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Sample records for numa rede unidimensional

  1. Unidimensional Interpretations for Multidimensional Test Items

    ERIC Educational Resources Information Center

    Kahraman, Nilufer

    2013-01-01

    This article considers potential problems that can arise in estimating a unidimensional item response theory (IRT) model when some test items are multidimensional (i.e., show a complex factorial structure). More specifically, this study examines (1) the consequences of model misfit on IRT item parameter estimates due to unintended minor item-level…

  2. NUMA: A Northern Paiute History.

    ERIC Educational Resources Information Center

    Inter-Tribal Council of Nevada, Reno.

    One in a series of four histories of native Nevadans, this volume presents the story of the Northern Paiute people, or Numa, who lived, hunted, and travelled in the Great Basin area which occupies one-third of present day Nevada and parts of Oregon, Idaho, and California. Based on interviews with tribal elders and research conducted at numerous…

  3. 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

  4. 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…

  5. Guessing and Dimensionality: The Search for a Unidimensional Latent Space.

    ERIC Educational Resources Information Center

    Reckase, Mark D.

    The purpose of this paper is to examine the capabilities of various procedures for sorting dichotomously-scored items into unidimensional subjects. The procedures include: factor analysis, nonmetric multidimensional scaling, cluster analysis, and latent trait analysis. Both simulated and real data sets of known structure were used to evaluate the…

  6. 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…

  7. 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.

  8. 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.

  9. Exploring Unidimensional Proficiency Classification Accuracy from Multidimensional Data in a Vertical Scaling Context

    ERIC Educational Resources Information Center

    Kroopnick, Marc Howard

    2010-01-01

    When Item Response Theory (IRT) is operationally applied for large scale assessments, unidimensionality is typically assumed. This assumption requires that the test measures a single latent trait. Furthermore, when tests are vertically scaled using IRT, the assumption of unidimensionality would require that the battery of tests across grades…

  10. Assessing the Unidimensionality of Psychological Scales: Using Multiple Criteria from Factor Analysis

    ERIC Educational Resources Information Center

    Slocum-Gori, Suzanne L.; Zumbo, Bruno D.

    2011-01-01

    Whenever one uses a composite scale score from item responses, one is tacitly assuming that the scale is dominantly unidimensional. Investigating the unidimensionality of item response data is an essential component of construct validity. Yet, there is no universally accepted technique or set of rules to determine the number of factors to retain…

  11. Can a Multidimensional Test Be Evaluated with Unidimensional Item Response Theory?

    ERIC Educational Resources Information Center

    Wiberg, Marie

    2012-01-01

    The aim of this study was to evaluate possible consequences of using unidimensional item response theory (UIRT) on a multidimensional college admission test. The test consists of 5 subscales and can be divided into two sections, that is, it can be considered both as a unidimensional and a multidimensional test. The test was examined with both UIRT…

  12. A Comparison Study of the Unidimensional IRT Estimation of Compensatory and Noncompensatory Multidimensional Item Response Data.

    ERIC Educational Resources Information Center

    Ackerman, Terry A.

    Concern has been expressed over the item response theory (IRT) assumption that a person's ability can be estimated in a unidimensional latent space. To examine whether or not the response to an item requires only a single latent ability, unidimensional ability estimates were compared for data generated from the multidimensional item response…

  13. Statistical distribution of bonding distances in a unidimensional solid

    NASA Astrophysics Data System (ADS)

    Belousov, Roman; De Gregorio, Paolo; Rondoni, Lamberto; Conti, Livia

    2014-10-01

    We study a Fermi-Pasta-Ulam-like chain with Lennard-Jones potentials to model a unidimensional solid in contact with heat baths at a given temperature. We formulate an explicit analytical expression for the probability density of bonding distances between neighboring particles, which depends on temperature similarly to the distribution of velocities. For a finite number of particles, its validity is verified with high accuracy through molecular dynamics simulations. We also provide a theoretical framework which is consistent with the numerical findings. We give an analytic expression of the mean bond distance and elastic constant in the case of the square-well and harmonic interparticle potentials: we outline the role played by the hard-core repulsion. We also calculate the same quantities in the case of series expansions of Lennard-Jones potential truncated at different, even series power.

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

    PubMed

    Nandakumar, R

    1993-01-01

    Unidimensionality is one of the important assumptions the data should satisfy in order to apply unidimensional item response models. There are several methodologies available to date to assess the dimensionality of the latent space underlying binary item responses. Rosenbaum (1984) and Holland and Rosenbaum (1986) have proved theorems concerning conditional associations that can be applied to assess dimensionality. Holland and Rosenbaum's method has been applied to assess dimensionality by Zwick (1987), Ben- Simon and Cohen (1990), and Nandakumar (1991) to various test situations. This article outlines the Holland and Rosenbaum's (1986) methodology to assess unidimensionality, illustrates the procedure through a simulated data set, and describes how to interpret the results.

  15. Caregiver Burden: Looking Beyond the Unidimensional Total Score.

    PubMed

    Lau, Sabrina; Chong, Mei Sian; Ali, Noorhazlina; Chan, Mark; Chua, Kia Chong; Lim, Wee Shiong

    2015-01-01

    The Zarit Burden Interview allows caregiver burden to be interpreted from a total score. However, recent studies propose a multidimensional Zarit Burden Interview model. This study aims to determine the agreement between unidimensional (UD) and multidimensional (MD) classification of burden, and differences in predictors among identified groups. We studied 165 dyads of dementia patients and primary caregivers. Caregivers were dichotomized into low-burden and high-burden groups based upon: (1) UD score using quartile cutoffs; and (2) MD model via exploratory cluster analysis. We compared UD versus MD 2×2 classification of burden using κ statistics. Caregivers not showing agreement by either definition were classified as "intermediate" burden. We performed binary logistic regression to ascertain differences in predictive factors. The 2 models showed moderate agreement (κ=0.72, P<0.01), yielding 104 low, 20 intermediate (UD "low burden"/MD "high burden"), and 41 high-burden caregivers. Neuropsychiatric symptoms [odds ratio (OR)=1.27, P=0.003], coresidence (OR=6.32, P=0.040), and decreased caregiving hours (OR=0.99, P=0.018) were associated with intermediate burden, whereas neuropsychiatric symptoms (OR=1.21, P=0.001) and adult children caregivers (OR=2.80, P=0.055) were associated with high burden. Our results highlight the differences between UD and MD classification of caregiver burden. Future studies should explore the significance of the noncongruent intermediate group and its predictors.

  16. Increasing Item Complexity: A Possible Cause of Scale Shrinkage for Unidimensional Item Response Theory.

    ERIC Educational Resources Information Center

    Yen, Wendy M.

    1985-01-01

    An approximate relationship is devised between the unidimensional model used in data analysis and a multidimensional model hypothesized to be generating the item responses. Scale shrinkage is successfully predicted for several sets of simulated data. (Author/LMO)

  17. 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.

  18. Target Rotations and Assessing the Impact of Model Violations on the Parameters of Unidimensional Item Response Theory Models

    ERIC Educational Resources Information Center

    Reise, Steven; Moore, Tyler; Maydeu-Olivares, Alberto

    2011-01-01

    Reise, Cook, and Moore proposed a "comparison modeling" approach to assess the distortion in item parameter estimates when a unidimensional item response theory (IRT) model is imposed on multidimensional data. Central to their approach is the comparison of item slope parameter estimates from a unidimensional IRT model (a restricted model), with…

  19. 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…

  20. 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…

  1. 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.…

  2. Circular Unidimensional Scaling: A New Look at Group Differences in Interest Structure

    ERIC Educational Resources Information Center

    Armstrong, Patrick Ian; Hubert, Lawrence; Rounds, James

    2003-01-01

    The fit of J. L. Holland's (1959, 1997) RIASEC model to U.S. racial-ethnic groups was assessed using circular unidimensional scaling. Samples of African American, Asian American, Caucasian American and Hispanic American high school students and employed adults who completed either the UNIACT Interest Inventory (K. B. Swaney, 1995) or the Strong…

  3. 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…

  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 Asymptotic Distribution of Ability Estimates: Beyond Dichotomous Items and Unidimensional IRT Models

    ERIC Educational Resources Information Center

    Sinharay, Sandip

    2015-01-01

    The maximum likelihood estimate (MLE) of the ability parameter of an item response theory model with known item parameters was proved to be asymptotically normally distributed under a set of regularity conditions for tests involving dichotomous items and a unidimensional ability parameter (Klauer, 1990; Lord, 1983). This article first considers…

  6. 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…

  7. Quantifying NUMA and Contention Effects in Multi-GPU Systems

    SciTech Connect

    Spafford, Kyle L; Meredith, Jeremy S; Vetter, Jeffrey S

    2011-01-01

    As system architects strive for increased density and power efficiency, the traditional compute node is being augmented with an increasing number of graphics processing units (GPUs). The integration of multiple GPUs per node introduces complex performance phenomena including non-uniform memory access (NUMA) and contention for shared system resources. Utilizing the Keeneland system, this paper quantifies these effects and presents some guidance on programming strategies to maximize performance in multi-GPU environments.

  8. Program partitioning for NUMA multiprocessor computer systems. [Nonuniform memory access

    SciTech Connect

    Wolski, R.M.; Feo, J.T. )

    1993-11-01

    Program partitioning and scheduling are essential steps in programming non-shared-memory computer systems. Partitioning is the separation of program operations into sequential tasks, and scheduling is the assignment of tasks to processors. To be effective, automatic methods require an accurate representation of the model of computation and the target architecture. Current partitioning methods assume today's most prevalent models -- macro dataflow and a homogeneous/two-level multicomputer system. Based on communication channels, neither model represents well the emerging class of NUMA multiprocessor computer systems consisting of hierarchical read/write memories. Consequently, the partitions generated by extant methods do not execute well on these systems. In this paper, the authors extend the conventional graph representation of the macro-dataflow model to enable mapping heuristics to consider the complex communication options supported by NUMA architectures. They describe two such heuristics. Simulated execution times of program graphs show that the model and heuristics generate higher quality program mappings than current methods for NUMA architectures.

  9. Rae1 interaction with NuMA is required for bipolar spindle formation

    PubMed Central

    Wong, Richard W.; Blobel, Günter; Coutavas, Elias

    2006-01-01

    In eukaryotic cells, the faithful segregation of daughter chromosomes during cell division depends on formation of a microtubule (MT)-based bipolar spindle apparatus. The Nuclear Mitotic Apparatus protein (NuMA) is recruited from interphase nuclei to spindle MTs during mitosis. The carboxy terminal domain of NuMA binds MTs, allowing a NuMA dimer to function as a “divalent” crosslinker that bundles MTs. The messenger RNA export factor, Rae1, also binds to MTs. Lowering Rae1 or increasing NuMA levels in cells results in spindle abnormalities. We have identified a mitotic-specific interaction between Rae1 and NuMA and have explored the relationship between Rae1 and NuMA in spindle formation. We have mapped a specific binding site for Rae1 on NuMA that would convert a NuMA dimer to a “tetravalent” crosslinker of MTs. In mitosis, reducing Rae1 or increasing NuMA concentration would be expected to alter the valency of NuMA toward MTs; the “density” of NuMA-MT crosslinks in these conditions would be diminished, even though a threshold number of crosslinks sufficient to stabilize aberrant multipolar spindles may form. Consistent with this interpretation, we found that coupling NuMA overexpression to Rae1 overexpression or coupling Rae1 depletion to NuMA depletion prevented the formation of aberrant spindles. Likewise, we found that overexpression of the specific Rae1-binding domain of NuMA in HeLa cells led to aberrant spindle formation. These data point to the Rae1–NuMA interaction as a critical element for normal spindle formation in mitosis. PMID:17172455

  10. Towards Exascale Computing with NUMA: an Element-based Galerkin Nonhydrostatic Global and Mesoscale Atmospheric Modeling

    NASA Astrophysics Data System (ADS)

    Giraldo, F.; Mueller, A.; Kopera, M. A.; Abdi, D. S.; Wilcox, L.

    2015-12-01

    In this talk, we shall describe the NUMA atmospheric model, focusing in particular on its unified continuous/discontinuous (CG and DG) Galerkin numerical methods that are used to represent the spatial derivatives. We shall describe how these two methods are formulated in a unified approach and the advantages that this brings. We will also report on the progress in extending NUMA to using adaptive mesh refinement. Lastly, we will report on the scalability and performance of NUMA on the leadership computing facilities (LCF) of the Department of Energy where we have scaled NUMA to over 3 million MPI threads achieving a 90% efficiency.

  11. 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.

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

    PubMed

    Lupsor-Platon, Monica; Badea, Radu

    2015-11-14

    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.

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

    PubMed

    Lupsor-Platon, Monica; Badea, Radu

    2015-11-14

    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

  14. 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.

  15. Unidimensional versus multidimensional approaches to the assessment of acculturation for Asian American populations.

    PubMed

    Abe-Kim, J; Okazaki, S; Goto, S G

    2001-08-01

    This study used generational status and the Suinn-Lew Asian Self-Identity Acculturation scale to examine unidimensional versus multidimensional approaches to the conceptualization and measurement of acculturation and their relationships to relevant cultural indicator variables, including measures of Individualism-Collectivism, Independent-Interdependent Self-Construal, Loss of Face, and Impression Management. Multivariate analyses of covariance and partial correlations were used to examine the relationship between the acculturation models and each set of cultural indicator variables while controlling for socioeconomic status. Given that acculturation differences are often cited as evidence for a culture effect between groups, the present findings of an uneven nature of these relationships as a function of the particular acculturation measurement strategy have important implications for research on Asian Americans.

  16. The Effect of Fitting a Unidimensional IRT Model to Multidimensional Data in Content-Balanced Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Song, Tian

    2010-01-01

    This study investigates the effect of fitting a unidimensional IRT model to multidimensional data in content-balanced computerized adaptive testing (CAT). Unconstrained CAT with the maximum information item selection method is chosen as the baseline, and the performances of three content balancing procedures, the constrained CAT (CCAT), the…

  17. 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

  18. Memphis: Finding and Fixing NUMA-related Performance Problems on Multi-core Platforms

    SciTech Connect

    McCurdy, Collin B; Vetter, Jeffrey S

    2010-01-01

    Until recently, most high-end scientific applications have been immune to performance problems caused by Non-Uniform Memory Access (NUMA). However, current trends in micro-processor design are pushing NUMA to smaller and smaller scales. This paper examines the current state of NUMA and makes several contributions. First, we summarize the performance problems that NUMA can present for multithreaded applications and describe methods of addressing them. Second, we demonstrate that NUMA can indeed be a significant problem for scientific applications, showing that it can mean the difference between an application scaling perfectly and failing to scale at all. Third, we describe, in increasing order of usefulness, three methods of using hardware performance counters to aid in finding NUMA-related problems. Finally, we introduce Memphis, a data-centric toolset that uses Instruction Based Sampling to help pinpoint problematic memory accesses, and demonstrate how we used it to improve the performance of several production-level codes - HYCOM, XGC1 and CAM - by 13%, 23% and 24% respectively.

  19. Highly efficient peptide separations in proteomics Part 1. Unidimensional high performance liquid chromatography.

    PubMed

    Sandra, Koen; Moshir, Mahan; D'hondt, Filip; Verleysen, Katleen; Kas, Koen; Sandra, Pat

    2008-04-15

    Sample complexity and dynamic range constitute enormous challenges in proteome analysis. The back-end technology in typical proteomics platforms, namely mass spectrometry (MS), can only tolerate a certain complexity, has a limited dynamic range per spectrum and is very sensitive towards ion suppression. Therefore, component overlap has to be minimized for successful mass spectrometric analysis and subsequent protein identification and quantification. The present review describes the advances that have been made in liquid-based separation techniques with focus on the recent developments to boost the resolving power. The review is divided in two parts; the first part deals with unidimensional liquid chromatography and the second part with bi- and multidimensional liquid-based separation techniques. Part 1 mainly focuses on reversed-phase HPLC due to the fact that it is and will, in the near future, remain the technique of choice to be hyphenated with MS. The impact of increasing the column length, decreasing the particle diameter, replacing the traditional packed beds by monolithics, amongst others, is described. The review is complemented with data obtained in the laboratories of the authors. PMID:18006394

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Interconnected contribution of tissue morphogenesis and the nuclear protein NuMA to the DNA damage response

    PubMed Central

    Vidi, Pierre-Alexandre; Chandramouly, Gurushankar; Gray, Matthew; Wang, Lei; Liu, Er; Kim, Joseph J.; Roukos, Vassilis; Bissell, Mina J.; Moghe, Prabhas V.; Lelièvre, Sophie A.

    2012-01-01

    Epithelial tissue morphogenesis is accompanied by the formation of a polarity axis – a feature of tissue architecture that is initiated by the binding of integrins to the basement membrane. Polarity plays a crucial role in tissue homeostasis, preserving differentiation, cell survival and resistance to chemotherapeutic drugs among others. An important aspect in the maintenance of tissue homeostasis is genome integrity. As normal tissues frequently experience DNA double-strand breaks (DSBs), we asked how tissue architecture might participate in the DNA damage response. Using 3D culture models that mimic mammary glandular morphogenesis and tumor formation, we show that DSB repair activity is higher in basally polarized tissues, regardless of the malignant status of cells, and is controlled by hemidesmosomal integrin signaling. In the absence of glandular morphogenesis, in 2D flat monolayer cultures, basal polarity does not affect DNA repair activity but enhances H2AX phosphorylation, an early chromatin response to DNA damage. The nuclear mitotic apparatus protein 1 (NuMA), which controls breast glandular morphogenesis by acting on the organization of chromatin, displays a polarity-dependent pattern and redistributes in the cell nucleus of basally polarized cells upon the induction of DSBs. This is shown using high-content analysis of nuclear morphometric descriptors. Furthermore, silencing NuMA impairs H2AX phosphorylation – thus, tissue polarity and NuMA cooperate to maintain genome integrity. PMID:22331358

  8. 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

  9. 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.

  10. 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. PMID:25624210

  11. 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.

  12. 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

  13. 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

  14. NuMA promotes homologous recombination repair by regulating the accumulation of the ISWI ATPase SNF2h at DNA breaks

    PubMed Central

    Vidi, Pierre-Alexandre; Liu, Jing; Salles, Daniela; Jayaraman, Swaathi; Dorfman, George; Gray, Matthew; Abad, Patricia; Moghe, Prabhas V.; Irudayaraj, Joseph M.; Wiesmüller, Lisa; Lelièvre, Sophie A.

    2014-01-01

    Chromatin remodeling factors play an active role in the DNA damage response by shaping chromatin to facilitate the repair process. The spatiotemporal regulation of these factors is key to their function, yet poorly understood. We report that the structural nuclear protein NuMA accumulates at sites of DNA damage in a poly[ADP-ribose]ylation-dependent manner and functionally interacts with the ISWI ATPase SNF2h/SMARCA5, a chromatin remodeler that facilitates DNA repair. NuMA coimmunoprecipitates with SNF2h, regulates its diffusion in the nucleoplasm and controls its accumulation at DNA breaks. Consistent with NuMA enabling SNF2h function, cells with silenced NuMA exhibit reduced chromatin decompaction after DNA cleavage, lesser focal recruitment of homologous recombination repair factors, impaired DNA double-strand break repair in chromosomal (but not in episomal) contexts and increased sensitivity to DNA cross-linking agents. These findings reveal a structural basis for the orchestration of chromatin remodeling whereby a scaffold protein promotes genome maintenance by directing a remodeler to DNA breaks. PMID:24753406

  15. 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. PMID:16958026

  16. 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.

  17. A{sub 2}TiF{sub 5}.nH{sub 2}O (A=K, Rb, or Cs; n=0 or 1): Synthesis, structure, characterization, and calculations of three new uni-dimensional titanium fluorides

    SciTech Connect

    Jo, Vinna; Woo Lee, Dong; Koo, Hyun-Joo; Ok, Kang Min

    2011-04-15

    Three new uni-dimensional alkali metal titanium fluoride materials, A{sub 2}TiF{sub 5}.nH{sub 2}O (A=K, Rb, or Cs; n=0 or 1) have been synthesized by hydrothermal reactions. The structures of A{sub 2}TiF{sub 5}.nH{sub 2}O have been determined by single-crystal X-ray diffraction. The Ti{sup 4+} cations have been reduced to Ti{sup 3+} during the synthesis reactions. All three A{sub 2}TiF{sub 5}.nH{sub 2}O materials contain novel 1-D chain structures that are composed of the slightly distorted Ti{sup 3+}F{sub 6} corner-sharing octahedra attributable to the Jahn-Teller distortion. The coordination environment of the alkali metal cations plays an important role to determine the degree of turning in the chain structures. Complete structural analyses, Infrared and UV-vis diffuse reflectance spectra, and thermal analyses are presented, as are electronic structure calculations. -- Graphical abstract: Ball-and-stick and polyhedral representations for (a) {beta}-K{sub 2}TiF{sub 5} and (b) Rb{sub 2}TiF{sub 5}.H{sub 2}O or Cs{sub 2}TiF{sub 5}.H{sub 2}O with the K{sup +} and Rb{sup +} (or Cs{sup +}) coordination environment emphasized. Display Omitted Research highlights: > Synthesis, structure, characterization, and calculation of new titanium fluorides. > Study of reduction of starting Ti{sup 4+} cations to Ti{sup 3+} by DMF. > Novel 1-D chain structures with Jahn-Teller distorted TiF{sub 6} octahedra.

  18. 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…

  19. A unidimensional model of comet ionosphere structure

    NASA Astrophysics Data System (ADS)

    Eviatar, A.; Goldstein, B. E.

    1988-03-01

    The authors have considered the one-dimensional continuity and momentum equations for the plasma created in the expanding coma of a comet near the Sun. For an inverse square dependence of neutral density they have solved the continuity equation in the presence of radial plasma flow. For distances large compared to the size of the nucleus, the distribution falls off as r-1 with a velocity dependent coefficient which reduces to the photochemical steady state case in the limit of vanishing radial plasma outflow. This density distribution is used in the treatment of the momentum equation from which an analytic expression for the magnetic field configuration is derived in the presence of outflow, photoionization, dissociative recombination, plasma fluid pressure, and friction between the ions and neutrals.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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…

  5. Unidimensional Scaling of Two Person Non-Zero Sum Games.

    ERIC Educational Resources Information Center

    Baerwaldt, James; Talley, Martha

    Groups of students were required to respond to the same eight two-person games, two variants each of four qualitatively different separable games including Prisoner's Dilemma. The games were generated by varying a payoff parameter which altered the potential maximum per trial difference between payoffs for the two players. The groups differed…

  6. Unidimensional thermal gradients Tn in a nanoscopic superconductor

    NASA Astrophysics Data System (ADS)

    Barba-Ortega, J.; Carrillo, H. M.; Sjogreen-Blanco, C. A.

    2016-06-01

    In general, few studies of the Abrikosov state in mesoscopic superconductors have been carried out with the presence of temperature gradients. We know that there can be situations where a sample near a heater source leads to a variable temperature system. Thus, in this work we studied the influence of several thermal gradients on the vortex configuration and the thermodynamics properties of a low critical temperature nanoscopic superconducting long square prism of size d × d. For this purposes, we simulated a hypothetical physical situation where the temperature varies into the sample as T =T1 +(x / d) n(T2 -T1) , with T =T1(x = 0) , T =T2(x = d) and n = 1 , 2 , 3 , 4 , 5 , 6 , T1 < T2. The field for the first vortex penetration H1 presents a slow dependence on n and d.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. Limits on Log Odds Ratios for Unidimensional Item Response Theory Models

    ERIC Educational Resources Information Center

    Haberman, Shelby J.; Holland, Paul W.; Sinharay, Sandip

    2007-01-01

    Bounds are established for log odds ratios (log cross-product ratios) involving pairs of items for item response models. First, expressions for bounds on log odds ratios are provided for one-dimensional item response models in general. Then, explicit bounds are obtained for the Rasch model and the two-parameter logistic (2PL) model. Results are…

  12. 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…

  13. 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

  14. 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,…

  15. A Monte Carlo Approach to Unidimensionality Testing in Polytomous Rasch Models

    ERIC Educational Resources Information Center

    Christensen, Karl Bang; Kreiner, Svend

    2007-01-01

    Many statistical tests are designed to test the different assumptions of the Rasch model, but only few are directed at detecting multidimensionality. The Martin-Lof test is an attractive approach, the disadvantage being that its null distribution deviates strongly from the asymptotic chi-square distribution for most realistic sample sizes. A Monte…

  16. The limits of the separation power of unidimensional column liquid chromatography.

    PubMed

    Guiochon, Georges

    2006-09-01

    The practical limit of the separation power of HPLC depends on time, money, and skill. That is it depends on the time available for the analysis, on the quality and performance of the pump and hardware and particularly on the maximum pressure at which the pump can deliver the mobile phase to the column, and on the temperature at which the column can be operated. It also depends on the properties of the packing material selected (e.g., its particle size, its pore geometry, and its connectivity) and on the packing method used since it affects the coefficients of the HETP equation. Finally, it depends on the thermal stability of the sample and the packing material. The complexity of the sample also plays an important role in that it determines whether the analysis should be made under isocratic, isothermal conditions, in gradient elution, in temperature programming, or with a combination of both types of programming. The various phenomena that affect column properties and separation performance are discussed. Past achievements suggest that columns providing efficiencies in excess of a million plates in less than 1 day are within the grasp of current technology. The possibility of further advances are considered.

  17. 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…

  18. 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…

  19. 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)

  20. Is Self-Confidence in Teaching Multidimensional or Unidimensional? An Exploratory Study.

    ERIC Educational Resources Information Center

    Kalaian, Hripsime A.; And Others

    1994-01-01

    A 12-item Self-Confidence in Teaching Scale was completed by 1,176 students entering a teacher preparation program and 861 teacher candidates completing their final semester. For the total sample, gender subsamples, and "entry"/"exit" subsamples, principal axis factor analyses yielded only one factor with an eigenvalue greater than 1.0, suggesting…

  1. Hierarchical diagnostic classification models morphing into unidimensional 'diagnostic' classification models-a commentary.

    PubMed

    von Davier, Matthias; Haberman, Shelby J

    2014-04-01

    This commentary addresses the modeling and final analytical path taken, as well as the terminology used, in the paper "Hierarchical diagnostic classification models: a family of models for estimating and testing attribute hierarchies" by Templin and Bradshaw (Psychometrika, doi: 10.1007/s11336-013-9362-0, 2013). It raises several issues concerning use of cognitive diagnostic models that either assume attribute hierarchies or assume a certain form of attribute interactions. The issues raised are illustrated with examples, and references are provided for further examination.

  2. 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…

  3. 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.…

  4. 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…

  5. 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.…

  6. 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…

  7. 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.…

  8. 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…

  9. Continuum beliefs about psychotic symptoms are a valid, unidimensional construct: Construction and validation of a revised continuum beliefs questionnaire.

    PubMed

    Schlier, Björn; Scheunemann, Jakob; Lincoln, Tania M

    2016-07-30

    Growing evidence supports a continuum model of psychosis, with mild psychotic symptoms being frequently experienced by the general population. Moreover, believing in the continuum model correlates with less stigmatization of schizophrenia. This study explores whether continuum beliefs are a valid construct and develops a continuum beliefs scale. First, expert-generated items were reduced to a candidate scale (study 1, n=95). One-dimensionality was tested using confirmatory factor analysis (study 2, n=363). Convergent validity was tested with a previous continuum beliefs scale, essentialist beliefs, and stigmatization (study 2), while self-reported psychotic experiences (i.e. frequency and conviction) served to test discriminant validity (study 3, n=229). A nine item questionnaire that assesses continuum beliefs about schizophrenia symptoms showed acceptable to good psychometric values, high correlations with a previous continuum beliefs scale and small correlations with essentialist beliefs, stereotypes, and desired social distance. No correlations with psychotic experiences were found. Thus, continuum beliefs can be considered a valid construct. The construed CBQ-R asks about symptoms rather than the abstract category "schizophrenia", which may increase understandability of the scale. Validation confirms previous studies and highlights the difference between continuum beliefs and personal psychotic experiences. PMID:27175910

  10. Relating Unidimensional IRT Parameters to a Multidimensional Response Space: A Review of Two Alternative Projection IRT Models for Scoring Subscales

    ERIC Educational Resources Information Center

    Kahraman, Nilufer; Thompson, Tony

    2011-01-01

    A practical concern for many existing tests is that subscore test lengths are too short to provide reliable and meaningful measurement. A possible method of improving the subscale reliability and validity would be to make use of collateral information provided by items from other subscales of the same test. To this end, the purpose of this article…

  11. Unidimensional Approximations for a Computerized Classification Test When the Item Pool and Latent Space Are Multidimensional. ACT Research Report Series 97-5.

    ERIC Educational Resources Information Center

    Spray, Judith A.; Abdel-fattah, Abdel-fattah A.; Huang, Chi-Yu; Lau, C. Allen

    The primary concern or focus of a certification or licensure test is to obtain valid criterion-referenced information regarding a candidate's competence to practice. When the test is administered by computer, a valid pass/fail decision can be made with fewer items than an equivalent paper/pencil test by targeting items at the passing score and…

  12. 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.

  13. 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…

  14. 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 the…

  15. 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

  16. The Short Mood and Feelings Questionnaire (SMFQ): A Unidimensional Item Response Theory and Categorical Data Factor Analysis of Self-Report Ratings from a Community Sample of 7-through 11-Year-Old Children

    ERIC Educational Resources Information Center

    Sharp, Carla; Goodyer, Ian M.; Croudace, Tim J.

    2006-01-01

    Item response theory (IRT) and categorical data factor analysis (CDFA) are complementary methods for the analysis of the psychometric properties of psychiatric measures that purport to measure latent constructs. These methods have been applied to relatively few child and adolescent measures. We provide the first combined IRT and CDFA analysis of a…

  17. 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

  18. 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.

  19. 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)

  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. 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…

  3. 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…

  4. 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…

  5. The DSM-IV Construct of Cocaine Dependence in a Treatment Sample of Black, Mexican American, and White Men.

    ERIC Educational Resources Information Center

    Schafer, John; Caetano, Raul

    1996-01-01

    The unidimensionality of the fourth edition of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-IV) construct of cocaine dependence was examined among 263 black, 212 Mexican American, and 256 white men in treatment. Results generally support a unidimensional model of the cocaine dependence indicators, with one indicator considered…

  6. 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…

  7. 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…

  8. 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

  9. 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.

  10. 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…

  11. 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)

  12. 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)

  13. Differentiation inducing factor-1 (DIF-1) induces gene and protein expression of the Dictyostelium nuclear calmodulin-binding protein nucleomorphin.

