Science.gov

Sample records for numa rede unidimensional

  1. Assessing Unidimensionality of Polytomous Data.

    ERIC Educational Resources Information Center

    Nandakumar, Ratna; Yu, Feng; Li, Hsin-Hung; Stout, William

    1998-01-01

    Investigated the performance of the Poly-DIMTEST (PD) procedure (and associated computer program) in assessing the unidimensionality of test data produced by polytomous items through Monte Carlo simulation. Results show that PD can confirm unidimensionality for unidimensional simulated data and can detect lack of unidimensionality. (SLD)

  2. 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…

  3. Parallel Analysis with Unidimensional Binary Data

    ERIC Educational Resources Information Center

    Weng, Li-Jen; Cheng, Chung-Ping

    2005-01-01

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

  4. 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…

  5. An Assessment of Stout's Index of Essential Unidimensionality.

    ERIC Educational Resources Information Center

    Hattie, John; And Others

    1996-01-01

    A simulation study was conducted to evaluate the dependability of the "T" index of unidimensionality developed by W. F. Stout and used in his DIMTEST procedure. DIMTEST was found to provide dependable indications of unidimensionality, to be reasonably robust, and to allow for practical demarcation between one and many dimensions. (SLD)

  6. Unidimensional continuous-variable quantum key distribution

    NASA Astrophysics Data System (ADS)

    Usenko, Vladyslav C.; Grosshans, Frédéric

    2015-12-01

    We propose the continuous-variable quantum key distribution protocol based on the Gaussian modulation of a single quadrature of the coherent states of light, which is aimed to provide simplified implementation compared to the symmetrically modulated Gaussian coherent-state protocols. The protocol waives the necessity in one of the quadrature modulations and the corresponding channel transmittance estimation. The security of the protocol against collective attacks in a generally phase-sensitive Gaussian channel is analyzed and is shown achievable upon certain conditions. Robustness of the protocol to channel imperfections is compared to that of the symmetrical coherent-state protocol. The simplified unidimensional protocol is shown possible at a reasonable quantitative cost in terms of key rate and of tolerable channel excess noise.

  7. 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

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

    PubMed Central

    MacCoun, Robert J.

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Kuo, Tzu-Chun

    2015-01-01

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

  10. Developing an Essentially Unidimensional Test with Cognitively Designed Items

    ERIC Educational Resources Information Center

    Bryant, Damon U.; Wooten, William

    2006-01-01

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

  11. An Empirical Study of Various Indices for Determining Unidimensionality.

    ERIC Educational Resources Information Center

    Hattie, John

    1984-01-01

    This paper describes a simulation that determines the adequacy of various indices as decision criteria for assessing unidimensionality. Using the sum of absolute residuals from the two-parameter latent trait model, indices were obtained that could discriminate between one latent trait and more than one latent trait. (Author/BW)

  12. 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…

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

    ERIC Educational Resources Information Center

    Raykov, Tenko; Pohl, Steffi

    2013-01-01

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

  14. Application of Unidimensional Item Response Models to Tests with Items Sensitive to Secondary Dimensions

    ERIC Educational Resources Information Center

    Zhang, Bo

    2008-01-01

    In this research, the author addresses whether the application of unidimensional item response models provides valid interpretation of test results when administering items sensitive to multiple latent dimensions. Overall, the present study found that unidimensional models are quite robust to the violation of the unidimensionality assumption due…

  15. 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.

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

    ERIC Educational Resources Information Center

    Dawadi, Bhaskar R.

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

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

    ERIC Educational Resources Information Center

    Ackerman, Terry A.

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

  18. 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…

  19. 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…

  20. 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.

  1. 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.

  2. Critical Path-Based Thread Placement for NUMA Systems

    SciTech Connect

    Su, Chun-Yi; Li, Dong; Nikolopoulos, Dimitrios; Grove, Matthew; Cameron, Kirk W.; de Supinski, Bronis R.

    2012-01-01

    Multicore multiprocessors use 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 an algorithm that optimizes the placement of OpenMP threads on NUMA processors. By collecting information from hardware counters and defining new metrics to capture the effects of thread placement, the algorithm reduces NUMA performance penalty by minimizing the critical path of OpenMP parallel regions and by avoiding local memory resource contention. We evaluate our algorithm with NPB benchmarks and achieve performance improvement between 8.13% and 25.68%, compared to the OS default scheduling.

  3. HYPERS: A Unidimensional Asynchronous Framework for Multiscale Hybrid Simulations

    NASA Astrophysics Data System (ADS)

    Omelchenko, Y. A.; Karimabadi, H.; Vu, H. X.

    2011-12-01

    Kinetic ion-driven processes are crucial for understanding the complex dynamics of the closely coupled Earth magnetosphere-ionosphere system. Largely varying time and length scales impose severe numerical constraints on global simulations with hybrid (particle ions + fluid electrons) codes. To enable larger simulations we developed a unique, uni-dimensional multiscale hybrid code, HYPERS. Instead of stepping all simulation variables uniformly in time, HYPERS tracks physically meaningful changes to individual particles and cell-based electromagnetic fields via asynchronous discrete events. HYPERS has been parallelized with the Preemptive Event Processing (PEP) technique. The parallel algorithm enables arbitrary domain decompositions and processor configurations on restarts. This is a critical prerequisite for implementing a full load balancing functionality in the future. We validate HYPERS by simulating the interaction of streaming plasmas with dipole magnetospheres and show that our approach results in superior numerical metrics (stability, accuracy and speed) compared to conventional techniques. We also discuss further extensions to the HYPERS framework that would enable seemless integration of ion fluid and kinetic schemes.

  4. 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)

  5. 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.

  6. 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…

  7. 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…

  8. 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…

  9. 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.…

  10. 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…

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

    ERIC Educational Resources Information Center

    Raykov, Tenko

    2009-01-01

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

  12. 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…

  13. 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…

  14. 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…

  15. 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.

  16. 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.

  17. NuMA Influences Higher Order Chromatin Organization in Human Mammary Epithelium

    PubMed Central

    Abad, Patricia C.; Lewis, Jason; Mian, I. Saira; Knowles, David W.; Sturgis, Jennifer; Badve, Sunil; Xie, Jun

    2007-01-01

    The coiled-coil protein NuMA is an important contributor to mitotic spindle formation and stabilization. A potential role for NuMA in nuclear organization or gene regulation is suggested by the observations that its pattern of nuclear distribution depends upon cell phenotype and that it interacts and/or colocalizes with transcription factors. To date, the precise contribution of NuMA to nuclear function remains unclear. Previously, we observed that antibody-induced alteration of NuMA distribution in growth-arrested and differentiated mammary epithelial structures (acini) in three-dimensional culture triggers the loss of acinar differentiation. Here, we show that in mammary epithelial cells, NuMA is present in both the nuclear matrix and chromatin compartments. Expression of a portion of the C terminus of NuMA that shares sequence similarity with the chromatin regulator HPC2 is sufficient to inhibit acinar differentiation and results in the redistribution of NuMA, chromatin markers acetyl-H4 and H4K20m, and regions of deoxyribonuclease I-sensitive chromatin compared with control cells. Short-term alteration of NuMA distribution with anti-NuMA C-terminus antibodies in live acinar cells indicates that changes in NuMA and chromatin organization precede loss of acinar differentiation. These findings suggest that NuMA has a role in mammary epithelial differentiation by influencing the organization of chromatin. PMID:17108325

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

    PubMed Central

    Lupsor-Platon, Monica; Badea, Radu

    2015-01-01

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

  19. 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

  20. Redistribution of the nuclear mitotic apparatus protein (NuMA) during mitosis and nuclear assembly. Properties of purified NuMA protein.

    PubMed

    Price, C M; Pettijohn, D E

    1986-10-01

    Monoclonal antibodies and human autoimmune sera specific for the nuclear mitotic apparatus protein (NuMA protein) were applied to study the structure of this protein and its intracellular distribution. The NuMA protein was purified using immuno-affinity columns. Studies on this large (250 kD) nuclear protein indicated that it is a highly asymmetric phosphoprotein. It is present in all mammalian cells examined and in those of some non-mammals. Immunofluorescence studies on fixed cells demonstrated that its intracellular distribution is essentially the same in all species at all stages of the cell cycle. Immunoblot (western blot) analysis showed that the size of the NuMA protein varies slightly in different species. At the onset of mitosis the NuMA protein redistributes from the nucleus to two centrosomal structures that later will become part of the mitotic spindle pole. This occurs at the time of nuclear breakdown and eventually leads to an accumulation of the NuMA protein at the polar region of the mitotic spindle. After anaphase the protein redistributes from the spindle polar region into the reforming nucleus and concentrates initially at the site where nuclear lamins and perichomatin have been reported to assemble. Living cells microinjected with fluorescent anti-NuMA antibodies were studied to examine parameters that effect the redistribution of the NuMA protein in vivo. These experiments indicate that microtubule assembly is essential for the NuMA protein to accumulate in the polar region. PMID:3527729

  1. Cell cycle-regulated membrane binding of NuMA contributes to efficient anaphase chromosome separation.

    PubMed

    Zheng, Zhen; Wan, Qingwen; Meixiong, Gerry; Du, Quansheng

    2014-03-01

    Accurate and efficient separation of sister chromatids during anaphase is critical for faithful cell division. It has been proposed that cortical dynein-generated pulling forces on astral microtubules contribute to anaphase spindle elongation and chromosome separation. In mammalian cells, however, definitive evidence for the involvement of cortical dynein in chromosome separation is missing. It is believed that dynein is recruited and anchored at the cell cortex during mitosis by the α subunit of heterotrimeric G protein (Gα)/mammalian homologue of Drosophila Partner of Inscuteable/nuclear mitotic apparatus (NuMA) ternary complex. Here we uncover a Gα/LGN-independent lipid- and membrane-binding domain at the C-terminus of NuMA. We show that the membrane binding of NuMA is cell cycle regulated-it is inhibited during prophase and metaphase by cyclin-dependent kinase 1 (CDK1)-mediated phosphorylation and only occurs after anaphase onset when CDK1 activity is down-regulated. Further studies indicate that cell cycle-regulated membrane association of NuMA underlies anaphase-specific enhancement of cortical NuMA and dynein. By replacing endogenous NuMA with membrane-binding-deficient NuMA, we can specifically reduce the cortical accumulation of NuMA and dynein during anaphase and demonstrate that cortical NuMA and dynein contribute to efficient chromosome separation in mammalian cells. PMID:24371089

  2. 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.

  3. Perhaps Unidimensional Is Not Unidimensional

    ERIC Educational Resources Information Center

    Dodds, Pennie; Rae, Babette; Brown, Scott

    2012-01-01

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

  4. 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. PMID:25106393

  5. NuMA Is Required for the Selective Induction of p53 Target Genes

    PubMed Central

    Ohata, Hirokazu; Miyazaki, Makoto; Otomo, Ryo; Matsushima-Hibiya, Yuko; Otsubo, Chihiro; Nagase, Takahiro; Arakawa, Hirofumi; Yokota, Jun; Nakagama, Hitoshi

    2013-01-01

    The p53 tumor suppressor protein is a transcription factor controlling various outcomes, such as growth arrest and apoptosis, through the regulation of different sets of target genes. The nuclear mitotic apparatus protein (NuMA) plays important roles in spindle pole organization during mitosis and in chromatin regulation in the nucleus during interphase. Although NuMA has been shown to colocalize with several nuclear proteins, including high-mobility-group proteins I and Y and GAS41, the role of NuMA during interphase remains unclear. Here we report that NuMA binds to p53 to modulate p53-mediated transcription. Acute and partial ablation of NuMA attenuates the induction of the proarrested p21 gene following DNA damage, subsequently causing impaired cell cycle arrest. Interestingly, NuMA knockdown had little effect on the induction of the p53-dependent proapoptotic PUMA gene. Furthermore, NuMA is required for the recruitment of cyclin-dependent kinase 8 (Cdk8), a component of the Mediator complex and a promoter of p53-mediated p21 gene function. These data demonstrate that NuMA is critical for the target selectivity of p53-mediated transcription. PMID:23589328

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

    ERIC Educational Resources Information Center

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

    2005-01-01

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

  7. A Comparison of Estimation Methods for a Multi-unidimensional Graded Response IRT Model

    PubMed Central

    Kuo, Tzu-Chun; Sheng, Yanyan

    2016-01-01

    This study compared several parameter estimation methods for multi-unidimensional graded response models using their corresponding statistical software programs and packages. Specifically, we compared two marginal maximum likelihood (MML) approaches (Bock-Aitkin expectation-maximum algorithm, adaptive quadrature approach), four fully Bayesian algorithms (Gibbs sampling, Metropolis-Hastings, Hastings-within-Gibbs, blocked Metropolis), and the Metropolis-Hastings Robbins-Monro (MHRM) algorithm via the use of IRTPRO, BMIRT, and MATLAB. Simulation results suggested that, when the intertrait correlation was low, these estimation methods provided similar results. However, if the dimensions were moderately or highly correlated, Hastings-within-Gibbs had an overall better parameter recovery of item discrimination and intertrait correlation parameters. The performances of these estimation methods with different sample sizes and test lengths are also discussed. PMID:27375545

  8. A Comparison of Estimation Methods for a Multi-unidimensional Graded Response IRT Model.

    PubMed

    Kuo, Tzu-Chun; Sheng, Yanyan

    2016-01-01

    This study compared several parameter estimation methods for multi-unidimensional graded response models using their corresponding statistical software programs and packages. Specifically, we compared two marginal maximum likelihood (MML) approaches (Bock-Aitkin expectation-maximum algorithm, adaptive quadrature approach), four fully Bayesian algorithms (Gibbs sampling, Metropolis-Hastings, Hastings-within-Gibbs, blocked Metropolis), and the Metropolis-Hastings Robbins-Monro (MHRM) algorithm via the use of IRTPRO, BMIRT, and MATLAB. Simulation results suggested that, when the intertrait correlation was low, these estimation methods provided similar results. However, if the dimensions were moderately or highly correlated, Hastings-within-Gibbs had an overall better parameter recovery of item discrimination and intertrait correlation parameters. The performances of these estimation methods with different sample sizes and test lengths are also discussed. PMID:27375545

  9. Saltatory conduction revealed by unidimensional latency-topography of peripheral nerve impulse.

    PubMed

    Homma, S; Mizote, M; Nakajima, Y

    1983-09-01

    The ventral or dorsal root of the rat was placed on 12 electrodes arranged side by side at 0.4 mm intervals. Impulse conduction along the fiber was displayed using unidimensional latency-topography, which corresponds to the relation between latency and electrode distance. The relation revealed step-like displacement, which implies saltatory conduction of the impulse. Since the distance between the plateaux correspond to internodal length, the conduction velocity could be calculated from the length and the time differences between plateaux. It was found from 36 observations that : (i) mean internodal length was 0.92 +/- 0.13 mm (range 0.70--1.25 mm); (ii) mean conduction velocity was 76.1 +/- 20.7 m/s; and (iii) the correlation coefficient of conduction velocity and internodal length was statistically significant at r = 0.38 (P less than 0.025), so the longer the internodal length, the higher the conduction velocity. PMID:6633955

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  11. 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…

  12. 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

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

    PubMed

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

    2016-02-22

    Spindle positioning is essential for tissue morphogenesis and homeostasis. The signaling network synchronizing spindle placement with mitotic progression relies on timely recruitment at the cell cortex of NuMA:LGN:Gαi complexes, in which NuMA acts as a receptor for the microtubule motor Dynein. To study the implication of Aurora-A in spindle orientation, we developed protocols for the partial inhibition of its activity. Under these conditions, in metaphase NuMA and Dynein accumulate abnormally at the spindle poles and do not reach the cortex, while the cortical distribution of LGN remains unperturbed. FRAP experiments revealed that Aurora-A governs the dynamic exchange between the cytoplasmic and the spindle pole-localized pools of NuMA. We show that Aurora-A phosphorylates directly the C terminus of NuMA on three Ser residues, of which Ser1969 determines the dynamic behavior and the spindle orientation functions of NuMA. Most interestingly, we identify a new microtubule-binding domain of NuMA, which does not overlap with the LGN-binding motif. Our study demonstrates that in metaphase the direct phosphorylation of NuMA by Aurora-A controls its cortical enrichment, and that this is the major event underlying the spindle orientation functions of Aurora-A in transformed and non-transformed cells in culture. Phosphorylation of NuMA by Aurora-A does not affect its affinity for microtubules or for LGN but rather determines the mobility of the protein at the spindle poles. The finding that NuMA can associate concomitantly with LGN and microtubules suggests that its microtubule-binding activity contributes to anchor Dynein-loaded microtubule +TIPs at cortical sites with LGN. PMID:26832443

  14. 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.

