These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

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

PubMed

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

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

2014-11-01

2

Validities and abilities in criminal profiling: a critique of the studies conducted by Richard Kocsis and his colleagues.  

PubMed

In a recent issue of this journal, Kocsis reviewed the criminal profiling research that he and his colleagues have conducted during the past 4 years. Their research examines the correlates of profile accuracy with respect to the skills of the individual constructing the profile, and it has led Kocsis to draw conclusions that are important to the profiling field. In this article, the authors review the contributions of the Kocsis studies and critique their methodological and conceptual foundations. The authors raise a number of concerns and argue that data from the Kocsis studies fail to support many of the conclusions presented in his recent review. The authors present evidence in support of their assertions and provide recommendations that will allow future research in the area to generate data that are more meaningful and generalizable. PMID:16648388

Bennell, Craig; Jones, Natalie J; Taylor, Paul J; Snook, Brent

2006-06-01

3

Validities and Abilities in Criminal Profiling: A Critique of the Studies Conducted by Richard Kocsis and His Colleagues  

Microsoft Academic Search

In a recent issue of this journal, Kocsis reviewed the criminal profiling research that he and his colleagues have conducted during the past 4 years. Their research examines the correlates of profile accuracy with respect to the skills of the individual constructing the profile, and it has led Kocsis to draw conclusions that are important to the profiling field. In

Craig Bennell; Natalie J. Jones; Paul J. Taylor; Brent Snook

2006-01-01

4

Simulators' validation study: Problem solution logic  

NASA Technical Reports Server (NTRS)

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

Schoultz, M. B.

1974-01-01

5

SASSYS validation studies  

Microsoft Academic Search

A strong validation base for the systems thermal hydraulic code SASSYS is required because of the extensive application to the innovative design LMRs, PRISM and SAFR, and because of the forthcoming application to updating the FFTF FSAR for operation with metal fuel. As part of the validation process, SASSYS has been applied to the EBR-II Shutdown Heat Removal Tests and

Hill

1988-01-01

6

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. PMID:24755265

2014-01-01

7

Validation studies and proficiency testing.  

PubMed

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

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

2002-01-01

8

Bioconversion study conducted by JPL  

NASA Technical Reports Server (NTRS)

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

Kalvinskas, J.

1978-01-01

9

Sociometric Assessment: A Validity Study  

ERIC Educational Resources Information Center

This paper reports a validity study of a sociometric technique described by Barclay. The sample was 103 elementary school children. Sociometric scores were compared against the criterion of adjustment of Referral versus Non-referral to the school counseling service. Data were analyzed by a point biserial r, t tests, and a comparison of percentages…

Kennedy, Daniel A.

10

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

11

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

12

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

ERIC Educational Resources Information Center

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

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

2008-01-01

13

Thinking and Creative Styles: A Validity Study  

Microsoft Academic Search

The validity evidences of thinking and creative styles were analyzed. Two studies are reported, one analyzing the dimensionality of creative styles and the other verifying their external validity. Participants were Brazilians, 1,752 in the first study (55% women) and 128 in the second study (53% women), among whom 45% had demonstrated creative talent. The instruments were a scale of thinking

Solange Muglia Wechsler; Claudette Maria Medeiros Vendramini; Thomas Oakland

2012-01-01

14

NORMAL CONDUCTING RADIO FREQUENCY X-BAND DEFLECTING CAVITY FABRICATION AND VALIDATION*  

E-print Network

NORMAL CONDUCTING RADIO FREQUENCY X-BAND DEFLECTING CAVITY FABRICATION AND VALIDATION* R. Agustsson- picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam will be presented. INTRODUCTION Some of the most compelling and demanding applications in high-energy electron beam

Brookhaven National Laboratory

15

NORMAL CONDUCTING RADIO FREQUENCY X-BAND DEFLECTING CAVITY FABRICATION AND VALIDATION*  

E-print Network

NORMAL CONDUCTING RADIO FREQUENCY X-BAND DEFLECTING CAVITY FABRICATION AND VALIDATION* R. Agustsson of the sub- picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron will be presented. INTRODUCTION Some of the most compelling and demanding applications in high-energy electron beam

Brookhaven National Laboratory

16

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

17

Homework Purpose Scale for High School Students: A Validation Study  

ERIC Educational Resources Information Center

The purpose of this study is to test the validity of scores on the Homework Purpose Scale using 681 rural and 306 urban high school students. First, confirmatory factor analysis was conducted on the rural sample. The results reveal that the Homework Purpose Scale comprises three separate yet related factors, including Learning-Oriented Reasons,…

Xu, Jianzhong

2010-01-01

18

FETAX interlaboratory validation study: Phase 2 testing  

SciTech Connect

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

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

1994-10-01

19

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

Microsoft Academic Search

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

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

2008-01-01

20

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

SciTech Connect

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

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

2012-02-01

21

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

22

Fundamental study of electrically conductive adhesives (ECAs)  

Microsoft Academic Search

Variations of volume resistivity of three electrically conductive adhesives (Ag-filled epoxy, Ag-filled cyanate ester, and Ni-filled epoxy) during 85°C\\/85%RH aging were studied. Volume resistivity of the two Ag-filled ECAs decreased slightly at the beginning of aging and then remained stable. However, the volume resistivity of the Ni-filled epoxy increased substantially. Joint resistance variations of these conductive adhesives with different metals

C. P. Wong; D. Lu; L. Meyers; Q. K. Tong

1997-01-01

23

How was the APECC study conducted?  

Cancer.gov

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

24

Homework Purpose Scale for High School Students: A Validation Study  

Microsoft Academic Search

The purpose of this study is to test the validity of scores on the Homework Purpose Scale using 681 rural and 306 urban high school students. First, confirmatory factor analysis was conducted on the rural sample. The results reveal that the Homework Purpose Scale comprises three separate yet related factors, including Learning-Oriented Reasons, Adult-Oriented Reasons, and Peer-Oriented Reasons. This factor

Jianzhong Xu

2010-01-01

25

Intercostal nerve conduction study in man.  

PubMed Central

A new surface technique for the conduction study of the lower intercostal nerves has been developed and applied to 30 normal subjects. The problem of the short available nerve segment of the intercostal nerves and the bizzare compound motor action potential (CMAP) of inconsistent latency while recording over the intercostal muscles, is overcome by applying recording electrodes over the rectus abdominis muscle and stimulating the nerves at two points at a fair distance away. With the use of multiple recording sites over the rectus abdominis, the motor points for different intercostal nerves were delineated. CMAP of reproducible latencies and waveforms with sharp take-off points were obtained. Conduction velocity of the intercostal nerves could be determined. PMID:2526200

Pradhan, S; Taly, A

1989-01-01

26

Intercostal nerve conduction study in man.  

PubMed

A new surface technique for the conduction study of the lower intercostal nerves has been developed and applied to 30 normal subjects. The problem of the short available nerve segment of the intercostal nerves and the bizzare compound motor action potential (CMAP) of inconsistent latency while recording over the intercostal muscles, is overcome by applying recording electrodes over the rectus abdominis muscle and stimulating the nerves at two points at a fair distance away. With the use of multiple recording sites over the rectus abdominis, the motor points for different intercostal nerves were delineated. CMAP of reproducible latencies and waveforms with sharp take-off points were obtained. Conduction velocity of the intercostal nerves could be determined. PMID:2526200

Pradhan, S; Taly, A

1989-06-01

27

Two phase detonation studies conducted in 1971  

NASA Technical Reports Server (NTRS)

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

Nicholls, J. A.

1972-01-01

28

Conducting Record Review Studies in Clinical Practice  

PubMed Central

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

Seshadri, Divya

2014-01-01

29

HREELS and Auger studies of conducting polymers  

NASA Astrophysics Data System (ADS)

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

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

1985-04-01

30

Conducting record review studies in clinical practice.  

PubMed

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

Sarkar, Siddharth; Seshadri, Divya

2014-09-01

31

CFD Validation Studies for Hypersonic Flow Prediction  

NASA Technical Reports Server (NTRS)

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

Gnoffo, Peter A.

2001-01-01

32

CFD Validation Studies for Hypersonic Flow Prediction  

NASA Technical Reports Server (NTRS)

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

Gnoffo, Peter A.

2001-01-01

33

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

34

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

35

A reliability and validity study of the Palliative Performance Scale  

PubMed Central

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. Fifty-three participants were recruited and randomly divided into two groups, each evaluating 11 cases at two time points. The validity study was based on the content validation of 15 palliative care experts conducted over telephone interviews, with discussion on five themes: PPS as clinical assessment tool, the usefulness of PPS, PPS scores affecting decision making, the problems in using PPS, and the adequacy of PPS instruction. Results The intraclass correlation coefficients for absolute agreement were 0.959 and 0.964 for Group 1, at Time-1 and Time-2; 0.951 and 0.931 for Group 2, at Time-1 and Time-2 respectively. Results showed that the participants were consistent in their scoring over the two times, with a mean Cohen's kappa of 0.67 for Group 1 and 0.71 for Group 2. In the validity study, all experts agreed that PPS is a valuable clinical assessment tool in palliative care. Many of them have already incorporated PPS as part of their practice standard. Conclusion The results of the reliability study demonstrated that PPS is a reliable tool. The validity study found that most experts did not feel a need to further modify PPS and, only two experts requested that some performance status measures be defined more clearly. Areas of PPS use include prognostication, disease monitoring, care planning, hospital resource allocation, clinical teaching and research. PPS is also a good communication tool between palliative care workers. PMID:18680590

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

2008-01-01

36

Reliability and validity study of the technology proficiency self-assessment scale  

Microsoft Academic Search

The principle aim of this study is to conduct validity and reliability studies of “Technology Proficiency Self-Assessment (TPSA)” scale, developed by Ropp (1999). For this aim, in the first place; the language validity of the scale was provided with the help of experts. Then in order to analyze the factors, the scale was applied to 205 in-service primary school teachers

Ebru Gençtürk; Tuba Gökçek; Gönül Güne?

2010-01-01

37

Thermal conductivity studies on ceramic floor tiles  

Microsoft Academic Search

Thermal diffusivity, thermal conductivity and specific heat of several materials used as floor tiles have been measured using the laser flash method. Natural stones, particularly granite, porcelain stoneware and red stoneware materials of low water absorption, are more effective thermal conductors than white stoneware and vinyl, which have thermal conductivities below 1Wm?1K?1. Therefore, last two should not be recommended for

E. García; A. de Pablos; M. A. Bengoechea; L. Guaita; M. I. Osendi; P. Miranzo

2011-01-01

38

Electrochemical studies of some conducting polythiophene films  

SciTech Connect

Polythiophene and ..beta..-substituted polythiophenes are prepared by electrochemical oxidation and polymerization of their respective monomers. A property-structure correlation between monomers and their corresponding polymers is obtained by systematic variation of the chemical structure of the monomers. Film growth and conductivities are dependent on ..beta..-substituents, with conductivity of the order of 1 ohm/sup -1/ cm/sup -1/ obtained for poly(..beta..-methylthiophene).

Waltman, R.J.; Bargon, J.; Diaz, A.F.

1983-04-14

39

Global Electrical Conductivity Magnetic Satellite Induction Studies  

E-print Network

induction to measure Earth conductivity: · Magnetotelluric (MT) method Measure electric and magnetic fields-varying magnetic field induces electric currents in conductors. � E = - B t Secondary magnetic fields created by these currents appose the primary magnetic field. So, conductors attenuate magnetic fields. 2nd

Constable, Steve

40

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

41

[Validation study of the Depressive Experience Questionnaire].  

PubMed

Sidney Blatt, considering as being insufficient the categorical-symptomatic approach of depression, has worked out a theory of depression and psychopathology that integrates the contributions of psychoanalysis as well as cognitive and developmental psychology. Within a broad psychoanalytic framework, Blatt's formulation focus on the quality of interpersonal relationship, the nature of object representation and early life experiences. Personality development is viewed as the consequence of the interaction of 2 basic developmental tasks: the establishment of the capacity to form stable, enduring, mutually satisfying interpersonal relationships and the achievement of a differentiated, realistic, essentially positive identity. The relationship between these 2 developmental lines involves a complex dialectical process during which progress in each line is essential for progress in the other and which contributes to the development of both a sense of identity and the capacity for interpersonal relatedness. These developmental lines permit not only to define an during individual's primary personality configuration but also enable to identify cognitive structures that are inherent in various forms of psychopathology, including depression. Disruptions at different developmental stages create vulnerability to different subsequent psychological disturbances. Blatt characterised as anaclitic or dependent the axis concerned with interpersonal relationship and as introjective or self-critical the axis concerned with development of the sense of self and identity. Depressive Experience Questionnaire was developed by Blatt et al. to determine the validity of this model of psychopathology which emphazises continuities between normal and pathological forms of depression. The instrument was developed by Blatt et al. by assembling a pool of items describing experiences frequently reported by depressed individual. Sixty-six items were selected and administered to a large nonclinical sample (500 female and 160 male undergraduates). Principal component analysis within sex performed on the answers to DEQ confirmed his assumption in identifying two principal depressive dimensions. The first factor involved items that are primarily externally directed and refer to a disturbance of interpersonal relationships (anaclitism); the second factor consists of items that are more internally directed and reflect concerns about self-identity (self-criticism). A third factor emerged, assessing the good functioning of subject and confidence in his resources and capacities (efficacy). Scales derived from these factors have high internal consistency and substantial test-retest reliability. The solutions for men and women were highly congruent. Factor structure has been replicated in several nonclinical and clinical samples, supporting considerable evidence to the construct validity of the DEQ Dependency and Self-criticism scales. An adolescent form of DEQ (DEQ-A) has successively been developed. Factor analysis revealed three factors that were highly congruent in female and male students and with the three factors of the original DEQ. The reliability, internal consistency and validity of DEQ-A indicate that the DEQ-A closely parallels the DEQ, especially in the articulation of Dependency and Self-criticism as two factors in depression. These formulations and clinical observations about the importance of differentiating a depression focused on issues of self-criticism from issues of dependency are consistent with the formulations of others theorists which, from very different theoretical perspectives, posit 2 types of depression, one in which either perceived loss or rejection in social relationships is central and the other in which perceived failure in achievement, guilt or lack of control serves as the precipitant of depression. These 2 types of experiences have been characterized as dominant other and dominant goal , as anxiously attached and compulsively self-reliant and as sociotropic and autonomous . Our work presents the results of a validation study of b

Atger, F; Frasson, G; Loas, G; Guibourgé, S; Corcos, M; Perez Diaz, F; Speranza, M; Venisse, J-L; Lang, F; Stephan, Ph; Bizouard, P; Flament, M; Jeammet, Ph

2003-01-01

42

O`ahu Grid Study: Validation of Grid Models  

E-print Network

O`ahu Grid Study: Validation of Grid Models Prepared for the U.S. Department of Energy Office............................................................................................................. 1 2 Model Validation.................................................................. 8 2.2.2 Dynamic Data Model

43

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

44

Electrochemical corrosion studies in low conductivity propellants  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

45

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

46

The grief evaluation measure (GEM): an initial validation study.  

PubMed

This article describes the development of the Grief Evaluation Measure (GEM), a new instrument designed to screen for the development of a complicated mourning response in a bereaved adult. The GEM provides a quantitative and qualitative assessment of risk factors, including the mourner's loss and medical history, coping resources before and after the death, and circumstances surrounding the death. It is designed to provide an in-depth evaluation of the bereaved adult's subjective grief experience and associated symptoms. Reliability and validity studies were conducted with two samples of bereaved adults (n = 23 and n = 92, respectively) from various clinical and support settings. Data on the two central sections of the GEM that assess the mourner's grief response and the level of symptomatology are described. Results indicate that the GEM's internal consistency and test-retest reliability are high. The GEM demonstrates good concurrent validity for established measures of bereavement, trauma, and physical and psychiatric symptoms, and good predictive validity for mourner adjustment one year after initial assessment. Plans for future development and an invitation for other researchers to collaborate with research on the GEM are also discussed. PMID:15849881

Jordan, John R; Baker, John; Matteis, Margherite; Rosenthal, Saul; Ware, Eugenia S

2005-05-01

47

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

ERIC Educational Resources Information Center

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

Stancavage, Frances B.

48

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

49

Ecological validity of laboratory studies of videopoker gaming.  

PubMed

This study compared the cognitive and behavioral components of videopoker players under laboratory and natural settings. Twenty regular gamblers (19 men and 1 woman) were matched into two groups on age and on frequency of gambling. Irrational verbalizations during gambling, monetary risk (number of bets doubled and number of tokens bet), and motivation served as dependent variables. Results showed no significant differences between laboratory and natural settings for the number of inadequate verbalizations, bets doubled, and motivation. The amount of money gambled was greater in the laboratory than in the natural setting. The practical and theoretical implications of these results are discussed according to the ecological validity of gambling studies conducted in laboratory settings. PMID:24242983

Ladouceur, R; Gaboury, A; Bujold, A; Lachance, N; Tremblay, S

1991-06-01

50

A Validation Study of Self-Disclosure.  

ERIC Educational Resources Information Center

The validity of the Self-Disclosure Inventory and of the theoretical framework in which Jourard sets self-disclosure was investigated. Sixty-seven male and fifty-one female college students from various fraternity and sorority organizations were used as subjects. The Self-Disclosure Inventory for the extent of disclosure to the subject's best…

DeLeon, Patrick H.; And Others

51

Validity Studies of the Kindergarten Screening Inventory.  

ERIC Educational Resources Information Center

Research is reviewed on the validity of the Kindergarten Screening Inventory (KSI), an instrument developed by the Houston, Texas Independent School District to screen kindergarten students for possible difficulties that could lead to learning problems. The KSI includes eye-hand coordination, language learning, gross-motor subtests, as well as…

Alston, Herbert L.; Doughtie, Eugene B.

52

The conduct and reporting of intervention studies  

Microsoft Academic Search

This commentary begins with a description of the various types of comparison or control groups that have been used in intervention studies and notes the need for researchers to meet and make recommendations about which types of comparison groups are most appropriate. I then discuss the importance of instruction and (a) present a list of instructional procedures that might be

Barak Rosenshine

1994-01-01

53

Construct Validation Theory Applied to the Study of Personality Dysfunction  

PubMed Central

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

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

2013-01-01

54

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

55

A validation study of homeopathic prescribing and patient care indicators.  

PubMed

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

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

2014-10-01

56

A Validation Study of Homeopathic Prescribing and Patient Care Indicators  

PubMed Central

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

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

2014-01-01

57

Charge transport studies of proton and ion conducting materials  

NASA Astrophysics Data System (ADS)

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

Versek, Craig Wm

58

FETAX interlaboratory validation study: Phase 2 testing  

Microsoft Academic Search

The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a 96-h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that

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

1994-01-01

59

Construction and validation of a plunge electrode array for three-dimensional determination of conductivity in the heart.  

PubMed

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 confirmation of this concept. We report the design, fabrication, and validation of a novel plunge electrode array capable of addressing this issue. A new technique involving nylon coating of 24G hypodermic needles is performed to achieve nonconductive electrodes that can be combined to give moderate-density multisite intramural measurement of extracellular potential in the heart. Each needle houses 13 silver wires within a total diameter of 0.7 mm, and the combined electrode array gives 137 sites of recording. The ability of the electrode array to accurately assess conductances is validated by mapping the potential field induced by a point current source within baths of saline of varying concentration. A bidomain model of current injection in the heart is then used to test an approximate relationship between the monodomain conductivities measured by the array, and the full set of bidomain conductivities that describe cardiac tissue. PMID:18269998

Hooks, Darren A; Trew, Mark L

2008-02-01

60

The dynamic conductivity of strongly non-ideal plasmas: is the Drude model valid?  

E-print Network

The method of moments is used to calculate the dynamic conductivity of strongly coupled fully ionized hydrogen plasmas. The electron density $n_{e}$ and temperature $T$ vary in the domains $ 10^{21} < n_{e} < 10^{24} {\\rm cm}^{-3}$, $10^{4} {\\rm K} < T < 10^{6} {\\rm K}$. The results are compared to some theoretical data.

V. M. Adamyan; A. A. Mihajlov; N. M. Sakan; V. A. Sreckovic; I. M. Tkachenko

2013-03-03

61

The internal validity of aphasiological single-subject studies  

Microsoft Academic Search

The internal validity of 25 recent studies investigating the efficacy of language therapy for aphasic patients making use of single-subject designs is sometimes low due to experimentally weak designs, an insufficient amount of assessments, and the use of observational measurement without a blind procedure. The internal validity can be increased by the application of ABAB, crossover, and multiple-baseline designs, increasing

Ruben Fukkink

1996-01-01

62

Validating Action Research Field Studies: PEArL  

Microsoft Academic Search

The difficulty of establishing the validity of Action Research field studies has been well documented. Enabling interested individuals to follow the route of inquiry, or “recover” the inquiry process, has provided some means of addressing the difficult issue of validation. Such an approach, however, still fails to provide a sense of the manner in which an inquiry was undertaken, which

Donna Champion; Frank A. Stowell

2003-01-01

63

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

64

Study of potassium-ion-conducting electrolytes for electrochromic windows  

Microsoft Academic Search

Different anhydrous potassium ion conducting polymer electrolytes have been studied: (POE)nKTFSI (trifluorosulfonimide), plasticized (POE)nKTFSI, (PEM)nKTFSI, and (POE-Acetal)nKTFSI. DSC and conductivity measurements have been used to characterize these electrolytes. Several solutions to avoid crystallization have been examined. The best conductivity has been obtained with (POE-Acetal)nKTFSI. This electrolyte exhibits good transmission in the VIS-IR region. The response time of cells using these

Jean-Guy Beraud; Daniel Deroo

1992-01-01

65

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

66

Task-Specific Occupational Self-Efficacy Scale: A Predictive Validity Study  

Microsoft Academic Search

Using the social cognitive theory of career and academic behavior as a guide, we conducted a predictive validity study for the Quantitative and Verbal scales of the Task-Specific Occupational Self-Efficacy Scale (TSOSS). The Quantitative and Verbal TSOSS scale scores of a large group of undecided college freshmen were correlated with concurrent quantitative and verbal ability measures (SAT scores) and with

Kevin R. Kelly; Russell C. Nelson

1999-01-01

67

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).

68

Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study  

Microsoft Academic Search

Background: In the assessment of severity in community acquired pneumonia (CAP), the modified Brit- ish Thoracic Society (mBTS) rule identifies patients with severe pneumonia but not patients who might be suitable for home management. A multicentre study was conducted to derive and validate a practi- cal severity assessment model for stratifying adults hospitalised with CAP into different management groups. Methods:

W S Lim; M M van der Eerden; R Laing; W G Boersma; N Karalus; G I Town; S A Lewis; J T Macfarlane

2009-01-01

69

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

70

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

71

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

72

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

PubMed Central

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

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

2013-01-01

73

Study of potassium-ion-conducting electrolytes for electrochromic windows  

NASA Astrophysics Data System (ADS)

Different anhydrous potassium ion conducting polymer electrolytes have been studied : (POE)nKTFSI (trifluorosulfonimide), plasticized (POE)nKTFSI, (PEM)nKTFSI and (POE-Acetal)nKTFSI. DSC and conductivity measurements have been used to characterize these electrolytes. Several solutions to avoid cristallization have been examined. The best conductivity has been obtained with (POE-Acetal)nKTFSI. This electrolyte exhibits good transmission in the VIS-IR region. The response time of cells using these electrolytes and Prussian blue and KXWO3 as electrodes has been measured and compared.

