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1

Validation of a one-stop carpal tunnel clinic including nerve conduction studies and hand therapy  

PubMed Central

INTRODUCTION Carpal tunnel syndrome is the most common hand disorder. We describe a pathway that includes clinical assessment, neurophysiological testing, surgery and physical therapy all at the same visit. METHODS All referrals for carpal tunnel syndrome were screened for inclusion in a ‘one-stop’ surgeon-led clinic. Prospective clinical data collected included patient reported outcome measures and satisfaction scores, touch threshold, pinch and grip strength. Patients were assessed clinically, underwent nerve conduction studies and surgery as indicated, all on the same day. Baseline and one-year follow-up data were analysed for 57 patients (62 hands). RESULTS There was significant improvement in all domains of the Boston Carpal Tunnel and Michigan Hand Outcomes questionnaires, grip strength and touch threshold. There were no adverse events. The total mean operating time was 12.8 minutes (range: 5–15 minutes) and the mean tourniquet time was 2.5 minutes (range: 1–11 minutes). Using a dual theatre model produced a short mean turnaround time of 14.8 minutes (range: 2–37 minutes). Patient satisfaction as judged using a Picker questionnaire was very high. CONCLUSIONS A highly efficient clinical service involving both diagnostics and treatment can be delivered at a single hospital visit while maintaining optimal outcomes and high patient satisfaction.

Ball, C; Pearse, M; Kennedy, D; Hall, A; Nanchahal, J

2011-01-01

2

Validity of bone conduction stimulated ABR, MLR and otoacoustic emissions.  

PubMed

The present study considers the validity of objective auditory investigation via bone conduction. Auditory Brainstem Responses (ABR) and Middle Latency Responses (MLR) were recorded in response to a bone vibrator stimulation with or without continuous bilateral air white noise masking. In all cases, such masking was found to result in an absence of recorded evoked potentials. It shows that under bone-conducted stimulation the evoked potential recorded is purely auditory, with no additional mechanical somatosensory component. In a further study, the feasibility of oto-acoustic emissions (OAEs) via bone conduction is demonstrated. These OAEs are, for a given subject, comparable to those found for air-transmission stimulation. PMID:2749175

Collet, L; Chanal, J M; Hellal, H; Gartner, M; Morgon, A

1989-01-01

3

Threats to Validity in the Design and Conduct of Preclinical Efficacy Studies: A Systematic Review of Guidelines for In Vivo Animal Experiments  

PubMed Central

Background The vast majority of medical interventions introduced into clinical development prove unsafe or ineffective. One prominent explanation for the dismal success rate is flawed preclinical research. We conducted a systematic review of preclinical research guidelines and organized recommendations according to the type of validity threat (internal, construct, or external) or programmatic research activity they primarily address. Methods and Findings We searched MEDLINE, Google Scholar, Google, and the EQUATOR Network website for all preclinical guideline documents published up to April 9, 2013 that addressed the design and conduct of in vivo animal experiments aimed at supporting clinical translation. To be eligible, documents had to provide guidance on the design or execution of preclinical animal experiments and represent the aggregated consensus of four or more investigators. Data from included guidelines were independently extracted by two individuals for discrete recommendations on the design and implementation of preclinical efficacy studies. These recommendations were then organized according to the type of validity threat they addressed. A total of 2,029 citations were identified through our search strategy. From these, we identified 26 guidelines that met our eligibility criteria—most of which were directed at neurological or cerebrovascular drug development. Together, these guidelines offered 55 different recommendations. Some of the most common recommendations included performance of a power calculation to determine sample size, randomized treatment allocation, and characterization of disease phenotype in the animal model prior to experimentation. Conclusions By identifying the most recurrent recommendations among preclinical guidelines, we provide a starting point for developing preclinical guidelines in other disease domains. We also provide a basis for the study and evaluation of preclinical research practice. Please see later in the article for the Editors' Summary

Henderson, Valerie C.; Kimmelman, Jonathan; Fergusson, Dean; Grimshaw, Jeremy M.; Hackam, Dan G.

2013-01-01

4

Conducting Student Retention Studies.  

ERIC Educational Resources Information Center

Techniques for conducting student-attrition studies using the Student-Outcomes Information Service (SOIS) are outlined. General concepts to effectively guide an institutional research effort are discussed, with attention to better defining student attrition and a summary of results of recent research on the reasons why students withdraw from…

Ewell, Peter T.

5

Primary Coolant Conductivity Study.  

National Technical Information Service (NTIS)

The AF NETF, a 10 MW water-cooled research reactor, monitors the conductivity of its coolant to detect erosion/corrosion of its structural systems and fuel element failure. When a gradual increase in this conductivity sent it above the defined limit, a st...

J. W. Baker A. N. Fasano L. B. Hary F. B. Buoni

1967-01-01

6

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

7

Verbal autopsy as a tool for identifying children dying of sickle cell disease: a validation study conducted in Kilifi district, Kenya  

PubMed Central

Background Sickle cell disease (SCD) is common in many parts of sub-Saharan Africa (SSA), where it is associated with high early mortality. In the absence of newborn screening, most deaths among children with SCD go unrecognized and unrecorded. As a result, SCD does not receive the attention it deserves as a leading cause of death among children in SSA. In the current study, we explored the potential utility of verbal autopsy (VA) as a tool for attributing underlying cause of death (COD) in children to SCD. Methods We used the 2007 WHO Sample Vital Registration with Verbal Autopsy (SAVVY) VA tool to determine COD among child residents of the Kilifi Health and Demographic Surveillance System (KHDSS), Kenya, who died between January 2008 and April 2011. VAs were coded both by physician review (physician coded verbal autopsy, PCVA) using COD categories based on the WHO International Classification of Diseases 10th Edition (ICD-10) and by using the InterVA-4 probabilistic model after extracting data according to the 2012 WHO VA standard. Both of these methods were validated against one of two gold standards: hospital ICD-10 physician-assigned COD for children who died in Kilifi District Hospital (KDH) and, where available, laboratory confirmed SCD status for those who died in the community. Results Overall, 6% and 5% of deaths were attributed to SCD on the basis of PCVA and the InterVA-4 model, respectively. Of the total deaths, 22% occurred in hospital, where the agreement coefficient (AC1) for SCD between PCVA and hospital physician diagnosis was 95.5%, and agreement between InterVA-4 and hospital physician diagnosis was 96.9%. Confirmatory laboratory evidence of SCD status was available for 15% of deaths, in which the AC1 against PCVA was 87.5%. Conclusions Other recent studies and provisional data from this study, outlining the importance of SCD as a cause of death in children in many parts of the developing world, contributed to the inclusion of specific SCD questions in the 2012 version of the WHO VA instruments, and a specific code for SCD has now been included in the WHO and InterVA-4 COD listings. With these modifications, VA may provide a useful approach to quantifying the contribution of SCD to childhood mortality in rural African communities. Further studies will be needed to evaluate the generalizability of our findings beyond our local context.

2014-01-01

8

Developing and Validating the Youth Conduct Problems Scale-Rwanda: A Mixed Methods Approach  

PubMed Central

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

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

2014-01-01

9

Nerve conduction studies in adrenomyeloneuropathy.  

PubMed Central

OBJECTIVE--Adrenomyeloneuropathy (AMN) is an X linked metabolic disorder presenting with progressive spastic paraparesis in the third to fifth decade of life. Although peripheral neuropathy is also present in most patients, prominent pyramidal signs may make its clinical recognition difficult. The objective was to characterise the peripheral neuropathy in patients with AMN by nerve conduction studies. METHODS--Nerve conduction studies were performed in 99 men known to have AMN and in 38 heterozygous women, all of whom had neurological disabilities. RESULTS--Of the 13 variables obtained, at least one was abnormal in 82% of patients. The abnormalities were more common in men than in women (87% v 67%); in legs than in arms (77% v 38%); in motor than in sensory conduction (80% v 39%); and in latency (distal and F wave) and velocity compared with amplitude (80% v 29%). Twenty six patients had at least one nerve variable value in the demyelinating range. Four variables (sural velocity, peroneal amplitude, peroneal velocity, and peroneal F wave) were correlated with the expanded disability status scale; five variables (peroneal velocity, tibial H reflex, median distal latency, median conduction velocity, and median F wave latency) were correlated with serum very long chain fatty acids (VLCFAs); and two variables (sural amplitude and peroneal distal latency) were more likely to be abnormal in patients with normal adrenal function than in patients with Addison's disease. CONCLUSIONS--Nerve conduction studies in patients with AMN are often abnormal and suggest a mixture of axonal loss and multifocal demyelination. Their correlation with disability status and serum VLCFAs suggests that measures from nerve conduction studies may be useful in evaluating future treatments. Images

Chaudhry, V; Moser, H W; Cornblath, D R

1996-01-01

10

External validation of multivariable prediction models: a systematic review of methodological conduct and reporting  

PubMed Central

Background Before considering whether to use a multivariable (diagnostic or prognostic) prediction model, it is essential that its performance be evaluated in data that were not used to develop the model (referred to as external validation). We critically appraised the methodological conduct and reporting of external validation studies of multivariable prediction models. Methods We conducted a systematic review of articles describing some form of external validation of one or more multivariable prediction models indexed in PubMed core clinical journals published in 2010. Study data were extracted in duplicate on design, sample size, handling of missing data, reference to the original study developing the prediction models and predictive performance measures. Results 11,826 articles were identified and 78 were included for full review, which described the evaluation of 120 prediction models. in participant data that were not used to develop the model. Thirty-three articles described both the development of a prediction model and an evaluation of its performance on a separate dataset, and 45 articles described only the evaluation of an existing published prediction model on another dataset. Fifty-seven percent of the prediction models were presented and evaluated as simplified scoring systems. Sixteen percent of articles failed to report the number of outcome events in the validation datasets. Fifty-four percent of studies made no explicit mention of missing data. Sixty-seven percent did not report evaluating model calibration whilst most studies evaluated model discrimination. It was often unclear whether the reported performance measures were for the full regression model or for the simplified models. Conclusions The vast majority of studies describing some form of external validation of a multivariable prediction model were poorly reported with key details frequently not presented. The validation studies were characterised by poor design, inappropriate handling and acknowledgement of missing data and one of the most key performance measures of prediction models i.e. calibration often omitted from the publication. It may therefore not be surprising that an overwhelming majority of developed prediction models are not used in practice, when there is a dearth of well-conducted and clearly reported (external validation) studies describing their performance on independent participant data.

2014-01-01

11

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

ERIC Educational Resources Information Center

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

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

2011-01-01

12

Vascular elastography: a validation study.  

PubMed

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

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

2014-08-01

13

Critical validation studies of neurofeedback.  

PubMed

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

Gruzelier, John; Egner, Tobias

2005-01-01

14

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

15

Reliability, validity, and factor structure of the Swedish Youth Psychopathic Trait Inventory in a UK sample of conduct disordered boys  

Microsoft Academic Search

The Swedish Youth Psychopathy Traits Inventory (YPI) is a newly developed self-report measure of psychopathy. Currently, there are no studies looking at the reliability, validity, and factor structure of this measure in conduct disordered adolescents in the UK. A sample of 115 male adolescents (mean age 16.22) with a range of conduct problems on the Kiddie Schedule for Affective Disorders

Mairead C. Dolan; Charlotte E. Rennie

2006-01-01

16

The Self-Consciousness Scale: A Discriminant Validity Study  

ERIC Educational Resources Information Center

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

Carver, Charles S.; Glass, David C.

1976-01-01

17

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

18

Guide for Conducting Treatability Studies under CERCLA.  

National Technical Information Service (NTIS)

The guide describes an approach for conducting treatability studies that consists of laboratory screening, bench-scale testing, and pilot-scale testing. The guide also presents a stepwise approach or protocol for conducting treatability studies for determ...

1989-01-01

19

29 CFR 1607.5 - General standards for validity studies.  

Code of Federal Regulations, 2013 CFR

...content validity studies or construct validity studies, in accordance...Criterion-related, content, and construct validity. Evidence of the validity...selection procedure through a construct validity study should consist of...

2013-07-01

20

Conducting and Reporting Case Studies.  

ERIC Educational Resources Information Center

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

Lichtman, Merilyn; Taylor, Satomi Izumi

21

Nuts and Bolts of Conducting Feasibility Studies  

PubMed Central

Many factors can affect the successful implementation and validity of intervention studies. A primary purpose of feasibility and pilot studies is to assess the potential for successful implementation of the proposed main intervention studies and to reduce threats to the validity of these studies. This article describes a typology to guide the aims of feasibility and pilot studies designed to support the development of randomized controlled trials and provides an example of the studies underlying the development of one rehabilitation trial. The purpose of most feasibility and pilot studies should be to describe information and evidence related to the successful implementation and validity of a planned main trial. Null hypothesis significance testing is not appropriate for these studies unless the sample size is properly powered. The primary tests of the intervention effectiveness hypotheses should occur in the main study, not in the studies that are serving as feasibility or pilot studies.

2013-01-01

22

Computerized Offender Assessment: Validation Study  

Microsoft Academic Search

The validity of a computer-based test interpretation (CBTI) system for mental health screening in correctional settings was evaluated. First, 100 adult male felons were administered a brief mental status interview and a series of psychological tests, including the MMPI, the revised Beta IQ Examination, and the Buss-Durkee Hostility Inventory. Psychiatric diagnoses and CBTI ratings of victimization, violence, suicide, and substance

Ron P. Jemelka; Geoffrey A. Wiegand; Edward A. Walker; Eric W. Trupin

1992-01-01

23

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

24

Bremsstrahlung studies with conducting and non-conducting radiators  

SciTech Connect

Total bremsstrahlung intensities emanating from targets of conducting and non-conducting materials have been measured by completely stopping the beta radiations in the targets. While confirming the approximately linear variation of bremsstrahlung intensity with target atomic number the values of effective atomic numbers for multi-component systems obtained from the present measurements agree with those calculated from their chemical compositions. It is found that the target bremsstrahlung increases more rapidly with beta end-point energy than the internal bremsstrahlung from the beta emitters. Therefore it will be more appropriate to use beta emitters with high end-point energies and targets of dielectrics with high effective atomic numbers in studies of bremsstrahlung attenuation with charge build up.

Singh, M.; Powar, M.S.

1984-02-01

25

Conducting a wind sensing study  

NASA Technical Reports Server (NTRS)

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

Byer, R. L.

1985-01-01

26

Validity of DSM?IV Subtypes of Conduct Disorder Based on Age of Onset  

Microsoft Academic Search

ObjectiveTo present data from the DSM-IV field trials that led to the distinction between subtypes of conduct disorder (CD) that emerge in childhood or adolescence. In addition, data from a household sample were used to attempt to cross-validate these findings.

BENJAMIN B. LAHEY; ROLF LOEBER; HERBERT C. QUAY; BROOKS APPLEGATE; DAVID SHAFFER; IRWIN WALDMAN; ELIZABETH L. HART; KEITH MCBURNETT; PAUL J. FRICK; PETER S. JENSEN; MINA K. DULCAN; GLORISA CANINO; HECTOR R. BIRD

1998-01-01

27

Guide for Conducting Treatability Studies under CERCLA.  

National Technical Information Service (NTIS)

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

1992-01-01

28

GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA  

EPA Science Inventory

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

29

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

30

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.

31

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.

32

The Karolinska Directed Emotional Faces: A validation study  

Microsoft Academic Search

Although affective facial pictures are widely used in emotion research, standardised affective stimuli sets are rather scarce, and the existing sets have several limitations. We therefore conducted a validation study of 490 pictures of human facial expressions from the Karolinska Directed Emotional Faces database (KDEF). Pictures were evaluated on emotional content and were rated on an intensity and arousal scale.

Ellen Goeleven; Rudi De Raedt; Lemke Leyman; Bruno Verschuere

2008-01-01

33

Severity prediction rules in community acquired pneumonia: a validation study  

Microsoft Academic Search

BACKGROUNDThe British Thoracic Society (BTS) developed a rule (BTSr) based on severity criteria to predict short term mortality in adults admitted to hospital with community acquired pneumonia (CAP). However, neither the BTSr nor a recent modification of it (mBTSr) have been validated in the UK. A case-control study was conducted in a typical UK population to determine the clinical factors

W S Lim; S Lewis; J T Macfarlane

2000-01-01

34

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.

35

Courseware Validation: A Case Study.  

ERIC Educational Resources Information Center

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

Persico, D.

1996-01-01

36

PLAE, a Validated Study Strategy.  

ERIC Educational Resources Information Center

Investigates the effectiveness of PLAE (Preplan, List, Activate, and Evaluate), a model designed to characterize the operations and processes students must perform to control and regulate their learning. Concludes that the ability to construct, implement, and evaluate a study plan as defined by PLAE's stages improves students' test performances…

Nist, Sherrie L.; Simpson, Michele L.

1989-01-01

37

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

38

Gas release and conductivity modification studies  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

39

DC electrical conductivity study of cerium doped conducting glass systems  

NASA Astrophysics Data System (ADS)

The glass samples of composition 60V2O5-5P2O5-(35-x)B2O3-xCeO2, (1 <= x <= 5) were prepared by the conventional melt quench method. The samples were characterized by X-ray diffraction and thermo gravimetric-differential thermal analysis. The glass transition temperature and crystallization temperature determined from TG-DTA analysis. The DC electrical conductivity has been carried out in the temperature range 303-473 K. The maximum conductivity and minimum activation energy were found to be 0.039 Scm-1 and 0.15 eV at 473 K for x=1, respectively.

Barde, R. V.; Waghuley, S. A.

2013-06-01

40

Proton Conductivity Studies on Biopolymer Electrolytes  

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

41

Conductivity study of chitosan based nanocomposites  

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

42

Validation of Nursing Home Quality Indicators Study.  

National Technical Information Service (NTIS)

The goal of this study was to develop a system by which a series of Quality Indicators (QIs) could be used in conjunction with claims data to monitor quality of care in nursing facilities. Fifty QIs were developed and validated using a sample of nursing h...

A. Chawla D. Schroeder M. Monane S. Tillisch S. A. Flanagan

1997-01-01

43

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

44

Validity and Quality in Self-Study.  

ERIC Educational Resources Information Center

Responds to an article, "Guidelines for Quality in Autobiographical Forms of Self-Study," asserting that in addition to criteria for the quality of research, researchers must have ways to demonstrate its validity because of the moral and political aspects of educational research. The article's assertion is based in part on the existential nature…

Feldman, Allan

2003-01-01

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

Validity and Quality in Self-Study  

Microsoft Academic Search

In this response to Bullough and Pinnegar’s “Guidelines for Quality in Autobiographical Forms of Self-Study,” the author argues that in addition to criteria for the quality of research, researchers need to have ways to demonstrate its validity because of the moral and political aspects of educational research. The argument is based in part on the existential nature of self-study. The

Allan Feldman

2003-01-01

47

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

Microsoft Academic Search

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

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

1990-01-01

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

Lightning electromagnetic radiation over a stratified conducting ground: 2. Validity of simplified approaches  

NASA Astrophysics Data System (ADS)

In the first part of this paper, the rigorous theory describing the electromagnetic field radiated by a lightning return stroke over a two-layered conducting ground was presented and the exact expressions for the lightning electromagnetic fields were developed and discussed. In this part of the paper, the theory along with its time domain numerical evaluation algorithm is used for the assessment of the validity of simplified approaches proposed in the literature for the vertical electric and horizontal magnetic field components. The simplified approaches are based on the concept of ground surface impedance and its corresponding attenuation function. It is shown that the results obtained using the simplified approaches are in excellent agreement with exact results in both near (50 m) and intermediate (1000 m) distance range. However, since the vertical electric and azimuthal magnetic field components are not appreciably affected by the ground finite conductivity, they can also be evaluated assuming the ground as a perfectly conducting ground. On the other hand, the horizontal electric field above a horizontally stratified ground is very much affected by the ground electrical parameters. Its waveform is characterized by an early negative excursion due to the currents flowing into the ground followed by a late time positive excursion which is due to the elevation of the observation point from the ground level. The magnitude of the negative peak is sharper for subsequent return strokes than first return strokes and is higher for lower conducting grounds. A new formula is proposed for the evaluation of the horizontal electric field at a given height above the air-ground interface. The formula can be viewed as the generalization of the Cooray-Rubinstein formula for the case of a two-layer ground. We show that the new formula is able to reproduce in a satisfactory manner the horizontal electric field above a two-layer ground. The proposed formulation is, however, less accurate at distances as close to 10 m from the channel base and for very poor ground conductivity (0.0001 S/m).

Shoory, Abdolhamid; Rachidi, Farhad; Delfino, Federico; Procopio, Renato; Rossi, Mansueto

2011-06-01

50

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

51

Studies on graphite based conductive paint coatings  

Microsoft Academic Search

Electrically conductive coatings are mainly required for static charge dissipation and electromagnetic\\/radio frequency interference (EMI\\/RFI) shielding. Electrically conductive coatings are prepared by the incorporation of the metallic pigments\\/graphite onto the binder. In the present investigation graphite is used as the conductive filler and epoxy polymer as binder. Optimization of the solid content and pigment volume concentration (PVC) of the coating

S. Syed Azim; A. Satheesh; K. K. Ramu; S. Ramu; G. Venkatachari

2006-01-01

52

A study of conductivity in a complex geometry  

NASA Astrophysics Data System (ADS)

I present a study of the conductivity of a material with a complex geometry. There are three main parts in this dissertation, the determination of the isotropic conductivity, anisotropic conductivity, and effective conductivity. In the first part, a method using a multi-probe measurement together with a numerical simulation is introduced for the determination of the isotropic conductivity in a complex geometry. This method has been demonstrated on micron-sized diamond crystallites and diamond homoepitaxial films. The 3d-computer image for the finite element method (FEM) has been reconstructed from the scanning electron microscope (SEM) photos. For a sample with four probes, a 6 x 6 geometrical factor matrix is generated from the FEM analysis. In addition, the experimental measurement on the sample provides another 6 x 6 resistance matrix. The sample conductivity and contact resistances can be determined by the least-square fitting for the geometrical factors and the resistances. In the second part, this method is generalized for the anisotropic conductivity that is represented by a 3 x 3 tensor. It has been validated on computer models and real material (bismuth). This modified numerical scheme using the FEM analysis and the iterative linearization technique has identified the anisotropic conductivity tensor within acceptable errors in most cases. Some conditions for the application of this technique have been suggested from the analysis of the results. In the last part, I describe the effective conductivity of a composite material. Much research has been done to investigate the electric, thermal, and elastic properties of composite materials. However, only a few problems with a simple geometry have been solved analytically. For instance, the dielectric properties of a composite that includes two perfect circular conductors have been determined analytically by a multipole expansion method. However, for complex composites, the analytic solutions cannot be obtained in most cases. Therefore, a numerical technique using the finite element method has been introduced for problems where the analytic approach fails. The FEM analysis is known as the most effective scheme to solve a boundary value problem in a complicated geometry. The simulation using this method is a primary step to understanding the effective medium theory for a complex composite material. To demonstrate this technique in the study of composite materials, numerical simulations have been performed and the results have been compared with the analytical solutions for a simple composite material.

Hyun, Sangil

53

Conductivity  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

54

GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: CHEMICAL DEHALOGENATION  

EPA Science Inventory

Systematically conducted, well-documented treatability studies are an important component of remedy evaluation and selection under the Superfund program. his manual focuses on chemical dehalogenation treatability studies conducted in support of remedy selection that is conducted ...

55

A Cross-Validation Study of Police Recruit Performance as Predicted by the IPI and MMPI.  

ERIC Educational Resources Information Center

Validation and cross-validation studies were conducted using the Minnesota Multiphasic Personality Inventory (MMPI) and Inwald Personality Inventory (IPI) to predict job performance for 698 urban male police officers who completed a six-month training academy. Job performance criteria evaluated included absence, lateness, derelictions, negative…

Shusman, Elizabeth J.; And Others

56

40 CFR 761.392 - Preparing validation study samples.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

57

40 CFR 761.395 - A validation study.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

58

[Validation study of the Mannheim Peritonitis Index].  

PubMed

113 patients suffering from purulent peritonitis entered this retrospective study for evaluation of the prognostic value of the Mannheim Peritonitis-Index. There was no lethality below an index x = 21, between x = 21 and x = 29, it was 29% and lethality increased to 100% in patients with an index x greater than or equal to 30. Statistical validation showed that prognosis was correct in 93% for the index x = 27, with a sensitivity and specificity of also 93%. Between x = 21 and x = 29 prognosis of the MPI was correct in at least 65%. The MPI is shown as a prognostic index for peritonitis with high accuracy in individual prognosis, that could be easy routinely documented. PMID:3229167

Függer, R; Rogy, M; Herbst, F; Schemper, M; Schulz, F

1988-09-01

59

Study on Electrical Conductivity of Coal.  

National Technical Information Service (NTIS)

One of the engineering techniques in underground coal gasification is the electrical linking of holes drilled into the coal seam. The magnitude of electrical conductivity is one of the factors that will determine whether electrical linking is appropriate....

H. Ohuchi J. Soma T. Isobe

1968-01-01

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

Ethical Issues in Conducting Migrant Farmworker Studies  

Microsoft Academic Search

Migrant farmworkers should be considered a vulnerable population because they work in a hazardous industry, are often members of an ethnic minority, have known difficulty in accessing health care, and are often of lower socioeconomic status. For these reasons, too, it is extremely important to conduct health-related research with this often-underserved group. However, because migrant farmworkers are vulnerable, investigators must

Sharon P. Cooper; Elizabeth Heitman; Erin E. Fox; Beth Quill; Paula Knudson; Sheila H. Zahm; Nancy MacNaughton; Roberta Ryder

2004-01-01

62

Statistical Study of Thermal Contact Conductance.  

National Technical Information Service (NTIS)

A theoretical analysis of the principles of interfacial thermal conductance between two heated metal surfaces in mutual contact is presented. It was determined that when heat flows from one metal to the other, the flow lines converge toward the actual con...

V. T. Nejat

1972-01-01

63

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

64

A simple and validated tool for the clinician to assess psychosocial status when conducting anticonvulsant drug trials.  