    PubMed

    O'Day, Danton H; Poloz, Yekaterina; Myre, Michael A

    2009-02-01

    The nucleomorphin gene numA1 from Dictyostelium codes for a multi-domain, calmodulin binding protein that regulates nuclear number. To gain insight into the regulation of numA, we assessed the effects of the stalk cell differentiation inducing factor-1 (DIF-1), an extracellular signalling molecule, on the expression of numA1 RNA and protein. For comparison, the extracellular signalling molecules cAMP (mediates chemotaxis, prestalk and prespore differentiation) and ammonia (NH(3)/NH(4)(+); antagonizes DIF) were also studied. Starvation, which is a signal for multicellular development, results in a greater than 80% decrease in numA1 mRNA expression within 4 h. Treatment with ammonium chloride led to a greater than 90% inhibition of numA1 RNA expression within 2 h. In contrast, the addition of DIF-1 completely blocked the decrease in numA1 gene expression caused by starvation. Treatment of vegetative cells with cAMP led to decreases in numA1 RNA expression that were equivalent to those seen with starvation. Western blotting after various morphogen treatments showed that the maintenance of vegetative levels of numA1 RNA by DIF-1 in starved cells was reflected in significantly increased numA1 protein levels. Treatment with cAMP and/or ammonia led to decreased protein expression and each of these morphogens suppressed the stimulatory effects of DIF-1. Protein expression levels of CBP4a, a calcium-dependent binding partner of numA1, were regulated in the same manner as numA1 suggesting this potential co-regulation may be related to their functional relationship. NumA1 is the first calmodulin binding protein shown to be regulated by developmental morphogens in Dictyostelium being upregulated by DIF-1 and down-regulated by cAMP and ammonia. PMID:19000924

  14. 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.

  15. Percepção Astronômica de um Grupo de Alunos do Ensino Médio de uma Escola da Rede Estadual de São Paulo

    NASA Astrophysics Data System (ADS)

    de Oliveira, E. F.

    2007-06-01

    Being the Astronomy one of the oldest sciences of the humanity, and considering its historical and cultural importance, it is of extreme relevance that topics related to it are taught and studied at schools. Although the National Curriculum Parameters of the Senior High School (PCN-EM) and the Complementary Orientations to the Parameters (PCN+) indicate the importance of a significant approach of concepts related to the Astronomy in the Physics classes, many students finish the Senior High School (EM) without understanding the reason of certain events of celestial origin, although these are part of their daily lives and are a subject of natural curiosity for the youngsters. From the perception of the natural curiosity of the students of a São Paulo's Public School in the city of Suzano, came up the interest to investigate the basic knowledge in Astronomy of the Senior High School students at this school, becoming this the main goal of this research. A questionnaire of multiple choices was elaborated and initially applied to 34 students of the first grade and later, to more 310 students. It was distributed among the three grades of the Senior High School in the morning and night periods. In the way, it was observed that 73.9% of the students identified the Sun as a star, 67.1% demonstrated to understand the succession between the day and the night and 52.3% related the Big Bang to the origin of the Universe. In compensation, only 34.5% related the seasons of the year to the inclination of the rotation axis of the Earth, 21.3% indicated the simultaneous gravitational influence of the Moon and the Sun as responsible for the tides phenomenon, 24.5% correctly indicated which are the closest celestial objects to the Earth, 36.1% identified the light-year as a distance measure and only 34.2% recognized the shooting stars as meteors, being evidenced the small discernment of the students about the phenomena and astronomical terms of the daily life. Besides, the answers of different grade students and periods were compared, being observed, among other things, that the third grade students present a percentile of correct answers similar to the performance of the first grade students, demonstrating that the approach of topics related to the astronomy in the Senior High School has not been contributing in a significant way to a better understanding of the phenomena and the concepts.

  16. 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…

  17. 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.

  18. 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.

  19. 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

  20. 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

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

    PubMed

    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.

  2. Cross-cultural equivalence in translation of the oral health impact profile: how to interpret the final score?

    PubMed

    Denis, Frederic; Trojak, Benoit; Rude, Nathalie

    2016-06-01

    The oral health impact profile (OHIP) is one of the most widely known oral health-related quality of life instruments. In Community Dentistry and Oral Epidemiology, MacEntee and Brondani report the results of a systematic review to identify acceptable methods for translating psychometric instruments for cross-cultural equivalence of the OHIP scale. But in no study has unidimensionality, one aspect of the validity of the internal structure of the scale, been verified, whereas it is a major psychometric step. In the absence of the study of unidimensionality, it is difficult to interpret the final score. The methodology of transcultural validation of the OHIP could be improved, and the study of the unidimensionality is a psychometrically necessary step for the interpretation of the finale score.

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. Investigating the Psychometric Properties of School Counselor Self-Advocacy Questionnaire

    ERIC Educational Resources Information Center

    Clemens, Elysia V.; Shipp, Adria; Kimbel, Tyler

    2011-01-01

    This article reports on the development and the exploration of the underlying psychometric properties of the School Counselor Self-Advocacy Questionnaire, a measure of skills school counselors can use to advocate for their roles and programs. An exploratory factor analysis (N = 188) suggested a unidimensional model, and a confirmatory factor…

  8. Component Structure, Reliability, and Stability of Lawrence's Self-Esteem Questionnaire (LAWSEQ)

    ERIC Educational Resources Information Center

    Rae, Gordon; Dalto, Georgia; Loughrey, Dolores; Woods, Caroline

    2011-01-01

    Lawrence's Self-Esteem Questionnaire (LAWSEQ) was administered to 120 Year 1 pupils in six schools in Belfast, Northern Ireland. A principal components analysis indicated that the scale items were unidimensional and that the reliability of the scores, as estimated by Cronbach's alpha, was satisfactory ([alpha] = 0.73). There were no differences…

  9. 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…

  10. 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…

  11. An Investigation of Sample Size Splitting on ATFIND and DIMTEST

    ERIC Educational Resources Information Center

    Socha, Alan; DeMars, Christine E.

    2013-01-01

    Modeling multidimensional test data with a unidimensional model can result in serious statistical errors, such as bias in item parameter estimates. Many methods exist for assessing the dimensionality of a test. The current study focused on DIMTEST. Using simulated data, the effects of sample size splitting for use with the ATFIND procedure for…

  12. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  13. Some Issues in Item Response Theory: Dimensionality Assessment and Models for Guessing

    ERIC Educational Resources Information Center

    Smith, Jessalyn

    2009-01-01

    Currently, standardized tests are widely used as a method to measure how well schools and students meet academic standards. As a result, measurement issues have become an increasingly popular topic of study. Unidimensional item response models are used to model latent abilities and specific item characteristics. This class of models makes…

  14. 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…

  15. 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…

  16. An Interactive Multiobjective Programming Approach to Combinatorial Data Analysis.

    ERIC Educational Resources Information Center

    Brusco, Michael J.; Stahl, Stephanie

    2001-01-01

    Describes an interactive procedure for multiobjective asymmetric unidimensional seriation problems that uses a dynamic-programming algorithm to generate partially the efficient set of sequences for small to medium-sized problems and a multioperational heuristic to estimate the efficient set for larger problems. Applies the procedure to an…

  17. 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,…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. Electrohydrodynamically driven large-area liquid ion sources

    DOEpatents

    Pregenzer, Arian L.

    1988-01-01

    A large-area liquid ion source comprises means for generating, over a large area of the surface of a liquid, an electric field of a strength sufficient to induce emission of ions from a large area of said liquid. Large areas in this context are those distinct from emitting areas in unidimensional emitters.

  3. 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…

  4. 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 general…

  5. Constant Latent Odds-Ratios Models and the Mantel-Haenszel Null Hypothesis

    ERIC Educational Resources Information Center

    Hessen, David J.

    2005-01-01

    In the present paper, a new family of item response theory (IRT) models for dichotomous item scores is proposed. Two basic assumptions define the most general model of this family. The first assumption is local independence of the item scores given a unidimensional latent trait. The second assumption is that the odds-ratios for all item-pairs are…

  6. 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…

  7. 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…

  8. 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…

  9. Computerized Adaptive Testing with the Zinnes and Griggs Pairwise Preference Ideal Point Model

    ERIC Educational Resources Information Center

    Stark, Stephen; Chernyshenko, Oleksandr S.

    2011-01-01

    This article delves into a relatively unexplored area of measurement by focusing on adaptive testing with unidimensional pairwise preference items. The use of such tests is becoming more common in applied non-cognitive assessment because research suggests that this format may help to reduce certain types of rater error and response sets commonly…

  10. Application of a General Polytomous Testlet Model to the Reading Section of a Large-Scale English Language Assessment. Research Report. ETS RR-10-21

    ERIC Educational Resources Information Center

    Li, Yanmei; Li, Shuhong; Wang, Lin

    2010-01-01

    Many standardized educational tests include groups of items based on a common stimulus, known as "testlets". Standard unidimensional item response theory (IRT) models are commonly used to model examinees' responses to testlet items. However, it is known that local dependence among testlet items can lead to biased item parameter estimates when…

  11. 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,…

  12. Psychometric Properties of a Portuguese Version of the Subjective Happiness Scale

    ERIC Educational Resources Information Center

    Spagnoli, Paola; Caetano, Antonio; Silva, Ana

    2012-01-01

    The Subjective Happiness Scale (SHS) constitutes an instrument for assessing subjective happiness. This study aims to present the validation of the SHS in a Portuguese adult population. A large representative sample (1,017 participants), from five different age groups was considered. Configurational invariance of the unidimensional structure of…

  13. 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…

  14. 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.…

  15. Construct Validity of Four Frailty Measures in an Older Australian Population: A Rasch Analysis.

    PubMed

    Widagdo, I S; Pratt, N; Russell, M; Roughead, E E

    2016-01-01

    Individuals identified as frail have been shown to be at an increased risk of adverse health outcomes. However, there is no gold standard frailty measure and frailty status can vary depending on the measure used, suggesting the measures perform differently. Construct validity can be used to assess a measure's performance. This study aimed to examine the construct validity of four frailty measures in an Australian older population using Rasch analysis. Frailty status among the 2087 participants aged 65 years and above from the Australian Longitudinal Study of Ageing (ALSA) was assessed using: frailty phenotype--FP, simplified frailty phenotype--SFP, frailty index--FI, and prognostic frailty score--PFS. Rasch analysis was used to assess the unidimensionality of the measures, which is the extent to which the underlying characteristic of frailty is assessed. The criteria for unidimensionality from principal component analysis of the residuals was when 50% or more of the raw variance was explained by the measures, and less than 5% was unexplained variance. Only FI meet the unidimensionality criteria with 74% of explained variance and 2.1% of unexplained variance. SFP did not show a unidimensional construct with 13.3% of explained variance and 47.1% of unexplained variance. FP and PFS had 39.6%, 18.1% and 46.5%, 8.7% of explained and unexplained variance, respectively. Our findings showed that FI has better construct validity than the other three measures in assessing frailty among the Australian older population. PMID:27224497

  16. Two Dimensions of Visibility Revealed by Multidimensional Scaling of Metacontrast

    ERIC Educational Resources Information Center

    Sackur, Jerome

    2013-01-01

    An increasing number of studies use subjective reports of visibility, so as to delineate the domain of perceptual awareness. It is generally assumed that degrees of visibility can be ordered on a single unidimensional scale. Here, I put this assumption to test with metacontrast, one of the most studied visual masking paradigms. By means of…

  17. Dimensionality of Thoughts of Death and Suicide: Evidence from a Study of Homeless Adolescents

    ERIC Educational Resources Information Center

    Yoder, Kevin A.; Whitbeck, Les B.; Hoyt, Dan R.

    2008-01-01

    This study used data from a sample of 444 homeless adolescents to determine whether thoughts of death and suicide form one construct (unidimensionality) or two distinct but correlated constructs (multi-dimensionality). Thoughts of death and suicide were common in the sample; over two-thirds of the adolescents positively endorsed at least one of…

  18. 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…

  19. Brief Psychometric Analysis of the Self-Efficacy Parent Report Scale (SEPRS)

    ERIC Educational Resources Information Center

    Erford, Bradley T.; Gavin, Kate

    2013-01-01

    The Self-Efficacy Parent-Report Scale was designed to assess parent perceptions of self-efficacy of their children aged 7 to 17 years. Internal aspects of validity indicated a marginal fit of the data to the unidimensional model. External facets of validity indicated the Self-Efficacy Parent-Report Scale had excellent convergent and discriminant…

  20. Construct Validity of Four Frailty Measures in an Older Australian Population: A Rasch Analysis.

    PubMed

    Widagdo, I S; Pratt, N; Russell, M; Roughead, E E

    2016-01-01

    Individuals identified as frail have been shown to be at an increased risk of adverse health outcomes. However, there is no gold standard frailty measure and frailty status can vary depending on the measure used, suggesting the measures perform differently. Construct validity can be used to assess a measure's performance. This study aimed to examine the construct validity of four frailty measures in an Australian older population using Rasch analysis. Frailty status among the 2087 participants aged 65 years and above from the Australian Longitudinal Study of Ageing (ALSA) was assessed using: frailty phenotype--FP, simplified frailty phenotype--SFP, frailty index--FI, and prognostic frailty score--PFS. Rasch analysis was used to assess the unidimensionality of the measures, which is the extent to which the underlying characteristic of frailty is assessed. The criteria for unidimensionality from principal component analysis of the residuals was when 50% or more of the raw variance was explained by the measures, and less than 5% was unexplained variance. Only FI meet the unidimensionality criteria with 74% of explained variance and 2.1% of unexplained variance. SFP did not show a unidimensional construct with 13.3% of explained variance and 47.1% of unexplained variance. FP and PFS had 39.6%, 18.1% and 46.5%, 8.7% of explained and unexplained variance, respectively. Our findings showed that FI has better construct validity than the other three measures in assessing frailty among the Australian older population.

  1. Alphabet Knowledge in Preschool: A Rasch Model Analysis

    ERIC Educational Resources Information Center

    Drouin, Michelle; Horner, Sherri L.; Sondergeld, Toni A.

    2012-01-01

    In this study, we used Rasch model analyses to examine (1) the unidimensionality of the alphabet knowledge construct and (2) the relative difficulty of different alphabet knowledge tasks (uppercase letter recognition, names, and sounds, and lowercase letter names) within a sample of preschoolers (n=335). Rasch analysis showed that the four…

  2. An Outcomes-Based Assessment of Quality of Life in Social Services

    ERIC Educational Resources Information Center

    Gomez, Laura Elisabet; Arias, Benito; Verdugo, Miguel Angel; Navas, Patricia

    2012-01-01

    The goal of this article consists of describing the calibration of an instrument to assess quality of life-related personal outcomes using Rasch analysis. The sample was composed of 3.029 recipients of social services from Catalonia (Spain) and was selected using a probabilistic polietapic sample design. Results related to unidimensionality, item…

  3. 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 organization;…

  4. 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…

  5. Confirmatory Factor Analysis of the Work Locus of Control Scale

    ERIC Educational Resources Information Center

    Oliver, Joseph E.; Jose, Paul E.; Brough, Paula

    2006-01-01

    Original formulations of the Work Locus of Control Scale (WLCS) proposed a unidimensional structure of this measure; however, more recently, evidence for a two-dimensional structure has been reported, with separate subscales for internal and external loci of control. The current study evaluates the one- and two-factor models with confirmatory…

  6. Structural Robustness and Ability Estimation in Item Response Theory: A Survey.

    ERIC Educational Resources Information Center

    Junker, Brian W.; And Others

    Some item response theory (IRT) techniques work in applications even though the usual structural IRT assumptions, and local independence (LI) in particular, do not hold. When the departure from LI is too great, traditional procedures will break down. Although violations of strictly unidimensional, monotone, locally independent latent structure can…

  7. 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…

  8. 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…

  9. 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…

  10. Verbal Behavior and Drive: A Theory in Crisis.

    ERIC Educational Resources Information Center

    Bradac, James J.; Elliot, Norman D.

    There is increasing debate over the unidimensionality of the construct "drive" in theories of behavior. The earliest drive theory postulated a simple entity which increased or decreased as a function of external or internal stimulation and affected behavior monotonically. Duffy and Malmo have recently hypothesized that the effects of drive are not…

  11. The Mediating Effects of Parenting Behaviors on Maternal Affect and Reports of Children's Behavior

    ERIC Educational Resources Information Center

    Karazsia, Bryan T.; Wildman, Beth G.

    2009-01-01

    Parenting behaviors have received ample support as a mediator of the relationship between maternal affect and child behavior problems. The majority of these research efforts were based on a uni-dimensional conceptualization of maternal mood, even though decades of theory and research suggest that mood is multidimensional. We examined the mediating…

  12. 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…

  13. 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…

  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. Examining Measurement Properties of an English Self-Efficacy Scale for English Language Learners in Korea

    ERIC Educational Resources Information Center

    Wang, Chuang; Kim, Do-Hong; Bong, Mimi; Ahn, Hyun Seon

    2013-01-01

    This study provides evidence for the validity of the Questionnaire of English Self-Efficacy in a sample of 167 college students in Korea. Results show that the scale measures largely satisfy the Rasch model for unidimensionality. The rating scale appeared to function effectively. The item hierarchy was consistent with the expected item order. The…

  16. An Instrument to Measure Anomia.

    ERIC Educational Resources Information Center

    Moore, Allen B.

    1980-01-01

    Four hundred and eighty-six disadvantaged adults from North Carolina were the subjects in a study that factor-analyzed three instruments designed to measure anomia, yielding a 12-item unidimensional scale. (The refined combination scale is presented as of potential usefulness for research on the effects of educational intervention on anomia.) (LRA)

  17. A Rasch Model for Continuous Ratings.

    ERIC Educational Resources Information Center

    Muller, Hans

    1987-01-01

    A unidimensional latent trait model for continuous ratings extends Andrich's rating formulation which assumes the response process at latent thresholds is based on the dichotomous Rasch model. The separability of the structural and incidental parameters is demonstrated and a procedure for estimating the parameters is outlined. (Author/GDC)

  18. 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)

  19. 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)

  20. Strategies of Administrative Control and Organizational Effectiveness

    ERIC Educational Resources Information Center

    Reimann, Bernard C.; Negandhi, Anant R.

    1975-01-01

    The results of a comparative study of 30 manufacturing firms in India indicated that the most effective organizations tended to choose a unidimensional strategy of administrative control. This strategy consisted of the use of formalized procedures to control decentralized decision-making with respect to both human and material resources. (Author)

  1. 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…

  2. 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…

  3. 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…

  4. 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.…

  5. The Strength of Weak Identities: Social Structural Sources of Self, Situation and Emotional Experience

    ERIC Educational Resources Information Center

    Smith-Lovin, Lynn

    2007-01-01

    Modern societies are highly differentiated, with relatively uncorrelated socially salient dimensions and a preponderance of weak, unidimensional (as opposed to strong, multiplex) ties. What are the implications of a society with fewer strong ties and more weak ties for the self? What do these changes mean for our emotional experience in everyday…

  6. 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…

  7. 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…

  8. 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…

  9. 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.…

  10. 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…

  11. Is Lawson's Classroom Test of Formal Reasoning Valid?

    ERIC Educational Resources Information Center

    Pratt, C.; Hacker, R. G.

    1984-01-01

    A unidimensional latent trait model was used to test a single-factor hypothesis of the Lawson Classroom Test of Formal Reasoning. The test failed to provide a valid measure of formal reasoning. This was a result of test format which neglected aspects of formal reasoning emphasized by Inhelder and Piaget. (Author/DWH)

  12. Technical Analysis of Teacher Responses to the Self-Evaluation Scale-Teacher (SES-T) Version

    ERIC Educational Resources Information Center

    Erford, Bradley T.; Lowe, Samantha; Chang, Catherine Y.

    2011-01-01

    The Self-Evaluation Scale--Teacher version, used to assess teacher perceived self-esteem of students, was analyzed. A unidimensional model emerged from exploratory factor analysis, with cautious acceptance of data fit. Reliability and external aspects of validity were supported by the Self-Evaluation Scale--Teacher data.

  13. 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…

  14. 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…

  15. Some Statistics for Assessing Person-Fit Based on Continuous-Response Models

    ERIC Educational Resources Information Center

    Ferrando, Pere Joan

    2010-01-01

    This article proposes several statistics for assessing individual fit based on two unidimensional models for continuous responses: linear factor analysis and Samejima's continuous response model. Both models are approached using a common framework based on underlying response variables and are formulated at the individual level as fixed regression…

  16. 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…

  17. 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…

  18. 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…

  19. The Multivariate Nature of Professional Job Satisfaction.

    ERIC Educational Resources Information Center

    Wood, Donald A.; LeBold, William K.

    Discussed are two theories of professional job satisfaction--(1) unidimensional and (2) multidimensional with special reference to Herzberg's two factor theory. A national sample of over 3,000 engineering graduates responded to a questionnaire and satisfaction index. Analysis of results revealed that job satisfaction is multidimensional. Job…

  20. 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…

  1. 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…

  2. 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…

  3. Development of a Performance-Based Measure of Executive Functions in Patients with Schizophrenia

    PubMed Central

    Chiu, En-Chi; Kuo, Chian-Jue; Lung, For-Wey; Hsieh, Ching-Lin

    2015-01-01

    A performance-based measure for assessing executive functions (EF) is useful to understand patients’ real life performance of EF. This study aimed to develop a performance-based measure of executive functions (PEF) based on the Lezak model and to examine psychometric properties (i.e., unidimensionality and reliability) of the PEF using Rasch analysis in patients with schizophrenia. We developed the PEF in three phases: (1) designing the preliminary version of PEF; (2) consultation with experts, cognitive interviews with patients, and pilot tests on patients to revise the preliminary PEF; (3) establishment of the final version of the PEF and examination of unidimensionality and Rasch reliability. Two hundred patients were assessed using the revised PEF. After deleting items which did not satisfy the Rasch model’s expectations, the final version of the PEF contained 1 practice item and 13 test items for assessing the four domains of EF (i.e., volition, planning, purposive action, and effective performance). For unidimensional and multidimensional Rasch analyses, the 4 domains showed good reliability (i.e., 0.77–0.85 and 0.87–0.90, respectively). Our results showed that the PEF had satisfactory unidimensionality and Rasch reliability. Therefore, clinicians and researchers could use the PEF to assess the four domains of EF in patients with schizophrenia. PMID:26561862

  4. 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…

  5. 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…

  6. Access of Black Students to Graduate And Professional Schools.

    ERIC Educational Resources Information Center

    Blackwell, James E.

    The issue of access at the level of graduate and professional training is multifaceted. Absolutely nothing about this issue is unidimensional and singularly focused except perhaps the persistent effort of black Americans to attain their rights to higher education. Hence, this study highlights such important components of the access issue as…

  7. 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…

  8. Cueing Strategies and Basic Skills in Early Reading.

    ERIC Educational Resources Information Center

    Beebe, Mona J.; Bulcock, Jeffrey W.

    The extent to which cuing strategies and basic skills explanations of early reading constitute complementary approaches was examined in a study involving 94 fourth grade students. Basic skills--a unidimensional component based on measures of vocabulary development, language skills, and work-study skills--proved to be a powerful variable mediating…

  9. 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…

  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. 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 specific…

  12. 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…

  13. 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…

  14. Examining the Bifactor IRT Model for Vertical Scaling in K-12 Assessment

    ERIC Educational Resources Information Center

    Koepfler, James R.

    2012-01-01

    Over the past decade, educational policy trends have shifted to a focus on examining students' growth from kindergarten through twelfth grade (K-12). One way states can track students' growth is with a vertical scale. Presently, every state that uses a vertical scale bases the scale on a unidimensional IRT model. These models make a…

  15. Using Logistic Approximations of Marginal Trace Lines to Develop Short Assessments

    ERIC Educational Resources Information Center

    Stucky, Brian D.; Thissen, David; Edelen, Maria Orlando

    2013-01-01

    Test developers often need to create unidimensional scales from multidimensional data. For item analysis, "marginal trace lines" capture the relation with the general dimension while accounting for nuisance dimensions and may prove to be a useful technique for creating short-form tests. This article describes the computations needed to obtain…

  16. 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…

  17. 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…

  18. 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

  19. 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…

  20. A Method of Optimal Scaling for Multivariate Ordinal Data and Its Extensions.

    ERIC Educational Resources Information Center

    Saito, Takayuki; Otsu, Tatsuo

    1988-01-01

    A method of optimal scaling for multivariate ordinal data--OSMOD--is described, within a generalized principal component analysis. It yields a: multidimensional configuration of items, unidimensional scale of category weights for each item, and multidimensional configuration of subjects. OSMOD involves solving an eigenvalue problem and executing a…

  1. 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…

  2. 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…

  3. Development of a Performance-Based Measure of Executive Functions in Patients with Schizophrenia.

    PubMed

    Chiu, En-Chi; Lee, Shu-Chun; Kuo, Chian-Jue; Lung, For-Wey; Hsueh, I-Ping; Hsieh, Ching-Lin

    2015-01-01

    A performance-based measure for assessing executive functions (EF) is useful to understand patients' real life performance of EF. This study aimed to develop a performance-based measure of executive functions (PEF) based on the Lezak model and to examine psychometric properties (i.e., unidimensionality and reliability) of the PEF using Rasch analysis in patients with schizophrenia. We developed the PEF in three phases: (1) designing the preliminary version of PEF; (2) consultation with experts, cognitive interviews with patients, and pilot tests on patients to revise the preliminary PEF; (3) establishment of the final version of the PEF and examination of unidimensionality and Rasch reliability. Two hundred patients were assessed using the revised PEF. After deleting items which did not satisfy the Rasch model's expectations, the final version of the PEF contained 1 practice item and 13 test items for assessing the four domains of EF (i.e., volition, planning, purposive action, and effective performance). For unidimensional and multidimensional Rasch analyses, the 4 domains showed good reliability (i.e., 0.77-0.85 and 0.87-0.90, respectively). Our results showed that the PEF had satisfactory unidimensionality and Rasch reliability. Therefore, clinicians and researchers could use the PEF to assess the four domains of EF in patients with schizophrenia. PMID:26561862

  4. 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.)

  5. Bully-Victimization Scale: Using Rasch Modeling in the Analysis of a Qualitative Scale

    ERIC Educational Resources Information Center

    Lehto, Marybeth

    2009-01-01

    The primary purpose of this study was to determine whether the data from the qualitative study fit Rasch model requirements for the definition of a measure, as well as to address concern in the extant literature regarding the appropriate number of items needed in analysis to assure unidimensionality. The self-report victimization scale was…

  6. Mixed Rasch Modeling of the Self-Rating Depression Scale

    ERIC Educational Resources Information Center

    Hong, Sehee; Min, Sae-Young

    2007-01-01

    In this study, mixed Rasch modeling was used on the Self-Rating Depression Scale (SDS), a widely used measure of depression, among a non-Western sample of 618 Korean college students. The results revealed three latent classes and confirmed the unidimensionality of the SDS. In addition, there was a significant effect for gender in terms of class…

  7. Validity of the Strong Interest Inventory and Skills Confidence Inventory with Mexican American High School Students

    ERIC Educational Resources Information Center

    Flores, Lisa Y.; Spanierman, Lisa B.; Armstrong, Patrick Ian; Velez, Alexandra D.

    2006-01-01

    The structural and concurrent validity of the Strong Interest Inventory (SII) and Skills Confidence Inventory (SCI) was explored with a sample of 487 Mexican American high school students, and findings were compared with normative samples of the SII and SCI. Holland's (1997) structure was evaluated using circular unidimensional scaling. The…

  8. 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…

  9. Modeling Repeated Count Data: Some Extensions of the Rasch Poisson Counts Model.

    ERIC Educational Resources Information Center

    Duijn, Marijtje A. J. van; Jansen, Margo G. H.

    1995-01-01

    The Rasch Poisson Counts Model, a unidimensional latent trait model for tests that postulates that intensity parameters are products of test difficulty and subject ability parameters, is expanded into the Dirichlet-Gamma-Poisson model that takes into account variation between subjects and interaction between subjects and tests. (SLD)

  10. Measuring the Self-Stigma Associated with Seeking Psychological Help

    ERIC Educational Resources Information Center

    Vogel, David L.; Wade, Nathaniel G.; Haake, Shawn

    2006-01-01

    Self-stigma is an important factor in people's decisions not to engage in therapy. To measure this construct, the authors developed the 10-item Self-Stigma of Seeking Help (SSOSH) scale. In Study 1 (n = 583), the SSOSH had a unidimensional factor structure and good reliability (0.91) among participants. Study 2 (n = 470) confirmed the factor…

  11. 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…

  12. 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…

  13. A Scalable Set of ESL Reading Comprehension Items.

    ERIC Educational Resources Information Center

    Perkins, Kyle

    Guttman implicational scaling techniques were used to identify a unidimensional set of English as a Second Language reading comprehension items. Data were analyzed from 202 students who sat for an institutional administration of the Test of English as a Foreign Language (TOEFL). The examinees who contributed to the scalable set had significantly…

  14. 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…

  15. 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,…

  16. 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…

  17. A New Perspective on Perspective Taking: A Multidimensional Approach to Conceptualizing an Aptitude

    ERIC Educational Resources Information Center

    Gehlbach, Hunter

    2004-01-01

    Social perspective taking (SPT) is thought to be important in its own right and is often associated with other important skills, such as interpersonal conflict resolution. Previous research on SPT, however, has conceptualized it as a unidimensional construct leaving scholars with an insufficient understanding of this aptitude and how it relates to…

  18. The Effects on Parameter Estimation of Correlated Abilities Using a Two-Dimensional, Two-Parameter Logistic Item Response Model.

    ERIC Educational Resources Information Center

    Batley, Rose-Marie; Boss, Marvin W.

    The effects of correlated dimensions on parameter estimation were assessed, using a two-dimensional item response theory model. Past research has shown the inadequacies of the unidimensional analysis of multidimensional item response data. However, few studies have reported multidimensional analysis of multidimensional data, and, in those using…

  19. An Empirical Comparison of Two LISREL Chi-Square Goodness-of-Fit Statistics and the Implications for Dimensionality Assessment of Item Response Data.

    ERIC Educational Resources Information Center

    De Champlain, Andre F.; Gessaroli, Marc E.

    A study was conducted to compare, with simulated unidimensional and two-dimensional sets, the Type I error probabilities and rejection rates obtained with two versions of the LISREL computer program, the earlier version PRELIS/LISREL 7 and the later version PRELIS2/LISREL8, a version that corrects the asymptotic covariance matrix. Unidimensional…

  20. The Use of Partial Order Structures for Investigating Suicidal Behavior.

    ERIC Educational Resources Information Center

    Dancer, L. Suzanne

    This study had two purposes: to test the usefulness of partial order scalogram analysis with multivariate response data; and to illustrate the multidimensional nature of suicide risk. A detailed introduction describes partial order scalograms, which locate respondents' profiles in a two-dimensional space (rather than on a unidimensional Guttman…

  1. 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…

  2. 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)…

  3. An Application of Unfolding and Cumulative Item Response Theory Models for Noncognitive Scaling: Examining the Assumptions and Applicability of the Generalized Graded Unfolding Model

    ERIC Educational Resources Information Center

    Sgammato, Adrienne N.

    2009-01-01

    This study examined the applicability of a relatively new unidimensional, unfolding item response theory (IRT) model called the generalized graded unfolding model (GGUM; Roberts, Donoghue, & Laughlin, 2000). A total of four scaling methods were applied. Two commonly used cumulative IRT models for polytomous data, the Partial Credit Model and the…

  4. Rasch Analysis of the General Self-Efficacy Scale in Workers with Traumatic Limb Injuries.

    PubMed

    Wu, Tzu-Yi; Yu, Wan-Hui; Huang, Chien-Yu; Hou, Wen-Hsuan; Hsieh, Ching-Lin

    2016-09-01

    Purpose The purpose of this study was to apply Rasch analysis to examine the unidimensionality and reliability of the General Self-Efficacy Scale (GSE) in workers with traumatic limb injuries. Furthermore, if the items of the GSE fitted the Rasch model's assumptions, we transformed the raw sum ordinal scores of the GSE into Rasch interval scores. Methods A total of 1076 participants completed the GSE at 1 month post injury. Rasch analysis was used to examine the unidimensionality and person reliability of the GSE. The unidimensionality of the GSE was verified by determining whether the items fit the Rasch model's assumptions: (1) item fit indices: infit and outfit mean square (MNSQ) ranged from 0.6 to 1.4; and (2) the eigenvalue of the first factor extracted from principal component analysis (PCA) for residuals was <2. Person reliability was calculated. Results The unidimensionality of the 10-item GSE was supported in terms of good item fit statistics (infit and outfit MNSQ ranging from 0.92 to 1.32) and acceptable eigenvalues (1.6) of the first factor of the PCA, with person reliability = 0.89. Consequently, the raw sum scores of the GSE were transformed into Rasch scores. Conclusions The results indicated that the items of GSE are unidimensional and have acceptable person reliability in workers with traumatic limb injuries. Additionally, the raw sum scores of the GSE can be transformed into Rasch interval scores for prospective users to quantify workers' levels of self-efficacy and to conduct further statistical analyses.

