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Sample records for numa rede unidimensional

  1. Parallel Analysis with Unidimensional Binary Data

    ERIC Educational Resources Information Center

    Weng, Li-Jen; Cheng, Chung-Ping

    2005-01-01

    The present simulation investigated the performance of parallel analysis for unidimensional binary data. Single-factor models with 8 and 20 indicators were examined, and sample size (50, 100, 200, 500, and 1,000), factor loading (.45, .70, and .90), response ratio on two categories (50/50, 60/40, 70/30, 80/20, and 90/10), and types of correlation…

  2. Are Utilitarian/Deontological Preferences Unidimensional?

    PubMed Central

    Laakasuo, Michael; Sundvall, Jukka

    2016-01-01

    Utilitarian versus deontological inclinations have been studied extensively in the field of moral psychology. However, the field has been lacking a thorough psychometric evaluation of the most commonly used measures. In this paper, we examine the factorial structure of an often used set of 12 moral dilemmas purportedly measuring utilitarian/deontological moral inclinations. We ran three different studies (and a pilot) to investigate the issue. In Study 1, we used standard Exploratory Factor Analysis and Schmid-Leimann (g factor) analysis; results of which informed the a priori single-factor model for our second study. Results of Confirmatory Factor Analysis in Study 2 were replicated in Study 3. Finally, we ran a weak invariance analysis between the models of Study 2 and 3, concluding that there is no significant difference between factor loading in these studies. We find reason to support a single-factor model of utilitarian/deontological inclinations. In addition, certain dilemmas have consistent error covariance, suggesting that this should be taken into consideration in future studies. In conclusion, three studies, pilot and an invariance analysis, systematically suggest the following. (1) No item needs to be dropped from the scale. (2) There is a unidimensional structure for utilitarian/deontological preferences behind the most often used dilemmas in moral psychology, suggesting a single latent cognitive mechanism. (3) The most common set of dilemmas in moral psychology can be successfully used as a unidimensional measure of utilitarian/deontological moral inclinations, but would benefit from using weighted averages over simple averages. (4) Consideration should be given to dilemmas describing infants. PMID:27582721

  3. The organizational learning survey: a re-evaluation of unidimensionality.

    PubMed

    Goh, Swee C; Quon, Tony K; Cousins, J Bradley

    2007-12-01

    An earlier study by Chakrabarty and Rogé evaluated the dimensionality of the Organizational Learning Survey for assessing the learning capability of organizations developed by Goh and Richards. In this paper, the survey was re-evaluated for unidimensionality using both exploratory and confirmatory factor analysis. Retaining 18 of the original 21 items was sufficient to establish unidimensionality. A number of different confirmatory models validated the unidimensional measurement model on two independent data sets. Implications for further empirical research using this inventory are discussed.

  4. Identification and characterization of novel NuMA isoforms

    SciTech Connect

    Wu, Jin; Xu, Zhe; He, Dacheng; Lu, Guanting

    2014-11-21

    Highlights: • Seven NuMA isoforms generated by alternative splicing were categorized into 3 groups: long, middle and short. • Both exons 15 and 16 in long NuMA were “hotspot” for alternative splicing. • Lower expression of short NuMA was observed in cancer cells compared with nonneoplastic controls. • Distinct localization pattern of short isoforms indicated different function from that of long and middle NuMA. - Abstract: The large nuclear mitotic apparatus (NuMA) has been investigated for over 30 years with functions related to the formation and maintenance of mitotic spindle poles during mitosis. However, the existence and functions of NuMA isoforms generated by alternative splicing remains unclear. In the present work, we show that at least seven NuMA isoforms (categorized into long, middle and short groups) generated by alternative splicing from a common NuMA mRNA precursor were discovered in HeLa cells and these isoforms differ mainly at the carboxyl terminus and the coiled-coil domains. Two “hotspot” exons with molecular mass of 3366-nt and 42-nt tend to be spliced during alternative splicing in long and middle groups. Furthermore, full-length coding sequences of long and middle NuMA obtained by using fusion PCR were constructed into GFP-tagged vector to illustrate their cellular localization. Long NuMA mainly localized in the nucleus with absence from nucleoli during interphase and translocated to the spindle poles in mitosis. Middle NuMA displayed the similar cell cycle-dependent distribution pattern as long NuMA. However, expression of NuMA short isoforms revealed a distinct subcellular localization. Short NuMA were present in the cytosol during the whole cycle, without colocalization with mitotic apparatus. These results have allowed us tentatively to explore a new research direction for NuMA’s various functions.

  5. The Puzzling Unidimensionality of DSM-5 Substance Use Disorder Diagnoses

    PubMed Central

    MacCoun, Robert J.

    2013-01-01

    There is a perennial expert debate about the criteria to be included or excluded for the DSM diagnoses of substance use dependence. Yet analysts routinely report evidence for the unidimensionality of the resulting checklist. If in fact the checklist is unidimensional, the experts are wrong that the criteria are distinct, so either the experts are mistaken or the reported unidimensionality is spurious. I argue for the latter position, and suggest that the traditional reflexive measurement model is inappropriate for the DSM; a formative measurement model would be a more accurate characterization of the institutional process by which the checklist is created, and a network or causal model would be a more appropriate foundation for a scientifically grounded diagnostic system. PMID:24324446

  6. Developing an Essentially Unidimensional Test with Cognitively Designed Items

    ERIC Educational Resources Information Center

    Bryant, Damon U.; Wooten, William

    2006-01-01

    The purpose of this study was to demonstrate how cognitive and measurement principles can be integrated to create an essentially unidimensional test. Two studies were conducted. In Study 1, test questions were created by using the feature integration theory of attention to develop a cognitive model of performance and then manipulating complexity…

  7. Delimiting Coefficient a from Internal Consistency and Unidimensionality

    ERIC Educational Resources Information Center

    Sijtsma, Klaas

    2015-01-01

    I discuss the contribution by Davenport, Davison, Liou, & Love (2015) in which they relate reliability represented by coefficient a to formal definitions of internal consistency and unidimensionality, both proposed by Cronbach (1951). I argue that coefficient a is a lower bound to reliability and that concepts of internal consistency and…

  8. Essential Unidimensionality Examination for Multicomponent Scales: An Interrelationship Decomposition Approach

    ERIC Educational Resources Information Center

    Raykov, Tenko; Pohl, Steffi

    2013-01-01

    A procedure for examining essential unidimensionality in multicomponent measuring instruments is discussed. The method is based on an application of latent variable modeling and is concerned with the extent to which a common factor for all components of a given scale accounts for their correlations. The approach provides point and interval…

  9. Bayesian Estimation of Multi-Unidimensional Graded Response IRT Models

    ERIC Educational Resources Information Center

    Kuo, Tzu-Chun

    2015-01-01

    Item response theory (IRT) has gained an increasing popularity in large-scale educational and psychological testing situations because of its theoretical advantages over classical test theory. Unidimensional graded response models (GRMs) are useful when polytomous response items are designed to measure a unified latent trait. They are limited in…

  10. The Effect of NUMA Tunings on CPU Performance

    NASA Astrophysics Data System (ADS)

    Hollowell, Christopher; Caramarcu, Costin; Strecker-Kellogg, William; Wong, Antonio; Zaytsev, Alexandr

    2015-12-01

    Non-Uniform Memory Access (NUMA) is a memory architecture for symmetric multiprocessing (SMP) systems where each processor is directly connected to separate memory. Indirect access to other CPU's (remote) RAM is still possible, but such requests are slower as they must also pass through that memory's controlling CPU. In concert with a NUMA-aware operating system, the NUMA hardware architecture can help eliminate the memory performance reductions generally seen in SMP systems when multiple processors simultaneously attempt to access memory. The x86 CPU architecture has supported NUMA for a number of years. Modern operating systems such as Linux support NUMA-aware scheduling, where the OS attempts to schedule a process to the CPU directly attached to the majority of its RAM. In Linux, it is possible to further manually tune the NUMA subsystem using the numactl utility. With the release of Red Hat Enterprise Linux (RHEL) 6.3, the numad daemon became available in this distribution. This daemon monitors a system's NUMA topology and utilization, and automatically makes adjustments to optimize locality. As the number of cores in x86 servers continues to grow, efficient NUMA mappings of processes to CPUs/memory will become increasingly important. This paper gives a brief overview of NUMA, and discusses the effects of manual tunings and numad on the performance of the HEPSPEC06 benchmark, and ATLAS software.

  11. Critical Path-Based Thread Placement for NUMA Systems

    SciTech Connect

    Su, C Y; Li, D; Nikolopoulos, D S; Grove, M; Cameron, K; de Supinski, B R

    2011-11-01

    Multicore multiprocessors use a Non Uniform Memory Architecture (NUMA) to improve their scalability. However, NUMA introduces performance penalties due to remote memory accesses. Without efficiently managing data layout and thread mapping to cores, scientific applications, even if they are optimized for NUMA, may suffer performance loss. In this paper, we present algorithms and a runtime system that optimize the execution of OpenMP applications on NUMA architectures. By collecting information from hardware counters, the runtime system directs thread placement and reduces performance penalties by minimizing the critical path of OpenMP parallel regions. The runtime system uses a scalable algorithm that derives placement decisions with negligible overhead. We evaluate our algorithms and runtime system with four NPB applications implemented in OpenMP. On average the algorithms achieve between 8.13% and 25.68% performance improvement compared to the default Linux thread placement scheme. The algorithms miss the optimal thread placement in only 8.9% of the cases.

  12. The Use of Unidimensional Item Parameter Estimates of Multidimensional Items in Adaptive Testing.

    ERIC Educational Resources Information Center

    Ackerman, Terry A.

    The purpose of this study was to investigate the effect of using multidimensional items in a computer adaptive test (CAT) setting which assumes a unidimensional item response theory (IRT) framework. Previous research has suggested that the composite of multidimensional abilities being estimated by a unidimensional IRT model is not constant…

  13. Robustness of the Polytomous IRT Model to Violations of the Unidimensionality Assumption.

    ERIC Educational Resources Information Center

    Dawadi, Bhaskar R.

    The robustness of the polytomous Item Response Theory (IRT) model to violations of the unidimensionality assumption was studied. A secondary purpose was to provide guidelines to practitioners to help in deciding whether to use an IRT model to analyze their data. In a simulation study, the unidimensionality assumption was deliberately violated by…

  14. Empirical Memory-Access Cost Models in Multicore NUMA Architectures

    SciTech Connect

    McCormick, Patrick S.; Braithwaite, Ryan Karl; Feng, Wu-chun

    2011-01-01

    Data location is of prime importance when scheduling tasks in a non-uniform memory access (NUMA) architecture. The characteristics of the NUMA architecture must be understood so tasks can be scheduled onto processors that are close to the task's data. However, in modern NUMA architectures, such as AMD Magny-Cours and Intel Nehalem, there may be a relatively large number of memory controllers with sockets that are connected in a non-intuitive manner, leading to performance degradation due to uninformed task-scheduling decisions. In this paper, we provide a method for experimentally characterizing memory-access costs for modern NUMA architectures via memory latency and bandwidth microbenchmarks. Using the results of these benchmarks, we propose a memory-access cost model to improve task-scheduling decisions by scheduling tasks near the data they need. Simple task-scheduling experiments using the memory-access cost models validate the use of empirical memory-access cost models to significantly improve program performance.

  15. A FORTRAN Program for Assessing Unidimensionality of Binary Data Using Holland and Rosenbaum's Methodology.

    ERIC Educational Resources Information Center

    Nandakumar, Ratna

    1993-01-01

    The methodology of P. E. Holland and P. R. Rosenbaum (1986) to assess unidimensionality of binary data is outlined and illustrated through a simulation with 36 items for 2,000 examinees. How to interpret the results is discussed. (SLD)

  16. Dimensions of "unidimensional" ratings of pain and emotions in patients with chronic musculoskeletal pain.

    PubMed

    Huber, Alexa; Suman, Anna Lisa; Rendo, Carmela Anna; Biasi, Giovanni; Marcolongo, Roberto; Carli, Giancarlo

    2007-08-01

    The use of unidimensional scales to measure pain intensity has been criticised because of the multidimensional nature of pain. We conducted multiple linear regression analyses to determine which dimensions of pain--sensory versus affective--predicted scores on unidimensional scales measuring pain intensity and emotions in 109 Italian women suffering from chronic, non-malignant musculoskeletal pain. We then compared the results with earlier findings in two groups of cancer patients suffering from acute post-operative pain and chronic cancer-related pain, respectively. Age, physical capacity and scores on the multidimensional affect and pain survey (MAPS) were used to predict patients' ratings on one visual analogue scale (VAS) and three numerical rating scales (NRS) measuring pain intensity, anxiety and depressed mood. Unidimensional pain intensity ratings were predicted better from sensory than from affective pain predictors, and the affective predictors made no unique contribution (NRS), or only a very small one (VAS). Both sensory and emotional pain aspects were unique predictors of NRS anxiety and depression. Therefore, in contrast to earlier findings in two different types of cancer patients, in subjects affected by chronic non-malignant musculoskeletal pain, the scores on unidimensional pain intensity scales mainly reflect sensory pain dimensions, supporting the discriminant validity of the NRS and VAS used. However, the patients had some difficulty in distinguishing between sensory and emotional information. For this reason, several unidimensional scales to rate pain intensity and emotions separately should be used to obtain a complete picture of the status and needs of any given patient.

  17. Cell cycle-dependent SUMO-1 conjugation to nuclear mitotic apparatus protein (NuMA)

    SciTech Connect

    Seo, Jae Sung; Kim, Ha Na; Kim, Sun-Jick; Bang, Jiyoung; Kim, Eun-A; Sung, Ki Sa; Yoon, Hyun-Joo; Yoo, Hae Yong; Choi, Cheol Yong

    2014-01-03

    Highlights: •NuMA is modified by SUMO-1 in a cell cycle-dependent manner. •NuMA lysine 1766 is the primary target site for SUMOylation. •SUMOylation-deficient NuMA induces multiple spindle poles during mitosis. •SUMOylated NuMA induces microtubule bundling. -- Abstract: Covalent conjugation of proteins with small ubiquitin-like modifier 1 (SUMO-1) plays a critical role in a variety of cellular functions including cell cycle control, replication, and transcriptional regulation. Nuclear mitotic apparatus protein (NuMA) localizes to spindle poles during mitosis, and is an essential component in the formation and maintenance of mitotic spindle poles. Here we show that NuMA is a target for covalent conjugation to SUMO-1. We find that the lysine 1766 residue is the primary NuMA acceptor site for SUMO-1 conjugation. Interestingly, SUMO modification of endogenous NuMA occurs at the entry into mitosis and this modification is reversed after exiting from mitosis. Knockdown of Ubc9 or forced expression of SENP1 results in impairment of the localization of NuMA to mitotic spindle poles during mitosis. The SUMOylation-deficient NuMA mutant is defective in microtubule bundling, and multiple spindles are induced during mitosis. The mitosis-dependent dynamic SUMO-1 modification of NuMA might contribute to NuMA-mediated formation and maintenance of mitotic spindle poles during mitosis.

  18. Development and Validation of a Unidimensional Maltreatment Scale in the Add Health Data Set

    ERIC Educational Resources Information Center

    Marszalek, Jacob M.; Hamilton, Jessica L.

    2012-01-01

    Four maltreatment items were examined from Wave III (N = 13,516) of the National Longitudinal Study of Adolescent Health. Item analysis, confirmatory factor analysis, cross-validation, reliability estimates, and convergent validity coefficients strongly supported the validity of using the four items as a unidimensional composite. Implications for…

  19. Evaluation of Scale Reliability for Unidimensional Measures Using Latent Variable Modeling

    ERIC Educational Resources Information Center

    Raykov, Tenko

    2009-01-01

    This article outlines a readily and widely applicable procedure of reliability evaluation for scales with unidimensional measures. The method is developed within the framework of the popular latent variable modeling methodology, and it accomplishes point, as well as interval, estimation of measuring instrument reliability. The approach can be…

  20. The Greatest Lower Bound to the Reliability of a Test and the Hypothesis of Unidimensionality

    ERIC Educational Resources Information Center

    Berge, Jos M. F. Ten; Socan, Gregor

    2004-01-01

    To assess the reliability of congeneric tests, specifically designed reliability measures have been proposed. This paper emphasizes that such measures rely on a unidimensionality hypothesis, which can neither be confirmed nor rejected when there are only three test parts, and will invariably be rejected when there are more than three test parts.…

  1. Georg Rasch and Benjamin Wright's Struggle with the Unidimensional Polytomous Model with Sufficient Statistics

    ERIC Educational Resources Information Center

    Andrich, David

    2016-01-01

    This article reproduces correspondence between Georg Rasch of The University of Copenhagen and Benjamin Wright of The University of Chicago in the period from January 1966 to July 1967. This correspondence reveals their struggle to operationalize a unidimensional measurement model with sufficient statistics for responses in a set of ordered…

  2. A Class of Multidimensional IRT Models for Testing Unidimensionality and Clustering Items

    ERIC Educational Resources Information Center

    Bartolucci, Francesco

    2007-01-01

    We illustrate a class of multidimensional item response theory models in which the items are allowed to have different discriminating power and the latent traits are represented through a vector having a discrete distribution. We also show how the hypothesis of unidimensionality may be tested against a specific bidimensional alternative by using a…

  3. Assessing Model Data Fit of Unidimensional Item Response Theory Models in Simulated Data

    ERIC Educational Resources Information Center

    Kose, Ibrahim Alper

    2014-01-01

    The purpose of this paper is to give an example of how to assess the model-data fit of unidimensional IRT models in simulated data. Also, the present research aims to explain the importance of fit and the consequences of misfit by using simulated data sets. Responses of 1000 examinees to a dichotomously scoring 20 item test were simulated with 25…

  4. Performance of Parallel Analysis in Retrieving Unidimensionality in the Presence of Binary Data

    ERIC Educational Resources Information Center

    Tran, Ulrich S.; Formann, Anton K.

    2009-01-01

    Parallel analysis has been shown to be suitable for dimensionality assessment in factor analysis of continuous variables. There have also been attempts to demonstrate that it may be used to uncover the factorial structure of binary variables conforming to the unidimensional normal ogive model. This article provides both theoretical and empirical…

  5. The Effects of Multidimensional Polytomous Response Data on Unidimensional Many-FACET Rasch Model Parameter Estimates.

    ERIC Educational Resources Information Center

    Wang, Shudong; Wang, Ning

    When categorical responses were simulated from a Multidimensional Many-FACETS Rasch Compensatory Model (MMFRCM), the effects of ability, task difficulty, and step difficulty estimates with the unidimensional Many-FACETS Rasch Model (MFRM; Linacre, 1999) were examined in terms of three error indexes, average absolute difference (AAD), bias, and…

  6. On Reporting IRT Ability Scores When the Test Is Not Unidimensional.

    ERIC Educational Resources Information Center

    Dirir, Mohamed A.; Sinclair, Norma

    The purpose of this study was to examine the effect of test dimensionality on the stability of examinee ability estimates and item response theory (IRT) based score reports. A simulation procedure based on W. F. Stout's Essential Unidimensionality was used to generate test data with one dominant trait for the whole test and three minor traits…

  7. Effect of Violating Unidimensional Item Response Theory Vertical Scaling Assumptions on Developmental Score Scales

    ERIC Educational Resources Information Center

    Topczewski, Anna Marie

    2013-01-01

    Developmental score scales represent the performance of students along a continuum, where as students learn more they move higher along that continuum. Unidimensional item response theory (UIRT) vertical scaling has become a commonly used method to create developmental score scales. Research has shown that UIRT vertical scaling methods can be…

  8. NuMA localization, stability, and function in spindle orientation involve 4.1 and Cdk1 interactions

    PubMed Central

    Seldin, Lindsey; Poulson, Nicholas D.; Foote, Henry P.; Lechler, Terry

    2013-01-01

    The epidermis is a multilayered epithelium that requires asymmetric divisions for stratification. A conserved cortical protein complex, including LGN, nuclear mitotic apparatus (NuMA), and dynein/dynactin, plays a key role in establishing proper spindle orientation during asymmetric divisions. The requirements for the cortical recruitment of these proteins, however, remain unclear. In this work, we show that NuMA is required to recruit dynactin to the cell cortex of keratinocytes. NuMA's cortical recruitment requires LGN; however, LGN interactions are not sufficient for this localization. Using fluorescence recovery after photobleaching, we find that the 4.1-binding domain of NuMA is important for stabilizing its interaction with the cell cortex. This is functionally important, as loss of 4.1/NuMA interaction results in spindle orientation defects, using two distinct assays. Furthermore, we observe an increase in cortical NuMA localization as cells enter anaphase. Inhibition of Cdk1 or mutation of a single residue in NuMA mimics this effect. NuMA's anaphase localization is independent of LGN and 4.1 interactions, revealing two distinct mechanisms responsible for NuMA cortical recruitment at different stages of mitosis. This work highlights the complexity of NuMA localization and reveals the importance of NuMA cortical stability for productive force generation during spindle orientation. PMID:24109598

  9. NuMA Phosphorylation by Aurora-A Orchestrates Spindle Orientation.

    PubMed

    Gallini, Sara; Carminati, Manuel; De Mattia, Fabiola; Pirovano, Laura; Martini, Emanuele; Oldani, Amanda; Asteriti, Italia Anna; Guarguaglini, Giulia; Mapelli, Marina

    2016-02-22

    Spindle positioning is essential for tissue morphogenesis and homeostasis. The signaling network synchronizing spindle placement with mitotic progression relies on timely recruitment at the cell cortex of NuMA:LGN:Gαi complexes, in which NuMA acts as a receptor for the microtubule motor Dynein. To study the implication of Aurora-A in spindle orientation, we developed protocols for the partial inhibition of its activity. Under these conditions, in metaphase NuMA and Dynein accumulate abnormally at the spindle poles and do not reach the cortex, while the cortical distribution of LGN remains unperturbed. FRAP experiments revealed that Aurora-A governs the dynamic exchange between the cytoplasmic and the spindle pole-localized pools of NuMA. We show that Aurora-A phosphorylates directly the C terminus of NuMA on three Ser residues, of which Ser1969 determines the dynamic behavior and the spindle orientation functions of NuMA. Most interestingly, we identify a new microtubule-binding domain of NuMA, which does not overlap with the LGN-binding motif. Our study demonstrates that in metaphase the direct phosphorylation of NuMA by Aurora-A controls its cortical enrichment, and that this is the major event underlying the spindle orientation functions of Aurora-A in transformed and non-transformed cells in culture. Phosphorylation of NuMA by Aurora-A does not affect its affinity for microtubules or for LGN but rather determines the mobility of the protein at the spindle poles. The finding that NuMA can associate concomitantly with LGN and microtubules suggests that its microtubule-binding activity contributes to anchor Dynein-loaded microtubule +TIPs at cortical sites with LGN.

  10. Noninvasive assessment of alcoholic liver disease using unidimensional transient elastography (Fibroscan®)

    PubMed Central

    Lupsor-Platon, Monica; Badea, Radu

    2015-01-01

    Unidimensional transient elastography (TE) is a noninvasive technique, which has been increasingly used in the assessment of diffuse liver diseases. This paper focuses on reviewing the existing data on the use of TE in the diagnosis of fibrosis and in monitoring disease progression in alcoholic liver disease, on the factors that may influence the result of fibrosis prediction, and last but not least, on its potential use in assessing the steatosis degree. Therefore, this field is far from being exhausted and deserves more attention. Further studies are required, on large groups of biopsied patients, in order to find answers to all the remaining questions in this field. PMID:26576080

  11. Assessing item fit for unidimensional item response theory models using residuals from estimated item response functions.

    PubMed

    Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee

    2013-07-01

    Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.

  12. How to conduct research on burnout: advantages and disadvantages of a unidimensional approach in burnout research

    PubMed Central

    Brenninkmeijer, V; VanYperen, N

    2003-01-01

    When conducting research on burnout, it may be difficult to decide whether one should report results separately for each burnout dimension or whether one should combine the dimensions. Although the multidimensionality of the burnout concept is widely acknowledged, for research purposes it is sometimes convenient to regard burnout as a unidimensional construct. This article deals with the question of whether and when it may be appropriate to treat burnout as a unidimensional variable, and presents a decision rule to distinguish between people high and low in burnout. To develop a guideline for obtaining a dichotomous measure of burnout, the scores on the Utrecht Burnout Scale (UBOS) of 44 well functioning individuals were compared with the scores of 29 individuals diagnosed as suffering from burnout. Based on these data, the authors recommend the "exhaustion + 1" criterion for research in non-clinical populations. Following this criterion, individuals can be considered as burnt out when they report, compared to a norm group, high emotional exhaustion, in combination with high depersonalisation or low personal accomplishment. The criterion may be used to estimate the percentage in a sample of individuals in a state of burnout. PMID:12782742

  13. Perhaps Unidimensional Is Not Unidimensional

    ERIC Educational Resources Information Center

    Dodds, Pennie; Rae, Babette; Brown, Scott

    2012-01-01

    Miller (1956) identified his famous limit of 7 plus or minus 2 items based in part on absolute identification--the ability to identify stimuli that differ on a single physical dimension, such as lines of different length. An important aspect of this limit is its independence from perceptual effects and its application across all stimulus types.…

  14. An IRT Approach to Constructing and Scoring Pairwise Preference Items Involving Stimuli on Different Dimensions: The Multi-Unidimensional Pairwise-Preference Model

    ERIC Educational Resources Information Center

    Stark, Stephen; Chernyshenko, Oleksandr S.; Drasgow, Fritz

    2005-01-01

    This article proposes an item response theory (IRT) approach to constructing and scoring multidimensional pairwise preference items. Individual statements are administered and calibrated using a unidimensional single-stimulus model. Tests are created by combining multidimensional items with a small number of unidimensional pairings needed to…

  15. Optimal Least-Squares Unidimensional Scaling: Improved Branch-and-Bound Procedures and Comparison to Dynamic Programming

    ERIC Educational Resources Information Center

    Brusco, Michael J.; Stahl, Stephanie

    2005-01-01

    There are two well-known methods for obtaining a guaranteed globally optimal solution to the problem of least-squares unidimensional scaling of a symmetric dissimilarity matrix: (a) dynamic programming, and (b) branch-and-bound. Dynamic programming is generally more efficient than branch-and-bound, but the former is limited to matrices with…

  16. The Unidimensional Relationship Closeness Scale (URCS): Reliability and Validity Evidence for a New Measure of Relationship Closeness

    ERIC Educational Resources Information Center

    Dibble, Jayson L.; Levine, Timothy R.; Park, Hee Sun

    2012-01-01

    A fundamental dimension along which all social and personal relationships vary is closeness. The Unidimensional Relationship Closeness Scale (URCS) is a 12-item self-report scale measuring the closeness of social and personal relationships. The reliability and validity of the URCS were assessed with college dating couples (N = 192), female friends…

  17. Unidimensionality of the Chinese version of the Foreign Language Reading Anxiety Scale.

    PubMed

    Hsiao, Tsung-Yuan

    2002-12-01

    Previous research showed the Foreign Language Reading Anxiety Scale is reliable and valid for assessing reading anxiety in groups of American college students beginning study of French, Japanese, or Russian. Because Saito, Horwitz, and Garza (1999) reported that reading anxiety tends to vary with the target language, the present investigation examined the factorial validity of the Chinese version of the scale in college students of English as a foreign language in Taiwan, Confirmatory factor analysis with maximum likelihood method supports the unidimensionality of the scale, which is reliable and valid for eliciting reading anxiety of Chinese college foreign language learners and for predicting their global language performance. This study suggests exploring how language proficiency, culture, and topic familiarity may be related to such anxiety.

  18. Prevendo a atividade solar através de redes neurais nebulosas

    NASA Astrophysics Data System (ADS)

    Martin, V. A. F.; Poppe, P. C. R.

    2003-08-01

    Atualmente, a integração de redes neurais com técnicas da Matemática Nebulosa (Fuzzy Sets), tem sido usada robustamente para fazer previsões em vários sistemas físicos. Este trabalho representa uma continuidade da contribuição apresentada anteriormente durante a XXVIIa Reunião Anual da SAB, onde exploramos a aplicação de redes neurais para previsões futuras de séries temporais. Para este, enfatizamos o uso da técnica ANFIS (Adaptative Neuro-Fuzzy Inference System), que consiste em uma rede do tipo back-propagation, onde os dados são processados em uma camada intermediária, tendo numa camada de saída, os dados numéricos. Para que a previsão seja feita com sucesso utilizando-se técnicas matemáticas adequadas, é fundamental a existência de uma série razoavelmente longa de modo que a dinâmica contida nesta possa ser melhor extraída pela rede neural. Nesse sentido, foram utilizados novamente os dados históricos das manchas do Sol (1818-2002) afim de verificar o comportamento futuro da atividade solar (Ciclos de Schawbe) a partir da técnica descrita acima. Previsões realizadas para o ciclo anterior (n.22, máximo de 158,5 em julho de 1989), bem como para o atual (n.23, máximo de 153 em setembro de 2000), apontam valores bastante coerentes com os publicados na literatura, levando em consideração, respectivamente, as barras de erros associadas: 166+/-18 e 160+/-14. Para o próximo ciclo de Schawbe (2006-2017), nossa previsão aponta o valor de 172+/-23 como máximo para o primeiro semestre de 2011 (Abril +/- 3 meses). A ANFIS acompanha de maneira satisfatória o movimento das séries estudadas durante o treinamento e durante a verificação (menor dispersão das funções de pertinência), com erro absoluto inferior a 20 por cento.

  19. Katanin p80, NuMA and cytoplasmic dynein cooperate to control microtubule dynamics

    PubMed Central

    Jin, Mingyue; Pomp, Oz; Shinoda, Tomoyasu; Toba, Shiori; Torisawa, Takayuki; Furuta, Ken’ya; Oiwa, Kazuhiro; Yasunaga, Takuo; Kitagawa, Daiju; Matsumura, Shigeru; Miyata, Takaki; Tan, Thong Teck; Reversade, Bruno; Hirotsune, Shinji

    2017-01-01

    Human mutations in KATNB1 (p80) cause severe congenital cortical malformations, which encompass the clinical features of both microcephaly and lissencephaly. Although p80 plays critical roles during brain development, the underlying mechanisms remain predominately unknown. Here, we demonstrate that p80 regulates microtubule (MT) remodeling in combination with NuMA (nuclear mitotic apparatus protein) and cytoplasmic dynein. We show that p80 shuttles between the nucleus and spindle pole in synchrony with the cell cycle. Interestingly, this striking feature is shared with NuMA. Importantly, p80 is essential for aster formation and maintenance in vitro. siRNA-mediated depletion of p80 and/or NuMA induced abnormal mitotic phenotypes in cultured mouse embryonic fibroblasts and aberrant neurogenesis and neuronal migration in the mouse embryonic brain. Importantly, these results were confirmed in p80-mutant harboring patient-derived induced pluripotent stem cells and brain organoids. Taken together, our findings provide valuable insights into the pathogenesis of severe microlissencephaly, in which p80 and NuMA delineate a common pathway for neurogenesis and neuronal migration via MT organization at the centrosome/spindle pole. PMID:28079116

  20. Katanin p80, NuMA and cytoplasmic dynein cooperate to control microtubule dynamics.

    PubMed

    Jin, Mingyue; Pomp, Oz; Shinoda, Tomoyasu; Toba, Shiori; Torisawa, Takayuki; Furuta, Ken'ya; Oiwa, Kazuhiro; Yasunaga, Takuo; Kitagawa, Daiju; Matsumura, Shigeru; Miyata, Takaki; Tan, Thong Teck; Reversade, Bruno; Hirotsune, Shinji

    2017-01-12

    Human mutations in KATNB1 (p80) cause severe congenital cortical malformations, which encompass the clinical features of both microcephaly and lissencephaly. Although p80 plays critical roles during brain development, the underlying mechanisms remain predominately unknown. Here, we demonstrate that p80 regulates microtubule (MT) remodeling in combination with NuMA (nuclear mitotic apparatus protein) and cytoplasmic dynein. We show that p80 shuttles between the nucleus and spindle pole in synchrony with the cell cycle. Interestingly, this striking feature is shared with NuMA. Importantly, p80 is essential for aster formation and maintenance in vitro. siRNA-mediated depletion of p80 and/or NuMA induced abnormal mitotic phenotypes in cultured mouse embryonic fibroblasts and aberrant neurogenesis and neuronal migration in the mouse embryonic brain. Importantly, these results were confirmed in p80-mutant harboring patient-derived induced pluripotent stem cells and brain organoids. Taken together, our findings provide valuable insights into the pathogenesis of severe microlissencephaly, in which p80 and NuMA delineate a common pathway for neurogenesis and neuronal migration via MT organization at the centrosome/spindle pole.

  1. Development of the Nonhydrostatic Unified Model of the Atmosphere (NUMA): Limited-Area Mode (Preprint)

    DTIC Science & Technology

    2011-04-14

    Applied Mathematics, Naval Postgraduate School , Monterey, CA Abstract This paper describes a Nonhydrostatic Unified Model of the Atmosphere (NUMA) based on...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School ,Department of Applied Mathematics...integrators and/or “ soundproof ” equation sets to confront the fast acoustic and gravity waves present in non-hydrostatic models, and 4) developing scalable

  2. Implicit-Explicit Formulations of a Three-Dimensional Nonhydrostatic Unified Model of the Atmosphere (NUMA)

    DTIC Science & Technology

    2013-01-01

    unification across various metrics. NUMA is unified in terms of spatial discretization methods and can use high-order continuous and discontinuous Galerkin ...dominate the solution error because we tend to use much higher order in space (e.g., 4th through 8th order) in the continuous/ discontinuous Galerkin ...tions, 52 (2006), pp. 1325–1342. [12] F. X. Giraldo and M. Restelli, A study of spectral element and discontinuous Galerkin methods for the Navier

  3. Current and Future Development of a Non-hydrostatic Unified Atmospheric Model (NUMA)

    DTIC Science & Technology

    2010-09-09

    Based on Spectral Elements and Discontinuous Galerkin methods –  Tested with simple moist physics (Kessler Physics) •  2010: 3D Mesoscale Atmospheric...Model (NUMA) –  Nonhydrostatic Equations –  Based on Spectral Element and Discontinuous Galerkin methods –  Tested as Limited-Area model (NRBCs...following capabilities: 1.  Highly scalable on current and future computer architectures (exascale computing and beyond and GPUs ) 2.  Flexibility

  4. The assessment of commitment: advantages of a unidimensional, target-free approach.

    PubMed

    Klein, Howard J; Cooper, Joseph T; Molloy, Janice C; Swanson, Jacqueline A

    2014-03-01

    This study presents a new approach to assessing commitment reflecting the Klein, Molloy, and Brinsfield (2012) reconceptualization. Klein et al. recast the construct to address issues hindering commitment scholarship, but their claims cannot be tested with existing measures. This paper presents a 4-item measure consistent with the Klein et al. conceptual definition, a measure intended to be unidimensional and applicable across all workplace targets. Our purpose is to present the development of and provide initial validity evidence for this new commitment measure and to compare it to existing alternative measures. Hypotheses around these objectives were tested with data gathered across 5 samples yielding 2,487 participants representing a wide range of jobs, organizations, and industries. Each sample examined a unique set of variables and targets that together provide a comprehensive test of this new measure relative to 8 different targets, several constructs within the nomological network, and 4 prior commitment measures. Results support our hypotheses regarding (a) the measure's properties and structure, (b) convergence and divergence with prior measures of commitment and other constructs in the nomological network, and (c) advantages over prior measures. These findings support the validity of this new approach to assessing commitment, laying the foundation for future research to address critiques of the commitment construct; better examine the multiple commitments individuals simultaneously hold; and bring consistency, synergy, and integration to commitment scholarship across workplace targets. The conceptual, methodological, and practical benefits of the measure are discussed, along with study limitations and future research opportunities.

  5. Unidimensional Measurement May Evaluate Target Lymph Nodal Response After Induction Chemotherapy for Nasopharyngeal Carcinoma

    PubMed Central

    Chen, Chuanben; Zhang, Mingwei; Xu, Yuanji; Yue, Qiuyuan; Bai, Penggang; Zhou, Lin; Xiao, Youping; Zheng, Dechun; Lin, Kongqi; Qiu, Sufang; Chen, Yunbin; Pan, Jianji

    2016-01-01

    Abstract The aim of the study was to evaluate whether short axis and long axis on axial and coronal magnetic resonance imaging planes would reflect the tumor burden or alteration in size after induction chemotherapy in nasopharyngeal carcinoma. Patients with pathologically confirmed nasopharyngeal carcinoma (n = 37) with at least 1 positive cervical lymph node (axial short axis ≥15 mm) were consecutively enrolled in this prospective study. Lymph nodal measurements were performed along its short axis and long axis in both axial and coronal magnetic resonance imaging planes at diagnosis and after 2 cycles of induction chemotherapy. In addition, lymph nodal volumes were automatically calculated in 3D treatment-planning system, which were used as reference standard. Student's t test or nonparametric Mann–Whitney U test was used to compare the continuous quantitative variables. Meanwhile, the κ statistic and McNemar's test were used to evaluate the degree of agreement and discordance in response categorization among different measurements. Axial short axis was significantly associated with volumes at diagnosis (P < 0.001). A good agreement (κ=0.583) was found between axial short axis and volumetric criteria. However, the inconsistent lymph nodal shrinkage in 4 directions was observed. Axial short-axis shrinking was more rapid than the other 3 parameters. Interestingly, when utilizing the alternative planes for unidimensional measurements to assess tumor response, coronal short-axis showed the best concordance (κ=0.792) to the volumes. Axial short axis may effectively reflect tumor burden or change in tumor size in the assessment of target lymph nodal response after induction chemotherapy for nasopharyngeal carcinoma. However, it should be noted that axial short axis may amplify the therapeutic response. In addition, the role of coronal short axis in the assessment of tumor response needs further evaluation. PMID:26945354

  6. Epitope mapping and direct visualization of the parallel, in-register arrangement of the double-stranded coiled-coil in the NuMA protein.

    PubMed Central

    Harborth, J; Weber, K; Osborn, M

    1995-01-01

    NuMA, a 238 kDa protein present in the nucleus during interphase, translocates to the spindle poles in mitosis. NuMA plays an essential role in mitosis, since microinjection of the NuMA SPN-3 monoclonal antibody causes mitotic arrest and micronuclei formation. We have mapped the approximate position of the epitopes of six monoclonal NuMA antibodies using recombinant NuMA fragments. The SPN-3 epitope has been located to residues 255-267 at the C-terminus of the first helical subdomain of the central rod domain and several residues crucial for antibody binding have been identified. To gain insight into the ultrastructure of NuMA, several defined fragments, as well as the full-length recombinant protein, were expressed in Escherichia coli and purified to homogeneity. They were then characterized by chemical cross-linking, circular dichroism spectra and electron microscopy. The results directly reveal the tripartate structure of NuMA. A long central rod domain is flanked by globular end domains. The rod is 207 nm long and is at least 90% alpha-helical. It reflects a double-stranded coiled-coil with the alpha-helices arranged parallel and in register. The NuMA protein thus forms the longest coiled-coil currently known. Our analyses reveal no indication that recombinant NuMA assembles into filaments or other higher order structures. Images PMID:7781599

  7. Developments in REDES: The rocket engine design expert system

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) is being developed at the NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP, a nozzle design program named RAO, a regenerative cooling channel performance evaluation code named RTE, and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES is built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  8. Developments in REDES: The Rocket Engine Design Expert System

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) was developed at NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP; a nozzle design program named RAO; a regenerative cooling channel performance evaluation code named RTE; and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES was built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  9. Performance of the likelihood ratio difference (G2 Diff) test for detecting unidimensionality in applications of the multidimensional Rasch model.

    PubMed

    Harrell-Williams, Leigh; Wolfe, Edward W

    2014-01-01

    Previous research has investigated the influence of sample size, model misspecification, test length, ability distribution offset, and generating model on the likelihood ratio difference test in applications of item response models. This study extended that research to the evaluation of dimensionality using the multidimensional random coefficients multinomial logit model (MRCMLM). Logistic regression analysis of simulated data reveal that sample size and test length have a large effect on the capacity of the LR difference test to correctly identify unidimensionality, with shorter tests and smaller sample sizes leading to smaller Type I error rates. Higher levels of simulated misfit resulted in fewer incorrect decisions than data with no or little misfit. However, Type I error rates indicate that the likelihood ratio difference test is not suitable under any of the simulated conditions for evaluating dimensionality in applications of the MRCMLM.

  10. Parallel calculations on shared memory, NUMA-based computers using MATLAB

    NASA Astrophysics Data System (ADS)

    Krotkiewski, Marcin; Dabrowski, Marcin

    2014-05-01

    Achieving satisfactory computational performance in numerical simulations on modern computer architectures can be a complex task. Multi-core design makes it necessary to parallelize the code. Efficient parallelization on NUMA (Non-Uniform Memory Access) shared memory architectures necessitates explicit placement of the data in the memory close to the CPU that uses it. In addition, using more than 8 CPUs (~100 cores) requires a cluster solution of interconnected nodes, which involves (expensive) communication between the processors. It takes significant effort to overcome these challenges even when programming in low-level languages, which give the programmer full control over data placement and work distribution. Instead, many modelers use high-level tools such as MATLAB, which severely limit the optimization/tuning options available. Nonetheless, the advantage of programming simplicity and a large available code base can tip the scale in favor of MATLAB. We investigate whether MATLAB can be used for efficient, parallel computations on modern shared memory architectures. A common approach to performance optimization of MATLAB programs is to identify a bottleneck and migrate the corresponding code block to a MEX file implemented in, e.g. C. Instead, we aim at achieving a scalable parallel performance of MATLABs core functionality. Some of the MATLABs internal functions (e.g., bsxfun, sort, BLAS3, operations on vectors) are multi-threaded. Achieving high parallel efficiency of those may potentially improve the performance of significant portion of MATLABs code base. Since we do not have MATLABs source code, our performance tuning relies on the tools provided by the operating system alone. Most importantly, we use custom memory allocation routines, thread to CPU binding, and memory page migration. The performance tests are carried out on multi-socket shared memory systems (2- and 4-way Intel-based computers), as well as a Distributed Shared Memory machine with 96 CPU

  11. LAMTOR1-PRKCD and NUMA1-SFMBT1 fusion genes identified by RNA sequencing in aneurysmal benign fibrous histiocytoma with t(3;11)(p21;q13).

    PubMed

    Panagopoulos, Ioannis; Gorunova, Ludmila; Bjerkehagen, Bodil; Lobmaier, Ingvild; Heim, Sverre

    2015-11-01

    RNA sequencing of an aneurysmal benign fibrous histiocytoma with the karyotype 46,XY,t(3;11)(p21;q13),del(6)(p23)[17]/46,XY[2] showed that the t(3;11) generated two fusion genes: LAMTOR1-PRKCD and NUMA1-SFMBT1. RT-PCR together with Sanger sequencing verified the presence of fusion transcripts from both fusion genes. In the LAMTOR1-PRKCD fusion, the part of the PRKCD gene coding for the catalytic domain of the serine/threonine kinase is under control of the LAMTOR1 promoter. In the NUMA1-SFMBT1 fusion, the part of the SFMBT1 gene coding for two of four malignant brain tumor domains and the sterile alpha motif domain is controlled by the NUMA1 promoter. The data support a neoplastic genesis of aneurysmal benign fibrous histiocytoma and indicate a pathogenetic role for LAMTOR1-PRKCD and NUMA1-SFMBT1.

  12. Is acculturation unidimensional or bidimensional? A head-to-head comparison in the prediction of personality, self-identity, and adjustment.

    PubMed

    Ryder, A G; Alden, L E; Paulhus, D L

    2000-07-01

    The unidimensional model of acculturation posits that heritage and mainstream culture identifications have a strong inverse relation, whereas the bidimensional model posits that the 2 identifications are independent. The authors compared these models in 3 samples of ethnic Chinese (ns = 164, 150, and 204), 1 sample of non-Chinese East Asians (n = 70), and one diverse group of acculturating individuals (n = 140). Although the unidimensional measure showed a coherent pattern of external correlates, the bidimensional measure revealed independent dimensions corresponding to heritage and mainstream culture identification. These dimensions displayed patterns of noninverse correlations with personality, self-identity, and psychosocial adjustment. The authors conclude that the bidimensional model is a more valid and useful operationalization of acculturation.

  13. Reciprocal Effects of Self-Concept and Performance From a Multidimensional Perspective: Beyond Seductive Pleasure and Unidimensional Perspectives.

    PubMed

    Marsh, Herbert W; Craven, Rhonda G

    2006-06-01

    We (Marsh & Craven, 1997) have claimed that academic self-concept and achievement are mutually reinforcing, each leading to gains in the other. Baumeister, Campbell, Krueger, and Vohs (2003) have claimed that self-esteem has no benefits beyond seductive pleasure and may even be detrimental to subsequent performance. Integrating these seemingly contradictory conclusions, we distinguish between (a) older, unidimensional perspectives that focus on global self-esteem and underpin the Baumeister et al. review and (b) more recent, multidimensional perspectives that focus on specific components of self-concept and are the basis of our claim. Supporting the construct validity of a multidimensional perspective, studies show that academic achievement is substantially related to academic self-concept, but nearly unrelated to self-esteem. Consistent with this distinction, research based on our reciprocal-effects model (REM) and a recent meta-analysis show that prior academic self-concept (as opposed to self-esteem) and achievement both have positive effects on subsequent self-concept and achievement. We provide an overview of new support for the generality of the REM for young children, cross-cultural research in non-Western countries, health (physical activity), and nonelite (gymnastics) and elite (international swimming championships) sport. We conclude that future reviews elucidating the significant implications of self-concept for theory, policy, and practice need to account for current research supporting the REM and a multidimensional perspective of self-concept.

  14. NMR characterisation of the minimal interacting regions of centrosomal proteins 4.1R and NuMA1: effect of phosphorylation

    PubMed Central

    2010-01-01

    Background Some functions of 4.1R in non-erythroid cells are directly related with its distinct sub-cellular localisation during cell cycle phases. During mitosis, 4.1R is implicated in cell cycle progression and spindle pole formation, and co-localizes with NuMA1. However, during interphase 4.1R is located in the nucleus and only partially co-localizes with NuMA1. Results We have characterized by NMR the structural features of the C-terminal domain of 4.1R and those of the minimal region (the last 64 residues) involved in the interaction with NuMA1. This subdomain behaves as an intrinsically unfolded protein containing a central region with helical tendency. The specific residues implicated in the interaction with NuMA1 have been mapped by NMR titrations and involve the N-terminal and central helical regions. The segment of NuMA1 that interacts with 4.1R is phosphorylated during mitosis. Interestingly, NMR data indicates that the phosphorylation of NuMA1 interacting peptide provokes a change in the interaction mechanism. In this case, the recognition occurs through the central helical region as well as through the C-terminal region of the subdomain meanwhile the N-terminal region do not interact. Conclusions These changes in the interaction derived from the phosphorylation state of NuMA1 suggest that phosphorylation can act as subtle mechanism of temporal and spatial regulation of the complex 4.1R-NuMA1 and therefore of the processes where both proteins play a role. PMID:20109190

  15. O Universo das Sociedades Numa Perspectiva Relativa: Exercícios de Etnoastronomia

    NASA Astrophysics Data System (ADS)

    Fares, Érika Akel; Pessoa Martins, Karla; Maciel Araujo, Lidiane; Sauma Filho, Michel

    2004-12-01

    This work developed at the Planetarium of Pará employing workshops designed for visitor schools (public, private, specials groups), promotes the popularization of the Ethnoastronomy with the aim of diffusing values based on a cultural diversity tolerance and the need of harmonic interplay between people and environment. Using stories and debates, the relationship between humans and the Cosmos is traced from antiquity until today, with the help of slides as a didactic resource. Thus, many conceptions about the origin of the Universe are shown; as well as some constellations created along the History, ending with the present scientific manner of know and explain the World. We then demonstrate the links between space, time and culture with the Cosmos vision. The need to think the World within a plural context to create respect for other different persons is emphasized. Este trabalho, desenvolvido no Planetário do Pará através de oficinas com escolas visitantes (públicas, privadas e grupos especiais), promove a popularização da Etnoastronomia, com o objetivo de difundir valores pautados na tolerância à diversidade cultural e na necessidade da convivência harmônica entre o ser humano e o meio ambiente. Através da contação de histórias e promoção de debate, é tratada a relação dos humanos com o céu desde a antiguidade até os dias atuais, tendo como apoio didático o uso de slides. Assim, são mostradas diversas concepções de origem do Universo; algumas constelações criadas no decorrer da História; e a atual forma científica de conhecer e explicar o mundo. Demonstrando-se, então, a interligação entre espaço, tempo e cultura com a visão do Cosmo. Enfatiza-se a necessidade de se pensar o mundo numa perspectiva relativa ou plural, de forma a propiciar o respeito ao ser diferente.

  16. Achieving High Performance With TCP Over 40 GbE on NUMA Architectures for CMS Data Acquisition

    SciTech Connect

    Bawej, Tomasz; et al.

    2014-01-01

    TCP and the socket abstraction have barely changed over the last two decades, but at the network layer there has been a giant leap from a few megabits to 100 gigabits in bandwidth. At the same time, CPU architectures have evolved into the multicore era and applications are expected to make full use of all available resources. Applications in the data acquisition domain based on the standard socket library running in a Non-Uniform Memory Access (NUMA) architecture are unable to reach full efficiency and scalability without the software being adequately aware about the IRQ (Interrupt Request), CPU and memory affinities. During the first long shutdown of LHC, the CMS DAQ system is going to be upgraded for operation from 2015 onwards and a new software component has been designed and developed in the CMS online framework for transferring data with sockets. This software attempts to wrap the low-level socket library to ease higher-level programming with an API based on an asynchronous event driven model similar to the DAT uDAPL API. It is an event-based application with NUMA optimizations, that allows for a high throughput of data across a large distributed system. This paper describes the architecture, the technologies involved and the performance measurements of the software in the context of the CMS distributed event building.

  17. Sensitivity to changes during antidepressant treatment: a comparison of unidimensional subscales of the Inventory of Depressive Symptomatology (IDS-C) and the Hamilton Depression Rating Scale (HAMD) in patients with mild major, minor or subsyndromal depression.

    PubMed

    Helmreich, Isabella; Wagner, Stefanie; Mergl, Roland; Allgaier, Antje-Kathrin; Hautzinger, Martin; Henkel, Verena; Hegerl, Ulrich; Tadić, André

    2012-06-01

    In the efficacy evaluation of antidepressant treatments, the total score of the Hamilton Depression Rating Scale (HAMD) is still regarded as the 'gold standard'. We previously had shown that the Inventory of Depressive Symptomatology (IDS) was more sensitive to detect depressive symptom changes than the HAMD17 (Helmreich et al. 2011). Furthermore, studies suggest that the unidimensional subscales of the HAMD, which capture the core depressive symptoms, outperform the full HAMD regarding the detection of antidepressant treatment effects. The aim of the present study was to compare several unidimensional subscales of the HAMD and the IDS regarding their sensitivity to changes in depression symptoms in a sample of patients with mild major, minor or subsyndromal depression (MIND). Biweekly IDS-C28 and HAMD17 data from 287 patients of a 10-week randomised, placebo-controlled trial comparing the effectiveness of sertraline and cognitive-behavioural group therapy in patients with MIND were converted to subscale scores and analysed during the antidepressant treatment course. We investigated sensitivity to depressive change for all scales from assessment-to-assessment, in relation to depression severity level and placebo-verum differences. The subscales performed similarly during the treatment course, with slight advantages for some subscales in detecting treatment effects depending on the treatment modality and on the items included. Most changes in depressive symptomatology were detected by the IDS short scale, but regarding the effect sizes, it performed worse than most subscales. Unidimensional subscales are a time- and cost-saving option in judging drug therapy outcomes, especially in antidepressant treatment efficacy studies. However, subscales do not cover all facets of depression (e.g. atypical symptoms, sleep disturbances), which might be important for comprehensively understanding the nature of the disease depression. Therefore, the cost-to-benefit ratio must be

  18. Regional Emissions Data Base and Evaluation System (REDES): Technical and system documentation of Version 2. 0

    SciTech Connect

    Rausch, J.V.; Boyd, G.A.

    1990-11-01

    The US Department of Energy (DOE) Innovative Clean Coal Technology (ICCT) program has solicited proposals from the private sector to demonstrate innovative technologies that allow the clean use of coal as an energy source. To aid in evaluating the potential of these proposed technologies to reduce environmental residuals, DOE and ICCT Source Evaluation Board asked Argonne National Laboratory to develop a series of data bases and a personal-computer-based model. Argonne created version 1.0 of the Regional Emissions Data Base and Evaluation System (REDES) in 1988. Version 1.0 was revised, and Version 2.0 was released in 1989. Version 2.0 of REDES is available to the public through the National Energy Software Center (telephone 708-972-7250). In 1988, Argonne National Laboratory published Regional Emissions Data Base and Evaluation System (REDES), report ANL/EES-TM-351, to document Version 1.0 of the REDES data bases and the computer model. In 1990, Argonne prepared this report to describe the changes and improvements that were made to Version 1.0 of REDES to create Version 2.0. Together with ANL/EES/TM-351, this report provides the user with a complete description of REDES, which is designed to forecast the change in emissions that could result from using a particular clean coal technology. 29 figs., 6 tabs.