Beraud, Jean-Guy; Deroo, Daniel

1992-11-01

74

Adult Outcomes of Child Conduct Problems: A Cohort Study  

Microsoft Academic Search

The present study assessed the mental health and criminal records of 6,449 males and 6,268 females who presented conduct problems as children by examining an unselected birth cohort followed up to age 30. Conduct problems were defined by teacher ratings of behavior problems and\\/or antisocial behavior in the community. There was little overlap in the children identified by teachers and

Lynn Kratzer; Sheilagh Hodgins

1997-01-01

75

Verification, Validation and Sensitivity Studies in Computational Biomechanics  

PubMed Central

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

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

2012-01-01

76

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

ERIC Educational Resources Information Center

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

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

2012-01-01

77

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.

78

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

79

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

80

Five-year predictive validity of DSM-IV conduct disorder research diagnosis in 4 1/2 -5-year-old children  

PubMed Central

Objective This longitudinal study of a non-referred, population-based sample tested the 5-year predictive validity of the DSM-IV conduct disorder (CD) research diagnosis in children 4½–5 years of age. Method In the E-Risk Study, a representative birth cohort of 2,232 children, mothers were interviewed and teachers completed mailed questionnaires to assess children’s past 6-month CD symptoms. A follow-up assessment was conducted when children were 10 years old. Results CD-diagnosed 5-year-olds were significantly more likely than controls to have behavioural and educational difficulties at age 10. Increased risk for age-10 educational difficulties persisted after controlling for age-5 IQ and ADHD diagnosis. Although the majority of CD-diagnosed 5-year-olds had no CD symptoms at age 10, findings suggest that these “remitted” children continued to experience behavioural and educational problems 5 years later despite their apparent remission from CD. Conclusions DSM-IV CD symptoms validly identify preschool-aged children who continue to have behavioural and educational problems in middle-childhood. PMID:19165535

Arseneault, Louise; Newcombe, Rhiannon; Adams, Felicity; Bolton, Heather; Cant, Lisa; Delgado, Kira; Freeman, Jo; Golaszewski, Ania; Kelesidi, Katerina; Matthews, Charlotte; Mountain, Nicky; Oxley, Donna; Watson, Susanne; Werts, Helen; Caspi, Avshalom; Moffitt, Terrie E.

2014-01-01

81

Computational study of NMDA conductance and cortical oscillations in schizophrenia  

PubMed Central

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

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

2014-01-01

82

The validity of items in a study habits inventory  

Microsoft Academic Search

Of items previously used in other study-habits questionnaires, 75 were selected and given to 276 college students above the freshman level. The interrelationships of study-habits scores, American Council on Education Test records, and grade-point ratios were studied by the method of contrasted high- and low-score groups and by correlation. Validity, interpreted as the tendency of a study-habits item to distinguish

F. D. Brooks; J. C. Heston

1945-01-01

83

Meteorological conditions during the winter validation study at Rocky Flats, Colorado: An overview  

SciTech Connect

The objective for the Winter Validation Study was to gather field data for validation of the Terrain-Responsive Atmospheric Code (TRAC) under winter time meteorological conditions. Twelve tracer tests were conducted during a two-week period in February 1991. Each test lasted 12 hours, with releases of SF{sub 6} tracer from the Rocky Flats Plant near Golden, Colorado. The tests included ground-based and airborne sampling to 16 km from the release point. This presentation summarizes meteorological conditions during the testing period. Forty six viewgraphs are included.

Hodgin, C.R.

1991-11-06

84

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

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

85

FIBULAR MOTOR NERVE CONDUCTION STUDIES AND ANKLE SENSORIMOTOR CAPACITIES*  

PubMed Central

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

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

2012-01-01

86

Nerve Conduction Studies: Clinical Challenges and Engineering Solutions  

Microsoft Academic Search

Nerve conduction studies (NCSs) have played an important role in the evaluation of neuromuscular disease for the past 50 years. When patients present with complaints of pain, numbness, tingling, or weakness, NCS is often one of the earliest tests obtained by physicians, because it enables the quantitative assessment of peripheral nerve and muscle function and, therefore, aid the physician in

Xuan Kong; EUGENE A. LESSER; SHAI N. GOZANI

2010-01-01

87

Instruments for the assessment of social anxiety disorder: Validation studies  

PubMed Central

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

Osorio, Flavia de Lima; Crippa, Jose Alexandre de Souza; Loureiro, Sonia Regina

2012-01-01

88

A Validation Study of the Existential Anxiety Scale.  

ERIC Educational Resources Information Center

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

Hullett, Michael A.

89

Teachers' Engagement at Work: An International Validation Study  

ERIC Educational Resources Information Center

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

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

2012-01-01

90

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

91

A quantitative approach to perceived health status: a validation study  

Microsoft Academic Search

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

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

1980-01-01

92

Homework Purpose Scale for Middle School Students: A Validation Study  

ERIC Educational Resources Information Center

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

Xu, Jianzhong

2011-01-01

93

Preparation, characterization and conductivity studies of chlorinated natural rubber  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

94

How was the ECHOS-NHL study conducted?  

Cancer.gov

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

95

Reliability and validity of the foot and ankle outcome score: a validation study from Iran.  

PubMed

The aims of this study were to culturally adapt and validate the Persian version of Foot and Ankle Outcome Score (FAOS) and present data on its psychometric properties for patients with different foot and ankle problems. The Persian version of FAOS was developed after a standard forward-backward translation and cultural adaptation process. The sample included 93 patients with foot and ankle disorders who were asked to complete two questionnaires: FAOS and Short-Form 36 Health Survey (SF-36). To determine test-retest reliability, 60 randomly chosen patients completed the FAOS again 2 to 6 days after the first administration. Test-retest reliability and internal consistency were assessed using intraclass correlation coefficient (ICC) and Cronbach's alpha, respectively. To evaluate convergent and divergent validity of FAOS compared to similar and dissimilar concepts of SF-36, the Spearman's rank correlation was used. Dimensionality was determined by assessing item-subscale correlation corrected for overlap. The results of test-retest reliability show that all the FAOS subscales have a very high ICC, ranging from 0.92 to 0.96. The minimum Cronbach's alpha level of 0.70 was exceeded by most subscales. The Spearman's correlation coefficient for convergent construct validity fell within 0.32 to 0.58 for the main hypotheses presented a priori between FAOS and SF-36 subscales. For dimensionality, the minimum Spearman's correlation coefficient of 0.40 was exceeded by most items. In conclusion, the results of our study show that the Persian version of FAOS seems to be suitable for Iranian patients with various foot and ankle problems especially lateral ankle sprain. Future studies are needed to establish stronger psychometric properties for patients with different foot and ankle problems. PMID:20140474

Negahban, Hossein; Mazaheri, Masood; Salavati, Mahyar; Sohani, Soheil Mansour; Askari, Marjan; Fanian, Hossein; Parnianpour, Mohamad

2010-05-01

96

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

97

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

SciTech Connect

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

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

2012-01-01

98

A heat conduction study at non-continuum scales  

NASA Astrophysics Data System (ADS)

An extensive and detailed description of heat conduction at the micro- and nano-scale is presented. During the last two decades this phenomenon has become very attractive to study because of the shrinking in size of thermoelectric technologies and electronic devices. These newer technologies are at the micro- and nano-scale. Due to the small size, a power dissipation problem has presented itself in these applications. The proper thermal performance is related with the performance of the technology. Because of these facts a description of the thermal transport in different materials at these scales is required. This problem is important because understanding the energy transport will allow engineers to design faster electronic devices and more efficient thermoelectric applications. For macro-scale it is known that diffusive behavior is presented in heat conduction; here models that show different behavior than diffusive such as wave-like are presented. One extra tool to understand heat conduction is to calculate the thermal conductivity. Equilibrium molecular dynamics combined with the Green-Kubo formula can be used to calculate the thermal conductivity of materials such as germanium and carbon. The foundation of this calculation is extracting the heat current from the results, and implementing it into the Green-Kubo formula. This work considers all formulations from the literature that calculate the heat current for the Tersoff potential, the interatomic potential most applicable to semiconductor materials. The formulations for the heat current are described, and results for germanium and carbon are presented. The formulations are compared with respect to how well they capture the physics of the Tersoff potential and how well the calculated value of the thermal conductivity reflects the experimentally-measured value. The second part of this work deals with heat transport in low dimensions at the nano-scale. The energy transport in a two dimensional graphene sheet is studied and compared to that in a one dimensional chain. The equations of motion for each individual atom of the sheet are solved numerically to generate the distribution of kinetic energy in the structure. The distribution of kinetic energy in the sheet shows two different characteristics of the transport. The components of frequency of the kinetic energy in the graphene structure are identified. The components allow the identification under which potential more low frequency carriers are expected. The presence of chaos in the graphene sheet using the anharmonic potential is identified. Finally, conclusions and recommendations for the study of heat conduction at the nano-scale are presented.

Guajardo Cuellar, Alejandro

99

Studying Pretrial Publicity Effects: New Methods for Improving Ecological Validity and Testing External Validity  

Microsoft Academic Search

Although research examining the effects of pretrial publicity (PTP) on individuals' appraisals of a defendant and verdict decision making generally has been found to be internally valid, the external validity has been questioned by some social scientists as well as lawyers and judges. It is often proposed that the verisimilitude (or ecological validity) of the research should be increased in

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

2002-01-01

100

Verification, validation and sensitivity studies in computational biomechanics.  

PubMed

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 (V&V). 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 V&V principles in the field of computational biomechanics, thereby improving the peer acceptance of studies that use computational modeling techniques. PMID:17558646

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

2007-06-01

101

Conductivity and dielectric studies on LiCeO 2  

Microsoft Academic Search

LiCeO2 was prepared by a solid-state reaction method using microwave heat treatment and identified by X-ray diffractometry. LiCeO2 has monoclinic crystal structure whose conductivity and dielectric properties were studied over a range of frequency (42 Hz to 1 MHz) and temperatures (30–500 °C) using ac technique of complex impedance analyzer HIOKI 3532. Combined impedance and modulus plots were used as

M. Prabu; S. Selvasekarapandian; A. R. Kulkarni; G. Hirankumar; C. Sanjeeviraja

2010-01-01

102

Reliability and validity of self-assessment of mouth opening: a validation study  

PubMed Central

Background The objective of this study was to evaluate the reproducibility and validity of patients’ mouth opening measurements in a research setting. Methods Firstly, 68 patients made repeated self-measurements of mouth opening using a cardboard scale (Therabite Range of Motion Scale – TRMS). Secondly, 80 patients enrolled in a clinical trial on morbidity after lower third molar surgery, made daily assessments during the postoperative week. Patients’ measurements were then compared to gold-standard clinicians’ measurements. Results Reliability of patients’ measurements was excellent with an intraclass correlation coefficient of 0.92. The patient’s measurements correlated well with the gold-standard clinician’s measurements, both for the first 68 patients (Pearson’s rho ranging from 0.86 to 0.90, p < 0.0001) as well as for the 80 patients enrolled in the clinical trial (rho = 0.82, p < 0.0001 at day 2, rho = 0.83, p < 0.0001 at final visit). Conclusions TRMS can be used by patients to produce reproducible and valid mouth opening measurements. PMID:23145559

2012-01-01

103

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.

104

[French validation study of the levels of emotional awareness scale].  

PubMed

According to a thesis based on the idea of an influence of cognitions in the structuring of internal reality, emotional awareness, ie the capacity of representing your own emotional experience and that of others, is a cognitive process that goes into maturation. Defining this concept, Lane and Schwartz present a cognitivo-developmental model in five stages of the processes of symbolization, accounting for the differences in levels of emotional awareness observed in individuals. The organization of these cognitive processes would thus be structured in well differentiated stages, in which the development of the emotions would be inseparable from the development of ego and of the relation to others. These authors focus on the capacity of representing in a conscious way the emotional experience and consider that verbal representations used to describe the contents of what is experience constitute a good reflection of the organization structural of the emotional awareness. Therefore, they worked out an instrument of evaluation: the Levels of Emotional Awareness Scale (LEAS), which measures the capacity to describe your own emotional experience and the one you allow to others, in an emotional situation. The system of quotation of this scale is based on the analysis of the verbal contents of the provided answers, in direct reference to the authors' theory of the levels of differentiation and integration of the emotional experience. It is therefore an empirical measurement which is centered specifically on the structural organization of the emotional experience. The various studies of validation of this instrument show that it presents solid metrological properties. This work presents the validation of the French version of Lane and Schwartz's LEAS. Validity and fidelity were studied in a group of 121 healthy subjects. This setting is part of a larger clinical evaluation, also including a collection of socio-demographic and clinical data, and other instruments of self-evaluation (Beck Depression Inventory, BDI, Hospital Anxiety and Depression Scale, HAD, and Toronto Alexithymia Scale, TAS). The face validity appears correct: the questionnaire was well accepted and seemed easy to complete. A principal components analysis of the correlation matrix of the set of items was used as the method of extraction of the various factors and made it possible to confirm the unidimensionality of the instrument. The number of factors to be retained was given according to Kaiser and Cattell criteria. The internal consistency was evaluated through computation of the Cronbach coefficient, whose value is 0.75 for the scale's global score. The confidence interval of the margin of error of LEAS scores was also measured; for the global score it is IC=[m 6.1]. The measure given by this rating scale may therefore be considered sufficiently accurate, since this interval is weak. A study of the frequency of quotation of each item of the instrument was carried out, in order to check the homogeneity and the uniformity of quotations, as well as a diagram of distribution of the score, showing that it follows a law which is close to a normal law. The concurrent validity could only be studied via the similar concept of alexithymia, measured with the TAS, for there is not other instrument validated in French evaluating the levels of emotional awareness, and these two instruments seem to measure different notions, because none of the correlations between the scores of these two questionnaires are significant. Concerning discriminant validity, the Pearson correlation coefficients between the global score for the LEAS, the BDI score and the HAD sub-scores for depression and anxiety were measured; it is clear that the level of emotional awareness is independent from negative affects. Furthermore, the study of the reliability made it possible to highlight excellent intra-class correlation coefficients (r=0.993). The French version of the Levels of Emotional Awareness Scale thus appears to be valid and accurate and should allow the study of levels of emotional awarenes

Bydlowski, S; Corcos, M; Paterniti, S; Guilbaud, O; Jeammet, P; Consoli, S M

2002-01-01

105

The Significance of Member Validation in Qualitative Analysis: Experiences from a Longitudinal Case Study  

Microsoft Academic Search

This article explores the concept of member validation and its potential role in the process of constructing case descriptions and interpretations in qualitative research. Although generally approved as a required step in qualitative inquiry, the format, conduct, and purpose of this vary significantly according to different research perspectives. The paper discusses methodological and validity aspects of member validation, and illustrates

Bendik Bygstad; Bjørn Erik Munkvold

2007-01-01

106

Validity and reliability of in-situ air conduction thresholds measured through hearing aids coupled to closed and open instant-fit tips.  

PubMed

Audiometric measurements through a hearing aid ('in-situ') may facilitate provision of hearing services where these are limited. This study investigated the validity and reliability of in-situ air conduction hearing thresholds measured with closed and open domes relative to thresholds measured with insert earphones, and explored sources of variability in the measures. Twenty-four adults with sensorineural hearing impairment attended two sessions in which thresholds and real-ear-to-dial-difference (REDD) values were measured. Without correction, significantly higher low-frequency thresholds in dB HL were measured in-situ than with insert earphones. Differences were due predominantly to differences in ear canal SPL, as measured with the REDD, which were attributed to leaking low-frequency energy. Test-retest data yielded higher variability with the closed dome coupling due to inconsistent seals achieved with this tip. For all three conditions, inter-participant variability in the REDD values was greater than intra-participant variability. Overall, in-situ audiometry is as valid and reliable as conventional audiometry provided appropriate REDD corrections are made and ambient sound in the test environment is controlled. PMID:20812890

O'Brien, Anna; Keidser, Gitte; Yeend, Ingrid; Hartley, Lisa; Dillon, Harvey

2010-12-01

107

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

Microsoft Academic Search

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

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

2010-01-01

108

Fit-for-purpose bioanalytical cross-validation for LC-MS/MS assays in clinical studies.  

PubMed

The paradigm shift of globalized research and conducting clinical studies at different geographic locations worldwide to access broader patient populations has resulted in increased need of correlating bioanalytical results generated in multiple laboratories, often across national borders. Cross-validations of bioanalytical methods are often implemented to assure the equivalency of the bioanalytical results is demonstrated. Regulatory agencies, such as the US FDA and European Medicines Agency, have included the requirement of cross-validations in their respective bioanalytical validation guidance and guidelines. While those documents provide high-level expectations, the detailed implementation is at the discretion of each individual organization. At Bristol-Myers Squibb, we practice a fit-for-purpose approach for conducting cross-validations for small-molecule bioanalytical methods using LC-MS/MS. A step-by-step proposal on the overall strategy, procedures and technical details for conducting a successful cross-validation is presented herein. A case study utilizing the proposed cross-validation approach to rule out method variability as the potential cause for high variance observed in PK studies is also presented. PMID:23256474

Xu, Xiaohui; Ji, Qin C; Jemal, Mohammed; Gleason, Carol; Shen, Jim X; Stouffer, Bruce; Arnold, Mark E

2013-01-01

109

Numerical Study of Thermal Conductivities of Carbon-Based Mesoporous Composites  

NASA Astrophysics Data System (ADS)

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

Feng, Daili; Feng, Yanhui; Zhang, Xinxin

2014-10-01

110

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

111

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

PubMed Central

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

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

2010-01-01

112

A construct validity study of a Differentiation of Self Scale.  

PubMed

The purpose of this study was to establish construct validity of the Haber Level of Differentiation of Self Scale (LDSS) that measures selected aspects of the construct, differentiation of self, the key concept of the Bowen Theory. During stage one of this study, a 32-item Likert-type LDSS, which contained two subscales, Emotional Maturity, (EM), and Emotional Dependency (ED), was administered to 372 volunteer subjects. Factor analytic and correlational findings indicated support for a 24-item unidimensional rather than a 32-item two subscale instrument. Recalculation of coefficient alpha (.90) also supported the unidimensional structure of the LDSS. During stage two of this study, the revised 24-item LDSS was administered to 372 volunteer subjects, who also completed the State-Trait Anxiety Inventory, the Life Experience Survey, and the Behavior Checklist. Hypotheses predicted that there would be negative relationships between differentiation of self and trait anxiety, state anxiety, adult psychological dysfunction, and negative impact stress. Findings indicate support for all hypotheses at the p < .01 level of significance or greater. Data from this study suggest that the 24-item LDSS is a valid and reliable unidimensional family assessment tool that accurately measures specific aspects of the construct, differentiation of self. The LDSS can be used by nurses and other professionals to assess individual and family functioning in a variety of health care settings. PMID:8272677

Haber, J

1993-01-01

113

Annotations on Mexico's WISC-IV: a validity study.  

PubMed

This project seeks to provide evidence on the internal structure of the Escala Wechsler de Inteligencia para Niños-IV (EWIN-IV; Wechsler, 2007a ) through a confirmatory factor analysis and intercorrelational study. Also provided is information on the adaptation process and other sources of validity evidence in support of the EWIN-IV norms. The standardization data for the EWIN-IV were used for all analyses. The factor loadings and correlational patterns found on the EWIN-IV are comparable to those seen in the American versions of the test. The proposed factor and scoring structure of the EWIN-IV was supported. PMID:23428273

Fina, Anthony D; Sánchez-Escobedo, Pedro; Hollingworth, Liz

2012-01-01

114

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

115

STUDY OF THE EXCESS CONDUCTIVITY IN PLASTICALLY DEFORMED ALKALI HALIDES  

Microsoft Academic Search

The results of measurements on the excess ionic conductivity of ; plastically deformed alkali halides are given. The recovery of conductivity ; after deformation was investigated at various temperatures in KCl, KBr, NaCl, and ; LiF, with the aim to reach some knowledge on the nature of the defects ; responsible for enhanced conduction. It was found that the excess

P. Camagni; G. Chiarotti; A. Manara

1962-01-01

116

Studies of electrical conduction in pyroelectric DTGS: PVDF composites  

NASA Astrophysics Data System (ADS)

The AC and DC conductivities of pyroelectric composite, deuterated triglycine sulfate (DTGS): polyvinylidene fluoride (PVDF) having 15%, 20%, and 40% DTGS content (by weight) have been measured at temperature ranging from room temperature to 55 °C. The ac conductivity of composites at 1 MHz shows very weak temperature dependence. The dc conductivity for 20% and 40% DTGS content (by weight) composites shows activated behavior.

Batra, Ashok K.; Simmons, M.; Guggilla, Padmaja; Aggarwal, M. D.; Lal, R. B.

2004-06-01

117

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. PMID:24053267

2013-01-01

118

Validation study of the Chinese Early Development Instrument (CEDI)  

PubMed Central

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

2013-01-01

119

Study on thermo-conductive plastic finned tube radiators  

NASA Astrophysics Data System (ADS)

This paper discusses thermo-conductive plastic finned tube radiators used in water saving type power stations. First, the development of thermo-conductive plastics is introduced. Second, in order to determine the rational geometric dimensions of thermo-conductive plastic finned tubes, an objective function which takes the minimum volume of the consumed material for making finned tubes as an object is introduced. On the basis of the function, the economy comparison between thermo-conductive plastic finned tubes and metal finned tubes is conducted.

Yang, Jiehui; Cheng, Lixin

1997-03-01

120

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

PubMed Central

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

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

2014-01-01

121

Validation Study of the Integral-Differential Scheme for Multi-Block Grids  

NASA Astrophysics Data System (ADS)

This MS Thesis seeks to validate the accuracy of the Integral-Differential Scheme (IDS). In the attempts to accomplish this task, research efforts were focused on the scheme's ability to capture the physics of known flow fields, as well as the scheme's ability to predict the features of flow field quantities that may be derived from experimental measurements. The IDS was developed with the goal of being computationally efficient, from a programming perspective, as well as being numerically accurate, stable, and robust, from a mathematical perspective. The IDS is designed to solve the full Navier-Stokes equations in their integral forms. Unlike traditional control volume schemes, the IDS is built upon two sets of cells: spatial and temporal cells. For 2-D flows, the IDS considers an elementary control volume as a collection of four spatial cells and a single temporal cell. Similar to other explicit CFD schemes, the IDS relies on the use of the Taylor series expansion and other traditional CFD criteria. It is of interest to note that there are previous IDS validation studies which were conducted at North Carolina A&T State University. These past studies mainly focused on the qualitative aspects of the flow field physics. Furthermore, in all cases, they focused on flow field problems that can be represented by single-block grids. In this analysis, the validation studies are focused on multi-block grids in which the physics of the flow field is made complicated due to the presence of shock waves and flow separation zones. Of interest to this MS Thesis are two supersonic flow field problems that are supported by experimental data; namely, the supersonic flow over a rearward-facing step problem and the supersonic flow over a cavity problem. The validation studies conducted herein demonstrated that the IDS was able to predict the experimental data in both cases.

Mrema, Honest Frank

122

A validation study of the influence of alcohol on handwriting.  

PubMed

The purposes of this article are to report experimental findings and to validate prior selected studies that examined handwriting comparisons and alcohol consumption. Subjects who participated in this experiment were given handwriting testing forms which were completed at assigned intervals throughout the testing period. The setting for the completion of the experiment was within a controlled environment with adult students attending the Breath Tests for Intoxication School for the use of blood alcohol concentration (BAC) instruments for law enforcement purposes. Handwriting data and pertinent information, BAC level and time, were recorded on the testing forms which were completed before, during, and after drinking. This study does not attempt to determine handwriting characteristics that can be predicted at various blood alcohol levels, but rather demonstrate, as noted in prior studies, if handwriting trends develop during or after the consumption of alcohol. The results of the handwriting comparisons, between and among test subjects, are discussed and applied to prior findings. PMID:9144930

Stinson, M D

1997-05-01

123

Some limitations on the external validity of psychotherapy efficacy studies and suggestions for future research.  

