi; Sharma, Parveen; Garg, Amandeep; Dhillon, Guneet

    2013-01-01

    Abstract: Background: The Department of Oral and Maxillofacial Surgery, D.A.V [C] Dental College and Hospital, Yamuna Nagar, Haryana, India conducted a study on patients with maxillofacial fractures in a time span of seven years (2003-2010). The purpose of this study was to evaluate their aetiology, incidence, patterns and different modalities employed for management. Methods: In this study, 740 patients with 1054 fractures were evaluated clinically and radiographically, based on which closed reduction and open reduction was undertaken. Review of patient records included: Age, sex, time, mechanism and etiology of injury, history of bleeding, unconsciousness and prior first aid, type of vehicle and use of preventive measures, type of fracture and treatment modalities. Results: Road traffic accidents accounted for highest number of fractures predominantly occurring in the age group of 21-30 years (38.3%)1,2. Males incurred more fractures with a male female ratio of 4.2: 1.Mandible was the most commonly fractured bone with parasymphysis being the commonest affected site.76.66% patients had associated head injury and 15.68 % had history of unconsciousness. Open reduction and internal fixation was the preferred modality for mandible whereas the mid face fractures were treated more often by closed methods. Conclusions: Injuries occurred more commonly in 20 – 40 age range with road traffic accident being the major etiological factor. Majority of the patients were driving two wheelers and most were under the effect of alcohol. Most of the injuries occurred during night and road traffic accidents (71.89%) were found to be the major etiological factor. Out of 532 road traffic accidents, 490 patients (66.2%) were on two wheelers, among whom 49(10%) were wearing helmet. In the mandible, fractures occurred most commonly in the parasymphyseal region (224, 30.2%), and out of the 314 fractures of the middle third showed, 155 (49.4%) ZMC. OPG was the most commonly advised X-ray. With regard to treatment modalities, 36.8% of all the mandibular fractures (740) were treated by closed reduction, 62.6% were treated using open reduction and 0.5% was under observation only. PMID:23594725

  4. Health problem behaviors in Iranian adolescents: a study of cross-cultural adaptation, reliability, and validity

    PubMed Central

    Eslami, Ahmad Ali; Ghofranipour, Fazlollah; Bonab, Bagher Ghobari; Zadeh, Davood Shojaei; Shokravi, Farkhondeh Amin; Tabatabaie, Mahmoud Ghazi

    2010-01-01

    BACKGROUND: The main purpose of this study was to assess the factorial validity and reliability of the Iranian versions of the personality and behavior system scales (49 items) of the AHDQ (The Adolescent Health and Development Questionnaire) and interrelations among them based on Jessor’s PBT (Problem Behavior Theory). METHODS: A multi-staged approach was employed. The cross-cultural adaptation was performed according to the internationally recommended methodology, using the following guidelines: translation, back-translation, revision by a committee, and pretest. After modifying and identifying of the best items, a cross-sectional study was conducted to assess the psychometric properties of Persian version using calibration and validation samples of adolescents. Also 113 of them completed it again two weeks later for stability. RESULTS: The findings of the exploratory factor analysis suggested that the 7-factor solution with low self concept, emotional distress, general delinquency, cigarette, hookah, alcohol, and hard drugs use provided a better fitting model. The ? range for these identified factors was 0.69 to 0.94, the ICC range was 0.73 to 0.93, and there was a significant difference in mean scores for these instruments in compare between the male normative and detention adolescents. The first and second-order measurement models testing found good model fit for the 7-factor model. CONCLUSIONS: Factor analyses provided support of existence internalizing and externalizing problem behavior syndrome. With those qualifications, this model can be applied for studies among Persian adolescents. PMID:21526075

  5. Validation of the Spanish Center for Epidemiological Studies Depression and Zung Self-Rating Depression Scales: A Comparative Validation Study

    PubMed Central

    Arevalo, Jorge M.; Chavez, Kristhy; Vilela, Ana; Lazo, Maria; Huapaya, Julio

    2012-01-01

    Background Depressive disorders are leading contributors to burden of disease in developing countries. Research aiming to improve their diagnosis and treatment is fundamental in these settings, and psychometric tools are widely used instruments to support mental health research. Our aim is to validate and compare the psychometric properties of the Spanish versions of the Center for Epidemiological Studies Depression Scale (CES-D) and the Zung Self-Rating Depression Scale (ZSDS). Methodology/Principal Findings A Spanish version of the CES-D was revised by 5 native Spanish speaking psychiatrists using as reference the English version. A locally standardized Spanish version of the ZSDS was used. These Spanish versions were administered to 70 patients with a clinical diagnosis of DSM-IV Major Depressive Episode (MDE), 63 without major depression but with clinical diagnosis of other psychiatric disorders (OPD), and 61 with no evidence of psychiatric disorders (NEP). For both scales, Cronbach's alpha (C-?) and Hierarchical McDonald Omega for polychoric variables (MD-?) were estimated; and receiver operating characteristics (ROC) analysis performed. For the CES-D and ZSDS scales, C-? was 0.93 and 0.89 respectively, while MD-? was 0.90 and 0.75 respectively. The area under the ROC curve in MDE+OPD was 0.83 for CES-D and 0.84 for ZSDS; and in MDE+NEP was 0.98 for CES-D and 0.96 for ZSDS. Cut-off scores (co) for the highest proportions of correctly classified (cc) individuals among MDE+OPD were ?29 for CES-D (sensitivity (ss)?=?77.1/specificity (sp)?=?79.4%/(cc)?=?78.2%) and ?47 for ZSDS (ss?=?85.7%/sp?=?71.4%/cc?=?78.9%). In the MDE+NEP, co were ?24 for the CES-D (ss?=?91.4%/sp?=?96.7%/cc?=?93.9%) and ?45 for the ZSDS (ss?=?91.4%/sp?=?91.8%/cc?=?91.6%). Conclusion Spanish versions of the CES-D and ZSDS are valid instruments to detect depression in clinical settings and could be useful for both epidemiological research and primary clinical settings in settings similar as those of public hospitals in Lima, Peru. PMID:23056202

  6. Propeller aircraft interior noise model utilization study and validation

    NASA Astrophysics Data System (ADS)

    Pope, L. D.

    1984-09-01

    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  7. Propeller aircraft interior noise model utilization study and validation

    NASA Technical Reports Server (NTRS)

    Pope, L. D.

    1984-01-01

    Utilization and validation of a computer program designed for aircraft interior noise prediction is considered. The program, entitled PAIN (an acronym for Propeller Aircraft Interior Noise), permits (in theory) predictions of sound levels inside propeller driven aircraft arising from sidewall transmission. The objective of the work reported was to determine the practicality of making predictions for various airplanes and the extent of the program's capabilities. The ultimate purpose was to discern the quality of predictions for tonal levels inside an aircraft occurring at the propeller blade passage frequency and its harmonics. The effort involved three tasks: (1) program validation through comparisons of predictions with scale-model test results; (2) development of utilization schemes for large (full scale) fuselages; and (3) validation through comparisons of predictions with measurements taken in flight tests on a turboprop aircraft. Findings should enable future users of the program to efficiently undertake and correctly interpret predictions.

  8. Electrical Characterization and Morphological Studies of Conducting Polymer Nanofibers

    NASA Technical Reports Server (NTRS)

    Pinto, N. J.; Zhou, Y. X.; Freitag, M.; Johnson, A. T.; MacDiarmid, A. G.; Mueller, C. H.; Theofylaktos, N.; Robinson, D. C.; Miranda, F. A.

    2003-01-01

    Doped polyaniline blended with poly(ethylene oxide) has been electrospun in air to give fibers with diameters in the range 3 nm 200 nm. These fibers were captured on wafers of degenerately doped Si/SiO2 by placing the wafer in the path of the fiber jet formed during the electrospinning process. Individual fibers were contacted using shadow mask evaporation and were also captured on prepatterned wafers. Fibers having diameters greater than 100 nm show a slight increase in the conductivity as compared to the bulk film, while fibers with diameters less than 30 nm had lower conductivity than the bulk. Data on Scanning Conductance Microscopy along the length of individual fibers will be presented. For fibers where the diameter was not uniform, we found that below a certain diameter ( approx.15 nm) the fiber was less conducting as compared to thicker diameter fibers. Dependence of the fiber conductivity on a gate bias is underway and these results will also be presented.

  9. Lessons Learned from CFD Validation Study of Protuberance Heating

    NASA Technical Reports Server (NTRS)

    Oliver, Brandon; Blaisdell, Greogory

    2011-01-01

    The objectives of this presentation are: (1) Share lessons learned from a recent exercise in CFD validation of protuberance heating (2) Impact of experimental data reduction assumptions and techniques on validation activity (3) Advanced data reduction techniques may provide useful data from non-typical test methods (4) Significance of the recovery factor for high-speed flows (5) Show typical results of the Lag turbulence model on protuberances (6) Introduce and inform the listener of a protuberance heating dataset which will soon be available for comparison

  10. Simulation verification techniques study. Subsystem simulation validation techniques

    NASA Technical Reports Server (NTRS)

    Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

    1974-01-01

    Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given.

  11. Ultrasound Assessment of Transverse Carpal Ligament Thickness: A Validity and Reliability Study

    PubMed Central

    Shen, Zhilei Liu; Li, Zong-Ming

    2012-01-01

    The transverse carpal ligament (TCL) forms the palmar boundary of the carpal tunnel and plays an important role in carpal tunnel mechanics. TCL hypertrophy has been observed for individuals with carpal tunnel syndrome (CTS) and postulated as a potential etiological factor. Ultrasound is particularly advantageous for TCL imaging because of its capability of detecting the interfaces between the TCL and other tissues. The purposes of this study were to develop an ultrasound based method to measure the TCL thickness and to test the validity and reliability of this method. Three operators conducted two sessions of ultrasound examination on 8 cadaveric specimens and 8 healthy volunteers. A custom script was used to calculate TCL thickness along the TCL length from the ultrasound images. The ultrasound based TCL thickness of the cadaveric specimens was compared to the dissection based TCL thickness for validation. The results showed Pearson’s correlation coefficients of 0.867–0.928, intraclass correlation coefficient (ICC) values of 0.726–0.865, a standard error of measurement of 0.02–0.07 mm, and a minimal detectable difference of 0.05–0.15 mm. The high correlation coefficients and small errors indicate that the ultrasound based method is valid for measuring TCL thickness. Furthermore, ultrasound measurements showed excellent intra-operator and inter-operator reliability with ICC values as 0.826–0.933 and 0.840–0.882, respectively. The ultrasound based TCL thickness was in the range of 0.93–2.34 (1.54 ± 0.33) mm and agreed well with previous studies. The ultrasound method developed in this study is a valuable tool to examine morphological properties of healthy and pathological TCLs. PMID:22502882

  12. Reanalysis of the Harvard Six Cities Study, part I: validation and replication.

    PubMed

    Krewski, D; Burnett, R T; Goldberg, M; Hoover, K; Siemiatycki, J; Abrahamowicz, M; White, W

    2005-01-01

    Because the results of the Harvard Six Cities Study played a critical role in the establishment of the current U.S. ambient air quality objective for fine particles (PM(2.5)), the U.S. Environmental Protection Agency, industry, and nongovernmental organizations called for an independent reanalysis of this study to validate the original findings reported by Dockery and colleagues in the New England Journal of Medicine (vol. 329, pp. 1753-1759) in 1993. Validation of the original findings was accomplished by a detailed statistical audit and replication of original results. With the exception of occupational exposure to dust (14 discrepancies of 249 questionnaires located for evaluation) and fumes (15/249), date of death (2/250), and cause of death (2/250), the audit identified no discrepancies between the original questionnaires and death certificates in the audit sample and the analytic file used by the original investigators. The data quality audit identified a computer programming problem that had resulted in early censorship in 5 of the 6 cities, which resulted in the loss of approximately 1% of the reported person-years of follow-up; the reanalysis team updated the Six Cities cohort to include the missing person-years of observation, resulting in the addition of 928 person-years of observation and 14 deaths. The reanalysis team was able to reproduce virtually all of the original numerical results, including the 26% increase in all-cause mortality in the most polluted city (Stubenville, OH) as compared to the least polluted city (Portage, WI). The audit and validation of the Harvard Six Cities Study conducted by the reanalysis team generally confirmed the quality of the data and the numerical results reported by the original investigators. The discrepancies noted during the audit were not of epidemiologic importance, and did not substantively alter the original risk estimates associated with particulate air pollution, nor the main conclusions reached by the original investigators. PMID:16020032

  13. 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

  14. 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

  15. Identification and Prediction of Diabetic Sensorimotor Polyneuropathy Using Individual and Simple Combinations of Nerve Conduction Study Parameters

    PubMed Central

    Weisman, Alanna; Bril, Vera; Ngo, Mylan; Lovblom, Leif E.; Halpern, Elise M.; Orszag, Andrej; Perkins, Bruce A.

    2013-01-01

    Objective Evaluation of diabetic sensorimotor polyneuropathy (DSP) is hindered by the need for complex nerve conduction study (NCS) protocols and lack of predictive biomarkers. We aimed to determine the performance of single and simple combinations of NCS parameters for identification and future prediction of DSP. Materials and Methods 406 participants (61 with type 1 diabetes and 345 with type 2 diabetes) with a broad spectrum of neuropathy, from none to severe, underwent NCS to determine presence or absence of DSP for cross-sectional (concurrent validity) analysis. The 109 participants without baseline DSP were re-evaluated for its future onset (predictive validity). Performance of NCS parameters was compared by area under the receiver operating characteristic curve (AROC). Results At baseline there were 246 (60%) Prevalent Cases. After 3.9 years mean follow-up, 25 (23%) of the 109 Prevalent Controls that were followed became Incident DSP Cases. Threshold values for peroneal conduction velocity and sural amplitude potential best identified Prevalent Cases (AROC 0.90 and 0.83, sensitivity 80 and 83%, specificity 89 and 72%, respectively). Baseline tibial F-wave latency, peroneal conduction velocity and the sum of three lower limb nerve conduction velocities (sural, peroneal, and tibial) best predicted 4-year incidence (AROC 0.79, 0.79, and 0.85; sensitivity 79, 70, and 81%; specificity 63, 74 and 77%, respectively). Discussion Individual NCS parameters or their simple combinations are valid measures for identification and future prediction of DSP. Further research into the predictive roles of tibial F-wave latencies, peroneal conduction velocity, and sum of conduction velocities as markers of incipient nerve injury is needed to risk-stratify individuals for clinical and research protocols. PMID:23533591

  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. 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.

  18. 29 CFR 1607.5 - General standards for validity studies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...support the use of the same procedure on a ranking basis under these guidelines. Thus...decides to use a selection procedure on a ranking basis, and that method of use has a...validity and utility to support the use on a ranking basis. See sections 3B, 14B (5)...

  19. 29 CFR 1607.5 - General standards for validity studies.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...support the use of the same procedure on a ranking basis under these guidelines. Thus...decides to use a selection procedure on a ranking basis, and that method of use has a...validity and utility to support the use on a ranking basis. See sections 3B, 14B (5)...

  20. 29 CFR 1607.5 - General standards for validity studies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...support the use of the same procedure on a ranking basis under these guidelines. Thus...decides to use a selection procedure on a ranking basis, and that method of use has a...validity and utility to support the use on a ranking basis. See sections 3B, 14B (5)...

  1. 29 CFR 1607.5 - General standards for validity studies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...support the use of the same procedure on a ranking basis under these guidelines. Thus...decides to use a selection procedure on a ranking basis, and that method of use has a...validity and utility to support the use on a ranking basis. See sections 3B, 14B (5)...

  2. Ecological Validity in Eye-Tracking: An Empirical Study

    ERIC Educational Resources Information Center

    Spinner, Patti; Gass, Susan M.; Behney, Jennifer

    2013-01-01

    Eye-trackers are becoming increasingly widespread as a tool to investigate second language (L2) acquisition. Unfortunately, clear standards for methodology--including font size, font type, and placement of interest areas--are not yet available. Although many researchers stress the need for ecological validity--that is, the simulation of natural…

  3. Training Objectives, Transfer, Validation and Evaluation: A Sri Lankan Study

    ERIC Educational Resources Information Center

    Wickramasinghe, Vathsala M.

    2006-01-01

    Using a stratified random sample, this paper examines the training practices of setting objectives, transfer, validation and evaluation in Sri Lanka. The paper further sets out to compare those practices across local, foreign and joint-venture companies based on the assumption that there may be significant differences across companies of different…

  4. 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…

  5. Conductance method study on the swelling kinetics of the superabsorbent

    Microsoft Academic Search

    Zhenbin Chen; Mingzhu Liu; Xiaohua Qi; Falu Zhan; Zhen Liu

    2007-01-01

    By measuring the conductance evolution of the sodium chloride (NaCl) aqueous solution during the superabsorbent swelling in it, a monotonic increasing cubic function, between the changes of sodium chloride molar number (?n) in 1m3 swelling medium and swelling ratios (Q) of the superabsorbent was discovered. Based on the relationship between ?n and Q, a monotonic increasing quasi cubic function between

  6. Analogous studies of simultaneous conductive and radiative heat transfer

    Microsoft Academic Search

    D W Stops; R E Pearson

    1966-01-01

    The process of radiative heat transfer is electrically simulated by using voltage-dependent resistors in conjunction with current transference circuits, and so an analogue is devised which shows how the overall uni-directional heat transfer by simultaneous conduction and radiation across a transparent gas space is a function of the positions of radiation shields which may be interposed between the bounding surfaces.

  7. Nerve biopsy and conduction studies in diabetic neuropathy

    Microsoft Academic Search

    F Behse; F Buchthal; F Carlsen

    1977-01-01

    Morphological findings in sural nerves were related to nerve conduction in 12 patients with diabetic neuropathy, five with mainly sensory involvement, four with severe, symmetrical sensory-motor polyneuropathy, and three with multiple mononeuropathy. All had loss of large and small myelinated and of unmyelinated fibres, even early in the disease; segmental remyelination was the most prominent myelin alteration in teased fibres,

  8. 40 CFR 152.93 - Citation of a previously submitted valid study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Citation of a previously submitted valid study...Data Submitters' Rights § 152.93 Citation of a previously submitted valid study...submitter, no documentation other than the citation is necessary. (b) Study...

  9. 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

  10. Performance Tested Method multiple laboratory validation study of ELISA-based assays for the detection of peanuts in food.

    PubMed

    Park, Douglas L; Coates, Scott; Brewer, Vickery A; Garber, Eric A E; Abouzied, Mohamed; Johnson, Kurt; Ritter, Bruce; McKenzie, Deborah

    2005-01-01

    Performance Tested Method multiple laboratory validations for the detection of peanut protein in 4 different food matrixes were conducted under the auspices of the AOAC Research Institute. In this blind study, 3 commercially available ELISA test kits were validated: Neogen Veratox for Peanut, R-Biopharm RIDASCREEN FAST Peanut, and Tepnel BioKits for Peanut Assay. The food matrixes used were breakfast cereal, cookies, ice cream, and milk chocolate spiked at 0 and 5 ppm peanut. Analyses of the samples were conducted by laboratories representing industry and international and U.S governmental agencies. All 3 commercial test kits successfully identified spiked and peanut-free samples. The validation study required 60 analyses on test samples at the target level 5 microg peanut/g food and 60 analyses at a peanut-free level, which was designed to ensure that the lower 95% confidence limit for the sensitivity and specificity would not be <90%. The probability that a test sample contains an allergen given a prevalence rate of 5% and a positive test result using a single test kit analysis with 95% sensitivity and 95% specificity, which was demonstrated for these test kits, would be 50%. When 2 test kits are run simultaneously on all samples, the probability becomes 95%. It is therefore recommended that all field samples be analyzed with at least 2 of the validated kits. PMID:15759737

  11. 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.

  12. 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 non-intrusive 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 sub-critical 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.

  13. The Study of Diagnostic Efficacy of Nerve Conduction Study Parameters in Cervical Radiculopathy

    PubMed Central

    Pawar, Sachin; Kashikar, Aditi; Shende, Vinod; Waghmare, Satish

    2013-01-01

    Background: Cervical Radiculopathy (CR) is a neurologic condition characterised by dysfunction of a cervical spinal nerve, the roots of the nerve, or both. Diagnostic criteria for CR are not well defined, and no universally accepted criteria for its diagnosis have been established. Clinical examination, radiological imaging and electrophysiologic evaluation are the different modalities to diagnose CR. The incidence of Cervical Spondylosis and related conditions is increasing in the present scenario and the use of radiologic examination is time consuming and uneconomical for the common Indian setup. Thus, there is a definite need to establish a cost effective, reliable, and accurate means for establishing the diagnosis of cervical radiculopathy. Electrodiagnostic tests are the closest to fulfill these criteria. Aim: To evaluate diagnostic utility of various motor and sensory nerve conduction study parameters in cervical radiculopathy. Setting and Design: It was a cross-sectional study conducted on 100 subjects of age > 40 years. Material and Methods: The consecutive patients clinically diagnosed to have cervical radiculopathy, referred from department of Orthopaedics were prospectively recruited for the motor and sensory nerve conduction study using RMS EMG EP Mark-II. Parameters studied were Compound Muscle Action Potential (CMAP), Distal Motor Latency (DML) and Conduction Velocity (CV) for motor nerves and Sensory Nerve Action Potential (SNAP) and CV for sensory nerves. Statistical Analysis: Study observations and results were analysed to find the Specificity, Sensitivity, Positive Predictive Value and Negative Predictive Value using SPSS 16.0. Results: Among various motor nerve conduction parameters CMAP was found to be more sensitive with high positive predicative value. CV was found to have greater specificity and DML had least negative predictive value. Sensory nerve conduction parameters were found to have less sensitivity but higher specificity as compared to motor parameters. Conclusion: Nerve conduction studies are useful supportive diagnostic tool for suspected cervical radiculopathy as they are found to have reliable sensitivity and specificity. PMID:24551610

  14. 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?

  15. Development, Validation and Application of a Novel Method for Estimating the Thermal Conductance of Critical Interfaces in the Jaws of the LHC Collimation System

    E-print Network

    Leitao, I V

    2013-01-01

    The motivation for this project arises from the difficulty in quantifying the manufacturing quality of critical interfaces in the water cooled jaws of the TCTP and TCSP (Target Collimator Tertiary Pickup and Target Collimator Secondary Pickup) collimators. These interfaces play a decisive role in the transfer of heat deposited by the beam towards the cooling system avoiding excessive deformation of the collimator. Therefore, it was necessary to develop a non-destructive method that provides an estimation of the thermal conductance during the acceptance test of the TCTP and TCSP jaws. The method is based on experimental measurements of temperature evolution and numerical simulations. By matching experimental and numerical results it is possible to estimate the thermal conductance in several sections of the jaw. A simplified experimental installation was built to validate the method, then a fully automatic Test-Bench was developed and built for the future acceptance of the TCTP/TCSP jaws which will be manufactu...

  16. BENNINGTON COLLEGE STUDY The Bennington College study was conducted by soci-

    E-print Network

    Reber, Paul J.

    BENNINGTON COLLEGE STUDY Definition The Bennington College study was conducted by soci- ologist with students' willingness to break with existing beliefs and a desire to assume leadership posi- tions within students after 25 years. New York: Wiley. BETRAYAL Definition Betrayal refers to situations in which

  17. Paraoxonase-1 Enzyme Activity Assay for Clinical Samples: Validation and Correlation Studies

    PubMed Central

    Garelnabi, Mahdi; Younis, Abdelmoneim

    2015-01-01

    Background Paraoxonase-1 (PON1) enzyme is reported in various types of tissues and linked to numerous pathophysiological disorders. It is a potential biomarker in many pathological conditions such as cardiovascular diseases. Material/Methods We conducted several small-scale studies to evaluate PON1 performance as affected by sample types, storage, and interferences. We also carried out short-term studies to compare the performance of the widely used PON1 assay to the similar commercially available PON1 kit assay method; sample size for the method comparison was N=40, and the number varied for other validation experiments. Results Our studies using various types of anticoagulants show that samples collected in tubes with NaF, citrate, EDTA, clot activator, and sodium heparin have increased PON1 levels that are 49%, 24.5%, 19.8%, 11.4%, and 8%, respectively, higher compared to serum samples collected in plain tubes. However, samples collected in lithium heparin tubes demonstrated 10.4% lower PON1 levels compared to serum collected in plain tubes. Biological interference such as hemolysis has little effect on PON1 levels; however, samples spiked with lipids have shown 13% lower PON 1 levels. Our studies comparing the PON1 method commonly available for PON1 assay and a similar non-ELISA commercially available PON1 kit method showed a weak Spearman correlation coefficient of R2=0.40 for the range of 104.9–245.6 U/L. Conclusions The current study provides new validation data on enzyme PON1 performance. While no appreciable change was seen with storage, samples type affects the enzyme performance. Our results should encourage additional clinical studies to investigate other aspects of factors known to affect PON1 enzyme function and performance. PMID:25814092

  18. The Umeå University Database of Facial Expressions: A Validation Study

    PubMed Central

    2012-01-01

    Background A set of face stimuli, called the Umeå University Database of Facial Expressions, is described. The set consists of 30 female and 30 male models aged 17–67 years (M = 30.19, SD = 10.66). Each model shows seven different facial expressions (angry, surprised, happy, sad, neutral, afraid, and disgusted). Most models are ethnic Swedes but models of Central European, Arabic, and Asian origin are also included. Objective Creating and validating a new database of facial expressions that can be used for scientific experiments. Methods The images, presented in random order one at a time, were validated by 526 volunteers rating on average 125 images on seven 10-point Likert-type scales ranging from “completely disagree” to “completely agree” for each emotion. Results The proportion of the aggregated results that were correctly classified was considered to be high (M = 88%). Conclusions The results lend empirical support for the validity of this set of facial expressions. The set can be used freely by the scientific community. PMID:23047935

  19. Validation of the Hygicult E dipslides method in surface hygiene control: a Nordic collaborative study.

    PubMed

    Salo, Satu; Alanko, Timo; Sjöberg, Anna-Maija; Wirtanen, Gun

    2002-01-01

    A collaborative study with Enterobacteriaceae was conducted to validate Hygicult E dipslides by comparison with violet red bile glucose agar (VRBGA) contact plates and swabbing, using stainless steel surfaces artificially contaminated with microbes at various levels. Twelve laboratories participated in the validation procedure. The total number of collaborative samples was 108. The microbial level in each sample was assessed in triplicate by using the 3 above-mentioned methods. No Enterobacteriaceae were used at the low inoculation level. At the middle inoculation level, the percentages detached from the test surfaces were 16.6 with the Hygicult E method, 15.3 with the contact plate method, and 14.6 with swabbing; at the high innoculation level, the percentages were 14.5, 15.8, and 9.8, respectively. The percentage of acceptable results after the removal of outliers was 97.2. Repeatability relative standard deviations ranged from 33.4 to 44.9%; reproducibility relative standard deviations ranged from 45.2 to 77.1%. The Hygicult E dipslide, VRBGA contact plate, and swabbing methods gave similar results at all 3 microbial levels tested: <1.0 colony-forming units (CFU)/cm2 at the low level, 1.2-1.3 CFU/cm2 at the middle level (theoretical yield 8.0 CFU/cm2), and 1.2-2.0 CFU/cm2 at the high level (theoretical yield 12.5 CFU/cm2). PMID:11990024

  20. Comparative Study in Laboratory Rats to Validate Sperm Quality Methods and Endpoints

    NASA Technical Reports Server (NTRS)

    Price, W. A.; Briggs, G. B.; Alexander, W. K.; Still, K. R.; Grasman, K. A.