  19. Uni-dimensional double development HPTLC-densitometry method for simultaneous analysis of mangiferin and lupeol content in mango (Mangifera indica) pulp and peel during storage.

    PubMed

    Jyotshna; Srivastava, Pooja; Killadi, Bharti; Shanker, Karuna

    2015-06-01

    Mango (Mangifera indica) fruit is one of the important commercial fruit crops of India. Similar to other tropical fruits it is also highly perishable in nature. During storage/ripening, changes in its physico-chemical quality parameters viz. firmness, titrable acidity, total soluble solid content (TSSC), carotenoids content, and other biochemicals are inevitable. A uni-dimensional double-development high-performance thin-layer chromatography (UDDD-HPTLC) method was developed for the real-time monitoring of mangiferin and lupeol in mango pulp and peel during storage. The quantitative determination of both compounds of different classes was achieved by densitometric HPTLC method. Silica gel 60F254 HPTLC plates and two solvent systems viz. toluene/EtOAC/MeOH and EtOAC/MeOH, respectively were used for optimum separation and selective evaluation. Densitometric quantitation of mangiferin was performed at 390nm, while lupeol at 610nm after post chromatographic derivatization. Validated method was used to real-time monitoring of mangiferin and lupeol content during storage in four Indian cultivars, e.g. Bombay green (Bgreen), Dashehari, Langra, and Chausa. Significant correlations (p<0.05) between of acidity and TSSC with mangiferin and lupeol in pulp and peel during storage were also observed.

  20. Comparing the responsiveness of a brief, multidimensional risk screening tool for back pain to its unidimensional reference standards: the whole is greater than the sum of its parts.

    PubMed

    Wideman, Timothy H; Hill, Jonathan C; Main, Chris J; Lewis, Martyn; Sullivan, Michael J L; Hay, Elaine M

    2012-11-01

    Back pain is a leading cause of disability. Previous research suggests that modifiable risk factors influence recovery from back pain, and practice guidelines recommend integrating such factors within primary care management. Toward this goal, a brief, multidimensional questionnaire, the STarT Back Tool, was designed to facilitate risk assessment by reducing the need to administer multiple, unidimensional questionnaires. However, aspects of this tool's clinical utility remain unaddressed. For instance, it is unclear whether this tool is responsive to treatment-related changes or whether clinically meaningful information is lost when it replaces multiple risk questionnaires. This study compared the responsiveness of the STarT Back Tool to its corresponding full-length measures, and evaluated its ability to detect clinically meaningful improvement. The study sample included 300 participants that consulted their doctor with disabling back pain. The STarT Back Tool and its reference standard questionnaires (disability, catastrophizing, fear, and depression) were administered at baseline and 4 months later. Regression analyses tested whether, after controlling for its reference standard questionnaires, the STarT Back Tool (independent variable) predicted treatment-related changes in global improvement, pain severity, disability, catastrophizing, fear, and depression (dependent variables). Receiver operating characteristic analyses determined the level of STarT Back change needed for clinically meaningful improvement. STarT Back scores predicted changes in all dependent variables except depression. Reductions in STarT Back scores predicted meaningful improvement on all dependent variables. These findings suggest that the STarT Back Tool, instead of multiple risk questionnaires, can be used to measure recovery from back pain. Implications for future research and clinical practice are discussed.

  1. Regional emissions data base and evaluation system (REDES): Volume 1, Methodology and user guide

    SciTech Connect

    Boyd, G.A.; VanGroningen, C.; Abel, L.

    1988-06-01

    This report describes an IBM personal-computer (PC) based system designed to aid in the evaluation of proposals to develop and demonstrate new technologies making clean use of coal. It forecasts the emissions that could result from the commercial introduction of a proposed clean coal technology, based on a user-defined market. These emission evaluations for each proposed technology can be saved for future analysis and comparison. The REDES program gives the user a systematic process for entering the characteristics of a particular clean coal technology; it then evaluates and reports on the potential impact that the introduction and commercialization of this proposed technology would have on the environment. In a sense, REDES is like a black box. It will produce evaluations based on any technology characteristics that it receives as input. To help the user of REDES determine the performance that might be expected from these emerging technologies, a set of generic technology characterizations are provided in the data base as a guide (see Vol.3). REDES is written as a run-time module in GURU, an expert system and relational data-base package from Micro Database Systems, Inc. (MDBS) for the IBM PC and compatibles. REDES cannot be executed without the run-time GURU program. This program must be obtained directly from MDBS; it is not available from Argonne National Laboratory (ANL). 15 figs., 5 tabs.

  2. Redes En Acción. Increasing Hispanic participation in cancer research, training, and awareness.

    PubMed

    Ramirez, Amelie G; Talavera, Gregory A; Marti, Jose; Penedo, Frank J; Medrano, Martha A; Giachello, Aida L; Pérez-Stable, Eliseo J

    2006-10-15

    Hispanics are affected by many health care disparities. The National Cancer Institute (NCI), through its Special Populations Branch, is supporting networking and capacity-building activities designed to increase Hispanic participation and leadership in cancer research. Redes En Acción established a national network of cancer research centers, community-based organizations, and federal partners to facilitate opportunities for junior Hispanic scientists to participate in training and research projects on cancer control. Since 2000, Redes En Acción has established a network of more than 1800 Hispanic leaders involved in cancer research and education. The project has sustained 131 training positions and submitted 29 pilot projects to NCI for review, with 16 awards for a total of $800,000, plus an additional $8.8 million in competing grant funding based on pilot study results to date. Independent research has leveraged an additional $32 million in non-Redes funding, and together the national and regional network sites have participated in more than 1400 community and professional awareness events. In addition, the program conducted extensive national survey research that provided the basis for the Redes En Acción Latino Cancer Report, a national agenda on Hispanic cancer issues. Redes En Acción has increased participation in cancer control research, training, and awareness among Hispanic scientists and within Hispanic communities. Cancer 2006. (c) 2006 American Cancer Society.

  3. High-content image informatics of the structural nuclear protein NuMA parses trajectories for stem/progenitor cell lineages and oncogenic transformation.

    PubMed

    Vega, Sebastián L; Liu, Er; Arvind, Varun; Bushman, Jared; Sung, Hak-Joon; Becker, Matthew L; Lelièvre, Sophie; Kohn, Joachim; Vidi, Pierre-Alexandre; Moghe, Prabhas V

    2017-02-01

    Stem and progenitor cells that exhibit significant regenerative potential and critical roles in cancer initiation and progression remain difficult to characterize. Cell fates are determined by reciprocal signaling between the cell microenvironment and the nucleus; hence parameters derived from nuclear remodeling are ideal candidates for stem/progenitor cell characterization. Here we applied high-content, single cell analysis of nuclear shape and organization to examine stem and progenitor cells destined to distinct differentiation endpoints, yet undistinguishable by conventional methods. Nuclear descriptors defined through image informatics classified mesenchymal stem cells poised to either adipogenic or osteogenic differentiation, and oligodendrocyte precursors isolated from different regions of the brain and destined to distinct astrocyte subtypes. Nuclear descriptors also revealed early changes in stem cells after chemical oncogenesis, allowing the identification of a class of cancer-mitigating biomaterials. To capture the metrology of nuclear changes, we developed a simple and quantitative "imaging-derived" parsing index, which reflects the dynamic evolution of the high-dimensional space of nuclear organizational features. A comparative analysis of parsing outcomes via either nuclear shape or textural metrics of the nuclear structural protein NuMA indicates the nuclear shape alone is a weak phenotypic predictor. In contrast, variations in the NuMA organization parsed emergent cell phenotypes and discerned emergent stages of stem cell transformation, supporting a prognosticating role for this protein in the outcomes of nuclear functions.

  4. A comparative analysis of the categorization of multidimensional stimuli: I. Unidimensional classification does not necessarily imply analytic processing; evidence from pigeons (Columba livia), squirrels (Sciurus carolinensis), and humans (Homo sapiens).

    PubMed

    Wills, A J; Lea, Stephen E G; Leaver, Lisa A; Osthaus, Britta; Ryan, Catriona M E; Suret, Mark B; Bryant, Catherine M L; Chapman, Sue J A; Millar, Louise

    2009-11-01

    Pigeons (Columba livia), gray squirrels (Sciurus carolinensis), and undergraduates (Homo sapiens) learned discrimination tasks involving multiple mutually redundant dimensions. First, pigeons and undergraduates learned conditional discriminations between stimuli composed of three spatially separated dimensions, after first learning to discriminate the individual elements of the stimuli. When subsequently tested with stimuli in which one of the dimensions took an anomalous value, the majority of both species categorized test stimuli by their overall similarity to training stimuli. However some individuals of both species categorized them according to a single dimension. In a second set of experiments, squirrels, pigeons, and undergraduates learned go/no-go discriminations using multiple simultaneous presentations of stimuli composed of three spatially integrated, highly salient dimensions. The tendency to categorize test stimuli including anomalous dimension values unidimensionally was higher than in the first set of experiments and did not differ significantly between species. The authors conclude that unidimensional categorization of multidimensional stimuli is not diagnostic for analytic cognitive processing, and that any differences between human's and pigeons' behavior in such tasks are not due to special features of avian visual cognition.

  5. Regional emissions data base and evaluation system (REDES): Volume 2, Regional emissions evaluation data base (REED)

    SciTech Connect

    Boyd, G.A.; Campbell, A.P.; Davis, M.J.; Veselka, T.D.

    1988-08-01

    A three-volume report has been prepared to document these REDES data bases and computer model. This volume documents the data base for forecasting emissions. This disaggregated forecast data base of energy use and emissions for electric utility and industrial boilers for 1985 through 2010 is called REED (Regional Emissions Evaluation Data Base). The other volumes describe the methodology of the evaluation system and user-driven menu system (Vol. 1) and document the data base that characterizes 21 generic technologies (Vol. 3). All three volumes provide the user with a complete description of REDES, which is designed to forecast the change in emissions that could result from using a particular clean coal technology. The US Department of Energy's Innovative Clean Coal Technology (ICCT) program has solicited proposals from the private sector to demonstrate innovative technologies that allow the clean use of coal as an energy source. The US Department of Energy and the ICCT Source Evaluation Board requested that Argonne National Laboratory develop two data bases and a personal-computer-based model to aid in evaluating the potential for these proposed technologies to reduce environmental residuals. Version 1.0 of the Regional Emissions Data Base and Evaluation System (REDES) is available to the public through the National Energy Software Center. 41 refs., 16 tabs.

  6. National Urbanization Monitoring Assessment (NUMA)

    USGS Publications Warehouse

    Hester, Dave

    2006-01-01

    A core geographic science element of the U.S. Geological Survey's Geographic Analysis and Monitoring (GAM) Program is to monitor land-surface change for the Nation through time. The Nation's land surface is dynamically evolving and transitioning in response to natural and human processes. The need to understand the transformations and locations where changes are taking place, their underlying causes, and the rate at which the transitions are occurring is fundamental to the health and viability of the Nation's natural and developed environments.

  7. Advances in the U.S. Navy Non-hydrostatic Unified Model of the Atmosphere (NUMA): LES as a Stabilization Methodology for High-Order Spectral Elements in the Simulation of Deep Convection

    NASA Astrophysics Data System (ADS)

    Marras, Simone; Giraldo, Frank

    2015-04-01

    The prediction of extreme weather sufficiently ahead of its occurrence impacts society as a whole and coastal communities specifically (e.g. Hurricane Sandy that impacted the eastern seaboard of the U.S. in the fall of 2012). With the final goal of solving hurricanes at very high resolution and numerical accuracy, we have been developing the Non-hydrostatic Unified Model of the Atmosphere (NUMA) to solve the Euler and Navier-Stokes equations by arbitrary high-order element-based Galerkin methods on massively parallel computers. NUMA is a unified model with respect to the following criteria: (a) it is based on unified numerics in that element-based Galerkin methods allow the user to choose between continuous (spectral elements, CG) or discontinuous Galerkin (DG) methods and from a large spectrum of time integrators, (b) it is unified across scales in that it can solve flow in limited-area mode (flow in a box) or in global mode (flow on the sphere). NUMA is the dynamical core that powers the U.S. Naval Research Laboratory's next-generation global weather prediction system NEPTUNE (Navy's Environmental Prediction sysTem Utilizing the NUMA corE). Because the solution of the Euler equations by high order methods is prone to instabilities that must be damped in some way, we approach the problem of stabilization via an adaptive Large Eddy Simulation (LES) scheme meant to treat such instabilities by modeling the sub-grid scale features of the flow. The novelty of our effort lies in the extension to high order spectral elements for low Mach number stratified flows of a method that was originally designed for low order, adaptive finite elements in the high Mach number regime [1]. The Euler equations are regularized by means of a dynamically adaptive stress tensor that is proportional to the residual of the unperturbed equations. Its effect is close to none where the solution is sufficiently smooth, whereas it increases elsewhere, with a direct contribution to the

  8. Rainfall Erosivity Database on the European Scale (REDES): A product of a high temporal resolution rainfall data collection in Europe

    NASA Astrophysics Data System (ADS)

    Panagos, Panos; Ballabio, Cristiano; Borrelli, Pasquale; Meusburger, Katrin; Alewell, Christine

    2016-04-01

    The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the R-factor in the (R)USLE model. The R-factor is calculated from a series of single storm events by multiplying the total storm kinetic energy with the measured maximum 30-minutes rainfall intensity. This estimation requests high temporal resolution (e.g. 30 minutes) rainfall data for sufficiently long time periods (i.e. 20 years) which are not readily available at European scale. The European Commission's Joint Research Centre(JRC) in collaboration with national/regional meteorological services and Environmental Institutions made an extensive data collection of high resolution rainfall data in the 28 Member States of the European Union plus Switzerland in order to estimate rainfall erosivity in Europe. This resulted in the Rainfall Erosivity Database on the European Scale (REDES) which included 1,541 rainfall stations in 2014 and has been updated with 134 additional stations in 2015. The interpolation of those point R-factor values with a Gaussian Process Regression (GPR) model has resulted in the first Rainfall Erosivity map of Europe (Science of the Total Environment, 511, 801-815). The intra-annual variability of rainfall erosivity is crucial for modelling soil erosion on a monthly and seasonal basis. The monthly feature of rainfall erosivity has been added in 2015 as an advancement of REDES and the respective mean annual R-factor map. Almost 19,000 monthly R-factor values of REDES contributed to the seasonal and monthly assessments of rainfall erosivity in Europe. According to the first results, more than 50% of the total rainfall erosivity in Europe takes place in the period from June to September. The spatial patterns of rainfall erosivity have significant differences between Northern and Southern Europe as summer is the most erosive period in Central and Northern Europe and autumn in the

  9. Understanding Parameter Invariance in Unidimensional IRT Models

    ERIC Educational Resources Information Center

    Rupp, Andre A.; Zumbo, Bruno D.

    2006-01-01

    One theoretical feature that makes item response theory (IRT) models those of choice for many psychometric data analysts is parameter invariance, the equality of item and examinee parameters from different examinee populations or measurement conditions. In this article, using the well-known fact that item and examinee parameters are identical only…

  10. Progress in Characterizing Strictly Unidimensional IRT Representations

    DTIC Science & Technology

    1990-11-29

    Education Armidalie. New South Wales 23SI Research Laboratory AUTRALIA Dr. Paul Horst University 01 Illinois 677 G Sure.184 UrbanaIL 61801 Mr. Paul Foley...dimensionality of standardized tests for tile National Assessment of Educational Progress is described by Zwick (1987). 2.2 Essential independence A successful...Measurement Laboratory, Department of Educational Psy- chology, University of Illinois at Urbana-Champaign. Lord, F. M. (1980). Application of Item Response

  11. Estimativa de imagens solares soho através de redes neurais artificiais

    NASA Astrophysics Data System (ADS)

    Andrade, M. C.; Fernandes, F. C. R.; Cecatto, J. R.; Rios Neto, A.; Rosa, R. R.; Sawant, H. S.

    2003-08-01

    A Rede Neural Artificial (RNA), no âmbito da teoria computacional, constitui uma teoria emergente que, por possuir habilidade em aprender a partir de dados de entrada, encontra diferentes aplicações em diferentes áreas. Um exemplo é a utilização de RNA na caracterização de padrões associados à dinâmica de processos espaço-temporais relacionados a fenômenos físicos não-lineares. Para obter informações sobre o comportamento destes fenômenos físicos utiliza-se, em diversos casos, seqüências de imagens digitalizadas, onde a caracterização de alguns fenômenos espaço-temporais é o procedimento mais viável para descrever a dinâmica das regiões ativas do Sol. Com base em imagens observadas por telescópios a bordo de satélites, estudos de previsão de eventos solares podem ser programados, permitindo prever possíveis efeitos posteriores nas regiões mais próximas da Terra (tempestades geomagnéticas e irregularidades ionosféricas). Neste trabalho avaliamos o desempenho da RNA para estimar padrões espaço-temporais, ou seja, imagens solares em ultravioleta, obtidas através do telescópio a bordo do satélite SOHO. Os resultados mostraram que as RNA conseguem generalizar os padrões de maneira satisfatória sem perder de forma significativa os principais aspectos da configuração global da atmosfera solar, comprovando a eficácia da RNA como ferramenta para esse tipo de aplicação. Portanto, este trabalho comprova a viabilidade de uso desta ferramenta em projetos voltados ao estudo do comportamento solar, em trabalhos do grupo de Física do Meio Interplanetário (FMI) na DAS e em programas desenvolvidos pelo Núcleo de Simulação e Análise de Sistemas Complexos (NUSASC) do Laboratório Associado de Computação e Matemática Aplicada (LAC) do INPE.

  12. Development of an Unified Atmospheric Model (NUMA)

    DTIC Science & Technology

    2010-08-12

    order mode, primarily used with quads and inexact integration (e.g., using Lobatto points avoids non-diagonal mass matrix with slight error since...integration is O(2N-1)) •  No analog of Lobatto points exist on the triangle so costly to use •  Excellent scalability on MPP Discontinuous...functions: 3D tensor products of Lobatto -Gauss-Legendre (LGL) points. Elements are hexahedra (Triangular prisms coming soon). •  Time-Integrators are

  13. Assessing Fit of Unidimensional Graded Response Models Using Bayesian Methods

    ERIC Educational Resources Information Center

    Zhu, Xiaowen; Stone, Clement A.

    2011-01-01

    The posterior predictive model checking method is a flexible Bayesian model-checking tool and has recently been used to assess fit of dichotomous IRT models. This paper extended previous research to polytomous IRT models. A simulation study was conducted to explore the performance of posterior predictive model checking in evaluating different…

  14. Bias Coefficients for Lack of Invariance in Unidimensional IRT Models.

    ERIC Educational Resources Information Center

    Rupp, Andre A.; Zumbo, Bruno D.

    The feature that makes item response theory (IRT) models the models of choice for many psychometric data analysts is parameter invariance, the equality of item and examinee parameters from different populations. Using the well-known fact that item and examinee parameters are identical only up to a set of linear transformations specific to the…

  15. Controlling chaos in unidimensional maps using macroevolutionary algorithms.

    PubMed

    Marín, Jesús; Solé, Ricard V

    2002-02-01

    We introduce a simple search algorithm that explores the parameter of periodically perturbed discrete maps in order to find desired orbits through chaos control. The method has been applied to one-dimensional maps but is easily extendable to higher-dimensional systems. Here, we consider two types of chaos control involving proportional pulses in the system variables [Phys. Rev. Lett. 72, 1455 (1994)] and constant feedback [Phys. Rev. E 51, 6239 (1995)], the first case being presented in detail. It is shown that our method allows a rapid exploration of parameter space and the finding of high-fitness (i.e., controlled) solutions close to the target orbits, even when high periodicities are required.

  16. Limitations of Coefficient Alpha as an Index of Test Unidimensionality

    ERIC Educational Resources Information Center

    Green, Samual B.; And Others

    1977-01-01

    Confusion in the literature between the concepts of internal consistency and homogeneity has led to a misuse of coefficient alpha as an index of item homogeneity. This misuse is discussed and several indices of item homogeneity derived from the model of common factor analysis are offered as alternatives. (Author/JKS)

  17. Shape determination of unidimensional objects: the virtual image correlation method

    NASA Astrophysics Data System (ADS)

    Francois, M.; Semin, B.; Auradou, H.; Vatteville, J.

    2010-06-01

    The proposed method, named Virtual Image Correlation, allows one to identify an analytical expression of the shape of a curvilinear object from its image. It uses a virtual beam, whose curvature field is expressed as a truncated mathematical series. The virtual beam width only needs to be close to the physical one; its gray level (in the transverse direction) is bell-shaped. The method consists in finding the coefficients of the series for which the correlation between physical and virtual beams is the best. The accuracy and the robustness of the method is shown by the mean of two examples. The first details a Young’s modulus identification from a cantilever beam image. The second is relative to a thermal plume image, that have a weak contrast and a lot of noise.

  18. Unidimensional and Multidimensional Models for Item Response Theory.

    ERIC Educational Resources Information Center

    McDonald, Roderick P.

    This paper provides an up-to-date review of the relationship between item response theory (IRT) and (nonlinear) common factor theory and draws out of this relationship some implications for current and future research in IRT. Nonlinear common factor analysis yields a natural embodiment of the weak principle of local independence in appropriate…

  19. The Oral Health Impact Profile-14: a unidimensional scale?

    PubMed

    Santos, Camila Mello dos; Oliveira, Branca Heloisa de; Nadanovsky, Paulo; Hilgert, Juliana Balbinot; Celeste, Roger Keller; Hugo, Fernando Neves

    2013-04-01

    The aim of this study was to investigate the dimensional structure of the Oral Health Impact Profile-14: (OHIP-14). Data was obtained from studies carried out in Rio de Janeiro (N = 504) and Carlos Barbosa (N = 872), in the State of Rio Grande do Sul, Brazil. Exploratory factor analysis (EFA) was performed to identify the latent dimensions of the OHIP-14. Confirmatory factor analysis (CFA) was carried out of both samples to compare the one-dimensional structure found by the EFA and the proposed three-dimensional structure. This factorial structure was assessed using goodness-of-fit indices. In the Rio de Janeiro study, the eigenvalue was 9.2 and this one factor explained 65.6% of total variance, while in the Carlos Barbosa study the eigenvalue was 7.9 and this one factor explained 56.6% of variance. CFA indicated an adequate fit of the one-factor model for the Rio de Janeiro study (RMSEA = 0.04; CFI = 0.98; TLI = 0.98) and for the Carlos Barbosa study (RMSEA = 0.05; CFI = 0.97; TLI = 0.97). Our findings suggest that the OHIP-14 measures one single construct.

  20. Quaternary glacial geomorphosites from the Cantabrian Mountains (northern Iberian Peninsula): the Redes Natural Reservation and Picos de Europa Regional Park

    NASA Astrophysics Data System (ADS)

    Rodríguez-Rodríguez, Laura; Jiménez-Sánchez, Montserrat; José Domínguez-Cuesta, María

    2013-04-01

    The Cantabrian Mountains is a mountain range 480 km-long and up to 2,648 m altitude (Torre Cerredo Peak) trending parallel to the Cantabrian Coastline between Pyrenees and the northwest corner of the Iberian Peninsula (~43oN 5oW). This mountain range is an outstanding area to research the climatic patterns across South Europe during the Quaternary glaciations since well-preserved glacial features evidence the occurrence of past mountain glaciations in a climatic environment marked by the transition from a maritime climate (Atlantic) to Mediterranean one across the mountain range. The available studies in the Cantabrian Mountains stand that the regional glacial maximum recorded here is prior to ca 38, and that glaciers were in some locations remarkably retreated by the time of the global Last Glacial Maximum (Jiménez-Sánchez et al., in press; Serrano et al., in press). This study is focused on an area about 800 km2 that includes 36 peaks over 2,000 m (Pico Mampodre; 2,192 m) and partially covers the Redes Natural Reservation and Picos de Europa Regional Park. A geomorphologic database in ArcGIS was produced for this area as a previous step to reconstruct in detail the extent, flow pattern and chronology of the former glaciers (PhD under progress). Here we present a selection of 18 glacial geomorphosites classified according to genetic criteria in sites that show: (i) a nicely preserved moraine sequence recording the transition from glacial to periglacial conditions; (ii) glacial erosion features; (iii) glacial and ice related deposits (like moraines, ice-dammed deposits, erratic boulders or fluvio-glacial deposits); (iv) slope instability related to glacial debuttressing (complex landslides and rock avalanches); and (v) the interaction between the landscape and human activity. The interest of the geomorphosites is supported by its good quality of preservation, allowing its use as a basis to reconstruct the glacial and paraglacial processes in this region during

  1. [Strategies for integration of health care practices and sanitary surveillance in the context of the implementation of Rede Cegonha - a Brazilian mother and infant health care network].

    PubMed

    Fernandes, Roberta Zanelli Sartori; Vilela, Maria Filomena de Gouveia

    2014-11-01

    Mother and infant mortality has been the scope of analysis throughout the history of public health in Brazil and various strategies to tackle the issue have been proposed to date. The Ministry of Health has been working on this and the Rede Cegonha strategy is the most recent policy in this context. Given the principle of comprehensive health care and the structure of the Unified Health System in care networks, it is necessary to ensure the integration of health care practices, among which are the sanitary surveillance actions (SSA). Considering that the integration of health care practices and SSA can contribute to reduce mother and infant mortality rates, this article is a result of qualitative research that analyzed the integration of these actions in four cities in the State of São Paulo/Brazil: Campinas, Indaiatuba, Jaguariúna and Santa Bárbara D'Oeste. The research was conducted through interviews with SSA and maternal health managers, and the data were evaluated using thematic analysis. The results converge with other studies, identifying the isolation of health care practices and SSA. The insertion of SSA in collectively-managed areas appears to be a potential strategy for health planning and implementation of actions in the context under scrutiny.

  2. Economic evaluation of the Programs Rede Farmácia de Minas do SUS versus Farmácia Popular do Brasil.

    PubMed

    Garcia, Marina Morgado; Guerra, Augusto Afonso; Acúrcio, Francisco de Assis

    2017-01-01

    We conducted an economic assessment of the Pharmaceutical Assistance - Rede Farmácia de Minas Gerais-RFMG and Farmácia Popular do Brasil-FPB to ascertain which of the two models stands out as the most efficient. To do this, a model, which consisted of a study of incurred costs in both programs, up to the dispensing of medicine to citizens, was developed. The uncertainties of the proposed model were tested using the Monte Carlo method. If the entire population initially estimated in the RFMG were attended in the FPB, there would be an additional cost of R$ 139,324,050.19. The sensitivity analysis appeared to be favorable to the RFMG. A total of 10000 simulations were carried out, resulting in a median value of R$ 114,053,709.99 for the RFMG and R$ 254,106,120.65 for the FPB. The current National Drug Policy emphasizes the need to strengthen pharmaceutical services beyond the mere acquisition and delivery of pharmaceutical products. The public healthcare service model, consistent with the principles and guidelines of the SUS, seems to be more appropriate in ensuring complete and universal quality healthcare services to the citizens. The economic study conducted reinforces this fact, as it appears to be a more efficient alternative of the direct use of resources in the public health network.

  3. An update on the Kevorkian-Reding 93 physician-assisted deaths in Michigan: is Kevorkian a savior, serial-killer or suicidal martyr?

    PubMed

    Kaplan, K J; O'Dell, J; Dragovic, L J; McKeon, M C; Bentley, E; Telmet, K L

    This report presents an update of the Kevorkian-Reding physician-assisted (or physician-aided) deaths to include the ninety-three publicly acknowledged cases as of November 25, 1998. These deaths are divided into ten distinct time phases. The following trends emerge. Over two-thirds of the decedents are women, the ratio of females to males varying widely with phase. The proportion of women seems to be the highest when Kevorkian is free to act as he wants and lowest when he seems to be acting under legal or political restraints. Based on autopsy results, only 29.0 percent of the cases are terminal, this percentage being higher among men (37.9%) than among women (25.4%). However, 66.7% of the decedents were disabled, no significant difference emerging between men and women. Further, five out of the six decedents showing no apparent anatomical sign of disease at autopsy were women. Over 80 percent of the physician-assisted deaths are cremated, approximately twice as high a proportion as that emerging for suicides in Michigan and four times as high as cremations occurring with regard to overall deaths. Finally, death by carbon monoxide decreases dramatically with time phase while the use of the contraption dubbed the "suicide machine" increases, suggesting an increasing routinization over time. Finally, during the ninth and tenth phases, Kevorkian's aims and his own suicidality emerge more clearly involving 1) harvesting organs and 2) threat of starving himself in prison if he is convicted. Phase 10 can be seen as an escalation from assisted death to overt euthanasia, repeating the same need for a demonstration (Thomas Youk) that was first exhibited in Phase I (Janet Adkins).

  4. Como os Alunos do Ensino Médio da Rede Estadual de São Paulo obtém Conhecimentos Astronômicos?

    NASA Astrophysics Data System (ADS)

    da Cunha, W. S.; Voelzke, M. R.; Amaral, L. H.

    2005-08-01

    Atualmente vivencia-se um mundo globalizado onde os computadores e a internet permitiram um acesso rápido e seguro a todo tipo de informação e conhecimento. O presente trabalho visa analisar a maneira pela qual alunos de segundo grau da rede estadual da cidade de São Paulo obtiveram, caso tenham, conhecimentos básicos de astronomia quanto aos fenômenos celestes que os rodeiam, tais como a sucessão dos dias e das estações do ano, além de questioná~los sobre fatos genéricos tais como: o que vem a ser o Sol, o Big Bang, o que ocasionou a extinção dos dinossauros. Para tanto foi elaborado um formulário constando de questões de múltipla escolha, o qual foi aplicado no primeiro colegial diurno da Escola Estadual Guilherme de Almeida. Num espaço amostral de 44 alunos constatou-se que 41% dos alunos adquiriram seus conhecimentos astronômicos na escola e 59% através da mídia em geral. Neste mesmo espaço amostral apenas 11% dos alunos usaram computadores na escola, 41% na residência, 5% no trabalho e 43% não utilizaram. O presente estudo revelou também que para 50% dos alunos o professor jamais utilizou um programa de computador a respeito de astronomia ou fez alguma apresentação sobre o tema. Embora em sua fase inicial este estudo revela claramente que a maioria dos alunos não obtém na escola seus conhecimentos astronômicos, estes provém de fontes não especificamente didático-pedagógicas tais como filmes e revistas populares que não raramente geram conhecimentos incompletos e em muitos casos inclusive falhos.

  5. Percepção Astronômica de Alunos do Ensino Médio da Rede Estadual de São Paulo

    NASA Astrophysics Data System (ADS)

    de Oliveira, E. F.; Voelzke, M. R.; Amaral, L. H.

    2005-08-01

    Embora a astronomia seja uma das ciências mais antigas da humanidade e muitos dos conceitos astronômicos serem populares, principalmente nesta época de alta globalização do conhecimento por intermédio de eficientes meios de comunicação e de obtenção da informação, notadamente através da internet, observa-se que uma parcela significativa dos estudantes encontra-se à margem dessas informações. O presente trabalho visa analisar o nível de conhecimento básico dos alunos de Ensino Médio da rede estadual da cidade de Suzano quanto aos fenômenos astronômicos que os rodeiam, tais como a sucessão dos dias e das estações do ano, além de questioná-los sobre fatos genéricos tais como: quais são os astros que se encontram mais próximos do planeta Terra, o que vem a ser o Sol, o Big Bang, um ano-luz, uma estrela cadente, a estrela de Bélem e o que ocasionou a extinção dos dinossauros. Para tanto foi elaborado um formulário constando de questões de múltipla escolha, o qual foi aplicado no primeiro colegial noturno da Escola Estadual Batista Renzi. Num espaço amostral de 34 alunos constatou-se que apenas 29,4% compreendiam a sucessão dos dias da semana, que apenas 20,6% explicaram corretamente as estações do ano, que apenas 20,6% tinham idéia de quais são os objetos celestes mais próximos da Terra, em contraposição 67,6% sabiam classificar corretamente o Sol como estrela, 55,9% relacionavam o Big Bang à origem do universo, apenas 20,6% identificavam um ano-luz como unidade de distância, 32,4% reconheciam uma estrela cadente como meteoro, 41,2% consideravam a estrela de Belém como um cometa e 50,0% explicaram corretamente a extinção dos dinossauros. A presente análise será expandida para as demais classes de primeiro colegial, não somente do período noturno, mas também do diurno da Escola Estadual Batista Renzi, bem como o formulário será devidamente ampliado. Já nesta primeira fase nota-se claramente o pequeno discernimento

  6. Unidimensional IRT Item Parameter Estimates across Equivalent Test Forms with Confounding Specifications within Dimensions

    ERIC Educational Resources Information Center

    Matlock, Ki Lynn; Turner, Ronna

    2016-01-01

    When constructing multiple test forms, the number of items and the total test difficulty are often equivalent. Not all test developers match the number of items and/or average item difficulty within subcontent areas. In this simulation study, six test forms were constructed having an equal number of items and average item difficulty overall.…

  7. The Graded Unfolding Model: A Unidimensional Item Response Model for Unfolding Graded Responses.

    ERIC Educational Resources Information Center

    Roberts, James S.; Laughlin, James E.

    Binary or graded disagree-agree responses to attitude items are often collected for the purpose of attitude measurement. Although such data are sometimes analyzed with cumulative measurement models, recent investigations suggest that unfolding models are more appropriate (J. S. Roberts, 1995; W. H. Van Schuur and H. A. L. Kiers, 1994). Advances in…

  8. A Unidimensional Item Response Model for Unfolding Responses from a Graded Disagree-Agree Response Scale.

    ERIC Educational Resources Information Center

    Roberts, James S.; Laughlin, James E.

    1996-01-01

    A parametric item response theory model for unfolding binary or graded responses is developed. The graded unfolding model (GUM) is a generalization of the hyperbolic cosine model for binary data of D. Andrich and G. Luo (1993). Applicability of the GUM to attitude testing is illustrated with real data. (SLD)

  9. The Assessment of Unidimensionality of Normal and Lognormal Data: A Look at Two Nonparametric Procedures.

    ERIC Educational Resources Information Center

    Seraphine, Anne E.; Algina, James J.; Miller, M. David

    2001-01-01

    Examined the Type I error rate and the power of the Stout T procedure (DIMTEST) (W. Stout, 19987, 1990) and the Holland-Rosenbaum procedure (P. Holland and P. Rosenbaum, 1986) for normal and nonnormal data sets through a Monte Carlo study. Both procedures performed adequately under some conditions, but the Stout T procedure showed adequate power…

  10. Between-Person and Within-Person Subscore Reliability: Comparison of Unidimensional and Multidimensional IRT Models

    ERIC Educational Resources Information Center

    Bulut, Okan

    2013-01-01

    The importance of subscores in educational and psychological assessments is undeniable. Subscores yield diagnostic information that can be used for determining how each examinee's abilities/skills vary over different content domains. One of the most common criticisms about reporting and using subscores is insufficient reliability of subscores.…

  11. Bias of Exploratory and Cross-Validated DETECT Index under Unidimensionality

    ERIC Educational Resources Information Center

    Monahan, Patrick O.; Stump, Timothy E.; Finch, Holmes; Hambleton, Ronald K.

    2007-01-01

    DETECT is a nonparametric "full" dimensionality assessment procedure that clusters dichotomously scored items into dimensions and provides a DETECT index of magnitude of multidimensionality. Four factors (test length, sample size, item response theory [IRT] model, and DETECT index) were manipulated in a Monte Carlo study of bias, standard error,…

  12. The Robustness of IRT-Based Vertical Scaling Methods to Violation of Unidimensionality

    ERIC Educational Resources Information Center

    Yin, Liqun

    2013-01-01

    In recent years, many states have adopted Item Response Theory (IRT) based vertically scaled tests due to their compelling features in a growth-based accountability context. However, selection of a practical and effective calibration/scaling method and proper understanding of issues with possible multidimensionality in the test data is critical to…

  13. Providing Subscale Scores for Diagnostic Information: A Case Study when the Test Is Essentially Unidimensional

    ERIC Educational Resources Information Center

    Stone, Clement A.; Ye, Feifei; Zhu, Xiaowen; Lane, Suzanne

    2010-01-01

    Although reliability of subscale scores may be suspect, subscale scores are the most common type of diagnostic information included in student score reports. This research compared methods for augmenting the reliability of subscale scores for an 8th-grade mathematics assessment. Yen's Objective Performance Index, Wainer et al.'s augmented scores,…

  14. A GPU-Based Gibbs Sampler for a Unidimensional IRT Model

    PubMed Central

    Welling, William S.; Zhu, Michelle M.

    2014-01-01

    Item response theory (IRT) is a popular approach used for addressing large-scale statistical problems in psychometrics as well as in other fields. The fully Bayesian approach for estimating IRT models is usually memory and computationally expensive due to the large number of iterations. This limits the use of the procedure in many applications. In an effort to overcome such restraint, previous studies focused on utilizing the message passing interface (MPI) in a distributed memory-based Linux cluster to achieve certain speedups. However, given the high data dependencies in a single Markov chain for IRT models, the communication overhead rapidly grows as the number of cluster nodes increases. This makes it difficult to further improve the performance under such a parallel framework. This study aims to tackle the problem using massive core-based graphic processing units (GPU), which is practical, cost-effective, and convenient in actual applications. The performance comparisons among serial CPU, MPI, and compute unified device architecture (CUDA) programs demonstrate that the CUDA GPU approach has many advantages over the CPU-based approach and therefore is preferred. PMID:27355058

  15. Applying Unidimensional and Multidimensional Item Response Theory Models in Testlet-Based Reading Assessment

    ERIC Educational Resources Information Center

    Min, Shangchao; He, Lianzhen

    2014-01-01

    This study examined the relative effectiveness of the multidimensional bi-factor model and multidimensional testlet response theory (TRT) model in accommodating local dependence in testlet-based reading assessment with both dichotomously and polytomously scored items. The data used were 14,089 test-takers' item-level responses to the testlet-based…

  16. The Analysis of Dominance Matrices: Extraction of Unidimensional Orders within a Multidimensional Context

    DTIC Science & Technology

    1976-06-01

    index of dimension consistency that is comparable to classical measures such as the Kuder - Richardson formulae (1937) and the Loevinger homogeneity...1975b) is a measure of internal con- sistency calculated from a dominance matrix that functions like the standard Kuder - Richardson formulae (KR...corresponds directly to such classical indices as the Kuder - Richardson formulae (1937) like the internal consistency index proposed by Cliff (1975b

  17. Exploratory Mokken Scale Analysis as a Dimensionality Assessment Tool: Why Scalability Does Not Imply Unidimensionality

    ERIC Educational Resources Information Center

    Smits, Iris A. M.; Timmerman, Marieke E.; Meijer, Rob R.

    2012-01-01

    The assessment of the number of dimensions and the dimensionality structure of questionnaire data is important in scale evaluation. In this study, the authors evaluate two dimensionality assessment procedures in the context of Mokken scale analysis (MSA), using a so-called fixed lowerbound. The comparative simulation study, covering various…

  18. A GPU-Based Gibbs Sampler for a Unidimensional IRT Model.

    PubMed

    Sheng, Yanyan; Welling, William S; Zhu, Michelle M

    2014-01-01

    Item response theory (IRT) is a popular approach used for addressing large-scale statistical problems in psychometrics as well as in other fields. The fully Bayesian approach for estimating IRT models is usually memory and computationally expensive due to the large number of iterations. This limits the use of the procedure in many applications. In an effort to overcome such restraint, previous studies focused on utilizing the message passing interface (MPI) in a distributed memory-based Linux cluster to achieve certain speedups. However, given the high data dependencies in a single Markov chain for IRT models, the communication overhead rapidly grows as the number of cluster nodes increases. This makes it difficult to further improve the performance under such a parallel framework. This study aims to tackle the problem using massive core-based graphic processing units (GPU), which is practical, cost-effective, and convenient in actual applications. The performance comparisons among serial CPU, MPI, and compute unified device architecture (CUDA) programs demonstrate that the CUDA GPU approach has many advantages over the CPU-based approach and therefore is preferred.

  19. Rational Synthesis of New Unidimensional Solids: Chemical and Physical Studies of Mixed Valence Polyiodides.

    DTIC Science & Technology

    1977-12-28

    further structural definition of changes induced by iodination, and extension of physicochemical measurements. The spectroscopic results on Ni(bqd)2...presence of multiple redox states, and the inherent chemical flexibility of phthalo- cyanines suggested attractive donor molecules for the

  20. Unrestricted Factor Analytic Procedures for Assessing Acquiescent Responding in Balanced, Theoretically Unidimensional Personality Scales

    ERIC Educational Resources Information Center

    Ferrando, Pere J.; Lorenzo-Seva, Urbano; Chico, Eliseo

    2003-01-01

    This article describes and proposes an unrestricted factor analytic procedure to: (a) assess the dimensionality and structure of a balanced personality scale taking into account the potential effects of acquiescent responding, and (b) correct the individual trait estimates for acquiescence. The procedure can be considered as an extension of ten…

  1. Psychometric Characteristics of Integrated Multi-Specialty Examinations: Ebel Ratings and Unidimensionality

    ERIC Educational Resources Information Center

    Homer, Matt; Darling, Jonathan; Pell, Godfrey

    2012-01-01

    Over recent years, UK medical schools have moved to more integrated summative examinations. This paper analyses data from the written assessment of undergraduate medical students to investigate two key psychometric aspects of this type of high-stakes assessment. Firstly, the strength of the relationship between examiner predictions of item…

  2. The Development of the Non-hydrostatic Unified Model of the Atmosphere (NUMA)

    DTIC Science & Technology

    2011-09-19

    Space-Time) Spatial Discretization Methods •  Element-based Galerkin Methods –  Continuous Galerkin –  Discontinuous Galerkin Element-based Galerkin ...Challenges Remain •  Continuous and Discontinuous Galerkin methods are good choices for hydrostatic and non-hydrostatic atmospheric models. •  The...capabilities: 1.  Highly scalable on current and future computer architectures (exascale computing: this means CPUs and GPUs ) 2.  Flexibility to use a

  3. The Confounding Effects of Ability, Item Difficulty, and Content Balance within Multiple Dimensions on the Estimation of Unidimensional Thetas

    ERIC Educational Resources Information Center

    Matlock, Ki Lynn

    2013-01-01

    When test forms that have equal total test difficulty and number of items vary in difficulty and length within sub-content areas, an examinee's estimated score may vary across equivalent forms, depending on how well his or her true ability in each sub-content area aligns with the difficulty of items and number of items within these areas.…

  4. A Comparison of Item Parameter Standard Error Estimation Procedures for Unidimensional and Multidimensional Item Response Theory Modeling

    ERIC Educational Resources Information Center

    Paek, Insu; Cai, Li

    2014-01-01

    The present study was motivated by the recognition that standard errors (SEs) of item response theory (IRT) model parameters are often of immediate interest to practitioners and that there is currently a lack of comparative research on different SE (or error variance-covariance matrix) estimation procedures. The present study investigated item…

  5. A Q3 Statistic for Unfolding Item Response Theory Models: Assessment of Unidimensionality with Two Factors and Simple Structure

    ERIC Educational Resources Information Center

    Habing, Brian; Finch, Holmes; Roberts, James S.

    2005-01-01

    Although there are many methods available for dimensionality assessment for items with monotone item response functions, there are few methods available for unfolding item response theory models. In this study, a modification of Yen's Q3 statistic is proposed for the case of these nonmonotone item response models. Through a simulation study, the…

  6. Not All Same-Different Discriminations Are Created Equal: Evidence Contrary to a Unidimensional Account of Same-Different Learning

    ERIC Educational Resources Information Center

    Gibson, Brett M.; Wasserman, Edward A.; Cook, Robert G.

    2006-01-01

    In Experiment 1, we trained four pigeons to concurrently discriminate displays of 16 same icons (16S) from displays of 16 different icons (16D) as well as between displays of same icons (16S) from displays that contained 15 same icons and one different icon (15S:1D). The birds rapidly learned to discriminate 16S vs. 16D displays, but they failed…

  7. Menopausal Sexual Interest Questionnaire (MSIQ): a unidimensional scale for the assessment of sexual interest in postmenopausal women.

    PubMed

    Rosen, Raymond C; Lobo, Rogerio A; Block, Barbara A; Yang, Hwa-Ming; Zipfel, Lisa M

    2004-01-01

    A panel of experts formulated relevant domains of sexual function with a focus on sexual interest and desire. The resulting 10-item scale, the Menopausal Sexual Interest Questionnaire (MSIQ), was examined for reliability (internal consistency and test-retest repeatability), construct validity (concurrent, convergent, and discriminant), sensitivity, and specificity in a clinical trial. A principal components analysis identified three factors (desire, responsiveness, and satisfaction) with eigenvalues > 1. A high degree of internal consistency was observed for each of the three domains. Test-retest repeatability correlation coefficients for domain scores were all highly significant. The MSIQ demonstrated adequate construct validity, with all three domains showing a high degree of sensitivity and with two of the three exhibiting specificity to the effects of treatment.

  8. Rede und Gesinnung (Speech and Ways of Thinking)

    ERIC Educational Resources Information Center

    Kienzle, Bertram

    1974-01-01

    Analyzes some of the basic ideas in Georg Franklin's book "Versuch einer neuen Lehre von den vornehmsten Gegenstanden der deutschen Sprachlehre; nach den Regeln der Vernunftlehre in sechs Abhandlungen verfasst" (1778) and compares them to those of such modern linguists and philosophers a s Searle, Austin and Wunderlich. Concludes that…

  9. Literacy as a Unidimensional Multilevel Construct: Validation, Sources of Influence, and Implications in a Longitudinal Study in Grades 1 to 4

    ERIC Educational Resources Information Center

    Mehta, Paras D.; Foorman, Barbara R.; Branum-Martin, Lee; Taylor, W. Patrick

    2005-01-01

    This study examined the extent to which literacy is a unitary construct, the differences between literacy and general language competence, and the relative roles of teachers and students in predicting literacy outcomes. Much of past research failed to make a distinction between variability in outcomes for individual students and variability for…

  10. Assessing the Unidimensionality of the School and College Ability Test (SCAT, Spanish Version) Using Non-Parametric Methods Based on Item Response Theory

    ERIC Educational Resources Information Center

    Touron, Javier; Lizasoain, Luis; Joaristi, Luis

    2012-01-01

    The aim of this work is to analyze the dimensional structure of the Spanish version of the School and College Ability Test, employed in the process for the identification of students with high intellectual abilities. This test measures verbal and mathematical (or quantitative) abilities at three levels of difficulty: elementary (3rd, 4th, and 5th…

  11. Understanding the Psychopathic Personality Inventory (PPI) in terms of the unidimensionality, orthogonality, and construct validity of PPI-I and -II.

    PubMed

    Neumann, Craig S; Uzieblo, Katarzyna; Crombez, Geert; Hare, Robert D

    2013-01-01

    Comments on an article by Marcus et al. (see record 2011-23134-001). Marcus et al. (this issue) hold that PPI-I and PPI-II are generally orthogonal (uncorrelated). Examination of the primary PPI scales calls this into question. Specifically, the scales that make up Psychopathic Personality Inventory (PPI)-I and PPI-II are differentially correlated in offenders (Neumann et al., 2008) and college students (as reported in Lilienfeld, 1990, final sample). This pattern of correlations indicates that the socalled orthogonal association between PPI-I and PPI-II may be attributable to a statistical "washout" effect, rather than zero correlations across scales. The scales that make up PPI-I and PPI-II may also be correlated differentially with external correlates, rendering interpretation of PPI-I and PPI-II associations with such correlates ambiguous. The overlap of PPI scale scores among forensic and nonforensic samples also is problematic, particularly for the PPI-I scales.

  12. Reciprocal effects between academic self-concept, self-esteem, achievement, and attainment over seven adolescent years: unidimensional and multidimensional perspectives of self-concept.

    PubMed

    Marsh, Herbert W; O'Mara, Alison

    2008-04-01

    In their influential review, Baumeister, Campbell, Krueger, and Vohs (2003) concluded that self-esteem--the global component of self-concept--has no effect on subsequent academic performance. In contrast, Marsh and Craven's (2006) review of reciprocal effects models from an explicitly multidimensional perspective demonstrated that academic self-concept and achievement are both a cause and an effect of each other. Ironically, both reviews cited classic Youth in Transition studies in support of their respective claims. In definitive tests of these counter claims, the authors reanalyze these data-including self-esteem (emphasized by Baumeister et al.), academic self-concept (emphasized by Marsh & Craven), and postsecondary educational attainment-using stronger statistical methods based on five waves of data (grade 10 through 5 years after graduation; N=2,213). Integrating apparently discrepant findings under a common theoretical framework based on a multidimensional perspective, academic self-concept had consistent reciprocal effects with both achievement and educational attainment, whereas self-esteem had almost none.

  13. First-passage-time statistics of a Brownian particle driven by an arbitrary unidimensional potential with a superimposed exponential time-dependent drift

    NASA Astrophysics Data System (ADS)

    Urdapilleta, Eugenio

    2015-12-01

    In one-dimensional systems, the dynamics of a Brownian particle are governed by the force derived from a potential as well as by diffusion properties. In this work, we obtain the first-passage-time statistics of a Brownian particle driven by an arbitrary potential with an exponential temporally decaying superimposed field up to a prescribed threshold. The general system analyzed here describes the sub-threshold signal integration of integrate-and-fire neuron models, of any kind, supplemented by an adaptation-like current, whereas the first-passage-time corresponds to the declaration of a spike. Following our previous studies, we base our analysis on the backward Fokker-Planck equation and study the survival probability and the first-passage-time density function in the space of the initial condition. By proposing a series solution we obtain a system of recurrence equations, which given the specific structure of the exponential time-dependent drift, easily admit a simpler Laplace representation. Naturally, the present general derivation agrees with the explicit solution we found previously for the Wiener process in (2012 J. Phys. A: Math. Theor. 45 185001). However, to demonstrate the generality of the approach, we further explicitly evaluate the first-passage-time statistics of the underlying Ornstein-Uhlenbeck process. To test the validity of the series solution, we extensively compare theoretical expressions with the data obtained from numerical simulations in different regimes. As shown, agreement is precise whenever the series is truncated at an appropriate order. Beyond the fact that both the Wiener and Ornstein-Uhlenbeck processes have a direct interpretation in the context of neuronal models, given their ubiquity in different fields, our present results will be of interest in other settings where an additive state-independent temporal relaxation process is being developed as the particle diffuses.

  14. Astronomical Perception of the Secondary School's Students in São Paulo's State School in Suzano City. (Spanish Title: Percepción Astronómica de Alumnos de la Enseñanza Media de la Red Estatal de San Pablo en la Ciudad de Suzano.) Percepção Astronômica de um Grupo de Alunos do Ensino Médio da Rede Estadual de São Paulo da Cidade de Suzano

    NASA Astrophysics Data System (ADS)

    França de Oliveira, Edilene; Voelzke, Marcos Rincon; Amaral, Luis Henrique

    2007-12-01

    año y 20,6% tenían la idea de cuales son los objetos celestes más cercanos de la Tierra. En contraposición, 67,6% clasificaron correctamente el Sol como una estrella; 55,9% relacionaron el Big Bang al origen del Universo; solamente 20,6% identificaron un año-luz como unidad de distancia y 32,4% reconocieron una estrella fugaz como meteoro. El presente análisis fue expandido para otros grupos de la Enseñanza Media, no solamente del período nocturno, sino también diurno de la misma escuela. En esta primera fase se nota el pequeño conocimiento de los alumnos sobre eventos astronómicos y principalmente la gran confusión sobre el significado correcto de los términos astronómicos populares. Embora a Astronomia seja uma das ciências mais antigas da humanidade e muitos dos conceitos astronômicos serem populares, observa-se que uma parcela significativa dos estudantes encontra-se à margem dessas informações. O presente trabalho visa analisar o nível de conhecimento básico dos alunos do Ensino Médio da Rede Estadual da cidade de Suzano quanto aos fenômenos astronômicos que os rodeiam. Para tanto foi elaborado um formulário constando de questões de múltipla escolha, aplicado no primeiro ano noturno da Escola Estadual Batista Renzi. Num espaço amostral de 34 alunos constatou-se que apenas 29,4% compreendiam a sucessão dos dias; 20,6% explicaram corretamente as estações do ano e 20,6% tinham idéia de quais são os objetos celestes mais próximos da Terra. Em contraposição, 67,6% classificaram corretamente o Sol como estrela; 55,9% relacionaram o Big Bang à origem do Universo; apenas 20,6% identificaram um ano-luz como unidade de distância e 32,4% reconheceram uma estrela cadente como meteoro. A presente análise foi expandida para mais 310 alunos de outras classes de Ensino Médio, não somente do período noturno, mas também diurno da mesma escola. Nesta primeira fase nota-se o pequeno discernimento dos alunos sobre eventos astronômicos e

  15. Nuevas tecnicas basadas en redes neuronales para el diseno de filtros de microondas multicapa apantallados

    NASA Astrophysics Data System (ADS)

    Pascual Garcia, Juan

    In this PhD thesis one method of shielded multilayer circuit neural network based analysis has been developed. One of the most successful analysis procedures of these kind of structures is the Integral Equation technique (IE) solved by the Method of Moments (MoM). In order to solve the IE, in the version which uses the media relevant potentials, it is necessary to have a formulation of the Green's functions associated to the mentioned potentials. The main computational burden in the IE resolution lies on the numerical evaluation of the Green's functions. In this work, the circuit analysis has been drastically accelerated thanks to the approximation of the Green's functions by means of neural networks. Once trained, the neural networks substitute the Green's functions in the IE. Two different types of neural networks have been used: the Radial basis function neural networks (RBFNN) and the Chebyshev neural networks. Thanks mainly to two distinct operations the correct approximation of the Green's functions has been possible. On the one hand, a very effective input space division has been developed. On the other hand, the elimination of the singularity makes feasible the approximation of slow variation functions. Two different singularity elimination strategies have been developed. The first one is based on the multiplication by the source-observation points distance (rho). The second one outperforms the first one. It consists of the extraction of two layers of spatial images from the whole summation of images. With regard to the Chebyshev neural networks, the OLS training algorithm has been applied in a novel fashion. This method allows the optimum design in this kind of neural networks. In this way, the performance of these neural networks outperforms greatly the RBFNNs one. In both networks, the time gain reached makes the neural method profitable. The time invested in the input space division and in the neural training is negligible with only few circuit analysis. To show, in a practical way, the ability of the neural based analysis method, two new design procedures have been developed. The first method uses the Genetic Algorithms to optimize an initial filter which does not fulfill the established specifications. A new fitness function, specially well suited to design filters, has been defined in order to assure the correct convergence of the optimization process. This new function measures the fulfillment of the specifications and it also prevents the appearance of the premature convergence problem. The second method is found on the approximation, by means of neural networks, of the relations between the electrical parameters, which defined the circuit response, and the physical dimensions that synthesize the aforementioned parameters. The neural networks trained with these data can be used in the design of many circuits in a given structure. Both methods had been show their ability in the design of practical filters.