PubMed

Increased emphasis on identifying empirically supported treatments (ESTs) has enhanced the scientific basis for psychotherapy practice, but uncritical acceptance of ESTs as the basis for credentialing and policy decisions risks stifling innovation and creativity in the field. There are limitations inherent in efficacy studies of psychotherapy that can constrain external validity. This article discusses several limitations on the external validity of efficacy studies, as well as other issues related to evaluating psychotherapy outcome research. These limitations and concerns include: 1) the practice of maximizing homogeneity by selecting participants diagnosed with a single Axis I disorder; 2) the practice of requiring manualized therapies for efficacy research; 3) the assumption that lasting and meaningful changes occur and can be assessed within a relatively short time frame; 4) the assumption that valid assessments of outcome can be conducted in randomized control trials studies without concern for researcher allegiance; and 5) the view that evidence of effectiveness from non-RCT design studies can be ignored. Finally, alternative research approaches for studying psychotherapy that can potentially supplement knowledge gained from efficacy studies and foster continued innovation and creativity in the field are discussed. PMID:23091884

Shean, Glenn D

2012-01-01

124

The problem of validity in field studies of psychological disorder  

Microsoft Academic Search

Results of over 25 attempts to count untreated cases of psychological disorder in community populations are reviewed, and the problem of validity in the measures of disorder is analyzed. Evidence of validity is found to be scant. The position is taken that, with no generally accepted criteria available, and no universe of content agreed upon, construct validity takes on added

Bruce P. Dohrewend; Barbara Snell Dohrewend

1965-01-01

125

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

126

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

127

A Validity Study of the AGS Early Screening Profiles with the Stanford-Binet Fourth Edition as Criterion.  

ERIC Educational Resources Information Center

The AGS Early Screening Profiles (AGS:ESP) instrument (P. Harrison, 1990) has been introduced recently as a screening instrument for predicting mental ability. A study was conducted to determine the degree of concurrent validity between the AGS:ESP and the Stanford Binet Fourth Edition (SB:FE), an instrument often used by psychologists to detect…

Genteman, Michelle R.

128

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.

129

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

130

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

131

New York State TrueAllele ® casework validation study.  

PubMed

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

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

2013-11-01

132

Water balance at an arid site: a model validation study of bare soil evaluation  

SciTech Connect

This report contains results of model validation studies conducted by Pacific Northwest Laboratory (PNL) for the Department of Energy's (DOE) National Low Level Waste Management Program (NLLWMP). The model validation tests consisted of using unsaturated water flow models to simulate water balance experiments conducted at the Buried Waste Test Facility (BWTF) located at the Department of Energy's Hanford site, near Richland, Washington. The BWTF is a lysimeter facility designed to collect field data on long-term water balance and radionuclide tracer movement. It has been operated by PNL for the NLLWMP since 1978. An experimental test case, developed from data collected at the BWTF, was used to evaluate predictions from different water flow models. The major focus of the validation study was to evaluate how the use of different evaporation models affected the accuracy of predictions of evaporation, storage, and drainage made by the whole model. Four evaporation models were tested including two empirical models and two mechanistic models. The empirical models estimate actual evaporation from potential evaporation; the mechanistic models describe water vapor diffusion within the soil profile and between the soil and the atmosphere in terms of fundamental soil properties, and transport processes. The water flow models that included the diffusion-type evaporation submodels performed best overall. The empirical models performed poorly in their description of evaporation and profile water storage during summer months. The predictions of drainage were supported quite well by the experimental data. This indicates that the method used to estimate hydraulic conductivity needed for the Darcian submodel was adequate. This important result supports recommendations for these procedures that were made previously based on laboratory results.

Jones, T.L.; Campbell, G.S.; Gee, G.W.

1984-03-01

133

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. PMID:22080337

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

2011-01-01

134

Molecular Dynamics study of the mixed oxide fuel thermal conductivity  

NASA Astrophysics Data System (ADS)

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

Nichenko, S.; Staicu, D.

2013-08-01

135

A benchmark study on the thermal conductivity of nanofluids  

E-print Network

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

Buongiorno, Jacopo

136

Experimental Study of Acid Fracture Conductivity of Austin Chalk Formation  

E-print Network

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

Nino Penaloza, Andrea

2013-05-01

137

[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

138

A controlled study of Tourette syndrome. II. Conduct.  

PubMed

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

Comings, D E; Comings, B G

1987-11-01

139

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

140

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

141

Portuguese validation of the Internet Addiction Test: An empirical study  

PubMed Central

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

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

2014-01-01

142

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

PubMed Central

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

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

2014-01-01

143

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

144

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

145

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

Microsoft Academic Search

As a follow-up to a prevalidation study on in vitro tests for replacing the in vivo rabbit test for skin corrosivity, an international validation study was conducted during 1996 and 1997 under the auspices of ECVAM. The main objectives of the study were to: (a) identify tests capable of discriminating corrosives from non-corrosives for selected types of chemicals and\\/or all

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

1998-01-01

146

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

147

Thermal conductivity of porous UO2: Molecular Dynamics study  

NASA Astrophysics Data System (ADS)

Classical Molecular Dynamics (MD) was used to investigate the effect of nanometric size pores on the thermal conductivity of irradiated UO2. The Green-Kubo approach was used for the thermal conductivity calculation. The effects of pores size, porosity and pores separation were simulated. A comparison with existing theoretical models is presented and an analytical model adapted to irradiated fuel is obtained. The results demonstrate that, for realistic bubbles size and concentrations, the impact on the fuel thermal conductivity is higher than predicted by the correlations used to quantify the impact of porosity: the impact of 0.3 vol.% of nanometric pores is of the same order of magnitude as that of 4.5 vol.% of micrometric pores.

Nichenko, S.; Staicu, D.

2014-11-01

148

Development, characterization and conductivity studies of chlorinated EPDM  

NASA Astrophysics Data System (ADS)

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

Nihmath, A.; Ramesan, M. T.

2014-10-01

149

Eagle Mountain Watershed: Calibration, Validation, and Best Management Practices  

E-print Network

9. The result of flow calibration and validation by accumulated flow at USGS gage station 08044500. 3. Sediment Calibration and Validation Two sediment survey studies were conducted on Eagle Mountain Lake. The first study was conducted... 9. The result of flow calibration and validation by accumulated flow at USGS gage station 08044500. 3. Sediment Calibration and Validation Two sediment survey studies were conducted on Eagle Mountain Lake. The first study was conducted...

Lee, Taesoo; Narasimhan, Balaji; Srinivasan, Raqhavan

150

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. PMID:25071621

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

2014-01-01

151

Studies of inherently conducting polymers in ionic liquids  

Microsoft Academic Search

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

Jakub Mazurkiewicz

2007-01-01

152

Nerve biopsy and conduction studies in diabetic neuropathy  

Microsoft Academic Search

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

F Behse; F Buchthal; F Carlsen

1977-01-01

153

NMR Studies of Magnetic and Fast Ionic Conducting Amorphous Borates.  

NASA Astrophysics Data System (ADS)

NMR studies were performed on lead borate glasses containing significant concentrations of Fe(,2)O(,3) and on lithium borate glasses containing lithium halides (LiCl or LiF). ('11)B and ('207)Pb NMR investigations of glasses in the system x Fe(,2)O(,3)(.)y PbO(.)z B(,2)O(,3) (0 (LESSTHEQ) x (LESSTHEQ) 15.3 Mol %, z/y (DOT=) 3) revealed that the NMR line broadening contains Gaussian field-independent and field-dependent components, and field-dependent Lorentzian components, resulting in broadening lineshapes of the Voight type. The ('11)B NMR linewidth data were in excellent agreement with a model which assumes the Fe atoms are distributed uniformly and isotropically throughout the glass matrix, and suggests the absence of significant concentrations of B-Fe linkages in these glasses. While the ('11)B NMR linewidth and magnetic susceptibility data vary smoothly and monotonically over the sample composition range, the density, N(,4) (fraction of 4-coordinated borons), and ('207)Pb NMR absorption peak position display evidence of two-region behavior with the break between regions near 4 Mol % Fe(,2)O(,3). The NMR data is interpreted in terms of changes in the borate network. The results of N(,4) and ('11)B NMR lineshape measurement performed on the fast ionic conducting lithium flouroborate (Li(,2)O-Li(,2)F(,2)-B(,2)O(,3)) and lithium chloroborate (Li(,2)O-Li(,2)Cl(,2)-B(,2)O(,3)) glass systems were found to be in excellent agreement with a model which assumes that the types and quantities of borate configurations present in the glasses are totally unaffected by the presence of the lithium halide species. The model employs a semi -empirical theory of the borate network developed for the binary Li(,2)O-B(,2)O(,3) system and predicts that N(,4) should depend entirely on R = Mol % Li(,2)O)/(Mol % B(,2)O(,3)). This agreement suggests that the lithium halide enters the glass network interstitially.

Bucholtz, Frank

154

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

PubMed

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

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

2014-07-01

155

The Feasibility and Validity of a Remote Pulse Oximetry System for Pulmonary Rehabilitation: A Pilot Study  

PubMed Central

Pulmonary rehabilitation is an effective treatment for people with chronic obstructive pulmonary disease. However, access to these services is limited especially in rural and remote areas. Telerehabilitation has the potential to deliver pulmonary rehabilitation programs to these communities. The aim of this study was threefold: to establish the technical feasibility of transmitting real-time pulse oximetry data, determine the validity of remote measurements compared to conventional face-to-face measures, and evaluate the participants' perception of the usability of the technology. Thirty-seven healthy individuals participated in a single remote pulmonary rehabilitation exercise session, conducted using the eHAB telerehabilitation system. Validity was assessed by comparing the participant's oxygen saturation and heart rate with the data set received at the therapist's remote location. There was an 80% exact agreement between participant and therapist data sets. The mean absolute difference and Bland and Altman's limits of agreement fell within the minimum clinically important difference for both oxygen saturation and heart rate values. Participants found the system easy to use and felt confident that they would be able to use it at home. Remote measurement of pulse oximetry data for a pulmonary rehabilitation exercise session was feasible and valid when compared to conventional face-to-face methods. PMID:23049549

Tang, Jonathan; Mandrusiak, Allison; Russell, Trevor

2012-01-01

156

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

157

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

158

Validation of an experimental polyurethane model for biomechanical studies on implant-supported prosthesis – compression tests  

PubMed Central

Objectives The complexity and heterogeneity of human bone, as well as ethical issues, most always hinder the performance of clinical trials. Thus, in vitro studies become an important source of information for the understanding of biomechanical events on implantsupported prostheses, although study results cannot be considered reliable unless validation studies are conducted. The purpose of this work was to validate an artificial experimental model based on its modulus of elasticity, to simulate the performance of human bone in vivo in biomechanical studies of implant-supported prostheses. Material and Methods In this study, fast-curing polyurethane (F16 polyurethane, Axson) was used to build 40 specimens that were divided into five groups. The following reagent ratios (part A/part B) were used: Group A (0.5/1.0), Group B (0.8/1.0), Group C (1.0/1.0), Group D (1.2/1.0), and Group E (1.5/1.0). A universal testing machine (Kratos model K – 2000 MP) was used to measure modulus of elasticity values by compression. Results Mean modulus of elasticity values were: Group A – 389.72 MPa, Group B – 529.19 MPa, Group C – 571.11 MPa, Group D – 470.35 MPa, Group E – 437.36 MPa. Conclusion The best mechanical characteristics and modulus of elasticity value comparable to that of human trabecular bone were obtained when A/B ratio was 1:1. PMID:21437469

MORETTI NETO, Rafael Tobias; HIRAMATSU, Daniel Afonso; SUEDAM, Valdey; CONTI, Paulo César Rodrigues; RUBO, José Henrique

2011-01-01

159

Disentangling the Underlying Dimensions of Psychopathy and Conduct Problems in Childhood: A Community Study  

Microsoft Academic Search

The psychometric and predictive validity of callous-unemotional (CU) traits as an early precursor of conduct disorder and antisocial behavior were assessed. A community sample of children (4–9 years of age) were tested 12 months apart with the Antisocial Process Screening Device (APSD; P. J. Frick & R. D. Hare, 2002), a measure of early signs of psychopathy in children. Factor

Mark R. Dadds; Jenny Fraser; Aaron Frost; David J. Hawes

2005-01-01

160

Evidence for the predictive validity of DSM-IV oppositional defiant and conduct disorders diagnosed in a clinically referred sample of preschoolers  

PubMed Central

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 has accumulated, but predictive validity is limited. Predictive validity is critical to refuting the hypothesis that diagnosing ODD and CD in young children leads to pathologizing normal behavior. ODD and CD have emerged as gateway disorders to many forms of adult psychopathology. Establishing how early we can identify symptoms and disorders that herald poor prognosis is one of the most important goals for research on etiology and prevention. Methods Subjects were 3–5 year old consecutive referrals to a child psychiatry clinic (n=123) and demographically matched children from a pediatric clinic (n=100). A diagnostic interview was used to assess DSM-IV ODD and CD in a prospective follow-up design from preschool to school age. Stability of ODD and CD diagnoses and level of impairment were tested as a function of preschool diagnosis. Results Over 80% of preschoolers diagnosed with ODD and approximately 60% of preschoolers diagnosed with CD met criteria for the same disorder during follow-up. Impairment over time varied significantly as a function of stability of diagnosis across three years. Conclusions These results provide the first evidence of the predictive validity of DSM-IV ODD and CD in clinically referred preschool children. The findings challenge the assumption that symptoms of disruptive behavior disorders that occur during the preschool period tend to be transient. PMID:20738448

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

2010-01-01

161

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

162

Scanning Ion Conductance Microscopy for Studying Biological Samples  

PubMed Central

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

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

2012-01-01

163

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

PubMed Central

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

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

2014-01-01

164

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. PMID:24551610

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

2013-01-01

165

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

PubMed Central

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

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

2012-01-01

166

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

167

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

168

Fullerene peapods: In-situ conductivity study during synthesis  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

169

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

170

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

171

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

PubMed

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. PMID:21322717

Sankaranarayanan, Subramanian K R S; Ramanathan, Shriram

2011-02-14

172

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

173

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. PMID:21526075

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

2010-01-01

174

Reliability and Validity Studies on Modified Essay Questions.  

ERIC Educational Resources Information Center

The use of modified essay questions (MEQs), developed at the University of Newcastle to assess clinical problem-solving, is reported. Reliability estimates as high as 0.91 were reported. The validity of assessment by MEQ was based on one model of medical problem-solving and another of cognitive skill taxonomies. (Author/MLW)

Feletti, Grahame I.

1980-01-01

175

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

176

Eligibility Worker Selection Process: Biographical Inventory Validation Study.  

ERIC Educational Resources Information Center

One way for agencies to reduce fiscal stress is to minimize employee turnover. A project undertaken by San Bernardino County (California) to reduce employee turnover through the development, validation, and use of a non-traditional worker selection instrument (biographical inventory) is described. This project was aimed at the specific…

Darany, Theodore; And Others

177

Behavioral and Emotional Rating Scale: Two Studies of Convergent Validity  

Microsoft Academic Search

As the field of mental health services shifts its focus to early intervention, the need to develop valid and reliable measures of young children's behavioral functioning is clear. Traditional assessment instruments have focused on deficits, problems, and pathologies to the exclusion of strengths and competencies. However, assessing child strengths provides parents, direct service providers, and educators with a more holistic

Alexandra L. Trout; Joseph B. Ryan; Steven P. La Vigne; Michael H. Epstein

2003-01-01

178

Behavioral and Emotional Rating Scale: Two Studies of Convergent Validity  

ERIC Educational Resources Information Center

As the field of mental health services shifts its focus to early intervention, the need to develop valid and reliable measures of young children's behavioral functioning is clear. Traditional assessment instruments have focused on deficits, problems, and pathologies to the exclusion of strengths and competencies. However, assessing child strengths…

Trout, Alexandra L.; Ryan, Joseph B.; La Vigne, Steven P.; Epstein, Michael H.

2003-01-01

179

Factors in Validating Affective Scales: An Applied Study  

Microsoft Academic Search

In spite of claims to the contrary, affective factors related to teaching and learning can be measured. Recent development of affective scales in reading attest to this, yet caution must be observed that as new-scales are developed, they are adequately validated so that the research emanating from their use can be regarded with a high degree of credibility. In that

Joseph Vaughan; Darrell Sabers

1977-01-01

180

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

181

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

182

Acid Fracture and Fracture Conductivity Study of Field Rock Samples  

E-print Network

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

Underwood, Jarrod

2013-11-15

183

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

184

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

185

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. PMID:21975708

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

2009-01-01

186

AMS method validation for quantitation in pharmacokinetic studies with concomitant extravascular and intravenous administration.  

PubMed

A technique has emerged in the past few years that has enabled a drug's intravenous pharmacokinetics to be readily obtained in humans without having to conduct extensive toxicology studies by this route of administration or expand protracted effort in formulation. The technique involves the intravenous administration of a low dose of (14)C-labelled drug (termed a tracer dose) concomitantly with a non-labelled extravascular dose given at therapeutically levels. Plasma samples collected over time are analysed to determine the total parent drug concentration by LC-MS (which essentially measures that arising from the oral dose) and by LC followed by accelerator mass spectrometry (AMS) to determine the (14)C-drug concentration (i.e., that arising from the intravenous dose). There are currently no published accounts of how the principles of bioanalytical validation might be applied to intravenous studies using AMS as an analytical technique. The authors describe the primary elements of AMS when used with LC separation and how this off-line technique differs from LC-MS. They then discuss how the principles of bioanalytical validation might be applied to determine selectivity, accuracy, precision and stability of methods involving LC followed by AMS analysis. PMID:21338259

Lappin, Graham; Seymour, Mark; Young, Graeme; Higton, David; Hill, Howard M

2011-02-01

187

Validating and Calibrating Agent-Based Models: A Case Study  

Microsoft Academic Search

In this paper we deal with some validation and calibration experiments on a modified version of the Complex Adaptive Trivial\\u000a System (CATS) model proposed in Gallegati et al. (2005 Journal of Economic Behavior and Organization, 56, 489–512). The CATS model has been extensively used to replicate a large number of scaling types stylized facts with a remarkable\\u000a degree of precision. For

Carlo Bianchi; Pasquale Cirillo; Mauro Gallegati; Pietro A. Vagliasindi

2007-01-01

188

Ecological Validity in the Study of Human Pheromones  

Microsoft Academic Search

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

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

189

Dynamic CT Measurement of Cerebral Blood Flow: A Validation Study  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Our objective was to develop a method to correct for the effect of partial volume averaging (PVA) in the CT measurement of contrast enhancement in small arteries, and to validate a dynamic contrast-enhanced CT method for the measurement of regional cerebral blood flow (rCBF). METHODS: Contrast-enhanced CT scans of tubes of known inner diameters were obtained to

Aleksa Cenic; Darius G. Nabavi; Rosemary A. Craen; Adrian W. Gelb; Ting-Yim Lee

1999-01-01

190

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

191

NMR Studies of Magnetic and Fast Ionic Conducting Amorphous Borates  

Microsoft Academic Search

NMR studies were performed on lead borate glasses containing significant concentrations of Fe(,2)O(,3) and on lithium borate glasses containing lithium halides (LiCl or LiF). ('11)B and ('207)Pb NMR investigations of glasses in the system x Fe(,2)O(,3)(.)y PbO(.)z B(,2)O(,3) (0 (LESSTHEQ) x (LESSTHEQ) 15.3 Mol %, z\\/y (DOT=) 3) revealed that the NMR line broadening contains Gaussian field-independent and field-dependent components,

Frank Bucholtz

1982-01-01

192

Validation study of the magnetically self-consistent inner magnetosphere model RAM-SCB  

NASA Astrophysics Data System (ADS)

The validation of the magnetically self-consistent inner magnetospheric model RAM-SCB developed at Los Alamos National Laboratory is presented here. The model consists of two codes: a kinetic ring current-atmosphere interaction model (RAM) and a 3-D equilibrium magnetic field code (SCB). The validation is conducted by simulating two magnetic storm events and then comparing the model results against a variety of satellite in situ observations, including the magnetic field from Cluster and Polar spacecraft, ion differential flux from the Cluster/CODIF (Composition and Distribution Function) analyzer, and the ground-based SYM-H index. The model prediction of the magnetic field is in good agreement with observations, which indicates the model's capability of representing well the inner magnetospheric field configuration. This provides confidence for the RAM-SCB model to be utilized for field line and drift shell tracing, which are needed in radiation belt studies. While the SYM-H index, which reflects the total ring current energy content, is generally reasonably reproduced by the model using the Weimer electric field model, the modeled ion differential flux clearly depends on the electric field strength, local time, and magnetic activity level. A self-consistent electric field approach may be needed to improve the model performance in this regard.

Yu, Yiqun; Jordanova, Vania; Zaharia, Sorin; Koller, Josef; Zhang, Jichun; Kistler, Lynn M.

2012-03-01

193

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

Microsoft Academic Search

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

Orit Shechtman; Sherrilene Classen; Kezia Awadzi; William Mann

2009-01-01

194

An aging study by semi-conductive microstrip gas chambers  

NASA Astrophysics Data System (ADS)

The aging behavior of wire chambers have been of great interest for many years. Recently, a new generation of proportional chambers have been built including the microstrip gas chamber (MSGC) microgap chamber (MGC) and gaseous electron multiplier (GEM). Aging studies of these detectors are of particular interest to the Large Hadron Collider (LHC) community because the baseline design of the CMS experiment includes MSGCs as part of the tracking system. We have performed a series of aging tests of large pitch, 1 mm MSGC's constructed on semiconductive glass substrates operated in argon and dimethyl ether (DME). The quencher, DME is believed to chemically react with some materials of organic origin commonly used in gas systems, shortening the lifetime and deteriorating the performance of the detectors. Great care was taken to minimize unwanted chemical reactions and all materials suspected to react with DME were removed from areas where the DME gas flows. With these precautions, we have demonstrated that the MSGC can tolerate about 150 mC/cm of accumulated charge without significant degradation of the chamber performance. This corresponds to about 15 yr of operation at the LHC.

Gerndt, E. K. E.; Knapp, B. A.; Miyamoto, J.; Shipsey, I. P. J.; Zhang, Q.

1999-02-01

195

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

196

Emotional Reactivity and the Emergence of Conduct Problems and Emotional Symptoms in 7- to 11-Year-Olds: A 1-Year Follow-up Study  

ERIC Educational Resources Information Center

A study to investigate the relation between psychopathology and predictive validity of emotional reactivity in children over a 1-year follow up period was conducted. The investigation was done using the International Affective Picture System to determine individual differences in the emotional and attention process involved in appetitive and…

Sharp, Carla; Petersen, Nancy; Goodyer, Ian

2008-01-01

197

Factor Structure of the French Version of the Wechsler Adult Intelligence Scale-III. Validity Studies  

ERIC Educational Resources Information Center

The standardization of the French version of the Wechsler Adult Intelligence Scale (WAIS-III) was conducted after carefully adapting the French version from the U.S. version and extensive field testing. The standardization sample was composed of 1,104 participants from 16 to 89 years. To assess the construct validity of the French version,…

Gregoire, Jacques

2004-01-01

198

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

E-print Network

This empirical research study had two main purposes with regard to competency cluster validation. First, this empirical research study was focused upon finding the gaps in the literature that existed pertaining to the Motivations...

