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1

WISC-R Incentives and the Academic Achievement of Conduct Disordered Adolescent Females: A Validity Study.  

ERIC Educational Resources Information Center

Studied the relationship between Wechsler Intelligence Scale for Children (Revised) scores obtained through three testing conditions (praise, neutral feedback, and token reinforcement) and previous records of academic achievement for conduct-disordered adolescent girls (N=51). Results showed that regardless of testing conditions, the subtests were…

Saigh, Philip A.; Antoun, Fuad T.

1983-01-01

2

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

PubMed

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

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

2014-11-01

3

29 CFR 1607.7 - Use of other validity studies.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Use of other validity studies. 1607.7 Section 1607.7 Labor Regulations...Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user. Users may,...

2011-07-01

4

29 CFR 1607.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2011 CFR

...false Technical standards for validity studies. 1607.14 Section 1607.14 Labor...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2011-07-01

5

29 CFR 1607.7 - Use of other validity studies.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Use of other validity studies. 1607.7 Section 1607.7 Labor Regulations...Principles § 1607.7 Use of other validity studies. A. Validity studies not conducted by the user. Users may,...

2010-07-01

6

29 CFR 1607.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2013 CFR

...false Technical standards for validity studies. 1607.14 Section 1607.14 Labor...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2013-07-01

7

29 CFR 1607.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2012 CFR

...false Technical standards for validity studies. 1607.14 Section 1607.14 Labor...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2012-07-01

8

29 CFR 1607.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2014 CFR

...false Technical standards for validity studies. 1607.14 Section 1607.14 Labor...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2014-07-01

9

Simulators' validation study: Problem solution logic  

NASA Technical Reports Server (NTRS)

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.

Schoultz, M. B.

1974-01-01

10

Carbon Fibers Conductivity Studies  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

11

41 CFR 60-3.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2011 CFR

...true Technical standards for validity studies. 60-3.14 Section 60-3.14...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2011-07-01

12

41 CFR 60-3.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2013 CFR

...false Technical standards for validity studies. 60-3.14 Section 60-3.14...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2013-07-01

13

41 CFR 60-3.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2014 CFR

...false Technical standards for validity studies. 60-3.14 Section 60-3.14...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2014-07-01

14

41 CFR 60-3.14 - Technical standards for validity studies.  

Code of Federal Regulations, 2012 CFR

...true Technical standards for validity studies. 60-3.14 Section 60-3.14...14 Technical standards for validity studies. The following minimum standards...should be met in conducting a validity study. Nothing in these guidelines is...

2012-07-01

15

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

16

RTEMS Validation and Testing Study  

NASA Astrophysics Data System (ADS)

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

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

2007-08-01

17

CANFOR Portuguese version: validation study  

PubMed Central

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

2013-01-01

18

NOAA's hydrolab conducts reef studies  

NASA Astrophysics Data System (ADS)

This summer, scuba-diving scientists operating from Hydrolab, NOAA's undersea laboratory, are carrying out four experiments aimed at producing better management of coral reefs and their fishery resources. Hydrolab is located at a depth of 50 feet, near the mouth of the Salt River, off St. Croix, U.S. Virgin Islands. The lab houses four scientists for up to 2 weeks at a time, permitting them to swim out into the water to conduct research. The projects make use of both the natural coral reef near Hydrolab and the nearby artificial reef constructed for comparison studies.

19

Assessing the Risk of Domestic Violence Reoffending: A Validation Study  

Microsoft Academic Search

Little research has been conducted to validate available instruments for assessing the risk of domestic violence reoffending, especially research using some form of prospective design. This study uses a prospective design to determine the reliability and validity of the Domestic Violence Screening Instrument (DVSI). The analysis is based on a sample of 1,465 male domestic violence offenders selected consecutively over

Kirk R. Williams; Amy Barry Houghton

2004-01-01

20

A Validation Study of a Transferred Group Intelligence Test  

Microsoft Academic Search

The purpose of the research was to conduct a validation study of a transferred group intelligence test. The Lorge-Thorndike Intelligence Test, Level A, Form 1 was translated to Hebrew and administered to an Israeli sample comparable to the original norming group. The results obtained were concerned with variability, reliability, validity, item analysis, intercorrelations among subtests, and factor analysis. While few

Mordechai Miron

1977-01-01

21

VALIDATION OF A THERMAL CONDUCTIVITY MEASUREMENT SYSTEM FOR FUEL COMPACTS  

SciTech Connect

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.

Jeff Phillips; Colby Jensen; Changhu Xing; Heng Ban

2011-03-01

22

Test of Creative Imagination: Validity and Reliability Study  

ERIC Educational Resources Information Center

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…

Gundogan, Aysun; Ari, Meziyet; Gonen, Mubeccel

2013-01-01

23

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

ERIC Educational Resources Information Center

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

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

2008-01-01

24

41 CFR 60-3.7 - Use of other validity studies.  

Code of Federal Regulations, 2011 CFR

... 2009-07-01 true Use of other validity studies. 60-3.7 Section 60-3.7 Public Contracts...Principles § 60-3.7 Use of other validity studies. A. Validity studies not conducted by the user. Users may,...

2011-07-01

25

41 CFR 60-3.7 - Use of other validity studies.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 true Use of other validity studies. 60-3.7 Section 60-3.7 Public Contracts...Principles § 60-3.7 Use of other validity studies. A. Validity studies not conducted by the user. Users may,...

2010-07-01

26

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

ERIC Educational Resources Information Center

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…

Clay, Rex J.

27

Factor Validity Study of the Learning Style Profile.  

ERIC Educational Resources Information Center

A factor validity study of the Learning Style Profile (LSP) developed by the National Association of Secondary School Principals was conducted. Developed for use with students in grades 6 through 12, the Profile, which consists of 26 questions representing 24 independent subscales, requires approximately 60 minutes to finish. A random sample of…

Hardigan, Patrick C.; Sisco, Burton R.

28

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.

29

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

30

FETAX interlaboratory validation study: Phase 2 testing  

SciTech Connect

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.

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

31

Critical validation studies of neurofeedback  

Microsoft Academic Search

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

John Gruzelier; Tobias Egner

2005-01-01

32

Code Validation Study for Base Flows  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

33

Design and Validation of a High-Temperature Comparative Thermal-Conductivity Measurement System  

NASA Astrophysics Data System (ADS)

A measurement system has been designed and built for the specific application of measuring the effective thermal conductivity of a composite, nuclear-fuel compact (small cylinder) over a temperature range of 100 °C to 800 °C. Because of the composite nature of the sample as well as the need to measure samples pre- and post-irradiation, measurement must be performed on the whole compact non-destructively. No existing measurement system is capable of obtaining its thermal conductivity in a non-destructive manner. The designed apparatus is an adaptation of the guarded-comparative-longitudinal heat flow technique. The system uniquely demonstrates the use of a radiative heat sink to provide cooling which greatly simplifies the design and setup of such high-temperature systems. The design was aimed to measure thermal-conductivity values covering the expected range of effective thermal conductivity of the composite nuclear fuel from 10 W . m-1 . K-1 to 70 W . m-1 . K-1. Several materials having thermal conductivities covering this expected range have been measured for system validation, and results are presented. A comparison of the results has been made to data from existing literature. Additionally, an uncertainty analysis is presented finding an overall uncertainty in sample thermal conductivity to be 6 %, matching well with the results of the validation samples.

Jensen, C.; Xing, C.; Folsom, C.; Ban, H.; Phillips, J.

2012-02-01

34

Studying pretrial publicity effects: new methods for improving ecological validity and testing external validity.  

PubMed

Although research examining the effects of pretrial publicity (PTP) on individuals' appraisals of a defendant and verdict decision making generally has been found to be internally valid, the external validity has been questioned by some social scientists as well as lawyers and judges. It is often proposed that the verisimilitude (or ecological validity) ofthe research should be increased in the service of increasing external validity; however, increasing verisimilitude can be costly in terms of both time and money. It is proposed that the Internet is a viable means of conducting PTP research that allows high verisimilitude without high costs. This is demonstrated with a study in which we used the Internet to examine PTP effects in an actual trial as it was taking place. Successful use of the Internet to conduct experimental research in other areas of psychology and law is discussed, as well as the importance of future research examining whether independent variables interact with methods in ways that undermine the generalizability of research findings. PMID:11868618

Studebaker, Christina A; Robbennolt, Jennifer K; Penrod, Steven D; Pathak-Sharma, Maithilee K; Groscup, Jennifer L; Devenport, Jennifer L

2002-02-01

35

40 CFR 761.392 - Preparing validation study samples.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Preparing validation study samples. 761.392 Section 761.392...COMMERCE, AND USE PROHIBITIONS Comparison Study for Validating a New Performance-Based... § 761.392 Preparing validation study samples. (a)(1) To...

2010-07-01

36

29 CFR 1607.5 - General standards for validity studies.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false General standards for validity studies. 1607.5 Section 1607.5 Labor ...1607.5 General standards for validity studies. A. Acceptable types of validity studies. For the purposes of satisfying...

2010-07-01

37

29 CFR 1607.5 - General standards for validity studies.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false General standards for validity studies. 1607.5 Section 1607.5 Labor ...1607.5 General standards for validity studies. A. Acceptable types of validity studies. For the purposes of satisfying...

2011-07-01

38

40 CFR 761.392 - Preparing validation study samples.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Preparing validation study samples. 761.392 Section 761.392...COMMERCE, AND USE PROHIBITIONS Comparison Study for Validating a New Performance-Based... § 761.392 Preparing validation study samples. (a)(1) To...

2011-07-01

39

Design and Validation of a High-Temperature Comparative Thermal-Conductivity Measurement System  

SciTech Connect

A measurement system has been designed and built for the specific application of measuring the effective thermal conductivity of a composite, nuclear-fuel compact (small cylinder) over a temperature range of 100 C to 800 C. Because of the composite nature of the sample as well as the need to measure samples pre- and postirradiation, measurement must be performed on the whole compact non-destructively. No existing measurement system is capable of obtaining its thermal conductivity in a non-destructive manner. The designed apparatus is an adaptation of the guardedcomparative-longitudinal heat flow technique. The system uniquely demonstrates the use of a radiative heat sink to provide cooling which greatly simplifies the design and setup of such high-temperature systems. The design was aimed to measure thermalconductivity values covering the expected range of effective thermal conductivity of the composite nuclear fuel from 10W {center_dot} m{sup -1} {center_dot} K{sup -1} to 70W {center_dot} m{sup -1} {center_dot} K{sup -1}. Several materials having thermal conductivities covering this expected range have been measured for system validation, and results are presented. A comparison of the results has been made to data from existing literature.Additionally, an uncertainty analysis is presented finding an overall uncertainty in sample thermal conductivity to be 6%, matching well with the results of the validation samples.

Jeff Phillips; Colby Jensen; C Xing; H. Ban

2012-02-01

40

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

E-print Network

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?

Massimo Cencini; Fabio Cecconi; Massimo Falcioni; Angelo Vulpiani

2008-04-04

41

Connected Classroom Climate: A Validity Study  

Microsoft Academic Search

Connected classroom climate, which focuses on the role of student–student communication in establishing a positive classroom climate, is a relatively new construct with the potential to enhance the understanding of classroom interaction. Results of this study support both the content and construct validity of Dwyer et al.'s (2004) Connected Classroom Climate Inventory as a measure of connected classroom climate. As

Danette Ifert Johnson

2009-01-01

42

The Validity of Comparative Educational Studies.  

ERIC Educational Resources Information Center

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)

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

1999-01-01

43

Proton Conductivity Studies on Biopolymer Electrolytes  

SciTech Connect

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

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

2010-07-07

44

Nerve conduction studies in early tuberculoid leprosy  

PubMed Central

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

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

2014-01-01

45

Validity  

NSDL National Science Digital Library

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

Christmann, Edwin P.; Badgett, John L.

2008-11-01

46

CFD Validation Studies for Hypersonic Flow Prediction  

NASA Technical Reports Server (NTRS)

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.

Gnoffo, Peter A.

2001-01-01

47

CFD Validation Studies for Hypersonic Flow Prediction  

NASA Technical Reports Server (NTRS)

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.

Gnoffo, Peter A.

2001-01-01

48

Statistical power in criterion-related validation studies  

Microsoft Academic Search

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

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

1976-01-01

49

Two phase detonation studies conducted in 1971  

NASA Technical Reports Server (NTRS)

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.

Nicholls, J. A.

1972-01-01

50

Conducting record review studies in clinical practice.  

PubMed

Clinical record review or chart review is a previously recorded data to answer clinical queries. Such a study can be used to answer specific clinical questions in a relatively easy and less resource intensive manner. But these studies may be constrained by the limited information retrievable and inadequacy of records. Various types of data sources may be available for conducting such reviews (like case charts, computerized registries, etc), each with specific strengths and weaknesses. The procedure usually consists of drawing up the research question, identifying the appropriate data source, devising a data extraction plan, extracting the data, checking for errors, data analysis, and appropriate archiving and dissemination of the findings. The ethical aspects in such studies primarily pertain to issues of informed consent and confidentiality. This paper provides a broad overview of how to go about a clinical record review, and serves as a ready reference for those who would like to undertake such record reviews. PMID:25386466

Sarkar, Siddharth; Seshadri, Divya

2014-09-01

51

Conducting Record Review Studies in Clinical Practice  

PubMed Central

Clinical record review or chart review is a previously recorded data to answer clinical queries. Such a study can be used to answer specific clinical questions in a relatively easy and less resource intensive manner. But these studies may be constrained by the limited information retrievable and inadequacy of records. Various types of data sources may be available for conducting such reviews (like case charts, computerized registries, etc), each with specific strengths and weaknesses. The procedure usually consists of drawing up the research question, identifying the appropriate data source, devising a data extraction plan, extracting the data, checking for errors, data analysis, and appropriate archiving and dissemination of the findings. The ethical aspects in such studies primarily pertain to issues of informed consent and confidentiality. This paper provides a broad overview of how to go about a clinical record review, and serves as a ready reference for those who would like to undertake such record reviews. PMID:25386466

Seshadri, Divya

2014-01-01

52

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

Microsoft Academic Search

With rapid advancements in computer hardware and numerical algorithms, computational fluid dynamics (CFD) has been increasingly employed as a useful tool for investigating the complex hydrodynamics inherent in multiphase flows. An important step during the development of a CFD model and prior to its application is conducting careful and comprehensive verification and validation studies. Accordingly, efforts to verify and validate

Tingwen Li; Rahul Garg; Janine Galvin; Sreekanth Pannala

2012-01-01

53

The validation of the robust input estimation approach to two-dimensional inverse heat conduction problems  

SciTech Connect

A novel adaptive and robust input estimation inverse methodology of estimating the time-varying unknown heat flux, named as the input, on the two active boundaries of a 2-D inverse heat conduction problem is presented. The algorithm includes using the Kalman filter to propose a regression model between the residual innovation and the two thermal unknown boundaries flux through given 2-D heat conduction state-space models and noisy measurement sequence. Based on this regression equation, a recursive least-square estimator (RLSE) weighted by the forgetting factor is proposed to on-line estimate these unknowns. The adaptive and robust weighting technique is essential since unknowns input are time-varied and have unpredictable changing status. In this article, the authors provide the bandwidth analysis together with bias and variance tests to construct an efficient and robust forgetting factor as the ratio between the standard deviation of measurement and observable bias innovation at each time step. Herein, the unknowns are robustly and adaptively estimated under the system involving measurement noise, process error, and unpredictable change status of time-varying unknowns. The capabilities of the proposed algorithm are demonstrated through the comparison with the conventional input estimation algorithm and validated by two benchmark performance tests in 2-D cases. Results show that the proposed algorithm not only exhibits superior robust capability but also enhances the estimation performance and highly facilitates practical implementation.

Tuan, P.C.; Ju, M.C.

2000-03-01

54

Conducting a multi family member interview study.  

PubMed

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

Reczek, Corinne

2014-06-01

55

40 CFR 160.130 - Conduct of a study.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Conduct of a study. 160.130 Section 160.130 Protection...PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The study shall be conducted in...

2011-07-01

56

40 CFR 160.130 - Conduct of a study.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Conduct of a study. 160.130 Section 160.130 Protection...PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The study shall be conducted in...

2010-07-01

57

40 CFR 792.130 - Conduct of a study.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 true Conduct of a study. 792.130 Section 792.130 Protection...PRACTICE STANDARDS Protocol for and Conduct of A Study § 792.130 Conduct of a study. (a) The study shall be conducted in...

2010-07-01

58

40 CFR 792.130 - Conduct of a study.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Conduct of a study. 792.130 Section 792.130 Protection...PRACTICE STANDARDS Protocol for and Conduct of A Study § 792.130 Conduct of a study. (a) The study shall be conducted in...

2011-07-01

59

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

ERIC Educational Resources Information Center

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…

Stancavage, Frances B.

60

Structural and Electrical Study of Conducting Polymers  

NASA Astrophysics Data System (ADS)

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.

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

2010-06-01

61

Neuroscience Investigations: An Overview of Studies Conducted  

NASA Technical Reports Server (NTRS)

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.

Reschke, Millard F.

1999-01-01

62

College of the Canyons Predictive Validity Studies.  

ERIC Educational Resources Information Center

Matriculation regulations in California require that community colleges which adopt standardized placement tests demonstrate that the tests are valid predictors of future course success. A positive correlation of at least .35 between test score and subsequent student performance in a particular course is needed to demonstrate the predictive…

College of the Canyons, Valencia, CA. Office of Institutional Development.

63

29 CFR 1607.5 - General standards for validity studies.  

Code of Federal Regulations, 2012 CFR

...through a construct validity study should consist of data showing...standardization. Validity studies should be carried out under...of time and in a majority of cases, progress to a higher level...when technically feasible, a study which is designed to...

2012-07-01

64

29 CFR 1607.5 - General standards for validity studies.  

Code of Federal Regulations, 2013 CFR

...through a construct validity study should consist of data showing...standardization. Validity studies should be carried out under...of time and in a majority of cases, progress to a higher level...when technically feasible, a study which is designed to...

2013-07-01

65

29 CFR 1607.5 - General standards for validity studies.  

Code of Federal Regulations, 2014 CFR

...through a construct validity study should consist of data showing...standardization. Validity studies should be carried out under...of time and in a majority of cases, progress to a higher level...when technically feasible, a study which is designed to...

2014-07-01

66

A validation study of homeopathic prescribing and patient care indicators.  

PubMed

A preliminary version of the homeopathic prescribing and patient care indicators was available. The instrument was modified further in this study with an intention to address formally its validity and reliability, audit prescriptions, identify areas of sub-optimal prescribing, and highlight target areas for improving the quality of practices. A cross-sectional study with record analysis was conducted on systematically sampled 377 patients of Mahesh Bhattacharyya Homeopathic Medical College and Hospital (MBHMC and H), Howrah, West Bengal, India. The outcome measures were homeopathic prescribing indicators (6 items) and patient care indicators (5 items). Individualized homeopathic prescriptions predominated in the encounters. Areas demanding immediate attention were extremely poor labeling of drugs dispensed from the hospital pharmacy, improper record of case history and disease diagnosis, ongoing therapies, and investigational findings in the prescriptions. Internal consistency of the overall instrument was estimated to be good (Cronbach's alpha: Prescribing indicators 0.752 and patient care indicators 0.791). The prescribing indicators, except items 1 and 3, reflected acceptable item-corrected total correlations - Pearson's r from 0.58 (95% CI: 0.52-0.65) to 0.74 (95% CI: 0.69-0.78). The patient care indicators, except item 2, showed acceptable correlations - Pearson's r from 0.40 (95% CI: 0.31-0.48) to 0.82 (95% CI: 0.78-0.85). The instrument also showed high discriminant validity (prescribing indicators P < 0.0001 and patient care indicators P < 0.0001). Improper prescribing practice was quite rampant and corrective measures are warranted. The developed indicators appeared to be validated and reliable; however, they are amendable for further development. PMID:25379474

Koley, Munmun; Saha, Subhranil; Ghosh, Shubhamoy; Nag, Goutam; Kundu, Monojit; Mondal, Ramkumar; Purkait, Rajib; Patra, Supratim

2014-10-01

67

Study of Electrohydrodynamic Micropumping Through Conduction Phenomenon  

Microsoft Academic Search

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

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

2011-01-01

68

18 CFR 5.15 - Conduct of studies.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Conduct of studies. 5.15 Section 5.15 Conservation...APPLICATION PROCESS § 5.15 Conduct of studies. (a) Implementation. The potential...applicant must gather information and conduct studies as provided for in the approved...

2010-04-01

69

18 CFR 5.15 - Conduct of studies.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Conduct of studies. 5.15 Section 5.15 Conservation...APPLICATION PROCESS § 5.15 Conduct of studies. (a) Implementation. The potential...applicant must gather information and conduct studies as provided for in the approved...

2011-04-01

70

SAMICS Validation. SAMICS Support Study, Phase 3  

NASA Technical Reports Server (NTRS)

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.

1979-01-01

71

63Cu NMR study of conducting delafossites  

Microsoft Academic Search

NMR data are presented for the conducting delafossites Y0.99Ca0.01CuO2.65 and LaCuO2.64. These materials exhibit a planar structure with triangular arrays of exchange-coupled S=1\\/2(Cu2+) spins. The two compounds examined show strikingly different quadrupole-broadened NMR powder patterns, which is evidence for different in-plane arrangements of O2- ions. Their doped-hole carrier densities are comparable to those of the superconducting cuprates. In consequence, they

R. E. Walstedt; R. J. Cava; R. F. Bell; J. J. Krajewski; W. F. Peck Jr.

1994-01-01

72

40 CFR 761.395 - A validation study.  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

73

40 CFR 761.395 - A validation study.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

74

40 CFR 761.395 - A validation study.  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

75

40 CFR 761.395 - A validation study.  

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

76

40 CFR 761.395 - A validation study.  

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

77

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

ERIC Educational Resources Information Center

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…

Roberts, Jean

78

Practical challenges in conducting respiratory studies  

PubMed Central

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

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

2015-01-01

79

Validation of High-Resolution DNA Melting Analysis for Mutation Scanning of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Gene  

PubMed Central

High-resolution melting analysis of polymerase chain reaction products for mutation scanning, which began in the early 2000s, is based on monitoring of the fluorescence released during the melting of double-stranded DNA labeled with specifically developed saturation dye, such as LC-Green. We report here the validation of this method to scan 98% of the coding sequence of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We designed 32 pairs of primers to amplify and analyze the 27 exons of the gene. Thanks to the addition of a small GC-clamp at the 5? ends of the primers, one single melting domain and one identical annealing temperature were obtained to co-amplify all of the fragments. A total of 307 DNA samples, extracted by the salt precipitation method, carrying 221 mutations and 21 polymorphisms, plus 20 control samples free from variations (confirmed by denaturing high-performance liquid chromatography analysis), was used. With the conditions described in this study, 100% of samples that carry heterozygous mutations and 60% of those with homozygous mutations were identified. The study of a cohort of 136 idiopathic chronic pancreatitis patients enabled us to prospectively evaluate this technique. Thus, high-resolution melting analysis is a robust and sensitive single-tube technique for screening mutations in a gene and promises to become the gold standard over denaturing high-performance liquid chromatography, particularly for highly mutated genes such as CFTR, and appears suitable for use in reference diagnostic laboratories. PMID:18687795

Audrezet, Marie-Pierre; Dabricot, Aurélia; Le Marechal, Cédric; Ferec, Claude

2008-01-01

80

FETAX interlaboratory validation study: Phase 2 testing  

Microsoft Academic Search

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

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

81

Experimental Study of Acid Fracture Conductivity of Austin Chalk Formation  

E-print Network

condition of the fracture surfaces on acid fracture conductivity in the Austin Chalk formation. While temperature and rock-acid contact are variables normally studied in fracture conductivity tests, the effect of the initial condition of the fracture surface...

Nino Penaloza, Andrea

2013-05-01

82

Validation of FE model for transient hot wire thermal conductivity measurements  

Microsoft Academic Search

The paper focuses on an analysis of the FE solution of a 2D model for the transient hot wire method which is a technique for measuring the thermal conductivity of fluids over a wide range of temperatures. Knowledge of the thermal conductivity of fluids and molten materials, especially metals, is of particular interest in the electronics manufacturing industry for the

Jaromir Bilek; John Atkinson; William Wakeham

2005-01-01

83

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

Code of Federal Regulations, 2010 CFR

...primary specimen. You must also determine its specific gravity if you find the creatinine concentration to be less than 20 mg/dL. (b) You must determine the pH of each primary specimen. (c) You must perform one or more validity tests for...

2010-10-01

84

Validation study on avermectine residues in foodstuffs.  

PubMed

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

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

2011-08-26

85

Accuracy of dietary recall using the USDA five-step multiple-pass method in men: An observational validation study  

Microsoft Academic Search

ObjectiveThis 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 five-step multiple-pass method for dietary recall.

Joan M. Conway; Linda A. Ingwersen; Alanna J. Moshfegh

2004-01-01

86

Cross-study validation for the assessment of prediction algorithms  

PubMed Central

Motivation: Numerous competing algorithms for prediction in high-dimensional settings have been developed in the statistical and machine-learning literature. Learning algorithms and the prediction models they generate are typically evaluated on the basis of cross-validation error estimates in a few exemplary datasets. However, in most applications, the ultimate goal of prediction modeling is to provide accurate predictions for independent samples obtained in different settings. Cross-validation within exemplary datasets may not adequately reflect performance in the broader application context. Methods: We develop and implement a systematic approach to ‘cross-study validation’, to replace or supplement conventional cross-validation when evaluating high-dimensional prediction models in independent datasets. We illustrate it via simulations and in a collection of eight estrogen-receptor positive breast cancer microarray gene-expression datasets, where the objective is predicting distant metastasis-free survival (DMFS). We computed the C-index for all pairwise combinations of training and validation datasets. We evaluate several alternatives for summarizing the pairwise validation statistics, and compare these to conventional cross-validation. Results: Our data-driven simulations and our application to survival prediction with eight breast cancer microarray datasets, suggest that standard cross-validation produces inflated discrimination accuracy for all algorithms considered, when compared to cross-study validation. Furthermore, the ranking of learning algorithms differs, suggesting that algorithms performing best in cross-validation may be suboptimal when evaluated through independent validation. Availability: The survHD: Survival in High Dimensions package (http://www.bitbucket.org/lwaldron/survhd) will be made available through Bioconductor. Contact: levi.waldron@hunter.cuny.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24931973

Bernau, Christoph; Riester, Markus; Boulesteix, Anne-Laure; Parmigiani, Giovanni; Huttenhower, Curtis; Waldron, Levi; Trippa, Lorenzo

2014-01-01

87

Academic Self-Efficacy as a Predictor of College Outcomes: Two Incremental Validity Studies  

ERIC Educational Resources Information Center

A growing body of literature supports the relationship between students' self-efficacy beliefs for academic tasks and milestones and their academic performance. Not surprisingly, some researchers have investigated the role that academic self-efficacy beliefs play in predicting college success. Two incremental validity studies were conducted to…

Gore, Paul A. Jr

2006-01-01

88

Nephrotoxicity screening in rats: a validation study.  