  5. 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.

  6. 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

  7. 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 Brasileir

  8. 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.

  9. La doctora Amelie Ramírez y la investigación de desigualdades de salud por cáncer en la comunidad la

    Cancer.gov

    La doctora Ramírez es la investigadora principal de Redes en Acción, un centro del programa de redes comunitarias subvencionado por el NCI que se propone reducir la incidencia del cáncer en la comunidad latina a través de una red nacional de grupos comunitarios, investigadores, agencias de salud gubernamentales y la población en general.

  10. 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. PMID:25562335

  11. Assessment of fatigue among working people: a comparison of six questionnaires

    PubMed Central

    De Vries, J; Michielsen, H; Van Heck, G L

    2003-01-01

    Aims: To compare the psychometric qualities of six fatigue questionnaires in a sample of working persons. Methods: Internal consistency and test-retest reliability, content validity, convergent validity, and the dimensionality of the fatigue instruments were explored. Results: All scales had a satisfactory internal consistency. Furthermore, based on factor analyses and Mokken scale analyses, all scales were unidimensional and appeared to measure an identical construct. The Fatigue Assessment Scale (FAS) had the highest factor loading on the one factor solution obtained in a factor analysis of the total scores of all scales. Conclusions: All the questionnaires were unidimensional and had good reliability and validity. The FAS was the most promising fatigue measure. PMID:12782741

  12. Back to "the Future": Evidence of a Bifactor Solution for Scores on the Consideration of Future Consequences Scale.

    PubMed

    McKay, Michael T; Morgan, Grant B; van Exel, N Job; Worrell, Frank C

    2015-01-01

    Despite its widespread use, disagreement remains regarding the structure of the Consideration of Future Consequences Scale (CFCS). In particular there is disagreement regarding whether the scale assesses future orientation as a unidimensional or multidimensional (immediate and future) construct. Using 2 samples of high school students in the United Kingdom, 4 models were tested. The totality of results including item loadings, goodness-of-fit indexes, and reliability estimates all supported the bifactor model, suggesting that the 2 hypothesized factors are better understood as grouping or method factors rather than as representative of latent constructs. Accordingly this study supports the unidimensionality of the CFCS and the scoring of all 12 items to produce a global future orientation score. Researchers intending to use the CFCS, and those with existing data, are encouraged to examine a bifactor solution for the scale.

  13. 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.

  14. Investigating the measurement properties of the social responsiveness scale in preschool children with autism spectrum disorders.

    PubMed

    Duku, Eric; Vaillancourt, Tracy; Szatmari, Peter; Georgiades, Stelios; Zwaigenbaum, Lonnie; Smith, Isabel M; Bryson, Susan; Fombonne, Eric; Mirenda, Pat; Roberts, Wendy; Volden, Joanne; Waddell, Charlotte; Thompson, Ann; Bennett, Teresa

    2013-04-01

    The purpose of this study was to examine the measurement properties of the Social Responsiveness Scale in an accelerated longitudinal sample of 4-year-old preschool children with the complementary approaches of categorical confirmatory factor analysis and Rasch analysis. Measurement models based on the literature and other hypothesized measurement models which were tested using categorical confirmatory factor analysis did not fit well and were not unidimensional. Rasch analyses showed that a 30-item subset met criteria of unidimensionality and invariance across item, person, and over time; and this subset exhibited convergent validity with other child outcomes. This subset was shown to have enhanced psychometric properties and could be used in measuring social responsiveness among preschool age children with Autism Spectrum Disorders. PMID:22915306

  15. Validation of the BRIEF-P in a sample of Canadian preschool children.

    PubMed

    Duku, Eric; Vaillancourt, Tracy

    2014-01-01

    The Behavior Rating Inventory for Executive Function-Preschool (BRIEF-P) is an instrument designed to assess preschoolers' executive function (EF) in the context of where the behavior occurs. The present study examined the psychometric properties and measurement structure of the BRIEF-P using parents' and teachers' reports on 625 typically developing children aged 25 to 74 months. Results indicated that the BRIEF-P scales had good internal consistency and convergent validity in this sample of children. However, the measurement models examined exhibited poor fit statistics and showed that the EF construct was not unidimensional but rather multidimensional with interrelated subconstructs. Further analyses showed that three of the clinical scales (Emotional Control, Plan/Organize, and Working Memory) were unidimensional and invariant across informant. The other two clinical scales (Inhibit and Shift) were multidimensional and differed by informant. Results support a multidimensional construct of EF and, accordingly, different measurement models are proposed by informant. PMID:23721091

  16. 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.

  17. A psychometric assessment of the GAIN individual severity scale (GAIN-GISS) and short screeners (GAIN-SS) among adolescents in outpatient treatment programs.

    PubMed

    Stucky, Brian D; Edelen, Maria Orlando; Ramchand, Rajeev

    2014-02-01

    The global appraisal of individual needs (GAIN)-general individual severity scale (GAIN-GISS), and GAIN-short screener (GAIN-SS) are widely used diagnostic measures of internalizing disorders, externalizing disorders, substance abuse, and criminal and violent behavior. Although prevalent in clinical and research settings, there is only limited psychometric evidence of the dimensional structure of these scales. Our investigation used intake data from 6,909 adolescents presenting to outpatient substance abuse treatment facilities in the United States. Our analytic approach used exploratory and item factor analyses to evaluate the underlying factor structure. Multi- and unidimensional item response theory models were employed to evaluate the utility of the scales at providing precise score estimates at various locations of severity. Most scales were confirmed as unidimensional; scales with evidence of multidimensionality, identified as having a weak general dimension and strong specific dimensions using a bifactor IRT model, include the Crime and Violence Scale and the GAIN-SS.

  18. A Psychometric Assessment of the GAIN General Individual Severity Scale (GAIN-GISS) and Short Screeners (GAIN-SS) Among Adolescents in Outpatient Treatment Programs

    PubMed Central

    Stucky, Brian D.; Edelen, Maria Orlando; Ramchand, Rajeev

    2013-01-01

    The Global Appraisal of Individual Needs (GAIN) - General Individual Severity Scale (GAIN-GISS), and GAIN-Short Screener (GAIN-SS) are widely used diagnostic measures of internalizing disorders, externalizing disorders, substance abuse, and criminal and violent behavior. Though prevalent in clinical and research settings, there is only limited psychometric evidence of the dimensional structure of these scales. Our investigation used intake data from 6,909 adolescents presenting to outpatient substance abuse treatment facilities in the United States. Our analytic approach used exploratory and item factor analyses to evaluate the underlying factor structure. Multi- and unidimensional item response theory models were employed to evaluate the utility of the scales at providing precise score estimates at various locations of severity. Most scales were confirmed as unidimensional; scales with evidence of multidimensionality, identified as having a weak general dimension and strong specific dimensions using a bifactor IRT model, include the Crime Violence Scale and the GAIN-SS. PMID:23994048

  19. Investigating the measurement properties of the social responsiveness scale in preschool children with autism spectrum disorders.

    PubMed

    Duku, Eric; Vaillancourt, Tracy; Szatmari, Peter; Georgiades, Stelios; Zwaigenbaum, Lonnie; Smith, Isabel M; Bryson, Susan; Fombonne, Eric; Mirenda, Pat; Roberts, Wendy; Volden, Joanne; Waddell, Charlotte; Thompson, Ann; Bennett, Teresa

    2013-04-01

    The purpose of this study was to examine the measurement properties of the Social Responsiveness Scale in an accelerated longitudinal sample of 4-year-old preschool children with the complementary approaches of categorical confirmatory factor analysis and Rasch analysis. Measurement models based on the literature and other hypothesized measurement models which were tested using categorical confirmatory factor analysis did not fit well and were not unidimensional. Rasch analyses showed that a 30-item subset met criteria of unidimensionality and invariance across item, person, and over time; and this subset exhibited convergent validity with other child outcomes. This subset was shown to have enhanced psychometric properties and could be used in measuring social responsiveness among preschool age children with Autism Spectrum Disorders.

  20. 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.

  1. ThurCatD: a tool for analyzing ratings on an ordinal category scale.

    PubMed

    Boschman, M C

    2000-08-01

    An algorithm for analyzing ordinal scaling results is described. Frequency data on ordinal categories are modeled for unidimensional psychological attributes according to Thurstone's judgment scaling model. The algorithm applies maximum likelihood estimation of model parameters. The Cramér-Rao bounds of the standard errors of the estimated parameters are calculated, and a stress measure and a goodness-of-fit measure are supplied. PMID:11029809

  2. Bifactor Models and Rotations: Exploring the Extent to which Multidimensional Data Yield Univocal Scale Scores

    PubMed Central

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

    2010-01-01

    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 and target bifactor rotations) and confirmatory bifactor modeling, c) differentiate between bifactor and second-order models, 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 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. PMID:20954056

  3. L'utilisation des algorithmes génétiques pour l'identification de profils hydriques de sol à partir de courbes réflectométriques

    NASA Astrophysics Data System (ADS)

    Todoroff, Pierre; Lorion, Richard; Lan Sun Luk, Jean-Daniel

    1998-11-01

    We developed a unidimensional microwave propagation model in a stratified medium. It calculates, from a given soil water content profile, the reflected signal trace one would measure by timedomain reflectometry along a transmission line inserted in the soil. We identify the soil water content profile corresponding to a measured reflected signal trace using an identification technique based on optimisation of the model parameters by a genetic algorithm.

  4. 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.

  5. 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

  6. [Mathematic model of the cupuloendolymphatic system for various densities of cupula and endolymph].

    PubMed

    Kondrachuk, A V; Sirenko, S P

    1986-01-01

    This paper presents a mathematical model of time-course variations of the cupulo-endolymphatic system which can be described by the Steinhauzen phenomenological equation for the case of a unidimensional toroid, assuming that the densities of the cupula and endolymph are identical. If the densities are different, the time-course variations of the cupuloendolymphatic system may aggravate and manifest at the powered stages of space flight.

  7. 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.

  8. Dimensionality and predictive validity of the HAM-Nat, a test of natural sciences for medical school admission

    PubMed Central

    2011-01-01

    Background Knowledge in natural sciences generally predicts study performance in the first two years of the medical curriculum. In order to reduce delay and dropout in the preclinical years, Hamburg Medical School decided to develop a natural science test (HAM-Nat) for student selection. In the present study, two different approaches to scale construction are presented: a unidimensional scale and a scale composed of three subject specific dimensions. Their psychometric properties and relations to academic success are compared. Methods 334 first year medical students of the 2006 cohort responded to 52 multiple choice items from biology, physics, and chemistry. For the construction of scales we generated two random subsamples, one for development and one for validation. In the development sample, unidimensional item sets were extracted from the item pool by means of weighted least squares (WLS) factor analysis, and subsequently fitted to the Rasch model. In the validation sample, the scales were subjected to confirmatory factor analysis and, again, Rasch modelling. The outcome measure was academic success after two years. Results Although the correlational structure within the item set is weak, a unidimensional scale could be fitted to the Rasch model. However, psychometric properties of this scale deteriorated in the validation sample. A model with three highly correlated subject specific factors performed better. All summary scales predicted academic success with an odds ratio of about 2.0. Prediction was independent of high school grades and there was a slight tendency for prediction to be better in females than in males. Conclusions A model separating biology, physics, and chemistry into different Rasch scales seems to be more suitable for item bank development than a unidimensional model, even when these scales are highly correlated and enter into a global score. When such a combination scale is used to select the upper quartile of applicants, the proportion of

  9. National intelligence estimates and the Failed State Index.

    PubMed

    Voracek, Martin

    2013-10-01

    Across 177 countries around the world, the Failed State Index, a measure of state vulnerability, was reliably negatively associated with the estimates of national intelligence. Psychometric analysis of the Failed State Index, compounded of 12 social, economic, and political indicators, suggested factorial unidimensionality of this index. The observed correspondence of higher national intelligence figures to lower state vulnerability might arise through these two macro-level variables possibly being proxies of even more pervasive historical and societal background variables that affect both.

  10. 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.

  11. Virtual Testing of Composite Motorcycle Helmets

    NASA Astrophysics Data System (ADS)

    Cernicchi, Alessandro; Galvanetto, Ugo; Olsson, Robin

    A study about the response of motorcycle helmets to impacts is described in this paper and possible ways to improve current designs are discussed. Firstly, a simple unidimensional model of helmet is analyzed and the main parameters that affect its response are pointed out. Subsequently, the generation and testing of the Finite Element model of a commercially available helmet are described and numerical results are compared to experimental results. Finally, the FE modeled is used to compare different design configurations.

  12. 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

  13. 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.

  14. Dopaminergic Genetic Polymorphisms Predict Rule-Based Category Learning

    PubMed Central

    Byrne, Kaileigh A.; Davis, Tyler; Worthy, Darrell A.

    2016-01-01

    Dopaminergic genes play an important role in cognitive function. DRD2 and DARPP-32 dopamine receptor gene polymorphisms affect striatal dopamine binding potential, while the Val158Met single nucleotide polymorphism of the COMT gene moderates dopamine availability in the prefrontal cortex. Our study assesses the role of these gene polymorphisms on performance in two rule-based category learning tasks. Participants completed unidimensional and conjunctive rule-based tasks. In the unidimensional task, a rule along a single stimulus dimension can be used to distinguish category members. In contrast, a conjunctive rule utilizes a combination of two dimensions to distinguish category members. DRD2 C957T TT homozygotes outperformed C allele carriers on both tasks, and DARPP-32 AA homozygotes outperformed G allele carriers on both tasks. However, we found an interaction between COMT and task-type where Met allele carriers outperformed Val homozygotes in the conjunctive rule task, but both groups performed equally well in the unidimensional task. Thus, striatal dopamine binding may play a critical role in both types of rule-based tasks, while prefrontal dopamine binding is important for learning more complex conjunctive rule tasks. Modeling results suggest that striatal dopaminergic genes influence selective attention processes while cortical genes mediate the ability to update complex rule-representations. PMID:26918585

  15. 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. PMID:24940657

  16. An informant questionnaire for detecting Alzheimer's disease: are some items better than others?

    PubMed

    Sikkes, Sietske A M; Knol, Dirk L; van den Berg, Mark T; de Lange-de Klerk, Elly S M; Scheltens, Philip; Klein, Martin; Pijnenburg, Yolande A L; Uitdehaag, Bernard M J

    2011-07-01

    A decline in everyday cognitive functioning is important for diagnosing dementia. Informant questionnaires, such as the informant questionnaire on cognitive decline in the elderly (IQCODE), are used to measure this. Previously, conflicting results on the IQCODEs ability to discriminate between Alzheimer's disease (AD), mild cognitive impairment (MCI), and cognitively healthy elderly were found. We aim to investigate whether specific groups of items are more useful than others in discriminating between these patient groups. Informants of 180 AD, 59 MCI, and 89 patients with subjective memory complaints (SMC) completed the IQCODE. To investigate the grouping of questionnaire items, we used a two-dimensional graded response model (GRM).The association between IQCODE, age, gender, education, and diagnosis was modeled using structural equation modeling. The GRM with two groups of items fitted better than the unidimensional model. However, the high correlation between the dimensions (r=.90) suggested unidimensionality. The structural model showed that the IQCODE was able to differentiate between all patient groups. The IQCODE can be considered as unidimensional and as a useful addition to diagnostic screening in a memory clinic setting, as it was able to distinguish between AD, MCI, and SMC and was not influenced by gender or education. PMID:22882809

  17. 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.

  18. The Psychometric Development and Initial Validation of the DCI-A Short Form for Adolescent Therapeutic Community Treatment Process

    PubMed Central

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

    2014-01-01

    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. PMID:24462245

  19. Identifying an appropriate measurement modeling approach for the Mini-Mental State Examination.

    PubMed

    Rubright, Jonathan D; Nandakumar, Ratna; Karlawish, Jason

    2016-02-01

    The Mini-Mental State Examination (MMSE) is a 30-item, dichotomously scored test of general cognition. A number of benefits could be gained by modeling the MMSE in an item response theory (IRT) framework, as opposed to the currently used classical additive approach. However, the test, which is built from groups of items related to separate cognitive subdomains, may violate a key assumption of IRT: local item independence. This study aimed to identify the most appropriate measurement model for the MMSE: a unidimensional IRT model, a testlet response theory model, or a bifactor model. Local dependence analysis using nationally representative data showed a meaningful violation of the local item independence assumption, indicating multidimensionality. In addition, the testlet and bifactor models displayed superior fit indices over a unidimensional IRT model. Statistical comparisons showed that the bifactor model fit MMSE respondent data significantly better than the other models considered. These results suggest that application of a traditional unidimensional IRT model is inappropriate in this context. Instead, a bifactor model is suggested for future modeling of MMSE data as it more accurately represents the multidimensional nature of the scale. (PsycINFO Database Record

  20. 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

  1. 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…

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

    PubMed

    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. PMID:26765568

  3. 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

  4. Interaction of the transforming acidic coiled-coil 1 (TACC1) protein with ch-TOG and GAS41/NuBI1 suggests multiple TACC1-containing protein complexes in human cells.

    PubMed Central

    Lauffart, Brenda; Howell, Scott J; Tasch, Jason E; Cowell, John K; Still, Ivan H

    2002-01-01

    Dysregulation of the human transforming acidic coiled-coil (TACC) proteins is thought to be important in the evolution of breast cancer and multiple myeloma. However, the exact role of these proteins in the oncogenic process is currently unknown. Using the full-length TACC1 protein as bait to screen a human mammary epithelial cDNA library, we have identified two genes that are also amplified and overexpressed in tumours derived from different cellular origins. TACC1 interacts with the C-terminus of both the microtubule-associated colonic and hepatic tumour overexpressed (ch-TOG) protein, and the oncogenic transcription factor glioma amplified sequence 41/NuMA binding protein 1 (GAS41/NuBI1; where NuMA stands for nuclear mitotic apparatus protein 1). This suggests that the TACC proteins can form multiple complexes, dysregulation of which may be an important step during tumorigenesis. PMID:11903063

  5. 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

  6. 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

  7. Self-reported Cognitive Concerns and Abilities: Two sides of one coin?

    PubMed Central

    Lai, Jin-Shei; Wagner, Lynne I.; Jacobsen, Paul B.; Cella, David

    2014-01-01

    OBJECTIVE Patient-reported cognitive function can be measured using negatively-worded items (Concerns) and positively-worded (Abilities) items. It is possible reporting Abilities is less subject to the influence of emotional states. This study evaluated the relationship between cognitive concerns and cognitive abilities. METHODS Cancer patients (N = 509; mean age=61 years; 50% males; 86% White) completed Concerns and Abilities items developed by the NIH Patient Reported Outcomes Information System (PROMIS). Confirmatory factor analysis (CFA) was used to evaluate the extent to which items loaded on one single factor (unidimensionality). Multidimensionality was evaluated using bi-factor analysis (local factors: Concerns and Abilities). Slope parameters from multidimensional Item Response Theory (MIRT) and unidimensional IRT (UIRT) were compared to evaluate which factor solution fit best. RESULTS Acceptable fit indices were found in both one-factor CFA (CFI=0.96, RMSEA=0.062) and bi-factor analysis (CFI=0.98; RMSEA=0.043). Thus, Abilities and Concerns could be considered as a single dimension. Yet high loadings on the local factor in bi-factor analysis and slope discrepancies between UIRT and MIRT indicate that Abilities should be considered as a separate factor from Concerns. CONCLUSIONS Concerns and Abilities could be measured using one unidimensional item bank. Results also support measuring each construct separately. We recommend a conservative approach by measuring and reporting Concerns and Abilities separately. We therefore recommend two separate but co-calibrated item banks in the PROMIS network: Cognitive Function Item Bank - Concerns, and Cognitive Function Item Bank - Abilities. Both item banks showed good psychometric properties and are available for research and clinical purposes. PMID:24700645

  8. Characterizing kernels of operators related to thin-plate magnetizations via generalizations of Hodge decompositions

    NASA Astrophysics Data System (ADS)

    Baratchart, L.; Hardin, D. P.; Lima, E. A.; Saff, E. B.; Weiss, B. P.

    2013-01-01

    Recently developed scanning magnetic microscopes measure the magnetic field in a plane above a thin-plate magnetization distribution. These instruments have broad applications in geoscience and materials science, but are limited by the requirement that the sample magnetization must be retrieved from measured field data, which is a generically nonunique inverse problem. This problem leads to an analysis of the kernel of the related magnetization operators, which also has relevance to the ‘equivalent source problem’ in the case of measurements taken from just one side of the magnetization. We characterize the kernel of the operator relating planar magnetization distributions to planar magnetic field maps in various function and distribution spaces (e.g., sums of derivatives of Lp (Lebesgue spaces) or bounded mean oscillation (BMO) functions). For this purpose, we present a generalization of the Hodge decomposition in terms of Riesz transforms and utilize it to characterize sources that do not produce a magnetic field either above or below the sample, or that are magnetically silent (i.e. no magnetic field anywhere outside the sample). For example, we show that a thin-plate magnetization is silent (i.e. in the kernel) when its normal component is zero and its tangential component is divergence free. In addition, we show that compactly supported magnetizations (i.e. magnetizations that are zero outside of a bounded set in the source plane) that do not produce magnetic fields either above or below the sample are necessarily silent. In particular, neither a nontrivial planar magnetization with fixed direction (unidimensional) compact support nor a bidimensional planar magnetization (i.e. a sum of two unidimensional magnetizations) that is nontangential can be silent. We prove that any planar magnetization distribution is equivalent to a unidimensional one. We also discuss the advantages of mapping the field on both sides of a magnetization, whenever experimentally

  9. Improving the utility of the Brunnstrom recovery stages in patients with stroke: Validation and quantification.

    PubMed

    Huang, Chien-Yu; Lin, Gong-Hong; Huang, Yi-Jing; Song, Chen-Yi; Lee, Ya-Chen; How, Mon-Jane; Chen, Yi-Miau; Hsueh, I-Ping; Chen, Mei-Hsiang; Hsieh, Ching-Lin

    2016-08-01

    The Brunnstrom recovery stages (the BRS) consists of 2 items assessing the poststroke motor function of the upper extremities and 1 assessing the lower extremities. The 3 items together represent overall motor function. Although the BRS efficiently assesses poststroke motor functions, a lack of rigorous examination of the psychometric properties restricts its utility. We aimed to examine the unidimensionality, Rasch reliability, and responsiveness of the BRS, and transform the raw sum scores of the BRS into Rasch logit scores once the 3 items fitted the assumptions of the Rasch model.We retrieved medical records of the BRS (N = 1180) from a medical center. We used Rasch analysis to examine the unidimensionality and Rasch reliability of both upper-extremity items and the 3 overall motor items of the BRS. In addition, to compare their responsiveness for patients (n = 41) assessed with the BRS and the Stroke Rehabilitation Assessment of Movement (STREAM) on admission and at discharge, we calculated the effect size (ES) and standardized response mean (SRM).The upper-extremity items and overall motor items fitted the assumptions of the Rasch model (infit/outfit mean square = 0.57-1.40). The Rasch reliabilities of the upper-extremity items and overall motor items were high (0.91-0.92). The upper-extremity items and overall motor items had adequate responsiveness (ES = 0.35-0.41, SRM = 0.85-0.99), which was comparable to that of the STREAM (ES = 0.43-0.44, SRM = 1.00-1.13).The results of our study support the unidimensionality, Rasch reliability, and responsiveness of the BRS. Moreover, the BRS can be transformed into an interval-level measure, which would be useful to quantify the extent of poststroke motor function, the changes of motor function, and the differences of motor functions in patients with stroke.

  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.

    PubMed

    Myre, Michael A; O'Day, Danton H

    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 (171EDVSRFIKGKLLQKQQKIYKDLERF195) 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 48KKSYQDPEIIAHSRPRK64 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 48EF49 abolished the stability of the GFP fusion at the protein but not RNA level preventing subcellular analyses. Cells transfected with the 48EF49 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. PMID:15896312

  11. A splicing alteration of 4.1R pre-mRNA generates 2 protein isoforms with distinct assembly to spindle poles in mitotic cells.

    PubMed

    Delhommeau, François; Vasseur-Godbillon, Corinne; Leclerc, Philippe; Schischmanoff, Pierre-Olivier; Croisille, Laure; Rince, Patricia; Morinière, Madeleine; Benz, Edward J; Tchernia, Gil; Tamagnini, Gabriel; Ribeiro, Leticia; Delaunay, Jean; Baklouti, Faouzi

    2002-10-01

    The C-terminal region of erythroid cytoskeletal protein 4.1R, encoded by exons 20 and 21, contains a binding site for nuclear mitotic apparatus protein (NuMA), a protein needed for the formation and stabilization of the mitotic spindle. We have previously described a splicing mutation of 4.1R that yields 2 isoforms: One, CO.1, lacks most of exon 20-encoded peptide and carries a missense C-terminal sequence. The other, CO.2, lacks exon 20-encoded C-terminal sequence, but retains the normal exon 21-encoded C-terminal sequence. Knowing that both shortened proteins are expressed in red cells and assemble to the membrane skeleton, we asked whether they would ensure 4.1R mitotic function in dividing cells. We show here that CO.2, but not CO.1, assembles to spindle poles, and colocalizes with NuMA in erythroid and lymphoid mutated cells, but none of these isoforms interact with NuMA in vitro. In microtubule-destabilizing conditions, again only CO.2 localizes to the centrosomes. These data suggest that the stability of 4.1R association with centrosomes requires an intact C-terminal end, either for a proper conformation of the protein, for a direct binding to an unknown centrosome-cytoskeletal network, or for both. We also found that 4.1G, a ubiquitous homolog of 4.1R, is present in mutated as well as control cells and that its C-terminal region binds efficiently to NuMA, suggesting that in fact mitotic spindles host a mixture of the two 4.1 family members. These findings led to the postulate that the coexpression at the spindle poles of 2 related proteins, 4.1R and 4.1G, might reflect a functional redundancy in mitotic cells. PMID:12239178

  12. 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.

  13. The BRCA1-binding protein BRAP2 can act as a cytoplasmic retention factor for nuclear and nuclear envelope-localizing testicular proteins.

    PubMed

    Davies, Rebecca G; Wagstaff, Kylie M; McLaughlin, Eileen A; Loveland, Kate L; Jans, David A

    2013-12-01

    Regulation of nuclear protein import is central to many cellular processes such as development, with a key mechanism being factors that retain cargoes in the cytoplasm that normally localize in the nucleus. The breast cancer antigen BRCA1-binding protein BRAP2 has been reported as a novel negative regulator of nuclear import of various nuclear localization signal (NLS)-containing viral and cellular proteins, but although implicated in differentiation pathways and highly expressed in tissues including testis, the gamut of targets for BRAP2 action in a developmental context is unknown. As a first step towards defining the BRAP2 interactome, we performed a yeast-2-hybrid screen to identify binding partners of BRAP2 in human testis. Here we report characterization for the first time of three of these: the high mobility group (HMG)-box-domain-containing chromatin component HMG20A, nuclear mitotic apparatus protein NuMA1 and synaptic nuclear envelope protein SYNE2. Co-immunoprecipitation experiments indicate association of BRAP2 with HMG20A, NuMA1, and SYNE2 in testis, underlining the physiological relevance of the interactions, with immunohistochemistry showing that where BRAP2 is co-expressed with HMG20A and NuMA1, both are present in the cytoplasm, in contrast to their nuclear localization in other testicular cell types. Importantly, quantitative confocal microscopic analysis of cultured cells indicates that ectopic expression of BRAP2 inhibits nuclear localization of HMG20A and NuMA1, and prevents nuclear envelope accumulation of SYNE2, the first report of BRAP2 altering localization of a non-nuclear protein. These results imply for the first time that BRAP2 may have an important role in modulating subcellular localization during testicular development. PMID:23707952

  14. The early days of caesarian section.

    PubMed

    Ellis, Harold

    2010-05-01

    The story of the early days of caesarian section is shrouded in mystery, myths and old folk tales. The very name itself is the subject of debate. One thing is certain--it is nothing at all to do with Julius Caesar; his mother was still alive when he invaded Britain in 55BC. The most probable explanation of the term is the law promulgated by King Numa Pompillius of Rome in the year 715BC. PMID:20521579

  15. 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.

  16. Bistability By Self-Reflection In A Saturable Absorber

    NASA Astrophysics Data System (ADS)

    Roso-Franco, Luis

    1987-01-01

    Propagation of laser light through a saturable absorber is theoretically studied. Computed steady state solutions of the Maxwell equations describing the unidimensional propagation of a plane monochromatic wave without introducing the slowly-varying envelope approximation are presented showing how saturation effects can influence the absorption of the field. At a certain range of refractive index and extintion coefficients, computed solutions display a very susprising behaviour, and a self-reflected wave appears inside the absorber. This can be useful for a new kind of biestable device, similar to a standard bistable cavity but with the back mirror self-induced by the light.

  17. 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

  18. Conceptualizing and measuring global interpersonal mistrust-trust.

    PubMed

    Omodei, M M; McLennan, J

    2000-06-01

    Global interpersonal mistrust is conceptualized as a general mistrust of the motives of others in situations related to one's well-being: a general tendency to view others as mean, selfish, malevolent, or unreliable people who are, thus, not to be depended on to treat one well. The authors developed an 18-item unidimensional self-report inventory measuring interpersonal mistrust as a negative cognitive orientation toward others. The measure comprises items describing perceptions of specific hypothetical interpersonal situations rather than items asking respondents to describe their own general behavior. The measure was reliable and evidenced construct validity in a heterogeneous sample of Australians.

  19. The measurement properties of mentoring relationship quality scales for mentoring programs.

    PubMed

    Ferro, Annalise; Wells, Samantha; Speechley, Kathy Nixon; Lipman, Ellen; DeWit, David

    2014-10-01

    The measurement properties of two new scales designed to measure global and engagement mentoring relationship quality (Global Mentoring Relationship Quality Scale and Quality of Mentoring Relationship Engagement Scale) were examined among 272 mentors, 491 children, and 554 parents participating in Big Brothers Big Sisters community mentoring programs across Canada. Results demonstrated their unidimensionality, moderate convergent validity, good external validity, and weak-to-moderate reporter concordance. Longitudinal analyses demonstrated good predictive validity of mentor and parent mentoring relationship quality scales with respect to predicting mentoring relationship status.