Stevens, Jeffery Allen

2004-09-30

199

What Forty Years of Research Says about the Impact of Technology on Learning: A Second-Order Meta-Analysis and Validation Study  

ERIC Educational Resources Information Center

This research study employs a second-order meta-analysis procedure to summarize 40 years of research activity addressing the question, does computer technology use affect student achievement in formal face-to-face classrooms as compared to classrooms that do not use technology? A study-level meta-analytic validation was also conducted for purposes…

Tamim, Rana M.; Bernard, Robert M.; Borokhovski, Eugene; Abrami, Philip C.; Schmid, Richard F.

2011-01-01

200

Construct Validation of the Test of Emotional Intelligence (TEMINT): A Two-Study Investigation  

Microsoft Academic Search

This research seeks to further validate the Test of Emotional Intelligence (TEMINT), an ability-based measure of emotional reasoning skills that has accrued an impressive record of validating evidence. With a sample of 192 university students, Study 1 showed that TEMINT was associated most closely with the \\

Gerhard Blickle; Tassilo Momm; Yongmei Liu; Alexander Witzki; Ricarda Steinmayr

2011-01-01

201

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

202

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

203

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

ERIC Educational Resources Information Center

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

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

2014-01-01

204

The Voodoo Doll Task: Introducing and Validating a Novel Method for Studying Aggressive Inclinations  

E-print Network

The Voodoo Doll Task: Introducing and Validating a Novel Method for Studying Aggressive--the voodoo doll task (VDT)--that offers a reliable and valid trait and state measure of aggressive712), we propose that people transfer characteristics of a person onto a voodoo doll representing

Reber, Paul J.

205

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

ERIC Educational Resources Information Center

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

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

2010-01-01

206

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

207

Cross-Cultural Validation of the Marital Satisfaction Inventory-Revised: A confirmatory factor analytic study  

E-print Network

CROSS-CULTURAL VALIDATION OF THE MARITAL SATISFACTION INVENTORY-REVISED: A CONFIRMATORY FACTOR ANALYTIC STUDY A Thesis by MOLLY FAITHE GASBARRINI Submitted to the Office of Graduate Studies of Texas A&M University... Factor Analytic Study Copyright 2010 Molly Faithe Gasbarrini CROSS-CULTURAL VALIDATION OF THE MARITAL SATISFACTION INVENTORY-REVISED: A CONFIRMATORY FACTOR ANALYTIC STUDY A Thesis by MOLLY FAITHE GASBARRINI Submitted to the Office...

Gasbarrini, Molly Faithe

2011-10-21

208

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

SciTech Connect

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

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

2013-01-01

209

An exploratory study into the effect of time-restricted internet access on face-validity, construct validity and reliability of postgraduate knowledge progress testing  

PubMed Central

Background Yearly formative knowledge testing (also known as progress testing) was shown to have a limited construct-validity and reliability in postgraduate medical education. One way to improve construct-validity and reliability is to improve the authenticity of a test. As easily accessible internet has become inseparably linked to daily clinical practice, we hypothesized that allowing internet access for a limited amount of time during the progress test would improve the perception of authenticity (face-validity) of the test, which would in turn improve the construct-validity and reliability of postgraduate progress testing. Methods Postgraduate trainees taking the yearly knowledge progress test were asked to participate in a study where they could access the internet for 30 minutes at the end of a traditional pen and paper test. Before and after the test they were asked to complete a short questionnaire regarding the face-validity of the test. Results Mean test scores increased significantly for all training years. Trainees indicated that the face-validity of the test improved with internet access and that they would like to continue to have internet access during future testing. Internet access did not improve the construct-validity or reliability of the test. Conclusion Improving the face-validity of postgraduate progress testing, by adding the possibility to search the internet for a limited amount of time, positively influences test performance and face-validity. However, it did not change the reliability or the construct-validity of the test. PMID:24195696

2013-01-01

210

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

E-print Network

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

Paris-Sud XI, Université de

211

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

PubMed

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

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

2003-06-01

212

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

PubMed

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

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

2012-11-01

213

Model Validation Lessons Learned: A Case Study at Oak Ridge National Laboratory.  

National Technical Information Service (NTIS)

A groundwater flow and contaminant transport model validation study was performed to determine the applicability of typical groundwater flow models for performance assessment of proposed waste disposal facilities at Oak Ridge, Tennessee. Standard practice...

R. H. Ketelle, R. R. Lee, J. M. Bownds, T. A. Rizk

1989-01-01

214

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.

215

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

NASA Astrophysics Data System (ADS)

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

Barman, Saswati

2011-10-01

216

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

217

76 FR 75875 - Plan for Conduct of 2012 Electric Transmission Congestion Study  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF ENERGY Plan for Conduct of 2012 Electric Transmission Congestion Study AGENCY: Office of...in connection with the preparation of a study of electric transmission congestion pursuant to section...

2011-12-05

218

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...

219

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...

220

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

221

A Comparative Study Of Nerve Conduction Velocity Between Left And Right Handed Subjects  

PubMed Central

Background & Objectives Nerve conduction velocity is being used as a widespread measure of diagnosis of nerve function abnormalities. Dependence of nerve conduction parameters on intrinsic factors like age and sex, as well as extrinsic factors like temperature is well known. Lateralization of various cerebral functions like speech, language, visuospatial relations, analysis of face, recognition of musical themes and use of hand for fine motor movements have also been studied. Some differences have been noted between left and right hander for nerve conduction. The aim of this study is to compare the nerve conduction velocity between left handed and right handed subjects using median nerve and find out whether there is any difference in nerve conduction velocity (motor or sensory) with handedness. Method The study was carried out in students of B J Medical College by the use of standard 2 channel physiograph. Comparison of motor and sensory nerve conduction velocity between left and right handed subjects was done under paired-t test. Results Hemispheric specialization is primarily responsible for difference of dexterity. Some skills like music, sports activities are also due to hemispheric difference. On comparison of nerve conduction velocity between left and right handed persons the study shows that there is significant difference in sensory nerve conduction velocity between left and right handed subjects. Interpretation & Conclusion From the results we can conclude that there should be different set of standards for sensory nerve conduction velocity of left and right handed subjects.

Patel, Anup; Mehta, Anju

2014-01-01

222

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

Microsoft Academic Search

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

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

2007-01-01

223

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

SciTech Connect

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

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

2014-01-01

224

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. PMID:16795604

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

1979-01-01

225

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.

226

Numerical Study of the Spin-Hall Conductance in the Luttinger Model  

Microsoft Academic Search

We present first numerical studies of the disorder effect on the recently\\u000aproposed intrinsic spin Hall conductance in a three dimensional (3D) lattice\\u000aLuttinger model. The results show that the spin Hall conductance remains finite\\u000ain a wide range of disorder strength, with large fluctuations. The\\u000adisorder-configuration-averaged spin Hall conductance monotonically decreases\\u000awith the increase of disorder strength and vanishes

W. Q. Chen; Z. Y. Weng; D. N. Sheng

2005-01-01

227

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

228

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

229

Ecological validity of laboratory studies of videopoker gaming  

Microsoft Academic Search

This study compared the cognitive and behavioral components of videopoker players under laboratory and natural settings. Twenty regular gamblers (19 men and 1 woman) were matched into two groups on age and on frequency of gambling. Irrational verbalizations during gambling, monetary risk (number of bets doubled and number of tokens bet), and motivation served as dependent variables. Results showed no

Robert Ladouceur; Anne Gaboury; Annie Bujold; Nadine Lachance; Sarah Tremblay

1991-01-01

230

Unmasking the Capability of Strategic Learning: A Validation Study  

ERIC Educational Resources Information Center

Purpose: The strategic learning perspective has attracted increased interest among strategic management scholars, yet the operationalisation of this concept is still in its infancy. The aim of this study is to develop a multidimensional understanding of the strategic learning process and to build an instrument to measure this concept.…

Siren, Charlotta A.

2012-01-01

231

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

PubMed Central

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

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

2011-01-01

232

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

233

Rorschach Measures of Aggression: A Laboratory-Based Validity Study  

Microsoft Academic Search

This study sought to complement the archival research designs that have established the empirical foundations of Rorschach aggression scores, including Exner's (2003) Aggressive Movement (AG) score and Meloy and Gacono's (1992) Aggressive Content (AgC), Aggressive Past (AgPast), and Aggressive Potential (AgPot) variables. Utilizing a highly controlled laboratory-based aggression paradigm and self-report measures of violence history in a sample of 35

Aaron J. Kivisto; Scott A. Swan

2012-01-01

234

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

ERIC Educational Resources Information Center

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

Romano, Jeanine; Kromrey, Jeffrey D.

235

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

Microsoft Academic Search

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

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

2004-01-01

236

Photoluminescence measurements to study conductance switching and data storage in polythiophene based devices  

NASA Astrophysics Data System (ADS)

We have fabricated devices based on oriented thin film of a conjugated polymer, namely a polythiophene derivative, which exhibited the presence of two conducting states and switching between the states. Conductance switching in such devices has been studied by photoluminescence (PL) measurements. Depending on the conducting state of the polymer, the PL intensity of the polymer showed switching between high and low values. Both the conducting states displayed an associated memory for data-storage applications. We have shown that the induced states of the polymer, which are retained for more than 2h, can be read by the contact-less and nondestructive PL measurement.

Botta, Chiara; Mercogliano, Clara; Bolognesi, Alberto; Majumdar, Himadri S.; Pal, Amlan J.

2004-09-01

237

A simulation and experimental study on packing of nanoinks to attain better conductivity  

NASA Astrophysics Data System (ADS)

A simulation and experimental study on the packing of nanoinks has been carried out. Simulation predicted that the packing of two different sized monodispersed colloids would results in a more densely packed structure than a single sized monodispered colloid alone. The simulated results were confirmed by conducting experiments with two different sized-monodispersed silver colloids. A binary sized ink was printed in a rectangular pattern using a direct write method system and then the final pattern was sintered. The pattern was confirmed to be highly conductive and the final conductivity obtained from this pattern gave 47% of the bulk conductivity of silver.

Amert, Anthony K.; Oh, Dong-Hoon; Kim, Nam-Soo

2010-11-01

238

An Empirical Study of Hear-Through Augmented Reality: Using Bone Conduction to Deliver Spatialized Audio  

E-print Network

: a speaker array, headphones, and a bone-conduction headset. Analogous to optical-see-through AR-conduction device for sounds that were moving, and that both devices outperformed standard headphones for moving standard headphones. In this paper, we present the first results from a formal, empirical study comparing

Lindeman, Robert W.

239

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

E-print Network

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

Li, Baowen

240

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

PubMed

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

DeVoe, D; Dalleck, L

2001-08-01

241

Bladder pain syndrome: validation of simple tests for diagnosis in women with chronic pelvic pain: BRaVADO study protocol  

PubMed Central

Background Bladder pain syndrome (BPS), a condition with no gold standard diagnosis, comprises of a cluster of signs and symptoms. Bladder filling pain and bladder wall tenderness are two basic clinical features, present in a high number of sufferers. This study will validate the performance of these simple tests for BPS in women with chronic pelvic pain (CPP). Methods/design We will conduct a prospective test validation study amongst women with unexplained CPP presenting to gynaecology outpatient clinics. Two index tests will be performed: patient reported bladder filling pain and bladder wall tenderness on internal pelvic bimanual examination. A final diagnosis of BPS will be made by expert consensus panel. We will assess the rates of index tests in women with CPP; evaluate the correlation between index tests and Pelvic Pain Urgency/ Frequency (PUF) questionnaire results; and determine index test sensitivity and specificity using a range of analytical methods. Assuming a 50% prevalence of BPS and an 80% power approximately 152 subjects will be required exclude sensitivity of < 55% at 70% sensitivity. Discussion The results of this test validation study will be used to identify whether a certain combination of signs and symptoms can accurately diagnose BPS. Trial registration ISRCTN13028601 PMID:24304546

2013-01-01

242

A study on validity of cortical alpha connectivity for schizophrenia.  

PubMed

Abnormalities in schizophrenia are thought to be associated with functional disconnections between different brain regions. Most previous studies on schizophrenia have considered high-band connectivity in preference to the Alpha band, as there has been some uncertainty correlating the latter to the condition. In this paper we attempt to clarify this correlation using an Electroencephalogram (EEG) analysis of the Alpha band from schizophrenic patients. Global, regional Omega and dimensional complexity and local Omega complexity differentials (LCD) of single channel are calculated using 16 channels of resting EEG data from 31 adult patients with schizophrenia and 31 age/sex matched control subjects. It was found that, compared to the controls, anterior alpha Omega and dimensional complexity are higher in schizophrenia patients (p<0.05) with the single channel LCD also increasing at FP1, FP2, F7 and F8 electrodes. Furthermore, higher left hemisphere dimensional complexity and LCD at T3 point was also found. The results suggest there is lower connectivity in the pre-frontal and left temporal regions with respect to the alpha band in schizophrenia patients. PMID:24110430

Peng, Hong; Hu, Bin; Li, Lanlan; Ratcliffe, Martyn; Zhai, Jingwei; Zhao, Qinglin; Shi, Qiuxia; Li, Yunpeng; Liu, Quanying

2013-01-01

243

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

244

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

PubMed

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

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

2014-11-01

245

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

246

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

247

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2012 CFR

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

2012-10-01

248

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

249

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

250

42 CFR 90.7 - Decision to conduct health effects study.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

251

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

252

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

253

The Validity of an Academic Study-Time Questionnaire for College Students  

Microsoft Academic Search

For a sample of 70 university students the validity of a questionnaire on academic study time entitled Student Study Time Survey (SSTS) was estimated in relation to data provided by a criterion measure called Student Study Time Interview Schedule (SSTIS). This schedule contains a record sheet of an interview involving an in-depth interactive discussion between an interviewer and student. During

Patrick Reed; Debra Puchalski; Carolyn Denham; William B. Michael

1984-01-01

254

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

255

Synthesis and study of conductivity behaviour of blended conducting polymer films irradiated with swift heavy ions of silicon  

Microsoft Academic Search

In recent times, blended polymers have shown a lot of promise in terms of easy processability in different shapes and forms. In the present work, polyaniline emeraldine base (PANi-EB) was doped with camphor sulfonic acid (CSA) and combined with the conducting polymer polyfluorene (PF) as well as the insulating polymer polyvinyl chloride (PVC) to synthesize CSA doped PANi–PF and PANi–PVC

Prashant Sonar; Amit L Sharma; Amita Chandra; Klaus Muellen; Alok Srivastava

2003-01-01

256

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

257

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

258

Significance of Childhood Conduct Problems to Later Development of Conduct Disorder among Children with ADHD: A Prospective Follow-Up Study  

ERIC Educational Resources Information Center

This study investigates whether low to moderate levels of childhood oppositional defiant disorder (ODD) and conduct disorder (CD) behaviors contribute to the development of clinically diagnosed CD in adolescence, in children with attention deficit hyperactivity disorder (ADHD). Participants were 207 White boys (ages 6-12) with ADHD free of conduct

Mannuzza, Salvatore; Klein, Rachel G.; Abikoff, Howard; Moulton, John L., III

2004-01-01

259

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

260

Influence of Asthma on the Validity of Reported Lifelong Environmental Tobacco Smoke in the EGEA Study  

Microsoft Academic Search

The aim of this study was to assess the short-term reproducibility and the validity of reported ETS (environmental tobacco smoke) exposure, with a special emphasis on the potential misclassification related to personal or family history of asthma. Analyses were based on the data on the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA), a

Valérie Siroux; Philippe Guilbert; Nicole Le Moual; Marie-Pierre Oryszczyn; Francine Kauffmann

2004-01-01

261

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

262

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

263

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

ERIC Educational Resources Information Center

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

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

2014-01-01

264

The Brief Fear of Negative Evaluation Scale (BFNE): translation and validation study of the Iranian version  

Microsoft Academic Search

BACKGROUND: The Brief Fear of Negative Evaluation Scale (BFNE) is a commonly used instrument to measure social anxiety. This study aimed to translate and to test the reliability and validity of the BFNE in Iran. METHODS: The English language version of the BFNE was translated into Persian (Iranian language) and was used in this study. The questionnaire was administered to

Azadeh Tavoli; Mahdiyeh Melyani; Maryam Bakhtiari; Gholam Hossein Ghaedi; Ali Montazeri

2009-01-01

265

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

ERIC Educational Resources Information Center

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

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

2014-01-01

266

Multiple approaches to the validation of the scores from the study anxiety inventory  

Microsoft Academic Search

The Study Anxiety Inventory (SAI), consisting of the factors of worry and emotionality, was developed to measure college students' self-reported levels of anxiety while studying for an exam. Data from 2002 undergraduate students from four colleges (Arts and Sciences, Engineering, Business, and Education) at a southeastern state university were used to evaluate the validity of the scores from the 16-item

George Douglas Lunsford

2009-01-01

267

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

268

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

ERIC Educational Resources Information Center

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

Korkmaz, Ozgen

2012-01-01

269

Using virtual reality to evaluate executive functioning among persons with schizophrenia: a validity study.  

PubMed

Persons with Schizophrenia experience difficulties with Executive Functioning (EF) that affect independence and participation in activities. Specifically, EF impacts performance in Instrumental Activities of Daily Living (IADL) that require flexible thinking and accommodation to complex environments. However, less is known how schizophrenia affects EF and individuals' performance in activities. IADL performance can be tested using a virtual reality (VR) environment that simulates real life activities. The purpose of this study was: 1) to examine the feasibility and validity of the Virtual Action Planning-Supermarket (VAP-S) to assess EF in persons with schizophrenia as compared to a standardized EF measure (the Behavioral Assessment of Dysexecutive Syndrome, BADS); 2) to compare performance of persons with schizophrenia and healthy controls in the VAP-S; 3) to assess the ability of the VAP-S to differentiate between different levels of EF within schizophrenia; 4) to explore the relationships between negative and positive symptoms and performance on the tests. Thirty persons with schizophrenia were matched with 30 healthy controls. Significant differences in performance between research and control groups were detected on the VAP-S and BADS, with the research group performing worse. Large variations in number of purchases within the VAP-S by the research group point to level of task completion thus secondary analysis was conducted. There was a significant negative correlation between level of the negative signs and overall performance on the BADS and on most measures of the VAP-S. Results of this study support the use the VAP-S to assess EF among persons with Schizophrenia. PMID:19850451

Josman, Naomi; Schenirderman, Anat Elbaz; Klinger, Evelyne; Shevil, Eynat

2009-12-01

270

Retrograde conduction in complete atrioventricular block Study using His bundle recordings.  

PubMed Central

Using His bundle recordings and ventricular stimulation retrograde conduction was studied in 57 cases of complete AV block. VA conduction was observed in 13 patients. Of the 13, 12 had AV block distal to H, and during cardiac pacing 5 of them showed a retrograde His bundle potential. In all cases the AV node-His pathway was implicated in the transmission of the retrograde impulse. There was no retrograde atrial response in the remaining patients. VA block usually occurred at the same level as AV block. Nevertheless, two cases of AV block distal to H were associated with concealed retrograde conduction which stopped within the AV node. Images PMID:973895

Touboul, P; Huerta, F; Delahaye, J P

1976-01-01

271

The underestimated thermal conductivity of graphene in thermal-bridge measurement: A computational study  

NASA Astrophysics Data System (ADS)

The effect of substrate coupling on thermal conductivity of graphene is studied by using molecular dynamic simulations. It was found that heat flux along real suspended single-layer graphene is only 40% with respect to that in the ideal suspended single-layer graphene, due to remarkable temperature jump and thermal contact resistance at the contact region. With the strength of inter-layer (or graphene-substrate) interaction increases, the temperature jump increases and leads to further reduction in heat flux and the estimated thermal conductivity. Our results give a reasonable explanation to the underestimated thermal conductivity of graphene in thermal-bridge measurement.

Yu, Chenxi; Zhang, Gang

2013-06-01

272

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

NASA Technical Reports Server (NTRS)

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

Catchings, R. M.

1979-01-01

273

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

PubMed

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

Lv, Yi; Cui, Jian; Jiang, Zuimin M; Yang, Xinju

2012-01-01

274

Feasible Study for Multi-photon Stereolithography Method of Electro Conductive Polymer Actuator with Complex Shape  

NASA Astrophysics Data System (ADS)

Recently, a soft actuator was developed using an electro-conducting polymer and an ionic conducting polymer. Moreover, stereolithography that uses a femtosecond laser was researched as a method of multiphoton-sensitized polymerization. In this study, we tried a more stable and more rapid stereolithography method for fabricating an electro-conducting polymer using a protein material. From the results of this study, we found that the method was 10 times faster when an aqueous solid that included an electro-conducting polymer, a catalyst, and gelatine was used. In addition, it was stable in that the temperature of the aqueous solid was controlled at 10 degree. We built a 3D shape using the newly developed method, and we will apply this method to a complex actuator.

Sone, Junji; Asami, Akihisa; Yamada, Katsumi; Chen, Jun

275

Experimental study of negative differential conductivity in GaAs:Cr  

Microsoft Academic Search

We have studied the temperature and illumination dependencies of the current versus voltage characteristics I(V) of a Cr-doped GaAs sample. An S-shaped negative differential conductivity with a threshold at around 1 kV cm-1 was associated with a trap with activation energy of 90 meV. The low-conductivity state in I(V) characteristics is strongly influenced by illumination and temperature. We also present

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

2000-01-01

276

Experimental study of electrical conduction in RuO 2 -based thick resistive films  

Microsoft Academic Search

Electrical conduction and noise of thick resistive films prepared from RuO2 and lead borosilicate glass were studied. Two series of pastes were prepared differing by the specific surface area of RuO2 powder (77 m2\\/g and 24 m2\\/g). It was concluded that two regions on resistanceR versus volume fractionv of conducting component characteristics may be specified. For small values ofv resistance

K. Bobran

1989-01-01

277

Selection of Conductive Additives in Li-Ion Battery Cathodes A Numerical Study  

E-print Network

Selection of Conductive Additives in Li-Ion Battery Cathodes A Numerical Study Y.-H. Chen,a, * C been successively improved with adoption of new cathode electrochemistries, from LiCoO2 to higher- capacity LiNi1-xCoxO2 to lower cost LiNi1-xCoxO2. The addition of conductive additives to cathode materials

Sastry, Ann Marie

278

Fluorine mobility in an aluminum-doped CeF 3 crystal: NMR and conductivity studies  

Microsoft Academic Search

Electrical conductivity and NMR measurements were carried out for an aluminum-doped CeF3 crystal to study the influence of substitutional impurities on the superionic fluorine mobility. Activation enthalpy was\\u000a found to remain constant from low temperatures to about 325 K and to increase as compared to that of a pure CeF3 crystal. Above about 325 K, a trend towards gradual conductivity

C. Tien; E. V. Charnaya; A. B. Sherman

2004-01-01

279

Nerve conduction studies and its importance in diagnosis of acute poliomyelitis  

Microsoft Academic Search

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

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

1993-01-01

280

A study of contact resistance of conductive adhesives based on anhydride-cured epoxy systems  

Microsoft Academic Search

Electrically conductive adhesives (ECAs) are an environmentally friendly alternative to tin\\/lead (Sn\\/Pb) solders in electronics packaging applications. However, current conductive technology is still in its infancy and limitations do exist. One of the critical reliability issues is that contact resistance of silver flake-filled ECAs on nonnoble metals increases in elevated temperature and humidity environments. The main objective of this study

Daoqiang Lu; C. P. Wong

2000-01-01

281

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

PubMed

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

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

2009-03-31

282

A reliability and validity study of the Women's Role Strain Inventory.  