PubMed

A validation of our non-invasive screening test for the detection of renal damage (Zbinden et al. 1988) is presented. The test is based on repetitive, quantitative urine analysis in groups of six female Sprague-Dawley rats treated on 5 consecutive days with low doses of test substances. Higher doses were administered in the following weeks until nephrotoxic effects or signs of general toxicity were observed. Thirteen reference substances (hexachloro-1:3-butadiene [HCBD], cisplatin, carboplatin, suramin, chloroform, neomycin, rifampicin, phenacetin, phenylbutazone, methicilline, sodium oxalate, ethylene glycol and furosemide) were used. The percentage of rats reaching the test criteria, i.e., pathologic values defined on the basis of measured control values, was determined. In the controls, the overall percentage of rats reaching or exceeding the test criteria was 4.48%, a value that is close to the expected 5%. Evidence of nephrotoxicity was found with all reference compounds. Elevated excretion of cells and occurrence of cylinders were the most sensitive indicators of renal damage. Hematuria was the most frequent finding. Of the other urine constituents measured the enzyme malate dehydrogenase (MDH) was frequently increased. Water consumption, urine volume, pH and specific gravity were occasionally, and protein, glucose, electrolytes, amino acids and gamma-glutamyl-transpeptidase (GGT) were only rarely changed. It is concluded that the screening which is based on quantitative and repeated urine analysis is a useful procedure to detect nephrotoxic chemicals acting by a variety of mechanisms. The histopathological examination of the kidneys contributed useful information of the nature of the toxic effects, but as a screening tool it is less sensitive than quantitative urine analysis. PMID:3395246

Fent, K; Mayer, E; Zbinden, G

1988-04-01

89

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

NASA Technical Reports Server (NTRS)

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.

1991-01-01

90

Dosimetric studies for gamma radiation validation of medical devices.  

PubMed

The delivery and validation of a specified dose to medical devices are key concerns to operators of gamma radiation facilities. The objective of the present study was to characterize the industrial gamma radiation facility and map the dose distribution inside the product-loading pattern during the validation and routine control of the sterilization process using radiochromic films. Cardboard phantoms were designed to achieve the homogeneity of absorbed doses. The uncertainty of the dose delivered during validation of the sterilization process was assessed. PMID:23079487

Soliman, Y S; Beshir, W B; Abdel-Fattah, A A; Abdel-Rehim, F

2013-01-01

91

Job Involvement: A Construct Validity Study.  

ERIC Educational Resources Information Center

The interrelationships among job involvement, values, personal background, participation in decision making, and job attitudes were investigated by questionnaire for a sample of 2,775 employees of six manufacturing organizations, representing a 66 percent response rate. The results of this study indicated that job involvement, a basic orientation…

Ruh, Robert A.; White, J. Kenneth

92

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

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 currently or have ever had a student conduct or criminal charge, this may affect your acceptance by a host

Hu, Hui

93

Reader studies for validation of CAD systems.  

PubMed

Evaluation of computational intelligence (CI) systems designed to improve the performance of a human operator is complicated by the need to include the effect of human variability. In this paper we consider human (reader) variability in the context of medical imaging computer-assisted diagnosis (CAD) systems, and we outline how to compare the detection performance of readers with and without the CAD. An effective and statistically powerful comparison can be accomplished with a receiver operating characteristic (ROC) experiment, summarized by the reader-averaged area under the ROC curve (AUC). The comparison requires sophisticated yet well-developed methods for multi-reader multi-case (MRMC) variance analysis. MRMC variance analysis accounts for random readers, random cases, and correlations in the experiment. In this paper, we extend the methods available for estimating this variability. Specifically, we present a method that can treat arbitrary study designs. Most methods treat only the fully-crossed study design, where every reader reads every case in two experimental conditions. We demonstrate our method with a computer simulation, and we assess the statistical power of a variety of study designs. PMID:18215501

Gallas, Brandon D; Brown, David G

2008-01-01

94

Assessing Interpersonal Aspects of Schizoid Personality Disorder: Preliminary Validation Studies  

Microsoft Academic Search

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

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

2008-01-01

95

Validation study for secretarial/administrative classifications using computer-based testing  

SciTech Connect

This paper presents the results of a content and concurrent criterion-related validity study conducted at Los Alamos National Laboratory for clerical, secretarial and administrative classifications using computer-based testing. The advantages and disadvantages of different types of testing software incorporated in the study are explored. Job analysis methodology, adverse impact analysis, procedure for establishing cut-off score and problems associated with criterion development and restriction of range are discussed. 6 tabs.

Burns, J.M.

1991-01-01

96

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

97

FETAX interlaboratory validation study: phase III--Part 1 testing.  

PubMed

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 aids in embryo staging and identifying malformations. As part of the ASTM process, a three-phase interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FETAX. Seven different participants collaborated in the study. In Phase I, FETAX proved to be more repeatable and reliable than many bioassays. However, some excessive variation was observed in a few laboratories. An initial lack of assay experience by some technicians caused variation. Phase II showed far less intra- and interlaboratory variability than Phase I. Non-teratogens showed the most consistent results, while more variability was observed for the two teratogens tested. Interlaboratory coefficient of variation values for all endpoints ranged from 7.3 to 54.7. Phase III--Part 1, using coded samples and test concentration ranges selected by each laboratory, showed results similar to Phase I. Analysis of the causes of variation suggested that some technicians judged some embryos to be malformed while others consistently judged similar embryos as normal. Concentration ranges tested by some of the laboratories varied greatly and a new protocol for selecting concentrations for initial testing was written to reduce variation from this source. Testing to date suggests that FETAX is as repeatable and reliable as other standard bioassays. PMID:8956098

Bantle, J A; Finch, R A; Burton, D T; Fort, D J; Dawson, D A; Linder, G; Rayburn, J R; Hull, M; Kumsher-King, M; Gaudet-Hull, A M; Turley, S D

1996-01-01

98

Verification, Validation and Sensitivity Studies in Computational Biomechanics  

PubMed Central

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

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

2012-01-01

99

Developing the Educational Belief Scale: The Validity and Reliability Study  

ERIC Educational Resources Information Center

The aim of this study is to develop a valid and reliable scale that can be used in determining educational beliefs of teachers and prospective teachers. After studies such as scale expert views and the evaluation of intelligibility, the measure is administered to a sample consisting of 154 teachers and 305 prospective teachers with a total number…

Yilmaz, Kursad; Altinkurt, Yahya; Cokluk, Omay

2011-01-01

100

Structural, thermal studies and ionic conductivity of doped polymer electrolytes  

NASA Astrophysics Data System (ADS)

In this paper we present, the structural, thermal studies and ionic conductivity of cadmium chloride (CdCl2) doped polyethylene oxide (PEO). The XRD, FTIR, SEM and DSC were used to confirm the structural, chemical, morphology and thermal studies of doped PEO. The ionic conductivity measurement was done at different temperatures. The polymer electrolyte observed a maximum ionic conductivity of the order of 2.5×10-7 Sm/cm at 303K. The obtained results suggest that, these polymer systems are suitable candidates for solid state battery, optoelectronics display & electro chromic devices etc.

Kilarkaje, Subramanya; Raghu, S.; Devendrappa, H.

2012-06-01

101

A study of temperature distributions due to conduction reservoir heating  

E-print Network

A STUDY OF TEMPERATURE DISTRIBUTIONS DUE TO CONDUCTION RESERVOIR HEATING A Thesis by CHARLES RICHARD CONNAUGHTON Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE January 1969 MAJOR SUBJECT: PETROLEUM ENGINEERING A STUDY OF TEMPERATURE DISTRIBUTIONS DUE TO CONDUCTION RESERVOIR HEATING A Thesis by CHARLES RICHARD CONNAUGHTON Approved as to style and content by: Chairman of Committee (Head of Departm...

Connaughton, Charles Richard

1969-01-01

102

AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses  

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

103

18 CFR 5.15 - Conduct of studies.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

104

18 CFR 5.15 - Conduct of studies.  

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

105

18 CFR 5.15 - Conduct of studies.  

Code of Federal Regulations, 2014 CFR

...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...

2014-04-01

106

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

PubMed Central

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

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

2013-01-01

107

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

SciTech Connect

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

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

2012-01-01

108

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

SciTech Connect

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

Li, Tingwen

2012-04-01

109

Science Sampler: Validating assessment--Teacher study groups  

NSDL National Science Digital Library

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.

Peters, Erin

2008-01-01

110

40 CFR 761.392 - Preparing validation study samples.  

Code of Federal Regulations, 2013 CFR

...Contain any liquids which spill or flow off the surface. Allow the spiking solution to drip drain off into a container and then evaporate the spiking solution off the contaminated surface prior to beginning the validation study. Contaminate a minimum of...

2013-07-01

111

40 CFR 761.392 - Preparing validation study samples.  

Code of Federal Regulations, 2014 CFR

...Contain any liquids which spill or flow off the surface. Allow the spiking solution to drip drain off into a container and then evaporate the spiking solution off the contaminated surface prior to beginning the validation study. Contaminate a minimum of...

2014-07-01

112

A Cross-Validation Study of the Posttraumatic Growth Inventory  

ERIC Educational Resources Information Center

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…

Sheikh, Alia I.; Marotta, Sylvia A.

2005-01-01

113

Conceptualization and Utility of University Mattering: A Construct Validity Study  

ERIC Educational Resources Information Center

The purpose of this study was to gather validity evidence for the University Mattering Scale. Theoretically based factor structures were tested, resulting in the four-factor conceptualization of mattering being championed. As predicted, university mattering related positively to academic motivational and relatedness constructs and negatively to…

France, Megan K.; Finney, Sara J.

2010-01-01

114

Teachers' Engagement at Work: An International Validation Study  

ERIC Educational Resources Information Center

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…

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

2012-01-01

115

Dimensions of Intuition: First-Round Validation Studies  

ERIC Educational Resources Information Center

This study utilized confirmatory factor analysis (CFA), canonical correlation analysis (CCA), regression analysis (RA), and correlation analysis (CA) for first-round validation of the researcher's Dimensions of Intuition (DOI) instrument. The DOI examined 25 personal characteristics and situations purportedly predictive of intuition. Data was…

Vrugtman, Rosanne

2009-01-01

116

Reflective Thinking Scale: A Validity and Reliability Study  

ERIC Educational Resources Information Center

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…

Basol, Gulsah; Evin Gencel, Ilke

2013-01-01

117

Rap-Music Attitude and Perception Scale: A Validation Study  

ERIC Educational Resources Information Center

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…

Tyson, Edgar H.

2006-01-01

118

The CPT Reading Comprehension Test: A Validity Study.  

ERIC Educational Resources Information Center

Describes a study done at Suffolk County Community College (New York) that assessed the validity of the College Board's Computerized Placement Test in Reading Comprehension (CPT-R) by comparing test results of 1,154 freshmen with the results of the Degree of Power Reading Test. Results confirmed the CPT-R's reliability in identifying basic…

Napoli, Anthony R.; Raymond, Lanette A.; Coffey, Cheryl A.; Bosco, Diane M.

1998-01-01

119

Lamb wave Shearwave Dispersion Ultrasound Vibrometry (SDUV) validation study  

Microsoft Academic Search

Our group has been investigating the use of Shearwave Dispersion Ultrasound Vibrometry (SDUV) for quantifying viscoelasticity of the myocardium. The primary aim of this study is the design and testing of viscoelastic materials suitable for validation of the Lamb wave model in the heart. The Lamb wave SDUV method was used to measure shear wave velocity dispersion of gelatin and

Ivan Nenadic; Matthew W. Urban; Scott A. Mitchell; James F. Greenleaf

2010-01-01

120

Direct Methanol Fuel Cell Experimental and Model Validation Study  

E-print Network

Direct Methanol Fuel Cell Experimental and Model Validation Study M. Mench, J. Scott, S. Thynell boundary Fuel cell performance Current density distribution measurements Conclusions #12;3 Method, flow rate, species inlet and fuel cell temperature, and humidity. Transparent polycarbonate windows

Wang, Chao-Yang

121

Homework Purpose Scale for Middle School Students: A Validation Study  

ERIC Educational Resources Information Center

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…

Xu, Jianzhong

2011-01-01

122

A Concurrent Validity Study of the 2008 "HSTW" Assessment Scores  

ERIC Educational Resources Information Center

"High Schools That Work" (HSTW) is a school improvement initiative that was inaugurated by the Southern Regional Education Board (SREB) in 1987. The main purpose of this concurrent validity study is to evaluate one or more measures by investigating their relationship to other commonly used and established measures given at or about the same time…

Young, John W.; Cline, Fred

2009-01-01

123

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

PubMed

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

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

2012-10-22

124

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

PubMed

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

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

2014-06-01

125

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

PubMed Central

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

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

2014-01-01

126

Measurement of Cortical Thickness Using an Automated 3-D Algorithm: A Validation Study  

Microsoft Academic Search

A validation study was conducted to assess the accuracy of the algorithm developed by MacDonald et al. (1999) for measuring cortical thickness. This algorithm automatically determines the cortical thickness by 3-D extraction of the inner and outer surfaces of the cerebral cortex from an MRI scan. A manual method of tagging the grey-csf and grey-white interface was used on 20

Noor Kabani; Georges Le Goualher; David MacDonald; Alan C. Evans

2001-01-01

127

Electrical studies on silver based fast ion conducting glassy materials  

SciTech Connect

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.

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

128

Environmental education curriculum evaluation questionnaire: A reliability and validity study  

NASA Astrophysics Data System (ADS)

The intention of this research project was to bridge the gap between social science research and application to the environmental domain through the development of a theoretically derived instrument designed to give educators a template by which to evaluate environmental education curricula. The theoretical base for instrument development was provided by several developmental theories such as Piaget's theory of cognitive development, Developmental Systems Theory, Life-span Perspective, as well as curriculum research within the area of environmental education. This theoretical base fueled the generation of a list of components which were then translated into a questionnaire with specific questions relevant to the environmental education domain. The specific research question for this project is: Can a valid assessment instrument based largely on human development and education theory be developed that reliably discriminates high, moderate, and low quality in environmental education curricula? The types of analyses conducted to answer this question were interrater reliability (percent agreement, Cohen's Kappa coefficient, Pearson's Product-Moment correlation coefficient), test-retest reliability (percent agreement, correlation), and criterion-related validity (correlation). Face validity and content validity were also assessed through thorough reviews. Overall results indicate that 29% of the questions on the questionnaire demonstrated a high level of interrater reliability and 43% of the questions demonstrated a moderate level of interrater reliability. Seventy-one percent of the questions demonstrated a high test-retest reliability and 5% a moderate level. Fifty-five percent of the questions on the questionnaire were reliable (high or moderate) both across time and raters. Only eight questions (8%) did not show either interrater or test-retest reliability. The global overall rating of high, medium, or low quality was reliable across both coders and time, indicating that the questionnaire can discriminate differences in quality of environmental education curricula. Of the 35 curricula evaluated, 6 were high quality, 14 were medium quality and 15 were low quality. The criterion-related validity of the instrument is at current time unable to be established due to the lack of comparable measures or a concretely usable set of multidisciplinary standards. Face and content validity were sufficiently demonstrated.

Minner, Daphne Diane

129

The children's developmental play instrument (CDPI): a validity study  

Microsoft Academic Search

This is a construct validity study of The Children's Developmental Play Instrument (CDPI), a multidimensional scale to measure play activity among mainstream children based on the psychoanalytic concepts of coping and defense strategies. The focus of this study is upon four play styles: Adaptive; Impulsive; Inhibited\\/Conflicted, and Disorganized. Ten-minute videotapes of 71 children between the ages of 1.3 and 6.1

Saralea E. Chazan

2012-01-01

130

Validity of the Convergence Insufficiency Symptom Survey: A Confirmatory Study  

PubMed Central

Purpose The objectives of the present study were to evaluate whether investigator bias influenced the Convergence Insufficiency Symptom Survey (CISS) scores of children with normal binocular vision (NBV) in our original validation study, reevaluate the usefulness of the cut-off score of 16, and reexamine the validity of the CISS. Methods Six clinical sites participating in the Convergence Insufficiency Treatment Trial (CITT) enrolled 46 children 9 - <18 years with NBV. Examiners masked to the child’s binocular vision status administered the CISS. The mean CISS score was compared to that from the children with NBV in the original, unmasked CISS study and also to that of the 221 symptomatic CI children enrolled in the CITT. Results The mean (±SD) CISS score for 46 subjects with NBV was 10.4 (±8.1). This was comparable to that from our prior unmasked NBV study (mean = 8.1(± 6.2); p = 0.11), but was significantly different from that of the CITT CI group (mean = 29.8 ± 9.0; p < 0.001). Eighty-three percent of these NBV subjects scored less than 16 on the CISS, which is not statistically different from the 87.5% found in the original unmasked study (p = 0.49). Conclusions Examiner bias did not affect the CISS scores for subjects with NBV in our prior study. The CISS continues to be a valid instrument for quantifying symptoms in 9 to <18 year-old children and these results confirm the validity of a cut-point of ? 16 in distinguishing children with symptomatic CI from those with NBV. PMID:19289977

2009-01-01

131

Commentary: Issues in Conducting Meta-Analyses of Intervention Studies.  

ERIC Educational Resources Information Center

Compares two meta-analyses of instructional interventions for students with learning disabilities conducted by Gersten and Baker, and Swanson, focusing on issues of grouping and reporting such studies and of treating differing outcome measures. Considers the identification of important instructional components in both meta-analyses. (JPB)

Rosenshine, Barak

2001-01-01

132

Dynamics in Music Conducting: A Computational Comparative Study Among Subjects  

E-print Network

Dynamics in Music Conducting: A Computational Comparative Study Among Subjects Álvaro Sarasúa Escola Superior de Musica de Catalunya Padilla 155, Barcelona, Spain alvaro.sarasua@esmuc.cat Enric Guaus Escola Superior de Musica de Catalunya Padilla 155, Barcelona, Spain enric.guaus@esmuc.cat ABSTRACT Many

133

Paraphasias in Multilingual Conduction Aphasia: A Single Case Study  

ERIC Educational Resources Information Center

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

Hegde, Medha; Bhat, Sapna

2007-01-01

134

Ab-initio study of napthelene based conducting polymer  

SciTech Connect

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

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

2014-04-24

135

Preparation, characterization and conductivity studies of chlorinated natural rubber  

NASA Astrophysics Data System (ADS)

Chlorinated natural rubber (CNR) was prepared by alkaline hydrolysis of chloroform using phase transfer catalyst. The chlorination in CNR was monitored by FTIR and UV spectroscopy and these studies indicated the formation of dichloro cyclopropyl ring to the double bond of natural rubber (NR). XRD and SEM analysis revealed the extent of chlorination in natural rubber. Electrical properties such as AC conductivity, dielectric constant and dielectric loss of CNR was higher than that of NR. Conductivity of NR increased with the increase in the concentration of chlorine percentage. LOI values indicated that the chemical modification imparts better flame resistant to NR.

M, Subburaj; Ramesan, M. T.; Pradyumnan, P. P.

2014-10-01

136

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

Microsoft Academic Search

Staff of the Environmental Assessment and Information Sciences Division of Argonne National Laboratory (ANL) studies the role played by the organizational participants in the Department of Veterans Affairs (VA) that conduct verification, validation, and testing (VV T) activities at various stages in the automated data processing (ADP) system development life cycle (SDLC). A case-study methodology was used to assess the

Riemer

1990-01-01

137

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

SciTech Connect

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.

Sullivan, R.; Winkelmann, F.

1998-06-01

138

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).

139

Metaanalysis of Validity Studies Published Between 1964 and 1982 and the Investigation of Study Characteristics.  

ERIC Educational Resources Information Center

Reviewed published validation studies for the years 1964-1982 of the Journal of Applied Psychology and Personnel Psychology. Results indicated minimal differences across study designs in the average validity coefficient and found selection ratios, standard deviations, reliabilities, predictor and criterion intercorrelations to be rarely and…

Schmitt, Neal; And Others

1984-01-01

140

Simple models for stomatal conductance derived from a process model: cross-validation against sap flux data.  

PubMed

Representation of stomatal physiology in models of plant-atmosphere gas exchange is minimal, and direct application of process-based models is limited by difficulty of parameter estimation. We derived simple models of stomatal conductance from a recent process-based model, and cross-validated them against measurements of sap flux (176-365 d in length) in 36 individual trees of two age classes for two Eucalyptus species across seven sites in the mountains of southeastern Australia. The derived models - which are driven by irradiance and evaporative demand and have two to four parameters that represent sums and products of biophysical parameters in the process model - reproduced a median 83-89% of observed variance in half-hourly and diurnally averaged sap flux, and performed similarly whether fitted using a random sample of all data or using 1 month of data from spring or autumn. Our simple models are an advance in predicting plant water use because their parameters are transparently related to reduced processes and properties, enabling easy accommodation of improved knowledge about how those parameters respond to environmental change and differ among species. PMID:22486530

Buckley, Thomas N; Turnbull, Tarryn L; Adams, Mark A

2012-09-01

141

Nerve conduction studies of upper extremities in tennis players  

PubMed Central

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

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

2004-01-01

142

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

SciTech Connect

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.

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

143

Low frequency eddy current benchmark study for model validation  

SciTech Connect

This paper presents results of an eddy current model validation study. Precise measurements were made using an impedance analyzer to investigate changes in impedance due to Electrical Discharge Machining (EDM) notches in aluminum plates. Each plate contained one EDM notch at an angle of 0, 10, 20, or 30 degrees from the normal of the plate surface. Measurements were made with the eddy current probe both scanning parallel and perpendicular to the notch length. The experimental response from the vertical and oblique notches will be reported and compared to results from different numerical simulation codes.

Mooers, R. D.; Boehnlein, T. R. [University of Dayton Research Institute, Structural Integrity Division, Dayton, OH, 45469 (United States); Cherry, M. R.; Knopp, J. S. [Air Force Research Lab, NDE Division, Wright Patterson, OH 45433 (United States); Aldrin, J. C. [Computational Tools, Gurnee, IL 60031 (United States); Sabbagh, H. A. [Victor Technologies LLC, Bloomington, IN 47401 (United States)

2011-06-23

144

A Known Group Analysis Validity Study of the Vanderbilt Assessment of Leadership in Education in US Elementary and Secondary Schools  

ERIC Educational Resources Information Center

The Vanderbilt Assessment of Leadership in Education (VAL-ED) provides educators with a tool for principal evaluation based on principal, teacher, and supervisor reports of principals' learning-centered leadership. In this study, we conduct a known group analysis as part of a larger argument for the validity of the VAL-ED in US elementary and…

Covay Minor, Elizabeth; Porter, Andrew C.; Murphy, Joseph; Goldring, Ellen B.; Cravens, Xiu; Elloitt, Stephen N.

2014-01-01

145

Validation study of the Chinese Early Development Instrument (CEDI)  

PubMed Central

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

2013-01-01

146

Numerical Study of Thermal Conductivities of Carbon-Based Mesoporous Composites  

NASA Astrophysics Data System (ADS)

The thermal conductivities of ordered mesoporous carbon CMK-3 filled with Al nanoclusters were studied in this article. CMK-3 is a typical example of carbon rods which are arranged in a relatively regular two-dimensional hexagonal array. The initial structure of CMK-3 was generated from the amorphous carbon and validated by XRD simulation which is coincident with experimental data. The thermal conductivities of carbon rods in CMK-3 and Al nanoclusters with 133 atoms were simulated by an equilibrium molecular dynamics method. Then, the effective thermal conductivity (ETC) of a mesoporous composite, CMK-3 filled with , was obtained via one-dimensional heat conduction analysis. The influences of the substrate porosity, nanocluster filling ratio, and temperature were discussed. As an anisotropic material, ETCs along the and directions are extremely poor, due to the overwhelming effect of the air thermal resistance. However, in the direction, the ETC improves almost linearly as the porosity decreases, and the value is much higher than those of and directions. In the case of a 70 % filling ratio, when the porosity is below 59.7 %, the ETC in the direction exceeds the thermal conductivity of Al nanoclusters and approaches a peak value around the melting temperature of nanoclusters. The results indicate that the carbon-based mesoporous CMK-3 filled with Al nanoclusters might become a promising phase change material.

Feng, Daili; Feng, Yanhui; Zhang, Xinxin

2014-10-01

147

Principles for the conduct of non-drug clinical studies*.  

PubMed

Synopsis The World Medical Association's Declaration of Helsinki outlines the principles for the conduct of drug and non-drug clinical studies. The key difference between drug and non-drug biomedical research is to be seen in the fact that for non-drugs, the potential benefits, hazards and discomforts for the volunteer enrolled in a clinical study cannot be weighed against advantages of improving current diagnostic or therapeutic methods. The principles reflected in the Guidelines for Good Clinical Practice for Trials on Medicinal Products in the European Community, issued by the Commission of the European Communities in substantial parts also apply for trials on non-medicinal products. Specifically this is true with regard to the requirements for the privacy, integrity, and well-being of volunteers subjected to research, and fully informing them about the risks and benefits potentially associated with the use of a test product. Skin care products are the most prominent group of non-drug products for which clinical studies are conducted. Using these products, the key differences between executing the principles in a non-drug and a drug clinical study are highlighted. PMID:19250503

Schmitt, G J

1994-02-01

148

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

ERIC Educational Resources Information Center

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

Salter, Daniel W.; Junco, Reynol

2007-01-01

149

Pilot In-Trail Procedure Validation Simulation Study  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

150

Lamb wave Shearwave dispersion ultrasound Vibrometry (SDUV) validation study.  