PubMed

Using 94 people with epilepsy, categorized as either idiopathic or post-traumatic, and subdivided according to the severity of the disorder, the WPSI was tested and found to be a simple and validated tool for the clinician to assess psychosocial status when conducting anticonvulsant drug trials. PMID:3843219

Flanagan, P J; Beran, R G

1985-01-01

65

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

Microsoft Academic Search

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

O?uzhan Erdinç; Paul H. P. Yeow

2011-01-01

66

Equilibrium Molecular Dynamics Study of Lattice Thermal Conductivity\\/Conductance of Au-SAM-Au Junctions  

Microsoft Academic Search

In this paper, equilibrium molecular dynamics simulations were performed on Au-SAM (self-assembly monolayer)-Au junctions. The SAM consisted of alkanedithiol molecules. The out-of-plane (z-direction) thermal conductance and in-plane (x- and y-direction) thermal conductivities were calculated. Simulation finite size effect, gold substrate thickness effect, temperature effect, normal pressure effect, molecule chain length effect and molecule coverage effect on thermal conductivity\\/conductance were studied.

Tengfei Luo; John R. Lloyd

2009-01-01

67

Thermal and electrical contact conductance studies  

NASA Technical Reports Server (NTRS)

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

Vansciver, S. W.; Nilles, M.

1985-01-01

68

Portable device for vaginal thermal conductance studies.  

PubMed

Design and development of a portable and self-contained vaginal probe, consisting of an acetone-filled silver cylinder attached to a pressure gauge, is described. Qualitative changes in vaginal thermal conductance were inferred from rates of thermal expansion of precooled acetone measured as a pressure rise. Administration of 10 mg estradiol-17 beta i.v. to ovariectomized heifers resulted in significant increases in rate of thermal expansion. PMID:1176036

Abrams, R M; Thatcher, W W; Gwazdauskas, F C; Sharp, D C; Bazer, F W; Wilcox, C J; Stolwijk, J A

1975-01-01

69

40 CFR 761.326 - Conducting the comparison study.  

Code of Federal Regulations, 2013 CFR

... Conducting the comparison study. 761.326 Section 761...COMMERCE, AND USE PROHIBITIONS Self-Implementing Alternative... Conducting the comparison study. Extract or analyze the comparison study samples using the...

2013-07-01

70

A Study on Effective Thermal Conductivity of Composite Materials with Coiled Conductive Solids  

NASA Astrophysics Data System (ADS)

The authors have reported the works for the phase change process of heterogeneous composite materials involving coiled conductive solids in a medium. In these works,the effective thermal conductivity has been pointed out as an important one of the thermal properties of the composite materials. In the present study,the effective thermal conductivity of composite materials in which coiled conductive solids are packed in some medium,namely,ice,water,ethylene glycol or air,is measured by a steady state method. Otherwise,a heat conduction model is proposed by the authors and is compared with the experimental values. As a result,it was found that the effective thermal conductivity is considerably affected by factors such as the volume ratio of the conductive solids,the thermal conductivity ratio,the shape of the coils and the direction of the coils and the numerical calculations of the model agree qualitatively with the experimental values.

Takegoshi, Eisyun; Hirasawa, Yoshio; Matsuo, Jun; Saito, Akio; Okui, Ken-Ichi

71

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

Code of Federal Regulations, 2010 CFR

...content validity studies or construct validity studies, in accordance with...Criterion-related, content, and construct validity. Evidence of the validity...selection procedure through a construct validity study should consist of...

2009-07-01

72

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

Code of Federal Regulations, 2010 CFR

...content validity studies or construct validity studies, in accordance with...Criterion-related, content, and construct validity. Evidence of the validity...selection procedure through a construct validity study should consist of...

2010-07-01

73

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

Code of Federal Regulations, 2013 CFR

...content validity studies or construct validity studies, in accordance with...Criterion-related, content, and construct validity. Evidence of the validity...selection procedure through a construct validity study should consist of...

2013-07-01

74

Expert system verification and validation study  

NASA Technical Reports Server (NTRS)

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

French, Scott W.; Hamilton, David

1992-01-01

75

Validation of three-dimensional conduction models using experimental mapping: are we getting closer?  

Microsoft Academic Search

The anisotropic material properties, irregular geometry, and specialized conduction system of the heart all affect the three-dimensional (3D) spread of electrical activation. A limited number of research groups have tried accounting for these features in 3D conduction models to investigate more thoroughly their observations of cardiac electrical activity in 3D experimental preparations. The full potential of these large scale conduction

A. L. Muzikant; C. S. Henriquez

1998-01-01

76

Digital Signal Processing in Clinical Validation Studies with Impedance Plethysmography  

Microsoft Academic Search

We provide here an automated method for calculating the volume change (?V) from the tissue impedance change (?Z) signal acquired using an impedance plethysmograph. This presents our approaches to signal processing in two of our studies: a longitudinal pathologic validation study on monkeys, and a human clinical validation study. In both these studies, plethysmographic data were acquired at three different

Ravi Shankar; Mural Gopinathan; John G Webster

2008-01-01

77

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

78

Causation and effectuation processes: A validation study  

Microsoft Academic Search

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

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

2011-01-01

79

Equilibrium Molecular Dynamics Study of Lattice Thermal Conductivity\\/Conductance of Au-SAM-Au Junctions  

Microsoft Academic Search

In this paper, equilibrium molecular dynamics simulations were performed on\\u000aAu-SAM (self-assembly monolayer)-Au junctions. The SAM consisted of\\u000aalkanedithiol molecules. The out-of-plane (z-direction) thermal conductance and\\u000ain-plane (x- and y-direction) thermal conductivities were calculated.\\u000aSimulation finite size effect, gold substrate thickness effect, temperature\\u000aeffect, normal pressure effect, molecule chain length effect and molecule\\u000acoverage effect on thermal conductivity\\/conductance were studied.

Tengfei Luo; John R. Lloyd

2010-01-01

80

A molecular dynamics-stochastic model for thermal conductivity of nanofluids and its experimental validation.  

PubMed

A model to predict the enhanced thermal conductivity of water based copper nanofluid on the basis of molecular dynamics simulation coupled with stochastic simulation shows for the first time that the temperature of a copper nanoparticle colliding with a heat source can rise rapidly within the short collision period (e.g., 10-50 ps) estimated by impact dynamics due to phonon transfer. Thereafter the particles undergo Brownian movement in the base fluid and transfer the excess heat in about 2 to 3 ms to the surrounding fluid resulting in an appreciable enhancement of the thermal conductivity of the fluid. Microconvection has minor contribution to the enhanced thermal conductivity of nanofluids. The predicted thermal conductivity of nanofluid and its variation with the volume fraction of the nanoparticles agree well with the present experiments, as well as, with the data reported in the literature. PMID:21449369

Ghosh, Madan Mohan; Roy, Someshwar; Pabi, Shyamal Kumar; Ghosh, Sudipto

2011-03-01

81

VALIDATION STUDY OF THE ACUTE BIOTIC LIGAND MODEL FOR SILVER  

Microsoft Academic Search

An important final step in development of an acute biotic ligand model for silver is to validate predictive capabilities of the biotic ligand model developed for fish and invertebrates. To accomplish this, eight natural waters, collected from across North America, were characterized with respect to ionic composition, pH, dissolved organic carbon, and sulfide. Tests were conducted with the cladoceran Ceriodaphnia

Gretchen K. Bielmyer; Martin Grosell; Paul R. Paquin; Rooni Mathews; Kuen B. Wu; Robert C. Santore; Kevin V. Brix

2007-01-01

82

Optimizing State NAEP: Issues and Possible Improvements. NAEP Validity Studies.  

ERIC Educational Resources Information Center

The National Assessment of Educational Progress (NAEP) has conducted state assessments in 1990, 1992, 1994, and 1996. At present, after the fourth round of state assessments, it is clear that the program is generally successful. A survey of state testing directors indicates that the NAEP has considerable credibility as a valid and reliable source…

Mullis, Ina V. S.

83

Numerical study on electrical conductivity of spin-fermion models  

NASA Astrophysics Data System (ADS)

The DC electrical conductivity is studied numerically in finite-size spin-fermion models with antiferromagnetic couplings between localized spins by a direct numerical estimation of the Kubo formula. In contrast with an ordinary magnetoresistance, in a system where the localized spins form an antiferromagnetically coupled two-leg ladder, conductivity shows an anomalous non-monotonic field dependence. It is attributed to a spin configuration where two spins on the ladder rung dimerize into a spin singlet. In addition, we study conductivity of a square lattice and observe the direction dependence of conductivity. We obtained remarkable and qualitative differences in behavior of conductivity depending on the direction of current.

Ogasahara, Akira; Kusakabe, Koichi

2005-04-01

84

The differential validity of hyperactivity\\/attention deficits and conduct problems among mentally retarded children  

Microsoft Academic Search

The independence of hyperactivity, attention deficits, and conduct problems among mentally retarded children was addressed using factors of the Conners' Teacher Rating Scale-39 (CTRS-39) and the more recently developed IOWA Conners' inattention\\/overactivity (IO) and aggression (A) subscales. CTRS-39 ratings were obtained for children of normal intelligence and for mentally retarded children. Differences between the groups were examined as were intercorrelations

Virginia E. Fee; Johnny L. Matson; Lisa A. Moore; Debra A. Benavidez

1993-01-01

85

Measuring Long-Distance Romantic Relationships: A Validity Study  

ERIC Educational Resources Information Center

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

Pistole, M. Carole; Roberts, Amber

2011-01-01

86

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

SciTech Connect

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

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

1991-10-01

87

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

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

88

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.

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

2014-01-01

89

Comparison of conduct disorder and hyperkinetic conduct disorder : a retrospective clinial study from north India.  

PubMed

In a retrospective descriptive study of hyperkinetic conduct disorders (HCD) and conduct disorders (CD), as per ICD-10 diagnostic criteria, their clinical and phenomenological correlates were compared; with an aim of describing their distinctive clinical profiles. 20 cases of HCD and 25 cases of CD were compared on socio-demographic variables, temperament and specified clinical variables. The two groups differed in terms of the HCD group having younger age of onset, a more gradual development of and longer duration of conduct symptoms as compared to CD children. HCD children also had temperamental deviance (in the form of inattention, distractibility), lower IQ, more perinatal complications and delayed milestones as compared to the CD group; which made significant contribution to discriminant functions between the two groups. Results point towards different pathways of development of conduct symptomatology in HCD group as compared to the CD group. PMID:21455373

Malhotra, S; Aga, V M; Balraj; Gupta, N

1999-04-01

90

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

PubMed Central

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

SANAZ, Aazami; SYAQIRAH, Akmal; KHADIJAH, Shamsuddin

2014-01-01

91

High pressure electrical conductivity studies of acid doped polybenzimidazole  

Microsoft Academic Search

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

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

1998-01-01

92

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

93

MFIX Validation Studies December 1994 to November 1996.  

National Technical Information Service (NTIS)

Presented are validation results for MFIX, a finite difference, transient code that solves the equations of transport for interacting fluid and granular phases. The predictions of MFIX are compared to four different experimental studies involving the beha...

E. J. Boyle W. N. Sams M. Syamlal S. M. Cho

1998-01-01

94

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

ERIC Educational Resources Information Center

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

Nugent, William R.

2004-01-01

95

Study of the validity of Goldberg's 60-item G. H. Q. in its Spanish version  

Microsoft Academic Search

A study has been conducted to establish the validity of a Spanish version of Goldberg's G. H. Q. in its 60-item final form. This screening instrument was tested on a sample of 200 patients who attended four general out-patient clinics. One hundred and nine of the patients were interviewed by various psychiatrists using the Standardized Psychiatric Interview.

P. E. Muñoz; J. L. Vázquez; E. Pastrana; F. Rodríguez; C. Oneca

1978-01-01

96

Scientists Begin Validation Study of Test to Detect Recurrence of Bladder Cancer  

Cancer.gov

A three-year study to validate a test to detect the recurrence of bladder cancer has been initiated by the National Cancer Institute (NCI), part of the National Institutes of Health (NIH), at 12 centers* across the United States and Canada. This test was conceived and is being conducted by NCI's Early Detection Research Network (EDRN).

97

Study of the conductance of ultrathin tin diphthalocyanine films  

SciTech Connect

The frequency dependences of the conductance and capacitance of Langmuir-Blodgett tin diphthalocyanine films in vacuum and in the case of adsorption of water molecules were studied. An increase in the film conductance due to adsorption was detected. Possible conduction mechanisms of tin diphthalocyanine in vacuum and water vapor are discussed. The permittivity of tin diphthalocyanine films was estimated from an analysis of the frequency dependence of the capacitance.

Levshin, N. L.; Pronin, N. N.; Forsh, P. A., E-mail: forsh@vega.phys.msu.ru [Moscow State University (Russian Federation); Yudin, S. G. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2008-02-15

98

Hyper-X Stage Separation Trajectory Validation Studies  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

99

Defect formation in LaGa(Mg,Ni)O3-delta : A statistical thermodynamic analysis validated by mixed conductivity and magnetic susceptibility measurements  

Microsoft Academic Search

A statistical thermodynamic approach to analyze defect thermodynamics in strongly nonideal solid solutions was proposed and validated by a case study focused on the oxygen intercalation processes in mixed-conducting LaGa0.65Mg0.15Ni0.20O3-delta perovskite. The oxygen nonstoichiometry of Ni-doped lanthanum gallate, measured by coulometric titration and thermogravimetric analysis at 923-1223K in the oxygen partial pressure range 5×10-5to0.9atm , indicates the coexistence of Ni2+

E. N. Naumovich; V. V. Kharton; A. A. Yaremchenko; M. V. Patrakeev; D. G. Kellerman; D. I. Logvinovich; V. L. Kozhevnikov

2006-01-01

100

A Simulation Study of Electrical Fiber Composite Conductivity  

NASA Astrophysics Data System (ADS)

Percolation concept has been used in this study to estimate the amount of conductive fibers embedded in polymeric matrix, necessary to establish conduction in this kind of composites. The resistance of composite materials is calculated by simulating composite samples with different size, containing conductive fibers with various lengths Calculation is based on detecting conductive pathways through the insulating matrix, these pathways are assumed to be resistances in parallel. Electrical resistance curves showed a percolative behavior of the samples versus volume fraction of filler. Lower conduction thresholds are obtained for fiber aspect ratio of 20 and sample size of 100. The electrical resistivity and the conduction thresholds of the carbon fiber reinforced polycarbonate composites have been characterized. Simulation results are in good agreement with an experimental result found in the literature.

Mezdour, D.; Sahli, S.

2008-11-01

101

Revised Space Fortress: A validation study  

Microsoft Academic Search

We describe briefly the redevelopment of Space Fortress (SF), a research tool widely used to study training of complex tasks\\u000a involving both cognitive and motor skills, to be executed on currentgeneration systems with significantly extended capabilities,\\u000a and then compare the performance of human participants on an original PC version of Space Fortress (SF) with the revised Space\\u000a Fortress (RSF). Participants

Wayne L. Shebilske; Richard A. Volz; Kevin M. Gildea; Judson W. Workman; Maitreyi Nanjanath; Sen Cao; Jonathan Whetzel

2005-01-01

102

A Validation Study of the Resilience Scale for Adolescents (READ)  

Microsoft Academic Search

In this study, the validity of the recently developed 28-item Resilience Scale for Adolescents (READ) was examined. Survey\\u000a data from a representative sample of 6,723 Norwegian senior high school students between 18 and 20 years of age were used\\u000a for this purpose. Validity and reliability were investigated by means of exploratory and confirmatory factor analysis, correlations\\u000a with other relevant variables, and

Tilmann von Soest; Svein Mossige; Kari Stefansen; Odin Hjemdal

2010-01-01

103

Hypersonic code efficiency and validation studies  

NASA Technical Reports Server (NTRS)

Renewed interest in hypersonic and supersonic flows spurred the development of the Compressible Navier-Stokes (CNS) code. Originally developed for external flows, CNS was modified to enable it to also be applied to internal high speed flows. In the initial phase of this study CNS was applied to both internal flow applications and fellow researchers were taught to run CNS. The second phase of this research was the development of surface grids over various aircraft configurations for the High Speed Research Program (HSRP). The complex nature of these configurations required the development of improved surface grid generation techniques. A significant portion of the grid generation effort was devoted to testing and recommending modifications to early versions of the S3D surface grid generation code.

Bennett, Bradford C.

1992-01-01

104

Structure and Mechanism Studies of High Conductivity Solid Ionic Conductors.  

National Technical Information Service (NTIS)

The structures and mechanisms of ion transport have been studied for key representatives of the class of superionic conductors (i.e., substances exhibiting ionic conductivity orders of magnitude larger than those of the classical defect ionic conductors)....

J. S. Kasper, W. L. Roth

1974-01-01

105

Conducting Phase IV clinical studies: a moral imperative?  

PubMed Central

The answer to this question lies in knowing the moral standing of Phase IV studies and whether we ought to conduct them. And to know this, in part, we need to compare them to studies in Phases I, II, and III and then determine where Phase IV studies stand in relation to Phase I–III studies scientifically and commercially.

Hill, TP

2012-01-01

106

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

107

Emphatic Tendency Scale for Student Teachers: Validity and Reliability Studies  

ERIC Educational Resources Information Center

The purpose of this study was to analyze the validity and reliability of the Empathic Tendency Scale, which was developed in order to identify student teachers' empathic tendencies. The sampling of the study consisted of 730 student teachers studying at Hacettepe University Faculty of Education. To determine the factor pattern of Empathic…

Kocak, Canan; Onen, Aysem Seda

2013-01-01

108

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.

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

2012-01-01

109

Conducting longitudinal studies of behavior using interactive voice response technology  

Microsoft Academic Search

Interactive voice response (IVR) systems represent a convergence of automated computerized interview techniques with telephone\\u000a survey research. This convergence affords unparalleled opportunities for conducting longitudinal behavioral research. Our\\u000a experiences, after several years of conducting multiple IVR studies investigating the circumstances and consequences of daily\\u000a alcohol use patterns, continues to generate excitement regarding the research potential of this methodology. This article

James C. Mundt; John S. Searles; M. W. Perrine; Dan Walter

1997-01-01

110

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

111

The Jackson Career Explorer: Two Further Validity Studies  

ERIC Educational Resources Information Center

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

Schermer, Julie Aitken

2012-01-01

112

Electrical studies on silver based fast ion conducting glassy materials  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

113

Faculty Conduct: An Empirical Study of Ethical Activism.  

ERIC Educational Resources Information Center

A study examined ethical activism, the willingness of college professors to inquire about or report possible unethical conduct by colleagues. Using data from a national empirical study of ethics and the academic profession, characteristics of faculty who engaged in ethical activism are examined, as are the consequences of ethical activism for…

Knight, Jonathan; Auster, Carol J.

1999-01-01

114

Skin Conductance Prestimulus Response: Analyses, Artifacts and a Pilot Study  

Microsoft Academic Search

Previous studies have suggested that the human autonomic nervous system responds to stimuli 2- 3 seconds before presentation. In these studies randomly chosen photographs with high and low affectivity were presented to participants. Ensemble averaging of skin conductance in the prestimulus epochs showed a differential response between high and low affectivity photographs. In our protocol the problem of idiosyncratic responses

S. JAMES P. SPOTTISWOODE; E. C. MAY

2003-01-01

115

Study Suggests Physicians Conduct Unnecessary Surveillance Colonoscopies: Questions and Answers  

Cancer.gov

The study was designed to understand the physician factors that influence the effective use of colorectal cancer surveillance in the United States. Researchers conducted this study to determine how gastroenterologists and general surgeons recommend surveillance for various polyps detected during an initial screening colonoscopy and compare their recommendations to published clinical practice guidelines.

116

Theoretical Study of the Quantum Conductance of Carbon Nanotube Structures  

NASA Astrophysics Data System (ADS)

We present a first-principles study of the quantum conductance of various carbon nanotube structures. First, the structural deformation and electrical conductance of crossed carbon nanotube junctions are studied. The structures are determined by constrained minimization of total energy, and the linear-response conductance is calculated using the Landauer-Büttiker formula. We show that the reason one sees a sizable intertube conductance is because of the structural deformation resulting from a contact force at the junction. In addition, the intertube conductance is very sensitive to external applied force, and hence the crossed junctions are potentially useful as nanoscale electro-mechanical devices. Second, the electronic structure and quantum conductance of nano-peapods, single walled carbon nanotubes with C_60 buckyballs in the interior, are studied. The energetics of buckyball motion is clarified within an ab initio pseudopotential density functional approach with a linear combination of atomic orbitals. Hybridization of C_60 states and nanotube states in the presence of potassium dopants leads to molecular level shifts until the C_60 LUMO level is pinned at the Fermi level. Consequently, resonant scattering together with controlled dopant concentration may produce interesting I-V characteristics. Third, we present tight-binding calculations on the effects of disorder on the conductance of the carbon nanotubes. Backscattering by long-range disorder is suppressed in metallic (n,n) tubes, but not in doped or gated semiconducting tubes. These results explain the distinctly different mean free paths of different kind of nanotubes as observed in Coulomb blockade measurements. The carbon nanotubes in various structures thus show unique and interesting electronic and transport properties, leading to new physical phenomena and making potential use in device application very promising.

Yoon, Young-Gui

2001-03-01

117

Research Measures for Dyscalculia: A Validity and Reliability Study.  

ERIC Educational Resources Information Center

This study sought to evaluate a measure of dyscalculia to determine its validity and reliability. It also tested use of the instrument with seventh graders and ascertained where errors attributed to dyscalculia were also present in an average sample of seventh graders. Results varied. (MNS)

Geiman, R. M.

1986-01-01

118

A Validation Study of the Student Oral Proficiency Assessment (SOPA).  

ERIC Educational Resources Information Center

This study validated the Student Oral Proficiency Assessment (SOPA), an oral proficiency instrument designed for students in elementary foreign language programs. Elementary students who were tested with the SOPA were also administered other instruments designed to measure proficiency. These instruments included the Stanford Foreign Language Oral…

Thompson, Lynn E.; Kenyon, Dorry M.; Rhodes, Nancy C.

119

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

120

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

121

Understanding Foreign Language Learning Strategies: A Validation Study  

ERIC Educational Resources Information Center

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

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

2013-01-01

122

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

123

Assessing Meritorious Teacher Performance: A Differential Validity Study.  

ERIC Educational Resources Information Center

The Teacher Assessment and Development System (TADS) - Meritorious Teacher Program (MTP) FORM instrument is used in the Dade County Public Schools, Miami, Florida, to evaluate teachers. Its validity for decisions concerning merit pay for master teachers was examined in this study. Specifically, its ability to discriminate between high performing…

Ellett, Chad D; Capie, William

124

College Study Skill Text Analysis Based on Validated Research Recommendations.  

ERIC Educational Resources Information Center

Ten randomly sampled college reading/study skill texts published since 1987 were analyzed based on external text aids and validated research recommendations. Many articles exist that contain a detailed description of one specific skill such as mapping, underlining, sequencing, etc., but only one recent article, "Ten Recommendations from Research…

Bryant, Diane; Lindeman, Troy

125

Reliable Digit Span: a systematic review and cross-validation study.  

PubMed

Reliable Digit Span (RDS) is a heavily researched symptom validity test with a recent literature review yielding more than 20 studies ranging in dates from 1994 to 2011. Unfortunately, limitations within some of the research minimize clinical generalizability. This systematic review and cross-validation study was conducted to address these limitations, thus increasing the measure's clinical utility. Sensitivity and specificity rates were calculated for the ?6 and ?7 cutoffs when data were globally combined and divided by clinical groups. The cross-validation of specific diagnostic groups was consistent with the data reported in the literature. Overall, caution should be used when utilizing the ?7 cutoff in all clinical groups and when utilizing the ?6 cutoff in the following groups: cerebrovascular accident, severe memory disorders, mental retardation, borderline intellectual functioning, and English as a second language. Additional limitations and cautions are provided. PMID:22156721

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

2012-03-01

126

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

127

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

128

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

129

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

PubMed Central

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

Steinert, Tilman; Hamann, Karen

2012-01-01

130

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.

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

2014-01-01

131

AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses  

SciTech Connect

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

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

2011-07-15

132

A reliability and validity study of the Palliative Performance Scale  

Microsoft Academic Search

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

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

2008-01-01

133

A comparative study of hydraulic conductivity estimations using geostatistics  

NASA Astrophysics Data System (ADS)

Three approaches for estimating the hydraulic conductivity ( K) of the Trifa aquifer, Morocco were investigated: (1) kriging of the K values obtained from pumping tests, (2) cokriging of the pumping test data with electrical resistivity data as a secondary variable, and (3) cokriging of the pumping test data with the slope of the water table. Gauss-transformed values of the variables are used because they provide more robust variograms and transformed values of the primary and secondary variables show correlations higher than the raw values, which is beneficial in cokriging. In cokriging with electrical resistivity, two zones are considered since the geological deposits are different from the north to the south of the aquifer, which is reflected in different correlations between the variables. Comparison of the three approaches is based mainly on the estimation errors, and to a lesser degree on the cross-validations of the corresponding variogram models and general considerations, like the measurements’ reliability and aquifer make-up. The best-estimated K is given by cokriging with the slope of the water table and is therefore preferred for further use in groundwater flow modeling. Thus, electrical resistivity or the slope of the water table can both be used as secondary variables to estimate K, especially in heterogeneous aquifers with lateral variations in lithology, as is the case of the Trifa aquifer.