  20. Controlling decremental and inflationary effects in reliability estimation resulting from violations of assumptions.

    PubMed

    Becker, G

    2001-10-01

    Two assumptions in classical test theory, essential tau-equivalence and independence of measurement errors, when violated may produce attenuated or inflated estimates of reliability, respectively. Inflation stemming from correlated errors can be controlled by a procedure in which systematically created equivalent halves of a given measuring instrument are administered across two occasions. When poor approximations to equivalent halves are constructed for this purpose, however, distortion in the opposite direction may result, being sometimes quite large when measuring instruments are not essentially tau-equivalent (or, at the practical level, unidimensional). The nature of these decrements are discussed and illustrated, and a number of procedures for eliminating them introduced. PMID:11783569

  1. Multidimensional perfectionism and academic procrastination: relationships with depression in university students.

    PubMed

    Saddler, C D; Sacks, L A

    1993-12-01

    Depression in university students is associated with numerous problematic outcomes. Unidimensional perfectionism and academic procrastination have each independently been related with depression and with one another in university students. Multidimensional perfectionism, consisting of self and social dimensions, and academic procrastination have not been simultaneously examined for their interrelationships with one another and with depression. Measures of multidimensional perfectionism, academic procrastination, and depression were administered to 150 undergraduate and graduate students. Analyses showed that only one dimension of perfectionism was correlated with procrastination, although both perfectionism and procrastination were important in accounting for depression in these students. Findings are discussed as they relate to the treatment of university students for the symptoms of depression.

  2. 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. PMID:22610830

  3. 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.

  4. 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.

  5. Dictyostelium calcium-binding protein 4a interacts with nucleomorphin, a BRCT-domain protein that regulates nuclear number.

    PubMed

    Myre, Michael A; O'Day, Danton H

    2004-09-17

    Nucleomorphin from Dictyostelium discoideum is a nuclear calmodulin-binding protein that is a member of the BRCT-domain containing cell cycle checkpoint proteins. Two differentially expressed isoforms, NumA and NumB, share an extensive acidic domain (DEED) that when deleted produces highly multinucleated cells. We performed a yeast two-hybrid screen of a Dictyostelium cDNA library using NumA as bait. Here we show that nucleomorphin interacts with calcium-binding protein 4a (CBP4a) in a Ca(2+)-dependent manner. Further deletion analysis suggests this interaction requires residues found within the DEED domain. NumA and CBP4a mRNAs are expressed at the same stages of development. CBP4a belongs to a large family of Dictyostelium CBPs, for which no cellular or developmental functions had previously been determined. Since the interaction of CBP4a with nucleomorphin requires the DEED domain, this suggests that CBP4a may respond to Ca(2+)-signalling through modulating factors that might function in concert to regulate nuclear number. PMID:15325281

  6. 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

  7. 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.

  8. Locality-Aware Parallel Process Mapping for Multi-Core HPC Systems

    SciTech Connect

    Hursey, Joshua J; Squyres, Jeffrey M.; Dontje, Terry

    2011-01-01

    High Performance Computing (HPC) systems are composed of servers containing an ever-increasing number of cores. With such high processor core counts, non-uniform memory access (NUMA) architectures are almost universally used to reduce inter-processor and memory communication bottlenecks by distributing processors and memory throughout a server-internal networking topology. Application studies have shown that the tuning of processes placement in a server s NUMA networking topology to the application can have a dramatic impact on performance. The performance implications are magnified when running a parallel job across multiple server nodes, especially with large scale HPC applications. This paper presents the Locality-Aware Mapping Algorithm (LAMA) for distributing the individual processes of a parallel application across processing resources in an HPC system, paying particular attention to the internal server NUMA topologies. The algorithm is able to support both homogeneous and heterogeneous hardware systems, and dynamically adapts to the available hardware and user-specified process layout at run-time. As implemented in Open MPI, the LAMA provides 362,880 mapping permutations and is able to naturally scale out to additional hardware resources as they become available in future architectures.

  9. The novel tankyrase inhibitor (AZ1366) enhances irinotecan activity in tumors that exhibit elevated tankyrase and irinotecan resistance

    PubMed Central

    Quackenbush, Kevin S.; Bagby, Stacey; Tai, Wai Meng; Messersmith, Wells A.; Schreiber, Anna; Greene, Justin; Kim, Jihye; Wang, Guoliang; Purkey, Alicia; Pitts, Todd M.; Nguyen, Anna; Gao, Dexiang; Blatchford, Patrick; Capasso, Anna; Schuller, Alwin G.; Eckhardt, S. Gail; Arcaroli, John J.

    2016-01-01

    Background Dysregulation of the canonical Wnt signaling pathway has been implicated in colorectal cancer (CRC) development as well as incipient stages of malignant transformation. In this study, we investigated the antitumor effects of AZ1366 (a novel tankyrase inhibitor) as a single agent and in combination with irinotecan in our patient derived CRC explant xenograft models. Results Six out of 18 CRC explants displayed a significant growth reduction to AZ1366. There was one CRC explant (CRC040) that reached the threshold of sensitivity (TGII ≤ 20%) in this study. In addition, the combination of AZ1366 + irinotecan demonstrated efficacy in 4 out of 18 CRC explants. Treatment effects on the WNT pathway revealed that tankyrase inhibition was ineffective at reducing WNT dependent signaling. However, the anti-tumor effects observed in this study were likely a result of alternative tankyrase effects whereby tankyrase inhibition reduced NuMA levels. Materials and Methods Eighteen CRC explants were treated with AZ1366 single agent or in combination for 28 days and treatment responses were assessed. Pharmacokinetic (AZ1366 drug concentrations) and pharmacodynamic effects (Axin2 levels) were investigated over 48 hours. Immunohistochemistry of nuclear β-catenin levels as well as western blot was employed to examine the treatment effects on the WNT pathway as well as NuMA. Conclusions Combination AZ1366 and irinotecan achieved greater anti-tumor effects compared to monotherapy. Activity was limited to CRC explants that displayed irinotecan resistance and increased protein levels of tankyrase and NuMA. PMID:27070088

  10. 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…

  11. 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…

  12. 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…

  13. "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…

  14. 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 ...

  15. The tobacco dependence dimension in Colombia.

    PubMed

    Posada-Villa, Jose; Cheng, Hui G; Martins, Silvia S; Storr, Carla L; Aguilar-Gaxiola, Sergio A; Anthony, James C

    2011-01-01

    This epidemiological study of a sample of smokers from the general population of Colombia examined the population distribution and dimensionality of eight hypothesized inter-correlated clinical features (CFs) associated with tobacco dependence syndrome (TDS). Data were drawn from interviews of 4 426 smokers conducted in a national survey in Colombia as part of the World Mental Health Survey Initiative. Daily smokers completed a Spanish-language TDS module, and the 237 smokers who had begun smoking during the five years prior to the assessment were selected. Confirmatory factor analysis (CFA) for a unidimensional TDS provided discrimination and difficulty parameter estimates. Two CFs that were reported very infrequently among the study sample were dropped from the CFA. Among the six remaining CFs, discrimination (D1) estimates ranged from 1.1 to 6.0 and difficulty (D2) estimates ranged from 1.1 to 2.2, providing evidentiary support for a unidimensional tobacco dependence construct. The Spanish-language TDS module used in this study could serve as a valuable tool in future studies for evaluating public health outreach and early intervention programs directed toward community residents who have begun smoking tobacco.

  16. The Challenges of Fitting an Item Response Theory Model to the Social Anhedonia Scale

    PubMed Central

    Reise, Steven P.; Horan, William P.; Blanchard, Jack J.

    2011-01-01

    This study explored the application of latent variable measurement models to the Social Anhedonia Scale (SAS; Eckblad, Chapman, Chapman, & Mishlove, 1982), a widely used and influential measure in schizophrenia-related research. Specifically, we applied unidimensional and bifactor item response theory (IRT) models to data from a community sample of young adults (n = 2,227). Ordinal factor analyses revealed that identifying a coherent latent structure in the 40-item SAS data was challenging due to: a) the presence of multiple small content clusters (e.g., doublets), b) modest relations between those clusters which, in turn, implies a general factor of only modest strength, c) items that shared little variance with the majority of items, and d) cross-loadings in bifactor solutions. Consequently, we conclude that SAS responses cannot be modeled accurately by either unidimensional or bifactor IRT models. Although the application of a bifactor model to a reduced 17-item set met with better success, significant psychometric and substantive problems remained. Results highlight the challenges of applying latent variable models to scales there were not originally designed to fit these models. PMID:21516580

  17. 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

  18. [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.

  19. 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.

  20. 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.

  1. Rasch modeling and confirmatory factor analysis of the systemizing quotient-revised (SQ-R) scale.

    PubMed

    Allison, Carrie; Baron-Cohen, Simon; Stone, Mark H; Muncer, Steven J

    2015-01-01

    This study assessed the dimensionality of the Systemizing Quotient-Revised (SQ-R), a measure of how strong a person's interest is in systems, using two statistical approaches: Rasch modeling and Confirmatory Factor Analysis (CFA). Participants included N = 675 with an autism spectrum condition (ASC), N = 1369 family members of people with ASC, and N = 2014 typical controls. Data were applied to the Rasch model (Rating Scale) using WINSTEPS. The data fit the Rasch model quite well lending support to the idea that systemizing could be seen as unidimensional. Reliability estimates were .99 for items and .92 for persons. A CFA parceling approach confirmed that a unidimensional model fit the data. There was, however, differential functioning by sex in some of these items. An abbreviated 44-item version of the scale, consisting of items without differential item functioning by sex was developed. This shorter scale also was tested from a Rasch perspective and confirmed through CFA. All measures showed differences on total scale scores between those participants with and without ASC (d = 0.71, p < .005), and between sexes (d = 0.53, p < .005). We conclude that the SQ-R is an appropriate measure of systemizing which can be measured along a single dimension.

  2. The Communicative Participation Item Bank (CPIB): Item bank calibration and development of a disorder-generic short form

    PubMed Central

    Baylor, Carolyn; Yorkston, Kathryn; Eadie, Tanya; Kim, Jiseon; Chung, Hyewon; Amtmann, Dagmar

    2015-01-01

    Purpose The purpose of this study was to calibrate the items for the Communicative Participation Item Bank (CPIB) using Item Response Theory (IRT). One overriding objective was to examine if the IRT item parameters would be consistent across different diagnostic groups, thereby allowing creation of a disorder-generic instrument. The intended outcomes were the final item bank and a short form ready for clinical and research applications. Methods Self-report data were collected from 701 individuals representing four diagnoses: multiple sclerosis, Parkinson’s disease, amyotrophic lateral sclerosis and head and neck cancer. Participants completed the CPIB and additional self-report questionnaires. CPIB data were analyzed using the IRT Graded Response Model (GRM). Results The initial set of 94 candidate CPIB items were reduced to an item bank of 46 items demonstrating unidimensionality, local independence, good item fit, and good measurement precision. Differential item function (DIF) analyses detected no meaningful differences across diagnostic groups. A 10-item, disorder-generic short form was generated. Conclusions The CPIB provides speech-language pathologists with a unidimensional, self-report outcomes measurement instrument dedicated to the construct of communicative participation. This instrument may be useful to clinicians and researchers wanting to implement measures of communicative participation in their work. PMID:23816661

  3. Rasch-Built Measure of Pleasant Touch through Active Fingertip Exploration

    PubMed Central

    Klöcker, Anne; Arnould, Carlyne; Penta, Massimo; Thonnard, Jean-Louis

    2012-01-01

    Background: Evidence suggests that somatic sensation has a modality for pleasant touch. Objective: To investigate pleasant touch at the fingertip level (i.e., glabrous skin site) through the elaboration of a linear unidimensional scale that measures (i) various materials according to the level of pleasantness they elicit through active fingertip explorations and (ii) subjects according to their pleasantness leniency levels. Subjects: We enrolled 198 healthy subjects without any neurological disease. Methods: Blindfolded subjects actively explored 48 materials with their index fingertips and reported the perceived pleasantness of each on a 4-level scale. The fingertip moisture levels on each subject were measured before the experimental session. Data were analyzed using the Rasch model. Results: We elaborated unidimensional linear scale that included 37 materials according to their pleasantness of touch. The pleasantness level of 21 materials was perceived differently, depending on the fingertip moisture levels of the subjects. Conclusion: Based on our findings, we formulated a Pleasant Touch Scale. Fingertip moisture levels appeared to be a major factor for (un)pleasant feelings during active exploration. PMID:22737122

  4. Development of CRIS: measure of community reintegration of injured service members.

    PubMed

    Resnik, Linda; Plow, Matthew; Jette, Alan

    2009-01-01

    Identification and prevention of community reintegration problems of veterans is an important public health mandate. However, no veteran-specific measure exists. Study purposes were to (1) develop the Community Reintegration for Service Members (CRIS) measure and (2) test the validity and reliability of the measure. Formative research identified challenges in community reintegration postdeployment. The World Health Organization's International Classification of Functioning, Disability and Health participation domain guided item-bank development. Items were refined through cognitive interviews and clinician consultation. Pilot studies with 126 veterans examined unidimensionality, internal consistency, reliability, and construct validity. Three unidimensional CRIS scales were developed. Working subjects had better CRIS scores then unemployed subjects. Subjects with posttraumatic stress disorder, substance abuse, or mental health problems had worse scores than subjects without these conditions. The correlations between the CRIS and the 36-Item Short Form Health Survey scales of role physical, role emotional, and social functioning were 0.44-0.80. CRIS has strong reliability, conceptual integrity, and construct validity.

  5. Measuring Participation: The Patient-Reported Outcomes Measurement Information System Experience

    PubMed Central

    Bode, Rita K.; Hahn, Elizabeth A.; DeVellis, Robert; Cella, David

    2013-01-01

    Objectives To describe the lessons learned in the initial development of PROMIS social function item banks. Design Development and testing of two item pools within a general population to create item banks that measure ability-to-participate and satisfaction-with-participation in social activities. Setting Administration via the Internet. Participants General population members (N=956) of a national polling organization registry participated; data for 768 and 778 participants used in the analysis. Interventions Not applicable. Main Outcome Measures Measures of ability-to-participate and satisfaction-with-participation in social activities. Results Fifty six items measuring the ability-to-participate were essentially unidimensional but did not fit an IRT model. As a result, item banks were not developed for these items. Of the 56 items measuring satisfaction-with-participation, 14 items measuring social roles and 12 items measuring discretionary activities were unidimensional and met IRT model assumptions. Two 7-item short forms were also developed. Conclusions Four lessons, mostly concerning item content, were learned in the development of banks measuring social function. These lessons led to item revisions that are being tested in subsequent studies. PMID:20801282

  6. Cable analysis in quiescent and active sheep Purkinje fibres.

    PubMed

    Pressler, M L

    1984-07-01

    Cable properties of sheep cardiac Purkinje fibres were studied under resting and paced conditions. Standard micro-electrode techniques were used to apply intracellular current pulses and record the resultant voltage changes at various distances from the current input. In a parallel set of experiments, fibre dimensions were measured after freezing and serial sectioning. Fibres selected on the basis of a cylindrical appearance had approximately uniform cross-sectional diameters which varied +/- 12% along their length. Electrotonic potentials recorded at rest and in diastole (under conditions that minimized diastolic depolarization) adhered quite closely to the behaviour expected for a unidimensional cable provided voltages were recorded greater than or equal to one fibre diameter from the current source. The unidimensional space constant, input resistance, and membrane time constant were significantly larger during quiescence than in diastole. These differences were accounted for by a 90% increase in membrane resistance at rest. There was no significant change in internal longitudinal resistance nor membrane capacitance associated with activity. The voltage distribution close to the current input (i.e. within one fibre diameter) strongly deviated from the theoretical three-dimensional voltage decay expected for a homogeneous cylinder. This finding suggests that the transverse resistance to current flow is much greater than the longitudinal resistance. The anisotropic behaviour within the cardiac Purkinje fibre may explain several previous observations: (i) the lack of a relationship between conduction velocity and fibre diameter; and (ii) the much shorter liminal length for excitation in Purkinje fibres than for point-stimulated squid axons.

  7. Development and Psychometric Evaluation of a German Version of the PROMIS® Item Banks for Satisfaction With Participation.

    PubMed

    Nagl, Michaela; Gramm, Lukas; Heyduck, Katja; Glattacker, Manuela; Farin, Erik

    2015-06-01

    The Patient Reported Outcomes Measurement Information System (PROMIS) initiative aims to provide reliable and precise item banks measuring patient-reported outcomes in different health domains. The aim of the present work was to provide a German translation of the PROMIS item banks for satisfaction with participation and to psychometrically test these German versions. Cognitive interviews followed a forward-backward translation. Distribution characteristics, unidimensionality, Rasch model fit, reliability, construct validity, and internal responsiveness were tested in 262 patients with chronic low back pain undergoing rehabilitation. Results for the final 13- and 10-item German static scales (Satisfaction with Participation in Social Roles-German version [PSR-G] and Satisfaction for Participation in Discretionary Social Activities-German version [PSA-G]) regarding unidimensionality were satisfactory. The scales are reliable and show good Rasch model fit and distribution characteristics. Both scales are sensitive to small to moderate clinical changes, and we observed initial proof of construct validity. These German versions of the Satisfaction with Participation scales can be recommended to assess participation in a clinical context. The scales' applicability in other contexts should be examined.

  8. 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

  9. Combining item response theory and diagnostic classification models: a psychometric model for scaling ability and diagnosing misconceptions.

    PubMed

    Bradshaw, Laine; Templin, Jonathan

    2014-07-01

    Traditional testing procedures typically utilize unidimensional item response theory (IRT) models to provide a single, continuous estimate of a student's overall ability. Advances in psychometrics have focused on measuring multiple dimensions of ability to provide more detailed feedback for students, teachers, and other stakeholders. Diagnostic classification models (DCMs) provide multidimensional feedback by using categorical latent variables that represent distinct skills underlying a test that students may or may not have mastered. The Scaling Individuals and Classifying Misconceptions (SICM) model is presented as a combination of a unidimensional IRT model and a DCM where the categorical latent variables represent misconceptions instead of skills. In addition to an estimate of ability along a latent continuum, the SICM model provides multidimensional, diagnostic feedback in the form of statistical estimates of probabilities that students have certain misconceptions. Through an empirical data analysis, we show how this additional feedback can be used by stakeholders to tailor instruction for students' needs. We also provide results from a simulation study that demonstrate that the SICM MCMC estimation algorithm yields reasonably accurate estimates under large-scale testing conditions.

  10. 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

  11. 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

  12. Assessing the factor structure of a role functioning item bank

    PubMed Central

    Ware, John E.; Bjorner, Jakob B.

    2013-01-01

    Purpose Role functioning (RF) is an important part of health-related quality of life, but is hard to measure due to the wide definition of roles and fluctuations in role participation. This study aims to explore the dimensionality of a newly developed item bank assessing the impact of health on RF. Methods A battery of measures with skip patterns including the new RF bank was completed by 2,500 participants answering only questions on social roles relevant to them. Confirmatory factor analyses were conducted for the participants answering items from all conceptual domains (N = 1193). Conceptually based dimensionality and method effects reflecting positively and negatively worded items were explored in a series of models. Results A bi-factor model (CFI = .93, RMSEA = .08) with one general and four conceptual factors (social, family, occupation, generic) was retained. Positively worded items were excluded from the final solution due to misfit. While a single factor model with methods factors had a poor fit (CFI = .88, RMSEA = .13), high loadings on the general factor in the bi-factor model suggest that the RF bank is sufficiently unidimensional for IRT analysis. Conclusions The bank demonstrated sufficient unidimensionality for IRT-based calibration of all the items on a common metric and development of a computerized adaptive test. PMID:21153710

  13. Validation of a Targeted Peer Relations Scale for Adolescents Treated for Substance Use Disorder: An Application of Rasch Modeling

    PubMed Central

    Ciesla, James R.; Yao, Ping

    2011-01-01

    The objective of this research is to use item response theory (IRT) to validate a 14-item peer relations scale for use in the adolescent treatment population. Subjects are 509 adolescents discharged from substance abuse treatment from 2004–2009. The person reliability is 0.76 and the Cronbach’s alpha person raw score reliability is 0.93 both indicating the scale is a strong metric. The item reliability of 0.99 is high showing the model is reliable. The real separation (8.49) meaning items are placed on the Rasch “ruler” with about eight levels of importance identified. The mean-square statistics of the infit and outfit values were between 0.5 and 1.5 for the items indicating a low level of randomness and thus unidimensionality of the scale. Inspection of a Wright Item Map shows the hierarchical structure of the scale with a moderate degree of inter-item spread. The analysis shows the scale is a reliable unidimensional metric. PMID:22879749

  14. 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

  15. Development of the PROMIS® Coping Expectancies of Smoking Item Banks

    PubMed Central

    Edelen, Maria Orlando; Tucker, Joan S.; Stucky, Brian D.; Hansen, Mark; Cai, Li

    2014-01-01

    Objective: Smoking is a coping strategy for many smokers who then have difficulty finding new ways to cope with negative affect when they quit. This paper describes analyses conducted to develop and evaluate item banks for assessing the coping expectancies of smoking for daily and nondaily smokers. Methods: Using data from a large 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 (DIF) analyses (according to gender, age, and ethnicity) to arrive at a unidimensional set of items for daily and nondaily smokers. We also evaluated performance of short forms (SFs) and computer adaptive tests (CATs) for assessing coping expectancies of smoking. Results: For both daily and nondaily smokers, the unidimensional Coping Expectancies item banks (21 items) are relatively DIF free and are highly reliable (0.96 and 0.97, respectively). A common 4-item SF for daily and nondaily smokers also showed good reliability (0.85). Adaptive tests required an average of 4.3 and 3.7 items for simulated daily and nondaily respondents, respectively, and achieved reliabilities of 0.91 for both when the maximum test length was 10 items. Conclusions: This research provides a new set of items that can be used to reliably assess coping expectancies of smoking, through a SF, CAT, or a tailored set selected for a specific research purpose. PMID:25118227

  16. 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

  17. An item factor analysis and item response theory-based revision of the Everyday Discrimination Scale.

    PubMed

    Stucky, Brian D; Gottfredson, Nisha C; Panter, A T; Daye, Charles E; Allen, Walter R; Wightman, Linda F

    2011-04-01

    The Everyday Discrimination Scale (EDS), a widely used measure of daily perceived discrimination, is purported to be unidimensional, to function well among African Americans, and to have adequate construct validity. Two separate studies and data sources were used to examine and cross-validate the psychometric properties of the EDS. In Study 1, an exploratory factor analysis was conducted on a sample of African American law students (N = 589), providing strong evidence of local dependence, or nuisance multidimensionality within the EDS. In Study 2, a separate nationally representative community sample (N = 3,527) was used to model the identified local dependence in an item factor analysis (i.e., bifactor model). Next, item response theory (IRT) calibrations were conducted to obtain item parameters. A five-item, revised-EDS was then tested for gender differential item functioning (in an IRT framework). Based on these analyses, a summed score to IRT-scaled score translation table is provided for the revised-EDS. Our results indicate that the revised-EDS is unidimensional, with minimal differential item functioning, and retains predictive validity consistent with the original scale.

  18. The challenges of fitting an item response theory model to the Social Anhedonia Scale.

    PubMed

    Reise, Steven P; Horan, William P; Blanchard, Jack J

    2011-05-01

    This study explored the application of latent variable measurement models to the Social Anhedonia Scale (SAS; Eckblad, Chapman, Chapman, & Mishlove, 1982), a widely used and influential measure in schizophrenia-related research. Specifically, we applied unidimensional and bifactor item response theory (IRT) models to data from a community sample of young adults (n = 2,227). Ordinal factor analyses revealed that identifying a coherent latent structure in the 40-item SAS data was challenging due to (a) the presence of multiple small content clusters (e.g., doublets); (b) modest relations between those clusters, which, in turn, implies a general factor of only modest strength; (c) items that shared little variance with the majority of items; and (d) cross-loadings in bifactor solutions. Consequently, we conclude that SAS responses cannot be modeled accurately by either unidimensional or bifactor IRT models. Although the application of a bifactor model to a reduced 17-item set met with better success, significant psychometric and substantive problems remained. Results highlight the challenges of applying latent variable models to scales that were not originally designed to fit these models.

  19. 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.

  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. A reexamination of the factor structure of the Center for Epidemiologic Studies Depression Scale: is a one-factor model plausible?

    PubMed

    Edwards, Michael C; Cheavens, Jennifer S; Heiy, Jane E; Cukrowicz, Kelly C

    2010-09-01

    The Center for Epidemiologic Studies Depression Scale (CES-D) is one of the most widely used measures of depressive symptoms in research today. The original psychometric work in support of the CES-D (Radloff, 1977) described a 4-factor model underlying the 20 items on the scale. Despite a long history of evidence supporting this structure, researchers routinely report single-number summaries from the CES-D. The research described in this article examines the plausibility of 1-factor model using an initial sample of 595 subjects and a cross-validation sample of 661. After comparing a series of models found in the literature or suggested by analyses, we determined that the good fit of the 4-factor model is mostly due to its ability to model excess covariance associated with the 4 reverse-scored items. A 2-factor model that included a general depression factor and a positive wording method factor loading only on those 4 items had fit that was nearly as good as the original 4-factor model. We conclude that although a 1-factor model may not be the best model for the full 20-item CES-D, it is at least plausible. If a unidimensional set of items is required (e.g., for a unidimensional item response theory analysis), by dropping 5 items, we were able to find a 1-factor model that had very similar fit to the 4-factor model with the original 20 items. PMID:20822284

  2. [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.

  3. Two protein 4.1 domains essential for mitotic spindle and aster microtubule dynamics and organization in vitro.

    PubMed

    Krauss, Sharon Wald; Lee, Gloria; Chasis, Joel Anne; Mohandas, Narla; Heald, Rebecca

    2004-06-25

    Multifunctional structural proteins belonging to the 4.1 family are components of nuclei, spindles, and centrosomes in vertebrate cells. Here we report that 4.1 is critical for spindle assembly and the formation of centrosome-nucleated and motor-dependent self-organized microtubule asters in metaphase-arrested Xenopus egg extracts. Immunodepletion of 4.1 disrupted microtubule arrays and mislocalized the spindle pole protein NuMA. Remarkably, assembly was completely rescued by supplementation with a recombinant 4.1R isoform. We identified two 4.1 domains critical for its function in microtubule polymerization and organization utilizing dominant negative peptides. The 4.1 spectrin-actin binding domain or NuMA binding C-terminal domain peptides caused morphologically disorganized structures. Control peptides with low homology or variant spectrin-actin binding domain peptides that were incapable of binding actin had no deleterious effects. Unexpectedly, the addition of C-terminal domain peptides with reduced NuMA binding caused severe microtubule destabilization in extracts, dramatically inhibiting aster and spindle assembly and also depolymerizing preformed structures. However, the mutant C-terminal peptides did not directly inhibit or destabilize microtubule polymerization from pure tubulin in a microtubule pelleting assay. Our data showing that 4.1 is a crucial factor for assembly and maintenance of mitotic spindles and self-organized and centrosome-nucleated microtubule asters indicates that 4.1 is involved in regulating both microtubule dynamics and organization. These investigations underscore an important functional context for protein 4.1 in microtubule morphogenesis and highlight a previously unappreciated role for 4.1 in cell division.

  4. Improving the utility of the Brunnstrom recovery stages in patients with stroke

    PubMed Central

    Huang, Chien-Yu; Lin, Gong-Hong; Huang, Yi-Jing; Song, Chen-Yi; Lee, Ya-Chen; How, Mon-Jane; Chen, Yi-Miau; Hsueh, I-Ping; Chen, Mei-Hsiang; Hsieh, Ching-Lin

    2016-01-01

    Abstract The Brunnstrom recovery stages (the BRS) consists of 2 items assessing the poststroke motor function of the upper extremities and 1 assessing the lower extremities. The 3 items together represent overall motor function. Although the BRS efficiently assesses poststroke motor functions, a lack of rigorous examination of the psychometric properties restricts its utility. We aimed to examine the unidimensionality, Rasch reliability, and responsiveness of the BRS, and transform the raw sum scores of the BRS into Rasch logit scores once the 3 items fitted the assumptions of the Rasch model. We retrieved medical records of the BRS (N = 1180) from a medical center. We used Rasch analysis to examine the unidimensionality and Rasch reliability of both upper-extremity items and the 3 overall motor items of the BRS. In addition, to compare their responsiveness for patients (n = 41) assessed with the BRS and the Stroke Rehabilitation Assessment of Movement (STREAM) on admission and at discharge, we calculated the effect size (ES) and standardized response mean (SRM). The upper-extremity items and overall motor items fitted the assumptions of the Rasch model (infit/outfit mean square = 0.57–1.40). The Rasch reliabilities of the upper-extremity items and overall motor items were high (0.91–0.92). The upper-extremity items and overall motor items had adequate responsiveness (ES = 0.35–0.41, SRM = 0.85–0.99), which was comparable to that of the STREAM (ES = 0.43–0.44, SRM = 1.00–1.13). The results of our study support the unidimensionality, Rasch reliability, and responsiveness of the BRS. Moreover, the BRS can be transformed into an interval-level measure, which would be useful to quantify the extent of poststroke motor function, the changes of motor function, and the differences of motor functions in patients with stroke. PMID:27495103

  5. 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.

  6. [The use of water as indication of the presence of life: technical ways of employment in the archaelogical documentation].

    PubMed

    Cancellieri, M

    1995-01-01

    Ancient urbanization often is strictly connected with rivers and sources. In the ancient world, the usage of water is also linked with the idea of sacrum and with specific religious cults (i.e. the King's Numa mith or the legend of the nymph Egeria). A complex technique of rain water preservation has been elaborated in Rome by building structures of water supplying: the exemples of Segni's colony and Ventotene's imperial island are here examined. Due to the general absence of water supply directly in the houses, public fountains were largely present in the public ways. PMID:11623481

  7. [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.

  8. [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. PMID:24866301

  9. [Functional connectivity and complex networks in focal epilepsy. Pathophysiology and therapeutic implications].

    PubMed

    Pastor, Jesús; Sola, Rafael G; Vega-Zelaya, Lorena; Garnes, Óscar; Ortega, Guillermo J

    2014-05-01

    Introduccion. El modelo tradicional de cirugia de la epilepsia focal consiste en la localizacion y reseccion de la zona epileptogena. Sin embargo, una minoria significativa de pacientes epilepticos sigue teniendo crisis tras la reseccion, lo que muestra el nivel de conocimiento incompleto que actualmente se tiene sobre esta materia. Objetivo. Introducir algunos conceptos de conectividad funcional y redes complejas y su aplicacion al estudio de registros neurofisiologicos de pacientes con epilepsia focal farmacorresistente, principalmente del lobulo temporal. Desarrollo. Con el objeto de entender con plenitud los nuevos desarrollos en el area de redes complejas y sus aplicaciones al estudio de la epilepsia, se revisaran los conceptos fundamentales de la metodologia de redes complejas, sincronizacion y conectividad funcional. Asimismo, se revisaran algunos de los trabajos mas recientes en los que se analizan registros neurofisiologicos y resonancias funcionales de pacientes con epilepsia focal bajo esta nueva perspectiva. Conclusiones. Una vision mas amplia en la perspectiva para el entendimiento de la epilepsia focal, como la tratada en este trabajo, permitira tambien plantear nuevas alternativas al tratamiento quirurgico de la epilepsia focal, tanto con el desarrollo de nuevos metodos no invasivos como con la mejora y optimizacion de algunos de los metodos invasivos ya existentes.