  15. Program partitioning and scheduling for NUMA computer architectures

    SciTech Connect

    Wolski, R.M.

    1994-03-01

    To effect the parallel execution of a program on a multiprocessor, each of the program`s constituent computations must be assigned to a processing resource within the multiprocessor. The problem of making this assignment so that execution time is minimized (known as the mapping problem) has been shown to be NP-complete. However, heuristics based on the performance characteristics of the target multiprocessor can yield execution times that approach the minimum possible. The mapping problem can be divided in to the problem of partitioning the computations into sequential threads, and the problem of scheduling those threads on the processors of the target system. This dissertation presents a logical framework and a set of heuristics that operate within the framework for the automatic partitioning and scheduling of programs at compile-time. The framework is based on the memory-node execution model which correctly captures the interaction between computations, processors, and the communication resources within a multiprocessor. The CP and HEF heuristics manipulate the features of the memory-node model to produce efficient program mappings. The effectiveness of the partitioning and scheduling techniques is investigated for Non-uniform Memory Access (NUMA) architecture types. To test the versatility of the approach, results are presented both for processors implementing strict execution semantics, and non-strict load/store semantics popular with RISC systems. The partitioner and scheduler are also used to investigate the possible advantages of multithreading (using either hardware or software), and the effectiveness of massively parallel systems, within a scientific programming context.

  16. 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

  17. 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.

  18. Interaction between RB protein and NuMA is required for proper alignment of spindle microtubules.

    PubMed

    Uchida, Chiharu; Hattori, Takayuki; Takahashi, Hirotaka; Yamamoto, Naoki; Kitagawa, Masatoshi; Taya, Yoichi

    2014-02-01

    Retinoblastoma protein (pRB) controls cell cycle progression and cell cycle exit through interactions with cellular proteins. Many pRB-binding proteins, which function in gene transcription or modulation of chromatin structure, harbor LXCXE motifs in their binding domain for pRB. In this study, we found that nuclear mitotic apparatus protein (NuMA), a mitotic spindle organizer, interacts with pRB through LSCEE sequences located in its C-terminal region. siRNA-mediated down-regulation of pRB caused aberrant distribution of NuMA and alignment of spindle microtubules in mitotic cells. Abnormal organization of spindle microtubules was also accompanied by misalignment of an over-expressed NuMA mutant (mut-NuMA) with a defect in pRB binding caused by an LSGEK mutation. The mut-NuMA-over-expressing cells showed lower potency for survival than wild-type NuMA (wt-NuMA)-over-expressing cells during 2 weeks of culture. Interestingly, knockdown of pRB reduced the population of wt-NuMA-over-expressing cells to the same level as mut-NuMA cells after 2 weeks. Taken together, pRB may have a novel function in regulating the mitotic function of NuMA and spindle organization, which are required for proper cell cycle progression. PMID:24350565

  19. Exact solution of the unidimensional Poisson-Boltzmann equation for a 1:2 (2:1) electrolyte.

    PubMed Central

    Andrietti, F; Peres, A; Pezzotta, R

    1976-01-01

    The unidimensional Poisson-Boltzmann equation for a 1:2 (2:1) electrolyte has been solved analytically. The results have been compared with those obtained from the linearized equation. It is shown that in physiological conditions the difference may be greater than 10%. The value of the derivative of the potential in x=0, (dpsi/dx)x=0, has been used by many authors in the evaluation of the superficial charges of biological membranes. The value of (dpsi/dx)x-0 have also been compared with the ones derived from the linearized equation. The difference may be greater than 25%. Our results suggest that the linearization of the Poisson-Boltzmann equation for a 1:2(2:1) electrolyte may be greatly misleading. PMID:963209

  20. 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.

  1. 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.

  2. A Nonerythroid Isoform of Protein 4.1R Interacts with the Nuclear Mitotic Apparatus (NuMA) Protein

    PubMed Central

    Mattagajasingh, Subhendra N.; Huang, Shu-Ching; Hartenstein, Julia S.; Snyder, Michael; Marchesi, Vincent T.; Benz, Edward J.

    1999-01-01

    Red blood cell protein 4.1 (4.1R) is an 80- kD erythrocyte phosphoprotein that stabilizes the spectrin/actin cytoskeleton. In nonerythroid cells, multiple 4.1R isoforms arise from a single gene by alternative splicing and predominantly code for a 135-kD isoform. This isoform contains a 209 amino acid extension at its NH2 terminus (head piece; HP). Immunoreactive epitopes specific for HP have been detected within the cell nucleus, nuclear matrix, centrosomes, and parts of the mitotic apparatus in dividing cells. Using a yeast two-hybrid system, in vitro binding assays, coimmunolocalization, and coimmunoprecipitation studies, we show that a 135-kD 4.1R isoform specifically interacts with the nuclear mitotic apparatus (NuMA) protein. NuMA and 4.1R partially colocalize in the interphase nucleus of MDCK cells and redistribute to the spindle poles early in mitosis. Protein 4.1R associates with NuMA in the interphase nucleus and forms a complex with spindle pole organizing proteins, NuMA, dynein, and dynactin during cell division. Overexpression of a 135-kD isoform of 4.1R alters the normal distribution of NuMA in the interphase nucleus. The minimal sequence sufficient for this interaction has been mapped to the amino acids encoded by exons 20 and 21 of 4.1R and residues 1788–1810 of NuMA. Our results not only suggest that 4.1R could, possibly, play an important role in organizing the nuclear architecture, mitotic spindle, and spindle poles, but also could define a novel role for its 22–24-kD domain. PMID:10189366

  3. Converging Assessments of Unidimensionality.

    ERIC Educational Resources Information Center

    Tanaka, J. S.

    Using Goodman's (1975) notion of quasi-independence as a method of obtaining goodness of fit measures for non-scalable types in a scalogram analysis, archival data sets were examined using available Guttman scaling techniques, recent developments in latent structure analysis, and multidimensional scaling procedures. The Stouffer-Toby (1951) data…

  4. 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

  5. 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. PMID:26432191

  6. 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.

  7. Modeling and Testing Differential Item Functioning in Unidimensional Binary Item Response Models with a Single Continuous Covariate: A Functional Data Analysis Approach.

    PubMed

    Liu, Yang; Magnus, Brooke E; Thissen, David

    2016-06-01

    Differential item functioning (DIF), referring to between-group variation in item characteristics above and beyond the group-level disparity in the latent variable of interest, has long been regarded as an important item-level diagnostic. The presence of DIF impairs the fit of the single-group item response model being used, and calls for either model modification or item deletion in practice, depending on the mode of analysis. Methods for testing DIF with continuous covariates, rather than categorical grouping variables, have been developed; however, they are restrictive in parametric forms, and thus are not sufficiently flexible to describe complex interaction among latent variables and covariates. In the current study, we formulate the probability of endorsing each test item as a general bivariate function of a unidimensional latent trait and a single covariate, which is then approximated by a two-dimensional smoothing spline. The accuracy and precision of the proposed procedure is evaluated via Monte Carlo simulations. If anchor items are available, we proposed an extended model that simultaneously estimates item characteristic functions (ICFs) for anchor items, ICFs conditional on the covariate for non-anchor items, and the latent variable density conditional on the covariate-all using regression splines. A permutation DIF test is developed, and its performance is compared to the conventional parametric approach in a simulation study. We also illustrate the proposed semiparametric DIF testing procedure with an empirical example. PMID:26155757

  8. 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

  9. 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

  10. 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…

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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…

  16. ALAM and ALAS: Questioning Error Assignments in Unidimensional Guttman Scaling

    ERIC Educational Resources Information Center

    Wimberley, Ronald C.

    1976-01-01

    When researchers use the Guttman scalogram rather than multidimensional techniques, scalogram error assignment techniques should be questioned. An alternative to the customary minimizing error rule is suggested through ALAM and ALAS criteria which use ordinal information in scalable item marginals. (Author)

  17. 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…

  18. 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

  19. 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

  20. Multidimensional Rule, Unidimensional Rule, and Similarity Strategies in Categorization: Event-Related Brain Potential Correlates

    ERIC Educational Resources Information Center

    Folstein, Jonathan R.; Van Petten, Cyma

    2004-01-01

    Forty participants assigned artificial creatures to categories after explicit rule instruction or feedback alone. Stimuli were typical and atypical exemplars of 2 categories with independent prototypes, conflicting exemplars sharing features of both categories, and "Others" with only 1 or 2 features of the well-defined categories. Ten…

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

    ERIC Educational Resources Information Center

    Homer, Matt; Darling, Jonathan; Pell, Godfrey

    2012-01-01

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

  2. 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.…

  3. Unidimensional versus Multidimensional Approaches to the Assessment of Acculturation for Asian American Populations.

    ERIC Educational Resources Information Center

    Abe-Kim, Jennifer; Okazaki, Sumie; Goto, Sharon G.

    2001-01-01

    Examines approaches to assessing acculturation among Asian Americans college students in relation to the cultural indicators of individualism-collectivism, self-construal, impression management, and loss of face. An uneven nature of these relationships was found which is significant in light of the fact that acculturation differences are often…

  4. An Algorithm for Testing Unidimensionality and Clustering Items in Rasch Measurement

    ERIC Educational Resources Information Center

    Debelak, Rudolf; Arendasy, Martin

    2012-01-01

    A new approach to identify item clusters fitting the Rasch model is described and evaluated using simulated and real data. The proposed method is based on hierarchical cluster analysis and constructs clusters of items that show a good fit to the Rasch model. It thus gives an estimate of the number of independent scales satisfying the postulates of…

  5. Is patient satisfaction a unidimensional construct? Factor analysis of the Munich Patient Satisfaction Scale (MPSS-24).

    PubMed

    Möller-Leimkühler, Anne Marie; Dunkel, Ralf; Müller, Peter; Pukies, Guido; de Fazio, Sarino; Lehmann, Erlo

    2002-02-01

    Although patients' satisfaction with treatment has gained much attention, conceptual and methodological issues are not sufficiently investigated. Consequently, well-validated satisfaction scales are rare. In order to respond to methodological requirements being associated with the measurement of patient satisfaction, the Munich Patient Satisfaction Scale (MPSS-24) was developed for psychiatric in-patients. The scale was validated on the basis of three independent samples (n=85, n= 161, n=91), and the effects of moderating variables were controlled. In several steps of item selection the initial pool of 133 items was reduced to 24 items, which were subjected to factor analysis. The MPSS-24 demonstrates one major principal component with two minor factors which indicates that doctor-patient communication is the essential source for patient satisfaction. The instrument is of high internal consistency and reliability, and convergent validity is satisfactory. PMID:12056577

  6. 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

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

    ERIC Educational Resources Information Center

    Roberts, James S.; Laughlin, James E.

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

  8. 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…

  9. 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. PMID:24478022

  10. 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…

  11. 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…

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  13. 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.…

  14. Development of Depth Perception Mediated by Motion Parallax in Unidimensional Projections of Rotation in Depth.

    ERIC Educational Resources Information Center

    Carpenter, David L.

    1979-01-01

    Six motion projections were presented to first graders, seventh graders, and college students (N=72) in order to determine whether children can utilize the same motion parallax information as can adults. (MP)

  15. A Comparison of Unidimensional and Three-Dimensional Differential Item Functioning Analysis Using Two-Dimensional Data

    ERIC Educational Resources Information Center

    Snow, Teresa K.; Oshima, T. C.

    2009-01-01

    Oshima, Raju, and Flowers demonstrated the use of an item response theory-based technique for analyzing differential item function (DIF) and differential test function for dichotomously scored data that are intended to be multidimensional. Their study assumed that the number of intended-to-be measured dimensions was correctly identified. In…

  16. Development of a Unidimensional Composite Measure of Neuropsychological Functioning in Older Cardiac Surgery Patients with Good Measurement Precision

    PubMed Central

    Jones, Richard N.; Rudolph, James L.; Inouye, Sharon K; Yang, Frances M.; Fong, Tamara G.; Milberg, William P.; Tommet, Douglas; Metzger, Eran D.; Cupples, L. Adrienne; Marcantonio, Edward R.

    2010-01-01

    The objective of this analysis was to develop a measure of neuropsychological performance for cardiac surgery and assess its psychometric properties. Older patients (n=210) underwent a neuropsychological battery using nine assessments. The number of factors was identified with variable reduction methods. Item response theory-based factor analysis methods were used to evaluate the measure. Modified parallel analysis supported a single factor, and the battery formed an internally consistent set (coefficient alpha=0.82). The developed measure provided a reliable, continuous measure (reliability >0.90) across a broad range of performance (−1.5 SD units to +1.0 SD units) with minimal ceiling and floor effects. PMID:20446144

  17. The Analysis of Dominance Matrices: Extraction of Unidimensional Orders Within a Multidimensional Context. Technical Report No. 3.

    ERIC Educational Resources Information Center

    Reynolds, Thomas J.

    A method of factor extraction specific to a binary matrix, illustrated here as a person-by-item response matrix, is presented. The extraction procedure, termed ERGO, differs from the more commonly implemented dimensionalizing techniques, factor analysis and multidimensional scaling, by taking into consideration item difficulty. Utilized in the…

  18. 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

  19. 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…

  20. 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…

  1. 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.…

  2. NuMas: A LAN-based materials control and accounting system in production

    SciTech Connect

    Strickland, T.W.; Bracey, J.T.; McMahon, S.A.

    1995-12-31

    A state-of-the-art Nuclear Materials Control and Accounting (NMC and A) System has been implemented and is fully operational at the Paducah Gaseous Diffusion Plant (PGDP) as of September 1994. The uranium enrichment facility is currently regulated by the Department of Energy (DOE) and is in the process of obtaining Nuclear Regulatory Commission (NRC) certification. Implementation of this system has resulted in a tremendous cost savings to the facility as well as improvements to the overall efficiency of the NMC and A department. This paper outlines the benefits of implementing a Personal Computer/Local Area Network (PC/LAN)-based system in hopes of attracting other facilities to explore and utilize its application at their sites.

  3. 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…

  4. 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.

  5. 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…

  6. 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…

  7. 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.

    PubMed

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

    2006-06-01

    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 clinical measure (the Short Mood and Feelings Questionnaire--SMFQ) in a community sample of 7-through 11-year-old children. Both latent variable models supported the internal construct validity of a single underlying continuum of severity of depressive symptoms. SMFQ items discriminated well at the more severe end of the depressive latent trait. Item performance was not affected by age, although age correlated significantly with latent SMFQ scores suggesting that symptom severity increased within the age period of 7-11. These results extend existing psychometric studies of the SMFQ and confirm its scaling properties as a potential dimensional measure of symptom severity of childhood depression in community samples. PMID:16649000

  8. 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…

  9. 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

  10. 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.

  11. 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

  12. 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)

  13. 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.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

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

  16. 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…

  17. 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…

  18. Projective Item Response Model for Test-Independent Measurement

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  19. Calibration of Response Data Using MIRT Models with Simple and Mixed Structures

    ERIC Educational Resources Information Center

    Zhang, Jinming

    2012-01-01

    It is common to assume during a statistical analysis of a multiscale assessment that the assessment is composed of several unidimensional subtests or that it has simple structure. Under this assumption, the unidimensional and multidimensional approaches can be used to estimate item parameters. These two approaches are equivalent in parameter…

  20. 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…

  1. 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…

  2. Why Factor Analysis Often Is the Incorrect Model for Analyzing Bipolar Concepts, and What Model To Use Instead.

    ERIC Educational Resources Information Center

    van Schuur, Wijbrandt H.; Kiers, Henk A. L.

    1994-01-01

    The identification of two factors when one factor is expected is an artifact caused by using factor analysis on data that would be more appropriately analyzed with a unidimensional unfolding model. A numerical illustration is given, and ways to determine whether data conform to the unidimensional unfolding model are reviewed. (SLD)

  3. 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…

  4. 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)

  5. 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…

  6. 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)

  7. 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.

  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. 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

  10. 76 FR 59180 - Agency Information Collection Activities: Proposed Request and Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-23

    ... criteria. Respondents complete Form SSA-1026-REDE under the following circumstances: (1) When individuals...-SM-REDE 225,000 1 18 67,500 Total 236,400 70,920 II. SSA submitted the information collection...

  11. Understanding Spatial Statistics for Purposes of Identifying Non-Primary and Saturated Impact Crater Populations

    NASA Astrophysics Data System (ADS)

    Riggs, J. D.; Robbins, S. J.; Kirchoff, M. R.; Bierhaus, E. B.; Weaver, B. P.

    2015-05-01

    We discuss some traditional unidimensional summarization statistics and some newer spatial point statistical methods for understanding and identifying non-primary and saturated impact crater populations observed on a variety of solar system bodies.