El Idrysy, El Houcyne; de Smedt, Florimond

2007-05-01

134

Study on the bimodal filler influence on the effective thermal conductivity of thermal conductive adhesive  

Microsoft Academic Search

The thermal management for electronics systems becomes more crucial to the overall system performance as the packaging density\\u000a becomes much higher and the IC power increases at the same time. Thermal conductive adhesives (TCAs) have been widely adopted\\u000a in electronics systems. As an epoxy matrix with conductive fillers, it is essential to figure out the effective thermal conductivity\\u000a of this

Yan Zhang; Jing-yu Fan; Cong Yue; Johan Liu; Masahiro Inoue

2011-01-01

135

Studies on conducting polymer and conducting polymerinorganic composite electrodes prepared via a new cathodic polymerization method  

Microsoft Academic Search

A novel approach for the electrodeposition of conducting polymers and conducting polymer-inorganic composite materials is presented. The approach shows that conducting polymers, such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) can be electrodeposited by the application of a cathodic bias that generates an oxidizing agent, NO+, via the in-situ reduction of nitrate anions. This new cathodic polymerization method allows for the

Nikhilendra Singh

2010-01-01

136

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

Cancer.gov

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

137

The Tridimensional Personality Questionnaire: Reliability and Validity Studies and Derivation of a Short Form  

Microsoft Academic Search

A series of interrelated analyses were conducted on 2 samples of college students to examine the reliability and validity of the Tridimensional Personality Questionnaire (TPQ) and to develop and validate a short version of the scale. Factor analyses were conducted and tended to approximate Cloninger's proposed model. Novelty Seeking predicted a range of substance use and abuse measures, and substance

Kenneth J. Sher; Mark D. Wood; Timothy M. Crews; P. A. Vandiver

1995-01-01

138

Studies on conducting polymer and conducting polymerinorganic composite electrodes prepared via a new cathodic polymerization method  

NASA Astrophysics Data System (ADS)

A novel approach for the electrodeposition of conducting polymers and conducting polymer-inorganic composite materials is presented. The approach shows that conducting polymers, such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) can be electrodeposited by the application of a cathodic bias that generates an oxidizing agent, NO+, via the in-situ reduction of nitrate anions. This new cathodic polymerization method allows for the deposition of PPy and PEDOT as three dimensional, porous films composed of spherical polymer particles. The method is also suitable for the co-deposition of inorganic species producing conducting polymer-inorganic composite electrodes. Such composites are used as high surface area electrodes in Li-ion batteries, electrochemical hydrogen evolution and in the development of various other conducting polymer-inorganic composite electrodes. New Sn-PPy and Sb-PPy composite electrodes where Sn and Sb nanoparticles are well dispersed among the PPy framework are reported. These structures allow for decreased stress during expansion and contraction of the active material (Sn, Sb) during the alloying and de-alloying processes of a Li-ion battery anode, significantly alleviating the loss of active material due to pulverization processes. The new electrochemical synthesis mechanism allows for the fabrication of Sn-PPy and Sb-PPy composite electrodes directly from a conducting substrate and eliminates the use of binding materials and conducting carbon used in modern battery anodes, which significantly simplifies their fabrication procedures. Platinum (Pt) has long been identified as the most efficient catalyst for electrochemical water splitting, while nickel (Ni) is a cheaper, though less efficient alternative to Pt. A new morphology of PPy attained via the aforementioned cathodic deposition method allows for the use of minimal quantities of Pt and Ni dispersed over a very high surface area PPy substrate. These composite electrodes show significantly improved performance over bulk Pt or Ni electrodes in electrochemical hydrogen evolution applications. A variety of conducting polymer-inorganic composite materials are considered, showing that the obtained results are not limited to the mentioned inorganic materials and polymers. Various conducting polymer-inorganic composite electrodes with silver (Ag), gold (Au) and PEDOT are also reported and discussed in detail. The results presented herein open new pathways into the exploration, fabrication and applications of conducting polymer and conducting polymer-based inorganic composites in the field of energy storage and electrocatalysis.

Singh, Nikhilendra

139

Photoelectron studies of electrochemical diffusion of conducting polymer\\/transparent conductive metal oxide film interfaces  

Microsoft Academic Search

X-ray photoelectron spectroscopy (XPS) investigations of conducting polymer polythiophene (PT)\\/indium tin oxide (ITO) and PT\\/SnO2 interfaces have been conducted. Interfacial electrochemical diffusion of the metal oxide substrate species has been observed in both cases through electrochemical reduction process. XPS investigation has focused on the core-level energies and spectral profiles of the diffused substrate species into polymer matrix. A larger part

S. Takemura; H Kato; Y Nakajima

1999-01-01

140

Field Studies for Validation of Urban Dispersion Models - Current Status and Research Needs  

NASA Astrophysics Data System (ADS)

Urban dispersion models are important tools in addressing consequences from potential releases of harmful airborne materials in urban areas. These models are used by emergency management, law enforcement, and intelligence personnel to effectively plan for and respond to potential terrorist attacks and accidents. Field studies are vitally important for improving and validating these urban dispersion models which are used to simulate contaminant dispersion in and around cities. Over the past decade, three major urban field studies have been designed and conducted in the United States. The primary objectives of these studies have been to advance the state-of-science of understanding and modeling atmospheric flows and dispersion in and around cities, and to provide field observation for validation of urban dispersion models. The three major field studies (Salt Lake City, October 2000; Oklahoma City, July 2003; and New York City, August 2005) were conducted in cities of different sizes, in different geographic regions and during different times of the year. The tracer and meteorological data from these three field campaigns provide a rich dataset for validation of urban dispersion models over a range of conditions. The status and uses of the three urban dispersion datasets will be summarized, followed by a discussion of the current observational gaps and research needs in characterizing specific urban dispersion processes, such as outdoor-indoor coupling and outdoor-subway coupling.

Allwine, J.

2007-12-01

141

In pursuit of a valid information assessment method for continuing education: a mixed methods study  

PubMed Central

Background The Information Assessment Method (IAM) is a popular tool for continuing education and knowledge translation. After a search for information, the IAM allows the health professional to report what was the search objective, its cognitive impact, as well as any use and patient health benefit associated with the retrieved health information. In continuing education programs, professionals read health information, rate it using the IAM, and earn continuing education credit for this brief individual reflective learning activity. IAM items have been iteratively developed using literature reviews and qualitative studies. Thus, our research question was: what is the content validity of IAM items from the users’ perspective? Methods A two-step content validation study was conducted. In Step 1, we followed a mixed methods research design, and assessed the relevance and representativeness of IAM items. In this step, data from a longitudinal quantitative study and a qualitative multiple case study involving 40 family physicians were analyzed. In Step 2, IAM items were analyzed and modified based on a set of guiding principles by a multi-disciplinary expert panel. Results The content validity of 16 IAM items was supported, and these items were not changed. Nine other items were modified. Three new items were added, including two that were extensions of an existing item. Conclusion A content validated version of the IAM (IAM 2011) is available for the continuing education of health professionals.

2013-01-01

142

A Validation Study of the Barth-Shermis Social Studies Preference Scale.  

ERIC Educational Resources Information Center

Describes a study which tested the reliability and validity of the Barth-Shermis Social Studies Preference Scale as a measure of teaching orientations with respect to Barth and Shermis' three traditions. Subjects were 190 secondary social studies teachers. (AM)

White, Charles S.

1982-01-01

143

Automated removal of stimulus artifact in nerve conduction studies.  

PubMed

An algorithm for automated removal of stimulus artifact has been developed and tested on nerve conduction study data. The algorithm uses a hardware-based model of the stimulus artifact (SA). Model parameters are estimated from portions of the data that are judged to contain only the artifact. The model can be used to remove SA even when it is temporally overlapped with the nerve signal. Data are shown to demonstrate the algorithm's performance and to quantify the effect of SA removal on clinical parameters. PMID:17945961

Tracey, Brian H; Krishnamachari, Srivathsan

2006-01-01

144

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 {Al}_{133} , 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 X and Y directions are extremely poor, due to the overwhelming effect of the air thermal resistance. However, in the Z direction, the ETC improves almost linearly as the porosity decreases, and the value is much higher than those of X and Y directions. In the case of a 70 % filling ratio, when the porosity is below 59.7 %, the ETC in the Z direction exceeds the thermal conductivity of Al nanoclusters and approaches a peak value around the melting temperature of {Al}_{133} 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

2014-04-01

145

Preparation of organosoluble conductive polyaniline via precipitation polymerization and study of its conductivity  

Microsoft Academic Search

A new polymerization method for directly preparing organosoluble conductive polyaniline (PAn) doped with functionalized protonic acid with high yield was developed. Aniline was polymerized in the presence of functionalized protonic acid and oxidant in an aqueous medium containing a small part of acetone into PAn precipitate. Dibutylnaphthalene sulfonic acid (DBNSA) was found to be a better functionalized protonic acid than

Hong-Quan Xie; Yong-Mei Ma; Ding-Song Feng

2000-01-01

146

Hopping Conduction and Chemical Structure : a study on Silicon Suboxides  

NASA Astrophysics Data System (ADS)

Using an rf magnetron reactive sputtering technique thin films (<~ 1 mu-m) of amorphous silicon suboxides (a-SiOx, 0 < x < 2) have been deposited. The substrate temperature during deposition remained below 100oC. The films appear rather homogenous in composition (O/Si ratio), with an incorporated fraction of hydrogen and argon atoms of about 2-5 at.%. Taking into account the incorporated argon atoms no large (empty) void fraction has been detected. The films appear composed of Si-Si4-nOn (n= 0, ..., 4) building blocks, with an occurrence of the five individual building blocks in the different compounds generally in agreement with the statistical distribution of randomly dispersed O atoms in a bridging con- figuration between Si atoms. Furthermore, a large density of neutral paramagnetic defects (~ 1021 cm) has been observed. These defects are predominantly associated with silicon dangling bonds (DBs) in a silicon rich environment ( Si-Si3), although in the as deposited compounds with higher O/Si ratio x also Si DBs in more oxygenated environments ( Si-Si2O, Si-SiO2) are observed. Simultaneously, the electrical conductivity of the films indicates a dominant variable range hopping (vrh) mechanism in the compounds, at least up to room temperature. This conduction mechanism is described by a charge transport via thermally assisted tunneling events through localized (defect) states. Since the host network of the defect states in our SiOx films appears rather homogeneous on both macroscopic (mu-m) and microscopic (nm) scale the localized hopping states are expected to be more or less randomly distributed throughout the material. The energy distribution of the corresponding hopping sites is expected to extend over several tenths of an eV, as indicated by measurements on the conductivity around room temperature and supported by a theoretical Density Of States (DOS) model based on a defect-poole model. As a result the vrh conduction process in these SiOx films is adequately described by a system of localized states, randomly distributed in both space and energy. Analytically, it is possible to express the conductivity in such a system qualitatively in terms of the density and localization of the states around the position of the chemical potential. The conductivity appears to depend on the external parameters temperature (T) and electric field (F) and is described differently in different regimes of T and F. In this thesis a more quantitative description of the vrh process is derived numerically using percolation theory. To this purpose calculations on the percolation threshold of the site-to-site impedance in a system of randomly distributed hopping sites were performed. The results appear in qualitative agreement with the analytically derived results. Moreover, the calculations result in a clear quantified description of 1. the temperature dependence of the vrh conduction at low field strengths and 2. the field dependence of the conduction at low field strengths and/or low temperatures. Furthermore, a numerical study on the vrh conduction in a system of non-uniform localized states shows that the conductivity is effectively dominated by the charge transport through a subset of more weakly localized states. Measurements on the temperature and field dependence of the electrical conductivity in the deposited SiOx films appear in good agreement with the theoretical vrh models. Furthermore, quantitative information on the density and localization of the electronic states dominating the macroscopic charge transport is obtained by fitting the measured data with the numerically derived relations. The observed differences in resistivity of the investigated SiOx films appear well explained by a stronger localization of the hopping sites in the more oxygenated environments. Furthermore, it appears that only a small fraction of the neutral paramagnetic states, viz. the more weakly localized states, contributes significantly to the macroscopic charge transport in the vrh conduction process. Both observations are supported by mea

van Hapert, J. J.

2002-06-01

147

Low Frequency Eddy Current Benchmark Study for Model Validation  

NASA Astrophysics Data System (ADS)

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.; Cherry, M. R.; Knopp, J. S.; Aldrin, J. C.; Sabbagh, H. A.; Boehnlein, T. R.

2011-06-01

148

Ulnar nerve at the elbow - normative nerve conduction study  

PubMed Central

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

2013-01-01

149

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

150

Job Training Partnership Act Matching Fund Validation Study.  

ERIC Educational Resources Information Center

The Job Training Partnership Act (JTPA) of 1982 is a federally funded program for, and directed by, the states and provides that the governor of the state is the official recipient of JTPA funds. A study was conducted in Tennessee to identify and document a generalizable formula for determining eligible funds used to match JTPA expenditures to…

Bellott, Fred K.; And Others

151

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

152

Challenges of conducting experimental studies within a clinical nursing context.  

PubMed

In recent years, several distinguished scholars have advocated for nursing research that may carry strong evidence for practice. Their advocacy have highlighted that nursing science has reached a point where as nurse researchers we need to develop the questions we ask and design studies that have the power to produce solid, translational, evidence-based knowledge. To do so, we need to carry out experimental tests on complex, everyday nursing interventions and activities. We also need to create public space to present accounts of our endeavours pursuing this type of design in clinical practice. This paper will discuss some of the most important insights gained from conducting a quasi-experimental study in which the aim was to investigate the effect of a theory-based intervention, targeting knowledge and attitudes among registered nurses regarding cancer pain management. The importance of careful practical and methodological planning is emphasised, and the need for participation-friendly interventions is discussed. PMID:24355415

Gustafsson, M; Bohman, D M; Borglin, G

2014-05-01

153

Assessment of Junior Doctor performance: a validation study  

PubMed Central

Background In recent years, Australia has developed a National Junior Doctor Curriculum Framework that sets out the expected standards and describes areas of performance for junior doctors and through this has allowed a national approach to junior doctor assessment to develop. Given the significance of the judgments made, in terms of patient safety, development of junior doctors, and preventing progression of junior doctors moving to the next stage of training, it is essential to develop and validate assessment tools as rigorously as possible. This paper reports on a validation study of the Junior Doctor Assessment Tool as used for PGY1 doctors to evaluate the psychometric properties of the instrument and to explore the effect of length of experience as a PGY1 on assessment scores. Methods This validation study of the Australian developed Junior Doctor Assessment Tool as it was used in three public and other associated hospitals in Western Australia for PGY1 across a two year period addressed two core aims, namely: (1) to evaluate the psychometric properties of the instrument; (2) to explore the effect of length of experience as a PGY1 on assessment scores. Results The highest mean scores were for professional behaviours, teamwork and interpersonal skills and the lowest were for procedures. Most junior doctors were assessed three or more times and scores were not different in the first rotation compared to subsequent rotations. While statistically significant, there appeared to be little practical influence on scores obtained by the number of times they were assessed. Principal component analysis identified two principal components of junior doctor performance are being assessed rather than the commonly reported three. A Cronbach Alpha of .883 was calculated for the 10 item scale. Conclusions Now that the components of the tool have been analysed it will be more meaningful and potentially more influential to consider these factors on the potential educational impact of this assessment process for monitoring junior doctor development and progression.

2013-01-01

154

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.

2013-01-01

155

Crustal conductivity anomaly under the Black Hills: a magnetotelluric study  

Microsoft Academic Search

Magnetotelluric sounding results from the Black Hills of South Dakota provide evidence for a highly conducting layer in the upper crust. The cause of this high conductivity is attributed to the dehydration process in the lower crust.

D. Rankin; I. K. Reddy

1973-01-01

156

NAEP Validity Studies: A Study of Equating in NAEP.  

National Technical Information Service (NTIS)

This study investigates the amount of uncertainty added to NAEP estimates by equating error under both ideal and less than ideal circumstances. For example, circumstances led to a situation in which the 1994 to 1992 reading assessment equating had to be b...

2003-01-01

157

A Study of Equating in NAEP. NAEP Validity Studies.  

ERIC Educational Resources Information Center

This study investigates the amount of uncertainty added to National Assessment of Educational Progress (NAEP) estimates by equating error under both ideal and less than ideal circumstances. Data from past administrations are used to guide simulations of various equating designs and error due to equating is estimated empirically. The design…

Hedges, Larry V.; Vevea, Jack L.

158

Change over Time: Conducting Longitudinal Studies of Children's Cognitive Development  

PubMed Central

Developmental scientists have argued that the implementation of longitudinal methods is necessary for obtaining an accurate picture of the nature and sources of developmental change (Magnusson & Cairns, 1996; Morrison & Ornstein, 1996; Magnusson & Stattin, 2006). Developmentalists studying cognition have been relatively slow to embrace longitudinal research, and thus few exemplar studies have tracked individual children’s cognitive performance over time and even fewer have examined contexts that are associated with this growth. In this article we first outline some of the benefits of implementing longitudinal designs. Using illustrations from existing studies of children’s basic cognitive development and of their school-based academic performance, we discuss when it may be appropriate to employ longitudinal (versus other) methods. We then outline methods for integrating longitudinal data into one’s research portfolio, contrasting the leveraging of existing longitudinal data sets with the launching of new longitudinal studies in order to address specific questions concerning cognitive development. Finally, for those who are interested in conducting longitudinal investigations of their own, we provide practical on-the-ground guidelines for designing and carrying out such studies of cognitive development.

Grammer, Jennie K.; Coffman, Jennifer L.; Ornstein, Peter A.; Morrison, Frederick J.

2014-01-01

159

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

160

Spectroscopic and Electrical Conductivity Studies of Some Semicarbazide Hydrochloride Complexes  

NASA Astrophysics Data System (ADS)

The infrared and electronic absorption spectra of semicarbazide hydrochloride and its complexes with anthracene, tetracyanoquinodimethane TCNQ, Na-fluorescein and cupferron were recorded in the regions 200-4000cm-1 and 200-400nm. The new bands that appeared in the complex spectra were assigned. The effect of the complex formation on the frequency and intensity of the active vibrational bands was also studied. The internal energy changes of the complexes were calculated in a new line of calculation to give a clear insight about the stability of the investigated complexes. The electrical conductivity of the complexes was measured in the temperature range 25-130°C. The activation energy E was calculated and discussed on the basis of the spectroscopic information.

Fadly, M.; El-Manakhly, H.

1998-11-01

161

A Comparative Study of Construct Validity of Graduation English Proficiency Tests between Universities in Taiwan and Mainland China  

Microsoft Academic Search

This paper reports findings from an analytical study of how construct validity is reflected in national mandatory English graduation tests that have been widely conducted at universities in Taiwan and Mainland China. The findings relate to key test perceptions for test designers and stakeholders to consider should the mandatory testing systems in use be further endorsed by the educational authorities

Byron Gong

162

A Cross-Validation Study of the Kirton Adaption-Innovation Inventory in Three Research and Development Organizations.  

ERIC Educational Resources Information Center

A cross-validation study of the Kirton Adaption-Innovation Inventory (KAI) was conducted with 256 professional employees from three applied research and development organizations. The KAI correlated well with both direct and indirect measures of innovativeness in all three organizations. (Author/MH)

Keller, Robert T.; Holland, Winford E.

1979-01-01

163

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

Microsoft Academic Search

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

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

2001-01-01

164

An Aptitude-Test Battery for Court-Reporter Training: Initial Results of a Longitudinal Validation Study.  

ERIC Educational Resources Information Center

In order to identify a battery of aptitude tests which could adequately predict the success of applicants to its court-reporting program, MacCormac Junior College contracted with Science Research Associates in Fall 1976 to conduct a longitudinal validation study of court-reporting aptitude measures. Eight tests were administered to each…

Jacobsen, Linda S.; Borchardt, Gordon C.

165

The Competence Assessment for Standing Trial for Defendants with Mental Retardation (Cast-MR)A Validation Study  

Microsoft Academic Search

The purpose of this study was to develop and validate an instrument for the assessment of competence to stand trial in criminal defendants with mental retardation. Three experiments were conducted on the instrument developed, Competence Assessment for Standing Trial for Defendants with Mental Retardation (CAST-MR). Experiment 1 consisted of three pilot testings with mentally retarded group home residents, Experiment 2

CAROLINE T. EVERINGTON

1990-01-01

166

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

Microsoft Academic Search

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

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

167

Hypertension Knowledge-Level Scale (HK-LS): A Study on Development, Validity and Reliability  

PubMed Central

This study was conducted to develop a scale to measure knowledge about hypertension among Turkish adults. The Hypertension Knowledge-Level Scale (HK-LS) was generated based on content, face, and construct validity, internal consistency, test re-test reliability, and discriminative validity procedures. The final scale had 22 items with six sub-dimensions. The scale was applied to 457 individuals aged ?18 years, and 414 of them were re-evaluated for test-retest reliability. The six sub-dimensions encompassed 60.3% of the total variance. Cronbach alpha coefficients were 0.82 for the entire scale and 0.92, 0.59, 0.67, 0.77, 0.72, and 0.76 for the sub-dimensions of definition, medical treatment, drug compliance, lifestyle, diet, and complications, respectively. The scale ensured internal consistency in reliability and construct validity, as well as stability over time. Significant relationships were found between knowledge score and age, gender, educational level, and history of hypertension of the participants. No correlation was found between knowledge score and working at an income-generating job. The present scale, developed to measure the knowledge level of hypertension among Turkish adults, was found to be valid and reliable.

Erkoc, Sultan Baliz; Isikli, Burhanettin; Metintas, Selma; Kalyoncu, Cemalettin

2012-01-01

168

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

169

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

170

The Cancer Message Literacy Tests: Psychometric Analyses and Validity Studies  

PubMed Central

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

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

2012-01-01

171

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

NASA Astrophysics Data System (ADS)

It is shown how both the principles of extremum of entropy production, which are often used in the study of complex systems, follow from the maximization of overall system conductivities, under appropriate constraints. In this way, the maximum rate of entropy production (MEP) occurs when all the forces in the system are kept constant. On the other hand, the minimum rate of entropy production (mEP) occurs when all the currents that cross the system are kept constant. A brief discussion on the validity of the application of the mEP and MEP principles in several cases, and in particular to the Earth's climate is also presented.

Heitor Reis, A.

2014-07-01

172

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

173

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

174

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

175

A protocol for conducting rainfall simulation to study soil runoff.  

PubMed

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

176

Conductivity and thermal studies of polymer electrolytes based on polyetheresters  

Microsoft Academic Search

A series of aliphatic polyetheresters of poly(ethylene glycol) and diacyl chloride containing a different number of methylene units was synthesized. The polyetheresters synthesized were complexed with lithium perchlorate to obtain a polymer electrolyte with high ionic conductivity and reduced crystallinity. The effect of polymer structure on the ionic conductivity and thermal properties of the polymer electrolytes was investigated. The ionic

Dong-Won Kim; Young-Gi Lee; Jung-Ki Park

1996-01-01

177

Thermal conductivity studies on Si\\/SiC ceramic composites  

Microsoft Academic Search

Ceramic heat exchangers are increasingly used in many nuclear power plants. Silicon carbide has been treated as a promising material for heat exchanger application since it has good thermal conductivity and corrosion resistance. In this work, four different types of Si\\/SiC ceramic composites were prepared by liquid silicon infiltration technique. Thermal conductivities of these ceramic composites at different temperatures are

G. Amirthan; A. Udaya kumar; M. Balasubramanian

2011-01-01

178

IDENTIFYING SPECIFIC CHEMOTHERAPEUTIC AGENTS IN MEDICARE DATA: A VALIDATION STUDY  

PubMed Central

Background Large healthcare databases are increasingly used to examine the dissemination and benefits and harms of chemotherapy treatment in routine practice, particularly among patients excluded from trials (e.g., the elderly). Misclassification of chemotherapy could bias estimates of frequency and association, warranting an updated assessment. Methods We evaluated the validity of Medicare claims to identify receipt of chemotherapy and specific agents delivered to elderly stage II/III colorectal (CRC), in situ/early stage breast, non-small cell lung, and ovarian cancer patients using the National Cancer Institute’s Patterns of Care studies (POC) as the gold standard. The POC collected data on chemotherapy treatment by re-abstracting hospital records, contacting physicians, and reviewing medical records. Patients’ POC data were linked and compared to their Medicare claims for 2–12 months post-diagnosis. Kappa, sensitivity (Se), specificity (Sp), positive and negative predictive values and 95% confidence intervals were calculated for the receipt of any chemotherapy and specific agents. Results Se and Sp of Medicare claims to identify any chemotherapy were high across all cancer sites. We found substantial variation in validity across agents, by site and administration modality. Capecitabine, an oral CRC treatment, was identified in claims with high specificity (98%) but low sensitivity (47%), whereas oxaliplatin, an intravenously administered CRC agent had higher sensitivity (75%) and similar specificity (97%). Conclusions Receipt of chemotherapy and specific intravenous agents can be identified using Medicare claims, showing improvement from prior reports; yet, variation exists. Future studies should assess newly-approved agents and the impact of coverage decisions for these agents under the Medicare Part D program.

Lund, Jennifer L.; Sturmer, Til; Harlan, Linda C.; Sanoff, Hanna K.; Sandler, Robert S.; Brookhart, M. Alan; Warren, Joan L.

2011-01-01

179

GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: CHEMICAL DEHALOGENATION (QUICK REFERENCE FACT SHEET)  

EPA Science Inventory

Systematically conducted, well-documented treatability studies are an important component of remedy evaluation and selection under the Superfund program. his manual focuses on chemical dehalogenation treatability studies conducted in support of remedy selection that is conducted ...

180

Genome-wide association study of conduct disorder symptomatology  

PubMed Central

Conduct disorder (CD) is one of the most prevalent childhood psychiatric conditions, and is associated with a number of serious concomitant and future problems. CD symptomatology is known to have a considerable genetic component, with heritability estimates in the range of 50%. Despite this, there is a relative paucity of studies aimed at identifying genes involved in the susceptibility to CD. In this study, we report results from a genome-wide association study of CD symptoms. CD symptoms were retrospectively reported by a psychiatric interview among a sample of cases and controls, in which cases met the criteria for alcohol dependence. Our primary phenotype was the natural log transformation of the number of CD symptoms that were endorsed, with data available for 3963 individuals who were genotyped on the Illumina Human 1M beadchip array. Secondary analyses are presented for case versus control status, in which caseness was established as endorsing three or more CD symptoms (N= 872 with CD and N= 3091 without CD). We find four markers that meet the criteria for genome-wide significance (P < 5 × 10?8) with the CD symptom count, two of which are located in the gene C1QTNF7 (C1q and tumor necrosis factor-related protein 7). There were six additional SNPs in the gene that yielded converging evidence of association. These data provide the first evidence of a specific gene that is associated with CD symptomatology. None of the top signals resided in traditional candidate genes, underscoring the importance of a genome-wide approach for identifying novel variants involved in this serious childhood disorder.

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

2013-01-01

181

Genome-wide association study of conduct disorder symptomatology.  