PubMed

The purpose of this study was to theoretically conceptualize, develop and test the Women's Role Strain Inventory (WRSI) which assesses role strain in women who have multiple roles. There is limited research published related to role strain of women, although role strain, role conflict and role stress have been documented to have negative and positive effects (Hall 1975, Hall 1992). The theoretical basis for this study is based upon Goode's Theory of Role Strain (1960) and Sieber's Theory of Role Accumulation (1974). The pilot consisted of 62 female nurses, and the sample used for construct validity consisted of 445 female nurses. Content validity resulted in a content validity index of (.91). Exploratory factor analysis with varimax rotation resulted in a three-factor solution supporting Goode's (1960) theory of role strain, and Sieber's (1974) theory of role accumulation. Alpha coefficients for the three subscales were .89 (role distress), .86 (role enhancement), and .81 (role support). Internal consistency of .93 was achieved for the overall WRSI. Test-retest coefficients ranged from .61 to .91. The high reliability and validity of the WRSI make it a reliable and valid instrument to measure role strain of women. PMID:9538586

Lengacher, C A

1997-01-01

283

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

284

Solid State Ionics: Studies of Lithium-Conducting Sulfide Glasses and a Superconducting Oxide Compound.  

NASA Astrophysics Data System (ADS)

The first part of this work studies lithium-conducting sulfide glasses for battery applications, while the second part studies the thermodynamic properties of a superconducting oxide compound by using an oxide electrolyte. Lithium conducting glasses based on the SiS _2-Li_2S system are possible solid electrolytes for high-energy-density lithium batteries. The foremost requirement for solid electrolytes is that they should have high ionic conductivities. Unfortunately, most crystalline lithium conductors have low ionic conductivities at room temperature. However, glass ionic conductors show higher ionic conductivities than do crystalline forms of the same material. In addition to higher ionic conductivities, glasses appear to have several advantages over crystalline materials. These advantages include isotropic conductivity, absence of grain boundary effects, ease of glass forming, and the potential for a wide range of stability to oxidizing and reducing conditions. Using pyrolitic graphite-coated quartz ampoules, new ternary compounds and glasses in the SiS_2 -Li_2S system were prepared. Several techniques were used to characterize the materials: powder x-ray diffraction, differential thermal analysis, differential scanning calorimetry, and AC impedance spectroscopy. The measured lithium conductivity of the sulfide glasses was one of the highest among the known solid lithium conductors. Measuring the equilibrium open circuit voltages assisted in determining the electrochemical stabilities of the ternary compounds and glasses with respect to pure Li. Forming associated structural defects in the sulfide glass results in the wide range of stoichiometry, the low electronic conductivity, the high ionic conductivity, and the narrow electrochemical stability of the glass. Both the higher carrier concentration and the higher mobility enhances the ionic conductivity of the glasses compared to the crystalline phase. The composition dependence of the ionic conductivity indicates that the mobility change, rather than the carrier concentration change, is the dominant factor. The narrow electrochemical stability window of the glass results from the formation of the associated defects in the glasses; thus the Fermi level in the glasses is fixed near the intrinsic energy level. A solid-state ionic technique called oxygen coulometric titration solves these problems. Using this technique, the thermodynamic stability, the oxygen stoichiometry, and the effects of the oxygen stoichiometry and the cooling rate on superconductivity of the YBa_2Cu _3O_{rm 7-x} compound were investigated. (Abstract shortened with permission of author.).

Ahn, Byung Tae

285

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

E-print Network

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

Sonnenburg, Justin L.

286

An Automated Methodology for Conducting a Social Network Study of a University Faculty*  

E-print Network

report describes the data-collection and analysis methodology used in a social- network study of computer and discuss its utility as a tool for complex network-analysis; next, we describe the data collectionAn Automated Methodology for Conducting a Social Network Study of a University Faculty* CASOS

Sadeh, Norman M.

287

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

ERIC Educational Resources Information Center

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

Kelly, Michael P.; Moore, Tessa A.

2011-01-01

288

Effects of Age, Gender, Height, and Weight on Late Responses and Nerve Conduction Study Parameters  

Microsoft Academic Search

1 Abstract- Background: Different methods in performing nerve conduction studies (NCS) yield different results. The results of NCS can also be affected by factors such as gender, age, height, and weight. This study aimed (1) to survey the effects of such factors, (2) to determine the importance of these factors, and (3) to ana- lyze them for building equations in

Chi-Ren Huang; Wen-Neng Chang; Hsueh-Wen Chang; Nai-Wen Tsai; Cheng-Hsien Lu

289

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...

290

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...

291

NCAA Division I Athletics Certification Draft Written Plan for Conducting the Self-Study  

E-print Network

1 NCAA Division I Athletics Certification Draft Written Plan for Conducting the Self-Study November 10, 2005 (updated in December 2005 based on consultation with the NCAA) Outline A. Objectives") in connection with current NCAA athletics certification process is to produce an exemplary self-study report

California at Davis, University of

292

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

EPA Science Inventory

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

293

SOCIOECONOMIC FACTORS AFFECTING TO JUVENILE DELINQUENCY: A STUDY CONDUCTED AT BORSTAL JAILS OF PUNJAB  

Microsoft Academic Search

This study aims to explore the socio-economic factors effecting juvenile delinquency. The research was conducted at Faisalabad and Bahawalpur Borstal jails of Punjab. The main objectives of the study were to find out the background characteristics of the Juveniles, to explore social factors that influence on juvenile delinquency and to identify the economic factors that influence on juvenile delinquency. Quantitative

Haq Nawaz Anwar; Malik Muhammad Sohail

2012-01-01

294

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

SciTech Connect

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

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

1999-03-15

295

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

296

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

SciTech Connect

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

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

2013-08-14

297

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

298

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

299

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

300

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

301

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

Microsoft Academic Search

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

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

2008-01-01

302

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

Microsoft Academic Search

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

Olga Nacajauskaite; Milda Endziniene; Kristina Jureniene; Harald Schrader

2006-01-01

303

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

E-print Network

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

Thomas, Jeremy N.

304

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

ERIC Educational Resources Information Center

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

Korkmaz, Ozgen

2011-01-01

305

Dynamic modeling and validation studies of a tubular solid oxide fuel cell  

Microsoft Academic Search

Solid oxide fuel cell (SOFC) is a key component in the new vision of distributed power generation. However, for connecting SOFC reliably to a load-varying grid, its transient behavior needs to be studied in detail with a thoroughly validated dynamic model. Dynamic models are also important for synthesizing efficient controllers. In this paper, a detailed dynamic model of a tubular

Debangsu Bhattacharyya; Raghunathan Rengaswamy; Caine Finnerty

2009-01-01

306

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.

307

Validation Evidence for the Netherlands Physical Activity Questionnaire for Young Children: The Iowa Bone Development Study  

ERIC Educational Resources Information Center

In this paper, the authors present reliability and validity information for the Netherlands (Health Education Project) Physical Activity Questionnaire (NPAQ), a global proxy report of children's everyday activity preferences (Montoye, Kemper, Saris, & Washburn, 1996). In this study, the authors examined the measurement properties of a global proxy…

Janz, Kathleen F.; Broffitt, Barbara; Levy, Steven M.

2005-01-01

308

`Revised Criteria for Mild Cognitive Impairment (MCI-R): Validation within a longitudinal population study'  

E-print Network

`Revised Criteria for Mild Cognitive Impairment (MCI-R): Validation within a longitudinal 13/10/2006; 22(5-6): 465-470 #12;2 Abstract Background: Mild Cognitive impairment (MCI) refers studies. Objective: To evaluate revised diagnostic criteria for Mild Cognitive Impairment (MCI

Boyer, Edmond

309

A Construct Validation Study of Phonological Awareness for Children Entering Prekindergarten  

ERIC Educational Resources Information Center

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

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

2004-01-01

310

Nova Acta Leopoldina NF 112, Nr. 384, 281289 (2010) Mountain Permafrost A Valid Archive to Study  

E-print Network

Nova Acta Leopoldina NF 112, Nr. 384, 281­289 (2010) 281 Mountain Permafrost ­ A Valid Archive permafrost is highly sensitive to changing air temperatures because they affect the thawing depth conditions to study changes of mountain permafrost. The sites provide high quality climate data, together

Williams, Mark W.

311

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

312

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

...study should be based upon a review of information about...The review should include a job analysis except as...Technical feasibility. Users choosing to validate a selection procedure by a...with substantially the same major work behaviors may be...

2014-07-01

313

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

Microsoft Academic Search

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

Susan E. Cashin; Patricia B. Elmore

2005-01-01

314

A psychometric study of the Adult Attachment Interview: Reliability and discriminant validity  

Microsoft Academic Search

The Adult Attachment Interview (AAI) stimulates Ss to retrieve and evaluate attachment- related autobiographical memories and has increasingly been used to predict the quality of parent—child interactions and infant—parent attachment relationships. Its reliability and discriminant validity, however, have not yet been examined. In this study, 83 mothers were interviewed twice, 2 months apart, by different interviewers so that the instrument's

Marian J. Bakermans-Kranenburg; Marinus H. Van IJzendoorn

1993-01-01

315

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

ERIC Educational Resources Information Center

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

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

2009-01-01

316

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

ERIC Educational Resources Information Center

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

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

2010-01-01

317

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

318

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

319

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

320

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

PubMed Central

Recently, Gotham et al. (2007) proposed revised algorithms for the Autism Diagnostic Observation Schedule (ADOS) with improved diagnostic validity. The aim of the current study was to replicate predictive validity, factor structure, and correlations with age and verbal and nonverbal IQ of the ADOS revised algorithms for Modules 1 and 2 in a large independent Dutch sample (N = 532). Results showed that the improvement of diagnostic validity was most apparent for autism, except in very young or low functioning children. Results for other autism spectrum disorders were less consistent. Overall, these findings support the use of the more homogeneous revised algorithms, with the use of similar items across developmental cells making it easier to compare ADOS scores within and between individuals. PMID:20148299

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

2010-01-01

321

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

NASA Astrophysics Data System (ADS)

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

Anilkumar, T.; Ramesan, M. T.

2014-10-01

322

Clinical prediction models for bronchopulmonary dysplasia: a systematic review and external validation study  

PubMed Central

Background Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth. Very different models using clinical parameters at an early postnatal age to predict BPD have been developed with little extensive quantitative validation. The objective of this study is to review and validate clinical prediction models for BPD. Methods We searched the main electronic databases and abstracts from annual meetings. The STROBE instrument was used to assess the methodological quality. External validation of the retrieved models was performed using an individual patient dataset of 3229 patients at risk for BPD. Receiver operating characteristic curves were used to assess discrimination for each model by calculating the area under the curve (AUC). Calibration was assessed for the best discriminating models by visually comparing predicted and observed BPD probabilities. Results We identified 26 clinical prediction models for BPD. Although the STROBE instrument judged the quality from moderate to excellent, only four models utilised external validation and none presented calibration of the predictive value. For 19 prediction models with variables matched to our dataset, the AUCs ranged from 0.50 to 0.76 for the outcome BPD. Only two of the five best discriminating models showed good calibration. Conclusions External validation demonstrates that, except for two promising models, most existing clinical prediction models are poor to moderate predictors for BPD. To improve the predictive accuracy and identify preterm infants for future intervention studies aiming to reduce the risk of BPD, additional variables are required. Subsequently, that model should be externally validated using a proper impact analysis before its clinical implementation. PMID:24345305

2013-01-01

323

Resistivity and Conductivity Studies of the Rattlesnake Springs, New Mexico Watershed  

NASA Astrophysics Data System (ADS)

Rattlesnake Springs are a high-discharge artesian springs situated in the upper Black River Valley in southwestern Eddy Country, New Mexico. The aquifer that supplies the Rattlesnake Springs has been the main water source for domestic use by visitors of Carlsbad Caverns National Park and residents of neighboring ranches since the 1930s. Several geological studies relying on surface geology and limited water wells had previously been conducted in the area to examine the trend of ground water flow. We collected ground conductivity data at ~10m spacing around the perimeter and easily accessible areas owned by the National Park and surrounding ranches. In addition, we conducted Schlumberger and Wenner vertical electrical sounding at 10 sites, primarily to investigate the depth extend of conductivity anomalies, and a lateral resistivity survey across a suspected barrier to fluid flow. The conductivity and resistivity data indicate higher conductivities north and east of the springs reflecting moist soils, while two other highs at the eastern and western boundaries of the park are likely due to increased clay content of the soil.

Santiago, C.; Doser, D. I.

2009-12-01

324

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

NASA Astrophysics Data System (ADS)

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.

Maeda, Nobuo

2013-01-01

325

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...

326

Sleep in conduct-disordered adolescents--a polysomnographic and spectral power analysis study.  

PubMed

The aim of the present study was to characterize sleep in conduct-disordered adolescents using polysomnography and spectral power analysis. The two hypotheses were that conduct disorder would be associated with objective sleep problems, and that conduct disorder--as a precursor of adult antisocial personality disorder--would be associated with the same kind of abnormal sleep architecture, with both increased deep sleep and delta power, as previously reported in antisocial personality disorder. The patients consisted of 15 adolescents (age range 13-17 years, mean age 14.7 years) with histories of antisocial behavior so functionally impairing that they were ordered by child welfare to undergo a psychosocial evaluation in a closed social services ward. The healthy age-matched controls comprised 20 volunteers recruited with a newspaper advertisement. Opposite to earlier subjective sleep studies among conduct-disordered children, no significant differences in sleep parameters were observed between the two groups. The adolescents with conduct disorder slept a little bit longer, but the percentage amount of different sleep stages did not differ significantly between the two groups. Relative spectral power of sleep, delta power in particular, was similar in both groups, assessed in total sleep time as well as in first half of it. Different alternative explanations for these findings are discussed. PMID:18462804

Lindberg, Nina; Tani, Pekka; Sailas, Eila; Virkkala, Jussi; Urrila, Anna-Sofia; Virkkunen, Matti

2008-06-30

327

Ultrafast conductivity in a low-band-gap polyphenylene and fullerene blend studied by terahertz spectroscopy  

E-print Network

Ultrafast conductivity in a low-band-gap polyphenylene and fullerene blend studied by terahertz-band-gap polyphenylene copolymer and fullerene derivative. The optical excitation pulse generates free holes delocalized in these systems. The pri- mary excitation in polymer/fullerene bulk heterojunctions is an exciton on the polymer

KuÂ?el, Petr

328

Transport and solid state battery characteristic studies of silver based super ion conducting glasses  

Microsoft Academic Search

Silverarsenotellurite (SAT), silverphosphotellurite (SPT) and silvervanadotellurite (SVT) quaternary glass systems were prepared with various formers compositions by a melt quenching method. Glass nature, glass transition temperature (Tg) and structure of the prepared glasses were identified respectively by X-ray diffraction (XRD), differential scanning calorimetric (DSC) and Fourier transform infrared (FT-IR) technique. Electrical conductivity studies were carried out by impedance measurement in

S. Jayaseelan; P. Muralidharan; M. Venkateswarlu; N. Satyanarayana

2005-01-01

329

New studies conducted at the Salk Institute show that the only largely successful human  

E-print Network

human gene therapy treatment to date is, in fact, riskier than realized. Salk Institute researchers, led with the IL2RG gene three times longer than any study had ever before and found that one-third of the animals trials conducted in France, the United States, the United Kingdom, and Australia. Gene therapy

Sejnowski, Terrence J.

330

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

ERIC Educational Resources Information Center

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

Payne, Thomas A.

331

Compact EMC model of power electronics converter for conducted EMC studies in embedded networks  

E-print Network

Page 1/7 Compact EMC model of power electronics converter for conducted EMC studies in embedded - University of Lyon Abstract This paper presents a "black box" model for EMC prediction of power electronics, EMI, Power Electronics 1. Introduction With the generalization of the "Power by Wire" concept

Paris-Sud XI, Université de

332

USING CONTINUOUS MONITORS FOR CONDUCTING TRACER STUDIES IN WATER DISTRIBUTION SYSTEMS  

EPA Science Inventory

The use of online monitors for conducting a distribution system tracer study is proving to be an essential tool to accurately understand the flow dynamics in a distribution system. In a series of field testing sponsored by U. S. Environmental Protection Agency (EPA) and Greater ...

333

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

PubMed Central

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

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

2014-01-01

334

The Patient-Doctor Relationship Questionnaire (PDRQ-9) in Primary Care: A Validity Study.  

PubMed

This study assessed the validity of the Patient-Doctor Relationship Questionnaire-9 (PDRQ-9) in a primary care sample (N = 180). Convergent validity was assessed through a correlation between the patient-rated PDRQ-9 and the physician-rated Difficult Doctor Patient Relationship Questionnaire-10 (DDPRQ-10). Discriminant validity was assessed through correlations between the PDRQ-9 and patient age, patient- and physician-reported health and psychological distress. To determine if the PDRQ-9 could discriminate between groups, patient PDRQ-9 ratings were compared between patients who were treated by faculty physicians versus those who were treated by residents. An exploratory factor analysis confirmed that the PDRQ-9 was made up of a single factor. The PDRQ-9 scale was internally consistent (? = .96) and significantly and negatively correlated with the DDPRQ-10 (r = -.22, p = .003) and was not significantly correlated with patient age, health, or psychological distress. PDRQ-9 ratings were statistically greater in patients who were treated by faculty physicians than those who were treated by residents (p = .01). This study provides additional support for the reliability and validity of the PDRQ-9 as a measure of the doctor-patient relationship in a primary care sample. PMID:25106125

Porcerelli, John H; Murdoch, William; Morris, Pierre; Fowler, Shannon

2014-09-01

335

Radiographic human identification using bones of the hand: a validation study.  

PubMed

The 1993 Supreme Court case Daubert v. Merrell-Dow Pharmaceuticals, Inc. underscores the importance of validating forensic science techniques. This research examines the validity of using posterior-anterior radiographs of the hand to make positive identifications of unknown human remains. Furthermore, this study was constructed to satisfy the requirements of Daubert's guidelines of scientific validity by establishing a standard methodology for hand radiograph analysis, testing the technique, and noting rates of error. This validation study required twelve participant examiners from the forensic science community, working independently, to attempt to match 10 simulated postmortem radiographs of skeletonized hands to 40 simulated antemortem radiographs of fleshed cadaver hands. The overall accuracy rate of the twelve examiners was 95%, while their collective sensitivity and specificity were 95% and 92%, respectively. However, the accuracy of each examiner was related to the amount of radiological training and experience of the observer. Six Ph.D. forensic anthropologists and four experienced forensic anthropology graduate students correctly identified all the matches. Participant examiners noted bone morphology, trabecular patterns of the proximal and middle phalanges, and distinctive radiopaque and radiolucent features as the anatomical features that aided the identification process. The hand can be an important skeletal element for radiographic positive identification because it contains 27 individual bones for comparative analysis. PMID:15813535

Koot, Michael G; Sauer, Norman J; Fenton, Todd W

2005-03-01

336

Primary Care COPD Patients Compared with Large Pharmaceutically-Sponsored COPD Studies: An UNLOCK Validation Study  

PubMed Central

Background Guideline recommendations for chronic obstructive pulmonary disease (COPD) are based on the results of large pharmaceutically-sponsored COPD studies (LPCS). There is a paucity of data on disease characteristics at the primary care level, while the majority of COPD patients are treated in primary care. Objective We aimed to evaluate the external validity of six LPCS (ISOLDE, TRISTAN, TORCH, UPLIFT, ECLIPSE, POET-COPD) on which current guidelines are based, in relation to primary care COPD patients, in order to inform future clinical practice guidelines and trials. Methods Baseline data of seven primary care databases (n?=?3508) from Europe were compared to baseline data of the LPCS. In addition, we examined the proportion of primary care patients eligible to participate in the LPCS, based on inclusion criteria. Results Overall, patients included in the LPCS were younger (mean difference (MD)-2.4; p?=?0.03), predominantly male (MD 12.4; p?=?0.1) with worse lung function (FEV1% MD -16.4; p<0.01) and worse quality of life scores (SGRQ MD 15.8; p?=?0.01). There were large differences in GOLD stage distribution compared to primary care patients. Mean exacerbation rates were higher in LPCS, with an overrepresentation of patients with ?1 and ?2 exacerbations, although results were not statistically significant. Our findings add to the literature, as we revealed hitherto unknown GOLD I exacerbation characteristics, showing 34% of mild patients had ?1 exacerbations per year and 12% had ?2 exacerbations per year. The proportion of primary care patients eligible for inclusion in LPCS ranged from 17% (TRISTAN) to 42% (ECLIPSE, UPLIFT). Conclusion Primary care COPD patients stand out from patients enrolled in LPCS in terms of gender, lung function, quality of life and exacerbations. More research is needed to determine the effect of pharmacological treatment in mild to moderate patients. We encourage future guideline makers to involve primary care populations in their recommendations. PMID:24598945

Kruis, Annemarije L.; Stallberg, Bjorn; Jones, Rupert C. M.; Tsiligianni, Ioanna G.; Lisspers, Karin; van der Molen, Thys; Kocks, Jan Willem H.; Chavannes, Niels H.

2014-01-01

337

25 CFR 900.196 - Do covered services include the conduct of clinical studies and investigations and the provision...  

Code of Federal Regulations, 2013 CFR

...include the conduct of clinical studies and investigations and the...Coverage General Provisions Medical-Related Claims § 900...include the conduct of clinical studies and investigations and the...to transport passengers for medical...

2013-04-01

338

25 CFR 900.196 - Do covered services include the conduct of clinical studies and investigations and the provision...  

Code of Federal Regulations, 2012 CFR

...include the conduct of clinical studies and investigations and the...Coverage General Provisions Medical-Related Claims § 900...include the conduct of clinical studies and investigations and the...to transport passengers for medical...

2012-04-01

339

25 CFR 900.196 - Do covered services include the conduct of clinical studies and investigations and the provision...  

Code of Federal Regulations, 2011 CFR

...include the conduct of clinical studies and investigations and the...Coverage General Provisions Medical-Related Claims § 900...include the conduct of clinical studies and investigations and the...to transport passengers for medical...

2011-04-01

340

25 CFR 900.196 - Do covered services include the conduct of clinical studies and investigations and the provision...  

Code of Federal Regulations, 2010 CFR

...include the conduct of clinical studies and investigations and the...Coverage General Provisions Medical-Related Claims § 900...include the conduct of clinical studies and investigations and the...to transport passengers for medical...

2010-04-01

341

25 CFR 900.196 - Do covered services include the conduct of clinical studies and investigations and the provision...  

...include the conduct of clinical studies and investigations and the...Coverage General Provisions Medical-Related Claims § 900...include the conduct of clinical studies and investigations and the...to transport passengers for medical...

2014-04-01

342

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

343

Comparative study of electrically conductive thick films with and without glass  

Microsoft Academic Search

An air-fireable, glass-free, electrically conductive thick-film material (96.6% Ag, 1.38% Cu, 0.28% Al, 0.35% Ti, and 1.39%\\u000a Sn by weight) and a conventional glass-containing, electrically conductive thick-film materials (96.6% Ag and 3.4% glass frit\\u000a by weight), both on alumina substrates, were studied by electrical, mechanical, thermal, and microscopic methods. The volume\\u000a electrical resistivity of the glass-free thick film (2.510?6 ?cm,

Zongrong Liu; D. D. L. Chung

2004-01-01

344

Picosecond pulse-conductivity technique applied to study excess-electron reactions in hydrocarbon mixtures  

SciTech Connect

To measure electron reactions on a picosecond timescale the investigators developed a picosecond pulse-conductivity technique, which makes use of the electron fine-structure pulses of our LINAC (pulse width 25 vs FWHM) to produce excess electrons and now detects changes in sample conductance under optimum conditions with an instrumental response of 18 ps. This resolution is in agreement with a theoretical estimate. This technique has been successfully applied to study excess electron reactions in solvents covering a mobility range from 0.24 to 100 cm/sup 2/V/sup -1/s/sup -1/; extension to lower mobility liquids seem possible.