  10. Scanning in biomedical imaging: from classical devices to handheld heads and micro-systems

    NASA Astrophysics Data System (ADS)

    Duma, Virgil-Florin

    2014-01-01

    We review some of the most important scanning systems that are competitive in high-end biomedical imaging applications such as Optical Coherence Tomography (OCT), but also Confocal Microscopy (CM) or multiphoton microscopy. Both 1-D (uni-dimensional) and 2-D (bi-dimensional) scanning systems are considered. The paper discusses different scanners, including polygon mirror, galvanometer-based and Risley prisms. Their configurations and characteristics, as well some of our contributions in the domain are presented. The tendency of applying them into special designs such as handheld scanning probes and endoscopes - the latter with MEMS (Micro-Electro-Mechanical Systems) and micro-systems is pointed out. A discussion on further advancements of scanning technology in biomedical applications in general and in OCT in particular concludes the study.

  11. Multidimensional relationships between paternalistic leadership and perceptions of organizational ethical climates.

    PubMed

    Wu, Yu-Chi; Tsai, Ping Ju

    2012-10-01

    This study investigated how paternalistic leadership is linked to ethical climates based on a multidimensional construct perspective. This experimental study utilized the partial least squares (PLS) techniques to analyze the data. Participants were 258 civil servants working in various public sectors in Taiwan, who were asked to rate their leaders' paternalistic leadership behaviors and their perception of the ethical climates in their organizations using the Paternalistic Leadership Scale and the Ethical Climate Questionnaire. Using the unidimensional constructs of paternalistic leadership and ethical climates, prior research showed vidence of a positive relationship; however, in the current study, multidimensional relations among these constructs may be positive or negative. The findings of this study suggested that leaders may implement specific types of paternalistic leadership to enhance the intended ethical climate in their organizations.

  12. Substance use disorder symptoms: evidence of differential item functioning by age.

    PubMed

    Conrad, Kendon J; Dennis, Michael L; Bezruczko, Nikolaus; Funk, Rodney R; Riley, Barth B

    2007-01-01

    This study examined the applicability of substance abuse diagnostic criteria for adolescents, young adults, and adults using the Global Appraisal of Individual Need's Substance Problems Scale (SPS) from 7,408 clients. Rasch analysis was used to: 1) evaluate whether the SPS operationalized a single reliable dimension, and 2) examine the extent to which the severity of each symptom and the overall test functioned the same or differently by age. Rasch analysis indicated that the SPS was unidimensional with a person reliability of .84. Eight symptoms were significantly different between adolescents and adults. Young adult calibrations tended to fall between adolescents and adults. Differential test functioning was clinically negligible for adolescents but resulted in about 7% more adults being classified as high need. These findings have theoretical implications for screening and treatment of adolescents vs. adults. SPS can be used across age groups though age-specific calibrations enable greater precision of measurement.

  13. Stress, externality, and depression.

    PubMed

    Ganellen, R J; Blaney, P H

    1984-12-01

    Previous research has found mixed support for the possibility that locus of control moderates the effects of life stress on depression. Two methodological choices may have influenced previous findings: the use of a unidimensional rather than a multidimensional locus of control scale, and reliance on linear statistical methods using median splits. We attempted to correct these choices by using the Levenson IPC scale (1974) and multiple regression analyses in a female undergraduate population (N = 158). The results supported use of a multidimensional scale, since Stress, Internality, and Powerful Others were found to have main effects on depression whereas Chance interacted with life stress. The question of whether locus of control refers to responsibility for causing an event, i.e., self-blame, or belief in control over future events, i.e., coping behavior, was discussed.

  14. 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.

  15. Digital system of invariant correlation to position and rotation

    NASA Astrophysics Data System (ADS)

    Solorza, Selene; Álvarez-Borrego, Josué

    2010-10-01

    A new correlation digital system invariant to position and rotation is presented. This new algorithm requires low computational cost, because it uses uni-dimensional signatures (vectors). The signature of the target so like the signature of the object to be recognized in the problem image is obtained using a binary ring mask constructed based on the real positive values of the Fourier transform of the corresponding image. In this manner, each image will have one unique binary ring mask, avoiding in this form the relevant information leak. Using linear and non-linear correlations, this methodology is applied first in the identification of the alphabet letters in Arial font style and then in the classification of fossil diatoms images. Also, this system is tested using the diatom images with additive Gaussian noise. The non-linear correlation results were excellent, obtaining in this way a simple but efficient method to achieve rotation and translation invariance pattern recognition.

  16. 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

    2013-01-01

    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.

  17. Assessing peer victimization across adolescence: measurement invariance and developmental change.

    PubMed

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

    2013-03-01

    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 general victimization factor) or a 3-factor model (separately examining verbal, physical, and social victimization). The 2-factor model best represented the data, and we found support for longitudinal invariance of this model across 7th through 10th grades for both boys and girls. Such findings of temporal invariance are important for further longitudinal comparisons, and we suggest future directions for using the Revised Adolescent Social Experience Questionnaire to examine stability and change in victimization as well as evaluating the effectiveness of intervention programs.

  18. 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

  19. Demographic response to rural restructuring and counterurbanisation in South Australia, 1981-1991.

    PubMed

    Smailes, P J

    1996-09-01

    "Using South Australia as a case study, this paper seeks to trace and demonstrate two processes (counterurbanisation and rural restructuring) whose effects overlap to differentiate and characterise the population geography of...two zones, separated by a transition along the outer fringe of Adelaide's urban field.... In the demographic core zone [rural restructuring] has been partly offset by continued counterurbanisation, resulting in demographic mixing and rural dilution. The 1981-91 population growth in rural communities is shown to be more a function of population density at the outset of the period than of initial population size. Demographic growth...is shown to conform to a simple unidimensional scale, allowing the production of a clear, easily interpretable typology of rural demographic change with few non-conforming statistical areas. At a local level within individual rural communities, demographic decline is shown to be accompanied by increased concentration of the population into small towns, while demographic growth is associated with deconcentration."

  20. Measuring Mental Health Recovery: An Application of Rasch Modeling to the Consumer Recovery Measure.

    PubMed

    Lusczakoski, Kathryn Kd; Olmos-Gallo, P Antonio; Milnor, William; McKinney, Christopher J

    2016-01-01

    As the need for recovery-oriented outcomes increases, it is critical to understand how numeric recovery scores are developed. In the current article, the modern Rasch modeling techniques were applied to establish numeric scores of consumers' perceptions of recovery. A sample of 1,973 adult consumers at a community-based mental health center (57.5% male; average age of 47 years old) completed the 15-item Consumer Recovery Measure. A confirmatory factor analysis revealed the unidimensional nature of the Consumer Recovery Measure and provided construct validity evidence. The Rasch analysis displayed that the items produced acceptable model fit, reliability, and identified the difficulty of the items. The conclusion emphasizes the value of Rasch modeling regarding the measurement of recovery and its relevance to consumer-derived assessments in the clinical decision-making process.

  1. Development of measures of organizational leadership for health promotion.

    PubMed

    Barrett, Linda; Plotnikoff, Ronald C; Raine, Kim; Anderson, Donna

    2005-04-01

    This study describes the development and psychometric evaluation of four scales measuring leadership for health promotion at an organizational level in the baseline survey (n=144) of the Alberta Heart Health Project. Content validity was established through a series of focus groups and expert opinion appraisals, pilot testing of a draft based on capacity assessment instruments developed by other provinces involved in the Canadian Heart Health Initiative, and the literature. Psychometric analyses provided empirical evidence of the construct validity and reliability of the organizational leadership scales. Principal component analysis verified the unidimensionality of the leadership scales of (a) Practices for Organizational Learning, (b) Wellness Planning, (c) Workplace Climate, and (d) Organization Member Development. Scale alpha coefficients ranged between .79 and .91 thus establishing good to high scale internal consistencies. These measures can be used by both researchers and practitioners for the assessment of organizational leadership for health promotion and heart health promotion.

  2. The Duke University Religion Index (DUREL): validation and reliability of the Farsi version.

    PubMed

    Hafizi, Sina; Memari, Amir Hossein; Pakrah, Mohammad; Mohebi, Farnam; Saghazadeh, Amene; Koenig, Harold G

    2013-02-01

    This study examined the validation and reliability of the Farsi version of the Duke University Religion Index (FDUREL), a brief measure designed to evaluate the primary dimensions of religiosity. The study was conducted in two phases. In the first phase, after translation of the original version of DUREL by using standard forward-backward translation, the FDUREL was administered to 427 medical students at different training levels. Reliability of the FDUREL was assessed by internal consistency and test-retest reliability. Principal components factor analysis was employed to assess the construct validity of the measure. In the second phase, 557 medical students were asked to fill out the FDUREL and Hoge Intrinsic Religiosity Scale to examine concurrent validity. The FDUREL was unidimensional and had good internal consistency and test-retest reliability. Results suggest that the FDUREL is a reliable and valid measure of religiosity in Farsi-speaking populations.

  3. 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

  4. 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.

  5. Psychometric properties of the Chinese translation of the proactive personality scale.

    PubMed

    Zhou, Le; Shi, Junqi

    2009-08-01

    The purpose of the present study was to examine the psychometric properties of the Chinese translation of the Proactive Personality Scale. Four samples were surveyed. In Sample 1 and Sample 2, exploratory and confirmatory factor analysis results confirmed the unidimensional structure of the 10-item abbreviated version of the scale. In Sample 2, Proactive Personality scores were found to be positively correlated with the personality factors of Extraversion, Conscientiousness, Openness, and Agreeableness, and negatively correlated with Neuroticism. In Sample 3, Proactive Personality was found to be positively related to self-efficacy and political skill. In Sample 4, demographics controlled, Proactive Personality explained significant incremental variance in the employees' self-rated career satisfaction and job performance as rated by immediate supervisors. PMID:19810432

  6. 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. PMID:27630595

  7. Long-term persistence of sort strategy in free classification.

    PubMed

    Milton, Fraser; Wills, Andy J

    2009-02-01

    Two free classification experiments that investigate the persistence of sort strategy are reported. Participants tend to persist with their initial categorization type (family resemblance or unidimensional) for the remaining sorts, overriding the effects of otherwise influential stimulus properties. Sort type was found to persist even after a one-week delay. Stimulus-driven models of free classification (e.g., the SUSTAIN model, [Love, B. C., Medin, D. L., & Gureckis, T. M. (2004). SUSTAIN: A network model of category learning. Psychological Review, 111, 309-332]) cannot predict the sort type persistence effects we observe, but they are naturally accounted for by theories that posit strategic selection of a problem-solving strategy (e.g., Hypothesis theory, [Levine, M. (1971). Hypothesis theory and nonlearning despite ideal S-R-reinforcement contingencies. Psychological Review, 78, 130-140]).

  8. From wishing to intending: differences in salience of positive versus negative consequences.

    PubMed

    Wicker, F W; Wiehe, J A; Hagen, A S; Brown, G

    1994-09-01

    Goal ratings by 345 subjects in seven data samples supported a functional distinction between two types of positive incentive value, one based on approaching positive affect (positive-based value or PBV), the other on avoiding negative affect (negative-based value or NBV). Ratings of PBV were more related to ratings of earlier action-phases of motivation ("wishing"), whereas ratings of NBV tended to be more related to factors entailed in later action-phases ("urgency/priority" and "intention"). These findings and previous ones are consistent with the proposal that this distinction parallels distinctions in Maslow's motivation theory. If the parallel is accepted, the findings support predictions from Maslow's theory. Results also indicate that purportedly unidimensional rating scales of motivation can reflect more than one underlying attribute.

  9. The Body Appreciation Scale-2: item refinement and psychometric evaluation.

    PubMed

    Tylka, Tracy L; Wood-Barcalow, Nichole L

    2015-01-01

    Considered a positive body image measure, the 13-item Body Appreciation Scale (BAS; Avalos, Tylka, & Wood-Barcalow, 2005) assesses individuals' acceptance of, favorable opinions toward, and respect for their bodies. While the BAS has accrued psychometric support, we improved it by rewording certain BAS items (to eliminate sex-specific versions and body dissatisfaction-based language) and developing additional items based on positive body image research. In three studies, we examined the reworded, newly developed, and retained items to determine their psychometric properties among college and online community (Amazon Mechanical Turk) samples of 820 women and 767 men. After exploratory factor analysis, we retained 10 items (five original BAS items). Confirmatory factor analysis upheld the BAS-2's unidimensionality and invariance across sex and sample type. Its internal consistency, test-retest reliability, and construct (convergent, incremental, and discriminant) validity were supported. The BAS-2 is a psychometrically sound positive body image measure applicable for research and clinical settings.

  10. The firefighter coping self-efficacy scale: measure development and validation.

    PubMed

    Lambert, Jessica E; Benight, Charles C; Harrison, Erica; Cieslak, Roman

    2012-01-01

    The authors evaluated the psychometric properties of the Firefighter Coping Self-Efficacy (FFCSE) Scale, a new measure developed to assess firefighters' perceived competence in managing stressful and traumatic experiences encountered on the job. Two samples of firefighters completed the FFCSE Scale at two different time points. Exploratory factor analysis yielded a unidimensional structure, which was further supported with confirmatory factor analysis using a second sample. Internal consistency of the measure was excellent. Analysis of cross-sectional data indicated FFCSE was positively associated with measures of psychological well-being and social support, and negatively associated with work-related stress and psychological distress. FFCSE also uniquely contributed to the variance in psychological distress, over and above variables previously shown to be associated with distress among this population. Implications and suggestions for future research are discussed. PMID:21476153

  11. Rasch Analysis of the Lubben Social Network Scale-6 (LSNS-6).

    PubMed

    Gray, Jennifer; Kim, Jinsook; Ciesla, James R; Yao, Ping

    2016-05-01

    The purposes of this article are to review the psychometric properties of the Lubben Social Network Scale-6 (LSNS-6) and to determine its utility in assessing social networks of an older adult community sample. We tested the LSNS-6 with Rasch methodology using a sample of 196 older adults, aged 55 and above who live in public and subsidized housing facilities. Rasch analysis showed unidimensionality of the overall scale, high person and item reliability, and good fit of individual items with one exception. Principal component analysis (PCA) of Rasch model residuals suggested family and friend subdimensions. Response categories demonstrated improvement when six categories were collapsed to four. A person-threshold map indicated ceiling and floor effects due to lack of items measuring less and more developed social networks. Recommendations provided in this article can make the LSNS-6 more psychometrically sound and useful in research and practical contexts.

  12. 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.

  13. 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.

  14. The Dutch Social Interaction Anxiety Scale and the Social Phobia Scale: Reliability, Validity, and Clinical Utility

    PubMed Central

    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. PMID:24701560

  15. 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.

  16. IRTs of the ABCs: Children's Letter Name Acquisition

    PubMed Central

    Piasta, Shayne B.; Anthony, Jason L.; Lonigan, Christopher J.; Francis, David J.

    2015-01-01

    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 & 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. PMID:22710016

  17. 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.

  18. Weakly nonlinear localization for a 1-D FPU chain with clustering zones

    NASA Astrophysics Data System (ADS)

    Martínez-Farías, F.; Panayotaros, P.; Olvera, A.

    2014-12-01

    We study weakly nonlinear spatially localized solutions of a Fermi-Pasta-Ulam model describing a unidimensional chain of particles interacting with a number of neighbors that can vary from site to site. The interaction potential contains quadratic and quartic terms, and is derived from a nonlinear elastic network model proposed by Juanico et al. [1]. The FPU model can be also derived for arbitrary dimensions, under a small angular displacement assumption. The variable interaction range is a consequence of the spatial inhomogeneity in the equilibrium particle distribution. We here study some simple one-dimensional examples with only a few, well defined agglomeration regions. These agglomerations are seen to lead to spatially localized linear modes and gaps in the linear spectrum, which in turn imply a normal form that has spatially localized periodic orbits.

  19. Development and validation of the College Life Alcohol Salience Scale: a measure of beliefs about the role of alcohol in college life.

    PubMed

    Osberg, Timothy M; Atkins, Lindsay; Buchholz, Laura; Shirshova, Victoria; Swiantek, Andrew; Whitley, Jessica; Hartman, Sabrina; Oquendo, Natasha

    2010-03-01

    This article reports the development and validation of the College Life Alcohol Salience Scale (CLASS), which assesses college students' beliefs about the centrality of alcohol to the college experience. Developed using procedures designed to increase its ecological validity, the CLASS was administered to three samples of college students (total N = 571). Its unidimensional factor structure was first established via exploratory factor analysis and parallel analysis on one sample and then verified via confirmatory factor analysis on a separate sample. Scores on the CLASS were predictably related to a nomological network of drinking and personality variables and it provided incremental validity in accounting for drinking frequency and amount, when added to drinking motive scores. The importance of assessing and developing interventions to target the types of beliefs measured by the CLASS is discussed.

  20. 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

  1. Composite Health Plan Quality Scales

    PubMed Central

    Caldis, Todd

    2007-01-01

    This study employs exploratory factor analysis and scale construction methods with commercial Health Plan Employers Data Information Set (HEDIS®) process of care and outcome measures from 1999 to uncover evidence for a unidimensional composite health maintenance organization (HMO) quality scale. Summated scales by categories of care are created and are then used in a factor analysis that has a single factor solution. The category of care scales were used to construct a summated composite scale which exhibits strong evidence of internal consistency (alpha= 0.90). External validity of the composite quality scale was checked by regressing the composite scale on Consumer Assessment of Healthcare Providers and Systems (CAHPS®) survey results for 1999. PMID:17645158

  2. 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.

  3. Promoting healthy lifestyles with aging: development and validation of the Health Enhancement Lifestyle Profile (HELP) using the Rasch measurement model.

    PubMed

    Hwang, Jengliang Eric

    2010-01-01

    This study was conducted to develop and validate the Health Enhancement Lifestyle Profile (HELP), a self-report measure for examining various aspects of health-related lifestyle in older adults. Data derived from 253 community-dwelling older adults were analyzed through the Rasch measurement model. Unidimensionality and data-model fit of HELP were largely supported through the analyses of principal components of residuals, fit statistics, local dependency, and differential item functioning. The item hierarchy formed through logits provided an expected pattern of healthy lifestyle behaviors. Acceptable to good person separation and reliability statistics supported the clinical applicability and consistency of the HELP scores. Finally, analysis of the rating scale structure confirmed the functioning of the 0- to 5-point rating scale used. HELP can assist in monitoring lifestyle risk factors and measuring the outcome of services aimed at promoting healthy lifestyles among older adults.

  4. 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.

  5. 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. PMID:25263396

  6. Empirical contribution to the question of sex-dependent inheritance of spatial ability.

    PubMed

    Gittler, G; Vitouch, O

    1994-04-01

    The X-linked recessive gene hypothesis, a theory to predict the mode of genetic inheritance of spatial ability, was tested using a new Rasch-calibrated space test, the Three-dimensional Cube Test (Gittler, 1990). This allowed solving the homogeneity problem (insufficient unidimensionality of test material) by which earlier research in this field was affected. The empirical correlations from our sample of 134 families were compared with the theoretically predicted values. Present data do no corroborate the model; however, the problems of its general falsification are discussed. The fact that differences in performance in favour of males exist in the parental generation but not in the filial generation accentuates the importance of environmental factors.

  7. Dimensions and Severity of Marijuana Consequences: Development and Validation of the Marijuana Consequences Questionnaire (MACQ)

    PubMed Central

    Simons, Jeffrey S.; Dvorak, Robert D.; Merrill, Jennifer E.; Read, Jennifer P.

    2012-01-01

    The Marijuana Consequences Questionnaire (MACQ) is a 50-item self-report measure modeled after the Young Adult Alcohol Consequences Questionnaire (YAACQ). College students (n = 315) completed questionnaires online. A confirmatory factor analysis supported the hypothesized 8-factor structure. The results indicate good convergent and discriminant validity of the MACQ. A brief, unidimensional, 21-item version (B-MACQ) was developed by a Rasch model. Comparison of item severity estimates of the B-MACQ items and the corresponding items from the YAACQ indicate that the severity of alcohol- and marijuana- problems is defined by a relatively unique pattern of consequences. The MACQ and B-MACQ provide promising new alternatives to assessing marijuana-related problems. PMID:22305645

  8. Generalization of category knowledge and dimensional categorization in humans (Homo sapiens) and nonhuman primates (Macaca mulatta).

    PubMed

    Smith, J David; Zakrzewski, Alexandria C; Johnston, Jennifer J R; Roeder, Jessica L; Boomer, Joseph; Ashby, F Gregory; Church, Barbara A

    2015-10-01

    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 questions of (a) how closely macaques' dimensional categorization verges on humans' explicit/declarative categorization, and (b) how far macaques' dimensional categorization has advanced beyond that in other vertebrate species. PMID:26167774

  9. 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.

  10. Psychometric Properties of the Lower Extremity Subscale of the Fugl-Myer Assessment for Community-dwelling Hemiplegic Stroke Patients.

    PubMed

    Park, Eun Young; Choi, Yoo Im

    2014-11-01

    [Purpose] The purpose of this study was to investigate the psychometric properties of the lower extremity subscale of the Fugl-Meyer Assessment lower extremity (FMA-LE) for community-dwelling hemiplegic stroke patients. [Subjects] The participants were 140 community-dwelling hemiplegic stroke patients. [Methods] To determine the psychometric properties of the FMA-LE, we examined construct validity, response characteristics, item discrimination, and internal consistency. [Results] Factor analysis of the FMA-LE revealed that the first factor explained 61.73% of the variance and provided evidence of unidimensionality. The FMA-LE did not show ceiling or floor effects; Cronbach's α was 0.935 (95% CI: 0.919-0.950). [Conclusion] Because the FMA-LE seems to be both valid and reliable, we conclude that it is appropriate for the measurement of the lower extremity motor impairment of community-dwelling hemiplegic stroke patients.

  11. 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. PMID:24597456

  12. The ARSQ: the athletes' received support questionnaire.

    PubMed

    Freeman, Paul; Coffee, Pete; Moll, Tjerk; Rees, Tim; Sammy, Nadine

    2014-04-01

    To address calls for context-specific measurement of social support, this article reports the development of the Athletes' Received Support Questionnaire (ARSQ) and demonstrates initial evidence for its validity. Across four studies there was support for a four-dimensional structure reflecting emotional, esteem, informational, and tangible received support. There was also support for unidimensional and higher-order models. Further, Study 3 provided some support for convergent validity, with significant correlations between the corresponding dimensions of the ARSQ and the Inventory of Socially Supportive Behaviors. Study 4 provided evidence for the nomological validity of the ARSQ. Emotional and esteem support significantly predicted self-confidence and positive affect, and tangible support significantly moderated the relationship between stress and negative affect. Collectively, these results provide initial evidence for the validity of the ARSQ, and offer researchers flexibility to adopt either a multidimensional or aggregated approach to measuring received support. PMID:24686955

  13. 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

  14. Improving measurement methods in rehabilitation: core concepts and recommendations for scale development.

    PubMed

    Velozo, Craig A; Seel, Ronald T; Magasi, Susan; Heinemann, Allen W; Romero, Sergio

    2012-08-01

    Validated measurement scales are essential to evaluating clinical outcomes and conducting meaningful and reliable research. The purpose of this article is to present the clinician and researcher with a contemporary 8-stage framework for measurement scale development based on a mixed-methods qualitative and quantitative approach. Core concepts related to item response theory are presented. Qualitative methods are described to conceptualize scale constructs; obtain patient, family, and other stakeholder perspectives; and develop item pools. Item response theory statistical methodologies are presented, including approaches for testing the assumptions of unidimensionality, local independence, monotonicity, and indices of model fit. Lastly, challenges faced by scale developers in implementing these methodologies are discussed. While rehabilitation research has recently started to apply mixed-methods qualitative and quantitative methodologies to scale development, these approaches show considerable promise in advancing rehabilitation measurement. PMID:22840881

  15. 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.

  16. 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.

  17. 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.

  18. Hierarchical Self-Assembly of Supramolecular Muscle-Like Fibers.

    PubMed

    Goujon, Antoine; Du, Guangyan; Moulin, Emilie; Fuks, Gad; Maaloum, Mounir; Buhler, Eric; Giuseppone, Nicolas

    2016-01-11

    An acid-base switchable [c2]daisy chain rotaxane terminated with two 2,6-diacetylamino pyridine units has been self-assembled with a bis(uracil) linker. The complementary hydrogen-bond recognition patterns, together with lateral van der Waals aggregations, result in the hierarchical formation of unidimensional supramolecular polymers associated in bundles of muscle-like fibers. Microscopic and scattering techniques reveal that the mesoscopic structure of these bundles depends on the extended or contracted states that the rotaxanes show within individual polymer chains. The observed local dynamics span over several length scales because of a combination of supramolecular and mechanical bonds. This work illustrates the possibility to modify the hierarchical mesoscopic structuring of large polymeric systems by the integrated actuation of individual molecular machines. PMID:26582752

  19. Using bifactor exploratory structural equation modeling to examine global and specific factors in measures of sports coaches' interpersonal styles.

    PubMed

    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

  20. 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.

  1. 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

  2. Laser ablation of CsI analyzed by delayed extraction

    NASA Astrophysics Data System (ADS)

    Fernández-Lima, F.; Collado, V. M.; Ponciano, C. R.; Farenzena, L. S.; Pedrero, E.; da Silveira, E. F.

    2003-07-01

    Secondary ion emission from polycrystalline CsI irradiated by pulsed-UV laser (337 nm) is analyzed by time-of-flight (TOF) mass spectrometry. Measurements were performed for different laser intensities and for several delayed extraction times (0-200 ns). The TOF peak shape is characterized by a Gaussian-like structure (fast component), followed by a tail (slow component) that is more pronounced when the extraction field is delayed. A thermal-sputtering uni-dimensional model is employed to describe the solid surface and plasma temperatures as a function of time. Heat diffusion, vapor photo-ionization, radiative emission and plume expansion are considered. Within the approximations used, the model predicts reasonable drift velocities of the plume (≈1.4 km s -1) but very high plasma temperatures (≈10 5 K). The width of the TOF peak fast component allows determination of the plume temperature during its expansion.

  3. 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

  4. Toward a theory-driven model of acculturation in public health research.

    PubMed

    Abraído-Lanza, Ana F; Armbrister, Adria N; Flórez, Karen R; Aguirre, Alejandra N

    2006-08-01

    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.

  5. 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.

  6. 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.

  7. Exploratory factor analysis of borderline personality disorder criteria in monolingual Hispanic outpatients with substance use disorders†

    PubMed Central

    Becker, Daniel F.; Añez, Luis Miguel; Paris, Manuel; Grilo, Carlos M.

    2009-01-01

    This study examined the factor structure of the DSM-IV criteria for borderline personality disorder (BPD) in Hispanic patients. Subjects were 130 monolingual Hispanic adults who had been admitted to a specialty outpatient clinic that provides psychiatric and substance abuse services to Spanish-speaking individuals. All were reliably assessed with the Spanish-Language Version of the Diagnostic Interview for DSM-IV Personality Disorders. After evaluating internal consistency of the BPD criterion set, an exploratory factor analysis was performed using principal axis factoring. Results suggested a unidimensional structure, and were consistent with similar studies of the DSM-IV criteria for BPD in non-Hispanic samples. These findings have implications for understanding borderline psychopathology in this population, and for the overall validity of the DSM-IV BPD construct. PMID:20472296

  8. Assessing outcome expectations in older adults: the multidimensional outcome expectations for exercise scale.

    PubMed

    Wójcicki, Thomas R; White, Siobhan M; McAuley, Edward

    2009-01-01

    Outcome expectations, an important element of social cognitive theory, have been associated with physical activity in older adults. Yet, the measurement of this construct has often adopted a unidimensional approach. We examined the validity of a theoretically consistent three-factor (physical, social, and self-evaluative) outcome expectations exercise scale in middle-aged and older adults (N = 320; M age = 63.8). Participants completed questionnaires assessing outcome expectations, physical activity, self-efficacy, and health status. Comparisons of the hypothesized factor structure with competing models indicated that a three-factor model provided the best fit for the data. Construct validity was further demonstrated by significant association with physical activity and self-efficacy and differential associations with age and health status. Further evidence of validity and application to social cognitive models of physical activity is warranted.

  9. Postdisaster stress in the United States and Mexico: a cross-cultural test of the multicriterion conceptual model of posttraumatic stress disorder.

    PubMed

    Norris, F H; Perilla, J L; Murphy, A D

    2001-11-01

    Data on symptoms of posttraumatic stress disorder (PTSD) were collected 6 months after Hurricanes Paulina (N = 200; Mexico) and Andrew (non-Hispanic n = 270; United States) using the Revised Civilian Mississippi Scale. A 4-factor measurement model that represented the accepted multicriterion conceptualization of PTSD fit the data of the U.S. and Mexican samples equally well. The 4 factors of Intrusion, Avoidance, Numbing, and Arousal correlated significantly and equivalently with severity of trauma in each sample. A single construct explained much of the covariance of the symptom factors in each sample. However, modeling PTSD as a unidimensional construct masked differences between samples in symptom severity. With severity of trauma controlled, the Mexican sample was higher in Intrusion and Avoidance, whereas the U.S. sample was higher in Arousal. The results suggest that PTSD is a meaningful construct to study in Latin American societies.

  10. The Body Appreciation Scale-2: item refinement and psychometric evaluation.

    PubMed

    Tylka, Tracy L; Wood-Barcalow, Nichole L

    2015-01-01

    Considered a positive body image measure, the 13-item Body Appreciation Scale (BAS; Avalos, Tylka, & Wood-Barcalow, 2005) assesses individuals' acceptance of, favorable opinions toward, and respect for their bodies. While the BAS has accrued psychometric support, we improved it by rewording certain BAS items (to eliminate sex-specific versions and body dissatisfaction-based language) and developing additional items based on positive body image research. In three studies, we examined the reworded, newly developed, and retained items to determine their psychometric properties among college and online community (Amazon Mechanical Turk) samples of 820 women and 767 men. After exploratory factor analysis, we retained 10 items (five original BAS items). Confirmatory factor analysis upheld the BAS-2's unidimensionality and invariance across sex and sample type. Its internal consistency, test-retest reliability, and construct (convergent, incremental, and discriminant) validity were supported. The BAS-2 is a psychometrically sound positive body image measure applicable for research and clinical settings. PMID:25462882

  11. Distributed detection of temperature gradients with single-wavelength phase-sensitive OTDR and speckle analysis methods

    NASA Astrophysics Data System (ADS)

    Garcia-Ruiz, Andres; Pastor-Graells, Juan; Martins, Hugo F.; Martin-Lopez, Sonia; Gonzalez-Herraez, Miguel

    2016-05-01

    A method to evaluate distributed temperature gradients along an optical fiber using phase-sensitive optical time domain reflectometry (ΦOTDR) with direct detection is proposed and experimentally validated. The measurement principle derives from the perturbation response of a single-wavelength ΦOTDR signal, which is analyzed as a unidimensional speckle pattern. Our method can be implemented in real-time, relies solely on a low-cost post-processing of the standard ΦOTDR traces and requires no scanning of the laser frequency. This post-processing method can be implemented over a conventional ΦOTDR system used for distributed intrusion detection, without affecting its operation or requiring any additional hardware.

  12. 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.