PubMed

Conduct disorder (CD) is one of the most prevalent childhood psychiatric conditions, and is associated with a number of serious concomitant and future problems. CD symptomatology is known to have a considerable genetic component, with heritability estimates in the range of 50%. Despite this, there is a relative paucity of studies aimed at identifying genes involved in the susceptibility to CD. In this study, we report results from a genome-wide association study of CD symptoms. CD symptoms were retrospectively reported by a psychiatric interview among a sample of cases and controls, in which cases met the criteria for alcohol dependence. Our primary phenotype was the natural log transformation of the number of CD symptoms that were endorsed, with data available for 3963 individuals who were genotyped on the Illumina Human 1M beadchip array. Secondary analyses are presented for case versus control status, in which caseness was established as endorsing three or more CD symptoms (N = 872 with CD and N = 3091 without CD). We find four markers that meet the criteria for genome-wide significance (P<5 × 10(-8)) with the CD symptom count, two of which are located in the gene C1QTNF7 (C1q and tumor necrosis factor-related protein 7). There were six additional SNPs in the gene that yielded converging evidence of association. These data provide the first evidence of a specific gene that is associated with CD symptomatology. None of the top signals resided in traditional candidate genes, underscoring the importance of a genome-wide approach for identifying novel variants involved in this serious childhood disorder. PMID:20585324

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

2011-08-01

182

Ionic Conductivity Study on Polycrystalline LiFeVO4  

NASA Astrophysics Data System (ADS)

The compound LiFeVO4 was prepared by solid state reaction at 570° C for 8 h. The X-ray diffraction pattern revealed an orthorhombic crystal structure. Thermogravimetric measurements revealed a reversible mechanism which is attributed to moisture loss and uptake. Impedance spectroscopy measurements were carried out at temperatures from 25 to 500° C at 25° C steps. Equivalent circuits were drawn to fit the impedance measurement results at each temperature step. The elements of the equivalent circuits were assigned to three different conductivity processes, i.e., to bulk, grain boundary and protonic conductivity. The protonic conductivity was attributed to the moisture uptake revealed in the thermogravimetric measurements. Arrhenius plots were drawn for the bulk and grain boundary conductivity processes and the activation energies were calculated. The activation energy of the bulk conductivity process was calculated to be 0.3 eV over the temperature range from 175 to 500° C and the activation energy of the grain boundary conductivity process was calculated to be 0.5 eV from 300 to 500° C and 0.15 eV from 175 to 275° C. An explanation of the existence of these two grain boundary activation energies is given based on easy paths theory. The log-log plot of conductivity versus temperature was drawn at temperatures 200, 250, 300, 400, 450 and 500° C and the hopping rates were determined at each of the above temperatures.

Kazakopoulos, A.; Chrissafis, K.; Kalogirou, O.

2010-01-01

183

Perovskite transparent conducting oxides: an ab initio study.  

PubMed

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

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

2013-10-16

184

Perovskite transparent conducting oxides: an ab initio study  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

185

Matching in epidemiologic studies: validity and efficiency considerations.  

PubMed

Validity and efficiency issues are considered with regard to the use of matching and random sampling as alternative methods of subject selection in follow-up and case-control studies. We discuss the simple situation involving dichotomous disease and exposure variables and a single dichotomous matching factor, and we consider the influence on efficiency of a possible loss of subjects due to matching constraints. The decision to match or not should be motivated by efficiency considerations. An efficiency criterion based on a comparison of confidence intervals under matching and random sampling for the effect measure of interest (the risk ratio and risk difference in follow-up studies, and the odds ratio in case-control studies) leads to the following conclusions when the sampling method does not influence the size of the comparison group. In follow-up studies, matching on a confounder is expected to lead to a gain in efficiency over random sampling, while matching on a nonconfounder is not expected to result in a loss of efficiency. In case-control studies, the same conclusions hold, except that matching is not as advantageous as in follow-up studies and can lead to a loss of efficiency in some situations (usually of little practical importance). When matching reduces the size of the comparison group, there is likely to be a meaningful gain in efficiency due to random sampling only when the matched comparison group is at most 40-50% the size of the randomly-sampled comparison group is a follow-up study, and at most 50-65% the size in a case-control study. PMID:7272415

Kupper, L L; Karon, J M; Kleinbaum, D G; Morgenstern, H; Lewis, D K

1981-06-01

186

Validating a satisfaction questionnaire using multiple approaches: A case study  

Microsoft Academic Search

We examined the validity of a questionnaire designed to measure the satisfaction of users of health services, using multiple tests of construct validity. Members of 2 health insurance plans in Geneva (Switzerland) answered a mailed questionnaire in 1992 (n = 1007) and 1993 (n = 1424). Response rates were 82%, participants were 18–44 years old in 1992. The questionnaire included

Jean-François Etter; Thomas V. Perneger

1997-01-01

187

The Anomalous Sentences Repetition Test: Replication and Validation Study.  

ERIC Educational Resources Information Center

Presents a brief clinical test, derived from earlier neuropsychological instruments, with evidence for its reliability, interscorer agreement, and validity. The latter is based upon correlations with both CAT scan measures of cortical atrophy and ventricular enlargement, as well as correlations with seven other previously validated cognitive…

Weeks, David J.

1986-01-01

188

Soil moisture estimation through Active and Passive sensors : An intercomparison and validation study in Northeast Asia  

NASA Astrophysics Data System (ADS)

Soil moisture is an important role for hydrological cycle as well as exchanges of energy and water between the land surface and the atmosphere. Although intercomparison and validation are a weighty task and particularly challenging work for analyzing remote sensing of soil moisture, such tasks are indispensable for understanding soil moisture spatio-temporal variability at different scales. A key point in the validation of soil moisture products is the gap in spatial and temporal scales between satellite and in situ observations. In this study, we estimate the Active (ASCAT) and Passive (AMSR-E) sensors soil moisture dynamics for assessing the accuracy of satellite-based soil moisture products and comparing what sensor is more good agreement with the ground soil moisture pattern over a growing season period in 2010 on Northeast Asia. Satellite soil moisture products were systematically compared with in situ observations from 4 different sites (Suwon, Seosan, Jeonju, Cheorwon) located in the Korea peninsula. Furthermore, we conducted with renormalisation methods for removing the systematic differences (bias, RMSE). As a result, ASCAT product gave the highest correlation coefficient (r = 0.788) with the in situ data. Our study will contribute not only to understand satellite validation of remotely sensed soil moisture products, but also to utilize these products as application areas including flood forecasting, drought monitoring and asian dust research.

Cho, E.; Choi, M.

2013-12-01

189

Verification and Validation Studies for the LAVA CFD Solver  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

190

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

Microsoft Academic Search

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

Bayram Çetin; Erkan Yaman; Adem Peker

2011-01-01

191

Cyber Victim and Bullying Scale: A Study of Validity and Reliability  

ERIC Educational Resources Information Center

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

Cetin, Bayram; Yaman, Erkan; Peker, Adem

2011-01-01

192

Study on Mixed-Pixel Clumping Index Calculation and Validation  

NASA Astrophysics Data System (ADS)

Clumping index is an important vegetation structure parameter to describe the foliage clumping in canopy quantitatively. The effect of foliage clumping is generally considered at the canopy and below canopy scale in pure vegetation pixel. The mixed-pixel clumping index (MPCI) is an equivalent clumping index. In previous studies, it is usually equal to the clumping index of the dominated vegetation type in the mixed pixel. However, this calculation method cannot consider the effect of mixed pixels and it is almost impossible to get an accurate clumping index of mixed pixels. We propose a new method to calculate the clumping index of mixed pixels by combining the medium-spatial resolution image. The method coupled the linear mixture model and the directional gap fraction formula, and the formula of the mixed-pixel clumping index is deduced (Eq. 1). The scale difference caused by the inhomogeneity of fractional vegetation of cover, clumping index and leaf angle distributions inside the mixed pixel can be better considered in the method. cos(?) ·ln[1 n? P (? )] ----c--ni=1-f,i-c--- ?c = - 1 n? -ln[Pf,i(?f)] cos(?f)·Gc(?c)·ni=1?f,i·Gf,i(?f) (1) where the subscripts f and c correspond to the medium- and coarse-resolution of satellite data respectively. ? is clumping index, ? is view zenith angle, P is gap frequency and G is the projection of unit leaf area in the ? direction. It is assumed that nis the number of medium-resolution pixels covered inside the coarse-resolution pixel. And the end-member gap fraction and clumping index inside mixed pixels are known. They are obtained from medium-resolution images. To analyze the influence of the inhomogeneity inside mixed pixels to the equivalent clumping index, we made the analysis in two cases: one is that the pixel is mixed with the same vegetation type but different fractional cover; the other is that the pixel is mixed with different vegetation types. The result shows that the inhomogeneity of vegetation type and fractional vegetation of cover inside mixed-pixel has an important influence on the mixed-pixel clumping index and according to the above analysis we found that in some area the clumping index difference before and after the mixed pixel correction is obvious. At present there is no a direct way to measure the large scale clumping index. We validate the method by indirect method, which is we employed it to VALERI (VAlidation of Land European Remote sensing Instruments) datasets. Then we correct the coarse resolution effective LAI (Leaf Area Index) with MPCI and compare the results to the true LAI. The Preliminary validation shows good accuracy. The correlation coefficient, R2 is above 0.90; the root-mean-square error (RMSE) is about 0.1, and the average relative error is below 10%. Based on the MPCI method, we employ HJ-1A/1B CCD data to make 1km x 1km MPCI product over Heihe area of China. Through the analysis and validation, the method of MPCI is capable of correcting the scale difference caused by the inhomogeneity of the vegetation cover inside mixed pixels and has more accuracy, which is significant for LAI inversion of coarse spatial resolution and the precision accuracy application of carbon cycle model.

Ma, Q. M.; Li, J.; Liu, Q.; Liu, Q. H.

2012-04-01

193

[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

194

Heat conduction in graphene: experimental study and theoretical interpretation  

NASA Astrophysics Data System (ADS)

We review the results of our experimental investigation of heat conduction in suspended graphene and offer a theoretical interpretation of its extremely high thermal conductivity. The direct measurements of the thermal conductivity of graphene were performed using a non-contact optical technique and special calibration procedure with bulk graphite. The measured values were in the range of ~3000-5300 W mK-1 near room temperature and depended on the lateral dimensions of graphene flakes. We explain the enhanced thermal conductivity of graphene as compared to that of bulk graphite basal planes by the two-dimensional nature of heat conduction in graphene over the whole range of phonon frequencies. Our calculations show that the intrinsic Umklapp-limited thermal conductivity of graphene grows with the increasing dimensions of graphene flakes and can exceed that of bulk graphite when the flake size is on the order of a few micrometers. The detailed theory, which includes the phonon-mode-dependent Gruneisen parameter and takes into account phonon scattering on graphene edges and point defects, gives numerical results that are in excellent agreement with the measurements for suspended graphene. Superior thermal properties of graphene are beneficial for all proposed graphene device applications.

Ghosh, S.; Nika, D. L.; Pokatilov, E. P.; Balandin, A. A.

2009-09-01

195

A controlled study of Tourette syndrome. II. Conduct.  

PubMed Central

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

Comings, D E; Comings, B G

1987-01-01

196

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.

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

2013-01-01

197

Construction and Validation of a Plunge Electrode Array for Three-Dimensional Determination of Conductivity in the Heart  

Microsoft Academic Search

The heart's response to electrical shock, electrical propagation in sinus rhythm, and the spatiotemporal dynamics of ventricular fibrillation all depend critically on the electrical anisotropy of cardiac tissue. Analysis of the microstructure of the heart predicts that three unique intracellular electrical conductances can be defined at any point in the ventricular wall; however, to date, there has been no experimental

Darren A. Hooks; Mark L. Trew

2008-01-01

198

Comparing the Validity of Clinician-Generated Diagnosis of Conduct Disorder to the Diagnostic Interview Schedule for Children  

ERIC Educational Resources Information Center

Clinician diagnoses of conduct disorder (CD) were compared to the diagnoses of CD generated by a structured interview against an observed criterion. Participants were 534 youth from a large residential program in the Midwest for delinquent youth. Rates of in-program CD behaviors were gathered from staff observations of the youth over a 9-month…

Jewell, Jeremy; Handwerk, Michael; Almquist, Julie; Lucas, Christopher

2004-01-01

199

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

200

The Ego Impairment Index and schizophrenia: a validation study.  

PubMed

This study is an extension of our work on a new scale, the Ego Impairment Index (EII; Perry & Viglione, 1991). The index is theoretically based on Beres's (1956) model of ego assessment and was empirically developed on a sample of melancholic, depressed outpatients, diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (3rd ed. [DSM-III]; American Psychiatric Association, 1980). The EII is derived from the Rorschach Inkblot Test and offers a single composite score of ego impairment. This study validates the use of the EII with a heterogeneous sample of schizophrenic patients. In support of the trait-like characteristics of the scale, the EII continues to be expressed as a single factor, with a correlation of .98 when comparing the original factor derived from a melancholic population with this sample of schizophrenic patients. Significant correlations were also found between the EII and other clinical indices, including the Magical Ideation Scale, the Schizophrenia Index, and the Minnesota Multiphasic Personality Inventory (MMPI). Finally, the EII was found to differentiate between a paranoid subgroup and a mixed undifferentiated/disorganized subgroup who theoretically have more ego impairment. These results offer support for the use of the EII as an empirical means of quantitatively and qualitatively assessing thought disorder within a theoretical framework. Further research is needed to understand the application of the EII across different diagnostic groups and its relationship to other indices of psychological disturbance. PMID:1512674

Perry, W; Viglione, D; Braff, D

1992-08-01

201

Moral judgment reloaded: a moral dilemma validation study  

PubMed Central

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

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

2014-01-01

202

An automated tube-type blood viscometer: validation studies.  

PubMed

The technical complexity of previous rheometers has tended to limit the availability of blood viscosity data obtained over a wide range of shear rates. However, an automated tube-type viscometer, the Rheolog, has been developed; it employs a disposable flow assembly and less than five minutes are required to obtain blood viscosity results over a shear rate range of 1-1500 s(-1). We have carried out validation studies of the Rheolog using normal human blood and have compared these results with those obtained by cone-plate and Couette viscometers; storage time and temperature effects were also evaluated. Replicate measurements indicated mean CV levels less than 5%, and were independent of hematocrit and shear rate. Rheolog blood viscosity data agreed closely with those from other viscometers: average Rheolog differences from mean cone-plate and Couette values were -0.3% at 28% hematocrit, -1.4% at 41% hematocrit (i.e., native), and 1.0% at 56% hematocrit. Storage at room temperature up to 8 hours and at 4 degrees C up to 4 days had minimal effects whereas notable changes were observed when stored for 3 hours at 37 degrees C. Our results indicate that, within the hematocrit and shear rate limits employed herein, the Rheolog provides rapid, accurate and reproducible blood viscosity data, and suggest its usefulness for both basic science and clinical studies. PMID:15894822

Alexy, T; Wenby, R B; Pais, E; Goldstein, L J; Hogenauer, W; Meiselman, H J

2005-01-01

203

Estimating Anesthesia Time Using the Medicare Claim: A Validation Study  

PubMed Central

Introduction Procedure length is a fundamental variable associated with quality of care, though seldom studied on a large scale. We sought to estimate procedure length through information obtained in the anesthesia claim submitted to Medicare to validate this method for future studies. Methods The Obesity and Surgical Outcomes Study enlisted 47 hospitals located across New York, Texas and Illinois to study patients undergoing hip, knee, colon and thoracotomy procedures. 15,914 charts were abstracted to determine body mass index and initial patient physiology. Included in this abstraction were induction, cut, close and recovery room times. This chart information was merged to Medicare claims which included anesthesia Part B billing information. Correlations between chart times and claim times were analyzed, models developed, and median absolute differences in minutes calculated. Results Of the 15,914 eligible patients, there were 14,369 where both chart and claim times were available for analysis. In these 14,369, the Spearman correlation between chart and claim time was 0.94 (95% CI 0.94, 0.95) and the median absolute difference between chart and claim time was only 5 minutes (95% CI: 5.0, 5.5). The anesthesia claim can also be used to estimate surgical procedure length, with only a modest increase in error. Conclusion The anesthesia bill found in Medicare claims provides an excellent source of information for studying operative time on a vast scale throughout the United States. However, errors in both chart abstraction and anesthesia claims can occur. Care must be taken in the handling of outliers in this data.

Silber, Jeffrey H.; Rosenbaum, Paul R.; Even-Shoshan, Orit; Mi, Lanyu; Kyle, Fabienne; Teng, Yun; Bratzler, Dale W.; Fleisher, Lee A.

2012-01-01

204

Conductivity and Structural Studies of Magnesium Based Solid Electrolytes  

NASA Astrophysics Data System (ADS)

In this investigation, magnesium based solid electrolyte was prepared via ball milling method. MgI2-Mg3(PO4)2 were mixed in varied compositions and ball milled for 1 hour. The milled mixtures were pelletized and the conductivity was measured using the Impedance Spectroscopy (IS) method. The MgI2-Mg3(PO4)2 pellet containing 30% wt of MgI2 showed maximum conductivity of 7.00×10-4 S/cm. Further structural characterization and analysis of these Mg2+ ion conductors were carried out by using X-ray diffraction (XRD), Fourier Transform Infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM). The sample with maximum conductivity has been chosen to be used as an electrolyte in the magnesium solid state battery. The fabricated coin cell showed open circuit voltage (OCV) of 0.743 Volts.

Ahmad, A. Hanom; Ghani, F. S. Abdul

2009-06-01

205

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

206

Thermal conductivity of model zeolites: molecular dynamics simulation study  

NASA Astrophysics Data System (ADS)

The thermal conductivity of model zeolites was investigated using non-equilibrium molecular dynamics calculations. This type of calculation was found to overestimate the thermal conductivity of low-density silica polymorphs. A better reproduction of the experimental results was found for zeolites, and this was related to the lower phonon mean free path. The thermal conductivity of framework silicates was shown to be determined primarily by the vibrations of the continuous oxygen sublattice. Thus, the most drastic suppression of the heat transfer was related to alterations of the O-O distances; for example, a sixfold reduction in thermal conductivity compared to that of siliceous LTA zeolite was found for LTA-A1PO4. Framework cations were shown to affect the heat transfer by changing the vibrational modes of the structural building units of the framework and non-framework counter-cations, by disturbing the oxygen sublattice locally and acting as Rayleigh and resonant scatterers. A model assuming the heat transfer to be due only to non-dispersive acoustic phonons failed to reproduce the dependence of the thermal conductivity on the mass of the cations and the unit-cell dimension, thus suggesting a more sophisticated mechanism of heat transfer to be operative in framework materials. The effect of non-framework non-ionic species on the thermal conductivity was shown to be determined by their effect on the characteristics of the oxygen framework vibrations. Thus, repulsive interactions between the oxygen sublattice and Xe8 clusters, reducing the anisotropy and anharmonicity of the oxygen vibrations, give rise to enhanced heat transfer in LTA-SiO2 at ambient conditions.

Murashov, Vladimir V.

1999-02-01

207

Exploratory study of the thermal conductivity of methane hydrate  

SciTech Connect

Recent discoveries of natural gas hydrates in permafrost and sub-oceanic environments have led us to measure the thermal conductivity of methane hydrate. A guarded hot-plate cell was constructed and tested with various ice specimens. We find the conductivity of methane hydrate near -60/sup 0/C is 0.45 W/mk, a value close to that obtained for other clathrate hydrates by us and others. It is much lower than for ice (by a factor of about 5), so that a logging tool based on this property should prove to be of use in identification of gas hydrates in permafrost zones.

Cook, J.G.; Leaist, D.G.

1983-05-01

208

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

Code of Federal Regulations, 2010 CFR

...well-designed and well-conducted foreign clinical study not conducted under an IND...conducted in accordance with good clinical practice (GCP). For the purposes...recording, analysis, and reporting of clinical trials in a way that provides...

2010-04-01

209

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

Code of Federal Regulations, 2010 CFR

...well-designed and well-conducted foreign clinical study not conducted under an IND...conducted in accordance with good clinical practice (GCP). For the purposes...recording, analysis, and reporting of clinical trials in a way that provides...

2009-04-01

210

Quantitative validation of the Boltzmann transport equation phonon thermal conductivity model under the single-mode relaxation time approximation  

Microsoft Academic Search

The phonon thermal conductivity of the Lennard-Jones argon face-centered cubic crystal is predicted between temperatures of 20 K and 80 K using the Boltzmann transport equation under the single-mode relaxation time approximation. The temperature and frequency dependencies of the phonon dispersion and phonon relaxation times are obtained from lattice-dynamics calculations based on the results of molecular-dynamics simulations. No fitting parameters

A. J. McGaughey; M. Kaviany

2004-01-01

211

Validity Study of a Selection Procedure for Student Airline Pilots.  

National Technical Information Service (NTIS)

Predictive validities of an aptitude test battery for student airline pilots were determined, on the basis of the two criteria: training success (pass/fail) and pilot instructor's rating. Of 4207 applicants tested, 399 persons were accepted for training a...

H. Hoermann P. Maschke

1987-01-01

212

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

213

Validity and repeatability of the EPIC physical activity questionnaire: a validation study using accelerometers as an objective measure  

Microsoft Academic Search

BACKGROUND: A primary aim of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study is to examine the association between total physical activity levels (comprising occupational, household and recreational activity) and the incidence of cancer. We examined the validity and long-term repeatability of total physical activity measurements estimated from the past-year recall EPIC questionnaire, using accelerometers as an

Anne E Cust; Ben J Smith; Josephine Chau; Hidde P van der Ploeg; Christine M Friedenreich; Bruce K Armstrong; Adrian Bauman

2008-01-01

214

The Psychiatric Care Satisfaction Questionnaire: a reliability and validity study  

Microsoft Academic Search

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

D. A. Barker; M. W. Orrell

1999-01-01

215

Novel Conductive Coatings of Carbon Nanotubes: A Fundamental Study.  

National Technical Information Service (NTIS)

Among several CNT samples we tested, the best performance result we have achieved is with metallic SWNT (m- SWNT) coated on PEN (poly-ethylene- naphthalate) transparent composite film: it gave conductivity of 1 30/sq with 80% transmittance at 400-700nm wa...

D. J. Yang

2008-01-01

216

Comparative study of ion conducting pathways in borate glasses  

SciTech Connect

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; Swenson, Jan [Department of Applied Physics, Chalmers University of Technology, S-412 96 Goeteborg (Sweden); Adams, Stefan [Department of Materials Science and Engineering, National University of Singapore, 117576 (Singapore)

2006-11-01

217

Contributions of Middle Grade Students to the Validation Process of a National Science Assessment Study  

ERIC Educational Resources Information Center

This study used a national validity project to investigate specific research questions regarding the intersections among aspects of validity, educational measurement, and cognitive theory. Validity evidence was collected through traditional paper and pencil tests, surveys, think-alouds, and exit interviews of fifth and sixth grade students, as…

Morell, Linda

2008-01-01

218

AN ANALYTICAL STUDY OF CAUSING CRIMES: A STUDY CONDUCTED AT SARGODHA & SHAHPUR JAILS  

Microsoft Academic Search

The study was conducted to analyze the causes and socio-economic factors that are possibly responsible for crimes in Pakistan. Crimes have always overwhelmed every society in human history. The history of crime is as old as history of mankind. The present study was conducted on the prisoners of Sargodha and Shahpur jails. Major constructs were i.e. socio-economic factors and unemployment.

Shahzad Ali; Babak Mahmood; Malik Muhammad Sohail

2012-01-01

219

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

SciTech Connect

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

Benjamin Michael Meyer

2003-05-31

220

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

221

STATUS OF SOIL ELECTRICAL CONDUCTIVITY STUDIES BY CENTRAL STATE RESEARCHERS  

Microsoft Academic Search

Practical tools are needed to identify and advance sustainable management practices to optimize economic return, conserve soil, and minimize negative off-site environmental effects. The objective of this article is to review current research in non-saline soils of the central U.S. to consider bulk soil electrical conductivity (EC a) as an assessment tool for: (1) tracking N dynamics, (2) identifying management

C. K. Johnson; R. A. Eigenberg; J. W. Doran; B. J. Wienhold; B. Eghball; B. L. Woodbury

222

Alkaline Activation of Metakaolin An Isothermal Conduction Calorimetry Study  

Microsoft Academic Search

The alkaline activation of metakaolin leads to high mechanical performance inorganic polymers.\\u000a \\u000a A JAF conduction calorimeter was used to follow the reaction of metakaolin with NaOH solutions. The alkaline activation of\\u000a metakaolin to yield a cementitious material is an exothermic process involving three steps: an initial and very fast process\\u000a of dissolution, which is strongly exothermic, followed by an induction

M. L. Granizo; M. T. Blanco

1998-01-01

223

A study of electron beam-induced conductivity in resists.  

PubMed

The charging of polymeric resist materials during electron beam irradiation leads to significant problems during imaging and lithography processes. Charging occurs because of charge deposition in the polymer and charge generation/trapping due to formation of electron-hole pairs in the dielectric. The presence of such charge also results in the phenomena of electron beam-induced conductivity (EBIC). Electron beam-induced conductivity data have been obtained for three commercial e-beam resists under a variety of dose rate and temperature conditions. From the observed values of induced conductivity under varying conditions significant information about the generation of electron-hole pair and the transport of charge in the resist can be obtained. Three electron beam resists, EBR900, ZEP7000, and PBS are examined by an external bias method. The difference in resist chemistry is considered to play the role in the initial state EBIC behaviors among three resists even though the way that it affects the behaviors is not clear. A comparison of the power consumption comparison is proposed as a measure to give a preliminary estimate of the carrier concentration and carrier drift velocity differences among the resists. A simple single trap model with constant activation energy is proposed and provides good agreement with experiment. PMID:10483881

Hwu, J J; Joy, D C

1999-01-01

224

Alaska North Slope Tundra Travel Model and Validation Study  

SciTech Connect

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

Harry R. Bader; Jacynthe Guimond

2006-03-01

225

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.

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

2013-01-01

226

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

PubMed

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

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

1999-08-01

227

Propeller aircraft interior noise model utilization study and validation  

NASA Technical Reports Server (NTRS)

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

Pope, L. D.

1984-01-01

228

Propeller aircraft interior noise model utilization study and validation  

NASA Astrophysics Data System (ADS)

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

Pope, L. D.