    2000-01-01

    Abstract The Naval Health Research Center, Detachment (Toxicology) performs toxicity studies in laboratory animals to characterize the risk of exposure to chemicals of Navy interest. Research was conducted at the Toxicology Detachment at WPAFB, OH in collaboration with Wright State University, Department of Biological Sciences for the validation of new bioassay methods for evaluating reproductive toxicity. The Hamilton Thorne sperm analyzer was used to evaluate sperm damage produced by exposure to a known testicular toxic agent, methoxyacetic acid and by inhalation exposure to JP-8 and JP-5 in laboratory rats. Sperm quality parameters were evaluated (sperm concentration, motility, and morphology) to provide evidence of sperm damage. The Hamilton Thorne sperm analyzer utilizes a DNA specific fluorescent stain (similar to flow cytometry) and digitized optical computer analysis to detect sperm cell damage. The computer assisted sperm analysis (CASA) is a more rapid, robust, predictive and sensitive method for characterizing reproductive toxicity. The results presented in this poster report validation information showing exposure to methoxyacetic acid causes reproductive toxicity and inhalation exposure to JP-8 and JP-5 had no significant effects. The CASA method detects early changes that result in reproductive deficits and these data will be used in a continuing program to characterize the toxicity of chemicals, and combinations of chemicals, of military interest to formulate permissible exposure limits.

  1. The effects of surface condition on an ultrasonic inspection: Engineering studies using validated computer model

    SciTech Connect

    Greenwood, M.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-04-01

    This report documents work on the effects of surface roughness on the reliability of an ultrasonic inservice inspection. The primary objective of this research is to develop ASME Code recommendations in order to limit the adverse effects of a rough surface and thereby increase the reliability of ultrasonic inservice inspections. Engineering studies were conducted that included experimental validation of computer codes. The basic problem associated with a rough surface in an inservice inspection is that as the transducer rotates slightly to accommodate the rough surface, the beam direction in the metal changes and the time of flight of the echo changes as well. One problem is the excessive weld crown, where weld material protrudes above the adjoining surfaces. In this research this condition is modeled by considering a step discontinuity on the top surface. CNDE developed several models of increasing complexity in order to model an inservice inspection. This report describes the validation of four computer codes. These codes were used to mimic an inservice inspection in order to understand effects associated with rotation of the transducer as it traverses a step discontinuity.

  2. Validation of extravascular lung water measurement by single transpulmonary thermodilution: human autopsy study

    Microsoft Academic Search

    Takashi Tagami; Shigeki Kushimoto; Yasuhiro Yamamoto; Takahiro Atsumi; Ryoichi Tosa; Kiyoshi Matsuda; Renpei Oyama; Takanori Kawaguchi; Tomohiko Masuno; Hisao Hirama; Hiroyuki Yokota

    2010-01-01

    ABSTRACT: INTRODUCTION: Gravimetric validation of single-indicator extravascular lung water (EVLW) and normal EVLW values has not been well studied in humans thus far. The aims of this study were (1) to validate the accuracy of EVLW measurement by single transpulmonary thermodilution with postmortem lung weight measurement in humans and (2) to define the statistically normal EVLW values. METHODS: We evaluated

  3. Ionic Conductivity And Structural Relaxation Studies on Lithium Niobophosphate Glass

    SciTech Connect

    Dabas, Prashant; Hariharan, K. [Department of physics, Indian Institute of Technology Madras, Chennai-600036 (India)

    2011-07-15

    Niobium pentoxide (Nb{sub 2}O{sub 5}) increases the chemical and thermal stability of otherwise hygroscopic alkali phosphate glasses and also enhances the conduction characteristics. Ion dynamics and structural relaxation have been investigated for mol%50Li{sub 2}0-45P{sub 2}0{sub 5}-5Nb{sub 2}O{sub 5}. The non-linearity parameter 'x' in the Tool-Narayanaswamy model is evaluated using the dependence of fictive and glass transition temperatures on the cooling and heating rates.

  4. Tracking Study for Top-off Safety Validation at SSRL

    SciTech Connect

    Huang, X.; Bauer, J.; Corbett, J.; Dell'Orco, D.; Hettel, B.; Liu, J.; Rabedeau, T.; Safranek, J.; Schmerge, J.; Sebek, J.; Tanabe, J.; Terebilo, A.; Wang, L.; ,

    2011-08-19

    A tracking study was performed at SSRL to identify necessary controls and to prove the safety of top-off operation from radiation hazard under such conditions. The safety rationale, tracking setup and the results are presented. Top-off operational mode has become a trend for existing and planned third-generation storage ring light sources for the many benefits such as increased average brightness, improved thermal stability and elimination of the interruption to user experiments due to traditional injection [1, 2]. Unlike the traditional decay mode injection which happens a few times a day and during which the photon beamline shutters are closed, top-off mode injection requires photon beamline shutters to remain open during injection and occurs much more frequently, from once every 5 seconds to once every 30 minutes. Therefore injection may be transparent to user experiments and the stored current variation can be significantly reduced. For a facility equipped with a full-energy injector, the biggest challenge to the implementation of the top-off mode may be the control of radiation hazard. Studies at ALS and SSRL [2, 3] have shown that a single injected electron pulse that enters the photon beamline and exits the radiation shield wall would cause unacceptable radiation doses on the experimental floor. For the protection of users and experimental equipment, it is hence a prerequisite for top-off operation to establish controls that absolutely prevent such occurrences. Similar to other facilities such as ALS and APS [2, 4], tracking simulations were conducted at SSRL to identify the control measures, define the specifications and prove the radiation safety. However, a different approach toward the proof of safety is taken at SSRL. In this paper we first describe the SSRL accelerator complex with emphasis on the aspects related to top-off in section 2. The general considerations and requirements for top-off are presented in section 3. Section 4 and 5 give a detailed description of the tracking setup and results. Concluding remarks are given in section 6.

  5. Fullerene peapods: In-situ conductivity study during synthesis

    NASA Astrophysics Data System (ADS)

    You, Young Gyu; Kim, Sung Won; Uhm, Tae Woo; Jhang, Sung Ho; Park, Yung Woo

    2014-06-01

    We report in-situ measurement of the conductivity during the synthesis of C60-filled single-walled carbon nanotubes (SWNTs), so-called fullerene peapods. The synthesis was performed in a sealed quartz tube at 773 K by using the sublimation of C60 into the hollow space of the SWNTs. The change in the resistance in the SWNT buckypaper was monitored during the C60-filling process, and the temperature dependence of the resistance was compared to that for empty SWNTs and fullerene peapods. The SWNT networks became more metallic due to the encapsulation of C60, and a reduced temperature dependence of the resistivity was observed in the peapods, with an overall decrease in the resistivity. The interaction between the SWNT and C60 molecules, changing the electronic properties of SWNTs, can provide a way to functionalize the SWNTs.

  6. 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

  7. A short form of the Maximization Scale: Factor structure, reliability and validity studies

    Microsoft Academic Search

    Gergana Y. Nenkov; Maureen Morrin; Andrew Ward; Barry Schwartz; John Hulland

    2008-01-01

    We conducted an analysis of the 13-item Maximization Scale (Schwartz et al., 2002) with the goal of establishing its factor structure, reliability and validity. We also investigated the psychometric properties of several proposed refined versions of the scale. Four sets of analyses are reported. The first analysis confirms the 3-part factor structure of the scale and assesses its reliability. The

  8. Construct Validity of Cognitive Reserve in a Multi-Ethnic Cohort: the Northern Manhattan Study

    PubMed Central

    Siedlecki, Karen L.; Stern, Yaakov; Reuben, Aaron; Sacco, Ralph L.; Elkind, Mitchell S.V.; Wright, Clinton B.

    2009-01-01

    Cognitive reserve is a hypothetical construct that has been used to inform models of cognitive aging, and is presumed to be indicative of life experiences that may mitigate the effects of brain pathology. The purpose of this study was to evaluate the construct validity of cognitive reserve by examining both its convergent and discriminant validity across three different samples of participants using structural equation modeling. The cognitive reserve variables were found to correlate highly with one another (thereby providing evidence of convergent validity) but demanding tests of discriminant validity indicated that, in two of the samples, the cognitive reserve construct was highly related to an executive functioning construct. PMID:19573274

  9. Oxygen flux and dielectric response study of Mixed Ionic-Electronic Conducting (MIEC) heterogeneous functional materials

    NASA Astrophysics Data System (ADS)

    Rabbi, Fazle

    Dense mixed ionic-electronic conducting (MIEC) membranes consisting of ionic conductive perovskite-type and/or fluorite-type oxides and high electronic conductive spinel type oxides, at elevated temperature can play a useful role in a number of energy conversion related systems including the solid oxide fuel cell (SOFC), oxygen separation and permeation membranes, partial oxidization membrane reactors for natural gas processing, high temperature electrolysis cells, and others. This study will investigate the impact of different heterogeneous characteristics of dual phase ionic and electronic conductive oxygen separation membranes on their transport mechanisms, in an attempt to develop a foundation for the rational design of such membranes. The dielectric behavior of a material can be an indicator for MIEC performance and can be incorporated into computational models of MIEC membranes in order to optimize the composition, microstructure, and ultimately predict long term membrane performance. The dielectric behavior of the MIECs can also be an indicator of the transport mechanisms and the parameters they are dependent upon. For this study we chose a dual phase MIEC oxygen separation membrane consisting of an ionic conducting phase: gadolinium doped ceria-Ce0.8 Gd0.2O2 (GDC) and an electronic conductive phase: cobalt ferrite-CoFe2O4 (CFO). The membranes were fabricated from mixtures of Nano-powder of each of the phases for different volume percentages, sintered with various temperatures and sintering time to form systematic micro-structural variations, and characterized by structural analysis (XRD), and micro-structural analysis (SEM-EDS). Performance of the membranes was tested for variable partial pressures of oxygen across the membrane at temperatures from 850°C-1060°C using a Gas Chromatography (GC) system. Permeated oxygen did not directly correlate with change in percent mixture. An intermediate mixture 60%GDC-40%CFO had the highest flux compared to the 50%GDC-50%CFO and 80%GDC-20%CFO mixtures. Material characterization suggests the emergence of a third phase contributing to the behavior. Microstructural studies suggested changes in micro-structure of a given volume fraction for different sintering temperature and sintering time. Flux variation was observed for membranes with the same constituent volume fraction but different micro-structure indicating the effects of the micro-structure on the overall oxygen permeation. To correlate the experimental flux measurement with a standard Wagner's flux equation, different microstructural characteristics were studied to incorporate them into a modified Wagner's flux equation. In-situ broadband dielectric spectroscopy measurements over a temperature range of 850°C-1060°C and frequency range of (0.1Hz-1MHz) of the operating 60%GDC-40%CFO mixture oxygen separation membranes were measured using a NOVOCONTROL dielectric spectroscopy test system. Dielectric response of the operating membrane was studied to identify the charge transfer process in the membrane. A computational model to study the dielectric impedance response of different microstructure was developed using a COMSOL(TM) Multiphysics qasi-static electromagnetic module. This model was validated using model materials with regular geometric shapes. To measure impedance of real micro/nano-structures of the membrane material, domains required for the COMSOL calculation were obtained from actual micro/nano structures by using 3D scans from X-ray nano and micro tomography. Simpleware(TM) software was used to generate 3D domains from image slices obtained from the 3D x-ray scans. Initial voltage distributions on the original microstructure were obtained from the computational model. Similarly, development of a primary model for simulating ionic/electronic species flow inside of an MIEC was also begun. The possibility of using broadband dielectric spectroscopy methods to understand and anticipate the flux capabilities of MIECs to reduce the cost and time of development of such material systems was explored.

  10. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

  11. 21 CFR 58.130 - Conduct of a nonclinical laboratory study.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

  12. 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 ...

  13. 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…

  14. The Validity of the Achievement-Orientation Model for Gifted Middle School Students: An Exploratory Study

    ERIC Educational Resources Information Center

    Ritchotte, Jennifer A.; Matthews, Michael S.; Flowers, Claudia P.

    2014-01-01

    Gifted underachievement represents a frustrating loss of potential for society. Although attempts have been made to develop interventions to reverse gifted underachievement, the theoretical underpinnings of these interventions have yet to be empirically validated. The purpose of this study was to investigate the validity of the…

  15. 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…

  16. Validation of a Computerized Cognitive Assessment System for Persons with Stroke: A Pilot Study

    ERIC Educational Resources Information Center

    Yip, Chi Kwong; Man, David W. K.

    2009-01-01

    This study investigates the validity of a newly developed computerized cognitive assessment system (CCAS) that is equipped with rich multimedia to generate simulated testing situations and considers both test item difficulty and the test taker's ability. It is also hypothesized that better predictive validity of the CCAS in self-care of persons…

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

    E-print Network

    Plotkin, Joshua B.

    with the Charter of Biomedical Graduate Studies Student Judicial System. Alleged research ethics violations it for an assignment, cloning someone else's ideas without attribution, failing to use quotation marks where

  18. Acid Fracture and Fracture Conductivity Study of Field Rock Samples

    E-print Network

    Underwood, Jarrod

    2013-11-15

    Acid fracturing is a well stimulation strategy designed to increase the productivity of a producing well. The parameters of acid fracturing and the effects of acid interaction on specific rock samples can be studied experimentally. Acid injection...

  19. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...used; and (3) Fairness evidence. The studies include a study of test fairness for each race, sex, and ethnic group which constitutes a significant...for the job or jobs in question. If the studies under consideration satisfy...

  20. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...used; and (3) Fairness evidence. The studies include a study of test fairness for each race, sex, and ethnic group which constitutes a significant...for the job or jobs in question. If the studies under consideration satisfy...

  1. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...used; and (3) Fairness evidence. The studies include a study of test fairness for each race, sex, and ethnic group which constitutes a significant...for the job or jobs in question. If the studies under consideration satisfy...

  2. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...used; and (3) Fairness evidence. The studies include a study of test fairness for each race, sex, and ethnic group which constitutes a significant...for the job or jobs in question. If the studies under consideration satisfy...

  3. 29 CFR 1607.7 - Use of other validity studies.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...used; and (3) Fairness evidence. The studies include a study of test fairness for each race, sex, and ethnic group which constitutes a significant...for the job or jobs in question. If the studies under consideration satisfy...

  4. Validation sampling can reduce bias in healthcare database studies: an illustration using influenza vaccination effectiveness

    PubMed Central

    Nelson, Jennifer C.; Marsh, Tracey; Lumley, Thomas; Larson, Eric B.; Jackson, Lisa A.; Jackson, Michael

    2014-01-01

    Objective Estimates of treatment effectiveness in epidemiologic studies using large observational health care databases may be biased due to inaccurate or incomplete information on important confounders. Study methods that collect and incorporate more comprehensive confounder data on a validation cohort may reduce confounding bias. Study Design and Setting We applied two such methods, imputation and reweighting, to Group Health administrative data (full sample) supplemented by more detailed confounder data from the Adult Changes in Thought study (validation sample). We used influenza vaccination effectiveness (with an unexposed comparator group) as an example and evaluated each method’s ability to reduce bias using the control time period prior to influenza circulation. Results Both methods reduced, but did not completely eliminate, the bias compared with traditional effectiveness estimates that do not utilize the validation sample confounders. Conclusion Although these results support the use of validation sampling methods to improve the accuracy of comparative effectiveness findings from healthcare database studies, they also illustrate that the success of such methods depends on many factors, including the ability to measure important confounders in a representative and large enough validation sample, the comparability of the full sample and validation sample, and the accuracy with which data can be imputed or reweighted using the additional validation sample information. PMID:23849144

  5. 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

  6. Detection of Circulating Tumor Cells in Peripheral Blood of Patients with Metastatic Breast Cancer: A Validation Study of the CellSearch System

    Microsoft Academic Search

    Sabine Riethdorf; Herbert Fritsche; V. Muller; Thomas Rau; Christian Schindlbeck; Brigitte Rack; Wolfgang Janni; Cornelia Coith; Katrin Beck; F. Janicke; S. Jackson; T. Gornet; M. Cristofanilli; K. Pantel

    2007-01-01

    Purpose: The CellSearch system (Veridex,Warren, NJ) is designed to enrich and enumerate cir- culating tumor cells (CTCs) from peripheral blood. Here, we validated the analytic performance of this system for clinical use in patients with metastatic breast cancer. Experimental Design: This prospective multicenter study conducted at three independent laboratories involved samples from 92 patients with metastatic breast cancer. Intra- and

  7. Validity Study of U.T. Austin Test for Use in Credit by Examination in Introduction to Electronic Data Processing (DPA 310), Fall 1987.

    ERIC Educational Resources Information Center

    Appenzellar, Anne B.; Kelley, H. Paul

    The Measurement and Evaluation Center of the University of Texas (Austin) conducted a validity study to assist the Department of Management Science and Information (DMSI) at the College of Business Administration in establishing a program of credit by examination for an introductory course in electronic data processing--Data Processing Analysis…

  8. 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…

  9. The ECVAM International Validation Study on In Vitro Tests for Skin Corrosivity. 2. Results and Evaluation by the Management Team.

    PubMed

    Fentem, J H; Archer, G E; Balls, M; Botham, P A; Curren, R D; Earl, L K; Esdaile, D J; Holzhütter, H G; Liebsch, M

    1998-08-01

    As a follow-up to a prevalidation study on in vitro tests for replacing the in vivo rabbit test for skin corrosivity, an international validation study was conducted during 1996 and 1997 under the auspices of ECVAM. The main objectives of the study were to: (a) identify tests capable of discriminating corrosives from non-corrosives for selected types of chemicals and/or all chemicals; and (b) determine whether these tests could identify correctly known R35 (UN packing group I) and R34 (UN packing groups II & III) chemicals. The tests evaluated were the rat skin transcutaneous electrical resistance (TER) assay, CORROSITEX(TM), the Skin(2TM) ZK1350 corrosivity test and EPISKIN(TM). Each test was conducted in three independent laboratories. 60 coded chemicals were tested. All of the tests evaluated showed acceptable intralaboratory and interlaboratory reproducibilities, and the TER, Skin(2) and EPISKIN tests proved applicable to testing a diverse group of chemicals of different physical forms, including organic acids, organic bases, neutral organics, inorganic acids, inorganic bases, inorganic salts, electrophiles, phenols and soaps/surfactants. Two of the four tests evaluated, the TER assay and EPISKIN, met the criteria agreed by the Management Team concerning acceptable underprediction and overprediction rates for them to be considered scientifically validated for use as replacements for the animal test for distinguishing between corrosive and non-corrosive chemicals for all of the chemical types studied [objective (a)]. EPISKIN was the only test able to distinguish between known R35 (UN packing group I) and R34 (UN packing groups II & III) chemicals, for all of the chemical types included, on an acceptable number of occasions [objective (b)]. The corrosive potentials of about 40% of the test chemicals could not be assessed with CORROSITEX, and the assay did not meet all of the criteria for it to be considered acceptable as a replacement test. However, CORROSITEX may be valid for testing specific classes of chemicals, such as organic bases and inorganic acids. The Skin(2) assay did not meet the criteria for it to be considered scientifically validated. Thus, the validities of (i) the TER and EPISKIN assays for discriminating corrosives from non-corrosives, and (ii) the EPISKIN assay for identifying correctly known R35/I and R34/II & III chemicals, have been demonstrated in this study. CORROSITEX appears to be valid when used only with certain types of chemicals. PMID:20654431

  10. 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.

  11. Nerve conduction study of the medial and lateral plantar nerves.

    PubMed

    Antunes, A C; Nobrega, J A; Manzano, G M

    2000-01-01

    The medial and lateral plantar nerves may be evaluated through the recordings of the compound sensory nerve action potentials (CSNAP), compound mixed nerve action potentials (CMNAP) and compound muscular action potentials (CMAP). As some of these potentials are not easily and always obtainable in normal individuals, our purpose was to verify the consistency of these potentials for the study of these nerves. Fifty-one normal adult volunteers were examined. The CSNAP, CMNAP and CMAP, related to the medial and lateral plantar nerves were evaluated bilaterally. CSNAP were not obtained in 7.8% and in 17.6% from the medial and lateral plantar nerves respectively. CMNAP from the lateral plantar nerve were not obtained in 15.6%. CMNAP from the medial plantar nerves and CMAPs from the abductor hallucis and abductor digiti quinti were obtained for all nerves tested. Our results, therefore, suggest that these last 3 parameters are the ones more reliable for clinical application. PMID:10812535

  12. Study of the Conductivity of Dielectric Under High Energy Electron Irradiation

    NASA Astrophysics Data System (ADS)

    Chen, Yifeng; Yang, Shengsheng; Li, Detian; Qin, Xiaogang; Liu, Qing; Tang, Daotang; Feng, Na; Shi, Liang; Zhang, Lei

    2012-12-01

    High energy electron irradiation was performed on a theoretical and experimental study of the dielectric conductivity. This paper presents a theoretical method to the determination of the conductivity of dielectric materials under irradiation, and the conductivity of kapton is measured under 0.8 MeV electron irradiation. The results from theory and experiment clearly illustrate the expected dependence of conductivity of dielectric on dose rate, and the resistance of kapton decreases in 102.

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

    E-print Network

    Stevens, Jeffery Allen

    2004-09-30

    development and performance measurement tool as well as a communication tool and a blueprint for success for employees. The MIFV is a sequentially upward funneling competency cluster validation model. The MIFV will provide an opportunity for the study...

  14. 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.

  15. A field study of frame-of-reference effects on personality test validity.

    PubMed

    Hunthausen, John M; Truxillo, Donald M; Bauer, Talya N; Hammer, Leslie B

    2003-06-01

    As part of a test validation study at a major U.S.-based airline, the authors tested the effects of providing an "at work" frame-of-reference on the validity of the NEO Five-Factor Inventory among a sample of customer service supervisors (N = 206). Frame-of-reference moderated the validity of the Extraversion and Openness to Experience subscales after controlling for cognitive ability. In addition, the frame-of-reference personality test showed incremental validity over cognitive ability (deltaR2 = .16), but the standard personality test did not (deltaR2 = .05). The authors' discussion focuses on implications for personality theory and research and on implications for increasing the validity of personality tests in organizational settings. PMID:12814302

  16. Parametric Study Conducted of Rocket- Based, Combined-Cycle Nozzles

    NASA Technical Reports Server (NTRS)

    Steffen, Christopher J., Jr.; Smith, Timothy D.

    1998-01-01

    Having reached the end of the 20th century, our society is quite familiar with the many benefits of recycling and reusing the products of civilization. The high-technology world of aerospace vehicle design is no exception. Because of the many potential economic benefits of reusable launch vehicles, NASA is aggressively pursuing this technology on several fronts. One of the most promising technologies receiving renewed attention is Rocket-Based, Combined-Cycle (RBCC) propulsion. This propulsion method combines many of the efficiencies of high-performance jet aircraft with the power and high-altitude capability of rocket engines. The goal of the present work at the NASA Lewis Research Center is to further understand the complex fluid physics within RBCC engines that govern system performance. This work is being performed in support of NASA's Advanced Reusable Technologies program. A robust RBCC engine design optimization demands further investigation of the subsystem performance of the engine's complex propulsion cycles. The RBCC propulsion system under consideration at Lewis is defined by four modes of operation in a singlestage- to-orbit configuration. In the first mode, the engine functions as a rocket-driven ejector. When the rocket engine is switched off, subsonic combustion (mode 2) is present in the ramjet mode. As the vehicle continues to accelerate, supersonic combustion (mode 3) occurs in the ramjet mode. Finally, as the edge of the atmosphere is approached and the engine inlet is closed off, the rocket is reignited and the final accent to orbit is undertaken in an all-rocket mode (mode 4). The performance of this fourth and final mode is the subject of this present study. Performance is being monitored in terms of the amount of thrust generated from a given amount of propellant.

  17. A Validation Study of Pin Heat Transfer for MOX Fuel Based on the IFA-597 Experiments

    SciTech Connect

    Phillippe, Aaron M [ORNL; Clarno, Kevin T [ORNL; Banfield, James E [ORNL; Ott, Larry J [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Hamilton, Steven P [ORNL

    2014-01-01

    Abstract The IFA-597 (Integrated Fuel Assessment) experiments from the International Fuel Performance Experiments (IFPE) database were designed to study the thermal behavior of mixed oxide (MOX) fuel and the effects of an annulus on fission gas release in light-water-reactor fuel. An evaluation of nuclear fuel pin heat transfer in the FRAPCON-3.4 and Exnihilo codes for MOX fuel systems was performed, with a focus on the first 20 time steps ( 6 GWd/MT(iHM)) for explicit comparison between the codes. In addition, sensitivity studies were performed to evaluate the effect of the radial power shape and approximations to the geometry to account for the thermocouple hole, dish, and chamfer. The analysis demonstrated relative agreement for both solid (rod 1) and annular (rod 2) fuel in the experiment, demonstrating the accuracy of the codes and their underlying material models for MOX fuel, while also revealing a small energy loss artifact in how gap conductance is currently handled in Exnihilo for chamfered fuel pellets. The within-pellet power shape was shown to significantly impact the predicted centerline temperatures. This has provided an initial benchmarking of the pin heat transfer capability of Exnihilo for MOX fuel with respect to a well-validated nuclear fuel performance code.