PubMed

Our group has been investigating the use of Shearwave Dispersion Ultrasound Vibrometry (SDUV) for quantifying viscoelasticity of the myocardium. The primary aim of this study is the design and testing of viscoelastic materials suitable for validation of the Lamb wave model in the heart. The Lamb wave SDUV method was used to measure shear wave velocity dispersion of gelatin and urethane rubber plates in the range 40-500 Hz and estimate the material properties. A finite element model (FEM) of a viscoelastic plate submerged in water was used to study the appropriateness of the Lamb wave dispersion equations. An embedded sphere method was used as an independent measurement of viscoelasticity. The FEM wave velocity dispersion data were in excellent agreement with the theoretical predictions. Elasticity and viscosity of urethane and gelatin obtained using the Lamb wave SDUV and embedded sphere methods agree within one standard deviation. PMID:21095878

Nenadic, Ivan; Urban, Matthew W; Mitchell, Scott A; Greenleaf, James F

2010-01-01

151

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

NASA Technical Reports Server (NTRS)

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.

Tinetti, Ana F.; Dunn, Mark H.

2011-01-01

152

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2011 CFR

...false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory Study § 58.130 Conduct of a...

2011-04-01

153

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2010 CFR

...false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory Study § 58.130 Conduct of a...

2010-04-01

154

The Adolescent Depression Rating Scale (ADRS): a validation study  

PubMed Central

Background To examine the psychometric properties of the Adolescent Depression Rating Scale (ADRS), a new measure was specifically designed to evaluate adolescent depression. Methods The 11-item clinician-report and 44-item self-report versions of the ADRS were developed from a qualitative phase involving interviews of experts and adolescents. These two instruments were then administered to 402 French speaking adolescents with and without depressive disorders. Item distribution, internal consistency, convergent validity, discriminant validity and factorial structure were assessed. Results After reduction procedures, a 10-item clinician version and a 10-item self-report version were obtained. The ADRS demonstrated good internal consistency (alpha Cronbach coefficient >.70). It also discriminated better between adolescents with and without depression than the Hamilton Depressive Rating Scale and the Beck Depression Inventory (BDI-13). Conclusion The ADRS is a useful, short, clinician-report and self-report scale to evaluate adolescent depression. Further studies to replicate our findings and evaluate ADRS sensitivity to effects of treatment and psychometric properties in populations of adolescents with several psychiatric disorders are warranted. PMID:17222346

Revah-Levy, Anne; Birmaher, Boris; Gasquet, Isabelle; Falissard, Bruno

2007-01-01

155

Conducting Simulation Studies in the R Programming Environment  

PubMed Central

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

Hallgren, Kevin A.

2014-01-01

156

41 CFR 60-3.5 - General standards for validity studies.  

Code of Federal Regulations, 2011 CFR

...2009-07-01 true General standards for validity studies. 60-3.5 Section 60-3.5 Public...60-3.5 General standards for validity studies. A. Acceptable types of validity studies. For the purposes of satisfying these...

2011-07-01

157

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

Code of Federal Regulations, 2010 CFR

...Citation of a previously submitted valid study. 152.93 Section 152.93 Protection...Citation of a previously submitted valid study. An applicant may demonstrate compliance for a data requirement by citing a valid study previously submitted to the Agency....

2010-07-01

158

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

Code of Federal Regulations, 2011 CFR

...Citation of a previously submitted valid study. 152.93 Section 152.93 Protection...Citation of a previously submitted valid study. An applicant may demonstrate compliance for a data requirement by citing a valid study previously submitted to the Agency....

2011-07-01

159

41 CFR 60-3.5 - General standards for validity studies.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true General standards for validity studies. 60-3.5 Section 60-3.5 Public...60-3.5 General standards for validity studies. A. Acceptable types of validity studies. For the purposes of satisfying these...

2010-07-01

160

Electrical conduction and dielectric studies of ZnO pellets  

NASA Astrophysics Data System (ADS)

A series of Zinc Oxide pellets sintered at different temperatures was studied by means of dielectric spectroscopy in the wide frequency range of 1-106 Hz and temperature interval from -100 °C to 30 °C. Electrical conductivity was analysed using Jonsher's universal power law, and the values of s were found to decrease with the increase in temperature, which agrees well with the correlation barrier hopping (CBH) model. As the temperature increased, energy activation Edc became less than 0.39 eV and dc conductivity (?dc) values in the range of 1.9×10-14-9.7×10-10 ? m-1 were observed. The dielectric modulus showed ionic polarisation at the intermediate and high frequencies related to oxygen interstitial Oi, oxygen vacancy VO and Zinc interstitial Zni. At low frequency, it revealed a Maxwell-Wagner-Sillars relaxation with barrier heights of grain boundaries between 0.74 and 0.88 eV for all the studied pellets.

Chaari, Mariem; Matoussi, Adel

2012-09-01

161

A validation study of a stochastic model of human interaction  

NASA Astrophysics Data System (ADS)

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

Burchfield, Mitchel Talmadge

162

New York State TrueAllele® Casework Validation Study*  

PubMed Central

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

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

2013-01-01

163

Secondary traumatic stress and vicarious trauma: a validational study.  

PubMed

Vicarious trauma (VT) and secondary traumatic stress (STS) or compassion fatigue both describe effects of working with traumatized persons on therapists. Despite conceptual similarities, their emphases differ: cognitive schemas vs. posttraumatic symptoms and burnout, respectively. The TSI Belief Scale (TSI-BSL) measures VT; the Compassion Fatigue Self-Test (CFST) for Psychotherapists measures STS. Neither has substantial psychometric evidence yet, nor has their association been studied. Results for 99 sexual assault and domestic violence counselors show concurrent validity between TSI-BSL and CFST, moderate convergence with burnout but useful discrimination, and strong convergence with general distress, but adequate independent shared variance. Counselors with interpersonal trauma histories scored higher on CFST, but not TSI-BSL or burnout, consistent with the CFST's emphasis on trauma symptomatology. PMID:12392231

Jenkins, Sharon Rae; Baird, Stephanie

2002-10-01

164

Teacher Stress Questionnaire: validity and reliability study in Italy.  

PubMed

This study analyses the psychometric properties of the Italian version of the Teacher Stress Questionnaire elaborated in England by Travers and Cooper in 1996. This Italian survey was completed by 863 teachers randomly drawn from a cross-section of Italian school levels. The construct validity of the questionnaire was verified by factor analysis and by measuring the internal consistency of the single scales. All dimensions measured by the Teacher Stress Questionnaire were compared for sample subgroups of all teacher levels. Several meaningful and reliable factors emerged from the factor analysis of the scales. The internal consistency of each scale (Cronbach's alpha) revealed satisfactory values. Teachers' age and school level were determining factors for all dimensions of stress explored. The Italian version of the Teacher Stress Questionnaire showed satisfactory psychometric properties and constitutes a useful and reliable measure to analyse stress in Italian schools. PMID:24597443

Zurlo, Maria Clelia; Pes, Daniela; Capasso, Roberto

2013-10-01

165

A Construct Validation Study of the Expectations about Counseling-Brief Form: Factorial Validity.  

ERIC Educational Resources Information Center

Administered Expectations About Counseling-Brief Form (EAC-B) to 153 college students to examine instrument's factorial validity. Students also completed Developing Purpose section of the Student Development Task Inventory, second edition; the Counseling Readiness Scale; and the Career Counseling Diagnostic Inventory. Results support the factorial…

Tinsley, Diane J.; And Others

1991-01-01

166

Studies on the Preparation of Polystyrene Thermal Conductivity Composites  

Microsoft Academic Search

Various thermally conductive fillers including aluminum oxide(Al2O3), magnesium oxide(MgO), ?-silicon carbide particle(?-SiCp) and ?-silicon carbide whisker(?-SiCw) were used to prepare polystyrene thermal conductivity composites. Experimental results showed that, for given filler loading, the thermal conductivity of the composites was higher for PS flake than that of PS particle, and the thermal conductivity was optimal by powder blending method. The SiCw

Jun-Wei Gu; Qiuyu Zhang; Junping Zhang; Wenwen Wang

2010-01-01

167

Skin conductance fear conditioning impairments and aggression: A longitudinal study.  

PubMed

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

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

2015-02-01

168

Portuguese validation of the Internet Addiction Test: An empirical study  

PubMed Central

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

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

2014-01-01

169

A Validity Study of Selected Self-Concept Instruments  

ERIC Educational Resources Information Center

Investigated construct validity of four self-report, self-concept instruments: Bledsoe Self-Concept Scale (BSCS), Children's Self-Concept Scale (CSCS), Self-Esteem Inventory (SEI) and Purdue Self-Concept Scale (PSCS). In assessing the self-concepts of 175 fourth-grade children convergent validity of the tests was not established. (Author)

Cowan, Robert; And Others

1978-01-01

170

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

Code of Federal Regulations, 2010 CFR

...experimental conditions for the validation study and subsequent use during decontamination...COMMERCE, AND USE PROHIBITIONS Comparison Study for Validating a New Performance-Based...experimental conditions for the validation study and subsequent use during...

2010-07-01

171

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

Code of Federal Regulations, 2011 CFR

...experimental conditions for the validation study and subsequent use during decontamination...COMMERCE, AND USE PROHIBITIONS Comparison Study for Validating a New Performance-Based...experimental conditions for the validation study and subsequent use during...

2011-07-01

172

Phase behaviour and conductivity study of electrolytes in supercritical hydrofluorocarbons.  

PubMed

The purpose of this work was to characterise supercritical hydrofluorocarbons (HFC) that can be used as solvents for electrodeposition. The phase behaviour of CHF(3), CH(2)F(2), and CH(2)FCF(3) containing [NBu(n)(4)][BF(4)], [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] and Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] was studied and the conditions for forming a single supercritical phase established. Although all three HFCs are good solvents for [NBu(n)(4)][BF(4)] the results show that the CH(2)F(2) system has the lowest p(r) for dissolving a given amount of [NBu(n)(4)][BF(4)]. The solubility of Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] in CH(2)F(2) was found to be unexpectedly high. Studies of the phase behaviour of CH(2)F(2) containing [NBu(n)(4)][BF(4)] and [Cu(CH(3)CN)(4)][BF(4)] showed that the copper complex was unstable in the absence of CH(3)CN. For CHF(3), [Cu(hfac)(2)] was more soluble and more stable than [Cu(CH(3)CN)(4)][BF(4)] and only increased the phase-separation pressure by a moderate amount. Studies of the conductivity of [NBu(n)(4)][B(C(6)F(5))(4)], [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)], [NR(f)Bu(n)(3)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] (R(f) = (CH(2))(3)C(7)F(15)), and Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] were carried out in scCH(2)F(2). The results show that these salts are more conducting than [NBu(n)(4)][BF(4)] under the same conditions although the increase is much less significant than that reported in previous work in supercritical CO(2) + CH(3)CN. Consequently, either [NBu(n)(4)][BF(4)] or the corresponding BARF salts would be suitable background electrolytes for electrodeposition from scCH(2)F(2). PMID:21072413

Bartlett, Philip N; Cook, David C; George, Michael W; Ke, Jie; Levason, William; Reid, Gillian; Su, Wenta; Zhang, Wenjian

2011-01-01

173

A Protocol for Conducting Rainfall Simulation to Study Soil Runoff  

PubMed Central

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

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

174

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

175

Molecular dynamics study for the thermal conductivity of diatomic liquid  

NASA Astrophysics Data System (ADS)

The thermal conductivity of diatomic liquids was analyzed using a nonequilibrium molecular dynamics (NEMD) method. Five liquids, namely, O 2, CO, CS 2, Cl 2 and Br 2, were assumed. The two-center Lennard-Jones (2CLJ) model was used to express the intermolecular potential acting on liquid molecules. First, the equation of state of each liquid was obtained using MD simulation, and the critical temperature, density and pressure of each liquid were determined. Heat conduction of each liquid at various liquid states [metastable ( ?=1.9 ?cr), saturated ( ?=2.1 ?cr), and stable ( ?=2.3 ?cr)] at T=0.7 Tcr was simulated and the thermal conductivity was estimated. These values were compared with experimental results and it was confirmed that the simulated results were consistent with the experimental data within 10%. Obtained thermal conductivities at saturated state were reduced by the critical temperature, density and mass of molecules and these values were compared with each other. It was found that the reduced thermal conductivity increased with the increase in the molecular elongation. Detailed analysis of the molecular contribution to the thermal conductivity revealed that the contribution of the heat flux caused by energy transport and by translational energy transfer to the thermal conductivity is independent of the molecular elongation while the contribution of the heat flux caused by rotational energy transfer to the thermal conductivity increases with the increase in the molecular elongation. Moreover, by comparing the reduced thermal conductivity at various states, it was found that the increase of thermal conductivity with the increase in the density, or pressure, was caused by the increase of the contribution of energy transfer due to molecular interaction.

Tokumasu, Takashi; Kamijo, Kenjiro

2004-03-01

176

Validation study of the Questionnaire on School Maladjustment Problems (QSMP).  

PubMed

The aim of this study was to analyze the exploratory and confirmatory structure, as well as other psychometric properties, of the Cuestionario de Problemas de Convivencia Escolar (CPCE; in Spanish, the Questionnaire on School Maladjustment Problems [QSMP]), using a sample of Spanish adolescents. The instrument was administered to 60 secondary education teachers (53.4% females and 46.6% males) between the ages of 28 and 54 years (M= 41.2, SD= 11.5), who evaluated a total of 857 adolescent students. The first-order exploratory factor analysis identified 7 factors, explaining a total variance of 62%. A second-order factor analysis yielded three dimensions that explain 84% of the variance. A confirmatory factor analysis was subsequently performed in order to reduce the number of factors obtained in the exploratory analysis as well as the number of items. Lastly, we present the results of reliability, internal consistency, and validity indices. These results and their implications for future research and for the practice of educational guidance and intervention are discussed in the conclusions. PMID:22420365

de la Fuente Arias, Jesús; Peralta Sánchez, Francisco Javier; Sánchez Roda, María Dolores; Trianes Torres, María Victoria

2012-05-01

177

Measurement of Pancreatic Volume by Abdominal MRI: A Validation Study  

PubMed Central

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

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

2013-01-01

178

Examining the validity of pressure ulcer risk assessment scales: a replication study.  

PubMed

Risk assessment scales (RASs) intended to identify patients most at risk of developing pressure ulcers have been widely used for many years. Numerous studies have evaluated their predictive validity but potential bias has been inherent in the design of all. To overcome these problems a simulation study was conducted in which clinical nurses were asked to identify the degree of risk experienced by four patients employing the three RASs discussed most frequently in the literature (Norton, Braden and Waterlow Scores). These findings were compared with nurses' clinical judgment rated on a visual analogue scale. The simulations consisted of high-resolution photographs accompanied by case studies of the patients. The nurses' scores were compared to estimates of risk generated by an expert panel. Nurses' clinical judgment agreed much more closely with expert opinion than any of the RASs. A replication study was undertaken to confirm these findings. One hundred and fifteen nurses participated in replication. Again the nurses' clinical judgment matched expert opinion much more closely than the results of the RASs. Replication also drew attention to a number of methodological issues which deserve consideration when using simulation to test the effectiveness of clinical tools and the need to establish adequate measures of external validity whenever use of this method is contemplated. PMID:14967190

Gould, Dinah; Goldstone, Len; Kelly, Daniel; Gammon, John

2004-03-01

179

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

PubMed Central

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

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

2014-01-01

180

Studying conduction-electron/interface interactions using transverse electron focusing  

NASA Astrophysics Data System (ADS)

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

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

1999-10-01

181

Carbonyl mediated conductance through metal bound peptides: a computational study  

NASA Astrophysics Data System (ADS)

Large increases in the conductance of peptides upon binding to metal ions have recently been reported experimentally. The mechanism of the conductance switching is examined computationally. It is suggested that oxidation of the metal ion occurs after binding to the peptide. This is caused by the bias potential placed across the metal-peptide complex. A combination of configurational changes, metal ion involvement and interactions between carbonyl group oxygen atoms and the gold leads are all shown to be necessary for the large improvement in the conductance seen experimentally. Differences in the molecular orbitals of the nickel and copper complexes are noted and serve to explain the variation of the improvement in conductance upon binding to either a nickel or copper ion.

Perrine, Trilisa M.; Dunietz, Barry D.

2007-10-01

182

A benchmark study on the thermal conductivity of nanofluids  

E-print Network

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

Buongiorno, Jacopo

183

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

PubMed

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

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

2013-12-01

184

A comprehensive study on maxillofacial trauma conducted in Yamunanagar, India  

PubMed Central

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

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

2013-01-01

185

Physics validation studies for muon collider detector background simulations  

SciTech Connect

Within the broad discipline of physics, the study of the fundamental forces of nature and the most basic constituents of the universe belongs to the field of particle physics. While frequently referred to as 'high-energy physics,' or by the acronym 'HEP,' particle physics is not driven just by the quest for ever-greater energies in particle accelerators. Rather, particle physics is seen as having three distinct areas of focus: the cosmic, intensity, and energy frontiers. These three frontiers all provide different, but complementary, views of the basic building blocks of the universe. Currently, the energy frontier is the realm of hadron colliders like the Tevatron at Fermi National Accelerator Laboratory (Fermilab) or the Large Hadron Collider (LHC) at CERN. While the LHC is expected to be adequate for explorations up to 14 TeV for the next decade, the long development lead time for modern colliders necessitates research and development efforts in the present for the next generation of colliders. This paper focuses on one such next-generation machine: a muon collider. Specifically, this paper focuses on Monte Carlo simulations of beam-induced backgrounds vis-a-vis detector region contamination. Initial validation studies of a few muon collider physics background processes using G4beamline have been undertaken and results presented. While these investigations have revealed a number of hurdles to getting G4beamline up to the level of more established simulation suites, such as MARS, the close communication between us, as users, and the G4beamline developer, Tom Roberts, has allowed for rapid implementation of user-desired features. The main example of user-desired feature implementation, as it applies to this project, is Bethe-Heitler muon production. Regarding the neutron interaction issues, we continue to study the specifics of how GEANT4 implements nuclear interactions. The GEANT4 collaboration has been contacted regarding the minor discrepancies in the neutron interaction cross sections for boron. While corrections to the data files themselves are simple to implement and distribute, it is quite possible, however, that coding changes may be required in G4beamline or even in GEANT4 to fully correct nuclear interactions. Regardless, these studies are ongoing and future results will be reflected in updated releases of G4beamline.

Morris, Aaron Owen; /Northern Illinois U.

2011-07-01

186

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

PubMed Central

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

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

2012-01-01

187

21 CFR 312.120 - Foreign clinical studies not conducted under an IND.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Foreign clinical studies not conducted under an IND. 312.120...Miscellaneous § 312.120 Foreign clinical studies not conducted under an IND. (a) Acceptance of studies. (1) FDA will accept as...

2011-04-01

188

43 CFR 404.47 - How will a feasibility study be conducted under this program?  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false How will a feasibility study be conducted under this program? 404.47...RECLAMATION RURAL WATER SUPPLY PROGRAM Feasibility Studies § 404.47 How will a feasibility study be conducted under this program?...

2010-10-01

189

43 CFR 404.47 - How will a feasibility study be conducted under this program?  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false How will a feasibility study be conducted under this program? 404.47...RECLAMATION RURAL WATER SUPPLY PROGRAM Feasibility Studies § 404.47 How will a feasibility study be conducted under this program?...

2011-10-01

190

21 CFR 312.120 - Foreign clinical studies not conducted under an IND.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Foreign clinical studies not conducted under an IND. 312.120...Miscellaneous § 312.120 Foreign clinical studies not conducted under an IND. (a) Acceptance of studies. (1) FDA will accept as...

2010-04-01

191

The knowledge, efficacy, and practices instrument for oral health providers: a validity study with dental students.  

PubMed

Valid and reliable instruments to measure and assess cultural competence for oral health care providers are scarce in the literature, and most published scales have been contested due to a lack of item analysis and internal estimates of reliability. The purposes of this study were, first, to develop a standardized instrument to measure dental students' knowledge of diversity, skills in culturally competent patient-centered communication, and use of culture-centered practices in patient care and, second, to provide preliminary validity support for this instrument. The initial instrument used in this study was a thirty-six-item Likert-scale survey entitled the Knowledge, Efficacy, and Practices Instrument for Oral Health Providers (KEPI-OHP). This instrument is an adaption of an initially thirty-three-item version of the Multicultural Awareness, Knowledge, and Skills Scale-Counselor Edition (MAKSS-CE), a scale that assesses factors related to social justice, cultural differences among clients, and cross-cultural client management. After the authors conducted cognitive and expert interviews, focus groups, pilot testing, and item analysis, their initial instrument was reduced to twenty-eight items. The KEPI-OHP was then distributed to 916 dental students (response rate=48.6 percent) across the United States to measure its reliability and assess its validity. Both exploratory and confirmatory factor analyses were conducted to test the scale's validity. The modification of the survey into a sensible instrument with a relatively clear factor structure using factor analysis resulted in twenty items. A scree test suggested three expressive factors, which were retained for rotation. Bentler's comparative fit and Bentler and Bonnett's non-normed indices were 0.95 and 0.92, respectively. A three-factor solution, including efficacy of assessment, knowledge of diversity, and culture-centered practice subscales, comprised of twenty-items was identified. The KEPI-OHP was found to have reasonable internal consistency reliability to warrant its use for baseline and repeated measures in assessing changes in dental students' growth in cultural competence across four-year dental curricula. PMID:23929569

Behar-Horenstein, Linda S; Garvan, Cyndi W; Moore, Thomas E; Catalanotto, Frank A

2013-08-01

192

Thermal conductivity of suspended GaAs nanostructures: Theoretical study  

NASA Astrophysics Data System (ADS)

We present a theoretical investigation of the magnitude and temperature variation of the recently measured [Phys. Rev. B 66, 045302 (2002)] thermal conductivity of undoped and doped GaAs nanobeams of cross sections 100nm×250nm and 150nm×250nm , respectively. The calculations have been performed by employing Callaway’s theoretical model and Srivastava’s rigorous treatment of three-phonon interactions, based on an isotropic continuum phonon dispersion relation. It is found that an increased rate of diffuse surface scattering in undoped nanobeams explains the attenuation of the thermal conductivity below that of bulk GaAs well. The drop in thermal conductivity of doped nanobeams compared to that of the undoped beams arises from electron-phonon scattering and additional phonon scattering from a large number of point impurities due to the presence of dopant atoms. It is further shown that specular reflection of phonons from rough surfaces plays only a minor role in controlling the thermal conductivity of the nanobeams. The present calculations also allow for estimating the contributions of the longitudinal phonon branches and the three-phonon N -drift term towards the total conductivity.

Barman, Saswati; Srivastava, G. P.

2006-05-01

193

Electrical Characterization and Morphological Studies of Conducting Polymer Nanofibers  

NASA Technical Reports Server (NTRS)

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.

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

194

Materials characterization study of conductive flexible second surface mirrors  

NASA Technical Reports Server (NTRS)

The status of prequalification and qualification work on conductive flexible second surface mirrors is described. The basic material is FEP Teflon witn either aluminium or silver vacuum deposited reflectors. The top layer has been made conductive by deposition of layer of a indium oxide. The results of a prequalification program comprised of decontamination, humidity, thermal cycling, thermal shock and vibration tests are presented. Thermo-optical and electrical properties. The results of a prequalification program comprised of decontamination, humidity, thermal cycling, thermal shock and vibration tests are presented. Thermo-optical and electrical properties, the electrostatic behavior of the materials under simulated substorm environment and electrical conductivity at low temperatures are characterized. The effects of simulated ultra violet and particles irradiation on electrical and thermo-optical properties of the materials are also presented.

Levadou, F.; Bosma, S. J.; Paillous, A.

1981-01-01

195

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

PubMed Central

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

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

2013-01-01

196

Development, characterization and conductivity studies of chlorinated EPDM  

NASA Astrophysics Data System (ADS)

Halogenation of EPDM has been carried out by passing chlorine gas by a simple and inexpensive chemical method. Chlorinated EPDM was characterized by FTIR and UV spectroscopy, SEM, TGA, DSC and AC conductivity measurements. FTIR and UV spectra revealed the attachment of chlorine to double bond of EPDM. SEM images showed the coarsen morphology arising from polar nature of the resulting polymer. TGA and DSC analysis indicated that the chlorination on EPDM affected the basic decomposition pattern and glass transition temperature of synthesized polymer. Conductivity of halogenated polymer was significantly increased with increase in chlorine content and also with increase in frequency.

Nihmath, A.; Ramesan, M. T.

2014-10-01

197

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

PubMed

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

Langford, Rae; Young, Anne

2013-01-01

198

Ecological Validity in Eye-Tracking: An Empirical Study  

ERIC Educational Resources Information Center

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…

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

2013-01-01

199

A Validity Study of the Salter Environmental Type Assessment.  

ERIC Educational Resources Information Center

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

Salter, Daniel W.

2002-01-01

200

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

ERIC Educational Resources Information Center

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…

Wickramasinghe, Vathsala M.

2006-01-01

201

100 Area excavation treatability study data validation report  

Microsoft Academic Search

This report presents the results of sampling and chemical analyses at Hanford Reservation. The samples were analyzed by Thermo-Analytic Laboratories and Roy F. Weston Laboratories using US Environmental Protection Agency CLP protocols. Sample analyses included: volatile organics; semivolatile organics; inorganics; and general chemical parameters. The data from the chemical analyses were reviewed and validated to verify that reported sample results

Frain

1994-01-01

202

The Concept of Personal Initiative: An Overview of Validity Studies  

Microsoft Academic Search

Construct validity of an interview measure of personal initiative (PI) is examined in two parts. The first part assembles the results from 11 samples, showing that PI is meaningfully related to a nomological network of variables, based on environmental supports; knowledge, skills, and cognitive abilities; personality variables and orienta- tions; and behavior and performance, confirming our hypotheses. In the second

Doris Fay; Michael Frese

2001-01-01

203

41 CFR 60-3.5 - General standards for validity studies.  

Code of Federal Regulations, 2012 CFR

...through a construct validity study should consist of data showing...standardization. Validity studies should be carried out under...of time and in a majority of cases, progress to a higher level...when technically feasible, a study which is designed to...

2012-07-01

204

41 CFR 60-3.5 - General standards for validity studies.  

Code of Federal Regulations, 2013 CFR

...through a construct validity study should consist of data showing...standardization. Validity studies should be carried out under...of time and in a majority of cases, progress to a higher level...when technically feasible, a study which is designed to...