1984-09-01

229

A Predictive Validity Study of the Pharmacy College Admission Test  

PubMed Central

Objective To examine the validity of Pharmacy College Admission Test (PCAT) scores for predicting grade point averages (GPAs) of students in years 1-4 of pharmacy programs. Methods Data were collected from 11 colleges and schools of pharmacy: entering cumulative and math/science GPAs, PCAT scaled scores, pharmacy program GPAs for years 1-4, student status after 4 years. Correlation, regression, discriminant, and diagnostic accuracy analyses were used to determine the validity of the PCAT for predicting subsequent GPAs. Results PCAT scaled scores and entering GPAs were positively correlated with subsequent GPAs. Regression analyses showed the predictive value of the PCAT scores, especially in combination with entering GPAs. Discriminant and diagnostic accuracy analyses supported these findings and provided practical suggestions regarding optimal PCAT scores for identifying students most likely to succeed. Conclusion Both PCAT scaled scores and entering cumulative GPAs showed moderate to strong predictive validity as indicators of candidates likely to succeed in pharmacy school.

Meagher, Donald G.; Lin, Anli; Stellato, Christina P.

2006-01-01

230

Molecular modelling approaches for cystic fibrosis transmembrane conductance regulator studies.  

PubMed

Cystic fibrosis (CF) is one of the most common genetic disorders, caused by loss of function mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein. CFTR is a member of ATP-binding cassette (ABC) transporters superfamily and functions as an ATP-gated anion channel. This review summarises the vast majority of the efforts which utilised molecular modelling approaches to gain insight into the various aspects of CFTR protein, related to its structure, dynamic properties, function and interactions with other protein partners, or drug-like compounds, with emphasis to its relation to CF disease. PMID:24735712

Odolczyk, Norbert; Zielenkiewicz, Piotr

2014-07-01

231

Ionic Conductivity And Structural Relaxation Studies on Lithium Niobophosphate Glass  

SciTech Connect

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

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

2011-07-15

232

Simulation verification techniques study. Subsystem simulation validation techniques  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

233

Lessons Learned from CFD Validation Study of Protuberance Heating  

NASA Technical Reports Server (NTRS)

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

Oliver, Brandon; Blaisdell, Greogory

2011-01-01

234

Application of artificial mussels (AMs) under South African marine conditions: a validation study.  

PubMed

Over the last three decades there has been a significant decline in the number of marine pollution monitoring-related studies in South Africa. Thus, the current study was conducted to assess the current state of metal contamination within the South African marine environment through the validation of the artificial mussel (AM). Indigenous reference mussels (Perna perna) were deployed alongside the passive device within the South African marine environment for a 6 week exposure period. Analysis of metal uptake (Cd, Cr, Cu, Pb and Zn) was determined by filtration and elution of the AM chelex resins, microwave digestion of the transplanted mussels, and determination of their metal concentrations by ICP-MS and ICP-OES analysis. Uptake patterns between the AM and transplanted mussels showed significant temporal and spatial correlation for the majority of the elements analysed. While the AM provided relevant and complementary information on the dissolved metal concentrations, limitations were also observed. PMID:21596395

Degger, N; Wepener, V; Richardson, B J; Wu, R S S

2011-01-01

235

Study of Conductivity and EOS Variations in Exploding Wire Simulations  

NASA Astrophysics Data System (ADS)

Present day Z pinches have achieved particularly impressive peak powers and total energies when initiated with a cylindrical array of many wires. The heating and the expansion of the wires in response to the high current densities is believed to play an important role in the subsequent Z pinch dynamics, especially in the seeding of the Rayleigh-Taylor instability. These wires pass through complex conductivity and EOS regimes in their evolution from cold solid to liquid, vapor, and plasma, and thus represent a challenging test case for simulation codes and the accompanying physics packages. We present simulation results from the Mach II code illustrating the sensitivity of the modeled behavior to variations in the electrical conductivity and the equation of state, with special attention given to variations in the vicinity of the metal-insulator and metal-liquid-vapor transitions. For reference exploding-wire experiments, we use primarily those of Cornell University with aluminum wires in the 12 to 25 ?m range.

Desjarlais, M. P.; Rosenthal, S. E.; Douglas, M. R.; Cochrane, K.; Spielman, R. B.; Mehlhorn, T. A.

2000-10-01

236

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.

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

2012-01-01

237

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

PubMed Central

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

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

2010-01-01

238

Validity of clinical associations of biomarkers in translational research studies: the case of systemic autoimmune diseases  

Microsoft Academic Search

INTRODUCTION: Validity of biomarkers may be affected if studies do not include certain features in their design. We evaluated whether translational research studies of potential biomarkers incorporated design features important for valid clinical associations. METHODS: We searched 10 journals for translational studies in six systemic autoimmune diseases published in 2004 through 2009. We included studies that reported associations between laboratory

Maria G Tektonidou; Michael M Ward

2010-01-01

239

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

PubMed Central

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

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

2013-01-01

240

Open-source MFIX-DEM software for gas-solids fluidized beds: 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; Garg, Rahul; Galvin, Janine; Sreekanth, Pannala

2012-04-01

241

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

242

A Validity Study of Two Projective Object Representations Measures.  

ERIC Educational Resources Information Center

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

Hibbard, Stephen; And Others

1995-01-01

243

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

244

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

245

Nuclear spin lattice relaxation and conductivity studies of the non-Arrhenius conductivity behavior in lithium fast ion conducting sulfide glasses  

NASA Astrophysics Data System (ADS)

Homogeneous xB2O3 + (1-x)B 2S3 glasses were prepared between 0 ? x ? 0.80. Raman, IR, and 11B NMR spectroscopies show that the boron oxide structures of B2O3, especially the six-membered rings, quickly diminish with increasing sulfide content, whereas the corresponding sulfide structures in B2S3 remain relatively intense as oxide content is increased. Differential scanning calorimetry (DSC) and density measurements show that physical properties of these boron oxysulfide glasses heavily favor the B2S3 properties regardless of the amount of B2O3 added to the system. It is hypothesized that the stability of the thioboroxol ring group relative to that of the BS 3/2 trigonal group is a possible source of this behavior. The formation of mixed boron oxysulfide structures of composition BSzO3-z where 0 < z < 3 is proposed. Structural studies of the ternary xLi2S + (1-x)[0.5 B2S3 + 0.5 GeS2] glasses using IR, Raman, and 11B NMR show that these glasses do not have equal sharing of the lithium atoms between GeS2 and B2S3. The IR spectra indicates that the B2S3 glass network are under-doped in comparison to corresponding compositions in the xLi 2S + (1-x)B2S3 binary system. Additionally, the Raman spectra show that the GeS2 glass network is over-modified. 11Boron static NMR gives evidence that ˜80% of the boron atoms are in tetrahedral coordinated. A super macro tetrahedron is proposed as one of the structures in these glasses in which some of them may contain boron sites substituted by germanium atoms at lower Li2S content. Nuclear Spin Lattice Relaxation and ionic conductivity measurements of Li doped Li2S + GeS2 + B2S3 glasses were performed to investigate the ion hopping dynamics and the non-Arrhenius conductivity behavior that has been observed in some fast ion conducting glasses. A distribution of activation energies model was used to fit the NSLR results and conductivity results. Comparisons are made to previously studied binary lithium thio-germanate and binary lithium thio-borate glasses to help yield information about the conduction mechanisms in these new glasses. An ion trapping model is used in conjunction with the distribution of activation energies model to describe the non-Arrhenius behavior observed in the dc conductivity.

Meyer, Benjamin Michael

246

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

PubMed Central

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

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

2010-01-01

247

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

PubMed Central

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

Shen, Zhilei Liu; Li, Zong-Ming

2012-01-01

248

Conducting systematic reviews of diagnostic studies: didactic guidelines  

PubMed Central

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

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

2002-01-01

249

Interface proximity effects on ionic conductivity in nanoscale oxide-ion conducting yttria stabilized zirconia: An atomistic simulation study  

NASA Astrophysics Data System (ADS)

We present an atomistic simulation study on the size dependence of dopant distribution and the influence of nanoscale film thickness on carrier transport properties of the model oxide-ion conductor yttria stabilized zirconia (YSZ). Simulated amorphization and recrystallization approach was utilized to generate YSZ films with varying thicknesses (3-9 nm) on insulating MgO substrates. The atomic trajectories generated in the molecular dynamics simulations are used to study the structural evolution of the YSZ thin films and correlate the resulting microstructure with ionic transport properties at the nanoscale. The interfacial conductivity increases by 2 orders of magnitude as the YSZ film size decreases from 9 to 3 nm owing to a decrease in activation energy barrier from 0.54 to 0.35 eV in the 1200-2000 K temperature range. Analysis of dopant distribution indicates surface enrichment, the extent of which depends on the film thickness. The mechanisms of oxygen conductivity for the various film thicknesses at the nanoscale are discussed in detail and comparisons with experimental and other modeling studies are presented where possible. The study offers insights into mesoscopic ion conduction mechanisms in low-dimensional solid oxide electrolytes.

Sankaranarayanan, Subramanian K. R. S.; Ramanathan, Shriram

2011-02-01

250

Validation Study of the Mini-Mental State Examination in a Malay-Speaking Elderly Population in Malaysia  

Microsoft Academic Search

Background\\/Aims: In view of the differing sensitivity and specificity of the Mini-Mental State Examination (MMSE) in the non-English-speaking populations, we conducted the first validation study of the Malay version (M-MMSE) in Malaysia among 300 subjects (from the community and outpatient clinics). Methods: Three versions were used: M-MMSE-7 (serial 7), M-MMSE-3 (serial 3) and M-MMSE-S (spell ‘dunia’ backwards). Dementia was assessed

Norlinah M. Ibrahim; Shamarina Shohaimi; Heng-Thay Chong; Abdul Hamid Abdul Rahman; Rosdinom Razali; Ebernezer Esther; Hamidon B. Basri

2009-01-01

251

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

Microsoft Academic Search

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

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

252

Guide for Conducting Treatability Studies under CERCLA: Thermal Desorption Quick Reference Fact Sheet.  

National Technical Information Service (NTIS)

Systematically conducted, well documented treatability studies are an important component of remedy evaluation and selection under the Superfund program. This fact sheet focuses on thermal desorption remedy selection treatability studies conducted in supp...

J. Rawe

1992-01-01

253

Pregnancy Studies Conducted by the Organization of Teratology Specialists (OTIS)  

MedlinePLUS

... Form Research Sponsorship Completed Studies Publications From Our Research Team Physician Biographies Principal Investigators Physicians Ongoing Pregnancy Studies Autoimmune Diseases Asthma Influenza Vaccine / Antiviral Medications Meningitis Vaccines Home Help Other ...

254

Using case studies as an approach for conducting agribusiness research  

Microsoft Academic Search

Case study research is increasingly important in agricultural economics as a means of collecting data, and building and testing theory. Case study research has a prescribed set of objectives, espitemology, methodology, and methods that have been developed and tested in a wide range of scholarly and problem-solving situations. This article reviews these fundamentals and then demonstrates the case study approach

James A. Sterns; David B. Schweikhardt; H. Christopher Peterson

1998-01-01

255

Training Otologic Surgical Skills Through Simulation--Moving Toward Validation: A Pilot Study and Lessons Learned  

PubMed Central

Introduction Methods for surgical education and training have changed little over the years. Recent calls to improve surgical efficiency and safety impose additional pressures that have an impact on surgical education and training. Use of Simulation Integration of data from advanced imaging technologies and computer technologies are creating simulation environments of unprecedented realism. Surgical education and training are poised to exploit low-cost simulation technologies to mitigate these pressures that are having an adverse impact on curricula. To become effective, simulation needs to undergo rigorous validation studies. Intervention With funding from that National Institute on Deafness and Other Communicative Disorders, we have embarked on a research design project to develop, disseminate, and validate a surgical system for use in otologic resident training and assessment and present key steps from this process. Discussion We discuss limiting factors related to technology and conducting multi-institutional studies, along with current developments to integrate curricula, as well as training and assessment capabilities in surgical education using simulation.

Wiet, Gregory J.; Rastatter, Jeff C.; Bapna, Sumit; Packer, Mark; Stredney, Don; Welling, D. Bradley

2009-01-01

256

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

NASA Technical Reports Server (NTRS)

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

Glaab, Patricia C.

2011-01-01

257

Validation Study on Alos Prism Dsm Mosaic and Aster Gdem 2  

NASA Astrophysics Data System (ADS)

This study aims to evaluate height accuracy of two datasets obtained by spaceborne optical instruments of a digital elevation data for a large-scale area. The digital surface model (DSM) was generated by the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS, nicknamed 'Daichi'), and the global digital elevation model (DEM) version 2 (GDEM-2) was derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard NASA's TERRA satellite. The test site of this study was the entire country of Bhutan, which is located on the southern slopes of the eastern Himalayas. Bhutan is not a large country, covering about 330 km from east to west, and 170 km from north to south; however, it has large height variation from 200 m to more than 7,000 m. This therefore makes it very interesting for validating digital topographic information in terms of national scale generation as well as wide height range. Regarding the reference data, field surveys were conducted in 2010 and 2011, and collected ground control points by a global positioning system were used for evaluating precise height accuracies in point scale as check points (CPs), with a 3 arc-sec DEM created by the Shuttle Radar Topography Mission (SRTM-3) used to validate the wide region. The results confirmed a root mean square error of 8.1 m for PRISM DSM and 29.4 m for GDEM-2 by CPs.

Tadono, T.; Takaku, J.; Shimada, M.

2012-07-01

258

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

Microsoft Academic Search

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

Maria Lage Barca; Knut Engedal; Geir Selbæk

2010-01-01

259

43 CFR 404.18 - How can I request assistance to conduct a feasibility study?  

Code of Federal Regulations, 2013 CFR

...assistance to conduct a feasibility study? To request assistance to conduct a feasibility study under § 404.11(a) or (b...appraisal report, you must submit a full proposal to conduct a feasibility study in response to the program...

2013-10-01

260

Validation study of gas chromatographic determination of pentachlorophenol in animal liver  

SciTech Connect

A validation study was conducted of a gas chromatographic procedure for the determination of pentachlorophenol (PCP) in chicken, pork, and beef liver. Five analysts representing 5 laboratories analyzed randomly numbered blind duplicates at 3 fortified tissue concentrations and one incurred tissue on 2 consecutive days. The PCP concentrations ranged from approximately 40 to 400 parts per billion (ppb). All data were reported to 3 significant figures in ppb. The coefficients of variation for repeatability were between 2.8 and 8.5%, except for the beef liver, at a mean value of 80 ppb PCP, where the CV was 11.3%. The CVs for reproducibility were in the range of 9.7 - 16.5% with little significant difference by species. The CV asymptotically approached 10% as the PCP level increased.

Gillard, D.; Epstein, R.L.; Ashworth, R.B.; Curry, K.; Nathan, Q.

1988-01-01

261

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

262

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

263

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

ERIC Educational Resources Information Center

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

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

264

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

265

Methodological considerations in conducting an olfactory fMRI study.  

PubMed

The sense of smell is a complex chemosensory processing in human and animals that allows them to connect with the environment as one of their chief sensory systems. In the field of functional brain imaging, many studies have focused on locating brain regions that are involved during olfactory processing. Despite wealth of literature about brain network in different olfactory tasks, there is a paucity of data regarding task design. Moreover, considering importance of olfactory tasks for patients with variety of neurological diseases, special contemplations should be addressed for patients. In this article, we review current olfaction tasks for behavioral studies and functional neuroimaging assessments, as well as technical principles regarding utilization of these tasks in functional magnetic resonance imaging studies. PMID:23619085

Vedaei, Faezeh; Fakhri, Mohammad; Harirchian, Mohammad Hossein; Firouznia, Kavous; Lotfi, Yones; Ali Oghabian, Mohammad

2013-01-01

266

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

267

MergeMaid: R Tools for Merging and Cross-Study Validation of Gene Expression Data  

Microsoft Academic Search

Cross-study validation of gene expression investigations is critical in genomic analysis. We developed an R package and associated object definitions to merge and visualize multiple gene expression datasets. Our merging functions use arbitrary character IDs and generate objects that can efficiently support a variety of joint analyses. Visualization tools support exploration and cross-study validation of the data, without requiring normalization

Leslie Cope; Xiaogang Zhong; Elizabeth Garrett-Mayer; Giovanni Parmigiani

2004-01-01

268

Electrochemistry of conductive polymers 36. pH dependence of polyaniline conductivities studied by current-sensing atomic force microscopy.  

PubMed

We demonstrate from our current-sensing atomic force microscopic studies that both electrical and topographical properties of electrochemically prepared polyaniline (PAn) films are affected by their preparation conditions. The electrical properties of the fully doped PAn films prepared in 0.30 M nitric acid with its pH and ionic strength adjusted to 0.50 can be described as a conductor with an average conductivity of 49 (+/-13) S/cm with primarily a compact structure resulting from a relatively small growth rate. The doped PAn films prepared at pH 5.0, for example, have compact structures with large grains and lightly doped semiconducting properties with an average conductivity of about 1.54 (+/-0.09) x 10(-4) S/cm. From these data, we conclude that the degree of protonation of the monomers and the main reactions taking place during an early stage of the polymerization reaction are important factors determining the chemical structures as well as their conductivities and morphologies of the PAn films. PMID:16852113

Hong, Sun-Young; Park, Su-Moon

2005-05-19

269

MRI measurement of hepatic magnetic susceptibility-phantom validation and normal subject studies.  

PubMed

A magnetic resonance (MR) imaging method with the potential for assessing hepatic iron overload from measurements of hepatic magnetic susceptibility in vivo is described. Using the blood in the portal and hepatic veins as an internal reference, this technique uses the orientation dependence of signal phase to measure the susceptibility of the liver parenchyma. Computer simulations were done to investigate the requirements on spatial resolution and contrast ratio between the vessels and the background liver tissue for data acquisition. Validation studies were conducted using tube-embedded gel phantoms doped with iron-dextran from 0 to 10 mg Fe/mL to mimic healthy and iron-overloaded livers. The phantom measurements were conducted without motion and flow, under respiration-like oscillatory motion, and with flow. Studies on six normal human subjects demonstrated excellent reproducibility and precision. All images were collected at 1.5 T using a 3D T(1)-weighted turbo field echo sequence for inflow MR angiographies with full flow compensation and capable of cardiac synchronization, navigator gating, and motion correction. PMID:15562494

Chu, Zili; Cohen, Alan R; Muthupillai, Raja; Chung, Taylor; Wang, Zhiyue J

2004-12-01

270

Development of Conductivity Probe and Temperature Probe for in-Situ Measurements in Hydrological Studies.  

National Technical Information Service (NTIS)

A conductivity probe and a temperature probe have been developed for in-situ measurements in various hydrological field studies. The conductivity probe has platinum electrodes and is powered with two 12 volt batteries. The sensing element of the temperatu...

U. Chandra B. J. Galindo A. C. G. Castagnet

1981-01-01

271

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

272

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

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

273

The self-consciousness scale: a discriminant validity study.  

PubMed

A recent Self-Consciousness Scale (SCS) measures Private and Public Self-Consciousness and Social Anxiety. The present research was intended to establish discriminant validity for the two Self-consciousness components with respect to several other variables. 105 male undergraduates completed the SCS, the Otis Test of Mental Ability, an abbreviated Edwards Personal Preference Schedule (measuring need for achievement), a Test Anxiety Questionnaire, and the EASI Temperament Survey. Private Self-consciousness did not correlate significantly with any other measure. Public Self-consciousness correlated weakly with the temperaments of Sociability and Emotionality. The Self-consciousness components of the SCS thus appear to be relatively independent of the other measures tested. PMID:16367389

Carver, C S; Glass, D C

1976-04-01

274

Using standardised patients to measure physicians' practice: validation study using audio recordings  

Microsoft Academic Search

Objective To assess the validity of standardised patients to measure the quality of physicians' practice. Design Validation study of standardised patients' assessments. Physicians saw unannounced standardised patients presenting with common outpatient conditions. The standardised patients covertly tape recorded their visit and completed a checklist of quality criteria immediately afterwards. Their assessments were compared against independent assessments of the recordings by

Jeff Luck; John W Peabody

2002-01-01

275

Factorial and Discriminant Validity of the Center for Epidemiological Studies Depression (CES-D) Scale.  

ERIC Educational Resources Information Center

Examined the factorial and discriminant validity of the Center for Epidemiological Studies Depression (CES-D) scale for 116 parents participating in family support programs. Factorial validity was adequate, and results indicated a moderate correlation between the CES-D and self-esteem and state anxiety. However, a high correlation was obtained…

Orme, John G.; And Others

1986-01-01

276

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

Microsoft Academic Search

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

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

1997-01-01

277

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

ERIC Educational Resources Information Center

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

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

2012-01-01

278

Mortality control charts for comparing performance of surgical units: validation study using hospital mortality data  

Microsoft Academic Search

Objective To design and validate a statistical method for evaluating the performance of surgical units that adjusts for case volume and case mix. Design Validation study using routinely collected data on in-hospital mortality. Data sources Two UK databases, the ASCOT prospective database and the risk scoring collaborative (RISC) database, covering 1042 patients undergoing surgery in 29 hospitals for gastro-oesophageal cancer

Peter McCulloch; Adrian C Steger; Irving S Benjamin; Jan D Poloniecki

2003-01-01

279

Validating teaching competencies for faculty members in higher education: A national study using the Delphi method  

Microsoft Academic Search

In this study the Delphi Method was used to validate teaching competencies of faculty members in higher education. Through the use of expert opinion, a panel of national leaders in college-level teaching validated twenty seven competencies as important or very important for faculty members who teach. Seven other competencies were rated slightly below a mean score of 4.0 suggesting, based

Kathleen S. Smith; Ronald D. Simpson

1995-01-01

280

On Standards of Descriptive Validity in Studies of Classroom Activity. Occasional Paper No. 16.  

ERIC Educational Resources Information Center

The author argues here that progress toward greater validity in description through increasingly specifiable standards for quality control is crucial for the advancement of theory as well as for the improvement of method in descriptive studies of classroom life. Some standards for judging the validity of descriptions of classroom action are…

Erickson, Frederick

281

Study of the Conductivity of Dielectric Under High Energy Electron Irradiation  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

282

Assessment of the face validity of two pain scales in Kenya: a validation study using cognitive interviewing  

PubMed Central

Background Patients in sub-Saharan Africa commonly experience pain, which often is un-assessed and undertreated. One hindrance to routine pain assessment in these settings is the lack of a single-item pain rating scale validated for the particular context. The goal of this study was to examine the face validity and cultural acceptability of two single-item pain scales, the Numerical Rating Scale (NRS) and the Faces Pain Scale-Revised (FPS-R), in a population of patients on the medical, surgical, and pediatric wards of Moi Teaching and Referral Hospital in Kenya. Methods Swahili versions of the NRS and FPS-R were developed by standard translation and back-translation. Cognitive interviews were performed with 15 patients at Moi Teaching and Referral Hospital in Eldoret, Kenya. Interview transcripts were analyzed on a question-by-question basis to identify major themes revealed through the cognitive interviewing process and to uncover any significant problems participants encountered with understanding and using the pain scales. Results Cognitive interview analysis demonstrated that participants had good comprehension of both the NRS and the FPS-R and showed rational decision-making processes in choosing their responses. Participants felt that both scales were easy to use. The FPS-R was preferred almost unanimously to the NRS. Conclusions The face validity and acceptability of the Swahili versions of the NRS and FPS-R has been demonstrated for use in Kenyan patients. The broader application of these scales should be evaluated and may benefit patients who currently suffer from pain.

2012-01-01

283

Conductivity studies on PEMA based polymer electrolyte system with LiClO4 salt  

NASA Astrophysics Data System (ADS)

The present work describes the surface and conductivity studies on PEMA based polymer electrolytes prepared by solvent casting technique. Polymer electrolytes were characterized by SEM and conductivity studies. The maximum ionic conductivity value is found to be 2.0245 × 10-5 Scm-1 at 303K for PEMA (25wt %)-LiClO4 (8wt %)-EC (67wt %) electrolyte system. Surface morphology was examined from scanning electron microscopic studies.

Rajendran, S.; Senthil, K.; Kesavan, K.; Mathew, Chithra M.; Mahalingam, T.

2013-02-01

284

Validation of a susceptibility, benefits, and barrier scale for mammography screening among Peruvian women: a cross-sectional study  

PubMed Central

Background Perceived beliefs about breast cancer and breast cancer screening are important predictors for mammography utilization. This study adapted and validated the Champion's scale in Peru. This scale measures perceived susceptibility for breast cancer and perceived benefits and barriers for mammography. Methods A cross-sectional study was conducted among women ages 40 to 65 attending outpatient gynecology services in a public hospital in Peru. A group of experts developed and pre-tested a Spanish version of the Champion's scale to assess its comprehensibility (N = 20). Factor analysis, internal consistency, and test-retest reliability analyses were performed (N = 285). Concurrent validity compared scores from participants who had a mammogram and those who did not have it in the previous 15 months. T-test and multiple regression analysis adjusting for socio-demographic factors, mammography knowledge and other preventive behaviors were performed. Results The construct validity and reliability were optimal. Cronbach-Alpha coefficients were 0.75 (susceptibility), 0.72 (benefits) and 0.86 (barriers). Concurrent validity analysis showed an association between barriers and mammography screening use in bivariate (22.3 ± 6.7 vs. 30.2 ± 7.6; p < 0.001) and multiple regression analysis (OR = 0.28, 95% CI = 0.18-0.43). Ages 50-60 years (OR = 2.35, 95% CI = 1.19-4.65), history of prior Papanicolaou test (OR = 3.69, 95% CI = 1.84-7.40), and knowledge about breast cancer and mammography (OR = 3.69, 95% CI = 1.84-7.40) were also independently associated with mammography screening use. Conclusion Concurrent validity analysis showed that the Champion's scale has important limitations for assessing perceived susceptibility for breast cancer and perceived benefits for mammography among Peruvian women. There is still a need for developing valid and reliable instruments for measuring perceived beliefs about breast cancer and mammography screening among Peruvian women.