  16. Actividad funcional cerebral en estado de reposo: REDES EN CONEXIÓN

    PubMed Central

    Proal, Erika; Alvarez-Segura, Mar; de la Iglesia-Vayá, Maria; Martí-Bonmatí, Luis; Castellanos, F. Xavier

    2015-01-01

    Resumen El análisis de la conectividad funcional mediante resonancia magnética funcional (RMf) puede llevarse a cabo durante la realización de una tarea, la percepción de un estímulo o en estado de reposo. Estos análisis han demostrado su fiabilidad y reproducibilidad con diferentes enfoques (matemáticos, estadísticos, físicos) para seleccionar los vóxeles activados. El estudio de la señal de baja frecuencia en la actividad cerebral a través del contraste BOLD en estado de reposo ha revelado patrones de actividad cortical sincronizados, permitiendo describir la arquitectura funcional intrínseca del cerebro humano. La comunidad científica internacional dispone de recursos compartidos que contribuirán mediante este análisis de RMf en estado de reposo a la obtención de diagnósticos y tratamientos más precisos y avanzados en el campo de las neurociencias. PMID:21365601

  17. Assessing the Dimensionality of NAEP Reading Data.

    ERIC Educational Resources Information Center

    Zwick, Rebecca

    1987-01-01

    National Assessment of Educational Progress reading data were scaled using a unidimensional item response theory model. Bock's full-information factor analysis and Rosenbaum's test of unidimensionality were applied. Conclusions about unidimensionality for balanced incomplete block spiralled data were the same as for complete data. (Author/GDC)

  18. Assessing Dimensionality of a Set of Item Responses--Comparison of Different Approaches.

    ERIC Educational Resources Information Center

    Nandakumar, Ratna

    1994-01-01

    Using simulated and real data, this study compares the performance of three methodologies for assessing unidimensionality: (1) DIMTEST; (2) the approach of Holland and Rosenbaum; and (3) nonlinear factor analysis. All three models correctly confirm unidimensionality, but they differ in their ability to detect the lack of unidimensionality.…

  19. Innovation and communicative action: health management networks and technologies.

    PubMed

    Rivera, Francisco Javier Uribe; Artmann, Elizabeth

    2016-11-03

    This article discusses elements of a theory of innovation from the perspective of innovation networks and social construction of technology, based on Habermas' Theory of Communicative Action and authors from the Sociology of Innovation. Based on the theoretical framework of the communicative production of scientific facts, we focus on innovation management as a basic dimension that must meet some organizational and methodological requirements in order to power its results. We present and discuss instruments such as Situational Planning, Prospective Analysis, Strategic Portfolio Management, and Networks Management that can help deal with the challenge of innovation and exploration of the future. We conclude that network organizational formats centered on reflexivity of interdisciplinary groups and planning approaches that encourage innovation criteria in assessing the attractiveness of activities and that help anticipate forms of innovation through systematic prospective analysis can potentiate the process of generating innovation as a product of networks. Resumo: No artigo são discutidos elementos de uma teoria da inovação numa perspectiva de redes de inovação e de construção social da tecnologia, a partir da Teoria do Agir Comunicativo de Habermas e de autores da Sociologia da Inovação. Com base no marco teórico da produção comunicativa de fatos científicos, focamos a gestão da inovação como uma dimensão fundamental que deve contemplar alguns requisitos, tanto de natureza organizacional quanto metodológica, para potencializar seus resultados. Apresentamos e discutimos instrumentos como o Planejamento Situacional, a Análise Prospectiva, a Gestão Estratégica de Portfólios e a Gestão de Redes que podem contribuir para o desafio da inovação e exploração do futuro. Conclui-se que formas organizativas em rede, centradas na reflexividade de grupos interdisciplinares, e enfoques de planejamento que estimulem o uso de critérios de inovação na

  20. Utilization of nuclear structural proteins for targeted therapy and detection of proliferative and differentiation disorders

    DOEpatents

    Lelievre, Sophie; Bissell, Mina

    2001-01-01

    The localization of nuclear apparatus proteins (NUMA) is used to identify tumor cells and different stages in the tumor progression and differentiation processes. There is a characteristic organization of NuMA in tumor cells and in phenotypically normal cells. NuMA distribution patterns are significantly less diffuse in proliferating non-malignant cells compared to malignant cells. The technique encompasses cell immunostaining using a NuMA specific antibody, and microscopic analysis of NuMA distribution within each nucleus.

  1. The Moon Phases in a Paper Box. (Spanish Title: Las Fases de la Luna en Una Caja de Cartón.) As Fases da Lua Numa Caixa de Papelão

    NASA Astrophysics Data System (ADS)

    de Fátima O. Saraiva, Maria; Amador, Cláudio B.; Kemper, Érico; Goulart, Paulo; Muller, Angela

    2007-12-01

    We present a very simple concrete model to demonstrate the concept of phases of an illuminated body. The main objective of our model is to help the understanding of the Moon phases as viewed from the perspective of an observer on Earth. The material allows the visualization of two important effects: (1st) even though all the time half Moon is illuminated by the Sun, we see different fractions of the illuminated Moon surface, depending on our angle of sight; (2nd) the orientation of the convex part of the Moon in the crescent and waning phases on the sky also depends on our perspective from Earth. The use of a closed box allows one to see the contrast among the different phases with no need of a dark room. We also present a text on the Moon phases, emphasizing the dependence of the aspect of the bright part on the angle of sight. En este trabajo proponemos la construcción de material didáctico de bajo costo para demostración del concepto de fases de un cuerpo iluminado. El principal objetivo de nuestro material es facilitar la comprensión de las fases de la Luna desde la perspectiva de un observador en la Tierra. El material ayuda la visualización de dos efectos importantes: (1º) a pesar de tener siempre la mitad de la Luna (representada por una bolita de espuma plástica o de ping-pong), iluminada por el Sol ( representado por una fuente de luz natural o artificial), vemos diferentes fracciones de su superficie iluminada, dependiendo del ángulo por el cual la vemos; (2º) la orientación del borde convexo de la Luna en las fases Creciente y Menguante también depende de la perspectiva por la cual la miramos desde la Tierra. El uso de una caja cerrada permite observar el contraste entre las diferentes fases sin necesidad de estar en un recinto oscuro. Presentamos también un texto explicativo sobre las fases de la Luna, enfatizando la dependencia de la apariencia de la parte iluminada con el ángulo de visión. Neste trabalho propomos a construção de material didático de baixo custo para demonstração do conceito de fases de um corpo iluminado. O principal objetivo de nosso material é facilitar a compreensão das fases da Lua da perspectiva de um observador na Terra. O material ajuda na visualização de dois efeitos importantes: (1º) mesmo tendo sempre a metade da "Lua" (representada por uma bolinha de isopor ou de ping-pong) iluminada pelo "Sol" (representado por uma fonte de luz natural ou artificial), nós vemos diferentes frações de sua superfície iluminada, dependendo do ângulo pelo qual a olhamos; (2º) a orientação da borda convexa da Lua nas fases Crescente e Minguante também depende da perspectiva pela qual a olhamos da Terra. O uso de uma caixa fechada permite observar o contraste entre as diferentes fases sem necessidade de estar em uma sala escurecida. Apresentamos também um texto explicativo sobre fases da Lua, enfatizando a dependência da aparência da parte iluminada com o ângulo de visada.

  2. Actividad solar del ciclo 23. Predicción del máximo y fase decreciente utilizando redes neuronales

    NASA Astrophysics Data System (ADS)

    Parodi, M. A.; Ceccatto, H. A.; Piacentini, R. D.; García, P. J.

    Different methods have been proposed in order to predict the maximum amplitude of solar cycles, either as a consequence of the intrinsic importance of this event and because of its relation with solar storms and possible effects upon satellites, communication systems, etc. In this work, a neural network solar activity prediction is presented, measured through the sunspot number (SSN). The 16-units neural network, with a 12:3:1 architecture, was trained in a ``feed-forward" propagation way and learning by the so called ``back propagation rule". The annual mean SSN data in the 1700-1975 and 1987-1998 periods were used as the training set. The solar cycle 21 (1976-1986) was taken as the cross-validation data set. After performing the network training we obtained a prediction of the maximum annual mean for the current solar cycle 23, SSNmax= 135 ±17 at the year 2000, which is 13% smaller than the International Consensus Commitee's mean maximum prediction obtained through ``precursor techniques". On the other hand, our prediction is only about 4% smaller than the Consensus's neural network mean prediction. A ``multiple step" prediction technique was also performed and SSN annual mean predicted values for the near-maximum (from the present year 1999 to beyond the maximum) and the declining activity of solar cycle 23 are presented in this work. The sensibility of predictions is also tested. To do so, we changed the interval width and comparated our results with those of a previous neural network prediction and those of others authors using differents methods.

  3. Hacia la predicción del Número R de Wolf de manchas solares utilizando Redes Neuronales con retardos temporales

    NASA Astrophysics Data System (ADS)

    Francile, C.; Luoni, M. L.

    We present a prediction of the time series of the Wolf number R of sunspots using "time lagged feed forward neural networks". We use two types of networks: the focused and distributed ones which were trained with the back propagation of errors algorithm and the temporal back propagation algorithm respectively. As inputs to neural networks we use the time series of the number R averaged annually and monthly with the method IR5. As data sets for training and test we choose certain intervals of the time series similar to other works, in order to compare the results. Finally we discuss the topology of the networks used, the number of delays used, the number of neurons per layer, the number of hidden layers and the results in the prediction of the series between one and six steps ahead. FULL TEXT IN SPANISH

  4. Regional Emissions Data Base and Evaluation System (REDES): Volume 3, Environmental profiles of selected clean coal technologies

    SciTech Connect

    Poch, L.A.; Gillette, J.L.; Boyd, G.A.

    1988-06-01

    The clean coal technologies described in this report make use of advanced combustors, alternative fuels, coal preparation processes, fluidized-bed combustors, flue-gas cleanup technologies, coal liquefaction processes, and surface gasification. Each profile begins with a brief description of the technology, followed by an assessment of its applicability to the utility or industrial sector in terms of fuel sulfur content, boiler size, and boiler market (new, repower, and/or retrofit). The sulfur content of the coal is described as being low, medium, or high. Low-sulfur coal contains less than 1.5% sulfur, medium-sulfur coal has 1.5--3% sulfur, and high-sulfur coal contains greater than 3% sulfur. Boiler size (or unit output of electricity) is discussed in terms of being small, medium, or large. A small boiler has less than 100 MW output, a medium boiler has 100--400 MW output, and a large boiler has greater than 400 MW output. Removal efficiencies or emission levels for sulfur dioxide (SO/sub 2/), oxides of nitrogen (NO/sub x/), and particulates are described, as are the anticipated changes in heat rate that would result from the use of each technology. The wastes generated by each technology are also discussed. Following each technology's profile is a bibliography that lists the sources used to compile the values for the various parameters. 49 refs.

  5. A Next Generation Atmospheric Prediction System for the Navy

    DTIC Science & Technology

    2014-09-30

    MPAS) and the Navy’s NEPTUNE (Navy Environmental Prediction sysTem Utilizing the NUMA corE) using the Naval Postgraduate School’s Nonhydrostatic...The NEPTUNE makes use of the NUMA dynamical core, which is based on the spectral element method. The discretization is performed on hexahedral...NUMA as NEPTUNE (Navy Environmental Prediction sysTem Utilizing NUMA for Efficiency). We have focused on building the infrastructure to run real

  6. One or Two Dimensions in Spontaneous Classification: A Simplicity Approach

    ERIC Educational Resources Information Center

    Pothos, Emmanuel M.; Close, James

    2008-01-01

    When participants are asked to spontaneously categorize a set of items, they typically produce unidimensional classifications, i.e., categorize the items on the basis of only one of their dimensions of variation. We examine whether it is possible to predict unidimensional vs. two-dimensional classification on the basis of the abstract stimulus…

  7. Assessment of the Dimensionality of NAEP Year 15 Reading Data.

    ERIC Educational Resources Information Center

    Zwick, Rebecca

    Reading test data from the National Assessment of Educational Progress (NAEP) were scaled using the unidimensional item response theory model. Data were collected for students aged 9, 13, and 17. To determine whether the responses to the reading items were consistent with unidimensionality, four different methods were applied: (1) principal…

  8. Formulation of a DIMTEST Effect Size Measure (DESM) and Evaluation of the DESM Estimator Bias

    ERIC Educational Resources Information Center

    Seo, Minhee; Roussos, Louis A.

    2010-01-01

    DIMTEST is a widely used and studied method for testing the hypothesis of test unidimensionality as represented by local item independence. However, DIMTEST does not report the amount of multidimensionality that exists in data when rejecting its null. To provide more information regarding the degree to which data depart from unidimensionality, a…

  9. Projective Item Response Model for Test-Independent Measurement

    ERIC Educational Resources Information Center

    Ip, Edward Hak-Sing; Chen, Shyh-Huei

    2012-01-01

    The problem of fitting unidimensional item-response models to potentially multidimensional data has been extensively studied. The focus of this article is on response data that contains a major dimension of interest but that may also contain minor nuisance dimensions. Because fitting a unidimensional model to multidimensional data results in…

  10. A Note on the Dimensionality of Quality of Life Scales: An Illustration with the Satisfaction with Life Scale (SWLS)

    ERIC Educational Resources Information Center

    Slocum-Gori, Suzanne L.; Zumbo, Bruno D.; Michalos, Alex C.; Diener, Ed

    2009-01-01

    A case is made that measures used in quality of life and happiness research will be essentially unidimensional: inherently tapping minor dimensions. This is illustrated using Diener's Satisfaction with Life Scale (SWLS). It is shown that the SWLS does not meet the standard of strict unidimensionality, but that the interpretation of the total scale…

  11. Simultaneous Estimation of Overall and Domain Abilities: A Higher-Order IRT Model Approach

    ERIC Educational Resources Information Center

    de la Torre, Jimmy; Song, Hao

    2009-01-01

    Assessments consisting of different domains (e.g., content areas, objectives) are typically multidimensional in nature but are commonly assumed to be unidimensional for estimation purposes. The different domains of these assessments are further treated as multi-unidimensional tests for the purpose of obtaining diagnostic information. However, when…

  12. An Examination of the Effect of Multidimensionality on Parallel Forms Construction.

    ERIC Educational Resources Information Center

    Ackerman, Terry A.

    This paper examines the effect of using unidimensional item response theory (IRT) item parameter estimates of multidimensional items to create weakly parallel test forms using target information curves. To date, all computer-based algorithms that have been devised to create parallel test forms assume that the items are unidimensional. This paper…

  13. Pragma- und textilinguistische Untersuchungsmethoden zur indirekten Rede im Englischen (Pragmatic and Text-Linguistic Research Methods on Indirect Discourse in English)

    ERIC Educational Resources Information Center

    Ziegesar, Detlef von

    1976-01-01

    Examines the mechanisms involved in changing from direct to indirect discourse, taking as a starting point research findings in linguistic pragmatics, which involve the practical application of speech symbol use between speaker and hearer. (Text is in German.) (IFS/WGA)

  14. Textlinguistik und Schulunterricht. Am Beispiel der Behandlung der indirekten Rede im Englischen. (Text Linguistics and Instruction in the Schools: Example: The Treatment of Indirect Discourse in English).

    ERIC Educational Resources Information Center

    Kueper, Christoph

    1979-01-01

    Compares sentence grammar with text linguistics, giving a survey of the treatment of indirect discourse in school grammars, and finding them inadequate. Recommends rules derived from text linguistics in spite of their greater complexity, because they do not hold the student to mechanical recasting of sentences. (IFS/WGA)

  15. Die Indirekte Rede als Diskursstrategie: Innovative Lehrmethoden zum Konjunktiv I (Indirect Speech as a Discourse Strategy: Innovative Teaching Methods for the Subjunctive).

    ERIC Educational Resources Information Center

    Gramberg, Anne-Kathrin; Heinze, Karin U.

    1993-01-01

    This article talks about the subjunctive of indirect speech, in which its important functions and meanings are depicted. An analysis of the instructional materials used in the first and second years of language study, followed by practical curriculum recommendations, demonstrates how this grammatical phenomenon can be established in an advanced…

  16. Extracción de conocimiento en bases de datos astronómicas mediante redes de neuronas artificiales: aplicaciones en la misión Gaia

    NASA Astrophysics Data System (ADS)

    Fustes Villadóniga, Diego

    2014-02-01

    In the so-called IT era, the capabilities of data acquisition systems have increased to such an extent that it has become difficult to store all the information they produce, and analyse it. This explosion of data has recently appeared in the field of Astronomy, where an increasing number of objects are being observed on a regular basis. An example of this is the upcoming Gaia mission, which will pick up multiple properties of a billion stars, whose information will have a volume of approximately a petabyte. The analysis of a similar amount of information inevitably requires the development of new data analysis methods to extract all the knowledge it contains. This thesis is devoted to the development of data analysis methods to be integrated in the Gaia pipeline, such that knowledge can be extracted from the data collected by the mission. In order to analyze the data from the Gaia mission, the European Space Agency organized the Data Processing and Analysis Consortium (DPAC) which is composed of hundreds of scientists and engineers. DPAC is divided into eight Coordination Units (CUs). This thesis is dedicated to algorithm development in CU8, which is responsible for source classification and astrophysical parameters (AP) estimation. Methods based on Artificial Neural Networks (ANNs) are developed to perform the tasks related to two different work packages in CU8: the GSP-Spec package (GWP-823), and the OA package (GWP-836). The GSP-Spec package is responsible for estimating stellar APs by means of the Radial Velocity Spectrograph (RVS) spectrum. This work presents the development of one of the GSP-Spec modules, which is based on the application of feed-forward ANNs. A methodology is described, based on the optimization of genetic algorithms and aimed at obtaining an optimal set of configuration parameters for the ANN in each case, depending on the signal to noise ratio (SNR) in the RVS spectrum and on the type of star to parameterize. Furthermore, in order to improve the AP estimates, wavelet signal processing techniques, applied to the RVS spectrum, are studied. Despite the effectiveness shown by ANNs in estimating APs, in principle they lack the ability to provide an uncertainty value on these estimates, making it impossible to determine their reliability. Because of this, a new architecture for the ANN is presented in which the inputs and outputs are reversed, so that the ANN estimates the RVS spectrum from the APs. Such an architecture is called Generative ANN (GANN) and is applied to the AP estimation of a set of simulated RVS spectra for the Gaia mission, where it is more effective than the conventional ANN model, in the case of faint stars with low SNR. Finally, the GANN can be applied for obtaining the posterior probability of each of the APs according to the RVS spectrum, allowing for their more complete analysis. Given the nature of the Gaia mission, which is the first astronomical mission that will observe, in an unbiased way, the entire sky up to magnitude 20, a large number of outliers are expected. The OA package in CU8 handles the processing of this type of objects, which are defined as those that could not be reliably classified by the methods in the upstream classification packages. OA methods are based on the unsupervised learning of all outliers. Such learning has two parts: clustering and dimensionality reduction. The Self-Organizing Map (SOM) algorithm is selected as a basis for this learning. Its effectiveness is demonstrated when it is applied, with an optimal configuration, to the Gaia simulations. Furthermore, the algorithm is applied to real outliers from the SDSS catalog. Since a subsequent identification of the clusters obtained by the SOM is necessary, two different methods of identification are applied. The first method is based on the similarity between the SOM prototypes and the Gaia simulations, and the second method is based on the recovery of stored classifications in the SIMBAD catalog by cross-matching celestial coordinates. Thanks to the visualization of the SOM planes, and to both methods of identification, it is possible to distinguish between valid observations and observational artifacts. Furthermore, the method allows for the selection of objects of interest for follow-up observations, in order to determine their nature.

  17. Gaseous detonations

    SciTech Connect

    Nettleton, M.A.

    1987-01-01

    Focusing predominantly on safety problems in handling combustible gas or dust mixtures with air or oxygen, the book is a reference on gaseous detonations. Topics covered include: unidimensional models, structure of detonation fronts, and interaction of a detonation with confinement.

  18. An evaluation of the Organizational Learning Survey.

    PubMed

    Chakrabarty, Subhra; Rogé, Joseph N

    2002-12-01

    A mail survey of a national random sample of 2,000 marketing managers was conducted. The data provided by 221 respondents were analyzed to assess the unidimensionaliry of the 21-item 1997 Organizational Learning Survey developed by Goh and Richards. A confirmatory factor analysis using LISREL 8.30 did not support the unidimensionality of the 21-item survey; however, unidimensionality was established for most of the dimensions. Managerial implications and directions for research were suggested.

  19. Inclusion of Astronomy Themes in an Inovative Approach of Informal Physics Teaching for High School Students. (Spanish Title: Inclusión de Temas Astronómicos en Uma Abordaje Innovadora de la Enseñanza Informal de Física Para Estudiantes de Secumdaria.) Inclusão de Temas Astronômicos Numa Abordagem Inovadora do Ensino Informal de Física Para Estudantes do Ensino Médio

    NASA Astrophysics Data System (ADS)

    Tiara Mota, Aline; de Morais Bonomini, Iracema Ariel; Meloni Martins Rosado, Ricardo

    2009-12-01

    The current work reports on an experience on Astronomy education at the Federal University of Itajubá through an extra-curricular course offered for High School students. This initiative was motivated by the low attention paid to the Astronomy subjects at this stage of the Brazilian Formal Education, in spite that the National Curricular Parameters (PCN and PCN+, in Brazil) point out the importance of their inclusion Este artículo relata una experiencia en la enseñanza de la astronomía efectuada en la Universidad Federal de Itajubá en la forma de un curso de extensión orientado para los estudiantes del colegio secundario. Esta iniciativa surgió de constatar la poca atención dada a la Astronomía en esta etapa de la Educación formal brasileña, a pesar que los Parámetros Curriculares Nacionales (PCN y PCN+, en Brasil) destacan la importancia de su inclusión. Este artigo relata uma experiência em ensino de Astronomia realizada na Universidade Federal de Itajubá na forma de um curso de extensão voltado para alunos do Ensino Médio. Esta iniciativa surgiu da pouca atenção que se dá à Astronomia nesta etapa da Educação embora os Parâmetros Curriculares Nacionais (PCN e PCN+) apontem a importância de sua inclusão.

  20. Memorias Conferencia Internacional IEEE Mexico 1971, Sobre Sistemas, Redes Y Computadoras. Volumen I and Volumen II. (Proceedings of International Conference of IEEE Concerning Systems, Networks, and Computers. Volume I and Volume II.

    ERIC Educational Resources Information Center

    Concheiro, A. Alonso, Ed.; And Others

    The following papers in English from this international conference may be of particular interest to those in the field of education. T. Nakahara, A. Tsukamota, and M. Matsumoto describe a computer-aided design technique for an economical urban cable television system. W. D. Wasson and R. K. Chitkara outline a recognition scheme based on analysis…

  1. Aplicación de técnicas de análisis de redes sociales y de co-ocurrencia de palabras en la determinación de frentes de investigación

    NASA Astrophysics Data System (ADS)

    Boeris, C. E.

    A bibliometric study of the scientific production of the IAR researchers has been performed, with the aim of determining the institute's research fronts and groups of researchers working on these fronts. Methods of analysis of co-occurrence of words, authorship analysis and social network analysis (SNA) has been applied by extracting keywords and the names of the authors on the base of published works. The results support the existence of two research fronts within the institution. FULL TEXT IN SPANISH

  2. Percepção astronómica de um grupo de alunos do ensino médio de uma escola da rede estadual de São Paulo

    NASA Astrophysics Data System (ADS)

    de Oliveria, E. F.; Voelzke, M. R.

    2009-03-01

    Sendo a Astronomia uma das cièncias mais antigas da humanidade, e considerando sua importáncia histórica e cultural, é de extrema releváncia que tópicos relacionados a ela sejam tratados nas escolas. Embora os Parámetros Curriculares Nacionais do Ensino Médio (PCN-EM) e as Orientaçiacute;es Complementares aos Parámetros (PCN+) apontem a importáncia de uma abordagem significativa de conceitos relacionados à Astronomia nas aulas de Física, muitos estudantes terminam o Ensino Médio (EM) sem compreender a razão de certos acontecimentos de origem celeste, ainda que estes façam parte de seu cotidiano e sejam alvos da curiosidade natural dos jovens. Da observação dessa curiosidade em alunos de uma escola pública paulista, na cidade de Suzano, surgiu o interesse em investigar os conhecimentos básicos em Astronomia dos alunos do Ensino Médio desta escola, constituindo-se este como principal objetivo desta pesquisa. Para tanto foi elaborado um questionário de múltipla escolha aplicado inicialmente a 34 alunos do primeiro ano e, posteriormente, a mais 310, distribuídos entre as très séries do Ensino Médio dos períodos matutino e noturno. Dessa forma, observou-se que 73,9% dos estudantes identificaram o Sol como sendo uma estrela, 67,1% mostraram compreender a sucessão entre dia e noite e 52,3% relacionaram o Big Bang à origem do Universo. Em contrapartida, apenas 34,5% relacionaram as estaçíes do ano à inclinação do eixo de rotação da Terra, 21,3% indicaram a influència gravitacional simultánea da Lua e do Sol como responsável pelo fenòmeno das marés, 24,5% indicaram corretamente quais são os objetos celestes mais próximos da Terra, 36,1% identificaram ano-luz como uma medida de distáncia e 34,2% reconheceram as estrelas cadentes como meteoros, evidenciando-se assim o pequeno discernimento dos estudantes quanto aos fenòmenos e termos astronòmicos do cotidiano. Além disso, foram comparadas as respostas de alun! os de diferentes séries e períodos, observando-se, dentre ou tras coi sas, que os estudantes do terceiro ano apresentam um percentual de acertos semelhante ao dos alunos do primeiro, caracterizando que a abordagem de tópicos relacionados à astronomia no Ensino Médio não tem contribuído de forma significativa para uma maior compreensão dos fenòmenos e conceitos.

  3. Análise sobre o Conhecimento de um Grupo de Alunos do Ensino Médio da Rede Estadual de São Paulo sobre Termos e Fenômenos Astronômicos do Cotidiano

    NASA Astrophysics Data System (ADS)

    de Oliveira, E. F.; Voelzke, M. R.; Amaral, L. H.

    2007-08-01

    Embora os Parâmetros Curriculares Nacionais do Ensino Médio (PCN-EM) e as orientações complementares a esses Parâmetros (PCN+) apontem a importância de uma abordagem significativa de conceitos relacionados à astronomia nas aulas de Física, muitos estudantes terminam o Ensino Médio (EM) sem compreender a razão de certos acontecimentos de origem celeste, ainda que estes façam parte de seu cotidiano. Este trabalho tem por objetivo analisar os conhecimentos básicos em astronomia dos alunos de EM da escola estadual Batista Renzi, bem como investigar os meios através dos quais estes conhecimentos foram adquiridos. Para tanto foi elaborado um questionário de múltipla escolha aplicado a 310 alunos distribuídos entre as três séries do EM dos períodos matutino e noturno. Dessa forma, observou-se que apenas 34,5% relacionaram as estações do ano à inclinação do eixo de rotação da Terra, 21,3% indicaram a influência gravitacional da Lua e do Sol como responsáveis pelo fenômeno das marés, 24,5% indicaram corretamente quais são os objetos celestes mais próximos da Terra, 36,1% identificaram ano-luz como uma medida de distância e 34,2% reconheceram uma estrela cadente como meteoro. Em contrapartida, 67,1% compreendiam a sucessão entre dia e noite, 73,9% identificaram o Sol como estrela e 52,3% relacionaram o Big Bang à origem do Universo. Além disso, foram comparadas as respostas de alunos de diferentes séries e períodos, observando-se, dentre outras coisas, que os estudantes do terceiro ano apresentam um percentual de acertos semelhante ao dos alunos do primeiro, caracterizando que a abordagem de tópicos relacionados à astronomia no EM não tem contribuído para uma maior compreensão dos fenômenos e conceitos.

  4. Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions

    PubMed Central

    Park, Yoon Soo; Lee, Young-Sun; Xing, Kuan

    2016-01-01

    This study investigates the impact of item parameter drift (IPD) on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT) models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS) were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results also showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effects on item parameters and examinee ability. PMID:26941699

  5. The Factor Structure of the Values in Action Inventory of Strengths (VIA-IS): An Item-Level Exploratory Structural Equation Modeling (ESEM) Bifactor Analysis.

    PubMed

    Ng, Vincent; Cao, Mengyang; Marsh, Herbert W; Tay, Louis; Seligman, Martin E P

    2016-10-13

    The factor structure of the Values in Action Inventory of Strengths (VIA-IS; Peterson & Seligman, 2004) has not been well established as a result of methodological challenges primarily attributable to a global positivity factor, item cross-loading across character strengths, and questions concerning the unidimensionality of the scales assessing character strengths. We sought to overcome these methodological challenges by applying exploratory structural equation modeling (ESEM) at the item level using a bifactor analytic approach to a large sample of 447,573 participants who completed the VIA-IS with all 240 character strengths items and a reduced set of 107 unidimensional character strength items. It was found that a 6-factor bifactor structure generally held for the reduced set of unidimensional character strength items; these dimensions were justice, temperance, courage, wisdom, transcendence, humanity, and an overarching general factor that is best described as dispositional positivity. (PsycINFO Database Record

  6. The multidimensional assessment of perfectionistic automatic thoughts: a commentary on "Examining mutual suppression effects in the assessment of perfectionism cognitions: evidence supporting multidimensional assessment".

    PubMed

    Flett, Gordon L; Hewitt, Paul L

    2014-12-01

    In the current article, we comment on a recent article by Stoeber, Kobori, and Brown that provided evidence suggesting that a multidimensional approach to perfectionistic cognitions is superior to a unidimensional approach in predicting maladjustment. They also showed with their data from a university student sample that our Perfectionism Cognitions Inventory has multiple factors in contrast to our unidimensional approach. Our commentary focuses primarily on the issue of whether the Perfectionism Cognitions Inventory should be considered unidimensional versus multidimensional and outlines concerns about how perfectionism cognition factors should be used and interpreted. Although there are serious interpretive problems inherent in existing multidimensional measures of perfectionism cognitions, it is apparent that a cognitive approach is an important and viable supplement to the extensive focus on the trait multidimensional perfectionism that is currently in vogue. We conclude by discussing the potential clinical uses of cognitive assessments of perfectionism.

  7. Instruction on Piagetian concepts for children with mental retardation.

    PubMed

    McCormick, P K; Campbell, J W; Pasnak, R; Perry, P

    1990-12-01

    Eighteen children with mild mental retardation were pretested on unidimensional classification (oddity), unidimensional seriation, number conservation, Slosson's Intelligence Test, and the Peabody Picture Vocabulary Test (PPVT). The children were instructed on the Piagetian concepts twice per week for 4 months via a learning-set technique. All 315 problems (except 20 verbal classification and 15 verbal seriation items) involved concrete items. When posttested at the semester's end, the children had, with few exceptions, mastered the Piagetian concepts and made significant gains on performance on the PPVT.

  8. Problem Articulation and the Processes of Assistance: An Activity Theoretic View of Mediation in Game Play

    ERIC Educational Resources Information Center

    Stone, Lynda D.; Gutierrez, Kris D.

    2007-01-01

    In this article, we study a local adaptation of the Fifth Dimension [Cole, M. (1996). "Cultural psychology: A once and future discipline." Cambridge: Cambridge University Press] known as Las Redes (i.e., Networks of Collaboration in the Fifth Dimension) to examine how the multiple activity systems of Las Redes, e.g. the undergraduate course and…

  9. 76 FR 78068 - Agency Information Collection Activities: Proposed Request and Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... criteria. Respondents complete Form SSA-1026-REDE under the following circumstances: (1) When individuals...) (hours) SSA-1026-OCR-MS-SCE 11,400 1 18 3,420 SSA-1026-OCR-SM-REDE 225,000 1 18 67,500 Total 236,400...

  10. Particulate Meso-scale Mechanics Diagnostics: Magnetic Sensors for Dynamic State Orientation

    DTIC Science & Technology

    2013-12-01

    Research Laboratory for giving this opportunity to work at the Eglin AFB, FL. REFERENCES 1. Brian D. Reding , “Development of Particulate Materials...Measurements," Sandia Report, 1984. 15. I.N. Tansel, B. Reding , W. L. Cooper, “Lagrangian Point State Estimation with Optimized, Redundant Induction Coil

  11. The Meaning and Measurement of Quality in the Undergraduate Experience.

    ERIC Educational Resources Information Center

    Kuh, George D.

    In an examination of the meaning and measurement of quality in the undergraduate experience, quality is compared with the conceptually similar but distinct concepts of adequacy and excellence. Most of the conceptual frameworks available for assessing quality are essentially unidimensional assessment strategies that rely almost exclusively on…

  12. A Mokken Scale to Assess Secondary Pupils' Experience of Violence in Terms of Severity

    ERIC Educational Resources Information Center

    Mooij, Ton

    2012-01-01

    Violence assessment can potentially be improved by Item Response Theory, that is, ordinal Mokken Scale Analysis. The research question is as follows: Does Mokken Scale Analysis of secondary pupils' experience of violence result in a homogeneous, reliable, and valid unidimensional scale that fits all the requirements of Mokken scaling? The method…

  13. A Rasch-Based Validation of the Hooper Visual Organization Test in Chinese-Speaking Children

    ERIC Educational Resources Information Center

    Wuang, Yee-Pay; Wang, Li-Chen; Su, Chwen-Yng

    2010-01-01

    The aim of this study was to examine the validation of the Hooper Visual Organization Test (HVOT) for use in children by testing for item fit, unidimensionality, item hierarchy, reliability, and screening capacity. A modified scoring system was devised for the HVOT so that children received some credit for being able to describe the function of…

  14. Multigroup Generalizability Analysis of Verbal, Quantitative, and Nonverbal Ability Tests for Culturally and Linguistically Diverse Students

    ERIC Educational Resources Information Center

    Lakin, Joni M.; Lai, Emily R.

    2012-01-01

    For educators seeking to differentiate instruction, cognitive ability tests sampling multiple content domains, including verbal, quantitative, and nonverbal reasoning, provide superior information about student strengths and weaknesses compared with unidimensional reasoning measures. However, these ability tests have not been fully evaluated with…

  15. Cognitive Correlates of Math Skills in Third-Grade Students

    ERIC Educational Resources Information Center

    Mannamaa, Mairi; Kikas, Eve; Peets, Katlin; Palu, Anu

    2012-01-01

    Math achievement is not a unidimensional construct but includes different skills that require different cognitive abilities. The focus of this study was to examine associations between a number of cognitive abilities and three domains of math skills (knowing, applying and problem solving) simultaneously in a multivariate framework. Participants…

  16. A Binary Programming Approach to Automated Test Assembly for Cognitive Diagnosis Models

    ERIC Educational Resources Information Center

    Finkelman, Matthew D.; Kim, Wonsuk; Roussos, Louis; Verschoor, Angela

    2010-01-01

    Automated test assembly (ATA) has been an area of prolific psychometric research. Although ATA methodology is well developed for unidimensional models, its application alongside cognitive diagnosis models (CDMs) is a burgeoning topic. Two suggested procedures for combining ATA and CDMs are to maximize the cognitive diagnostic index and to use a…

  17. Development and Application of Methods for Estimating Operating Characteristics of Discrete Test Item Responses without Assuming any Mathematical Form.

    ERIC Educational Resources Information Center

    Samejima, Fumiko

    In latent trait theory the latent space, or space of the hypothetical construct, is usually represented by some unidimensional or multi-dimensional continuum of real numbers. Like the latent space, the item response can either be treated as a discrete variable or as a continuous variable. Latent trait theory relates the item response to the latent…

  18. A General Model for Free Response Data

    ERIC Educational Resources Information Center

    Samejima, Fumiko

    1972-01-01

    This paper proposes a general model for free-response data collected for measuring a specified unidimensional psychological process; systematizes situations which vary with respect to the scoring level of items; and finds out general conditions for the operating characteristic of an item response category to provide a unique maximum likelihood…

  19. Psychometric Properties of Measures of Team Diversity with Likert Data

    ERIC Educational Resources Information Center

    Deng, Lifang; Marcoulides, George A.; Yuan, Ke-Hai

    2015-01-01

    Certain diversity among team members is beneficial to the growth of an organization. Multiple measures have been proposed to quantify diversity, although little is known about their psychometric properties. This article proposes several methods to evaluate the unidimensionality and reliability of three measures of diversity. To approximate the…

  20. Daring to Care: The Role of Culturally Relevant Care in Mentoring Black and Latino Male High School Students

    ERIC Educational Resources Information Center

    Watson, Wanda; Sealey-Ruiz, Yolanda; Jackson, Iesha

    2016-01-01

    This study seeks to challenge the uni-dimensional way care in school is written about by highlighting an often overlooked aspect of care--the kind that students do for each other. Data is drawn from focus groups conducted with the youth participants and founder of Umoja Network for Young Men (UMOJA), an all-male, school-based mentoring program for…

  1. Child's Positive and Negative Impacts on Parents--A Person-Oriented Approach to Understanding Temperament in Preschool Children with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Bostrom, P. K.; Broberg, M.; Bodin, L.

    2011-01-01

    Background: Despite previous efforts to understand temperament in children with intellectual disability (ID), and how child temperament may affect parents, the approach has so far been unidimensional. Child temperament has been considered in relation to diagnosis, with the inherent risk of overlooking individual variation of children's temperament…

  2. Ramsay-Curve Item Response Theory for the Three-Parameter Logistic Item Response Model

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2008-01-01

    In Ramsay-curve item response theory (RC-IRT), the latent variable distribution is estimated simultaneously with the item parameters of a unidimensional item response model using marginal maximum likelihood estimation. This study evaluates RC-IRT for the three-parameter logistic (3PL) model with comparisons to the normal model and to the empirical…

  3. Ramsay-Curve Item Response Theory (RC-IRT) to Detect and Correct for Nonnormal Latent Variables

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2006-01-01

    Popular methods for fitting unidimensional item response theory (IRT) models to data assume that the latent variable is normally distributed in the population of respondents, but this can be unreasonable for some variables. Ramsay-curve IRT (RC-IRT) was developed to detect and correct for this nonnormality. The primary aims of this article are to…

  4. Toward a Descriptive Science of Teaching: How the TDOP Illuminates the Multidimensional Nature of Active Learning in Postsecondary Classrooms

    ERIC Educational Resources Information Center

    Hora, Matthew T.

    2015-01-01

    Detailed accounts of teaching can shed light on the nature and prevalence of active learning, yet common approaches reduce teaching to unidimensional descriptors or binary categorizations. In this paper, I use the instructional systems-of-practice framework and the Teaching Dimensions Observation Protocol (TDOP) to advance an approach to thinking…

  5. Identifying Country-Specific Cultures of Physics Education: A Differential Item Functioning Approach

    ERIC Educational Resources Information Center

    Mesic, Vanes

    2012-01-01

    In international large-scale assessments of educational outcomes, student achievement is often represented by unidimensional constructs. This approach allows for drawing general conclusions about country rankings with respect to the given achievement measure, but it typically does not provide specific diagnostic information which is necessary for…

  6. Dimensions, Patterns, and Personality Correlates of Drug Abuse in an Offender Population.

    ERIC Educational Resources Information Center

    Holland, Terrill R.

    1978-01-01

    Drug abuse scores from prisoners resulted in two factors describing lifetime use of cannabis versus opiates. Analysis of Minnesota Multiphasic Personality Inventory (MMPI) profiles versus drug abuse patterns indicated moderate, unidimensional relationship between variables. MMPI profiles of opiate users were similar to those identified in research…

  7. Variability in Parameter Estimates and Model Fit across Repeated Allocations of Items to Parcels

    ERIC Educational Resources Information Center

    Sterba, Sonya K.; MacCallum, Robert C.

    2010-01-01

    Different random or purposive allocations of items to parcels within a single sample are thought not to alter structural parameter estimates as long as items are unidimensional and congeneric. If, additionally, numbers of items per parcel and parcels per factor are held fixed across allocations, different allocations of items to parcels within a…

  8. Concurrent Adaptive Measurement of Multiple Abilities.

    ERIC Educational Resources Information Center

    Ackerman, Terry A.; Davey, Tim C.

    An adaptive test can usually match or exceed the measurement precision of conventional tests several times its length. This increased efficiency is not without costs, however, as the models underlying adaptive testing make strong assumptions about examinees and items. Most troublesome is the assumption that item pools are unidimensional. Truly…

  9. Measuring Interpersonal Callousness in Boys from Childhood to Adolescence: An Examination of Longitudinal Invariance and Temporal Stability

    ERIC Educational Resources Information Center

    Obradovic, Jelena; Pardini, Dustin A.; Long, Jeffrey D.; Loeber, Rolf

    2007-01-01

    Studies show interpersonal callousness (IC) plays an important role in understanding persistent antisocial behaviors; however, it remains unclear whether IC is a unidimensional construct, represented by invariant behavioral indexes and stable across different developmental periods. This study explores the structure and stability of IC using parent…

  10. Fitting the Mixed Rasch Model to a Reading Comprehension Test: Identifying Reader Types

    ERIC Educational Resources Information Center

    Baghaei, Purya; Carstensen, Claus H.

    2013-01-01

    Standard unidimensional Rasch models assume that persons with the same ability parameters are comparable. That is, the same interpretation applies to persons with identical ability estimates as regards the underlying mental processes triggered by the test. However, research in cognitive psychology shows that persons at the same trait level may…

  11. Sustainable Communities: A Lens for Envisioning and Achieving a Community-Based Culture of Social and Ecological Peace

    ERIC Educational Resources Information Center

    Verhagen, Frans C.

    2014-01-01

    One of the obstacles to dealing with the social and ecological crises that obstruct the achievement of a culture of peace is silo thinking in global governance. A unidimensional mode of planning, silo thinking leads to decisions based on the area of expertise of a particular agency or intergovernmental organization and fails to recognize linkages…

  12. Implications of Contemporary Intelligence Theories to Marketing Education

    ERIC Educational Resources Information Center

    Muncy, James A.

    2006-01-01

    In recent years, prominent psychologists have redefined intelligence to refer to one's ability to successfully perform within a sociocultural context. They have also questioned the historical unidimensional conceptualization of intelligence. In this article, the author briefly reviews the history of intelligence research to this point then…

  13. A Comparison of Responses on the Attitudes toward Women Scale and Attitudes toward Feminism Scale: Is There a Difference between College-Age and Later-Life Adults with the Original Norms?

    ERIC Educational Resources Information Center

    Byrne, Zinta S.; Felker, Sydney; Vacha-Haase, Tammi; Rickard, Kathryn M.

    2011-01-01

    Responses from college-age students and those 50 years and older were compared using the Attitudes Toward Women Scale and the Attitudes Toward Feminism Scale. Results from a multigroup confirmatory factor analysis showed groups differed on each scale, suggesting unidimensional scales no longer represent attitudes toward women or feminism.…

  14. Similarity, Separability, and the Triangle Inequality.

    ERIC Educational Resources Information Center

    Tversky, Amos; Gati, Itamar

    1982-01-01

    The coincidence hypothesis predicts that dissimilarity between objects that differ on two separable dimensions is larger than predicted from their unidimensional differences on the basis of triangle inequality and segmental additivity. The coincidence hypothesis was supported in two-dimensional stimuli studies. (Author/CM)

  15. AHIMSA - Ad hoc histogram information measure sensing algorithm for feature selection in the context of histogram inspired clustering techniques

    NASA Technical Reports Server (NTRS)

    Dasarathy, B. V.

    1976-01-01

    An algorithm is proposed for dimensionality reduction in the context of clustering techniques based on histogram analysis. The approach is based on an evaluation of the hills and valleys in the unidimensional histograms along the different features and provides an economical means of assessing the significance of the features in a nonparametric unsupervised data environment. The method has relevance to remote sensing applications.

  16. Some Better Practices for Measuring Racial and Ethnic Identity Constructs

    ERIC Educational Resources Information Center

    Helms, Janet E.

    2007-01-01

    Racial and ethnic identity (REI) measures are in danger of becoming conceptually meaningless because of evaluators' insistence that they conform to measurement models intended to assess unidimensional constructs, rather than the multidimensional constructs necessary to capture the complexity of internalized racial or cultural socialization. Some…

  17. Assessing Dimensionality of a Set of Items--Comparison of Different Approaches.

    ERIC Educational Resources Information Center

    Nandakumar, Ratna

    The performance of the following four methodologies for assessing unidimensionality was examined: (1) DIMTEST; (2) the approach of P. W. Holland and P. R. Rosenbaum; (3) linear factor analysis; and (4) non-linear factor analysis. Each method is examined and compared with other methods using simulated data sets and real data sets. Seven data sets,…

  18. Measuring Learned Resourcefulness in College Students: Factor Structure of the Self-Control Schedule (SCS)

    ERIC Educational Resources Information Center

    McWhirter, Benedict T.; Burrow-Sanchez, Jason J.; Townsend, Katesy C.

    2008-01-01

    Rosenbaum's Self-Control Schedule (SCS) has been used as a unidimensional measure of Learned Resourcefulness (LR) in previous research. In this study we clarified the factor structure of the SCS among college students (N = 583) by conducting a principal axis factor analysis with oblique (Oblimin) rotation on the SCS. Results revealed a…

  19. Assessing Dimensionality of a Set of Items--Comparison of Different Approaches.

    ERIC Educational Resources Information Center

    Nandakumar, Ratna

    Performance in assessing the unidimensionality of tests was examined for four methods: (1) W. F. Stout's procedure (1987); (2) the approach of P. W. Holland and P. R. Rosenbaum (1986); (3) linear factor analysis; and (4) non-linear factor analysis. Each method was examined and compared with the others using simulated and real test data. Seven data…

  20. What Does the Just World Scale Measure: Dimension or Style?

    ERIC Educational Resources Information Center

    Ellard, John H.; Lerner, Melvin J.

    Rubin and Peplau's Just World Scale is based on the belief that a just world is a unidimensional construct in which individual beliefs are polarized according to immanent justice or ultimate justice. To investigate the effect of personal style on just world view, 109 male and female college students (who previously had completed the Just World…

  1. Measuring Kindness at School: Psychometric Properties of a School Kindness Scale for Children and Adolescents

    ERIC Educational Resources Information Center

    Binfet, John Tyler; Gadermann, Anne M.; Schonert-Reichl, Kimberly A.

    2016-01-01

    In this study, we sought to create and validate a brief measure to assess students' perceptions of kindness in school. Participants included 1,753 students in Grades 4 to 8 attending public schools in a large school district in southern British Columbia. The School Kindness Scale (SKS) demonstrated a unidimensional factor structure and adequate…

  2. Impact of Violation of the Missing-at-Random Assumption on Full-Information Maximum Likelihood Method in Multidimensional Adaptive Testing

    ERIC Educational Resources Information Center

    Han, Kyung T.; Guo, Fanmin

    2014-01-01

    The full-information maximum likelihood (FIML) method makes it possible to estimate and analyze structural equation models (SEM) even when data are partially missing, enabling incomplete data to contribute to model estimation. The cornerstone of FIML is the missing-at-random (MAR) assumption. In (unidimensional) computerized adaptive testing…

  3. Robustness of Hierarchical Modeling of Skill Association in Cognitive Diagnosis Models

    ERIC Educational Resources Information Center

    Templin, Jonathan L.; Henson, Robert A.; Templin, Sara E.; Roussos, Louis

    2008-01-01

    Several types of parameterizations of attribute correlations in cognitive diagnosis models use the reduced reparameterized unified model. The general approach presumes an unconstrained correlation matrix with K(K - 1)/2 parameters, whereas the higher order approach postulates K parameters, imposing a unidimensional structure on the correlation…

  4. A Confirmatory Factor Analysis of the Life Orientation Test-Revised with Competitive Athletes

    ERIC Educational Resources Information Center

    Appaneal, Renee N.

    2012-01-01

    Current reviews outside of sport indicate that the Life Orientation Test-Revised (LOT-R) items load on two separate factors (optimism and pessimism) and, therefore, should be treated as independent constructs. However, researchers in the sport sciences continue to use the single composite score reflecting a unidimensional definition of optimism.…

  5. Assessing Peer Victimization across Adolescence: Measurement Invariance and Developmental Change

    ERIC Educational Resources Information Center

    Rosen, Lisa H.; Beron, Kurt J.; Underwood, Marion K.

    2013-01-01

    An upward extension of the Revised Social Experience Questionnaire (Paquette & Underwood, 1999) was tested in a sample of adolescents followed longitudinally from 7th through 10th grade. We hypothesized that a 2-factor model with overt and social victimization factors would fit the data better than would a unidimensional model (a single…

  6. Development and Psychometric Evaluation of the Personal Growth Initiative Scale-II

    ERIC Educational Resources Information Center

    Robitschek, Christine; Ashton, Matthew W.; Spering, Cynthia C.; Geiger, Nathaniel; Byers, Danielle; Schotts, G. Christian; Thoen, Megan A.

    2012-01-01

    The original Personal Growth Initiative Scale (PGIS; Robitschek, 1998) was unidimensional, despite theory identifying multiple components (e.g., cognition and behavior) of personal growth initiative (PGI). The present research developed a multidimensional measure of the complex process of PGI, while retaining the brief and psychometrically sound…

  7. Using Perceived Health to Test the Construct-Related Validity of Global Quality of Life

    ERIC Educational Resources Information Center

    Beckie, Theresa M.; Hayduk, Leslie A.

    2004-01-01

    Quality of life (QOL) is considered as a global, yet unidimensional, subjective assessment of one's satisfaction with life. We examine the construct validity of the available indicators of global QOL by constructing a causal model in which QOL is viewed as causally responding to several dimensions of perceived health. Global QOL is measured with…

  8. Impact of Diagnosticity on the Adequacy of Models for Cognitive Diagnosis under a Linear Attribute Structure: A Simulation Study

    ERIC Educational Resources Information Center

    de La Torre, Jimmy; Karelitz, Tzur M.

    2009-01-01

    Compared to unidimensional item response models (IRMs), cognitive diagnostic models (CDMs) based on latent classes represent examinees' knowledge and item requirements using discrete structures. This study systematically examines the viability of retrofitting CDMs to IRM-based data with a linear attribute structure. The study utilizes a procedure…

  9. Effect Size Measures for Differential Item Functioning in a Multidimensional IRT Model

    ERIC Educational Resources Information Center

    Suh, Youngsuk

    2016-01-01

    This study adapted an effect size measure used for studying differential item functioning (DIF) in unidimensional tests and extended the measure to multidimensional tests. Two effect size measures were considered in a multidimensional item response theory model: signed weighted P-difference and unsigned weighted P-difference. The performance of…

  10. Career Decision Self-Efficacy Scale-Short Form: A Rasch Analysis of the Portuguese Version

    ERIC Educational Resources Information Center

    Miguel, Jose P.; Silva, Jose T.; Prieto, Gerardo

    2013-01-01

    The present study analyzes the psychometric properties of the Career Decision Self-Efficacy Scale-Short Form (CDSE-SF) in a sample of Portuguese secondary education students using the Rasch model. The results indicate that the 25 items of the CDSE-SF are well fitted to a latent unidimensional structure, as required by Rasch modeling. The response…

  11. A Factor-Analytic Comparison of Two Measures of Masculinity-Femininity in Post and Early Adolescent Populations.

    ERIC Educational Resources Information Center

    Mills, Carol J.

    Many researchers have questioned the validity of the underlying assumptions, the psychometric properties, and conceptualizations for both the older and new measures that generate two independent scores for masculinity and femininity. The assumptions of bipolarity and unidimensionality and the construct validity of existing masculinity/femininity…

  12. A Test of the Dimensionality Assumptions of Rotter's Internal-External Scale

    ERIC Educational Resources Information Center

    Klockars, Alan J.; Varnum, Susan W.