  13. The impact of crime victimization and fear of crime on attitudes toward death penalty defendants.

    PubMed

    Seltzer, R; McCormick, J P

    1987-01-01

    A 1983 telephone survey of 610 respondents in two Maryland counties found that the general disposition of the respondents toward the criminal justice system was a better predictor of abstract attitudes toward the death penalty than either the respondents' fear of becoming crime victims or whether they had been victims of crime. Yet respondents' fear of crime victimization was a better predictor of their willingness to impose the death penalty or to accept mitigating circumstances during the penalty phase of a capital case than their abstract attitudes toward the criminal justice system. Respondents who were "somewhat" afraid of crime victimization were less likely to support the death penalty than were respondents who were "very" afraid or "not" afraid of victimization. These finding indicate that previous research on the death penalty may have been flawed because the wording of the questions asked was too abstract and unidimensional.

  14. The psychometric property and validation of a fatalism scale.

    PubMed

    Shen, Lijiang; Condit, Celeste M; Wright, Lanelle

    2009-06-01

    In this article, we conceptualised fatalism as a set of health beliefs that encompass the dimensions of predetermination, luck and pessimism. A 20-item scale was developed as a measurement instrument. Confirmatory factor analyses were performed to test the dimensionality of the scale. Three external variables (i.e. genetic determinism, perceived benefits of lifestyle change and intention to engage in healthy behaviour) were used as reference variables to test the construct validity of the scale. Data from a web-based national survey (N = 1218) showed that the scale was unidimensional on the second order, and with good reliability (alpha = 0.88). The relationships between the external variables and the first- and second-order factors provided evidence of the scale's external consistency and construct validity.

  15. Fatigue among working people: validity of a questionnaire measure

    PubMed Central

    Beurskens, A.; Bultmann, U.; Kant, I.; Vercoulen, J.; Bleijenberg, G.; Swaen, G.

    2000-01-01

    OBJECTIVES—To evaluate the validity of the checklist individual strength questionnaire (CIS) in the working population. This 20 item self reported questionnaire has often been used in patients with chronic fatigue. To date, no research has focused on the validity of the CIS in occupational groups.
METHODS—To evaluate the discriminant validity the CIS was filled out by five groups of employees with expected differences in fatigue. The convergent validity was evaluated by comparing the results of the CIS with the results of three related measures: measured unidimensional fatigue, burnout, and need for recovery.
RESULTS—The CIS was able to discriminate between fatigued and non-fatigued employees in occupational groups. The expected agreement between the results of the CIS and related measures was confirmed.
CONCLUSIONS—The CIS seems to be an appropriate instrument for measuring fatigue in the working population.


Keywords: fatigue; occupational groups; measurement PMID:10769302

  16. 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. PMID:26971117

  17. 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.

  18. Psychometric properties of a hurricane coping self-efficacy measure.

    PubMed

    Benight, C C; Ironson, G; Durham, R L

    1999-04-01

    This brief report describes the psychometric properties of an instrument designed to measure Hurricane Coping Self-Efficacy (HCSE). Survivors of Hurricane Andrew (n = 165) and Hurricane Opal (n = 63) completed the HCSE and assessments of optimism, social support, distress, and resource loss. Principal components factor analyses revealed a unidimensional structure for the HCSE. Internal consistency of the HCSE was strong. In both samples, HCSE was positively associated with optimism and social support, but negatively associated with general psychological distress, trauma related distress, and resource loss. Finally, hierarchical regression analyses demonstrated that the HCSE explained a significant amount of experimental variance for intrusive thoughts and avoidance after controlling for social support, lost resources, and optimism.

  19. Photonic superdiffusive motion in resonance radiation trapping

    SciTech Connect

    Berberan-Santos, M. N.; Nunes-Pereira, E. J.; Martinho, J. M. G.

    2006-11-07

    In this work we consider the relation between the jump length probability density function and the line shape function in resonance radiation trapping in atomic vapors. The two-sided jump length probability density function suitable for a unidimensional formulation of radiative transfer is also derived. As a side result, a procedure to obtain the Maxwell distribution of velocities from the Maxwell-Boltzmann distribution of speeds was obtained. General relations that give the asymptotic jump length behavior and the Levy flight parameter {mu} for any line shape are obtained. The results are applied to generalized Doppler, generalized Lorentz, and Voigt line shape functions. It is concluded that the lighter the tail of the line shape function, the less heavy the tail of the jump length probability density function, although this tail is always heavy, with {mu}{<=}1.

  20. A note on the estimation of the Pareto efficient set for multiobjective matrix permutation problems.

    PubMed

    Brusco, Michael J; Steinley, Douglas

    2012-02-01

    There are a number of important problems in quantitative psychology that require the identification of a permutation of the n rows and columns of an n × n proximity matrix. These problems encompass applications such as unidimensional scaling, paired-comparison ranking, and anti-Robinson forms. The importance of simultaneously incorporating multiple objective criteria in matrix permutation applications is well recognized in the literature; however, to date, there has been a reliance on weighted-sum approaches that transform the multiobjective problem into a single-objective optimization problem. Although exact solutions to these single-objective problems produce supported Pareto efficient solutions to the multiobjective problem, many interesting unsupported Pareto efficient solutions may be missed. We illustrate the limitation of the weighted-sum approach with an example from the psychological literature and devise an effective heuristic algorithm for estimating both the supported and unsupported solutions of the Pareto efficient set.

  1. 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. PMID:25562339

  2. Environmental degradation and remediation: is economics part of the problem?

    PubMed

    Dore, Mohammed H I; Burton, Ian

    2003-01-01

    It is argued that standard environmental economic and 'ecological economics', have the same fundamentals of valuation in terms of money, based on a demand curve derived from utility maximization. But this approach leads to three different measures of value. An invariant measure of value exists only if the consumer has 'homothetic preferences'. In order to obtain a numerical estimate of value, specific functional forms are necessary, but typically these estimates do not converge. This is due to the fact that the underlying economic model is not structurally stable. According to neoclassical economics, any environmental remediation can be justified only in terms of increases in consumer satisfaction, balancing marginal gains against marginal costs. It is not surprising that the optimal policy obtained from this approach suggests only small reductions in greenhouse gases. We show that a unidimensional metric of consumer's utility measured in dollar terms can only trivialize the problem of global climate change.

  3. 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).

  4. Interconversion of linearly viscoelastic material functions expressed as Prony series: a closure

    NASA Astrophysics Data System (ADS)

    Luk-Cyr, Jacques; Crochon, Thibaut; Li, Chun; Lévesque, Martin

    2013-02-01

    Interconversion of viscoelastic material functions is a longstanding problem that has received attention since the 1950s. There is currently no accepted methodology for interconverting viscoelastic material functions due to the lack of stability and accuracy of the existing methods. This paper presents a new exact, analytical interconversion method for linearly viscoelastic material functions expressed as Prony series. The new algorithm relies on the equations of the thermodynamics of irreversible processes used for defining linearly viscoelastic constitutive theories. As a result, interconversion is made possible for unidimensional and tridimensional materials for arbitrary material symmetry. The algorithm has been tested over a broad range of cases and was found to deliver accurate interconversion in all cases. Based on its accuracy and stability, the authors believe that their algorithm provides a closure to the interconversion of linearly viscoelastic constitutive theories expressed with Prony series.

  5. Psychometric properties of the Muscle Appearance Satisfaction Scale among Irish and British men.

    PubMed

    Ryan, Travis A; Morrison, Todd G

    2010-06-01

    The psychometric soundness of the Muscle Appearance Satisfaction Scale (MASS; Mayville, Williamson, White, Netemeyer, & Drab, 2002), a measure of muscle dysmorphia symptoms, was investigated using two independent online samples of Irish and British men (ns=307 and 306, respectively). Exploratory and confirmatory factor analyses showed that, compared to the original 5-component solution for the 19-item MASS, a 6-item unidimensional version offered better fit to the data. Findings further upheld the internal consistency reliability, construct validity (e.g., via its associations with internalization of the muscular ideal and physical appearance comparisons), and discriminant validity (e.g., via its nonsignificant relationship with social desirability) of the MASS's scores. The limitations associated with the current research are discussed and directions for future research are articulated. PMID:20378436

  6. Beyond Symptom Counts for Diagnosing Oppositional Defiant Disorder and Conduct Disorder?

    PubMed

    Lindhiem, Oliver; Bennett, Charles B; Hipwell, Alison E; Pardini, Dustin A

    2015-10-01

    Conduct Disorder (CD) and Oppositional Defiant Disorder (ODD) are among the most commonly diagnosed childhood behavioral health disorders. Although there is substantial evidence of heterogeneity of symptom presentations, DSM diagnoses of CD and ODD are formally diagnosed on the basis of symptom counts without regard to individual symptom patterns. We used unidimensional item response theory (IRT) two-parameter logistic (2PL) models to examine item parameters for the individual symptoms of CD and ODD using data on 6,491 adolescents (ages 13-17) from the National Comorbidity Study: Adolescent Supplement (NCS-A). For each disorder, the symptoms differed in terms of severity and discrimination parameters. As a result, some adolescents who were above DSM diagnostic thresholds for disruptive behavior disorders exhibited lower levels of the underlying construct than others below the thresholds, based on their unique symptom profile. In terms of incremental benefit, our results suggested an advantage of latent trait scores for CD but not ODD.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Beyond "homophobia": a social psychological perspective on attitudes toward lesbians and gay men.

    PubMed

    Herek, G M

    1984-01-01

    Homophobia, a term often used to describe hostile reactions to lesbians and gay men, implies a unidimensional construct of attitudes as expressions of irrational fears. This paper argues that a more complex view is needed of the psychology of positive and negative attitudes toward homosexual persons. Based upon a review of previous empirical research, a model is proposed that distinguishes three types of attitudes according to the social psychological function they serve: (1) experiential, categorizing social reality by one's past interactions with homosexual persons; (2) defensive, coping with one's inner conflicts or anxieties by projecting them onto homosexual persons; and (3) symbolic, expressing abstract ideological concepts that are closely linked to one's notion of self and to one's social network and reference groups. Strategies are proposed for changing attitudes serving each of the functions. The importance of distinguishing attitudes toward lesbians from those focused on gay men is also discussed.

  13. Two-dimensional liquid chromatography/mass spectrometry/mass spectrometry separation of water-soluble metabolites.

    PubMed

    Fairchild, Jacob N; Horvath, Krisztian; Gooding, Jessica R; Campagna, Shawn R; Guiochon, Georges

    2010-12-24

    Off-line two-dimensional liquid chromatography with tandem mass spectrometry detection (2D-LC/MS-MS) was used to separate a set of metabolomic species. Water-soluble metabolites were extracted from Escherichia coli and Saccharomyces cerevisae cultures and were immediately analyzed using strong cation exchange (SCX)-hydrophilic interaction chromatography (HILIC). Metabolite mixtures are well-suited for multidimensional chromatography as the range of components varies widely with respect to polarity and chemical makeup. Some currently used methods employ two different separations for the detection of positively and negatively ionized metabolites by mass spectrometry. Here we developed a single set of chromatographic conditions for both ionization modes and were able to detect a total of 141 extracted metabolite species, with an overall peak capacity of ca. 2500. We show that a single two-dimensional separation method is sufficient and practical when a pair or more of unidimensional separations are used in metabolomics. PMID:21094946

  14. Indian politics encourages durgas, snubs women.

    PubMed

    Kishwar, M

    1999-01-01

    This article talks about four Indian women--Sonia Gandhi, Jayalitha, Mayawati, and Mamta Banerjee--in contrast with India's stereotypes in the political realm. India is a land of mind-boggling diversity. Yet stereotypes about India, which reduce the Indian reality to a unidimensional monolith, hold powerful sway. One such powerful stereotype is that Indian women are brutally oppressed, denied a voice in their family and community, and marginalized in politics as in other power structures. Without doubt, there is much truth in this stereotype; but how can the current political scene be explained? A few women are holding the entire political establishment of India at ransom. The machinations of Sonia Gandhi, Jayalalitha, Mayawati, and Mamta Banerjee have caused enormous upheavals in the polity and recently brought about the fall of the BJP government. Powerful politicians dance to the erratic tunes of these women and are shamefully submissive to them.

  15. Health Disparity and Structural Violence: How Fear Undermines Health Among Immigrants at Risk for Diabetes.

    PubMed

    Page-Reeves, Janet; Niforatos, Joshua; Mishra, Shiraz; Regino, Lidia; Gingrich, Andrew; Bulten, Robert

    2013-01-01

    Diabetes is a national health problem, and the burden of the disease and its consequences particularly affect Hispanics. While social determinants of health models have improved our conceptualization of how certain contexts and environments influence an individual's ability to make healthy choices, a structural violence framework transcends traditional uni-dimensional analysis. Thus, a structural violence approach is capable of revealing dynamics of social practices that operate across multiple dimensions of people's lives in ways that may not immediately appear related to health. Working with a Hispanic immigrant community in Albuquerque, New Mexico, we demonstrate how structural forces simultaneously directly inhibit access to appropriate healthcare services and create fear among immigrants, acting to further undermine health and nurture disparity. Although fear is not normally directly associated with diabetes health outcomes, in the community where we conducted this study participant narratives discussed fear and health as interconnected.

  16. 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.

  17. [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. PMID:18940104

  18. 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. PMID:27423161

  19. The Nature of Science Instrument-Elementary (NOSI-E): the end of the road?

    PubMed

    Peoples, Shelagh M; O'Dwyer, Laura M

    2014-01-01

    This research continues prior work published in this journal (Peoples, O'Dwyer, Shields and Wang, 2013). The first paper described the scale development, psychometric analyses and part-validation of a theoretically-grounded Rasch-based instrument, the Nature of Science Instrument-Elementary (NOSI-E). The NOSI-E was designed to measure elementary students' understanding of the Nature of Science (NOS). In the first paper, evidence was provided for three of the six validity aspects (content, substantive and generalizability) needed to support the construct validity of the NOSI-E. The research described in this paper examines two additional validity aspects (structural and external). The purpose of this study was to determine which of three competing internal models provides reliable, interpretable, and responsive measures of students' understanding of NOS. One postulate is that the NOS construct is unidimensional;. alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. The vast body of evidence supported the claim that the NOS construct is multidimensional. Measures from the multidimensional model were positively related to student science achievement and students' perceptions of their classroom environment; this provided supporting evidence for the external validity aspect of the NOS construct. As US science education moves toward students learning science through engaging in authentic scientific practices and building learning progressions (NRC, 2012), it will be important to assess whether this new approach to teaching science is effective, and the NOSI-E may be used as a measure of the impact of this reform.

  20. Electronic Quality of Life Assessment Using Computer-Adaptive Testing

    PubMed Central

    2016-01-01

    Background Quality of life (QoL) questionnaires are desirable for clinical practice but can be time-consuming to administer and interpret, making their widespread adoption difficult. Objective Our aim was to assess the performance of the World Health Organization Quality of Life (WHOQOL)-100 questionnaire as four item banks to facilitate adaptive testing using simulated computer adaptive tests (CATs) for physical, psychological, social, and environmental QoL. Methods We used data from the UK WHOQOL-100 questionnaire (N=320) to calibrate item banks using item response theory, which included psychometric assessments of differential item functioning, local dependency, unidimensionality, and reliability. We simulated CATs to assess the number of items administered before prespecified levels of reliability was met. Results The item banks (40 items) all displayed good model fit (P>.01) and were unidimensional (fewer than 5% of t tests significant), reliable (Person Separation Index>.70), and free from differential item functioning (no significant analysis of variance interaction) or local dependency (residual correlations < +.20). When matched for reliability, the item banks were between 45% and 75% shorter than paper-based WHOQOL measures. Across the four domains, a high standard of reliability (alpha>.90) could be gained with a median of 9 items. Conclusions Using CAT, simulated assessments were as reliable as paper-based forms of the WHOQOL with a fraction of the number of items. These properties suggest that these item banks are suitable for computerized adaptive assessment. These item banks have the potential for international development using existing alternative language versions of the WHOQOL items. PMID:27694100

  1. 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. PMID:26228413

  2. Assessing Social Support, Companionship, and Distress: NIH Toolbox Adult Social Relationship Scales

    PubMed Central

    Cyranowski, Jill M.; Zill, Nicholas; Bode, Rita; Butt, Zeeshan; Kelly, Morgen A. R.; Pilkonis, Paul A.; Salsman, John M.; Cella, David

    2013-01-01

    Objective The quality of our daily social interactions – including perceptions of support, feelings of loneliness, and distress stemming from negative social exchanges – influence physical health and well-being. Despite the importance of social relationships, brief yet precise, unidimensional scales that assess key aspects of social relationship quality are lacking. As part of the NIH Toolbox for the Assessment of Neurological and Behavioral Function, we developed brief self-report scales designed to assess aspects of social support, companionship, and social distress across age cohorts. This report details the development and psychometric testing of the adult NIH Toolbox Social Relationship scales. Methods Social relationship concepts were selected, and item sets were developed and revised based on expert feedback and literature review. Items were then tested across a community-dwelling U.S. internet panel sample of adults aged 18 and above (N=692) using traditional (classic) psychometric methods and item response theory (IRT) approaches to identify items for inclusion in 5–8 item unidimensional scales. Finally, concurrent validity of the newly-developed scales was evaluated with respect to their inter-relationships with classic social relationship validation instruments. Results Results provide support for the internal reliability and concurrent validity of resulting self-report scales assessing Emotional Support, Instrumental Support, Friendship, Loneliness, Perceived Rejection, and Perceived Hostility. Conclusion These brief social relationship scales provide the pragmatic utility and enhanced precision needed to promote future epidemiological and social neuroscience research on the impact of social relationships on physical and emotional health outcomes. PMID:23437856

  3. 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.

  4. Development of the PROMIS® Social Motivations for Smoking Item Banks

    PubMed Central

    Shadel, William G.; Edelen, Maria Orlando; Stucky, Brian D.; Kuhfeld, Megan; Hansen, Mark; Cai, Li

    2014-01-01

    Introduction: Smoking behavior is influenced by social motivations such as the expected social benefits of smoking and the social cues that induce craving. This paper describes development of the PROMIS® Social Motivations for Smoking item banks, which will serve to standardize assessment of these social motivations among daily and nondaily smokers. Methods: Daily (N = 4,201) and nondaily (N =1,183) smokers completed an online survey. Item factor analyses, item response theory analyses, and differential item functioning analyses were conducted to identify a unidimensional set of items for each group. Short forms (SFs) and computer adaptive tests (CATs) were evaluated as tools for more efficiently assessing this construct. Results: A total of 15 items were included in the item banks (9 items common to daily and nondaily smokers, 3 unique to daily, 3 unique to nondaily). Scores based on full item banks are highly reliable (reliability = 0.90–0.91). Additionally, the item banks are strongly unidimensional and perform similarly across gender, age, and race/ethnicity groups. A fixed SF for use with both daily and nondaily smokers consists of 4 items (reliability = 0.80). Results from simulated CATs showed that, on average, fewer than 5 items are needed to assess this construct with adequate precision using the item banks. Conclusions: A new set of items has been identified for assessing the social motivations for smoking in a reliable, standardized manner for daily and nondaily smokers. In addition to using the full item banks, efficient assessment can be achieved by using SFs, employing CATs, or selecting items tailored to specific research or clinical purposes. PMID:25118231

  5. 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

  6. Development of the PROMIS® Positive Emotional and Sensory Expectancies of Smoking Item Banks

    PubMed Central

    Shadel, William G.; Edelen, Maria Orlando; Stucky, Brian D.; Li, Zhen; Hansen, Mark; Cai, Li

    2014-01-01

    Introduction: The positive emotional and sensory expectancies of cigarette smoking include improved cognitive abilities, positive affective states, and pleasurable sensorimotor sensations. This paper describes development of Positive Emotional and Sensory Expectancies of Smoking item banks that will serve to standardize the assessment of this construct among daily and nondaily cigarette smokers. Methods: Data came from daily (N = 4,201) and nondaily (N =1,183) smokers who completed an online survey. To identify a unidimensional set of items, we conducted item factor analyses, item response theory analyses, and differential item functioning analyses. Additionally, we evaluated the performance of fixed-item short forms (SFs) and computer adaptive tests (CATs) to efficiently assess the construct. Results: Eighteen items were included in the item banks (15 common across daily and nondaily smokers, 1 unique to daily, 2 unique to nondaily). The item banks are strongly unidimensional, highly reliable (reliability = 0.95 for both), and perform similarly across gender, age, and race/ethnicity groups. A SF common to daily and nondaily smokers consists of 6 items (reliability = 0.86). Results from simulated CATs indicated that, on average, less than 8 items are needed to assess the construct with adequate precision using the item banks. Conclusions: These analyses identified a new set of items that can assess the positive emotional and sensory expectancies of smoking in a reliable and standardized manner. Considerable efficiency in assessing this construct can be achieved by using the item bank SF, employing computer adaptive tests, or selecting subsets of items tailored to specific research or clinical purposes. PMID:25118228

  7. Development of the PROMIS® Negative Psychosocial Expectancies of Smoking Item Banks

    PubMed Central

    Edelen, Maria Orlando; Tucker, Joan S.; Shadel, William G.; Cerully, Jennifer; Kuhfeld, Megan; Hansen, Mark; Cai, Li

    2014-01-01

    Introduction: Negative psychosocial expectancies of smoking include aspects of social disapproval and disappointment in oneself. This paper describes analyses conducted to develop and evaluate item banks for assessing psychosocial expectancies among daily and nondaily smokers. 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 psychosocial expectancies items for daily and nondaily smokers. We also evaluated performance of short forms (SFs) and computer adaptive tests (CATs) to efficiently assess psychosocial expectancies. Results: A total of 21 items were included in the Psychosocial Expectancies item banks: 14 items are common across daily and nondaily smokers, 6 are unique to daily, and 1 is unique to nondaily. For both daily and nondaily smokers, the Psychosocial Expectancies item banks are strongly unidimensional, highly reliable (reliability = 0.95 and 0.93, respectively), and perform similarly across gender, age, and race/ethnicity groups. A SF common to daily and nondaily smokers consists of 6 items (reliability = 0.85). Results from simulated CATs showed that, on average, fewer than 8 items are needed to assess psychosocial expectancies with adequate precision when using the item banks. Conclusions: Psychosocial expectancies of smoking can be assessed on the basis of these item banks via the SF, by using CAT, or through a tailored set of items selected for a specific research purpose. PMID:25118230

  8. Performance of the Family Satisfaction with the End-of-Life Care (FAMCARE) measure in an ethnically diverse cohort: Psychometric analyses using item response theory

    PubMed Central

    Teresi, Jeanne A.; Ornstein, Katherine; Ocepek-Welikson, Katja; Ramirez, Mildred; Siu, Albert

    2013-01-01

    The Family Satisfaction with End-of-Life Care (FAMCARE) has been used widely among caregivers to individuals with cancer. The aim of this study was to evaluate the psychometric properties of this measure using item response theory (IRT). Methods The analytic sample was comprised of caregivers to 1983 patients with advanced cancer. Among the patients, 56% were female, with mean age 59.9 (s.d. = 11.8); 20% were non-Hispanic Black. The majority were family members either living with (44%) or not living with (35%) the patient. Factor analyses and IRT were used to examine the dimensionality, information and reliability of the FAMCARE. Results Although a bi-factor model fit the data slightly better than did a unidimensional model, the loadings on the group factors were very low. Thus, a unidimensional model appears to provide adequate representation for the item set. The reliability estimates, calculated along the satisfaction (theta) continuum were adequate (>0.80) for all levels of theta for which subjects had scores. Examination of the category response functions from IRT showed overlap in the lower categories with little unique information provided; moreover the categories were not observed to be interval. Based on these analyses, a three response category format was recommended: very satisfied, satisfied and not satisfied. Most information was provided in the range indicative of either dissatisfaction or high satisfaction. Conclusions These analyses support the use of fewer response categories, and provide item parameters that form a basis for developing shorter-form scales. Such a revision has the potential to reduce respondent burden. PMID:24091717

  9. 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

  10. Development of the PROMIS® Nicotine Dependence Item Banks

    PubMed Central

    Edelen, Maria Orlando; Tucker, Joan S.; Stucky, Brian D.; Hansen, Mark; Cai, Li

    2014-01-01

    Introduction: Nicotine dependence is a core construct important for understanding cigarette smoking and smoking cessation behavior. This article describes analyses conducted to develop and evaluate item banks for assessing nicotine dependence among daily and nondaily smokers. 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 nicotine dependence items for daily and nondaily smokers. We also evaluated performance of short forms (SFs) and computer adaptive tests (CATs) to efficiently assess dependence. Results: A total of 32 items were included in the Nicotine Dependence item banks; 22 items are common across daily and nondaily smokers, 5 are unique to daily smokers, and 5 are unique to nondaily smokers. For both daily and nondaily smokers, the Nicotine Dependence item banks are strongly unidimensional, highly reliable (reliability = 0.97 and 0.97, respectively), and perform similarly across gender, age, and race/ethnicity groups. SFs common to daily and nondaily smokers consist of 8 and 4 items (reliability = 0.91 and 0.81, respectively). Results from simulated CATs showed that dependence can be assessed with very good precision for most respondents using fewer than 6 items adaptively selected from the item banks. Conclusions: Nicotine dependence on cigarettes can be assessed on the basis of these item banks via one of the SFs, by using CATs, or through a tailored set of items selected for a specific research purpose. PMID:25118226

  11. Construct Validity of the eHealth Literacy Scale (eHEALS) Among Two Adult Populations: A Rasch Analysis

    PubMed Central

    Moorhouse, Michael; Curbow, Barbara; Christie, Juliette; Walsh-Childers, Kim; Islam, Sabrina

    2016-01-01

    Background The Internet has become a ubiquitous venue for information seeking, especially for health information. Public health practitioners have noticed the promise and potential of the Internet, however, little is known about individuals' skills of their eHealth literacy. The eHealth Literacy Scale, eHEALS, was designed to measure perceptions of individuals' eHealth literacy skills. Objective The objective of the study was to examine the psychometric validity and reliability of the eHEALS with two adult populations using the Rasch Model. Methods A college-aged sample and an Internet-based sample (Amazon's MTurk) were recruited to complete the eHEALS, demographic questions, and a health literacy scale. Using WINSTEPS and SPSS, unidimensionality, item fit, rating scale, item hierarchy, person ability-item match, and reliability were analyzed, compared, and contrasted against each sample and to other samples found in the literature. Results An exploratory factor analysis supported unidimensionality in both samples. More than 90% of respondents from both samples fit the model. No items were outright misfitting. Both samples separated into three distinct groups. Conclusions Based on the results, the eHEALS is a reliable and consistent measurement tool for a college sample and an Internet-based sample. As these individuals are most likely to use the Internet as a health resource, it is necessary to learn and know their skills versus perceiving that they can critically and successfully navigate the Internet. Further analyses are necessary to ensure that the eHEALS can serve as a standard eHealth literacy measure for public health. PMID:27244771

  12. [INDICATORS OF EMOTIONAL WELL-BEING IN PSYCHOGERIATRIC CARE].

    PubMed

    Diesfeldt, H F A

    2015-06-01

    Responses of 1,442 consecutive participants in psychogeriatric day care (mean age 78.8; SD 6.5) to 15 items of a mood questionnaire were analyzed by Mokken scale analysis which is based on nonparametric item response theory models. As from 2002, 825 participants also answered eight self-esteem questions. For the purpose of an exploratory and confirmatory study the sample was split into random halves. The sample represented a broad range of cognitive impairment, from moderately severe to mild dementia. An automated item selection procedure available in the R package mokken revealed a scale for emotional well-being consisting of nine items fitting the monotone homogeneity model of unidimensionality and adequate person separation (Loevingers H=0.37; SE=0.02; Cronbach's coefficient alpha=0.79; SE=0.02). A confirmatory analysis in the second random half of the sample confirmed these results. The scale for emotional well-being consists of the items feeling 'contented', 'healthy', 'tired', 'lonely', 'down', 'in good spirits', 'helpless', 'weak' and 'having faith in the future'. Mokken scale analysis of the eight self-worth items confirmed the unidimensionality and discriminatory power of the self-esteem scale (H=0.41; SE=0.03; Cronbach's alpha=0.80; SE=0.02). Emotional well-being was positively associated with self-worth (Spearman correlation=0.56; 95%-confidence interval [0.49;0.62]). The two scales allow the objective ordering of persons on the latent variables of emotional well-being and self-worth by their test scores. Three case vignettes illustrate application of the indicators in clinical psychogeriatric practice. PMID:25475410

  13. Functional Status in the Young–Old: Establishing a Working Prototype of an Extended-Instrumental Activities of Daily Living Scale

    PubMed Central

    Fieo, Robert; Manly, Jennifer J.; Schupf, Nicole

    2014-01-01

    Background. Instrumental activities of daily living (IADLs) exhibit strong predictive power for the presence of dementia and mild cognitive impairment. However, IADLs are often less effective in younger cohorts or in healthy community-dwelling samples, presenting with large ceiling effects. This study aimed to construct an IADL scale with an extended range. An effort was made to incorporate leisure activity tasks that were more stimulating, and potentially more challenging, into a set of traditional IADLs. Methods. Beginning with a set of IADL and leisure activity items, nonparametric item response theory methodology was used to construct a scale with appropriate dimensionality, monotonicity, item discrimination power, and scalability within a large cohort of young–old (aged 65–75). Dimensionality was further scrutinized by principal component analysis of the residuals. The predictive validity of the resulting scale for poor cognitive performance was evaluated using logistic regression. Results. A reliable (ρ = .73) unidimensional construct was established, meeting the Mokken item response theory criteria of medium scalability. Excluding demented participants, the adjusted model proved sensitive to relatively subtle cognitive deficits; each additional task endorsed (nine-item scale) significantly decreased the odds of being in the bottom quarter of composite domains relating to processing speed (odds ratio = 0.73 [confidence interval: 0.56–0.97], p < .05) and visuospatial ability (odds ratio = 0.70 [confidence interval: 0.73–0.87], p < .01). Conclusions. A reliable extended-IADL scale was constructed meeting item response theory assumptions relating to unidimensionality, monotonicity, and invariant item ordering. The range of measurement extends well beyond traditional IADL scales. Finally, the scale appears to be sensitive to cognitive differences within the normal spectrum. PMID:24149431

  14. The de Morton Mobility Index (DEMMI): An essential health index for an ageing world

    PubMed Central

    de Morton, Natalie A; Davidson, Megan; Keating, Jennifer L

    2008-01-01

    Background Existing instruments for measuring mobility are inadequate for accurately assessing older people across the broad spectrum of abilities. Like other indices that monitor critical aspects of health such as blood pressure tests, a mobility test for all older acute medical patients provides essential health data. We have developed and validated an instrument that captures essential information about the mobility status of older acute medical patients. Methods Items suitable for a new mobility instrument were generated from existing scales, patient interviews and focus groups with experts. 51 items were pilot tested on older acute medical inpatients. An interval-level unidimensional mobility measure was constructed using Rasch analysis. The final item set required minimal equipment and was quick and simple to administer. The de Morton Mobility Index (DEMMI) was validated on an independent sample of older acute medical inpatients and its clinimetric properties confirmed. Results The DEMMI is a 15 item unidimensional measure of mobility. Reliability (MDC90), validity and the minimally clinically important difference (MCID) of the DEMMI were consistent across independent samples. The MDC90 and MCID were 9 and 10 points respectively (on the 100 point Rasch converted interval DEMMI scale). Conclusion The DEMMI provides clinicians and researchers with a valid interval-level method for accurately measuring and monitoring mobility levels of older acute medical patients. DEMMI validation studies are underway in other clinical settings and in the community. Given the ageing population and the importance of mobility for health and community participation, there has never been a greater need for this instrument. PMID:18713451

  15. Dictyostelium nucleomorphin is a member of the BRCT-domain family of cell cycle checkpoint proteins.

    PubMed

    Myre, Michael A; O'Day, Danton H

    2004-11-18

    A search of the Dictyostelium genome project database (http://dictybase.org/db/cgi-bin/blast.pl) with nucleomorphin, a protein that regulates the nuclear number, predicted it to be encoded by a larger gene containing a putative breast cancer carboxy-terminus domain (BRCT). Using RT-PCR, Northern and Western blotting we have identified a differentially expressed, 2318 bp cDNA encoding a protein isoform of Dictyostelium NumA with an apparent molecular weight of 70 kDa that we have called NumB. It contains a single amino-terminal BRCT-domain spanning residues 125-201. Starvation of shaking cultures reduces NumA expression by approximately 88+/-5.6%, whereas NumB expression increases approximately 35+/-3.5% from vegetative levels. NumC, a third isoform that is also expressed during development but not growth, remains to be characterized. These findings suggest NumB may be a member of the BRCT-domain containing cell cycle checkpoint proteins. PMID:15535983

  16. The Fz-Dsh planar cell polarity pathway induces oriented cell division via Mud/NuMA in Drosophila and zebrafish

    PubMed Central

    Ségalen, Marion; Johnston, Christopher A.; Martin, Charlotte A.; Dumortier, Julien G.; Prehoda, Kenneth E.; David, Nicolas B.; Doe, Chris Q.; Bellaïche, Yohanns

    2010-01-01

    SUMMARY The Frizzled receptor and Dishevelled effector regulate mitotic spindle orientation in both vertebrates and invertebrates, but how Dishevelled orients the mitotic spindle is unknown. Using the Drosophila S2 cell "induced polarity" system, we find that Dishevelled cortical polarity is sufficient to orient the spindle, and that Dishevelled's DEP domain mediates this function. This domain binds a C-terminal domain of Mud (the Drosophila NuMA ortholog), and Mud is required for Dishevelled-mediated spindle orientation. In Drosophila, Frizzled-Dishevelled planar cell polarity (PCP) orients the sensory organ precursor (pI) spindle along the anterior-posterior axis. We show that Dishevelled and Mud colocalize at the posterior cortex of pI, Mud localization at the posterior cortex requires Dsh, and Mud loss-of-function randomizes spindle orientation. During zebrafish gastrulation, the Wnt11-Frizzled-Dishevelled PCP pathway orients spindles along the animal-vegetal axis, and reducing NuMA levels disrupts spindle orientation. Overall, we describe a Frizzled-Dishevelled-NuMA pathway that orients division from Drosophila to vertebrates. PMID:21074723

  17. Polyglutamylated Tubulin Binding Protein C1orf96/CSAP Is Involved in Microtubule Stabilization in Mitotic Spindles

    PubMed Central

    Ohta, Shinya; Hamada, Mayako; Sato, Nobuko; Toramoto, Iyo

    2015-01-01

    The centrosome-associated C1orf96/Centriole, Cilia and Spindle-Associated Protein (CSAP) targets polyglutamylated tubulin in mitotic microtubules (MTs). Loss of CSAP causes critical defects in brain development; however, it is unclear how CSAP association with MTs affects mitosis progression. In this study, we explored the molecular mechanisms of the interaction of CSAP with mitotic spindles. Loss of CSAP caused MT instability in mitotic spindles and resulted in mislocalization of Nuclear protein that associates with the Mitotic Apparatus (NuMA), with defective MT dynamics. Thus, CSAP overload in the spindles caused extensive MT stabilization and recruitment of NuMA. Moreover, MT stabilization by CSAP led to high levels of polyglutamylation on MTs. MT depolymerization by cold or nocodazole treatment was inhibited by CSAP binding. Live-cell imaging analysis suggested that CSAP-dependent MT-stabilization led to centrosome-free MT aster formation immediately upon nuclear envelope breakdown without γ-tubulin. We therefore propose that CSAP associates with MTs around centrosomes to stabilize MTs during mitosis, ensuring proper bipolar spindle formation and maintenance. PMID:26562023

  18. Self-organization of stabilized microtubules by both spindle and midzone mechanisms in Xenopus egg cytosol

    PubMed Central

    Mitchison, Timothy J.; Nguyen, Phuong; Coughlin, Margaret; Groen, Aaron C.