  12. 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

  13. Subgrouping For Patients With Low Back Pain: A Multidimensional Approach Incorporating Cluster Analysis & The STarT Back Screening Tool

    PubMed Central

    Beneciuk, Jason M.; Robinson, Michael E.; George, Steven Z.

    2014-01-01

    Early screening for psychological distress has been suggested to improve patient management for individuals experiencing low back pain. This study compared two approaches to psychological screening (i.e., multidimensional and unidimensional) so that preliminary recommendations on which approach may be appropriate for use in clinical settings other than primary care could be provided. Specifically, this study investigated STarT Back Screening Tool (SBT): 1) discriminant validity by evaluating its relationship with unidimensional psychological measures and 2) construct validity by evaluating how SBT risk categories compared to empirically derived subgroups using unidimensional psychological and disability measures. Patients (n = 146) receiving physical therapy for LBP were administered the SBT and a battery of unidimensional psychological measures at initial evaluation. Clinical measures consisted of pain intensity and self-reported disability. Several SBT risk dependent relationships (i.e., SBT low < medium < high risk) were identified for unidimensional psychological measure scores with depressive symptom scores associated with the strongest influence on SBT risk categorization. Empirically derived subgroups indicated that there was no evidence of distinctive patterns amongst psychological or disability measures other than high or low profiles, therefore two groups may provide a more clear representation of the level of pain associated psychological distress, maladaptive coping and disability in this setting, as compared to three groups which have been suggested when using the SBT in primary care settings. PMID:25451622

  14. 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. PMID:26941699

  15. 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

  16. 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.

  17. 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.

  18. 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…

  19. 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.

  20. 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.

  1. Using multidimensional Rasch to enhance measurement precision: initial results from simulation and empirical studies.

    PubMed

    Mok, Magdalena Mo Ching; Xu, Kun

    2013-01-01

    This study aimed to explore the effect on measurement precision of multidimensional, as compared with unidimensional, Rasch measurement for constructing measures from multidimensional Likert-type scales. Many educational and psychological tests are multidimensional but common practice is to ignore correlations among the latent traits in these multidimensional scales in the measurement process. These practices may have serious validity and reliability implications. This study made use of both empirical data from 208,083 students, and simulated data simulated by 24 systematic combinations, each replicated 1000 times, of three conditions, namely, sample size, degree of dimensionality, and scale length to compare unidimensional and multidimensional approaches and to identify effects of sample size, dimensionality and scale length on measurement precision. Results showed that the multidimensional Rasch approach yielded more precise estimates than did unidimensional approach if the two dimensions were strongly correlated. The effect was more pronounced for long scales. PMID:23442326

  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. PMID:26879212

  3. Periodontal disease activity: a development strategy for its investigation by means of accurate 3-dimensional clinical measurement.

    PubMed

    Watts, T L; Beards, C f; Ewing, P D; Leeman, S

    1995-03-01

    The central problem in all previous approaches to clinical assessment of periodontal disease activity is the use of unidimensional measurement, which implies a number of unjustifiable assumptions. In addition, the use of unidimensional probing measurement has established that there are several distinct problems of validity and reliability in currently available techniques. The present paper begins with an analysis of these matters, leading to an approach to accurate clinical measurement of periodontitis in 3 dimensions, with the possibility of future development of a valid system for assessing the nature of disease activity. PMID:7790525

  4. 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…

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

    ERIC Educational Resources Information Center

    Ganis, Frank M.

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

  6. 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…

  7. Comparison of Factor Simplicity Indices for Dichotomous Data: DETECT R, Bentler's Simplicity Index, and the Loading Simplicity Index

    ERIC Educational Resources Information Center

    Finch, Holmes; Stage, Alan Kirk; Monahan, Patrick

    2008-01-01

    A primary assumption underlying several of the common methods for modeling item response data is unidimensionality, that is, test items tap into only one latent trait. This assumption can be assessed several ways, using nonlinear factor analysis and DETECT, a method based on the item conditional covariances. When multidimensionality is identified,…

  8. 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,…

  9. 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…

  10. Constructing Linkage Disequilibrium Map with Iterative Approach

    NASA Astrophysics Data System (ADS)

    Ao, S. I.

    2008-05-01

    With recent advance of the genotyping single nucleotide polymorphisms (SNPs) in mass scale of high density in a candidate region of the human genome, the linkage disequilibrium analysis can offer a much higher resolution of the biological samples than the traditional linkage maps. We have formulated this LD mapping problem as a constrained unidimensional scaling problem. Our method, which is directly based on the measurement of LD among SNPs, is non-parametric. Therefore it is different from LD maps derived from the given Malecot model. We have formulated with the quadratic programming approach for solving this constrained unidimensional scaling problem. Different from the classical metric unidimensional scaling problem, the constrained problem is not an NP-hard combinatorial problem. The optimal solution is determined by using the quadratic programming solver. Nevertheless, because of the large requirement for memory during the running time that may cause the out of memory problems, and the high computational time of the quadratic programming algorithm, the iterative algorithm has been developed for solving this LD constrained unidimensional scaling problem.

  11. 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…

  12. 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…

  13. 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…

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

    NASA Technical Reports Server (NTRS)

    Dasarathy, B. V.

    1976-01-01

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

  15. 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…

  16. An Analysis of the Dimensionality of the Pupil Control Ideology Scale.

    ERIC Educational Resources Information Center

    Graham, Steve; And Others

    1985-01-01

    The present study replicated an earlier investigation using the Pupil Control Ideology (PCI). The findings were congruent with earlier results. Consequently, it was recommended that the PCI should be refined and that the 10 item, unidimensional scale should be used in future investigations. (Author/LMO)

  17. 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…

  18. 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.…

  19. 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;…

  20. 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

  1. 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…

  2. 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…

  3. Ramsay Curve IRT for Likert-Type Data

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2007-01-01

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

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

    ERIC Educational Resources Information Center

    Woods, Carol M.; Lin, Nan

    2009-01-01

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

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

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2006-01-01

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

  6. Differential School Effectiveness in Relation to Sex and Social Class: Some Implications for Policy Evaluation

    ERIC Educational Resources Information Center

    Kyriakides, Leonidas

    2004-01-01

    This article reviews school effectiveness theory, concentrating on the unidimensionality of the school effect concept, and focuses on differential school effectiveness, by which is meant the capacity of the school to be effective with different groups of pupils. It presents findings from research exploring the associations between sex, social…

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

    ERIC Educational Resources Information Center

    Gaffey, Abigail R.; Rottinghaus, Patrick J.

    2009-01-01

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

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

    ERIC Educational Resources Information Center

    Joosten, Annette V.; Bundy, Anita C.

    2008-01-01

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

  9. Evaluation of DTF and DIF in Two-Dimensional IRT.

    ERIC Educational Resources Information Center

    Oshima, T. C.; And Others

    In 1992 N. S. Raju and others proposed a general procedure for assessing differential test functioning (DTF) and item bias (differential item functioning or DIF) in tests developed with unidimensional, multidimensional, or polytomous item response theory (IRT) models. The purpose of this paper is to assess the adequacy and validity of their…

  10. 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…

  11. 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…

  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. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. A Pearson-Type-VII Item Response Model for Assessing Person Fluctuation

    ERIC Educational Resources Information Center

    Ferrando, Pere J.

    2007-01-01

    Using Lumsden's Thurstonian fluctuation model as a starting point, this paper attempts to develop a unidimensional item response theory model intended for binary personality items. Under some additional assumptions, a new model is obtained in which the item characteristic curves are defined by a cumulative Pearson-Type-VII distribution, and the…

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

    ERIC Educational Resources Information Center

    Tartaglia, Stefano

    2006-01-01

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

  1. 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)

  2. 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…

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

    ERIC Educational Resources Information Center

    Joyce, Tan Bei Yu; Yates, Shirley M.

    2007-01-01

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

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

    ERIC Educational Resources Information Center

    Hutchison, Steven

    1997-01-01

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

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  7. Le Modele de Rasch: les principes sous-jacents et son application a la validation de tests (The Rasch Model: Underlying Principles and Application to Test Validation).

    ERIC Educational Resources Information Center

    de Jong, John H. A. L.

    1988-01-01

    The one-parameter psychometric model known as the Rasch model is described and examined. The basic principles underlying the model and the concepts of unidimensionality, local stochastic independence, and additivity are explained in non-mathematical terms. The requirements of measurement procedures, the measurement of latent traits, the control on…

  8. 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…

  9. Objective Measurement of Fear of Success and Fear of Failure: A Factor Analytic Approach.

    ERIC Educational Resources Information Center

    Sadd, Susan; And Others

    1978-01-01

    Fear of success and failure scales were administered. Scores were intercorrelated. Results indicated fear of success is not unidimensional. Measures of fear of success and fear of failure were highly related. Stable orthogonal factors were obtained: fear of success, test anxiety, sex-role-related attitudes, neurotic insecurity, and the value of…

  10. 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,…

  11. 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…

  12. 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.…

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

    ERIC Educational Resources Information Center

    Mooij, Ton

    2012-01-01

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

  14. 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…

  15. 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…

  16. In Search of the Illusive View of Man.

    ERIC Educational Resources Information Center

    Varenhorst, Barbara B.

    The author presents contemporary views of the quest for knowledge about human beings and the human experience. She then presents criticism of the natural science model as a basis for social and behavioral science research. She notes that the human being and his behavior are so complex that unidimensional research models are inadequate. However,…

  17. A Note on the Invariance of the DINA Model Parameters

    ERIC Educational Resources Information Center

    de la Torre, Jimmy; Lee, Young-Sun

    2010-01-01

    Cognitive diagnosis models (CDMs), as alternative approaches to unidimensional item response models, have received increasing attention in recent years. CDMs are developed for the purpose of identifying the mastery or nonmastery of multiple fine-grained attributes or skills required for solving problems in a domain. For CDMs to receive wider use,…

  18. 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…

  19. The Relationship between Polytomous DFIT and Other Polytomous DIF Procedures.

    ERIC Educational Resources Information Center

    Flowers, Claudia P.; And Others

    An item response theory-based parametric procedure proposed by N. S. Raju, W. J. van der Linden, and P. F. Fleer (1995) known as differential functioning of items and tests (DFIT) can be used with unidimensional and multidimensional data with dichotomous or polytomous scoring. This study describes the polytomous DFIT framework and evaluates and…

  20. Development and Demonstration of Multidimensional IRT-Based Internal Measures of Differential Functioning of Items and Tests.

    ERIC Educational Resources Information Center

    Oshima, T. C.; Raju, Nambury S. Rajo; Flowers, Claudia P.

    1997-01-01

    Defines and demonstrates a framework for studying differential item functioning and differential test functioning for tests that are intended to be multidimensional. The procedure, which is illustrated with simulated data, is an extension of the unidimensional differential functioning of items and tests approach (N. Raju, W. van der Linden, and P.…

  1. 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…

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

    ERIC Educational Resources Information Center

    Li, Ying; Rupp, Andre A.

    2011-01-01

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

  3. 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…

  4. Slower Implicit Categorical Learning in Adult Poor Readers

    ERIC Educational Resources Information Center

    Sperling, Anne J.; Lu, Zhong-Lin; Manis, Franklin R.

    2004-01-01

    We investigated the relationship between reading and explicit and implicit categorical learning by comparing university students with poor reading to students with normal reading abilities on two categorical learning tasks. One categorical learning task involved sorting simple geometric shapes into two groups according to a unidimensional rule.…

  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. 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…

  7. 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…

  8. 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.…

  9. 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…

  10. How Should We Use Student Ratings to Evaluate Teaching?

    ERIC Educational Resources Information Center

    Abrami, Philip C.

    1989-01-01

    Two divergent views are contrasted: the multidimensional and the unidimensional views of faculty evaluation. The views of H. W. Marsh, the most outspoken advocate of the multidimensional view of evaluation based on factor scores, is summarized and a response to his concerns is presented. (Author/MLW)

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. Bayesian Multidimensional IRT Models with a Hierarchical Structure

    ERIC Educational Resources Information Center

    Sheng, Yanyan; Wikle, Christopher K.

    2008-01-01

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

  17. 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…

  18. 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…

  19. 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.

  20. 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…

  1. 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…

  2. 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,…

  3. 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…

  4. 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

  5. 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…

  6. 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…

  7. The Latent Structure and Measurement Invariance of Scores on the Torrance Tests of Creative Thinking-Figural

    ERIC Educational Resources Information Center

    Kim, Kyung Hee; Cramond, Bonnie; Bandalos, Deborah L.

    2006-01-01

    There is disagreement among researchers as to whether creativity is a unidimensional or multidimensional trait. Much of the debate centers around the most widely used measure of creativity, the Torrance Tests of Creative Thinking (TTCT). This study used data from 1,000 kindergartners (ages 5-7), 1,000 third graders (ages 7-11) and 1,000 sixth…

  8. How Should Attributions Be Measured? A Reanalysis of Data from Elig and Frieze.

    ERIC Educational Resources Information Center

    Maruyama, Geoffrey

    1982-01-01

    T.W. Elig and I.H. Frieze used a multitrait, multimethod approach to contrast three methods for measuring attributions: unstructured/open-ended, structured/unidimensional, and structured/ipsative. This paper reanalyzed their data using confirmatory factor analysis techniques. (Author/PN)

  9. 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

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

  11. 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.)

  12. Scaling Attitude Items: A Comparison of Scalogram Analysis and Ordering Theory

    ERIC Educational Resources Information Center

    Airasian, Peter W.; And Others

    1975-01-01

    Compared two methods of identifying item hierarchies in the evaluation of attitude measures. Scalogram analysis revealed that items did not form a unidimensional and cumulative hierarchy. Ordering-theoretic analysis identified a branched, nonlinear hierarchy which had higher reproducibility and scalability than the linear hierarchy identified by…

  13. A Way to Evaluate and To Improve Classroom Teaching Effectiveness.

    ERIC Educational Resources Information Center

    Hayes, Robert B.

    This paper reports results of efforts over a 7-year period (1960-67) to determine if the Hayes Pupil-Teacher Reaction Scale is a reliable, valid unidimensional instrument which may be used to measure the attitude of students toward the teaching effectiveness of their teachers. Criteria used were 1) each respondent's total score describes with at…

  14. The Examination of Factorial Invariance in the Construct Validation of a Reading Achievement Test.

    ERIC Educational Resources Information Center

    Gamache, LeAnn M.

    To support the construct validity of a locally developed, sixth grade reading achievement test, an investigation of factorial invariance was made across 1556 majority, 327 Black minority, and 136 Asian minority examinees. Although the hypothesis of a unidimensional factor pattern was retained for each group, hypotheses of equal factor weights…

  15. 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…

  16. 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…

  17. 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)

  18. 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…

  19. 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)…

  20. ECRHS Screening Questionnaire Scoring: A Methodological Suggestion for Asthma Assessment.

    ERIC Educational Resources Information Center

    Biino, G.; Rezzani, C.; Grassi, M.; Marinoni, A.

    2001-01-01

    Investigated the unidimensionality of the European Community Respiratory Health Survey (ECRHS) screening questionnaire and determined and validated a scoring of asthma-like symptoms seriousness. Data from 6,946 adults at 3 Italian screening centers found a single dimension underlying the screening questionnaire. A scoring of asthma-like symptoms…

  1. 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…

  2. 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…

  3. 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…

  4. 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.…

  5. 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…

  6. 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…

  7. 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…

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  9. 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…

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

    ERIC Educational Resources Information Center

    de La Torre, Jimmy; Karelitz, Tzur M.

    2009-01-01

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

  11. 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…

  12. 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…

  13. Item Analysis of the Paper Folding Test (Wks. 622). Technical Report No. 1988-6.

    ERIC Educational Resources Information Center

    Wothke, Werner; Zimowski, Michele F.

    Large-sample item response data for the 10-item Paper Folding worksample 622 (N=2,749) and for five new experimental paper folding items (N=2,514) are analyzed with the logistic item response model and with full-information item factor analysis. The main results of the unidimensional analysis are that: (1) item discrimination is heterogeneous, so…

  14. 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…

  15. Integration of Impulsivity and Positive Mood to Predict Risky Behavior: Development and Validation of a Measure of Positive Urgency

    ERIC Educational Resources Information Center

    Cyders, Melissa A.; Smith, Gregory T.; Spillane, Nichea S.; Fischer, Sarah; Annus, Agnes M.; Peterson, Claire

    2007-01-01

    In 3 studies, the authors developed and began to validate a measure of the propensity to act rashly in response to positive affective states (positive urgency). In Study 1, they developed a content-valid 14-item scale, showed that the measure was unidimensional, and showed that positive urgency was distinct from impulsivity-like constructs…

  16. 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…

  17. Promise and Limits of Mentoring in Academic Science: A Look at Research on Impact and Effectiveness.

    ERIC Educational Resources Information Center

    Grant, Linda; Ward, Kathryn

    2000-01-01

    Considers the importance of mentoring in physical, chemical, and social sciences research. Discusses the mentoring program of the Association for Women in Science (AWIS) which focuses on helping women and minority scientists. Describes mentoring as "typically an asymmetrical power relation but it is not entirely unidimensional in flow of sources."…

  18. Reliability and Validity of the Pilot National Board Dental Examination.

    ERIC Educational Resources Information Center

    Kramer, Gene A.; DeMarais, David R.