    1975-01-01

    Examined two assumptions about the dimensionality of Rotters' Internal-External (I-E) scale: First, the bipolarity of the two statements within each item pair; second, the unidimensionality of the overall construct. Both assumptions regarding Rotters' I-E Scale were found untenable. (Author/BJG)

  13. Development and Application of a New Approach to Testing the Bipolarity of Semantic Differential Items.

    ERIC Educational Resources Information Center

    Cogliser, Claudia C.; Schriesheim, Chester A.

    1994-01-01

    A method of testing semantic differential scales for bipolarity is developed using a new conception of bipolarity that does not require unidimensionality. Assessment of Fielder's Least Preferred Coworker instrument with 63 college student subjects using multidimensional scaling revealed its significant departures from bipolarity. (SLD)

  14. Using the Advanced Progressive Matrices (Set I) to Assess Fluid Ability in a Short Time Frame: An Item Response Theory-Based Analysis

    ERIC Educational Resources Information Center

    Chiesi, Francesca; Ciancaleoni, Matteo; Galli, Silvia; Primi, Caterina

    2012-01-01

    This article is aimed at evaluating the possibility that Set I of the Advanced Progressive Matrices (APM-Set I) can be employed to assess fluid ability in a short time frame. The APM-Set I was administered to a sample of 1,389 primary and secondary school students. Confirmatory factor analysis attested to the unidimensionality of the scale. Item…

  15. The Analysis of a Construct That Does Not Exist: Misunderstanding the Multidimensional Nature of Trait Anxiety.

    ERIC Educational Resources Information Center

    Endler, Norman S.; Parker, James D. A.

    1990-01-01

    C. Davis and M. Cowles (1989) analyzed a total trait anxiety score on the Endler Multidimensional Anxiety Scales (EMAS)--a unidimensional construct that this multidimensional measure does not assess. Data are reanalyzed using the appropriate scoring procedure for the EMAS. Subjects included 145 undergraduates in 1 of 4 testing conditions. (SLD)

  16. Bayesian Multidimensional IRT Models with a Hierarchical Structure

    ERIC Educational Resources Information Center

    Sheng, Yanyan; Wikle, Christopher K.

    2008-01-01

    As item response models gain increased popularity in large-scale educational and measurement testing situations, many studies have been conducted on the development and applications of unidimensional and multidimensional models. Recently, attention has been paid to IRT-based models with an overall ability dimension underlying several ability…

  17. Model-Based Collaborative Filtering Analysis of Student Response Data: Machine-Learning Item Response Theory

    ERIC Educational Resources Information Center

    Bergner, Yoav; Droschler, Stefan; Kortemeyer, Gerd; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.

    2012-01-01

    We apply collaborative filtering (CF) to dichotomously scored student response data (right, wrong, or no interaction), finding optimal parameters for each student and item based on cross-validated prediction accuracy. The approach is naturally suited to comparing different models, both unidimensional and multidimensional in ability, including a…

  18. Latent Trait Theory Approach to Measuring Person-Organization Fit: Conceptual Rationale and Empirical Evaluation

    ERIC Educational Resources Information Center

    Chernyshenko, Oleksandr S.; Stark, Stephen; Williams, Alex

    2009-01-01

    The purpose of this article is to offer a new approach to measuring person-organization (P-O) fit, referred to here as "Latent fit." Respondents were administered unidimensional forced choice items and were asked to choose the statement in each pair that better reflected the correspondence between their values and those of the…

  19. Creating a Desirable Education System.

    ERIC Educational Resources Information Center

    Theobald, Robert

    The basic purpose of education is to prepare people to be successful in the world which will exist during their life span. Present day education is failing in this because our schools were organized for the industrial era. The resulting model requires that phenomena be predictable, understandable, and unidimensional. Today, we know that everything…

  20. IRTPRO 2.1 for Windows (Item Response Theory for Patient-Reported Outcomes)

    ERIC Educational Resources Information Center

    Paek, Insu; Han, Kyung T.

    2013-01-01

    This article reviews a new item response theory (IRT) model estimation program, IRTPRO 2.1, for Windows that is capable of unidimensional and multidimensional IRT model estimation for existing and user-specified constrained IRT models for dichotomously and polytomously scored item response data. (Contains 1 figure and 2 notes.)

  1. Evaluation of Weighted Scale Reliability and Criterion Validity: A Latent Variable Modeling Approach

    ERIC Educational Resources Information Center

    Raykov, Tenko

    2007-01-01

    A method is outlined for evaluating the reliability and criterion validity of weighted scales based on sets of unidimensional measures. The approach is developed within the framework of latent variable modeling methodology and is useful for point and interval estimation of these measurement quality coefficients in counseling and education…

  2. A Preliminary Study for a New Model of Sense of Community

    ERIC Educational Resources Information Center

    Tartaglia, Stefano

    2006-01-01

    Although Sense of Community (SOC) is usually defined as a multidimensional construct, most SOC scales are unidimensional. To reduce the split between theory and empirical research, the present work identifies a multifactor structure for the Italian Sense of Community Scale (ISCS) that has already been validated as a unitary index of SOC. This…

  3. Chemistry Education: Ten Facets to Shape Us

    ERIC Educational Resources Information Center

    Talanquer, Vicente

    2013-01-01

    The chemistry knowledge that we want our students to develop is rich, complex, and multifaceted. However, some teachers and instructors at the secondary school and college levels approach it in rather rigid and unidimensional ways. The central goal of this contribution is to describe and discuss 10 different complementary perspectives or…

  4. Semi-Nonparametric Methods for Detecting Latent Non-Normality: A Fusion of Latent Trait and Ordered Latent Class Modeling

    ERIC Educational Resources Information Center

    Schmitt, J. Eric; Mehta, Paras D.; Aggen, Steven H.; Kubarych, Thomas S.; Neale, Michael C.

    2006-01-01

    Ordered latent class analysis (OLCA) can be used to approximate unidimensional latent distributions. The main objective of this study is to evaluate the method of OLCA in detecting non-normality of an unobserved continuous variable (i.e., a common factor) used to explain the covariation between dichotomous item-level responses. Using simulation,…

  5. Perceived Organizational Support: Further Evidence of Construct Validity.

    ERIC Educational Resources Information Center

    Hutchison, Steven

    1997-01-01

    Confirmatory factor analysis was used to examine the construct validity of scores from the Survey of Perceived Organizational Support (SPOS)(R. Eisenberger and others, 1986) using responses of 205 college faculty and staff members. Consistent with previous research, the SPOS was found to be unidimensional and distinguishable from two similarly…

  6. Validity of the Beck Depression Inventory with Eating Disorder Patients.

    ERIC Educational Resources Information Center

    Pulos, Steven

    1996-01-01

    The factor structure of the Beck Depression Inventory (BDI) was studied with a subsample of 93 bulimic women from a total sample of 110 women with eating disorders. Results suggested that the BDI appears to assess a unidimensional construct in patients with eating disorders. (SLD)

  7. Development of an Instrument to Measure Staff-Reported Resident-to-Resident Elder Mistreatment (R-REM) Using Item Response Theory and Other Latent Variable Models

    PubMed Central

    Ramirez, Mildred

    2014-01-01

    Objectives: Although numerous studies have measured behaviors among individuals in congregate settings, few have focused on resident-to-resident elder mistreatment (R-REM). To our knowledge, there is no psychometrically developed measure of R-REM extant. The quantitative development of a measure of staff-reported R-REM is described. Methods: The design was a prevalent cohort study of residents of 5 long-term care facilities. The primary certified nursing assistant was interviewed about R-REM. Advanced measurement methods were used to develop a measure of R-REM. Results: The loadings on the general factor for the final 11-item scale were greater than those on the group factor except for the item “other physical behavior” (0.63 vs. 0.74), suggesting essential unidimensionality. Although the bifactor model fit was slightly better than that of the unidimensional model, the difference was trivial (bifactor comparative fit index [CFI] = 0.997, root mean square error of approximation [RMSEA] = 0.013, unidimensional CFI = 0.979, and RMSEA = 0.030). However, modest support was provided for use of verbal and physical subscales. The explained common variance statistics were 0.76 for the bifactor model compared with 0.63 for the unidimensional model. Discussion: The development of this R-REM measure will help to advance the measurement and ultimately evaluation of interventions associated with this important and under recognized problem facing residents in long-term care settings. PMID:23448960

  8. Knowledge Contribution in Virtual Communities: Accounting for Multiple Dimensions of Social Presence through Social Identity

    ERIC Educational Resources Information Center

    Shen, Kathy Ning; Yu, Angela Yan; Khalifa, Mohamed

    2010-01-01

    Integrating social presence theory and social identity theory, this study brings system design and social influence aspects together to explain their joint effects on knowledge contribution in virtual communities (VCs). Different from most prior information systems (IS) research that adopts a uni-dimensional approach and restricts social presence…

  9. A Rasch Analysis of the Academic Self-Concept Questionnaire

    ERIC Educational Resources Information Center

    Joyce, Tan Bei Yu; Yates, Shirley M.

    2007-01-01

    This study used the Rasch model to assess the unidimensionality and item-person fit of an Academic Self-Concept Questionnaire (ASCQ) that is based on the Confucian Heritage Culture (CHC) perspective. Knowledge of the relationship between academic achievement and academic self-concept is particularly useful because academic achievement is…

  10. The Twofold Multidimensionality of Academic Self-Concept: Domain Specificity and Separation between Competence and Affect Components

    ERIC Educational Resources Information Center

    Arens, A. Katrin; Yeung, Alexander Seeshing; Craven, Rhonda G.; Hasselhorn, Marcus

    2011-01-01

    Academic self-concept is consistently proven to be multidimensional rather than unidimensional as it is domain specific in nature. However, each specific self-concept domain may be further separated into competence and affect components. This study examines the twofold multidimensionality of academic self-concept (i.e., its domain specificity and…

  11. Acculturation Style and Alcohol Use among African American College Students: An Exploration of Potential Moderators

    ERIC Educational Resources Information Center

    Abdullah, Tahirah; Brown, Tamara L.

    2012-01-01

    This study examined whether a relationship exists between acculturation and alcohol use among African American college students and if the relationship varies by religiosity and gender. Most researchers use unidimensional African American acculturation measures that cannot capture the construct's complexity; this study is the first to use a…

  12. A Simulation Study on the Performance of Four Multidimensional IRT Scale Linking Methods

    ERIC Educational Resources Information Center

    Wei, Youhua

    2008-01-01

    Scale linking is the process of developing the connection between scales of two or more sets of parameter estimates obtained from separate test calibrations. It is the prerequisite for many applications of IRT, such as test equating and differential item functioning analysis. Unidimensional scale linking methods have been studied and applied…

  13. Multidimensional CAT Item Selection Methods for Domain Scores and Composite Scores: Theory and Applications

    ERIC Educational Resources Information Center

    Yao, Lihua

    2012-01-01

    Multidimensional computer adaptive testing (MCAT) can provide higher precision and reliability or reduce test length when compared with unidimensional CAT or with the paper-and-pencil test. This study compared five item selection procedures in the MCAT framework for both domain scores and overall scores through simulation by varying the structure…

  14. Graded Response Model Based on the Logistic Positive Exponent Family of Models for Dichotomous Responses

    ERIC Educational Resources Information Center

    Samejima, Fumiko

    2008-01-01

    Samejima ("Psychometrika "65:319--335, 2000) proposed the logistic positive exponent family of models (LPEF) for dichotomous responses in the unidimensional latent space. The objective of the present paper is to propose and discuss a graded response model that is expanded from the LPEF, in the context of item response theory (IRT). This…

  15. A Correlational Analysis of Test Anxiety and Response Time on a Computerized Adaptive Math Test among Seventh Grade Students by Gender

    ERIC Educational Resources Information Center

    Brom, Michael Wayde

    2016-01-01

    Studies have shown that test anxiety has become more prevalent since the adoption of the No Child Left Behind Act in 2001 and that test anxiety negatively affects student achievement. Early research viewed test anxiety as being a unidimensional construct; however, recent research has purported that test anxiety is a multidimensional construct.…

  16. Effortful Control in "Hot" and "Cool" Tasks Differentially Predicts Children's Behavior Problems and Academic Performance

    ERIC Educational Resources Information Center

    Kim, Sanghag; Nordling, Jamie Koenig; Yoon, Jeung Eun; Boldt, Lea J.; Kochanska, Grazyna

    2013-01-01

    Effortful control (EC), the capacity to deliberately suppress a dominant response and perform a subdominant response, rapidly developing in toddler and preschool age, has been shown to be a robust predictor of children's adjustment. Not settled, however, is whether a view of EC as a heterogeneous rather than unidimensional construct may offer…

  17. Confirming the Multidimensionality of Psychologically Controlling Parenting among Chinese-American Mothers: Love Withdrawal, Guilt Induction, and Shaming

    ERIC Educational Resources Information Center

    Yu, Jing; Cheah, Charissa S. L.; Hart, Craig H.; Sun, Shuyan; Olsen, Joseph A.

    2015-01-01

    Despite the theoretical conceptualization of parental psychological control as a multidimensional construct, the majority of previous studies have examined psychological control as a unidimensional scale. Moreover, the conceptualization of shaming and its associations with love withdrawal and guilt induction are unclear. The current study aimed to…

  18. Community Agricultural Processing Services: A Reflection of Urban Differentiation or County Agricultural Structure.

    ERIC Educational Resources Information Center

    Moxley, Robert L.; Calloway, Michael O.

    Questionnaire data from 81 North Carolina communities were analyzed in 1981 to test the hypothesis that 5 institutional subcategories (education, general community services, transportation, agricultural services, and health and sanitation) exhibit the underlying characteristic of unidimensionality and that they reflect comparable levels of…

  19. Posterior Predictive Model Checking for Multidimensionality in Item Response Theory

    ERIC Educational Resources Information Center

    Levy, Roy; Mislevy, Robert J.; Sinharay, Sandip

    2009-01-01

    If data exhibit multidimensionality, key conditional independence assumptions of unidimensional models do not hold. The current work pursues posterior predictive model checking, a flexible family of model-checking procedures, as a tool for criticizing models due to unaccounted for dimensions in the context of item response theory. Factors…

  20. Posterior Predictive Model Checking for Conjunctive Multidimensionality in Item Response Theory

    ERIC Educational Resources Information Center

    Levy, Roy

    2011-01-01

    If data exhibit multidimensionality, key conditional independence assumptions of unidimensional models do not hold. The current work pursues posterior predictive model checking (PPMC) as a tool for criticizing models due to unaccounted for dimensions in data structures that follow conjunctive multidimensional models. These pursuits are couched in…

  1. The Economic Benefits of Predicting Job Performance

    DTIC Science & Technology

    1989-09-01

    placement, and to be able to use a terminology that permits the consideration of both unidimensional and multidimensional test and criterion sets for...largely random. The reason for the relatively low assignment efficiency is the reliance on low job standart - for a high quality recruit population

  2. Lord-Wingersky Algorithm Version 2.0 for Hierarchical Item Factor Models with Applications in Test Scoring, Scale Alignment, and Model Fit Testing. CRESST Report 830

    ERIC Educational Resources Information Center

    Cai, Li

    2013-01-01

    Lord and Wingersky's (1984) recursive algorithm for creating summed score based likelihoods and posteriors has a proven track record in unidimensional item response theory (IRT) applications. Extending the recursive algorithm to handle multidimensionality is relatively simple, especially with fixed quadrature because the recursions can be defined…

  3. Application of the Bifactor Model to Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Seo, Dong Gi

    2011-01-01

    Most computerized adaptive tests (CAT) have been studied under the framework of unidimensional item response theory. However, many psychological variables are multidimensional and might benefit from using a multidimensional approach to CAT. In addition, a number of psychological variables (e.g., quality of life, depression) can be conceptualized…

  4. A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means

    ERIC Educational Resources Information Center

    Polak, Marike; De Rooij, Mark; Heiser, Willem J.

    2012-01-01

    In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chave's (1929) "criterion…

  5. Conditional Covariance-Based Subtest Selection for DIMTEST

    ERIC Educational Resources Information Center

    Froelich, Amy G.; Habing, Brian

    2008-01-01

    DIMTEST is a nonparametric hypothesis-testing procedure designed to test the assumptions of a unidimensional and locally independent item response theory model. Several previous Monte Carlo studies have found that using linear factor analysis to select the assessment subtest for DIMTEST results in a moderate to severe loss of power when the exam…

  6. Three Approaches to Determining the Dimensionality of Binary Items.

    ERIC Educational Resources Information Center

    Roznowski, Mary; And Others

    1991-01-01

    Three heuristic methods of assessing the dimensionality of binary item pools were evaluated in a Monte Carlo investigation. The indices were based on (1) the local independence of unidimensional tests; (2) patterns of second-factor loadings derived from simplex theory; and (3) the shape of the curve of successive eigenvalues. (SLD)

  7. Sequential Dependencies in Categorical Judgments of Radiographic Images

    ERIC Educational Resources Information Center

    Beckstead, Jason W.; Boutis, Kathy; Pecaric, Martin; Pusic, Martin V.

    2017-01-01

    Sequential context effects, the psychological interactions occurring between the events of successive trials when a sequence of similar stimuli are judged, have interested psychologists for decades. It has been well established that individuals exhibit sequential context effects in psychophysical experiments involving unidimensional stimuli.…

  8. Measuring Adolescent Life Satisfaction: Psychometric Properties of the Satisfaction With Life Scale in a Sample of Italian Adolescents and Young Adults

    ERIC Educational Resources Information Center

    Di Fabio, Annamaria; Gori, Alessio

    2016-01-01

    This study examined the factor structure and the psychometric properties of the Satisfaction With Life Scale (SWLS) in a sample of 1,515 Italian (females = 60.26%, males = 39.74%) adolescents and young adults (M[subscript age] = 17.6 years, SD = 1.21). Results confirmed the unidimensionality, good reliability, and concurrent validity of the…

  9. A Revised Semantic Differential Scale Distinguishing between Negative and Positive God Images

    ERIC Educational Resources Information Center

    Francis, Leslie J.; Robbins, Mandy; Gibson, Harry M.

    2006-01-01

    A sample of 755 school pupils between the ages of 11 and 18 years completed the Benson and Spilka semantic differential measure of God images. Factor analysis indicated the advantages of re-scoring the measure as an eight item unidimensional index, defining semantic space relating to God images ranging from negative affect to positive affect.…

  10. Performance of the S - [chi][squared] Statistic for Full-Information Bifactor Models

    ERIC Educational Resources Information Center

    Li, Ying; Rupp, Andre A.

    2011-01-01

    This study investigated the Type I error rate and power of the multivariate extension of the S - [chi][squared] statistic using unidimensional and multidimensional item response theory (UIRT and MIRT, respectively) models as well as full-information bifactor (FI-bifactor) models through simulation. Manipulated factors included test length, sample…

  11. Multidimensional Models for Matrix-Sampled Reading Tasks.

    ERIC Educational Resources Information Center

    Palaszewski, Bo

    The International Adult Literacy Survey (IALS) was conducted in 1994 in seven European countries with the aim of producing literacy profiles to be used in individual national analyses as well as in international comparisons. It was assumed that the test items could be divided into three unidimensional scales corresponding to the aspects…

  12. Ramsay Curve IRT for Likert-Type Data

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2007-01-01

    Ramsay curve item response theory (RC-IRT) was recently developed to detect and correct for nonnormal latent variables when unidimensional IRT models are fitted to data using maximum marginal likelihood estimation. The purpose of this research is to evaluate the performance of RC-IRT for Likert-type item responses with varying test lengths, sample…

  13. Development and Validation of a 2 x 2 Model of Time-Related Academic Behavior: Procrastination and Timely Engagement

    ERIC Educational Resources Information Center

    Strunk, Kamden K.; Cho, YoonJung; Steele, Misty R.; Bridges, Stacey L.

    2013-01-01

    Procrastination is an educational concern for classroom instructors because of its negative psychological and academic impacts on students. However, the traditional view of procrastination as a unidimensional construct is insufficient in two regards. First, the construct needs to be viewed more broadly as time-related academic behavior,…

  14. Measurement Invariance versus Selection Invariance: Is Fair Selection Possible?

    ERIC Educational Resources Information Center

    Borsman, Denny; Romeijn, Jan-Willem; Wicherts, Jelte M.

    2008-01-01

    This article shows that measurement invariance (defined in terms of an invariant measurement model in different groups) is generally inconsistent with selection invariance (defined in terms of equal sensitivity and specificity across groups). In particular, when a unidimensional measurement instrument is used and group differences are present in…

  15. Individualism and the Emerging "Modern" Ideology of Death.

    ERIC Educational Resources Information Center

    Kearl, Michael C.; Harris, Richard

    1981-01-01

    Begins with a theoretical elaboration of individualism. Argues its development is associated with an emergent death ideology emphasizing personal control. In two national samples attitudes toward suicide, abortion and the right to die scaled unidimensionally. Results indicated indices of individualism were the best predictors of position on this…

  16. Multiple-Group Noncompensatory Differential Item Functioning in Raju's Differential Functioning of Items and Tests

    ERIC Educational Resources Information Center

    Oshima, T. C.; Wright, Keith; White, Nick

    2015-01-01

    Raju, van der Linden, and Fleer (1995) introduced a framework for differential functioning of items and tests (DFIT) for unidimensional dichotomous models. Since then, DFIT has been shown to be a quite versatile framework as it can handle polytomous as well as multidimensional models both at the item and test levels. However, DFIT is still limited…

  17. Measuring Trait Communication Apprehension: A Test of Rival Measurement Models of the PRCA-24.

    ERIC Educational Resources Information Center

    Levine, Timothy R.; McCroskey, James C.

    1990-01-01

    Tests three rival measurement models of a common measure of trait communication apprehension, the Personal Report of Communication Apprehension (PRCA-24). Finds that the second-order factor model better fits the data in terms of conceptual implications, psychometric properties, and empirical evidence than the linear, unidimensional model or the…

  18. Implementation and Measurement Efficiency of Multidimensional Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Chen, Po-Hsi

    2004-01-01

    Multidimensional adaptive testing (MAT) procedures are proposed for the measurement of several latent traits by a single examination. Bayesian latent trait estimation and adaptive item selection are derived. Simulations were conducted to compare the measurement efficiency of MAT with those of unidimensional adaptive testing and random…

  19. On the Relationship between Classical Test Theory and Item Response Theory: From One to the Other and Back

    ERIC Educational Resources Information Center

    Raykov, Tenko; Marcoulides, George A.

    2016-01-01

    The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. It is pointed out that popular item response models can be directly obtained from classical test theory-based models by accounting for the discrete…

  20. Analysis of Letter Name Knowledge Using Rasch Measurement

    ERIC Educational Resources Information Center

    Bowles, Ryan P.; Skibbe, Lori E.; Justice, Laura M.

    2011-01-01

    Letter name knowledge (LNK) is a key predictor of later reading ability and has been emphasized strongly in recent educational policy. Studies of LNK have implicitly treated it as a unidimensional construct with all letters equally relevant to its measurement. However, some empirical research suggests that contextual factors can affect the…

  1. The Impact of Different Ability Distributions on IRT Preequating.

    ERIC Educational Resources Information Center

    Stocking, Martha L.; Eignor, Daniel R.

    In item response theory (IRT), preequating depends upon item parameter estimate invariance. Three separate simulations, all using the unidimensional three-parameter logistic item response model, were conducted to study the impact of the following variables on preequating: (1) mean differences in ability; (2) multidimensionality in the data; and…

  2. Construct Validity of Scores/Measures from a Developmental Assessment in Mathematics Using Classical and Many-Facet Rasch Measurement.

    ERIC Educational Resources Information Center

    Banerji, Madhabi

    2000-01-01

    Validated data from a developmental mathematics assessment using classical and three-faceted Rasch measurement methods. Analysis of field test data for 289 elementary school students suggested that a unidimensional construct was being measured, as defined by Rasch criteria. Discusses limitations in confirming content-related validity of the…

  3. Item Response Theory with Estimation of the Latent Density Using Davidian Curves

    ERIC Educational Resources Information Center

    Woods, Carol M.; Lin, Nan

    2009-01-01

    Davidian-curve item response theory (DC-IRT) is introduced, evaluated with simulations, and illustrated using data from the Schedule for Nonadaptive and Adaptive Personality Entitlement scale. DC-IRT is a method for fitting unidimensional IRT models with maximum marginal likelihood estimation, in which the latent density is estimated,…

  4. Mokken Scale Analysis Using Hierarchical Clustering Procedures

    ERIC Educational Resources Information Center

    van Abswoude, Alexandra A. H.; Vermunt, Jeroen K.; Hemker, Bas T.; van der Ark, L. Andries

    2004-01-01

    Mokken scale analysis (MSA) can be used to assess and build unidimensional scales from an item pool that is sensitive to multiple dimensions. These scales satisfy a set of scaling conditions, one of which follows from the model of monotone homogeneity. An important drawback of the MSA program is that the sequential item selection and scale…

  5. Multidimensional Item Response Theory Models in Vocational Interest Measurement: An Illustration Using the AIST-R

    ERIC Educational Resources Information Center

    Wetzel, Eunike; Hell, Benedikt

    2014-01-01

    Vocational interest inventories are commonly analyzed using a unidimensional approach, that is, each subscale is analyzed separately. However, the theories on which these inventories are based often postulate specific relationships between the interest traits. This article presents a multidimensional approach to the analysis of vocational interest…

  6. When Cognitive Diagnosis Meets Computerized Adaptive Testing: CD-CAT

    ERIC Educational Resources Information Center

    Cheng, Ying

    2009-01-01

    Computerized adaptive testing (CAT) is a mode of testing which enables more efficient and accurate recovery of one or more latent traits. Traditionally, CAT is built upon Item Response Theory (IRT) models that assume unidimensionality. However, the problem of how to build CAT upon latent class models (LCM) has not been investigated until recently,…

  7. A Study of Confidence and Accuracy Using the Rasch Modeling Procedures. Research Report. ETS RR-08-42

    ERIC Educational Resources Information Center

    Paek, Insu; Lee, Jihyun; Stankov, Lazar; Wilson, Mark

    2008-01-01

    This study investigated the relationship between students' actual performance (accuracy) and their subjective judgments of accuracy (confidence) on selected English language proficiency tests. The unidimensional and multidimensional IRT Rasch approaches were used to model the discrepancy between confidence and accuracy at the item and test level…

  8. The Motivation of Stereotypic and Repetitive Behavior: Examination of Construct Validity of the Motivation Assessment Scale

    ERIC Educational Resources Information Center

    Joosten, Annette V.; Bundy, Anita C.

    2008-01-01

    Construct validity of the Motivation Assessment Scale (MAS) (Durand, Crimmins, The Motivation Assessment Scale 1988) was studied using Rasch analysis data from 67 children (246 MASs), with dual diagnosis of autism and intellectual disability or with intellectual disability only. Results failed to support the proposed unidimensional construct or…

  9. An Investigation of Computer Anxiety by Gender and Grade.

    ERIC Educational Resources Information Center

    King, John; Bond, Trevor; Blandford, Sonya

    2002-01-01

    Describes a study of Australian students in grades seven, nine, and 11 that used the Computer Anxiety Index (CAIN), to test its unidimensionality and avoid the conceptual confusion of multi-dimensionality. Discusses the use of Rasch analysis, and analyzes differences in grade levels and gender. (Contains 51 references.) (Author/LRW)

  10. Using Necessary Information to Identify Item Dependence in Passage-Based Reading Comprehension Tests

    ERIC Educational Resources Information Center

    Baldonado, Angela Argo; Svetina, Dubravka; Gorin, Joanna

    2015-01-01

    Applications of traditional unidimensional item response theory models to passage-based reading comprehension assessment data have been criticized based on potential violations of local independence. However, simple rules for determining dependency, such as including all items associated with a particular passage, may overestimate the dependency…

  11. Sufficiency and Conditional Estimation of Person Parameters in the Polytomous Rasch Model

    ERIC Educational Resources Information Center

    Andrich, David

    2010-01-01

    Rasch models are characterised by sufficient statistics for all parameters. In the Rasch unidimensional model for two ordered categories, the parameterisation of the person and item is symmetrical and it is readily established that the total scores of a person and item are sufficient statistics for their respective parameters. In contrast, in the…

  12. On the Value of Homogeneous Constructs for Construct Validation, Theory Testing, and the Description of Psychopathology

    ERIC Educational Resources Information Center

    Smith, Gregory T.; McCarthy, Denis M.; Zapolski, Tamika C. B.

    2009-01-01

    The authors argue for a significant shift in how clinical psychology researchers conduct construct validation and theory validation tests. They argue that sound theory and validation tests can best be conducted on measures of unidimensional or homogeneous constructs. Hierarchical organizations of such constructs are useful descriptively and…

  13. How to Use Chromatography as a Science Teaching Aid.

    ERIC Educational Resources Information Center

    Ganis, Frank M.

    Presented are five procedures which permit the effective teaching of chromatography with equipment which is readily available, economical, and simple in design. The first procedure involves a study of solute partition in two immiscible solvents and of countercurrent distribution. The second illustrates the use of unidimensional ascending paper…

  14. A Prospective Study Investigating the Impact of School Belonging Factors on Negative Affect in Adolescents

    ERIC Educational Resources Information Center

    Shochet, Ian M.; Smith, Coral L.; Furlong, Michael J.; Homel, Ross

    2011-01-01

    School belonging, measured as a unidimensional construct, is an important predictor of negative affective problems in adolescents, including depression and anxiety symptoms. A recent study found that one such measure, the Psychological Sense of School Membership scale, actually comprises three factors: Caring Relations, Acceptance, and Rejection.…

  15. Comparing Categorization Models

    ERIC Educational Resources Information Center

    Rouder, Jeffrey N.; Ratcliff, Roger

    2004-01-01

    Four experiments are presented that competitively test rule- and exemplar-based models of human categorization behavior. Participants classified stimuli that varied on a unidimensional axis into 2 categories. The stimuli did not consistently belong to a category; instead, they were probabilistically assigned. By manipulating these assignment…

  16. The Evidence for a Subscore Structure in a Test of English Language Competency for English Language Learners

    ERIC Educational Resources Information Center

    Reckase, Mark D.; Xu, Jing-Ru

    2015-01-01

    How to compute and report subscores for a test that was originally designed for reporting scores on a unidimensional scale has been a topic of interest in recent years. In the research reported here, we describe an application of multidimensional item response theory to identify a subscore structure in a test designed for reporting results using a…

  17. Checking the Appropriateness of Item Response Theory Models by Predicting the Distribution of Observed Scores: The Program EO-Fit.

    ERIC Educational Resources Information Center

    Ferrando, Pere J.; Lorenzo-Seva, Urbano

    2001-01-01

    Describes a Windows program for checking the suitability of unidimensional logistic item response models for binary and ordered polytomous responses with respect to a given set of data. The program is based on predicting the observed test score distributions from the item characteristic curves. (SLD)

  18. TH-SCORE: A Program for Obtaining Ability Estimates under Different Psychometric Models.

    ERIC Educational Resources Information Center

    Ferrando, Pere J.; Lorenzo, Urbano

    1998-01-01

    A program for obtaining ability estimates and their standard errors under a variety of psychometric models is documented. The general models considered are (1) classical test theory; (2) item factor analysis for continuous censored responses; and (3) unidimensional and multidimensional item response theory graded response models. (SLD)

  19. Longitudinal Tests of Competing Factor Structures for the Rosenberg Self-Esteem Scale: Traits, Ephemeral Artifacts, and Stable Response Styles

    ERIC Educational Resources Information Center

    Marsh, Herbert W.; Scalas, L. Francesca; Nagengast, Benjamin

    2010-01-01

    Self-esteem, typically measured by the Rosenberg Self-Esteem Scale (RSE), is one of the most widely studied constructs in psychology. Nevertheless, there is broad agreement that a simple unidimensional factor model, consistent with the original design and typical application in applied research, does not provide an adequate explanation of RSE…

  20. Satisfaction Ratings of QOLPAV: Psychometric Properties Based on the Graded Response Model

    ERIC Educational Resources Information Center

    Chen, Ssu-Kuang; Hwang, Fang-Ming; Lin, Sunny S. J.

    2013-01-01

    A scale measuring quality of life (QOL) is important in adolescent research. Using the graded response model (GRM), this study evaluates the psychometric properties of the satisfaction ratings of the Quality of Life Profile Adolescent Version (QOLPAV). Data for 1,392 adolescents were used to check IRT assumptions such as unidimensionality and…

  1. Dimensionality Analyses of the "GRE"® revised General Test Verbal and Quantitative Measures. ETS GRE® Board Research Report. ETS GRE®-16-02. ETS Research Report. RR-16-20

    ERIC Educational Resources Information Center

    Robin, Frédéric; Bejar, Isaac; Liang, Longjuan; Rijmen, Frank

    2016-01-01

    Exploratory and confirmatory factor analyses of domestic data from the" GRE"® revised General Test, introduced in 2011, were conducted separately for the verbal (VBL) and quantitative (QNT) reasoning measures to evaluate the unidimensionality and local independence assumptions required by item response theory (IRT). Results based on data…

  2. A Multiple Motives Approach to Tobacco Dependence: The Wisconsin Inventory of Smoking Dependence Motives (WISDM-68)

    ERIC Educational Resources Information Center

    Piper, Megan E.; Piasecki, Thomas M.; Federman, E. Belle; Bolt, Daniel M.; Smith, Stevens S.; Fiore, Michael C.; Baker, Timothy C.

    2004-01-01

    The dependence construct fills an important explanatory role in motivational accounts of smoking and relapse. Frequently used measures of dependence are either atheoretical or grounded in a unidimensional model of physical dependence. This research creates a multidimensional measure of dependence that is based on theoretically grounded motives for…

  3. Orthogonal Higher Order Factor Structure of the Stanford-Binet Intelligence Scales--Fifth Edition for Children and Adolescents

    ERIC Educational Resources Information Center

    Canivez, Gary L.

    2008-01-01

    Orthogonal higher-order factor structure of the Stanford-Binet Intelligence Scales-Fifth Edition (SB-5; Roid, 2003a) for child and adolescent samples is reported. Multiple criteria for factor extraction unanimously supported extraction of only one dimension and a unidimensional model. However, following results from DiStefano and Dombrowski (2006)…

  4. Easier Said than Done: Rejoinder on Sijtsma and on Green and Yang

    ERIC Educational Resources Information Center

    Davenport, Ernest C.; Davison, Mark L.; Liou, Pey-Yan; Love, Quintin U.

    2016-01-01

    The main points of Sijtsma and Green and Yang in Educational Measurement: Issues and Practice (34, 4) are that reliability, internal consistency, and unidimensionality are distinct and that Cronbach's alpha may be problematic. Neither of these assertions are at odds with Davenport, Davison, Liou, and Love in the same issue. However, many authors…

  5. Development and Initial Validation of the Inventory of Microaggressions against Black Individuals

    ERIC Educational Resources Information Center

    Mercer, Sterett H.; Zeigler-Hill, Virgil; Wallace, Marion; Hayes, DeMarquis M.

    2011-01-01

    The present article describes the development and initial validation of the Inventory of Microaggressions Against Black Individuals (IMABI) using a sample of 385 undergraduates who self-identified as Black or African American. The IMABI is a 14-item, unidimensional measure of racial microaggressions that captures both microinsults and…

  6. Personality Correlates of Aggression: Evidence from Measures of the Five-Factor Model, UPPS Model of Impulsivity, and BIS/BAS

    ERIC Educational Resources Information Center

    Miller, Joshua D.; Zeichner, Amos; Wilson, Lauren F.

    2012-01-01

    Although many studies of personality and aggression focus on multidimensional traits and higher order personality disorders (e.g., psychopathy), lower order, unidimensional traits may provide more precision in identifying specific aspects of personality that relate to aggression. The current study includes a comprehensive measurement of lower…

  7. The Tenacious Goal Pursuit and Flexible Goal Adjustment Scales: Examination of Their Validity

    ERIC Educational Resources Information Center

    Mueller, Daniel J.; Kim, Kyung

    2004-01-01

    This study tested the unidimensionality of the Tenacious Goal Pursuit (TGP) and Flexible Goal Adjustment (FGA) scales and examined the relationships of the factors measured in these scales with two criterion constructs (happiness and self-acceptance) and with age in a sample 292 adults (ranging from 50 to 90 years). Confirmatory factor analyses…

  8. Diversity Identity Development Training: Theory Informs Practice.

    ERIC Educational Resources Information Center

    Ramsey, MaryLou

    1996-01-01

    Most identity development models are unidimensional and mutually independent. They rarely acknowledge multiple cultural identifications or their relationship to diversity-awareness training. This article discusses this relationship in a four-stage conceptual model for diversity identity development and its implications for the design, structuring,…

  9. How Should Discrepancy Be Assessed in Perfectionism Research? A Psychometric Analysis and Proposed Refinement of the Almost Perfect Scale-Revised

    ERIC Educational Resources Information Center

    Flett, Gordon L.; Mara, Constance A.; Hewitt, Paul L.; Sirois, Fuschia; Molnar, Danielle S.

    2016-01-01

    Research on perfectionism with the Almost Perfect Scale-Revised (APS-R) distinguishes adaptive perfectionists versus maladaptive perfectionists based primarily on their responses to the 12-item unidimensional APS-R Discrepancy subscale, which assesses the sense of falling short of standards. People described as adaptive perfectionists have high…

  10. Best Design for Multidimensional Computerized Adaptive Testing with the Bifactor Model

    ERIC Educational Resources Information Center

    Seo, Dong Gi; Weiss, David J.

    2015-01-01

    Most computerized adaptive tests (CATs) have been studied using the framework of unidimensional item response theory. However, many psychological variables are multidimensional and might benefit from using a multidimensional approach to CATs. This study investigated the accuracy, fidelity, and efficiency of a fully multidimensional CAT algorithm…

  11. Educational Mismatch of Graduates: A Multidimensional and Fuzzy Indicator

    ERIC Educational Resources Information Center

    Betti, Gianni; D'Agostino, Antonella; Neri, Laura

    2011-01-01

    In this paper we attempt to measure the educational mismatch, seen as a problem of overeducation, using a multidimensional and fuzzy methodology. Educational mismatch can be difficult to measure because many factors can converge to its definition and the traditional unidimensional indicators presented in literature can offer a restricted view of…

  12. The Development of a Hierarchical Polychotomous ADL-IADL Scale for Noninstitutionalized Elders.

    ERIC Educational Resources Information Center

    Kempen, G. I. J. M.; Suurmeijer, T. P. B. M.

    1990-01-01

    Tested hierarchical scale comprising 18 activities of daily living (ADL) and instrumental activities of daily living (IADL) items on 101 noninstitutionalized older adults in Netherlands. Results confirmed possibility of constructing unidimensional, hierarchical. polychotomous scale measuring "functional problems on ADL-IADL." Considered…

  13. Comparing Three Estimation Methods for the Three-Parameter Logistic IRT Model

    ERIC Educational Resources Information Center

    Lamsal, Sunil

    2015-01-01

    Different estimation procedures have been developed for the unidimensional three-parameter item response theory (IRT) model. These techniques include the marginal maximum likelihood estimation, the fully Bayesian estimation using Markov chain Monte Carlo simulation techniques, and the Metropolis-Hastings Robbin-Monro estimation. With each…

  14. Estimating Decision Indices Based on Composite Scores

    ERIC Educational Resources Information Center

    Knupp, Tawnya Lee

    2009-01-01

    The purpose of this study was to develop an IRT model that would enable the estimation of decision indices based on composite scores. The composite scores, defined as a combination of unidimensional test scores, were either a total raw score or an average scale score. Additionally, estimation methods for the normal and compound multinomial models…

  15. The Factor Structure of the Work-Family Conflict Multidimensional Scale: Exploring the Expectations of College Students

    ERIC Educational Resources Information Center

    Gaffey, Abigail R.; Rottinghaus, Patrick J.

    2009-01-01

    Work-family conflict (WFC) has been examined from a unidimensional approach, yet recent research has revealed three types (i.e., time, strain, and behavior) and two directions of work-family conflict. Previous researchers suggested that college students are unable to discern between the multiple-facets of WFC, thus measured anticipated WFC…

  16. Tissue phenotype depends on reciprocal interactions between the extracellular matrix and the structural organization of the nucleus

    SciTech Connect

    Lelie'vre, S.A.; Weaver, V.M.; Nickerson, J.A.; Larabell, C.A.; Bhaumik, A.; Petersen, O.W.; Bissell, M.J.

    1998-08-14

    What determines the nuclear organization within a cell and whether this organization itself can impose cellular function within a tissue remains unknown. To explore the relationship between nuclear organization and tissue architecture and function, we used a model of human mammary epithelial cell acinar morphogenesis. When cultured within a reconstituted basement membrane (rBM), HMT-3522 cells form polarized and growth-arrested tissue-like acini with a central lumen and deposit an endogenous BM. We show that rBM-induced morphogenesis is accompanied by relocalization of the nuclear matrix proteins NuMA, splicing factor SRm160, and cell cycle regulator Rb. These proteins had distinct distribution patterns specific for proliferation, growth arrest, and acini formation, whereas the distribution of the nuclear lamina protein, lamin B, remained unchanged. NuMA relocalized to foci, which coalesced into larger assemblies as morphogenesis progressed. Perturbation of histone acetylation in the acini by trichostatin A treatment altered chromatin structure, disrupted NuMA foci, and induced cell proliferation. Moreover, treatment of transiently permeabilized acini with a NuMA antibody led to the disruption of NuMA foci, alteration of histone acetylation, activation of metalloproteases, and breakdown of the endogenous BM. These results experimentally demonstrate a dynamic interaction between the extracellular matrix, nuclear organization, and tissue phenotype. They further show that rather than passively ref lecting changes in gene expression, nuclear organization itself can modulate the cellular and tissue phenotype.

  17. Tank binding kinase 1 is a centrosome-associated kinase necessary for microtubule dynamics and mitosis.

    PubMed

    Pillai, Smitha; Nguyen, Jonathan; Johnson, Joseph; Haura, Eric; Coppola, Domenico; Chellappan, Srikumar

    2015-12-10

    TANK Binding Kinase 1 (TBK1) is a non-canonical IκB kinase that contributes to KRAS-driven lung cancer. Here we report that TBK1 plays essential roles in mammalian cell division. Specifically, levels of active phospho-TBK1 increase during mitosis and localize to centrosomes, mitotic spindles and midbody, and selective inhibition or silencing of TBK1 triggers defects in spindle assembly and prevents mitotic progression. TBK1 binds to the centrosomal protein CEP170 and to the mitotic apparatus protein NuMA, and both CEP170 and NuMA are TBK1 substrates. Further, TBK1 is necessary for CEP170 centrosomal localization and binding to the microtubule depolymerase Kif2b, and for NuMA binding to dynein. Finally, selective disruption of the TBK1-CEP170 complex augments microtubule stability and triggers defects in mitosis, suggesting that TBK1 functions as a mitotic kinase necessary for microtubule dynamics and mitosis.

  18. United States Air Force Statistical Digest, Fiscal Year 1964, Nineteenth Edition

    DTIC Science & Technology

    1964-09-30

    East Air Forces. 3 August 1944; re- dcsignated as Pacific Air Command. USArmy. 6 De- cember 1945; rede stgnated , Far East Air Forces. 1 July 1957...changes in title and GAINS Not Beyond Economic Repair Transfer and From Diversion MISSION, DESIGN; AND SKRIES Pro- MAP, From Redes - Total duc- USA...Oth- igna- Total Redes - Obso- Recla- tien and er tieD igna- lete ""- USN tien tioD MAP USA USN Oth-er . FDlST HALF IT 1964 (1 JuJ.y TOTAL 1,165 122 36

  19. United States Air Force Statistical Digest, Fiscal Year 1963, Eighteenth Edition

    DTIC Science & Technology

    1963-09-30

    AIR FORCE BASE • CA1’INONAIR FORCEBASE CARSWELL AIR FORCEBASE. CASTLEAIR FORCEBASE CRANlJI’E AIR FORCEBASE• o o o o K 9 miles South of Peru , Indiana 7...3 OCTOBER � about 1,300 troops and 39 tons aircraft also participated in and back to Central Europe. (U) of equipment to Europe and later rede ...SERIES Pro- MAP, From Redes - futa1 due- USA, other rgne- futa1 Redes - Obso- Recla- taon and tion 19na- lete ma- USN tion tion FIRST !!ALP py 1963 (1

  20. Void Growth and Coalescence Simulations

    DTIC Science & Technology

    2013-08-01

    AFRL-RW-EG-TR-2013-080 VOID GROWTH AND COALESCENCE SIMULATIONS Derek J. Reding 1 Pavol Stofko 2 Robert J. Dorgan 3 Michael E. Nixon 4...3002 W0AQ Derek J. Reding 1 Pavol Stofko 2 Robert J. Dorgan 3 Michael E. Nixon 4 1 Jacobs TEAS Team; 1030 Titan Court; Fort Walton Beach, FL 32547...on Steady-State Fluid Flow and Heat Transfer," Journal of Fluids Engineering, vol. 125, no. 4, pp. 731-733, 2003. [19] D. J. Reding and S. Hanagud

  1. Sting Interference Effects as Determined by Measurements of Dynamic Stability Derivatives, Surface Pressure, and Base Pressure for Mach Numbers 2 through 8

    DTIC Science & Technology

    1980-10-01

    Ericsson, Lars E. and Reding , J. Peter, "Aerodynamic Effects of Bulbous Bases." NASA CR-1339, August 1969. 21. Wehrend, William R., Jr. "An Experimental...Flight at Mach Numbers from 0.7 to 1.3." NACA-RM-L52E06, September 1952. 36. Ericsson, Lars E. and Reding , J. Peter. "Viscous Interactions or Support...Interference -The Dynamicist’s Dilemma." AJAA Journal, Vol. 16, No.4, April 1978, pp. 363-368. 37. Reding , J. Peter and Ericsson, Lars E. "Dynamic

  2. Function of donor cell centrosome in intraspecies and interspecies nuclear transfer embryos

    SciTech Connect

    Zhong Zhisheng; Zhang Gang; Meng Xiaoqian; Zhang Yanling; Chen Dayuan; Schatten, Heide; Sun Qingyuan . E-mail: sunqy1@yahoo.com

    2005-05-15

    Centrosomes, the main microtubule-organizing centers (MTOCs) in most animal cells, are important for many cellular activities such as assembly of the mitotic spindle, establishment of cell polarity, and cell movement. In nuclear transfer (NT), MTOCs that are located at the poles of the meiotic spindle are removed from the recipient oocyte, while the centrosome of the donor cell is introduced. We used mouse MII oocytes as recipients, mouse fibroblasts, rat fibroblasts, or pig granulosa cells as donor cells to construct intraspecies and interspecies nuclear transfer embryos in order to observe centrosome dynamics and functions. Three antibodies against centrin, {gamma}-tubulin, and NuMA, respectively, were used to stain the centrosome. Centrin was not detected either at the poles of transient spindles or at the poles of first mitotic spindles. {gamma}-tubulin translocated into the two poles of the transient spindles, while no accumulated {gamma}-tubulin aggregates were detected in the area adjacent to the two pseudo-pronuclei. At first mitotic metaphase, {gamma}-tubulin was translocated to the spindle poles. The distribution of {gamma}-tubulin was similar in mouse intraspecies and rat-mouse interspecies embryos. The NuMA antibody that we used can recognize porcine but not murine NuMA protein, so it was used to trace the NuMA protein of donor cell in reconstructed embryos. In the pig-mouse interspecies reconstructed embryos, NuMA concentrated between the disarrayed chromosomes soon after activation and translocated to the transient spindle poles. NuMA then immigrated into pseudo-pronuclei. After pseudo-pronuclear envelope breakdown, NuMA was located between the chromosomes and then translocated to the spindle poles of first mitotic metaphase. {gamma}-tubulin antibody microinjection resulted in spindle disorganization and retardation of the first cell division. NuMA antibody microinjection also resulted in spindle disorganization. Our findings indicate that (1) the

  3. Astronomy, Art and Mythology in a Public Elementary School in Itaocara/rj. (Spanish Title: Astronomía, Arte y Mitologia en el Ensino Fundamental en Una Escuela de la Red Estatal en ITAOCARA/RJ.) Astronomia, Arte e Mitologia no Ensino Fundamental em Escola da Rede Estadual em ITAOCARA/RJ

    NASA Astrophysics Data System (ADS)

    Oliveira Bernardes, Adriana; Ramos dos Santos, Arleidimar

    2008-12-01

    Volunteer advisors at Itaocara Astronomy Club Marcos Pontes(CAIMP), in their majority high school students, introduced students at Teotônio Brandão Vilela Elementary School to basic concepts in Astronomy, Physics, and Mythology. Computer Science, Arts, puppetry, and educational videos were used to stimulate students to share their feelings and test their knowledge of the concepts presented. The work done by the volunteers helped boost the student's self-esteem and improved their oral skills by applying their knowledge of Physics and Astronomy in Lab experiments. The main goals of the CAIMP are the possibility of including astronomy in Elementary school curricula and developing an interdisciplinary work involving Astronomy, Arts, and Mythology. Through tests and reports, the students who participated in the Brazilian Astronomy Olympics, showed an increase in their knowldge of the sujects presented during the volunteer work. Durante el curso de un trabajo voluntario con estudiantes de nivel primario (1 º a 4 º grado), los guías de Astronomía miembros del CAIMP (Club de Astronomía de Itaocara "Marcos Puentes"), en su mayoría estudiantes secundarios, desarrollaron un trabajo de introducción a las Ciencias y Astronomía con alumnos del colegio estatal Teotônio Vilela Brandão. A través de talleres de informática, artes, videos educativos y teatro de títeres, los estudiantes pudieron expresar sus conocimientos y emociones frente a las leyendas mitológicas con las que se inició el trabajo de introducción. La labor desarrollada por los guías con los alumnos promovió la integración entre las aulas del colegio haciéndolos participar en actividades con el fin de estimular su expresión verbal y aumentar su autoestima. Trabajando diversas formas de expresión, los alumnos pudieron realizar experimentos y conocer algunos conceptos de Física y Astronomía al mismo tiempo que adquirían autonomía para la libre expresión de sus sentimientos y de los conocimientos recibidos. El trabajo en sí ha mostrado además de la posibilidad de la inclusión de la Astronomía en la Educación Primaria, la posibilidad de un trabajo interdisciplinario en los niveles iniciales incluyendo Astronomía, Arte y Mitología. Los resultados presentados por los estudiantes en las Olimpiadas promovidas en la escuela y por la OBA (Olimpiada Brasilera de Astronomía) permitieron verificar un creciente aprendizaje y estimulo hacia las materias científicas, comprobados por la apropiada expresión de los conceptos adquiridos de astronomía y presentados en evaluaciones o en informes obtenidos de ellos mismos, sus familias y profesores. Desenvolvendo um trabalho voluntário junto aos alunos do ensino fundamental no 1º ciclo (1ª a 4ª série), os monitores de Astronomia membros do CAIMP (Clube de Astronomia de Itaocara Marcos Pontes), que eram em sua maioria alunos do ensino médio, desenvolveram um trabalho de aproximação entre os alunos do Colégio Estadual Teotônio Brandão Vilela e os temas envolvendo Ciências e Astronomia. Através de oficinas de informática, artes, vídeos educativos e teatros de fantoches, os alunos puderam expressar seus conhecimentos e emoções diante das lendas mitológicas com as quais começaram a ter contato. O trabalho desenvolvido pelos monitores junto aos alunos proporcionou a integração entre as turmas do colégio e os levou a participação em atividades de maneira a estimular sua oralidade e aumentar sua auto-estima. Trabalhando várias formas de expressões, os alunos puderam realizar seus experimentos e conhecer alguns conceitos de Física e Astronomia, enquanto adquiriam autonomia para se expressarem de acordo com seus sentimentos e conhecimentos adquiridos. O trabalho em si mostrou além da possibilidade de inserção de Astronomia no Ensino Fundamental, a possibilidade de realização de um trabalho interdisciplinar nas séries iniciais envolvendo Astronomia, Arte e Mitologia. Os resultados apresentados pelos alunos nas Olimpíadas promovidas na escola e pela OBA (Olimpíada Brasileira de Astronomia) possibilitaram a verificação de uma crescente aprendizagem e estímulo ao conhecimento de temas científicos, que foi comprovado diante da apropriação dos conceitos de Astronomia adquiridos e apresentados em resultados como avaliações, ou ainda, diante dos relatos obtidos dos mesmos, suas famílias e professores.

  4. EPA Awards $400K in Brownfields Grants to Cleanup and Revitalize West Point, Mississippi

    EPA Pesticide Factsheets

    ATLANTA - Today, the U.S. Environmental Protection Agency (EPA) announced the selection of two new grant investments totaling $400,000 in West Point, Miss. These investments will provide the community with funding necessary to assess, clean and rede

  5. Transport on a lattice with dynamical defects.

    PubMed

    Turci, Francesco; Parmeggiani, Andrea; Pitard, Estelle; Romano, M Carmen; Ciandrini, Luca

    2013-01-01

    Many transport processes in nature take place on substrates, often considered as unidimensional lanes. These unidimensional substrates are typically nonstatic: Affected by a fluctuating environment, they can undergo conformational changes. This is particularly true in biological cells, where the state of the substrate is often coupled to the active motion of macromolecular complexes, such as motor proteins on microtubules or ribosomes on mRNAs, causing new interesting phenomena. Inspired by biological processes such as protein synthesis by ribosomes and motor protein transport, we introduce the concept of localized dynamical sites coupled to a driven lattice gas dynamics. We investigate the phenomenology of transport in the presence of dynamical defects and find a regime characterized by an intermittent current and subject to severe finite-size effects. Our results demonstrate the impact of the regulatory role of the dynamical defects in transport not only in biology but also in more general contexts.