2011-01-01

285

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

PubMed Central

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

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

2014-01-01

286

Validation study of air-sea gas transfer modeling  

SciTech Connect

Laboratory results have demonstrated the importance of bubble plumes to air-water gas transfer (Asher et al., 1994). Bubble plumes enhance gas transfer by disrupting surface films, by directly transporting a gas, and by the creation of turbulence. Models of bubble gas transfer have been developed by different authors (Atkinson, 1973; Memery and Merlivat, 1985; Woolf and Thorpe, 1991) to determine the magnitude of gas transfer due to bubbles. Laboratory measurements of both the gas transfer rate k{sub L}, and the bubble distribution {phi} in a whitecap simulation tank (WST) have allowed these models to be validated and deficiencies in the theoretical assumptions to be explored. In the WST, each bucket tip simulates a wave breaking event. Important tests of these models include whether they can explain the experimentally determined solubility and Schmidt number dependency of k{sub L}, predict the time varying bubble concentrations, predict the evasion-invasion asymmetry, and predict the fraction of k{sub L} due to bubble plumes. Four different models were tested, a steady state model (Atkinson, 1973), a non-turbulence model with constant bubble radius (Memery and Merlivat, 1985), a turbulence model with constant bubble radius (Wolf and Thorpe, 1991), and a turbulence model with varying bubble radius. All models simulated multiple bubble tip cycles. The two turbulence models were run for sufficient tip cycles to generate statistically significant number of eddies ({number_sign}{gt}50) for bubbles affected by turbulence (V{sub B}{le}V{sub T}), found to be at least four tip cycles. The models allowed up to nine gases simultaneously and were run under different conditions of trace and major gas concentrations and partial pressures.

Asher, W.E.; Farley, P.J. [Pacific Northwest Lab., Richland, WA (United States); Leifer, I.S. [Georgia Inst. of Tech., Atlanta, GA (United States)

1995-07-01

287

Statistical study of the conductance and shot noise in open quantum-chaotic cavities: Contribution from whispering gallery modes  

NASA Astrophysics Data System (ADS)

In the past, a maximum-entropy model was introduced and applied to the study of statistical scattering by chaotic cavities, when short paths may play an important role in the scattering process. In particular, the validity of the model was investigated in relation with the statistical properties of the conductance in open chaotic cavities. In this paper we investigate further the validity of the maximum-entropy model, by comparing the theoretical predictions with the results of computer simulations, in which the Schrödinger equation is solved numerically inside the cavity for one and two open channels in the leads; we analyze, in addition to the conductance, the zero-frequency limit of the shot-noise power spectrum. We also obtain theoretical results for the ensemble average of this last quantity, for the orthogonal and unitary cases of the circular ensemble and an arbitrary number of channels. Generally speaking, the agreement between theory and numerics is good. In some of the cavities that we study, short paths consist of whispering gallery modes, which were excluded in previous studies. These cavities turn out to be all the more interesting, as it is in relation with them that we found certain systematic discrepancies in the comparison with theory. We give evidence that it is the lack of stationarity inside the energy interval that is analyzed, and hence the lack of ergodicity—a property assumed in the maximum-entropy model—that gives rise to the discrepancies. Indeed, the agreement between theory and numerical simulations is improved when the energy interval is reduced to a point and the statistics is then collected over an ensemble obtained by varying the position of an obstacle inside the cavity. It thus appears that the maximum-entropy model is valid beyond the domain where it was originally derived. An understanding of this situation is still lacking at the present moment.

Bulgakov, Evgeny N.; Gopar, Víctor A.; Mello, Pier A.; Rotter, Ingrid

2006-04-01

288

Validation Study of Existing Neutronics Tools Against ZPPR-21 and ZPPR-15 Critical Experiments.  

National Technical Information Service (NTIS)

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 Crit...

S. J. Kim W. S. Yang

2007-01-01

289

NCI Begins Validation Study of New Test to Detect Early-Stage Liver Cancer  

Cancer.gov

A two-year study to validate a test to detect early-stage liver cancer has been initiated by the National Cancer Institute (NCI), part of the National Institutes of Health, at six centers* across the United States.

290

How Valid Are the National Board of Professional Teaching Standards Assessments for Predicting the Quality of Actual Classroom Teaching and Learning? Results of Six Mini Case Studies.  

ERIC Educational Resources Information Center

Conducted mini case studies of teachers certified by the National Board for Professional Teaching Standards (NBPTS) using classroom observations, teacher interviews, and focus group interviews. Findings show considerable variation in the quality of teaching and learning associated with these teachers. Discusses implications for the validity of…

Pool, Jonelle E.; Ellett, Chad D.; Schiavone, Salvatore; Carey-Lewis, Charmaine

2001-01-01

291

A Study of Equating in NAEP. NAEP Validity Studies. Working Paper Series.  

ERIC Educational Resources Information Center

A computer simulation study was conducted to investigate the amount of uncertainty added to National Assessment of Educational Progress estimates by equating error under three different equating methods and while varying a number of factors that might affect accuracy of equating. Data from past NAEP administrations were used to guide the…

Hedges, Larry V.; Vevea, Jack L.

292

Validation study on five different cytotoxicity assays in Japan—an intermediate report  

Microsoft Academic Search

In October 1992, the Japanese Society of Alternatives to Animal Experiments (JSAAE) organized a first-step inter-laboratory validation study on five Cytotoxicity assays: crystal-violet staining assay, neutral red uptake, MTT assay, colony formation, and lactate dehydrogenase release assay. This study is to clarify problems in organizing system of validation, protocols and intra- and inter-laboratory variation of ED50 values on six representative

T. Ohno; H. Itagaki; N. Tanaka; H. Ono

1995-01-01

293

Use of a food frequency questionnaire in American Indian and Caucasian pregnant women: a validation study  

Microsoft Academic Search

BACKGROUND: Food frequency questionnaires (FFQs) have been validated in pregnant women, but few studies have focused specifically on low-income women and minorities. The purpose of this study was to examine the validity of the Harvard Service FFQ (HSFFQ) among low-income American Indian and Caucasian pregnant women. METHODS: The 100-item HSFFQ was administered three times to a sample of pregnant women,

Heather J Baer; Robin E Blum; Helaine RH Rockett; Jill Leppert; Jane D Gardner; Carol W Suitor; Graham A Colditz

2005-01-01

294

A validation study of four Navier-Stokes codes for high-speed flows  

NASA Technical Reports Server (NTRS)

A code validation study has been conducted for four different codes for solving the compressible Navier-Stokes equations. Computations for a series of nominally two-dimensional high-speed laminar separated flows were compared with detailed experimental shock-tunnel results. The shock wave-boundary layer interactions considered were induced by a compression ramp in one case and by an externally-generated incident shock in the second case. In general, good agreement was reached between the grid-refined calculations and experiment for the incipient- and small-separation conditions. For the most highly separated flow, three-dimensional calculations which included the finite-span effects of the experiment were required in order to obtain agreement with the data. The finite-span effects were important in determining the extent of separation as well as the time required to establish the steady-flow interaction. The results presented provide a resolution of discrepancies with the experimental data encountered in several recent computational studies.

Rudy, David H.; Thomas, James L.; Kumar, Ajay; Chakravarthy, Sukumar R.; Gnoffo, Peter A.

1989-01-01

295

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

PubMed Central

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

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

1979-01-01

296

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

297

CASE STUDY: Using TCGA Data to Validate GBM Signaling Pathways  

Cancer.gov

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

298

Noise sensitivity and subjective health: questionnaire study conducted along trunk roads in Kusatsu, Japan.  

PubMed

A questionnaire study was conducted in a residential area along trunk roads in Kusatsu, Japan, in order to investigate the association between noise exposure, noise sensitivity, and subjective health. Subjective health of the respondents was measured by the General Health Questionnaire (GHQ-28) which yields the total score as an index of psychiatric disorder and four subscales. Noise sensitivity was measured by the improved version of the Weinstein's noise sensitivity scale named WNS-6B. The original WNS and a single question directly asking respondents' noise sensitivity were also applied to confirm the validity of the WNS-6B for investigating the effects of road traffic noise on subjective health. Respondents were also asked about disturbances of daily life due to noise exposure to find the cause of the health effects. Three hundred and twenty three answers were entered into the analysis. Applying the WNS-6B as the noise sensitivity measurement scale, a significant correlation was found between subjective health and noise exposure in the noise-sensitive group, while no significant correlation was observed in the insensitive group. These results suggest that the adverse health effects may exist especially in the sensitive group. Application of the other two noise sensitivity measurement scales showed no significant relationship either in the sensitive group or in the insensitive group. The WNS-6B would have greater advantage for detecting adverse health effects than the other scales. Furthermore, the primary cause of the adverse health effect was investigated. The results of the analysis indicated that the adverse health effects were mainly caused by the sleep disturbance and were not caused by hearing interference. PMID:19414931

Kishikawa, Hiroki; Matsui, Toshihito; Uchiyama, Iwao; Miyakawa, Masamitsu; Hiramatsu, Kozo; Stansfeld, Stephen A

2009-01-01

299

Outcomes of childhood conduct problem trajectories in early adulthood: findings from the ALSPAC study.  

PubMed

Although conduct problems in childhood are stably associated with problem outcomes, not every child who presents with conduct problems is at risk. This study extends previous studies by testing whether childhood conduct problem trajectories are predictive of a wide range of other health and behavior problems in early adulthood using a general population sample. Based on 7,218 individuals from the Avon longitudinal study of parents and children, a three-step approach was used to model childhood conduct problem development and identify differences in early adult health and behavior problems. Childhood conduct problems were assessed on six occasions between age 4 and 13 and health and behavior outcomes were measured at age 18. Individuals who displayed early-onset persistent conduct problems throughout childhood were at greater risk for almost all forms of later problems. Individuals on the adolescent-onset conduct problem path consumed more tobacco and illegal drugs and engaged more often in risky sexual behavior than individuals without childhood conduct problems. Levels of health and behavior problems for individuals on the childhood-limited path were in between those for stable low and stable high trajectories. Childhood conduct problems are pervasive and substantially affect adjustment in early adulthood both in at-risk samples as shown in previous studies, but also in a general population sample. Knowing a child's developmental course can help to evaluate the risk for later maladjustment and be indicative of the need for early intervention. PMID:24197169

Kretschmer, Tina; Hickman, Matthew; Doerner, Rita; Emond, Alan; Lewis, Glyn; Macleod, John; Maughan, Barbara; Munafò, Marcus R; Heron, Jon

2014-07-01

300

Reduced conduction reserve of the propagating cardiac impulse in the diabetic rat heart: a model study.  

PubMed

Conduction velocity is dependent on two main factors: intercellular electrical coupling and cellular electrical excitability. There is significant redundancy, 'conduction reserve', in these parameters such that significant reduction in the conduction velocity of the action potential requires either a severe change in one of these parameters or a combined change in both parameters. Studies in diabetic rat hearts have shown a significant reduction in the conduction reserve and it was hypothesized that this is mainly due to the lateralization of the gap junction protein connexin 43 (Cx43). To gain a better understanding of the effect of reduced intercellular coupling, a rat ventricle myocyte model was used to simulate propagation along a strand of cells. Simulations were performed to assess the effect of reduction of intercellular conductance on the conduction velocity. As the conductance of the gap junction decreased a significant reduction in the conduction velocity was observed. The relationship between conduction velocity and intercellular coupling became steeper with decreasing coupling, such that conduction velocity became increasingly sensitive to further uncoupling. This is consistent with experimental results, in which application of the gap junction uncoupler heptanol caused a larger conduction slowing in diabetic hearts than in controls. PMID:19164067

Ghaly, H; Boyle, P; Vigmond, E; Nygren, A

2008-01-01

301

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

302

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

EPA Science Inventory

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

303

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

EPA Science Inventory

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

304

GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOLVENT EXTRACTION QUICK REFERENCE FACT SHEET  

EPA Science Inventory

Systematically conducted, well-documented treatability studies are an important component of remedy evaluation and selection under the Superfund Program. his fact sheet focuses on solvent extraction treatability studies, and is highly abridged version of the guide which bears the...

305

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.

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

2011-01-01

306

Virtual Environment Interpersonal Trust Scale: Validity and Reliability Study  

ERIC Educational Resources Information Center

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

Usta, Ertugrul

2012-01-01

307

GETTING CLOSURE ON CLOZE: A VALIDATION STUDY OF THE \\  

Microsoft Academic Search

The present study was designed to (a) test the notion that the cloze procedure is related to the idea of closure in Gestalt psychology and (b) investigate the degree to which specific language skills (grammar knowledge, reading ability, and vocabulary knowledge) contribute to cloze test performance for second language learners and (c) investigate the degree to which cloze tests may

TREELA MCKAMEY

308

A validation study of the Competency Screening Test  

Microsoft Academic Search

This study was designed to assess the utility of the Competency Screening Test (CST) as a method of determining competency to stand trial. Fifty male residents of a state forensic unit were administered the CST. These residents were later interviewed by the Forensic Team who determined whether they were competent to stand trial. The CST correctly predicted the competency recommendations

Edgar J. Nottingham; Robert E. Mattson

1981-01-01

309

A Validation Study of the Youth Development Assessment Device  

ERIC Educational Resources Information Center

This article details the development of the Youth Development Assessment Device (YDAD), an instrument designed to measure a youth's experiences within youth development programs. A total of 1,074 adolescents, between 12 and 18 years of age, participated in the study. Exploratory factor analysis yielded three factors: Supportive Environment,…

Sabatelli, Ronald M.; Anderson, Stephen A.; Kosutic, Iva; Sanderson, Jessica; Rubinfeld, Stacey

2009-01-01

310

The UK Biobank sample handling and storage validation studies  

Microsoft Academic Search

Background UK Biobank is a large prospective study in the United Kingdom to and aims investigate the role of genetic factors, environmental exposures and lifestyle in the causes of major diseases of late and middle age. It involves the collection of blood and urine from 500000 individuals aged between 40 and 69 years. How the samples are collected, processed and

Tim C Peakman; Paul Elliott

311

A Validation Study of a Measure of Musical Creativity.  

ERIC Educational Resources Information Center

Studies reliability of the Measures of Creativity in Sound and Music (MCSM), a test developed by Cecilia Wang. Compares the MCSM scores with subjects' academic achievement scores, sex, and age with music and classroom teacher ratings of subjects' creativity. Concludes that research is still needed to define a theory of musical creativity, define…

Baltzer, Sam

1988-01-01

312

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

313

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

PubMed

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

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

2014-02-01

314

Clinical examination of varicose veins--a validation study.  

PubMed Central

The aim of this study was to determine the accuracy of clinical tests compared to colour duplex imaging in patients with primary varicose veins using a prospective, blinded comparison study. A total of 44 patients (70 limbs) with primary, previously untreated varicose veins presenting to the vascular laboratory of a university teaching hospital were studied. The patients underwent physical examination using the cough test, the tap test, Trendelenbergs' test, Perthes' test and hand-held Doppler (HHD) assessment prior to undergoing colour duplex scanning. Reflux was detected on duplex scanning, at the sapheno-femoral junction in 39/70 limbs (54%), the long saphenous vein in 47/70 limbs (64%) and the sapheno-popliteal junction in 9/70 limbs (13%). The cough test had low sensitivity (0.59) and specificity (0.67). The tap test had low sensitivity (0.18) and high specificity (0.92). The Trendelenberg test had high sensitivity (0.91) but low specificity (0.15). Perthes' test had a high sensitivity (0.97) but low specificity (0.20). Hand-held Doppler assessment of reflux at the sapheno-femoral junction, in the long saphenous vein and at the sapheno-popliteal junction had high sensitivity (0.97, 0.82, and 0.80, respectively) and specificity (0.73, 0.92, and 0.90, respectively) of detecting reflux. Clinical tests used in the examination of patients with primary varicose veins are inaccurate. Assessment using hand-held Doppler is more accurate. Courses and clinical textbooks should be revised to replace these tests with instruction in how to use hand-held Doppler in the clinical examination of patients with varicose veins.

Kim, J.; Richards, S.; Kent, P. J.

2000-01-01

315

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

PubMed

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

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

2013-04-01

316

Simulation in laparoscopic surgery: a concurrent validity study for FLS  

Microsoft Academic Search

Background  Current assessments using the fundamentals of laparoscopic surgery (FLS) tasks are labour intensive and depend heavily on\\u000a expert raters. Hand motion analysis may offer an alternative method of objective evaluation of FLS performance.\\u000a \\u000a \\u000a \\u000a Purpose  The aim of this study was to assess whether a correlation exists between the expert rated assessments of the FLS tasks and\\u000a computer-based assessment of motion efficiency

George Xeroulis; Adam Dubrowski; Ken Leslie

2009-01-01

317

Rorschach aggression variables: a study of reliability and validity.  

PubMed

This study investigated the extent to which 6 Rorschach variables of aggression (A1, A2, AG, MOR, AgC, AgPast) are related to one another, to the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994) Cluster B personality disorder criteria, and to self-report measures of anger, aggression, and antisocial behavior. Seventy-eight patients were found to meet DSM-IV criteria for an Axis II disorder, Cluster A personality disorder (paranoid, schizoid, schizotypal) = 9, Cluster B (antisocial personality disorder [ANPD] = 16, borderline personality disorder [BPD] = 23, histrionic personality disorder = 5, narcissistic personality disorder = 12) = 56, and Cluster C personality disorder (avoidant, dependent, obsessive-compulsive) = 13. The results of this study indicated that (a) these 6 Rorschach aggression variables can be scored reliably; (b) 2 factors, revealed by factor analysis, accounted for 77% of the total variance; (c) selected variables were found to be empirically related to DSM-IV diagnostic criteria for ANPD and BPD; and (d) selected variables were found to be empirically related to a self-report measure of anger and antisocial practices. The conceptual nature and clinical utility of these Rorschach aggression variables as well as implications for future research are discussed. PMID:10205872

Baity, M R; Hilsenroth, M J

1999-02-01

318

Conduction in polyaniline emeraldine salt in the terahertz region: A temperature dependence study  

NASA Astrophysics Data System (ADS)

The temperature-dependent conductivity of polyaniline emeraldine salt (PAni-ES) was studied by terahertz (THz) time-domain spectroscopy from 80 to 290 K to investigate conduction properties in the THz region. The absorption coefficient and index of refraction increase with temperature. This reflects an increasing conductivity, which indicates a thermally assisted hopping transition. The frequency-dependent behavior of the conductivity is described by using the Mott-Davis model. The model fitting parameter, S, decreases with increasing temperature, indicating a possible correlated barrier hopping mechanism. Lastly, the activation energy at THz frequencies decreases with increasing frequency, suggesting intraband transitions.

Tapia, Alvin Karlo G.; Tominaga, Keisuke

2014-04-01

319

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

320

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

321

A Setup for Studying the Low-Temperature Thermal Conductivity of Powder Samples  

Microsoft Academic Search

A setup for studying the thermal conductivity of powder samples in the temperature range 2–200 K using the stationary heat flow method is described. The design of the cryogenic part of the setup allows a sample to be loaded at low temperatures. The effective thermal conductivities of methane hydrate powder and the ice powder obtained upon methane hydrate decomposition were

A. I. Krivchikov; B. Ya. Gorodilov; O. A. Korolyuk

2005-01-01

322

Genomewide study and validation of markers associated with production traits in German Landrace boars.  

PubMed

We present results from a genomewide association study (GWAS) and a single-marker association study. The GWAS was performed with the Illumina PorcineSNP60 BeadChip from which 5 markers were selected for a validation analysis. Genetic effects were estimated for feed intake, weight gain, and traits of fat and muscle tissue in German Landrace boars kept on performance test stations. The GWAS was performed in a population of 288 boars and the validation study for another 432 boars. No statistically significant effect was found in the GWAS after adjusting for multiple testing. Effects of 2 markers, which were significant genomewide before correction for multiple testing (P < 0.00005), could be confirmed in the validation study. The major allele of marker ALGA0056781 on SSC1 was positively associated with both higher weight gain and fat deposition. The effect on live-weight gain was 2.25 g/d in the GWAS (P = 0.0003) and 3.73 g/d in the validation study (P = 0.01) and for back fat thickness was 0.15 mm in the GWAS (P < 0.0001) and 0.20 mm in the validation study (P = 0.02). The marker had similar effects on test-day weight gain (GWAS: 3.85 g/d, P = 0.001; validation study: 6.80 g/d, P = 0.003) and back fat area (GWAS: 0.27 cm(2), P < 0.0001; validation study: 0.35 cm(2), P = 0.03). Marker ASGA0056782 on SSC13 was associated with live-weight gain. The major allele had negative effects in both studies (GWAS: -4.88 g/d, P < 0.0001; validation study: -3.75 g/d, P = 0.02). The effects of these 2 markers would have been excluded based on the GWAS alone but were shown to be significantly trait associated in the validation study indicating a false-negative result. The G protein-coupled receptor 126 (GPR126) gene approximately 200 kb downstream of marker ALGA0001781 was shown to be associated with human height and therefore might explain the association with weight gain in pigs. Several traits were affected in an economically desired direction by the minor allele of the markers, pointing to the possibility of improvement through further selection. PMID:24671582

Strucken, E M; Schmitt, A O; Bergfeld, U; Jurke, I; Reissmann, M; Brockmann, G A

2014-05-01

323

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

ERIC Educational Resources Information Center

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

Bas, Gokhan

2013-01-01

324

Experimental studies of characteristic combustion-driven flows for CFD validation  

Microsoft Academic Search

A series of rocket-related studies intended to develop a suitable data base for validation of Computational Fluid Dynamics (CFD) models of characteristic combustion-driven flows was undertaken at the Propulsion Engineering Research Center at Penn State. Included are studies of coaxial and impinging jet injectors as well as chamber wall heat transfer effects. The objective of these studies is to provide

R. J. Santoro; M. Moser; W. Anderson; S. Pal; H. Ryan; C. L. Merkle

1992-01-01

325

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

326

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

327

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

328

Ballistic perforation of oxygen-free high conductivity copper and 7039 aluminum targets: A microstructural and hydrocode study  

NASA Astrophysics Data System (ADS)

This research involves an effort to study and compare the residual microstructures and dynamic behavior of two metallic targets of finite thicknesses, namely OFHC (oxygen-free high-conductivity) copper and 7039 aluminum, subjected to ballistic impact and perforation by a tungsten heavy alloy (WHA) projectile. Also included in this work is an attempt to validate mathematical modelling of experimental results through the use of a computer hydrocode, AUTODYN-2D, which allows for the simulation of ballistic penetration/perforation events and possible differentiation of fundamental mechanisms through validation strategies. These targets represent two very different FCC materials. The 7039 aluminum is extremely hard in contrast to a softer, ductile copper. The "failure" mechanisms appear to be different on a macroscopic scale, but may be similar on a microscopic scale. A preliminary investigation of the residual penetration channels in these two targets revealed significant microstructural differences. In the 7039 aluminum target there is a limited extent of microstructural deformation seen through optical microscopy, though numerous shear bands are observed near the channel wall and at the spalled region. Observations of the OHFC target, on the other hand, show a narrow region of recrystallized grains adjacent to the crater wall, beyond which is an extensive area of microband clusters. Similar features have been observed previously in connection with hypervelocity impact cratering in copper. This investigation will attempt to provide clues to the fundamental issues involved in the differing dynamic behavior of the two FCC materials. A detailed analysis of microstructures and their evolution will be conducted through metallography and transmission electron microscopy. Microhardness measurements will be performed to correlate the results of ballistic computer simulations through residual stress and hardness profiles. Computational modeling will be used to simulate the impact behavior of the two target materials and will be corroborated by experimental results to establish a validation of perforation geometry and residual stress mappings which can be related to actual residual hardness maps constructed experimentally. This study is an attempt to correlate microstructural issues with computer simulations and especially validation of these simulations to improve predictive models and general ballistic and hypervelocity perforation behavior in metal targets.

Kennedy, Christine

329

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2013 CFR

42 Public Health 1 2013-10-01 2013-10-01 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...

2013-10-01

330

Electrical Conductivity and NMR Studies of Methanol/Water Mixtures in Nafion Membranes.  

National Technical Information Service (NTIS)

Complex impedance studies have been carried out in acid form NAFION 117 treated with various amounts of methanol and methanol-water mixtures. At room temperature and atmospheric pressure the conductivity for NAFION treated with 'pure' methanol is about a ...

C. A. Edmondson P. E. Stallworth M. C. Wintersgill J. J. Fontanella Y. Dai

1996-01-01

331

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

332

Study of the variation of thermal conductivity with water saturation using nuclear magnetic resonance  

NASA Astrophysics Data System (ADS)

In this paper, we present a method that allows one to correct thermal conductivity measurements for the effect of water loss when extrapolating laboratory data to in situ conditions. The water loss in shales and unconsolidated rocks is a serious problem that can introduce errors in the characterization of reservoirs. For this study, we measure the thermal conductivity of four sandstones with and without clay minerals according to different water saturation levels using an optical scanner. Thermal conductivity does not decrease linearly with water saturation. At high saturation and very low saturation, thermal conductivity decreases more quickly because of spontaneous liquid displacement and capillarity effects. Apart from these two effects, thermal conductivity decreases quasi-linearly. We also notice that the samples containing clay minerals are not completely drained, and thermal conductivity reaches a minimum value. In order to fit the variation of thermal conductivity with the water saturation as a whole, we used modified models commonly presented in thermal conductivity studies: harmonic and arithmetic mean and geometric models. These models take into account different types of porosity, especially those attributable to the abundance of clay, using measurements obtained from nuclear magnetic resonance (NMR). For argillaceous sandstones, a modified arithmetic-harmonic model fits the data best. For clean quartz sandstones under low water saturation, the closest fit to the data is obtained with the modified arithmetic-harmonic model, while for high water saturation, a modified geometric mean model proves to be the best.

Jorand, Rachel; Fehr, Annick; Koch, Andreas; Clauser, Christoph

2011-08-01

333

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

334

The assessment of postoperative pain by monitoring skin conductance: results of a prospective study  

Microsoft Academic Search

Summary The number of fluctuations of skin conductance per second correlates with postoperative pain. The aim of this prospective study was to test the cut-off value for the number of fluctuations of skin conductance per second obtained from a previous study. Seventy-five patients were asked to quantify their level of pain on a numeric rating scale (0-10) in the recovery

T. Ledowski; J. Bromilow; J. Wu; M. J. Paech; H. Storm; S. A. Schug

2007-01-01

335

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.