  18. Standardized classroom management program: Social validation and replication studies in Utah and Oregon

    PubMed Central

    Greenwood, Charles R.; Hops, Hyman; Walker, Hill M.; Guild, Jacqueline J.; Stokes, Judith; Young, K. Richard; Keleman, Kenneth S.; Willardson, Marlyn

    1979-01-01

    A comprehensive validation study was conducted of the Program for Academic Survival Skills (PASS), a consultant-based, teacher-mediated program for student classroom behavior. The study addressed questions related to: (a) brief consultant training, (b) subsequent teacher training by consultants using PASS manuals, (c) contrasts between PASS experimental teachers and students and equivalent controls on measures of teacher management skills, student classroom behavior, teacher ratings of student problem behaviors, and academic achievement, (d) reported satisfaction of participants, and (e) replication of effects across two separate school sites. Results indicated that in both sites significant effects were noted in favor of the PASS experimental group for (a) teacher approval, (b) student appropriate classroom behavior, and (c) four categories of student inappropriate behavior. Program satisfaction ratings of students, teachers, and consultants were uniformly positive, and continued use of the program was reported a year later. Discussion focused upon issues of cost-effectiveness, differential site effects, and the relationship between appropriate classroom behavior and academic achievement. PMID:16795604

  19. CASE STUDY: Using TCGA Data to Validate GBM Signaling Pathways

    Cancer.gov

    Neurosurgeon Cameron Brennan of Memorial Sloan-Kettering Cancer Center used TCGA data to define subgroups of patients with a deadly brain cancer called glioblastoma multiforme. Learn more about his research in this TCGA in Action case study.

  20. Validation of immunoassay for protein biomarkers: bioanalytical study plan implementation to support pre-clinical and clinical studies.

    PubMed

    Valentin, Marie-Anne; Ma, Shenglin; Zhao, An; Legay, François; Avrameas, Alexandre

    2011-07-15

    Biomarkers have emerged as an important tool to optimize the benefit/risk ratio of therapeutics. The scientific impact of biomarker studies is directly related to the quality of the underlying data. It is therefore important that guidance be established for validation of assays used to support drug development. This paper specifically focuses on validation of immunoassay for protein biomarker to support pre-clinical and clinical studies. Therapeutics (small- and macro-molecules) and their respective target/ligand are out of scope. This paper describes the implementation of a bioanalytical study plan for the validation of immunoassays to support decision-making biomarkers and biomarker selection during preclinical and clinical studies. It establishes the complete operating procedure as well as the parameters and their respective acceptance criteria and defines milestones and decision points to be followed during the assay validation that should result in high quality bioanalytical data in a limited timeframe and with reduced costs. The bioanalytical study plan can be applied to the validation of a wild range of immunoassay technology such as monoplex ELISA, automated analyzer, multiplex assays or cutting edge technology. Before any validation, a feasibility study is performed to assess the performance of the immunoassay using biological samples which should mimic the clinical population. The feasibility study addresses the likelihood that an assay will be able to achieve its intended purpose with parallelism being the most critical element (milestone 1). At the end of the feasibility study, a decision is taken to either continue with the validation or change the assay (milestone 2). The milestone 3 consists of the establishment of the nominal value of quality control to be used during the validation. The quality controls used to validate an assay should preferentially be prepared using neat (non-spiked) biological matrix (ideally derived from the specific trial population). The last milestone (milestone 4), the formal validation, includes demonstration of the assay performance meeting accuracy and precision acceptance criteria within (intra-run) and between (inter-run) validation runs for each QC sample. Validation also includes the assessment of stability of the protein biomarker in the biological matrix. It is recognized that the extent of the validation should be correlated to the intended use of the data and the assay acceptance criteria should take into consideration the study objective(s), nature of the methodology and the biological variability of the biomarker. PMID:21530130

  1. 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.

  2. A Validation Study of the Mathematics Anxiety Rating Scale (Mars

    Microsoft Academic Search

    Lorelei R. Brush

    1978-01-01

    The Mathematics Anxiety Rating Scale (MARS) was given to two groups of undergraduates. The first group also completed a questionnaire on their background in mathematics; the second, the Suinn Test Anxiety Behavior Scale (STABS). In both studies Humanities majors scored higher in mathematical anxiety than did Social Science majors who in turn had higher MARS scores than did Physical Science

  3. Evaluating the Reliability, Validity, and Usefulness of Education Cost Studies

    ERIC Educational Resources Information Center

    Baker, Bruce D.

    2006-01-01

    Recent studies that purport to estimate the costs of constitutionally adequate education have been described as either a "gold standard" that should guide legislative school finance policy design and judicial evaluation, or as pure "alchemy." Methods for estimating the cost of constitutionally adequate education can be roughly divided into two…

  4. 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…

  5. 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…

  6. Book Reading Motivation Scale: Reliability and Validity Study

    ERIC Educational Resources Information Center

    Katranci, Mehmet

    2015-01-01

    Book reading enhances the intellectual world of people. It is very important to know the factors that motivate children to read books as it will help to instill book reading habit in them. As such, the present study aims to develop a "Book Reading Motivation Scale" to determine elementary and secondary school students' reading…

  7. 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

  8. 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

  9. A Set of Principles for Conducting and Evaluating Interpretive Field Studies in Information Systems

    Microsoft Academic Search

    Heinz K. Klein; Michael D. Myers

    1999-01-01

    This article discusses the conduct and evaluation of interpretive research in information systems. While the conventions for evaluating information systems case studies conducted according to the natural science model of social science are now widely accepted, this is not the case for interpre- tive field studies. A set of principles for the con- duct and evaluation of interpretive field research

  10. A Review of Nerve Conduction Studies in Cases of Suspected Compression Neuropathies of the Upper Limb

    Microsoft Academic Search

    A. Neligan; S. S. O’Sullivan; G. M. Mullins; A. McCarthy; R. G. Kowalski; J. Kinsella; B. McNamara

    2010-01-01

    Introduction: Entrapment neuropathies, particularly those affecting upper limbs, are common reasons for referral for nerve conduction studies (NCS). However, concordance between clinical findings and NCS findings, especially in patients being considered for intervention including decompressive surgery, has not been assessed. Methods: We conducted a retrospective study using records from a tertiary referral centre’s neurophysiology database. We aimed to establish the

  11. 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

  12. Apples-to-apples in cross-validation studies: pitfalls in classifier performance measurement

    Microsoft Academic Search

    George Forman; Martin Scholz

    2010-01-01

    Cross-validation is a mainstay for measuring performance and progress in machine learning. There are subtle differences in how exactly to compute accuracy, F-measure and Area Under the ROC Curve (AUC) in cross-validation studies. However, these details are not discussed in the literature, and incompatible methods are used by various papers and software packages. This leads to inconsistency across the research

  13. A study of the interrelationships of several validity scales used in police selection

    Microsoft Academic Search

    William U. Weiss; Gerald Serafino; Ann Serafino

    2000-01-01

    Validity scale data have received attention recently as providing valuable information about potential problematic police\\u000a officer candidates. In this study, validity scale data from a number of selection instruments were obtained using 42 state\\u000a police officer candidates. The scale used were the MMPI-2 L scale, the MMPI-2 K scale, the PAI Positive Impression Scale (PIM),\\u000a the PAI Defensiveness Index (DI),

  14. A rapid screening tool for psychological distress in children 3–6years old: results of a validation study

    PubMed Central

    2012-01-01

    Background The mental health needs of young children in humanitarian contexts often remain unaddressed. The lack of a validated, rapid and simple tool for screening combined with few mental health professionals able to accurately diagnose and provide appropriate care mean that young children remain without care. Here, we present the results of the principle cross-cultural validation of the “Psychological Screening for Young Children aged 3 to 6” (PSYCAa3-6). The PSYCa 3–6 is a simple scale for children 3 to 6 years old administered by non-specialists, to screen young children in crises and thereby refer them to care if needed. Methods This study was conducted in Maradi, Niger. The scale was translated into Hausa, using corroboration of independent translations. A cross-cultural validation was implemented using quantitative and qualitative methods. A random sample of 580 mothers or caregivers of children 3 to 6 years old were included. The tool was psychometrically examined and diagnostic properties were assessed comparing the PSYCa 3–6 against a clinical interview as the gold standard. Results The PSYCa 3–6 Hausa version demonstrated good concurrent validity, as scores correlated with the gold standard and the Clinical Global Impression Severity Scale (CGI-S) [rho?=?0.41, p-value?=?0.00]. A reduction procedure was used to reduce the scale from 40 to 22 items. The test-retest reliability of the PSYCa 3–6 was found to be high (ICC 0.81, CI95% [0.68; 0.89]). In our sample, although not the purpose of this study, approximately 54 of 580 children required subsequent follow-up with a psychologist. Conclusions To our knowledge, this is the first validation of a screening scale for children 3 to 6 years old with a cross-cultural validation component, for use in humanitarian contexts. The Hausa version of the PSYCa 3–6 is a reliable and a valuable screening tool for psychological distress. Further studies to replicate our findings and additional validations of the PSYCa 3–6 in other populations may help improve the delivery of mental health care to children. PMID:23072651

  15. 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

  16. [Prospective validation of a pharmacogenetic test: the PREDICT-1 study].

    PubMed

    Muñoz de Benito, Rosa M; Arribas López, José Ramón

    2008-05-01

    The aim of the PREDICT-1 study was to determine the clinical utility of the pharmacogenetic test identifying HLA-B*5701 to reduce the incidence of hypersensitivity reaction to abacavir, diagnosed clinically and with immunological confirmation, as well as to reduce unwarranted withdrawal of this drug. In the PREDICT-1 study, 1,956 patients were randomized to be screened for HLA-B*5701 before starting abacavir treatment (excluding participants who were HLA-B*5701-positive) or to receive abacavir without knowing their HLA-B*5701 status under conventional clinical monitoring. The prevalence of HLA-B*5701-positivity was 5.7%. In the group that underwent prospective screening, no hypersensitivity tests with immunological confirmation (by positive epicutaneous patch testing) were observed compared with an incidence of 2.7% in the group undergoing standard follow-up. The sensitivity of prospective screening in predicting immunologically confirmed hypersensitivity reaction to abacavir was 100% and its negative predictive value was 100%. The number of clinically suspected hypersensitivity reactions to abacavir was also lower in the screened group (3.4% versus 7.8% in the group undergoing conventional follow-up). The sensitivity of epicutaneous patch testing for immunological confirmation was 100%. PMID:18680695

  17. Effect of isotopic purity on thermal conductivity of boron nitride: A theoretical study

    NASA Astrophysics Data System (ADS)

    Barman, Saswati

    2011-10-01

    In this letter we report the theoretical study of the effect of isotopic purity on the temperature dependence of the lattice thermal conductivity of cubic BN single crystals. The maximum thermal conductivity of pure BN is very high (~105 W/m/K) and it is comparable to the thermal conductivity of the carbon nanotube. It is two orders of magnitude higher than that of BN with 50%10B. We find that the very high contribution (~ 95%) of the usually neglected N-drift scattering at the thermal conductivity peak is the reason for such an increase in thermal conductivity of pure BN, compared to that of natural BN. The thermal conductivity is nearly symmetric with respect to the isotopic composition of boron and it is minimum for 50%10B and 50%11B. The role of phonon scattering by boron isotopes present in BN, in controlling the temperature dependence of thermal conductivity has been accurately quantified.

  18. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: THERMAL DESORPTION - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and Liab...

  19. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: AEROBIC BIODEGRADATION REMEDY SCREENING

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (KU FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and L...

  20. Validation of the Ottawa Knee Rule in children: A multicenter study

    Microsoft Academic Search

    Blake Bulloch; Gina Neto; Amy Plint; Rodrick Lim; Per Lidman; Martin Reed; Cheri Nijssen-Jordan; Milton Tenenbein; Terry P. Klassen

    2003-01-01

    Study objective: The main objective of this study was to determine the sensitivity and specificity of the Ottawa Knee Rules when they were applied to children. The secondary objective was to determine post hoc whether use of the rules would reduce the number of knee radiographs ordered. Methods: This prospective, multicenter validation study included children aged 2 to 16 years

  1. 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…

  2. Do placebo based validation standards mimic real batch products behaviour? Case studies.

    PubMed

    Bouabidi, A; Talbi, M; Bouklouze, A; El Karbane, M; Bourichi, H; El Guezzar, M; Ziemons, E; Hubert, Ph; Rozet, E

    2011-06-01

    Analytical methods validation is a mandatory step to evaluate the ability of developed methods to provide accurate results for their routine application. Validation usually involves validation standards or quality control samples that are prepared in placebo or reconstituted matrix made of a mixture of all the ingredients composing the drug product except the active substance or the analyte under investigation. However, one of the main concerns that can be made with this approach is that it may lack an important source of variability that come from the manufacturing process. The question that remains at the end of the validation step is about the transferability of the quantitative performance from validation standards to real authentic drug product samples. In this work, this topic is investigated through three case studies. Three analytical methods were validated using the commonly spiked placebo validation standards at several concentration levels as well as using samples coming from authentic batch samples (tablets and syrups). The results showed that, depending on the type of response function used as calibration curve, there were various degrees of differences in the results accuracy obtained with the two types of samples. Nonetheless the use of spiked placebo validation standards was showed to mimic relatively well the quantitative behaviour of the analytical methods with authentic batch samples. Adding these authentic batch samples into the validation design may help the analyst to select and confirm the most fit for purpose calibration curve and thus increase the accuracy and reliability of the results generated by the method in routine application. PMID:21377822

  3. 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.

  4. Is questionnaire information valid in the study of a chronic disease such as diabetes? The Nord-Trøndelag diabetes study

    Microsoft Academic Search

    K Midthjell; J Holmen; A Bjørndal; G Lund-Larsen

    1992-01-01

    STUDY OBJECTIVE--The aim was to validate information about diabetes mellitus collected by questionnaire in a large epidemiological survey. DESIGN--Questions on diabetes diagnosis, medical treatment for diabetes, diabetes duration, and hypertension treatment were selected from the Nord-Trøndelag health survey questionnaires. One of the municipalities was selected for the validation study. SETTING--The health survey 1984-86 addressed all inhabitants > or = 20

  5. Validation study of the Colorado Learning Attitudes about Science Survey at a Hispanic-serving institution

    NASA Astrophysics Data System (ADS)

    Sawtelle, Vashti; Brewe, Eric; Kramer, Laird

    2009-12-01

    The Colorado Learning Attitudes about Science Survey (CLASS) has been widely acknowledged as a useful measure of student cognitive attitudes about science and learning. The initial University of Colorado validation study included only 20% non-Caucasian student populations. In this Brief Report we extend their validation to include a predominately under-represented minority population. We validated the CLASS instrument at Florida International University, a Hispanic-serving institution, by interviewing students in introductory physics classes using a semistructured protocol, examining students’ responses on the CLASS item statements, and comparing them to the items’ intended meaning. We find that in our predominately Hispanic population, 94% of the students’ interview responses indicate that the students interpret the CLASS items correctly, and thus the CLASS is a valid instrument. We also identify one potentially problematic item in the instrument which one third of the students interviewed consistently misinterpreted.

  6. 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...

  7. Validity and Feasibility of a Digital Diet Estimation Method for Use with Preschool Children: A Pilot Study

    ERIC Educational Resources Information Center

    Nicklas, Theresa A.; O'Neil, Carol E.; Stuff, Janice; Goodell, Lora Suzanne; Liu, Yan; Martin, Corby K.

    2012-01-01

    Objective: 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." Methods: Preschool children and their caregivers participated in validation (n = 22) and feasibility (n = 24) pilot studies. Validity was determined in the metabolic research unit using…

  8. 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.

  9. 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

  10. 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; Wilcke, Renate A. I.

    2015-01-01

    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. In this paper, 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.

  11. Validation of the automatic image analyser to assess retinal vessel calibre (ALTAIR): a prospective study protocol

    PubMed Central

    Garcia-Ortiz, Luis; Gómez-Marcos, Manuel A; Recio-Rodríguez, Jose I; Maderuelo-Fernández, Jose A; Chamoso-Santos, Pablo; Rodríguez-González, Sara; de Paz-Santana, Juan F; Merchan-Cifuentes, Miguel A; Corchado-Rodríguez, Juan M

    2014-01-01

    Introduction The fundus examination is a non-invasive evaluation of the microcirculation of the retina. The aim of the present study is to develop and validate (reliability and validity) the ALTAIR software platform (Automatic image analyser to assess retinal vessel calibre) in order to analyse its utility in different clinical environments. Methods and analysis A cross-sectional study in the first phase and a prospective observational study in the second with 4 years of follow-up. The study will be performed in a primary care centre and will include 386 participants. The main measurements will include carotid intima-media thickness, pulse wave velocity by Sphygmocor, cardio-ankle vascular index through the VASERA VS-1500, cardiac evaluation by a digital ECG and renal injury by microalbuminuria and glomerular filtration. The retinal vascular evaluation will be performed using a TOPCON TRCNW200 non-mydriatic retinal camera to obtain digital images of the retina, and the developed software (ALTAIR) will be used to automatically calculate the calibre of the retinal vessels, the vascularised area and the branching pattern. For software validation, the intraobserver and interobserver reliability, the concurrent validity of the vascular structure and function, as well as the association between the estimated retinal parameters and the evolution or onset of new lesions in the target organs or cardiovascular diseases will be examined. Ethics and dissemination The study has been approved by the clinical research ethics committee of the healthcare area of Salamanca. All study participants will sign an informed consent to agree to participate in the study in compliance with the Declaration of Helsinki and the WHO standards for observational studies. Validation of this tool will provide greater reliability to the analysis of retinal vessels by decreasing the intervention of the observer and will result in increased validity through the use of additional information, especially in the areas of vascularisation and vessel branching patterns. Trial registration number Clinical Trials.gov Identifier: NCT02087605. PMID:25468505

  12. 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

  13. Risser patient satisfaction scale: a validation study in Greek cancer patients

    PubMed Central

    2012-01-01

    Background The current healthcare climate is characterized by a constant battle for the provision of quality care with limited resources and with patient satisfaction receiving increased attention, there is a need for reliable and valid assessment measures. This study describes the adaptation, testing and validation of the Risser Patient satisfaction Scale in an oncology care setting in Greece. The rationale for this study lies in the scarcity of such measures in the Greek language. Methods This is a test retest validation study in Greece. Data were collected from 298 hospitalized cancer patients. The validation methodology included the assessment of the item internal consistency, using the Cronbach alpha coefficient. The test-retest reliability was tested by the Kappa correlation coefficient. Results The scale demonstrated very good psychometric properties. The internal consistency of the instrument was good, Cronbach’s alpha was found to be 0.78 (p<0.001) and Kappa coefficient for reproducibility was found to be K=0.89 (95% CI: 0.83-0.91 p<0.0001). Conclusion The findings demonstrated strong agreement of the scale, suggesting that the Greek version offers substantial reliability. This study provides a valid and reliable tool to assess patient satisfaction in oncology settings. Means to monitor patient satisfaction, a key aspect of the policy agenda for quality care remain important for nurse leaders to develop better care in oncology settings. PMID:23190625

  14. 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

  15. Thermal conductivity of epoxy nanocomposites filled with MWCNT and hydrotalcite clay: A preliminary study

    NASA Astrophysics Data System (ADS)

    Romano, Vittorio; Naddeo, Carlo; Guadagno, Liberata; Vertuccio, Luigi

    2014-05-01

    Aim of this work is to study the effect clay on the thermal conductivity of epoxy resin filled with CNTs. Experiments and theoretical predictions show that the presence of hydrotalcite clay in a mesh of carbon nanotubes gives rise to aggregates and twisted bundles, resulting in a lower carbon nanotubes length and a lower thermal conductivity of epoxy nanocomposites.

  16. Nonballistic heat conduction in an integrable random-exchange Ising chain studied with quantum master equations

    E-print Network

    Li, Baowen

    Nonballistic heat conduction in an integrable random-exchange Ising chain studied with quantum numerically investigate the heat conduction in a random-exchange Ising spin chain by using the quantum master equation. The chain is subject to a uniform transverse field h, while the exchange couplings Qn between

  17. A Set Of Principles For Conducting And Evaluating Interpretive Field Studies In Information Systems

    E-print Network

    Heinz K. Klein; Michael D. Myers

    1999-01-01

    This article discusses the conduct and evaluation of interpretive research in information systems. While the conventions for evaluating information systems case studies conducted according to the natural science model of social science are now widely accepted, this is not the case for interpretive field studies. A set of principles for the conduct and evaluation of interpretive field research in information systems is proposed, along with their philosophical rationale. The usefulness of the principles is illustrated by evaluating three published interpretive field studies drawn from the IS research literature. The intention of the paper is to further reflection and debate on the important subject of grounding interpretive research methodology.

  18. Ring-Testing and Field-Validation of a Terrestrial Model Ecosystem (TME) – An Instrument for Testing Potentially Harmful Substances: Conceptual Approach and Study Design

    Microsoft Academic Search

    Thomas Knacker; Cornelis A. M. van Gestel; Susan E. Jones; Amadeu M. V. M. Soares; Hans-Joachim Schallnaß; Bernhard Förster; Clive A. Edwards

    2004-01-01

    During spring and summer 1999 a ring-test and field-validation study with an open, intact Terrestrial Model Ecosystem (TME) was conducted at four different European sites (Amsterdam, The Netherlands; Bangor, U.K.; Coimbra, Portugal; Flörsheim, Germany). The objective of the study was to establish a standardised method which allows the impact of chemical stressors on terrestrial compartments at ecosystem level to be

  19. 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…

  20. Walking index for spinal cord injury (WISCI): an international multicenter validity and reliability study

    Microsoft Academic Search

    JF Ditunno Jr; PL Ditunno; V Graziani; G Scivoletto; M Bernardi; V Castellano; M Marchetti; H Barbeau; HL Frankel; JM D'Andrea Greve; H-Y Ko; R Marshall; P Nance

    2000-01-01

    Study design: Construction of an international walking scale by a modified Delphi technique. Objective: The purpose of the study was to develop a more precise walking scale for use in clinical trials of subjects with spinal cord injury (SCI) and to determine its validity and reliability. Setting: Eight SCI centers in Australia, Brazil, Canada (2), Korea, Italy, the UK and

  1. 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…

  2. The Student Risk Screening Scale for Early Childhood: An Initial Validation Study

    ERIC Educational Resources Information Center

    Lane, Kathleen Lynne; Oakes, Wendy Peia; Menzies, Holly Mariah; Major, Rebecca; Allegra, Laurie; Powers, Lisa; Schatschneider, Chris

    2015-01-01

    We report findings of two exploratory validation studies of a revised instrument: the "Student Risk Screening Scale for Early Childhood" version (SRSS-EC). The SRSS-EC was modified to reflect characteristics of externalizing and internalizing behaviors manifested by preschool-age children. In Study 1, we explored the reliability of…

  3. How valid and reliable are patient satisfaction data? An analysis of 195 studies

    Microsoft Academic Search

    JOHN SITZIA

    1999-01-01

    Objective. To assess the properties of validity and reliability of instruments used to assess satisfaction in a broad sample of health service user satisfaction studies, and to assess the level of awareness of these issues among study authors. Design. Examination and analysis of 195 papers published in 1994 in 139 journals. The following databases were searched: British Nursing Index, CINAHL,

  4. A Validation and Reliability Study of Community Service Activities Scale in Turkey: A Social Evaluation

    ERIC Educational Resources Information Center

    Demir, Özden; Kaya, Halil Ibrahim; Tasdan, Murat

    2014-01-01

    The purpose of this study is to test the reliability and validity of Community Service Activities Scale (CSAS) developed by Demir, Kaya and Tasdan (2012) with a view to identify perceptions of Faculty of Education students regarding community service activities. The participants of the study are 313 randomly chosen students who attend six…

  5. Gender and Race Effects on Standardized Tests Predictive Validity: A Meta-analytical Study.

    ERIC Educational Resources Information Center

    Sanber, Shukri R.; Millman, Jason

    This paper summarizes and analyzes data from studies of differential validity and differential prediction for blacks versus whites and females versus males. Forty studies on racial differences and 53 on gender differences were selected from searches of the ERIC, PsychInfo, and Dissertation Abstracts International databases; Buros' Mental…

  6. 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…

  7. Ongoing Studies in Domain-Referenced Content Validity: First Look at the "Judgment" Issue.

    ERIC Educational Resources Information Center

    Baker, Eva; Polin, Linda

    The validity studies planned for the Test Design activities deal primarily with the appropriateness of items generated for a domain. Previous exploratory work in the field related to overall test content appropriateness ratings has not been satisfactory. Studies which are solely based on correlational data suffer from confounding with…

  8. The Volunteer Satisfaction Index: A Validation Study in the Chinese Cultural Context

    ERIC Educational Resources Information Center

    Wong, Lok Ping; Chui, Wing Hong; Kwok, Yan Yuen

    2011-01-01

    Using a Hong Kong-sourced sample of 261 participants, this study set out to validate the Volunteer Satisfaction Index (VSI) in the Chinese cultural context and to evaluate its psychometric properties. The VSI was originally developed by Galindo-Kuhn and Guzley (2001) to measure the outcomes of volunteer experiences. In this study, exploratory…

  9. A Validity and Reliability Study of the Online Cooperative Learning Attitude Scale (OCLAS)

    ERIC Educational Resources Information Center

    Korkmaz, Ozgen

    2012-01-01

    Determination of students' attitudes towards online cooperative learning is an important issue, which has not been studied adequately. In the literature, there are few scales to measure the attitude towards online cooperative learning for which validity and reliability have been proven. The main purpose of this study is to develop an attitude…

  10. 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…

  11. 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,…

  12. 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.

  13. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    42 Public Health 1 2011-10-01 2011-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS...