  6. The dimensionality of defense-mechanism parcels in the Defense Style Questionnaire-40.

    PubMed

    Wilkinson, Wayne W; Ritchie, Timothy D

    2015-03-01

    The Defense Style Questionnaire-40 (DSQ-40; Andrews, Singh, & Bond, 1993) uses pairs of items to measure 20 individual defense mechanisms. In a statistical sense, these item pairs represent parcels and are subject to the standards of unidimensionality demanded of parcels in general. Using a 2-facet modeling approach (N = 672), the present study examined the dimensionality of the defense-mechanism parcels in the DSQ-40 and found that the majority of the parcels did not satisfy the criteria for unidimensionality. In addition, the original 3-factor model of defense styles was not tenable with the present data. Overall, the results suggest caution when attempting to assess individual defense mechanisms using the DSQ-40.

  7. Properties of the Tampa Scale for Kinesiophobia across Workers with Different Pain Experiences and Cultural Backgrounds: A Rasch Analysis.

    PubMed

    Jørgensen, M B; Damsgård, E; Holtermann, A; Anke, A; Søgaard, K; Røe, C

    2015-01-01

    The main aim of this study was to evaluate whether the construct validity of the Tampa Scale for Kinesiophobia (TSK) is consistent with respect to its scaling properties, unidimensionality and targeting among workers with different levels of pain. The 311 participating Danish workers reported kinesiophobia by TSK (13 statement version) and number of days with pain during the past year (less than 8 days, less than 90 days and greater than 90 days). A Rasch analysis was used to evaluate the measurement properties of the TSK in the workers across pain levels, ages, genders and ethnicities. The TSK did not fit the Rasch model, but removing one item solved the poorness of fit. Invariance was found across the pain levels, ages and genders. Thus, with a few modifications, the TSK was shown to capture a unidimensional construct of fear of movement in workers with different pain levels, ages, and genders.

  8. Absolute magnitude estimation and relative judgement approaches to subjective workload assessment

    NASA Technical Reports Server (NTRS)

    Vidulich, Michael A.; Tsang, Pamela S.

    1987-01-01

    Two rating scale techniques employing an absolute magnitude estimation method, were compared to a relative judgment method for assessing subjective workload. One of the absolute estimation techniques used was an unidimensional overall workload scale and the other was the multidimensional NASA-Task Load Index technique. Thomas Saaty's Analytic Hierarchy Process was the unidimensional relative judgment method used. These techniques were used to assess the subjective workload of various single- and dual-tracking conditions. The validity of the techniques was defined as their ability to detect the same phenomena observed in the tracking performance. Reliability was assessed by calculating test-retest correlations. Within the context of the experiment, the Saaty Analytic Hierarchy Process was found to be superior in validity and reliability. These findings suggest that the relative judgment method would be an effective addition to the currently available subjective workload assessment techniques.

  9. Testing the multidimensionality of the inventory of school motivation in a Dutch student sample.

    PubMed

    Korpershoek, Hanke; Xu, Kun; Mok, Magdalena Mo Ching; McInerney, Dennis M; van der Werf, Greetje

    2015-01-01

    A factor analytic and a Rasch measurement approach were applied to evaluate the multidimensional nature of the school motivation construct among more than 7,000 Dutch secondary school students. The Inventory of School Motivation (McInerney and Ali, 2006) was used, which intends to measure four motivation dimensions (mastery, performance, social, and extrinsic motivation), each comprising of two first-order factors. One unidimensional model and three multidimensional models (4-factor, 8-factor, higher order) were fit to the data. Results of both approaches showed that the multidimensional models validly represented the school motivation among Dutch secondary school pupils, whereas model fit of the unidimensional model was poor. The differences in model fit between the three multidimensional models were small, although a different model was favoured by the two approaches. The need for improvement of some of the items and the need to increase measurement precision of several first-order factors are discussed.

  10. Evaluating the Psychometric Properties of a Clinical Vocational Rehabilitation Outcome Measurement: The Assessment of Work Performance (AWP).

    PubMed

    Fan, Chia-Wei; Taylor, Renée R; Ekbladh, Elin; Hemmingsson, Helena; Sandqvist, Jan

    2013-01-01

    This study examined the validity and reliability of the Assessment of Work Performance (AWP) using Rasch analysis. The AWP was administered to 365 clients with a variety of work-related problems. Rasch analysis and principal component analysis were used to examine the appropriateness of the rating scales and unidimensionality of AWP items. The person-response validity, internal consistency, targeting appropriateness, and differential item function were also analyzed. The Rasch analysis confirmed the 4-point rating scale, and the item set met the criteria of unidimensionality. The AWP exhibited satisfactory person-response validity and internal consistency. Among the three subdomains, the targeting of item-difficulty was sufficient in the motor skills and process skills subdomains. Differential item functioning was found across gender and diagnoses. This study presented evidence to support that the AWP functioned as a reliable and valid assessment in assessing work performance. [OTJR: Occupation, Participation and Health 2013;33(3):125-133.].

  11. The motivation of stereotypic and repetitive behavior: examination of construct validity of the motivation assessment scale.

    PubMed

    Joosten, Annette V; Bundy, Anita C

    2008-08-01

    Construct validity of the Motivation Assessment Scale (MAS) (Durand, Crimmins, The Motivation Assessment Scale 1988) was studied using Rasch analysis data from 67 children (246 MASs), with dual diagnosis of autism and intellectual disability or with intellectual disability only. Results failed to support the proposed unidimensional construct or the original 4-factor structure. Some motivators appear to form a unidimensional construct: "to gain attention", "to gain a tangible object", and "to escape". There was evidence that sensory stimulation represents a different construct. Children with intellectual disability were more apt to be motivated by desire to gain a tangible item or attention. Children with the dual diagnoses were more apt to have sensory stimulation or escape from task demand as a motivator for stereotypic and repetitive behavior.

  12. Transport on a lattice with dynamical defects

    NASA Astrophysics Data System (ADS)

    Turci, Francesco; Parmeggiani, Andrea; Pitard, Estelle; Romano, M. Carmen; Ciandrini, Luca

    2013-01-01

    Many transport processes in nature take place on substrates, often considered as unidimensional lanes. These unidimensional substrates are typically nonstatic: Affected by a fluctuating environment, they can undergo conformational changes. This is particularly true in biological cells, where the state of the substrate is often coupled to the active motion of macromolecular complexes, such as motor proteins on microtubules or ribosomes on mRNAs, causing new interesting phenomena. Inspired by biological processes such as protein synthesis by ribosomes and motor protein transport, we introduce the concept of localized dynamical sites coupled to a driven lattice gas dynamics. We investigate the phenomenology of transport in the presence of dynamical defects and find a regime characterized by an intermittent current and subject to severe finite-size effects. Our results demonstrate the impact of the regulatory role of the dynamical defects in transport not only in biology but also in more general contexts.

  13. Anopheles (Nyssorhynchus) konderi Galvao and Damasceno: Neotype Designation and Resurrection from Synonymy with Anopheles (Nyssorhynchus) oswaldoi (Peryassu) (Diptera: Culicidae)

    DTIC Science & Technology

    2004-01-07

    WILKERSON, AND RICARDO LOUREN•O DE OLIVEIRA (CFM) U.S. Naval Medical Research Center Detachment, Lima, Peru , APO AA 34031; (ELP) (deceased); (RCW...Nyssorhynchus) konderi Galvfio and Damasceno 1942 is rede - scribed with illustrations of the male and female genitalia and the larval and pupal stages...An. oswaldoi were conducted to distinguish these species and to rede - scribe the former. MATERIALS AND METHODS Progenies of females and immature

  14. Psychometric properties of the Francis Scale of Attitude Towards Christianity among Portuguese university students.

    PubMed

    Ferreira, Ana Veríssimo; Neto, Félix

    2002-12-01

    To facilitate use of the adult form of the Francis Scale of Attitude Towards Christianity in cross-cultural studies, the psychometric characteristics of the translated scale were examined among 323 university students in Portugal (130 men and 193 women). Their ages ranged from 18 to 31 years. Analysis supported the unidimensionality, internal consistency, and construct validity of this scale in this sample of Portuguese university students.

  15. The psychometric properties of the generalized anxiety disorder-7 scale in Hispanic Americans with English or Spanish language preference.

    PubMed

    Mills, Sarah D; Fox, Rina S; Malcarne, Vanessa L; Roesch, Scott C; Champagne, Brian R; Sadler, Georgia Robins

    2014-07-01

    The Generalized Anxiety Disorder-7 scale (GAD-7) is a self-report questionnaire that is widely used to screen for anxiety. The GAD-7 has been translated into numerous languages, including Spanish. Previous studies evaluating the structural validity of the English and Spanish versions indicate a unidimensional factor structure in both languages. However, the psychometric properties of the Spanish language version have yet to be evaluated in samples outside of Spain, and the measure has not been tested for use among Hispanic Americans. This study evaluated the reliability, structural validity, and convergent validity of the English and Spanish language versions of the GAD-7 for Hispanic Americans in the United States. A community sample of 436 Hispanic Americans with an English (n = 210) or Spanish (n = 226) language preference completed the GAD-7. Multiple-group confirmatory factor analysis (CFA) was used to examine the goodness-of-fit of the unidimensional factor structure of the GAD-7 across language-preference groups. Results from the multiple-group CFA indicated a similar unidimensional factor structure with equivalent response patterns and item intercepts, but different variances, across language-preference groups. Internal consistency was good for both English and Spanish language-preference groups. The GAD-7 also evidenced good convergent validity as demonstrated by significant correlations in expected directions with the Perceived Stress Scale, the Patient Health Questionnaire-9, and the Physical Health domain of the World Health Organization Quality of Life-BREF assessment. The unidimensional GAD-7 is suitable for use among Hispanic Americans with an English or Spanish language preference.

  16. Bifactor models and rotations: exploring the extent to which multidimensional data yield univocal scale scores.

    PubMed

    Reise, Steven P; Moore, Tyler M; Haviland, Mark G

    2010-11-01

    The application of psychological measures often results in item response data that arguably are consistent with both unidimensional (a single common factor) and multidimensional latent structures (typically caused by parcels of items that tap similar content domains). As such, structural ambiguity leads to seemingly endless "confirmatory" factor analytic studies in which the research question is whether scale scores can be interpreted as reflecting variation on a single trait. An alternative to the more commonly observed unidimensional, correlated traits, or second-order representations of a measure's latent structure is a bifactor model. Bifactor structures, however, are not well understood in the personality assessment community and thus rarely are applied. To address this, herein we (a) describe issues that arise in conceptualizing and modeling multidimensionality, (b) describe exploratory (including Schmid-Leiman [Schmid & Leiman, 1957] and target bifactor rotations) and confirmatory bifactor modeling, (c) differentiate between bifactor and second-order models, and (d) suggest contexts where bifactor analysis is particularly valuable (e.g., for evaluating the plausibility of subscales, determining the extent to which scores reflect a single variable even when the data are multidimensional, and evaluating the feasibility of applying a unidimensional item response theory (IRT) measurement model). We emphasize that the determination of dimensionality is a related but distinct question from either determining the extent to which scores reflect a single individual difference variable or determining the effect of multidimensionality on IRT item parameter estimates. Indeed, we suggest that in many contexts, multidimensional data can yield interpretable scale scores and be appropriately fitted to unidimensional IRT models.

  17. Revisiting the factorial validity of the Revised UCLA Loneliness Scale: a test of competing models in a sample of teachers.

    PubMed

    Dussault, Marc; Fernet, Claude; Austin, Stéphanie; Leroux, Mathieu

    2009-12-01

    Over the years, various studies addressing different populations have consistently raised concerns about the unidimensionality of the Revised UCLA Loneliness Scale. In the present study, the factorial structure of the scale was examined by comparing it to alternative models. In a sample of 1,157 French Canadian teachers, results of confirmatory factor analysis support a three-factor model solution. Support for the invariance of this model across sexes and teaching levels (i.e., elementary and high school) was also obtained.

  18. Constructor:synthesizing information about uncertain variables.

    SciTech Connect

    Tucker, W. Troy; Ferson, Scott; Hajagos, Janos; Myers, David S.

    2005-09-01

    Constructor is software for the Microsoft Windows microcomputer environment that facilitates the collation of empirical information and expert judgment for the specification of probability distributions, probability boxes, random sets or Dempster-Shafer structures from data, qualitative shape information, constraints on moments, order statistics, densities, and coverage probabilities about uncertain unidimensional quantities. These quantities may be real-valued, integer-valued or logical values.

  19. Construct continuity in the presence of multidimensionality

    NASA Astrophysics Data System (ADS)

    Staniewska, Dorota

    Unidimensionality -- a condition, under which only one dominant construct is being measured by the test, is a fundamental assumption of most modern day psychometric models. However, some tests are multidimensional by design. A test, for instance, might measure physics, biology and chemistry subscales combined to measure a "general science" composite. The relative magnitudes of those subscales sometimes shift from administration to administration, which results in an altered composite. This study examined the conditions under which two different forms of a multidimensional test measure the same composite construct to a degree that allows them to be equated, i.e. used interchangeably. IRT true-score equating was used in a simulation study to assess the closeness of the scores on the forms. Conditions examined included the correlations between subscales, varying number of items per subscale form to form, and different subpopulation ability estimates on the subscales. Differences in the equating errors due to generating model (1PL or 3PL) were also examined. A way of calculating a unidimensional composite from a two-dimensional ability was devised and compared to the unidimensional composite obtained from Parscale. It was found that in general, the errors increase with decreasing correlation between traits and increased divergence of the two forms to be equated, with the later being the main predictor of the equating errors. However, the magnitude of those errors was small for the population as a whole especially when all examinee abilities are drawn from the same distribution. It was concluded that IRT true score equating is relatively robust to multidimensionality for the conditions examined, especially if the overall population score is desired. However, when accurate estimate of the equated score for individuals at the extremes of the population is needed, or whenever population abilities are drawn from more than one distribution, the unidimensional true score

  20. Re-Estimation of Student Ability in Foreign Languages Using the Rasch Model

    DTIC Science & Technology

    1988-01-01

    assumed by evaluators that examinee scores on a valid test are reasonable by virtue of high reliability (usually measured by Kuder - Richardson 20) without...both subtests (split-half reliability ). If the domain sampling model (unidimensional) is in view, then the Kuder - Richardson (KR) formulae are more...separation reliability is a maximum-likelihood equivalent to the Kuder - Richardson -20 or Cronbach’s Coefficient Alpha reliability indices. This internal

  1. Job Satisfaction.

    DTIC Science & Technology

    1979-07-01

    well include an "overall, global or unidimensional component" (p 184) but that additional specific factors were also evident, ie. "job satisfaction is...between a person’s life style and organisational structure. They hypothesised that job satisfaction may be adversely affected if there is any significant...between job satisfaction and an independent life style, and; thirdly, that "job satisfac- tion is maximispd when the individual places a high value

  2. Rasch analysis of the Chedoke-McMaster Attitudes towards Children with Handicaps scale.

    PubMed

    Armstrong, Megan; Morris, Christopher; Tarrant, Mark; Abraham, Charles; Horton, Mike C

    2017-02-01

    Aim To assess whether the Chedoke-McMaster Attitudes towards Children with Handicaps (CATCH) 36-item total scale and subscales fit the unidimensional Rasch model. Method The CATCH was administered to 1881 children, aged 7-16 years in a cross-sectional survey. Data were used from a random sample of 416 for the initial Rasch analysis. The analysis was performed on the 36-item scale and then separately for each subscale. The analysis explored fit to the Rasch model in terms of overall scale fit, individual item fit, item response categories, and unidimensionality. Item bias for gender and school level was also assessed. Revised scales were then tested on an independent second random sample of 415 children. Results Analyses indicated that the 36-item overall scale was not unidimensional and did not fit the Rasch model. Two scales of affective attitudes and behavioural intention were retained after four items were removed from each due to misfit to the Rasch model. Additionally, the scaling was improved when the two most negative response categories were aggregated. There was no item bias by gender or school level on the revised scales. Items assessing cognitive attitudes did not fit the Rasch model and had low internal consistency as a scale. Conclusion Affective attitudes and behavioural intention CATCH sub-scales should be treated separately. Caution should be exercised when using the cognitive subscale. Implications for Rehabilitation The 36-item Chedoke-McMaster Attitudes towards Children with Handicaps (CATCH) scale as a whole did not fit the Rasch model; thus indicating a multi-dimensional scale. Researchers should use two revised eight-item subscales of affective attitudes and behavioural intentions when exploring interventions aiming to improve children's attitudes towards disabled people or factors associated with those attitudes. Researchers should use the cognitive subscale with caution, as it did not create a unidimensional and internally consistent scale

  3. Quantum-size effects in the titanosilicate molecular sieve

    NASA Astrophysics Data System (ADS)

    Borello, Enzo; Lamberti, Carlo; Bordiga, Silvia; Zecchina, Adriano; Areán, Carlos Otero

    1997-10-01

    The recently synthesized Engelhard titanosilicate (ETS-10) represents a material which contains in the structure well defined atomic ⋯O-Ti-O-Ti-O⋯ quantum wires embedded in a highly insulating siliceous matrix. We report and discuss the UV-Vis spectrum of this material and compare the experimentally determined optical band gap with the results predicted by simple modeling of a titanium oxide semiconductor wire unidimensionally confined by an infinite potential barrier.

  4. The psychometric development and initial validation of the DCI-A short form for adolescent therapeutic community treatment process.

    PubMed

    Stucky, Brian D; Edelen, Maria Orlando; Vaughan, Christine A; Tucker, Joan S; Butler, Jennifer

    2014-04-01

    The 5-factor client-report Dimensions of Change in Therapeutic Communities Treatment Instrument-Adolescent (DCI-A) was developed to assess adolescent substance abuse treatment process in the therapeutic community (TC). The goal of this study was to use bifactor modeling to derive a unidimensional DCI-A short-form (DCI-A-SF) that would represent content from the original DCI-A factors. Data are from 442 adolescents receiving treatment at one of seven residential TC programs. Bifactor analyses suggested selection of seven DCI-A items to comprise the short form. Three items are from the treatment motivation factor, and one item was selected from each of the remaining four factors. Confirmatory factor analysis suggested that the 7-item DCI-A-SF is strongly unidimensional, and unidimensional IRT analysis of the items indicated good internal consistency. A structural equation model that demonstrates the mediating relationship of DCI-A-SF with other measures, including demographic and pre-treatment characteristics, and subsequent treatment completion, provides preliminary evidence of internal validity.

  5. Measuring disability across cultures — the psychometric properties of the WHODAS II in older people from seven low- and middle-income countries. The 10/66 Dementia Research Group population-based survey

    PubMed Central

    Sousa, Renata M; Dewey, Michael E; Acosta, Daisy; Jotheeswaran, AT; Castro-Costa, Erico; Ferri, Cleusa P; Guerra, Mariella; Huang, Yueqin; Jacob, KS; Pichardo, Juana Guillermina Rodriguez; Ramírez, Nayeli Garcia; Rodriguez, Juan Llibre; Rodriguez, Marina Calvo; Salas, Aquiles; Sosa, Ana Luisa; Williams, Joseph; Prince, Martin J

    2010-01-01

    We evaluated the psychometric properties of the 12-item interviewer-administered screener version of the World Health Organization Disability Assessment Schedule – version II (WHODAS II) among older people living in seven low- and middle-income countries. Principal component analysis (PCA), confirmatory factor analysis (CFA) and Mokken analyses were carried out to test for unidimensionality, hierarchical structure, and measurement invariance across 10/66 Dementia Research Group sites. PCA generated a one-factor solution in most sites. In CFA, the two-factor solution generated in Dominican Republic fitted better for all sites other than rural China. The two factors were not easily interpretable, and may have been an artefact of differing item difficulties. Strong internal consistency and high factor loadings for the one-factor solution supported unidimensionality. Furthermore, the WHODAS II was found to be a ‘strong’ Mokken scale. Measurement invariance was supported by the similarity of factor loadings across sites, and by the high between-site correlations in item difficulties. The Mokken results strongly support that the WHODAS II 12-item screener is a unidimensional and hierarchical scale confirming to item response theory (IRT) principles, at least at the monotone homogeneity model level. More work is needed to assess the generalizability of our findings to different populations. Copyright © 2010 John Wiley & Sons, Ltd. PMID:20104493

  6. Examining mutual suppression effects in the assessment of perfectionism cognitions: evidence supporting multidimensional assessment.

    PubMed

    Stoeber, Joachim; Kobori, Osamu; Brown, Anna

    2014-12-01

    Perfectionism cognitions capture automatic perfectionistic thoughts and have explained variance in psychological adjustment and maladjustment beyond trait perfectionism. The aim of the present research was to investigate whether a multidimensional assessment of perfectionism cognitions has advantages over a unidimensional assessment. To this aim, we examined in a sample of 324 university students how the Perfectionism Cognitions Inventory (PCI) and the Multidimensional Perfectionism Cognitions Inventory (MPCI) explained variance in positive affect, negative affect, and depressive symptoms when factor or subscale scores were used as predictors compared to total scores. Results showed that a multidimensional assessment (PCI factor scores, MPCI subscale scores) explained more variance than a unidimensional assessment (PCI and MPCI total scores) because, when the different dimensions were entered simultaneously as predictors, perfectionistic strivings cognitions and perfectionistic concerns cognitions acted as mutual suppressors thereby increasing each others' predictive validity. With this, the present findings provide evidence that--regardless of whether the PCI or the MPCI is used--a multidimensional assessment of perfectionism cognitions has advantages over a unidimensional assessment in explaining variance in psychological adjustment and maladjustment.

  7. Perceptual ratings of opposite spatial properties: do they lie on the same dimension?

    PubMed

    Bianchi, Ivana; Savardi, Ugo; Burro, Roberto

    2011-11-01

    The issue of unidimensionality is dealt with in various research areas in the field of Psychology (e.g. conceptual spaces, semantic modeling, psychometrics) and always involves spatial modeling. An investigation of the dimensionality of opposite spatial scales (even basic) has however not yet been carried out. In this paper we look at whether opposite judgments of height, size, width and length (high/low, large/small, wide/narrow, and long/short) imply underlying unidimensional continua. In three experiments, independent ratings for the 8 above mentioned properties were elicited with participants looking at photographic representations of various objects (Study 1), real life objects (Study 2) and spatial extensions in object-independent conditions (Study 3). Explorative and confirmative factor analysis and Andrich Extended Rating Scale Models were applied in order to determine whether the ratings referred to opposite scales on the same linear continuum. Results from the three studies consistently revealed that this is not the case. A joint analysis of the data showed interesting interactions between the spatial properties analyzed suggesting a possible explanation for the lack of unidimensionality.

  8. Analyses Related to the Development of DSM-5 Criteria for Substance Use Related Disorders: 1. Toward Amphetamine, Cocaine and Prescription Drug Use Disorder Continua Using Item Response Theory

    PubMed Central

    Saha, Tulshi D.; Compton, Wilson M.; Chou, S. Patricia; Smith, Sharon; Ruan, W. June; Huang, Boji; Pickering, Roger P.; Grant, Bridget F.

    2011-01-01

    Background Prior research has demonstrated the dimensionality of alcohol, nicotine and cannabis use disorders criteria. The purpose of this study was to examine the unidimensionality of DSM-IV cocaine, amphetamine and prescription drug abuse and dependence criteria and to determine the impact of elimination of the legal problems criterion on the information value of the aggregate criteria. Methods Factor analyses and Item Response Theory (IRT) analyses were used to explore the unidimensionality and psychometric properties of the illicit drug use criteria using a large representative sample of the U.S. population. Results All illicit drug abuse and dependence criteria formed unidimensional latent traits. For amphetamines, cocaine, sedatives, tranquilizers and opioids, IRT models fit better for models without legal problems criterion than models with legal problems criterion and there were no differences in the information value of the IRT models with and without the legal problems criterion, supporting the elimination of that criterion. Conclusion Consistent with findings for alcohol, nicotine and cannabis, amphetamine, cocaine, sedative, tranquilizer and opioid abuse and dependence criteria reflect underlying unitary dimensions of severity. The legal problems criterion associated with each of these substance use disorders can be eliminated with no loss in informational value and an advantage of parsimony. Taken together, these findings support the changes to substance use disorder diagnoses recommended by the American Psychiatric Association’s DSM-5 Substance and Related Disorders Workgroup. PMID:21963414

  9. Biodiversity as a multidimensional construct: a review, framework and case study of herbivory's impact on plant biodiversity

    PubMed Central

    Naeem, S.; Prager, Case; Weeks, Brian; Varga, Alex; Flynn, Dan F. B.; Griffin, Kevin; Muscarella, Robert; Palmer, Matthew; Wood, Stephen; Schuster, William

    2016-01-01

    Biodiversity is inherently multidimensional, encompassing taxonomic, functional, phylogenetic, genetic, landscape and many other elements of variability of life on the Earth. However, this fundamental principle of multidimensionality is rarely applied in research aimed at understanding biodiversity's value to ecosystem functions and the services they provide. This oversight means that our current understanding of the ecological and environmental consequences of biodiversity loss is limited primarily to what unidimensional studies have revealed. To address this issue, we review the literature, develop a conceptual framework for multidimensional biodiversity research based on this review and provide a case study to explore the framework. Our case study specifically examines how herbivory by whitetail deer (Odocoileus virginianus) alters the multidimensional influence of biodiversity on understory plant cover at Black Rock Forest, New York. Using three biodiversity dimensions (taxonomic, functional and phylogenetic diversity) to explore our framework, we found that herbivory alters biodiversity's multidimensional influence on plant cover; an effect not observable through a unidimensional approach. Although our review, framework and case study illustrate the advantages of multidimensional over unidimensional approaches, they also illustrate the statistical and empirical challenges such work entails. Meeting these challenges, however, where data and resources permit, will be important if we are to better understand and manage the consequences we face as biodiversity continues to decline in the foreseeable future. PMID:27928041

  10. The Rosenberg Self-Esteem Scale: a bifactor answer to a two-factor question?

    PubMed

    McKay, Michael T; Boduszek, Daniel; Harvey, Séamus A

    2014-01-01

    Despite its long-standing and widespread use, disagreement remains regarding the structure of the Rosenberg Self-Esteem Scale (RSES). In particular, concern remains regarding the degree to which the scale assesses self-esteem as a unidimensional or multidimensional (positive and negative self-esteem) construct. Using a sample of 3,862 high school students in the United Kingdom, 4 models were tested: (a) a unidimensional model, (b) a correlated 2-factor model in which the 2 latent variables are represented by positive and negative self-esteem, (c) a hierarchical model, and (d) a bifactor model. The totality of results including item loadings, goodness-of-fit indexes, reliability estimates, and correlations with self-efficacy measures all supported the bifactor model, suggesting that the 2 hypothesized factors are better understood as "grouping" factors rather than as representative of latent constructs. Accordingly, this study supports the unidimensionality of the RSES and the scoring of all 10 items to produce a global self-esteem score.

  11. Biodiversity as a multidimensional construct: a review, framework and case study of herbivory's impact on plant biodiversity.

    PubMed

    Naeem, S; Prager, Case; Weeks, Brian; Varga, Alex; Flynn, Dan F B; Griffin, Kevin; Muscarella, Robert; Palmer, Matthew; Wood, Stephen; Schuster, William

    2016-12-14

    Biodiversity is inherently multidimensional, encompassing taxonomic, functional, phylogenetic, genetic, landscape and many other elements of variability of life on the Earth. However, this fundamental principle of multidimensionality is rarely applied in research aimed at understanding biodiversity's value to ecosystem functions and the services they provide. This oversight means that our current understanding of the ecological and environmental consequences of biodiversity loss is limited primarily to what unidimensional studies have revealed. To address this issue, we review the literature, develop a conceptual framework for multidimensional biodiversity research based on this review and provide a case study to explore the framework. Our case study specifically examines how herbivory by whitetail deer (Odocoileus virginianus) alters the multidimensional influence of biodiversity on understory plant cover at Black Rock Forest, New York. Using three biodiversity dimensions (taxonomic, functional and phylogenetic diversity) to explore our framework, we found that herbivory alters biodiversity's multidimensional influence on plant cover; an effect not observable through a unidimensional approach. Although our review, framework and case study illustrate the advantages of multidimensional over unidimensional approaches, they also illustrate the statistical and empirical challenges such work entails. Meeting these challenges, however, where data and resources permit, will be important if we are to better understand and manage the consequences we face as biodiversity continues to decline in the foreseeable future.

  12. Walker River Paiutes: A Tribal History.

    ERIC Educational Resources Information Center

    Johnson, Edward C.

    The Northern Paiute people of Nevada's Walker Lake area were known as the Agai Diccutta (Trout Eaters); they called themselves the Numa, or the People. For as long as anyone could recall, they had lived in the area, catching the huge trout from the lake and harvesting the pinon nuts and other foods from the surrounding desert. In the 1820's the…

  13. Electro-centers control conveyors

    SciTech Connect

    Adams, K.L.; Brewer, B.K.; Kovach, J.; Brown, M.

    1981-06-01

    A suitable conveyor drive and control system has been developed for the shiftable conveyor systems at Arch Mineral Corp's Captain coal mine in southern Illinois, USA. It comprises of Westinghouse electrocenters and Numa-Logic solid state control, plus wound rotor motors for the higher horsepower and squirrel cage motors for lower horsepower applications.

  14. Affinity-aware checkpoint restart

    SciTech Connect

    Saini, Ajay; Rezaei, Arash; Mueller, Frank; Hargrove, Paul; Roman, Eric

    2014-12-08

    Current checkpointing techniques employed to overcome faults for HPC applications result in inferior application performance after restart from a checkpoint for a number of applications. This is due to a lack of page and core affinity awareness of the checkpoint/restart (C/R) mechanism, i.e., application tasks originally pinned to cores may be restarted on different cores, and in case of non-uniform memory architectures (NUMA), quite common today, memory pages associated with tasks on a NUMA node may be associated with a different NUMA node after restart. Here, this work contributes a novel design technique for C/R mechanisms to preserve task-to-core maps and NUMA node specific page affinities across restarts. Experimental results with BLCR, a C/R mechanism, enhanced with affinity awareness demonstrate significant performance benefits of 37%-73% for the NAS Parallel Benchmark codes and 6-12% for NAMD with negligible overheads instead of up to nearly four times longer an execution times without affinity-aware restarts on 16 cores.

  15. Affinity-aware checkpoint restart

    DOE PAGES

    Saini, Ajay; Rezaei, Arash; Mueller, Frank; ...

    2014-12-08

    Current checkpointing techniques employed to overcome faults for HPC applications result in inferior application performance after restart from a checkpoint for a number of applications. This is due to a lack of page and core affinity awareness of the checkpoint/restart (C/R) mechanism, i.e., application tasks originally pinned to cores may be restarted on different cores, and in case of non-uniform memory architectures (NUMA), quite common today, memory pages associated with tasks on a NUMA node may be associated with a different NUMA node after restart. Here, this work contributes a novel design technique for C/R mechanisms to preserve task-to-core mapsmore » and NUMA node specific page affinities across restarts. Experimental results with BLCR, a C/R mechanism, enhanced with affinity awareness demonstrate significant performance benefits of 37%-73% for the NAS Parallel Benchmark codes and 6-12% for NAMD with negligible overheads instead of up to nearly four times longer an execution times without affinity-aware restarts on 16 cores.« less

  16. Opposing motor activities are required for the organization of the mammalian mitotic spindle pole

    PubMed Central

    1996-01-01

    We use both in vitro and in vivo approaches to examine the roles of Eg5 (kinesin-related protein), cytoplasmic dynein, and dynactin in the organization of the microtubules and the localization of NuMA (Nu-clear protein that associates with the Mitotic Apparatus) at the polar ends of the mammalian mitotic spindle. Perturbation of the function of Eg5 through either immunodepletion from a cell free system for assembly of mitotic asters or antibody microinjection into cultured cells leads to organized astral microtubule arrays with expanded polar regions in which the minus ends of the microtubules emanate from a ring-like structure that contains NuMA. Conversely, perturbation of the function of cytoplasmic dynein or dynactin through either specific immunodepletition from the cell free system or expression of a dominant negative subunit of dynactin in cultured cells results in the complete lack of organization of microtubules and the failure to efficiently concentrate the NuMA protein despite its association with the microtubules. Simultaneous immunodepletion of these proteins from the cell free system for mitotic aster assembly indicates that the plus end- directed activity of Eg5 antagonizes the minus end-directed activity of cytoplasmic dynein and a minus end-directed activity associated with NuMA during the organization of the microtubules into a morphologic pole. Taken together, these results demonstrate that the unique organization of the minus ends of microtubules and the localization of NuMA at the polar ends of the mammalian mitotic spindle can be accomplished in a centrosome-independent manner by the opposing activities of plus end- and minus end-directed motors. PMID:8896597

  17. Health Services OutPatient Experience questionnaire: factorial validity and reliability of a patient-centered outcome measure for outpatient settings in Italy

    PubMed Central

    Coluccia, Anna; Ferretti, Fabio; Pozza, Andrea

    2014-01-01

    Purpose The patient-centered approach to health care does not seem to be sufficiently developed in the Italian context, and is still characterized by the biomedical model. In addition, there is a lack of validated outcome measures to assess outpatient experience as an aspect common to a variety of settings. The current study aimed to evaluate the factorial validity, reliability, and invariance across sex of the Health Services OutPatient Experience (HSOPE) questionnaire, a short ten-item measure of patient-centeredness for Italian adult outpatients. The rationale for unidimensionality of the measure was that it could cover global patient experience as a process common to patients with a variety of diseases and irrespective of the phase of treatment course. Patients and methods The HSOPE was compiled by 1,532 adult outpatients (51% females, mean age 59.22 years, standard deviation 16.26) receiving care in ten facilities at the Santa Maria alle Scotte University Hospital of Siena, Italy. The sample represented all the age cohorts. Twelve percent were young adults, 57% were adults, and 32% were older adults. Exploratory and confirmatory factor analyses were conducted to evaluate factor structure. Reliability was evaluated as internal consistency using Cronbach’s α. Factor invariance was assessed through multigroup analyses. Results Both exploratory and confirmatory analyses suggested a clearly defined unidimensional structure of the measure, with all the ten items having salient loadings on a single factor. Internal consistency was excellent (α=0.95). Indices of model fit supported a single-factor structure for both male and female outpatient groups. Young adult outpatients had significantly lower scores on perceived patient-centeredness relative to older adults. No significant difference emerged on patient-centeredness between male and female outpatients. Conclusion The HSOPE questionnaire seemed to be a tool with high acceptability and excellent psychometric

  18. Multi-domain patient reported outcomes of irritable bowel syndrome: exploring person centered perspectives to better understand symptom severity scores

    PubMed Central

    Lackner, Jeffrey M.; Jaccard, James; Baum, Charles

    2012-01-01

    Objectives Patient reported outcomes (PRO) assessing multiple gastrointestinal symptoms are central to characterizing the therapeutic benefit of novel agents for irritable bowel syndrome (IBS). Common approaches that sum or average responses across different illness components must be unidimensional and have small unique variances to avoid aggregation bias and misinterpretation of clinical data. This study sought to evaluate the unidimensionality of the IBS Symptom Severity Scale (IBS-SSS) and to explore person centered cluster analytic methods for characterizing multivariate-based patient profiles. Methods Ninety-eight Rome-diagnosed IBS patients completed the IBS-SSS and a single, global item of symptom severity (UCLA Symptom Severity Scale) at pretreatment baseline of an NIH funded clinical trial. A k-means cluster analyses were performed on participants symptom severity scores. Results The IBS-SSS was not unidimensional. Exploratory cluster analyses revealed four common symptom profiles across five items of the IBS-SSS. One cluster of patients (25%) had elevated scores on pain frequency and bowel dissatisfaction, with less elevated but still high scores on life interference and low pain severity ratings. A second cluster (19%) was characterized by intermediate scores on both pain dimensions, but more elevated scores on bowel dissatisfaction. A third cluster (18%) was elevated across all IBS-SSS sub-components. The fourth and most common cluster (37%) had relatively low scores on all dimensions except bowel dissatisfaction and life interference due to IBS symptoms. Conclusions PRO endpoints and research on IBS more generally relying on multicomponent assessments of symptom severity should take into account the multidimensional structure of symptoms to avoid aggregation bias and to optimize the sensitivity of detecting treatment effects. PMID:23337220

  19. Human Amygdala Represents the Complete Spectrum of Subjective Valence

    PubMed Central

    Jin, Jingwen; Zelano, Christina; Gottfried, Jay A.

    2015-01-01

    Although the amygdala is a major locus for hedonic processing, how it encodes valence information is poorly understood. Given the hedonic potency of odor stimuli and the amygdala's anatomical proximity to the peripheral olfactory system, we combined high-resolution fMRI with pattern-based multivariate techniques to examine how valence information is encoded in the amygdala. Ten human subjects underwent fMRI scanning while smelling 9 odorants that systematically varied in perceived valence. Representational similarity analyses showed that amygdala codes the entire dimension of valence, ranging from pleasantness to unpleasantness. This unidimensional representation significantly correlated with self-reported valence ratings but not with intensity ratings. Furthermore, within-trial valence representations evolved over time, prioritizing earlier differentiation of unpleasant stimuli. Together, these findings underscore the idea that both spatial and temporal features uniquely encode pleasant and unpleasant odor valence in the amygdala. The availability of a unidimensional valence code in the amygdala, distributed in both space and time, would create greater flexibility in determining the pleasantness or unpleasantness of stimuli, providing a mechanism by which expectation, context, attention, and learning could influence affective boundaries for guiding behavior. SIGNIFICANCE STATEMENT Our findings elucidate the mechanisms of affective processing in the amygdala by demonstrating that this brain region represents the entire valence dimension from pleasant to unpleasant. An important implication of this unidimensional valence code is that pleasant and unpleasant valence cannot coexist in the amygdale because overlap of fMRI ensemble patterns for these two valence extremes obscures their unique content. This functional architecture, whereby subjective valence maps onto a pattern continuum between pleasant and unpleasant poles, offers a robust mechanism by which context

  20. [National Post Hospital Care Project and length of hospitalization of patients with stroke 2010-2011].

    PubMed

    Canha, Catarina; Massano, Ana; Esperto, Hélder; Rato, Joana; Ferreira, Teresa; Geraldo, Argemiro

    2013-01-01

    Introdução: A Rede Nacional de Cuidados Continuados Integrados surgiu para proporcionar a continuação de cuidados após internamento ou para pessoas funcionalmente dependentes. Actualmente há uma grande dificuldade na integração dos doentes no domicílio ou em estruturas de retaguarda. Pretende-se comparar o impacto da referenciação para a Rede Nacional de Cuidados Continuados Integrados versus alta para domicílio, no tempo de internamento dos doentes com Acidente Vascular Cerebral, entre 2010 e 2011.Material e Métodos: Estudo retrospectivo envolvendo os doentes internados na Neurologia A e Unidade de Acidente Vascular Cerebral dos Hospitais da Universidade de Coimbra, naquele anos. Analisaram-se 1 209 processos, incluídos 819, caracterizados demograficamente, tempo de internamento, Score de Rankin modificado e destino pós-alta. Compararam-se os dados, relativamente ao tempo de internamento dos doentes com Acidente Vascular Cerebral, referenciados para a Rede Nacional de Cuidados Continuados Integrados e os com alta para domicílio, atendendo ao Score de Rankin final.Resultados: Em 2011, aumentaram os doentes referenciados para a Rede Nacional de Cuidados Continuados Integrados, 23,5% comparativamente 21,4%. Em 2011 o tempo de internamento, para um mesmo Score de Rankin, da população referenciada manteve-se superior: para um Rankin de 1: 11 dias para domicílio, 26 dias para os doentes referenciados; para um Rankin de 2: 13 dias para domicílio, 29 dias para a rede; para Rankin de 3: 13 dias para domicílio, 23 dias para referenciados; para um Rankin de 4: 17 dias para domicílio, 33 dias para Rede; e para um Rankin de 5: 27 dias para domicílio, 39 dias para Rede. Comparando com os tempos de internamento da população com alta para domicílio, estima-se que tenha representado mais 1 718 dias de internamento, em 2010 e1 198 dias, em 2011.Conclusão: A Rede Nacional de Cuidados Continuados Integrados é incapaz de responder às necessidades actuais

  1. Atomic layer deposited second-order nonlinear optical metamaterial for back-end integration with CMOS-compatible nanophotonic circuitry

    NASA Astrophysics Data System (ADS)

    Clemmen, Stéphane; Hermans, Artur; Solano, Eduardo; Dendooven, Jolien; Koskinen, Kalle; Kauranen, Martti; Brainis, Edouard; Detavernier, Christophe; Baets, Roel

    2015-11-01

    We report the fabrication of artificial unidimensional crystals exhibiting an effective bulk second-order nonlinearity. The crystals are created by cycling atomic layer deposition of three dielectric materials such that the resulting metamaterial is non-centrosymmetric in the direction of the deposition. Characterization of the structures by second-harmonic generation Maker-fringe measurements shows that the main component of their nonlinear susceptibility tensor is about 5 pm/V which is comparable to well-established materials and more than an order of magnitude greater than reported for a similar crystal [1-Alloatti et al, arXiv:1504.00101[cond-mat.mtrl- sci

  2. The Chinese Parental Stress Scale: psychometric evidence using Rasch modeling on clinical and nonclinical samples.

    PubMed

    Leung, Cynthia; Tsang, Sandra K M

    2010-01-01

    In this study, we examined the psychometric properties of the Parental Stress Scale (PSS; Berry & Jones, 1995) with Chinese parents. Participants included 162 parents recruited through primary schools and 38 parents with children with attention deficit hyperactivity disorder (ADHD). Rasch analysis results indicated that 2 items were outside the accepted fit statistics range and that the Likert scale response categories were not functioning properly. We identified a reduced 16-item scale with 5 categories as unidimensional, with a person reliability of .86; the Likert scale response categories worked well. The revised PSS correlated with measures of child behavior and parenting stress and could differentiate between the 2 groups of parents.

  3. Measuring non-technical skills of medical emergency teams: an update on the validity and reliability of the Team Emergency Assessment Measure (TEAM).

    PubMed

    Cooper, Simon J; Cant, Robyn P

    2014-01-01

    Medical emergency team performance including non-technical skills, is receiving increased attention due to the influences on patient safety. The Team Emergency Assessment Measure (TEAM) was developed to enable standardized performance assessment and structured team debriefing. From several studies, the TEAM has demonstrated a substantial body of normative data confirming its validity and reliability. This includes high uni-dimensional validity, significant subscale relationships between Teamwork and Leadership and between Teamwork and Task Management (p<0.001), a Cronbach alpha of 0.92 and adequate construct validity. The tool has potential for team training to improve team's non-technical performance. Further testing is required in 'real' clinical settings.

  4. Simulation of a solar evacuated collector with black fluid

    SciTech Connect

    Samano, A.; Fernandez, A.

    1983-06-01

    The use of black fluids in an evacuated tube solar collector for intermediate temperatures is analyzed, and an operation mathematical model is proposed. The model is unidimensional and the integral equation for the mass, momentum and energy conservation balances are used. An expression for the pressure drop in the tube is obtained by integrating the momentum equation. The energy conservation equation is integrated analytically for constant insolation and numerically for transient insolation. An adjustment in the global emissivity value for the black fluid was made to make the representation in the mathematical model, and a discussion between the calculated and the experimental results is made.

  5. A tool for sexual minority mental health research: The Patient Health Questionnaire (PHQ-9) as a depressive symptom severity measure for sexual minority women in Viet Nam

    PubMed Central

    Nguyen, Trang Quynh; Bandeen-Roche, Karen; Bass, Judith K; German, Danielle; Nguyen, Nam Thi Thu; Knowlton, Amy R

    2016-01-01

    In a context with limited attention to mental health and prevalent sexual prejudice, valid measurements are a key first step to understanding the psychological suffering of sexual minority populations. We adapted the Patient Health Questionnaire as a depressive symptom severity measure for Vietnamese sexual minority women, ensuring its cultural relevance and suitability for internet-based research. Psychometric evaluation found that the scale is mostly unidimensional and has good convergent validity, good external construct validity, and excellent reliability. The sample’s high endorsement of scale items emphasizes the need to study minority stress and mental health in this population. PMID:27642381

  6. Gender identity and adjustment: understanding the impact of individual and normative differences in sex typing.

    PubMed

    Lurye, Leah E; Zosuls, Kristina M; Ruble, Diane N

    2008-01-01

    The relationship among gender identity, sex typing, and adjustment has attracted the attention of social and developmental psychologists for many years. However, they have explored this issue with different assumptions and different approaches. Generally the approaches differ regarding whether sex typing is considered adaptive versus maladaptive, measured as an individual or normative difference, and whether gender identity is regarded as a unidimensional or multidimensional construct. In this chapter, we consider both perspectives and suggest that the developmental timing and degree of sex typing, as well as the multidimensionality of gender identity, be considered when examining their relationship to adjustment.

  7. Personality correlates of aggression: evidence from measures of the five-factor model, UPPS model of impulsivity, and BIS/BAS.

    PubMed

    Miller, Joshua D; Zeichner, Amos; Wilson, Lauren F

    2012-09-01

    Although many studies of personality and aggression focus on multidimensional traits and higher order personality disorders (e.g., psychopathy), lower order, unidimensional traits may provide more precision in identifying specific aspects of personality that relate to aggression. The current study includes a comprehensive measurement of lower order personality traits in relation to three forms of aggression: reactive, proactive, and relational. Traits related to interpersonal antagonism and impulsivity, especially impulsive behavior in the context of negative affect, were consistently related to aggression across multiple indices. These findings suggest that certain lower order traits are of critical importance to understanding who engages in aggressive behavior and why this behavior occurs.

  8. The development and validation of the Workplace Ostracism Scale.

    PubMed

    Ferris, D Lance; Brown, Douglas J; Berry, Joseph W; Lian, Huiwen

    2008-11-01

    This article outlines the development of a 10-item measure of workplace ostracism. Using 6 samples (including multisource and multiwave data), the authors developed a reliable scale with a unidimensional factor structure that replicated across 4 separate samples. The scale possessed both convergent and discriminant validity, and criterion-related validity was demonstrated through the scale's relation with basic needs, well-being, job attitudes, job performance, and withdrawal. Overall, the present study suggests that the Workplace Ostracism Scale is a reliable and valid measure and that the workplace ostracism construct has important implications for both individuals and organizations.

  9. Conventional and Advanced Separations in Mass Spectrometry-Based Metabolomics: Methodologies and Applications

    SciTech Connect

    Heyman, Heino M.; Zhang, Xing; Tang, Keqi; Baker, Erin Shammel; Metz, Thomas O.

    2016-02-16

    Metabolomics is the quantitative analysis of all metabolites in a given sample. Due to the chemical complexity of the metabolome, optimal separations are required for comprehensive identification and quantification of sample constituents. This chapter provides an overview of both conventional and advanced separations methods in practice for reducing the complexity of metabolite extracts delivered to the mass spectrometer detector, and covers gas chromatography (GC), liquid chromatography (LC), capillary electrophoresis (CE), supercritical fluid chromatography (SFC) and ion mobility spectrometry (IMS) separation techniques coupled with mass spectrometry (MS) as both uni-dimensional and as multi-dimensional approaches.

  10. Support for gay and lesbian civil rights: development and examination of a new scale.

    PubMed

    Brown, Michael J; Henriquez, Ernesto

    2011-01-01

    This research outlines the development of a psychometrically sound, uni-dimensional scale to assess support for gay and lesbian civil rights. Initial scale development involved examining item-pool responses from 224 undergraduate students. The resulting Support for Gay and Lesbian Civil Rights (SGLCR) scale consisted of 20 items. In a series of studies, the SGLCR demonstrated a stable factor structure, strong internal consistency, test-retest reliability, and construct validity. The relationships between SGLCR scores and participants' sex, religiosity, political ideology, gender role beliefs, and attitudes toward lesbians and gays were significant and in the predicted directions.

  11. [The Frankfurt-Pamplona subjective experience scale].

    PubMed

    Cuesta Zorita, M J; Peralta Martín, V; Irigoyen Recalde, I

    1995-01-01

    Several instruments have been designed to assess subjective experiences (SE). The Frankfurt Complaint Questionnaire (FCQ) is the most widely used scale to assess SE. This study was aimed to replicate the factor validation of the scale in a Spanish sample. A factor analysis we carried out on the 98-items of FCQ. No a four-factor solution was found, as initially it had been proposed by authors of the scale. A simplified version of the FCQ was derived through procedures of unidimensionality analysis of factors.

  12. Dimensional structure of the Frankfurt Complaint Questionnaire.

    PubMed

    Loas, Gwenolé; Yon, Valérie; Brien, Denis

    2002-01-01

    The Frankfurt Complaint Questionnaire (FCQ) was designed to evaluate the subjective symptoms of schizophrenics. Several validation studies of the FCQ using principal components analyses (PCA) have shown one-, two-, or four-factor solutions. The present study was conducted using FCQ data on 310 schizophrenics who met the ICD-10 criteria for F20 (schizophrenia) disorder. Using several guidelines to select the number of factors, the PCA yielded one factor. This result suggests a unidimensionality underlying FCQ items. A new scale comprising 24 items was derived from those items with higher weights in the first factor.

  13. Social and Emotional Aging

    PubMed Central

    Charles, Susan; Carstensen, Laura L.

    2014-01-01

    The past several decades have witnessed unidimensional decline models of aging give way to life-span developmental models that consider how specific processes and strategies facilitate adaptive aging. In part, this shift was provoked by the stark contrast between findings that clearly demonstrate decreased biological, physiological, and cognitive capacity with those suggesting that people are generally satisfied in old age and experience relatively high levels of emotional well-being. In recent years, this supposed “paradox” of aging has been reconciled through careful theoretical analysis and empirical investigation. Viewing aging as adaptation sheds light on resilience, wellbeing, and emotional distress across adulthood. PMID:19575618

  14. [The evolution of dental echography: clinical and experimental research. The ultrasonic anatomy of the teeth and periodontal tissues].

    PubMed

    Cardinale, A; Lagalla, R; Davì, G; Davì, F

    1990-04-01

    Early clinico-experimental findings with real-time B-mode Echography of the odontological district are reported. On the basis of previous in vitro application references and using a unidimensional A-Mode technique, preliminary data of in vivo ultrasound semeiotics regarding the tooth and its periodontal structures are outlined experimentally. Although current "in vivo" experience relates exclusively to front central and para-central teeth, it can be hypothesised that further technical and methodological developments of echographic instruments may permit systematic employment of ultrasound diagnosis in the odontological sector.

  15. Examination of factor structure for the consumers' responses to the Value Consciousness Scale.

    PubMed

    Conrad, C A; Williams, J R

    2000-12-01

    The psychometric properties of the Value Consciousness Scale developed by Lichtenstein, Netemeyer, and Burton in 1990 were examined in a retail grocery study (N = 497). Original assessment of scale properties was undertaken using two convenience samples in a nonretail setting and additional scale performance has been documented by the scale authors. This study furthers previous research by (1) examining performance on the items in the retail grocery setting and (2) utilizing an appropriately rigorous sampling procedure. A confirmatory factor analysis indicated that the Value Consciousness Scale does not exhibit unidimensional properties, and one must be cautious if this scale is used in applications of market segmentation until further clarification can be provided.

  16. Design and Potentials of the Californium-252 Radiation Facility at WES

    DTIC Science & Technology

    1975-09-01

    INSTRUCTIONS BEPONB COMPLETING FONM 2. iOWT ACCtMION NO. -:6 1 «eClPIKHT’« CATALOG NUMaCN 4. TlTLf fand Su*(l(l*> DESIGN AND POTENTIALS...ol Ihlt r»pert) Unclassified IS«. DECLASSIMCATION’OOWNGRAOINO SCHEDULE I«. DISTRIBUTION STATEMENT fel Ihlt Rtporl) Approve 1 for public...DEVELOPMENTS AND APPLICATIONS 30 Developments 30 Applications 31 PART V: SUMMARY AND CONCLUSIONS 33 BIBLIOGRAPHY 36 TABLES 1 -3 APPENDIX A: DETAILED

  17. Grid Effect on Spherical Shallow Water Jets Using Continuous and Discontinuous Galerkin Methods

    DTIC Science & Technology

    2013-01-01

    set of common grids used in global circulation models (GCMs). Specifically, we study 1) the cubed-sphere ( Hex ) (Sadourny 1972), 2) the icosahedron (Ico...dimensional model NUMA. The logically structured Hex and Lat-Lon grids can be advantageous for a finite difference based solver, and are generally usable by...grid to grid. The gnomonic projection by Ronchi et al. (1996) was used to build the high order grids. In what follows, we describe how the RLL, Hex

  18. Acceptance test report 2721-Z upgrades

    SciTech Connect

    Keck, R.D.

    1998-02-03

    This test procedure provides instructions for acceptance testing of modifications to the 2721-Z diesel-generator system made by Project C-189. The modifications include (1) replacing the generator NUMA-LOGIC controller with connection to the PFP distributed control system (DCS), (2) replacing ATSI with a breaker switching scheme for 2736-ZB backup power and (3) providing a method for generator load and system testing.