    1992-01-01

    This study found that the restructured National Board Dental Examination Part II is a reliable test assessing a full range of cognitive behaviors, and a unidimensional test of comprehensive general dentistry, suggesting better testing of knowledge and problem-solving skills than on the traditional examination. Performance on the pilot and…

  19. 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…

  20. 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…

  1. The Relational Health Indices: Reanalysis of a Measure of Relational Quality

    ERIC Educational Resources Information Center

    Frey, Lisa L.; Beesley, Denise; Newman, Jody L.

    2005-01-01

    The study examined the component structure of the Relational Health Indices (B. Liang et al., 2002) with a mixed-sex sample of students seeking services at a university counseling center. In contrast to previous findings, results suggested a unidimensional structure for the peer and mentor composites and a 2-component structure for the community…

  2. Interval Estimation of Revision Effect on Scale Reliability via Covariance Structure Modeling

    ERIC Educational Resources Information Center

    Raykov, Tenko

    2009-01-01

    A didactic discussion of a procedure for interval estimation of change in scale reliability due to revision is provided, which is developed within the framework of covariance structure modeling. The method yields ranges of plausible values for the population gain or loss in reliability of unidimensional composites, which results from deletion or…

  3. 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…

  4. A Reliability Generalization Study on the Survey of Perceived Organizational Support: The Effects of Mean Age and Number of Items on Score Reliability

    ERIC Educational Resources Information Center

    Hellman, Chan M.; Fuqua, Dale R.; Worley, Jody

    2006-01-01

    The Survey of Perceived Organizational Support (SPOS) is a unidimensional measure of the general belief held by an employee that the organization is committed to him or her, values his or her continued membership, and is generally concerned about the employee's well-being. In the interest of efficiency, researchers are often compelled to use a…

  5. 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…

  6. Burnout: Testing for the Validity, Replication, and Invariance of Causal Structure across Elementary, Intermediate, and Secondary Teachers.

    ERIC Educational Resources Information Center

    Byrne, Barbara M.

    1994-01-01

    This study investigated the impact of organizational and personality factors on three factors of teacher burnout: emotional exhaustion, depersonalization, and reduced personal accomplishment. Results with 3,044 elementary, intermediate, and secondary teachers demonstrate that teacher burnout is not a unidimensional construct. (SLD)

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

    ERIC Educational Resources Information Center

    Andrich, David

    2010-01-01

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

  8. Tree Theory: A Theory-Generative Measurement Model.

    ERIC Educational Resources Information Center

    Airasian, Peter W.; Bart, William M.

    The inadequacies in present measurement models are indicated and a description is given of how tree theory, a theory-generative model, overcomes these inadequacies. Among the weaknesses cited in many measurement models are their untested assumptions of linear order and unidimensionality and their inability to generate non-associational…

  9. 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…

  10. Checking Dimensionality in Item Response Models with Principal Component Analysis on Standardized Residuals

    ERIC Educational Resources Information Center

    Chou, Yeh-Tai; Wang, Wen-Chung

    2010-01-01

    Dimensionality is an important assumption in item response theory (IRT). Principal component analysis on standardized residuals has been used to check dimensionality, especially under the family of Rasch models. It has been suggested that an eigenvalue greater than 1.5 for the first eigenvalue signifies a violation of unidimensionality when there…

  11. Motivational Correlates of Portuguese High Schoolers' Vocational Identity: Cultural Validation of the Goal Instability Scale

    ERIC Educational Resources Information Center

    Santos, Paulo Jorge; Casillas, Alex; Robbins, Steven B.

    2004-01-01

    This study examined the relevance of the Goal Instability Scale-Portuguese Adaptation (GIS-P) on the vocational identity and career certainty of 375 10th-, 11th-, and 12th-grade Portuguese high schoolers. After translating the GIS-P, confirmatory factor analysis was used to examine the factorial unidimensionality and reliability of the construct.…

  12. 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…

  13. Dimensionality in the Similarity Judgments of Young Children.

    ERIC Educational Resources Information Center

    Fahrmeier, Edward D.; Medin, Douglas L.

    In order to examine the nature of dimensional processing in children, 20 kindergarten and 20 third grade Chinese-American children were asked to make similarity judgments for unidimensional sets of stimuli differing in color (hue), size, and shape, respectively. Age differences were generally confined to the color set. The judgments of the older…

  14. Can Education Be Made "Intrinsically Interesting" to Children?

    ERIC Educational Resources Information Center

    Condry, John; Koslowski, Barbara

    This paper reviews the role of intrinsic and extrinsic motivation in children's learning. The paper contends that two types of learning exist: self-initiated learning which is intrinsically motivated, and learning initiated by another person which involves external rewards. The paper suggests that motivation is not unidimensional and that task…

  15. Assessing the Dimensionality of Polytomous Item Responses with Small Sample Sizes and Short Test Lengths: A Comparison of Procedures.

    ERIC Educational Resources Information Center

    De Champlain, Andre F.; Gessaroli, Marc E.; Tang, K. Linda; De Champlain, Judy E.

    The empirical Type I error rates of Poly-DIMTEST (H. Li and W. Stout, 1995) and the LISREL8 chi square fit statistic (K. Joreskog and D. Sorbom, 1993) were compared with polytomous unidimensional data sets simulated to vary as a function of test length and sample size. The rejection rates for both statistics were also studied with two-dimensional…

  16. 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…

  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. 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…

  19. 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…

  20. 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. PMID:26614307

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

    SciTech Connect

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

    1998-08-14

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

  2. Measuring Health-Related Quality of Life in Strabismus: A Modification of the Adult Strabismus-20 (AS-20) Questionnaire Using Rasch Analysis

    PubMed Central

    Gothwal, Vijaya K.; Bharani, Seelam; Kekunnaya, Ramesh; Chhablani, PreetiPatil; Sachdeva, Virender; Pehere, Niranjan K.; Narasaiah, Asa; Gunturu, Rekha

    2015-01-01

    Purpose To evaluate the psychometric properties of the Adult Strabismus-20 (AS-20)- a health-related quality of life (HRQoL) questionnaire in adults with strabismus, and if flawed, to revise the AS-20 and its subscales creating valid measurement scales. Methods 584 adults (meanage, 27.5 years) with strabismus were recruited from an outpatient clinic at a South Indian tertiary eye care centre and were administered the AS-20 questionnaire.The AS-20 was translated and back translated into two Indian languages. The AS-20 and its two 10-item subscales – ‘psychosocial’ and ‘function’were assessed separately for fit to the Rasch model, including an assessment of the rating scale, unidimensionality (by principal components analysis), measurement precision by person separation reliability, PSR, targeting, and differential item functioning (DIF; notable > 1.0 logits). Results Response categories were not used as intended, thereby, required re-organization and reducing their number from 5 to 3. The AS-20 had adequate measurement precision (PSR = 0.87) but lacked unidimensionality; however, deletion of the six multi-dimensionality causing items and an additional three misfitting items resulted in 11-item unidimensional questionnaire (AS-11). Two items failed to satisfy the model expectations in the ‘psychosocial’ subscale and were deleted – resulting in an 8-item unidimensional scale with adequate PSR (0.81) and targeting (0.23 logits). One item misfit in the ‘function’ subscale and was deleted—resulting in a 9 item Rasch-revised unidimensional subscale with acceptable PSR (0.80) and targeting (0.97 logits).None of the items displayed notable DIF by age, gender and level of education. Conclusions The AS-11 and its two Rasch-revised subscales – 8-item psychosocial and 9-item function subscale may be more appropriate than the original AS-20 and its two 10-item subscales for use as unidimensional measures of HRQoL in adults with strabismus in India

  3. 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

  4. 76 FR 78068 - Agency Information Collection Activities: Proposed Request and Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... published this information collection as an extension on September 23, 2011 at 76 FR 59180. Since we are... criteria. Respondents complete Form SSA-1026-REDE under the following circumstances: (1) When individuals...) (hours) SSA-1026-OCR-MS-SCE 11,400 1 18 3,420 SSA-1026-OCR-SM-REDE 225,000 1 18 67,500 Total 236,400...

  5. 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.

  6. 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

  7. Factor structure of the Body Appreciation Scale among Malaysian women.

    PubMed

    Swami, Viren; Chamorro-Premuzic, Tomas

    2008-12-01

    The present study examined the factor structure of a Malay version of the Body Appreciation Scale (BAS), a recently developed scale for the assessment of positive body image that has been shown to have a unidimensional structure in Western settings. Results of exploratory and confirmatory factor analyses based on data from community sample of 591 women in Kuala Lumpur, Malaysia, failed to support a unidimensional structure for the Malay BAS. Results of a confirmatory factor analysis suggested two stable factors, which were labelled 'General Body Appreciation' and 'Body Image Investment'. Multi-group analysis showed that the two-factor structure was invariant for both Malaysian Malay and Chinese women, and that there were no significant ethnic differences on either factor. Results also showed that General Body Appreciation was significant negatively correlated with participants' body mass index. These results are discussed in relation to possible cross-cultural differences in positive body image. PMID:18640882

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

    NASA Technical Reports Server (NTRS)

    Vidulich, Michael A.; Tsang, Pamela S.

    1987-01-01

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

  9. 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

  10. 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.

  11. Brief Report: Some Possible Uses Of Factor Analysis In Multivariate Studies.

    PubMed

    Stogdill, R M

    1966-07-01

    Factor analysis is used in item selection in the hopes of producing a small number of factors each of which will represent a unidimensional sub- scale. If item analysis has been successful in producing truly independent subscales, it might be hoped that the number of factors would equal the number of subscales and that each factor would be highly defined by a single subscale. Factor analysis when used in studies of organization, is not assumed to produce factors that represent unidimensional scales. Rather, factor analysis is used to reveal various substructures that exist within an organization. If several variables are loaded on a single factor, the variables can be regarded as nodes of interaction between measured dimensions of organization. PMID:26825604

  12. Effects of practice on identification of multidimensional stimuli.

    PubMed

    Shieh, K K; Lai, C J

    1996-10-01

    This study investigated the effects of practice on the identification of multidimensional stimuli. Subjects were instructed to perform a two dimensional identification task. The stimuli could be identified either physically or connotatively. There were two orders of reporting the two dimensions of a stimulus. Analysis showed that method of identification and order of report significantly affected speed of identification. Physical identification was faster than identification of meaning. An appropriate order of report shortened response times, and increased practice reduced response times. Practice in multidimensional identification seemed to follow the same laws and trends of unidimensional performance. The effects of practice on multimensional identification could be represented by straight lines if response times were plotted against the logarithm of the number of trials as noted in unidimensional performance. Further, practice attenuated initial differences in response times between physical identification and identification of meaning. PMID:8902016

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

    PubMed

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

    2015-01-01

    The main aim of this study was to evaluate whether the construct validity of the Tampa Scale for Kinesiophobia (TSK) is consistent with respect to its scaling properties, unidimensionality and targeting among workers with different levels of pain. The 311 participating Danish workers reported kinesiophobia by TSK (13 statement version) and number of days with pain during the past year (less than 8 days, less than 90 days and greater than 90 days). A Rasch analysis was used to evaluate the measurement properties of the TSK in the workers across pain levels, ages, genders and ethnicities. The TSK did not fit the Rasch model, but removing one item solved the poorness of fit. Invariance was found across the pain levels, ages and genders. Thus, with a few modifications, the TSK was shown to capture a unidimensional construct of fear of movement in workers with different pain levels, ages, and genders. PMID:26075669

  14. 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.

  15. 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

  16. Rf-induced steps in intermediate length Josephson-tunnel junctions

    SciTech Connect

    Costabile, G.; Monaco, R.; Pagano, S.

    1988-06-01

    We report on the behavior of the rf-induced steps in unidimensional Josephson-tunnel junctions having overlap geometry and length Lapprox. =lambda/sub j/. We have investigated the response of the junctions to the rf current in a range of frequency covering the geometrical resonance of the junctions. The experimental data are compared with the predictions of a model based on a multimode expansion of the junction phase

  17. 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.

  18. 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

  19. 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

  20. Quantum-size effects in the titanosilicate molecular sieve

    NASA Astrophysics Data System (ADS)

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

    1997-10-01

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

  1. Dopaminergic Genetic Polymorphisms Predict Rule-based Category Learning.

    PubMed

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

    2016-07-01

    Dopaminergic genes play an important role in cognitive function. DRD2 and DARPP-32 dopamine receptor gene polymorphisms affect striatal dopamine binding potential, and the Val158Met single-nucleotide polymorphism of the COMT gene moderates dopamine availability in the pFC. 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, whereas prefrontal dopamine binding is important for learning more complex conjunctive rule tasks. Modeling results suggest that striatal dopaminergic genes influence selective attention processes whereas cortical genes mediate the ability to update complex rule representations. PMID:26918585

  2. 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

  3. 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

  4. 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…

  5. Chromosome Movement in Mitosis Requires Microtubule Anchorage at Spindle Poles

    PubMed Central

    Gordon, Michael B.; Howard, Louisa; Compton, Duane A.

    2001-01-01

    Anchorage of microtubule minus ends at spindle poles has been proposed to bear the load of poleward forces exerted by kinetochore-associated motors so that chromosomes move toward the poles rather than the poles toward the chromosomes. To test this hypothesis, we monitored chromosome movement during mitosis after perturbation of nuclear mitotic apparatus protein (NuMA) and the human homologue of the KIN C motor family (HSET), two noncentrosomal proteins involved in spindle pole organization in animal cells. Perturbation of NuMA alone disrupts spindle pole organization and delays anaphase onset, but does not alter the velocity of oscillatory chromosome movement in prometaphase. Perturbation of HSET alone increases the duration of prometaphase, but does not alter the velocity of chromosome movement in prometaphase or anaphase. In contrast, simultaneous perturbation of both HSET and NuMA severely suppresses directed chromosome movement in prometaphase. Chromosomes coalesce near the center of these cells on bi-oriented spindles that lack organized poles. Immunofluorescence and electron microscopy verify microtubule attachment to sister kinetochores, but this attachment fails to generate proper tension across sister kinetochores. These results demonstrate that anchorage of microtubule minus ends at spindle poles mediated by overlapping mechanisms involving both NuMA and HSET is essential for chromosome movement during mitosis. PMID:11157972

  6. Classical test theory versus Rasch analysis for quality of life questionnaire reduction

    PubMed Central

    Prieto, Luis; Alonso, Jordi; Lamarca, Rosa

    2003-01-01

    Background Although health-related quality of life (HRQOL) instruments may offer satisfactory results, their length often limits the extent to which they are actually applied in clinical practice. Efforts to develop short questionnaires have largely focused on reducing existing instruments. The approaches most frequently employed for this purpose rely on statistical procedures that are considered exponents of Classical Test Theory (CTT). Despite the popularity of CTT, two major conceptual limitations have been pointed out: the lack of an explicit ordered continuum of items that represent a unidimensional construct, and the lack of additivity of rating scale data. In contrast to the CTT approach, the Rasch model provides an alternative scaling methodology that enables the examination of the hierarchical structure, unidimensionality and additivity of HRQOL measures. METHODS: In order to empirically compare CTT and Rasch Analysis (RA) results, this paper presents the parallel reduction of a 38-item questionnaire, the Nottingham Health Profile (NHP), through the analysis of the responses of a sample of 9,419 individuals. Results CTT resulted in 20 items (4 dimensions) whereas RA in 22 items (2 dimensions). Both instruments showed similar characteristics under CTT requirements: item-total correlation ranged 0.45–0.75 for NHP20 and 0.46–0.68 for NHP22, while reliability ranged 0.82–0.93 and 0.87–94 respectively. Conclusions Despite the differences in content, NHP20 and NHP22 convergent scores also showed high degrees of association (0.78–0.95). Although the unidimensional view of health of the NHP20 and NHP22 composite scores was also confirmed by RA, NHP20 dimensions failed to meet the goodness-of fit criteria established by the Rasch model, precluding the interval-level of measurement of its scores. PMID:12952544

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

    PubMed Central

    Coluccia, Anna; Ferretti, Fabio; Pozza, Andrea

    2014-01-01

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

  8. 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

  9. Development and calibration of an item bank for the assessment of activities of daily living in cardiovascular patients using Rasch analysis

    PubMed Central

    2013-01-01

    Background To develop and calibrate the activities of daily living item bank (ADLib-cardio) as a prerequisite for a Computer-adaptive test (CAT) for the assessment of ADL in patients with cardiovascular diseases (CVD). Methods After pre-testing for relevance and comprehension a pool of 181 ADL items were answered on a five-point Likert scale by 720 CVD patients, who were recruited in fourteen German cardiac rehabilitation centers. To verify that the relationship between the items is due to one factor, a confirmatory factor analysis (CFA) was conducted. A Mokken analysis was computed to examine the double monotonicity (i.e. every item generates an equivalent order of person traits, and every person generates an equivalent order of item difficulties). Finally, a Rasch analysis based on the partial credit model was conducted to test for unidimensionality and to calibrate the item bank. Results Results of CFA and Mokken analysis confirmed a one factor structure and double monotonicity. In Rasch analysis, merging response categories and removing items with misfit, differential item functioning or local response dependency reduced the ADLib-cardio to 33 items. The ADLib-cardio fitted to the Rasch model with a nonsignificant item-trait interaction (chi-square=105.42, df=99; p=0.31). Person-separation reliability was 0.81 and unidimensionality could be verified. Conclusions The ADLib-cardio is the first calibrated, unidimensional item bank that allows for the assessment of ADL in rehabilitation patients with CVD. As such, it provides the basis for the development of a CAT for the assessment of ADL in patients with cardiovascular diseases. Calibrating the ADLib-cardio in other than rehabilitation cardiovascular patient settings would further increase its generalizability. PMID:23914735

  10. 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.