Bakale, G.; Beck, G.

1983-01-01

345

Forced Degradation Study on Gliclazide and Application of Validated Stability-Indicating HPLC-UV Method in Stability Testing of Gliclazide Tablets  

Microsoft Academic Search

Forced degradation study on gliclazide was conducted under the conditions of hydrolysis, oxidation, dry heat and photolysis\\u000a and an isocratic stability-indicating HPLC-UV method was developed and validated. All the seven degradation products (I–VII)\\u000a formed under different conditions were optimally resolved on a C18 column with mobile phase composed of 40% acetonitrile and 60% ammonium acetate solution (0.025 M, pH 3.5) at

Gulshan Bansal; Manjeet Singh; Kaur Chand Jindal

2007-01-01

346

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

Microsoft Academic Search

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

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

1982-01-01

347

Electrical conductivity of activated carbon-metal oxide nanocomposites under compression: a comparison study.  

PubMed

From a granular commercial activated carbon (AC) and six metal oxide (Al2O3, Fe2O3, SnO2, TiO2, WO3 and ZnO) precursors, two series of AC-metal oxide nanocomposites were prepared by wet impregnation, oven-drying at 120 °C, and subsequent heat treatment at 200 or 850 °C in an inert atmosphere. Here, the electrical conductivity of the resulting products was studied under moderate compression. The influence of the applied pressure, sample volume, mechanical work, and density of the hybrid materials was thoroughly investigated. The DC electrical conductivity of the compressed samples was measured at room temperature by the four-probe method. Compaction assays suggest that the mechanical properties of the nanocomposites are largely determined by the carbon matrix. Both the decrease in volume and the increase in density were relatively small and only significant at pressures lower than 100 kPa for AC and most nanocomposites. In contrast, the bulk electrical conductivity of the hybrid materials was strongly influenced by the intrinsic conductivity, mean crystallite size, content and chemical nature of the supported phases, which ultimately depend on the metal oxide precursor and heat treatment temperature. The supported nanoparticles may be considered to act as electrical switches either hindering or favouring the effective electron transport between the AC cores of neighbouring composite particles in contact under compression. Conductivity values as a rule were lower for the nanocomposites than for the raw AC, all of them falling in the range of semiconductor materials. With the increase in heat treatment temperature, the trend is toward the improvement of conductivity due to the increase in the crystallite size and, in some cases, to the formation of metals in the elemental state and even metal carbides. The patterns of variation of the electrical conductivity with pressure and mechanical work were slightly similar, thus suggesting the predominance of the pressure effects rather than the volume ones. PMID:25331935

Barroso-Bogeat, A; Alexandre-Franco, M; Fernández-González, C; Macías-García, A; Gómez-Serrano, V

2014-10-22

348

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

E-print Network

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

Walden, Troy Duane

2005-08-29

349

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

350

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.

351

Small tropical reservoirs and fish cage culture: a pilot study conducted in Machakos district, Kenya  

Microsoft Academic Search

The findings of this study provide useful insights into the key aspects of fish cage farming to be considered during setting\\u000a and overall management of multi-purpose water resources so as to maximise their aquacultural potential. The study was conducted\\u000a in Machakos District, Kenya, to characterise limnochemistry and algal composition of three small man-made reservoirs Ngeki,\\u000a Ngei and Kavovi, used for

Mary N. KaggwaDavid; David M. Liti; Michael Schagerl

352

Summary and analysis of neutron measurements conducted during the Oak Ridge personnel dosimetry intercomparison studies  

Microsoft Academic Search

Since 1974, neutron personnel dosimetry intercomparison studies (PDIS) have been conducted annually at the Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research Facility. During these studies, neutron dosimeters are mailed to ORNL, exposed to low-level (less than 15 mSv) dose equivalents in a variety of mixed-radiation fields produced using the Health Physics Research Reactor (HPRR), and then returned to the

Swaja

1987-01-01

353

A Study of the Conduct of Korean IT Participants in Ethical Decision Making  

Microsoft Academic Search

This study focuses upon IT participant’s conduct in Korea and their respective feelings which develop during the decision\\u000a making process under the guise of the Mason’s information ethics system, which relies upon a system of ethical decision making\\u000a based upon the principles of privacy, accuracy, property and accessibility. The definitive purpose of this study is to not\\u000a only investigate the

Kwang Hyung Kim

2003-01-01

354

Mechanism of thermal conductivity suppression in doped silicon studied with nonequilibrium molecular dynamics  

NASA Astrophysics Data System (ADS)

We examined the underlying mechanisms for thermal conductivity suppression in crystalline silicon by substitutional doping with different elements (X = boron, aluminum, phosphorus, and arsenic). In particular, the relative effects of doping-induced mass disorder, bond disorder, and lattice strain were assessed using nonequilibrium molecular dynamics simulations. Stillinger-Weber potential parameters for Si-X interatomic interactions were optimized by fitting to relevant atomic forces from first-principles calculations. We first calculated the thermal conductivity variation of B-doped Si as a function of dopant concentration; the result shows excellent agreement with existing experimental data, indicating the reliability of our force-field-based simulations. At the dopant concentration of about 5 × 1020 cm-3, the Si thermal conductivity value is predicted to be reduced from 137 W/mK at 300 K in undoped Si to 18/39/57/78 W/mK in As/B/P/Al-doped Si. Our study demonstrates that the mass disorder effect is primarily responsible for the thermal conductivity suppression in the As- and B-doped cases, whereas the bond disorder contribution is found to be more important than the mass disorder contribution in the Al- and P-doped cases; for all these systems, the lattice strain effect turns out to play a minor role in the reduction of lattice thermal conductivity.

Lee, Yongjin; Hwang, Gyeong S.

2012-08-01

355

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

PubMed

Three natural clayey soils from Tunisia were studied to assess their suitability for use as a liner for an acid waste disposal site. An investigation of the effect of the mineral composition and mechanical compaction on the hydraulic conductivity and fluoride and phosphate removal of three different soils is presented. The hydraulic conductivity of these three natural soils are 8.5 × 10(-10), 2.08 × 10(-9) and 6.8 × 10(-10)m/s for soil-1, soil-2 and soil-3, respectively. Soil specimens were compacted under various compaction strains in order to obtain three wet densities (1850, 1950 and 2050 kg/m(3)). In this condition, the hydraulic conductivity (k) was reduced with increasing density of sample for all soils. The test results of hydraulic conductivity at long-term (>200 days) using acidic waste solution (pH=2.7, charged with fluoride and phosphate ions) shows a decrease in k with time only for natural soil-1 and soil-2. However, the specimens of soil-2 compressed to the two highest densities (1950 and 2050 kg/m(3)) are cracked after 60 and 20 days, respectively, of hydraulic conductivity testing. This damage is the result of a continued increase in the internal stress due to the swelling and to the effect of aggressive wastewater. The analysis of anions shows that the retention of fluoride is higher compared to phosphate and soil-1 has the highest sorption capacity. PMID:22980909

Hamdi, Noureddine; Srasra, Ezzeddine

2013-01-01

356

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

NASA Technical Reports Server (NTRS)

Electrochemical studies indicate that poly(Isothianaphthene) or PITN, can be p-doped only. Electrochemical properties of PITN and Nafion-PITN in acetonitrile solutions containing tetra-phenyl Phosphonium chloride as supporting electrolyte are compared. In both cases, the electrochemical behavior of thin films are different from that of thick films. In addition, Nafion does not seem to alter the electrochemical properties of PITN. Cyclic voltammetric and chronocoulometric measurements were made to compute the diffusion coefficient of the counter ions. Electrochemical behavior of both PITN and Nafion-PITN in acetonitrile solution containing different counter ions are described. PITN, when electrochemically deposited, apparently neither passivates surface states present nor forms ohmic contacts with p-Si or p(+)Si single-crystal electrodes.

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

1987-01-01

357

Eating Disorder Diagnostic Scale: Additional Evidence of Reliability and Validity  

Microsoft Academic Search

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

Eric Stice; Melissa Fisher; Erin Martinez

2004-01-01

358

Daily physical activity assessment with accelerometers: new insights and validation studies.  

PubMed

The field of application of accelerometry is diverse and ever expanding. Because by definition all physical activities lead to energy expenditure, the doubly labelled water (DLW) method as gold standard to assess total energy expenditure over longer periods of time is the method of choice to validate accelerometers in their ability to assess daily physical activities. The aim of this paper was to provide a systematic overview of all recent (2007-2011) accelerometer validation studies using DLW as the reference. The PubMed Central database was searched using the following keywords: doubly or double labelled or labeled water in combination with accelerometer, accelerometry, motion sensor, or activity monitor. Limits were set to include articles from 2007 to 2011, as earlier publications were covered in a previous review. In total, 38 articles were identified, of which 25 were selected to contain sufficient new data. Eighteen different accelerometers were validated. There was a large variability in accelerometer output and their validity to assess daily physical activity. Activity type recognition has great potential to improve the assessment of physical activity-related health outcomes. So far, there is little evidence that adding other physiological measures such as heart rate significantly improves the estimation of energy expenditure. PMID:23398786

Plasqui, G; Bonomi, A G; Westerterp, K R

2013-06-01

359

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. PMID:21423458

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

2010-01-01

360

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. PMID:24860223

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

2014-01-01

361

[Collaboration between science and practice: experiences of conducting a nursing intervention study].  

PubMed

In a five-year intervention study about the impact of pre-operative mobilisation training session of patients receiving an elective medial laparotomy experiences about the collaboration between practice (University Hospital Ulm) and science (Hessian Institute of Nursing Research) were made. During the project possibilities and borders of clinical nursing research became clear. A research question based on practice experiences of nurses helps to develop and maintain motivation to conduct a study at a nursing unit. There was a lack of nursing knowledge to develop the best possible design, e.g. outcome criteria for mobilisation and standardized assessment instruments. The cooperation with other health care professionals (human movement science, statistics) was important and without difficulties. In Germany, without doctors' agreement and common application it is impossible to conduct nursing intervention studies in hospitals. It is necessary to train nursing specialists with both scientific and clinical competence to explore systematically clinical research questions. PMID:19750976

Panfil, Eva-Maria; Kirchner, Elisabeth; Bauder-Missbach, Heidi; Haasenritter, Jörg; Eisenschink, Anna Maria

2009-09-01

362

The development and validation of an urbanicity scale in a multi-country study  

PubMed Central

Background Although urban residence is consistently identified as one of the primary correlates of non-communicable disease in low- and middle-income countries, it is not clear why or how urban settings predispose individuals and populations to non-communicable disease (NCD), or how this relationship could be modified to slow the spread of NCD. The urban–rural dichotomy used in most population health research lacks the nuance and specificity necessary to understand the complex relationship between urbanicity and NCD risk. Previous studies have developed and validated quantitative tools to measure urbanicity continuously along several dimensions but all have been isolated to a single country. The purposes of this study were 1) To assess the feasibility and validity of a multi-country urbanicity scale; 2) To report some of the considerations that arise in applying such a scale in different countries; and, 3) To assess how this scale compares with previously validated scales of urbanicity. Methods Household and community-level data from the Young Lives longitudinal study of childhood poverty in 59 communities in Ethiopia, India and Peru collected in 2006/2007 were used. Household-level data include parents’ occupations and education level, household possessions and access to resources. Community-level data include population size, availability of health facilities and types of roads. Variables were selected for inclusion in the urbanicity scale based on inspection of the data and a review of literature on urbanicity and health. Seven domains were constructed within the scale: Population Size, Economic Activity, Built Environment, Communication, Education, Diversity and Health Services. Results The scale ranged from 11 to 61 (mean 35) with significant between country differences in mean urbanicity; Ethiopia (30.7), India (33.2), Peru (39.4). Construct validity was supported by factor analysis and high corrected item-scale correlations suggest good internal consistency. High agreement was observed between this scale and a dichotomized version of the urbanicity scale (Kappa 0.76; Spearman’s rank-correlation coefficient 0.84 (p?validity in all three countries (p?study demonstrates and validates a robust multidimensional, multi-country urbanicity scale. It is an important step on the path to creating a tool to assess complex processes like urbanization. This scale provides the means to understand which elements of urbanization have the greatest impact on health. PMID:22818019

2012-01-01

363

Reliability and Validity of the Wisconsin Card Sorting Test in Studies of Autism  

Microsoft Academic Search

Three studies were conducted with the Wisconsin Card Sorting Test (WCST) with autistic individuals. In Study 1, it was found that the traditional WCST is a highly reliable test for use with both autistic children and children with learning disabilities over time. In Study 2, the equivalence of the standard and computerized versions of the WCST was examined. Low-to-moderate alternate

Sally Ozonoff

1995-01-01

364

The assessment of imminent inpatient aggression: a validation study of the DASA-IV in Scotland  

Microsoft Academic Search

Inpatient aggression in psychiatric settings poses a serious management problem. This study reports the findings of a prospective pilot study on the Dynamic Appraisal of Situational Aggression – Inpatient Version (DASA-IV), a structured risk assessment tool for imminent aggression. The study was conducted in the State Hospital, the high secure psychiatric hospital for Scotland and Northern Ireland. The outcome data were aggressive

Gabriele Vojt; Lisa A. Marshall; Lindsay D. G. Thomson

2010-01-01

365

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.

366

Discriminant validity of the Medical Outcomes Study cognitive function scale in HIV disease patients  

Microsoft Academic Search

Human immunodeficiency virus (HIV) infection results in a chronic course of disease progression and eventual death. With this disease progression comes decreases in health-related quality of life and cognitive function in many patients. We evaluated the construct and discriminant validity of the Medical Outcomes Study four-item and six-item cognitive function scale in a sample of 162 patients with HIV disease.

D. A. Revicki; K. Chan; F. Gevirtz

1998-01-01

367

A Psychometric Study of the Adult Attachment Interview: Reliability and Discriminant Validity  

Microsoft Academic Search

The Adult Attachment Interview (AAI) stimulates Ss to retrieve and evaluate attachment-related autobiographical memories and has increasingly been used to predict the quality of parent–child interactions and infant–parent attachment relationships. Its reliability and discriminant validity, however, have not yet been examined. In this study, 83 mothers were interviewed twice, 2 months apart, by different interviewers so that the instrument's test–retest

Marian J. Bakermans-Kranenburg; Marinus H. van IJzendoorn

1993-01-01

368

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

E-print Network

on the MASP and Harter Scales, 12 Correlations among Adolescent, Peer, Parent, and 2 Teacher Reports on the MASP Subscales . 14 Correlations between Self, Peer, Parent, and Teacher 3 Reports on the MASP and Harter Scales. . . . . 17 INTRODUCTION..., the MASP's validity was assessed with respect to demographic variables, teacher ratings of peer acceptance, and self-ratings of parent-adolescent conflict. In the second study, the association between the MASP and three aspects of adolescent social...

King, Sonia Rachelle

2012-06-07

369

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

Microsoft Academic Search

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

Allan I. Abrams; Larry M. Siegel

1978-01-01

370

National Validation Study of a Cellulose Sponge Wipe-Processing Method for Use after Sampling Bacillus anthracis Spores from Surfaces ?  

PubMed Central

This work was initiated to address the gaps identified by Congress regarding validated biothreat environmental sampling and processing methods. Nine Laboratory Response Network-affiliated laboratories participated in a validation study of a cellulose sponge wipe-processing protocol for the recovery, detection, and quantification of viable Bacillus anthracis Sterne spores from steel surfaces. Steel coupons (645.16 cm2) were inoculated with 1 to 4 log10 spores and then sampled with cellulose sponges (Sponge-Stick; 3M, St. Paul, MN). Surrogate dust and background organisms were added to the sponges to mimic environmental conditions. Labs processed the sponges according to the provided protocol. Sensitivity, specificity, and mean percent recovery (%R), between-lab variability, within-lab variability, and total percent coefficient of variation were calculated. The mean %R (standard error) of spores from the surface was 32.4 (4.4), 24.4 (2.8), and 30.1 (2.3) for the 1-, 2-, and 4-log10 inoculum levels, respectively. Sensitivities for colony counts were 84.1%, 100%, and 100% for the 1-, 2-, and 4-log10 inocula, respectively. These data help to characterize the variability of the processing method and thereby enhance confidence in the interpretation of the results of environmental sampling conducted during a B. anthracis contamination investigation. PMID:21965403

Rose, Laura J.; Hodges, Lisa; O'Connell, Heather; Noble-Wang, Judith

2011-01-01

371

Feasibility study to conduct windblown sediment experiments aboard a space station  

NASA Technical Reports Server (NTRS)

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

Greeley, R.; Iversen, J. D.

1983-01-01

372

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

PubMed Central

Objective To test the factorial validity and measurement equivalence/invariance of scales used to measure processes of change derived from the Transtheoretical Model (TTM) applied to physical activity. Methods Confirmatory factor analysis of questionnaire responses obtained from a diverse sample (N=1,429) of students enrolled in the Training Interventions and Genetics of Exercise Response (TIGER) Study at the University of Houston during academic years 2004–2005 through 2007–2008. Cohorts of students (N=1,163) completed the scales at the beginning and end of each Fall semester, permitting longitudinal analysis. Results Theoretically and statistically sound models were developed that support the factorial validity of nine of the ten hypothesized 1st-order factors. A structure of nine correlated 1st order factors or a hierarchical structure of those factors subordinate to two correlated 2nd-order factors were each defensible. Multi-group invariance of each model was confirmed across race/ethnicity groups (African American, Hispanic, non-Hispanic White), gender, age, BMI levels, employment status, physical activity level, and study adherence. Longitudinal invariance across the semester was also confirmed. Conclusion The scores from the scales provide valid assessments that can be used in observational studies of naturally occurring change or in interventions designed to test the usefulness of TTM processes as mediators of change in physical activity among college students. Item content and factor structure require further evaluation in other samples in order to advance TTM theory applied to physical activity. PMID:20734174

Jackson, Andrew S.; Bray, Molly S.

2011-01-01

373

How well do adolescents recall use of mobile telephones? Results of a validation study  

PubMed Central

Background In the last decade mobile telephone use has become more widespread among children. Concerns expressed about possible health risks have led to epidemiological studies investigating adverse health outcomes associated with mobile telephone use. Most epidemiological studies have relied on self reported questionnaire responses to determine individual exposure. We sought to validate the accuracy of self reported adolescent mobile telephone use. Methods Participants were recruited from year 7 secondary school students in Melbourne, Australia. Adolescent recall of mobile telephone use was assessed using a self administered questionnaire which asked about number and average duration of calls per week. Validation of self reports was undertaken using Software Modified Phones (SMPs) which logged exposure details such as number and duration of calls. Results A total of 59 adolescents participated (39% boys, 61% girls). Overall a modest but significant rank correlation was found between self and validated number of voice calls (? = 0.3, P = 0.04) with a sensitivity of 57% and specificity of 66%. Agreement between SMP measured and self reported duration of calls was poorer (? = 0.1, P = 0.37). Participants whose parents belonged to the 4th socioeconomic stratum recalled mobile phone use better than others (? = 0.6, P = 0.01). Conclusion Adolescent recall of mobile telephone use was only modestly accurate. Caution is warranted in interpreting results of epidemiological studies investigating health effects of mobile phone use in this age group. PMID:19523193

2009-01-01

374

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

SciTech Connect

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

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

2012-12-15

375

Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol  

PubMed Central

Background The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas. PMID:20487532

2010-01-01

376

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

ERIC Educational Resources Information Center

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

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

2007-01-01

377

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

NASA Astrophysics Data System (ADS)

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

Zou, Ling

378

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

PubMed

Recently, there has been considerable interest in the use of nanofluids for enhancing thermal performance. It has been shown that carbon nanotubes (CNTs) are capable of enhancing the thermal performance of conventional working liquids. Although much work has been devoted on the impact of CNT concentrations on the thermo-physical properties of nanofluids, the effects of preparation methods on the stability, thermal conductivity and viscosity of CNT suspensions are not well understood. This study is focused on providing experimental data on the effects of ultrasonication, temperature and surfactant on the thermo-physical properties of multi-walled carbon nanotube (MWCNT) nanofluids. Three types of surfactants were used in the experiments, namely, gum arabic (GA), sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS). The thermal conductivity and viscosity of the nanofluid suspensions were measured at various temperatures. The results showed that the use of GA in the nanofluid leads to superior thermal conductivity compared to the use of SDBS and SDS. With distilled water as the base liquid, the samples were prepared with 0.5 wt.% MWCNTs and 0.25% GA and sonicated at various times. The results showed that the sonication time influences the thermal conductivity, viscosity and dispersion of nanofluids. The thermal conductivity of nanofluids was typically enhanced with an increase in temperature and sonication time. In the present study, the maximum thermal conductivity enhancement was found to be 22.31% (the ratio of 1.22) at temperature of 45°C and sonication time of 40 min. The viscosity of nanofluids exhibited non-Newtonian shear-thinning behaviour. It was found that the viscosity of MWCNT nanofluids increases to a maximum value at a sonication time of 7 min and subsequently decreases with a further increase in sonication time. The presented data clearly indicated that the viscosity and thermal conductivity of nanofluids are influenced by the sonication time. Image analysis was carried out using TEM in order to observe the dispersion characteristics of all samples. The findings revealed that the CNT agglomerates breakup with increasing sonication time. At high sonication times, all agglomerates disappear and the CNTs are fragmented and their mean length decreases. PMID:24678607

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

2014-01-01

379

A novel way to conduct human studies and do some good  

Microsoft Academic Search

In this paper the authors describe a novel way to conduct large-scale human studies achieving the maximum outreach and impact with the minimum cost. An iPhone health application, 'Walk n' Play', was developed and released for free in the App Store. The application measures calories spent due to walking activities through the iPhone's accelerometer. It is a real-time awareness tool

Pradeep Buddharaju; Yuichi Fujiki; Ioannis Pavlidis; Ergun Akleman

2010-01-01

380

The heritability of the skin conductance orienting response: A longitudinal twin study  

Microsoft Academic Search

The orienting response is a widely used experimental paradigm that reflects the association between electrodermal activity and psychological processes. The present study examined the genetic and environmental etiology of skin conductance orienting response (SCOR) magnitude in a sample of twins assessed at ages 9–10, 11–13 and 14–16 years. Structural equation modeling at each visit showed that genetic influences explained 56%,

Catherine Tuvblad; Yu Gao; Joshua Isen; Theodore Botwick; Adrian Raine; Laura A. Baker

381

A study of single-crystal silicon diodes integrated on flexible substrates using conductive adhesives  

NASA Astrophysics Data System (ADS)

In this study, we investigated the possibility of fabricating flexible single-crystal Si-Pd diodes on polymer substrates using silver-filled conductive tape or epoxy. This simple technique mitigates the complexity of process-intensive metal-bonding schemes to achieve backside electrical contacts on semiconductor devices. The performance of such devices is evaluated while bent to a 1.2 cm radius of curvature. The longer-term stability of the devices fabricated is also briefly discussed.

Doran, C.; Chen, W.; Alford, T. L.; Lau, S. S.