2012-01-01

336

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

337

Study of electrical conductivity and Schottky contacts in single gallium nitride nanowire by Atomic Force Microscope  

NASA Astrophysics Data System (ADS)

We report the electrical conductivity of individual n-type gallium nitride (GaN) nanowires grown by the vapor-liquid-solid process. Longitudinal and transverse conductivity of bare and gold-decorated GaN nanowires were studied using conductive atomic force microscope (C-AFM) at room temperature. The devices were manufactured by photo-lithography technique in the nanotechnology cleanroom. We explored the nanodevices by scanning electron microscope (SEM) and identified the nanowires with good electrical contacts. The same nanowires were investigated under C-AFM for conductivity measurements. We observed a decrease in conductivity in terms of magnitude on gold-decorated nanowires compared to bare GaN nanowires due to the formation of depletion region. Schottky contacts employing individual n-type GaN nanowires were realized using Pt/Ir coated silicon AFM tip.

Pricilla Sundararajan, Jency; MacPherson, Quinn; Hare, Brian; McIlroy, David N.

2010-03-01

338

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

NASA Astrophysics Data System (ADS)

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.; Biddle, J. W.; Sengers, J. V.; Anisimov, M. A.

2014-04-01

339

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

340

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

ERIC Educational Resources Information Center

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

Bulbul, Tuncer

2012-01-01

341

The Validity and Reliability Studies of the Computer Anxiety Scale on Educational Administrators (CAS-EA)  

ERIC Educational Resources Information Center

This study aims at investigating the validity and reliability studies of the "Computer Anxiety Scale" (Ceyhan & Gurcan Namlu, 2000) on educational administrators. The data gathered from 143 educational administrators of state schools located in Eskisehir show that the scale consists of 2 factors. The first of these factors, affective anxiety…

Agaoglu, Esmahan; Ceyhan, Esra; Ceyhan, Aykut; Simsek, Yucel

2008-01-01

342

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

Microsoft Academic Search

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

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

2000-01-01

343

Family Emotional Involvement and Criticism Scale (FEICS): II. Reliability and Validity Studies  

Microsoft Academic Search

This article is a report on a replication study of the reliability and validity of the Family Emotional Involvement and Criticism Scale (FEICS). A sample of 928 people (a 63% return rate for 1,480 mailed questionnaires) participated in the study. The sample was drawn from patients in a Family Medicine practice. FEICS consists of 14 items: 7 items assess Perceived

Cleveland G. Shields; Peter Franks; Jeffrey J. Harp; Thomas L. Campbell; Susan H. McDaniel

1994-01-01

344

Validity and Usefulness in Four WIST Studies Recently Reported in the Journal  

ERIC Educational Resources Information Center

Four articles that reported studies that used the Whitaker Index of Schizophrenic Thinking (WIST) were published in the "Journal of Clinical Psychology" in early 1977. These articles are reviewed by the WIST's author in terms of necessary conditions for valid and useful studies of schizophrenic thinking. (Editor)

Whitaker, Leighton C.

1978-01-01

345

Validity and Cost of Self-Study in Accreditation of Medical Laboratory Science Educational Programs.  

ERIC Educational Resources Information Center

Although the value of self-study was found to be accepted by a majority of those involved in medical laboratory programs, it is evident that validity, in terms of improved educational programs, can be assessed only after a sufficient number of programs have had a second site visit based on a second or updated self-study. (Author/LBH)

Macpherson, Colin R.

1979-01-01

346

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

347

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

348

The Edinburgh Postnatal Depression Scale (EPDS): translation and validation study of the Iranian version  

Microsoft Academic Search

BACKGROUND: The Edinburgh Postnatal Depression Scale (EPDS) is a widely used instrument to measure postnatal depression. This study aimed to translate and to test the reliability and validity of the EPDS in Iran. METHODS: The English language version of the EPDS was translated into Persian (Iranian language) and was used in this study. The questionnaire was administered to a consecutive

Ali Montazeri; Behnaz Torkan; Sepideh Omidvari

2007-01-01

349

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

350

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

Microsoft Academic Search

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

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

2004-01-01

351

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

Microsoft Academic Search

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

JOHN SITZIA

1999-01-01

352

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

353

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

354

A general population twin study of conduct problems and the auditory p300 waveform.  

PubMed

Reduced amplitude of the P300 event-related potential has been consistently associated with a variety of externalising problems, including conduct disorder. The few available genetically-informative studies of these relationships, however, were conducted among adolescents/adults (i.e., at an age when conduct disorder has typically already become manifest). Among 200 general population twins with a mean age of 9 years (range 6-14 years), we studied the relationship between the P300 waveform elicited by an auditory oddball task and the DSM-oriented conduct problems scale of the Child Behavior Checklist 6-18. Conduct problems scores were negatively and significantly correlated (r?=?-0.19, p?=?0.01) with P300 amplitude; correlations between P300 amplitude and the other DSM-oriented Child Behavior Checklist scales were non-significant, except for oppositional defiant problems (p?=?0.01). We found moderate heritability estimates for both P300 amplitude (0.58, CI:0.37;0.73) and conduct problems (0.52, CI:0.25;0.70). Bivariate twin analyses indicated that the covariation between these two phenotypes can be explained by additive genetic factors only, with a genetic correlation of -0.33. An association between reduced P300 amplitude and conduct problems can be substantiated already in childhood, at an age that precedes the most typical onset of conduct disorder. This relationship appears to be genetic in nature. Reduced P300 amplitude can represent a valuable marker for conduct problems, and can contribute to the early identification of children at high-risk for conduct disorder. PMID:24337737

Bertoletti, Eleonora; Michelini, Giorgia; Moruzzi, Sara; Ferrer, Giuseppina; Ferini-Strambi, Luigi; Stazi, Maria Antonietta; Ogliari, Anna; Battaglia, Marco

2014-07-01

355

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.

Manganotti, Paolo; Amelio, Ernesto; Guerra, Claudio

2012-01-01

356

[Formal sample size calculation and its limited validity in animal studies of medical basic research].  

PubMed

Animal studies are highly relevant for basic medical research, although their usage is discussed controversially in public. Thus, an optimal sample size for these projects should be aimed at from a biometrical point of view. Statistical sample size calculation is usually the appropriate methodology in planning medical research projects. However, required information is often not valid or only available during the course of an animal experiment. This article critically discusses the validity of formal sample size calculation for animal studies. Within the discussion, some requirements are formulated to fundamentally regulate the process of sample size determination for animal experiments. PMID:24326876

Mayer, B; Muche, R

2013-01-01

357

Comparison of expert and algorithm agreement in measurement of nerve conduction study parameters  

Microsoft Academic Search

In this study, the nerve conduction study (NCS) waveform assignment performance of algorithms used in a commercial electrodiagnostic instrument was compared against three neurophysiology experts for motor, F-wave, and sensory parameters. Assignments were made on a common set of waveforms, thereby eliminating a source of variability present in earlier studies that relied on re-testing patients. The performance of the algorithms

Brian H. Tracey; Darshan Iyer; Eugene A. Lesser; Frisso J. Potts; Shai N. Gozani

2010-01-01

358

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

359

40 CFR 790.62 - Submission of study plans and conduct of testing.  

Code of Federal Regulations, 2010 CFR

The principal sponsor of testing conducted pursuant to a consent agreement shall submit a study plan no later than 45 days prior to the initiation of testing. (b) Content of study plans. All study plans are required to contain the following...

1997-07-01

360

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

361

A developmental study of bone conduction auditory brain stem response in infants.  

PubMed

Two studies, vibrator placement and masking, were performed to evaluate the developmental aspect of bone conduction auditory brain stem response (ABR) in human infants. Subject groups included newborns, 1-yr-olds, and adults. In the vibrator studies, ABRs were obtained from placements of the bone conduction vibrator on the frontal, occipital, and temporal bones. Results showed that temporal placements in neonates and 1-yr-olds produce significantly shorter wave V latencies of ABR than frontal or occipital placements. In adults, differences of wave V latencies from various vibrator placements were comparatively small. In the masking studies, ABRs were acquired from vibrator placements at the temporal bone in the presence of ipsilateral air conducted masking noise from the experimental groups. Results showed that interaural attenuations of bone conduction click stimuli are the largest in neonates, somewhat smaller from 1-yr-olds, and the smallest in adults. The findings of this research strongly suggest that temporal placements for bone conduction ABR should be used, in some instances, when testing infants and 1-yr-olds. The results of this study support the proposition that bone conduction ABR is a feasible and reliable diagnostic tool in testing infants. PMID:3653538

Yang, E Y; Rupert, A L; Moushegian, G

1987-08-01

362

Studies on Electrochemical, Optical and Electrical Conductivity of Conducting Composite of o-Anisidine, o-Toluidine and Their Copolymer  

Microsoft Academic Search

A conducting composite of poly(o-anisidine), poly(o-toluidine) and poly(o-anisidine-co-o-toluidine) using incorporation of TiO2 and SiO2 was prepared by electrochemical polymerization. The films were electropolymerized in solution containing 0.1 M monomer(s), 1 M sulphuric acid as supporting electrolyte and 10 M TiO2 and SiO2 by applying a sequential linear potential scan rate of 50 mV\\/s between –0.2 and 1.0 V versus an

D. D. Borole; U. R. Kapadi; P. P. Mahulikar; D. G. Hundiwale

2009-01-01

363

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

364

Theoretical study of the lattice thermal conductivity in Ge framework semiconductors.  

PubMed

The lattice thermal conductivity of Ge clathrates is investigated by evaluating the linear response theory heat current correlation functions using molecular dynamics. Clathrate crystals with and without guest atoms in their fullerane cages are studied. In comparison with that of diamond-phase Ge, the clathrate conductivity is reduced by approximately 1 order of magnitude due to the open framework itself. The addition of an encapsulated (rattling) Sr guest atom produces a further order of magnitude reduction in the conductivity, making it comparable to that of amorphous Ge. Our results are consistent with experiments, and have impact on the search for improved thermoelectric materials. PMID:11289929

Dong, J; Sankey, O F; Myles, C W

2001-03-12

365

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.

2012-01-01

366

In situ SEM studies on strain sensing mechanisms of PPy-coated electrically conducting fabrics  

Microsoft Academic Search

This paper studies a flexible fabric strain sensor from PPy-coated fabrics prepared by a chemical vapor deposition method under low temperature, placing an emphasis on mechanisms of its strain sensing behavior. In situ tensile tests in a scanning electron microscope (SEM) were conducted for PPy-coated electrically conducting yarns, which were prepared by the same procedure as that for the PPy-coated

P. Xue; X. M. Tao; H. Y. Tsang

2007-01-01

367

Study of dc conductivity, transport mechanism, and dielectric relaxation in cassava starch membranes plasticized with glycerol  

Microsoft Academic Search

In the current work, we studied dc conductivity and its relaxation in glycerol-plasticized starch membranes at various concentrations\\u000a using impedance spectroscopy in frequency ranges between 20 Hz and 3 MHz and temperature ranging from 303 K to 423 K. We observed\\u000a thermally activated dc conductivity following the Arrhenius model: $$ \\\\ln \\\\sigma = \\\\ln {\\\\sigma_o} - {E_{\\\\sigma }}\\/{k_B}T $$, where the activation energy, E

German Ayala; Ana C. Agudelo; Jefferson Paz; Ruben A. Vargas

368

Conduction of Na + and K + through the NaK Channel: Molecular and Brownian Dynamics Studies  

Microsoft Academic Search

Conduction of ions through the NaK channel, with M0 helix removed, was studied using both Brownian dynamics and molecular dynamics. Brownian dynamics simulations predict that the truncated NaK has approximately a third of the conductance of the related KcsA K+ channel, is outwardly rectifying, and has a Michaelis-Menten current-concentration relationship. Current magnitude increases when the glutamine residue located near the

Taira Vora; David Bisset; Shin-Ho Chung

2008-01-01

369

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

PubMed Central

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

2010-01-01

370

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

371

Experimental and theoretical study of AC electrical conduction mechanisms of semicrystalline parylene C thin films.  

PubMed

The electrical conduction mechanisms of semicrystalline thermoplastic parylene C (-H(2)C-C(6)H(3)Cl-CH(2)-)(n) thin films were studied in large temperature and frequency regions. The alternative current (AC) electrical conduction in parylene C is governed by two processes which can be ascribed to a hopping transport mechanism: correlated barrier hopping (CBH) model at low [77-155 K] and high [473-533 K] temperature and the small polaron tunneling mechanism (SPTM) from 193 to 413 K within the framework of the universal law of dielectric response. The conduction mechanism is explained with the help of Elliot's theory, and the Elliot's parameters are determined. From frequency- and temperature-conductivity characteristics, the activation energy is found to be 1.27 eV for direct current (DC) conduction interpreted in terms of ionic conduction mechanism. The power law dependence of AC conductivity is interpreted in terms of electron hopping with a density N(E(F)) (~10(18) eV cm(-3)) over a 0.023-0.03 eV high barrier across a distance of 1.46-1.54 Å. PMID:22191786

Kahouli, Abdelkader; Sylvestre, Alain; Jomni, Fethi; Yangui, Béchir; Legrand, Julien

2012-01-26

372

Molecular testing for oncogenic gene mutations in thyroid lesions: a case-control validation study in 413 postsurgical specimens.  

PubMed

Molecular testing for oncogenic gene alterations provides clinically actionable information essential for the optimal management of follicular cell thyroid cancer. We aimed to establish the distribution and frequency of common oncogenic gene mutations and chromosomal rearrangements in a comprehensive set of benign and malignant thyroid lesions. A case-control study was conducted in 413 surgical cases comprising 17 distinct histopathologic categories, 244 malignant, 169 benign, and 304 double-blinded specimens. Seventeen alterations of BRAF, HRAS, KRAS, NRAS, PAX8, and RET genes were evaluated using a single validated technology platform. Following verification of analytical sensitivity, accuracy, and precision in model and surgical specimens, 152 molecular positive results were generated in lesions representing multiple stages of progression and epithelial differentiation as well as rare subtypes of primary, secondary, or recurring tumors. Single mutations were found in 58% of primary malignant lesions and 12% of benign (P < .001). In the blinded validation set, mutation distribution and frequency were distinct across variants of follicular and papillary carcinomas. BRAF or RET-PTC was detected exclusively in malignant lesions but not in follicular carcinomas (P < .001). RAS or PAX8-PPARG were present in 23% of adenomas, and NRAS was found in a single nonneoplastic lesion (P = .0014). These data substantiate the diagnostic utility of molecular testing for oncogenic mutations and validate its performance in a variety of surgical specimens. Standardized and validated multianalyte molecular panels can complement the preoperative and postoperative assessment of thyroid nodules and support a growing number of clinical and translational applications with potential diagnostic, prognostic, or theranostic utility. PMID:24830619

Giordano, Thomas J; Beaudenon-Huibregtse, Sylvie; Shinde, Rupali; Langfield, Laura; Vinco, Michelle; Laosinchai-Wolf, Walairat; Labourier, Emmanuel

2014-07-01

373

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

USGS Publications Warehouse

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

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

2010-01-01

374

Preliminary report of a validation study of Instrumental Activities of Daily Living in a Greek sample.  

PubMed

To validate the Instrumental Activities of Daily Living in Greek, 44 men (M age=70.5 yr., SD=7.2) and 58 women (M age= 68.4, SD=9.2), outpatients of memory clinics, were studied. Sex differences in the item responses were evaluated. Reliability assessed as Cronbach alpha was .84, while validity was assessed by correlation of .77 with the Mini-Mental State Examination. 21 men and 20 women had moderate to severe dementia, with Mini-Mental State Examination scores <20. The results show that this Greek language version can be effectively used in Greece. PMID:17688151

Theotoka, Ioulia; Kapaki, Elisabeth; Vagenas, Vasileios; Ilias, Ioannis; Paraskevas, George P; Liappas, Ioannis

2007-06-01

375

Validation study of the Veratox R5 rapid ELISA for detection of gliadin.  

PubMed

Neogen Corp. developed the Veratox R5 Gliadin test kit for the detection of gliadin based on the monoclonal antibody R5 developed by Enrique Mendez (1). The purpose of this study was to validate the method under the requirements of the AOAC Research Institute Performance Tested Method program. There are two AOAC Official Methods for gluten detection in foods, 991.19 and 2012.01 (2), both of which are ELISAs. With the R5 Mendez method listed in the CODEX Alimentarius as a type 1 method for the detection of gluten in foods, the need to have additional rapid test kits validated by the AOAC Research Institute exists. PMID:23513967

Lupo, Anthony; Roebuck, Chris; Walsh, Aaron; Mozola, Mark; Abouzied, Mohamed

2013-01-01

376

Validation Study of the Hicks Cloze-Reading Test for Grades Two-Six.  

ERIC Educational Resources Information Center

This study was concerned with the validation of the "Hicks Cloze-Reading Test," an evaluative instrument to be used by the classroom teacher in assessing the reading ability levels of children. Three instruments, the Gates-MacGinitie Reading Test," the "Standard Reading Inventory," and the "Hicks Cloze-Reading Test," forms one and two, were…

Hicks, Donna Wheeler

377

Toward validation of atypical depression in the community: results of the Zurich cohort study  

Microsoft Academic Search

Aims: This paper (1) examines the validity of the atypical subtype of depression in a community-based longitudinal cohort study, (2) presents estimates of the prevalence and sex differences of DSM-IV atypical depression and a newly more broadly defined atypical syndrome in the community and (3) compares the clinical correlates and treatment patterns of those with atypical depression with other depressives.

Jules Angst; Alex Gamma; Robert Sellaro; Heping Zhang; Kathleen Merikangas

2002-01-01

378

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

ERIC Educational Resources Information Center

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

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

2013-01-01

379

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

380

The Structure-Based Expert Model of the Mental Disorders – A Validation Study  

Microsoft Academic Search

Background: In an earlier study, our research group presented an alternative approach to measuring knowledge about mental disorders by constructing a structure-based expert model of the ICD-10 mental disorders. This article presents a validation of this expert model by measuring the emergence of such knowledge structures in psychotherapy students. Sampling and Methods: The participants of a continuing education program in

Samy Egli; Roland Streule; Damian Läge

2008-01-01

381

Ambulatory accelerometry to quantify motor behaviour in patients after failed back surgery: a validation study  

Microsoft Academic Search

In the treatment of patients with pain, measures related to (pain) behaviour are of major importance. Ambulatory activity monitoring can be used to obtain insight into actual behaviour. This study was designed to validate the Activity Monitor (AM), an instrument based on long-term ambulatory monitoring of accelerometer signals, to assess several physical activities during normal daily life. Ten failed back

J. B. J Bussmann; Y. M van de Laar; M. P Neeleman; H. J Stam

1998-01-01

382

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

383

The Reading Essential Skills Screener-Elementary Version (RESS-E): Studies of Reliability and Validity  

ERIC Educational Resources Information Center

Technical characteristics of the Reading Essential Skills Screener-Elementary Version (RESS-E; B. T. Erford, G. Vitali, R. Haas, & R. R. Boykin, 1995) were studied using 4 independent samples of boys and girls between the ages of 6 and 8 years. Evidence of internal consistency, test-retest reliability, decision efficiency, factorial validity,…

Erford, Bradley T.; Stephens, Vicki M.

2005-01-01

384

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

ERIC Educational Resources Information Center

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

Allen, Reva I.

385

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

Cancer.gov

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

386

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

387

Turkish version of impact on family scale: a study of reliability and validity  

Microsoft Academic Search

BACKGROUND: Although there is a considerably high prevalence of developmental disorders in Turkey there are not many assessment tools related to evaluating the impact of these children on their family. The aim of this study was to determine the validity and reliability of the Turkish version of the Impact on Family Scale (IPFAM), a health related quality of life measurement

Nilgun Bek; I Engin Simsek; Suat Erel; Yavuz Yakut; Fatma Uygur

2009-01-01

388

Validity and responsiveness of the Clubfoot Assessment Protocol (CAP). A methodological study  

Microsoft Academic Search

BACKGROUND: The Clubfoot Assessment Protocol (CAP) is a multi dimensional instrument designed for longitudinal follow up of the clubfoot deformity during growth. Item reliability has shown to be sufficient. In this article the CAP's validity and responsiveness is studied using the Dimeglio classification scoring as a gold standard. METHODS: Thirty-two children with 45 congenital clubfeet were assessed prospectively and consecutively

Hanneke Andriesse; Ewa M Roos; Gunnar Hägglund; Gun-Britt Jarnlo

2006-01-01

389

Assessing Social Support in Mexican and Mexican American High School StudentsA Validation Study  

Microsoft Academic Search

This study is a means of validating the Harter's Social Support Scale for Children on a sample of Mexican and Mexican American ninth-grade students to assist researchers and practitioners to more accurately assess this variable on this specific Latino group. The psychometric information was obtained through intercorrelations and Cronbach's alpha. Results indicated that the scale was an adequate measure of

Eric J. López; Loretta Salas

2006-01-01

390

A Study of the Validity of the Two-Minute Bent Knee Sit-Up.  

National Technical Information Service (NTIS)

The U.S. Marine Corps Physical Fitness Test includes a two-minute bent knee sit-up. The purpose of the study was to investigate the validity of this item. It was concluded that this test does not measure the strength of the abdominal muscles and the hip f...

P. J. Rasch J. J. Krauer

1970-01-01

391

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

392

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

ERIC Educational Resources Information Center

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

Karathanos, Demetrius

1991-01-01

393

A Content Validity Study of the Children's Version of The Family Environment Scale.  

ERIC Educational Resources Information Center

Investigated the structural pictorial properties of a children's version of The Family Environment Scale as a content validity study of the scale. Age differences in results between third- and seventh-grade children were confirmed, and social comprehension levels increased with age. Implications for present use and future research are discussed.…

Pino, Christopher J.

1985-01-01

394

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

ERIC Educational Resources Information Center

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

Baig, Lubna; Violato, Claudio; Crutcher, Rodney

2010-01-01

395

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

ERIC Educational Resources Information Center

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

Derham, Carol; DiPerna, James

2007-01-01

396

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

397

Task-Independent Functional Brain Activity Correlation with Skin Conductance Changes: An fMRI Study  

Microsoft Academic Search

Lesionsof the ventromedial prefrontal cortex cause a loss of skin conductance response (SCR) to stimuli with affective content and an inability to integrate information with social consequences into decisions. Previous behavioral studies using a gambling task were able to differentiate patients with lesions in this region from normal subjects. In the present imaging study, this region, among others, was shown

James C. Patterson II; Leslie G. Ungerleider; Peter A. Bandettini

2002-01-01

398

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

399

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

EPA Science Inventory

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

400

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

EPA Science Inventory

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

401

A one year study of Mode Deactivation Therapy: Adolescent Residential Patients with Conduct and Personality Disorders  

Microsoft Academic Search

This case study is to evaluate the effectiveness of Mode Deactivation Therapy (MDT) implementation in a child and adolescent residential treatment unit and provide preliminary effectiveness data on MDT versus treatment as usual (TAU). This case study compared the efficacy of two treatment methodologies for adolescent males in residential treatment with conduct disorders and\\/or personality dysfunctions with physically or sexually

Christopher J. Murphy; Alexander M. Siv

2007-01-01

402

Characterizing Measurement Error in Test Scores across Studies: A Tutorial on Conducting "Reliability Generalization" Analyses.  

ERIC Educational Resources Information Center

Given the potential value of reliability generalization (RG) studies in the development of cumulative psychometric knowledge, the purpose of this paper is to provide a tutorial on how to conduct such studies and to serve as a guide for researchers wishing to use this methodology. After some brief comments on classical test theory, the paper…

Henson, Robin K.; Thompson, Bruce

403

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

SciTech Connect

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

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

2009-10-15

404

Conductivity, thermal and morphology studies of PEO based salted polymer electrolytes  

NASA Astrophysics Data System (ADS)

Polymer electrolyte has been prepared via solution-casting technique. The polymer electrolytes are formed from polyethylene oxide (PEO) and lithium hexafluorate is used as the doping salt. The conductivity increases from 10-9 to 10-4 S cm-1 upon the addition of various concentrations of salt. The results reveal that the conductivity increases with increasing temperature when the salt concentration increases up to 20 wt% The conductivity for 20 wt% of salt remains similar to the conductivity for 15 wt% of salt at 318 K. Differential scanning calorimetry studies show that the melting transition temperature and crystallinity decreases upon the addition of various concentrations of salt. Thermogravimetric analysis (TGA) results indicate that a significant effect on the thermal stability of polyethylene-lithium salt composites. SEM images reveal that the morphology of polymer electrolyte's surface changes when various concentrations of salt are added into the polymer system.

Ibrahim, Suriani; Yasin, Siti Mariah Mohd; Ahmad, Roslina; Johan, Mohd Rafie

2012-08-01

405

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

406

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

PubMed Central

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

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

2013-01-01

407

Guidelines for conducting and reporting case study research in software engineering  

Microsoft Academic Search

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

Per Runeson; Martin Höst

2009-01-01

408

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

409

The Word Associates Format: Validation Evidence  

ERIC Educational Resources Information Center

Although the Word Associates Format (WAF) is becoming more frequently used as a depth-of-knowledge measure, relatively little validation has been carried out on it. This report of two validation studies tackles various important WAF issues yet to be satisfactorily resolved. Study 1 conducted introspective interviews regarding students' WAF…

Schmitt, Norbert; Ng, Janice Wun Ching; Garras, John

2011-01-01

410

Evaluation of physicians' professional performance: An iterative development and validation study of multisource feedback instruments  

PubMed Central

Background There is a global need to assess physicians' professional performance in actual clinical practice. Valid and reliable instruments are necessary to support these efforts. This study focuses on the reliability and validity, the influences of some sociodemographic biasing factors, associations between self and other evaluations, and the number of evaluations needed for reliable assessment of a physician based on the three instruments used for the multisource assessment of physicians' professional performance in the Netherlands. Methods This observational validation study of three instruments underlying multisource feedback (MSF) was set in 26 non-academic hospitals in the Netherlands. In total, 146 hospital-based physicians took part in the study. Each physician's professional performance was assessed by peers (physician colleagues), co-workers (including nurses, secretary assistants and other healthcare professionals) and patients. Physicians also completed a self-evaluation. Ratings of 864 peers, 894 co-workers and 1960 patients on MSF were available. We used principal components analysis and methods of classical test theory to evaluate the factor structure, reliability and validity of instruments. We used Pearson's correlation coefficient and linear mixed models to address other objectives. Results The peer, co-worker and patient instruments respectively had six factors, three factors and one factor with high internal consistencies (Cronbach's alpha 0.95 - 0.96). It appeared that only 2 percent of variance in the mean ratings could be attributed to biasing factors. Self-ratings were not correlated with peer, co-worker or patient ratings. However, ratings of peers, co-workers and patients were correlated. Five peer evaluations, five co-worker evaluations and 11 patient evaluations are required to achieve reliable results (reliability coefficient ? 0.70). Conclusions The study demonstrated that the three MSF instruments produced reliable and valid data for evaluating physicians' professional performance in the Netherlands. Scores from peers, co-workers and patients were not correlated with self-evaluations. Future research should examine improvement of performance when using MSF.