  11. Development and validation of the Communicating with Family about Brain Death Scale.

    PubMed

    Bresnahan, Mary; Zhuang, Jie

    2016-07-01

    This study reports development of a scale assessing communication with family about brain-dead organ donation. Two cross-sectional studies demonstrated scale validity. Tests of internal, external, and predictive validity were conducted using confirmatory factor analysis. In both studies, the same 6 items were shown to be unidimensional with acceptable reliability. Parallelism was shown between the Brain Death Scale and a measure of communication with family. Predictive validity was exhibited between participants' donor status and the Brain Death Scale. The scale was associated with knowledge about brain death confirming misconceptions about brain-dead organ donation. PMID:25253626

  12. A psychometric analysis of the functional social support questionnaire in low-income pregnant women.

    PubMed

    Isaacs, Kathy B; Hall, Lynne A

    2011-01-01

    The purpose of this study was to examine the psychometric properties of the Functional Social Support Questionnaire (FSSQ) in pregnant women. A secondary analysis of data from 186 low-income pregnant women in their third trimester was conducted to assess the internal consistency reliability, dimensionality, and concurrent validity of the FSSQ. Cronbach's alpha was .83. Factor analysis supported the unidimensionality of the FSSQ. Correlations with the Interpersonal Support Evaluation List (ISEL) and the Center for Epidemiologic Studies-Depression Scale (CES-D) supported concurrent and construct validity. This secondary analysis provided evidence of the psychometric soundness of the FSSQ in this sample. PMID:22077749

  13. The spiritual experience index: A measure of spiritual maturity.

    PubMed

    Genia, V

    1991-12-01

    The Spiritual Experience Index was developed to measure spiritual maturity in persons of diverse religious and spiritual beliefs. The scale was constructed from a developmental rather than a multidimensional conceptualization of faith. Initial findings from a religiously heterogeneous college sample indicated good reliability for the SEI and supported its use as a unidimensional measure. Higher scores on the SEI were significantly related to lower dogmatism and intolerance of ambiguity. The SEI was also moderately related to higher religious participation and positively correlated with intrinsicness and quest. However, compared with the intrinsic and quest scales, the SEI emerged as the strongest indicator of adaptive spiritual functioning. Directions for future research are suggested. PMID:24272766

  14. 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

  15. 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

  16. A comparison of kinesthetic-tactual and visual displays via a critical tracking task. [for aircraft control

    NASA Technical Reports Server (NTRS)

    Jagacinski, R. J.; Miller, D. P.; Gilson, R. D.

    1979-01-01

    The feasibility of using the critical tracking task to evaluate kinesthetic-tactual displays was examined. The test subjects were asked to control a first-order unstable system with a continuously decreasing time constant by using either visual or tactual unidimensional displays. The results indicate that the critical tracking task is both a feasible and a reliable methodology for assessing tactual tracking. Further, that the critical tracking methodology is as sensitive and valid a measure of tactual tracking as visual tracking is demonstrated by the approximately equal effects of quickening for the tactual and visual displays.

  17. Optical beam steering using a 2D MEMS scanner

    NASA Astrophysics Data System (ADS)

    Pétremand, Yves; Clerc, Pierre-André; Epitaux, Marc; Hauffe, Ralf; Noell, Wilfried; de Rooij, N. F.

    2007-10-01

    This paper presents the design, fabrication and operation principle of an optical beam steerer for laser fiber coupling based on a MEMS device. The MEMS chip consists on a bi-dimensional movable platform based on uni-dimensional comb drive actuation. An optical lens is assembled onto the mobile platform to focus and steer the light comping from a laser diode and couple it into an optical fiber. Assembly of a complete system and measurements were performed and compared to simulation results. Both the trajectory of the MEMS and resonance frewquency measurements agree with the simulated ones.

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

    PubMed

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

    1990-04-01

    Early clinico-experimental findings with real-time B-mode Echography of the odontological district are reported. On the basis of previous in vitro application references and using a unidimensional A-Mode technique, preliminary data of in vivo ultrasound semeiotics regarding the tooth and its periodontal structures are outlined experimentally. Although current "in vivo" experience relates exclusively to front central and para-central teeth, it can be hypothesised that further technical and methodological developments of echographic instruments may permit systematic employment of ultrasound diagnosis in the odontological sector. PMID:2197539

  19. 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. PMID:24597444

  20. Measuring Personality in Wave I of the National Longitudinal Study of Adolescent Health

    PubMed Central

    Young, J. Kenneth; Beaujean, and A. Alexander

    2011-01-01

    The researchers sought to develop a personality measure from items in Wave I of the National Longitudinal Study of Adolescent Health. The study found 13 items from three dimensions of personality (neuroticism, extroversion, and conscientiousness), and then examined the factor structure and internal consistency of each of the three dimensions. Within each personality dimension, the items showed a unidimensional factor structure and internal consistency estimates of the summed similar to scores from NEO Personality Inventories. The results can be used to further examine how child/adolescent personality is related to multiple mental and physical health outcomes in the Add Health database. PMID:21808628

  1. Development of Implicit and Explicit Category Learning

    PubMed Central

    Huang-Pollock, Cynthia L.; Maddox, W. Todd; Karalunas, Sarah L.

    2011-01-01

    We present two studies that examine developmental differences in the implicit and explicit acquisition of category knowledge. College-attending adults consistently outperformed school-aged children on two separate information integration paradigms due to children’s more frequent use of an explicit rule-based strategy. Accuracy rates were also higher for adults on a unidimensional rule-based task due to children’s more frequent use of the irrelevant dimension to guide their behavior. Results across these two studies suggest that the ability to learn categorization structures may be dependent upon a child’s ability to inhibit output from the explicit system. PMID:21377688

  2. Huntingtin regulates mammary stem cell division and differentiation.

    PubMed

    Elias, Salah; Thion, Morgane S; Yu, Hua; Sousa, Cristovao Marques; Lasgi, Charlène; Morin, Xavier; Humbert, Sandrine

    2014-04-01

    Little is known about the mechanisms of mitotic spindle orientation during mammary gland morphogenesis. Here, we report the presence of huntingtin, the protein mutated in Huntington's disease, in mouse mammary basal and luminal cells throughout mammogenesis. Keratin 5-driven depletion of huntingtin results in a decreased pool and specification of basal and luminal progenitors, and altered mammary morphogenesis. Analysis of mitosis in huntingtin-depleted basal progenitors reveals mitotic spindle misorientation. In mammary cell culture, huntingtin regulates spindle orientation in a dynein-dependent manner. Huntingtin is targeted to spindle poles through its interaction with dynein and promotes the accumulation of NUMA and LGN. Huntingtin is also essential for the cortical localization of dynein, dynactin, NUMA, and LGN by regulating their kinesin 1-dependent trafficking along astral microtubules. We thus suggest that huntingtin is a component of the pathway regulating the orientation of mammary stem cell division, with potential implications for their self-renewal and differentiation properties. PMID:24749073

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Caspase-3 is required in the apoptotic disintegration of the nuclear matrix

    SciTech Connect

    Kivinen, Katri; Kallajoki, Markku; Taimen, Pekka . E-mail: pekka.taimen@utu.fi

    2005-11-15

    Apoptotic breakdown of cellular structures is largely mediated by caspases. One target of degradation is a proteinaceous framework of the nucleus termed the nuclear matrix. We compared the apoptotic changes of the nuclear matrix in staurosporine-treated caspase-3-deficient MCF-7 cells transfected with intact CASP-3 gene (MCF-7c3) or an empty vector (MCF-7v) as a control. Nuclear Mitotic Apparatus protein (NuMA), lamin A/C and lamin B were used as markers for internal nuclear matrix and peripheral nuclear lamina, respectively. In both cell lines, staurosporine induced rapid cytoplasmic shrinkage and partial chromatin condensation. MCF-7c3 cells formed apoptotic bodies, whereas MCF-7v cells did not. NuMA and lamins were actively cleaved in MCF-7c3 cells following caspase-3 activation, but only minimal or no cleavage was detected in MCF-7v cells. Interestingly, lamin B but not lamin A/C was relocated into cytoplasmic granules in apoptotic MCF-7v cells. Pancaspase inhibitor, z-VAD-fmk, prevented the apoptotic changes, while caspase-3 inhibitor, z-DEVD-fmk, induced lamin B granules in both cell lines. These results show that caspase-3 is involved in the cleavage of NuMA and lamins either directly or by activating other proteases. This may be essential for disintegration of the nuclear structure during apoptosis.

  11. 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

  12. Protein 4.1N binding to nuclear mitotic apparatus protein in PC12 cells mediates the antiproliferative actions of nerve growth factor.

    PubMed

    Ye, K; Compton, D A; Lai, M M; Walensky, L D; Snyder, S H

    1999-12-15

    Protein 4.1N is a neuronal selective isoform of the erythrocyte membrane cytoskeleton protein 4.1R. In the present study, we demonstrate an interaction between 4.1N and nuclear mitotic apparatus protein (NuMA), a nuclear protein required for mitosis. The binding involves the C-terminal domain of 4.1N. In PC12 cells treatment with nerve growth factor (NGF) elicits translocation of 4. 1N to the nucleus and promotes its association with NuMA. Specific targeting of 4.1N to the nucleus arrests PC12 cells at the G1 phase and produces an aberrant nuclear morphology. Inhibition of 4.1N nuclear translocation prevents the NGF-mediated arrest of cell division, which can be reversed by overexpression of 4.1N. Thus, nuclear 4.1N appears to mediate the antiproliferative actions of NGF by antagonizing the role of NuMA in mitosis. PMID:10594058

  13. 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.

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

    PubMed Central

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

    2015-01-01

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

  15. 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.

  16. 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…

  17. 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…

  18. 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…

  19. "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…

  20. 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 ...

  1. 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.

  2. Does Gender Contribute to Heterogeneity in Criteria for Cannabis Abuse and Dependence? Results from the National Epidemiological Survey on Alcohol and Related Conditions

    PubMed Central

    Agrawal, Arpana; Lynskey, Michael T.

    2007-01-01

    Previous research has noted that a unidimensional latent construct underlies criteria for cannabis abuse and dependence. However, no study to date has explored whether gender contributes to heterogeneity in the latent abuse and dependence construct and furthermore, whether after accounting for differences in the mean scores of abuse and dependence across genders, there is any evidence for heterogeneity in the individual abuse and dependence criteria. The present study utilizes data on criteria for cannabis abuse and dependence from a large, nationally representative sample (National Epidemiological Survey on Alcohol and Related Conditions) of 8,172 lifetime cannabis users to investigate whether gender contributes to heterogeneity in the underlying construct of cannabis abuse and dependence, and in each individual criterion as well. Analyses, all of which were conducted in MPlus, included factor analysis, as well as MIMIC and multiple-group models for an examination of dimensionality and gender heterogeneity, respectively. Results favor a uni-dimensional construct for cannabis abuse/dependence, as seen in prior research. We also identify 2 abuse (Legal and Hazard) and 2 dependence (Quit and Problems) criteria, which show significant gender heterogeneity with the abuse criteria exhibiting higher thresholds in women and the dependence criteria in men. We conclude that the criteria that serve as indicators of DSM-IV cannabis abuse and dependence do not function identically in men and women and that certain criteria (e.g. hazardous use) require further refinement. PMID:17084563

  3. Confirmatory factor analysis of the Oral Health Impact Profile.

    PubMed

    John, M T; Feuerstahler, L; Waller, N; Baba, K; Larsson, P; Celebić, A; Kende, D; Rener-Sitar, K; Reissmann, D R

    2014-09-01

    Previous exploratory analyses suggest that the Oral Health Impact Profile (OHIP) consists of four correlated dimensions and that individual differences in OHIP total scores reflect an underlying higher-order factor. The aim of this report is to corroborate these findings in the Dimensions of Oral Health-Related Quality of Life (DOQ) Project, an international study of general population subjects and prosthodontic patients. Using the project's Validation Sample (n = 5022), we conducted confirmatory factor analyses in a sample of 4993 subjects with sufficiently complete data. In particular, we compared the psychometric performance of three models: a unidimensional model, a four-factor model and a bifactor model that included one general factor and four group factors. Using model-fit criteria and factor interpretability as guides, the four-factor model was deemed best in terms of strong item loadings, model fit (RMSEA = 0·05, CFI = 0·99) and interpretability. These results corroborate our previous findings that four highly correlated factors - which we have named Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact - can be reliably extracted from the OHIP item pool. However, the good fit of the unidimensional model and the high interfactor correlations in the four-factor solution suggest that OHRQoL can also be sufficiently described with one score. PMID:24909797

  4. The responsiveness of the Hamilton Depression Rating Scale.

    PubMed

    Faries, D; Herrera, J; Rayamajhi, J; DeBrota, D; Demitrack, M; Potter, W Z

    2000-01-01

    In clinical studies of antidepressants, the Hamilton Depression Rating Scale (HAMD) total score has been the gold standard instrument for establishing and comparing the efficacy of new treatments. However, the HAMD is a multidimensional measure, which may reduce its ability to detect differences between treatments, in particular, changes in core symptoms of depression. Two meta-analyses were conducted to compare the responsiveness of the HAMD total score with several published unidimensional subscale scores based upon core symptoms of depression. The first compared the above instrument's ability to detect differences between fluoxetine and placebo across eight studies involving over 1600 patients. The second analysis involved four studies and over 1200 patients randomized to tricyclic antidepressants and placebo. In both meta-analyses, the unidimensional core subscales outperformed the HAMD total score at detecting treatment differences. The implications of this on sample sizes and power for clinical studies will be discussed. In fact, studies based on the observed effect sizes from the core subscales would require approximately one-third less patients than studies based on the HAMD total score. Effect sizes from each individual HAMD item will also be presented to help explain the differences in responsiveness between the scales. PMID:10696827

  5. Building a new Rasch-based self-report inventory of depression.

    PubMed

    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 (χ (2)=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

  6. Psychometric properties of the Dermatology Life Quality Index (DLQI) in 900 Italian patients with psoriasis.

    PubMed

    Mazzotti, Eva; Barbaranelli, Claudio; Picardi, Angelo; Abeni, Damiano; Pasquini, Paolo

    2005-01-01

    The Dermatology Life Quality Index (DLQI) is one of the most frequently used questionnaires to evaluate the impact of dermatological diseases on patients' lives. This study aimed to assess the reliability and validity of the instrument and to test its unidimensionality in a large sample of patients with psoriasis (n=976) hospitalized at IDI-IRCCS, Rome, Italy. Nine hundred patients completed the DLQI, the Psoriasis Disability Index (PDI) and the Skindex-29 (response rate 92%). The internal consistency of the DLQI was high (Cronbach's alpha=0.83). Evidence of convergent validity was provided by high (r=0.64-0.81) correlations between the DLQI, the PDI, and the functioning and emotions scales of Skindex-29. Exploratory factor analysis indicated the presence of four different principal common factors. Confirmatory factor analysis showed a clear second-order factor structure, with a homogeneous second-order factor underlying the four primary-surface factors. This study confirms that the DLQI is a reliable and valid instrument to assess patient-perceived impact of skin disease. Also, it supports the unidimensionality of the DLQI and hence corroborates the common practice of using the total score. PMID:16159732

  7. [Torrance Tests of Creative Thinking (TTCT): elements for construct validity in Portuguese adolescents].