  14. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    42 Public Health 1 2014-10-01 2014-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS...

  15. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    42 Public Health 1 2012-10-01 2012-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS...

  16. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    42 Public Health 1 2010-10-01 2010-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS...

  17. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    42 Public Health 1 2010-10-01 2010-10-01 false Conduct of health assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH...

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

    E-print Network

    Guo, Yuyan

    2009-05-15

    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...

  19. A summary report of the COLIPA international validation study on alternatives to the draize rabbit eye irritation test

    Microsoft Academic Search

    P. G. Brantom; L. H. Bruner; M. Chamberlain; O. De Silva; J. Dupuis; L. K. Earl; D. P. Lovell; W. J. W. Pape; M. Uttley; D. M. Bagley; F. W. Baker; M. Bracher; P. Courtellemont; L. Declercq; S. Freeman; W. Steiling; A. P. Walker; G. J. Carr; N. Dami; G. Thomas; J. Harbell; P. A. Jones; U. Pfannenbecker; J. A. Southee; M. Tcheng; H. Argembeaux; D. Castelli; R. Clothier; D. J. Esdaile; H. Itigaki; K. Jung; Y. Kasai; H. Kojima; U. Kristen; M. Larnicol; R. W. Lewis; K. Marenus; O. Moreno; A. Peterson; E. S. Rasmussen; C. Robles; M. Stern

    1997-01-01

    The principal goal of this study was to determine whether the results from a set of selected currently available alternative methods as used by cosmetics companies are valid for predicting the eye irritation potential of cosmetics formulations and ingredients and, as a consequence, could be valid replacements for the Draize eye irritation test. For the first time in a validation

  20. 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

  1. Measuring suicidality using the personality assessment inventory: a convergent validity study with federal inmates.

    PubMed

    Patry, Marc W; Magaletta, Philip R

    2015-02-01

    Although numerous studies have examined the psychometric properties and clinical utility of the Personality Assessment Inventory in correctional contexts, only two studies to date have specifically focused on suicide ideation. This article examines the convergent validity of the Suicide Ideation Scale and the Suicide Potential Index on the Personality Assessment Inventory in a large, nontreatment sample of male and female federal inmates (N = 1,120). The data indicated robust validity support for both the Suicide Ideation Scale and Suicide Potential Index, which were each correlated with a broad group of validity indices representing multiple assessment modalities. Recommendations for future research to build upon these findings through replication and extension are made. PMID:24947983

  2. Study of Electrical Conductivity and Dielectric Behaviour of Molybdenum containing Bismuth Borate Glasses

    NASA Astrophysics Data System (ADS)

    Kishore, N.; Sanjay; Agarwal, A.; Dahiya, Sanjay; Pal, Inder

    2015-02-01

    Bismuth borate glasses containing MoO3 content have been synthesized by the standard melt-quenching technique. The samples have been characterized by X-ray diffraction and scanning electron microscopy. Frequency and temperature dependent conductivity measurements have been carried out in the range of 20Hz to 1MHz and in the temperature range of 373K to 623K respectively. The frequency dependent conductivity has been studied using both conductivity and modulus formalisms. The dielectric permittivity (?' and ?"), electrical modulus (M*) and dielectric loss were also studied of the prepared glasses. The values of ?' and ?'' are found to decrease with increase in frequency.

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

    SciTech Connect

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

  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

    2014-10-23

    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. A functional observational battery for use in canine toxicity studies: development and validation.

    PubMed

    Gad, S C; Gad, S E

    2003-01-01

    The most commonly used nonrodent species in regulatory toxicity and safety assessment studies has been and remains the dog, with the beagle being the standard breed employed. Although a standard functional observational battery (FOB) or neurobehavioral screen for use in rodents (primarily rats) has been incorporated into rodent studies since the late 1980s, this is not the case in nonrodents. In the pharmaceutical area (where repeat exposure nonrodent studies are generally required to develop a drug for humans), some work has been previously conducted towards developing a similar screen in the dog but progress has been limited. Given both the differential metabolism and sensitivity of the dog compared to rodents and the extreme desirability of having as complete a set of toxicity and/or functionality measures in the same species (to simplify and improve the accuracy of dose/response metrics) as possible, the need for such a standardized and validated methodology is clear. Study data from prior work establish the susceptibility of dogs to a wide variety of neurotoxic agents, including 6-aminonicotinamide (ANA), methanol, lasalocid, metronidazole, acrylamide, clinoquinol, organo tins, and mercury. Additionally, the dog is likewise well established as a sensitive model for a wide range of peripheral and central nervous system-active pharmacologic agents, as required by recent regulatory requirements for safety pharmacology evaluations. Here we report on a robust and yet sensitive noninvasive screening methodology for detecting and providing initial quantitation and characterization of such direct and indirect neurotoxic and neuropharmacologic effects that has been developed. Additionally, an analysis and interpretation component that allows differentiation of neurotoxic from neuropharmacologic activities has also been adapted from prior work by one of the authors. Comparative species difference in sensitivity to neuroactive agents are also discussed, as well as means for integrating this evaluation screen into existing standard design. Particularly, with the recent promulgation of safety pharmacology testing requirements (the in vivo cardiovascular component of which is performed in the dog), the availability of such an evaluation paradigm presents a valuable potential addition to existing study designs without increasing animal usage. PMID:14680988

  6. 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

  7. Tuning the thermal conductivity of silicene with tensile strain and isotopic doping: A molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Pei, Qing-Xiang; Zhang, Yong-Wei; Sha, Zhen-Dong; Shenoy, Vivek B.

    2013-07-01

    Silicene is a monolayer of silicon atoms arranged in honeycomb lattice similar to graphene. We study the thermal transport in silicene by using non-equilibrium molecular dynamics simulations. We focus on the effects of tensile strain and isotopic doping on the thermal conductivity, in order to tune the thermal conductivity of silicene. We find that the thermal conductivity of silicene, which is shown to be only about 20% of that of bulk silicon, increases at small tensile strains but decreases at large strains. We also find that isotopic doping of silicene results in a U-shaped change of the thermal conductivity for the isotope concentration varying from 0% to 100%. We further show that ordered doping (isotope superlattice) leads to a much larger reduction in thermal conductivity than random doping. Our findings are important for the thermal management in silicene-based electronic devices and for thermoelectric applications of silicene.

  8. 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.

  9. Study of the Validity and Reliability of a Self-Efficacy Scale of Teaching Material Utilization

    ERIC Educational Resources Information Center

    Korkmaz, Ozgen

    2011-01-01

    The main purpose of this study is to develop a scale in order to detect the level of pre-service teachers' utilization from teaching materials based on their perception of self-efficacy. The sample group is composed of 439 students for the first application and 215 students for the second. In order to detect the validity of the scale, exploratory…

  10. The validity of post-concussion syndrome in children: A controlled historical cohort study

    Microsoft Academic Search

    Olga Nacajauskaite; Milda Endziniene; Kristina Jureniene; Harald Schrader

    2006-01-01

    The aim of this controlled historical cohort study was to assess the validity of post-concussion syndrome in children. We identified 301 children aged 4–15 years who had sustained an isolated brain concussion, and another group of 301 children who sustained any other mild body injury excluding the head. Parents from both groups filled in standardized questionnaires containing questions about the

  11. Student Evaluations of Teaching and Courses: Student Study Strategies as a Criterion of Validity.

    ERIC Educational Resources Information Center

    Prosser, Michael; Trigwell, Keith

    1990-01-01

    A study of 11 courses in 2 institutions (n=999 students) indicates that courses and teaching in which students have adopted deeper strategies for learning also have higher student ratings, supporting, in general, the validity of student ratings. (Author/MSE)

  12. 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 ...

  13. A Study of the Validity and Reliability of the Adult Career Concerns Inventory.

    ERIC Educational Resources Information Center

    Halpin, Glennelle; And Others

    A study was designed to investigate the validity and reliability of the adult Career Concerns Inventory, which assesses career concerns of adults of any age and occupation. Subjects, 4 male and 165 female students (ages 23 to 62) enrolled in the graduate nursing program at a southern university, were administered the adult Career Concerns…

  14. 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…

  15. 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…

  16. A Comparative Study of Adolescent Risk Assessment Instruments: Predictive and Incremental Validity

    ERIC Educational Resources Information Center

    Welsh, Jennifer L.; Schmidt, Fred; McKinnon, Lauren; Chattha, H. K.; Meyers, Joanna R.

    2008-01-01

    Promising new adolescent risk assessment tools are being incorporated into clinical practice but currently possess limited evidence of predictive validity regarding their individual and/or combined use in risk assessments. The current study compares three structured adolescent risk instruments, Youth Level of Service/Case Management Inventory…

  17. 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…

  18. Validation Studies of the Paffenbarger Physical Activity Questionnaire/College Alumnus Questionnaire (CAQ)

    Cancer.gov

    This article states the PA questionnaire used is the same as that used in the Singh 1996 validation study (which does appear to be the Paffenbarger). But in fact, the two questionnaires (which are provided in both articles) don’t appear to be the same; and the Singh 2001 version does not ask specific walking questions.

  19. 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…

  20. The OECD Program to Validate the Rat Uterotrophic Bioassay. Phase 2: Dose-Response Studies

    Microsoft Academic Search

    Jun Kanno; Lesley Onyon; Shyamal Peddada; John Ashby; Elard Jacob; William Owens

    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 valida- tion 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

  1. 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…

  2. The Survey of Attitudes Toward Statistics Scale: A Construct Validity Study

    ERIC Educational Resources Information Center

    Cashin, Susan E.; Elmore, Patricia B.

    2005-01-01

    The purpose of the present study is to investigate evidence of the validity of Survey of Attitudes Toward Statistics Scale (SATS) scores and their relationship with scores from two other measures of attitudes toward statistics, the Attitude Toward Statistics Scale (ATS) and the Statistics Attitude Survey. The pre- and postcourse responses of 342…

  3. WWLL global lightning detection system: Regional validation study in Erin H. Lay,1,2

    E-print Network

    Thomas, Jeremy N.

    WWLL global lightning detection system: Regional validation study in Brazil Erin H. Lay,1,2 Robert] An experimental lightning detection network, the World Wide Lightning Location network (WWLL), is being developed. This paper provides a ``worst case'' analysis of WWLL location accuracy in Brazil where the VLF lightning

  4. 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

  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. Family Early Literacy Practices Questionnaire: A Validation Study for a Spanish-Speaking Population

    ERIC Educational Resources Information Center

    Lewis, Kandia

    2012-01-01

    The purpose of the current study was to evaluate the psychometric validity of a Spanish translated version of a family involvement questionnaire (the FELP) using a mixed-methods design. Thus, statistical analyses (i.e., factor analysis, reliability analysis, and item analysis) and qualitative analyses (i.e., focus group data) were assessed.…

  7. Breast bud detection: a validation study in the Chilean Growth Obesity Cohort Study

    PubMed Central

    2014-01-01

    Background Early puberty onset has been related to future chronic disease; however breast bud assessment in large scale population studies is difficult because it requires trained personnel. Thus our aim is to assess the validity of self and maternal breast bud detection, considering girl’s body mass index (BMI) and maternal education. Methods In 2010, 481 girls (mean age?=?7.8) from the Growth and Obesity Chilean Cohort Study were evaluated by a nutritionist trained in breast bud detection. In addition, the girl(n?=?481) and her mother(n?=?341) classified the girl’s breast development after viewing photographs of Tanner stages. Concordance between diagnostics was estimated (kappa, Spearman correlation) considering girls’ BMI and mother’s educational level. Results 14% of the girls presented breast buds and 43% had excess weight (BMI z-score?>?1, World Health Organization 2007). Self-assessment showed low concordance with the evaluator (K?studies, particularly developing countries. PMID:25115568

  8. 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…

  9. Conducting multisite research studies in nursing education: brief practice of CPR skills as an exemplar.

    PubMed

    Oermann, Marilyn H; Hallmark, Beth F; Haus, Carol; Kardong-Edgren, Suzie E; McColgan, Jacqueline Keegan; Rogers, Nancy

    2012-01-01

    Few large, multisite studies have been conducted in nursing education, and literature pertaining to conducting those studies is lacking. We recently completed a randomized trial to examine the effects of brief practice on nursing students' retention of CPR psychomotor skills. The purpose of this article is to describe strategies for implementing a multisite study in nursing education, using our research as an exemplar. Strategies are presented for structuring a multisite study; selecting, preparing, and communicating with team members across sites; selecting sites; recruiting and retaining participants; managing the technical aspects of an intervention; and collecting and managing data. Ethical considerations also are explored. PMID:22132720

  10. Validation of the da Vinci Surgical Skill Simulator across three surgical disciplines: A pilot study

    PubMed Central

    Alzahrani, Tarek; Haddad, Richard; Alkhayal, Abdullah; Delisle, Josée; Drudi, Laura; Gotlieb, Walter; Fraser, Shannon; Bergman, Simon; Bladou, Frank; Andonian, Sero; Anidjar, Maurice

    2013-01-01

    Objective: In this paper, we evaluate face, content and construct validity of the da Vinci Surgical Skills Simulator (dVSSS) across 3 surgical disciplines. Methods: In total, 48 participants from urology, gynecology and general surgery participated in the study as novices (0 robotic cases performed), intermediates (1–74) or experts (?75). Each participant completed 9 tasks (Peg board level 2, match board level 2, needle targeting, ring and rail level 2, dots and needles level 1, suture sponge level 2, energy dissection level 1, ring walk level 3 and tubes). The Mimic Technologies software scored each task from 0 (worst) to 100 (best) using several predetermined metrics. Face and content validity were evaluated by a questionnaire administered after task completion. Wilcoxon test was used to perform pair wise comparisons. Results: The expert group comprised of 6 attending surgeons. The intermediate group included 4 attending surgeons, 3 fellows and 5 residents. The novices included 1 attending surgeon, 1 fellow, 13 residents, 13 medical students and 2 research assistants. The median number of robotic cases performed by experts and intermediates were 250 and 9, respectively. The median overall realistic score (face validity) was 8/10. Experts rated the usefulness of the simulator as a training tool for residents (content validity) as 8.5/10. For construct validity, experts outperformed novices in all 9 tasks (p < 0.05). Intermediates outperformed novices in 7 of 9 tasks (p < 0.05); there were no significant differences in the energy dissection and ring walk tasks. Finally, experts scored significantly better than intermediates in only 3 of 9 tasks (matchboard, dots and needles and energy dissection) (p < 0.05). Conclusions: This study confirms the face, content and construct validities of the dVSSS across urology, gynecology and general surgery. Larger sample size and more complex tasks are needed to further differentiate intermediates from experts. PMID:23914275

  11. 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.

  12. Eating Disorder Diagnostic Scale: Additional Evidence of Reliability and Validity

    Microsoft Academic Search

    Eric Stice; Melissa Fisher; Erin Martinez

    2004-01-01

    The authors conducted 4 studies investigating the reliability and validity of the Eating Disorder Diagnostic Scale (EDDS; E. Stice, C. F. Telch, & S. L. Rizvi, 2000), a brief self-report measure for diagnosing anorexia nervosa, bulimia nervosa, and binge eating disorder. Study 1 found that the EDDS showed criterion validity with interview-based diagnoses, convergent validity with risk factors for eating

  13. Vapor sensing mechanism of acid on copper phthalocyanine thin films studied by electrical conductivity

    NASA Astrophysics Data System (ADS)

    Singh, Sukhwinder; Saini, G. S. S.; Tripathi, S. K.

    2013-06-01

    The electrical conductivity of thin films of iron phthalocyanine on glass substrates by thermal evaporation technique have been investigated. The electrical conductivity of thin films of these complexes changes when exposed to oxidizing and reducing gases such as halogens, ammonia, water and NOX. Thermal activation energy in the intrinsic region and impurity scattering region can be calculated by using Arrhenius plot. The dark conductivity and photoconductivity have been taken at different temperatures in the range 312-389 K. These films have been studied as chemical sensors for dilute sulphuric acid.

  14. Thermally stimulated conductivity studies of trapping centers in alkali-borosilicate glasses

    NASA Technical Reports Server (NTRS)

    Catchings, R. M.

    1979-01-01

    Thermally stimulated conductivity studies have been performed on unirradiated borosilicate glasses made to contain various amounts of sodium, lithium, nickel, and iron oxides. Measurements were made between 77 and 570 K. All the samples gave one or more conductivity peaks below room temperature. Analysis of the initial-rise slope of the conductivity peaks of the various samples gave trapping-level energies ranging from 0.1 to 1.9 eV. The shape and temperature of the maximum of most of the peaks changed on each measurement cycle. A few samples exhibited a common peak that formed on annealing.

  15. Validation and Reliability of a Smartphone Application for the International Prostate Symptom Score Questionnaire: A Randomized Repeated Measures Crossover Study

    PubMed Central

    Shim, Sung Ryul; Sun, Hwa Yeon; Ko, Young Myoung; Chun, Dong-Il; Yang, Won Jae

    2014-01-01

    Background Smartphone-based assessment may be a useful diagnostic and monitoring tool for patients. There have been many attempts to create a smartphone diagnostic tool for clinical use in various medical fields but few have demonstrated scientific validity. Objective The purpose of this study was to develop a smartphone application of the International Prostate Symptom Score (IPSS) and to demonstrate its validity and reliability. Methods From June 2012 to May 2013, a total of 1581 male participants (?40 years old), with or without lower urinary tract symptoms (LUTS), visited our urology clinic via the health improvement center at Soonchunhyang University Hospital (Republic of Korea) and were enrolled in this study. A randomized repeated measures crossover design was employed using a smartphone application of the IPSS and the conventional paper form of the IPSS. Paired t test under a hypothesis of non-inferior trial was conducted. For the reliability test, the intraclass correlation coefficient (ICC) was measured. Results The total score of the IPSS (P=.289) and each item of the IPSS (P=.157-1.000) showed no differences between the paper version and the smartphone version of the IPSS. The mild, moderate, and severe LUTS groups showed no differences between the two versions of the IPSS. A significant correlation was noted in the total group (ICC=.935, P<.001). The mild, moderate, and severe LUTS groups also showed significant correlations (ICC=.616, .549, and .548 respectively, all P<.001).There was selection bias in this study, as only participants who had smartphones could participate. Conclusions The validity and reliability of the smartphone application version were comparable to the conventional paper version of the IPSS. The smartphone application of the IPSS could be an effective method for measuring lower urinary tract symptoms. PMID:24513507

  16. 41 CFR 105-50.202-2 - Preparation of or assistance in the conduct of statistical or other studies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...assistance in the conduct of statistical or other studies. 105-50...assistance in the conduct of statistical or other studies. ...includes preparation of statistical or other studies and compilations, technical tests and...

  17. 41 CFR 105-50.202-2 - Preparation of or assistance in the conduct of statistical or other studies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...assistance in the conduct of statistical or other studies. 105-50...assistance in the conduct of statistical or other studies. ...includes preparation of statistical or other studies and compilations, technical tests and...

  18. 41 CFR 105-50.202-2 - Preparation of or assistance in the conduct of statistical or other studies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...assistance in the conduct of statistical or other studies. 105-50...assistance in the conduct of statistical or other studies. ...includes preparation of statistical or other studies and compilations, technical tests and...

  19. 41 CFR 105-50.202-2 - Preparation of or assistance in the conduct of statistical or other studies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...assistance in the conduct of statistical or other studies. 105-50...assistance in the conduct of statistical or other studies. ...includes preparation of statistical or other studies and compilations, technical tests and...

  20. 41 CFR 105-50.202-2 - Preparation of or assistance in the conduct of statistical or other studies.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...assistance in the conduct of statistical or other studies. 105-50...assistance in the conduct of statistical or other studies. ...includes preparation of statistical or other studies and compilations, technical tests and...

  1. Nerve conduction in relation to vibration exposure - a non-positive cohort study

    PubMed Central

    2010-01-01

    Background Peripheral neuropathy is one of the principal clinical disorders in workers with hand-arm vibration syndrome. Electrophysiological studies aimed at defining the nature of the injury have provided conflicting results. One reason for this lack of consistency might be the sparsity of published longitudinal etiological studies with both good assessment of exposure and a well-defined measure of disease. Against this background we measured conduction velocities in the hand after having assessed vibration exposure over 21 years in a cohort of manual workers. Methods The study group consisted of 155 male office and manual workers at an engineering plant that manufactured pulp and paper machinery. The study has a longitudinal design regarding exposure assessment and a cross-sectional design regarding the outcome of nerve conduction. Hand-arm vibration dose was calculated as the product of self-reported occupational exposure, collected by questionnaire and interviews, and the measured or estimated hand-arm vibration exposure in 1987, 1992, 1997, 2002, and 2008. Distal motor latencies in median and ulnar nerves and sensory nerve conduction over the carpal tunnel and the finger-palm segments in the median nerve were measured in 2008. Before the nerve conduction measurement, the subjects were systemically warmed by a bicycle ergometer test. Results There were no differences in distal latencies between subjects exposed to hand-arm vibration and unexposed subjects, neither in the sensory conduction latencies of the median nerve, nor in the motor conduction latencies of the median and ulnar nerves. Seven subjects (9%) in the exposed group and three subjects (12%) in the unexposed group had both pathological sensory nerve conduction at the wrist and symptoms suggestive of carpal tunnel syndrome. Conclusion Nerve conduction measurements of peripheral hand nerves revealed no exposure-response association between hand-arm vibration exposure and distal neuropathy of the large myelinated fibers in a cohort of male office and manual workers. PMID:20642848

  2. Nerve conduction studies and its importance in diagnosis of acute poliomyelitis

    Microsoft Academic Search

    M. Agboatwalla; S. R. Kirmani; A. Sonawalla; D. Samin Akram

    1993-01-01

    Motor nerve conduction velocities was performed on 50 subjects in the pediatric age group. Thirty two patients with acute\\u000a poliomyelitis and 18 controls. The MNCV was studied in the median nerve in the upper limb and the posterior tibial in the\\u000a lower limb. The motor nerve conduction velocity in polio patients matched well with the controls, as well as within

  3. An Analytical Study on a Model Describing Heat Conduction in Rectangular Radial Fin with Temperature-Dependent Thermal Conductivity

    NASA Astrophysics Data System (ADS)

    Hedayati, F.; Ganji, D. D.; Hamidi, S. M.; Malvandi, A.

    2012-06-01

    The coupling of the homotopy perturbation method (HPM) and the variational iteration method (VIM) is a strong technique for solving higher dimensional initial boundary value problems. In this article, after a brief explanation of the mentioned method, the coupled techniques are applied to one-dimensional heat transfer in a rectangular radial fin with a temperature-dependent thermal conductivity to show the effectiveness and accuracy of the method in comparison with other methods. The graphical results show the best agreement of the three methods; however, the amount of calculations of each iteration for the combination of HPM and VIM was reduced markedly for multiple iterations. It was found that the variation of the dimensionless temperature strongly depends on the dimensionless small parameter {\\varepsilon_1}. Moreover, as the dimensionless length increases, the thermal conductivity of the fin decreases along the fin.

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

    Microsoft Academic Search

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

    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 effective college teachers. Participants were 912 undergraduate and graduate students (10.7% of student body) from various academic majors enrolled

  5. The EC\\/HO international validation study on alternatives to the draize eye irritation test

    Microsoft Academic Search

    M. Balls; P. A. Botham; L. H. Bruner; H. Spielmann

    1995-01-01

    This is the final report of the Management Team for a European Commission\\/British Home Office (EC\\/HO) validation study on alternatives to the Draize eye irritation test. The principal goal of the study was to establish whether one or more of nine non-animal tests could be used to replace the Draize test for all severely irritating materials (or those belonging to

  6. 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

  7. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOLVENT EXTRACTION - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation and Liabi...

  8. GUIDE TO CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOIL WASHING - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and Liab...

  9. 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 ...