2012-01-01

411

Development of a high pressure electrical conductivity probe for experimental studies of gas hydrates in electrolytes.  

PubMed

We previously reported the development of a high pressure automated lag time apparatus and a high pressure video cell for experimental study of nucleation and growth of gas hydrates. Here we report the development of a high pressure electrical conductivity probe that monitors the electrical conductivity of an electrolyte that is subjected to a linear cooling ramp at elevated hydrate-forming-gas pressures. The electrical conductivity steadily decreases as the linear cooling progresses because of the increasing viscosity of the electrolyte and the consequently decreasing mobility of the ions. The onset of the formation of methane-propane mixed gas hydrate films at the gas-electrolyte interface is marked by an upward spike in the electrical conductivity. The physical mechanisms behind this phenomenon remain to be elucidated. Continued cooling of the electrolyte to, and subsequent holding of, the temperature at 273 K eventually results in decreased electrical conductivity. This conductivity signal can be used for the detection of the onset of the formation of gas hydrates in optically opaque samples that contain electrolytes. PMID:23387698

Maeda, Nobuo

2013-01-01

412

Derivation and Validation of a MEDLINE Search Strategy for Research Studies That Use Administrative Data  

PubMed Central

Objective To derive and validate a search strategy that identifies administrative database research (ADR) in the MEDLINE database. Design Analytical survey. Methods We downloaded all articles published between January 1, 2008 and October 7, 2009 in 20 top journals in internal medicine, cardiovascular medicine, public health, and health services research. These were reviewed to determine whether they were ADR (in which the study cohort, exposure, or outcome was defined using electronic data created for or during the processing of patients through their health care). We used chi-squared recursive partitioning to create a search strategy that maximized sensitivity based on publication type, MeSH headings, and text words. Main Outcome Measures Sensitivity and positive predictive value of the search strategy for true ADR in three samples: derivation (n=5,513); internal validation (n=2,710); and external validation (n=1,500). Results The prevalence of ADR in the derivation, internal validation, and external validation samples was 2.6, 2.9, and 2.2 percent, respectively. The sensitivity of our search strategy in these samples was 90.9 percent (95 percent confidence interval [CI] 85.0–95.1), 88.5 percent (79.2–94.6), and 100 percent (99.3–100), respectively. The positive predictive value in these samples was 10.7 percent (9.0–12.6), 11.5 percent (9.1–14.4), and 3.3 percent (2.3–4.6), respectively. Conclusion We derived and validated a search strategy that is highly sensitive for ADR in MEDLINE.

van Walraven, Carl; Bennett, Carol; Forster, Alan J

2010-01-01

413

A validation of the first genome-wide association study of calcaneus ultrasound parameters in the European Male Ageing Study  

Microsoft Academic Search

BACKGROUND: A number of single nucleotide polymorphisms (SNPs) have been associated with broadband ultrasound attenuation (BUA) and speed of sound (SOS) as measured by quantitative ultrasound (QUS) at the calcaneus in the Framingham 100K genome-wide association study (GWAS) but have not been validated in independent studies. The aim of this analysis was to determine if these SNPs are associated with

Delnaz Roshandel; Wendy Thomson; Stephen R Pye; Steven Boonen; Herman Borghs; Dirk Vanderschueren; Ilpo T Huhtaniemi; Judith E Adams; Kate A Ward; Gyorgy Bartfai; Felipe Casanueva; Joseph D Finn; Gianni Forti; Aleksander Giwercman; Thang S Han; Krzysztof Kula; Michael E Lean; Neil Pendleton; Margus Punab; Alan J Silman; Frederick C Wu; Kate L Holliday; Terence W O’Neill

2011-01-01

414

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

EPA Science Inventory

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

415

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

NASA Astrophysics Data System (ADS)

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

Hirasawa, Yoshio; Ohta, Ryuma; Takegoshi, Eisyun

416

Effects of Fibroblast-Myocyte Coupling on Cardiac Conduction and Vulnerability to Reentry: A Computational Study  

PubMed Central

Background Recent experimental studies documented that functional gap junctions form between fibroblasts and myocytes, raising the possibility that fibroblasts play roles in cardiac electrophysiology that extend beyond acting as passive electrical insulators. Objectives Using computational models, we investigated how fibroblasts may affect cardiac conduction and vulnerability to reentry under different fibroblast-myocyte coupling conditions and tissue structures. Methods Computational models of two-dimensional tissue with fibroblast-myocyte coupling were developed and numerically simulated. Myocytes were modeled by the Phase I of the Luo-Rudy model and fibroblasts by a passive model. Results Besides slowing conduction by cardiomyocyte decoupling and electrotonic loading, fibroblast coupling to myocytes elevates myocyte resting membrane potential, causing conduction velocity to first increase and then decrease as fibroblast content increases, until conduction failure occurs. Fibroblast-myocyte coupling can also enhance conduction by connecting uncoupled myocytes. These competing effects of fibroblasts on conduction give rise to different conduction patterns under different fibroblast-myocyte coupling conditions and tissue structures. Elevation of myocyte resting potential due to fibroblast-myocyte coupling slows sodium channel recovery, which extends post-repolarization refractoriness. Due to this prolongation of myocyte refractory period, reentry was more readily induced by a premature stimulation in heterogeneous tissue models when fibroblasts were electrotonically coupled to myocytes compared to uncoupled fibroblasts acting as pure passive electrical insulators. Conclusions Fibroblasts affect cardiac conduction acting as obstacles, or by creating electrotonic loading and elevating myocyte resting potential. Functional fibroblast-myocyte coupling prolongs myocyte refractory period which may facilitate induction of reentry in cardiac tissue with fibrosis.

Xie, Yuanfang; Garfinkel, Alan; Camelliti, Patrizia; Kohl, Peter; Weiss, James N.; Qu, Zhilin

2010-01-01

417

Validating the Measurement of Real-World Functional Outcomes: Phase I Results of the VALERO Study  

PubMed Central

Objective Cognitive deficits are associated with disability in people with schizophrenia so treatment of cognitive impairment has been proposed as an intervention to reduce disability. However, studies relying on patient self-report have found very minimal relationships between ratings of real-world functioning and cognitive performance, raising questions about the measurement of real-world functioning as a treatment outcome. The Validation of Everyday Real-world Outcomes (VALERO) study was conducted to evaluate functional rating scales and to identify the rating scale or scales most robustly related to performance-based measures of cognition and everyday living skills. Method 198 adults with schizophrenia were tested with the neurocognitive measures from the MATRICS Consensus cognitive Battery and performed the UCSD performance-based skills assessment-Brief and advanced finances subtest from the Everyday Functioning Battery. They and a friend, relative, clinician, or case manager also reported their everyday functioning on 6 ratings scales: Social Behavior Schedule, Social Adjustment Scale, Heinrichs Carpenter Quality of Life Scale, Specific Levels of Functioning, Independent Living skills Survey, and Life Skills Profile. Best judgment ratings were generated by an interviewer who administered the rating scales to patients and informants. Results Statistical analyses developed an ability latent trait that reflected scores on the three performance-based (i.e., ability) measures and canonical correlation analysis related interviewer ratings to the latent trait. The overall fit of the model with all six rating scales was good: ?2 = 78.100, df = 56, p = .027, and RMSEA = .078. Individual rating scales that did not improve the fit of the model were systematically deleted and a final model with two rating scales fit the data: ?2 = 32.059, df = 24, p = .126, RMSEA = .072. A regression analysis found that the Specific Levels of Functioning was a superior predictor of the three-performance based ability measures. Conclusions We found that systematic assessments of real world functioning are related to performance on neurocognitive and functional capacity measures. Of the six rating scales evaluated, the Specific Levels of Functioning (SLOF) was best in this study. Use of a single rating scale provides a very efficient assessment of real-world functioning that accounts for considerable variance in performance-based scores.

Harvey, Philip D.; Raykov, Tenko; Twamley, Elizabeth; Vella, Lea; Heaton, Robert K.; Patterson, Thomas L.

2013-01-01

418

A Platform for the Remote Conduct of Gene-Environment Interaction Studies  

PubMed Central

Background Gene-environment interaction studies offer the prospect of robust causal inference through both gene identification and instrumental variable approaches. As such they are a major and much needed development. However, conducting these studies using traditional methods, which require direct participant contact, is resource intensive. The ability to conduct gene-environment interaction studies remotely would reduce costs and increase capacity. Aim To develop a platform for the remote conduct of gene-environment interaction studies. Methods A random sample of 15,000 men and women aged 50+ years and living in Cardiff, South Wales, of whom 6,012 were estimated to have internet connectivity, were mailed inviting them to visit a web-site to join a study of successful ageing. Online consent was obtained for questionnaire completion, cognitive testing, re-contact, record linkage and genotyping. Cognitive testing was conducted using the Cardiff Cognitive Battery. Bio-sampling was randomised to blood spot, buccal cell or no request. Results A heterogeneous sample of 663 (4.5% of mailed sample and 11% of internet connected sample) men and women (47% female) aged 50–87 years (median?=?61 yrs) from diverse backgrounds (representing the full range of deprivation scores) was recruited. Bio-samples were donated by 70% of those agreeing to do so. Self report questionnaires and cognitive tests showed comparable distributions to those collected using face-to-face methods. Record linkage was achieved for 99.9% of participants. Conclusion This study has demonstrated that remote methods are suitable for the conduct of gene-environment interaction studies. Up-scaling these methods provides the opportunity to increase capacity for large-scale gene-environment interaction studies.

Gallacher, John; Collins, Rory; Elliott, Paul; Palmer, Stephen; Burton, Paul; Mitchell, Clive; John, Gareth; Lyons, Ronan

2013-01-01

419

CALPUFF and AERMOD model validation study in the near field: Martins Creek revisited.  

PubMed

This paper describes a near-field validation study involving the steady-state, U.S. Environmental Protection Agency (EPA) guideline model AERMOD and the nonsteady-state puff model CALPUFF. Relative model performance is compared with field measurements collected near Martins Creek, PA-a rural, hilly area along the Pennsylvania-New Jersey border. The principal emission sources in the study were two coal-fired power plants with tall stacks and buoyant plumes. Over 1 yr of sulfur dioxide measurements were collected at eight monitors located at or above the two power plants' stack tops. Concurrent meteorological data were available at two sites. Both sites collected data 10 m above the ground. One of the sites also collected sonic detection and ranging measurements up to 420 m above ground. The ability of the two models to predict monitored sulfur dioxide concentrations was assessed in a four-part model validation. Each part of the validation applied different criteria and statistics to provide a comprehensive evaluation of model performance. Because of their importance in regulatory applications, an emphasis was placed on statistics that demonstrate the model's ability to reproduce the upper end of the concentration distribution. On the basis of the combined results of the four-part validation (i.e., weight of evidence), the performance of CALPUFF was judged to be superior to that of AERMOD. PMID:21751581

Dresser, Alan L; Huizer, Robert D

2011-06-01

420

A semi-automatic method for left ventricle volume estimate: an in vivo validation study  

NASA Technical Reports Server (NTRS)

This study aims to the validation of the left ventricular (LV) volume estimates obtained by processing volumetric data utilizing a segmentation model based on level set technique. The validation has been performed by comparing real-time volumetric echo data (RT3DE) and magnetic resonance (MRI) data. A validation protocol has been defined. The validation protocol was applied to twenty-four estimates (range 61-467 ml) obtained from normal and pathologic subjects, which underwent both RT3DE and MRI. A statistical analysis was performed on each estimate and on clinical parameters as stroke volume (SV) and ejection fraction (EF). Assuming MRI estimates (x) as a reference, an excellent correlation was found with volume measured by utilizing the segmentation procedure (y) (y=0.89x + 13.78, r=0.98). The mean error on SV was 8 ml and the mean error on EF was 2%. This study demonstrated that the segmentation technique is reliably applicable on human hearts in clinical practice.

Corsi, C.; Lamberti, C.; Sarti, A.; Saracino, G.; Shiota, T.; Thomas, J. D.

2001-01-01

421

A validation study of new cryopreservation bags for implementation in a blood and marrow transplant laboratory  

PubMed Central

BACKGROUND A new cryopreservation bag for hematopoietic cell transplantation requires validation as a safe alternative to the bag currently being used in the laboratory. STUDY DESIGN AND METHODS The new bag was validated using both laboratory and clinical criteria. Laboratory validation proceeded using paired samples of mononuclear cells processed using standard procedures. Cells cryopreserved in the new and old bags were compared for viability, cell counts, CD34 enumeration, colony-forming unit assays, and bag integrity. After completion of laboratory investigations, engraftment with the new bags was followed and compared to historical engraftment using the old bags. RESULTS There were no significant differences between the old and new bags detected using laboratory studies. Bag integrity was equivalent. The validation data suggested impaired cell function after cryopreservation in the new bags, but there were no significant differences in engraftment potential using either material. Days to engraftment was longer using the new bags, but statistical analysis revealed an association with CD34 dose and not with cryopreservation bag type. CONCLUSION The new bags were noninferior to the old bags. A change in cryopreservation bag type may appear to affect cell function and potentially affect engraftment. Multiple analyses may be needed to understand the effect of cell processing changes.

Pomper, Gregory J.; Wilson, Emily; Isom, Scott; Hurd, David D.

2013-01-01

422

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

Microsoft Academic Search

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

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

1995-01-01

423

Localized and long-distance charge hopping in fresh and thermally aged conductive copolymers of polypyrrole and polyaniline studied by combined TSDC and dc conductivity  

Microsoft Academic Search

The charge trapping centers in fresh and thermally aged conductive polyaniline–polypyrrole copolymers (starting from pure polyaniline and ending in pure polypyrrole by steps of 10wt%) were studied by thermally stimulated depolarization current (TSDC) spectroscopy and dc conductivity measurements. One low temperature (115–135K) relaxation mechanism appears in polyaniline-rich copolymers and disappears after thermal anneal. It is attributed to polaron trapping in

A. N Papathanassiou; J Grammatikakis; S Sakkopoulos; E Vitoratos; E Dalas

2002-01-01

424

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

425

A STUDY ON A COOPERATIVE RELATIONSHIP TO THE IMPROVEMENT OF THE REGIONAL FIRE FIGHTING VALIDITY -Case Study in Bangkok, Thailand-  

NASA Astrophysics Data System (ADS)

Generally, in order to improve some regional fire fighting validity, indispensable strategies are not only a reinforcement of the governmental fire fighting ability, but also a strengthening of the cooperative relationship between governmental and non-governmental fire fighting ability. However, for practical purposes, the effective strategy should be different depending on the actual situationin the subject area. So, in this study, we grasp the actual state and background of the problems that need to be solved for the improvement of the regional fire fighting validity in Bangkok as a case study, and examine the appropriate solution focusing on the relationship between official and voluntary fire fighting. Through some practicable activities such as interviews, investigati ons, and making the regional fire fighting validity map, it became clear that the problems of uncooperative relationship and the lack of trust between stakeholders should be solved first and foremost.

Sripramai, Keerati; Oikawa, Yasushi; Watanabe, Hiroshi; Katada, Toshitaka

426

The Use of Relational Databases as a Tool for Conducting Clinical Studies  

PubMed Central

Many clinical investigators already have access to powerful university mainframe-based relational database management systems. Many of these programs, with minimal expense in time and money, can be employed to assist the investigator in conducting clinical trials. We describe our experience using one such general relational database system (System 1022) in completing several academic studies.

Miller, Randolph A.; Kapoor, Wishwa N.; Peterson, Jacqueline

1983-01-01

427

Bibliography of Planning and Research Studies Conducted by Health Planning Agencies in DHEW Region II.  

National Technical Information Service (NTIS)

Planning and research studies conducted by health planning agencies in DHEW Region II are presented in a bibliography covering the period between January 1973 and June 1975. Included in Region II are New Jersey, New York, Puerto Rico, and the Virgin Islan...

1976-01-01

428

The use of computer animation of mapped cardiac potentials in studying electrical conduction properties of arrhythmias  

Microsoft Academic Search

It is shown how computer animation of potentials recorded from 121 electrodes on the canine heart surface is used to study the electrical conduction properties of the heart. Color indicates the magnitude of each electrode's recorded voltage on the workstation screen. As each electrode's recorded voltage changes over time the corresponding color on the screen changes. The colors for all

Cary Laxer; C. A. Alferness; William M. Smith; R. E. Ideker

1990-01-01

429

Acoustical and thermal conductivity studies on CuO/DEA-benzene hybrid nanofluids  

NASA Astrophysics Data System (ADS)

Binary organic liquid based copper oxide nanofluids of various concentrations have been prepared through ultrasonically assisted chemical solution method. Ultrasonic studies, refractive indices, densities are carried out for the nanofluids for various temperature where Thermal conductivity was also measured for the nanofluids at room temperature. The molecular interactions responsible for the changes in acoustical parameters with respect to concentration and temperature are discussed.

Rohini, B.; Gopalakrishnan, M.; Kiruba, R.; Mahalingam, T.; Kingson Solomon Jeevaraj, A.

2013-02-01

430

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

431

NMR, DSC and High Pressure Electrical Conductivity Studies on Liquid and Hybrid Electrolytes.  

National Technical Information Service (NTIS)

Electrical conductivity, DSC and Li-7 NMR studies have been carried out on liquid electrolytes such as EC:PC and EC:DMC containing LiPF6 (and LiCF3SO3 for NMR) and films plasticized using the same liquid electrolytes. The films are based on poly(vinyliden...

P. E. Stallworth J. J. Fontanella M. Wintersgill C. D. Scheidler J. J. Immel

1998-01-01

432

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

433

Predictability of Persistent Frequent Attendance in Primary Care: A Temporal and Geographical Validation Study  

PubMed Central

Background Frequent attenders are patients who visit their general practitioner exceptionally frequently. Frequent attendance is usually transitory, but some frequent attenders become persistent. Clinically, prediction of persistent frequent attendance is useful to target treatment at underlying diseases or problems. Scientifically it is useful for the selection of high-risk populations for trials. We previously developed a model to predict which frequent attenders become persistent. Aim To validate an existing prediction model for persistent frequent attendance that uses information solely from General Practitioners’ electronic medical records. Methods We applied the existing model (N?=?3,045, 2003–2005) to a later time frame (2009–2011) in the original derivation network (N?=?4,032, temporal validation) and to patients of another network (SMILE; 2007–2009, N?=?5,462, temporal and geographical validation). Model improvement was studied by adding three new predictors (presence of medically unexplained problems, prescriptions of psychoactive drugs and antibiotics). Finally, we derived a model on the three data sets combined (N?=?12,539). We expressed discrimination using histograms of the predicted values and the concordance-statistic (c-statistic) and calibration using the calibration slope (1?=?ideal) and Hosmer-Lemeshow tests. Results The existing model (c-statistic 0.67) discriminated moderately with predicted values between 7.5 and 50 percent and c-statistics of 0.62 and 0.63, for validation in the original network and SMILE network, respectively. Calibration (0.99 originally) was better in SMILE than in the original network (slopes 0.84 and 0.65, respectively). Adding information on the three new predictors did not importantly improve the model (c-statistics 0.64 and 0.63, respectively). Performance of the model based on the combined data was similar (c-statistic 0.65). Conclusion This external validation study showed that persistent frequent attenders can be prospectively identified moderately well using data solely from patients’ electronic medical records.

Smits, Frans T.; Brouwer, Henk J.; Zwinderman, Aeilko H.; van den Akker, Marjan; van Steenkiste, Ben; Mohrs, Jacob; Schene, Aart H.; van Weert, Henk C.; ter Riet, Gerben

2013-01-01

434

The Diagnostic Accuracy and Validity of the Teen Screen Questionnaire-Mental Health for Clinical and Epidemiological Studies in Primary-Care Settings  

PubMed Central

Background: To validate a brief, self-reported, Teen Symptom Questionnaire–Mental Health (TSQ-M), for identifying adolescents with mental ill-health, designed for conducting epidemiological studies and clinical work in primary-care settings. Materials and Methods: In this prospective, cross-sectional study of 146 adolescents, re-cruited six rural and urban schools, the newly developed TSQ-M as the measure for validation and General Health Questionnaire-12 item (GHQ-12) as the gold standard measure were administered by independent trained raters. Tests for diagnostic accuracy and validity were conducted. Results: A TSQ-M score of ?29 (Sn=75.68%, Sp=68.06, +LR=2.37, -LR=0.36, PPV=70.9, NPV=73.1) with the AUC of 0.79, is suggested for screening use in Indian populations. Besides the adequate face and content validity, TSQ-M has moderate internal consistency (Cronbach's ? = .64) suggesting that the construct of mental ill-health as conceptualized by TSQ-M has multiple sub-constructs. The presence of sub-constructs was demonstrated by an 8- factor structure, which explained 60% of variance. Conclusion: The TSQ-M is a psychometrically adequate, yet a brief measure, for clinical and research work in identifying mental ill-health among adolescents in primary-care settings in India.

Nair, MK; Chacko, Deepa; Rajaraman, Venkateswaran; George, Babu; Samraj, Leena; Russell, Paul Swamidhas

2014-01-01

435

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

PubMed

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

2014-06-01

436

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

PubMed Central

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

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

2010-01-01

437

Initial Teacher Licensure Testing in Tennessee: Test Validation.  

ERIC Educational Resources Information Center

In 1988 a study was conducted to determine the validity of candidate teacher licensure examinations for use in Tennessee under the 1984 Comprehensive Education Reform Act. The Department of Education conducted a study to determine the validity of 11 previously unvalidated or extensively revised tests for certification and to make recommendations…

Bowman, Harry L.; Petry, John R.

438

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

PubMed

A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9-12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for several years. Central motor conduction times were abnormal in all patients. Clinical conditions worsened significantly between successive examinations with significant increments in threshold and significant decrement of the amplitude of motor evoked potentials. The results are consistent with progressive pyramidal and cerebellar pathways involvement as the cause of clinical worsening in FA. PMID:9448647

Cruz-Martínez, A; Palau, F

1997-12-01

439

Ionic conductivity and FT-IR studies on plasticized PVC/PMMA blend polymer electrolytes  

NASA Astrophysics Data System (ADS)

Ionic conductivities of plasticized poly(vinylchoride) (PVC)/poly(methylmethacrylate) (PMMA) blend electrolyte films containing two different lithium salts, viz., lithium tetrafluroborate (LiBF 4) and lithium perchlorate (LiClO 4) are studied using the AC impedance technique at 25°C, 40°C, 50°C and 60°C. A mixture of ethylene carbonate (EC) and propylene carbonate (PC) is used as the plasticizer. Pure PMMA and PMMA-rich phases exhibited better conductivity. The variation of ionic conductivity for different plasticizer contents and for different lithium salts is reported. The variation in film morphology is examined by scanning electron microscopic examination. Finally, the existence of ion-ion pairs has been identified using Fourier Transform Infrared analysis (FT-IR) measurements.

Stephan, A. Manuel; Kumar, T. Prem; Renganathan, N. G.; Pitchumani, S.; Thirunakaran, R.; Muniyandi, N.

440

In situ SEM studies on strain sensing mechanisms of PPy-coated electrically conducting fabrics  

NASA Astrophysics Data System (ADS)

This paper studies a flexible fabric strain sensor from PPy-coated fabrics prepared by a chemical vapor deposition method under low temperature, placing an emphasis on mechanisms of its strain sensing behavior. In situ tensile tests in a scanning electron microscope (SEM) were conducted for PPy-coated electrically conducting yarns, which were prepared by the same procedure as that for the PPy-coated fabrics, enabling it possible to observe in situ the phenomena that occurred on the fiber surface during fabric deformation. The investigation revealed that the PPy-coated nylon/polyurethane fabrics exhibited a high strain sensitivity of over 400 and very large workable strain range greater than 50%, which mainly attributes to the high conductivity and crack-opening and crack-closing mechanisms of PPy-coated polyurethane yarn, as well as the excellent properties of knitted fabric structure.

Xue, P.; Tao, X. M.; Tsang, H. Y.

2007-01-01

441

Theoretical study of thermal conductivity in single-walled boron nitride nanotubes  

NASA Astrophysics Data System (ADS)

We perform a theoretical investigation on the thermal conductivity of single-walled boron nitride nanotubes (SWBNT) using the kinetic theory. By fitting to the phonon spectrum of the boron nitride sheet, we develop an efficient and stable Tersoff-derived interatomic potential which is suitable for the study of heat transport in sp2 structures. We work out the selection rules for the three-phonon process with the help of the helical quantum numbers (?,n) attributed to the symmetry group (line group) of the SWBNT. Our calculation shows that the thermal conductivity ?ph diverges with length as ?ph?L? with exponentially decaying ?(T)?e-T/Tc, which results from the competition between boundary scattering and three-phonon scattering for flexure modes. We find that the two flexure modes of the SWBNT make dominant contribution to the thermal conductivity, because their zero frequency locates at ?=±?, where ? is the rotational angle of the screw symmetry in SWBNT.

Jiang, Jin-Wu; Wang, Jian-Sheng

2011-08-01

442

Lessons Learned During the Conduct of Clinical Studies in The Dental PBRN  

PubMed Central

Effectively addressing challenges of conducting research in nonacademic settings is crucial to its success. A dental practice-based research network called The Dental Practice-Based Research Network (DPBRN) is comprised of practitioner-investigators in two health maintenance organizations, several universities, many U.S. states, and three Scandinavian countries. Our objective in this article is to describe lessons learned from conducting studies in this research context; the studies are conducted by clinicians in community settings who may be doing their first research study. To date, twenty-one studies have been completed or are in implementation. These include a broad range of topic areas, enrollment sizes, and study designs. A total of 1,126 practitioner-investigators have participated in at least one study. After excluding one study because it involved electronic records queries only, these studies included more than 70,000 patient/participant units. Because the DPBRN is committed to being both practitioner- and patient-driven, all studies must be approved by its Executive Committee and a formal study section of academic clinical scientists. As a result of interacting with a diverse range of institutional and regulatory entities, funding agencies, practitioners, clinic staff, patients, academi