    PubMed

    Oliveira, Ema; Almeida, Leandro; Ferrándiz, Carmen; Ferrando, Mercedes; Sainz, Marta; Prieto, María Dolores

    2009-11-01

    The aim of this work is to study the unidimensional and multidimensional nature of creativity when assessed through divergent thinking tasks, as proposed in Torrance's battery (Torrance Creative Thinking Test, TTCT). This battery is made up of various tasks with verbal and figurative content, aimed at estimating the level of creativity according to the dimensions or cognitive functions of fluency, flexibility, originality and elaboration of the individuals' ideas. This work used a sample of 595 Portuguese students from 5th and 6th grade. The results of confirmatory factor analysis reveals that the unidimensional model (a general factor of creativity) and the model of factors as a function of the cognitive dimensions of creativity, based on task content, do not fit well. The model with the best fit has a hierarchical factor structure, in which the first level comprises the factors for each of the subtests applied and the second level includes verbal or figurative content. The difficulty to verify the structural validity of the TTCT is noted, and the need for further studies to achieve, in practice, better individual creativity scores. PMID:19861099

  8. 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

  9. 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

  10. 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

  11. 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.

  12. A Psychometric Evaluation of an Advanced Pharmacy Practice Experience Clinical Competency Framework

    PubMed Central

    Doty, Randell E.; Nemire, Ruth E.

    2015-01-01

    Objective. To assess the psychometric properties of the clinical competency framework known as the System of Universal Clinical Competency Evaluation in the Sunshine State (SUCCESS), including its internal consistency and content, construct, and criterion validity. Methods. Sub-competency items within each hypothesized competency pair were subjected to principal components factor analysis to demonstrate convergent and discriminant validity. Varimax rotation was conducted for each competency pair (eg, competency 1 vs competency 2, competency 1 vs competency 3, competency 2 vs competency 3). Internal consistency was evaluated using Cronbach alpha. Results. Of the initial 78 pairings, 44 (56%) demonstrated convergent and discriminant validity. Five pairs of competencies were unidimensional. Of the 34 pairs where at least 1 competency was multidimensional, most (91%) were from competencies 7, 11, and 12, indicating modifications were warranted in those competencies. After reconfiguring the competencies, 76 (94%) of the 81 pairs resulted in 2 factors as required. A unidimensional factor emerged when all 13 of the competencies were entered into a factor analysis. The internal consistency of all of the competencies was satisfactory. Conclusion. Psychometric evaluation shows the SUCCESS framework demonstrates adequate reliability and validity for most competencies. However, it also provides guidance where improvements are needed as part of a continuous quality improvement program. PMID:25861100

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

    PubMed Central

    Cheah, Charissa; Yu, Jing; Hart, Craig; Sun, Shuyan; Olsen, Joseph

    2014-01-01

    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 fill these gaps by evaluating the latent factor structure underlying 18 items from Olsen et al. (2002) that were conceptually relevant to love withdrawal, guilt induction, and shaming practices in a sample of 169 mothers of Chinese-American preschoolers. A multidimensional three-factor model and bi-factor model were specified based on our formulated operational definitions for the three dimensions of psychological control. Both models were found to be superior to the unidimensional model. In addition, results from the bi-factor model and an additional second-order factor model indicated that psychological control is essentially empirically isomorphic with guilt induction. Although love withdrawal and shaming factors were also fairly strong indicators of psychological control, each exhibited important additional unique variability and mutual distinctiveness. Implications for the conceptualization of love withdrawal, guilt induction, and shaming as well as directions for future studies are discussed. PMID:26052168

  14. 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. PMID:24072786

  15. 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

  16. Congruence between a theoretical continuum of masculinity and the Rasch model: examining the Conformity to Masculine Norms Inventory.

    PubMed

    Ludlow, L H; Mahalik, J R

    2001-01-01

    The purpose of this study was to examine the psychometric structure of the Conformity to Masculine Norms Inventory (CMNI) in relation to the Rasch model. The CMNI was specifically constructed to measure a set of unidimensional constructs. As such, the items were intended to define a uniform spread of locations along each construct. The CMNI measures conformity to twelve masculine norms: winning, emotional control, risk-taking, violence, dominance, playboy, self-reliance, primacy of work, power over women, disdain for homosexuals, physical toughness, and pursuit of status. Three hundred forty-eight men participated in the study. In addition to examining global Rasch characteristics and the unidimensionality of each of the 12 scales, a detailed Rasch rating scale analysis is provided for the Violence Scale with unusual response patterns discussed in terms of their clinical usefulness. The results across all 12 scales reveal an excellent congruence between the theoretically derived construct of conformity to masculine norms and the theoretically defined objectives of the Rasch rating scale model. PMID:12011507

  17. [Internal statistical validation of a quality of life questionnaire].

    PubMed

    Hamon, A; Mesbah, M

    1999-12-01

    In this paper we present two different statistical approaches to evaluate the psychometric properties of a quality of life questionnaire. First the study of the factorial structure is briefly exposed. Then we present the unidimensional classical models. They are based on the linear relationship between the observed score and the true score. The definition of the reliability was first addressed in this classical framework. Its estimation with the Cronbach alpha coefficient is one important feature of the evaluation of an instrument. More recently, modern response theory gives a better statistical framework to deal with unidimensional latent traits. These models describe the probability of positive answer to an item as a function of the actual value of the latent trait and an item parameter. We expose the principles of the Rasch model: hypothesis, estimations methods and fit tests. Finally practical applications to the validation process of a questionnaire are explored with data from a study of a short French version of the SIP questionnaire. PMID:10673591

  18. The Mindful Attention Awareness Scale: Further Examination of Dimensionality, Reliability, and Concurrent Validity Estimates.

    PubMed

    Osman, Augustine; Lamis, Dorian A; Bagge, Courtney L; Freedenthal, Stacey; Barnes, Sean M

    2016-01-01

    We examined the factor structure and psychometric properties of the Mindful Attention Awareness Scale (MAAS) in a sample of 810 undergraduate students. Using common exploratory factor analysis (EFA), we obtained evidence for a 1-factor solution (41.84% common variance). To confirm unidimensionality of the 15-item MAAS, we conducted a 1-factor confirmatory factor analysis (CFA). Results of the EFA and CFA, respectively, provided support for a unidimensional model. Using differential item functioning analysis methods within item response theory modeling (IRT-based DIF), we found that individuals with high and low levels of nonattachment responded similarly to the MAAS items. Following a detailed item analysis, we proposed a 5-item short version of the instrument and present descriptive statistics and composite score reliability for the short and full versions of the MAAS. Finally, correlation analyses showed that scores on the full and short versions of the MAAS were associated with measures assessing related constructs. The 5-item MAAS is as useful as the original MAAS in enhancing our understanding of the mindfulness construct. PMID:26560259

  19. Nicotine dependence, abuse, and craving: dimensionality in an Israeli sample

    PubMed Central

    Shmulewitz, Dvora; Keyes, Katherine M.; Wall, Melanie M.; Aharonovich, Efrat; Aivadyan, Christina; Greenstein, Eliana; Spivak, Baruch; Weizman, Abraham; Frisch, Amos; Grant, Bridget F.; Hasin, Deborah

    2011-01-01

    Aims Evidence-based changes planned for DSM-5 substance use disorders (SUDs) include combining dependence and three of the abuse criteria into one disorder and adding a criterion indicating craving. Because DSM-IV did not include a category for nicotine abuse, little empirical support is available for aligning the nicotine use disorder criteria with the DSM-5 criteria for other SUDs. Design Latent variable analyses, likelihood ratio tests (LRT) and bootstrap tests were used to explore the unidimensionality, psychometric properties and information of the nicotine criteria. Setting, Participants A sample of household residents selected from the Israeli population register yielded 727 lifetime cigarette smokers. Measurements DSM-IV nicotine dependence criteria and proposed abuse and craving criteria, assessed with a structured interview. Findings Three abuse criteria (hazardous use, social/interpersonal problems, and neglect roles) were prevalent among smokers, formed a unidimensional latent trait with nicotine dependence criteria, were intermixed with dependence criteria across the severity spectrum, and significantly increased the diagnostic information over the dependence-only model. LRT results also supported including the abuse criteria (Χ23=259.63, p<0.0001). A craving criterion was shown to fit well with the other criteria. Conclusion Similar to findings from research on other substances, nicotine dependence, abuse, and craving criteria formed a single factor. The results support alignment of nicotine criteria with those for alcohol and drug use disorders in DSM-5. PMID:21545668

  20. 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

  1. 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

  2. Rasch Analysis of the Adult Strabismus Quality of Life Questionnaire (AS-20) among Chinese Adult Patients with Strabismus

    PubMed Central

    Wang, Zonghua; Zhou, Juan; Luo, Xingli; Xu, Yan; She, Xi; Chen, Ling; Yin, Honghua; Wang, Xianyuan

    2015-01-01

    Background The impact of strabismus on visual function, self-image, self-esteem, and social interactions decrease health-related quality of life (HRQoL).The purpose of this study was to evaluate and refine the adult strabismus quality of life questionnaire (AS-20) by using Rasch analysis among Chinese adult patients with strabismus. Methods We evaluated the fitness of the AS-20 with Rasch model in Chinese population by assessing unidimensionality, infit and outfit, person and item separation index and reliability, response ordering, targeting and differential item functioning (DIF). Results The overall AS-20 did not demonstrate unidimensional; however, it was achieved separately in the two Rasch-revised subscales: the psychosocial subscale (11 items) and the function subscale (9 items). The features of good targeting, optimal item infit and outfit, and no notable local dependence were found for each of the subscales. The rating scale was appropriate for the psychosocial subscale but a reduction to four response categories was required for the function subscale. No significant DIF were revealed for any demographic and clinical factors (e.g., age, gender, and strabismus types). Conclusion The AS-20 was demonstrated by Rasch analysis to be a rigorous instrument for measuring health-related quality of life in Chinese strabismus patents if some revisions were made regarding the subscale construct and response options. PMID:26544048

  3. 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. PMID:21604841

  4. 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

  5. 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

  6. A new look at the construct validity of the K6 using Rasch analysis.

    PubMed

    Khan, Asaduzzaman; Chien, Chi-Wen; Burton, Nicola W

    2014-03-01

    The Kessler six-item psychological distress (K6) scale is widely used to screen for mental disorders; however, information is lacking on the rating scale performance or dimensionality structure of the scale. This study used a population based sample (n = 7596) to evaluate the construct validity of the K6 scale using Rasch partial credit analysis. The analysis showed that almost all of the five-point rating scales in the K6 items were used appropriately to differentiate psychological distress of the study participants. The analysis provided evidence of unidimensionality of the scale, although items 1 (so sad) and 3 (restless or fidgety) might offer a potential second off-dimensional component. All items appeared to fit the Rasch model's expectation as demonstrated by the acceptable item fit statistics. The study participants demonstrated valid response patterns when answering K6 items, except for some who were younger or had higher psychological distress. This study using Rasch analysis confirms the construct validity of the K6 scale and suggests that the K6 is a useful and valid instrument for assessing psychological distress in the mid-aged general population. Further research can facilitate better understanding about the unidimensionality of the scale. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24431150

  7. 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

  8. Construct Validity of the Chinese Version of the Activities of Daily Living Rating Scale III in Patients with Schizophrenia

    PubMed Central

    Chiu, En-Chi; Lee, Yen; Lai, Kuan-Yu; Kuo, Chian-Jue; Lee, Shu-Chun; Hsieh, Ching-Lin

    2015-01-01

    Background The Chinese version of the Activities of Daily Living Rating Scale III (ADLRS-III), which has 10 domains, is commonly used for assessing activities of daily living (ADL) in patients with schizophrenia. However, construct validity (i.e., unidimensionality) for each domain of the ADLRS-III is unknown, limiting the explanations of the test results. Purpose This main purpose of this study was to examine unidimensionality of each domain in the ADLRS-III. We also examined internal consistency and ceiling/floor effects in patients with schizophrenia. Methods From occupational therapy records, we obtained 304 self-report data of the ADLRS-III. Confirmatory factor analysis (CFA) was conducted to examine the 10 one-factor structures. If a domain showed an insufficient model fit, exploratory factor analysis (EFA) was performed to investigate the factor structure and choose one factor representing the original construct. Internal consistency was examined using Cronbach’s alpha (α). Ceiling and floor effects were determined by the percentage of patients with the maximum and minimum scores in each domain, respectively. Results CFA analyses showed that 4 domains (i.e., leisure, picture recognition, literacy ability, communication tools use) had sufficient model fits. These 4 domains had acceptable internal consistency (α = 0.79-0.87) and no ceiling/floor effects, except the leisure domain which had a ceiling effect. The other 6 domains showed insufficient model fits. The EFA results showed that these 6 domains were two-factor structures. Conclusion The results supported unidimensional constructs of the leisure, picture recognition, literacy ability, and communication tool uses domains. The sum scores of these 4 domains can be used to represent their respective domain-specific functions. Regarding the 6 domains with insufficient model fits, we have explained the two factors of each domain and chosen one factor to represent its original construct. Future users may

  9. 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

  10. 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.

  11. Parallelization of Program to Optimize Simulated Trajectories (POST3D)

    NASA Technical Reports Server (NTRS)

    Hammond, Dana P.; Korte, John J. (Technical Monitor)

    2001-01-01

    This paper describes the parallelization of the Program to Optimize Simulated Trajectories (POST3D). POST3D uses a gradient-based optimization algorithm that reaches an optimum design point by moving from one design point to the next. The gradient calculations required to complete the optimization process, dominate the computational time and have been parallelized using a Single Program Multiple Data (SPMD) on a distributed memory NUMA (non-uniform memory access) architecture. The Origin2000 was used for the tests presented.

  12. [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

  13. [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

  14. Evolution: Treibende Kräfte in Natur und Kultur

    NASA Astrophysics Data System (ADS)

    Wuketits, Franz M.

    Vorbemerkung Der vorliegende Text ist sozusagen die Nachschrift meines im Dezember 2007 in Dresden gehaltenen Vortrags. Ich hielt den Vortrag im Wesentlichen in freier Rede, nur auf der Basis einiger Notizen, und schrieb den vollen Text danach. Dabei habe ich den Vortragsstil beibehalten. Allerdings habe ich nachträglich manches hinzugefügt, den Beitrag mit ein paar Anmerkungen versehen und einiges an zwischenzeitlich erschienener Literatur berücksichtigt.

  15. Reciprocal Suffering: Caregiver Concerns During Hospice Care

    PubMed Central

    Wittenberg-Lyles, Elaine; Demiris, George; Oliver, Debra Parker; Burt, Stephanie

    2010-01-01

    Context For many hospice caregivers, the constancy and difficulty of caregiving impact their physical quality of life and cause depression, psychological distress, guilt, loneliness, and restrictions on social activities. Objectives Deviating from traditional unidimensional research on hospice caregivers, this study explored the transactional nature of reciprocal suffering by examining caregiver concerns through four dimensions: physical, psychological, social, and spiritual. Methods Researchers analyzed audiotapes of intervention discussions between hospice caregivers and research social workers. Results Results indicated that of the 125 pain talk utterances, the majority referenced psychological concern (49%), followed by physical (28%), social (22%), and spiritual (2%). Reflections on concerns revealed a global perspective of caregiving, which highlighted the patient’s needs juxtaposed to the caregiver’s recognized limitations. Conclusion By examining the reciprocal nature of suffering for caregivers, this study reinforced the need for assessing caregivers in hospice care, with specific emphasis on the importance of providing caregiver education on pain management. PMID:21146356

  16. 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.