  10. 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

  11. 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…

  12. Money ethic, moral conduct and work related attitudes : Field study from the public sector in Swaziland

    Microsoft Academic Search

    Gbolahan Gbadamosi; Patricia Joubert

    2005-01-01

    Purpose – This study aims to investigate perception of ethical and moral conduct in the public sector in Swaziland, specifically, the relationship among: money ethic, attitude towards business ethics, corruption perception, turnover intention, job performance, job satisfaction, and the demographic profile of respondents. Design\\/methodology\\/approach – The study was a survey using self-administered questionnaires. Using stratified sampling technique in selected organisations,

  13. Gemifloxacin mesylate (GFM) stability evaluation applying a validated bioassay method and in vitro cytotoxic study.

    PubMed

    Paim, Clésio S; Führ, Fernanda; Barth, Aline B; Gonçalves, Carlos E I; Nardi, Nance; Steppe, Martin; Schapoval, Elfrides E S

    2011-02-15

    The validation of a microbiological assay applying the cylinder-plate method to determine the quinolone gemifloxacin mesylate (GFM) content is described. Using a strain of Staphylococcus epidermidis ATCC 12228 as the test organism, the GFM content in tablets at concentrations ranging from 0.5 to 4.5 ?g mL(-1) could be determined. A standard curve was obtained by plotting three values derived from the diameters of the growth inhibition zone. A prospective validation showed that the method developed is linear (r=0.9966), precise (repeatability and intermediate precision), accurate (100.63%), specific and robust. GFM solutions (from the drug product) exposed to direct UVA radiation (352 nm), alkaline hydrolysis, acid hydrolysis, thermal stress, hydrogen peroxide causing oxidation, and a synthetic impurity were used to evaluate the specificity of the bioassay. The bioassay and the previously validated high performance liquid chromatographic (HPLC) method were compared using Student's t test, which indicated that there was no statistically significant difference between these two validated methods. These studies demonstrate the validity of the proposed bioassay, which allows reliable quantification of GFM in tablets and can be used as a useful alternative methodology for GFM analysis in stability studies and routine quality control. The GFM reference standard (RS), photodegraded GFM RS, and synthetic impurity samples were also studied in order to determine the preliminary in vitro cytotoxicity to peripheral blood mononuclear cells. The results indicated that the GFM RS and photodegraded GFM RS were potentially more cytotoxic than the synthetic impurity under the conditions of analysis applied. PMID:21238783

  14. Extraction of tumor motion trajectories using PICCS-4DCBCT: A validation study

    SciTech Connect

    Qi Zhihua; Chen Guanghong [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, 53705 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, 53792 (United States); Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States) and Department of Human Oncology, University of Wisconsin-Madison, Madison, Wisconsin, 53792 (United States)

    2011-10-15

    Purpose: As a counterpart of 4DCT in the treatment planning stage of radiotherapy treatment, 4D cone beam computed tomography (4DCBCT) method has been proposed to verify tumor motion trajectories before radiation therapy treatment delivery. Besides 4DCBCT acquisition using slower gantry rotation speed or multiple rotations, a new method using the prior image constrained compressed sensing (PICCS) image reconstruction method and the standard 1-min data acquisition were proposed. In this paper, the PICCS-4DCBCT method was combined with deformable registration to validate its capability in motion trajectory extraction using physical phantom data, simulated human subject data from 4DCT and in vivo human subject data. Methods: Two methods were used to validate PICCS-4DCBCT for the purpose of respiratory motion delineation. The standard 1-min gantry rotation Cone Beam CT acquisition was used for both methods. In the first method, 4DCBCT projection data of a physical motion phantom were acquired using an on-board CBCT acquisition system (Varian Medical Systems, Palo Alto, CA). Using a deformable registration method, the object motion trajectories were extracted from both FBP and PICCS reconstructed 4DCBCT images, and compared against the programmed motion trajectories. In the second method, using a clinical 4DCT dataset, Cone Beam CT projections were simulated by forward projection. Using a deformable registration method, the tumor motion trajectories were extracted from the reconstructed 4DCT and PICCS-4DCBCT images. The performance of PICCS-4DCBCT is assessed against the 4DCT ground truth. The breathing period was varied in the simulation to study its effect on motion extraction. For both validation methods, the root mean square error (RMSE) and the maximum of the errors (MaxE) were used to quantify the accuracy of the extracted motion trajectories. After the validation, a clinical dataset was used to demonstrate the motion delineation capability of PICCS-4DCBCT for human subjects. Results: In both validation studies, the RMSEs of the extracted motion trajectories from PICCS-4DCBCT images are less than 0.7 mm, and their MaxEs are less than 1 mm, for all three directions. In comparison, FBP-4DCBCT shows considerably larger RMSEs in the physical phantom based validation. PICCS-4DCBCT also shows insensitivity to the breathing period in the 4DCT based validation. For the in vivo human subject study, high quality 3D motion trajectory of the tumor was obtained from PICCS-4DCBCT images and showed consistency with visual observation. Conclusions: These results demonstrate accurate delineation of tumor motion trajectory can be achieved using PICCS-4DCBCT and the standard 1-min data acquisition.

  15. Extraction of tumor motion trajectories using PICCS-4DCBCT: A validation study

    PubMed Central

    Qi, Zhihua; Chen, Guang-Hong

    2011-01-01

    Purpose: As a counterpart of 4DCT in the treatment planning stage of radiotherapy treatment, 4D cone beam computed tomography (4DCBCT) method has been proposed to verify tumor motion trajectories before radiation therapy treatment delivery. Besides 4DCBCT acquisition using slower gantry rotation speed or multiple rotations, a new method using the prior image constrained compressed sensing (PICCS) image reconstruction method and the standard 1-min data acquisition were proposed. In this paper, the PICCS-4DCBCT method was combined with deformable registration to validate its capability in motion trajectory extraction using physical phantom data, simulated human subject data from 4DCT and in vivo human subject data. Methods: Two methods were used to validate PICCS-4DCBCT for the purpose of respiratory motion delineation. The standard 1-min gantry rotation Cone Beam CT acquisition was used for both methods. In the first method, 4DCBCT projection data of a physical motion phantom were acquired using an on-board CBCT acquisition system (Varian Medical Systems, Palo Alto, CA). Using a deformable registration method, the object motion trajectories were extracted from both FBP and PICCS reconstructed 4DCBCT images, and compared against the programmed motion trajectories. In the second method, using a clinical 4DCT dataset, Cone Beam CT projections were simulated by forward projection. Using a deformable registration method, the tumor motion trajectories were extracted from the reconstructed 4DCT and PICCS-4DCBCT images. The performance of PICCS-4DCBCT is assessed against the 4DCT ground truth. The breathing period was varied in the simulation to study its effect on motion extraction. For both validation methods, the root mean square error (RMSE) and the maximum of the errors (MaxE) were used to quantify the accuracy of the extracted motion trajectories. After the validation, a clinical dataset was used to demonstrate the motion delineation capability of PICCS-4DCBCT for human subjects. Results: In both validation studies, the RMSEs of the extracted motion trajectories from PICCS-4DCBCT images are less than 0.7 mm, and their MaxEs are less than 1 mm, for all three directions. In comparison, FBP-4DCBCT shows considerably larger RMSEs in the physical phantom based validation. PICCS-4DCBCT also shows insensitivity to the breathing period in the 4DCT based validation. For the in vivo human subject study, high quality 3D motion trajectory of the tumor was obtained from PICCS-4DCBCT images and showed consistency with visual observation. Conclusions: These results demonstrate accurate delineation of tumor motion trajectory can be achieved using PICCS-4DCBCT and the standard 1-min data acquisition. PMID:21992371

  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. 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.

  18. The conductive properties of single DNA molecules studied by torsion tunneling atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Wang, W.; Niu, D. X.; Jiang, C. R.; Yang, X. J.

    2014-01-01

    The conductive properties of single natural ?-DNA molecules are studied by torsion tunneling atomic force microscopy (TR-TUNA). The currents both parallel to and perpendicular to the DNA chains are investigated, but only weak or even no current signals are detected by TR-TUNA. To improve the conductance of DNA molecules, silver and copper metallized DNAs are fabricated and their conductivities are checked by TR-TUNA. It is found that for both Cu- and Ag-DNAs, the conductivity perpendicular to the DNA chain is enhanced significantly as the metal clusters are attached to the DNA chains. But parallel to the chain the electrical transport is still weak, most probably due to the ‘beads-on-a-string’ constructions of metallized DNAs.

  19. Studies on Proton Conducting Polymer Electrolytes Based on Pvdf-Pva with NH4NO3

    NASA Astrophysics Data System (ADS)

    Muthuvinayagam, M.; Gopinathan, C.; Rajeswari, N.; Selvasekarapandian, S.; Sanjeeviraja, C.

    2013-07-01

    PVDF-PVA polymer electrolytes with various blend ratios are prepared by solution casting technique with DMF (Merck) as solvent to optimize the blend ratio on the basis of high ionic conductivity. Then, different concentrations of NH4NO3 are doped with the optimized PVDF-PVA blend ratio and polymer blend electrolytes are prepared. The complex formation has been confirmed by XRD and FTIR analysis. The ac impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte membranes in the range 303-323K and it is found that the temperature dependence of ionic conductivity of the polymer blend electrolytes obey the Arrhenius relation. The maximum ionic conductivity is found to be 5.99×10-4 S/cm with activation energy Ea=0.21 eV for PVDF-PVA-NH4NO3 (80:20:0.4MWt%) polymer electrolyte.

  20. A preliminary study on the thermal conductivity and flammability of WPC based on some tropical woods

    NASA Astrophysics Data System (ADS)

    Chia, L. H. L.; Chua, P. H.; Lee, E. E. N.

    Selected local woods and their wood-polymer combinations or composites (WPC) were tested for their thermal conductivity and their fire resistance. WPC were prepared by polymerizing monomers " in situ" in oven dried woods by gamma radiation. The monomers included acrylonitrile (AN), 60% styrene-40% acrylonitrile (STAN), methyl methacrylate (MMA), 95% methyl methacrylate —5% dioxane (MD), and vinylidene chloride (VDC). A reduction in thermal conductivity was exhibited by all the composites prepared. W-PAN showed the greatest reduction in thermal conductivity and W-PSTAN in general showed the least. An explanation is suggested for this behaviour. The polymers PMMA and PMD were found to enhance flammability of the woods while PVDC, PAN, and PSTAN imparted fire resistance to the woods. Of the six local woods studied, Ramin-and-Keruing-polymer composites showed the highest flammable tendencies obtained. The correlation of thermal conductivity to flammability is discussed.

  1. AC Conductivity Studies in Lithium-Borate Glass Containing Gold Nanoparticles

    NASA Astrophysics Data System (ADS)

    Shivaprakash, Y.; Anavekar, R. V.

    2011-07-01

    Gold nanoparticles have been synthesized in a base glass with composition 30Li2O-70B2O3 using gold chloride (HAuCl4.3H2O) as a dopant. The samples are characterized using XRD, ESR, SEM and optical absorption in the visible range. AC conductivity studies have been performed at RT over a frequency range 100 to 10 MHz. The dc conductivity is calculated from the complex impedence plot. The dc conductivity is found to be increasing with the increase of dopant concentration. AC conductivity data is fitted with Almond-West law with power exponent `s'. The values of `s' is found to lie in the range of 0.70-0.73.

  2. Validation of multivariate screening methodology. Case study: detection of food fraud.

    PubMed

    López, M Isabel; Colomer, Núria; Ruisánchez, Itziar; Callao, M Pilar

    2014-05-27

    Multivariate screening methods are increasingly being implemented but there is no worldwide harmonized criterion for their validation. This study contributes to establish protocols for validating these methodologies. We propose the following strategy: (1) Establish the multivariate classification model and use receiver operating characteristic (ROC) curves to optimize the significance level (?) for setting the model's boundaries. (2) Evaluate the performance parameter from the contingency table results and performance characteristic curves (PCC curves). The adulteration of hazelnut paste with almond paste and chickpea flour has been used as a case study. Samples were analyzed by infrared (IR) spectroscopy and the multivariate classification technique used was soft independent modeling of class analogies (SIMCA). The ROC study showed that the optimal ? value for setting the SIMCA boundaries was 0.03 in both cases. The sensitivity value was 93%, specificity 100% for almond and 98% for chickpea, and efficiency 97% for almond and 93% for chickpea. PMID:24832991

  3. Graphology and personality: an empirical study on validity of handwriting analysis.

    PubMed

    Dazzi, Carla; Pedrabissi, Luigi

    2009-12-01

    The aim of the present work was to examine validity of the graphological method to assess personality traits. The results of two studies are described. In Study 1, the Big Five Questionnaire was administered to a sample of 101 university students who provided a sample of a handwritten text. Two graphologists were asked to detect the same dimensions and facets measured by the Big Five Questionnaire using a 9-point scale. Correlations between the Big Five Questionnaire and graphological evaluations did not confirm the capability of handwriting analysis to measure Big Five personality traits. Also, interrater reliability was very low. Study 2 (N = 102) was carried out using handwritten texts with autobiographical content for the graphological analysis. Two different graphologists and two laypersons were involved. No evidence was found to validate the graphological method as a measure of personality. PMID:20229925

  4. Issues in the reporting and conduct of instrumental variable studies: a systematic review.

    PubMed

    Davies, Neil M; Smith, George Davey; Windmeijer, Frank; Martin, Richard M

    2013-05-01

    Instrumental variables can be used to estimate the causal effects of exposures on outcomes in the presence of residual or uncontrolled confounding. To assess the validity of analyses using instrumental variables, specific information about whether underlying assumptions are met must be presented, in particular to demonstrate that the instrument is associated with the exposure but not with measured confounding factors. We systematically reviewed the epidemiological literature in Embase and Medline for articles containing the term "instrumental variable$" to investigate whether reporting of test statistics in studies using instrumental variables was sufficient to assess the validity of the results. We extracted the information each study reported about their instrumental variables, including specification tests used to check assumptions. The search found 756 studies of which 90 were relevant and were included. Only 25 (28%) studies reported appropriate tests of the strength of the associations between instruments and exposure. Forty-four (49%) studies reported associations between the instrumental variables and observed covariates. Studies using instrumental variables had wide confidence intervals and so effect estimates were imprecise. We propose a checklist of information and specification tests that studies using instrumental variables should report. PMID:23532055

  5. Medical Student Quality-of-Life in the Clerkships: A Scale Validation Study.

    PubMed

    Brannick, Michael T; Horn, Gregory T; Schnaus, Michael J; Wahi, Monika M; Goldin, Steven B

    2015-04-01

    Many aspects of medical school are stressful for students. To empirically assess student reactions to clerkship programs, or to assess efforts to improve such programs, educators must measure the overall well-being of the students reliably and validly. The purpose of the study was to develop and validate a measure designed to achieve these goals. The authors developed a measure of quality of life for medical students by sampling (public domain) items tapping general happiness, fatigue, and anxiety. A quality-of-life scale was developed by factor analyzing responses to the items from students in two different clerkships from 2005 to 2008. Reliability was assessed using Cronbach's alpha. Validity was assessed by factor analysis, convergence with additional theoretically relevant scales, and sensitivity to change over time. The refined nine-item measure is a Likert scaled survey of quality-of-life items comprised of two domains: exhaustion and general happiness. The resulting scale demonstrated good reliability and factorial validity at two time points for each of the two samples. The quality-of-life measure also correlated with measures of depression and the amount of sleep reported during the clerkships. The quality-of-life measure appeared more sensitive to changes over time than did the depression measure. The measure is short and can be easily administered in a survey. The scale appears useful for program evaluation and more generally as an outcome variable in medical educational research. PMID:25831183

  6. A Population-Based Psychometric Validation Study of the Strengths and Difficulties Questionnaire – Hebrew Version

    PubMed Central

    Mansbach-Kleinfeld, Ivonne; Apter, Alan; Farbstein, Ilana; Levine, Stephen Z.; Ponizovsky, Alexander M.

    2010-01-01

    This study presents the psychometric properties of the Strengths and Difficulties Questionnaire – Hebrew version (SDQ-H), used in the Israel Survey on Mental Health among Adolescents (ISMEHA). The SDQ-H was administered to a representative sample of 611 adolescents and their mothers. Structural validity was evaluated by exploratory and confirmatory factor analysis and the Development and Well-Being Assessment (DAWBA) inventory was used as “gold standard” to test convergent and discriminant validity. Internal consistency and normative scores were established. Agreement was found with the original factor structure, except for the Peer problem scale. Concurrent and discriminant validity varied from fair to very good for most scales. Total Difficulties scores showed better discriminant validity for the adolescents’ than the mothers’ report for internalizing disorders, and the opposite for externalizing disorders. Internal consistency for the Total Difficulties was 0.77 and for the Hyperactivity scale it was 0.73. It was lower for the other scales, particularly for the Peer problems scale. The findings suggest reasonable psychometric properties of the SDQ-H. Comparisons with other translated SDQ versions are presented. PMID:21423458

  7. Validity and reliability study of the Turkish psychiatric nurses of job motivation scale.

    PubMed

    Engin, E; Cam, O

    2009-06-01

    This methodological study was planned to explore the validity and reliability of the evaluation scale for measuring the job motivation of nurses who work in psychiatric clinics. The sample was composed of 378 nurses who work in all psychiatric units or psychiatric hospitals located in Turkey's four large cities - Ankara, Istanbul, Izmir and Manisa. For testing reliability of 'job motivation scale', the internal consistency tests were executed with split scale analysis, Cronbach's alpha coefficient and item-total score correlation. For construct validity, factor analysis was used. For the first part of scale, Cronbach's alpha was determined to be 0.79. For the second part, Cronbach's alpha was 0.72. Factor analysis was performed in an attempt to establish validity and underlying associations between items in the scale. The first analysis produced nine eigenvalues (>1) and nine factors were extracted. The scree test indicated that a two-factor model would be suitable. The factor structure of the tool for measuring the job motivation of nurses who work in psychiatric clinics was parallel with motivation concepts. Validity and reliability levels of the scale for measuring the job motivation of nurses who work in psychiatric clinics were found to be sufficient in the Turkish population. PMID:19538603

  8. Synthesis and electrical conductivity studies of metal chloro and nitroxide group containing styrene butadiene rubber

    NASA Astrophysics Data System (ADS)

    Anilkumar, T.; Ramesan, M. T.

    2014-10-01

    The introduction of different functional group in SBR was done by a simple reaction between sodium nitrite and mercuric chloride in the presence of phase transfer catalyst. The attachment of chlorine and NO2 functional group in the double bond of the butadiene was monitored by FTIR and UV spectroscopy. The structure and morphology of chloro nitro SBR was studied by SEM and XRD. Flame retardency studies revealed that the chemical modification imparts better flame resistance to chemically modified SBR. AC conductivity and dielectric properties of chloro- nitro SBR was higher than that of SBR and conductivity increases with the level of chemical modification.

  9. 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

  10. Validation of the Spanish version of the hip outcome score: a multicenter study

    PubMed Central

    2014-01-01

    Background The Hip Outcome Score (HOS) is a self-reported questionnaire evaluating the outcomes of treatment interventions for hip pathologies, divided in 19 items of activities of daily life (ADL) and 9 sports’ items. The aim of the present study is to translate and validate HOS into Spanish. Methods A prospective and multicenter study with 100 patients undergoing hip arthroscopy was performed between June 2012 and January 2013. Crosscultural adaptation was used to translate HOS into Spanish. Patients completed the questionnaire before and after surgery. Feasibility, reliability, internal consistency, construct validity (correlation with Western Ontario and McMaster Universities Osteoarthritis Index), ceiling and floor effects and sensitivity to change were assessed for the present study. Results Mean age was 45.05 years old. 36 women and 64 men were included. Feasibility: 13% had at least one missing item within the ADL subscale and 17% within the sport subscale. Reliability: the translated version of HOS was highly reproducible with intraclass correlation coefficient of 0.95 for ADL and 0.94 for the sports subscale. Internal consistency was confirmed with Cronbach’s alpha >0.90 in both subscales. Construct validity showed statistically significant correlation with WOMAC. Ceiling effect was observed in 6% and 12% for ADL and sports subscale, respectively. Floor effect was found in 3% and 37% ADL and sports subscale, respectively. Large sensitivity to change was shown in both subscales. Conclusion The translated version of HOS into Spanish has shown to be feasible, reliable and sensible to changes for patients undergoing hip arthroscopy. This validated translation of HOS allows for comparisons between studies involving either Spanish- or English-speaking patients. Level of evidence Prognostic study, Level I PMID:24884511

  11. The effects of an unexpected spider stimulus on skin conductance responses and eye movements: an inattentional blindness study.

    PubMed

    Wiemer, Julian; Gerdes, Antje B M; Pauli, Paul

    2013-03-01

    Are spiders evolutionarily relevant threat cues that capture attention automatically and preattentively-also in non-fearful persons? Previous studies concerning this question did not examine responses to unexpected spider stimuli, although this is an ecologically valid situation. Therefore, we conducted an inattentional blindness (IB) experiment. While unselected participants (N = 120) were focusing their attention on a visual discrimination task, suddenly a spider or a flower image appeared. The rates of reported detection were not enhanced for spider images, and fear of spiders had no moderating influence on IB rates. However, spider pictures in general elicited greater skin conductance responses than flower pictures, and this difference was also observed for pictures that were not reported afterward. Moreover, eye movement data revealed that the spider stimulus was initially fixated more often than the flower stimulus. In sum, our findings imply that enhanced reactions to unexpected spider images are independent of fear level and include early engagement processes. Awareness of a spider picture does not seem to be a prerequisite for elevated arousal. PMID:22227916

  12. Results of an A109 simulation validation and handling qualities study

    NASA Technical Reports Server (NTRS)

    Eshow, Michelle M.; Orlandi, Diego; Bonaita, Giovanni; Barbieri, Sergio

    1989-01-01

    The results for the validation of a mathematical model of the Agusta A109 helicopter, and subsequent use of the model as the baseline for a handling qualities study of cockpit centerstick requirements, are described. The technical approach included flight test, non-realtime analysis, and realtime piloted simulation. Results of the validation illustrate a time- and frequency-domain approach to the model and simulator issues. The final A109 model correlates well with the actual aircraft with the Stability Augmentation System (SAS) engaged, but is unacceptable without the SAS because of instability and response coupling at low speeds. Results of the centerstick study support the current U.S. Army handling qualities requirements for centerstick characteristics.

  13. Results of an A109 simulation validation and handling qualities study

    NASA Technical Reports Server (NTRS)

    Eshow, Michelle M.; Orlandi, Diego; Bonaita, Giovanni; Barbieri, Sergio

    1990-01-01

    The results for the validation of a mathematical model of the Agusta A109 helicopter, and subsequent use of the model as the baseline for a handling qualities study of cockpit centerstick requirements, are described. The technical approach included flight test, non-realtime analysis, and realtime piloted simulation. Results of the validation illustrate a time- and frequency-domain approach to the model and simulator issues. The final A109 model correlates well with the actual aircraft with the Stability Augmentation System (SAS) engaged, but is unacceptable without the SAS because of instability and response coupling at low speeds. Results of the centerstick study support the current U.S. Army handling qualities requirements for centerstick characteristics.

  14. A study on Effective Thermal Conductivity of Packed Bed of Adsorbent Including Water

    NASA Astrophysics Data System (ADS)

    Hirasawa, Yoshio; Ohta, Ryuma; Takegoshi, Eisyun

    In the present study, an effective thermal conductivity of the packed bed of an adsorbent including water was measured experimentally by using the transient hot wire method in temperature range from about -40°C to room temperature. Zeolite particle and activated carbon particle were employed as the adsorbent. The water included in the adsorbent was classified to three kinds; namely, the adsorbed water in the adsorption site with a nanometer order in particle, the osmosis water existing in gap with lager size than the adsorption site and the free water around particle. The measurement was performed with changing the mass ratio of adsorbed water and osmosis water and was also performed for the particle filled by the free water. As the results, the effective thermal conductivity of the packed bed increased with the increase of temperature except the case containing free water. In zeolite, the effective thermal conductivity of the packed bed of particles with adsorbed water became bigger than that of the desorbed particle about 10% though the adsorbed water was trapped in the adsorption site as a single molecular in zeolite particle. In activated carbon, the effective thermal conductivity was larger than that of desorbed particle about 20%. Next, in the packed bed of particle with the osmosis water, the effective thermal conductivity indicated about two times of that of particle with the adsorbed water. In the packed bed of particle filled by free water, the effective thermal conductivity increased suddenly under 0°C. It is considered that the thermal conductivity of ice affected seriously to the effective thermal conductivity because ice was the continuous phase in the bed.

  15. 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

  16. Validation study of a ray-tracing simulator for focal construct geometry.

    PubMed

    Dicken, Anthony; Rogers, Keith; Godber, Simon; Prokopiou, Danae; Shevchuk, Alex; Tranfield, Graham; Evans, Paul

    2014-12-01

    We present the results of a computer modelling package designed to simulate X-ray diffraction imaging employing focal construct geometry. The paths of coherently diffracted X-rays are modelled by ray-tracing. The results of the study show good agreement between simulated and measured data obtained in the laboratory. The validation of the modelling package permits the rapid optimisation and prototyping of focal construct technology, which has wide applicability in security X-ray imaging. PMID:25238134

  17. 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.

  18. Empirical Validation of Measures for UML Class Diagrams: A Meta-Analysis Study

    Microsoft Academic Search

    M. Esperanza Manso; José A. Cruz-lemus; Marcela Genero; Mario Piattini

    2008-01-01

    The main goal of this paper is to show the findings obtained through a meta-analysis study carried out with the data obtained\\u000a from a family of five controlled experiments performed in academic environments. This family of experiments was carried out\\u000a to validate empirically two hypotheses applied to UML class diagrams, which investigate 1) The dependence between the structural\\u000a complexity and

  19. 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…

  20. 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

  1. The Transcendental Meditation® Program and Rehabilitation At Folsom State PrisonA Cross-Validation Study

    Microsoft Academic Search

    Allan I. Abrams; Larry M. Siegel

    1978-01-01

    The effects of the Transcendental Meditation program in a maximum security prison were studied via cross-validation design. Each of two experiments involved the pre- and postmeasurement of a treatment and a control group with a 14-week treatment interval. All subjects were administered the Eysenck Personality Inventory, the State-Trait Anxiety Inventory, the Buss-Durkee Hostility Inventory, and a survey of sleep patterns

  2. The Spanish version of the dementia quality of life questionnaire: A validation study

    Microsoft Academic Search

    Ramona Lucas-Carrasco; Juana Gómez-Benito; Javier Rejas; Meryl Brod

    2011-01-01

    Background: The aim of the study was to adapt and validate culturally the dementia-specific health-related quality of life instrument (HRQoL) into Spanish for patients with mild to moderate dementia.Methods: Two forward translations, a reconciled version, and then a back translation were completed and subjected to expert review. A total of 112 patients with dementia, diagnosed according to DSM-IV criteria, from

  3. 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.

  4. Study of the growth of conductive single-wall carbon nanotube films with ultra-high transparency

    E-print Network

    Resasco, Daniel

    Study of the growth of conductive single-wall carbon nanotube films with ultra-high transparency) is the fabrication of thin conductive films. Their excellent electrical conductivity and high optical transpar- ency replacement for indium tin oxide (ITO) glass. Although it is widely used today in most transparent conducting

  5. Construct Validity Evidence for Single-Response Items to Estimate Physical Activity Levels in Large Sample Studies

    ERIC Educational Resources Information Center

    Jackson, Allen W.; Morrow, James R., Jr.; Bowles, Heather R.; FitzGerald, Shannon J.; Blair, Steven N.