    2013-01-01

    Previous study of self-organization of Taxol-stabilized microtubules into asters in Xenopus meiotic extracts revealed motor-dependent organizational mechanisms in the spindle. We revisit this approach using clarified cytosol with glycogen added back to supply energy and reducing equivalents. We added probes for NUMA and Aurora B to reveal microtubule polarity. Taxol and dimethyl sulfoxide promote rapid polymerization of microtubules that slowly self-organize into assemblies with a characteristic morphology consisting of paired lines or open circles of parallel bundles. Minus ends align in NUMA-containing foci on the outside, and plus ends in Aurora B–containing foci on the inside. Assemblies have a well-defined width that depends on initial assembly conditions, but microtubules within them have a broad length distribution. Electron microscopy shows that plus-end foci are coated with electron-dense material and resemble similar foci in monopolar midzones in cells. Functional tests show that two key spindle assembly factors, dynein and kinesin-5, act during assembly as they do in spindles, whereas two key midzone assembly factors, Aurora B and Kif4, act as they do in midzones. These data reveal the richness of self-organizing mechanisms that operate on microtubules after they polymerize in meiotic cytoplasm and provide a biochemically tractable system for investigating plus-end organization in midzones. PMID:23515222

  19. The deubiquitinating enzyme complex BRISC is required for proper mitotic spindle assembly in mammalian cells

    PubMed Central

    Yan, Kaowen; Li, Li; Wang, Xiaojian; Hong, Ruisha; Zhang, Ying; Yang, Hua; Lin, Ming; Zhang, Sha; He, Qihua; Zheng, Duo; Tang, Jun; Yin, Yuxin

    2015-01-01

    Deubiquitinating enzymes (DUBs) negatively regulate protein ubiquitination and play an important role in diverse physiological processes, including mitotic division. The BRCC36 isopeptidase complex (BRISC) is a DUB that is specific for lysine 63–linked ubiquitin hydrolysis; however, its biological function remains largely undefined. Here, we identify a critical role for BRISC in the control of mitotic spindle assembly in cultured mammalian cells. BRISC is a microtubule (MT)-associated protein complex that predominantly localizes to the minus ends of K-fibers and spindle poles and directly binds to MTs; importantly, BRISC promotes the assembly of functional bipolar spindle by deubiquitinating the essential spindle assembly factor nuclear mitotic apparatus (NuMA). The deubiquitination of NuMA regulates its interaction with dynein and importin-β, which are required for its function in spindle assembly. Collectively, these results uncover BRISC as an important regulator of the mitotic spindle assembly and cell division, and have important implications for the development of anticancer drugs targeting BRISC. PMID:26195665

  20. The Mother Centriole Appendage Protein Cenexin Modulates Lumen Formation through Spindle Orientation.

    PubMed

    Hung, Hui-Fang; Hehnly, Heidi; Doxsey, Stephen

    2016-03-21

    Establishing apical-basal polarity is instrumental in the functional shaping of a solitary lumen within an acinus. By exploiting micropatterned slides, wound healing assays, and three-dimensional culture systems, we identified a mother centriole subdistal appendage protein, cenexin, as a critical player in symmetric lumen expansion through the control of microtubule organization. In this regard, cenexin was required for both centrosome positioning in interphase cells and proper spindle orientation during mitosis. In contrast, the essential mother centriole distal appendage protein CEP164 did not play a role in either process, demonstrating the specificity of subdistal appendages for these events. Importantly, upon closer examination we found that cenexin depletion decreased astral microtubule length, disrupted astral microtubule minus-end organization, and increased levels of the polarity protein NuMA at the cell cortex. Interestingly, spindle misorientation and NuMA mislocalization were reversed by treatment with a low dose of the microtubule-stabilizing agent paclitaxel. Taken together, these results suggest that cenexin modulates microtubule organization and stability to mediate spindle orientation. PMID:26948879

  1. Concomitant binding of Afadin to LGN and F-actin directs planar spindle orientation.

    PubMed

    Carminati, Manuel; Gallini, Sara; Pirovano, Laura; Alfieri, Andrea; Bisi, Sara; Mapelli, Marina

    2016-02-01

    Polarized epithelia form by oriented cell divisions in which the mitotic spindle aligns parallel to the epithelial plane. To orient the mitotic spindle, cortical cues trigger the recruitment of NuMA-dynein-based motors, which pull on astral microtubules via the protein LGN. We demonstrate that the junctional protein Afadin is required for spindle orientation and correct epithelial morphogenesis of Caco-2 cysts. Molecularly, Afadin binds directly and concomitantly to F-actin and to LGN. We determined the crystallographic structure of human Afadin in complex with LGN and show that it resembles the LGN-NuMA complex. In mitosis, Afadin is necessary for cortical accumulation of LGN and NuMA above the spindle poles, in an F-actin-dependent manner. Collectively, our results depict Afadin as a molecular hub governing the enrichment of LGN and NuMA at the cortex. To our knowledge, Afadin is the first-described mechanical anchor between dynein and cortical F-actin. PMID:26751642

  2. The Fz-Dsh planar cell polarity pathway induces oriented cell division via Mud/NuMA in Drosophila and zebrafish.

    PubMed

    Ségalen, Marion; Johnston, Christopher A; Martin, Charlotte A; Dumortier, Julien G; Prehoda, Kenneth E; David, Nicolas B; Doe, Chris Q; Bellaïche, Yohanns

    2010-11-16

    The Frizzled receptor and Dishevelled effector regulate mitotic spindle orientation in both vertebrates and invertebrates, but how Dishevelled orients the mitotic spindle is unknown. Using the Drosophila S2 cell "induced polarity" system, we find that Dishevelled cortical polarity is sufficient to orient the spindle and that Dishevelled's DEP domain mediates this function. This domain binds a C-terminal domain of Mud (the Drosophila NuMA ortholog), and Mud is required for Dishevelled-mediated spindle orientation. In Drosophila, Frizzled-Dishevelled planar cell polarity (PCP) orients the sensory organ precursor (pI) spindle along the anterior-posterior axis. We show that Dishevelled and Mud colocalize at the posterior cortex of pI, Mud localization at the posterior cortex requires Dsh, and Mud loss-of-function randomizes spindle orientation. During zebrafish gastrulation, the Wnt11-Frizzled-Dishevelled PCP pathway orients spindles along the animal-vegetal axis, and reducing NuMA levels disrupts spindle orientation. Overall, we describe a Frizzled-Dishevelled-NuMA pathway that orients division from Drosophila to vertebrates.

  3. Education for Disaster Prevention in Elementary School in Japan

    NASA Astrophysics Data System (ADS)

    Shida, Masakuni

    2013-04-01

    Education for disaster prevention has become more and more important since the Great East Japan Earthquake and tsunami in 2011. More than 18 thousand people were killed or have not been found yet in the tragedy, however, in Kesn'numa, which is a city located in the seriously damaged area, there were few student victims of tsunami. This is because every school in Kesen'numa has excellent education systems for disaster prevention. They have several safety exercises and conducts emergency drills each year in unique ways which have been developed upon the tragic experiences of serious earthquakes and tsunami in the past. For disaster prevention education, we should learn two important points from the case in Kesen'numa; to learn from the ancient wisdom, and to ensure for students to have enough opportunities of safety exercises and emergency drills at school. In addition to these two points, another issue from the viewpoint of science education can be added, which is to learn about the mechanisms of earthquake. We have developed disaster prevention and reduction programs in educational context, taking these three points into consideration. First part of the program is to study local history, focusing on ancient wisdom. In Kesen'numa City, there were thirty-three monumental stones with cautionary lessons of the possible danger of tsunami before the great earthquake. The lessons were based on the disasters actually happened in the past and brought down to the current generation. Kesen'numa-Otani elementary school has conducted education for disaster prevention referring to this information with full of ancient wisdom. Second part of the program is to make sure that every student has enough and rich opportunities to simulate the worst situation of any disasters. For example, in the case of earthquake and tsunami, teachers take students to the safest place through the designated evacuation rout according to each school's original manual. Students can experience this

  4. Exploring Shared Memory Protocols in FLASH

    SciTech Connect

    Horowitz, Mark; Kunz, Robert; Hall, Mary; Lucas, Robert; Chame, Jacqueline

    2007-04-01

    ABSTRACT The goal of this project was to improve the performance of large scientific and engineering applications through collaborative hardware and software mechanisms to manage the memory hierarchy of non-uniform memory access time (NUMA) shared-memory machines, as well as their component individual processors. In spite of the programming advantages of shared-memory platforms, obtaining good performance for large scientific and engineering applications on such machines can be challenging. Because communication between processors is managed implicitly by the hardware, rather than expressed by the programmer, application performance may suffer from unintended communication – communication that the programmer did not consider when developing his/her application. In this project, we developed and evaluated a collection of hardware, compiler, languages and performance monitoring tools to obtain high performance on scientific and engineering applications on NUMA platforms by managing communication through alternative coherence mechanisms. Alternative coherence mechanisms have often been discussed as a means for reducing unintended communication, although architecture implementations of such mechanisms are quite rare. This report describes an actual implementation of a set of coherence protocols that support coherent, non-coherent and write-update accesses for a CC-NUMA shared-memory architecture, the Stanford FLASH machine. Such an approach has the advantages of using alternative coherence only where it is beneficial, and also provides an evolutionary migration path for improving application performance. We present data on two computations, RandomAccess from the HPC Challenge benchmarks and a forward solver derived from LS-DYNA, showing the performance advantages of the alternative coherence mechanisms. For RandomAccess, the non-coherent and write-update versions can outperform the coherent version by factors of 5 and 2.5, respectively. In LS-DYNA, we obtain

  5. Energy-aware Thread and Data Management in Heterogeneous Multi-core, Multi-memory Systems

    SciTech Connect

    Su, Chun-Yi

    2014-12-16

    (NUMA) systems. I use critical path analysis to quantify memory contention in the NUMA memory system and determine thread mappings. In addition, I implement a runtime system that combines concurrent throttling and a novel thread mapping algorithm to manage thread resources and improve energy efficient execution in multi-core, NUMA systems.

  6. [FAMILY EATING HABITS AND PERCEPTION OF RISK IN EATING DISORDERS].

    PubMed

    Rodríguez Lazo, María; Hernández Camacho, Juan Diego; Bolaños Ríos, Patricia; Ruiz-Prieto, Inmaculada; Jáuregui Lobera, Ignacio

    2015-10-01

    Introducción: los aspectos relacionados con la comida, la figura, el peso y el ejercicio físico, transmitidos de padres a hijos, y los factores socioculturales de índole mediática, como las redes sociales, pueden influir en el desarrollo de Trastornos de la Conducta Alimentaria (TCA). Objetivos: analizar la influencia de la alimentación familiar y la percepción de esta sobre la influencia de las redes sociales en el inicio y mantenimiento del TCA. Método: 30 padres de pacientes con TCA participaron voluntariamente en este estudio cumplimentando una serie de cuestionarios, y recogiéndose su peso y talla. Resultados: se observa una subestimación del peso en casos de sobrepeso (33,33%) y obesidad (25%), ya que ni siquiera se plantean realizar una dieta futura (91,67% y 25%, respectivamente) (2 = 11,31; p < 0,01). Destaca un exceso en el consumo de carnes, snacks y dulces. Durante el fin de semana hay un incremento en el consumo de kcal y azúcar (p < 0,01) y colesterol (p < 0,05), disminuyendo la ingesta de fibra, Fe, Zn y Mg (p < 0,01). Asimismo, se consume menos agua y pan, aumentando el picoteo (p < 0,01) y la frecuencia de aparición de un único plato (p < 0,05). Discusión y conclusiones: los hábitos alimentarios de estos familiares mejoran gracias a la educación nutricional incluida en el tratamiento. Los familiares no perciben adecuadamente el riesgo de las redes sociales en sus hijos, pudiendo contribuir al mantenimiento y a futuras recaídas del TCA.

  7. Lebensmitteltechnologie

    NASA Astrophysics Data System (ADS)

    Perco, Adrian

    Der Terminus "Technologie" leitet sich aus dem Griechischen ab: τέχνη (Geschicklichkeit, Kunstfertigkeit, Handwerk, Kunst; geistige Gewandtheit, Kunstgriff, List) und λόγος (Wort, Rede, Erzählung; Lehre; Vernunft). Der von τέχνη abgeleitet Begriff Technik umfasst jenes Handeln, durch welches der Mensch naturgegebene Stoffe und Energien intelligent so umformt, dass sie seinem Bedarf und Gebrauch dienen (technisches Tun); dieses Handeln führt zu einer ständig wachsenden Summe an Dingen und Verfahren (technische Gegenstände) [1].

  8. [Adoption of information and communication technologies in the dialysis clinics of Bahia State].

    PubMed

    Mota, Fábio Batista; Ferreira Júnior, Hamilton de Moura

    2010-06-01

    The aim of this article is to investigate the adoption and use of information and communication technologies within private dialysis clinics in Bahia State. A case study was developed with companies by applying, to clinics' managerial teams, a research questionnaire adapted from RedeSist and from PINTEC. The sample included 20 companies, listed by CNES of the Ministry of Health, and obtained a positive usage rate data of 60%. The collected quantitative information was analyzed by interviewees' answer frequency distribution. Conclusion indicates that the adoption of information and communication technologies by the clinics is not directly related to their access to these technologies but to the under usage of their economical potential.

  9. Network as transconcept: elements for a conceptual demarcation in the field of public health.

    PubMed

    Amaral, Carlos Eduardo Menezes; Bosi, Maria Lúcia Magalhães

    2016-06-10

    The main proposal to set up an articulated mode of operation of health services has been the concept of network, which has been appropriated in different ways in the field of public health, as it is used in other disciplinary fields or even taking it from common sense. Amid the diversity of uses and concepts, we recognize the need for rigorous conceptual demarcation about networks in the field of health. Such concern aims to preserve the strategic potential of this concept in the research and planning in the field, overcoming uncertainties and distortions still observed in its discourse-analytic circulation in public health. To this end, we will introduce the current uses of network in different disciplinary fields, emphasizing dialogues with the field of public health. With this, we intend to stimulate discussions about the development of empirical dimensions and analytical models that may allow us to understand the processes produced within and around health networks. RESUMO A principal proposta para configurar um modo articulado de funcionamento dos serviços de saúde tem sido o conceito de rede, que vem sendo apropriado de diferentes formas no campo da saúde coletiva, conforme seu emprego em outros campos disciplinares ou mesmo tomando-o do senso comum. Em meio à pluralidade de usos e concepções, reconhecemos a necessidade de rigorosa demarcação conceitual acerca de redes no campo da saúde. Tal preocupação visa a preservar o potencial estratégico desse conceito na investigação e planificação no campo, superando precariedades e distorções ainda observadas em sua circulação discursivo-analítica na saúde coletiva. Para tanto, apresentaremos os usos correntes de rede em diferentes campos disciplinares, destacando interlocuções com o campo da saúde coletiva. Com isso, pretendemos estimular o debate acerca do desenvolvimento de dimensões empíricas e modelos de análise que permitam compreender os processos produzidos no interior e ao redor

  10. Network as transconcept: elements for a conceptual demarcation in the field of public health.

    PubMed

    Amaral, Carlos Eduardo Menezes; Bosi, Maria Lúcia Magalhães

    2016-08-22

    The main proposal to set up an articulated mode of operation of health services has been the concept of network, which has been appropriated in different ways in the field of public health, as it is used in other disciplinary fields or even taking it from common sense. Amid the diversity of uses and concepts, we recognize the need for rigorous conceptual demarcation about networks in the field of health. Such concern aims to preserve the strategic potential of this concept in the research and planning in the field, overcoming uncertainties and distortions still observed in its discourse-analytic circulation in public health. To this end, we will introduce the current uses of network in different disciplinary fields, emphasizing dialogues with the field of public health. With this, we intend to stimulate discussions about the development of empirical dimensions and analytical models that may allow us to understand the processes produced within and around health networks. RESUMO A principal proposta para configurar um modo articulado de funcionamento dos serviços de saúde tem sido o conceito de rede, que vem sendo apropriado de diferentes formas no campo da saúde coletiva, conforme seu emprego em outros campos disciplinares ou mesmo tomando-o do senso comum. Em meio à pluralidade de usos e concepções, reconhecemos a necessidade de rigorosa demarcação conceitual acerca de redes no campo da saúde. Tal preocupação visa a preservar o potencial estratégico desse conceito na investigação e planificação no campo, superando precariedades e distorções ainda observadas em sua circulação discursivo-analítica na saúde coletiva. Para tanto, apresentaremos os usos correntes de rede em diferentes campos disciplinares, destacando interlocuções com o campo da saúde coletiva. Com isso, pretendemos estimular o debate acerca do desenvolvimento de dimensões empíricas e modelos de análise que permitam compreender os processos produzidos no interior e ao redor

  11. IMPACC: A Tightly Integrated MPI+OpenACC Framework Exploiting Shared Memory Parallelism

    SciTech Connect

    Lee, Seyong; Vetter, Jeffrey S

    2016-01-01

    We propose IMPACC, an MPI+OpenACC framework for heterogeneous accelerator clusters. IMPACC tightly integrates MPI and OpenACC, while exploiting the shared memory parallelism in the target system. IMPACC dynamically adapts the input MPI+OpenACC applications on the target heterogeneous accelerator clusters to fully exploit target system-specific features. IMPACC provides the programmers with the unified virtual address space, automatic NUMA-friendly task-device mapping, efficient integrated communication routines, seamless streamlining of asynchronous executions, and transparent memory sharing. We have implemented IMPACC and evaluated its performance using three heterogeneous accelerator systems, including Titan supercomputer. Results show that IMPACC can achieve easier programming, higher performance, and better scalability than the current MPI+OpenACC model.

  12. Healthcare IT system in the midst of and after Great East Japan Earthquake Disaster : Grand design for reconstruction of Tohoku-region healthcare IT system

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroshi

    In this article, we described what was really going in the disaster medical care at the Great East Japan Earthquake, mainly in Ishinomaki and Kesen-numa areas. As for exchange tools of the disaster information, in contrast to the breakdown of fixed-line and mobile phone, MCA radio system, satellite mobiles and internet, especially SNS, were greatly helpful. Learned from the disaster experiences, we are making the grand design for “disaster-robust” regional healthcare IT systems, which are composed of (1) cloud center storing whole-prefecture medical records, (2) SS-MIX based regional healthcare information systems of “the second medical care zones”, (3) ASP/SaaS typed electronic medical record system for all clinics located at Pacific coastal areas, and (4) wireless communication environment supporting comprehensive care of elderly for daily living activities.

  13. Performance of the Cray T3D and Emerging Architectures on Canopy QCD Applications

    NASA Astrophysics Data System (ADS)

    Fischler, Mark; Uchima, Mike

    1996-03-01

    The Cray T3D, an MIMD system with NUMA shared memory capabilities and in principle very low communications latency, can support the Canopy framework for grid-oriented applications. CANOPY has been ported to the T3D, with the intent of making it available to a spectrum of users. The performance of the T3D running Canopy has been benchmarked on five QCD applications extensively run on ACPMAPS at Fermilab, requiring a variety of data access patterns. The net performance and scaling behavior reveals an efficiency relative to peak Gflops almost identical to that achieved on ACPMAPS. Detailed studies of the major factors impacting performance are presented. Generalizations applying this analysis to the newly emerging crop of commercial systems reveal where their limitations will lie. On these applications, efficiencies of above 25% are not to be expected; eliminating overheads due to Canopy will improve matters, but by less than a factor of two.

  14. Clomp

    2007-05-25

    CLOMP is the C version of the Livermore OpenMP benchmark deeloped to measure OpenMP overheads and other performance impacts due to threading (like NUMA memory layouts, memory contention, cache effects, etc.) in order to influence future system design. Current best-in-class implementations of OpenMP have overheads at least ten times larger than is required by many of our applications for effective use of OpenMP. This benchmark shows the significant negative performance impact of these relatively largemore » overheads and of other thread effects. The CLOMP benchmark highly configurable to allow a variety of problem sizes and threading effects to be studied and it carefully checks its results to catch many common threading errors. This benchmark is expected to be included as part of the Sequoia Benchmark suite for the Sequoia procurement.« less

  15. CLOMP: Accurately Characterizing OpenMP Application Overheads

    SciTech Connect

    Bronevetsky, G; Gyllenhaal, J; de Supinski, B

    2008-02-11

    Despite its ease of use, OpenMP has failed to gain widespread use on large scale systems, largely due to its failure to deliver sufficient performance. Our experience indicates that the cost of initiating OpenMP regions is simply too high for the desired OpenMP usage scenario of many applications. In this paper, we introduce CLOMP, a new benchmark to characterize this aspect of OpenMP implementations accurately. CLOMP complements the existing EPCC benchmark suite to provide simple, easy to understand measurements of OpenMP overheads in the context of application usage scenarios. Our results for several OpenMP implementations demonstrate that CLOMP identifies the amount of work required to compensate for the overheads observed with EPCC. Further, we show that CLOMP also captures limitations for OpenMP parallelization on NUMA systems.

  16. Performance of the Cray T3D and emerging architectures on canopy QCD applications

    SciTech Connect

    Fischler, M.; Uchima, M.

    1995-11-01

    The Cray T3D, an MIMD system with NUMA shared memory capabilities and in principle very low communications latency, can support the Canopy framework for grid-oriented applications. CANOPY has been ported to the T3D, with the intent of making it available to a spectrum of users. The performance of the T3D running Canopy has been benchmarked on five QCD applications extensively run on ACPMAPS at Fermilab, requiring a variety of data access patterns. The net performance and scaling behavior reveals an efficiency relative to peak Gflops almost identical to that achieved on ACPMAPS. Detailed studies of the major factors impacting performance are presented. Generalizations applying this analysis to the newly emerging crop of commercial systems reveal where their limitations will lie. On these applications, efficiencies of above 25% are not to be expected; eliminating overheads due to Canopy will improve matters, but by less than a factor of two.

  17. Human papillomavirus type 16 E7 oncoprotein engages but does not abrogate the mitotic spindle assembly checkpoint

    SciTech Connect

    Yu, Yueyang; Munger, Karl

    2012-10-10

    The mitotic spindle assembly checkpoint (SAC) ensures faithful chromosome segregation during mitosis by censoring kinetochore-microtubule interactions. It is frequently rendered dysfunctional during carcinogenesis causing chromosome missegregation and genomic instability. There are conflicting reports whether the HPV16 E7 oncoprotein drives chromosomal instability by abolishing the SAC. Here we report that degradation of mitotic cyclins is impaired in cells with HPV16 E7 expression. RNAi-mediated depletion of Mad2 or BubR1 indicated the involvement of the SAC, suggesting that HPV16 E7 expression causes sustained SAC engagement. Mutational analyses revealed that HPV16 E7 sequences that are necessary for retinoblastoma tumor suppressor protein binding as well as sequences previously implicated in binding the nuclear and mitotic apparatus (NuMA) protein and in delocalizing dynein from the mitotic spindle contribute to SAC engagement. Importantly, however, HPV16 E7 does not markedly compromise the SAC response to microtubule poisons.

  18. Parathyroid hormone regulates the expression of rat osteoblast and osteosarcoma nuclear matrix proteins.

    PubMed

    Bidwell, J; Feister, H; Swartz, D; Onyia, J; Holden, J; Hock, J

    1996-12-01

    Parathyroid hormone (PTH) alters osteoblast morphology. How these changes in cell shape modify nuclear structure and ultimately gene expression is not known. Chronic exposure to rat PTH (1-34) [10 nM] attenuated the expression of 200, 190, and 160 kD proteins in the nuclear matrix-intermediate filament subfraction of the rat osteosarcoma cells, ROS 17/2.8 [Bidwell et al. (1994b): Endocrinology 134:1738-1744]. Here, we determined that these same PTH-responsive proteins were expressed in rat metaphyseal osteoblasts. We identified the 200 kD protein as a non-muscle myosin. Although the molecular weights, subcellular distribution, and half-lives of the 190 and 160 kD proteins were similar to topoisomerase II-alpha and -beta, nuclear matrix enzymes that mediate DNA topology, the 190 and 160 kD proteins did not interact with topoisomerase antibodies. Nevertheless, the expression of topoisomerase II-alpha, and NuMA, a component of the nuclear core filaments, was also regulated by PTH in the osteosarcoma cells. The 190 kD protein was selectively expressed in bone cells as it was not observed in OK opossum kidney cells, H4 hepatoma cells, or NIH3T3 cells. PTH attenuated mRNA expression of the PTH receptor in our cell preparations. These results demonstrate that PTH selectively alters the expression of osteoblast membrane, cytoskeletal, and nucleoskeletal proteins. Topoisomerase II-alpha, NuMA, and the 190 and 160 kD proteins may direct the nuclear PTH signalling pathways to the target genes and play a structural role in osteoblast gene expression. PMID:8913889

  19. Dominant-Negative Effects of Adult-Onset Huntingtin Mutations Alter the Division of Human Embryonic Stem Cells-Derived Neural Cells

    PubMed Central

    Lopes, Carla; Aubert, Sophie; Bourgois-Rocha, Fany; Barnat, Monia; Rego, Ana Cristina; Déglon, Nicole

    2016-01-01

    Mutations of the huntingtin protein (HTT) gene underlie both adult-onset and juvenile forms of Huntington’s disease (HD). HTT modulates mitotic spindle orientation and cell fate in mouse cortical progenitors from the ventricular zone. Using human embryonic stem cells (hESC) characterized as carrying mutations associated with adult-onset disease during pre-implantation genetic diagnosis, we investigated the influence of human HTT and of an adult-onset HD mutation on mitotic spindle orientation in human neural stem cells (NSCs) derived from hESCs. The RNAi-mediated silencing of both HTT alleles in neural stem cells derived from hESCs disrupted spindle orientation and led to the mislocalization of dynein, the p150Glued subunit of dynactin and the large nuclear mitotic apparatus (NuMA) protein. We also investigated the effect of the adult-onset HD mutation on the role of HTT during spindle orientation in NSCs derived from HD-hESCs. By combining SNP-targeting allele-specific silencing and gain-of-function approaches, we showed that a 46-glutamine expansion in human HTT was sufficient for a dominant-negative effect on spindle orientation and changes in the distribution within the spindle pole and the cell cortex of dynein, p150Glued and NuMA in neural cells. Thus, neural derivatives of disease-specific human pluripotent stem cells constitute a relevant biological resource for exploring the impact of adult-onset HD mutations of the HTT gene on the division of neural progenitors, with potential applications in HD drug discovery targeting HTT-dynein-p150Glued complex interactions. PMID:26863614

  20. Dominant-Negative Effects of Adult-Onset Huntingtin Mutations Alter the Division of Human Embryonic Stem Cells-Derived Neural Cells.