  17. The multidimensional randomized response design: Estimating different aspects of the same sensitive behavior.

    PubMed

    Cruyff, Maarten J L F; Böckenholt, Ulf; van der Heijden, Peter G M

    2016-03-01

    The conventional randomized response design is unidimensional in the sense that it measures a single dimension of a sensitive attribute, like its prevalence, frequency, magnitude, or duration. This paper introduces a multidimensional design characterized by categorical questions that each measure a different aspect of the same sensitive attribute. The benefits of the multidimensional design are (i) a substantial gain in power and efficiency, and the potential to (i i) evaluate the goodness-of-fit of the model, and (i i i) test hypotheses about evasive response biases in case of a misfit. The method is illustrated for a two-dimensional design measuring both the prevalence and the magnitude of social security fraud. PMID:25877782

  18. Clines with partial panmixia across a geographical barrier.

    PubMed

    Nagylaki, Thomas

    2016-06-01

    In geographically structured populations, partial global panmixia can be regarded as the limiting case of long-distance migration. In the presence of a geographical barrier, an exact, discrete model for the evolution of the gene frequencies at a multiallelic locus under viability selection, local adult migration, and partial panmixia is formulated. For slow evolution, from this model a spatially unidimensional continuous approximation (a system of integro-partial differential equations with discontinuities at the barrier) is derived. For (i) the step-environment, (ii) homogeneous, isotropic migration on the entire line, and (iii) two alleles without dominance, an explicit solution for the unique polymorphic equilibrium is found. In most natural limiting cases, asymptotic expressions are obtained for the gene frequencies on either side of the barrier. PMID:26808902

  19. The Construct Validity of Passive-Aggressive Personality Disorder

    PubMed Central

    Hopwood, Christopher J.; Morey, Leslie C.; Markowitz, John C.; Pinto, Anthony; Skodol, Andrew E.; Gunderson, John G.; Zanarini, Mary C.; Shea, M. Tracie; Yen, Shirley; McGlashan, Thomas H.; Ansell, Emily B.; Grilo, Carlos M.; Sanislow, Charles A.

    2010-01-01

    Although Passive Aggressive personality disorder (PAPD) plays an important role in many theories of personality pathology, it was consigned to the appendix of the fourth edition of the DSM. The scientific basis of this decision has been questioned, but several controversies persist regarding PAPD, including its structure, content validity, overlap with other PDs, and relations to validating variables such as personality traits, childhood experiences, and clinically relevant correlates. This study examined these facets of PAPD’s construct validity in a large clinical sample. Results suggest that the construct is unidimensional, internally consistent, and reasonably stable. Furthermore, PAPD appears systematically related to borderline and narcissistic personality disorders, sets of personality traits, and childhood experiences consistent with several theoretical formulations, dysfunction, substance abuse disorders, and history of hospitalizations. Overall, results support the construct validity of PAPD. PMID:19821648

  20. An analysis of the DuPage County Regional Office of Education physics exam

    NASA Astrophysics Data System (ADS)

    Muehsler, Hans

    In 2009, the DuPage County Regional Office of Education (ROE) tasked volunteer physics teachers with creating a basic skills physics exam reflecting what the participants valued and shared in common across curricula. Mechanics, electricity & magnetism (E&M), and wave phenomena emerged as the primary constructs. The resulting exam was intended for first-exposure physics students. The most recently completed version was psychometrically assessed for unidimensionality within the constructs using a robust WLS structural equation model and for reliability. An item analysis using a 3-PL IRT model was performed on the mechanics items and a 2-PL IRT model was performed on the E&M and waves items; a distractor analysis was also performed on all items. Lastly, differential item functioning (DIF) and differential test functioning (DTF) analyses, using the Mantel-Haenszel procedure, were performed using gender, ethnicity, year in school, ELL, physics level, and math level as groupings.

  1. Expatriate ?experts? in Indonesia and Thailand: Professional and personal qualities for effective teaching and consulting

    NASA Astrophysics Data System (ADS)

    Cannon, Robert A.

    1991-12-01

    Structured group interviews with Thai and Indonesian educators indicate that expatriate experts require a wide range of personal and professional qualities to be effective: they must have expertise, be able to establish and maintain good relationships with people, be well organised and effective teachers, and transfer information and skills that are applicable and of benefit to the nation. None of these qualities is simple or uni-dimensional. The study shows, for example, that `expertise' has several elements including technical expertise, cultural knowledge, language ability and expertise in education. Practical implications of the findings are in overseas project design, management and placement of personnel, professional development of experts, and in the design, implementation and evaluation of teaching and training.

  2. Pigeons’ Categorization May Be Exclusively Nonanalytic

    PubMed Central

    Smith, J. David; Ashby, F. Gregory; Berg, Mark E.; Murphy, Matthew S.; Spiering, Brian; Cook, Robert G.; Grace, Randolph C.

    2012-01-01

    Recent theoretical and empirical developments in human category learning have differentiated an analytic, rule-based system of category learning from a nonanalytic system that integrates information across stimulus dimensions. The researchers applied this theoretical distinction to pigeons’ category learning. Pigeons learned to categorize stimuli varying in the tilt and width of their internal striping. The matched category problems had either a unidimensional (rule-based) or multidimensional (information-integration) solution. Whereas humans and nonhuman primates strongly dimensionalize these stimuli and learn rule-based tasks far more quickly than information-integration tasks, pigeons learned the two tasks equally quickly to the same accuracy level. Pigeons may represent a cognitive system in which the commitment to dimensional analysis and category rules was not strongly made. Their performance could suggest the character of the ancestral vertebrate categorization system from which that of primates emerged. PMID:21327382

  3. 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.

  4. 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. PMID:8302990

  5. The Psychometric Property and Validation of a Fatalism Scale

    PubMed Central

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

    2010-01-01

    In this paper, we conceptualized 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 behavior) 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 (α =.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. PMID:20205014

  6. 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.

  7. 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

  8. 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

  9. Material Models and Properties in the Finite Element Analysis of Knee Ligaments: A Literature Review

    PubMed Central

    Galbusera, Fabio; Freutel, Maren; Dürselen, Lutz; D’Aiuto, Marta; Croce, Davide; Villa, Tomaso; Sansone, Valerio; Innocenti, Bernardo

    2014-01-01

    Knee ligaments are elastic bands of soft tissue with a complex microstructure and biomechanics, which are critical to determine the kinematics as well as the stress bearing behavior of the knee joint. Their correct implementation in terms of material models and properties is therefore necessary in the development of finite element models of the knee, which has been performed for decades for the investigation of both its basic biomechanics and the development of replacement implants and repair strategies for degenerative and traumatic pathologies. Indeed, a wide range of element types and material models has been used to represent knee ligaments, ranging from elastic unidimensional elements to complex hyperelastic three-dimensional structures with anatomically realistic shapes. This paper systematically reviews literature studies, which described finite element models of the knee, and summarizes the approaches, which have been used to model the ligaments highlighting their strengths and weaknesses. PMID:25478560

  10. Mutually responsive orientation between parents and their young children: toward methodological advances in the science of relationships.

    PubMed

    Aksan, Nazan; Kochanska, Grazyna; Ortmann, Margaret R

    2006-09-01

    The authors captured mother-child and father-child relationships when children were 7 and 15 months old by coding 4 explicitly dyadic components of mutually responsive orientation (MRO): coordinated routines, harmonious communication, mutual cooperation, and emotional ambiance. These components were coded in 102 families in naturalistic contexts at home and in the laboratory. Using confirmatory factor analytic methods, the authors demonstrated that MRO (a) is a unidimensional latent construct, (b) can be distinguished from and is not reducible to the 2 interacting individuals' qualities (responsiveness and positive affect), and (c) has remarkable measurement equivalence from ages 7 to 15 months for both mother-child and father-child relationships and has remarkable measurement equivalence across both parent-child relationships at both child ages. This study represents an effort to advance the science of relationships by moving away from individual-based measures to dyadic measures and by using contemporary data analytic strategies. PMID:16953690

  11. Invariant recognition to position, rotation, and scale considering vectorial signatures

    NASA Astrophysics Data System (ADS)

    Lerma A., Jesús R.; Álvarez-Borrego, Josué; González-Fraga, José Ángel

    2008-08-01

    This work presents the development and utilization of vectorial signatures filters obtained from the application of properties of the scale and Fourier transform for images recognition. The filters were applied to different input scene, which consisted in the 26 letters of the alphabet. Each letter is an image of 256 × 256 pixels of black background with a centered white Arial letter. The image was rotated 360 degrees in increment of 1o and scaled from 70% to 130% in increment of 0.5%. In order to find a new invariant correlation digital system we obtained two unidimensional vector after to achieve different mathematical transformation in the target as well as the input scene. To recognize a target, signatures were compared, calculating the Euclidean distance between the target and the input scene; then, confidence levels are obtained. The results demonstrate that this system has a good performance to discriminate between letters.

  12. 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.

  13. 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

  14. 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. PMID:25428591

  15. Cross-national measure of fear-based xenophobia: development of a cumulative scale.

    PubMed

    van der Veer, Kees; Ommundsen, Reidar; Yakushko, Oksana; Higler, Laurens

    2011-08-01

    To apply a Mokken Scale Procedure in developing a hierarchical cross-national scale to measure xenophobia, a pool of 30 xenophobia-related items was collected from several sources and modified using established unidimensional criteria. The survey was administered to 608 undergraduate students in the USA, 193 undergraduate students in The Netherlands, and 303 undergraduate students in Norway. 14 items measuring perceived threat or fear and meeting the criteria of the Stereotype Content Model were selected for further analysis. A separate item analysis and, subsequently, Mokken Scale Procedure yielded a cumulative scale with the same five items for each of the three samples. The items and the total scale met criteria for homogeneity in all samples with H > .40. PMID:22049645

  16. Three dimensional ballisto- and seismo-cardiography: HIJ wave amplitudes are poorly correlated to maximal systolic force vector.

    PubMed

    Migeotte, P-F; De Ridder, S; Tank, J; Pattyn, N; Funtova, I; Baevsky, R; Neyt, X; Prisk, G K

    2012-01-01

    Ballistocardiography was recorded in 3-D on a free floating astronaut in space as well as on healthy volunteers participating to the ESA 55(th) and DLR 19(th) parabolic flights campaigns. In this paper we demonstrate further the usefulness of recording and analyzing ballistocardiograms (BCG) in three dimensions. The spatial curves of the displacement, velocity and acceleration vectors are analyzed instead of their individual 2-D components. The maximum magnitude of the force vector is shown to be poorly correlated to the HI and IJ wave amplitude traditionally computed on the longitudinal (feet-to-head) component of acceleration (uni-dimensional BCG). We also suggest that kinetic energy and work are useful parameters to consider for a physiological interpretation of the 3D-BCG. The technique presented is invariant from the axis of representation and provides important novel physiological information. We stress further the need of 3D recordings and analysis techniques for Ballisto- and Seismo-cardiography. PMID:23367062

  17. Development of a measure of "acculturation" for ethnic Fijians: methodologic and conceptual considerations for application to eating disorders research.

    PubMed

    Becker, Anne E; Fay, Kristen; Agnew-Blais, Jessica; Guarnaccia, Peter M; Striegel-Moore, Ruth H; Gilman, Stephen E

    2010-11-01

    Acculturation has been examined as a risk factor for eating disorders, but interpretation of findings has been limited by inconsistent operationalization of this construct across studies. The study aim was to develop and evaluate a population-specific measure of acculturation for ethnic Fijian adolescent schoolgirls, to use in future analyses related to eating disorders. Our findings suggest that acculturation is a multidimensional construct characterized by distinct, though related, dimensions of orientation to ethnic Fijian and/or western/global culture with respect to a range of behaviors and attitudes. In contrast to theoretical models positing uni-dimensional, orthogonal, or oblique relations between cultural identities in individuals undergoing acculturation, our study findings support a heterogeneous pattern among correlations of dimensions across contrasting cultural identities. We suggest multidimensional measures of acculturation are optimal--and socio-demographic proxies inadequate--for characterization of this complex process for health research. PMID:21088103

  18. The Role of Defensive Confidence in Preference for Proattitudinal Information: How Believing That One Is Strong Can Sometimes Be a Defensive Weakness

    PubMed Central

    Albarracín, Dolores; Mitchell, Amy L.

    2016-01-01

    This series of studies identified individuals who chronically believe that they can successfully defend their attitudes from external attack and investigated the consequences of this individual difference for selective exposure to attitude-incongruent information and, ultimately, attitude change. Studies 1 and 2 validated a measure of defensive confidence as an individual difference that is unidimensional, distinct from other personality measures, reliable over a 2-week interval, and organized as a trait that generalizes across various personal and social issues. Studies 3 and 4 provided evidence that defensive confidence decreases preference for proattitudinal information, therefore inducing greater reception of counterattitudinal materials. Study 5 demonstrated that people who are high in defensive confidence are more likely to change their attitudes as a result of exposure to counterattitudinal information and examined the perceptions that mediate this important phenomenon. PMID:15536240

  19. Does the DOG scale measure dogmatism? Another look at construct validity.

    PubMed

    Crowson, H Michael

    2009-06-01

    The author addressed the construct validity of B. Altemeyer's (1996) Dogmatism (DOG) scale. Confirmatory factor analyses of the scale provided evidence of unidimensionality, despite apparent method effects related to item wording. DOG scale scores correlated strongly and positively with the belief that knowledge is certain, providing convergent validity evidence for the measure. Scores on the DOG scale appeared empirically distinguishable from measures of need for cognition, need for structure, and need to evaluate. Criterion-related validity evidence came in the form of theoretically predictable relationships between the DOG scale and measures of religious fundamentalism, quest orientation, national identification, conservative ideology, dangerous world beliefs, and reactions to individuals and groups who hold worldview-incongruent beliefs and values. PMID:19537601

  20. 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

  1. 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

  2. Quantifying temporal change in biodiversity: challenges and opportunities

    PubMed Central

    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.; Øvreås, 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. PMID:23097514

  3. Periodontal probing: a review.

    PubMed

    Al Shayeb, Kwthar Nassar A; Turner, Wendy; Gillam, David G

    2014-08-01

    Periodontal probes are the main instruments that are used to assess the status of the periodontium, either for screening purposes or to evaluate periodontal changes throughout the treatment process. With increased knowledge and understanding of periodontal disease, the probes have evolved from a unidimensional manual shape into a more sophisticated computerised instrument. This is due to the need to increase the accuracy and reproducibility of readings and to improve efficiency (time, effort, money). Each probe has characteristic features that makes it unique and, in some cases, specific and limited to use. The aim of this paper is to present a brief introduction to periodontal disease and the methodology of measuring it, followed by probing limitations. The paper will also discuss the methodology of reducing probing error, examiner calibration and probing reproducibility. PMID:25198634

  4. 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]). PMID:19138769

  5. 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.

  6. Hope and General Self-efficacy: Two Measures of the Same Construct?

    PubMed

    Zhou, Mingming; Kam, Chester Chun Seng

    2016-07-01

    The aim of this study was to test the extent to which hope measure is equivalent to general self-efficacy measure. Questionnaire data on these two constructs and other external variables were collected from 199 Chinese college students. The factor analytic results suggested that hope and self-efficacy items measured the same construct. The unidimensional model combining hope items and GSE items fit the data as well as the bidimensional model, indicating that their corresponding items measured the same underlying construct. Further analyses showed that hope and GSE did not correlate with external variables differently in a systematic manner. Most of these correlational differences were non-significant and negligible. These findings suggested that the literatures studying GSE and hope could be considered to be integrated and that researchers need to recognize and acknowledge the conceptual and operational similarities among these constructs in the literature. PMID:26761605

  7. 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

  8. 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.

  9. Measuring Enjoyment of Physical Activity in Children: Validation of the Physical Activity Enjoyment Scale

    PubMed Central

    2009-01-01

    This study sought to determine the reliability and validity of the Physical Activity Enjoyment Scale (PACES) in elementary school children. The sample consisted of 564 3rd grade students (M age = 8.72 ± .54; 268 male, 296 female) surveyed at the beginning of the fall semester. Results indicated that the PACES displayed good internal consistency and item-total correlations. Confirmatory factor analyses supported a unidimensional factor structure. Scores on the PACES were significantly correlated with task goal orientation (r = .65, p < .01), athletic competence (r = .23, p < .01), physical appearance (r = .20, p < .01), and self-reported physical activity (r = .16, p < .01). However, results of invariance analysis suggested the factor structure is variant across sex. The present findings suggest support for the validity of the PACES as a valid measure of enjoyment of physical activity in children; nevertheless, further research examining the invariance of the factor structure across sex is warranted. PMID:20209028

  10. 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

  11. A confirmatory factor analysis of the Life Orientation Test-Revised with competitive athletes.

    PubMed

    Appaneal, Renee N

    2012-12-01

    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. Hence, I sought to explicitly examine the factor structure of the LOT-R with athletes. Results of this study support the two-factor structure, which is consistent with accumulating evidence outside of sport and exercise science. This contribution is an important first step toward continued examination of this instrument and future work on the influence of optimism (versus pessimism) on sport and exercise behavior. PMID:23367823

  12. 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

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

    PubMed

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

    2015-11-15

    We report the fabrication of artificial unidimensional crystals exhibiting an effective bulk second-order nonlinearity. The crystals are created by cycling atomic layer deposition of three dielectric materials such that the resulting metamaterial is noncentrosymmetric in the direction of the deposition. Characterization of the structures by second-harmonic generation Maker-fringe measurements shows that the main component of their nonlinear susceptibility tensor is about 5 pm/V, which is comparable to well-established materials and more than an order of magnitude greater than reported for a similar crystal [Appl. Phys. Lett.107, 121903 (2015)APPLAB0003-695110.1063/1.4931492]. Our demonstration opens new possibilities for second-order nonlinear effects on CMOS-compatible nanophotonic platforms. PMID:26565877

  14. 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. PMID:26784380

  15. 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.