    2007-01-01

    Valid measurement of physical activity is important for studying the risks for morbidity and mortality. The purpose of this study was to examine evidence of construct validity of two similar single-response items assessing physical activity via self-report. Both items are based on the stages of change model. The sample was 687 participants (men =…

  6. A cross-sectional validation study of the Swedish version of SWAL-QOL.

    PubMed

    Finizia, Caterina; Rudberg, Ingrid; Bergqvist, Henrik; Rydén, Anna

    2012-09-01

    The purpose of this study was to evaluate the psychometric properties of the Swedish version of the Swallowing Quality of Life questionnaire (SWAL-QOL). The study design was cross-sectional and the study was performed in patients with subjective oropharyngeal dysphagia due to head and neck (H&N) cancer (n = 85) or neurological disease (n = 30) and in a sample of age- and gender-matched controls (mean age = 63 years, 57% males) without subjective dysphagia (n = 115). The Short-Form 36 (SF-36) and Hospital Anxiety and Depression Scale (HADS) questionnaires were used for assessment of convergent and discriminant validity. The Swedish version of SWAL-QOL was well accepted, the response rate was high (>90%), and the number of missing items were very low (<1%). Overall, the questionnaire showed good to excellent psychometric properties, including floor and ceiling effects (range = 0-16 and 0-21%), internal consistency [Cronbach's ? > 0.70 for all domains except Eating Duration (0.69) and Sleep (0.68)], test-retest reliability (intraclass correlations = 0.75-0.98) and convergent and discriminant validity as assessed by correlations between SWAL-QOL and SF-36 and HADS. SWAL-QOL also proved able to differentiate between dysphagic and nondysphagic patients (P < 0.00001) (known-groups validity) and sensitive to disease severity as measured by different food textures. PMID:22006366

  7. Validation of the German version of the Nurse-Work Instability Scale: baseline survey findings of a prospective study of a cohort of geriatric care workers

    PubMed Central

    2013-01-01

    Background A prospective study of a cohort of nursing staff from nursing homes was undertaken to validate the Nurse-Work Instability Scale (Nurse-WIS). Baseline investigation data was used to test reliability, construct validity and criterion validity. Method A survey of nursing staff from nursing homes was conducted using a questionnaire containing the Nurse-WIS along with other survey instruments (including SF-12, WAI, SPE). The self-reported number of days’ sick leave taken and if a pension for reduced work capacity was drawn were recorded. The reliability of the scale was checked by item difficulty (P), item discrimination (rjt) and by internal consistency according to Cronbach’s coefficient. The hypotheses for checking construct validity were tested on the basis of correlations. Pearson’s chi-square was used to test concurrent criterion validity; discriminant validity was tested by means of binary logistic regression. Results 396 persons answered the questionnaire (21.3% response rate). More than 80% were female and mostly work full-time in a rotating shift pattern. Following the test for item discrimination, two items were removed from the Nurse-WIS test. According to Cronbach’s (0.927) the scale provides a high degree of measuring accuracy. All hypotheses and assumptions used to test validity were confirmed: As the Nurse-WIS risk increases, health-related quality of life, work ability and job satisfaction decline. Depressive symptoms and a poor subjective prognosis of earning capacity are also more frequent. Musculoskeletal disorders and impairments of psychological well-being are more frequent. Age also influences the Nurse-WIS result. While 12.0% of those below the age of 35 had an increased risk, the figure for those aged over 55 was 50%. Conclusion This study is the first validation study of the Nurse-WIS to date. The Nurse-WIS shows good reliability, good validity and a good level of measuring accuracy. It appears to be suitable for recording prevention and rehabilitation needs among health care workers. If, in the follow-up, the Nurse-WIS likewise proves to be a reliable screening instrument with good predictive validity, it could ensure that suitable action is taken at an early stage, thereby helping to counteract early retirement and the anticipated shortage of health care workers. PMID:24330532

  8. 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 ...

  9. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    42 Public Health 1 2011-10-01 2011-10-01 false Conduct of health...assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH...

  10. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    42 Public Health 1 2012-10-01 2012-10-01 false Conduct of health...assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH...

  11. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    42 Public Health 1 2013-10-01 2013-10-01 false Conduct of health...assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH...

  12. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    42 Public Health 1 2014-10-01 2014-10-01 false Conduct of health...assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH...

  13. Methods for Conducting Post-School Outcomes Follow-Up Studies: A Review of the Literature

    ERIC Educational Resources Information Center

    Alverson, Charlotte Y.; Bayliss, Camilla; Naranjo, Jason M.; Yamamoto, Scott H.; Unruh, Deanne

    2006-01-01

    The purpose of this brief is to summarize the methodologies and outcome measures used in Post-School Outcomes follow-up and follow-along studies of adolescents with disabilities. As a requisite in the Request for Proposal for funding of the National Post-School Outcomes Center (NPSO), knowledge development activities were to include: "Conducting a…

  14. Handbook for Conducting a Study of the Economic Impact of a Community College. (1981 Revised Edition).

    ERIC Educational Resources Information Center

    Wallhaus, Penny; Lach, Ivan J.

    Designed for use by community college personnel, this handbook provides information necessary to conduct a study of the impact of a community college on the business volume and other economic aspects of the community. Section I explains models for assessing the following seven types of economic impact: (1) college-related local business volume;…

  15. Treatment of Comorbid Conduct Problems and Depression in Youth: A Pilot Study

    ERIC Educational Resources Information Center

    Wolff, Jennifer C.; Ollendick, Thomas H.

    2012-01-01

    The purpose of this study was to pilot a cognitive behavioral treatment protocol for adolescents with co-occurring conduct problems and depression. A non-concurrent multiple baseline design was used to assess the effectiveness of the intervention. A sample of five adolescents, aged 11 to 14 years, participated; all five families completed the…

  16. 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…

  17. Considerations for conducting incubations to study the mechanisms of As release in reducing groundwater aquifers

    E-print Network

    van Geen, Alexander

    Considerations for conducting incubations to study the mechanisms of As release in reducing from aquifer sands in Bangladesh, but alternative explanations have been proposed. Long-term incubation a gradient of dissolved As concentrations (60­130­ 210 lg/L) in Bangladesh were incubated for 8 months

  18. Objective structured assessment of technical competence in transthoracic echocardiography: a validity study in a standardised setting

    PubMed Central

    2013-01-01

    Background Competence in transthoracic echocardiography (TTE) is unrelated to traditional measures of TTE competence, such as duration of training and number of examinations performed. This study aims to explore aspects of validity of an instrument for structured assessment of echocardiographic technical skills. Methods The study included 45 physicians with three different clinical levels of echocardiography competence who all scanned the same healthy male following national guidelines. An expert in echocardiography (OG) evaluated all the recorded, de-identified TTE images blindly using the developed instrument for assessment of TTE technical skills. The instrument consisted of both a global rating scale and a procedure specific checklist. Two scores were calculated for each examination: A global rating score and a total checklist score. OG rated ten examinations twice for intra-rater reliability, and another expert rated the same ten examinations for inter-rater reliability. A small pilot study was then performed with focus on content validity. This pilot study included nine physicians who scanned three patients with different pathologies as well as different technical difficulties. Results Validity of the TTE technical skills assessment instrument was supported by a significant correlation found between level of expertise and both the global score (Spearman 0.76, p<0.0001) and the checklist score (Spearman 0.74, p<0.001). Both scores were able to distinguish between the three levels of competence that were represented in the physician group. Reliability was supported by acceptable inter- and intra-rater values. The pilot study showed a tendency to improved scores with increasing expertise levels, suggesting that the instrument could also be used when pathologies were present. Conclusions We designed and developed a structured assessment instrument of echocardiographic technical skills that showed evidence of validity in terms of high correlations between test scores on a normal person and the level of physician competence, as well as acceptable inter- and intra-rater reliability scores. Further studies should, however, be performed to determine the adequate number of assessments needed to ensure high content validity and reliability in a clinical setting. PMID:23537204

  19. Validating a vignette-based instrument to study physician decision making in trauma triage

    PubMed Central

    Mohan, Deepika; Fischhoff, Baruch; Farris, Coreen; Switzer, Galen E.; Rosengart, Matthew R.; Yealy, Donald M.; Saul, Melissa; Angus, Derek C.; Barnato, Amber E.

    2013-01-01

    Background The evidence supporting the use of vignettes to study physician decision making comes primarily from the study of low-risk decisions and the demonstration of good agreement at the group level between vignettes and actual practice. The validity of using vignettes to predict decision making in more complex, high-risk contexts and at the individual level remains unknown. Methods We had previously developed a vignette-based instrument to study physician decision making in trauma triage. Here, we measured the re-test reliability, internal consistency, known-groups performance, and criterion validity of the instrument. Thirty-two emergency physicians, recruited at a national academic meeting, participated in reliability testing. Twenty-eight trauma surgeons, recruited using personal contacts, participated in known-groups testing. Twenty-eight emergency physicians, recruited from physicians working at hospitals for which we had access to medical records, participated in criterion validity testing. We measured rates of under-triage (the proportion of severely injured patients not transferred to trauma centers) and over-triage (the proportion of patients transferred with minor injuries) on the instrument. For physicians participating in criterion validity testing, we compared rates of triage on the instrument with rates in practice, based on chart review. Results Physicians made similar transfer decisions for cases (? = 0.42, p<0.01) on two administrations of the instrument. Responses were internally consistent (Kuder-Richardson 0.71–0.91). Surgeons had lower rates of under-triage than emergency physicians (13% v. 70%, p<0.01). No correlation existed between individual rates of under- or over-triage on the vignettes and in practice (r = ?0.17, p = 0.4; r = ?0.03, p = 0.85). Conclusions The instrument developed to assess trauma triage decision making performed reliably and detected known group differences. However it did not predict individual physician performance. PMID:24125789

  20. 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

  1. July 28-29, 2004: Research Strategies, Study Designs and Statistical Approaches to Biomarkers Validation for Cancer Diagnosis and Detection

    Cancer.gov

    The National Cancer Institute in cooperation with the Food and Drug Administration (FDA), invite you to participate in the workshop to be held in Gaithersburg, MD on July 28-29, 2004. The workshop is designed to review the basic considerations underpinning the study design, statistical methodologies and validation approaches to rapidly advancing field of cancer biomarker and consider approaches to their validation for clinical utility, including randomized controlled-trial (RCT)- based and non-RCT based validation designs.

  2. Elementary School Student Burnout Scale for Grades 6-8: A Study of Validity and Reliability

    ERIC Educational Resources Information Center

    Aypay, Ayse

    2011-01-01

    The purpose of this study is to develop an "Elementary School Student Burnout Scale for Grades 6-8". The study group included 691 students out of 10 schools in Eskisehir. Both Exploratory Factor Analysis and Confirmatory Factor Analysis were conducted on the data (Burnout stem from school activities, burnout stem from family, feeling of…

  3. 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

  4. 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

  5. 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

  6. Study of electrical conductivity response upon formation of ice and gas hydrates from salt solutions by a second generation high pressure electrical conductivity probe

    NASA Astrophysics Data System (ADS)

    Sowa, Barbara; Zhang, Xue Hua; Kozielski, Karen A.; Dunstan, Dave E.; Hartley, Patrick G.; Maeda, Nobuo

    2014-11-01

    We recently reported the development of a high pressure electrical conductivity probe (HP-ECP) for experimental studies of formation of gas hydrates from electrolytes. The onset of the formation of methane-propane mixed gas hydrate from salt solutions was marked by a temporary upward spike in the electrical conductivity. To further understand hydrate formation a second generation of window-less HP-ECP (MkII), which has a much smaller heat capacity than the earlier version and allows access to faster cooling rates, has been constructed. Using the HP-ECP (MkII) the electrical conductivity signal responses of NaCl solutions upon the formation of ice, tetrahydrofuran hydrates, and methane-propane mixed gas hydrate has been measured. The concentration range of the NaCl solutions was from 1 mM to 3M and the driving AC frequency range was from 25 Hz to 5 kHz. This data has been used to construct an "electrical conductivity response phase diagrams" that summarize the electrical conductivity response signal upon solid formation in these systems. The general trend is that gas hydrate formation is marked by an upward spike in the conductivity at high concentrations and by a drop at low concentrations. This work shows that HP-ECP can be applied in automated measurements of hydrate formation probability distributions of optically opaque samples using the conductivity response signals as a trigger.

  7. Development and validation of dissolution study of sustained release dextromethorphan hydrobromide tablets.

    PubMed

    Rajan, Sekar; Colaco, Socorrina; Ramesh, N; Meyyanathan, Subramania Nainar; Elango, K

    2014-02-01

    This study describes the development and validation of dissolution tests for sustained release Dextromethorphan hydrobromide tablets using an HPLC method. Chromatographic separation was achieved on a C18 column utilizing 0.5% triethylamine (pH 7.5) and acetonitrile in the ratio of 50:50. The detection wavelength was 280 nm. The method was validated and response was found to be linear in the drug concentration range of 10-80 microg mL(-1). The suitable conditions were clearly decided after testing sink conditions, dissolution medium and agitation intensity. The most excellent dissolution conditions tested, for the Dextromethorphan hydrobromide was applied to appraise the dissolution profiles. The method was validated and response was found to be linear in the drug concentration range of 10-80 microg mL(-1). The method was established to have sufficient intermediate precision as similar separation was achieved on another instrument handled by different operators. Mean Recovery was 101.82%. Intra precisions for three different concentrations were 1.23, 1.10 0.72 and 1.57, 1.69, 0.95 and inter run precisions were % RSD 0.83, 1.36 and 1.57%, respectively. The method was successfully applied for dissolution study of the developed Dextromethorphan hydrobromide tablets. PMID:24897800

  8. 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.

  9. Tree Canopy Characterization for EO-1 Reflective and Thermal Infrared Validation Studies: Rochester, New York

    NASA Technical Reports Server (NTRS)

    Ballard, Jerrell R., Jr.; Smith, James A.

    2002-01-01

    The tree canopy characterization presented herein provided ground and tree canopy data for different types of tree canopies in support of EO-1 reflective and thermal infrared validation studies. These characterization efforts during August and September of 2001 included stem and trunk location surveys, tree structure geometry measurements, meteorology, and leaf area index (LAI) measurements. Measurements were also collected on thermal and reflective spectral properties of leaves, tree bark, leaf litter, soil, and grass. The data presented in this report were used to generate synthetic reflective and thermal infrared scenes and images that were used for the EO-1 Validation Program. The data also were used to evaluate whether the EO-1 ALI reflective channels can be combined with the Landsat-7 ETM+ thermal infrared channel to estimate canopy temperature, and also test the effects of separating the thermal and reflective measurements in time resulting from satellite formation flying.

  10. 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.

  11. Behavioral trends in young children with conductive hearing loss: a case–control study

    Microsoft Academic Search

    Panagiota Gouma; Antonios Mallis; Vasilis Daniilidis; Haralambos Gouveris; Nikolaos Armenakis; Stephanos Naxakis

    2011-01-01

    Otitis media with effusion (OME) is a common condition affecting children and a well-known cause of conductive hearing loss\\u000a that can potentially lead to speech development disorders. Recent studies, however, have demonstrated the influence of OME\\u000a on development of attention disorders or social adaptation and acceptance. Hence, this study aimed to investigate the behavioral\\u000a trends of children with OME based

  12. Central motor conduction studies in internal capsule and corona radiata infarction

    Microsoft Academic Search

    U. K. Misra; J. Kalita

    1997-01-01

    Clinical and evoked-potential studies in internal capsule and corona radiata infarction are lacking. We report the results\\u000a of a clinical and central motor conduction time (CMCT) study in 16 patients with internal capsule and 17 with computed tomography\\u000a (CT)-proven corona radiata infarction. Patient’s outcome was defined at the end of 3 months on the basis of the Barthel Index\\u000a score.

  13. Thermal conductivity study at CH/Be interface by refraction-enhanced x-ray radiography

    NASA Astrophysics Data System (ADS)

    Ping, Yuan; Landen, Otto; Koch, Jeff; Hicks, Damien; Wallace, Russel; Collins, Gilbert

    2012-10-01

    Transport properties near the fuel-ablator interface at the edge of an ICF capsule are important for modeling the growth of hydrodynamic instabilities, which determines the mix level in the fuel and is critical for successful ignition (Hammel, et al. HEDP 6, 671, 2010). A novel technique, time-resolved refraction-enhanced x-ray radiography, is developed to study thermal conductivity at the interface (Ping et al. J. Instru. 2011). Experiments using OMEGA laser have been carried out for CH/Be targets isochorically heated by x-rays to measure the evolution of the density gradient at the interface due to thermal conduction. The sensitivity of this radiographic technique to discontinuities enabled observation of shock/rarefraction waves propagating away from the interface. Comparison of data and simulation results using various conductivity models will be presented.

  14. Conductance Studies on Trichotoxin_A50E and Implications for Channel Structure

    PubMed Central

    Duclohier, H.; Alder, G. M.; Bashford, C. L.; Brückner, H.; Chugh, J. K.; Wallace, B. A.

    2004-01-01

    Trichotoxin_A50E is an 18-residue peptaibol whose crystal structure has recently been determined. In this study, the conductance properties of trichotoxin_A50E have been investigated in neutral planar lipid bilayers. The macroscopic current-voltage curves disclose a moderate voltage-sensitivity and the concentration-dependence suggests the channels are primarily hexameric. Under ion gradients, shifts of the reversal potential indicate that cations are preferentially transported. Trichotoxin displays only one single-channel conductance state in a given experiment, but an ensemble of experiments reveals a distribution of conductance levels. This contrasts with the related peptaibol alamethicin, which produces multiple channel levels in a single experiment, indicative of recruitment of additional monomers into different multimeric-sized channels. Based on these conductance measurements and on the recently available crystal structure of trichotoxin_A50E, which is a shorter and straighter helix than alamethicin, a tightly-packed hexameric model structure has been constructed for the trichotoxin channel. It has molecular dimensions and surface electrostatic potential compatible with the observed conductance properties of the most probable and longer-lived channel. PMID:15345549

  15. External current source modeling and simultaneous source-conductivity inversion in global induction studies

    NASA Astrophysics Data System (ADS)

    Sun, J.; Kelbert, A.; Egbert, G. D.

    2012-12-01

    Global geomagnetic induction studies at longer periods have long relied on local transfer functions under a highly simplified P10 dipole source model. With such an approach data must be limited in period range, latitude extent,and/or geomagnetic conditions where such assumptions may be tenable. Even then, possibilities of source contamination are a serious concern. To overcome these challenges and improve global images of electrical conductivity (especially in the upper mantle) we propose to simultaneously estimate source and conductivity structures from the data. Our approach involves three steps: 1 Recently developed tools for frequency domain principal components analaysis with large amounts of missing data are applied to modern and historical geomagnetic observatory data to estimate the dominant modes of spatial variability at periods from 6 hours to 100 days. This analysis results in estimates of 3 components of the total (external + induced) magnetic field variations associated with unknown source currents. 2 Field components from step 1 are fit to external current source models, accounting for induction in a 1D Earth with a variable conductance thin-sheet at the surface. 3 Invert the field components from step 1 with a 3D spherical code, using the range of possible source models obtained from step 2, and explore trade-offs between deep Earth conductivity structure and source complications using an alternating iterative approach. We will present Earth conductivity and source models from application of this approach to longer period variations, as well as progress on source modeling for daily variation periods.

  16. Hydraulic conductivity study of compacted clay soils used as landfill liners for an acidic waste.

    PubMed

    Hamdi, Noureddine; Srasra, Ezzeddine

    2013-01-01

    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 × 10(-10), 2.08 × 10(-9) and 6.8 × 10(-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(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(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. PMID:22980909

  17. Validity and reliability of the Japanese version of the Newest Vital Sign: a preliminary study.

    PubMed

    Kogure, Takamichi; Sumitani, Masahiko; Suka, Machi; Ishikawa, Hirono; Odajima, Takeshi; Igarashi, Ataru; Kusama, Makiko; Okamoto, Masako; Sugimori, Hiroki; Kawahara, Kazuo

    2014-01-01

    Health literacy (HL) refers to the ability to obtain, process, and understand basic health information and services, and is thus needed to make appropriate health decisions. The Newest Vital Sign (NVS) is comprised of 6 questions about an ice cream nutrition label and assesses HL numeracy skills. We developed a Japanese version of the NVS (NVS-J) and evaluated the validity and reliability of the NVS-J in patients with chronic pain. The translation of the original NVS into Japanese was achieved as per the published guidelines. An observational study was subsequently performed to evaluate the validity and reliability of the NVS-J in 43 Japanese patients suffering from chronic pain. Factor analysis with promax rotation, using the Kaiser criterion (eigenvalues ?1.0), and a scree plot revealed that the main component of the NVS-J consists of three determinative factors, and each factor consists of two NVS-J items. The criterion-related validity of the total NVS-J score was significantly correlated with the total score of Ishikawa et al.'s self-rated HL Questionnaire, the clinical global assessment of comprehensive HL level, cognitive function, and the Brinkman index. In addition, Cronbach's coefficient for the total score of the NVS-J was adequate (alpha?=?0.72). This study demonstrated that the NVS-J has good validity and reliability. Further, the NVS-J consists of three determinative factors: "basic numeracy ability," "complex numeracy ability," and "serious-minded ability." These three HL abilities comprise a 3-step hierarchical structure. Adequate HL should be promoted in chronic pain patients to enable coping, improve functioning, and increase activities of daily living (ADLs) and quality of life (QOL). PMID:24762459

  18. Validity and Reliability of the Japanese Version of the Newest Vital Sign: A Preliminary Study

    PubMed Central

    Kogure, Takamichi; Sumitani, Masahiko; Suka, Machi; Ishikawa, Hirono; Odajima, Takeshi; Igarashi, Ataru; Kusama, Makiko; Okamoto, Masako; Sugimori, Hiroki; Kawahara, Kazuo

    2014-01-01

    Health literacy (HL) refers to the ability to obtain, process, and understand basic health information and services, and is thus needed to make appropriate health decisions. The Newest Vital Sign (NVS) is comprised of 6 questions about an ice cream nutrition label and assesses HL numeracy skills. We developed a Japanese version of the NVS (NVS-J) and evaluated the validity and reliability of the NVS-J in patients with chronic pain. The translation of the original NVS into Japanese was achieved as per the published guidelines. An observational study was subsequently performed to evaluate the validity and reliability of the NVS-J in 43 Japanese patients suffering from chronic pain. Factor analysis with promax rotation, using the Kaiser criterion (eigenvalues ?1.0), and a scree plot revealed that the main component of the NVS-J consists of three determinative factors, and each factor consists of two NVS-J items. The criterion-related validity of the total NVS-J score was significantly correlated with the total score of Ishikawa et al.'s self-rated HL Questionnaire, the clinical global assessment of comprehensive HL level, cognitive function, and the Brinkman index. In addition, Cronbach's coefficient for the total score of the NVS-J was adequate (alpha?=?0.72). This study demonstrated that the NVS-J has good validity and reliability. Further, the NVS-J consists of three determinative factors: “basic numeracy ability,” “complex numeracy ability,” and “serious-minded ability.” These three HL abilities comprise a 3-step hierarchical structure. Adequate HL should be promoted in chronic pain patients to enable coping, improve functioning, and increase activities of daily living (ADLs) and quality of life (QOL). PMID:24762459

  19. 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

  20. The predictive validity of the Leonhardean classification of endogenous psychoses: a 21-33-year follow-up of a prospective study ("BUDAPEST 2000").

    PubMed

    Petho, Bertalan; Tolna, Judit; Tusnády, Gábor; Farkas, Márta; Vizkeleti, Györgyi; Vargha, András; Czobor, Pál

    2008-09-01

    To our knowledge, no previous long-term studies of the Leonhardean classification in the whole spectrum of endogenous psychoses have been conducted. This prospective study (n = 276; female patients n = 222; normal control persons n = 54) started in 1967-1976. The same population was followed-up by participation of a "blinded control" psychiatrist in 1997-2002 [patients available at follow-up = 125 (56.3%); available controls = 38 (70.4%)]. Patients for this investigation were selected by two independent diagnosticians from eight nosological groups based on full diagnostic agreement. Diagnostic agreement at follow-up (weighted-kappa) was 0.87. Predictive validity of the diagnostic categories was measured empirically and using a stochastic (Markovian) model, thus combining validity and reliability. Hebephrenias, group of normal persons and of schizophrenias proved to be valid categories, with diagnostic stabilities of 0.94, 0.91, and 0.93, for the three groups, respectively. In addition, bipolar manic-depressive psychoses and cycloid psychoses were also valid (diagnostic stability of 0.77 and 0.76, respectively). Unipolar depression was valid (diagnostic stability = 0.84) only by forming a "nosological family" based on diagnostic stability and on current status and clinical presentation during the period preceding the follow-up with regard to other mood-congruent disorders and outcome-diagnosis "normal control". Validity of systematic paraphrenias (diagnostic stability = 0.69) was in the moderate range. Division of schizophrenias in "systematic versus non-systematic" nosological categories was inconclusive; the categories of affect-laden paraphrenia, periodic catatonia and systematic catatonias could not be confirmed reliably in this study. PMID:18299789

  1. A systematic review comparing antiretroviral adherence descriptive and intervention studies conducted in the USA.

    PubMed

    Sandelowski, Margarete; Voils, Corrine I; Chang, Yunkyung; Lee, Eun-Jeong

    2009-08-01

    We examined the extent to which studies aimed at testing interventions to improve antiretroviral adherence have targeted the facilitators of and barriers known to affect adherence. Of the 88 reports reviewed, 41 were reports of descriptive studies conducted with US HIV-positive women and 47 were reports of intervention studies conducted with US HIV-positive persons. We extracted from the descriptive studies all findings addressing any factor linked to antiretroviral adherence and from the intervention studies, information on the nature of the intervention, the adherence problem targeted, the persons targeted for the intervention, and the intervention outcomes desired. We discerned congruence between the prominence of substance abuse as a factor identified in the descriptive studies as a barrier to adherence and its prominence as the problem most addressed in those reports of intervention studies that specified the problems targeted for intervention. We also discerned congruence between the prominence of family and provider support as factors identified in the descriptive studies as facilitators of adherence and the presence of social support as an intervention component and outcome variable. Less discernible in the reports of intervention studies was specific attention to other factors prominent in the descriptive studies, which may be due to the complex nature of the problem, individualistic and rationalist slant of interventions, or simply the ways interventions were presented. Our review raises issues about niche standardization and intervention tailoring, targeting, and fidelity. PMID:20024751

  2. Thermal conductivity of ordered-disordered material: a case study of superionic Ag2Te

    NASA Astrophysics Data System (ADS)

    Ouyang, Tao; Zhang, Xiaoliang; Hu, Ming

    2015-01-01

    Thermoelectric devices, which can generate electricity from waste heat, offer an attractive pathway for addressing an important niche in the globally growing landscape of energy demand. In the past few decades, the search for high-efficiency thermoelectrics has been guided by the concept of ‘phonon-glass electron-crystal’ (PGEC), i.e. an ideal thermoelectric material should have high carrier mobility and low thermal conductivity. Although remarkable progress has already been made along this line, the efficiency of thermoelectrics is still too poor to compete with other electricity producing methods. Ordered-disordered material, an emerging trend of high performance thermoelectrics under the concept of PGEC, is a new hot topic in the current thermoelectric research community. Taking superionic phase silver telluride (?-Ag2Te) as an example, we performed a comprehensive study of the thermal transport properties and of its physical mechanism by means of equilibrium molecular dynamic simulations. The results show that the thermal conductivity of ?-Ag2Te is intrinsically very low. By analyzing the different contributions to the overall thermal conductivity, we revealed for the first time from atomistic simulations that the vibration of the Te2? sublattice dominates the thermal transport of ?-Ag2Te, while the collision between the randomly diffusing Ag+ ions and the Te2? sublattice yields a significant negative contribution to the thermal transport. We also studied the effect of isotropic compressive stain and carrier concentration on the thermal conductivity of ?-Ag2Te. It has been found that the thermal conductivity can be largely reduced by applying compressive strain or with stoichiometric quantity modulation. Our studies shed light on the governing mechanism of thermal transport in ordered-disordered materials and could offer useful guidance for engineering the thermal transport properties of superionic conductors in terms of enhancing their thermoelectric performance.