2012-02-01

382

Solid Polymer Electrolytes Based on Methylcellulose: FT-IR and Ionic Conductivity Studies  

Microsoft Academic Search

Polymer electrolytes of methylcellulose (MC) as the polymer host and ammonium fluoride (NH4F) as a dopant were prepared by the solution casting technique. Fourier Transform-infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) were used to study the complexation between the salt and polymer. The highest ionic conductivity value was found to be 6.40 × 10 Scm at room temperature (303 K) for sample AF-18. The

N. A. Nik Aziz; N. K. Idris; M. I. N. Isa

2010-01-01

383

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

PubMed Central

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

2013-01-01

384

Studies and projections of hydraulic conductivity of Devonian Plavinu and Daugava carbonate aquifers in Latvia  

NASA Astrophysics Data System (ADS)

Carbonate aquifers show a very wide range of hydrogeological characteristics. Carbonate rock hydrogeology display two extremes: on one hand hydrogeological properties of the carbonates are governed by the pathways of the preferential groundwater flow typical in karstic regions, on the other - some carbonate aquifers behave almost like a homogeneous, isotropic, porous medium. Most lie between these extremes, but these case variations complicates the study of carbonate aquifer properties. In this study the results of the hydraulic conductivity in carbonate aquifers measurements, hydraulic conductivity correlation between sediments lithology and the aquifer surface depth and fractures research is presented. Upper Devonian Frasnian stage P?avi?u and Daugava carbonate aquifers in the Latvian part of the Baltic basin is considered. The aim of this research is to elaborate characteristic hydraulic conductivity values for each aquifer based on existing data of the pumping test results and other aquifer properties. P?avi?u and Daugava carbonate aquifers mainly consist of jointed dolomite with intermediate layers of dolomitic marlstone, limestone, clays and gypsum. These aquifers are prevalent in most of the study area, except Northern and South - Eastern parts of the territory. In geological structure Daugava aquifer lies above P?avi?u aquifer. Daugava aquifer depth changes from 10 - 20 and even less meters in Eastern part to 250 - 300 m in South - West part of study area, but thickness varies from few meters to 30 m. P?avi?u aquifer surface depth varies from 20 - 30 m, but in uplands surface depth reaches more than 120 m, in Eastern part to more than 300 m in South - West part of study area. Aquifer average thickness varies from 20 - 40 m, but in areas with buried valleys thickness can be less than 10 meters. Outcrops of these sediments are occurring in banks of largest rivers and in some areas aquifers are karstified. In studies of the carbonate aquifers it is very important to take into account the fact that groundwater flow in carbonate aquifers is often almost entirely dependent on jointing and concomitant joint enlargement by dissolution. In this study pumping test results provide a wide range of hydraulic conductivity values, for example in P?avi?u aquifer hydraulic conductivity varies from 0,03 - 266 m/day but in Daugava aquifer values range from 0,06 - 735 m/day. Pumping test results is provided by Latvian Environment, Geology and Meteorology Centre. Studying average values of hydraulic conductivity there exists a correlation between K and aquifer flat depth - Daugava aquifer, which in geological structure, is located above the P?avi?u aquifer has higher average K value - 32 m/day, in P?avi?u aquifer - 27 m/day. Correlative study of the depth and hydraulic conductivity allowed to characterize the mean values as function of the aquifer depth for the regional groundwater flow modelling. This study is supported by the European Social Fund project No. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060

Perkone, E.; Delina, A.; Saks, T.; Raga, B.; J?tnieks, J.; Klints, I.; Popovs, K.; Babre, A.; Bikše, J.; Kalv?ns, A.; Retike, I.; Ukass, J.

2012-04-01

385

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

PubMed

Three validation studies were conducted by the Japanese Society for Alternatives to Animal Experiments in order to assess the performance of a skin irritation assay using reconstructed human epidermis (RhE) LabCyte EPI-MODEL24 (LabCyte EPI-MODEL24 SIT) developed by the Japan Tissue Engineering Co., Ltd. (J-TEC), and the results of these studies were submitted to the Organisation for Economic Co-operation and Development (OECD) for the creation of a Test Guideline (TG). In the summary review report from the OECD, the peer review panel indicated the need to resolve an issue regarding the misclassification of 1-bromohexane. To this end, a rinsing operation intended to remove exposed chemicals was reviewed and the standard operating procedure (SOP) revised by J-TEC. Thereafter, in order to confirm general versatility of the revised SOP, a new validation management team was organized by the Japanese Center for the Validation of Alternative Methods (JaCVAM) to undertake a catch-up validation study that would compare the revised assay with similar in vitro skin irritation assays, per OECD TG No. 439 (2010). The catch-up validation and supplementary studies for LabCyte EPI-MODEL24 SIT using the revised SOPs were conducted at three laboratories. These results showed that the revised SOP of LabCyte EPI-MODEL24 SIT conformed more accurately to the classifications for skin irritation under the United Nations Globally Harmonised System of Classification and Labelling of Chemicals (UN GHS), thereby highlighting the importance of an optimized rinsing operation for the removal of exposed chemicals in obtaining consistent results from in vitro skin irritation assays. PMID:24122860

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

2014-07-01

386

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

SciTech Connect

Enhanced software methodology and improved computing hardware have advanced the state of simulation technology to a point where large physics-based codes can be a major contributor in many systems analyses. This shift toward the use of computational methods has brought with it new research challenges in a number of areas including characterization of uncertainty, model validation, and the analysis of computer output. It is these challenges that have motivated the work described in this report. Approaches to and methods for model validation and (model-based) prediction have been developed recently in the engineering, mathematics and statistical literatures. In this report we have provided a fairly detailed account of one approach to model validation and prediction applied to an analysis investigating thermal decomposition of polyurethane foam. A model simulates the evolution of the foam in a high temperature environment as it transforms from a solid to a gas phase. The available modeling and experimental results serve as data for a case study focusing our model validation and prediction developmental efforts on this specific thermal application. We discuss several elements of the ''philosophy'' behind the validation and prediction approach: (1) We view the validation process as an activity applying to the use of a specific computational model for a specific application. We do acknowledge, however, that an important part of the overall development of a computational simulation initiative is the feedback provided to model developers and analysts associated with the application. (2) We utilize information obtained for the calibration of model parameters to estimate the parameters and quantify uncertainty in the estimates. We rely, however, on validation data (or data from similar analyses) to measure the variability that contributes to the uncertainty in predictions for specific systems or units (unit-to-unit variability). (3) We perform statistical analyses and hypothesis tests as a part of the validation step to provide feedback to analysts and modelers. Decisions on how to proceed in making model-based predictions are made based on these analyses together with the application requirements. Updating modifying and understanding the boundaries associated with the model are also assisted through this feedback. (4) We include a ''model supplement term'' when model problems are indicated. This term provides a (bias) correction to the model so that it will better match the experimental results and more accurately account for uncertainty. Presumably, as the models continue to develop and are used for future applications, the causes for these apparent biases will be identified and the need for this supplementary modeling will diminish. (5) We use a response-modeling approach for our predictions that allows for general types of prediction and for assessment of prediction uncertainty. This approach is demonstrated through a case study supporting the assessment of a weapons response when subjected to a hydrocarbon fuel fire. The foam decomposition model provides an important element of the response of a weapon system in this abnormal thermal environment. Rigid foam is used to encapsulate critical components in the weapon system providing the needed mechanical support as well as thermal isolation. Because the foam begins to decompose at temperatures above 250 C, modeling the decomposition is critical to assessing a weapons response. In the validation analysis it is indicated that the model tends to ''exaggerate'' the effect of temperature changes when compared to the experimental results. The data, however, are too few and to restricted in terms of experimental design to make confident statements regarding modeling problems. For illustration, we assume these indications are correct and compensate for this apparent bias by constructing a model supplement term for use in the model-based predictions. Several hypothetical prediction problems are created and addressed. Hypothetical problems are used because no guidance was provided concern

Dowding, Kevin J.; Rutherford, Brian Milne

2003-07-01

387

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

Cancer.gov

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

388

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

PubMed Central

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

2013-01-01

389

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

PubMed

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

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

2014-02-01

390

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

NASA Technical Reports Server (NTRS)

The Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure (ITP) Validation Simulation Study investigated the viability of an ITP designed to enable oceanic flight level changes that would not otherwise be possible. Twelve commercial airline pilots with current oceanic experience flew a series of simulated scenarios involving either standard or ITP flight level change maneuvers and provided subjective workload ratings, assessments of ITP validity and acceptability, and objective performance measures associated with the appropriate selection, request, and execution of ITP flight level change maneuvers. In the majority of scenarios, subject pilots correctly assessed the traffic situation, selected an appropriate response (i.e., either a standard flight level change request, an ITP request, or no request), and executed their selected flight level change procedure, if any, without error. Workload ratings for ITP maneuvers were acceptable and not substantially higher than for standard flight level change maneuvers, and, for the majority of scenarios and subject pilots, subjective acceptability ratings and comments for ITP were generally high and positive. Qualitatively, the ITP was found to be valid and acceptable. However, the error rates for ITP maneuvers were higher than for standard flight level changes, and these errors may have design implications for both the ITP and the study's prototype traffic display. These errors and their implications are discussed.

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

2008-01-01

391

Ride qualities criteria validation/pilot performance study: Flight simulator results  

NASA Technical Reports Server (NTRS)

Pilot performance was studied during simulated manual terrain following flight for ride quality criteria validation. An existing B-1 simulation program provided the data for these investigations. The B-1 simulation program included terrain following flights under varying controlled conditions of turbulence, terrain, mission length, and system dynamics. The flight simulator consisted of a moving base cockpit which reproduced motions due to turbulence and control inputs. The B-1 aircraft dynamics were programmed with six-degrees-of-freedom equations of motion with three symmetric and two antisymmetric structural degrees of freedom. The results provided preliminary validation of existing ride quality criteria and identified several ride quality/handling quality parameters which may be of value in future ride quality/criteria development.

Nardi, L. U.; Kawana, H. Y.; Borland, C. J.; Lefritz, N. M.

1976-01-01

392

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

393

An experimental study of characteristic combustion-driven flows for CFD validation  

NASA Technical Reports Server (NTRS)

The application of laser-based diagnostic techniques has become commonplace to a wide variety of combustion problems. New insights into combustion phenomena at a level previously unattainable has been made possible by non-intrusive measurements of velocity, temperature, and species. However, due to the adverse conditions which exist inside rocket engines, relatively few studies have addressed these combustion environments. The high pressure, high speed, combusting environment in a rocket engine prohibits the application of several measurement techniques. However, in the rocket community, there is a critical need for rocket flow field data to validate computational fluid dynamic (CFD) codes. Currently at Penn State, there is an effort to obtain flowfield measurements inside a rocket engine. Velocity measurements have been made inside the combustion chamber of a uni-element (shear coaxial injector) optically accessible rocket chamber at several axial locations downstream of the injector. These measurements, combined with future measurements, will provide benchmark data for CFD code validation.

Pal, S.; Merenich, J. J.; Moser, M. D.; Santoro, R. J.

1993-01-01

394

Measures of perceived social support from friends and from family: three validation studies.  

PubMed

Three studies are described in which measures of perceived social support from friends (PSS-Fr) and from family (PSS-Fa) were developed and validated. The PSS measures were internally consistent and appeared to measure valid constructs that were separate from each other and from network measures. PSS-Fr and PSS-Fa were both inversely related to symptoms of distress and psychopathology but the relationship was stronger for PSS-Fa. PSS-Fr was more closely related to social competence. PSS-Fa was unaffected by either positive or negative mood states (self-statements), but the reporting of PSS-Fr was lowered by negative mood states. High PSS-Fr subjects were significantly lower in trait anxiety and talked about themselves more to friends and sibs than low PSS-Fr subjects. Low PSS-Fa subjects showed marked verbal inhibition with sibs. PMID:6837532

Procidano, M E; Heller, K

1983-02-01

395

The IASPEI Reference Event List to Support 3D Velocity Model Validation Studies  

NASA Astrophysics Data System (ADS)

The IASPEI Reference Event List (Ground Truth database) maintained and hosted by the International Seismological Centre (ISC) on behalf of the IASPEI became an indispensable tool for the validation of 3D seismic velocity models. The Ground Truth database is regularly updated and currently consists of some 7,600 GT0-5 events (earthquakes, chemical and nuclear explosions). Recently the CTBTO has launched a global initiative to facilitate the development of the Regional Seismic Travel Time (RSTT) velocity model on a global scale by forming regional expert groups. We make a concentrated effort to increase the number and the coverage of ground truth events in Latin America. To further support the RSTT development and validation studies, the ISC has developed a version of its location software to accommodate local and regional travel-time predictions provided by the RSTT software package. The RSTT-enabled ISC locator is made available through the ISC website.

Bondar, I.; Storchak, D. A.

2013-05-01

396

A family smoking index to capture genetic influence in smoking: rationale and two validation studies.  

PubMed

Despite a growing appreciation that genetic factors may impart vulnerability toward smoking behavior, only a modest consensus has been created about the specific genetic mechanisms that may underlie various aspects of smoking. A core feature of genetic contribution toward any complex human behavior is familial resemblance. Most previous attempts to index familial smoking have classified individuals into discrete categories, based on the number of smokers in a family. We discuss the development of a continuous measure of familial smoking, the Family Smoking Index (FSI), which is based on the proportion of smokers in first- and second-degree family members and provides a more precise weighting according to genetic proximity. We present the psychometric characteristics of the FSI as well as initial validation data from two studies. We also describe current and future directions for continued FSI validation and application. PMID:15804676

Drobes, David J; Munafò, Marcus R; Leigh, Fiona; Saladin, Michael E

2005-02-01

397

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

PubMed Central

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

2013-01-01

398

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

NASA Astrophysics Data System (ADS)

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

Limouny, L.; Kaaouachi, A. El; Idrissi, H. El; Zatni, A.; Tata, O.; Daoudi, E.; Errai, M.; Dlimi, S.

2014-01-01

399

Parameterization of rain induced surface roughness and its validation study using a third generation wave model  

NASA Astrophysics Data System (ADS)

The effect of raindrops striking water surface and their role in modifying the prevailing sea-surface roughness is investigated. The work presents a new theoretical formulation developed to study rain-induced stress on sea-surface based on dimensional analysis. Rain parameters include drop size, rain intensity and rain duration. The influences of these rain parameters on young and mature waves were studied separately under varying wind speeds, rain intensity and rain duration. Contrary to popular belief that rain only attenuates surface waves, this study also points out rain duration under certain condition can contribute to wave growth at high wind speeds. Strong winds in conjunction with high rain intensity enhance the horizontal stress component on the sea-surface, leading to wave growth. Previous studies based on laboratory experiments and dimensional analysis do not account for rain duration when attempting to parameterize sea-surface roughness. This study signifies the importance of rain duration as an important parameter modifying sea-surface roughness. Qualitative as well quantitative support for the developed formulation is established through critical validation with reports of several researchers and satellite measurements for an extreme cyclonic event in the Indian Ocean. Based on skill assessment, it is suggested that the present formulation is superior to prior studies. Numerical experiments and validation performed by incorporating in state-of-art WAM wave model show the importance of treating rain-induced surface roughness as an essential pre-requisite for ocean wave modeling studies.

Rajesh Kumar, R.; Prasad Kumar, B.; Bala Subrahamanyam, D.

2009-09-01

400

Assessing the validity of road safety evaluation studies by analysing causal chains.  

PubMed

This paper discusses how the validity of road safety evaluation studies can be assessed by analysing causal chains. A causal chain denotes the path through which a road safety measure influences the number of accidents. Two cases are examined. One involves chemical de-icing of roads (salting). The intended causal chain of this measure is: spread of salt --> removal of snow and ice from the road surface --> improved friction --> shorter stopping distance --> fewer accidents. A Norwegian study that evaluated the effects of salting on accident rate provides information that describes this causal chain. This information indicates that the study overestimated the effect of salting on accident rate, and suggests that this estimate is influenced by confounding variables the study did not control for. The other case involves a traffic club for children. The intended causal chain in this study was: join the club --> improve knowledge --> improve behaviour --> reduce accident rate. In this case, results are rather messy, which suggests that the observed difference in accident rate between members and non-members of the traffic club is not primarily attributable to membership in the club. The two cases show that by analysing causal chains, one may uncover confounding factors that were not adequately controlled in a study. Lack of control for confounding factors remains the most serious threat to the validity of road safety evaluation studies. PMID:12850075

Elvik, Rune

2003-09-01

401

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

ERIC Educational Resources Information Center

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

Tyson, Edgar H.; Glisson, Charles

2005-01-01

402

Electrical conductivity studies on discotic liquid crystal-ferrocenium donor-acceptor systems.  

PubMed

The dispersion of electron-deficient ferrocenium ions was studied in the electron-rich media of two different triphenylene-based columnar hexagonal liquid-crystalline phases. These composites were characterized using polarizing optical micrography (POM), differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), visible absorption spectroscopy, and dc and ac conductivity measurements. It was found that these composites form donor-acceptor systems that enhance the quasi-one-dimensional conductivity of the discotic system without altering the hexagonal columnar mesophase. The absorbance spectra confirm the formation of a charge-transfer complex between the electron-rich discotic molecules and the electron-deficient ferrocenium ions. PMID:18373371

Kumar, P Suresh; Kumar, Sandeep; Lakshminarayanan, V

2008-04-24

403

Nerve conduction studies in chickens given phenyl saligenin phosphate and corticosterone.  

PubMed

Clinical signs of delayed neuropathy were induced in adult white leghorn chickens given the organophosphorus ester phenyl saligenin phosphate (PSP, 2.5 mg/kg im) 22-24 d before assessment of nerve conduction parameters. Damage to the myelinated sensory portion of the sciatic nerve was indicated by abnormal compound action potentials in treated chickens. In particular, the amplitude of the A beta response was markedly reduced. In addition, the A beta fibers did not respond normally to increasing stimulation intensity. These parameters were more like controls in chickens that had been given PSP and 30 ppm corticosterone for 11 d, beginning 1 d before PSP administration. These studies indicated that nerve conduction parameters could distinguish peripheral nerve damage in chickens given PSP and improvement could be noted in chickens treated with corticosterone. PMID:2299688

Lidsky, T I; Manetto, C; Ehrich, M

1990-01-01

404

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

PubMed

Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by inattention, excessive motor activity, impulsivity, and distractibility. Individuals with ADHD have significant impairment in family and peer relations, academic functioning, and show high co-morbidity with a wide range of psychiatric disorders including oppositional defiant disorder (ODD), conduct disorder (CD), anxiety disorder, depression, substance abuse, and pervasive developmental disorder (PDD). Family studies suggest that ADHD + CD represents a specific subtype of the ADHD disorder with familial risk factors only partly overlapping with those of ADHD alone. We performed a hypothesis-free analysis of the GAIN-ADHD sample to identify markers and genes important in the development of conduct problems in a European cohort of individuals with ADHD. Using the Family-Based Association Test (FBAT) package we examined three measures of conduct problems in 1,043,963 autosomal markers. This study is part of a series of exploratory analyses to identify candidate genes that may be important in ADHD and ADHD-related traits, such as conduct problems. We did not find genome-wide statistical significance (P < 5 x 10(-7)) for any of the tested markers and the three conduct problem traits. Fifty-four markers reached strong GWA signals (P < 10(-5)). We discuss these findings in the context of putative candidate genes and the implications of these findings in the understanding of the etiology of ADHD + CD. We aimed to achieve insight into the genetic etiology of a trait using a hypothesis-free study design and were able to identify a number of biologically interesting markers and genes for follow-up studies. PMID:18951430

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

2008-12-01

405

Organizing and Conducting a County Social Studies Fair: A Guide for Coordinators [and] West Virginia Social Studies Fair: Judges' Handbook.  

ERIC Educational Resources Information Center

This document contains a guide for coordinators and a brief handbook for judges. The coordinator's guide outlines nine steps for organizing and conducting a county social studies fair. Designed for elementary and secondary schools, the focus of the fair is student centered. Students choose topics of personal interest (usually a problem, issue,…

McCue, Lydia L.; Notter, Jane

406

Childhood conduct disorder trajectories, prior risk factors and cannabis use at age 16: birth cohort study  

PubMed Central

AimsTo investigate the prevalence of cannabis use and problem use in boys and girls at age 16 years, and to investigate the role of adversity in early life and of conduct disorder between the ages of 4 and 13 years as risk factors for these outcomes. DesignBirth cohort study. SettingEngland. ParticipantsA total of 4159 (2393 girls) participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort providing information on cannabis use at age 16. MeasurementsCannabis use and problem cannabis use at age 16 were assessed by postal questionnaire. Material adversity, maternal substance use, maternal mental health and child conduct disorder were all assessed by maternal report. FindingsCannabis use was more common among girls than boys (21.4% versus 18.3%, P?=?0.005). Problem cannabis use was more common in boys than girls (3.6% versus 2.8%, P?=?0.007). Early-onset persistent conduct problems were associated strongly with problem cannabis use [odds ratio (OR)?=?6.46, 95% confidence interval (CI)?=?4.06–10.28]. Residence in subsidized housing (OR?=?3.10, 95% CI?=?1.95, 4.92); maternal cannabis use (OR 8.84, 95% CI 5.64–13.9) and any maternal smoking in the postnatal period (OR?=?2.69, 95% CI?=?1.90–3.81) all predicted problem cannabis use. Attributable risks for adolescent problem cannabis use associated with the above factors were 25, 13, 17 and 24%, respectively. ConclusionsMaternal smoking and cannabis use, early material disadvantage and early-onset persistent conduct problems are important risk factors for adolescent problem cannabis use. This may have implications for prevention. PMID:23734913

Heron, Jon; Barker, Edward D; Joinson, Carol; Lewis, Glyn; Hickman, Matthew; Munafo, Marcus; Macleod, John

2013-01-01

407

Impedance study of tea with added taste compounds using conducting polymer and metal electrodes.  

PubMed

In this study the sensing capabilities of a combination of metals and conducting polymer sensing/working electrodes for tea liquor prepared by addition of different compounds using an impedance mode in frequency range 1 Hz-100 KHz at 0.1 V potential has been carried out. Classification of six different tea liquor samples made by dissolving various compounds (black tea liquor + raw milk from milkman), (black tea liquor + sweetened clove syrup), (black tea liquor + sweetened ginger syrup), (black tea liquor + sweetened cardamom syrup), (black tea liquor + sweet chocolate syrup) and (black tea liquor + vanilla flavoured milk without sugar) using six different working electrodes in a multi electrode setup has been studied using impedance and further its PCA has been carried out. Working electrodes of Platinum (Pt), Gold (Au), Silver (Ag), Glassy Carbon (GC) and conducting polymer electrodes of Polyaniline (PANI) and Polypyrrole (PPY) grown on an ITO surface potentiostatically have been deployed in a three electrode set up. The impedance response of these tea liquor samples using number of working electrodes shows a decrease in the real and imaginary impedance values presented on nyquist plots depending upon the nature of the electrode and amount of dissolved salts present in compounds added to tea liquor/solution. The different sensing surfaces allowed a high cross-selectivity in response to the same analyte. From Principal Component Analysis (PCA) plots it was possible to classify tea liquor in 3-4 classes using conducting polymer electrodes; however tea liquors were well separated from the PCA plots employing the impedance data of both conducting polymer and metal electrodes. PMID:23035436

Dhiman, Mopsy; Kapur, Pawan; Ganguli, Abhijit; Singla, Madan Lal

2012-09-01

408

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

ERIC Educational Resources Information Center

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

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

2010-01-01

409

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

ERIC Educational Resources Information Center

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

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

2003-01-01

410

Validity of the self reporting questionnaire-20 in epidemiological studies with older adults  

Microsoft Academic Search

Background  This study examined the validity of the self-reporting questionnaire (SRQ-20) in a population-based survey with older adults\\u000a in Sao Paulo, Brazil.\\u000a \\u000a \\u000a \\u000a Method  The study sample consisted of 2,008 individuals aged 65 years or more who were living in an economically disadvantaged area\\u000a of the city. The geriatric mental state (GMS) was used as the gold standard for the assessment of common mental

Marcia Scazufca; Paulo R. Menezes; Homero Vallada; Ricardo Araya

2009-01-01

411

Model Reduction, Validation, and Calibration of Wind Power Plants for Dynamic Studies  

SciTech Connect

Accurate representation of wind power plants (WPP) in both offline and online power system stability studies has gained importance because of the rapid increase in installation of wind generation around the world. On the other hand, reduced WPP representation is preferred due to computational efficiency. To improve the accuracy, other authors have proposed changes in structure of the reduced model for large WPPs. The use of model validation and calibration is an alternative to improve the accuracy of the reduced WPP model. In this paper, we compare accuracy improvements brought by changes in model structure with accuracy improvements brought by validation and calibration of the reduced WPP model with minimal changes in structure. We illustrate our findings using a 168-machine WPP connected to the IEEE-39-bus test system. The parameters of the reduced WPP model are either calculated with current equivalencing techniques or validated and calibrated against a more accurate model. The changes in structure of the reduced model are 1-machine or 2-machine reduced models connected with a 1-line or 2-line collector equivalents. We show that the most accurate response is obtained by calibrating the parameters of the reduced model with minimum changes in structure.