  19. NPS-NRL-Rice-UIUC Collaboration on Navy Atmosphere-Ocean Coupled Models on Many-Core Computer Architectures Annual Report

    DTIC Science & Technology

    2015-09-30

    the U.S. community that can synergistically move the knowledge of accelerator-based computing to many of the climate, weather , and ocean modeling...from the general climate, weather , and ocean modeling laboratories around the country. The third objective is to implement Earth System Modeling...is beneficial not only to the NUMA developers and user groups but also to the larger climate, weather , and ocean modeling community. The many-core

  20. Automated local bright feature image analysis of nuclear proteindistribution identifies changes in tissue phenotype

    SciTech Connect

    Knowles, David; Sudar, Damir; Bator, Carol; Bissell, Mina

    2006-02-01

    The organization of nuclear proteins is linked to cell and tissue phenotypes. When cells arrest proliferation, undergo apoptosis, or differentiate, the distribution of nuclear proteins changes. Conversely, forced alteration of the distribution of nuclear proteins modifies cell phenotype. Immunostaining and fluorescence microscopy have been critical for such findings. However, there is an increasing need for quantitative analysis of nuclear protein distribution to decipher epigenetic relationships between nuclear structure and cell phenotype, and to unravel the mechanisms linking nuclear structure and function. We have developed imaging methods to quantify the distribution of fluorescently-stained nuclear protein NuMA in different mammary phenotypes obtained using three-dimensional cell culture. Automated image segmentation of DAPI-stained nuclei was generated to isolate thousands of nuclei from three-dimensional confocal images. Prominent features of fluorescently-stained NuMA were detected using a novel local bright feature analysis technique, and their normalized spatial density calculated as a function of the distance from the nuclear perimeter to its center. The results revealed marked changes in the distribution of the density of NuMA bright features as non-neoplastic cells underwent phenotypically normal acinar morphogenesis. In contrast, we did not detect any reorganization of NuMA during the formation of tumor nodules by malignant cells. Importantly, the analysis also discriminated proliferating non-neoplastic cells from proliferating malignant cells, suggesting that these imaging methods are capable of identifying alterations linked not only to the proliferation status but also to the malignant character of cells. We believe that this quantitative analysis will have additional applications for classifying normal and pathological tissues.

  1. Conference on Receptor-Based Biosensors (3rd) Held in Aberdeen Proving Ground, Maryland, September 1987

    DTIC Science & Technology

    1988-07-01

    variety of organic calcium chazwel blockire agents including nifedipine, whioh is a m r of the dihydropyridine clams, o--- W7, which is the only... dihydropyridine -insenaitive calcium channel and injected into the oocytes? Leonard: Yes, he had. The preliminary indioations are that Numa has succeeded in getting...term of expressing that dihydropyridine receptor. 37 Leonard: With the proviso that there are other rat brain sodium charnela, for instance, one of

  2. Tank binding kinase 1 is a centrosome-associated kinase necessary for microtubule dynamics and mitosis

    PubMed Central

    Pillai, Smitha; Nguyen, Jonathan; Johnson, Joseph; Haura, Eric; Coppola, Domenico; Chellappan, Srikumar

    2015-01-01

    TANK Binding Kinase 1 (TBK1) is a non-canonical IκB kinase that contributes to KRAS-driven lung cancer. Here we report that TBK1 plays essential roles in mammalian cell division. Specifically, levels of active phospho-TBK1 increase during mitosis and localize to centrosomes, mitotic spindles and midbody, and selective inhibition or silencing of TBK1 triggers defects in spindle assembly and prevents mitotic progression. TBK1 binds to the centrosomal protein CEP170 and to the mitotic apparatus protein NuMA, and both CEP170 and NuMA are TBK1 substrates. Further, TBK1 is necessary for CEP170 centrosomal localization and binding to the microtubule depolymerase Kif2b, and for NuMA binding to dynein. Finally, selective disruption of the TBK1–CEP170 complex augments microtubule stability and triggers defects in mitosis, suggesting that TBK1 functions as a mitotic kinase necessary for microtubule dynamics and mitosis. PMID:26656453

  3. LDRD final report : managing shared memory data distribution in hybrid HPC applications.

    SciTech Connect

    Merritt, Alexander M.; Pedretti, Kevin Thomas Tauke

    2010-09-01

    MPI is the dominant programming model for distributed memory parallel computers, and is often used as the intra-node programming model on multi-core compute nodes. However, application developers are increasingly turning to hybrid models that use threading within a node and MPI between nodes. In contrast to MPI, most current threaded models do not require application developers to deal explicitly with data locality. With increasing core counts and deeper NUMA hierarchies seen in the upcoming LANL/SNL 'Cielo' capability supercomputer, data distribution poses an upper boundary on intra-node scalability within threaded applications. Data locality therefore has to be identified at runtime using static memory allocation policies such as first-touch or next-touch, or specified by the application user at launch time. We evaluate several existing techniques for managing data distribution using micro-benchmarks on an AMD 'Magny-Cours' system with 24 cores among 4 NUMA domains and argue for the adoption of a dynamic runtime system implemented at the kernel level, employing a novel page table replication scheme to gather per-NUMA domain memory access traces.

  4. NuMA-microtubule interactions are critical for spindle orientation and the morphogenesis of diverse epidermal structures

    PubMed Central

    Seldin, Lindsey; Muroyama, Andrew; Lechler, Terry

    2016-01-01

    Mitotic spindle orientation is used to generate cell fate diversity and drive proper tissue morphogenesis. A complex of NuMA and dynein/dynactin is required for robust spindle orientation in a number of cell types. Previous research proposed that cortical dynein/dynactin was sufficient to generate forces on astral microtubules (MTs) to orient the spindle, with NuMA acting as a passive tether. In this study, we demonstrate that dynein/dynactin is insufficient for spindle orientation establishment in keratinocytes and that NuMA’s MT-binding domain, which targets MT tips, is also required. Loss of NuMA-MT interactions in skin caused defects in spindle orientation and epidermal differentiation, leading to neonatal lethality. In addition, we show that NuMA-MT interactions are also required in adult mice for hair follicle morphogenesis and spindle orientation within the transit-amplifying cells of the matrix. Loss of spindle orientation in matrix cells results in defective differentiation of matrix-derived lineages. Our results reveal an additional and direct function of NuMA during mitotic spindle positioning, as well as a reiterative use of spindle orientation in the skin to build diverse structures. DOI: http://dx.doi.org/10.7554/eLife.12504.001 PMID:26765568

  5. Air and Space Power Journal. Volume 26, Number 1, January-February 2012

    DTIC Science & Technology

    2012-01-01

    as is working with international organi- zations and nongovernmental organizations (NGO). Thus, military health services contribute to social ...noncontroversial rede - ployments from humanitarian operations and an MSO exit strategy has proven a daunting challenge. Organizational and military cultural...later deployed together to an earthquake response in Pisco, Peru , where they provided interoperable medical services.17 This training in South America

  6. What Every Airman Needs to Know about Medical Stability Operations

    DTIC Science & Technology

    2012-01-01

    organizations (NGO). Thus, military health services contribute to social , political, and economic stability. JP 3-29, Foreign Humanitarian Assistance, 17...deployed for the health protection of US forces. Developing graceful, noncontroversial rede - ployments from humanitarian operations and an MSO exit...physi- cians from 15 nearby nations. Course graduates from several countries later deployed together to an earthquake response in Pisco, Peru , where

  7. Air & Space Power Journal. Volume 26, Number 1, January-February 2012

    DTIC Science & Technology

    2012-02-01

    and nongovernmental organizations (NGO). Thus, military health services contribute to social , political, and economic stability. JP 3-29, Foreign...than a few medics deployed for the health protection of US forces. Developing graceful, noncontroversial rede - ployments from humanitarian...Pisco, Peru , where they provided interoperable medical services.17 This training in South America also creates capacity to support peacekeeping

  8. Creative and Critical Thinking in the Arts and Sciences: Some Examples of Congruence

    ERIC Educational Resources Information Center

    Karakas, Scott L.

    2010-01-01

    In his landmark 1959 Rede lecture and subsequent publication, physicist Charles Percy Snow expressed concerns over what he saw as a growing rift between scientific and literary scholarly communities (Snow 1959). In the 50 years since that time, scholars and other commentators have expended a great deal of intellectual capital in the analysis of…

  9. Bilingual Education. Papers Presented at the Language Teaching Conference (3rd, La Trobe University, May 3-4, 1974).

    ERIC Educational Resources Information Center

    Rado, Marta, Ed.

    The conference was held to alert teachers and other interested persons to the complexities of linguistic diversity in Australia, with attention focused on the immigrant child. This report includes the individual conference papers, presented by Marta Rado, Bert Townsend, Michael Clyne, Alan Matheson, and Rede Lar, and the comments of symposium and…

  10. Granting Credit for College Proficiency and Regents External Degree Examinations in New York State: A Summary of Institutional Policies, 1981-82.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Independent Study and Programs Development.

    A guide is presented for students on the policies and practices of public and private New York colleges and universities in regard to granting credit, course waiver, or advanced standing to those who pass the College Proficiency Examinations (CPEs) and the Regents External Degree Examinations (REDEs). A chart indicates, for each institution and…

  11. "The Two Cultures" and the Historical Perspective on Science as a Culture

    ERIC Educational Resources Information Center

    Rocherberg, Francesca

    2007-01-01

    In the Rede lecture of 1959, C.P.Snow speaks in terms of two cultures, one of science, the other of literary intellectuals. Snow's discussion presupposes that science represents a culture of its own, independent of and superior to the arts and humanities, and unified within itself. At our present distance from this claim, Snow's point of view can…

  12. Foreign Humanitarian Assistance and Disaster-Relief Operations: Lessons Learned and Best Practices

    DTIC Science & Technology

    2012-01-01

    with the Taiwanese government, military, and relief personnel before rede - ploying to Sasebo. So, to review: first and foremost, the commodore and his...2011 11:04:30 AM Color profile: Generic CMYK printer profile Composite Default screen • Aggressively use social media and web pages, accessible to

  13. Support the Combatant Commander, Develop the Force, or Roll the Dice? What the Air Force’s Deployment Tasking Process Doesn’t Do

    DTIC Science & Technology

    2012-01-01

    mannerisms, and social habits beyond that found in text- books. Clearly, sending them back to that region or country would prove beneficial to the...observations lead toward a recommendation to rede - ploy Airmen to former duties and locations. Doing so, however, would ignore the importance of force

  14. Reference Manual on Interference Seals and Connectors for Undersea Electrical Applications

    DTIC Science & Technology

    1976-07-01

    Hydrostatic Pressure Range: RECOMMENDED ZONES OF APPLICATION Mated 5000 psi Power and instrumentation, electrica Unmated 0 tconnectors for severe...8217XA 7. Implement results; i.e., rervanend to design engineers rede - signing options that will rectify the possible failure modes. As quancitative data

  15. Report to Congress: Department of Defense Progress on Design and Implementation of the New DoD Personnel Management System and Appointment Procedures As Authorized by Section 9902(a) and (b) of Title 5, U.S. Code, As Amended by Section 1101(a) and (b) of the National Defense Authorization Act for Fiscal Year 2012 (Public Law 112-81, December 31, 2011)

    DTIC Science & Technology

    2014-12-01

    Personnel Management, providing for: o A new performance appraisal system that is fair, credible, and transparent; and o Redes igned procedures for... appraisal system for linking performance bonuses and other performance-based actions to employee performance appraisals , a process for ensuring on...going performance feedback throughout the appraisal period, development of attractive career paths, and development of performance assistance plans

  16. A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

    EPA Science Inventory

    Science has a critical role to play in guiding more sustainable development trajectories. Here we present the Sustainable Amazon Network (Rede Amazônia Sustentável, RAS): a multi-disciplinary research initiative involving more than 30 partner organisations working to assess both ...

  17. A Calculus of Macro-Events: Progress Report

    DTIC Science & Technology

    2000-01-01

    1410, USA iliano@itd.nrl.navy.mil Angelo Montanari Dipartimento di Matematica e Informatica Universita di Udine Via delle Scienze, 206 { 33100 Udine...nition of ECTD-structure only by the following points: M MT is a set of macro-events over T . The codomain of [jji and hjj] are rede ned to be

  18. Automatic Verification of Serializers.

    DTIC Science & Technology

    1980-03-01

    Programming Languages, Academic Press, New York, 1968. Dijkstra 71 E. Dijkstra, Hierarchical Ordering of Sequential Processes, Acta Informatica , vol. 1...Programming Languages, Las Vegas, January 1980, 174-185. Lanipson and Redell 79 B. Lanipson, 1). RedelI , Experience with monitors and processes in

  19. A Psychometric Evaluation of an Advanced Pharmacy Practice Experience Clinical Competency Framework

    PubMed Central

    Doty, Randell E.; Nemire, Ruth E.

    2015-01-01

    Objective. To assess the psychometric properties of the clinical competency framework known as the System of Universal Clinical Competency Evaluation in the Sunshine State (SUCCESS), including its internal consistency and content, construct, and criterion validity. Methods. Sub-competency items within each hypothesized competency pair were subjected to principal components factor analysis to demonstrate convergent and discriminant validity. Varimax rotation was conducted for each competency pair (eg, competency 1 vs competency 2, competency 1 vs competency 3, competency 2 vs competency 3). Internal consistency was evaluated using Cronbach alpha. Results. Of the initial 78 pairings, 44 (56%) demonstrated convergent and discriminant validity. Five pairs of competencies were unidimensional. Of the 34 pairs where at least 1 competency was multidimensional, most (91%) were from competencies 7, 11, and 12, indicating modifications were warranted in those competencies. After reconfiguring the competencies, 76 (94%) of the 81 pairs resulted in 2 factors as required. A unidimensional factor emerged when all 13 of the competencies were entered into a factor analysis. The internal consistency of all of the competencies was satisfactory. Conclusion. Psychometric evaluation shows the SUCCESS framework demonstrates adequate reliability and validity for most competencies. However, it also provides guidance where improvements are needed as part of a continuous quality improvement program. PMID:25861100

  20. Construct Validity and Measurement Invariance of the Peabody Picture Vocabulary Test-III Form A in the Performance of Struggling Adult Readers: Rasch Modeling

    PubMed Central

    Pae, Hye; Greenberg, Daphne; Morris, Robin D

    2011-01-01

    Purpose The aim of this study was to apply the Rasch model to an analysis of the psychometric properties of the PPVT-III Form A items with struggling adult readers. Methods The PPVT-IIIA was administered to 229 African-American adults whose isolated word reading skills were between third and fifth grades. Conformity of the adults’ performance on the PPVT-III items was evaluated using the Winsteps software. Results Analysis of all PPVT-IIIA items combined did not fully support its use as a useful measure of receptive vocabulary for struggling adult readers who were African Americans. To achieve an adequate model fit, items 73 through item 156 were analyzed. The items analyzed showed adequate internal consistency reliability, unidimensionality, and freedom from differential item functioning for ability, gender, and age, with a minor modification. Discussion With an appropriate treatment of misfit items, the results supported the measurement properties, internal consistency reliability, unidimensionality of the PPVT-IIIA items, and measurement invariance of the test across subgroups of ability, age, and gender. PMID:22639554

  1. Bounded Confidence under Preferential Flip: A Coupled Dynamics of Structural Balance and Opinions

    PubMed Central

    Parravano, Antonio; Andina-Díaz, Ascensión; Meléndez-Jiménez, Miguel A.

    2016-01-01

    In this work we study the coupled dynamics of social balance and opinion formation. We propose a model where agents form opinions under bounded confidence, but only considering the opinions of their friends. The signs of social ties -friendships and enmities- evolve seeking for social balance, taking into account how similar agents’ opinions are. We consider both the case where opinions have one and two dimensions. We find that our dynamics produces the segregation of agents into two cliques, with the opinions of agents in one clique differing from those in the other. Depending on the level of bounded confidence, the dynamics can produce either consensus of opinions within each clique or the coexistence of several opinion clusters in a clique. For the uni-dimensional case, the opinions in one clique are all below the opinions in the other clique, hence defining a “left clique” and a “right clique”. In the two-dimensional case, our numerical results suggest that the two cliques are separated by a hyperplane in the opinion space. We also show that the phenomenon of unidimensional opinions identified by DeMarzo, Vayanos and Zwiebel (Q J Econ 2003) extends partially to our dynamics. Finally, in the context of politics, we comment about the possible relation of our results to the fragmentation of an ideology and the emergence of new political parties. PMID:27716815

  2. PROMIS Pediatric Peer Relationships Scale: Development of a Peer Relationships Item Bank as Part of Social Health Measurement

    PubMed Central

    DeWalt, Darren A.; Thissen, David; Stucky, Brian D.; Langer, Michelle M.; DeWitt, Esi Morgan; Irwin, Debra E.; Lai, Jin-Shei; Yeatts, Karin B.; Gross, Heather E.; Taylor, Olivia; Varni, James W.

    2013-01-01

    Objective This study’s objective was to develop a measure of social health using item response theory as part of the Patient Reported Outcomes Measurement Information System (PROMIS). Methods After candidate items were generated from review of prior literature, focus groups, expert input, and cognitive interviews, items were administered to youth aged 8–17 as part of the PROMIS pediatric large scale testing. Exploratory and confirmatory factor analyses were used to assess dimensionality and to identify instances of local dependence. Items that met the unidimensionality criteria were subsequently calibrated using Samejima’s Graded Response Model. Differential item functioning was examined by gender and age. Results The sample included 3,048 youth who completed the questionnaire (51.8% female, 60% white, and 22.7% with chronic illness). The initial conceptualization of social function and sociability did not yield unidimensional item banks. Rather, factor analysis revealed dimensions contrasting peer relationships and adult relationships. The analysis also identified dimensions formed by responses to positively versus negatively worded items. The resulting 15-item bank measures quality of peer relationships and has strong psychometric characteristics as a full bank or an 8-item short form. Conclusions The PROMIS pediatric peer relationships scale demonstrates good psychometric characteristics and addresses an important aspect of child health. PMID:23772887

  3. Classification Accuracy of Mixed Format Tests: A Bi-Factor Item Response Theory Approach

    PubMed Central

    Wang, Wei; Drasgow, Fritz; Liu, Liwen

    2016-01-01

    Mixed format tests (e.g., a test consisting of multiple-choice [MC] items and constructed response [CR] items) have become increasingly popular. However, the latent structure of item pools consisting of the two formats is still equivocal. Moreover, the implications of this latent structure are unclear: For example, do constructed response items tap reasoning skills that cannot be assessed with multiple choice items? This study explored the dimensionality of mixed format tests by applying bi-factor models to 10 tests of various subjects from the College Board's Advanced Placement (AP) Program and compared the accuracy of scores based on the bi-factor analysis with scores derived from a unidimensional analysis. More importantly, this study focused on a practical and important question—classification accuracy of the overall grade on a mixed format test. Our findings revealed that the degree of multidimensionality resulting from the mixed item format varied from subject to subject, depending on the disattenuated correlation between scores from MC and CR subtests. Moreover, remarkably small decrements in classification accuracy were found for the unidimensional analysis when the disattenuated correlations exceeded 0.90. PMID:26973568

  4. On the factor structure of standardized educational achievement tests.

    PubMed

    Gaffney, Tim W; Cudeck, Robert; Ferrer, Emilio; Widaman, Keith F

    2010-01-01

    This research analyzed the factor structure at both the item- and subtest-level of California's norm- and criterion-referenced standardized educational achievement tests (SEAT) used in that state's high-stakes educational accountability assessments. It was shown through full information factor analysis and multidimensional IRT models (e.g., TESTFACT and NOHARM) that, at the item-level, SEATs are invariably highly unidimensional (i.e., they appear to tap a unidimensional theta scale) even when items representing such diverse content areas such as English, science, mathematics, and history are analyzed simultaneously as a single measure. These item-level factors also accounted for a relatively small proportion (1/4 to 1/3) of the variance. It was also shown that, when these tests are analyzed using more reliable indicators such as subtests, a much richer factor structure emerged that accounted for a larger portion (about 2/3) of the total common variance. As expected, these factor structure configurations (and underlying dimensionality) were preserved across the item- and subtest-levels. However, the factors emerging from both the item- and subtest-level analyses were highly correlated and produced strong second-order and general factors. The meaning underlying these results was examined, along with their implications with respect to the assumptions underlying modern approaches to test calibration, scaling, and score interpretation.

  5. Rasch analysis of the hospital anxiety and depression scale (hads) for use in motor neurone disease

    PubMed Central

    2011-01-01

    Background The Hospital Anxiety and Depression Scale (HADS) is commonly used to assess symptoms of anxiety and depression in motor neurone disease (MND). The measure has never been specifically validated for use within this population, despite questions raised about the scale's validity. This study seeks to analyse the construct validity of the HADS in MND by fitting its data to the Rasch model. Methods The scale was administered to 298 patients with MND. Scale assessment included model fit, differential item functioning (DIF), unidimensionality, local dependency and category threshold analysis. Results Rasch analyses were carried out on the HADS total score as well as depression and anxiety subscales (HADS-T, D and A respectively). After removing one item from both of the seven item scales, it was possible to produce modified HADS-A and HADS-D scales which fit the Rasch model. An 11-item higher-order HADS-T total scale was found to fit the Rasch model following the removal of one further item. Conclusion Our results suggest that a modified HADS-A and HADS-D are unidimensional, free of DIF and have good fit to the Rasch model in this population. As such they are suitable for use in MND clinics or research. The use of the modified HADS-T as a higher-order measure of psychological distress was supported by our data. Revised cut-off points are given for the modified HADS-A and HADS-D subscales. PMID:21955749

  6. The dimensionality of the Edinburgh Handedness Inventory: An analysis with models of the item response theory.

    PubMed

    Büsch, Dirk; Hagemann, Norbert; Bender, Nils

    2010-11-01

    Handedness is frequently measured with sum scores or quotients taken from laterality questionnaires like the Edinburgh Handedness Inventory (EHI). In classical test theory such data cannot be used to confirm either the unidimensionality (i.e., quantitative differentiation with the poles left-handed and right-handed) or multidimensionality (i.e., typological differentiation between left-, right-, and mixed-handers) of this personal characteristic. This study uses item response theory models to test the construct validity of the EHI on an item level in order to gather empirical support for the differentiation of handedness as well as the appropriateness of the items and the response format. The EHI was given to 540 participants (303 male and 237 female) aged 17-37 years. Results of mixed-Rasch analyses revealed that the best model was a two-class solution; that is, left- and right-handers (types) with quantitative differences between persons. Hence, unlike earlier model tests, this rejects both the unidimensionality of the handedness construct and the need to consider so-called mixed-handers. It is proposed that mixed-Rasch analyses should be applied more frequently to test the construct validity of other as well as more extensive handedness questionnaires.

  7. [Torrance Tests of Creative Thinking (TTCT): elements for construct validity in Portuguese adolescents].

    PubMed

    Oliveira, Ema; Almeida, Leandro; Ferrándiz, Carmen; Ferrando, Mercedes; Sainz, Marta; Prieto, María Dolores

    2009-11-01

    The aim of this work is to study the unidimensional and multidimensional nature of creativity when assessed through divergent thinking tasks, as proposed in Torrance's battery (Torrance Creative Thinking Test, TTCT). This battery is made up of various tasks with verbal and figurative content, aimed at estimating the level of creativity according to the dimensions or cognitive functions of fluency, flexibility, originality and elaboration of the individuals' ideas. This work used a sample of 595 Portuguese students from 5th and 6th grade. The results of confirmatory factor analysis reveals that the unidimensional model (a general factor of creativity) and the model of factors as a function of the cognitive dimensions of creativity, based on task content, do not fit well. The model with the best fit has a hierarchical factor structure, in which the first level comprises the factors for each of the subtests applied and the second level includes verbal or figurative content. The difficulty to verify the structural validity of the TTCT is noted, and the need for further studies to achieve, in practice, better individual creativity scores.

  8. A prototypicality validation of the Comprehensive Assessment of Psychopathic Personality model (CAPP).

    PubMed

    Hoff, Helge Andreas; Rypdal, Knut; Mykletun, Arnstein; Cooke, David J

    2012-06-01

    Cooke and colleagues recently developed the lexically based model of psychopathy named the Comprehensive Assessment of Psychopathic Personality (CAPP, Cooke, Hart, Logan, & Michie, 2004). The current study was the first to evaluate aspects of the validity of a translated version of the CAPP model, which comprises 33 symptoms from six domains of personality functioning. Prototypicality ratings from 796 Norwegian community residents, forensic mental health professionals, and corrections professionals were obtained. Most CAPP symptoms were evaluated as highly prototypical of psychopathy by all three groups. Symptoms from the Self, Dominance, and Attachment domains were perceived as more prototypical than those from the Behavioral domain. Confirmatory Factor Analysis (CFA) indicated that two CAPP domains were unidimensional whereas evidence of unidimensionality was somewhat weaker for the other domains, but improved substantially after removal of problematic symptoms. Overall, the findings support the content validity of the CAPP model. This may have relevance to the current considerations regarding reformulation of the criteria for Antisocial Personality Disorder in DSM-V.

  9. Bounded Confidence under Preferential Flip: A Coupled Dynamics of Structural Balance and Opinions.

    PubMed

    Parravano, Antonio; Andina-Díaz, Ascensión; Meléndez-Jiménez, Miguel A

    2016-01-01

    In this work we study the coupled dynamics of social balance and opinion formation. We propose a model where agents form opinions under bounded confidence, but only considering the opinions of their friends. The signs of social ties -friendships and enmities- evolve seeking for social balance, taking into account how similar agents' opinions are. We consider both the case where opinions have one and two dimensions. We find that our dynamics produces the segregation of agents into two cliques, with the opinions of agents in one clique differing from those in the other. Depending on the level of bounded confidence, the dynamics can produce either consensus of opinions within each clique or the coexistence of several opinion clusters in a clique. For the uni-dimensional case, the opinions in one clique are all below the opinions in the other clique, hence defining a "left clique" and a "right clique". In the two-dimensional case, our numerical results suggest that the two cliques are separated by a hyperplane in the opinion space. We also show that the phenomenon of unidimensional opinions identified by DeMarzo, Vayanos and Zwiebel (Q J Econ 2003) extends partially to our dynamics. Finally, in the context of politics, we comment about the possible relation of our results to the fragmentation of an ideology and the emergence of new political parties.

  10. Exploring visitor acceptability for hardening trails to sustain visitation and minimize impacts

    USGS Publications Warehouse

    Cahill, K.L.; Marion, J.L.; Lawson, S.R.

    2008-01-01

    Protected natural area managers are challenged to provide high quality recreation opportunities and ensure the protection of resources from impacts associated with visitation. Development of visitor use facilities and application of site hardening practices are commonly applied tools for achieving these competing management objectives. This study applies stated choice analysis to examine visitor opinions on acceptability when they are asked to make tradeoffs among competing social, resource and management attributes in backcountry and frontcountry settings of Acadia National Park. This study demonstrates that asking visitors about recreation setting attributes uni-dimensionally, a common approach, can yield less informative responses. Analyses that considered direct tradeoffs revealed more divergent opinions on acceptability for setting attributes than a unidimensional approach. Findings revealed that visitors to an accessible and popular attraction feature supported trail development options to protect resource conditions with unrestricted visitor access. In contrast, visitors to a remote undeveloped island expressed stronger support for no or limited trail development and access restrictions to protect resource conditions.

  11. Solution of two-dimensional problems of the statics of flexible shallow shells by spline approximation

    SciTech Connect

    Grigorenko, Ya.M.; Kryukov, N.N.; Ivanova, Yu.I.

    1995-10-01

    Spline functions have come into increasingly wide use recently in the solution of boundary-value problems of the theory of elasticity of plates and shells. This development stems from the advantages offered by spline approximations compared to other methods. Among the most important advantages are the following: (1) the behavior of the spline in the neighborhood of a point has no effect on the behavior of the spline as a whole; (2) spline interpolation converges well compared to polynomial interpolation; (3) algorithms for spline construction are simple and convenient to use. The use of spline functions to solve linear two-dimensional problems on the stress-strain state of shallow shells and plates that are rectangular in plan has proven their efficiency and made it possible to expand the range of problems that can be solved. The approach proposed in these investigations is based on reducing a linear two-dimensional problem to a unidimensional problem by the spline unidimensional problem by the method of discrete orthogonalization in the other coordinate direction. Such an approach makes it possible to account for local and edge effects in the stress state of plates and shells and obtain reliable solutions with complex boundary conditions. In the present study, we take the above approach, employing spline functions to solve linear problems, and use it to also solve geometrically nonlinear problems of the statics of shallow shells and plates with variable parameters.

  12. Congruence between a theoretical continuum of masculinity and the Rasch model: examining the Conformity to Masculine Norms Inventory.

    PubMed

    Ludlow, L H; Mahalik, J R

    2001-01-01

    The purpose of this study was to examine the psychometric structure of the Conformity to Masculine Norms Inventory (CMNI) in relation to the Rasch model. The CMNI was specifically constructed to measure a set of unidimensional constructs. As such, the items were intended to define a uniform spread of locations along each construct. The CMNI measures conformity to twelve masculine norms: winning, emotional control, risk-taking, violence, dominance, playboy, self-reliance, primacy of work, power over women, disdain for homosexuals, physical toughness, and pursuit of status. Three hundred forty-eight men participated in the study. In addition to examining global Rasch characteristics and the unidimensionality of each of the 12 scales, a detailed Rasch rating scale analysis is provided for the Violence Scale with unusual response patterns discussed in terms of their clinical usefulness. The results across all 12 scales reveal an excellent congruence between the theoretically derived construct of conformity to masculine norms and the theoretically defined objectives of the Rasch rating scale model.

  13. Evaluating Psychometric Properties of the Spanish-version of the Pediatric Functional Assessment of Chronic Illness Therapy-Perceived Cognitive Function (pedsFACIT-PCF)

    PubMed Central

    Wong, Alex W. K.; Correia, Helena; Cella, David

    2015-01-01

    Purpose The pediatric Functional Assessment of Chronic Illness Therapy-Perceived Cognitive Function (pedsFACIT-PCF) is a 13-item short-form derived from the pediatric Perceived Cognitive Function item bank (pedsPCF), which was developed to measure children’s daily cognitive behaviors and was validated on the US general population and children with cancer. This study evaluated the psychometric properties of Spanish language pedsFACIT-PCF and the measurement equivalence between Spanish and English versions. Methods pedsFACIT-PCF items were translated into Spanish using a standard iterative methodology. A total of 1358 English- and 604 Spanish-speaking children aged 8–17 years who completed English and Spanish versions of pedsFACIT-PCF, respectively, were administered through an Internet survey company. Unidimensionality was evaluated using confirmatory factor analysis. Item responses were modeled using item response theory. The presence and impact of differential item functioning (DIF) were evaluated using ordinal logistic regression. Results Unidimensionality of the pedsFACIT-PCF was supported. One of the 13 items demonstrated statistically significant DIF by language; however, impacts of language DIF on both individual scores and at the test level were negligible. No Spanish items showed DIF with respect to age and gender. Conclusions The 13-item pedsFACIT-PCF demonstrated stable measurement properties on language, gender and age and can be used for future trials. PMID:25749924

  14. Use of the Rasch measurement model to explore the relationship between content knowledge and topic-specific pedagogical content knowledge for organic chemistry

    NASA Astrophysics Data System (ADS)

    Davidowitz, Bette; Potgieter, Marietjie

    2016-06-01

    Research has shown that a high level of content knowledge (CK) is necessary but not sufficient to develop the special knowledge base of expert teachers known as pedagogical content knowledge (PCK). This study contributes towards research to quantify the relationship between CK and PCK in science. In order to determine the proportion of the variance in PCK accounted for by the variance in CK, instruments are required which are valid and reliable as well as being unidimensional to measure person abilities for CK and PCK. An instrument consisting of two paper-and-pencil tests was designed to assess Grade 12 teachers CK and PCK in organic chemistry. We used the Rasch measurement model to convert raw score data into interval measures and to provide empirical evidence for the validity, reliability and unidimensionality of the tests. The correlation between CK and PCK was estimated as r = .66 (p < .001). We found evidence to suggest that while topic-specific PCK (TSPCK) develops with increasing teaching experience, high levels of CK can be acquired with limited teaching experience. These findings support the hypothesis that CK is a requirement for the development of TSPCK; proficiency in CK is, however, not necessarily associated with high levels of TSPCK.

  15. Psychometric properties of the dimensional anxiety scales for DSM-5 in a Brazilian community sample.

    PubMed

    DeSousa, Diogo A; Moreno, André L; Osório, Flávia L; Crippa, José Alexandre S; LeBeau, Richard; Manfro, Gisele G; Salum, Giovanni A; Koller, Silvia H

    2016-10-16

    The DSM-5 highlights the use of dimensional assessments of mental health as a supplement to categorical diagnoses. This study investigated the psychometric properties of the DSM-5 Dimensional Anxiety Scales in a Brazilian community sample. Dimensional scales for generalized anxiety disorder, social anxiety disorder, panic disorder, agoraphobia, and specific phobia were administered to 930 adults aged 18 to 70, 64.2% female. Psychometric properties investigated were: unidimensionality; measurement invariance; internal consistency; composite reliability; test-retest reliability; convergent and divergent validity; category thresholds and item performance analyses. Analyses revealed unidimensionality for all scales except for specific phobia. Measurement invariance, high internal consistency and composite reliability, and convergent and divergent validity were demonstrated. Test-retest reliability was high for all scales but generalized anxiety disorder. Item-based analyses evidenced that none of the items were very easy to endorse and that the scales offered more information about subjects with high severity estimates of anxiety. The DSM-5 Dimensional Anxiety Scales are a valid and reliable alternative to assess anxiety symptomatology in community settings, although further evaluation is needed, especially for specific phobia. The scales seem to be more useful for characterizing dimensionality of symptoms for subclinical or clinical cases than for slight or mildly anxious subjects.

  16. Dimensions of the South Oaks Gambling Screen in Finland: A cross-sectional population study.

    PubMed

    Salonen, Anne H; Rosenström, Tom; Edgren, Robert; Volberg, Rachel; Alho, Hannu; Castrén, Sari

    2017-03-01

    The underlying structure of problematic gambling behaviors, such as those assessed by the South Oaks Gambling Screen (SOGS), remain unknown: Can problem gambling be assessed unidimensionally or should multiple qualitatively different dimensions be taken into account, and if so, what do these qualitative dimensions indicate? How significant are the deviations from unidimensionality in practice? A cross-sectional random sample of Finns aged 15-74 (n = 4,484) was drawn from the Population Information Registry and surveyed in 2011-2012. Analyses were conducted using descriptive statistics, Confirmatory factor analysis (CFA) and multidimensional item response theory (MIRT) models. Altogether, 14.9% of the population endorsed at least one of the 20 SOGS items, but nine items had low endorsement rates (≤ 0.2%). CFA and MIRT techniques suggested that individuals differed from each other in two positively correlated (r = 0.70) underlying dimensions: "impact on self primarily" and "impact on others also". This two-factor correlated-factors model can be reinterpreted as a bifactor model with one general gambling-problem factor and two specific factors with similar interpretation as in the correlated-factors model but with non-overlapping items. The two specific factors may provide clinically useful information without extra costs of assessment.

  17. The Psychometric Properties of the French Version of the Personality Inventory for DSM-5.

    PubMed

    Roskam, Isabelle; Galdiolo, Sarah; Hansenne, Michel; Massoudi, Koorosh; Rossier, Jérôme; Gicquel, Ludovic; Rolland, Jean-Pierre

    2015-01-01

    In the context of the publication of DSM-5, the Personality Inventory for DSM-5 (PID-5) has been proposed as a new dimensional assessment tool for personality disorders. This instrument includes a pool of 220 items organized around 25 facets included in a five-factor second-order domain structure. The examination of the replicability of the trait structure across methods and populations is of primary importance. In view of this need, the main objective of the current study was to validate the French version of the PID-5 among French-speaking adults from a European community sample (N=2,532). In particular, the assumption of unidimensionality of the 25 facet and the five domain scales was tested, as well as the extent to which the five-factor structure of the PID-5 and the DSM-5 personality trait hierarchical structure are replicated in the current sample. The results support the assumption of unidimensionality of both the facets and the domains. Exploratory factor and hierarchical analyses replicated the five-factor structure as initially proposed in the PID-5.

  18. Building a new Rasch-based self-report inventory of depression

    PubMed Central

    Balsamo, Michela; Giampaglia, Giuseppe; Saggino, Aristide

    2014-01-01

    This paper illustrates a sequential item development process to create a new self-report instrument of depression refined with Rasch analysis from a larger pool of potential diagnostic items elicited through a consensus approach by clinical experts according to the latest edition of the Diagnostic and Statistical Manual of Mental Disorders criteria for major depression. A 51-item pool was administered to a sample of 529 subjects (300 healthy community-dwelling adults and 229 psychiatric outpatients). Item selection resulted in a 21-item set, named the Teate Depression Inventory, with an excellent Person Separation Index and no evidence of bias due to an item–trait interaction (χ2=147.71; df =168; P=0.48). Additional support for the unidimensionality, local independence, appropriateness of the response format, and discrimination ability between clinical and nonclinical subjects was provided. No substantial differential item functioning by sex was observed. The Teate Depression Inventory shows considerable promise as a unidimensional tool for the screening of depression. Finally, advantages and disadvantages of this methodology will be discussed in terms of subsequent possible mathematical analyses, statistical tests, and implications for clinical investigations. PMID:24511231

  19. Is the Bifactor Model a Better Model or Is It Just Better at Modeling Implausible Responses? Application of Iteratively Reweighted Least Squares to the Rosenberg Self-Esteem Scale.

    PubMed

    Reise, Steven P; Kim, Dale S; Mansolf, Maxwell; Widaman, Keith F

    2016-01-01

    Although the structure of the Rosenberg Self-Esteem Scale (RSES) has been exhaustively evaluated, questions regarding dimensionality and direction of wording effects continue to be debated. To shed new light on these issues, we ask (a) for what percentage of individuals is a unidimensional model adequate, (b) what additional percentage of individuals can be modeled with multidimensional specifications, and (c) what percentage of individuals respond so inconsistently that they cannot be well modeled? To estimate these percentages, we applied iteratively reweighted least squares (IRLS) to examine the structure of the RSES in a large, publicly available data set. A distance measure, ds, reflecting a distance between a response pattern and an estimated model, was used for case weighting. We found that a bifactor model provided the best overall model fit, with one general factor and two wording-related group factors. However, on the basis of dr values, a distance measure based on individual residuals, we concluded that approximately 86% of cases were adequately modeled through a unidimensional structure, and only an additional 3% required a bifactor model. Roughly 11% of cases were judged as "unmodelable" due to their significant residuals in all models considered. Finally, analysis of ds revealed that some, but not all, of the superior fit of the bifactor model is owed to that model's ability to better accommodate implausible and possibly invalid response patterns, and not necessarily because it better accounts for the effects of direction of wording.

  20. Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

    PubMed Central

    Bazan, Ovandir; Ortiz, Jayme Pinto; Vieira Junior, Francisco Ubaldo; Vieira, Reinaldo Wilson; Antunes, Nilson; Tabacow, Fabio Bittencourt Dutra; Costa, Eduardo Tavares; Petrucci Junior, Orlando

    2013-01-01

    Introduction In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. Objective To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream. Methods To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements. Results It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found. Conclusions Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves. PMID:24598950

  1. The Psychometric Properties of the French Version of the Personality Inventory for DSM-5

    PubMed Central

    Roskam, Isabelle; Galdiolo, Sarah; Hansenne, Michel; Massoudi, Koorosh; Rossier, Jérôme; Gicquel, Ludovic; Rolland, Jean-Pierre

    2015-01-01

    In the context of the publication of DSM-5, the Personality Inventory for DSM-5 (PID-5) has been proposed as a new dimensional assessment tool for personality disorders. This instrument includes a pool of 220 items organized around 25 facets included in a five-factor second-order domain structure. The examination of the replicability of the trait structure across methods and populations is of primary importance. In view of this need, the main objective of the current study was to validate the French version of the PID-5 among French-speaking adults from a European community sample (N=2,532). In particular, the assumption of unidimensionality of the 25 facet and the five domain scales was tested, as well as the extent to which the five-factor structure of the PID-5 and the DSM-5 personality trait hierarchical structure are replicated in the current sample. The results support the assumption of unidimensionality of both the facets and the domains. Exploratory factor and hierarchical analyses replicated the five-factor structure as initially proposed in the PID-5. PMID:26193699

  2. Rasch analysis of the Developmental Test of Visual-Motor Integration in children with intellectual disabilities.

    PubMed

    Wuang, Yee-Pay; Su, Chwen-Yng

    2009-01-01

    The purpose of this study was to examine the measurement properties of the Developmental Test of Visual-Motor Integration (VMI) in children with intellectual disabilities (ID) ages 4-12 years using the dichotomous Rasch model. The VMI was administered individually to 454 children with ID. Rasch analysis was applied to investigate unidimensionality, item fit to the model, differential item functioning (DIF), and item targeting. Discriminative validity was obtained by receiver operating characteristic (ROC) curve analysis. Items were eliminated if the task was too easy or too difficult, or showed misfit to the Rasch model. The remaining items fitted the unidimensional construct the test was intended to measure and were free of DIF. The Rasch reduced version of the VMI with 9 items appeared to be suited to measure mild degrees of perceptual-motor impairment and demonstrated excellent reliability (0.91). VMI-9 had a larger area under the ROC curve in its ability to differentiate mild versus moderate to severe ID compared with the original version. Taken together, the VMI-9 provides a quick, reliable and valid measure for screening and identifying perceptual-motor deficits in children with ID.

  3. Psychometric Properties of 7- and 30-Day Versions of the PROMIS Emotional Distress Item Banks in an Australian Adult Sample.

    PubMed

    Batterham, Philip J; Sunderland, Matthew; Carragher, Natacha; Calear, Alison L

    2017-01-01

    This study aimed to examine the psychometric properties of the PROMIS depression, anxiety, and anger item banks in a large Australian population-based sample. The study tested for unidimensionality; evaluated invariance across age, gender, and education; assessed local independence; and tested item bank scores as an indicator for clinical criteria. In addition, equivalence of the 7-day time frame against an alternative 30-day time frame was assessed. A sample of 3,175 Australian adults were recruited into the study through online advertising. All three item banks showed strong evidence of unidimensionality and parsimony, with no items showing local dependence. All items were invariant across age, gender, and education. The item banks were accurate in detecting clinical criteria for major depressive disorder, generalized anxiety disorder, and panic disorder, although legacy measures designed for this purpose sometimes performed marginally better. Responses to the 30-day time frame were highly consistent with the original 7-day time frame. The study provided support for the validity of the PROMIS emotional distress item banks as measures of depression, anxiety, and anger in the Australian population, supporting the generalizability of the measures. The time frame chosen for assessing mental health outcomes using these item banks should be based on pragmatic considerations.

  4. Confirmatory factor analysis of the Oral Health Impact Profile.

    PubMed

    John, M T; Feuerstahler, L; Waller, N; Baba, K; Larsson, P; Celebić, A; Kende, D; Rener-Sitar, K; Reissmann, D R

    2014-09-01

    Previous exploratory analyses suggest that the Oral Health Impact Profile (OHIP) consists of four correlated dimensions and that individual differences in OHIP total scores reflect an underlying higher-order factor. The aim of this report is to corroborate these findings in the Dimensions of Oral Health-Related Quality of Life (DOQ) Project, an international study of general population subjects and prosthodontic patients. Using the project's Validation Sample (n = 5022), we conducted confirmatory factor analyses in a sample of 4993 subjects with sufficiently complete data. In particular, we compared the psychometric performance of three models: a unidimensional model, a four-factor model and a bifactor model that included one general factor and four group factors. Using model-fit criteria and factor interpretability as guides, the four-factor model was deemed best in terms of strong item loadings, model fit (RMSEA = 0·05, CFI = 0·99) and interpretability. These results corroborate our previous findings that four highly correlated factors - which we have named Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact - can be reliably extracted from the OHIP item pool. However, the good fit of the unidimensional model and the high interfactor correlations in the four-factor solution suggest that OHRQoL can also be sufficiently described with one score.

  5. Violations of transitivity: Implications for a theory of contextual choice

    PubMed Central

    Grace, Randolph C.

    1993-01-01

    Violations of strong stochastic transitivity in concurrent-chains choice were first reported by Navarick and Fantino. In a series of articles, Navarick and Fantino concluded that neither a unidimensional model capable of predicting exact choice probabilities nor a fixed-variable equivalence rule was possible for the concurrent-chains procedure. I show that when choice is modeled contextually (i.e., when preference for a schedule is affected by factors other than the schedule itself, e.g., aspects of the alternative schedule), a unidimensional, exact-choice probability model is possible that both predicts the intransitivities reported by Navarick and Fantino and provides a fixed-variable equivalence rule for the concurrent-chains procedure. The contextual model is an extension of the generalized matching law and violates a key assumption underlying traditional choice models—simple scalability—because of (a) schedule interdependence and (b) bias from procedural contingencies. Therefore, strong stochastic transitivity cannot be expected to hold. Contextual scalability is analyzed to reveal a hierarchy of context effects in choice. Navarick and Fantino's intransitivities can be satisfactorily explained by bias. If attribute sensitivity is context dependent, however, and if there are similarity structures among choice alternatives, the contextual model is shown to be able to predict violations of ordinal preference. Therefore, it may be possible to formulate a deterministic, general psychophysical model of choice as a behavioral alternative to probabilistic, multidimensional choice theories. PMID:16812697

  6. Examining multidimensional sport-confidence in athletes and non-athlete sport performers.

    PubMed

    Machida, Moe; Otten, Mark; Magyar, T Michelle; Vealey, Robin S; Ward, Rose Marie

    2017-03-01

    Sport-confidence is considered a critical success factor for sport performers at all levels. Researchers have suggested that sport-confidence is a multidimensional rather than a unidimensional construct, and the sport-confidence model identified three types of sport-confidence (i.e., physical skills and training, cognitive efficiency, and resilience) that are important for success in sport. However, such multidimensionality of sport-confidence and its measurement have not been fully examined. On a large sample of sport performers with varied skill levels and characteristics, the purpose of the present study was to examine the three-factor model of sport-confidence. We tested the measurement invariance of the Sport-Confidence Inventory across 512 athletes and 1170 non-athlete sport performers. Results from the multiple group model analysis showed that the three-factor model of sport-confidence fit better for the athlete sample than for the non-athlete sample. The results implicate that the three-factor model of sport-confidence model is suitable to athletes, though sport-confidence may appear more unidimensional for non-athletes. The use of the Sport-Confidence Inventory for non-athlete sport performers demands further consideration; however, the findings implicate that it could be a useful tool to assess sport-confidence of sport performers at any levels.

  7. [Social media monitoring of asthmatic children treated in a specialized program: Parents and caregivers expectations].

    PubMed

    Urrutia-Pereira, Marilyn; Ávila, Jennifer Bg; Cherrez-Ojeda, Ivan; Ivancevich, Juan Carlos; Solé, Dirceu

    2015-01-01

    Antecedentes: las redes sociales se utilizan para el apoyo de los pacientes con asma; sin embargo, no se conocen las expectativas de los padres y los cuidadores de los pacientes con respecto al uso de estas redes. Objetivo: evaluar las expectativas de los padres y los cuidadores de niños asmáticos atendidos en el Programa de Prevención del Asma Infantil (PIPA, Uruguaiana, RS) con respecto al uso de las redes sociales. Material y método: estudio observacional, descriptivo, de corte transversal, en el que padres y cuidadores de niños tratados en el Programa de Prevención del Asma Infantil respondieron a un cuestionario escrito acerca del uso de las nuevas tecnologías y las diversas aplicaciones para mejorar la información acerca del asma. Resultados: participaron 210 padres o cuidadores (mediana de edad: 25 años; intervalo de edad: 18-42 años) de pacientes con edad promedio de 7.3 años (intervalo de edad: 2 a 18 años) y duración del asma de 4.7 años; 65% de los padres o cuidadores tuvo menos de ocho años de grado de escolaridad. La mayoría de ellos (72%) no tenía acceso a Internet a través de sus teléfonos y sólo 18% obtenía información activamente acerca del asma por Internet; 87% refirió su interés por recibir información a través de las redes sociales. Conclusión: los padres o cuidadores de niños atendidos en el Programa de Prevención del Asma Infantil expresaron gran interés en el uso de redes sociales, pero pocos las usan para controlar la enfermedad de los niños. Aunque las redes sociales proporcionan un gran beneficio para la salud, esta información debe ser vigilarse en relación con su fiabilidad y calidad. La privacidad de los usuarios (médicos y pacientes) debe ser preservada y debe facilitarse su acceso a Internet.

  8. The Lung Image Database Consortium (LIDC): A comparison of different size metrics for pulmonary nodule measurements

    PubMed Central

    Reeves, Anthony P.; Biancardi, Alberto M.; Apanasovich, Tatiyana V.; Meyer, Charles R.; MacMahon, Heber; van Beek, Edwin J.R.; Kazerooni, Ella A.; Yankelevitz, David; McNitt-Gray, Michael F.; McLennan, Geoffrey; Armato, Samuel G.; Henschke, Claudia I.; Aberle, Denise R.; Croft, Barbara Y.; Clarke, Laurence P.

    2007-01-01

    Rationale and Objectives To investigate the effects of choosing between different metrics in estimating the size of pulmonary nodules as a factor both of nodule characterization and of performance of computer aided detection systems, since the latters are always qualified with respect to a given size range of nodules. Materials and Methods This study used 265 whole-lung CT scans documented by the Lung Image Database Consortium using their protocol for nodule evaluation. Each inspected lesion was reviewed independently by four experienced radiologists who provided boundary markings for nodules larger than 3 mm. Four size metrics, based on the boundary markings, were considered: a uni-dimensional and two bi-dimensional measures on a single image slice and a volumetric measurement based on all the image slices. The radiologist boundaries were processed and those with four markings were analyzed to characterize the inter-radiologist variation, while those with at least one marking were used to examine the difference between the metrics. Results The processing of the annotations found 127 nodules marked by all of the four radiologists and an extended set of 518 nodules each having at least one observation with three-dimensional sizes ranging from 2.03 to 29.4 mm (average 7.05 mm, median 5.71 mm). A very high inter-observer variation was observed for all these metrics: 95% of estimated standard deviations were in the following ranges [0.49, 1.25], [0.67, 2.55], [0.78, 2.11], and [0.96, 2.69] for the three-dimensional, the uni-dimensional, and the two bi-dimensional size metrics respectively (in mm). Also a very large difference among the metrics was observed: 0.95 probability-coverage region widths for the volume estimation conditional on uni-dimensional, and the two bi-dimensional size measurements of 10mm were 7.32, 7.72, and 6.29 mm respectively. Conclusions The selection of data subsets for performance evaluation is highly impacted by the size metric choice. The LIDC

  9. Construct Validity of the Chinese Version of the Activities of Daily Living Rating Scale III in Patients with Schizophrenia

    PubMed Central

    Chiu, En-Chi; Lee, Yen; Lai, Kuan-Yu; Kuo, Chian-Jue; Lee, Shu-Chun; Hsieh, Ching-Lin

    2015-01-01

    Background The Chinese version of the Activities of Daily Living Rating Scale III (ADLRS-III), which has 10 domains, is commonly used for assessing activities of daily living (ADL) in patients with schizophrenia. However, construct validity (i.e., unidimensionality) for each domain of the ADLRS-III is unknown, limiting the explanations of the test results. Purpose This main purpose of this study was to examine unidimensionality of each domain in the ADLRS-III. We also examined internal consistency and ceiling/floor effects in patients with schizophrenia. Methods From occupational therapy records, we obtained 304 self-report data of the ADLRS-III. Confirmatory factor analysis (CFA) was conducted to examine the 10 one-factor structures. If a domain showed an insufficient model fit, exploratory factor analysis (EFA) was performed to investigate the factor structure and choose one factor representing the original construct. Internal consistency was examined using Cronbach’s alpha (α). Ceiling and floor effects were determined by the percentage of patients with the maximum and minimum scores in each domain, respectively. Results CFA analyses showed that 4 domains (i.e., leisure, picture recognition, literacy ability, communication tools use) had sufficient model fits. These 4 domains had acceptable internal consistency (α = 0.79-0.87) and no ceiling/floor effects, except the leisure domain which had a ceiling effect. The other 6 domains showed insufficient model fits. The EFA results showed that these 6 domains were two-factor structures. Conclusion The results supported unidimensional constructs of the leisure, picture recognition, literacy ability, and communication tool uses domains. The sum scores of these 4 domains can be used to represent their respective domain-specific functions. Regarding the 6 domains with insufficient model fits, we have explained the two factors of each domain and chosen one factor to represent its original construct. Future users may

  10. An N-terminal nuclear localization sequence but not the calmodulin-binding domain mediates nuclear localization of nucleomorphin, a protein that regulates nuclear number in Dictyostelium

    SciTech Connect

    Myre, Michael A.; O'Day, Danton H. . E-mail: doday@utm.utoronto.ca

    2005-06-24

    Nucleomorphin is a novel nuclear calmodulin (CaM)-binding protein (CaMBP) containing an extensive DEED (glu/asp repeat) domain that regulates nuclear number. GFP-constructs of the 38 kDa NumA1 isoform localize as intranuclear patches adjacent to the inner nuclear membrane. The translocation of CaMBPs into nuclei has previously been shown by others to be mediated by both classic nuclear localization sequences (NLSs) and CaM-binding domains (CaMBDs). Here we show that NumA1 possesses a CaMBD ({sup 171}EDVSRFIKGKLLQKQQKIYKDLERF{sup 195}) containing both calcium-dependent-binding motifs and an IQ-like motif for calcium-independent binding. GFP-constructs containing only NumA1 residues 1-129, lacking the DEED and CaMBDs, still localized as patches at the internal periphery of nuclei thus ruling out a direct role for the CaMBD in nuclear import. These constructs contained the amino acid residues {sup 48}KKSYQDPEIIAHSRPRK{sup 64} that include both a putative bipartite and classical NLS. GFP-bipartite NLS constructs localized uniformly within nuclei but not as patches. As with previous work, removal of the DEED domain resulted in highly multinucleate cells. However as shown here, multinuclearity only occurred when the NLS was present allowing the protein to enter nuclei. Site-directed mutation analysis in which the NLS was changed to {sup 48}EF{sup 49} abolished the stability of the GFP fusion at the protein but not RNA level preventing subcellular analyses. Cells transfected with the {sup 48}EF{sup 49} construct exhibited slowed growth when compared to parental AX3 cells and other GFP-NumA1 deletion mutants. In addition to identifying an NLS that is sufficient for nuclear translocation of nucleomorphin and ruling out CaM-binding in this event, this work shows that the nuclear localization of NumA1 is crucial to its ability to regulate nuclear number in Dictyostelium.