    PubMed

    Lopes, Carla; Aubert, Sophie; Bourgois-Rocha, Fany; Barnat, Monia; Rego, Ana Cristina; Déglon, Nicole; Perrier, Anselme L; Humbert, Sandrine

    2016-01-01

    Mutations of the huntingtin protein (HTT) gene underlie both adult-onset and juvenile forms of Huntington's disease (HD). HTT modulates mitotic spindle orientation and cell fate in mouse cortical progenitors from the ventricular zone. Using human embryonic stem cells (hESC) characterized as carrying mutations associated with adult-onset disease during pre-implantation genetic diagnosis, we investigated the influence of human HTT and of an adult-onset HD mutation on mitotic spindle orientation in human neural stem cells (NSCs) derived from hESCs. The RNAi-mediated silencing of both HTT alleles in neural stem cells derived from hESCs disrupted spindle orientation and led to the mislocalization of dynein, the p150Glued subunit of dynactin and the large nuclear mitotic apparatus (NuMA) protein. We also investigated the effect of the adult-onset HD mutation on the role of HTT during spindle orientation in NSCs derived from HD-hESCs. By combining SNP-targeting allele-specific silencing and gain-of-function approaches, we showed that a 46-glutamine expansion in human HTT was sufficient for a dominant-negative effect on spindle orientation and changes in the distribution within the spindle pole and the cell cortex of dynein, p150Glued and NuMA in neural cells. Thus, neural derivatives of disease-specific human pluripotent stem cells constitute a relevant biological resource for exploring the impact of adult-onset HD mutations of the HTT gene on the division of neural progenitors, with potential applications in HD drug discovery targeting HTT-dynein-p150Glued complex interactions.

  1. Psychometric Properties of the Chinese Version of the Fear of Negative Evaluation Scale-Brief (BFNE) and the BFNE-Straightforward for Middle School Students

    PubMed Central

    Wei, Jia; Zhang, Chunyu; Li, Yadan; Xue, Song; Zhang, Jinfu

    2015-01-01

    Background The 12-item brief version of the Fear of Negative Evaluation Scale (BFNE) is one of the most widely used instruments to assess fear of negative evaluation. Recent evidence strongly supports the version composed of 8 straightforward items (BFNE-S), which possessesstronger psychometric properties. The purpose of the current study is to examine the psychometric prop-erties of the Chinese versions of the BFNE and BFNE-S for middle school students. Methodology A total of 1009 middle school students were recruited in this study. The BFNE, the BFNE-S, the Friedman-Bendas Text Anxiety Scale (FBTAS), and the Social Anxiety Scale (SAS) were administered to 497 participants, and 52 participants were re-tested after four weeks. The BFNE, the BFNE-S, the Rosenberg Self-Esteem Scale (RSES), and the Balanced Inventory of Desirable Responding (BIDR) wereadministered to 492 participants. The BFNE and BFNE-S significantly cor-related with all the scales, supporting their convergent, divergent and concurrent validity. Principal Findings The Cronbach's alpha of the BFNE (BFNE-S) was 0.864 (0.867) with 497 par-ticipants and 0.886 (0.844) with 492 participants, and the test-retest reliability coefficient was 0.791 (0.855) (ICC). Although the EFA identified a two-factor solution in which the 8 straightfor-ward items loaded on one factor and the 4 reversed items loaded on the other, the CFA, using a random intercept model to control the wording effect, supported a unidimensional factor struc-ture of the BFNE. Both EFA and CFA supported the unidimensional assumption of the BFNE-S. The correlations of the BFNE and BFNE-S were 0.929 and 0.952 in two samples. Conclusions The Chinese versions of the BFNE and BFNE-S demonstrate adequate psychometric properties for assessing fear of negative evaluation. The results support their use among the Chinese middle school students. Considering its greater parsimony and excellent reliability and validity, the BFNE-S is a better tool. PMID

  2. Gender identity and its implications for the concepts of masculinity and femininity.

    PubMed

    Spence, J T

    1984-01-01

    In this chapter, I have suggested that although the terms masculine and feminine and masculinity and femininity have rarely been defined, they appear to have two types of meaning both for psychologists and for the community at large. First, masculine and feminine have an empirical meaning, being used as labels to identify specific objects, events, or qualities that in a given culture are perceived as more closely associated with males or with females. Second, these adjectives and, even more exclusively the nouns masculinity and femininity, are used as theoretical constructs that refer to a fundamental property or aspect of the individual's self-concept that is not directly observable. Masculinity and femininity in this second sense are conceived as bipolar opposites, almost all men having a firm sense of their psychological masculinity and almost all women having a similar sense of their femininity. The implicit assumptions on which conventional theories of masculinity-femininity are predicated imply that all gender-related phenomena contribute to a bipolar femininity-masculinity factor so that assessment of an individual's masculine and feminine qualities (in the empirical sense of these terms) can be used to infer his or her position on the hypothetical masculinity-femininity continuum. Constructs such as sex-role identification and sex-role orientation are based on the same assumptions. More recently it as been proposed that masculine and feminine qualities and their accompanying self-images of masculinity and femininity constitute instead two separate, statistically independent dimensions. However, most investigators nominally advancing this two-factor model and tying the measurement of masculinity and femininity to instruments containing separate scales of masculine and feminine attributes have in fact employed unidimensional bipolar models, based on such concepts as sex-role identification, sex typing, or gender schema. The empirical data, however, support

  3. The Nature of Science Instrument-Elementary (NOSI-E): Using Rasch principles to develop a theoretically grounded scale to measure elementary student understanding of the nature of science

    NASA Astrophysics Data System (ADS)

    Peoples, Shelagh

    The purpose of this study was to determine which of three competing models will provide, reliable, interpretable, and responsive measures of elementary students' understanding of the nature of science (NOS). The Nature of Science Instrument-Elementary (NOSI-E), a 28-item Rasch-based instrument, was used to assess students' NOS understanding. The NOS construct was conceptualized using five construct dimensions (Empirical, Inventive, Theory-laden, Certainty and Socially & Culturally Embedded). The competing models represent three internal models for the NOS construct. One postulate is that the NOS construct is unidimensional where one latent construct explains the relationship between the 28 items of the NOSI-E. Alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. A validity argument was developed that hypothesized that the internal structure of the NOS construct is best represented by the multidimensional Rasch model. Four sets of analyses were performed in which the three representations were compared. These analyses addressed five validity aspects (content, substantive, generalizability, structural and external) of construct validity. The vast body of evidence supported the claim that the NOS construct is composed of five separate but inter-related dimensions that is best represented by the multidimensional Rasch model. The results of the multidimensional analyses indicated that the items of the five subscales were of excellent technical quality, exhibited no differential item functioning (based on gender), had an item hierarchy that conformed to theoretical expectations; and together formed subscales of reasonable reliability (> 0.7 on each subscale) that were responsive to change in the construct. Theory-laden scores from the multidimensional model predicted students' science achievement with

  4. Neuro-QOL: quality of life item banks for adults with neurological disorders: item development and calibrations based upon clinical and general population testing

    PubMed Central

    Lai, Jin Shei; Bode, Rita; Choi, Seung; Moy, Claudia; Bleck, Tom; Miller, Deborah; Peterman, Amy; Cella, David

    2013-01-01

    Purpose Neuro-QOL provides a clinically relevant and psychometrically robust health-related quality of life (HRQL) assessment tool for both adults and children with common neurological disorders. We now report the psychometric results for the adult tools. Methods An extensive research, survey and consensus process was used to produce a list of 5 priority adult neurological conditions (stroke, multiple sclerosis, Parkinson’s disease, epilepsy and ALS). We identified relevant health related quality of life (HRQL) domains through multiple methods and data sources including a comprehensive review of the literature and literature search, expert interviews and surveys and patient and caregiver focus groups. The final domain framework consisted of 17 domains of Physical, Mental and Social health. There were five phases of item development: (1) identification of 3,482 extant items, (2) item classification and selection, (3) item review and revision, (4) cognitive interviews with 63 patients to assess their understanding of individual items and (5) field testing of 432 representative items. Participants and Procedures Participants were drawn from the US general population and clinical settings, and included both English and Spanish speaking subjects (N = 3,246). Confirmatory factor analysis (CFA) was used to evaluate the dimensionality of unidimensional domains. Where the domain structure was previously unknown, the dataset was split and first analyzed with exploratory factor analysis and then CFA. Samejima’s graded response model (GRM) was used to calculate IRT parameters. We further evaluated differential item functioning (DIF) on gender, education and age. Results Thirteen unidimensional calibrated item banks consisting of 297 items were developed. All of the tested item banks had high reliability and few or no locally dependent items. The range of item slopes and thresholds with good information are reported for each of the item banks. The banks can support CAT and

  5. Development and Psychometric Testing of a Breast Cancer Survivor Self-Efficacy Scale

    PubMed Central

    Champion, Victoria L.; Ziner, Kim W.; Monahan, Patrick O.; Stump, Timothy E.; Cella, David; Smith, Lisa G.; Bell, Cynthia J.; Von Ah, Diane; Sledge, George W.

    2016-01-01

    Purpose/Objectives To describe the development of a self-efficacy instrument that measures perceived ability to manage symptoms and quality-of-life problems resulting from the diagnosis and treatment of breast cancer. Design Items were developed and content validity assessed. A 14-item scale was psychometrically evaluated using internal consistency reliability and several types of construct validity. Sample 1,127 female breast cancer survivors (BCSs). Methods Written consents were mailed to the research office. Data were collected via mail and telephone. Main Research Variables Demographics, symptom bother, communication with healthcare provider, attention function, fear of recurrence, depression, marital satisfaction, fatigue, sexual functioning, trait and state anxiety, and overall well-being. Findings Data demonstrated that the breast cancer self-efficacy scale (BCSES) was reliable, with an alpha coefficient of 0.89, inter-item correlations ranging from 0.3–0.6, and item-total correlation coefficients ranging from 0.5–0.73. Three of 14 items were deleted because of redundancy as identified through high (> 0.7) inter-item correlations. Factor analysis revealed that the scale was unidimensional. Predictive validity was supported through testing associations between self-efficacy and theoretically supported quality-of-life variables, including physical, psychological, and social dimensions, as well as overall well-being. Conclusions The BCSES demonstrated high internal consistency reliability, unidimensionality, and excellent content and construct validity. This scale should be integrated into interventions that target self-efficacy for managing symptoms in BCSs. Implications for Nursing Nurses working with BCSs may use this tool to assess areas in which survivors might need to build confidence to adequately cope with their specific survivorship concerns. Knowledge Translation The use of the BCSES can inform nurse researchers about the impact of an intervention

  6. The Piper Fatigue Scale-12 (PFS-12): Psychometric Findings and Item Reduction in a Cohort of Breast Cancer Survivors

    PubMed Central

    Reeve, Bryce B.; Stover, Angela M.; Alfano, Catherine M.; Smith, Ashley Wilder; Ballard-Barbash, Rachel; Bernstein, Leslie; McTiernan, Anne; Baumgartner, Kathy B.; Piper, Barbara F.

    2013-01-01

    Purpose Brief, valid measures of fatigue, a prevalent and distressing cancer symptom, are needed for use in research. This study’s primary aim was to create a shortened version of the revised Piper Fatigue Scale (PFS-R) based on data from a diverse cohort of breast cancer survivors. A secondary aim was to determine whether the PFS captured multiple distinct aspects of fatigue (a multidimensional model) or a single overall fatigue factor (a unidimensional model). Methods Breast cancer survivors (n=799; stages in situ through IIIa; ages 29–86 yrs) were recruited through 3 SEER registries (New Mexico, Western Washington, and Los Angeles, CA) as part of the Health, Eating, Activity, and Lifestyle (HEAL) study. Fatigue was measured approximately 3 years post-diagnosis using the 22-item PFS-R that has 4 subscales (Behavior, Affect, Sensory, and Cognition). Confirmatory factor analysis was used to compare unidimensional and multidimensional models. Six criteria were used to make item selections to shorten the PFS-R: scale’s content validity, items’ relationship with fatigue, content redundancy, differential item functioning by race and/or education, scale reliability, and literacy demand. Results Factor analyses supported the original 4-factor structure. There was also evidence from the bi-factor model for a dominant underlying fatigue factor. Six items tested positive for differential item functioning between African-American and Caucasian survivors. Four additional items either showed poor association, local dependence, or content validity concerns. After removing these 10 items, the reliability of the PFS-12 subscales ranged from 0.87–0.89, compared to 0.90–0.94 prior to item removal. Conclusion The newly developed PFS-12 can be used to assess fatigue in African-American and Caucasian breast cancer survivors and reduces response burden without compromising reliability or validity. This is the first study to determine PFS literacy demand and to compare PFS

  7. Development of hybrid composite co-pultruded structural members

    NASA Astrophysics Data System (ADS)

    Honickman, Hart Noah

    Fibre reinforced polymer (FRP) materials offer many advantages over conventional metallic structural materials due to their high specific strength and stiffness, long fatigue life, and resistance to environmental corrosion. However, these materials present some unique engineering challenges due to their anisotropy and heterogeneity. The connection of these composite parts to adjacent components often results in complex and counter-intuitive states of stress that can be quite difficult to model. Furthermore, since these materials are, in a sense, synthesized during the fabrication of the final part, the mechanical properties that can be expected from FRP structures are largely dependent upon highly skilled workmanship. Pultrusion is a manufacturing technique that is intended for the mass-production of long FRP parts having continuous cross-sectional geometry. Although it has not yet been optimized for the aerospace industry, with some qualification research, pultrusion may prove to offer many benefits over conventional methods of manufacturing composite aircraft parts. The present dissertation investigates the possibility of co-pultruding FRP parts with embedded non-FRP materials (such as metallic materials), which could serve as integral hard points to facilitate serviceable mechanical connections to adjacent parts. It is shown that these hybrid co-pultruded members offer substantial light-weighting benefits over conventional metallic components, while retaining the ability to employ serviceable mechanical fasteners. Simple unidimensional beam models are of great value when validating the results of complex finite element analyses of aircraft wing-stringers, or other similar structural members. It is demonstrated in the present dissertation that classical unidimensional beam-type analytical models often yield unconservative predictions (over-predictions) of stiffness and elastic stability when used for the analyses of FRP beams and columns. In fact, specific

  8. From Help-Seekers to Influential Users: A Systematic Review of Participation Styles in Online Health Communities

    PubMed Central

    Ali, Kathina; Cunningham, John Alastair; Griffiths, Kathleen Margaret

    2015-01-01

    Background Understanding how people participate in and contribute to online health communities (OHCs) is useful knowledge in multiple domains. It is helpful for community managers in developing strategies for building community, for organizations in disseminating information about health interventions, and for researchers in understanding the social dynamics of peer support. Objective We sought to determine if any patterns were apparent in the nature of user participation across online health communities. Methods The current study involved a systematic review of all studies that have investigated the nature of participation in an online health community and have provided a quantifiable method for categorizing a person based on their participation style. A systematic search yielded 20 papers. Results Participatory styles were classified as either multidimensional (based on multiple metrics) or unidimensional (based on one metric). With respect to the multidimensional category, a total of 41 different participation styles were identified ranging from Influential Users who were leaders on the board to Topic-Focused Responders who focused on a specific topic and tended to respond to rather than initiate posts. However, there was little overlap in participation styles identified both across OHCs for different health conditions and within OHCs for specific health conditions. Five of the 41 styles emerged in more than one study (Hubs, Authorities, Facilitators, Prime Givers, and Discussants), but the remainder were reported in only one study. The focus of the unidimensional studies was on level of engagement and particularly on high-engaged users. Eight different metrics were used to evaluate level of engagement with the greatest focus on frequency of posts. Conclusions With the exception of high-engaged users based on high post frequency, the current review found little evidence for consistent participatory styles across different health communities. However, this area

  9. Analytical study of nozzle performance for nuclear thermal rockets

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1991-01-01

    Nuclear propulsion has been identified as one of the key technologies needed for human exploration of the Moon and Mars. The Nuclear Thermal Rocket (NTR) uses a nuclear reactor to heat hydrogen to a high temperature followed by expansion through a conventional convergent-divergent nozzle. A parametric study of NTR nozzles was performed using the Rocket Engine Design Expert System (REDES) at the NASA Lewis Research Center. The REDES used the JANNAF standard rigorous methodology to determine nozzle performance over a range of chamber temperatures, chamber pressures, thrust levels, and different nozzle configurations. A design condition was set by fixing the propulsion system exit radius at five meters and throat radius was varied to achieve a target thrust level. An adiabatic wall was assumed for the nozzle, and its length was assumed to be 80 percent of a 15 degree cone. The results conclude that although the performance of the NTR, based on infinite reaction rates, looks promising at low chamber pressures, finite rate chemical reactions will cause the actual performance to be considerably lower. Parameters which have a major influence on the delivered specific impulse value include the chamber temperature and the chamber pressures in the high thrust domain. Other parameters, such as 2-D and boundary layer effects, kinetic rates, and number of nozzles, affect the deliverable performance of an NTR nozzle to a lesser degree. For a single nozzle, maximum performance of 930 seconds and 1030 seconds occur at chamber temperatures of 2700 and 3100 K, respectively.

  10. [Neuropsychological alterations are frequent in rolandic epilepsy and its atypical developments].

    PubMed

    Pesantez-Rios, G; Martinez-Bermejo, A; Pesantez-Cuesta, G

    2016-08-01

    Introduccion. La epilepsia rolandica o epilepsia benigna de la infancia con puntas centrotemporales se denomina benigna debido a lo favorables que suelen ser sus crisis y a la espontanea normalizacion del electroencefalograma al llegar a la pubertad, aunque se ha demostrado el impacto sobre el desarrollo cognitivo con la presencia de deficits cognitivos heterogeneos, relacionados especialmente con las descargas intercriticas persistentes durante el sueño no REM. El objetivo de este trabajo es estudiar las redes epileptogenas involucradas en los trastornos neuropsicologicos de esta patologia. Desarrollo. Las evoluciones atipicas tienen en comun una actividad epileptica persistente durante el sueño lento, que desempeña un papel importante en el desarrollo de los deficits neurocognitivos que se asocian a esta patologia. Factores como la edad de inicio de la epilepsia, el inicio de la evolucion atipica, la localizacion de las descargas interictales y la actividad epileptica continua durante el sueño que persista durante mas de dos años pueden provocar cambios en el funcionamiento de las redes neurocognitivas, con los consecuentes deficits en las funciones neuropsicologicas, que incluso pueden resultar irreversibles. Conclusiones. Es necesario un seguimiento cercano tanto clinico como electroencefalografico; ademas, deben realizarse estudios neuropsicologicos formales desde el inicio de la epilepsia benigna de la infancia con puntas centrotemporales y mas en los casos que es evidente una evolucion atipica para detectar y prevenir los deficits neuropsicologicos antes de que se instauren definitivamente.

  11. Replicational organization of three weakly expressed loci in Physarum polycephalum.

    PubMed

    Maric, Chrystelle; Swanston, Emma; Bailey, Juliet; Pierron, Gérard

    2002-06-01

    We previously mapped early-activated replication origins in the promoter regions of five abundantly transcribed genes in the slime mold Physarum polycephalum. This physical linkage between origins and genes is congruent with the preferential early replication of the active genes in mammalian cells. To determine how general this replicational organization is in the synchronous plasmodium of Physarum, we analyzed the replication of three weakly expressed genes. Bromodeoxyuridine (BrdUrd) density-shift and gene dosage experiments indicated that the redB (regulated in development) and redE genes replicate early, whereas redA replicates in mid-S phase. Bi-dimensional gel electrophoresis revealed that redA coincides with an origin that appears to be activated within a large temporal window in S phase so that the replication of the gene is not well defined temporally. The early replication of the redB and redE genes is due to the simultaneous activation of flanking origins at the onset of S phase. As a result, these two genes correspond to termination sites of DNA replication. Our data demonstrate that not all the Physarum promoters are preferred sites of initiation but, so far, all the expressed genes analyzed in detail either coincide with a replication origin or are embedded into a cluster of early firing replicons. PMID:12034812

  12. Rasch measurement of self-regulated learning in an information and communication technology (ICT)-rich environment.

    PubMed

    Njiru, Joseph N; Waugh, Russell F

    2007-01-01

    This report describes how a linear scale of self-regulated learning in an ICT-rich environment was created by analysing student data using the Rasch measurement model. A person convenience sample of (N = 409) university students in Western Australia was used. The stem-item sample was initially 41, answered in two perspectives ("I aim for this" and "I actually do this"), and reduced to 16 that fitted the measurement model to form a unidimensional scale. Items for motivation (extrinsic rewards, intrinsic rewards, and social rewards), academic goals (fear of performing poorly) (but not standards), self-learning beliefs (ability and interest), task management (strategies and time management) (but not cooperative learning), Volition (action control (but not environmental control), and self-evaluation (cognitive self-evaluation and metacognition) fitted the measurement model. The proportion of observed variance considered true was 0.90. A new instrument is proposed to handle the conceptually valid but non-fitting items. Characteristics of high self-regulated learners are measured. PMID:18250527

  13. Quality-of-Life Measures in Children With Neurological Conditions: Pediatric Neuro-QOL

    PubMed Central

    Lai, Jin-Shei; Nowinski, Cindy; Victorson, David; Bode, Rita; Podrabsky, Tracy; McKinney, Natalie; Straube, Don; Holmes, Gregory L.; McDonald, Craig M.; Henricson, Erik; Abresch, R. Ted; Moy, Claudia S.; Cella, David

    2013-01-01

    Background A comprehensive, reliable, and valid measurement system is needed to monitor changes in children with neurological conditions who experience lifelong functional limitations. Objective This article describes the development and psychometric properties of the pediatric version of the Quality of Life in Neurological Disorders (Neuro-QOL) measurement system. Methods The pediatric Neuro-QOL consists of generic and targeted measures. Literature review, focus groups, individual interviews, cognitive interviews of children and consensus meetings were used to identify and finalize relevant domains and item content. Testing was conducted on 1018 children aged 10 to 17 years drawn from the US general population for generic measures and 171 similarly aged children with muscular dystrophy or epilepsy for targeted measures. Dimensionality was evaluated using factor analytic methods. For unidimensional domains, item parameters were estimated using item response theory models. Measures with acceptable fit indices were calibrated as item banks; those without acceptable fit indices were treated as summary scales. Results Ten measures were developed: 8 generic or targeted banks (anxiety, depression, anger, interaction with peers, fatigue, pain, applied cognition, and stigma) and 2 generic scales (upper and lower extremity function). The banks reliably (r > 0.90) measured 63.2% to 100% of the children tested. Conclusions The pediatric Neuro-QOL is a comprehensive measurement system with acceptable psychometric properties that could be used in computerized adaptive testing. The next step is to validate these measures in various clinical populations. PMID:21788436

  14. Sing that tune: infants' perception of melody and lyrics and the facilitation of phonetic recognition in songs.

    PubMed

    Lebedeva, Gina C; Kuhl, Patricia K

    2010-12-01

    To better understand how infants process complex auditory input, this study investigated whether 11-month-old infants perceive the pitch (melodic) or the phonetic (lyric) components within songs as more salient, and whether melody facilitates phonetic recognition. Using a preferential looking paradigm, uni-dimensional and multi-dimensional songs were tested; either the pitch or syllable order of the stimuli varied. As a group, infants detected a change in pitch order in a 4-note sequence when the syllables were redundant (experiment 1), but did not detect the identical pitch change with variegated syllables (experiment 2). Infants were better able to detect a change in syllable order in a sung sequence (experiment 2) than the identical syllable change in a spoken sequence (experiment 1). These results suggest that by 11 months, infants cannot "ignore" phonetic information in the context of perceptually salient pitch variation. Moreover, the increased phonetic recognition in song contexts mirrors findings that demonstrate advantages of infant-directed speech. Findings are discussed in terms of how stimulus complexity interacts with the perception of sung speech in infancy. PMID:20472295

  15. Brief Report: Bifactor Modeling of General vs. Specific Factors of Religiousness Differentially Predicting Substance Use Risk in Adolescence

    PubMed Central

    Kim-Spoon, Jungmeen; Longo, Gregory S.; Holmes, Christopher J.

    2015-01-01

    Religiousness is important to adolescents in the U.S., and the significant link between high religiousness and low substance use is well known. There is a debate between multidimensional and unidimensional perspectives of religiousness (Gorsuch, 1984); yet, no empirical study has tested this hierarchical model of religiousness related to adolescent health outcomes. The current study presents the first attempt to test a bifactor model of religiousness related to substance use among adolescents (N = 220, 45% female). Our bifactor model using structural equation modeling suggested the multidimensional nature of religiousness as well as the presence of a superordinate general religiousness factor directly explaining the covariation among the specific factors including organizational and personal religiousness and religious social support. The general religiousness factor was inversely related to substance use. After accounting for the contribution of the general religiousness factor, high organizational religiousness related to low substance use, whereas personal religiousness and religious support were positively related to substance use. The findings present the first evidence that supports hierarchical structures of adolescent religiousness that contribute differentially to adolescent substance use. PMID:26043168

  16. Adherence is a multi-dimensional construct in the POUNDS LOST trial.

    PubMed

    Williamson, Donald A; Anton, Stephen D; Han, Hongmei; Champagne, Catherine M; Allen, Ray; LeBlanc, Eric; Ryan, Donna H; McManus, Katherine; Laranjo, Nancy; Carey, Vincent J; Loria, Catherine M; Bray, George A; Sacks, Frank M

    2010-02-01

    Research on the conceptualization of adherence to treatment has not addressed a key question: Is adherence best defined as being a uni-dimensional or multi-dimensional behavioral construct? The primary aim of this study was to test which of these conceptual models best described adherence to a weight management program. This ancillary study was conducted as a part of the POUNDS LOST trial that tested the efficacy of four dietary macronutrient compositions for promoting weight loss. A sample of 811 overweight/obese adults was recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: (1) Low fat (20% of energy), average protein (15% of energy); (2) High fat (40%), average protein (15%); (3) Low fat (20%), high protein (25%); (4) High fat (40%), high protein (25%). Throughout the first 6 months of the study, a computer tracking system collected data on eight indicators of adherence. Computer tracking data from the initial 6 months of the intervention were analyzed using exploratory and confirmatory analyses. Two factors (accounting for 66% of the variance) were identified and confirmed: (1) behavioral adherence and (2) dietary adherence. Behavioral adherence did not differ across the four interventions, but prescription of a high fat diet (vs. a low fat diet) was found to be associated with higher levels of dietary adherence. The findings of this study indicated that adherence to a weight management program was best conceptualized as being multi-dimensional, with two dimensions: behavioral and dietary adherence.

  17. Handheld scanning probes for optical coherence tomography: developments, applications, and perspectives

    NASA Astrophysics Data System (ADS)

    Duma, V.-F.; Demian, D.; Sinescu, C.; Cernat, R.; Dobre, G.; Negrutiu, M. L.; Topala, F. I.; Hutiu, Gh.; Bradu, A.; Podoleanu, A. G.

    2016-03-01

    We present the handheld scanning probes that we have recently developed in our current project for biomedical imaging in general and for Optical Coherence Tomography (OCT) in particular. OCT is an established, but dynamic imagistic technique based on laser interferometry, which offers micrometer resolutions and millimeters penetration depths. With regard to existing devices, the newly developed handheld probes are simple, light and relatively low cost. Their design is described in detail to allow for the reproduction in any lab, including for educational purposes. Two probes are constructed almost entirely from off-the-shelf components, while a third, final variant is constructed with dedicated components, in an ergonomic design. The handheld probes have uni-dimensional (1D) galvanometer scanners therefore they achieve transversal sections through the biological sample investigated - in contrast to handheld probes equipped with bi-dimensional (2D) scanners that can also achieve volumetric (3D) reconstructions of the samples. These latter handheld probes are therefore also discussed, as well as the possibility to equip them with galvanometer 2D scanners or with Risley prisms. For galvanometer scanners the optimal scanning functions studied in a series of previous works are pointed out; these functions offer a higher temporal efficiency/duty cycle of the scanning process, as well as artifact-free OCT images. The testing of the handheld scanning probes in dental applications is presented, for metal ceramic prosthesis and for teeth.

  18. Handheld probes and galvanometer scanning for optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Duma, V.-F.; Dobre, G.; Demian, D.; Cernat, R.; Sinescu, C.; Topala, F. I.; Negrutiu, M. L.; Hutiu, Gh.; Bradu, A.; Rolland, J. P.; Podoleanu, A. G.

    2015-09-01

    As part of the ongoing effort of the biomedical imaging community to move Optical Coherence Tomography (OCT) systems from the lab to the clinical environment and produce OCT systems appropriate for multiple types of investigations in a medical department, handheld probes equipped with different types of scanners need to be developed. These allow different areas of a patient's body to be investigated using OCT with the same system and even without changing the patient's position. This paper reviews first the state of the art regarding OCT handheld probes. Novel probes with a uni-dimensional (1D) galvanometer-based scanner (GS) developed in our groups are presented. Their advantages and limitations are discussed. Aspects regarding the use of galvoscanners with regard to Micro-Electro- Mechanical Systems (MEMS) are pointed out, in relationship with our studies on optimal scanning functions of galvanometer devices in OCT. These scanning functions are briefly discussed with regard to their main parameters: profile, theoretical duty cycle, scan frequency, and scan amplitude. The optical design of the galvoscanner and refractive optics combination in the probe head, optimized for various applications, is considered. Perspectives of the field are pointed out in the final part of the paper.

  19. Online Friendship, Romance, and Sex: Properties and Associations of the Online Relationship Initiation Scale.

    PubMed

    Harris, Keith M; Aboujaoude, Elias

    2016-08-01

    Online relationships are increasingly central to many people's lives. As a result, there is a growing need to scientifically examine their psychosocial implications. This study developed and tested the Online Relationship Initiation Scale (ORIS) through classical and item response theory analyses to address this need. An anonymous online survey included 713 adults, aged 18-71 years. The ORIS was tested on psychometric properties and examined for associations with gender and several standardized psychosocial measures. Results demonstrated unidimensionality of nine items, strong factor loadings, and high internal consistency (α = 0.90, ωt = 0.94). All items captured significant information on the latent trait and none showed differential item functioning by sex, age group, or ethnicity. General linear modeling confirmed hypotheses that men were more likely than women to initiate online relationships. Online relationship initiation was not strongly associated with perceived social support, but was positively related to financial distress, and willingness to engage in infidelity or unprotected sex. The ORIS was negatively associated with age and satisfaction with life and showed modest interactions with ethnicity and hours online. This study provided empirical evidence for an interpersonal relationship initiation construct. The ORIS was shown to be a psychometrically sound instrument for evaluating online interpersonal behaviors and their associations with psychosocial and demographic factors. Such psychometrically sound instruments can be useful in exploring online interpersonal behaviors and their significance. PMID:27447244

  20. Development and evaluation of a hypertension knowledge test for Korean hypertensive patients.

    PubMed

    Han, Hae-Ra; Chan, Kitty; Song, Heejung; Nguyen, Tam; Lee, Jong-Eun; Kim, Miyong T

    2011-10-01

    Patients' knowledge concerning high blood pressure (HBP) is a useful outcome measure in HBP education programs. However, valid and easy-to-use HBP knowledge assessment tools are scarce. The purpose of the study was to validate the HBP Knowledge Test (HKT) in two independent samples of Korean Americans with HBP (N=885). A total of 61% of the sample were women with a mean age of about 61 years (standard deviation=11.0) and 44% reported some college education or greater. Psychometric and item response theory analyses identified 21 items that fit a unidimensional model to form the HKT. Internal consistency was acceptable, with Cronbach's α=0.70. Construct validity testing revealed that patients with controlled BP had significantly higher HKT scores than those with uncontrolled BP (P=.012). The HKT is a simple questionnaire for assessing and monitoring HBP knowledge. It is sensitive to differences in blood pressure control status and should provide a valid, reliable, and standardized measure of HBP knowledge with wide relevance.