Elizondo, Marcelo A.; Lu, Shuai; Zhou, Ning; Samaan, Nader A.

2011-10-10

412

Study on rapid valid acidity evaluation of apple by fiber optic diffuse reflectance technique  

NASA Astrophysics Data System (ADS)

Some issues related to nondestructive evaluation of valid acidity in intact apples by means of Fourier transform near infrared (FTNIR) (800-2631nm) method were addressed. A relationship was established between the diffuse reflectance spectra recorded with a bifurcated optic fiber and the valid acidity. The data were analyzed by multivariate calibration analysis such as partial least squares (PLS) analysis and principal component regression (PCR) technique. A total of 120 Fuji apples were tested and 80 of them were used to form a calibration data set. The influence of data preprocessing and different spectra treatments were also investigated. Models based on smoothing spectra were slightly worse than models based on derivative spectra and the best result was obtained when the segment length was 5 and the gap size was 10. Depending on data preprocessing and multivariate calibration technique, the best prediction model had a correlation efficient (0.871), a low RMSEP (0.0677), a low RMSEC (0.056) and a small difference between RMSEP and RMSEC by PLS analysis. The results point out the feasibility of FTNIR spectral analysis to predict the fruit valid acidity non-destructively. The ratio of data standard deviation to the root mean square error of prediction (SDR) is better to be less than 3 in calibration models, however, the results cannot meet the demand of actual application. Therefore, further study is required for better calibration and prediction.

Liu, Yande; Ying, Yibin; Fu, Xiaping; Jiang, Xuesong

2004-03-01

413

Feasibility study of a swept frequency electromagnetic probe (SWEEP) using inductive coupling for the determination of subsurface conductivity of the earth and water prospecting in arid regions  

NASA Technical Reports Server (NTRS)

Techniques developed for electromagnetic probing of the lunar interior, and techniques developed for the generation of high power audio frequencies were combined to make practical a magnetic inductive coupling system for the rapid measurement of ground conductivity profiles which are helpful when prospecting for the presence and quality of subsurface water. A system which involves the measurement of the direction, intensity, and time phase of the magnetic field observed near the surface of the earth at a distance from a horizontal coil energized so as to create a field that penetrates the earth was designed and studied to deduce the conductivity and stratification of the subsurface. Theoretical studies and a rudimentary experiment in an arid region showed that the approach is conceptually valid and that this geophysical prospecting technique can be developed for the economical exploration of subterranean water resources.

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

1974-01-01

414

Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol  

Microsoft Academic Search

BACKGROUND: The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result,

Martin Röösli; Patrizia Frei; John Bolte; Georg Neubauer; Elisabeth Cardis; Maria Feychting; Peter Gajsek; Sabine Heinrich; Wout Joseph; Simon Mann; Luc Martens; Evelyn Mohler; Roger C Parslow; Aslak Harbo Poulsen; Katja Radon; Joachim Schüz; György Thuroczy; Jean-François Viel; Martine Vrijheid

2010-01-01

415

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

PubMed

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

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

2013-03-01

416

Validation studies of gyrofluid and gyrokinetic predictions of transport and turbulence stiffness using the DIII-D tokamak  

NASA Astrophysics Data System (ADS)

A series of carefully designed validation experiments conducted on DIII-D to rigorously test gyrofluid and gyrokinetic predictions of transport and turbulence stiffness in both the ion and electron channels have provided an improved assessment of the experimental fidelity of those models over a range of plasma parameters. The first set of experiments conducted was designed to test predictions of H-mode core transport stiffness at fixed pedestal density and temperature. In low triangularity lower single null plasmas, a factor of 3 variation in neutral beam injection (NBI) heating was obtained, with modest changes to pedestal conditions that slowly increased with applied heating. The measurements and trends with increased NBI heating at both low and high injected torque are generally well-reproduced by the quasilinear trapped gyro-Landau fluid (TGLF) transport model at the lowest heating levels, but with decreasing fidelity (particularly in the electron profiles) as the heating power is increased. Complementing these global stiffness studies, a second set of experiments was performed to quantify the relationship between the local electron energy flux Qe and electron temperature gradient by varying the deposition profile of electron cyclotron heating about a specified reference radius in low density, low current L-mode plasmas. Modelling of these experiments using both the TGLF model and the nonlinear gyrokinetic GYRO code yields systematic underpredictions of the measured fluxes and fluctuation levels.

Holland, C.; Kinsey, J. E.; DeBoo, J. C.; Burrell, K. H.; Luce, T. C.; Smith, S. P.; Petty, C. C.; White, A. E.; Rhodes, T. L.; Schmitz, L.; Doyle, E. J.; Hillesheim, J. C.; McKee, G. R.; Yan, Z.; Wang, G.; Zeng, L.; Grierson, B. A.; Marinoni, A.; Mantica, P.; Snyder, P. B.; Waltz, R. E.; Staebler, G. M.; Candy, J.

2013-08-01

417

Integrated experimental and modeling study of the ionic conductivity of samaria-doped ceria thin films  

SciTech Connect

Oxygen diffusion and ionic conductivity of samaria-doped ceria (SDC) thin films have been studied as a function of composition using experiment and atomistic simulation. SDC thin films were grown on Al2O3 (0001) substrates by oxygen plasma-assisted molecular beam epitaxy (OPA-MBE) technique. The experimental results show a peak in electrical conductivity of SDC at 15 mol% Sm2O3. The oxygen diffusion coefficient obtained from molecular dynamics simulation of the same system shows a peak at about 13 mol% Sm2O3. The activation energy for oxygen diffusion was found to be in the range from 0.8 to 1.0 eV by simulations depending on the Sm2O3 content, which compares well with the range from 0.6 to 0.9 eV given by the experimental work. The simulations also show that oxygen vacancies prefer Sm3+ ions as first neighbors over Ce4+ ions. The present results reveal that the optimum samaria content for ionic conductivity in single crystals of SDC is less than that in polycrystals, which can be related to the preferential segregation of dopant cations to grain boundaries in polycrystals.

Sanghavi, Rahul P.; Devanathan, Ramaswami; Nandasiri, Manjula I.; Kuchibhatla, Satyanarayana V N T; Kovarik, Libor; Thevuthasan, Suntharampillai; Prasad, Shalini

2011-12-12

418

Current at domain walls, roughly speaking: nanoscales studies of disorder roughening and conduction  

NASA Astrophysics Data System (ADS)

Domain walls in (multi)ferroic materials are the thin elastic interfaces separating regions with different orientations of magnetisation, electric polarisation, or spontaneous strain. Understanding their behaviour, and controlling domain size and stability, is key for their integration into applications, while fundamentally, domain walls provide an excellent model system in which the rich physics of disordered elastic interfaces can be accesses. In addition, domain walls can present novel properties, quite different from those of their parent materials, making them potentially useful as active components in future nano-devices. Here, we present our atomic force microscopy studies of ferroelectric domain walls in epitaxial Pb(Zr0.2Ti0.8)O3 and BiFeO3 thin films, in which we use piezorespose force microscopy to show unusual domain wall roughening behaviour, with very localised disorder regions in the sample leading to a complex, multi-affine scaling of the domain wall shape [1]. We also show the effects of temperature, environmental conditions, and defects on switching dynamics and domain wall roughness [2]. We combine these observations with parallel conductive-tip atomic force microscopy current measurements, which also show highly localised variations in conduction, and highlight the key role played by oxygen vacancies in the observed domain wall conduction [3]. [4pt] [1] Guyonnet et al., PRL 109, 147601 (2012)[0pt] [2] Paruch et al, PRB 85, 214115 (2012); Blaser et al, APL. 101, 142906 (2012)[0pt] [3] Guyonnet et al., Adv. Mat. 25, 5377 (2011)

Paruch, Patrycja

2013-03-01

419

A Study on Using AD5933 to Realize Soft-Sensing Measurement of Conductance and Capacitance  

NASA Astrophysics Data System (ADS)

A conductance and capacitance test system was designed in this paper. AD5933 a new chip for impedance testing was used in it. By designing the test system, and testing the impedance of a model, which is a resistor in parallel with a capacitor, under different frequency (range from1000Hz to 100kHz). The information of impedance, real part, and imaginary part of the model under the frequency points were get. Based on this, the internal relations between conductance, capacitance, impedance, real part and imaginary part were carefully analyzed, using the soft-sensing method established the capacitance support vector machine (SVM) regression model on MATLAB. The regression model is the relation between resistance, impedance and capacitance. The test results showed that the test relative error is small in the capacitance range (0.1 pf~33 pf) and the conductance range (9.05*10-3s~3.8*10-5s), the biggest, smallest and average test error of capacitance are -2.9%, 0.2%, 1.27% respectively. The study showed that using AD5933 and the soft-sensing method to realize the multi-parameter test is feasible.

Cui, Chuanjin; Wu, Haiyun; Zuo, Yueming

420

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

ERIC Educational Resources Information Center

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

Eseryel, Deniz; Ifenthaler, Dirk; Ge, Xun

2013-01-01

421

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

Microsoft Academic Search

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

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

2007-01-01

422

A Validation and Reliability Study of the Physical Activity and Healthy Food Efficacy Scale for Children (PAHFE)  

ERIC Educational Resources Information Center

The purpose of this study was to obtain validity evidence for the Physical Activity and Healthy Food Efficacy Scale for Children (PAHFE). Construct validity evidence identifies four subscales: Goal-Setting for Physical Activity, Goal-Setting for Healthy Food Choices, Decision-Making for Physical Activity, and Decision-Making for Healthy Food…

Perry, Christina M.; De Ayala, R. J.; Lebow, Ryan; Hayden, Emily

2008-01-01

423

The Math Essential Skills Screener--Upper Elementary Version (MESS-U): Studies of Reliability and Validity  

ERIC Educational Resources Information Center

The Math Essential Skills Screener--Upper Elementary Version (MESS-U) is part of a series of screening tests designed to help identify students ages 9-11 who are at risk for mathematics failure. Internal consistency, test-retest reliability, item analysis, decision efficiency, convergent validity and factorial validity of the MESS-U were studied

Erford, Bradley T.; Biddison, Amanda R.

2006-01-01

424

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. PMID:24039870

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

425

Experimental study of heat conductivity of n-heptane-n-octane-isooctane liquid ternary mixtures at high pressure  

SciTech Connect

Heat conductivity of liquid ternary mixtures of various compositions at various pressures and temperatures was experimentally studied. Dependence of heat conductivities of ternary mixtures on concentration of components was established. An equation linking the heat conductivities of ternary mixtures through those of pure components and appropriate binary mixtures was proposed.

Naziev, D.Ya. [Azerbaidzhan State Oil Academy, Baku (Russian Federation)

1994-03-20

426

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

Microsoft Academic Search

Responses to Life Satisfaction Scale for Problem Youth (LSSPY) items were exam- ined in a sample of 193 substance abusing and conduct disordered adolescents. In responding to the LSSPY, youth endorse their percentage of happiness (0 to 100%) in twelve domains (i.e., friendships, family, school, employment\\/work, fun activities, appearance, sex life\\/dating, use of drugs, use of alcohol, money\\/material possessions, transportation,

Brad Donohue; Gordon Teichner; Nathan Azrin; Noah Weintraub; Thomas A. Crum; Leah Murphy

2003-01-01

427

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

Microsoft Academic Search

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

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

2003-01-01

428

Structural and Conductivity Studies on Lanthanum Doped LiNiPO4 Prepared by Polyol Method  

NASA Astrophysics Data System (ADS)

Pure and Lanthanum doped LiNiPO4 (with different Molar concentrations) have been prepared by polyol method using 1,2 propanediol as a polyol medium. XRD analysis reveal that sample calcined at 650°C for 6 hrs shows good crystalline nature with orthorhombic structure and this result is consistent with TG/DTA result. It is found that the conductivity enhances upon doping of Lanthanum while backhoprate decreases compared with pure LiNiPO4. Dielectric studies have also been discussed.

Karthickprabhu, S.; Hirankumar, G.; Maheswaran, A.; Bella, R. S. Daries; Sanjeeviraja, C.

2013-07-01

429

Synthesis, characterization and ion conductivity study of nanocrystalline LiNaSO4  

NASA Astrophysics Data System (ADS)

The nanocrystallites of LiNaSO4 were prepared by co-precipitation method at room temperature and characterized by XRD, SEM and TG-DSC measurements. The average crystallite size is found to be 46 nm. The DSC curve shows two endothermic peaks at 255.8 °C and 508.8 °C. The electrical conductivity is studied as functions temperature and frequency and results are reported. The activation energy obtained for the stable phase of LiNaSO4 is 1.19 eV. The material becomes superionic conductor at high temperature phase.

Ganesha, K. N.; Govindaraj, G.

2013-02-01

430

Validity of parent-reported weight and height of preschool children measured at home or estimated without home measurement: a validation study  

Microsoft Academic Search

Background  Parental reports are often used in large-scale surveys to assess children's body mass index (BMI). Therefore, it is important\\u000a to know to what extent these parental reports are valid and whether it makes a difference if the parents measured their children's\\u000a weight and height at home or whether they simply estimated these values. The aim of this study is to

Inge Huybrechts; John H Himes; Charlene Ottevaere; Tineke De Vriendt; Willem De Keyzer; Bianca Cox; Inge Van Trimpont; Dirk De Bacquer; Stefaan De Henauw

2011-01-01

431

Case study 2. Practical analytical considerations for conducting in vitro enzyme kinetic studies.  

PubMed

Characterization of enzyme kinetics in an experiment is dependent on measurement of a change in concentration of either the substrate (loss of parent) or the product (formation of metabolite). Modern analytical techniques such as ultrahigh pressure liquid chromatography and high-resolution mass spectrometry have allowed accurate characterization of minute changes in concentration. Therefore, complex kinetic data such as a sigmoidal phase at low substrate concentrations or terminal half-life in a PK curve can be evaluated by stretching the limits of analytical quantification. This chapter presents some elementary do's and don'ts and provides insight into some of the underlying principles for utilizing the best possible analytical techniques when investigating enzyme kinetics. The objective of this case study is to answer the following questions: (a) Why is it necessary to determine lower and upper limits of quantification (LLOQ and ULOQ, respectively) of a bioanalytical assay specifically for enzyme kinetic assays? How do you utilize LLOQ and ULOQ to correctly interpret your kinetic data? (b) Why should one use a linear fit and not a quadratic fit for standard curves? (c) Is quantification of an analyte possible without a reference standard? Can one assume equal signal intensities regardless of analytical technique (MS, UV)? (d) In the absence of reference standards, can you still determine kinetic constants? (e) With the need to keep substrate depletion at less than 20 % for linearity assumptions, does bioanalytical variability matter? (f) What buffer do you use for your enzyme systems? How do you choose your buffer? Does choice of bioanalytical methods (LC, MS) dictate your choice of buffer? PMID:24523123

Argikar, Upendra A; Nagar, Swati

2014-01-01

432

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

E-print Network

Head of Department C mittee Committee January 1964 ABSTRACT The validity of early material balance estimates was studied by comparing the original oil in. place of four different reservoirs, cal- culated on the basis of data obtained shortly... of the Field Procedure Discussion of Results 26 26 27 CONC L USIONS APPENDIX REFERENCES 34 41 LIS'I OF TABLES AND FIGURES 'I able s 1 Rosenwald Pool: Production and Laboratory Data 2 Rosenwald Pool: Original Oil in Place 3 Kelly-Snyder Field...

Galindo, Christian Anze

2012-06-07

433

It's all about relationships: A qualitative study of health researchers' perspectives of conducting interdisciplinary health research  

PubMed Central

Background Interdisciplinary research has been promoted as an optimal research paradigm in the health sciences, yet little is known about how researchers experience interdisciplinarity in practice. This study sought to determine how interdisciplinary research was conceptualized and operationalized from the researcher's perspective and to better understand how best to facilitate interdisciplinary research success. Methods Key informant interviews were conducted with health researchers with expertise or experience in conducting interdisciplinary research. Interviews were completed either in person or over the telephone using a semi-structured interview guide. Data collection occurred simultaneously with data analysis so that emerging themes could be explored in subsequent interviews. A content analysis approach was used. Results Nineteen researchers took part in this study. Interdisciplinary research was conceptualized disparately between participants, and there was modest attention towards operationalization of interdisciplinary research. There was one overriding theme, "It's all about relationships", that emerged from the data. Within this theme, there were four related subthemes: 1) Involvement in interdisciplinary research; 2) Why do I do interdisciplinary research?; 3) Managing and fostering interdisciplinary relationships; and 4) The prickly side to interdisciplinary research. Together, these themes suggest that the choice to conduct interdisciplinary research, though often driven by the research question, is highly influenced by interpersonal and relationship-related factors. In addition, researchers preferred to engage in interdisciplinary research with those that they had already established relationships and where their role in the research process was clearly articulated. A focus on relationship building was seen as a strong facilitator of interdisciplinary success. Conclusion Many health researchers experienced mixed reactions towards their involvement in interdisciplinary research. A well thought-out rationale for interdisciplinary research, and strategies to utilize the contribution of each researcher involved were seen as facilitators towards maximizing the benefits that could be derived from interdisciplinary research. PMID:18501005

Nair, Kalpana M; Dolovich, Lisa; Brazil, Kevin; Raina, Parminder

2008-01-01

434

Study of correlations between microstructure and conductivity in a thermoplastic polyurethane electrolyte  

SciTech Connect

Micro-Raman and positron annihilation lifetime spectroscopy (PALS) have been used to investigate the structure of a thermoplastic polyurethane/LiClO{sub 4} solid flexible polymer electrolyte at room temperature. Correlation between the free volume and carrier concentration with ionic conductivity was observed. The polyurethane soft phase consisted of a poly(tetramethylene glycol-co-ethylene glycol) copolymer reinforced by condensation with hexamethyldiisocianate. The range of salt concentration between 5 and 35 wt %, which attained the beginning of phase segregation, was also studied by differential scanning calorimetry (DSC), which showed the presence of three thermal events; the soft-phase T{sub g}, a change in heat capacity suggested as the hard-phase T{sub g}, and a hard-phase ordering endotherm. The total ionic conductivity was found to be approximately 4 {times} 10{sup {minus}6} S cm{sup {minus}1} at 23 C up to 27 wt % salt, whereas there were pronounced changes observed by the spectroscopic techniques. The PALS measurements indicated a decrease of 40% of the ratio (V{sub f}I{sub 3}/(V{sub f}I{sub 3}){sub 0}) between the free volume parameters probed by the positron particle. This ratio is proportional to the fractional free volume of the system. The micro-Raman results showed an increase of ionic aggregation, although the charge carrier concentration increased significantly in the range of compositions studied. The opposite effects of the microstructural changes and the maximum conductivity value, in the observed range of concentrations, are discussed.

Furtado, C.A. [CDTN/CNEN, Belo Horizonte, MG (Brazil). Centro de Desenvolvimento da Tecnologia Nuclear] [CDTN/CNEN, Belo Horizonte, MG (Brazil). Centro de Desenvolvimento da Tecnologia Nuclear; Silva, G.G.; Machado, J.C.; Pimenta, M.A.; Silva, R.A. [UFMG/ICEx, Belo Horizonte, MG (Brazil)] [UFMG/ICEx, Belo Horizonte, MG (Brazil)

1999-08-26

435

CARCINOMA OF THE THYROID IN THE SALMONOID FISHES An investigation and experimental study conducted jointly by the  

E-print Network

CARCINOMA OF THE THYROID IN THE SALMONOID FISHES An investigation and experimental study conducted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 History of the disease , " . . . . . . . . .. .. . . . . . . . . . 369 Normal thyroid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 Anomalous deposits of thyroid

436

Performance evaluation of AERMOD, CALPUFF, and legacy air dispersion models using the Winter Validation Tracer Study dataset  

NASA Astrophysics Data System (ADS)

The performance of the steady-state air dispersion models AERMOD and Industrial Source Complex 2 (ISC2), and Lagrangian puff models CALPUFF and RATCHET were evaluated using the Winter Validation Tracer Study dataset. The Winter Validation Tracer Study was performed in February 1991 at the former Rocky Flats Environmental Technology Site near Denver, Colorado. Twelve, 11-h tests were conducted where a conservative tracer was released and measured hourly at 140 samplers in concentric rings 8 km and 16 km from the release point. Performance objectives were unpaired maximum one- and nine-hour average concentration, location of plume maximum, plume impact area, arc-integrated concentration, unpaired nine-hour average concentration, and paired ensemble means. Performance objectives were aimed at addressing regulatory compliance, and dose reconstruction assessment questions. The objective of regulatory compliance is not to underestimate maximum concentrations whereas for dose reconstruction, the objective is an unbiased estimate of concentration in space and time. Performance measures included the fractional bias, normalized mean square error, geometric mean, geometric mean variance, correlation coefficient, and fraction of observations within a factor of two. The Lagrangian puff models tended to exhibit the smallest variance, highest correlation, and highest number of predictions within a factor of two compared to the steady-state models at both the 8-km and 16-km distance. Maximum one- and nine-hour average concentrations were less likely to be under-predicted by the steady-state models compared to the Lagrangian puff models. The characteristic of the steady-state models not to under-predict maximum concentrations make them well suited for regulatory compliance demonstration, whereas the Lagrangian puff models are better suited for dose reconstruction and long range transport.

Rood, Arthur S.

2014-06-01

437

Psychometric Validation Study of the Liebowitz Social Anxiety Scale - Self-Reported Version for Brazilian Portuguese  

PubMed Central

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

Forni dos Santos, Larissa; Loureiro, Sonia Regina; Crippa, Jose Alexandre de Souza; Osorio, Flavia de Lima

2013-01-01

438

Neuropsychological assessment and the Disability Rating Scale (DRS): a concurrent validity study.  

PubMed

Assessment of current level of functioning among clients with traumatic brain injury (TBI) often guides the establishment of realistic outcome goals for post-acute rehabilitation. Further, data generated from neuropsychological testing provide a clinician with a better understanding of a client's pattern of cognitive strengths and weaknesses. The Disability Rating Scale (DRS) is commonly used by TBI rehabilitation facilities to assess a client's general level of funct