2013-07-01

205

41 CFR 60-3.5 - General standards for validity studies.  

Code of Federal Regulations, 2014 CFR

...through a construct validity study should consist of data showing...standardization. Validity studies should be carried out under...of time and in a majority of cases, progress to a higher level...when technically feasible, a study which is designed to...

2014-07-01

206

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

E-print Network

MSE-TA, Inc., Butte, MT 59702 Shock tube experiments were performed to measure the conductivity, a better understanding of the process that cou- ples the electromagnetic field to the high enthalpy, high-pressure plasmas in a pulsed mode, single-shot experiments were performed using a detonation-driven shock tube

Texas at Arlington, University of

207

Studies of inherently conducting polymers in ionic liquids  

Microsoft Academic Search

In this dissertation, the effect of ionic liquid (IL) or classical electrolyte (CE) employed on the redox behaviour of many inherently conducting polymers (ICPs) was investigated with the ultimate goal of producing flexible batteries. ICPs can be used in a range of unique applications, and also to replace many metal conductors or inorganic semiconductors. Commercialisation of ICPs has, however, been

Jakub Mazurkiewicz

2007-01-01

208

Comparative study of ion conducting pathways in borate glasses  

NASA Astrophysics Data System (ADS)

The conduction pathways in metal-halide doped silver, lithium, and sodium diborate glasses have been examined by bond valence analysis of reverse Monte Carlo (RMC) produced structural models of the glasses. Although all glass compositions have basically the same short-range structure of the boron-oxygen network, it is evident that the intermediate-range structure is strongly dependent on the type of mobile ion. The topography of the pathways and the coordination of the pathway sites differ distinctly between the three glass systems. The mobile silver ions in the AgI-doped glass tend to be mainly iodine-coordinated and travel in homogeneously distributed pathways located in salt-rich channels of the borate network. In the NaCl-doped glass, there is an inhomogeneous spatial distribution of pathways that reflects the inhomogeneous introduction of salt ions into the glass. However, since the salt clusters are not connected, no long-range conduction pathways are formed without including also oxygen-rich regions. The pathways in the LiCl-doped glass are slightly more evenly distributed compared to the NaCl-doped glass (but not as ordered as in the AgI-doped glass), and the regions of mainly oxygen-coordinated pathway sites are of higher importance for the long-range migration. In order to more accurately investigate how these differences in the intermediate-range order of the glasses affect the ionic conductivity, we have compared the realistic structure models to more or less randomized structures. An important conclusion from this comparison is that we find no evidence that a pronounced intermediate-range order in the atomic structure or in the network of conduction pathways, as in the AgI-doped glass, is beneficial for the dc conductivity.

Hall, Andreas; Adams, Stefan; Swenson, Jan

2006-11-01

209

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

NASA Technical Reports Server (NTRS)

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.

Santoro, Robert J.

1997-01-01

210

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

NASA Technical Reports Server (NTRS)

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.

Santoro, Robert J.

1997-01-01

211

Molecular dynamics study for the thermal conductivity of diatomic liquid  

Microsoft Academic Search

The thermal conductivity of diatomic liquids was analyzed using a nonequilibrium molecular dynamics (NEMD) method. Five liquids, namely, O2, CO, CS2, Cl2 and Br2, were assumed. The two-center Lennard-Jones (2CLJ) model was used to express the intermolecular potential acting on liquid molecules. First, the equation of state of each liquid was obtained using MD simulation, and the critical temperature, density

Takashi Tokumasu; Kenjiro Kamijo

2004-01-01

212

Ecological Validity in the Study of Human Pheromones  

Microsoft Academic Search

Several constituents of human axillary secretions have been proposed as candidate human pheromones, but their influence on\\u000a human behaviour remains controversial. Here we briefly review the literature on the behavioural effects of candidate compounds,\\u000a noting that inconsistencies in findings could be due in part to the variation in experimental context and potential lack of\\u000a ecological validity. We also report results

Tamsin K. Saxton; Anthony C. Little; S. Craig Roberts

213

100 Area excavation treatability study data validation report  

SciTech Connect

This report presents the results of sampling and chemical analyses at Hanford Reservation. The samples were analyzed by Thermo-Analytic Laboratories and Roy F. Weston Laboratories using US Environmental Protection Agency CLP protocols. Sample analyses included: volatile organics; semivolatile organics; inorganics; and general chemical parameters. The data from the chemical analyses were reviewed and validated to verify that reported sample results were of sufficient quality to support decisions regarding remedial actions performed at this site.

Frain, J.M.

1994-05-19

214

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

SciTech Connect

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.

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

1998-04-01

215

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

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

216

Reporting of Validity from School Health Promotion Studies Published in 12 Leading Journals.  

ERIC Educational Resources Information Center

Used the RE-AIM (reach, efficacy, adoption, implementation, and maintenance) evaluation framework to assess how thoroughly recent school-based studies in 12 leading journals addressed RE-AIM issues, emphasizing external validity. Studies rarely addressed RE-AIM dimensions regarding external validity. School-based behavior change interventions…

Estabrooks, Paul; Dzewaltowski, David A.; Glasgow, Russell E.; Klesges, Lisa M.

2003-01-01

217

Validity Study of the NAEP Mathematics Assessment: Grades 4 and 8  

ERIC Educational Resources Information Center

In Spring 2006,. the NAEP Validity Studies (NVS) Panel was asked by the National Center for Education Statistics (NCES) to undertake a validity study to examine the quality of the NAEP Mathematics Assessments at grades 4 and 8. Specifically, NCES asked the NVS Panel to address five questions: (1) Does the NAEP framework offer reasonable content…

Daro, Phil; Stancavage, Frances; Ortega, Moreica; DeStefano, Lizanne; Linn, Robert

2007-01-01

218

The conduct of drug metabolism studies considered good practice (II): in vitro experiments.  

PubMed

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

Jia, Lee; Liu, Xiaodong

2007-12-01

219

Tracking Study for Top-off Safety Validation at SSRL  

SciTech Connect

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.

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

220

Scanning Ion Conductance Microscopy for Studying Biological Samples  

PubMed Central

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

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

2012-01-01

221

Nuclear quadrupole resonance studies of transparent conducting oxides.  

PubMed

We report (63,65)Cu spin-lattice relaxation rates measured by nuclear quadrupole resonance (NQR) in the delafossite compound CuYO(2) and CuYO(2):Ca over a temperature range from 200 to 450K. CuYO(2):Ca is a prototype transparent oxide exhibiting p-type electrical conductivity. Relaxation rates in CuYO(2):Ca are enhanced by one to two orders of magnitude relative to undoped material, exhibit much stronger temperature dependence, and contain contributions from magnetic and quadrupolar relaxation mechanisms with roughly equal strengths. Relaxation in undoped CuYO(2) is of purely quadrupolar origin and is attributed to interactions with lattice phonons. The main focus of this paper is the magnetic contribution to the relaxation rate in CuYO(2):Ca which is attributed to the hyperfine fields of carriers. It is argued that the dynamics of the hyperfine field are dominated by the hopping rate for carrier transfers between neighboring atoms in the copper planes of the delafossite structure. Comparison of the magnetic relaxation rates with the DC conductivity permits an estimate of the carrier concentration and mobility. PMID:15388186

Warren, W W; Rajabzadeh, A; Olheiser, T; Liu, J; Tate, J; Jayaraj, M K; Vanaja, K A

2004-01-01

222

Fullerene peapods: In-situ conductivity study during synthesis  

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

223

Scanning ion conductance microscopy studies of amyloid fibrils at nanoscale  

NASA Astrophysics Data System (ADS)

Atomic force microscopy (AFM) has developed to become a very versatile nano-scale technique to reveal the three-dimensional (3D) morphology of amyloid aggregates under physiological conditions. However, the imaging principle of AFM is based on measuring the `force' between a sharp tip and a given nanostructure, which may cause mechanical deformation of relatively soft objects. To avoid the deformation, scanning ion conductance microscopy (SICM) is an alternative scanning probe microscopy technique, operating with alternating current mode. Here we can indeed reveal the 3D morphology of amyloid fibrils and it is capable of exploring proteins with nanoscale resolution. Compared with conventional AFM, we show that SICM can provide precise height measurements of amyloid protein aggregates, a feature that enables us to obtain unique insight into the detailed nucleation and growth mechanisms behind amyloid self-assembly.

Zhang, Shuai; Cho, Sang-Joon; Busuttil, Katerina; Wang, Chen; Besenbacher, Flemming; Dong, Mingdong

2012-05-01

224

Selection of test chemicals for the ECVAM international validation study on in vitro embryotoxicity tests. European Centre for the Validation of Alternative Methods.  

PubMed

The European Centre for the Validation of Alternative Methods (ECVAM) has sponsored a large international prevalidation and validation study of three embryotoxicity tests, involving embryonic stem cells, limb bud micromass cultures, and post-implantation whole-embryo cultures. The main objective of the study was to assess the performance of these in vitro tests in discriminating between non-embryotoxic, weakly embryotoxic and strongly embryotoxic compounds. An initial part of the study was to select 20 test substances for the formal validation trial, conducted under blind conditions. A database of in vivo and in vitro developmental toxicity test results was complied on 310 chemicals that had been used in previous validation studies, or suggested for such use, or that had good quality "segment II"-type in vivo data, or for which there were human data. From this database, a shortlist of about 30 candidates was constructed. Because the ECVAM study would not include metabolic activation, chemicals known to require activation for their developmental effects were excluded as candidates, although some known stable metabolites were included. Attempts were made: to include substances of diverse mechanism; to avoid overemphasis on pharmaceuticals; to avoid biologically inert substances as non-embryotoxicants; and to make the list different from those used previously. The candidates were of three categories: Class 3, strongly embryotoxic, was defined as developmentally toxic in all species tested, inducing multiple developmental effects, and with a high A/D ratio. Class 1, non-embryotoxic, was defined as not developmentally toxic at maternally toxic exposures, but which may show some minor embryo/fetal toxicity, which cannot be separated from maternal toxicity. Class 2, weakly embryotoxic, were chemicals of intermediate activity. From this candidate list, chemicals of known receptor (androgen, oestrogen, glucocorticoid, aryl hydrocarbon) mechanisms were excluded, on the basis that simple tests for such activity are already available. In addition, chemicals not freely available were excluded, and an emphasis on human data was applied. The final list of 20 chemicals was: Class 3--6-aminonicotinamide, 5-bromo- 2'-deoxyuridine, hydroxyurea, methylmercury chloride, methotrexate, all-trans-retinoic acid; Class 2--boric acid, dimethadione, lithium chloride, methoxyacetic acid, valproic acid (VPA), 2-propyl-4-pentynoic acid (4-yn-VPA), salicylic acid sodium salt; and Class 1--acrylamide, D-(+)-camphor, dimethyl phthalate, diphenhydramine hydrochloride, 2-ethyl-4- methylpentanoic acid (isobutyl-ethyl-VPA), Penicillin G sodium salt, saccharin sodium hydrate. PMID:11971754

Brown, Nigel A

2002-01-01

225

A HEAT CONDUCTION STUDY AT NON-CONTINUUM SCALES A Dissertation  

E-print Network

A HEAT CONDUCTION STUDY AT NON-CONTINUUM SCALES A Dissertation Submitted to the Graduate School Rights Reserved #12;A HEAT CONDUCTION STUDY AT NON-CONTINUUM SCALES Abstract by Alejandro Guajardo Cu´ellar An extensive and detailed description of heat conduction at the micro- and nano-scale is presented. During

Sen, Mihir

226

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

NASA Astrophysics Data System (ADS)

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.

Rabbi, Fazle

227

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

228

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

ERIC Educational Resources Information Center

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…

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

2014-01-01

229

Improved Diagnostic Validity of the ADOS Revised Algorithms: A Replication Study in an Independent Sample  

ERIC Educational Resources Information Center

Recently, Gotham et al. ("2007") proposed revised algorithms for the Autism Diagnostic Observation Schedule (ADOS) with improved diagnostic validity. The aim of the current study was to replicate predictive validity, factor structure, and correlations with age and verbal and nonverbal IQ of the ADOS revised algorithms for Modules 1 and 2 in a…

Oosterling, Iris; Roos, Sascha; de Bildt, Annelies; Rommelse, Nanda; de Jonge, Maretha; Visser, Janne; Lappenschaar, Martijn; Swinkels, Sophie; van der Gaag, Rutger Jan; Buitelaar, Jan

2010-01-01

230

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

Microsoft Academic Search

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

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

2003-01-01

231

Mechanistic study of silver nanoparticle formation on conducting polymer surfaces.  

PubMed

Conducting polymer (polyaniline) sheets are shown to be active substrates to promote the growth of nanostructured silver thin films with highly tunable morphologies. Using the spontaneous electroless deposition of silver, we show that a range of nanostructured metallic features can be controllably and reproducibly formed over large surface areas. The structural morphology of the resulting metal-polymer nanocomposite is demonstrated to be sensitive to experimental parameters such as ion concentration, temperature, and polymer processing and can range from densely packed oblate nanosheets to bulk crystalline metals. The deposition mechanisms are explained using a diffusion-limited aggregation (DLA) model to describe the semi-fractal-like growth of the metal nanostructures. We find these composite films to exhibit strong surface-enhanced Raman (SERS) activity, and the nanostructured features are optimized with respect to SERS activity using a self-assembled monolayer of mercapto-benzoic acid as a model Raman reporter. SERS enhancements are estimated to be on the order of 10(7). Through micro-Raman SERS mapping, these materials are shown to exhibit uniform SERS responses over macroscopic areas. These metal-polymer nanocomposites benefit from the underlying polymer's processability to yield SERS-active materials of almost limitless shape and size and show significant promise for future SERS-based sensing and detection schemes. PMID:21434643

Mack, Nathan H; Bailey, James A; Doorn, Stephen K; Chen, Chien-An; Gau, Han-Mou; Xu, Ping; Williams, Darrick J; Akhadov, Elshan A; Wang, Hsing-Lin

2011-04-19

232

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 ...

233

Studies of conduction electron tunneling across the ohmic metal-Si interface utilizing CESR. [CESR (Conduction Electron Spin Resonance)  

SciTech Connect

The transport of Phosphorus conduction electrons, in heavily doped (>10[sup 19] cm[sup [minus]3]) Si, from the si, into metal layers evaporated on the Si surface has been studied. The author utilized Conduction Electron Spin Resonance (CESR) as a method of spin labeling the phosphorous electrons. Electrons which tunnel from the Si into the metal overlayer, are subject to an increased relaxation rate, resulting in a change in the resonance width. This technique requires no leads or biasing, hence even submonolayer metal coverage can be studied. The electron transport, across the Si-metal interface, into bulk (>50[angstrom]) metal layers, was studied as a function of Phosphorus concentration at the Si surface. Metals studied were Al, Ag, Au, and Cu. The metal films were prepared in a UHV system, however, CESR measurements were made in air. These results are compared to a simple Schottky barrier theory. The change in CESR line width was studied as a function of metal layer thickness (submonolayer to 200[angstrom]). These studies were performed in a dedicated UHV apparatus, which is capable of in situ metal evaporation, CESR measurement, and Auger analysis. (The design of this system is discussed in detail). The metals studied are Al, Ag, and Cu. Results show little coupling to layers [approximately]3[angstrom] thick, with a rapid increase to the maximum coupling by 60[angstrom] of metal. The CESR line width was also studied with metal bilayers on the Si surface. In these experiments metal A is deposited on the Si surface, then metal B is deposited on metal A. Systems studied are Cu-Ag, Al-Ag, Al-Cu, and Cu-Al. These results can give insight to the metal layer thickness required to define the properties of the Schottky barrier.

Anderberg, J.M.

1992-01-01

234

Mission Specialist (MS) Allen conducts Vestibular Study Experiment on middeck  

NASA Technical Reports Server (NTRS)

Mission Specialist (MS) Allen, wearing headset and with electrodes placed on his face, relaxes on middeck floor while Vestibular Study Experiment hardware records eye movement data as it relates to motion sickness. The electrodes monitor his responses in zero gravity. Allen is wearing the multi-pieced constant wear garment.

1982-01-01

235

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

ERIC Educational Resources Information Center

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…

Ekinci, Hatice

2014-01-01

236

Validity study of self-reported pesticide exposure among orchardists  

Microsoft Academic Search

Self-reported work histories are often the only means of estimating occupational exposures in epidemiologic research. The objective of this study was to examine the accuracy of recall of historical pesticide use among orchardists. All 185 orchardists in this study had participated previously in a cohort study of men occupationally exposed to pesticides. In that study (1972 to 1976), subjects were

LAWRENCE S ENGEL; NOAH S SEIXAS; MATTHEW C KEIFER; W T LONGSTRETH JR; HAVEY CHECKOWAY

2001-01-01

237

Field emission study of MWCNT/conducting polymer nanocomposite  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

238

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

E-print Network

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

Boyer, Edmond

239

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

E-print Network

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

240

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

PubMed

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

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

2012-11-01

241

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

PubMed

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

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

242

Plume trajectory validation study: Brown cloud support project overview  

SciTech Connect

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.

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

1991-09-30

243

DC conductivity study of polyaniline and poly(acrylonitrile-butadiene-styrene) blends  

Microsoft Academic Search

In this study, conducting blends of poly(acrylonitrile-butadiene-styrene) and polyaniline doped with dodecylbenzene sulfonic acid were prepared by solution blending. In order to understand the electrical conduction mechanism of the samples, DC electrical conductivity measurements of the blends were carried out in the temperature range of 80–320K. The experimental results fit well with Mott's model of three-dimensional variable range hopping conduction.

Fernando H. Cristovan; Fernando R. de Paula; Sherlan G. Lemos; Adilson J. A. De Oliveira; Ernesto C. Pereira

2009-01-01

244

Formal Methods for Verification and Validation of partial specifications: A Case Study  

E-print Network

1 Formal Methods for Verification and Validation of partial specifications: A Case Study Steve This paper describes our work exploring the suitability of formal specification methods for independent specifications are represented. Lightweight formal methods show significant promise in this context

Easterbrook, Steve

245

Dynamic Causal Models and Physiological Inference: A Validation Study Using Isoflurane Anaesthesia in  

E-print Network

specific neurotransmitters. Here, we report a DCM validation study concerning inference on excitatory and inhibitory synaptic transmission, using different doses of a volatile anaesthetic agent (isoflurane) to parametrically modify excitatory and inhibitory synaptic processing while recording local field potentials (LFPs

Moran, Rosalyn

246

A study of the validity of early material balance estimates in petroleum reservoirs  

E-print Network

A STUDY OF THE VALIDITY OF EARLY MATERIAL BALANCE ESTIMATES IN PETROLEUM RESERVOIRS A Thesis by CHRISTIAN ANZE GALINDO Submitted to the Graduate College of the Texas ARM University in partia4 fulfillment of the requirements for the degree... of MASTER OF SCIENCE January 1964 Major Subject: Petroleum Engineering A STUDY OF THE VALIDITY OF EARLY MATERIAL BALANCE ESTIMATES IN PETROLEUM RESERVOIRS A Thesis by CHRISTIAN ANZE GALINDO App o ed as to style nd content by. Chairman of Committee...

Galindo, Christian Anze

2012-06-07

247

Statistical study of UHF scintillations conducted between 1994 and 2013  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

248

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

ERIC Educational Resources Information Center

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

Bozdogan, Aykut Emre

2011-01-01

249

Probabilistic Study Conducted on Sensor-Based Engine Life Calculation  

NASA Technical Reports Server (NTRS)

Turbine engine life management is a very complicated process to ensure the safe operation of an engine subjected to complex usage. The challenge of life management is to find a reasonable compromise between the safe operation and the maximum usage of critical parts to reduce maintenance costs. The commonly used "cycle count" approach does not take the engine operation conditions into account, and it oversimplifies the calculation of the life usage. Because of the shortcomings, many engine components are regularly pulled for maintenance before their usable life is over. And, if an engine has been running regularly under more severe conditions, components might not be taken out of service before they exceed their designed risk of failure. The NASA Glenn Research Center and its industrial and academic partners have been using measurable parameters to improve engine life estimation. This study was based on the Monte Carlo simulation of 5000 typical flights under various operating conditions. First a closed-loop engine model was developed to simulate the engine operation across the mission profile and a thermomechanical fatigue (TMF) damage model was used to calculate the actual damage during takeoff, where the maximum TMF accumulates. Next, a Weibull distribution was used to estimate the implied probability of failure for a given accumulated cycle count. Monte Carlo simulations were then employed to find the profiles of the TMF damage under different operating assumptions including parameter uncertainties. Finally, probabilities of failure for different operating conditions were analyzed to demonstrate the importance of a sensor-based damage calculation in order to better manage the risk of failure and on-wing life.

Guo, Ten-Huei

2004-01-01

250

An Arabic version of the effort-reward imbalance questionnaire: translation and validation study.  

PubMed

An Arabic version of the Effort-Reward Imbalance Questionnaire was developed and validated through a translation process with cross-cultural considerations. The translated questionnaire was evaluated for reliability and validity. A Principal Components Analysis was conducted following assessment of the suitability of data for factor analysis. Components with high eigenvalues were extracted, followed by Varimax rotation. Three components with eigenvalues greater than 1.0 (50% of variance) were indicated. The analysis showed Cronbach's alpha coefficients of .82 for the Effort scale, .88 for the Reward scale, and .74 for the Overcommitment scale. The test-retest reliability was high with intra-correlation coefficients of > or = .86. The Arabic version of the Effort-Reward Imbalance Questionnaire showed adequate reliability and validity and is a suitable instrument to assess work stress in Arabic-speaking people. PMID:24340817

Almadi, Tawfiq; Cathers, Ian; Chow, Chin Moi

2013-08-01

251

21 CFR 312.120 - Foreign clinical studies not conducted under an IND.  

Code of Federal Regulations, 2013 CFR

...data from a foreign clinical study not conducted under an IND...the protocol and results of the study and, should FDA request, case records maintained by the investigator...and drug product used in the study, including a description...

2013-04-01

252

21 CFR 312.120 - Foreign clinical studies not conducted under an IND.  

Code of Federal Regulations, 2012 CFR

...data from a foreign clinical study not conducted under an IND...the protocol and results of the study and, should FDA request, case records maintained by the investigator...and drug product used in the study, including a description...

2012-04-01

253

21 CFR 312.120 - Foreign clinical studies not conducted under an IND.  

Code of Federal Regulations, 2014 CFR

...data from a foreign clinical study not conducted under an IND...the protocol and results of the study and, should FDA request, case records maintained by the investigator...and drug product used in the study, including a description...

2014-04-01

254

Validation of New Symptom-Based Fibromyalgia Criteria for Irritable Bowel Syndrome Co-morbidity Studies  

PubMed Central

Background/Aims There is significant co-morbidity between irritable bowel syndrome (IBS) and fibromyalgia syndrome (FMS). However, FMS is diagnosed by physical examination, which limits the conduct of co-morbidity studies in a large population-based study. The purpose of this study was to determine the diagnostic validity of a new symptom-based criteria in patients with FMS and/or IBS using the American College of Rheumatology (ACR) criteria as a gold standard. Methods The study participants consisted of women with FMS (n = 30), IBS (n = 27) and controls (n = 28). A new symptom-based diagnostic criteria for FMS comprised a regional pain scale and a visual analogue scale for fatigue. All subjects underwent a physical examination for FMS (ACR criteria) and structured questionnaires of regional pain scale and visual analogue scale for fatigue. A fibromyalgia intensity score was calculated and thresholds of tenderness were determined by a dolorimeter. Results The number of participants diagnosed with FMS in the entire study population (n = 85) was 31 by the new criteria. Compared to the ACR, the sensitivity of the new criteria was 82.9%, specificity 96.0%, positive predictive value 93.5% and negative predictive value 88.9%. In addition, new criteria were useful for the diagnosis of FMS among the subjects with IBS. A fibromyalgia intensity score was significantly correlated with the threshold of tenderness (r = -0.62, P < 0.001). Conclusions The new symptom-based diagnostic criteria for the diagnosis of FMS can be used in large-scale clinical and epidemiological co-morbidity studies, in which physical examination is unfeasible. Gastroenterologists investigating the effects of co-morbid FMS in IBS patients can use these new ciriteria with confidence. PMID:21369494

Akiva, Smadar; Leshno, Moshe; Halpern, Zamir; Buskila, Dan

2011-01-01

255

In-Trail Procedure Air Traffic Control Procedures Validation Simulation Study  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

256

Experimental and numerical study of the effective thermal conductivity of silica nanocomposites with thermal boundary resistance  

SciTech Connect

The thermal interface resistance at the macro scale is mainly described by the physical gap between two interfaces and constriction resistance due to this gap. The small gaps between the two material faces makes up the majority of thermal interface resistance at the macro scale. So, most of the studies have been focused on characterizing effect of surface geometry and material properties to thermal interface resistance. This resistance is more widely known as thermal contact resistance, represented with Rc. There are various models to predict thermal contact resistance at macro scale. These models predict thermal resistance Rc for given two materials by utilizing their bulk thermomechanical properties. Although, Rc represents thermal resistance accurately for macro size contacts between two metals, it is not suitable to describe interface resistance of particles in modern TIMs, aka particulate composites. The particles inside recently available TIMs are micron size and with effort to further increase surface area this particle size is approaching nano scale. At this small scale, Rc does not accurately predict thermal interface, as it is very difficult to characterize the surface topography. The thermal discontinuity at perfectly bonded interface of two dissimilar materials is termed as thermal boundary resistance (Rb) or Kapitza resistance. The macroscopic assumptions that thermal discontinuity only exists due to gaps and surface geometry leads to substantial error in determining interface thermal properties at micron and nano scale. The phenomenon of thermal boundary resistance is an inherent material property and arises due to fundamental mechanism of thermal transport. For metal-matrix particulate composites, Rb plays more important role than Rc. The free flowing nature of the polymer would eliminate most of the gaps between the two materials at their interface. This means almost all of the thermal resistance at particle/matrix interface would occur due to Rb. The current study presents experimental study of thermal boundary resistance for silica nano particles embedded inside epoxy resin. The bulk conductivity of the sample is measured and Rc is back calculated using Hasselman-Johnson s (H-J) equation. The numerical validation of the equation is also presented, including extrapolation study to predict effective conductivity of the nanocomposite TIM.