  3. Thermal conductivity of ordered-disordered material: a case study of superionic Ag2Te.

    PubMed

    Ouyang, Tao; Zhang, Xiaoliang; Hu, Ming

    2015-01-16

    Thermoelectric devices, which can generate electricity from waste heat, offer an attractive pathway for addressing an important niche in the globally growing landscape of energy demand. In the past few decades, the search for high-efficiency thermoelectrics has been guided by the concept of 'phonon-glass electron-crystal' (PGEC), i.e. an ideal thermoelectric material should have high carrier mobility and low thermal conductivity. Although remarkable progress has already been made along this line, the efficiency of thermoelectrics is still too poor to compete with other electricity producing methods. Ordered-disordered material, an emerging trend of high performance thermoelectrics under the concept of PGEC, is a new hot topic in the current thermoelectric research community. Taking superionic phase silver telluride (?-Ag2Te) as an example, we performed a comprehensive study of the thermal transport properties and of its physical mechanism by means of equilibrium molecular dynamic simulations. The results show that the thermal conductivity of ?-Ag2Te is intrinsically very low. By analyzing the different contributions to the overall thermal conductivity, we revealed for the first time from atomistic simulations that the vibration of the Te(2-) sublattice dominates the thermal transport of ?-Ag2Te, while the collision between the randomly diffusing Ag(+) ions and the Te(2-) sublattice yields a significant negative contribution to the thermal transport. We also studied the effect of isotropic compressive stain and carrier concentration on the thermal conductivity of ?-Ag2Te. It has been found that the thermal conductivity can be largely reduced by applying compressive strain or with stoichiometric quantity modulation. Our studies shed light on the governing mechanism of thermal transport in ordered-disordered materials and could offer useful guidance for engineering the thermal transport properties of superionic conductors in terms of enhancing their thermoelectric performance. PMID:25525816

  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. A clinical construct validity study of a novel computerized battery for the diagnosis of ADHD in young adults

    Microsoft Academic Search

    Avraham Schweiger; Amitai Abramovitch; Glen M. Doniger; Ely S. Simon

    2007-01-01

    The cognitive profile of adult attention deficit hyperactivity disorder (ADHD) remains understudied despite difficulty in diagnosis. Further, no battery of neuropsychological tests has been shown valid in adult ADHD. Continuous performance tests are widely used for ADHD but provide limited information on cognitive functioning in general. The present study evaluated the construct and discriminant validity of Mindstreams® (NeuroTrax Corp., NY),

  6. 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…

  7. 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.

  8. Validation of reference genes for quantitative RT-PCR studies of gene expression in perennial ryegrass (Lolium perenne L.)

    PubMed Central

    2010-01-01

    Background Perennial ryegrass (Lolium perenne L.) is an important pasture and turf crop. Biotechniques such as gene expression studies are being employed to improve traits in this temperate grass. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) is among the best methods available for determining changes in gene expression. Before analysis of target gene expression, it is essential to select an appropriate normalisation strategy to control for non-specific variation between samples. Reference genes that have stable expression at different biological and physiological states can be effectively used for normalisation; however, their expression stability must be validated before use. Results Existing Serial Analysis of Gene Expression data were queried to identify six moderately expressed genes that had relatively stable gene expression throughout the year. These six candidate reference genes (eukaryotic elongation factor 1 alpha, eEF1A; TAT-binding protein homolog 1, TBP-1; eukaryotic translation initiation factor 4 alpha, eIF4A; YT521-B-like protein family protein, YT521-B; histone 3, H3; ubiquitin-conjugating enzyme, E2) were validated for qRT-PCR normalisation in 442 diverse perennial ryegrass (Lolium perenne L.) samples sourced from field- and laboratory-grown plants under a wide range of experimental conditions. Eukaryotic EF1A is encoded by members of a multigene family exhibiting differential expression and necessitated the expression analysis of different eEF1A encoding genes; a highly expressed eEF1A (h), a moderately, but stably expressed eEF1A (s), and combined expression of multigene eEF1A (m). NormFinder identified eEF1A (s) and YT521-B as the best combination of two genes for normalisation of gene expression data in perennial ryegrass following different defoliation management in the field. Conclusions This study is unique in the magnitude of samples tested with the inclusion of numerous field-grown samples, helping pave the way to conduct gene expression studies in perennial biomass crops under field-conditions. From our study several stably expressed reference genes have been validated. This provides useful candidates for reference gene selection in perennial ryegrass under conditions other than those tested here. PMID:20089196

  9. Use of screening nerve conduction studies for predicting future carpal tunnel syndrome.

    PubMed Central

    Werner, R A; Franzblau, A; Albers, J W; Buchele, H; Armstrong, T J

    1997-01-01

    OBJECTIVE: To determine if an abnormal sensory nerve conduction study consistent with median mononeuropathy in asymptomatic workers was predictive of future complaints of the hand or finger suggestive of carpal tunnel syndrome. METHODS: This was a case-control study of over 700 active workers at five different work sites: four sites involved manufacturing workers and one site represented clerical workers. Patients' reports of symptoms of pain, numbness, tingling, or burning in the hand or finger that lasted more than one week or occurred three or more times after the initial screening were investigated. 77 cases were defined as asymptomatic workers with electrodiagnostic findings of median mononeuropathy in either hand based on a comparison of median and ulnar sensory evoked peak latencies. A difference > or = 0.5 ms was defined as abnormal; a normal difference was < or = 0.2 ms. Controls were asymptomatic age, and sex matched workers with normal nerve conduction studies in both hands. Follow up questionnaires were completed 17 (SD 6) months later. RESULTS: The follow up participation rate was 72%. Cases had a 12% risk of developing symptoms during the follow up period compared with 10% in the control group, chi 2 = 0.12, P = 0.73. CONCLUSIONS: Abnormal median sensory nerve conduction studies in asymptomatic workers were not predictive of future hand or fingers complaints and if used for preplacement screening among active workers this should be done with caution. PMID:9072016

  10. Experimental and theoretical studies of nanofluid thermal conductivity enhancement: a review.

    PubMed

    Kleinstreuer, Clement; Feng, Yu

    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

  11. Feasibility study to conduct windblown sediment experiments aboard a space station

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Iversen, J. D.

    1983-01-01

    A feasibility study was undertaken to determine if a suitable apparatus could be designed to analyze aeolian processes for operation in space and to assess the feasibility of conducting meaningful experiments to address key aspects of aeolian processes. To meet this objective a prototype apparatus was fabricated and some limited experiments were run to determine its suitability for this application. At least three general types of experiments were devised that could be carried out aboard a space station: threshold studies, swirl (dust devil) experiments, and analyses of windblown particle trajectories. How experiments in a zero-g environment could advance knowledge of aeolian processes was studied.

  12. 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.

  13. A facile approach for shape selective synthesis of rhodium nanostructures and conductivity studies

    SciTech Connect

    Sathe, Bhaskar R. [Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University Aurangabad-431 004 (India)

    2012-12-15

    Shape selective synthesis of Rh nanostructures has been demonstrated with the help of a single step chemical vapor deposition, where different shapes like cubes at 500 Degree-Sign C, pyramids and hexagons at 500 Degree-Sign C, 700 Degree-Sign C and 900 Degree-Sign C respectively have been obtained as a function of temperature. Scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and four probe conductivity measurements were used to study the morphology, crystallinity and phase purity of the structures. The conductivity values for as synthesised nanostructures have been obtained in the range of 2-7 kS/cm{sup 2}. On the basis of the experimental results, from TGA and XPS studies possible mechanistic pathway for the evolution of Rh nanostructures was discussed.

  14. 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

  15. 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.

  16. 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

  17. An experimental study on thermal conductivity and viscosity of nanofluids containing carbon nanotubes

    PubMed Central

    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

  18. Ion conduction in ligand-gated ion channels: Brownian dynamics studies of four recent crystal structures.

    PubMed

    Song, Chen; Corry, Ben

    2010-02-01

    Four x-ray crystal structures of prokaryotic homologs of ligand-gated ion channels have recently been determined: ELIC from Erwinia chrysanthemi, two structures of a proton-activated channel from Gloebacter violaceus (GLIC1 and GLIC2) and that of the E221A mutant (GLIC1M). The availability of numerous structures of channels in this family allows for aspects of channel gating and ion conduction to be examined. Here, we determine the likely conduction states of the four structures as well as IV curves, ion selectivity, and steps involved in ion permeation by performing extensive Brownian dynamics simulations. Our results show that the ELIC structure is indeed nonconductive, but that GLIC1 and GLIC1M are both conductive of ions with properties different from those seen in experimental studies of the channel. GLIC2 appears to reflect an open state of the channel with a predicted conductance of 10.8-12.4 pS in 140 mM NaCl solution, which is comparable to the experimental value 8 +/- 2 pS. The extracellular domain of the channel is shown to have an important influence on the channel current, but a less significant role in ion selectivity. PMID:20141753

  19. Conduction of Na+ and K+ through the NaK channel: molecular and Brownian dynamics studies.

    PubMed

    Vora, Taira; Bisset, David; Chung, Shin-Ho

    2008-08-01

    Conduction of ions through the NaK channel, with M0 helix removed, was studied using both Brownian dynamics and molecular dynamics. Brownian dynamics simulations predict that the truncated NaK has approximately a third of the conductance of the related KcsA K+ channel, is outwardly rectifying, and has a Michaelis-Menten current-concentration relationship. Current magnitude increases when the glutamine residue located near the intracellular gate is replaced with a glutamate residue. The channel is blocked by extracellular Ca2+. Molecular dynamics simulations show that, under the influence of a strong applied potential, both Na+ and K+ move across the selectivity filter, although conduction rates for Na+ ions are somewhat lower. The mechanism of conduction of Na+ differs significantly from that of K+ in that Na+ is preferentially coordinated by single planes of pore-lining carbonyl oxygens, instead of two planes as in the usual K+ binding sites. The water-containing filter pocket resulting from a single change in the selectivity filter sequence (compared to potassium channels) disrupts several of the planes of carbonyl oxygens, and thus reduces the filter's ability to discriminate against sodium. PMID:18456826

  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. 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.

  2. Validity of Processes of Change in Physical Activity Among College Students in the TIGER Study

    Microsoft Academic Search

    Rod K. Dishman; Andrew S. Jackson; Molly S. Bray

    2010-01-01

    Objective  To test the factorial validity and measurement equivalence\\/invariance of scales used to measure processes of change derived\\u000a from the Transtheoretical Model (TTM) applied to physical activity.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Confirmatory factor analysis of questionnaire responses obtained from a diverse sample (N?=?1,429) of students enrolled in the Training Interventions and Genetics of Exercise Response (TIGER) Study at the University\\u000a of Houston during academic years

  3. Validity of injury data collected by interview: a study of men born in 1913 and 1923.

    PubMed Central

    Carlsson, G S

    1983-01-01

    An investigation of the validity of anamnestic injury data with special reference to head injuries, was performed, as part of an epidemiological population study of middle aged men. Injury data collected by interview were checked against control data from an emergency department, covering a 7-year period. About 65% of head injuries in the control data set, and 60% of all types of injuries were reported. Injury severity, alcohol intoxication, ambulance transportation and recall period were factors which tended to influence the reporting frequency. PMID:6619890

  4. Validation study of a multidimensional hydrologic model of rainfall, and the simulation of orographic influences, using data from Puerto Rico

    E-print Network

    Garcia-Hiraldo, Roberto

    1990-01-01

    VALIDATION STUDY OF A MULTIDIMENSIONAL HYDROLOGIC MODEL OF RAINFALL, AND THE SIMULATION OF OROGRAPHIC INFLUENCES, USING DATA FROM PUERTO RICO A Thesis by ROBERTO GARCIA-HIRALDO Submitted to the Office of Graduate Studies of Texas ABM... University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1990 Major Subject: Meteorology VALIDATION STUDY OF A MULTIDIMENSIONAL HYDROLOGIC MODEL OF RAINFALL, AND THE SIMULATION OF OROGRAPHIC INFLUENCES, USING...

  5. Hydraulic Conductivity of Riparian Mangrove Forest Peat Adjacent to the Harney River, Everglades National Park: A Comparative Field Study of Field Saturated and Saturated Hydraulic Conductivity Methods.

    NASA Astrophysics Data System (ADS)

    Anderson, G. H.; Smith, T. J.

    2002-05-01

    The Shark-Harney river estuary is located in the southwest region of Everglades National Park and is the principle outflow for the freshwater everglades slough. Periodic tidal inundation, rainfall and overland freshwater flow are the forcing functions on surface soil infiltration and drainage in the adjacent estuary mangrove forest peat. Empirical soil hydraulic conductivity (K) for the mangrove peat soil is needed for hydrologic modeling efforts such as "The Tides and Inflows in the Mangroves of the Everglades" (TIME). South Florida has a bi-seasonal weather pattern of a dry and mild winters and a wet tropical summers. During the drier winter months (November-May), the mangrove peat has a 30-60 cm, unsaturated vadose zone and in the wet summer months (June-October), the peat is totally saturated. This study's purpose is to determine reliable values of soil hydraulic conductivity for mangrove peat under both the unsaturated Kfs and saturated Ksat soil conditions. Rycroft (1975) reported that field measurements are the preferred method of testing hydraulic conductivity of peat. The principle field method used to determining soil hydraulic conductivity Kfs under unsaturated conditions utilized a cylindrical permeameter (Guelph Permeameter) and the auger-hole method was used to determine soil hydraulic conductivity Ksat under saturated soil conditions. The hydraulic conductivity K samples were taken along a 300-meter transect, perpendicular to the south Harney riverbank through a mixed mangrove riparian forest and ending in a freshwater sawgrass prairie. Initial measurements were recorded in May-June 2001. A second year measurement set will be collected in March-April 2002. Hydraulic conductivity K measurements were observed in shallow peat holes (15 cm) at five equally spaced sample sites (60 m) from the river edge. Soil cores were taken at each sampling site to determine soil profile and bulk density.

  6. Use of Physio-Hydrological Units for SMOS Validation at the Valencia Anchor Station Study Area

    NASA Astrophysics Data System (ADS)

    Millán-Scheiding, C.; Antolín, C.; Marco, J.; Soriano, M. P.; Torre, E.; Requena, F.; Carbó, E.; Cano, A.; Lopez-Baeza, E.

    2009-04-01

    The SMOS space mission will soil moisture over the continents and ocean surface salinity with the sufficient resolution to be used in global climate change studies. With the aim of validating SMOS land data and products at the Valencia Anchor Station site (VAS) in a Mediterranean Ecosystem area of Spain, we have designed a sample methodology using a subdivision of the landscape in environmental units related to the spatial variability of soil moisture (Millán-Scheiding, 2006; Lopez-Baeza, et al. 2008). These physio-hydrological units are heterogeneously structured entities which present a certain degree of internal uniformity of hydrological parameters. The units are delimited by integrating areas with the same physio-morphology, soil type, vegetation, geology and topography (Flugel, et al 2003; Millán-Scheiding et al, 2007). Each of these units presented over the same pedological characteristics, vegetation cover, and landscape position should have a certain degree of internal uniformity in its hydrological parameters and therefore similar soil moisture (SM). The main assumption for each unit is that the dynamical variation of the hydrological parameters within one unit should be minimum compared to the dynamics of another unit. This methodology will hopefully provide an effective sampling design consisting of a reduced number of measuring points, sparsely distributed over the area, or alternatively, using SM validation networks where each sampling point is located where it is representative of the mean soil moisture of a complete unit area. The Experimental Plan for the SMOS Validation Rehearsal Campaign at the VAS area of April-May 2008 used this environmental subdivision in the selection and sampling of over 21.000 soil moisture points in a control area of 10 x 10 km2. The ground measurements were carried out during 4 nights corresponding to a drying out period of the soil. The sampling consisted of 700 plots with 4 volumetric SM cylinders and 7 Delta-T Theta Probe measurements (with 3 repetitions each), covering the whole area. This experimental campaign permits the characterization of the soil moisture distribution within each physio-hydrological unit and results in a soil moisture map of the VAS site. All of it used for the validation of the aircraft observations done throughout the campaign. The ground measurement results obtained indicate that soil properties and vegetation cover are the parameters of the physio-hydrological units that most influence the moisture of the soil. This relationship will permit a more simple delimitation of the physio-hydrological Units and a reduction of the number of sample points for the calibration/validation of SMOS products. References: Lopez-Baeza, E., R. Acosta, M.C. Antolin, F. Belda, A. Cano, E. Carbo, M. Crapeau, A. Fidalgo S. Juglea, Y. Kerr, B. Martinez, C. Millan-Scheiding, D. Rodriguez, K. Saleh, J. Sanchis, J.-P. Wigneron(10), Other Contributors: J.E. Balling, C. Domenech, EOLAB, A.G. Ferreira J. Ferrer, J. Grant, J. Marco C. Narbon, B. Navascues, OCEANSNELL, E. Rodriguez-Camino, N. Skou, S. Søbjærg, P. Soriano, J. Tamayo, S. Tauriainen, E. Torre G. Torregrosa, A. Velazquez Blazquez, S. Vidal (2008): Validation of SMOS Products over Mediterranean Ecosystem Vegetation at the Valencia Anchor Station Reference Area. SMOS Cal/Val AO I.D. no. 3252. Experimental Plan SMOS Validation Rehearsal Campaign. University of Valencia, April 2008 Millan-Scheiding, C. (2006): Aproximación a la Humedad del Suelo en el Altiplano de Requena-Utiel. Preparación para la Campaña de Cal/Val de la Misión Espacial SMOS. Trabajo de Investigación de III Ciclo. Universidad de Valencia. Millán-Scheiding, C., C. Antolín, A. Cano, E. López-Baeza (2007): Uso de Unidades Fisio-Hidrológicas en la Monitorización de la Humedad del Suelo con SMOS. III Simposio Nacional sobre el Control de la Degradación de Suelos y la Desertificación. Costa Calma (Pájara), Fuerteventura, 16 al 20 de Septiembre 2007

  7. Analytical study of electrophoretic characterization of kidney cells. [conducted during the Apollo Soyuz Test Project

    NASA Technical Reports Server (NTRS)

    Knox, R. J.

    1978-01-01

    Embryonic kidney cells were studied as a follow-up to the MA-011 Electrophoresis Technology Experiment which was conducted during the Apollo Soyuz Test Project (ASTP). The postflight analysis of the performance of the ASTP zone electrophoresis experiment involving embryonic kidney cells is reported. The feasibility of producing standard particles for electrophoresis was also studied. This work was undertaken in response to a need for standardization of methods for producing, calibrating, and storing electrophoretic particle standards which could be employed in performance tests of various types of electrophoresis equipment. Promising procedures were tested for their suitability in the production of standard test particles from red blood cells.

  8. Study of the electrical conductivity at finite temperature in 2D Si- MOSFETs

    SciTech Connect

    Limouny, L., E-mail: kaaouachi21@yahoo.fr; Kaaouachi, A. El, E-mail: kaaouachi21@yahoo.fr; Tata, O.; Daoudi, E.; Errai, M.; Dlimi, S. [Research Group ESNPS, Physics Department, University Ibn Zohr, Faculty of Sciences, B.P 8106, Hay Dakhla, 80000 Agadir (Morocco); Idrissi, H. El [Faculté des Sciences et Techniques de Mohammedia, Département de physique. B.P 146 Quartier Yasmina Mohammedia (Morocco); Zatni, A. [Laboratoire MSTI, Ecole Supérieure de Technologie d'Agadir, B.P: 33/S Agadir (Morocco)

    2014-01-27

    We investigate the low temperature density dependent conductivity of two dimensional electron systems in zero magnetic field for sample Si-15 MOSFETs. The first purpose of this paper is to establish that the knee of the conductivity ?{sub 0} (?{sub 0} is the T = 0.3 conductivity obtained by linear extrapolation of the curves of ? (T) for different values of electron density, n{sub s}) as a function of the carrier densities n{sub s} for T = 0.3 K, observed by Lai et al. and Limouny et al. in previous work for two different samples, is independent of temperature. The second aim is the determination of the critical density, n{sub c}, of the metal-insulator transition. Many methods are used in this investigation of n{sub c} which have been already used for other samples. The motivation behind this last study is the observation of many values of n{sub c} that have been obtained from different methods and that are slightly different. We will use in this study three methods with the intention to infer which one is more appropriate to obtain n{sub c}.

  9. 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.

  10. Impact of carpal tunnel surgery according to pre-operative abnormality of sensory conduction in median nerve: a longitudinal study

    PubMed Central

    2013-01-01

    Background We have previously proposed that sensory nerve conduction (SNC) in the median nerve should be classed as abnormal when the difference between conduction velocities in the little and index fingers is > 8 m/s. In a prospective longitudinal study, we investigated whether this case definition distinguished patients who were more likely to benefit from surgical treatment. Methods We followed up 394 patients (response rate 56%), who were investigated by a neurophysiology service for suspected carpal tunnel syndrome. Information about symptoms, treatment and other possible determinants of outcome was obtained through questionnaires at baseline and after follow-up for a mean of 19.2 months. Analysis focused on 656 hands with numbness, tingling or pain at baseline. Associations of surgical treatment with resolution of symptoms were assessed by Poisson regression, and summarised by prevalence rate ratios (PRRs) and associated 95% confidence intervals (95% CIs). Results During follow-up, 154 hands (23%) were treated surgically, and sensory symptoms resolved in 241 hands (37%). In hands with abnormal median SNC, surgery was associated with resolution of numbness, tingling and pain (PRR 1.5, 95% CI 1.0-2.2), and of numbness and tingling specifically (PRR 1.8, 95% CI 1.3-2.6). In contrast, no association was apparent for either outcome when median SNC was classed as normal. Conclusions Our definition of abnormal median SNC distinguished a subset of patients who appeared to benefit from surgical treatment. This predictive capacity gives further support to its validity as a diagnostic criterion in epidemiological research. PMID:23947746

  11. Parametric study of simultaneous transient conduction and radiation in a two-dimensional participating medium

    NASA Astrophysics Data System (ADS)

    Chaabane, Raoudha; Askri, Faouzi; Nasrallah, Sassi Ben

    2011-10-01

    The lattice Boltzmann method (LBM) has been used to solve the energy equation of a transient conduction-radiation heat transfer problem in a two dimensional Cartesian enclosure filled with an emitting, absorbing and scattering media. The control volume finite element method (CVFEM) is used to obtain the radiative information. Based on this new nonlinear hybrid algorithm, the effects of various influencing parameters on the transient thermal response such as the scattering albedo, the conduction-radiation parameter, and the wall emissivity are studied on the distributions of temperature, radiative heat fluxes. Numerical results are presented as compared with other published works and they are found to be in satisfactory agreement. The advantages of the proposed numerical approach include, among others, simple implementation on a computer, accurate CPU time and capability of stable simulation. Therfore, the method can capture fundamental behaviours in thermal flows of engineering interest, in addition it will have computaional advantages when the geometry is more complex.

  12. 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.

  13. Atomistic study of dynamics for metallic filament growth in conductive-bridge random access memory.

    PubMed

    Qin, Shengjun; Liu, Zhan; Zhang, Guo; Zhang, Jinyu; Sun, Yaping; Wu, Huaqiang; Qian, He; Yu, Zhiping

    2015-04-14

    The growth dynamics for metallic filaments in conductive-bridge resistive-switching random access memory (CBRAM) are studied using the kinetic Monte Carlo (KMC) method. The physical process at the atomistic level is revealed in explaining the experimental observation that filament growth can originate at either the cathode or the anode. The statistical nature of the filament growth is best shown by the random topography of dendrite-like conductive paths obtained. Critical material properties, such as charged-particle mobility in the switching layer of a solid electrolyte or a dielectric, are mapped to KMC model parameters through activation energy, etc. The accuracy of the simulator is established by the good agreement between the simulated forming time and the measured data. PMID:25750983

  14. Trauma symptoms in pupils involved in school bullying--a cross sectional study conducted in Mostar, Bosnia and Herzegovina.

    PubMed

    Obrdalj, Edita Cerni; Sesar, Kristina; Santic, Zarko; Klari?, Miro; Sesar, Irena; Rumboldt, Mirjana

    2013-03-01

    To determine the association between involvement in school bullying and trauma symptoms and to find whether children with presence of trauma symptoms participate in school bullying more as victims, as bullies or as bully/victims. The study included 1055, 6th to 8th grade (12-14 years of age) elementary school pupils from the western part of Mostar, The pupils were self-interviewed using a Questionnaire on School Violence developed in 2003 and validated in Croatia, and Trauma Symptoms Check List for Children (TSCC). The pupils involved in the school violence, either as victims, bullies, bully/victims had significantly more trauma symptoms than the not involved. Involvement in school bullying as a bully/ victim was a strong indicator of trauma symptoms, particularly anxiety, anger, posttraumatic stress, dissociation, obvious dissociation, and dissociation fantasy symptoms, while the victims of school violence had the highest odds ratio for the development of depressive symptoms. There is strong association between bullying and trauma symptoms in young adolescents. From our results, emphasis should be placed at the regularly screening on bullying in praxis of family physicians and regularly conduction of preventive measures and early intervention in every primary school. PMID:23697244

  15. Conduct disorder and ADHD: evaluation of conduct problems as a categorical and quantitative trait in the international multicentre ADHD genetics study.