  11. Novel Array-Based Target Identification for Synergistic Sensitization of Breast Cancer to Herceptin

    DTIC Science & Technology

    2010-05-01

    BRD2, CtBP2, NUMA1, PGAP1, PTCH1, RBBP7(RbAp46), RIF1, WHSC1) and SOX2 (CtBP2, CLIC4, DKK1 ) (Figure 3). Previous studies have demonstrated that...ITGAE -0.21 0.013 DKK1 0.31 0.0002 RBBP7 -0.21 0.011 MARK2 0.31 0.0003 NUS1 -0.22 0.009 ATP5G1 0.3 0.0003 CLIC4 -0.22 0.008 IDH2 0.3 0.0003

  12. Novel Array-Based Target Identification for Synergistic Sensitization of Breast Cancer to Herceptin

    DTIC Science & Technology

    2010-05-01

    BAIP3, BRD2, CtBP2, NUMA1, PGAP1, PTCH1, RBBP7(RbAp46), RIF1, WHSC1) and SOX2 (CtBP2, CLIC4, DKK1 ) (Figure 3). Previous studies have demonstrated that...0.014 PFDN2 0.32 0.0002 RPL10A -0.21 0.013 ACOX2 0.32 0.0002 KCNAB2 -0.21 0.013 PRKCZ 0.32 0.0002 ITGAE -0.21 0.013 DKK1 0.31 0.0002 RBBP7 -0.21

  13. Prince George Apt, British Columbia, Canada, Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F.

    DTIC Science & Technology

    1971-11-02

    DO NOT REPRODUCE LEGIBLY. SEC,,RITY CASSIFICA ! ON OF Tn-S PAGE REh- -nt,/ . i I REPORT DOCUMENTATION PAGE RE MSTING FORM I REPORT NUMaLA ’ GOVT...standard, deviations, and observation counts of station pressure and sea-level pressure). Data in this report are presented in tabular form , in most cases...DrITOF$ OF tNIS FORM ARE OBSOLETE -" - ,I T ss : II I T;V.2 , 1’ FTE. WEATHER CONDITIONS ". ’ C-.,T A T- STATION STATION NAME YEARS MONTH I. E(-At F

  14. The OpenMP Implementation of NAS Parallel Benchmarks and its Performance

    NASA Technical Reports Server (NTRS)

    Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry

    1999-01-01

    As the new ccNUMA architecture became popular in recent years, parallel programming with compiler directives on these machines has evolved to accommodate new needs. In this study, we examine the effectiveness of OpenMP directives for parallelizing the NAS Parallel Benchmarks. Implementation details will be discussed and performance will be compared with the MPI implementation. We have demonstrated that OpenMP can achieve very good results for parallelization on a shared memory system, but effective use of memory and cache is very important.

  15. An Investigation of Magneto-Acoustic Effects in Conductive Fluids.

    DTIC Science & Technology

    1979-12-01

    California AN INVE STIGATION OF #AGNETO-# COUSTIC EFFECTS IN CONDUCTIVE FLUIDS$ by /0Robert Franz/Klaus Thesis Advisor: P.H. Moose Approved for public...NUMIUEN OEM=. 112: L RECIPIENT’S CATALOG MUMER ,. TvITLI ad a ..mbo) L TtP oF REPORT6, P.moo CovEMo0 An Investigation of Magneto-Acoustic Master’s...Thesis; Effects in Conductive Fluids December 1979 6. PERPOUMmD ORe. REPORT NumaI 7. AUTNOR A ) A 0 ANNUM N Robert Franz Klaus 9. P019PPa"ING oNI N0ZATION

  16. Assessing Perceived Empathic and Social Self-Efficacy Across Countries

    PubMed Central

    Di Giunta, Laura; Eisenberg, Nancy; Kupfer, Anne; Steca, Patrizia; Tramontano, Carlo; Caprara, Gian Vittorio

    2010-01-01

    The Perceived Empathic Self-Efficacy Scale (PESE) and the Perceived Social Self-Efficacy Scale (PSSE) were developed to assess, respectively, individuals’ self-efficacy beliefs regarding both empathic responding to others’ needs or feelings and managing interpersonal relationships. In this study of young adults, a unidimensional factorial structure of both scales was found in Italy, the United States, and Bolivia. Complete invariance at the metric level and partial invariance at the scalar level were found across gender and countries for both scales. The construct and incremental validity of both PESE and PSSE were further examined in a different sample of Italian young adults. Patterns of association of the PESE or PSSE with self-esteem, psychological well-being, and the use of adaptive and maladaptive coping strategies were found, often over and beyond their associations with empathy or extraversion, respectively. PMID:21228911

  17. Validating a developmental scale for young children using the Rasch model: applicability of the teaching strategies GOLD assessment system.

    PubMed

    Kim, Do-Hong; Lambert, Richard G; Burts, Diane C

    2014-01-01

    This article reports the results of an application of the Rasch rating scale model to the Teaching Strategies GOLD assessment system in a norm sample of children aged birth to 71 months. The analyses focused on the examination of dimensionality, rating scale effectiveness, the hierarchy of item difficulties, and the relationship of developmental scale scores to child age. Results show that each subscale satisfies the Rasch model for unidimensionality. Ratings were found to be less reliable at the lowest and highest ends of the scale and less distinct at 'In-between' levels. Items appear to form theoretically expected hierarchies, supporting evidence for construct validity for the measures. Moderately high correlations of developmental scale scores with child age suggest that teachers are able to make valid ratings of the developmental progress of children across the intended age range.

  18. Atomic layer deposited second-order nonlinear optical metamaterial for back-end integration with CMOS-compatible nanophotonic circuitry.

    PubMed

    Clemmen, Stéphane; Hermans, Artur; Solano, Eduardo; Dendooven, Jolien; Koskinen, Kalle; Kauranen, Martti; Brainis, Edouard; Detavernier, Christophe; Baets, Roel

    2015-11-15

    We report the fabrication of artificial unidimensional crystals exhibiting an effective bulk second-order nonlinearity. The crystals are created by cycling atomic layer deposition of three dielectric materials such that the resulting metamaterial is noncentrosymmetric in the direction of the deposition. Characterization of the structures by second-harmonic generation Maker-fringe measurements shows that the main component of their nonlinear susceptibility tensor is about 5 pm/V, which is comparable to well-established materials and more than an order of magnitude greater than reported for a similar crystal [Appl. Phys. Lett.107, 121903 (2015)APPLAB0003-695110.1063/1.4931492]. Our demonstration opens new possibilities for second-order nonlinear effects on CMOS-compatible nanophotonic platforms.

  19. Psychometric properties of Yelland and Tiggemann's Drive for Muscularity Scale.

    PubMed

    Tod, David; Morrison, Todd G; Edwards, Christian

    2012-06-01

    The purpose of the current study was to examine the dimensionality and validity of Yelland and Tiggemann's Drive for Muscularity Scale (YT-DMS). Participants were college students (305 women, M(AGE)=20.15 years, SD=4.00; 356 men, M(AGE)=20.24 years, SD=3.85) who completed the YT-DMS, the Drive for Muscularity Attitudes Questionnaire, the Drive for Leanness Scale, the Drive for Thinness Scale, and a socio-demographic questionnaire. Results indicated the YT-DMS had a stable unidimensional factor structure in both genders, and the pattern of relationships generally supported the measure's criterion and construct validity. These results reveal the YT-DMS has promise, but helps identify possible areas for improvement, such as a greater focus on sampling the content domain associated with the drive for muscularity.

  20. Measuring Problematic Mobile Phone Use: Development and Preliminary Psychometric Properties of the PUMP Scale

    PubMed Central

    Merlo, Lisa J.; Stone, Amanda M.; Bibbey, Alex

    2013-01-01

    This study aimed to develop and assess the psychometric properties of an English language measure of problematic mobile phone use. Participants were recruited from a university campus, health science center, and other public locations. The sample included 244 individuals (68.4% female) aged 18–75. Results supported a unidimensional factor structure for the 20-item self-report Problematic Use of Mobile Phones (PUMP) Scale. Internal consistency was excellent (α = 0.94). Strong correlations (r = .76, P < .001) were found between the PUMP Scale and an existing scale of cellular phone dependency that was validated in Asia, as well as items assessing frequency and intensity of mobile phone use. Results provide preliminary support for the use of the PUMP Scale to measure problematic use of mobile phones. PMID:24826371

  1. The commitment to quitting smoking scale: initial validation in a smoking cessation trial for heavy social drinkers.

    PubMed

    Kahler, Christopher W; Lachance, Heather R; Strong, David R; Ramsey, Susan E; Monti, Peter M; Brown, Richard A

    2007-10-01

    We tested the psychometric properties and predictive validity of a newly developed 8-item measure of commitment to quitting smoking, conceptualized as the state of being personally bound or obligated to persist in quitting smoking despite potential difficulties, craving and discomfort. Participants were 157 heavy drinking smokers enrolled in a clinical trial of smoking cessation treatments. The measure showed strong unidimensionality, good internal consistency, and moderate stability from baseline to quit date. Commitment significantly increased from baseline to quit date. Higher commitment to quitting at baseline predicted greater odds of abstinence at post-treatment and 16 and 26 weeks after quit date. Commitment predicted smoking outcome over and above level of tobacco dependence, self-reported importance of quitting smoking, and self-efficacy for remaining abstinent. Results suggest that commitment is a highly relevant construct for smoking cessation, which can be reliably assessed with the Commitment to Quitting Smoking Scale and which may be an excellent target for smoking cessation treatments.

  2. The Comprehensive Assessment of Psychopathic Personality (CAPP): content validation using prototypical analysis.

    PubMed

    Kreis, Mette K F; Cooke, David J; Michie, Christine; Hoff, Helge A; Logan, Caroline

    2012-06-01

    The Comprehensive Assessment of Psychopathic Personality (CAPP; Cooke, Hart, Logan, & Michie, 2004) is a new personality-based model and clinical assessment of psychopathy. This study was the first to examine the content validity of the English-language CAPP. Content validation is a crucial part of the development and refinement of any new instrument. Prototypical analysis was used to evaluate the representativeness of CAPP symptoms to the psychopathy construct in adults. Symptoms were rated by international mental health professionals (N = 132). Findings support good content validity of the CAPP, with most symptoms rated as highly representative of psychopathy. Domains relating to interpersonal style were particularly prototypical. Confirmatory factor analyses further suggested that CAPP domains are highly unidimensional. However, some CAPP symptoms may be weaker items in the model and further refinement is needed.

  3. Development of a questionnaire to assess university students’ intentions to use behavioral alcohol reduction strategies

    PubMed Central

    Bonar, Erin E.; Hoffmann, Erica; Rosenberg, Harold; Kryszak, Elizabeth; Young, Kathleen M.; Ashrafioun, Lisham; Kraus, Shane W.; Bannon, Erin E.

    2014-01-01

    Objective To evaluate the psychometric properties of a new self-report questionnaire designed to assess college students’ intentions to employ 31 specific alcohol-reduction strategies. Method Students attending a large public university were recruited to complete alcohol-reduction, drinking history, and personality questionnaires online. Results Based on item-total correlations and principal components analysis, we eliminated three items and calculated average intention ratings across the remaining 28 items. The resulting scale had appropriate unidimensionality and excellent internal consistency. Correlations of intention questionnaire scores with measures of drinking history, alcohol outcome expectancies, sensation seeking, and impression management provided some support for criterion and discriminant validity of the questionnaire. Conclusion This questionnaire could be employed as an outcome measure to evaluate prevention programs and as a clinical tool to identify clients who have little intention to employ drinking reduction strategies in heavy drinking situations. PMID:22686362

  4. Influence of proxy attributes on multiattribute decision analysis: An empirical investigation in the context of air pollution control

    SciTech Connect

    Damodaran, N.

    1988-01-01

    Three separate studies in decision analysis were conducted in the context of air pollution control wherein the preferences of informed subjects were individually assessed. The first study was designed to develop a decision model for the control of sulfur dioxide emissions by incorporating multi-media effects of pollution control using both fundamental and proxy attributes. The second study specifically compared fundamental and proxy attributes and tested the hypothesis that proxy attributes lead to biased decisions. The third study validated the results of the previous one and was extended to examine the hypothesis that proxy bias could be reduced by appropriate elicitation techniques. The findings of this study indicated that subjects behaved according to the norms of expected utility theory when the unidimensional utility function for the proxy attribute was assessed. However, subjects exhibited a near universal bias to overweight the proxy attribute, relative to prescriptions of expected utility theory, in a multi-attribute scenario.

  5. Psychometric evaluation of the Multidimensional Assessment of Fatigue scale for use with pregnant and postpartum women.

    PubMed

    Fairbrother, Nichole; Hutton, Eileen K; Stoll, Kathrin; Hall, Wendy; Kluka, Sandy

    2008-06-01

    Although fatigue is a common experience for pregnant women and new mothers, few measures of fatigue have been validated for use with this population. To address this gap, the authors assessed psychometric properties of the Multidimensional Assessment of Fatigue (MAF) scale, which was used in 2 independent samples of pregnant women. Results indicated that the psychometric properties of the scale were very similar across samples and time points. The scale possesses a high level of internal consistency, has good convergent validity with measures of sleep quality and depression, and discriminates well from a measure of social support. Contrary to previous evaluations of the MAF, data strongly suggest that the scale represents a unidimensional construct best represented by a single factor. Results indicate that the MAF is a useful measure of fatigue among pregnant and postpartum women.

  6. Generalization of Category Knowledge and Dimensional Categorization in Humans (Homo sapiens) and Nonhuman Primates (Macaca mulatta)

    PubMed Central

    Smith, J. David; Zakrzewski, Alexandria C.; Johnston, Jennifer J. R.; Roeder, Jessica L.; Boomer, Joseph; Ashby, F. Gregory; Church, Barbara A.

    2015-01-01

    A theoretical framework within neuroscience distinguishes humans’ implicit and explicit systems for category learning. We used a perceptual-categorization paradigm to ask whether nonhumans share elements of these systems. Participants learned categories that foster implicit or explicit categorization in humans, because they had a multidimensional, information-integration (II) solution or a unidimensional, rule-based (RB) solution. Then humans and macaques generalized their category knowledge to new, untested regions of the stimulus space. II generalization was impaired, suggesting that II category learning is conditioned and constrained by stimulus generalization to its original, trained stimulus contexts. RB generalization was nearly seamless, suggesting that RB category knowledge in humans and monkeys has properties that grant it some independence from the original, trained stimulus contexts. These findings raise the question of 1) how closely macaques’ dimensional categorization verges on humans’ explicit/declarative categorization, and 2) how far macaques’ dimensional categorization has advanced beyond that in other vertebrate species. PMID:26167774

  7. Proactive Parent Engagement in Public Schools: Using a Brief Strengths and Needs Assessment in a Multiple-Gating Risk Management Strategy.

    PubMed

    Moore, Kevin J; Garbacz, S Andrew; Gau, Jeff M; Dishion, Thomas J; Brown, Kimbree L; Stormshak, Elizabeth A; Seeley, John R

    2016-10-01

    This study examined the viability of a brief, parent-reported strengths and needs assessment as the first step in a multiple-gating approach to proactive positive behavior support for families. The Positive Family Support-Strengths and Needs Assessment (PFS-SaNA) was designed to collaboratively engage parents early in the school year in a home-school coordinated Positive Family Support (PFS) system. In this study, we evaluated the reliability and validity of the PFS-SaNA in the context of public middle schools. Findings suggest that the 14-item, unidimensional PFS-SaNA shows convergent validity with teacher ratings of risk. It can be easily and cost-effectively used by school personnel when parents register their children for school at the beginning of each school year.

  8. Proactive Parent Engagement in Public Schools: Using a Brief Strengths and Needs Assessment in a Multiple-Gating Risk Management Strategy

    PubMed Central

    Moore, Kevin J.; Garbacz, S. Andrew; Gau, Jeff M.; Dishion, Thomas J.; Brown, Kimbree L.; Stormshak, Elizabeth A.; Seeley, John R.

    2017-01-01

    This study examined the viability of a brief, parent-reported strengths and needs assessment as the first step in a multiple-gating approach to proactive positive behavior support for families. The Positive Family Support–Strengths and Needs Assessment (PFS-SaNA) was designed to collaboratively engage parents early in the school year in a home–school coordinated Positive Family Support (PFS) system. In this study, we evaluated the reliability and validity of the PFS-SaNA in the context of public middle schools. Findings suggest that the 14-item, unidimensional PFS-SaNA shows convergent validity with teacher ratings of risk. It can be easily and cost-effectively used by school personnel when parents register their children for school at the beginning of each school year. PMID:28082829

  9. The psychology of martyrdom: making the ultimate sacrifice in the name of a cause.

    PubMed

    Bélanger, Jocelyn J; Caouette, Julie; Sharvit, Keren; Dugas, Michelle

    2014-09-01

    Martyrdom is defined as the psychological readiness to suffer and sacrifice one's life for a cause. An integrative set of 8 studies investigated the concept of martyrdom by creating a new tool to quantitatively assess individuals' propensity toward self-sacrifice. Studies 1A-1C consisted of psychometric work attesting to the scale's unidimensionality, internal consistency, and temporal stability while examining its nomological network. Studies 2A-2B focused on the scale's predictive validity, especially as it relates to extreme behaviors and suicidal terrorism. Studies 3-5 focused on the influence of self-sacrifice on automatic decision making, costly and altruistic behaviors, and morality judgments. Results involving more than 2,900 participants from different populations, including a terrorist sample, supported the proposed conceptualization of martyrdom and demonstrated its importance for a vast repertoire of cognitive, emotional, and behavioral phenomena. Implications and future directions for the psychology of terrorism are discussed.

  10. Ultrasonic density measurement cell design and simulation of non-ideal effects.

    PubMed

    Higuti, Ricardo Tokio; Buiochi, Flávio; Adamowski, Júlio Cezar; de Espinosa, Francisco Montero

    2006-07-01

    This paper presents a theoretical analysis of a density measurement cell using an unidimensional model composed by acoustic and electroacoustic transmission lines in order to simulate non-ideal effects. The model is implemented using matrix operations, and is used to design the cell considering its geometry, materials used in sensor assembly, range of liquid sample properties and signal analysis techniques. The sensor performance in non-ideal conditions is studied, considering the thicknesses of adhesive and metallization layers, and the effect of residue of liquid sample which can impregnate on the sample chamber surfaces. These layers are taken into account in the model, and their effects are compensated to reduce the error on density measurement. The results show the contribution of residue layer thickness to density error and its behavior when two signal analysis methods are used.

  11. DEVELOPMENT OF A BRIEF SUBSTANCE USE SENSATION SEEKING SCALE: VALIDATION AND PREDICTION OF INJECTION-RELATED BEHAVIORS

    PubMed Central

    Werb, Dan; Richardson, Chris; Buxton, Jane; Shoveller, Jeannie; Wood, Evan; Kerr, Thomas

    2015-01-01

    Sensation seeking, a personality trait, has been shown to predict engagement in high-risk behaviors. However, little is known regarding the impact of sensation seeking on substance use among street youth. We therefore sought to modify a sensation seeking scale (SSS) for use among this population. Street youth from the Vancouver-based At-Risk Youth Study (n = 226) completed the modified SSS. Exploratory and confirmatory factor analysis (EFA/CFA) were undertaken to establish the scale’s dimensionality and internal validity. The association between SSS score and injection-related behaviors was tested using generalized estimating equation (GEE) analysis. EFA results indicated scale unidimensionality. The comparative fit index (CFI) suggested acceptable fit (CFI = 0.914). In multivariate analysis, sensation seeking was independently associated with injection drug use, crystal methamphetamine use, polysubstance use, and binge drug use (all p < 0.05). Our findings provide preliminary support for the use of the modified SSS among street youth. PMID:25119056

  12. Quantifying temporal change in biodiversity: challenges and opportunities.

    PubMed

    Dornelas, Maria; Magurran, Anne E; Buckland, Stephen T; Chao, Anne; Chazdon, Robin L; Colwell, Robert K; Curtis, Tom; Gaston, Kevin J; Gotelli, Nicholas J; Kosnik, Matthew A; McGill, Brian; McCune, Jenny L; Morlon, Hélène; Mumby, Peter J; Ovreås, Lise; Studeny, Angelika; Vellend, Mark

    2013-01-07

    Growing concern about biodiversity loss underscores the need to quantify and understand temporal change. Here, we review the opportunities presented by biodiversity time series, and address three related issues: (i) recognizing the characteristics of temporal data; (ii) selecting appropriate statistical procedures for analysing temporal data; and (iii) inferring and forecasting biodiversity change. With regard to the first issue, we draw attention to defining characteristics of biodiversity time series--lack of physical boundaries, uni-dimensionality, autocorrelation and directionality--that inform the choice of analytic methods. Second, we explore methods of quantifying change in biodiversity at different timescales, noting that autocorrelation can be viewed as a feature that sheds light on the underlying structure of temporal change. Finally, we address the transition from inferring to forecasting biodiversity change, highlighting potential pitfalls associated with phase-shifts and novel conditions.

  13. The Foreign Language Anxiety in a Medical Office Scale: developing and validating a measurement tool for Spanish-speaking individuals.

    PubMed

    Guntzviller, Lisa M; Jensen, Jakob D; King, Andy J; Davis, LaShara A

    2011-09-01

    Communication research has been hindered by a lack of validated measures for Latino populations. To develop and validate a foreign language anxiety in a medical office scale (the Foreign Language Anxiety in a Medical Office Scale [FLAMOS]), the authors conducted a survey of low income, primarily Spanish-speaking Latinos (N=100). The scale factored into a unidimensional construct and showed high reliability (α=.92). The Foreign Language Anxiety in a Medical Office Scale also demonstrated convergent and divergent validity compared with other communication anxiety scales (Personal Report of Communication Apprehension-24, Communication Anxiety Inventory, and Recipient Apprehension Test), and predictive validity for acculturation measures (the Short Acculturation Scale for Hispanics). The Foreign Language Anxiety in a Medical Office Scale provides a validated measure for researchers and may help to explain Latino health care communication barriers.

  14. The grateful disposition: a conceptual and empirical topography.

    PubMed

    Mccullough, Michael E; Emmons, Robert A; Tsang, Jo-Ann

    2002-01-01

    In four studies, the authors examined the correlates of the disposition toward gratitude. Study I revealed that self-ratings and observer ratings of the grateful disposition are associated with positive affect and well-being, prosocial behaviors and traits, and religiousness/spirituality. Study 2 replicated these findings in a large nonstudent sample. Study 3 yielded similar results to Studies I and 2 and provided evidence that gratitude is negatively associated with envy and materialistic attitudes. Study 4 yielded evidence that these associations persist after controlling for Extraversion/positive affectivity. Neuroticism/negative affectivity, and Agreeableness. The development of the Gratitude Questionnaire, a unidimensional measure with good psychometric properties, is also described.

  15. I am not a lucky person: an examination of the dimensionality of beliefs about chance.

    PubMed

    André, Nathalie

    2009-12-01

    The purpose of this article was to verify whether beliefs about chance are multi or unidimensional constructs. Traditionally, authors who assessed beliefs about chance postulated that individuals who perceive themselves as unlucky usually believe that chance is random and are less confident as well as more anxious. Curiously, it appears that sometimes these individuals act as if they were motivated to avoid negative consequences. In order to better understand these puzzling findings, two studies were performed to compare three instruments intended to assess beliefs about chance and to verify their causal properties. In total, 285 students filled out a battery of instruments, including chance questionnaires (LOC, BIGL and MBIC) and personality traits. Overall, results showed that luck, through perceived controllability, seems to be related to volitional control, whereas chance, which is more stable and less controllable than luck, can be associated with cognitive distortions. The implications of these results are discussed.

  16. An analysis of the cable properties of frog ventricular myocardium.

    PubMed Central

    Chapman, R A; Fry, C H

    1978-01-01

    1. The passive and active electrical parameters of frog ventricular myocardium have been measured. 2. The cytoplasmic resistivity has been determined by following changes in the resistance of a micro-electrode on penetration of a cell. 3. Unidimensional cable analysis using direct and alternating currents revealed the presence of a single time constant attributed to the surface membrane. 4. Longitudinal impedance measurements indicate that a second time constant is present in the intracellular pathway. 5. The results indicate that the resistance between cells is low so that action potentials can propagate from cell to cell by local circuits. 6. A three-dimensional cable analysis has also been carried out and compared to a simplified mathematical model which is presented in an Appendix and which closely approximates the experimental situation. PMID:309942

  17. Intrinsic and extrinsic motivation for stereotypic and repetitive behavior.

    PubMed

    Joosten, Annette V; Bundy, Anita C; Einfeld, Stewart L

    2009-03-01

    This study provides evidence for intrinsic and extrinsic motivators for stereotypical and repetitive behavior in children with autism and intellectual disability and children with intellectual disability alone. We modified the Motivation Assessment Scale (MAS) (1988b); dividing it into intrinsic and extrinsic measures and adding items to assess anxiety as an intrinsic motivator. Rasch analysis of data from 279 MASs (74 children) revealed that the items formed two unidimensional scales. Anxiety was a more likely intrinsic motivator than sensory seeking for children with dual diagnoses; the reverse was true for children with intellectual disability only. Escape and gaining a tangible object were the most common extrinsic motivators for those with dual diagnoses and attention and escape for children with intellectual disability.

  18. Expatriate ?experts? in Indonesia and Thailand: Professional and personal qualities for effective teaching and consulting

    NASA Astrophysics Data System (ADS)

    Cannon, Robert A.

    1991-12-01

    Structured group interviews with Thai and Indonesian educators indicate that expatriate experts require a wide range of personal and professional qualities to be effective: they must have expertise, be able to establish and maintain good relationships with people, be well organised and effective teachers, and transfer information and skills that are applicable and of benefit to the nation. None of these qualities is simple or uni-dimensional. The study shows, for example, that `expertise' has several elements including technical expertise, cultural knowledge, language ability and expertise in education. Practical implications of the findings are in overseas project design, management and placement of personnel, professional development of experts, and in the design, implementation and evaluation of teaching and training.

  19. Development and validation of an eating norms inventory. Americans' lay-beliefs about appropriate eating.

    PubMed

    Fisher, Robert J; Dubé, Laurette

    2011-10-01

    What do American adults believe about what, where, when, how much, and how often it is appropriate to eat? Such normative beliefs originate from family and friends through socialization processes, but they are also influenced by governments, educational institutions, and businesses. Norms therefore provide an important link between the social environment and individual attitudes and behaviors. This paper reports on five studies that identify, develop, and validate measures of normative beliefs about eating. In study 1 we use an inductive method to identify what American adults believe are appropriate or desirable eating behaviors. Studies 2 and 3 are used to purify and assess the discriminant and nomological validity of the proposed set of 18 unidimensional eating norms. Study 4 assesses predictive validity and finds that acting in a norm-consistent fashion is associated with lower Body Mass Index (BMI), and greater body satisfaction and subjective health. Study 5 assesses the underlying social desirability and perceived healthiness of the norms.

  20. The dutch social interaction anxiety scale and the social phobia scale: reliability, validity, and clinical utility.

    PubMed

    de Beurs, Edwin; Tielen, Deirdre; Wollmann, Lisa

    2014-01-01

    The social interaction anxiety scale (SIAS) and the social phobia scale (SPS) assess anxiety in social interactions and fear of scrutiny by others. This study examines the psychometric properties of the Dutch versions of the SIAS and SPS using data from a large group of patients with social phobia and a community-based sample. Confirmatory factor analysis revealed that the SIAS is unidimensional, whereas the SPS is comprised of three subscales. The internal consistency of the scales and subscales was good. The concurrent and discriminant validity was supported and the scales were well able to discriminate between patients and community-based respondents. Cut-off values with excellent sensitivity and specificity are presented. Of all self-report measures included, the SPS was the most sensitive for treatment effects. Normative data are provided which can be used to assess whether clinically significant change has occurred in individual patients.

  1. Validation of the Japanese Version of the Body Vigilance Scale.

    PubMed

    Saigo, Tatsuo; Takebayashi, Yoshitake; Tayama, Jun; Bernick, Peter J; Schmidt, Norman B; Shirabe, Susumu; Sakano, Yuji

    2016-06-01

    The Body Vigilance Scale is a self-report measure of attention to bodily sensations. The measure was translated into Japanese and its reliability, validity, and factor structure were verified. Participants comprised 286 university students (age: 19 ± 1 years). All participants were administered the scale, along with several indices of anxiety (i.e., Anxiety Sensitivity Index, Short Health Anxiety Inventory Illness Likelihood Scale, Social Interaction Anxiety Scale, and Hospital Anxiety and Depression Scale). The Japanese version of the Body Vigilance Scale exhibited a unidimensional factor structure and strong internal consistency. Construct validity was demonstrated by significant correlations with the above measures. Results suggest that the Japanese version of the scale is a reliable, valid tool for measuring body vigilance in Japanese university students.

  2. A test of two brief measures of grandiose narcissism: the narcissistic personality inventory-13 and the narcissistic personality inventory-16.

    PubMed

    Gentile, Brittany; Miller, Joshua D; Hoffman, Brian J; Reidy, Dennis E; Zeichner, Amos; Campbell, W Keith

    2013-12-01

    The most widely used measure of trait narcissism is the Narcissistic Personality Inventory (NPI), which can provide both total and subscale scores. However, with a length of 40 items, this measure may not be ideal in settings in which time or participant attention may limit the types of measures that can be administered. In response, Ames, Rose, and Anderson (2006) created the NPI-16, which provides a shorter, unidimensional measure of the construct. In the present research, we examine the reliability and validity of the NPI-16 in conjunction with a new short measure of narcissism, the NPI-13, which provides both a total score and 3 subscale scores (Leadership/Authority; Grandiose Exhibitionism; Entitlement/Exploitativeness). Across 2 studies, we demonstrate that both short measures manifest good convergent and discriminant validity and adequate overall reliability. The NPI-13 may be favored over the NPI-16 because it allows for the extraction of 3 subscales, consistent with the use of its parent measure.

  3. Development of a Measure of “Acculturation” for Ethnic Fijians: Methodologic and Conceptual Considerations for Application to Eating Disorders Research

    PubMed Central

    Becker, Anne E.; Fay, Kristen; Agnew-Blais, Jessica; Guarnaccia, Peter M.; Striegel-Moore, Ruth H.; Gilman, Stephen E.

    2010-01-01

    Acculturation has been examined as a risk factor for eating disorders, but interpretation of findings has been limited by inconsistent operationalization of this construct across studies. The study aim was to develop and evaluate a population-specific measure of acculturation for ethnic Fijian adolescent schoolgirls, to use in future analyses related to eating disorders. Our findings suggest that acculturation is a multidimensional construct characterized by distinct, though related, dimensions of orientation to ethnic Fijian and/or western/global culture with respect to a range of behaviors and attitudes. In contrast to theoretical models positing uni-dimensional, orthogonal, or oblique relations between cultural identities in individuals undergoing acculturation, our study findings support a heterogeneous pattern among correlations of dimensions across contrasting cultural identities. We suggest multidimensional measures of acculturation are optimal — and socio-demographic proxies inadequate — for characterization of this complex process for health research. PMID:21088103

  4. Factoring handedness data: II. Geschwind's multidimensional hypothesis.

    PubMed

    Messinger, H B; Messinger, M I

    1996-06-01

    The challenge in this journal by Peters and Murphy to the validity of two published factor analyses of handedness data because of bimodality was dealt with in Part I by identifying measures to normalize the handedness item distributions. A new survey using Oldfield's questionnaire format had 38 bell-shaped (unimodal) handedness-item distributions and 11 that were only marginally bimodal out of the 55 items used in Geschwind's 1986 study. Yet they were still non-normal and the factor analysis was unsatisfactory; bimodality is not the only problem. By choosing a transformation for each item that was optimal as assessed by D'Agostino's K2 statistic, all but two items could be normalized. Seven factors were derived that showed high congruence between maximum likelihood and principal components extractions before and after varimax rotation. Geschwind's assertion that handedness is not unidimensional is therefore supported.

  5. Potential applications of latent variable modeling for the psychometrics of medical simulation.

    PubMed

    Cai, Li

    2013-10-01

    Use of simulation-based assessments and training has become increasingly widespread in medicine. It is recognized that simulations can yield a wealth of real-time information about the trainee or examinee's performance, from which inferences about proficiency can potentially be drawn. However, for the inferences to be useful, psychometric evaluation should be conducted and validity evidence amassed. Traditionally, educational and psychological measurement has relied on psychometric models that are static, unidimensional, and based on observed scores. In this article, it is argued that modern psychometric models that are dynamic, multidimensional, and based on latent variables may be useful for evaluating medical simulations. It is also argued that modern computational methods based on Bayesian statistics may provide the technical foundation. Several examples are given and issues for further research are discussed.

  6. Smooth conditional distribution function and quantiles under random censorship.

    PubMed

    Leconte, Eve; Poiraud-Casanova, Sandrine; Thomas-Agnan, Christine

    2002-09-01

    We consider a nonparametric random design regression model in which the response variable is possibly right censored. The aim of this paper is to estimate the conditional distribution function and the conditional alpha-quantile of the response variable. We restrict attention to the case where the response variable as well as the explanatory variable are unidimensional and continuous. We propose and discuss two classes of estimators which are smooth with respect to the response variable as well as to the covariate. Some simulations demonstrate that the new methods have better mean square error performances than the generalized Kaplan-Meier estimator introduced by Beran (1981) and considered in the literature by Dabrowska (1989, 1992) and Gonzalez-Manteiga and Cadarso-Suarez (1994).

  7. Development of a New Scale to Measure Ambiguity Tolerance in Veterinary Students.

    PubMed

    Hammond, Jennifer A; Hancock, Jason; Martin, Margaret S; Jamieson, Susan; Mellor, Dominic J

    2017-01-01

    The ability to cope with ambiguity and feelings of uncertainty is an essential part of professional practice. Research with physicians has identified that intolerance of ambiguity or uncertainty is linked to stress, and some authors have hypothesized that there could be an association between intolerance of ambiguity and burnout. We describe the adaptation of the TAMSAD (Tolerance of Ambiguity in Medical Students and Doctors) scale for use with veterinary students. Exploratory factor analysis supports a uni-dimensional structure for the Ambiguity tolerance construct. Although internal reliability of the 29-item TAMSAD scale is reasonable (α=.50), an alternative 27-item scale (drawn from the original 41 items used to develop TAMSAD) shows higher internal reliability for veterinary students (α=.67). We conclude that there is good evidence to support the validity of this latter TAVS (Tolerance of Ambiguity in Veterinary Students) scale to study ambiguity tolerance in veterinary students.

  8. Acculturation and cigarette smoking in Hispanic women: A meta-analysis.

    PubMed

    Kondo, Karli K; Rossi, Joseph S; Schwartz, Seth J; Zamboanga, Byron L; Scalf, Carissa D

    2016-01-01

    The present study was a random-effects model meta-analysis of 26 studies published between 1990 and 2010 (k = 32; n = 39,777) that (a) examined the association between acculturation and cigarette smoking in Hispanic women and (b) evaluated age, national origin, and measure and dimensionality (unidimensional vs. bidimensional) of acculturation as moderating variables. Results indicate a strong positive relationship and suggest larger effects of acculturation on cigarette smoking in women of Mexican descent as compared with women originating from other Latin American countries for current and lifetime smoking, as well as smoking overall. The effect of acculturation on cigarette smoking was larger in adults as compared with adolescents for current smoking and smoking overall. Few differences in effect size by measure or dimensionality of acculturation emerged. Results are discussed with regard to implications for future research and the measurement of acculturation.

  9. Development of a measure of "acculturation" for ethnic Fijians: methodologic and conceptual considerations for application to eating disorders research.

    PubMed

    Becker, Anne E; Fay, Kristen; Agnew-Blais, Jessica; Guarnaccia, Peter M; Striegel-Moore, Ruth H; Gilman, Stephen E

    2010-11-01

    Acculturation has been examined as a risk factor for eating disorders, but interpretation of findings has been limited by inconsistent operationalization of this construct across studies. The study aim was to develop and evaluate a population-specific measure of acculturation for ethnic Fijian adolescent schoolgirls, to use in future analyses related to eating disorders. Our findings suggest that acculturation is a multidimensional construct characterized by distinct, though related, dimensions of orientation to ethnic Fijian and/or western/global culture with respect to a range of behaviors and attitudes. In contrast to theoretical models positing uni-dimensional, orthogonal, or oblique relations between cultural identities in individuals undergoing acculturation, our study findings support a heterogeneous pattern among correlations of dimensions across contrasting cultural identities. We suggest multidimensional measures of acculturation are optimal--and socio-demographic proxies inadequate--for characterization of this complex process for health research.

  10. Self-catalyzed carbon plasma-assisted growth of tin-doped indium oxide nanostructures by the sputtering method

    NASA Astrophysics Data System (ADS)

    Setti, Grazielle O.; de Jesus, Dosil P.; Joanni, Ednan

    2016-10-01

    In this work a new strategy for growth of nanostructured indium tin oxide (ITO) by RF sputtering is presented. ITO is deposited in the presence of a carbon plasma which reacts with the free oxygen atoms during the deposition, forming species like CO x . These species are removed from the chamber by the pumping system, and one-dimensional ITO nanostructures are formed without the need for a seed layer. Different values of substrate temperature and power applied to the gun containing the carbon target were investigated, resulting in different nanostructure morphologies. The samples containing a higher density of nanowires were covered with gold and evaluated as surface-enhanced Raman scattering substrates for detection of dye solutions. The concept might be applied to other oxides, providing a simple method for unidimensional nanostructural synthesis.

  11. [Therapeutic approach in the rehabilitation of chronic lower back pain. Comparative study of 3 techniques of lumbar reeducation].

    PubMed

    Amor, B; Heuleu, J N; Mery, C; Courtillon, A

    1979-12-01

    The short-term therapeutic effect of 3 techniques of rehabilitation of the lumbar spine (cyphosis gymnastics, kinebalneotherapy and differenciated rehabilitation) was studied out of 87 chronic lumbalgias selected at random and using one of the three techniques administered by 3 physical therapists. A comparison of these 9 couples (technique, technician) was based on criteria evaluated on a blind basis using the traditional unidimensional analysis and also multidimensional analysis. The cyphosis gymnastic reeducation gives less satisfactory results using 26 criteria out of 27. There is an underlying physical therapy factor. A certain number of prognostic factors with implications for any rehabilitation method and for all of the techniques, were disclosed. The comparative testing methods used in the study of drugs are applicable to rehabilitation techniques. However, it was not possible to carry out a comparative study of a reeducation method with a reeducation placebo.

  12. Re-examining the role of attitude in information system acceptance: a model from the satisfaction-dissatisfaction perspective

    NASA Astrophysics Data System (ADS)

    Guo, Bin; Zhou, Shasha

    2016-05-01

    This study attempts to re-examine the role of attitude in voluntary information system (IS) acceptance and usage, which has often been discounted in the previous technology acceptance research. We extend the unidimensional view of attitude into a bidimensional one, because of the simultaneous existence of both positive and negative evaluation towards IS in technology acceptance behaviour. In doing so, attitude construct is divided into two components: satisfaction as the positive attitudinal component and dissatisfaction as the negative attitudinal component. We argue that satisfaction and dissatisfaction will interactively affect technology usage intention. Besides, we explore the predictors of satisfaction and dissatisfaction based on the disconfirmation theory. Empirical results from a longitudinal study on bulletin board system (BBS) usage confirm the interaction effect of satisfaction and dissatisfaction on usage intention. Moreover, perceived task-related value has a significant effect on satisfaction, while perceived personal value has a significant effect on dissatisfaction. We also discuss the theoretical and managerial implications of our findings.

  13. Toward a Theory-Driven Model of Acculturation in Public Health Research

    PubMed Central

    Abraído-Lanza, Ana F.; Armbrister, Adria N.; Flórez, Karen R.; Aguirre, Alejandra N.

    2006-01-01

    Interest in studying the impact of acculturation on immigrant health has increased in tandem with the growth of the Latino population in the United States. Linear assimilation models continue to dominate public health research despite the availability of more complex acculturation theories that propose multidimensional frameworks, reciprocal interactions between the individual and the environment, and other acculturative processes among various Latino groups. Because linear and unidimensional assessments (e.g., nativity, length of stay in the United States, and language use) provide constricted measures of acculturation, the rare use of multidimensional acculturation measures and models has inhibited a more comprehensive understanding of the association between specific components of acculturation and particular health outcomes. A public health perspective that incorporates the roles of structural and cultural forces in acculturation may help identify mechanisms underlying links between acculturation and health among Latinos. PMID:16809597

  14. On the Measurement of Procrastination: Comparing Two Scales in Six European Countries

    PubMed Central

    Svartdal, Frode; Pfuhl, Gerit; Nordby, Kent; Foschi, Gioel; Klingsieck, Katrin B.; Rozental, Alexander; Carlbring, Per; Lindblom-Ylänne, Sari; Rębkowska, Kaja

    2016-01-01

    Procrastination is a common problem, but defining and measuring it has been subject to some debate. This paper summarizes results from students and employees (N = 2893) in Finland, Germany, Italy, Norway, Poland, and Sweden using the Pure Procrastination Scale (PPS) and the Irrational Procrastination Scale (IPS; Steel, 2010), both assumed to measure unidimensional and closely related constructs. Confirmatory factor analyses indicated inadequate configural fit for the suggested one-factor model for PPS; however, acceptable fit was observed for a three-factor model corresponding to the three different scales the PPS is based on. Testing measurement invariance over countries and students–employees revealed configural but not strong or strict invariance, indicating that both instruments are somewhat sensitive to cultural differences. We conclude that the PPS and IPS are valid measures of procrastination, and that the PPS may be particularly useful in assessing cultural differences in unnecessary delay. PMID:27630595

  15. Too many swipes for today: The development of the Problematic Tinder Use Scale (PTUS).

    PubMed

    Orosz, Gábor; Tóth-Király, István; Bőthe, Beáta; Melher, Dóra

    2016-09-01

    Background and aims Tinder is a very popular smartphone-based geolocated dating application. The goal of the present study was creating a short Problematic Tinder Use Scale (PTUS). Methods Griffiths' ( 2005 ) six-component model was implemented for covering all components of problematic Tinder use. Confirmatory factor analyses were carried out on a Tinder user sample (N = 430). Results Both the 12- and the 6-item versions were tested. The 6-item unidimensional structure has appropriate reliability and factor structure. No salient demography-related differences were found. Users irrespectively to their relationship status have similar scores on PTUS. Discussion Tinder users deserve the attention of scientific examination considering their large proportion among smartphone users. It is especially true considering the emerging trend of geolocated online dating applications. Conclusions Before PTUS, no prior scale has been created to measure problematic Tinder use. The PTUS is a suitable and reliable measure to assess problematic Tinder use.

  16. Complexity of chronic asthma and chronic obstructive pulmonary disease: implications for risk assessment, and disease progression and control

    PubMed Central

    Frey, Urs; Suki, Béla

    2009-01-01

    Although assessment of asthma control is important to guide treatment, it is difficult since the temporal pattern and risk of exacerbations are often unpredictable. In this Review, we summarise the classic methods to assess control with unidimensional and multidimensional approaches. Next, we show how ideas from the science of complexity can explain the seemingly unpredictable nature of bronchial asthma and emphysema, with implications for chronic obstructive pulmonary disease. We show that fluctuation analysis, a method used in statistical physics, can be used to gain insight into asthma as a dynamic disease of the respiratory system, viewed as a set of interacting subsystems (eg, inflammatory, immunological, and mechanical). The basis of the fluctuation analysis methods is the quantification of the long-term temporal history of lung function parameters. We summarise how this analysis can be used to assess the risk of future asthma episodes, with implications for asthma severity and control both in children and adults. PMID:18805337

  17. Acculturation and Cigarette Smoking in Hispanic Women: A Meta-Analysis

    PubMed Central

    Kondo, Karli K.; Rossi, Joseph S.; Schwartz, Seth J.; Zamboanga, Byron L.; Scalf, Carissa D.

    2015-01-01

    The present study was a random-effects model meta-analysis of 26 studies published between 1990 and 2010 (k = 32; n = 39,777) that (a) examined the association between acculturation and cigarette smoking in Hispanic women and (b) evaluated age, national origin, and measure and dimensionality (unidimensional vs. bidimensional) of acculturation as moderating variables. Results indicate a strong positive relationship and suggest larger effects of acculturation on cigarette smoking in women of Mexican descent as compared with women originating from other Latin American countries for current and lifetime smoking, as well as smoking overall. The effect of acculturation on cigarette smoking was larger in adults as compared with adolescents for current smoking and smoking overall. Few differences in effect size by measure or dimensionality of acculturation emerged. Results are discussed with regard to implications for future research and the measurement of acculturation. PMID:26114872

  18. AdjScales: Visualizing Differences between Adjectives for Language Learners

    NASA Astrophysics Data System (ADS)

    Sheinman, Vera; Tokunaga, Takenobu

    In this study we introduce AdjScales, a method for scaling similar adjectives by their strength. It combines existing Web-based computational linguistic techniques in order to automatically differentiate between similar adjectives that describe the same property by strength. Though this kind of information is rarely present in most of the lexical resources and dictionaries, it may be useful for language learners that try to distinguish between similar words. Additionally, learners might gain from a simple visualization of these differences using unidimensional scales. The method is evaluated by comparison with annotation on a subset of adjectives from WordNet by four native English speakers. It is also compared against two non-native speakers of English. The collected annotation is an interesting resource in its own right. This work is a first step toward automatic differentiation of meaning between similar words for language learners. AdjScales can be useful for lexical resource enhancement.

  19. On the reflection point where light reflects to a known destination on quadratic surfaces.

    PubMed

    Gonçalves, Nuno

    2010-01-15

    We address the problem of determining the reflection point on a specular surface where a light ray that travels from a source to a target is reflected. The specular surfaces considered are those expressed by a quadratic equation. So far, there is no closed form explicit equation for the general solution of this determination of the reflection point, and the usual approach is to use the Snell law or the Fermat principle whose equations are derived in multidimensional nonlinear minimizations. We prove in this Letter that one can impose a set of three restrictions to the reflection point that can impose a set of three restrictions that culminates in a very elegant formalism of searching the reflection point in a unidimensional curve in space. This curve is the intersection of two quadratic equations. Some applications of this framework are also discussed.

  20. The Role of Defensive Confidence in Preference for Proattitudinal Information: How Believing That One Is Strong Can Sometimes Be a Defensive Weakness

    PubMed Central

    Albarracín, Dolores; Mitchell, Amy L.

    2016-01-01

    This series of studies identified individuals who chronically believe that they can successfully defend their attitudes from external attack and investigated the consequences of this individual difference for selective exposure to attitude-incongruent information and, ultimately, attitude change. Studies 1 and 2 validated a measure of defensive confidence as an individual difference that is unidimensional, distinct from other personality measures, reliable over a 2-week interval, and organized as a trait that generalizes across various personal and social issues. Studies 3 and 4 provided evidence that defensive confidence decreases preference for proattitudinal information, therefore inducing greater reception of counterattitudinal materials. Study 5 demonstrated that people who are high in defensive confidence are more likely to change their attitudes as a result of exposure to counterattitudinal information and examined the perceptions that mediate this important phenomenon. PMID:15536240

  1. Analysis of letter name knowledge using Rasch measurement.

    PubMed

    Bowles, Ryan P; Skibbe, Lori E; Justice, Laura M

    2011-01-01

    Letter name knowledge (LNK) is a key predictor of later reading ability and has been emphasized strongly in recent educational policy. Studies of LNK have implicitly treated it as a unidimensional construct with all letters equally relevant to its measurement. However, some empirical research suggests that contextual factors can affect the measurement of LNK. In this study, we analyze responses from 909 children on measures of LNK using the Rasch model and its extensions, and consider two contextual factors: the format of assessment and the own-name advantage, which states that children are more likely to know letters in their own first names. Results indicate that both contextual factors have important impacts on measurement and that LNK does not meet the requirements of Rasch measurement even when accounting for the contextual factors. These findings introduce philosophical concerns for measurement of constrained skills which have limited content for assessment.

  2. Too many swipes for today: The development of the Problematic Tinder Use Scale (PTUS)

    PubMed Central

    Orosz, Gábor; Tóth-Király, István; Bőthe, Beáta; Melher, Dóra

    2016-01-01

    Background and aims Tinder is a very popular smartphone-based geolocated dating application. The goal of the present study was creating a short Problematic Tinder Use Scale (PTUS). Methods Griffiths’ (2005) six-component model was implemented for covering all components of problematic Tinder use. Confirmatory factor analyses were carried out on a Tinder user sample (N = 430). Results Both the 12- and the 6-item versions were tested. The 6-item unidimensional structure has appropriate reliability and factor structure. No salient demography-related differences were found. Users irrespectively to their relationship status have similar scores on PTUS. Discussion Tinder users deserve the attention of scientific examination considering their large proportion among smartphone users. It is especially true considering the emerging trend of geolocated online dating applications. Conclusions Before PTUS, no prior scale has been created to measure problematic Tinder use. The PTUS is a suitable and reliable measure to assess problematic Tinder use. PMID:27415602

  3. [Cross validity of the UCLA Loneliness Scale factorization].

    PubMed

    Borges, Africa; Prieto, Pedro; Ricchetti, Giacinto; Hernández-Jorge, Carmen; Rodríguez-Naveiras, Elena

    2008-11-01

    Loneliness is an unpleasant experience that takes place when a person's network of social relationships is significantly deficient in quality and quantity, and it is associated with negative feelings. Loneliness is a fundamental construct that provides information about several psychological processes, especially in the clinical setting. It is well known that this construct is related to isolation and emotional loneliness. One of the most well-known psychometric instruments to measure loneliness is the revised UCLA Loneliness Scale, which has been factorized in several populations. A controversial issue related to the UCLA Loneliness Scale is its factor structure, because the test was first created based on a unidimensional structure; however, subsequent research has proved that its structure may be bipolar or even multidimensional. In the present work, the UCLA Loneliness Scale was completed by two populations: Spanish and Italian undergraduate university students. Results show a multifactorial structure in both samples. This research presents a theoretically and analytically coherent bifactorial structure.

  4. Is Valuing Happiness Associated With Lower Well-Being? A Factor-Level Analysis using the Valuing Happiness Scale

    PubMed Central

    Luhmann, Maike; Necka, Elizabeth A.; Schönbrodt, Felix D.; Hawkley, Louise C.

    2015-01-01

    Recent studies suggest that valuing happiness is negatively associated with well-being. Most of these studies used the Valuing Happiness Scale (Mauss, Tamir, et al., 2011). In the present paper, we examined the factor structure of this scale using data pooled from six independent samples (Ntotal = 938). Exploratory and confirmatory factor analysis showed that the Valuing Happiness Scale is not unidimensional and that only one of its three factors correlates negatively with various indicators of well-being, whereas non-significant or positive correlations were found for the other factors. These findings indicate that valuing happiness may not necessarily be bad for one’s well-being, and call for a better definition, theoretical foundation, and operationalization of this construct. PMID:26778865

  5. Multidimensional student skills with collaborative filtering

    NASA Astrophysics Data System (ADS)

    Bergner, Yoav; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.

    2013-01-01

    Despite the fact that a physics course typically culminates in one final grade for the student, many instructors and researchers believe that there are multiple skills that students acquire to achieve mastery. Assessment validation and data analysis in general may thus benefit from extension to multidimensional ability. This paper introduces an approach for model determination and dimensionality analysis using collaborative filtering (CF), which is related to factor analysis and item response theory (IRT). Model selection is guided by machine learning perspectives, seeking to maximize the accuracy in predicting which students will answer which items correctly. We apply the CF to response data for the Mechanics Baseline Test and combine the results with prior analysis using unidimensional IRT.