Kothari, Rushabh M [ORNL; Dinwiddie, Ralph Barton [ORNL; Wang, Hsin [ORNL

2013-01-01

257

The Conduct of Drug Metabolism Studies Considered Good Practice (I): Analytical Systems and In Vivo Studies  

PubMed Central

This review serial outlines practical and scientifically-based approaches to conducting contemporary drug metabolism studies considered good practice for drug development and regulatory filing. The present part addresses analytical methods used in the drug metabolism studies and evaluates advantages and disadvantages of these methods as well as the related sample preparations. The methods described here cover from conventional radioactive labeling of drugs, which includes selection of a proper radioisotope, its labeling position, and modern radio-pharmacokinetics employed in microdosing by using a radionuclide to visualize drug distribution in vivo, to currently widely-used liquid chromatography (LC) in conjunction with mass spectrometry (MS), tandem mass spectrometry (MS/MS), and nuclear magnetic resonance (NMR) for quantitative detection of metabolites and characterization of their structures. Although the analytical tools have progressed sufficiently to allow determination of metabolites, proper in vitro models and in vivo studies have to be carefully designed in order to understand drug metabolism. Points for consideration when conducting in vivo drug metabolism studies include interspecies differences in systemic exposure and metabolism pathways, identification of the major metabolites and unique human metabolites that become the regulatory focus, local metabolism in addition to liver metabolism, time points for sampling, and synthesis of the authentic metabolites to confirm their formation. The next part of this serial article will focus on in vitro drug metabolism studies. PMID:18220562

Liu, Xiaodong; Jia, Lee

2009-01-01

258

Status Update on the GPM Ground Validation Iowa Flood Studies (IFloodS) Field Experiment  

NASA Astrophysics Data System (ADS)

The overarching objective of integrated hydrologic ground validation activities supporting the Global Precipitation Measurement Mission (GPM) is to provide better understanding of the strengths and limitations of the satellite products, in the context of hydrologic applications. To this end, the GPM Ground Validation (GV) program is conducting the first of several hydrology-oriented field efforts: the Iowa Flood Studies (IFloodS) experiment. IFloodS will be conducted in the central to northeastern part of Iowa in Midwestern United States during the months of April-June, 2013. Specific science objectives and related goals for the IFloodS experiment can be summarized as follows: 1. Quantify the physical characteristics and space/time variability of rain (rates, DSD, process/"regime") and map to satellite rainfall retrieval uncertainty. 2. Assess satellite rainfall retrieval uncertainties at instantaneous to daily time scales and evaluate propagation/impact of uncertainty in flood-prediction. 3. Assess hydrologic predictive skill as a function of space/time scales, basin morphology, and land use/cover. 4. Discern the relative roles of rainfall quantities such as rate and accumulation as compared to other factors (e.g. transport of water in the drainage network) in flood genesis. 5. Refine approaches to "integrated hydrologic GV" concept based on IFloodS experiences and apply to future GPM Integrated GV field efforts. These objectives will be achieved via the deployment of the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms with attendant soil moisture and temperature probes, a large network of both 2D Video and Parsivel disdrometers, and USDA-ARS gauge and soil-moisture measurements (in collaboration with the NASA SMAP mission). The aforementioned measurements will be used to complement existing operational WSR-88D S-band polarimetric radar measurements, USGS streamflow, and Iowa Flood Center stream monitoring measurements. Coincident satellite datasets will be archived from current microwave imaging and sounding radiometers flying on NOAA, DMSP, NASA, and EU (METOP) low-earth orbiters, and rapid-scanned IR datasets collected from geostationary (GOES) platforms. Collectively the observational assets will provide a means to create high quality (time and space sampling) ground "reference" rainfall and stream flow datasets. The ground reference radar and rainfall datasets will provide a means to assess uncertainties in both satellite algorithms (physics) and products. Subsequently, the impact of uncertainties in the satellite products can be evaluated in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction.

Petersen, Walt; Krajewski, Witold

2013-04-01

259

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

ERIC Educational Resources Information Center

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

Romano, Jeanine; Kromrey, Jeffrey D.

260

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

Microsoft Academic Search

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.

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

2004-01-01

261

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

ERIC Educational Resources Information Center

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…

Baker, Bruce D.

2006-01-01

262

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

ERIC Educational Resources Information Center

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…

Coleman, Daniel

2004-01-01

263

Numerical study on the validity of the diffusion approximation  

E-print Network

and the radiative transport as implemented by Monte Carlo simulation in the cases of point and ball sources. Our for biologi- cal studies and has been recently extended into living small animal models. Optical molecular tomography is that when light sources are small, weak, and deep in a living body, they cannot be effectively

Virginia Tech

264

Quasiparticle relaxation in Heavy Fermions studied using Inverse Fourier Transform of optical conductivity  

E-print Network

Quasiparticle relaxation in Heavy Fermions studied using Inverse Fourier Transform of optical Keywords: Optical conductivity Inverse Fourier Transform Heavy Fermions a b s t r a c t Inverse Fourier Transform of optical conductivity is used for studies of quasiparticle relaxation in Heavy Fermions in time

Dordevic, Sasha V.

265

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

E-print Network

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

Paris-Sud XI, Université de

266

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

PubMed Central

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

2012-01-01

267

Timed picture naming: Extended norms and validation against previous studies  

Microsoft Academic Search

Factors affecting word retrieval were compared in a timed picture-naming paradigm for 520 drawings of objects. In prior timed\\u000a and untimed studies by Snodgrass and Vanderwart (1980) and Snodgrass and Yuditsky (1996), concerns were raised that participants\\u000a could not reliably name large numbers of items in a single session. We show that reliable results are obtained in a single\\u000a session

Anna Székely; Simonetta D’Amico; Antonella Devescovi; Kara Federmeier; Dan Herron; Gowri Iyer; Thomas Jacobsen; Elizabeth Bates

2003-01-01

268

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

Microsoft Academic Search

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

George Forman; Martin Scholz

2010-01-01

269

Electric field studies: TLE-induced waveforms and ground conductivity impact on electric field propagation  

NASA Astrophysics Data System (ADS)

We review in this paper main results obtained from electric field (from VLF to HF) measurement campaigns realized by CEA in the framework of the Eurosprite program [Neubert et al., 2005, 2008] from 2003 to 2009 in France in different configurations. Two main topics have been studied: sprite or elve induced phenomena (radiation or perturbation) and wave propagation. Using a network of 4 stations, VLF radiations from sprite have been successfully located at 10 km from the sprite parent lightning, in agreement with possible sprite location, generally displaced from the parent lightning. The MF (300 kHz - 3 MHz) source bursts were identified simultaneously with the occurrence of sprites observed with cameras [Farges et al., 2004; Neubert et al., 2008]. These observations are compared to recent broadband measurements, assumed to be due to relativistic electron beam radiation related to sprites [Fullekrug et al., 2009]. Recently, in 2009, with a new instrumentation, an ELF tail has been clearly measured after the lightning waveform, while sprites were observed at about 500 km from our station. This ELF tail is usually observed at distances higher than thousand km and is associated to sprite generation. This opens the capacity to measure the charge moment of the parent-lightning, using such measurement close to the source. Farges et al. [2007] showed that just after a lightning return stroke, a strong transient attenuation is very frequently observed in the MF waves of radio transmissions. They showed that this perturbation is due to heating of the lower ionosphere by the lightning-induced EMP during few milliseconds. These perturbations are then the MF radio signature of the lightning EMP effects on the lower ionosphere, in the same way as elves correspond to their optical signature. The experiment also provided the electric field waveforms directly associated to elves, while lightning were not detected by Météorage. Many of them present a double peak feature. The propagation of the electromagnetic waves generated by lightning has also been studied in the frequency range 1 kHz-1MHz at distances lower than 1000 km from the lightning source. A propagation model has been developed to determine the ground waves which propagate in a homogenous medium using the analytical expression given by Maclean and Wu [1993]. This approach takes into account the electric finite conductivity and the fact that the Earth is spherical, which allow us to deal with over-the-horizon propagation. We installed in 2008 four stations which were more or less aligned - the maximum distance between two stations was about 870 km. Two stations were located close to the Mediterranean Sea and the two others inside the continent, at the centre of France. This station distribution and the observation period (from August to December) allowed statistical and physical studies, such as the influence of the electric conductivity on wave propagation. Comparison of electric field spectra, measured after propagation only over sea and only over ground, showed clearly the effects of ground conductivity on propagation. Comparison between observations and modelling has been used to evaluate the ground conductivity. In the future we will implement the sky-wave inside our model and validate it with the database.

Farges, Thomas; Garcia, Geraldine; Blanc, Elisabeth

2010-05-01

270

Improving DNA data exchange: validation studies on a single 6 dye STR kit with 24 loci.  

PubMed

The idea of developing a new multiplex STR amplification system was conceived in 2011 as an effective way to implement the new European standard set (ESS) of 12 STR markers adopted by The Council of the European Union in 2009 while maintaining an effective compatibility and information exchange with the historical DNA profiles contained in the Spanish national DNA database (around 200,000 DNA profiles) mainly based on the 13 CODIS core STR loci plus D19S433 and D2S1338 markers. With this goal in mind we proposed to test and validate a single STR amplification system for simultaneous analysis of 21 STR markers covering both CODIS and ESS core STR loci plus three additional markers (D19S433, D2S1338, and SE33) also contained in commonly used STR kits and national DNA databases. In 2012, we started the first beta-testing with a 6-dye STR kit prototype containing 24 loci (now known as the GlobalFiler™ PCR Amplification Kit) developed by Life Technologies in response to the CODIS Core Loci Working Group's recommendation to expand the CODIS Core Loci. This prototype included our proposal of 21 autosomal STR markers and two Y-chromosome markers (DYS391 and Y-indel) and maximizes concordance with established databases and previously analyzed samples by maintaining primer sequences of previous Identifiler(®)/NGM SElect™ kits for the 21 STR markers except for TPOX. This paper describes the validation studies conducted with the first commercial available 6-dye STR kit for casework using a 3500 genetic analyzer for fragment detection that included the analysis of the following parameters and aspects: analytical threshold, sensitivity & stochastic threshold, heterozygous balance, stutter threshold, precision and accuracy, repeatability and reproducibility, genotype concordance, DNA mixtures, species specificity, and stability studies with case type samples. The studies demonstrated that the GlobalFiler™ system provided equivalent overall performance to previous forensic STR PCR kits, but with enhanced discrimination power for a better match efficiency that would reduce the chance of adventitious matches during DNA data exchange among national DNA databases. PMID:25082138

Martín, Pablo; de Simón, Lourdes Fernández; Luque, Gracia; Farfán, María José; Alonso, Antonio

2014-11-01

271

Validation of protein carbonyl measurement: A multi-centre study  

PubMed Central

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

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

272

European Prospective Investigation into Cancer and Nutrition: Validity Studies on Dietary Assessment Methods  

Microsoft Academic Search

This supplement contains the results from studies in the eight countries participating in the European Prospect- ive Investigation into Cancer and Nutrition (EPIC) study. Each collaborating centre has assessed the relative va- lidity and reproducibility of the dietary assessment method being used in their centre. One study has also looked at the relative validity of a measure of physical activity,

BARRIE M MARGETTS; PIRJO PIETINEN

273

Validation of a virtual preoperative evaluation clinic: a pilot study.  

PubMed

Patients scheduled for surgery at the Omaha VA Medical Center were evaluated preoperatively via telemedicine. Following the examination, patients filled out a 15 item, 5 point Likert scale questionnaire regarding their opinion of preoperative evaluation in a VTC format. Evaluations were performed under the direction of nationally recognized guidelines and recommendations of experts in the field of perioperative medicine and were overseen by a staff anesthesiologist from the Omaha VA Medical Center. No significant difficulties were encountered by the patient or the evaluator regarding the quality of the audio/visual capabilities of the VTC link and its ability to facilitate preoperative evaluation. 87.5% of patients felt that virtual evaluation would save them travel time; 87.5% felt virtual evaluation could save them money; 7.3% felt uncomfortable using the VTC link; 12.2% felt the virtual evaluation took longer than expected; 70.7% preferred to be evaluated via VTC link; 21.9% were undecided; 9.7% felt they would rather be evaluated face-to-face with 26.8% undecided; 85.0% felt that teleconsultation was as good as being seen at the Omaha surgical evaluation unit; 7.5% were undecided. Our study has shown that effective preoperative evaluation can be performed using a virtual preoperative evaluation clinic; patients are receptive to the VTC format and, in the majority of cases, prefer it to face-to-face evaluation. PMID:21335890

Zetterman, Corey V; Sweitzer, Bobbie J; Webb, Brad; Barak-Bernhagen, Mary A; Boedeker, Ben H

2011-01-01

274

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...

275

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

276

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

Microsoft Academic Search

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

Andreas M. Riege

2003-01-01

277

Dyadic Adjustment Scale: A Validation Study among Older French-Canadians Living in Relationships.  

PubMed

ABSTRACT The principal objective of this study, the first of its kind to use this population, is to describe the factor analysis and validity of the Dyadic Adjustment Scale (EAD) among 895 French Canadian seniors living as couples. A confirmatory factor analysis was carried out using structural equation modeling. Results support Spanier's hierarchical model questionnaire (1976). Results also indicate evidence of validity and reliability satisfactorily set aside for the Affective Expression subscale having a lower Cronbach alpha coefficient. The results also indicate strong validity of the scale according to indices of convergent and discriminant validity. Finally, a discussion is presented addressing considerations to be taken into account for using the questionnaire among older couples. PMID:25247256

Villeneuve, Laurence; Trudel, Gilles; Préville, Michel; Dargis, Luc; Boyer, Richard; Bégin, Jean

2015-03-01

278

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

SciTech Connect

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.

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

279

Multiresidue method for determination of algal toxins in shellfish: single-laboratory validation and interlaboratory study.  

PubMed

A method that uses liquid chromatography with tandem mass spectrometry (LC/MS/MS) has been developed for the highly sensitive and specific determination of amnesic shellfish poisoning toxins, diarrhetic shellfish poisoning toxins, and other lipophilic algal toxins and metabolites in shellfish. The method was subjected to a full single-laboratory validation and a limited interlaboratory study. Tissue homogenates are blended with methanol-water (9 + 1), and the centrifuged extract is cleaned up with a hexane wash. LC/MS/MS (triple quadrupole) is used for quantitative analysis with reversed-phase gradient elution (acidic buffer), electrospray ionization (positive and negative ion switching), and multiple-reaction monitoring. Ester forms of dinophysis toxins are detected as the parent toxins after hydrolysis of the methanolic extract. The method is quantitative for 6 key toxins when reference standards are available: azaspiracid-1 (AZA1), domoic acid (DA), gymnodimine (GYM), okadaic acid (OA), pectenotoxin-2 (PTX2), and yessotoxin (YTX). Relative response factors are used to estimate the concentrations of other toxins: azaspiracid-2 and -3 (AZA2 and AZA3), dinophysis toxin-1 and -2 (DTX1 and DTX2), other pectenotoxins (PTX1, PTX6, and PTX11), pectenotoxin secoacid metabolites (PTX2-SA and PTX11-SA) and their 7-epimers, spirolides, and homoYTX and YTX metabolites (45-OHYTX and carboxyYTX). Validation data have been gathered for Greenshell mussel, Pacific oyster, cockle, and scallop roe via fortification and natural contamination. For the 6 key toxins at fortification levels of 0.05-0.20 mg/kg, recoveries were 71-99% and single laboratory reproducibilities, relative standard deviations (RSDs), were 10-24%. Limits of detection were <0.02 mg/kg. Extractability data were also obtained for several toxins by using successive extractions of naturally contaminated mussel samples. A preliminary interlaboratory study was conducted with a set of toxin standards and 4 mussel extracts. The data sets from 8 laboratories for the 6 key toxins plus DTX1 and DTX2 gave within-laboratories repeatability (RSD(R)) of 8-12%, except for PTX-2. Between-laboratories reproducibility (RSDR) values were compared with the Horwitz criterion and ranged from good to adequate for 7 key toxins (HorRat values of 0.8-2.0). PMID:16001850

McNabb, Paul; Selwood, Andrew I; Holland, Patrick T; Aasen, J; Aune, T; Eaglesham, G; Hess, P; Igarishi, M; Quilliam, M; Slattery, D; Van de Riet, J; Van Egmond, H; Van den Top, H; Yasumoto, T

2005-01-01

280

Development and validation of rapid ion-chromatographic method with conductivity detection for trace level determination of allylamine in sevelamer drug substances.  

PubMed

A sensitive and rapid ion chromatography (IC) method was developed for the low level determination of allylamine (AAM) in sevelamer (SVM) drug substances, i.e., sevelamer hydrochloride (SVH) and sevelamer carbonate (SVC). This method utilized a Dionex Ion Pack CS14 IC column, a mobile phase of 10mM methane sulfonic acid with conductivity detection. The total chromatographic run time was as short as 8 min. The various factors involved in the sample preparation such as, extraction solvent, extraction time and stirrer speed were evaluated. This method was validated as per United States Pharmacopoeia (USP) and International Conference on Harmonization (ICH) guidelines in terms of detection limit, quantitation limit, linearity, precision, accuracy, specificity and robustness. Linearity of the method was very good over the concentration range of 9-750 ?g/mL with the coefficient of determination (r(2)) 0.999. The detection and quantitation limit of AAM were 2.7 and 9.0 ?g/mL, respectively. The recovery data obtained for AAM were between 97% and 109%. Also, the specificity of the method was proved through IC coupled with mass spectrometer (IC-MS). The developed method was found to be robust and applied successfully to determine the content of AAM in Sevelamer bulk drugs. PMID:20724094

Karthikeyan, K; Shanmugasundaram, P; Ramadhas, R; Pillai, K Chandrasekara

2011-01-01

281

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

PubMed

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

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

282

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

PubMed Central

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

2012-01-01

283

Conductivity of nanosecond discharges in nitrogen and sulfur hexafluoride studied by particle-in-cell simulations  

NASA Astrophysics Data System (ADS)

The conductivity of the discharge gap during the nanosecond high-voltage pulsed discharge in nitrogen and sulfur hexafluoride is studied using particle-in-cell numerical simulations. It is shown that the conductivity in different locations of the cathode-anode gap is not uniform and that the conductivity is determined by both the runaway and the plasma electrons. In addition, it is shown that runaway electrons generated prior to the virtual cathode formation pre-ionize the discharge gap, which makes it conductive.

Levko, D.; Gurovich, V. Tz.; Krasik, Ya. E.

2012-06-01

284

First-Year Students' Expectations of Conduct and Consequence: A Case Study  

ERIC Educational Resources Information Center

Research on first-year students' expectations about college has explored areas of academic and social expectations, but not first-year college students' expectations about judicial conduct and consequence. The purpose of this study was to empirically explore two questions: what are first year students' expectations about campus conduct and…

Crance Gutmann, Gina-Lyn

2008-01-01

285

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

E-print Network

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

Wenseleers, Tom

286

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

E-print Network

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

Li, Baowen

287

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

Microsoft Academic Search

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

Douglas R. Langbehn; Remi J. Cadoret

2001-01-01

288

Electrohydrodynamic induction and conduction pumping of dielectric liquid film: theoretical and numerical studies  

E-print Network

. The theoretical model is further extended to study the effect of EHD conduction phenomenon for a two-phase flow (i.e. a stratified liquid/ vapor medium). The numerical results presented confirm the concept of liquid film net flow generation with the EHD conduction...

Al Dini, Salem A. S.

2007-04-25

289

External validity in a population-based national prospective study – the Norwegian Women and Cancer Study (NOWAC)  

Microsoft Academic Search

Objective: ‘The Norwegian Women and Cancer Study’ (NOWAC) was created as a national population-based cohort study by taking advantage of the existing population registers in Norway. Thus, the women in the NOWAC study should be representative for the entire female population in the corresponding age-groups. The aim of this paper was to study the external validity of the cohort as

Lund Eiliv; Kumle Merethe; Braaten Tonje; Hjartåker Anette; Bakken Kjersti; Eggen Elise; GramInger Torhild

2003-01-01

290

Detection of genetically modified rice: collaborative validation study of a construct-specific real-time PCR method for detection of transgenic Bt rice  

Microsoft Academic Search

A collaborative trial study has been conducted for validation of an extraction method and a subsequent real-time PCR for detection\\u000a of a transgenic Bt rice line (‘Bt63’) in rice products originating from China. A total of 17 laboratories participated in\\u000a the study and each laboratory received 16 coded samples comprising of rice grain flours, rice noodle flours and plasmid DNAs.

Lutz Grohmann; Dietrich Mäde

2009-01-01

291

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

ERIC Educational Resources Information Center

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…

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

2010-01-01

292

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

ERIC Educational Resources Information Center

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…

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

2014-01-01

293

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

ERIC Educational Resources Information Center

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

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

2014-01-01

294

The Gifted Rating Scales-School Form: A Validation Study Based on Age, Gender, and Race  

ERIC Educational Resources Information Center

This study examined the internal consistency and validity of a new rating scale to identify gifted students, the Gifted Rating Scales-School Form (GRS-S). The study explored the effect of gender, race/ethnicity, age, and rater familiarity on GRS-S ratings. One hundred twenty-two students in first to eighth grade from elementary and middle schools…

Pfeiffer, Steven; Petscher, Yaacov; Kumtepe, Alper

2008-01-01

295

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

Microsoft Academic Search

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

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

2006-01-01

296

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

ERIC Educational Resources Information Center

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…

Sad, Suleyman Nihat

2012-01-01

297

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

ERIC Educational Resources Information Center

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,…

Akin, Ahmet

2008-01-01

298

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

ERIC Educational Resources Information Center

This study investigates the construct validity of the Myers-Briggs Type Indicator (MBTI) with the hope of clarifying contradictions in previous studies using similar methods. Subjects' type categories generated by the MBTI, self-typings, and typing by subjects' spouses were used. (Author/AL)

Cohen, David; And Others

1981-01-01

299

Electrical conductivity and phase transition studies of TiO2-BaO system  

NASA Astrophysics Data System (ADS)

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.

Beg, Saba; Haneef, Sadaf

2015-01-01

300

Electrical conductivity studies on CuBr containing Al2O3 particles  

NASA Technical Reports Server (NTRS)

The conductivity of CuBr was studied and the role of a second phase, Al2O3, dispersed in CuBr was tested. CuBr melts at 493 C and exhibits three phases in the solid state. CuBr is a good ionic conductor with a transport number for copper ions of virtually unity with weighed proportions of the appropriate chemicals used. The CuBr materials were heated above melting point of CuBr, and the samples were sandwiched between copper electrodes. The ac conductivity, was determined at 1 kHz between 25 and 440 C depending on the sample. It was shown that at low temperatures, the conductivity for CuBr (Al2O3) increased by as much as 100, whereas in the beta phase the conductivity of CuBr containing Al2O3 decreased. The electrical conductivity studies are in agreement with earlier data.

Dubec, P. M.; Wagner, J. B., Jr.

1984-01-01

301

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

ERIC Educational Resources Information Center

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

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

2006-01-01

302

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

Code of Federal Regulations, 2014 CFR

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...

2014-10-01

303

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2014 CFR

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...

2014-10-01

304

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

Code of Federal Regulations, 2013 CFR

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...

2013-10-01

305

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2012 CFR

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...

2012-10-01

306

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

Code of Federal Regulations, 2010 CFR

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...

2010-10-01

307

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

Code of Federal Regulations, 2011 CFR

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...

2011-10-01

308

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2010 CFR

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...

2010-10-01

309

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

Code of Federal Regulations, 2012 CFR

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...

2012-10-01

310

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2011 CFR

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...

2011-10-01

311

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

PubMed

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

Patry, Marc W; Magaletta, Philip R

2015-02-01

312

The Gambling Symptom Assessment Scale (G-SAS): a reliability and validity study.  

PubMed

Two hundred seven patients with DSM-IV Pathological Gambling Disorder completed both the Gambling Symptom Assessment Scale (G-SAS) and the Yale-Brown Obsessive-Compulsive Scale--modified for Pathological Gambling (PG-YBOCS) at baseline visit and weekly or biweekly thereafter during the 12-week study period. The week 1 to week 2 visit data were used to assess test-retest reliability. Weekly or biweekly data were used for the G-SAS validity. The PG-YBOCS reliability and validity data have been published previously. We used the PG-YBOCS as the established scale and compared the G-SAS performance with the PG-YBOCS. Test-retest reliability was statistically significant. The correlations between the G-SAS and the PG-YBOCS and Clinical Global Impression rating were excellent. Findings suggest that the G-SAS is reliable and valid in assessing changes in symptoms during a drug treatment study. PMID:19200607

Kim, Suck Won; Grant, Jon E; Potenza, Marc N; Blanco, Carlos; Hollander, Eric

2009-03-31

313

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

SciTech Connect

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.

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

314

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

SciTech Connect

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

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

1999-03-15

315

Ethical problems in conducting research in acute epidemics: the Pfizer meningitis study in Nigeria as an illustration.  

PubMed

The ethics of conducting research in epidemic situations have yet to account fully for differences in the proportion and acuteness of epidemics, among other factors. While epidemics most often arise from infectious diseases, not all infectious diseases are of epidemic proportions, and not all epidemics occur acutely. These and other variations constrain the generalization of ethical decision-making and impose ethical demands on the individual researcher in a way not previously highlighted. This paper discusses a number of such constraints and impositions. It applies the ethical principles enunciated by Emmanuel et al.(1) to the controversial Pfizer study in Nigeria in order to highlight the particular ethical concerns of acute epidemic research, and suggest ways of meeting such challenges. The paper recommends that research during epidemics should be partly evaluated on its own merits in order to determine its ethical appropriateness to the specific situation. Snap decisions to conduct research during acute epidemics should be resisted. Community engagement, public notification and good information management are needed to promote the ethics of conducting research during acute epidemics. Individual consent is most at risk of being compromised, and every effort should be made to ensure that it is maintained and valid. Use of data safety management boards should be routine. Acute epidemics also present opportunities to enhance the social value of research and maximize its benefits to communities. Ethical research is possible in acute epidemics, if the potential challenges are thought of ahead of time and appropriate precautions taken. PMID:18665846

Ezeome, Emmanuel R; Simon, Christian

2010-04-01

316

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

PubMed

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

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

2014-04-28

317

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

SciTech Connect

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.

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

318

Validation studies of the OPCS scale — more useful than the Barthel Index?  