    PubMed

    Anney, Richard J L; Lasky-Su, Jessica; O'Dúshláine, Colm; Kenny, Elaine; Neale, Benjamin M; Mulligan, Aisling; Franke, Barbara; Zhou, Kaixin; Chen, Wai; Christiansen, Hanna; Arias-Vásquez, Alejandro; Banaschewski, Tobias; Buitelaar, Jan; Ebstein, Richard; Miranda, Ana; Mulas, Fernando; Oades, Robert D; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph; Sonuga-Barke, Edmund; Steinhausen, Hans; Asherson, Philip; Faraone, Stephen V; Gill, Michael

    2008-12-01

    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 ADHD + CD represents a specific subtype of the ADHD disorder with familial risk factors only partly overlapping with those of ADHD alone. We performed a hypothesis-free analysis of the GAIN-ADHD sample to identify markers and genes important in the development of conduct problems in a European cohort of individuals with ADHD. Using the Family-Based Association Test (FBAT) package we examined three measures of conduct problems in 1,043,963 autosomal markers. This study is part of a series of exploratory analyses to identify candidate genes that may be important in ADHD and ADHD-related traits, such as conduct problems. We did not find genome-wide statistical significance (P < 5 x 10(-7)) for any of the tested markers and the three conduct problem traits. Fifty-four markers reached strong GWA signals (P < 10(-5)). We discuss these findings in the context of putative candidate genes and the implications of these findings in the understanding of the etiology of ADHD + CD. We aimed to achieve insight into the genetic etiology of a trait using a hypothesis-free study design and were able to identify a number of biologically interesting markers and genes for follow-up studies. PMID:18951430

  16. Effect of Mechanical Strain on Solute Diffusion in Human TMJ Discs: An Electrical Conductivity Study

    PubMed Central

    Wright, Gregory J.; Kuo, Jonathan; Shi, Changcheng; Bacro, Thierry H.; Slate, Elizabeth H.; Yao, Hai

    2013-01-01

    This study investigated the effect of mechanical strain on solute diffusion in human TMJ discs (mean cadaver age 77.8) using the electrical conductivity method. The electrical conductivity, as well as small ion diffusivity, of male and female TMJ discs was determined under three compressive strains. In the male group, the average disc electrical conductivity (mean ± sd) at 0% strain was 5.14±0.97 mS/cm, decreased to 4.50±0.91 mS/cm (?12.3%) at 10% strain, and 3.93±0.81 mS/cm (?23.5%) at 20% compressive strain. Correspondingly, the average disc relative ion diffusivity at 0% strain was 0.44±0.08, decreased to 0.40±0.08 (?8.9%) at 10% strain, and 0.36±0.08 (?16.7%) at 20% compressive strain. In the female group, the average disc electrical conductivity at 0% strain was 5.84±0.59 mS/cm, decreased to 5.01±0.50 mS/cm (?14.2%) at 10% strain, and 4.33±0.46 mS/cm (?25.8%) at 20% compressive strain. Correspondingly, the average disc relative ion diffusivity at 0% strain was 0.49±0.05, decreased to 0.43±0.04 (?11.3%) at 10% strain, and 0.39±0.04 (?19.9%) at 20% compressive strain. The results indicated that mechanical strain significantly impeded solute diffusion through the disc. This mechanical strain effect was larger in the female than in the male human TMJ disc. This study may provide new insights into TMJ pathophysiology. PMID:23771300

  17. 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...

  18. Optimization Studies of a Compton Suppression Spectrometer Using Experimentally Validated Monte Carlo Simulations

    SciTech Connect

    W. Scates; W. Scates; M. E. Mc Ilwain; R. Aryaeinejad

    2005-10-01

    Recent developments associated with room temperature semiconductor detectors and inorganic scintillators suggest that these detectors may be viable alternatives for the primary detector in a Compton Suppression Spectrometer (CSS). The room temperature operation of these detectors allows removal of a substantial amount of material from between primary and secondary detector and if properly designed and should afford substantially better suppression factors than can be achieved by germanium-based spectrometers. We have chosen to study the optimum properties of a CSS with a LaX3:Ce scintillator (where X is chloride or bromide) as the primary gamma ray detector. A Monte Carlo photon transport model is used to determine the optimum geometric properties of this spectrometer. To validate the assumptions and basic design of the Monte Carlo simulations, the energy distribution of a 137Cs point source is measured and simulated for two experimental systems. Comparison of the suppression factors for the measured and simulated data validates the model accuracy. A range of CSS physical parameters are studied to determine optimal detector geometry and to maximize the Compton suppression factor. These physical parameters and their optimum values are discussed.

  19. Validation and Algorithms Comparative Study for Microwave Remote Sensing of Snow Depth over China

    NASA Astrophysics Data System (ADS)

    Bin, C. J.; Qiu, Y. B.; Shi, L. J.

    2014-03-01

    In this study, five different snow algorithms (Chang algorithm, GSFC 96 algorithm, AMSR-E SWE algorithm, Improved Tibetan Plateau algorithm and Savoie algorithm) were selected to validate the accuracy of snow algorithms over China. These algorithms were compared for the accuracy of snow depth algorithms with AMSR-E brightness temperature data and ground measurements on February 10-12, 2010. Results showed that the GSFC 96 algorithm was more suitable in Xinjiang with the RMSE range from 6.85cm to 7.48 cm; in Inner Mongolia and Northeast China. Improved Tibetan Plateau algorithm is superior to the other four algorithms with the RMSE of 5.46cm~6.11cm and 6.21cm~7.83cm respectively; due to the lack of ground measurements, we couldn't get valid statistical results over the Tibetan Plateau. However, the mean relative error (MRE) of the selected algorithms was ranging from 37.95% to 189.13% in four study areas, which showed that the accuracy of the five snow depth algorithms is limited over China.

  20. Assessing South China (Guangzhou) High School Students' Views on Nature of Science: A Validation Study

    NASA Astrophysics Data System (ADS)

    Deng, Feng; Chai, Ching Sing; Tsai, Chin-Chung; Lin, Tzung-Jin

    2014-04-01

    Research on students' views on nature of science (VNOS) in Asian countries such as China is notably lacking. This study aimed to develop and validate an instrument to measure South China high school students' VNOS. Based on the previously acquired qualitative data, the instrument included seven VNOS dimensions which reflect the crucial aspects of NOS indicated by the literature and/or the dominating ideology in China (i.e., Marxism). A sample (N = 604) was randomly divided into two groups used for exploratory analyses and confirmatory analyses. The results indicated that the instrument expressed satisfactory reliability and validity and the seven NOS dimensions could be explained by a higher-order dimension. That is, the data of this study supported the multi-dimensional framework that treats VNOS as comprising several more-or-less correlated dimensions. Two distinct dimensions, namely "Accumulative-Empirical Source" and "Pragmatic Justification" which have not been explicitly specified in the past literature, were found. In addition, the Chinese high school students generally held a constructivist/relativist-oriented view of all seven dimensions. Differences in gender and grade level were hardly observed in any dimension of the instrument. The findings are further discussed through a socio-cultural lens to enrich the current understanding of VNOS.

  1. Progress in GYRO Validation Studies of DIII-D H-mode Plasmas

    NASA Astrophysics Data System (ADS)

    Holland, C.; Burrell, K. H.; Petty, C. C.; Candy, J.; Holcomb, C. T.

    2011-11-01

    The need for a validated predictive capability of turbulent transport in ITER is now widely recognized. However, to date most validation studies of nonlinear codes such as GYRO have focused upon low power L-mode discharges, which have significant differences in key dimensionless parameters such as ? and &*circ;= ?s/a from more ITER-relevant H-mode discharges. In order to address this gap, the results of nonlinear GYRO simulations of a range of DIII-D H-mode discharges (including quiescent H-mode, hybrid, and steady state discharges) are presented. These H-mode studies focus upon three physics effects, motivated by key differences between L- and H-mode plasmas. The first is the linear and nonlinear effects of finite ? in plasmas where ?N= ?/(I/aB) varies from 1.5-2.5, 3-5 times higher than typical L-mode values. Second is the impact of nonlocality at typical DIII-D H-mode &*circ; values, which in contrast to typical L-modes can be non-negligible. Third is the stabilizing effect of a significant density of energetic particles.

  2. Validation of DEMs Derived from High Resolution SAR Data: a Case Study on Barcelona

    NASA Astrophysics Data System (ADS)

    Sefercik, U. G.; Schunert, A.; Soergel, U.; Watanabe, K.

    2012-07-01

    In recent years, Synthetic Aperture Radar (SAR) data have been widely used for scientific applications and several SAR missions were realized. The active sensor principle and the signal wavelength in the order of centimeters provide all-day and all-weather capabilities, respectively. The modern German TerraSAR-X (TSX) satellite provides high spatial resolution down to one meter. Based on such data SAR Interferometry may yield high quality digital surface models (DSMs), which includes points located on 3d objects such as vegetation, forest, and elevated man-made structures. By removing these points, digital elevation model (DEM) representing the bare ground of Earth is obtained. The primary objective of this paper is the validation of DEMs obtained from TSX SAR data covering Barcelona area, Spain, in the framework of a scientific project conducted by ISPRS Working Group VII/2 "SAR Interferometry" that aims the evaluation of DEM derived from data of modern SAR satellite sensors. Towards this purpose, a DSM was generated with 10 m grid spacing using TSX StripMap mode SAR data and converted to a DEM by filtering. The accuracy results have been presented referring the comparison with a more accurate (10 cm-1 m) digital terrain model (DTM) derived from large scale photogrammetry. The results showed that the TSX DEM is quite coherent with the topography and the accuracy is in between ±8-10 m. As another application, the persistent scatterer interferometry (PSI) was conducted using TSX data and the outcomes were compared with a 3d city model available in Google Earth, which is known to be very precise because it is based on LIDAR data. The results showed that PSI outcomes are quite coherent with reference data and the RMSZ of differences is around 2.5 m.

  3. Improved Titanium Billet Inspection Sensitivity through Optimized Phased Array Design, Part II: Experimental Validation and Comparative Study with Multizone

    SciTech Connect

    Hassan, W.; Vensel, F.; Knowles, B. [Honeywell Aerospace, 111 S. 34th Street, M/S 503-118 Phoenix, AZ 85034, Phoenix, AZ 85034 (United States); Lupien, V. [Acoustic Ideas Inc., 27 Eaton Street, Wakefield, MA 01880 (United States)

    2006-03-06

    The inspection of critical rotating components of aircraft engines has made important advances over the last decade. The development of Phased Array (PA) inspection capability for billet and forging materials used in the manufacturing of critical engine rotating components has been a priority for Honeywell Aerospace. The demonstration of improved PA inspection system sensitivity over what is currently used at the inspection houses is a critical step in the development of this technology and its introduction to the supply base as a production inspection. As described in Part I (in these proceedings), a new phased array transducer was designed and manufactured for optimal inspection of eight inch diameter Ti-6Al-4V billets. After confirming that the transducer was manufactured in accordance with the design specifications a validation study was conducted to assess the sensitivity improvement of the PAI over the current capability of Multi-zone (MZ) inspection. The results of this study confirm the significant ({approx_equal} 6 dB in FBH number sign sensitivity) improvement of the PAI sensitivity over that of MZI.

  4. Improved Titanium Billet Inspection Sensitivity through Optimized Phased Array Design, Part II: Experimental Validation and Comparative Study with Multizone

    NASA Astrophysics Data System (ADS)

    Hassan, W.; Vensel, F.; Knowles, B.; Lupien, V.

    2006-03-01

    The inspection of critical rotating components of aircraft engines has made important advances over the last decade. The development of Phased Array (PA) inspection capability for billet and forging materials used in the manufacturing of critical engine rotating components has been a priority for Honeywell Aerospace. The demonstration of improved PA inspection system sensitivity over what is currently used at the inspection houses is a critical step in the development of this technology and its introduction to the supply base as a production inspection. As described in Part I (in these proceedings), a new phased array transducer was designed and manufactured for optimal inspection of eight inch diameter Ti-6Al-4V billets. After confirming that the transducer was manufactured in accordance with the design specifications a validation study was conducted to assess the sensitivity improvement of the PAI over the current capability of Multi-zone (MZ) inspection. The results of this study confirm the significant (? 6 dB in FBH? sensitivity) improvement of the PAI sensitivity over that of MZI.

  5. 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.

  6. 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

  7. 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

  8. Review article: what makes a good healthcare quality indicator? A systematic review and validation study.

    PubMed

    Jones, Peter; Shepherd, Michael; Wells, Susan; Le Fevre, James; Ameratunga, Shanthi

    2014-04-01

    Indicators measuring aspects of performance to assess quality of care are often chosen arbitrarily. The present study aimed to determine what should be considered when selecting healthcare quality indicators, particularly focusing on the application to emergency medicine. Structured searches of electronic databases were supplemented by website searches of quality of care and benchmarking organisations, citation searches and discussions with experts. Candidate attributes of 'good' healthcare indicators were extracted independently by two authors. The validity of each attribute was independently assessed by 16 experts in quality of care and emergency medicine. Valid and reliable attributes were included in a critical appraisal tool for healthcare quality indicators, which was piloted by emergency medicine specialists. Twenty-three attributes were identified, and all were rated moderate to extremely important by an expert panel. The reliability was high: alpha = 0.98. Twelve existing tools explicitly stated a median (range) of 14 (8-17) attributes. A critical appraisal tool incorporating all the attributes was developed. This was piloted by four emergency medicine specialists who were asked to appraise and rank a set of six candidate indicators. Although using the tool took more time than implicit gestalt decision making: median (interquartile range) 190 (43-352) min versus 17.5 (3-34) min, their rankings changed after using the tool. To inform the appraisal of quality improvement indicators for emergency medicine, a comprehensive list of indicator attributes was identified, validated, developed into a tool and piloted. Although expert consensus is still required, this tool provides an explicit basis for discussions around indicator selection. PMID:24707999

  9. Validation and statistical power comparison of methods for analyzing free-response observer performance studies

    PubMed Central

    Chakraborty, Dev P.

    2009-01-01

    Rationale and Objectives The aim of this work was to validate and compare the statistical powers of proposed methods for analyzing free-response data using a search-model based simulator. Materials and Methods A free-response data simulator is described that can model a single reader interpreting the same cases in two modalities, or two CAD algorithms, or two human observers, interpreting the same cases in one modality. A variance components model, analogous to the Roe and Metz receiver operating characteristic (ROC) data simulator, is described, that models intra-case and inter-modality correlations in free-response studies. Two generic observers were simulated: a quasi-human observer and a quasi-CAD algorithm. Null hypothesis (NH) validity and statistical powers of ROC, jackknife alternative free-response operating characteristic (JAFROC), a variant of JAFROC termed JAFROC-1, initial detection and candidate analysis (IDCA) and a non-parametric (NP) approach were investigated. Results All methods had valid NH behavior over a wide range of simulator parameters. For equal numbers of normal and abnormal cases, for the human observer, the statistical power ranking of the methods was JAFROC-1 > JAFROC > (IDCA ~ NP) > ROC. For the CAD algorithm the ranking was (NP ~ IDCA) > (JAFROC-1~JAFROC) > ROC. In either case the statistical power of the highest ranked method exceeded that of the lowest ranked method by about a factor of two. Dependence of statistical power on simulator parameters followed expected trends. For data sets with more abnormal cases than normal cases, JAFROC-1 power significantly exceeded JAFROC power. Conclusion Based on this work the recommendation is to use JAFROC-1 for human observers (including human-observers with CAD assist) and the NP method for evaluating CAD algorithms. PMID:19000872

  10. 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

  11. Validity versus feasibility for quality of care indicators: expert panel results from the MI-Plus study

    PubMed Central

    Peña, Adolfo; Virk, Sandeep S.; Shewchuk, Richard M.; Allison, Jeroan J.; Dale Williams, O.; Kiefe, Catarina I.

    2010-01-01

    Background In the choice and definition of quality of care indicators, there may be an inherent tension between feasibility, generally enhanced by simplicity, and validity, generally enhanced by accounting for clinical complexity. Objectives To study the process of developing quality indicators using an expert panel and analyze the tension between feasibility and validity. Design and participants A multidisciplinary panel of 12 expert physicians was engaged in two rounds of modified Delphi process to refine and choose a smaller subset from 36 indicators; these were developed by a research team studying the quality of care in ambulatory post-myocardial infarction patients with co-morbidities. We studied the correlation between validity/feasibility ranks provided by the expert panel. The correlation between the quality indicators ranks on validity and feasibility scale and variance of experts' responses was also individually studied. Results Ten of 36 indicators were ranked in both the highest validity and feasibility groups. The strength of association between validity and feasibility of indicators measured by Kendall tau-b was 0.65. In terms of validity, a strong negative correlation was observed between the ranks of indicators and the variability in expert panel responses (Spearman's rho, r = ?0.85). A weak correlation was found between the ranks of feasibility and the variability of expert panel responses (Spearman's rho, r = 0.23). Conclusion There was an unexpectedly strong association between the validity and feasibility of quality indicators, with a high level of consensus among experts regarding both feasibility and validity for indicators rated highly on each of these attributes. PMID:20382663

  12. A theoretical study of wave dispersion and thermal conduction for HMX/additive interfaces

    NASA Astrophysics Data System (ADS)

    Long, Yao; Chen, Jun

    2014-04-01

    The wave dispersion rule for non-uniform material is useful for ultrasonic inspection and engine life prediction, and also is key in achieving an understanding of the energy dissipation and thermal conduction properties of solid material. On the basis of linear response theory and molecular dynamics, we derive a set of formulas for calculating the wave dispersion rate of interface systems, and study four kinds of interfaces inside plastic bonded explosives: HMX/{HMX, TATB, F2312, F2313}. (HMX: octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine; TATB: 1,3,5-triamino-2,4,6-trinitrobenzene; F2312, F2313: fluoropolymers). The wave dispersion rate is obtained over a wide frequency range from kHz to PHz. We find that at low frequency, the rate is proportional to the square of the frequency, and at high frequency, the rate couples with the molecular vibration modes at the interface. By using the results, the thermal conductivities of HMX/additive interfaces are derived, and a physical model is built for describing the total thermal conductivity of mixture explosives, including HMX multi-particle systems and {TATB, F2312, F2313}-coated HMX.

  13. Study of single-nucleotide polymorphisms by means of electrical conductance measurements

    NASA Astrophysics Data System (ADS)

    Hihath, Joshua; Xu, Bingqian; Zhang, Peiming; Tao, Nongjian

    2005-11-01

    Understanding the complexities of DNA has been a hallmark of science for over a half century, and one of the important topics in DNA research is recognizing the occurrence of mutations in the base-stack. In this article, we present a study of SNPs by direct-contact electrical measurements to a single DNA duplex. We have used short, 11- and 12-bp dsDNA to investigate the change in conductance that occurs if a single base pair, a single base, or two separate bases in the stack are modified. All measurements are carried out in aqueous solution with the DNA chemically bound to the electrodes. These measurements demonstrate that the presence of a single base pair mismatch can be identified by the conductance of the molecule and can cause a change in the conductance of dsDNA by as much as an order of magnitude, depending on the specific details of the double helix and the single nucleotide polymorphism. molecular electronics | scanning tunneling microscope break junction

  14. Current at domain walls, roughly speaking: nanoscales studies of disorder roughening and conduction

    NASA Astrophysics Data System (ADS)

    Paruch, Patrycja

    2013-03-01

    Domain walls in (multi)ferroic materials are the thin elastic interfaces separating regions with different orientations of magnetisation, electric polarisation, or spontaneous strain. Understanding their behaviour, and controlling domain size and stability, is key for their integration into applications, while fundamentally, domain walls provide an excellent model system in which the rich physics of disordered elastic interfaces can be accesses. In addition, domain walls can present novel properties, quite different from those of their parent materials, making them potentially useful as active components in future nano-devices. Here, we present our atomic force microscopy studies of ferroelectric domain walls in epitaxial Pb(Zr0.2Ti0.8)O3 and BiFeO3 thin films, in which we use piezorespose force microscopy to show unusual domain wall roughening behaviour, with very localised disorder regions in the sample leading to a complex, multi-affine scaling of the domain wall shape [1]. We also show the effects of temperature, environmental conditions, and defects on switching dynamics and domain wall roughness [2]. We combine these observations with parallel conductive-tip atomic force microscopy current measurements, which also show highly localised variations in conduction, and highlight the key role played by oxygen vacancies in the observed domain wall conduction [3]. [4pt] [1] Guyonnet et al., PRL 109, 147601 (2012)[0pt] [2] Paruch et al, PRB 85, 214115 (2012); Blaser et al, APL. 101, 142906 (2012)[0pt] [3] Guyonnet et al., Adv. Mat. 25, 5377 (2011)

  15. Gene expression-based survival prediction in lung adenocarcinoma: a multi-site, blinded validation study.

    PubMed

    Shedden, Kerby; Taylor, Jeremy M G; Enkemann, Steven A; Tsao, Ming-Sound; Yeatman, Timothy J; Gerald, William L; Eschrich, Steven; Jurisica, Igor; Giordano, Thomas J; Misek, David E; Chang, Andrew C; Zhu, Chang Qi; Strumpf, Daniel; Hanash, Samir; Shepherd, Frances A; Ding, Keyue; Seymour, Lesley; Naoki, Katsuhiko; Pennell, Nathan; Weir, Barbara; Verhaak, Roel; Ladd-Acosta, Christine; Golub, Todd; Gruidl, Michael; Sharma, Anupama; Szoke, Janos; Zakowski, Maureen; Rusch, Valerie; Kris, Mark; Viale, Agnes; Motoi, Noriko; Travis, William; Conley, Barbara; Seshan, Venkatraman E; Meyerson, Matthew; Kuick, Rork; Dobbin, Kevin K; Lively, Tracy; Jacobson, James W; Beer, David G

    2008-08-01

    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 proposed examined whether microarray measurements of gene expression either alone or combined with basic clinical covariates (stage, age, sex) could be used to predict overall survival in lung cancer subjects. Several models examined produced risk scores that substantially correlated with actual subject outcome. Most methods performed better with clinical data, supporting the combined use of clinical and molecular information when building prognostic models for early-stage lung cancer. This study also provides the largest available set of microarray data with extensive pathological and clinical annotation for lung adenocarcinomas. PMID:18641660

  16. Aircraft Wake Vortex Spacing System (AVOSS) Performance Update and Validation Study

    NASA Technical Reports Server (NTRS)

    Rutishauser, David K.; OConnor, Cornelius J.

    2001-01-01

    An analysis has been performed on data generated from the two most recent field deployments of the Aircraft Wake VOrtex Spacing System (AVOSS). The AVOSS provides reduced aircraft spacing criteria for wake vortex avoidance as compared to the FAA spacing applied under Instrument Flight Rules (IFR). Several field deployments culminating in a system demonstration at Dallas Fort Worth (DFW) International Airport in the summer of 2000 were successful in showing a sound operational concept and the system's potential to provide a significant benefit to airport operations. For DFW, a predicted average throughput increase of 6% was observed. This increase implies 6 or 7 more aircraft on the ground in a one-hour period for DFW operations. Several studies of performance correlations to system configuration options, design options, and system inputs are also reported. The studies focus on the validation performance of the system.

  17. Experimental Studies of Droplet Evaporation Kinetics: Validation of Models for Binary and Ternary Aqueous Solutions

    Microsoft Academic Search

    Huiwen Xue; Alfred M. Moyle; Nathan Magee; Jerry Y. Harrington; Dennis Lamb

    2005-01-01

    Experiments were conducted with an electrodynamic levitation system to study the kinetics of droplet evaporation under chemically rich conditions. Single solution droplets of known composition (HNO3\\/H2O or H2SO4\\/HNO3\\/H2O) were introduced into an environmentally controlled cubic levitation cell. The gaseous environment was set intentionally out of equilibrium with the droplet properties, thus permitting the HNO3 mass accommodation coefficient to be determined.

  18. Design and validation of a settling column for particle transport studies

    E-print Network

    Ducharme, Sharon Lynn

    1989-01-01

    for the technical assistance from Carl Frederickson, whose expertise in electronics I sought frequently. I would also like to give a special thanks to Bob Bolton for both technical assistance and moral support. Thanks also to Ravindra Malali for the flocculation..., sludge, and New Bedford Harbor sediments for parameters affecting transport, such as specific gravity, size, and flocculation potential. This will involve the use of the Coulter Counter Multisizer and the Mettler Paar Density Meter. Conduct sand studies...

  19. 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.

  20. Validation of a home safety questionnaire used in a series of case-control studies

    PubMed Central

    Watson, Michael; Benford, Penny; Coupland, Carol; Clacy, Rose; Hindmarch, Paul; Majsak-Newman, Gosia; Deave, Toity; Kendrick, Denise

    2014-01-01

    Objective To measure the validity of safety behaviours, safety equipment use and hazards reported on a questionnaire by parents/carers with children aged under 5 years participating in a series of home safety case-control studies. Methods The questionnaire measured safety behaviours, safety equipment use and hazards being used as exposures in five case-control studies. Responses to questions were compared with observations made during a home visit. The researchers making observations were blind to questionnaire responses. Results In total, 162 families participated in the study. Overall agreement between reported and observed values of the safety practices ranged from 48.5% to 97.3%. Only 3 safety practices (stair gate at the top of stairs, stair gate at the bottom of stairs, stairs are carpeted) had substantial agreement based on the ? statistic (k=0.65, 0.72, 0.74, respectively). Sensitivity was high (?70%) for 19 of the 30 safety practices, and specificity was high (?70%) for 20 of the 30 practices. Overall for 24 safety practices, a higher proportion of respondents over-reported than under-reported safe practice (negative predictive value>positive predictive value). For six safety practices, a higher proportion of respondents under-reported than over-reported safe practice (negative predictive valuestudy found that the validity of self-reports varied with safety practice. Questions with a high specificity will be useful for practitioners for identifying households who may benefit from home safety interventions and will be useful for researchers as measures of exposures or outcomes. PMID:24591447