  6. Measurement of academic entitlement.

    PubMed

    Miller, Brian K

    2013-10-01

    Members of Generation Y, or Millennials, have been accused of being lazy, whiny, pampered, and entitled, particularly in the college classroom. Using an equity theory framework, eight items from a measure of work entitlement were adapted to measure academic entitlement in a university setting in three independent samples. In Study 1 (n = 229), confirmatory factor analyses indicated good model fit to a unidimensional structure for the data. In Study 2 (n = 200), the questionnaire predicted unique variance in university satisfaction beyond two more general measures of dispositional entitlement. In Study 3 (n = 161), the measure predicted unique variance in perceptions of grade fairness beyond that which was predicted by another measure of academic entitlement. This analysis provides evidence of discriminant, convergent, incremental, concurrent criterion-related, and construct validity for the Academic Equity Preference Questionnaire.

  7. Determining the Internal Validity of the Inventory of Reading Occupations: An Assessment Tool of Children's Reading Participation.

    PubMed

    Grajo, Lenin C; Candler, Catherine; Bowyer, Patricia; Schultz, Sally; Thomson, Jennifer; Fong, Karen

    2016-01-01

    The Inventory of Reading Occupations (IRO) is an assessment tool of children's reading participation. In this study, we used Rasch methods to determine the internal validity of the IRO. Participants included 192 typical and struggling readers from kindergarten to third grade from five different states in the United States. We analyzed the fit of each of the items in the 17 reading categories, the test items in the three dimensions of reading participation, and the contexts of reading in the IRO. Analysis indicated that the IRO items support the Rasch model of unidimensionality. Analysis also indicated that 1 of the 30 test items can be revised to strengthen test validity. Moreover, the analysis also suggested that the IRO is more useful for first- to third-grade students. This study provides evidence of internal validity of a useful tool to assess children's reading participation.

  8. Spectral: Solving Schroedinger and Wheeler-DeWitt equations in the positive semi-axis by the spectral method

    NASA Astrophysics Data System (ADS)

    Corrêa Silva, E. V.; Monerat, G. A.; de Oliveira Neto, G.; Ferreira Filho, L. G.

    2014-01-01

    The Galerkin spectral method can be used for approximate calculation of eigenvalues and eigenfunctions of unidimensional Schroedinger-like equations such as the Wheeler-DeWitt equation. The criteria most commonly employed for checking the accuracy of results is the conservation of norm of the wave function, but some other criteria might be used, such as the orthogonality of eigenfunctions and the variation of the spectrum with varying computational parameters, e.g. the number of basis functions used in the approximation. The package Spectra, which implements the spectral method in Maple language together with a number of testing tools, is presented. Alternatively, Maple may interact with the Octave numerical system without the need of Octave programming by the user.

  9. Measuring ambivalence to science

    NASA Astrophysics Data System (ADS)

    Gardner, P. L.

    Ambivalence is a psychological state in which a person holds mixed feelings (positive and negative) towards some psychological object. Standard methods of attitude measurement, such as Likert and semantic differential scales, ignore the possibility of ambivalence; ambivalent responses cannot be distinguished from neutral ones. This neglect arises out of an assumption that positive and negative affects towards a particular psychological object are bipolar, i.e., unidimensional in opposite directions. This assumption is frequently untenable. Conventional item statistics and measures of test internal consistency are ineffective as checks on this assumption; it is possible for a scale to be multidimensional and still display apparent internal consistency. Factor analysis is a more effective procedure. Methods of measuring ambivalence are suggested, and implications for research are discussed.

  10. The multidimensional nature and multicultural validity of a new measure of social anxiety: the Social Anxiety Questionnaire for Adults.

    PubMed

    Caballo, Vicente E; Salazar, Isabel C; Irurtia, María Jesús; Arias, Benito; Hofmann, Stefan G

    2012-06-01

    Much has been written about the situations most often feared by persons with social phobia, and several self-report measures are frequently used to assess such feared situations. However, it is not clear whether the situations feared by persons with social phobia form unidimensional or multidimensional factors. If these situations are multidimensional, reliance on a total score of feared situations would not reflect important differences between those dimensions. This research examined the multidimensional nature and multicultural validity of a newly developed instrument (the Social Anxiety Questionnaire for Adults [SAQ-A]) in two studies with a total of 539 patients diagnosed with social phobia and 15,753 nonpatients from 20 different countries. The structure (five clear and solid factors) and psychometric properties of the final instrument (the SAQ-A30) support the multidimensional nature of social anxiety and provide a new perspective in the assessment of social phobia.

  11. On the Measurement of Procrastination: Comparing Two Scales in Six European Countries.

    PubMed

    Svartdal, Frode; Pfuhl, Gerit; Nordby, Kent; Foschi, Gioel; Klingsieck, Katrin B; Rozental, Alexander; Carlbring, Per; Lindblom-Ylänne, Sari; Rębkowska, Kaja

    2016-01-01

    Procrastination is a common problem, but defining and measuring it has been subject to some debate. This paper summarizes results from students and employees (N = 2893) in Finland, Germany, Italy, Norway, Poland, and Sweden using the Pure Procrastination Scale (PPS) and the Irrational Procrastination Scale (IPS; Steel, 2010), both assumed to measure unidimensional and closely related constructs. Confirmatory factor analyses indicated inadequate configural fit for the suggested one-factor model for PPS; however, acceptable fit was observed for a three-factor model corresponding to the three different scales the PPS is based on. Testing measurement invariance over countries and students-employees revealed configural but not strong or strict invariance, indicating that both instruments are somewhat sensitive to cultural differences. We conclude that the PPS and IPS are valid measures of procrastination, and that the PPS may be particularly useful in assessing cultural differences in unnecessary delay.

  12. On the meaning and measure of narcissism.

    PubMed

    Brown, Ryan P; Budzek, Karolyn; Tamborski, Michael

    2009-07-01

    For three decades, social-personality research on overt narcissism has relied almost exclusively on the Narcissistic Personality Inventory (NPI). However, the NPI suffers from a host of psychometric and validity concerns that make composite NPI scores (summed across its subscales) difficult to interpret. The present studies propose that narcissistic characteristics tend to fall under two general clusters: grandiosity and entitlement. The studies show that measures of grandiosity and entitlement interact to predict scores on the NPI, controlling for gender, self-esteem, and basic personality (Study 1), but also that grandiosity and entitlement function independently with respect to mental health (Study 2) and ethical misconduct (Study 3). Together, these results challenge the view of overt narcissism as a unidimensional construct and underscore the importance of distinguishing between grandiose and entitled aspects of the narcissistic self-concept.

  13. The development of scientific thinking in elementary school: a comprehensive inventory.

    PubMed

    Koerber, Susanne; Mayer, Daniela; Osterhaus, Christopher; Schwippert, Knut; Sodian, Beate

    2015-01-01

    The development of scientific thinking was assessed in 1,581 second, third, and fourth graders (8-, 9-, 10-year-olds) based on a conceptual model that posits developmental progression from naïve to more advanced conceptions. Using a 66-item scale, five components of scientific thinking were addressed, including experimental design, data interpretation, and understanding the nature of science. Unidimensional and multidimensional item response theory analyses supported the instrument's reliability and validity and suggested that the multiple components of scientific thinking form a unitary construct, independent of verbal or reasoning skills. A partial credit model gave evidence for a hierarchical developmental progression. Across each grade transition, advanced conceptions increased while naïve conceptions decreased. Independent effects of intelligence, schooling, and parental education on scientific thinking are discussed.

  14. Material Models and Properties in the Finite Element Analysis of Knee Ligaments: A Literature Review

    PubMed Central

    Galbusera, Fabio; Freutel, Maren; Dürselen, Lutz; D’Aiuto, Marta; Croce, Davide; Villa, Tomaso; Sansone, Valerio; Innocenti, Bernardo

    2014-01-01

    Knee ligaments are elastic bands of soft tissue with a complex microstructure and biomechanics, which are critical to determine the kinematics as well as the stress bearing behavior of the knee joint. Their correct implementation in terms of material models and properties is therefore necessary in the development of finite element models of the knee, which has been performed for decades for the investigation of both its basic biomechanics and the development of replacement implants and repair strategies for degenerative and traumatic pathologies. Indeed, a wide range of element types and material models has been used to represent knee ligaments, ranging from elastic unidimensional elements to complex hyperelastic three-dimensional structures with anatomically realistic shapes. This paper systematically reviews literature studies, which described finite element models of the knee, and summarizes the approaches, which have been used to model the ligaments highlighting their strengths and weaknesses. PMID:25478560

  15. Verbal ability and executive functioning development in preschoolers at head start.

    PubMed

    Fuhs, Mary Wagner; Day, Jeanne D

    2011-03-01

    Research suggests that executive functioning skills may enhance the school readiness of children from disadvantaged homes. Questions remain, however, concerning both the structure and the stability of executive functioning among preschoolers. In addition, there is a lack of research addressing potential predictors of longitudinal change in executive functioning during early childhood. This study examined the structure of executive functioning from fall to spring of the preschool year using a multimethod battery of measures. Confirmatory factor analyses revealed a unidimensional model fit the data well at both time points, and tests of measurement invariance across time points indicated that children's mean latent executive functioning scores significantly improved over time. Verbal ability was a significant predictor of longitudinal change in executive functioning. Theoretical implications and directions for future research are discussed.

  16. Generalization of the ordinary state-based peridynamic model for isotropic linear viscoelasticity

    NASA Astrophysics Data System (ADS)

    Delorme, Rolland; Tabiai, Ilyass; Laberge Lebel, Louis; Lévesque, Martin

    2017-02-01

    This paper presents a generalization of the original ordinary state-based peridynamic model for isotropic linear viscoelasticity. The viscoelastic material response is represented using the thermodynamically acceptable Prony series approach. It can feature as many Prony terms as required and accounts for viscoelastic spherical and deviatoric components. The model was derived from an equivalence between peridynamic viscoelastic parameters and those appearing in classical continuum mechanics, by equating the free energy densities expressed in both frameworks. The model was simplified to a uni-dimensional expression and implemented to simulate a creep-recovery test. This implementation was finally validated by comparing peridynamic predictions to those predicted from classical continuum mechanics. An exact correspondence between peridynamics and the classical continuum approach was shown when the peridynamic horizon becomes small, meaning peridynamics tends toward classical continuum mechanics. This work provides a clear and direct means to researchers dealing with viscoelastic phenomena to tackle their problem within the peridynamic framework.

  17. What Are You Measuring? Dimensionality and Reliability Analysis of Ability and Speed in Medical School Didactic Examinations.

    PubMed

    Thompson, James J

    2016-01-01

    Summative didactic evaluation often involves multiple choice questions which are then aggregated into exam scores, course scores, and cumulative grade point averages. To be valid, each of these levels should have some relationship to the topic tested (dimensionality) and be sufficiently reproducible between persons (reliability) to justify student ranking. Evaluation of dimensionality is difficult and is complicated by the classic observation that didactic performance involves a generalized component (g) in addition to subtest specific factors. In this work, 183 students were analyzed over two academic years in 13 courses with 44 exams and 3352 questions for both accuracy and speed. Reliability at all levels was good (>0.95). Assessed by bifactor analysis, g effects dominated most levels resulting in essential unidimensionality. Effect sizes on predicted accuracy and speed due to nesting in exams and courses was small. There was little relationship between person ability and person speed. Thus, the hierarchical grading system appears warrented because of its g-dependence.

  18. The Development of the de Morton Mobility Index (DEMMI) in an independent sample of older acute medical patients: refinement and validation using the Rasch model (part 2).

    PubMed

    de Morton, Natalie A; Davidson, Megan; Keating, Jennifer L

    2013-01-01

    This study describes the refinement and validation of the 17-item DEMMI in an independent sample of older acute medical patients. Instrument refinement was based on Rasch analysis and input from clinicians and researchers. The refined DEMMI was tested on 106 older general medical patients and a total of 312 mobility assessments were conducted. Based on the results of this study a further 2 items were removed and the 15 item DEMMI was adopted. The Rasch measurement properties of the DEMMI were consistent with estimates obtained from the instrument development sample. No differential item functioning was identified and an interval level scoring system was established. The DEMMI is the first mobility instrument for older people to be developed, refined and validated using the Rasch model. This study confirms that the DEMMI provides clinicians and researchers with a unidimensional instrument for measuring and monitoring changes in mobility of hospitalised older acute medical patients.

  19. Self-similar solution of the problem of consolidation and thawing of frozen soil

    SciTech Connect

    Klement'ev, A.F.; Klement'eva, E.A.

    1988-10-01

    This article presents a new mathematical model of the process of thawing of frozen soil taking consolidation into account. Two solutions were obtained: the self-similar solution for the unidimensional biphase problem and an approximate analytical solution for the simplified single-phase problem. A comparison with the results of physical modeling showed that the method is fairly effective in the case of warm permafrost. The mean error in predicting the position of the interface between the thawed and frozen zones for different soils over a period of one to ten years amounted to 20.9%. The use of the method of the All-Union Research Institute of Pipeline Construction yielded an error of 31.6% and the method of the All-Union Research Institute of the Gas Industry an error of 39.6% by comparison.

  20. Measurement Properties of the Nordic Questionnaire for Psychological and Social Factors at Work: A Rasch Analysis.

    PubMed

    Roe, C; Myhre, K; Marchand, G H; Lau, B; Leivseth, G; Bautz-Holter, E

    2016-01-01

    The main aim of this study was to evaluate the measurement properties of the Nordic Questionnaire for Psychological and Social Factors at Work (QPS Nordic) and the domains of demand, control and support. The Rasch analysis (RUMM 2030) was based on responses from 226 subjects with back pain who completed the QPS Nordic dimensions of demand, control, and social support (30 items) at one year follow up. The Rasch analysis revealed disordered thresholds in a total of 25 of the 30 items. The domains of demand, control and support fit the Rasch model when analyzed separately. The demand domain was well targeted, whereas patients with current neck and back pain had lower control and higher support than reflected by the questions. Two items revealed DIF by gender, otherwise invariance to age, gender, occupation and sick-leave was documented. The demand, control support domains of QPS Nordic comprised unidimensional constructs with adequate measurement properties.

  1. Assessing the efficacy of the Measure of Understanding of Macroevolution as a valid tool for undergraduate non-science majors

    NASA Astrophysics Data System (ADS)

    Romine, William Lee; Walter, Emily Marie

    2014-11-01

    Efficacy of the Measure of Understanding of Macroevolution (MUM) as a measurement tool has been a point of contention among scholars needing a valid measure for knowledge of macroevolution. We explored the structure and construct validity of the MUM using Rasch methodologies in the context of a general education biology course designed with an emphasis on macroevolution content. The Rasch model was utilized to quantify item- and test-level characteristics, including dimensionality, reliability, and fit with the Rasch model. Contrary to previous work, we found that the MUM provides a valid, reliable, and unidimensional scale for measuring knowledge of macroevolution in introductory non-science majors, and that its psychometric behavior does not exhibit large changes across time. While we found that all items provide productive measurement information, several depart substantially from ideal behavior, warranting a collective effort to improve these items. Suggestions for improving the measurement characteristics of the MUM at the item and test levels are put forward and discussed.

  2. Application of Item Response Theory to Tests of Substance-related Associative Memory

    PubMed Central

    Shono, Yusuke; Grenard, Jerry L.; Ames, Susan L.; Stacy, Alan W.

    2015-01-01

    A substance-related word association test (WAT) is one of the commonly used indirect tests of substance-related implicit associative memory and has been shown to predict substance use. This study applied an item response theory (IRT) modeling approach to evaluate psychometric properties of the alcohol- and marijuana-related WATs and their items among 775 ethnically diverse at-risk adolescents. After examining the IRT assumptions, item fit, and differential item functioning (DIF) across gender and age groups, the original 18 WAT items were reduced to 14- and 15-items in the alcohol- and marijuana-related WAT, respectively. Thereafter, unidimensional one- and two-parameter logistic models (1PL and 2PL models) were fitted to the revised WAT items. The results demonstrated that both alcohol- and marijuana-related WATs have good psychometric properties. These results were discussed in light of the framework of a unified concept of construct validity (Messick, 1975, 1989, 1995). PMID:25134051

  3. People for sale: the need for a multidisciplinary approach towards human trafficking.

    PubMed

    Van Impe, K

    2000-01-01

    The article addresses the question of how to develop appropriate measures to tackle trafficking in women, based on the findings of a study of trafficking between the Philippines and Belgium. It argues that there is no easy or unidimensional solution to human trafficking, since it is influenced by a complex set of factors, often working in combination with one another. It concludes that control measures alone cannot stop the flow of trafficking in women and that a legal approach which relies solely on one type of legislation would be too narrow. An effective strategy must combine and balance punitive measures with protection of human rights, stricter border control and the removal of the root causes of irregular movements. Measures must be agreed and coordinated between origin, transit and receiving countries.

  4. IRTs of the ABCs: children's letter name acquisition.

    PubMed

    Phillips, Beth M; Piasta, Shayne B; Anthony, Jason L; Lonigan, Christopher J; Francis, David J

    2012-08-01

    We examined the developmental sequence of letter name knowledge acquisition by children from 2 to five years of age. Data from 2 samples representing diverse regions, ethnicity, and socioeconomic backgrounds (ns = 1074 and 500) were analyzed using item response theory (IRT) and differential item functioning techniques. Results from factor analyses indicated that letter name knowledge represented a unidimensional skill; IRT results yielded significant differences between letters in both difficulty and discrimination. Results also indicated an approximate developmental sequence in letter name learning for the simplest and most challenging to learn letters--but with no clear sequence between these extremes. Findings also suggested that children were most likely to first learn their first initial. We discuss implications for assessment and instruction.

  5. Commitment to Health Scale.

    PubMed

    Kelly, Cynthia W

    2005-01-01

    The Commitment to Health Scale (CHS) was developed to predict likelihood of clients being able to permanently adopt new health-promoting behaviors. Commitment is based on the association between starting new health behaviors and long-term performance of those behaviors. The CHS evolved from an examination of Prochaska and DiClemente's Stages of Change Algorithm, Decisional Balance Scale, and Strong and Weak Principle (Velicer, Rossi, Prochaska, & DiClemente, 1996). Scale items were assessed by classical and Rasch measurement methods. The research was performed in three separate studies at various locations in the United States and included approximately 1100 subjects. A new unidimensional variable was identified called Commitment to Health. Internal consistency reliability of the scale was .94 (Cronbach's alpha). External validity and reliability were assessed based on expected and observed ordering and between known groups. Scale scores predicted self-reported health behaviors and body mass index.

  6. Using bifactor exploratory structural equation modeling to examine global and specific factors in measures of sports coaches' interpersonal styles

    PubMed Central

    Stenling, Andreas; Ivarsson, Andreas; Hassmén, Peter; Lindwall, Magnus

    2015-01-01

    In the present work we investigated distinct sources of construct-relevant psychometric multidimensionality in two sport-specific measures of coaches' need-supportive (ISS-C) and controlling interpersonal (CCBS) styles. A recently proposed bifactor exploratory structural equation modeling (ESEM) framework was employed to achieve this aim. In Study 1, using a sample of floorball players, the results indicated that the ISS-C can be considered as a unidimensional measure, with one global factor explaining most of the variance in the items. In Study 2, using a sample of male ice hockey players, the results indicated that the items in the CCBS are represented by both a general factor and specific factors, but the subscales differ with regard to the amount of variance in the items accounted for by the general and specific factors. These results add further insight into the psychometric properties of these two measures and the dimensionality of these two constructs. PMID:26388808

  7. Wording effect leads to a controversy over the construct of the social dominance orientation scale.

    PubMed

    Xin, Ziqiang; Chi, Liping

    2010-01-01

    Most investigations of individuals' social dominance orientation (SDO) have used the 16-item SDO scale developed by F. Pratto, J. Sidanius, L. M. Stallworth, and B. F. Malle (1994). The scale's authors believed it to be a unidimensional scale, but other researchers have found the scale has 2 or more factors. The present authors proposed a new hypothesis: The controversy of the scale structure was related to the wording effect of the scale. Based on a sample of Americans, Canadians, and Chinese, the present study indicated that what the scale measured was not only 1 trait of SDO, but also a negative-wording effect factor and that the scale structure was invariant across the 3 cultural groups. The existence of a wording effect reminds us to be cautious of the construct validity of the scale and interpretations of results.

  8. Investigating latent constructs with item response models: a MATLAB IRTm toolbox.

    PubMed

    Braeken, Johan; Tuerlinckx, Francis

    2009-11-01

    Item response theory (IRT) models are the central tools in modern measurement and advanced psychometrics. We offer a MATLAB IRT modeling (IRTm) toolbox that is freely available and that follows an explicit design matrix approach, giving the end user control and flexibility in building a model that goes beyond standard models, such as the Rasch model (Rasch, 1960) and the two-parameter logistic model. As such, IRTm allows for a large variety of unidimensional IRT models for binary responses, the incorporation of additional person and item information, and deviations from common model assumptions. An exclusive key feature of the toolbox is the inclusion of copula IRT models to handle local item dependencies. Two appendixes for this report, containing example code and information on the general copula IRT in IRTm, may be downloaded from brm.psychonomic-journals.org/content/supplemental.

  9. A multidimensional perspective of relations between self-concept (Self Description Questionnaire II) and adolescent mental health (Youth Self-Report).

    PubMed

    Marsh, Herbert W; Parada, Roberto H; Ayotte, Violaine

    2004-03-01

    Relations between self-concept and mental health are best understood from a multidimensional perspective. For responses by 903 adolescents (mean age = 12.6) to a new French translation of the Self Description Questionnaire II (SDQII), confirmatory factor analysis demonstrated a well-defined multidimensional factor structure of reliable, highly differentiated self-concept factors. Correlations between 11 SDQII factors and 7 mental health problems (Youth Self-Report; YSR) varied substantially (.11 to -.83; mean r = -.35). Single higher-order factors could not explain relations among SDQII factors, among YSR factors, or between the SDQII and YSR factors. This highly differentiated multivariate pattern of relations supports a multidimensional perspective of self-concept, not the unidimensional perspective still prevalent in mental health research and assessment.

  10. How should we revise diagnostic criteria for substance use disorders in the DSM-V?

    PubMed

    Martin, Christopher S; Chung, Tammy; Langenbucher, James W

    2008-08-01

    This article reviews literature on the validity and performance characteristics of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) diagnostic criteria for substance use disorders (SUDs) and recommends changes in these criteria that should be considered for the next edition of the DSM (DSM-V). Substantial data indicate that DSM-IV substance abuse and substance dependence are not distinct categories and that SUD criteria are best modeled as reflecting a unidimensional continuum of substance-problem severity. The conceptually and empirically problematic substance abuse diagnosis should be abandoned in the DSM-V, with substance dependence defined by a single set of criteria. Data also indicate that various individual SUD criteria should be revised, dropped, or considered for inclusion in the DSM-V. The DSM-V should provide a framework that allows the integration of categorical and dimensional approaches to diagnosis. Important areas for further research are noted.

  11. Validity of the Developmental Test of Visual-Motor Integration Supplemental Developmental Test of Visual Perception.

    PubMed

    Brown, Ted; Rodger, Sylvia

    2008-06-01

    Visual perceptual skills of school-age children are often assessed using the Supplemental Developmental Test of Visual Perception of the Developmental Test of Visual-Motor Integration. The study purpose was to consider the construct validity of this test by evaluating its scalability (interval level measurement), unidimensionality, differential item functioning, and hierarchical ordering of its items. Visual perceptual performance scores from a sample of 356 typically developing children (171 boys and 185 girls ages 5 to 11 years) were used to complete a Rasch analysis of the test. Seven items were discarded for poor fit, while none of the items exhibited differential item functioning by sex. The construct validity, scalability, hierarchical ordering, and lack of differential item functioning requirements were met by the final test version. Since 7 test items did not fit the Rasch analysis specifications, the clinical value of the test is questionable and limited.

  12. The latent structure of the Peritraumatic Dissociative Experiences Questionnaire.

    PubMed

    Brooks, Robert; Bryant, Richard A; Silove, Derrick; Creamer, Mark; O'Donnell, Meaghan; McFarlane, Alexander C; Marmar, Charles R

    2009-04-01

    This paper has been retracted due to a publisher's error: the order of the authors was incorrect. The Editor and Publisher of the Journal of Traumatic Stress apologize to the authors and our readership. The Peritraumatic Dissociative Experiences Questionnaire (PDEQ) is a widely used measure of peritraumatic dissociation, and is presumably a unidimensional construct. Two hundred forty-seven individuals admitted to five hospitals after traumatic injury were administered the Clinician Administered PTSD Scale, the Hospital Anxiety and Depression Scale, and the PDEQ. Factor analysis indicated that the PDEQ involved two factors containing four items each: one factor (altered awareness) indexes alterations in awareness and the other (derealization) reflects distortions in perceptions of the self and the world. Only the derealization factor was associated with acute stress, anxiety, and depression symptoms. Cross-validation with independent data provided only partial support for the 2-factor structure model. These data indicate that peritraumatic dissociation may involve two distinct constructs.

  13. Evaluation of the Factor Structure of the Rosenberg Self-Esteem Scale in Older Adults.

    PubMed

    Mullen, Sean P; Gothe, Neha P; McAuley, Edward

    2013-01-01

    The Rosenberg Self-Esteem Scale is the most utilized measure of global self-esteem. Although psychometric studies have generally supported the uni-dimensionality of this 10-item scale, more recently, a stable, response-bias has been associated with the wording of the items (Marsh, Scalas, & Nagengast, 2010). The purpose of this report was to replicate Marsh et al.'s findings in a sample of older adults and to test for invariance across time, gender and levels of education. Our results indicated that indeed a response-bias does exist in esteem responses. Researchers should investigate ways to meaningfully examine and practically overcome the methodological challenges associated with the RSE scale.

  14. Complexity of chronic asthma and chronic obstructive pulmonary disease: implications for risk assessment, and disease progression and control.

    PubMed

    Frey, Urs; Suki, Béla

    2008-09-20

    Although assessment of asthma control is important to guide treatment, it is difficult since the temporal pattern and risk of exacerbations are often unpredictable. In this Review, we summarise the classic methods to assess control with unidimensional and multidimensional approaches. Next, we show how ideas from the science of complexity can explain the seemingly unpredictable nature of bronchial asthma and emphysema, with implications for chronic obstructive pulmonary disease. We show that fluctuation analysis, a method used in statistical physics, can be used to gain insight into asthma as a dynamic disease of the respiratory system, viewed as a set of interacting subsystems (eg, inflammatory, immunological, and mechanical). The basis of the fluctuation analysis methods is the quantification of the long-term temporal history of lung function parameters. We summarise how this analysis can be used to assess the risk of future asthma episodes, with implications for asthma severity and control both in children and adults.

  15. Unnatural selection: talent identification and development in sport.

    PubMed

    Abbott, Angela; Button, Chris; Pepping, Gert-Jan; Collins, Dave

    2005-01-01

    The early identification of talented individuals has become increasingly important across many performance domains. Current talent identification (TI) schemes in sport typically select on the basis of discrete, unidimensional measures at unstable periods in the athlete's development. In this article, the concept of talent is revised as a complex, dynamical system in which future behaviors emerge from an interaction of key performance determinants such as psychological behaviors, motor abilities, and physical characteristics. Key nonlinear dynamics concepts are related to TI approaches such as sensitivity to initial conditions, transitions, and exponential behavioral distributions. It is concluded that many TI models place an overemphasis on early identification rather than the development of potentially talented performers. A generic model of talent identification and development is proposed that addresses these issues and provides direction for future research.

  16. Multifactor modeling of emotional and behavioral risk of preschool-age children.

    PubMed

    DiStefano, Christine; Greer, Fred W; Kamphaus, R W

    2013-06-01

    Screening for emotional and behavioral risk has become more prevalent with young children; however, not much is known about the latent structure for many of the brief instruments currently being used to assess children. Information concerning the latent structure of an instrument is necessary to support use of the scoring information. The underlying structure of the Behavioral and Emotional Screening System, Teacher Rating Form-Preschool (Kamphaus & Reynolds, 2007) was investigated. A sample of ratings of more than 1,400 preschoolers was used to test 4 different confirmatory factor analysis models: (a) unidimensional model, (b) correlated factor model, (c) higher order factor model, and (d) bifactor model. Results showed support for the bifactor model, suggesting that an overall score is useful for interpreting preschoolers' level of emotional and behavioral risk. Relationships between items and the maladaptive risk general factor varied according to content area.

  17. Wave-Turbulence-Sediment Dynamics on the Atchafalaya Shelf, Louisiana, USA

    NASA Astrophysics Data System (ADS)

    Safak, I.; Sheremet, A.; Allison, M.; Hsu, T. J.

    2008-12-01

    Two synchronized Sontek Hydra ADVs (Acoustic Doppler Velocimeter) were deployed for 2 weeks in early spring 2008 on the muddy Atchafalaya Shelf to observe near-bed wave, turbulence and cohesive sediment transport processes. The ADVs sampled at 10 Hz and were mounted in a vertical array to separate the effects of waves and turbulence and estimate Reynolds stresses. Near bottom velocity profile and suspended sediment concentration were also monitored using a pulse-coherent acoustic Doppler current profiler together with optical and acoustic backscatter sensors. A uni-dimensional boundary layer model for cohesive sediment transport was used to reconstruct the near bed suspended sediment concentration and simulate its interaction with the flow field.

  18. Standardization of the Hare Psychopathy Checklist-Revised in a Spanish prison sample.

    PubMed

    Moltó, J; Poy, R; Torrubia, R

    2000-01-01

    This investigation examined the reliability, validity, and factor structure of the Hare Psychopathy Checklist-Revised (PCL-R) in male adult Spanish prison populations (n = 117). The interrater reliability and internal consistency coefficients were high, and similar to those obtained in other countries. This data provides support for the homogeneity and unidimensionality of the psychopathy construct in Spanish male prison samples. The analysis of factor structure also replicated the two factor solution of previous studies. The two factors showed different patterns of intercorrelations with several self-report measures of personality, demographic, and criminal history variables, which confirmed the construct validity of PCL-R. The results confirm the psychometric properties of the PCL-R as a measure of psychopathy in Spanish male inmates, and suggest that psychopathy is a construct also observed in Southern European countries.

  19. Perceiving beauty in all women: Psychometric evaluation of the Broad Conceptualization of Beauty Scale.

    PubMed

    Tylka, Tracy L; Iannantuono, Amy C

    2016-06-01

    Women's ability to broadly conceptualize beauty (i.e., perceive many looks, appearances, body sizes/shapes, and inner characteristics as beautiful) has been identified as a facet of positive body image in qualitative research. A scale is needed to be able to assess this construct within quantitative research. Therefore, we developed the Broad Conceptualization of Beauty Scale (BCBS), which measures the extent women define female beauty widely within external and internal characteristics, and examined its psychometric properties among four community samples totaling 1086 women. Exploratory and confirmatory factor analyses revealed a unidimensional structure with nine items. The internal consistency, test-retest reliability, and construct (convergent, discriminant, and incremental) validity of its scores were upheld. Researchers and clinicians can use the BCBS alone to assess women's perceptions of female beauty, or they can use the BCBS alongside women's perceptions of self-beauty to more comprehensively explore women's ability to broadly conceptualize beauty for others and themselves.

  20. Gendered language attitudes: exploring language as a gendered construct using Rasch measurement theory.

    PubMed

    Knisely, Kris A; Wind, Stefanie A

    2015-01-01

    Gendered language attitudes (GLAs) are gender-based perceptions of language varieties based on connections between gender-related and linguistic characteristics of individuals, including the perception of language varieties as possessing degrees of masculinity and femininity. This study combines substantive theory about language learning and gender with a model based on Rasch measurement theory to explore the psychometric properties of a new measure of GLAs. Findings suggest that GLAs is a unidimensional construct and that the items used can be used to describe differences among students in terms of the strength of their GLAs. Implications for research, theory, and practice are discussed. Special emphasis is given to the teaching and learning of languages.

  1. Psychometric testing of an instrument measuring core competencies of nursing students: an application of Mokken scaling.

    PubMed

    Perng, Shoa-Jen; Watson, Roger

    2013-01-01

    Assessing the core competencies of nursing students provides information about students' learning outcomes for educational evaluation and improvement. The aim of this study was to develop the Nursing Students Core Competencies scale to measure 8 core competencies of nursing students in Taiwan. The study employed factor analysis and Mokken scaling analysis for psychometric testing of this instrument between a group of nursing graduates and their evaluators. The results indicated that the Nursing Students Core Competencies scale has demonstrated evidence of internal consistency, structural validity, unidimensionality, and a hierarchy of items for students' self-assessment and instructor's rating. The use of Mokken scaling analysis extends the knowledge of developing competence assessment tools; it can be used to reveal the domains or items of competency nursing students perceive that are easy or difficult, providing information for curricular design.

  2. From Deploying Individuals to Deploying Departments

    DTIC Science & Technology

    2010-06-01

    the help of regulators, lawyers, customs of!cials, and private sector and regional market experts to develop comprehensive and effective solutions...the management of deploying and rede - ploying personnel across the government. Continuous Education, Training, and Exercising. Classroom education...domestic agencies must con- duct periodic exercises in order to socialize new participants and to re!ne existing processes and policies in the forward and

  3. Wartime Burn Care in Iraq: 28th Combat Support Hospital, 2003

    DTIC Science & Technology

    2007-11-01

    provide medical support to both the Baghdad and Tikrit regions. In Baghdad, the CSH occupied Ibn Sina Hospital in the International Zone (Green Zone...The 28th CSH rede- ployed to the United States in February 2004, turning over operations at Ibn Sina Hospital to the 31st CSH. At the time of this...writing, Ibn Sina Hospital has been continuously operated by a U.S. Army CSH, providing care to U.S., coalition, and Iraqi military and civilian

  4. Recreation Carrying Capacity Facts and Considerations. Report 9. Shenango River Lake Project Area.

    DTIC Science & Technology

    1980-07-01

    specific problems and examines possible solutioins; and it does not include the methodologies for deter- mining and monitoring social and resource...Lake Peru enta ’ of Users Responding: Reasons NotPleasant Unpleasant Nmortnt General Reasons Characteristics and behavior of other people 73...t - - - - - Make area’s existence- less ObVious 6n3 Site Planning Tch n iques Redes -ign a-e-t a-ccommodate fewer users 1050 -- ’.1 Des igni

  5. An Approach to Naval Arms Control

    DTIC Science & Technology

    1989-07-01

    Deng San Rui, China; Mr. Minko-Mi-Endamne, Gabon; Mr. Jorge Morelli-Pando, Peru ; Mr. Jan Prawitz, Sweden; and Mr. Jan Hendrik van Rede , the Netherlands...ascription as cultural, since they comprise socially transmitted, learned, patterns of thought and behavior. 1 2 First, in keeping with the social ideology...of _.e New World, novelty has a social and political value for its freshness of form irrespective of its content. If the reports are to be believed

  6. Brazil and the US; A Bright Future?

    DTIC Science & Technology

    1987-03-23

    are the social and moral ones facing his country. At the same time Brazil seeks greater world responsibility and a high degree of cooperation with the...34Planning Minister Views IMF Before Japan Trip," Rio de Janeirno Rede Globo Television, in Portuguese, 30 October 1986 as reported in Foreign Broadcast...world market. It seeks a stable and peaceful South America and good relations with all nations. Social , health and educational problems are important in

  7. Military Review: The Professional Journal of the U.S. Army. Volume 80, Number 5, September-October 2000

    DTIC Science & Technology

    2000-10-01

    internal rivalries and governments unresponsive to or incapable of dealing with com- plex social , economic and political problems. In- creasingly...Service Support Control System (CSSCS) and FBCB2. 2. TPIO-ABCS Pamphlet, Operational Architecture, Change Catalyst to Rede - sign the Army (Fort...An Alpha Roster lists all personnel assigned to a unit, normally alphabet- ized. It contains personnel information, including name, rank, social

  8. Air Force Third Party Financing Management Guide.

    DTIC Science & Technology

    1984-05-01

    ritic: ’ lf(trical rcquiremerts and the potential value of increased electrica ! hOup capaility. All of the above suggests strong consideration of full...system. In the case of internal labor disturbances, management is usually capable of operating the essential utility services as reded . Other measures...relating to "third party" supply of thermal and/or electrica ’ energy to U.S. Air Force base installations in the United States. Incorpora- tion of

  9. [Promising networks, fruitful inquiry].

    PubMed

    Frenk, Silvestre

    2014-01-01

    This supplement of the Revista Médica del Instituto Mexicano del Seguro Social includes 10 original contributions, and also six current themes, all of them related to childhood obesity. It is the result of an institutional program that it has been identified as Redes de Investigación Institucional, and it has been promoted and developed by the Coordinación de Investigación of the Instituto Mexicano del Seguro Social.

  10. Rheological Properties of Thickened Liquids

    DTIC Science & Technology

    1942-12-07

    Seriul Ho. UU3 Copy No. y/ Dato : December 7» 19^1-2 * Copies No. 1 through 28 - Dr. Irvin Stewart Copy Ho. 29 - Chief, Chemical Wurfure...Little Is known of’the variables controlling this. It sppeers certain that the following reaulreraents must be matt 1. It must be soft enough so that...in diameter, so that movmrnt of the inner cylinder even with thr most viscous materlels is clmost negligible. The necessary rccurrcy In reding the

  11. Annotated Bibliography of the Air Force Human Resources Laboratory Technical Reports - 1979.

    DTIC Science & Technology

    1981-05-01

    individual and co1llect i ve imlipaict -. 11iii’ afford in~g in formnati concern11’ fl ig the "why as% 14(’I as the ’"what’* of t radeI4- o4ff analisi ...ii I aI Ig i I 441141 14111. I hall i41%% r reding ijitir mlh-t iili. 11)0 page.) 36 PERSONAL AUTHOR INDEX (Reference numbers identify serial numbers

  12. Development of the PROMIS® Health Expectancies of Smoking Item Banks

    PubMed Central

    Tucker, Joan S.; Shadel, William G.; Stucky, Brian D.; Cerully, Jennifer; Li, Zhen; Hansen, Mark; Cai, Li

    2014-01-01

    Introduction: Smokers’ health-related outcome expectancies are associated with a number of important constructs in smoking research, yet there are no measures currently available that focus exclusively on this domain. This paper describes the development and evaluation of item banks for assessing the health expectancies of smoking. Methods: Using data from a sample of daily (N = 4,201) and nondaily (N = 1,183) smokers, we conducted a series of item factor analyses, item response theory analyses, and differential item functioning analyses (according to gender, age, and race/ethnicity) to arrive at a unidimensional set of health expectancies items for daily and nondaily smokers. We also evaluated the performance of short forms (SFs) and computer adaptive tests (CATs) to efficiently assess health expectancies. Results: A total of 24 items were included in the Health Expectancies item banks; 13 items are common across daily and nondaily smokers, 6 are unique to daily, and 5 are unique to nondaily. For both daily and nondaily smokers, the Health Expectancies item banks are unidimensional, reliable (reliability = 0.95 and 0.96, respectively), and perform similarly across gender, age, and race/ethnicity groups. A SF common to daily and nondaily smokers consists of 6 items (reliability = 0.87). Results from simulated CATs showed that health expectancies can be assessed with good precision with an average of 5–6 items adaptively selected from the item banks. Conclusions: Health expectancies of smoking can be assessed on the basis of these item banks via SFs, CATs, or through a tailored set of items selected for a specific research purpose. PMID:25118229

  13. The dimensionality of alcohol use disorders and alcohol consumption in a cross-national perspective

    PubMed Central

    Borges, Guilherme; Ye, Yu; Bond, Jason; Cherpitel, Cheryl J.; Cremonte, Mariana; Moskalewicz, Jacek; Swiatkiewicz, Grazyna; Rubio-Stipec, Maritza

    2009-01-01

    Aims To replicate the finding that there is a single dimension trait in alcohol use disorders and to test whether usual 5+ drinks for men and/4+ drinks for women and other measures of alcohol consumption help to improve alcohol use disorder criteria in a series of diverse patients from Emergency Departments (EDs) in four countries. Design Cross-sectional surveys of patient 18 and older that reflected consecutive arrival at the ED. The Composite International Diagnostic Interview Core was used to obtain a diagnosis of DSM-IV alcohol dependence and alcohol abuse. Quantity and frequency of drinking and drunkenness as well as usual number of drinks consumed during the last year. Setting Participants were 5,195 injured and non-injured patients attending 7 EDs in 4 countries, Argentina, Mexico, Poland the U.S., (between 1995-2001). Findings Using exploratory factor analyses alcohol use disorders can be described as a single, unidimensional continuum without any clear cut distinction between the criterions for dependence and abuse in all sites. Results from item response theory analyses showed that the current DSM-IV criterions tap people in the middle-upper end of the alcohol use disorder continuum. Alcohol consumption (amount and frequency of use) can be used in all EDs with the current DSM-IV diagnostic criterions to help tap the middle-lower part of this continuum. Even though some specific diagnostic criterions and some alcohol consumption variables showed differential item function across sites, test response curves were invariant for ED sites and their inclusion would not impact the final (total) performance of the diagnostic system. Conclusions DSM-IV abuse and dependence form a unidimensional continuum in ED patients regardless of country of survey. Alcohol consumption variables, if added, would help to tap patients with more moderate severity. DSM diagnostic system for alcohol use disorders showed invariance and performed extremely well in these samples. PMID

  14. Testing the PROMIS® Depression measures for monitoring depression in a clinical sample outside the US.

    PubMed

    Vilagut, G; Forero, C G; Adroher, N D; Olariu, E; Cella, D; Alonso, J

    2015-09-01

    The Patient Reported Outcomes Measurement Information System (PROMIS) was devised to facilitate assessment of patient self-reported health status, taking advantage of Item Response Theory. We aimed to assess measurement properties of the PROMIS Depression item bank and an 8-item static short form in a Spanish clinical sample. A three-month follow-up study of patients with active mood/anxiety symptoms (n = 218) was carried out. We assessed model unidimensionality (Confirmatory Item Factor Analysis), reliability (internal consistency and Item Information Curves), and validity (convergent-discriminant with correlations; known-groups with comparison of means and effect sizes; and criterion validity with Receiver operating Characteristics (ROC) analysis). We also assessed 3-month responsiveness to change (Cohen's effect sizes (d) in stable and recovered patients). The unidimensional model showed adequate fit (CFI = 0.97, RMSEA = 0.08). Information Curves had reliabilities over 0.90 throughout most of the score continuum. As expected, we observed high correlations with external self-reported depression, and moderate with self-reported anxiety and clinical measures. The item bank showed an increasing severity gradient from no disorder (mean = 48, SE = 0.6) to depression with comorbid anxiety (mean = 55.8, SE = 0.4). PROMIS detected depression disorder with great accuracy according to the area under the curve (AUC = 0.89). Both formats, item bank and short form, were highly responsive to change in recovered patients (d > 0.7) and had small changes in stable patients (d < 0.2). The good metric properties of the Spanish PROMIS Depression measures provide further evidence of their adequacy for monitoring depression levels of patients in clinical settings. This double check of quality (within countries and populations) supports the ability of PROMIS measures for guaranteeing fair comparisons across languages and countries in specific clinical populations.

  15. Assessing social isolation in motor neurone disease: A Rasch analysis of the MND Social Withdrawal Scale☆

    PubMed Central

    Gibbons, Chris J.; Thornton, Everard W.; Ealing, John; Shaw, Pamela J.; Talbot, Kevin; Tennant, Alan; Young, Carolyn A.

    2013-01-01

    Objective Social withdrawal is described as the condition in which an individual experiences a desire to make social contact, but is unable to satisfy that desire. It is an important issue for patients with motor neurone disease who are likely to experience severe physical impairment. This study aims to reassess the psychometric and scaling properties of the MND Social Withdrawal Scale (MND-SWS) domains and examine the feasibility of a summary scale, by applying scale data to the Rasch model. Methods The MND Social Withdrawal Scale was administered to 298 patients with a diagnosis of MND, alongside the Hospital Anxiety and Depression Scale. The factor structure of the MND Social Withdrawal Scale was assessed using confirmatory factor analysis. Model fit, category threshold analysis, differential item functioning (DIF), dimensionality and local dependency were evaluated. Results Factor analysis confirmed the suitability of the four-factor solution suggested by the original authors. Mokken scale analysis suggested the removal of item five. Rasch analysis removed a further three items; from the Community (one item) and Emotional (two items) withdrawal subscales. Following item reduction, each scale exhibited excellent fit to the Rasch model. A 14-item Summary scale was shown to fit the Rasch model after subtesting the items into three subtests corresponding to the Community, Family and Emotional subscales, indicating that items from these three subscales could be summed together to create a total measure for social withdrawal. Conclusion Removal of four items from the Social Withdrawal Scale led to a four factor solution with a 14-item hierarchical Summary scale that were all unidimensional, free for DIF and well fitted to the Rasch model. The scale is reliable and allows clinicians and researchers to measure social withdrawal in MND along a unidimensional construct. PMID:24011605

  16. Assessing Sexual Orientation-Related Obsessions and Compulsions in Italian Heterosexual Individuals: Development and Validation of the Sexual Orientation Obsessive-Compulsive Scale (SO-OCS).

    PubMed

    Melli, Gabriele; Moulding, Richard; Gelli, Simona; Chiorri, Carlo; Pinto, Antonio

    2016-07-01

    Sexual Orientation-Obsessive-Compulsive Disorder (SO-OCD) is characterized by intrusive thoughts, images, and urges related to one's sexual orientation, and by consequent avoidance, reassurance seeking, and overt and covert compulsions. Currently there is no short self-report measure that assesses SO-OCD symptoms. The current article describes two studies that develop and evaluate the first version of the Sexual Orientation Obsessive-Compulsive Scale (SO-OCS), a 14-item Italian self-report measure targeted towards heterosexual individuals. In Study 1, the SO-OCS was developed and refined through item analysis and exploratory factor analysis from an initial pool of 33 items administered to 732 Italian nonclinical participants. The SO-OCS showed a unidimensional structure and an acceptable internal consistency. In Study 2, the factor structure, internal consistency, temporal stability, construct and criterion validity, and diagnostic sensitivity of the SO-OCS were investigated in three samples of Italian participants (294 from the general population, 52 OCD patients who reported sexual orientation-related symptoms or concerns as a primary complaint, and 51 OCD patients who did not report these symptoms as primary complaint). The SO-OCS was again found to have a unidimensional structure and good internal consistency, as well as to exhibit strong construct validity. Specifically, the SO-OCS showed an excellent criterion validity and diagnostic sensitivity, as it successfully discriminated between those with SO-OCD and all other groups of participants. Finally, evidence of temporal stability of the SO-OCS in a nonclinical subsample was found. The SO-OCS holds promise as a measure of SO-OCD symptoms in heterosexual individuals.

  17. Development of a Multimorbidity Illness Perceptions Scale (MULTIPleS)

    PubMed Central

    Gibbons, Chris J.; Kenning, Cassandra; Coventry, Peter A.; Bee, Penny; Bundy, Christine; Fisher, Louise; Bower, Peter

    2013-01-01

    Background Illness perceptions are beliefs about the cause, nature and management of illness, which enable patients to make sense of their conditions. These perceptions can predict adjustment and quality of life in patients with single conditions. However, multimorbidity (i.e. patients with multiple long-term conditions) is increasingly prevalent and a key challenge for future health care delivery. The objective of this research was to develop a valid and reliable measure of illness perceptions for multimorbid patients. Methods Candidate items were derived from previous qualitative research with multimorbid patients. Questionnaires were posted to 1500 patients with two or more exemplar long-term conditions (depression, diabetes, osteoarthritis, coronary heart disease and chronic obstructive pulmonary disease). Data were analysed using factor analysis and Rasch analysis. Rasch analysis is a modern psychometric technique for deriving unidimensional and intervally-scaled questionnaires. Results Questionnaires from 490 eligible patients (32.6% response) were returned. Exploratory factor analysis revealed five potential subscales ‘Emotional representations’, ‘Treatment burden’, ‘Prioritising conditions’, ‘Causal links’ and ‘Activity limitations’. Rasch analysis led to further item reduction and the generation of a summary scale comprising of items from all scales. All scales were unidimensional and free from differential item functioning or local independence of items. All scales were reliable, but for each subscale there were a number of patients who scored at the floor of the scale. Conclusions The MULTIPleS measure consists of five individual subscales and a 22-item summary scale that measures the perceived impact of multimorbidity. All scales showed good fit to the Rasch model and preliminary evidence of reliability and validity. A number of patients scored at floor of each subscale, which may reflect variation in the perception of multimorbidity

  18. The Stigma Scale for Chronic Illnesses 8-item version (SSCI-8): Development, validation, and use across neurological conditions

    PubMed Central

    Molina, Yamile; Choi, Seung W.; Cella, David; Rao, Deepa

    2013-01-01

    Purpose Although the impact of stigma has been highlighted for epileptic populations, the experiences of people living with other neurological conditions have been less studied. In order to promote research on stigma among people with neurological conditions, we sought to develop and psychometrically validate an 8-item questionnaire measuring internalised and enacted stigma experienced by people with epilepsy, multiple sclerosis (MS), Parkinson’s disease (PD), stroke, and amyotrophic lateral sclerosis (ALS). Methods We used Item Response Theory (IRT) methodologies to select items and field-tested our items with 587 participants from 8 academic medical centres across the United States. Results We conducted Exploratory and Confirmatory Factor Analysis as well as examined scale the reliability and validity. In addition, we conducted an analysis of variance (ANOVA) test to examine mean total score differences across the 5 neurological conditions. Data from people across conditions revealed that the shortened instrument conformed to an essentially unidimensional model of multi-faceted stigma as a 1-factor questionnaire with correlated residuals on a pair of items that distinctly measured internalised stigma. Conclusions Preliminary evidence suggests that the Stigma Scale for Chronic Illness 8-item version (SSCI-8) fits a unidimensional model, which assesses enacted and internalised stigma, and has adequate internal consistency/reliability and validity in relation to psychological distress and patient performance. Our results suggest fairly low stigma for neurological populations. In addition, our results suggest that stigma may be more severe for patients with ALS relative to those with MS and PD. Our results suggest that the scale could be used practically in the clinic setting to examine stigma without the patient burden associated with lengthier scales. PMID:22639392

  19. Factor structure of the functional movement screen in marine officer candidates.

    PubMed

    Kazman, Josh B; Galecki, Jeffrey M; Lisman, Peter; Deuster, Patricia A; OʼConnor, Francis G

    2014-03-01

    Functional movement screening (FMS) is a musculoskeletal assessment that is intended to fill a gap between preparticipation examinations and performance tests. Functional movement screening consists of 7 standardized movements involving multiple muscle groups that are rated 0-3 during performance; scores are combined into a final score, which is intended to predict injury risk. This use of a sum-score in this manner assumes that the items are unidimensional and scores are internally consistent, which are measures of internal reliability. Despite research into the FMS' predictive value and interrater reliability, research has not assessed its psychometric properties. The present study is a standard psychometric analysis of the FMS and is the first to assess the internal consistency and factor structure of the FMS, using Cronbach's alpha and exploratory factor analysis (EFA). Using a cohort of 877 male and 57 female Marine officer candidates who performed the FMS, EFA of polychoric correlations with varimax rotation was conducted to explore the structure of the FMS. Tests were repeated on the original scores, which integrated feelings of pain during movement (0-3), and then on scores discounting the pain instruction and based only on the performance (1-3), to determine whether pain ratings affected the factor structure. The average FMS score was 16.7 ± 1.8. Cronbach's alpha was 0.39. Exploratory factor analysis availed 2 components accounting for 21 and 17% and consisting of separate individual movements (shoulder mobility and deep squat, respectively). Analysis on scores discounting pain showed similar results. The factor structures were not interpretable, and the low Cronbach's alpha suggests a lack of internal consistency in FMS sum scores. Results do not offer support for validity of the FMS sum score as a unidimensional construct. In the absence of additional psychometric research, caution is warranted when using the FMS sum score.

  20. Hazard evaluation of ten organophosphorous insecticides against the midge, Chironomus riparius via QSAR

    USGS Publications Warehouse

    Landrum, Peter F.; Fisher, Susan W.; Hwang, Haejo; Hickey, James P.

    1999-01-01

    Toxicities of ten organophosphorus (OP) insecticides were measured against midge larvae (Chironomus riparius) under varying temperature (11, 18, and 25°C) and pH (6, 7, and 8) conditions and with and without sediment. Toxicity usually increased with increasing temperature and was greater in the absence of sediment. No trend was found with varying pH. A series of unidimensional parameters and multidimensional models were used to describe the changes in toxicity. Log Kow was able to explain about 40–60% of the variability in response data for aqueous exposures while molecular volume and aqueous solubility were less predictive. Likewise, the linear solvation energy relationship (LSER) model only explained 40–70% of the response variability, suggesting that factors other than solubility were most important for producing the observed response. Molecular connectivity was the most useful for describing the variability in the response. In the absence of sediment, 1χv and 3κ were best able to describe the variation in response among all compounds at each pH (70–90%). In the presence of sediment, even molecular connectivity could not describe the variability until the partitioning potential to sediment was accounted for by assuming equilibrium partitioning. After correcting for partitioning, the same molecular connectivity terms as in the aqueous exposures described most of the variability, 61–87%, except for the 11°C data where correlations were not significant. Molecular connectivity was a better tool than LSER or the unidimensional variables to explain the steric fitness of OP insecticides which was crucial to the toxicity.