Microsoft Academic Search

The OPCS scales of disability were developed as a survey tool to estimate the prevalence of disability amongst adults in the UK. This study evaluates the use of the OPCS scales in a clinical setting. A total of 265 patients attending a rehabilitation unit and wheelchair centre were assessed. The OPCS scales were validated against the standard Barthel Index and

K. McPherson; RL Sloan; J. Hunter; CM Dowell

1993-01-01

319

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

E-print Network

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

Thomas, Jeremy N.

320

A Construct Validity Study of the Myers-Briggs Type Indicator  

Microsoft Academic Search

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

David Cohen; Marilye Cohen; Herbert Cross

1981-01-01

321

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

ERIC Educational Resources Information Center

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

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

2012-01-01

322

Transcranial Doppler Measurement of Middle Cerebral Artery Blood Flow Velocity: A Validation Study  

Microsoft Academic Search

SUMMARY Measurement of intracranial arterial blood flow velocity is a new technique with potentially a number of very useful applications. This study validates the technique by comparing it to cerebral blood flow (CBF) measured using intravenous Xenon and extracranial clearance recording. We have measured the middle cerebral artery (MCA) blood flow velocity in 17 symptomatic patients with the EME TC

C. C. R. BISHOP; S. POWELL; D. RUTT; L. BROWSE

2010-01-01

323

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 ...

324

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

ERIC Educational Resources Information Center

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…

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

2010-01-01

325

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

ERIC Educational Resources Information Center

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…

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

2012-01-01

326

Validity of Student Ratings of Faculty. Indiana Studies in Higher Education, Number Forty.  

ERIC Educational Resources Information Center

A study using two types of analyses to examine the validity of student ratings of faculty is described. The first analysis examined faculty ratings in terms of how high-achieving sections of courses rate their instructors in contrast with how low-achieving sections rate their instructors to determine if those teachers who advance their students…

Chase, Clinton I.; Keene, John M., Jr.

327

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

E-print Network

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

Hays, Graeme

328

Study of Relationships of Reading Mastery Level to General Reading Achievement to Validate Diagnostic Reading Tests.  

ERIC Educational Resources Information Center

The validity of the word attack skill tests of the Wisconsin Design for Reading Skill Development is studied at six grade levels by an investigation of the relationship of these to several widely known reading achievement tests. The basic notion is that reading mastery scores derived from the diagnostic tests should be positively related to the…

Fischbach, Thomas J.

329

Vehicle Design Validation via Remote Vehicle Diagnosis: A feasibility study on battery management system  

Microsoft Academic Search

In recent years, passenger vehicle product development faces great challenges to maintain high vehicle quality due to the proliferation of Electronics, Control and Software (ECS) features and the resultant system complexity. Quickly detecting and trouble-shooting faults of integrated vehicle systems during the validation stage in a key to enhancing vehicle quality. In this paper, we present a feasibilty study of

Yilu Zhang; Gary W. Gantt Jr; Mark Rychlinski; Ryan Edwards; John Correia; Calvin Wolf

2008-01-01

330

Tree Canopy Characterization for EO1 Reflective and Thermal Infrared Validation Studies: Rochester, New York  

Microsoft Academic Search

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

Jerrell R. Ballard Jr.; James A. Smith

2002-01-01

331

Imbalances in Regional Lung Ventilation A Validation Study on Electrical Impedance Tomography  

Microsoft Academic Search

Imbalances in regional lung ventilation, with gravity-dependent collapse and overdistention of nondependent zones, are likely asso- ciated to ventilator-induced lung injury. Electric impedance tomog- raphy is a new imaging technique that is potentially capable of monitoring those imbalances. The aim of this study was to validate electrical impedance tomography measurements of ventilation dis- tribution, by comparison with dynamic computerized tomography

Joao B. Borges; Valdelis N. Okamoto; Gustavo F. J. Matos; Mauro R. Tucci; Maria P. R. Caramez; Harki Tanaka; Fernando Suarez Sipmann; Durval C. B. Santos; Carmen S. V. Barbas; Carlos R. R. Carvalho; Marcelo B. P. Amato

332

A validated stability-indicating HPLC method for analysis of glabridin prodrugs in hydrolysis studies  

Microsoft Academic Search

A simple, selective and precise stability- indicating HPLC method for determination of glabridin diacetate and dihexanoate prodrugs was developed, validated and applied to the enzymatic and chemical hydrolysis studies. The chromatographic separation was achieved on a reverse phase C18 (Thermo Hypersil-Keystone, 250 × 4.6 mm, 5 micron) column using the mixture of acetonitrile and water as mobile phase. Elution of

Warunee Jirawattanapong; Ekarin Saifah; Chamnan Patarapanich

2009-01-01

333

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

334

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

Microsoft Academic Search

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

W. S. Yang; S. J. Kim

2007-01-01

335

Beyond Credentials in Teacher Selection: A Validation Study of the Omaha Teacher Interview.  

ERIC Educational Resources Information Center

Addresses the relationship between teacher attitudes and teacher effectiveness. Discusses a local validation study of the Omaha Teacher Interview (OTI), a preemployment teacher selection device assessing attitudes and personality. Finds the relationship between OTI ratings and job performance positive but insufficient to justify basing selection…

Mickler, Mary Louise; Solomon, Gloria L.

1985-01-01

336

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

337

Statistical methods and software for validation studies on new in vitro toxicity assays.  

PubMed

When a new in vitro assay method is introduced, it should be validated against the best available knowledge or a reference standard assay. For assays resulting in a simple binary outcome, the data can be displayed as a 2 × 2 table. Based on the estimated sensitivity and specificity, and the assumed prevalence of true positives in the population of interest, the positive and negative predictive values of the new assay can be calculated. We briefly discuss the experimental design of validation experiments and previously published methods for computing confidence intervals for predictive values. The application of the methods is illustrated for two toxicological examples, by using tools available in the free software, namely, R: confidence intervals for predictive values are computed for a validation study of an in vitro test battery, and sample size calculation is illustrated for an acute toxicity assay. The R code necessary to reproduce the results is given. PMID:25413292

Schaarschmidt, Frank; Hothorn, Ludwig A

2014-11-01

338

Shock wave over hand muscles: a neurophysiological study on peripheral conduction nerves in normal subjects  

PubMed Central

Summary Background and purpose: shock waves are defined as a sequence of single sonic pulses largely used in the treatment of bone and tendon diseases and recently on muscular hypertonia in stroke patients. Our purpose is to investigate the short and long term effect of extra-corporeal shock wave therapy (ESWT) on the peripheral nerve conduction and central conductions from the treated muscles in normal human subjects in order to define safety criteria. Methods: we studied 10 patients normal subjects. Motor and sensory nerve conduction velocity and F response from right ipothenar eminence (abductor digiti minimi) of the hand was recorded. Furthermore MEP latency and amplitude and central conduction from the same muscles by transcranial magnetic stimulation was evaluated. In all subjects each neurophysiological measures were monitored before, immediately after, 15 minutes and after 30 minutes from the active ESWT treatment (1600 shots with an energy applied of 0.030 mj/mm2). Results: no significant short or long term changes were noted in sensory and motor peripheral nerve conduction and in central motor conduction in all the subjects evaluated after ESWT. Conclusions: the ESWT has no effect on sensory and motor peripheral nerve conduction and in central motor conduction. The ESWT using low level of energy represent a safety method for treating the muscles in human subjects without involvement of motor or sensory nervous trunks. Different mechanisms of action of ESWT are discussed. PMID:23738282

Manganotti, Paolo; Amelio, Ernesto; Guerra, Claudio

2012-01-01

339

Numerical study for enhancing the thermal conductivity of phase change material (PCM) storage using high thermal conductivity porous matrix  

Microsoft Academic Search

In this paper, the melting process inside an irregular geometry filled with high thermal conductivity porous matrix saturated with phase change material PCM is investigated numerically. The numerical model is resting on solving the volume averaged conservation equations for mass, momentum and energy with phase change (melting) in the porous medium. The convection motion of the liquid phase inside the

Osama Mesalhy; Khalid Lafdi; Ahmed Elgafy; Keith Bowman

2005-01-01

340

Bias-dependent conductive characteristics of individual GeSi quantum dots studied by conductive atomic force microscopy.  

PubMed

The bias-dependent electrical characteristics of individual self-assembled GeSi quantum dots (QDs) are investigated by conductive atomic force microscopy. The results reveal that the conductive characteristics of QDs are strongly influenced by the applied bias. At low (-0.5 to - 2.0 V) and high (-2.5 to - 4.0 V) biases, the current distributions of individual GeSi QDs exhibit ring-like and disc-like characteristics respectively. The current of the QD's central part increases more quickly than that of the other parts as the bias magnitude increases. Histograms of the magnitude of the current on a number of QDs exhibit the same single-peak feature at low biases, and double- or three-peak features at high biases, where additional peaks appear at large-current locations. On the other hand, histograms of the magnitude of the current on the wetting layers exhibit the same single-peak feature for all biases. This indicates the conductive mechanism is significantly different for QDs and wetting layers. While the small-current peak of QDs can be attributed to the Fowler-Nordheim tunneling model at low biases and the Schottky emission model at high biases respectively, the large-current peak(s) may be attributed to the discrete energy levels of QDs. The results suggest the conductive mechanisms of GeSi QDs can be regulated by the applied bias. PMID:21270493

Wu, R; Zhang, S L; Lin, J H; Jiang, Z M; Yang, X J

2011-03-01

341

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

Microsoft Academic Search

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

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

1982-01-01

342

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

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

343

[Heart conduction system under conditions of general anesthesia. Results of a 15-year study].  

PubMed

Effects of 14 anesthetics, narcotic analgesics, benzodiazepines, and their combinations on the cardiac conduction system (CCS) were studied in 470 surgical patients of a general profile during operation and narcosis by transesophageal electrocardiostimulation. Interactions between components of total anesthesia can improve or suppress the intracardiac conduction. The authors classified the data on the effects of agents used for narcosis on the sinus node function and atrioventricular and anteretrograde conduction. The results will help an anesthesiologist in a differentiated approach to the choice of anesthetics for surgical patients with initially disordered CCS and heart rhythm. PMID:11452776

Malyshev, V D; Vedenina, I V; Sviridov, S V; Omarov, Kh T; Alieva, R A; Bazhenov, V N; Dzhabrailova, O G; Orudzheva, S A; Sokolova, N A

1999-01-01

344

Nanoscale electrical property studies of individual GeSi quantum rings by conductive scanning probe microscopy  

PubMed Central

The nanoscale electrical properties of individual self-assembled GeSi quantum rings (QRs) were studied by scanning probe microscopy-based techniques. The surface potential distributions of individual GeSi QRs are obtained by scanning Kelvin microscopy (SKM). Ring-shaped work function distributions are observed, presenting that the QRs' rim has a larger work function than the QRs' central hole. By combining the SKM results with those obtained by conductive atomic force microscopy and scanning capacitance microscopy, the correlations between the surface potential, conductance, and carrier density distributions are revealed, and a possible interpretation for the QRs' conductance distributions is suggested. PMID:23194252

2012-01-01

345

Measurement of predictive validity in violence risk assessment studies: a second-order systematic review.  

PubMed

The objective of the present review was to examine how predictive validity is analyzed and reported in studies of instruments used to assess violence risk. We reviewed 47 predictive validity studies published between 1990 and 2011 of 25 instruments that were included in two recent systematic reviews. Although all studies reported receiver operating characteristic curve analyses and the area under the curve (AUC) performance indicator, this methodology was defined inconsistently and findings often were misinterpreted. In addition, there was between-study variation in benchmarks used to determine whether AUCs were small, moderate, or large in magnitude. Though virtually all of the included instruments were designed to produce categorical estimates of risk - through the use of either actuarial risk bins or structured professional judgments - only a minority of studies calculated performance indicators for these categorical estimates. In addition to AUCs, other performance indicators, such as correlation coefficients, were reported in 60% of studies, but were infrequently defined or interpreted. An investigation of sources of heterogeneity did not reveal significant variation in reporting practices as a function of risk assessment approach (actuarial vs. structured professional judgment), study authorship, geographic location, type of journal (general vs. specialized audience), sample size, or year of publication. Findings suggest a need for standardization of predictive validity reporting to improve comparison across studies and instruments. PMID:23444299

Singh, Jay P; Desmarais, Sarah L; Van Dorn, Richard A

2013-01-01

346

Item Validation of Online Postsecondary Courses: Rating the Proximity between Similarity and Dissimilarity among Item Pairs (Validation Study Series I: Multidimensional Scaling)  

ERIC Educational Resources Information Center

The purpose of this study was to identify and validate items applicable to evaluating online courses at the postsecondary level. Items were derived from a review of the literature. Four judges rated the similarity of the items by making pair-wise comparisons utilizing multidimensional scaling (MDS). The study consisted of five stages. Stage I…

Seok, Soonhwa

2009-01-01

347

Theoretical and Numerical Studies of Noncontinuum Gas-Phase Heat Conduction in Micro\\/Nano Devices  

Microsoft Academic Search

This article presents a comprehensive study of various modeling techniques for noncontinuum gas-phase heat conduction encountered in micro\\/nano devices over a broad range of Knudsen number. A new slip model is proposed for slip flows and an analytical approach is developed for collisionless steady-state heat conduction inside a fully diffuse enclosure. Excellent agreements with direct simulation Monte Carlo (DSMC) simulations

Taishan Zhu; Wenjing Ye

2010-01-01

348

Conductance of Alkanedithiol Single-Molecule Junctions: A Molecular Dynamics Study  

Microsoft Academic Search

We study the formation and conductance of alkanedithiol molecular wire junctions using density- functional based molecular dynamics and non-equilibrium Green's function techniques. The stretch- ing of the junction involves straightening of the wire, migration of thiol end-groups on the Au contact surfaces and pulling out of Au atoms. The low-bias conductance traces show clear plateaux which magnitude is found to

Magnus Paulsson; Casper Krag; Thomas Frederiksen; Mads Brandbyge

2009-01-01

349

Molecular dynamics studies of material property effects on thermal boundary conductance.  

PubMed

Thermal boundary resistance (inverse of conductance) between different material layers can dominate the overall thermal resistance in nanostructures and therefore impact the performance of the thermal property limiting nano devices. Because relationships between material properties and thermal boundary conductance have not been fully understood, optimum devices cannot be developed through a rational selection of materials. Here we develop generic interatomic potentials to enable material properties to be continuously varied in extremely large molecular dynamics simulations to explore the dependence of thermal boundary conductance on the characteristic properties of materials such as atomic mass, stiffness, and interfacial crystallography. To ensure that our study is not biased to a particular model, we employ different types of interatomic potentials. In particular, both a Stillinger-Weber potential and a hybrid embedded-atom-method + Stillinger-Weber potential are used to study metal-on-semiconductor compound interfaces, and the results are analyzed considering previous work based upon a Lennard-Jones (LJ) potential. These studies, therefore, reliably provide new understanding of interfacial transport phenomena particularly in terms of effects of material properties on thermal boundary conductance. Our most important finding is that thermal boundary conductance increases with the overlap of the vibrational spectra between metal modes and the acoustic modes of the semiconductor compound, and increasing the metal stiffness causes a continuous shift of the metal modes. As a result, the maximum thermal boundary conductance occurs at an intermediate metal stiffness (best matched to the semiconductor stiffness) that maximizes the overlap of the vibrational modes. PMID:23715116

Zhou, X W; Jones, R E; Duda, J C; Hopkins, P E

2013-07-14

350

Concurrent validity of the Learning and Study Strategies Inventory (LASSI): a study of African American precollege students.  

PubMed

Concurrent validation procedures were employed, using a sample of African American precollege students, to determine the extent to which scale scores obtained from the first edition of the Learning and Study Strategies Inventory (LASSI) were appropriate for diagnostic purposes. Data analysis revealed that 2 of the 10 LASSI scales (i.e., Anxiety and Test Strategies) significantly correlated with a measure of academic ability. These results suggested that scores obtained from these LASSI scales may provide valid assessments of African American precollege students’ academic aptitude. Implications for teachers, school counselors, and developmental studies professionals were discussed. PMID:22454973

Flowers, Lamont A; Bridges, Brian K; Moore III, James L

2012-01-01

351

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

352

Public summaries of feasibility studies conducted for the trinidad LNG project. Export trade information  

SciTech Connect

The study, conducted by The M. W. Kellog Company, was funded by the U.S. Trade and Development Agency on behalf of the National Gas Company of Trinidad and Tobago. It shows the results of Project Definition Phase which was implemented as a follow-up to two previous feasibility studies which were conducted for a LNG plant in Trinidad. The objective of this report is to develop a project design basis and implementation plan plus a cost estimate. The study is divided into the following sections: (1) Introduction; (2) Project Design Basis; (3) Seismic Hazard Assessment; (4) Geotechnical; and (5) Environmental Assessment.

NONE

1995-04-01

353

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

ERIC Educational Resources Information Center

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…

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

2011-01-01

354

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

Microsoft Academic Search

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,

Gbolahan Gbadamosi; Patricia Joubert

2005-01-01

355

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 ...

356

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

SciTech Connect

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.

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

357

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

358

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

SciTech Connect

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.

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

359

AC Conductivity Studies in Lithium-Borate Glass Containing Gold Nanoparticles  

NASA Astrophysics Data System (ADS)

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.

Shivaprakash, Y.; Anavekar, R. V.

2011-07-01

360

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

361

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

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

362

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

PubMed

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

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

2014-05-27

363

Collection and validation of data in the United Kingdom Atomic Energy Authority mortality study.  

PubMed Central

The United Kingdom Atomic Energy Authority mortality study investigated the relation between mortality and recorded exposure to ionising radiation among employees working at the authority's seven establishments between 1946 and 1979. This report examines the design of the study and methods of data collection and validation. The completeness of the study population was deemed to be unsatisfactory at two establishments, where records of employment before 1965 had been destroyed. Assessment of the magnitude of the deficit led to the conclusion that the data from these establishments were too incomplete for inclusion in the mortality analysis. At the other establishments validation showed that the data collected were accurate and unbiased. Certain characteristics of the 39 546 employees included in the mortality analysis were identified which were relevant in interpreting the findings. PMID:3926231

Fraser, P; Booth, M; Beral, V; Inskip, H; Firsht, S; Speak, S

1985-01-01

364

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

PubMed

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

Dazzi, Carla; Pedrabissi, Luigi

2009-12-01

365

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

NASA Astrophysics Data System (ADS)

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.

Anilkumar, T.; Ramesan, M. T.

2014-10-01

366

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

PubMed Central

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

2014-01-01

367

A catch-up validation study of an in vitro skin irritation test method using reconstructed human epidermis LabCyte EPI-MODEL24.  

PubMed

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

Kojima, Hajime; Katoh, Masakazu; Shinoda, Shinsuke; Hagiwara, Saori; Suzuki, Tamie; Izumi, Runa; Yamaguchi, Yoshihiro; Nakamura, Maki; Kasahawa, Toshihiko; Shibai, Aya

2014-07-01

368

Turkish lupusPRO: cross-cultural validation study for lupus.  

PubMed

LupusPRO is a disease-targeted patient-reported outcome measure that was developed and validated from and among US patients with systemic lupus erythematosus (SLE). We herein report the results of the cross-cultural adaptation and validation study of the Turkish translated version of the LupusPRO. Turkish LupusPRO and the Medical Outcomes Study Short Form (SF-36) (Turkish) were administered to the Turkish lupus patients. Disease activity was ascertained using the physician global assessment (PGA), Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI), and flare (defined by LFA-Lupus Foundation of America). Disease damage was assessed with Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI). Also, second Turkish LupusPRO tests were given to the patients to be completed within 2-3 days and sent back to us. Internal consistency reliability, test-retest reliability, and convergent and criterion validity (against disease activity or health status) were tested. All reported p values are two-tailed. The conceptual framework of the LupusPRO was evaluated using confirmatory factor analysis appropriate for categorical data. One hundred two SLE subjects (94 % women) were enrolled. The median (IQR) age and mean disease duration (±SD) were 38.5 (18) years and 60.3 (±56.3) months, respectively. The mean?±?SD, SLEDAI, and SDI scores were 3.1?±?3.7 and 0.52?±?0.75, respectively. There were 25 patients who had flares at the time of study. Forty-two patients with no change in their health status completed and sent back the second LupusPRO test and were included in the test-retest analysis. Test-retest reliability of LupusPRO domains ranged from 0.87 to 0.97, while internal consistency reliability of the domains ranged from 0.63 to 0.94. Convergent validity with corresponding domains of SF-36 was present. Health-related quality-of-life domains performed well against disease activity measures (PGA, total SLEDAI, LFA flare, and SF-6D-overall health status), establishing its criterion validity. Item-to-factor loadings representing the hypothesized item-to-scale relationships were satisfactory. The model fit for the hypothesized item-to-scale relationships was also satisfactory. The Turkish version of the LupusPRO is valid and appears to perform comparably to the English and Spanish language versions. It can be used as a patient-reported outcome parameter in clinical trials, as well as longitudinal studies for testing responsiveness to change. PMID:23934384

Kaya, Arif; Goker, Berna; Cura, Elife Senem; Tezcan, Mehmet Engin; Tufan, Abdurrahman; Mercan, R?dvan; Bitik, Berivan; Haznedaroglu, Seminur; Ozturk, Mehmet Akif; Mikolaitis-Preuss, Rachel A; Block, Joel A; Jolly, Meenakshi

2014-08-01

369

Forensic validation of the Genplex SNP typing system—Results of an inter-laboratory study  

Microsoft Academic Search

We present data from a multi-laboratory validation study of the Genplex typing system [C. Phillips, et al., Evaluation of the Genplex SNP typing system and a 49plex forensic marker panel, Forensic Sci. Int.: Genet. 1 (2) (2007) 180–185.] (Applied Biosystems), which interrogates a subset of 48 SNPs selected from the panel of 52 previously developed for forensic analysis by the

Esther Musgrave-Brown; David Ballard; Manuel Fondevila Álvarez; Rixun Fang; Cheryl Harrison; Chris Phillips; Yogesh Prasad; Bea Sobrino Rey; Catherine Thacker; Joerg Wiluhn; Angel Carracedo; Peter M. Schneider; Denise Syndercombe Court

2008-01-01

370

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

Microsoft Academic Search

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

Allan I. Abrams; Larry M. Siegel

1978-01-01

371

Validation Studies on Interfacing Techniques for Connecting Fully Digital and Analog Real Time Simulators  

NASA Astrophysics Data System (ADS)

This paper describes interfacing techniques for connecting fully digital and analog real time simulators. Three types of interfacing techniques, which are applicable for long transmission lines, short transmission lines, and transformers, are developed and tested. Further, these interfacing techniques are validated through detailed simulation studies carried out by actually connecting a fully digital real-time simulator (HYPERSIM) and an analog simulator (PSA). The interfacing technique using a transformer is shown to be quite promising for practical applications.

Verma, Suresh Chand; Odani, Hideki; Ogawa, Shigeaki; Kuroda, Kenichi; Kono, Yoshiyuki

372

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

ERIC Educational Resources Information Center

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 =…

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

2007-01-01

373

WHO Study on the reliability and validity of the alcohol and drug use disorder instruments: overview of methods and results  

Microsoft Academic Search

The WHO Study on the reliability and validity of the alcohol and drug use disorder instruments is an international study which has taken place in 12 centres in ten countries, aiming to test the reliability and validity of three diagnostic instruments for alcohol and drug use disorders: the Composite International Diagnostic Interview (CIDI), the Schedules for Clinical Assessment in Neuropsychiatry

B Üstün; W Compton; D Mager; T Babor; O Baiyewu; S Chatterji; L Cottler; A Gö?ü?; V Mavreas; L Peters; C Pull; J Saunders; R Smeets; M.-R Stipec; R Vrasti; D Hasin; R Room; W Van den Brink; D Regier; J Blaine; B. F Grant; N Sartorius

1997-01-01

374

A Validation Study for an Enzyme Analytical Method Xuan Liu advised by Helle Rootzen and Peter Thyregod  

E-print Network

Thyregod from Novozymes. This thesis deals with inter-laboratory validation study with mixed linear model. Different variance structures of Linear Mixed Models are presented, such as Homogeneous Variance Model-laboratory Validation Study, Linear Mixed Model, Homogeneous Vari- ance Model, Heterogeneous Variance Model

375

Performance and Persistence: A Validity Study of the SAT for Students with Disabilities. College Board Report No. 91-3.  

ERIC Educational Resources Information Center

This study evaluated the validity of the Scholastic Aptitude Test (SAT) in predicting overall performance and persistence in college of students with disabilities, especially those participating in special test administrations. An earlier validity study by H. Braun, M. Ragosta, and B. Kaplan (1986) had used grade point average (GPA) in college to…

Ragosta, Marjorie; And Others

376

Initial Reliability and Validity of the Perceived Social Competence Scale  

ERIC Educational Resources Information Center

Objective: This study describes the development and validation of a perceived social competence scale that social workers can easily use to assess children's and youth's social competence. Method: Exploratory and confirmatory factor analyses were conducted on a calibration and a cross-validation sample of youth. Predictive validity was also…

Anderson-Butcher, Dawn; Iachini, Aidyn L.; Amorose, Anthony J.

2008-01-01

377

A study of rock matrix diffusion properties by electrical conductivity measurements  

SciTech Connect

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.

Ohlsson, Y.; Neretnieks, I.

1999-07-01

378

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

PubMed

A prospective study of upper limb nerve conduction velocity was performed in 39 subjects (9 males, 30 females, mean age 46.8 years) with idiopathic Raynaud's phenomenon (RP) and 18 patients (3 males, 15 females, mean age 49.9 years) with RP secondary to systemic sclerosis (SS). Five subjects with idiopathic RP (13%) showed slowing of sensory conduction velocity (SCV) of the distal median nerve, associated with delayed distal motor latency (DML) of the same nerve in three patients, without clinical signs or symptoms of carpal tunnel syndrome (CTS). Three patients with secondary RP (17%) had reduction of SCV of the distal median nerve, associated with increased DML of the same nerve in one and with clinically silent slowing of SCV of the ulnar nerve in two (11%). Mean distal SCVs of the median nerve were significantly lower and mean DMLs were significantly higher in both groups with respect to a control group. Mean distal conduction of the ulnar nerve was significantly slower only in the group with secondary RP. No slowing was observed in the proximal part of any nerve. It seems likely that patients with idiopathic RP have slowing of conduction in the distal part of the median nerve, along the carpal tunnel. Since slowing does not occur in all parts of the nerves of the hand, it cannot be related to acral vasomotor disturbances, but to local or systemic factors. In contrast, patients with secondary RP had slowing of median and ulnar nerve conduction velocity, presumably related to subclinical distal peripheral neuropathy. A nerve conduction study of the hand could be useful in cases of suspected secondary origin of RP. In idiopathic RP, slowing of conduction may only affect the median nerve, whereas in secondary RP it may affect other nerves of the hand. PMID:10984133

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

2000-01-01

379

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

PubMed

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

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

2012-09-01

380

Biomarker Validation of Reports of Recent Sexual Activity: Results of a Randomized Controlled Study in Zimbabwe  

PubMed Central

Challenges in the accurate measurement of sexual behavior in human immunodeficiency virus (HIV) prevention research are well documented and have prompted discussion about whether valid assessments are possible. Audio computer-assisted self-interviewing (ACASI) may increase the validity of self-reported behavioral data. In 2006–2007, Zimbabwean women participated in a randomized, cross-sectional study that compared self-reports of recent vaginal sex and condom use collected through ACASI or face-to-face interviewing (FTFI) with a validated objective biomarker of recent semen exposure (prostate-specific antigen (PSA) levels). Of 910 study participants, 196 (21.5%) tested positive for PSA, an indication of semen exposure during the previous 2 days. Of these 196 participants, 23 (11.7%) reported no sex in the previous 2 days, with no difference in reported sexual activity between interview modes (12.5% ACASI vs. 10.9% FTFI; Fisher's exact test: P?=?0.72). In addition, 71 PSA-positive participants (36.2%) reported condom-protected vaginal sex only; their reports also indicated no difference between interview modes (33.7% ACASI vs. 39.1% FTFI; P?=?0.26). Only 52% of PSA-positive participants reported unprotected sex during the previous 2 days. Self-report was a poor predictor of recent sexual activity and condom use in this study, regardless of interview mode, providing evidence that such data should be interpreted cautiously. PMID:19741042

Steiner, Markus J.; Gallo, Maria F.; Warner, Lee; Hobbs, Marcia M.; van der Straten, Ariane; Chipato, Tsungai; Macaluso, Maurizio; Padian, Nancy S.

2009-01-01

381

[Study of sinus node function and atrioventricular conduction in patients with chagas disease (author's transl)].  

PubMed

In order to detect possible abnormalities in sinus node function and atrio-ventricular conduction, one hundred and fourty three chagasic patients were subjected to electrophysiologic and pharmacologic studies. These patients were placed in four categories based on the their clinical, hemodynamic and angiographic characteristics. The chagasic patient without cardiac involvement (group IA), had no detectable abnormalities. Ten percent of those patients with early myocardial damage (group IB), had impaired sinus node automaticity. In three percent, the autonomic innervation was also altered and four percent had abnormally prolonged atrio-ventricular conduction. Among chagasic patients with abnormal EKG'S without heart failure (Group II), 45% had impaired sinus node automaticity, autonomic innervation was altered in 12%, and atrio-ventricular conduction was prolonged in 37%. Sinus node automaticity was impaired in 22% of those patients with abnormal EKG'S and heart failure (Group III). Autonomic innervation was altered in 33%, and atrio-ventricular conduction was prolonged in 47%. We conclude that over half of our patients with abnormal EKG'S will eventually require permanent pacing. Therefore, in these chagasic patients sinus node function and atrioventricular conduction should be routinely studied. PMID:7114967

Carrasco, H A; Mora, R; Inglessis, G; Contreras, J M; Marval, J; Fuenmayor, A

1982-01-01

382

Host genetic factors in American cutaneous leishmaniasis: a critical appraisal of studies conducted in an endemic area of Brazil  

PubMed Central

American cutaneous leishmaniasis (ACL) is a vector-transmitted infectious disease with an estimated 1.5 million new cases per year. In Brazil, ACL represents a significant public health problem, with approximately 30,000 new reported cases annually, representing an incidence of 18.5 cases per 100,000 inhabitants. Corte de Pedra is in a region endemic for ACL in the state of Bahia (BA), northeastern Brazil, with 500-1,300 patients treated annually. Over the last decade, population and family-based candidate gene studies were conducted in Corte de Pedra, founded on previous knowledge from studies on mice and humans. Notwithstanding limitations related to sample size and power, these studies contribute important genetic biomarkers that identify novel pathways of disease pathogenesis and possible new therapeutic targets. The present paper is a narrative review about ACL immunogenetics in BA, highlighting in particular the interacting roles of the wound healing gene FLI1 with interleukin-6 and genes SMAD2 and SMAD3 of the transforming growth factor beta signalling pathway. This research highlights the need for well-powered genetic and functional studies on Leishmania braziliensis infection as essential to define and validate the role of host genes in determining resistance/susceptibility regarding this disease. PMID:24863979

Castellucci, Léa Cristina; de Almeida, Lucas Frederico; Jamieson, Sarra Elisabeth; Fakiola, Michaela; de Carvalho, Edgar Marcelino; Blackwell, Jenefer Mary

2014-01-01

383

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 ...

384

A Theoretical Study on Proton Conduction Mechanism in BaZrO3 Perovskite  

E-print Network

Chapter 14 A Theoretical Study on Proton Conduction Mechanism in BaZrO3 Perovskite Taku Onishi mechanism in BaZrO3 perovskite, from the viewpoint of energetics and bonding. The calculated activation investigated hydrogen defect around zirconium vacancy. 14.1 Introduction The perovskite-type cubic BaZrO3 shows

Helgaker, Trygve

385

Conducting a Follow-Up Study of Students in Writing Courses.  

ERIC Educational Resources Information Center

Recognizing the need to assess the long term effects of composition instruction, a study was conducted to determine whether students could remember significant aspects of a writing course up to two years later, to discern their assessment of the effects of the course on their subsequent writing attitudes, and to solicit suggestions based on…

Smith, Eugene

386

Meta-Analytic Synthesis of Studies Conducted at Marzano Research Laboratory on Instructional Strategies  

ERIC Educational Resources Information Center

This is a summary of 300 plus studies from Marzano Research Laboratory (MRL) on instructional strategies. This report synthesizes a series of action research projects conducted between the fall of 2004 and the spring of 2009. The data used for analysis can be found in MRL's Action Research Meta-Analysis Database. Appended are: (1) Instructions for…

Haystead, Mark W.; Marzano, Robert J.

2009-01-01

387

Conduct problems and early cannabis initiation: a longitudinal study of gender differences  

Microsoft Academic Search

Abstract Aim. To investigate the relationship between early conduct problems and early onset of cannabis use, with special emphasis on possible gender differences. Design. A prospective longitudinal study of a national sample of 2436 adolescents. The sample was followed up over a year and a half, when the adolescents were in their early teens. Setting. Norway. Measurements. On the basis

Willy Pedersen; Arne Mastekaasa; Lars Wichstrøm

2001-01-01

388

Conducting Studies of Transfer of Learning: A Practical Guide. Final Report.  

ERIC Educational Resources Information Center

This document is a guide for use by the practical researcher concerned with conducting studies of transfer of learning from pretraining of pilots in ground-based environments to performance in aircraft. While the material addresses principally transfer of learning of pilots, many of the issues should be applicable to other contexts, to include…

Payne, Thomas A.

389

Study of thermally reworkable epoxy materials and thermal conductivity enhancement using carbon fiber for electronics packaging  

Microsoft Academic Search

Epoxy resins are widely used as the underfill materials for the integrated circuit (IC) chips for the reliability enhancement and as the binder of electrically conductive adhesives (ECA). However, cured epoxy materials are infusible and insoluble networks which is a problem for the repair of a printed circuit board assembly packaged with epoxy materials. In this study, six diepoxides containing

Haiying Li

2003-01-01

390

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

PubMed Central

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

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

391

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.

392

A Cross-Ethnic Validity Study of the Shortform Assessment for Children (SAC)  

ERIC Educational Resources Information Center

Objective: This study examined the cross-ethnic measurement equivalence of the Shortform Assessment for Children (SAC) using a sample of 562 African American and 692 White children. Method: A prospective, two-panel survey design was used in this study. Baseline and 6-month follow-up data were used to conduct analyses of the reliability and…

Tyson, Edgar H.; Glisson, Charles

2005-01-01

393

Validation of the Use of Nonnaive Surgically Catheterized Rats for Pharmacokinetics Studies  

PubMed Central

Although large animals, such as dogs and nonhuman primates, often are used for more than 1 pharmacokinetics study, common practice is to use only naive rodents for pharmacokinetics studies. We undertook a series of studies to validate whether surgically cannulated nonnaive rats could be used again after a 7-d washout. When vascular catheters are cared for appropriately, we find that they remain patent for more than 2 wk, with negligible drug carryover. Hematocrit decreased approximately 11% after pharmacokinetics studies but rebounded to prestudy levels after a 7-d washout. We empirically tested whether drugs known to alter drug disposition (1-aminobenzotriazole and quinidine) had residual effects on drug disposition after a 7-d washout and found that they did not. This finding suggests that after a 7-d washout, nonnaive rats likely would produce pharmacokinetics data similar to those of naive rats. We also tested reference compounds in naive and nonnaive rats and found no difference in pharmacokinetics parameters. Using surgically cannulated rats for a second study was feasible because of the relatively noninvasive nature of pharmacokinetics sampling (unrestrained rats attached to automated blood samplers). In addition, reusing surgically altered animals yields considerable cost savings. Our studies indicate that pharmacokinetics parameters did not differ significantly between naive and nonnaive rats. Cost–benefit analysis, monetary considerations, and validation studies support using rats for a second study after a 7-d washout period. PMID:19049252

Deshmukh, Sujal V; Durston, Jessica; Shomer, Nirah H

2008-01-01

394

The methodological quality of three foundational law enforcement drug influence evaluation validation studies  

PubMed Central

Background A Drug Influence Evaluation (DIE) is a formal assessment of an impaired driving suspect, performed by a trained law enforcement officer who uses circumstantial facts, questioning, searching, and a physical exam to form an unstandardized opinion as to whether a suspect’s driving was impaired by drugs. This paper first identifies the scientific studies commonly cited in American criminal trials as evidence of DIE accuracy, and second, uses the QUADAS tool to investigate whether the methodologies used by these studies allow them to correctly quantify the diagnostic accuracy of the DIEs currently administered by US law enforcement. Results Three studies were selected for analysis. For each study, the QUADAS tool identified biases that distorted reported accuracies. The studies were subject to spectrum bias, selection bias, misclassification bias, verification bias, differential verification bias, incorporation bias, and review bias. The studies quantified DIE performance with prevalence-dependent accuracy statistics that are internally but not externally valid. Conclusion The accuracies reported by these studies do not quantify the accuracy of the DIE process now used by US law enforcement. These studies do not validate current DIE practice. PMID:24188398

2013-01-01

395

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

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

2012-01-01

396

An approach to model validation and model-based prediction -- polyurethane foam case study.  

SciTech Connect

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

Dowding, Kevin J.; Rutherford, Brian Milne

2003-07-01

397

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)

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.

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

2014-11-01

398

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

PubMed

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. PMID:25430143

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

2014-11-01

399

Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure Validation Simulation Study  

NASA Technical Reports Server (NTRS)

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.

Murdoch, Jennifer L.; Bussink, Frank J. L.; Chamberlain, James P.; Chartrand, Ryan C.; Palmer, Michael T.; Palmer, Susan O.

2008-01-01

400

The importance of choosing the appropriate matrix to validate a bioanalytical method according to the study needs.  

PubMed

Sylvain Lachance is a Bioanalytical Scientific Expert in the Bioanalytical Division of inVentiv Health Clinical Quebec City's (Canada) site, a CRO offering clinical, commercial and consulting services to the healthcare industry. He is responsible for following up on the conduct of bioanalytical method development activities by enhancing the scientific and technical knowledge of the researchers, bioanalytical project coordinators and of the laboratory technicians. He assists bioanalytical project coordinators in investigations during bioanalyses and method validations. He has been working in the Bioanalytical Division of inVentiv Health Clinical for over 16 years, working as a Research Scientist, Chromatographic Specialist and Scientific Expert. He has worked on multiple method developments in HPLC and LC-MS/MS, specifically on troubleshooting. He has been involved in more than 70 posters and publications in the bioanalytical field for different scientific meetings. Ann Lévesque obtained her PhD in Biochemistry at the Université Laval in Québec City in 1994 studying the biological actions of peptide analogs of the gastrin releasing peptide in the growth inhibition of cancer cells. Prior to joining inVentiv Health Clinical, she held management positions at other Contract Research Organizations. Her publications include over 100 posters, 17 scientific articles and book chapters in the clinical biochemistry and bioanalytical fields. Within inVentiv Health, Dr. Lévesque is responsible for managing the R&D and sample analysis teams performing bioanalytical analysis of small molecules and peptides. She is also acting as the Biomedical Laboratory Director accountable for the oversight of all activities related to the safety testing of samples from subjects enrolled in early stage clinical trials. Since joining the Bioanalytical Division, Dr. Lévesque has been instrumental in the great success of the laboratory by developing a culture of quality, innovation and value. Validation guidelines from different agencies mainly recommend that matrix effect should be studied with hemolyzed and hyperlipidemic samples, while the European agency requires also to investigate matrix effect on special population. When studies are done in countries with different dietary habits, or when a medication is administered to decrease the concentration of the endogenous compounds, should the matrix effect in these conditions be evaluated? Herein, three case studies are described to show the importance of choosing the appropriate matrix for the bioanalytical method validations and for their use to analyze the study samples according to the conditions required by the clinical trials. The case studies presented are related to the use of the testosterone, Omega-3 and cortisol methods. PMID:25529879

Lachance, Sylvain; Lévesque, Ann

2014-12-01

401

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

402

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

NASA Astrophysics Data System (ADS)

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.

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

2002-09-01

403

New technologies to support NASA's Mission to Planet Earth satellite remote sensing product validation: use of an unmanned autopiloted vehicle (UAV) as a platform to conduct remote sensing  

Microsoft Academic Search

As part of the US Global Change program, NASA has initiated its Mission to Planet Earth Program (MTPE) which requires continuous global satellite measurements over an extended 15 years period. Various US and International Earth Observing Satellites will be launched during this period. To ensure continuity of the measurements, a significant instrument calibration and product validation effort is required and

Patrick L. Coronado; Fran Stetina; Dan Jacob

1998-01-01

404

Conducting school-based research: lessons learned from an after-school intervention study.  

PubMed

Although conducting research within schools poses challenges, the knowledge gained from studying children within the context of their lives and the availability of participants makes the school site a valuable site for research with children. The process of scheduling the research program, identifying an appropriate school site, recruiting and retaining participants, and knowing the optimal times and methods of contact is paramount to enhancing the success of a school based study. PMID:22153147

White, Laura Santangelo

2012-01-01

405

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

PubMed

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

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

2014-01-01

406

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

PubMed Central

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

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

2014-01-01

407

Knowledge, attitudes and behavior of Italian mothers towards oral health: questionnaire validation and results of a pilot study  

PubMed Central

Summary Aims The study is focused on the analysis of knowledge, attitudes and behaviors of Italian mothers in regards to their oral health, deepening the understanding of how the initiation of habits and behaviors for a healthy lifestyle may influence the empowerment process of their children. Methods The questionnaire was composed by 14 sections and has been conducted using an online questionnaire on the mothers association’s website. Reliability analysis was tested and content validity was evaluated using Cronbach’s alpha to check internal consistency with the intention to obtain no misunderstanding results. Statistical analysis was performed through SPSS 19.0. Results The total number of the compiled questionnaires was 192. The highest value of the Cronbach’s alpha is obtainable in Section 13 (Quality of Life in relation to dental health between 8–17 years old kids) with a value of 0.998 (on 5 items). The total value of the Cronbach’s alpha considering the part of questionnaire dedicated only to the mothers that have more than 18 years old children is 0.490 on 116 items. Considering all the sections of the questionnaire on 134 items and 127 questions, we get an alpha value of 0.784. Conclusions The questionnaire for the mothers showed a good reliability in the pilot study and it seems it made good results in terms of internal coherence and validity. The online administration allowed the opportunity to optimize the data collection avoiding complications with papers and it offers potentially, a tool able to rapidly gather a vast sample in which to perfect other studies. PMID:23087789

Nardi, Gianna Maria; Giraldi, Guglielmo; Lastella, Paola; La Torre, Giuseppe; Saugo, Emilia; Ferri, Francesca; Pacifici, Luciano; Ottolenghi, Livia; Guerra, Fabrizio; Polimeni, Antonella

2012-01-01

408

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

NASA Astrophysics Data System (ADS)

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.

Ouyang, Tao; Zhang, Xiaoliang; Hu, Ming

2015-01-01

409

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

PubMed

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

Ouyang, Tao; Zhang, Xiaoliang; Hu, Ming

2015-01-16

410

Measuring Students' Writing Ability on a Computer-Analytic Developmental Scale: An Exploratory Validity Study  

ERIC Educational Resources Information Center

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…

Burdick, Hal; Swartz, Carl W.; Stenner, A. Jackson; Fitzgerald, Jill; Burdick, Don; Hanlon, Sean T.

2013-01-01

411

Theoretical Considerations for Extracting Meaning from Personal Profile System Data: The Need for Independent Construct Validity Studies.  

ERIC Educational Resources Information Center

The Personal Profile System (PPS) is a psychological testing instrument that has been widely used. The construct validity of the PPS was studied through a review of the literature. This paper organizes the literature review into three broad categories: the background of the PPS; the reliability of the PPS; and the validity of the PPS. The PPS is a…

Henkel, Thomas George; Wilmoth, James Noel

412

Validation Study of a Method for Assessing Complex Ill-Structured Problem Solving by Using Causal Representations  

ERIC Educational Resources Information Center

The important but little understood problem that motivated this study was the lack of research on valid assessment methods to determine progress in higher-order learning in situations involving complex and ill-structured problems. Without a valid assessment method, little progress can occur in instructional design research with regard to designing…

Eseryel, Deniz; Ifenthaler, Dirk; Ge, Xun

2013-01-01

413

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

PubMed Central

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

2010-01-01

414

The validity of a questionnaire-based epidemiological study of occupational dermatosis.  

PubMed

The aim of this study was to evaluate the validity of a questionnaire and medical anamnesis to identify persons with dermatitis in an occupational setting. The design was a clinical epidemiological cross-sectional study. The study was performed between the second and fourth week of January 2001. A questionnaire was followed a week later by a medical occupational interview and a clinical dermatological examination, including a comprehensive patch test with potential workplace chemicals. The anamnesis and the clinical examination were made independently by occupational and dermatological physicians, and the skin examination was performed blinded to anamnestic data. The setting was the mother plants of a Danish-based international company producing wind turbine systems. The study population was a workplace cohort, highly exposed to epoxy resin systems and other chemicals, and totalled 724 production workers at 4 facilities. The rate of participation was 84.7%. Using enquete questions of current skin rash against the clinical presence of dermatitis, we found a sensitivity of 22% and a specificity of 89%, compared to 45% and 87%, respectively, when the anamnestic work history, taken by an occupational physician, was the screening parameter. Using 'workplace periodic prevalence' of dermatitis, we found sensitivities in the range of 63-76% by a questionnaire and 70-83% by medical anamnesis. Questionnaire screening by skin symptoms gave the highest values for redness, a sensitivity of 33% and a specificity of 76%, and decreasing validity parameters as more symptoms were added to the list of screening questions. We found that the use of a questionnaire and medical anamnesis were problematic, when the purpose was screening for contact dermatitis and allergy, in this industrial cohort manufacturing reinforced plastic products. But these instruments might be useful for epidemiological surveillance, when the questionnaire has been validated in the given occupational setting. PMID:17026696

Carstensen, Ole; Rasmussen, Kurt; Pontén, Ann; Gruvberger, Birgitta; Isaksson, Marléne; Bruze, Magnus

2006-11-01

415

Validation of Welding Curriculum Manual.  

ERIC Educational Resources Information Center

A study was conducted to validate the welding curriculum materials developed and published by the Oklahoma State Department of Vocational and Technical Education. Twelve instructors collected achievement data (unit tests, assignment sheets, and evaluation forms) concerning the performance of 280 students on a total of 46 instructional units. Item…

Stone, Sheila D.

416

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

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Examined the hydraulic conductivity evolution as function of dry density of Tunisian clay soil. Black-Right-Pointing-Pointer Follow the hydraulic conductivity evolution at long-term of three clay materials using the waste solution (pH=2.7). Black-Right-Pointing-Pointer Determined how compaction affects the hydraulic conductivity of clay soils. Black-Right-Pointing-Pointer Analyzed the concentration of F and P and examined the retention of each soil. - Abstract: Three natural clayey soils from Tunisia were studied to assess their suitability for use as a liner for an acid waste disposal site. An investigation of the effect of the mineral composition and mechanical compaction on the hydraulic conductivity and fluoride and phosphate removal of three different soils is presented. The hydraulic conductivity of these three natural soils are 8.5 Multiplication-Sign 10{sup -10}, 2.08 Multiplication-Sign 10{sup -9} and 6.8 Multiplication-Sign 10{sup -10} m/s for soil-1, soil-2 and soil-3, respectively. Soil specimens were compacted under various compaction strains in order to obtain three wet densities (1850, 1950 and 2050 kg/m{sup 3}). In this condition, the hydraulic conductivity (k) was reduced with increasing density of sample for all soils. The test results of hydraulic conductivity at long-term (>200 days) using acidic waste solution (pH = 2.7, charged with fluoride and phosphate ions) shows a decrease in k with time only for natural soil-1 and soil-2. However, the specimens of soil-2 compressed to the two highest densities (1950 and 2050 kg/m{sup 3}) are cracked after 60 and 20 days, respectively, of hydraulic conductivity testing. This damage is the result of a continued increase in the internal stress due to the swelling and to the effect of aggressive wastewater. The analysis of anions shows that the retention of fluoride is higher compared to phosphate and soil-1 has the highest sorption capacity.

Hamdi, Noureddine, E-mail: nouryhamdi@gmail.com [Centre National des Recherches en Science des Materiaux, Borj Cedria Techno-Park, B.P. 95-2050, Hammam Lif, Tunis (Tunisia); Srasra, Ezzeddine [Centre National des Recherches en Science des Materiaux, Borj Cedria Techno-Park, B.P. 95-2050, Hammam Lif, Tunis (Tunisia)

2013-01-15

417

Electrochemical studies of thin films of conducting polymers and conducting polymer composites deposited on metal and semiconductor electrodes  

NASA Technical Reports Server (NTRS)

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.

Nagasubramanian, G.; Di Stefano, S.; Moacanin, J.

1987-01-01

418

The OECD program to validate the rat uterotrophic bioassay. Phase 2: dose-response studies.  

PubMed Central

The Organisation for Economic Co-operation and Development has completed phase 2 of an international validation program for the rodent uterotrophic bioassay. The purpose of the validation program was to demonstrate the performance of two versions of the uterotrophic bioassay, the immature female rat and the adult ovariectomized rat, in four standardized protocols. This article reports the dose-response studies of the validation program; the coded single-dose studies are reported in an accompanying paper. The dose-response study design used five selected weak estrogen agonists, bisphenol A, genistein, methoxychlor, nonylphenol, and o,p -DDT. These weak agonists were administered in a prescribed series of doses to measure the performance and reproducibility of the protocols among the participating laboratories. All protocols successfully detected increases in uterine weights when the weak agonists were administered. Within each protocol, there was good agreement and reproducibility of the dose response among laboratories with each substance. Substance-specific variations were observed in the influence of the route of administration on the uterine response, the potency as related to the dose producing the first statistically significant increase in uterine weights, and the maximum increase in uterine weight. Substantive performance differences were not observed between the uterotrophic bioassay versions or among the standardized protocols, and these were judged to be qualitatively equivalent. It is noteworthy that these results were reproducible under a variety of different experimental conditions (e.g., animal strain, diet, housing, bedding, vehicle, animal age), indicating that the bioassay's performance as a screen is robust. In conclusion, both the intact, immature, and adult OVX versions, and all protocols appear to be reproducible and transferable across laboratories and are able to detect weak estrogen agonists. PMID:12948896

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

2003-01-01

419

Neurological Examination of the Upper Limb: A Study of Construct Validity  

PubMed Central

Objective: We have previously demonstrated that neurological individual findings and patterns can be reliably assessed in the examination of the upper limb and also that they are related to pain, weakness, and/or numbness/tingling. This study aimed to study further aspects of the construct validity of the neurological examination. Methods: Blinded to patient-characteristics, two examiners assessed the function of 16 muscles, the sensibility in 7 territories, and the nerve-mechanosensitivity at 20 locations in 82 upper limbs. Based on anatomical patterns and pre-designed algorithms, one or both examiners rated neuropathy as “possible” or “definite” in 40 limbs and also determined the location( s). We developed and tested hypotheses on anatomically and regionally related locations of nerve afflictions (a selective vulnerability of neurons, double and multiple crush, and a tendency to regional spread) and examined the stability of the internal structure of the constructs in different situations. The interrelations of findings were analyzed by hypothesis testing and factor analyses, and the homogeneity of location profiles was analyzed by a conditional likelihood test. Results: Out of 30 limbs with related locations of neuropathy, the findings of each examiner correlated positively (gamma > 0.35) in 22/25, respectively. The patterns of the interrelations identified by the two examiners were similar, with no evidence of any heterogeneity of location profiles for either examiner. Conclusions: This study supports the validity of the physical examination. However, feasibility of its application requires the demonstration of further aspects of construct validity and a favorable influence on patient-management and/or prevention. PMID:20148172

Jepsen, Jørgen R; Laursen, Lise H; Kreiner, Svend; Larsen, Anders I

2009-01-01

420

NMR, DSC and high pressure electrical conductivity studies of liquid and hybrid electrolytes  

Microsoft Academic Search

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

P. E. Stallworth; J. J. Fontanella; M. C. Wintersgill; Christopher D. Scheidler; Jeffrey J. Immel; S. G. Greenbaum; A. S. Gozdz

1999-01-01

421

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

PubMed

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

Sadri, Rad; Ahmadi, Goodarz; Togun, Hussein; Dahari, Mahidzal; Kazi, Salim Newaz; Sadeghinezhad, Emad; Zubir, Nashrul

2014-01-01

422

Experimental study on subcooled flow boiling on heating surfaces with different thermal conductivities  

NASA Astrophysics Data System (ADS)

Subcooled flow boiling is generally characterized by high heat transfer capacity and low wall superheat, which is essential for cooling applications requiring high heat transfer rate, such as nuclear reactors and fossil boilers. In this study, subcooled flow boiling on copper and stainless steel heating surfaces was experimentally investigated from both macroscopic and microscopic points of view. Flow boiling heat flux and heat transfer coefficient were experimentally measured on both surfaces under different conditions, such as pressure, flow rate and inlet subcooling. Significant boiling heat transfer coefficient differences were found between the copper and the stainless steel heating surfaces. To explain the different flow boiling behaviors on these two heating surfaces, nucleation site density and bubble dynamics were visually observed and measured at different experimental conditions utilizing a high-speed digital video camera. These two parameters are believed to be keys in determining flow boiling heat flux. Wall superheat, critical cavity size and wall heat flux were used to correlate with nucleation site density data. Among them, wall heat flux shows the best correlation for eliminating both pressure and surface property effects. The observed nucleation site distribution shows a random distribution. When compared to the spatial Poisson distribution, similarity between them was found, while the measured nucleation site distribution is more uniform. From experimental observations, for the two surface materials investigated, which have similar surface wettability but sharply different thermal properties, bubble dynamics displayed fairly similar behavior. The obtained experimental results indicate that thermal conductivity of heating surface material plays an important role in boiling heat transfer. This is due to thermal conductivity having a significant impact on the lateral heat conduction at the heating surface and consequently temperature uniformity of the heating surface. A model was then developed and solved numerically for heat conduction at the heating surface when bubbles are present. Several key parameters which impact lateral heat conduction and surface temperature profile were studied. These parameters include material thermal conductivity, bubble size, heating surface thickness, etc. Numerical results show that, temperature profile on the heating surface tends to be more uniform and have a lower average value on a heating surface with higher thermal conductivity, which agrees well with the experimental observation.

Zou, Ling

423

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

PubMed Central

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

2014-01-01

424

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)

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.

Latorraca, G. A.; Bannister, L. H.

1974-01-01

425

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*  

PubMed Central

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

Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

2014-01-01

426

Assessing influence of conductivity in heart modelling with the aim of studying cardiovascular diseases  

NASA Astrophysics Data System (ADS)

The bidomain/monodomain equations have been widely used to model electrical activity in cardiac tissue. Here we present a sensitivity study of a crucial parameter in the bidomain model, the tissue conductivity. This study is necessary since there is no general agreement on the actual values that should be employed, mainly due to inconsistencies between the few sources of empirical information existent in the literature. Furthermore, estimates of this parameter from either imaging techniques or from experiments on isolated cardiac tissue have been inconsistent. For this study, a 3D biventricular model built from Multi-Detector Computer Tomography was used with the most relevant electrical structures, such as myocardial fiber orientation and the Purkinje system, were included. Specific ionic models for normal myocardium and for the Purkinje system were taken into account. Finite Element methods were used to solve the monodomain equation for a number of different conductivity settings. Comparative results using isochronal maps are shown in combination with statistical tests to measure changes in the sequence of electrical activation in the myocardium, conduction velocities (CV), and local activation times (LAT).

Sebastian, Rafael; Ordas, Sebastian; Plank, Gernot; Rodriguez, Blanca; Vigmond, Edward J.; Frangi, Alejandro F.

2008-03-01

427

Assessing the safety attitudes questionnaire (SAQ), German language version in Swiss university hospitals - a validation study  

PubMed Central

Background Improving patient safety has become a major focus of clinical care and research over the past two decades. An institution’s patient safety climate represents an essential component of ensuring a safe environment and thereby can be vital to the prevention of adverse events. Covering six patient safety related factors, the Safety Attitudes Questionnaire (SAQ) is a validated and widely used instrument to measure the patient safety climate in clinical areas. The objective of this study was to assess the psychometric properties of the German language version of the SAQ. Methods A survey was carried out in two University Hospitals in Switzerland in autumn 2009 where the SAQ was distributed to a sample of 406 nurses and physicians in medical and surgical wards. Following the American Educational Research Association guidelines, we tested the questionnaire validity by levels of evidence: content validity, internal structure and relations to other variables. Confirmatory factor analysis was used to examine factor structure. Cronbach’s alphas and inter-item correlations were calculated to examine internal consistency reliability. Results A total of 319 questionnaires were completed representing an overall response rate of 78.6%. For three items, the item content validity index was <0.75. Confirmatory factor analysis showed acceptable model fit (RMSEA = 0.045; CFI = 0.944) for the six-factor model. Additional exploratory factor analysis could not identify a better factor model. SAQ factor scores showed positive correlations with the Safety Organizing Scale (r = .56 - .72). The SAQ German version showed moderate to strong internal consistency reliability indices (Cronbach alpha = .65 - .83). Conclusions The German language version of the SAQ demonstrated acceptable to good psychometric properties and therefore shows promise to be a sound instrument to measure patient safety climate in Swiss hospital wards. However, the low item content validity and large number of missing responses for several items suggest that improvements and adaptations in translation are required for select items, especially within the perception of management scale. Following these revisions, psychometric properties should reassessed in a randomly selected sample and hospitals and departments prior to use in Swiss hospital settings. PMID:24016183

2013-01-01

428

A validated biorepository of retina and choroid tissues for gene expression studies.  

PubMed

Research studies on pathologies affecting the posterior segment of the eye are usually carried out either in animal models or cell lines of human origin that mimic the molecular patterns occurring in the human retina-pigment epithelium-choroid (RPC) complex in vivo. As this is not always the case, we were prompted to validate a biorepository of RPC tissues for research purposes. A PubMed literature search on "retina," "choroid," "bio-bank," or "biorepository" as keywords did not lead to any publication describing the collection and banking of samples from the RPC complex for research purposes. The possibility to obtain access to a validated collection of high quality human RPC tissues as starting material is likely to lead to more appropriate findings and treatments, which eventually may improve human ocular health. Here we show that when tissues are harvested (T <25 hours from donor death) and stored appropriately, RNAs are not degraded (RNA Integrity Number Values >8.0) and express specific genes and molecular/biochemical pathways occurring in the RPC complex. These quality controlled tissues/RNAs comprising the biorepository could therefore be used for gene expression studies by research scientists and clinicians interested in testing their hypotheses in a more appropriate setting, thus replacing studies performed on less relevant animal models and cells in vitro, and directly extrapolating the findings to human pathophysiology. PMID:25162462

Parekh, Mohit; Montanini, Luisa; Crafa, Pellegrino; Salvalaio, Gianni; Ruzza, Alessandro; Aaspõllu, Anu; Mora, Paolo; Orsoni, JelkaG; Ponzin, Diego; Ferrari, Stefano

2014-08-01

429

Psychometric validation study of the liebowitz social anxiety scale - self-reported version for Brazilian Portuguese.  

PubMed

Social Anxiety Disorder (SAD) is prevalent and rarely diagnosed due to the difficulty in recognizing its symptoms as belonging to a disorder. Therefore, the evaluation/screening scales are of great importance for its detection, with the most used being the Liebowitz Social Anxiety Scale (LSAS). Thus, this study proposed to evaluate the psychometric properties of internal consistency and convergent validity, as well as the confirmatory factorial analysis and reliability of the self-reported version of the LSAS (LSAS-SR), translated into Brazilian Portuguese, in a sample of the general population (N?=?413) and in a SAD clinical sample (N?=?252). The convergent validity with specific scales for the evaluation of SAD and a general anxiety scale presented correlations ranging from 0.21 to 0.84. The confirmatory factorial analysis did not replicate the previously indicated findings of the literature, with the difficulty being in obtaining a consensus factorial structure common to the diverse cultures in which the instrument was studied. The LSAS-SR presented excellent internal consistency (??=?0.90-0.96) and test-retest reliability (Intraclass Correlation Coefficient?=?0.81; Pearson's?=?0.82). The present findings support those of international studies that attest to the excellent psychometric properties of the LSAS-SR, endorsing its status as the gold standard. PMID:23922961

Forni dos Santos, Larissa; Loureiro, Sonia Regina; Crippa, José Alexandre de Souza; Osório, Flávia de Lima

2013-01-01

430

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

431

Injury in China: a systematic review of injury surveillance studies conducted in Chinese hospital emergency departments  

PubMed Central

Background Injuries represent a significant and growing public health concern in China. This Review was conducted to document the characteristics of injured patients presenting to the emergency department of Chinese hospitals and to assess of the nature of information collected and reported in published surveillance studies. Methods A systematic search of MEDLINE and China Academic Journals supplemented with a hand search of journals was performed. Studies published in the period 1997 to 2007 were included and research published in Chinese was the focus. Search terms included emergency, injury, medical care. Results Of the 268 studies identified, 13 were injury surveillance studies set in the emergency department. Nine were collaborative studies of which eight were prospective studies. Of the five single centre studies only one was of a prospective design. Transport, falls and industrial injuries were common mechanisms of injury. Study strengths were large patient sample sizes and for the collaborative studies a large number of participating hospitals. There was however limited use of internationally recognised injury classification and severity coding indices. Conclusion Despite the limited number of studies identified, the scope of each highlights the willingness and the capacity to conduct surveillance studies in the emergency department. This Review highlights the need for the adoption of standardized injury coding indices in the collection and reporting of patient health data. While high level injury surveillance systems focus on population-based priority setting, this Review demonstrates the need to establish an internationally comparable trauma registry that would permit monitoring of the trauma system and would by extension facilitate the optimal care of the injured patient through the development of informed quality assurance programs and the implementation of evidence-based health policy. PMID:22029774

2011-01-01

432

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

NASA Technical Reports Server (NTRS)

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.

Knox, R. J.

1978-01-01

433

Reliability of molecular breeding values for Warner-Bratzler shear force and carcass traits of beef cattle - an independent validation study.  

PubMed

Interest in genetic improvement of carcass and tenderness traits of beef cattle using genome-based selection (GS) and marker-assisted management programs is increasing. The success of such a program depends on the presence of linkage disequilibrium between the observed markers and the underlying QTL as well as on the relationship between the discovery, validation, and target populations. For molecular breeding values (MBV) predicted for a target population using SNP markers, reliabilities of these MBV can be obtained from validation analyses conducted in an independent population distinct from the discovery set. The objective of this study was to test MBV predicted for carcass and tenderness traits of beef cattle in a Canadian-based validation population that is largely independent of a United States-based discovery set. The discovery data set comprised of genotypes and phenotypes from >2,900 multibreed beef cattle while the validation population consisted of 802 crossbred feeder heifers and steers. A bivariate animal model that fitted actual phenotype and MBV was used for validation analyses. The reliability of MBV was defined as square of the genetic correlation (R(2) g) that represents the proportion of the additive genetic variance explained by the SNP markers. Several scenarios involving different starting marker panels (384, 3K, 7K, and 50K) and different sets of SNP selected to compute MBV (50, 100, 200, 375, 400, 600, and 800) were investigated. Validation results showed that the most reliable MBV (R(2) g) were 0.34 for HCW, 0.36 for back fat thickness, 0.28 for rib eye area, 0.30 for marbling score, 0.25 for yield grade, and 0.38 for Warner-Bratzler shear force across the different scenarios explored. The results indicate that smaller SNP panels can be developed for use in genetic improvement of beef carcass and tenderness traits to exploit GS benefits. PMID:24802042

Akanno, E C; Plastow, G; Woodward, B W; Bauck, S; Okut, H; Wu, X-L; Sun, C; Aalhus, J L; Moore, S S; Miller, S P; Wang, Z; Basarab, J A

2014-07-01

434

The construct and criterion validity of emotional intelligence and its potential utility for management studies.  

PubMed

In this study, the authors reviewed the definition of emotional intelligence (EI) and argued that El is conceptually distinct from personality. In Study 1, the authors showed that EI was related to yet distinct from personality dimensions and that it had incremental predictive power on life satisfaction. The authors examined the construct validity of self-reports and others' ratings of EI using two samples in Study 2. In a student sample, parents' ratings explained additional variance in the students' life satisfaction and feelings of powerlessness after controlling for the Big Five personality dimensions. In the work sample, peer ratings were found to be significant predictors of job performance ratings provided by supervisors after controlling for the Big Five personality dimensions. Other implications for future research on EI are discussed. PMID:15161407

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

2004-06-01

435

Critical reading of articles about diagnostic tests (Part I): Are the results of the study valid?  

PubMed

In the era of evidence-based medicine, one of the most important skills a radiologist should have is the ability to analyze the diagnostic literature critically. This tutorial aims to present guidelines for determining whether primary diagnostic articles are valid for clinical practice. The following elements should be evaluated: whether the study can be applied to clinical practice, whether the technique was compared to the reference test, whether an appropriate spectrum of patients was included, whether expectation bias and verification bias were limited, the reproducibility of the study, the practical consequences of the study, the confidence intervals for the parameters analyzed, the normal range for continuous variables, and the placement of the test in the context of other diagnostic tests. We use elementary practical examples to illustrate how to select and interpret the literature on diagnostic imaging and specific references to provide more details. PMID:25443434

Arana, E

2014-10-23

436

Validation of a low-cost EEG device for mood induction studies.  

PubMed

New electroencephalography (EEG) devices, more portable and cheaper, are appearing on the market. Studying the reliability of these EEG devices for emotional studies would be interesting, as these devices could be more economical and compatible with Virtual Reality (VR) settings. Therefore, the aim in this work was to validate a low-cost EEG device (Emotiv Epoc) to monitor brain activity during a positive emotional induction procedure. Emotional pictures (IAPS) were used to induce a positive mood in sixteen participants. Changes in the brain activity of subjects were compared between positive induction and neutral conditions. Obtained results were in accordance with previous scientific literature regarding frontal EEG asymmetry, which supports the possibility of using this low-cost EEG device in future mood induction studies combined with VR. PMID:23792840

Rodríguez, Alejandro; Rey, Beatriz; Alcañiz, Mariano

2013-01-01

437

Combined ion conductance and fluorescence confocal microscopy for biological cell membrane transport studies  

NASA Astrophysics Data System (ADS)

Optical visualization of nanoscale morphological changes taking place in living biological cells during such important processes as endo- and exocytosis is challenging due to the low refractive index of lipid membranes. In this paper we summarize and discuss advances in the powerful combination of two complementary live imaging techniques, ion conductance and fluorescence confocal microscopy, that allows cell membrane topography to be related with molecular-specific fluorescence at high spatial and temporal resolution. We demonstrate the feasibility of the use of ion conductance microscopy to image apical plasma membrane of mouse embryo trophoblast outgrowth cells at a resolution sufficient to depict single endocytic pits. This opens the possibility to study individual endocytic events in embryo trophoblast outgrowth cells where endocytosis plays a crucial role during early stages of embryo development.

Shevchuk, A. I.; Novak, P.; Velazquez, M. A.; Fleming, T. P.; Korchev, Y. E.

2013-09-01

438

Study for double-layered AZO/ATO transparent conducting thin film  

NASA Astrophysics Data System (ADS)

The purpose of this study is to provide transparent conductive composite films, used for such as dye-sensitized solar cells (DSSCs). In this work, transparent conductive oxide films with double-layer structure, ATO(antimony doped tin oxide)films covered on AZO(aluminum doped zinc oxide)films, were prepared on glass substrates by RF magnetron sputtering method. Subsequently the films were post-annealed at different temperature. The structure, surface morphology, optical and electrical properties of the films were investigated as a function of annealing temperature. Our results indicate that the composite films can maintain good electrical and optical properties at a temperature higher than 450°C compared to that of single-layer film.

Cao, Miaomiao; Li, Yudong; Yang, Jing; Chen, Yigang

2013-03-01

439

Molecular dynamics study of influence of vacancy types defects on thermal conductivity of ?-SiC  

NASA Astrophysics Data System (ADS)

A molecular dynamics technique has been used to study the impact of single vacancies and small vacancy clusters/microvoids on thermal conductivity of Si and ?-SiC. It is found that single vacancies reduce thermal conductivity more significantly than do microvoids with the same total number of vacancies in the crystal. The vacancy concentration dependence of the relative change of thermal resistivity of both Si and SiC changes from linear at low concentrations to square-root at higher values. In contrast, the dependence on the volume fraction of microvoids switches from square-root at small swelling values to nearly linear dependence at higher swelling. In the case of SiC the results obtained for vacancies and microvoids agree reasonably well with experimental values. The computational results are compared with the commonly used Debye-Callaway model.

Samolyuk, G. D.; Golubov, S. I.; Osetsky, Y. N.; Stoller, R. E.

2011-11-01

440

Conducting polymers doped with a mineral phase: structural and electrical study  

NASA Astrophysics Data System (ADS)

This work reports the results obtained of a series of novel doped conducting polymers (CPs) of polyaniline/hematite (PANI/HEM), which were synthesized in acidic aqueous solution by the in situ chemical oxidative polymerization, using ammonium peroxydisulfate as oxidant reagent. The synthesis was carried out with 20, 40 y 60 % (weight percent) contents of hematite (HEM) at 8 and 14 h of polymerization times (tP). These composites were structurally characterized by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). An electrochemical analysis was made by Electrochemical impedance spectroscopy (EIS). Results of this study allow to evaluate the influence of hematite on the improvement of the structural properties and in the increase of the electric conductivity (sac) of the doped polymers compared to CPs without dopant agents.

González, C. P.; Montaño, A. M.; Estrada, S.; Ortiz, C.

2013-11-01

441

Two-Year Predictive Validity of Conduct Disorder Subtypes in Early Adolescence: A Latent Class Analysis of a Canadian Longitudinal Sample  

ERIC Educational Resources Information Center

Background: Investigating the latent structure of conduct disorder (CD) can help clarify how symptoms related to aggression, property destruction, theft, and serious violations of rules cluster in individuals with this disorder. Discovering homogeneous subtypes can be useful for etiologic, treatment, and prevention purposes depending on the…

Lacourse, Eric; Baillargeon, Raymond; Dupere, Veronique; Vitaro, Frank; Romano, Elisa; Tremblay, Richard

2010-01-01

442

Initial Reliability and Validity of the Life Satisfaction Scale for Problem Youth in a Sample of Drug Abusing and Conduct Disordered Youth  

ERIC Educational Resources Information Center

Responses to Life Satisfaction Scale for Problem Youth (LSSPY) items were examined in a sample of 193 substance abusing and conduct disordered adolescents. In responding to the LSSPY, youth endorse their percentage of happiness (0 to 100%) in twelve domains (i.e., friendships, family, school, employment/work, fun activities, appearance, sex…

Donohue, Brad; Teichner, Gordon; Azrin, Nathan; Weintraub, Noah; Crum, Thomas A.; Murphy, Leah; Silver, N. Clayton

2003-01-01

443

A Study of the Construct Validity of the Interactive Computer Interview System (ICIS) using Student Evaluations as the Outcome Measure  

E-print Network

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 ...

Evans, Chad Gerhold

2010-06-30

444

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

SciTech Connect

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.

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

2005-10-01

445

Development and validation of a notational system to study the offensive process in football.  

PubMed

The most striking change within football development is the application of science to its problems and in particular the use of increasingly sophisticated technology that, supported by scientific data, allows us to establish a "code of reading" the reality of the game. Therefore, this study describes the process of the development and validation of an ad hoc system of categorization, which allows the different methods of offensive game in football and the interaction to be analyzed. Therefore, through an exploratory phase of the study, we identified 10 vertebrate criteria and the respective behaviors observed for each of these criteria. We heard a panel of five experts with the purpose of a content validation. The resulting instrument is characterized by a combination of field formats and systems of categories. The reliability of the instrument was calculated by the intraobserver agreement, and values above 0.95 for all criteria were achieved. Two FC Barcelona games were coded and analyzed, which allowed the detection of various T-patterns. The results show that the instrument serves the purpose for which it was developed and can provide important information for the understanding of game interaction in football. PMID:20944448

Sarmento, Hugo; Anguera, Teresa; Campaniço, Jorge; Leitão, José

2010-01-01

446

Standardised clients as assessors in a veterinary communication OSCE: a reliability and validity study.  

PubMed

In human medicine, standardised patients (SP) have been shown to reliably and accurately assess learners' communication performance in high-stakes certification Objective Structured Clinical Examinations (OSCE), offering a feasible way to reduce the need for recruitment, time commitment and coordination of faculty assessors. In this study, we evaluated the use of standardised clients (SC) as a viable option for assessing veterinary students' communication performance. We designed a four-station, two-track communication skills OSCE. SC assessors used an adapted nine-item Liverpool Undergraduate Communication Assessment Scale (LUCAS). Faculty used a 21-item checklist derived from the Calgary-Cambridge Guide (CCG) and a five-point global rating scale. Participants were second year veterinary students (n=96). For the four stations, intrastation reliability (?) ranged from 0.63 to 0.82 for the LUCAS, and 0.73 to 0.87 for the CCG. The interstation reliability coefficients were 0.85 for the LUCAS and 0.89 for the CGG. The calculated Generalisability (G) coefficients were 0.62 for the LUCAS and 0.60 for the CGG. Supporting construct validity, SC and faculty assessors showed a significant correlation between the LUCAS and CCG total percent scores (r=0.45, P<0.001), and likewise between the LUCAS and global rating scores (r=0.49, P<0.001).Study results support that SC assessors offer a reliable and valid approach for assessing veterinary communication OSCE. PMID:25170035

Artemiou, E; Adams, C L; Hecker, K G; Vallevand, A; Violato, C; Coe, J B

2014-11-22

447

Multicenter Validation Study of a Prognostic Index for Portal Vein Tumor Thrombosis in Hepatocellular Carcinoma  

PubMed Central

Purpose We previously reported on a staging system and prognostic index (PITH) for portal vein tumor thrombosis (PVTT) in hepatocellular carcinoma (HCC) patients treated with radiotherapy (RT) at a single institution. The aim of this study is to validate the PITH staging system using data from patients at other institutions and to compare it with other published staging systems. Materials and Methods A total of 994 HCC patients with PVTT who were treated with RT between 1998 and 2011 by the Korean Radiation Oncology Group were analyzed retrospectively. All patients were staged using the Cancer of the Liver Italian Program (CLIP), Japanese Integrated Staging (JIS), Okuda, and PITH staging systems, and survival data were analyzed. The likelihood ratio, Akaike information criteria (AIC), time-dependent receiver operating characteristics, and prediction error curve analysis were used to determine discriminatory ability for comparison of staging systems. Results The median survival was 9.2 months. Compared with the other staging systems, the PITH score gave the highest values for likelihood ratio and lowest AIC values, demonstrating that PITH may be a better prognostic model. Although the values were not significant and differences were not exceptional, the PITH score showed slightly better performance with respect to time-dependent area under curve and integrated Brier score of prediction error curve. Conclusion The PITH staging system was validated in this multicenter retrospective study and showed better stratification ability in HCC patients with PVTT than other systems. PMID:25036573

Yu, Jeong Il; Yoon, Sang Min; Park, Hee Chul; Kim, Jong Hoon; Kim, Tae Hyun; Park, Joong-Won; Seong, Jinsil; Lee, Ik Jae; Jang, Hong Seok; Kay, Chul Seung; Kim, Chul Yong; Chie, Eui Kyu; Kim, Jin Hee; Kim, Mi-Sook; Choi, Young Min

2014-01-01

448

Development and Evaluation of Validity Scales for the Neuropsychology Behavior and Affect Profile: A Dissembling Study  

Microsoft Academic Search

The Neuropsychology Behavior and Affect Profile (NBAP) is a peer-rated inventory of behavioral and affective changes in brain injured individuals and consists of five Clinical Scales that have demonstrated strong external validity. A potential confound is the NBAP's susceptibility to rater bias. In the present investigation, four validity scales were developed and external validity and psychometric properties were examined through

Paul Satz; Steven G. Holston; Craig Lyons Uchiyama; Grace Shimahara; Maura Mitrushina; David L. Forney; Ken Zaucha; Roger Light; Robert Asarnow; Charles Drebing; Amy E. Kline; Wilfred van Gorp; Linda D. Nelson; Jacqueline Foster; John Fahy; Norman Namerow

1996-01-01

449

Validity of Self-Report Screening Scale for Elder Abuse: Women's Health Australia Study.  

ERIC Educational Resources Information Center

Examines the reliability and validity of the Vulnerability to Abuse Screening Scale (VASS) for the early identification of elder abuse. Results confirmed the VASS factor structure and construct validity. The Vulnerability and Coercion factors held the strongest face and construct validity for physical and psychological abuse. (Contains 52…

Schofield, Margot J.; Mishra, Gita D.

2003-01-01

450

A validated finite element method study of orthodontic tooth movement in the human subject.  

PubMed

The aim of the study was to develop a 3D computer model of the movement of a maxillary incisor tooth when subjected to an orthodontic load. A novel method was to be developed to directly and accurately measure orthodontic tooth movement in a group of human volunteers. This was to be used to validate the finite element-based computer model. The design took the form of a prospective experiment at a laboratory at the University of Wales in 1996/7. A laser apparatus was used to sample tooth movement every 0.01 seconds over a 1-minute cycle for 10 healthy volunteers, whilst a constant 0.39 N load was applied. This process was repeated on eight separate occasions and the most consistent five readings taken for each subject. Data were used to calculate the physical properties of the periodontal ligament (PDL). The data gleaned by this method were used to validate the 3D FEM model. This was formed of 15,000 four-noded tetrahedral elements. Tooth displacements ranged from 0.012 to 0.133 mm. An appropriate elastic modulus of 1 N/mm(2) and Poisson's Ratio of 0.45 was derived for the PDL. Strain analysis, using the model, suggested that a maximum PDL strain of 4.77 x 10(-3) was recorded at the alveolar crest, while the largest apical strain recorded was 1.55 x 10(-3). The maximum strains recorded in the surrounding alveolar bone were 35 times less than for the PDL. A novel method for direct measurement of PDL physical properties in the human subject has been developed. The validated FEM model lends further evidence that the PDL is the main mediator of orthodontic tooth movement. PMID:11254801

Jones, M L; Hickman, J; Middleton, J; Knox, J; Volp, C

2001-03-01

451

Active transmembrane drug transport in microgravity: a validation study using an ABC transporter model  

PubMed Central

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

Vaquer, Sergi; Cuyàs, Elisabet; Rabadán, Arnau; González, Albert; Fenollosa, Felip; de la Torre, Rafael

2014-01-01

452

Validation of FSP Reactor Design with Sensitivity Studies of Beryllium-Reflected Critical Assemblies  

SciTech Connect

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 uncerta