  16. 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.

  17. Potential applications of latent variable modeling for the psychometrics of medical simulation.

    PubMed

    Cai, Li

    2013-10-01

    Use of simulation-based assessments and training has become increasingly widespread in medicine. It is recognized that simulations can yield a wealth of real-time information about the trainee or examinee's performance, from which inferences about proficiency can potentially be drawn. However, for the inferences to be useful, psychometric evaluation should be conducted and validity evidence amassed. Traditionally, educational and psychological measurement has relied on psychometric models that are static, unidimensional, and based on observed scores. In this article, it is argued that modern psychometric models that are dynamic, multidimensional, and based on latent variables may be useful for evaluating medical simulations. It is also argued that modern computational methods based on Bayesian statistics may provide the technical foundation. Several examples are given and issues for further research are discussed. PMID:24084312

  18. 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

  19. Nd2Sn2O7 : An all-in-all-out pyrochlore magnet with no divergence-free field and anomalously slow paramagnetic spin dynamics

    NASA Astrophysics Data System (ADS)

    Bertin, A.; Dalmas de Réotier, P.; Fâk, B.; Marin, C.; Yaouanc, A.; Forget, A.; Sheptyakov, D.; Frick, B.; Ritter, C.; Amato, A.; Baines, C.; King, P. J. C.

    2015-10-01

    We report measurements performed on a polycrystalline sample of the pyrochlore compound Nd2Sn2O7 . It undergoes a second order magnetic phase transition at Tc≈0.91 K to a noncoplanar all-in-all-out magnetic structure of the Nd3 + magnetic moments. The thermal behavior of the low temperature specific heat fingerprints excitations with linear dispersion in a three-dimensional lattice. The temperature independent spin-lattice relaxation rate measured below Tc and the anomalously slow paramagnetic spin dynamics detected up to ≈30 Tc are suggested to be due to magnetic short-range correlations in unidimensional spin clusters, i.e., spin loops. The observation of a spontaneous field in muon spin relaxation measurements is associated with the absence of a divergence-free field for the ground state of an all-in-all-out pyrochlore magnet as predicted recently.

  20. Gendered language attitudes: exploring language as a gendered construct using Rasch measurement theory.

    PubMed

    Knisely, Kris A; Wind, Stefanie A

    2015-01-01

    Gendered language attitudes (GLAs) are gender-based perceptions of language varieties based on connections between gender-related and linguistic characteristics of individuals, including the perception of language varieties as possessing degrees of masculinity and femininity. This study combines substantive theory about language learning and gender with a model based on Rasch measurement theory to explore the psychometric properties of a new measure of GLAs. Findings suggest that GLAs is a unidimensional construct and that the items used can be used to describe differences among students in terms of the strength of their GLAs. Implications for research, theory, and practice are discussed. Special emphasis is given to the teaching and learning of languages. PMID:25562339

  1. 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. PMID:21711346

  2. Determining the Internal Validity of the Inventory of Reading Occupations: An Assessment Tool of Children's Reading Participation.

    PubMed

    Grajo, Lenin C; Candler, Catherine; Bowyer, Patricia; Schultz, Sally; Thomson, Jennifer; Fong, Karen

    2016-01-01

    The Inventory of Reading Occupations (IRO) is an assessment tool of children's reading participation. In this study, we used Rasch methods to determine the internal validity of the IRO. Participants included 192 typical and struggling readers from kindergarten to third grade from five different states in the United States. We analyzed the fit of each of the items in the 17 reading categories, the test items in the three dimensions of reading participation, and the contexts of reading in the IRO. Analysis indicated that the IRO items support the Rasch model of unidimensionality. Analysis also indicated that 1 of the 30 test items can be revised to strengthen test validity. Moreover, the analysis also suggested that the IRO is more useful for first- to third-grade students. This study provides evidence of internal validity of a useful tool to assess children's reading participation. PMID:27089292

  3. Emotional inhibition: a discourse analysis of disclosure.

    PubMed

    Ellis, Darren; Cromby, John

    2012-01-01

    Evidence generated within the emotional disclosure paradigm (EDP) suggests that talking or writing about emotional experiences produces health benefits, but recent meta-analyses have questioned its efficacy. Studies within the EDP typically rely upon a unidimensional and relatively unsophisticated notion of emotional inhibition, and tend to use quantitative forms of content analysis to identify associations between percentages of word types and positive or negative health outcomes. In this article, we use a case study to show how a qualitative discourse analysis has the potential to identify more of the complexity linking the disclosure practices and styles that may be associated with emotional inhibition. This may illuminate the apparent lack of evidence for efficacy of the EDP by enabling more comprehensive theorisations of the variations within it. PMID:21678182

  4. 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

  5. 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.

  6. 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. PMID:22710016

  7. Study of AOT-stabilized microemulsions of urea dispersed in carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Ruggirello, A.; Turco Liveri, V.

    2003-03-01

    Measurements of some physico-chemical properties (density, viscosity, permittivity) of the urea/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/CCl 4 system as a function of the volume fraction of the dispersed phase (0< Φ<0.7) at various urea to AOT molar ratio ( Rurea) have been carried out at 25 °C. The experimental data analysis are consistent with the hypothesis that urea is entrapped as small-size molecular clusters within the hydrophilic core of the AOT reversed micelles and that this structure is preserved well above a threshold Φ value where a percolative transition occurs. Besides, X-ray diffraction spectra of samples at Φ=1, obtained by complete evaporation under vacuum of the apolar solvent of urea/AOT/CCl 4 solutions, indicates that, even in the typical two-dimensional hexagonal structure of AOT liquid crystals, urea is encapsulated as uni-dimensional molecular clusters.

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

    PubMed Central

    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. PMID:24052924

  9. Development and validation of an eating norms inventory. Americans' lay-beliefs about appropriate eating.

    PubMed

    Fisher, Robert J; Dubé, Laurette

    2011-10-01

    What do American adults believe about what, where, when, how much, and how often it is appropriate to eat? Such normative beliefs originate from family and friends through socialization processes, but they are also influenced by governments, educational institutions, and businesses. Norms therefore provide an important link between the social environment and individual attitudes and behaviors. This paper reports on five studies that identify, develop, and validate measures of normative beliefs about eating. In study 1 we use an inductive method to identify what American adults believe are appropriate or desirable eating behaviors. Studies 2 and 3 are used to purify and assess the discriminant and nomological validity of the proposed set of 18 unidimensional eating norms. Study 4 assesses predictive validity and finds that acting in a norm-consistent fashion is associated with lower Body Mass Index (BMI), and greater body satisfaction and subjective health. Study 5 assesses the underlying social desirability and perceived healthiness of the norms. PMID:21621572

  10. Validation of the Japanese Version of the Body Vigilance Scale.

    PubMed

    Saigo, Tatsuo; Takebayashi, Yoshitake; Tayama, Jun; Bernick, Peter J; Schmidt, Norman B; Shirabe, Susumu; Sakano, Yuji

    2016-06-01

    The Body Vigilance Scale is a self-report measure of attention to bodily sensations. The measure was translated into Japanese and its reliability, validity, and factor structure were verified. Participants comprised 286 university students (age: 19 ± 1 years). All participants were administered the scale, along with several indices of anxiety (i.e., Anxiety Sensitivity Index, Short Health Anxiety Inventory Illness Likelihood Scale, Social Interaction Anxiety Scale, and Hospital Anxiety and Depression Scale). The Japanese version of the Body Vigilance Scale exhibited a unidimensional factor structure and strong internal consistency. Construct validity was demonstrated by significant correlations with the above measures. Results suggest that the Japanese version of the scale is a reliable, valid tool for measuring body vigilance in Japanese university students. PMID:27207736

  11. 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. PMID:24870400

  12. Rasch analysis of the Mental Health Recovery Measure.

    PubMed

    Chang, Yen-Ching; Ailey, Sarah H; Heller, Tamar; Chen, Ming-De

    2013-01-01

    Consumer-oriented recovery among people with mental illness has been discussed for more than two decades, but few reliable and valid recovery measurements are currently available. This study used Rasch methods to assess the Mental Health Recovery Measure (MHRM). Participants were 156 adults with mental illness who lived in the community. After the Rasch analyses, the MHRM was modified to a 26-item measure with a 4-point Likert scale. Unidimensionality was confirmed for the revised MHRM, and it also showed proper rating scale functioning and high reliability. The revised MHRM is sufficient to assess only those in the initial and middle stages of recovery. More high-recovery-level items are needed to assess people in a high-recovery stage. Occupational therapists can use the revised MHRM in future quantitative studies and program evaluation. PMID:23791322

  13. 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

  14. Promoting and measuring family caregiver self-efficacy in caregiver-physician interactions.

    PubMed

    Moore, Crystal Dea; Cook, Kevin M

    2011-01-01

    This article describes the development of a 5-item scale that assesses family caregivers' self-efficacy in communicating with physicians about ill family members (Perceived Efficacy in Caregiver-Physician Interactions-PECPI) in the context of an evaluation study of an online training in health care communication skills for caregivers. A national sample of 197 self-identified family caregivers participated in an online webinar and completed a brief evaluation instrument before and immediately after the training. Results indicated that the webinar was effective in increasing perceived self-efficacy and self-reported knowledge about and level of preparation for medical visits. Principal component analysis indicates that the PECPI is unidimensional with a Cronbach's alpha of .91. PMID:22136346

  15. [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

  16. 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.

  17. 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

  18. Research Burnout: a refined multidimensional scale.

    PubMed

    Singh, Surendra N; Dalal, Nikunj; Mishra, Sanjay

    2004-12-01

    In a prevailing academic climate where there are high expectations for faculty to publish and generate grants, the exploration of Research Burnout among higher education faculty has become increasingly important. Unfortunately, it is a topic that has not been well researched empirically. In 1997 Singh and Bush developed a unidimensional scale to measure Research Burnout. A closer inspection of the definition of this construct and the composition of its items suggests, however, that the construct may be multidimensional and analogous to Maslach's Psychological Burnout Scale. In this paper, we propose a refined, multidimensional Research Burnout scale and test its factorial validity using confirmatory factor analysis. The nomological validity of this refined scale is established by examining hypothesized relationships between Research Burnout and other constructs such as Intrinsic Motivation for doing research, Extrinsic Pressures to do research, and Knowledge Obsolescence. PMID:15762409

  19. 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

  20. Validation of the General Self-Efficacy Scale among Qatari young women.

    PubMed

    Crandall, A; Rahim, H F Abdul; Yount, K M

    2016-12-01

    The General Self-Efficacy Scale (GSES) is a measure of people's beliefs about their capacity to cope with life's demands. Self-efficacy may be particularly relevant in transitional stages such as in late adolescence, when young people make decisions that will impact their adult lives. In the present study, we aimed to validate an Arabic version of GSES among 355 Qatari young women aged 18+ years and finishing their final year of high school. We conducted exploratory and confirmatory factor analyses to assess the scale dimensionality. The final model fit was adequate (root mean square error of approximation = 0.07, comparative fit index = 1.00, Tucker-Lewis index = 0.99), confirming a unidimensional self-efficacy measure. The Qatari Standard Arabic GSES is a reliable tool for measuring general self-efficacy among young Qatari women. PMID:26996362

  1. 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

  2. Nasopharyngeal Cancers: Which Method Should be Used to Measure these Irregularly Shaped Tumors on Cross-Sectional Imaging?

    SciTech Connect

    King, Ann D. Zee, Benny; Yuen, Edmund H.Y.; Leung Singfai; Yeung, David K.W.; Ma, Brigette B.; Wong, Jeffrey K.T.; Kam, Michael K.M.; Ahuja, Anil T.; Chan, Anthony T.C.

    2007-09-01

    Purpose: To determine whether the standard techniques of measuring tumor size and change in size after treatment could be applied to the measurement of nasopharyngeal cancers, which are often irregular in shape. Methods and Materials: The standard measurements of bidimensional (BDM) (World Health Organization criteria) and unidimensional (UDM) (Response Evaluation Criteria in Solid Tumors [RECIST] criteria), together with the maximum depth of the tumor perpendicular to the pharyngeal wall (DM), were acquired from axial magnetic resonance images of primary nasopharyngeal carcinoma in 44 patients at diagnosis and in 29 of these patients after treatment. Tumor volume measurements (VM), acquired from the summation of areas from the axial magnetic resonance images, were used as the reference standard. Results: There was a significant association between VM and BDM with respect to tumor size at diagnosis (p = 0.002), absolute change in tumor size after treatment (p < 0.001), and percentage change in tumor size after treatment (p = 0.044), but not between VM and UDM. There was also a significant association between VM and DM with respect to percentage change in tumor size after treatment (p = <0.0001) but not absolute change (p = 0.222). Conclusion: When using simple measurements to assess irregularly shaped nasopharyngeal cancers, the BDM should be used to measure size at diagnosis and the BDM and percentage change in size with treatment. Unidimensional measurement does not reflect size or change in size, and therefore the RECIST criteria may not be applicable to all tumor shapes. The use of DM requires further evaluation.

  3. 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

  4. DEFINING DISABILITY: DEVELOPMENT AND VALIDATION OF A DISABILITY SEVERITY INDEX IN INHERITED NEUROPATHY

    PubMed Central

    Ramchandren, Sindhu; Shy, Michael E.; Feldman, Eva L.; Carlos, Ruth C.; Siskind, Carly

    2016-01-01

    Objective To develop and validate a reliable patient-reported scale that grades the severity of disability in inherited neuropathy, from an in-depth analysis of patient and healthcare provider perspectives on what constitutes mild, moderate and severe disability. Design In this prospective, cross-sectional study, a 19-item Disability questionnaire was developed following literature and expert review. Between 2011–2012, the Disability Questionnaire was provided to Health Care Providers experienced in inherited neuropathy attending national scientific meetings, and to patients self-registered with the Inherited Neuropathy Consortium – Rare Diseases Clinical Research Consortium on-line contact registry. Provider and patient responses were compared utilizing a 2-sided unpaired t-test with Bonferroni correction. The questionnaire was then assessed for validity, reliability, and unidimensionality. Results We analyzed 259 Disability Questionnaires (167 patients, 92 providers); these showed perfect agreement between patient and provider responses on qualitative descriptions of disability, but significant differences in quantitative responses on items corresponding to minimal or severe disability (p < 0.001). Validity and Test-retest reliability of the Questionnaire was excellent (Cronbach’s alpha =0.96; ICC= 0.977 [0.951–0.993]. Exploratory factor analysis and the Mokken Scaling Procedure supported the unidimensionality of the Disability Severity Index. Conclusion The Disability Severity Index is a unique instrument, categorizing disability from the patient’s perspective, and will undergo further cross-validation studies in inherited neuropathy. This Index may have applications to other peripheral neuropathies, and would thus benefit from future validation studies in the appropriate cohorts. PMID:25157034

  5. 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

  6. Psychometric properties of the 16-item Quick Inventory of Depressive Symptomatology: a systematic review and meta-analysis.

    PubMed

    Reilly, Thomas J; MacGillivray, Steve A; Reid, Ian C; Cameron, Isobel M

    2015-01-01

    Effective management of depression is predicated upon reliable assessment. The Quick Inventory of Depressive Symptomatology (QIDS) is a depression severity scale with both self-rated (QIDS-SR16) and clinician-rated (QIDS-C16) versions. Although widely used in research, the psychometric properties of the QIDS16 have not been systematically reviewed. We performed a systematic review of studies of the psychometric properties (factor structure, internal consistency, convergent validity, discriminant validity, test-retest reliability and responsiveness to change) of the QIDS-SR16 or QIDS-C16. Six databases were searched: MEDLINE, EMBASE, PsycINFO, CinAHL, Web of Science and the Cochrane Central Register of Controlled Trials. Findings were summarised, bias assessed and correlations with reference standards were pooled. 37 studies (17,118 participants) were included in the review. Both versions of the QIDS16 were unidimensional. Cronbach's alpha ranged from 0.69 to 0.89 for the QIDS-SR16 and 0.65 to 0.87 for the QIDS-C16. The QIDS-SR16 correlated moderately to highly with several depression severity scales. Seven studies were pooled where QIDS-SR16 was correlated with the HRSD-17 (r = 0.76, CI 0.69, 0.81) in patients diagnosed with depression. Four studies examined convergent validity with the QIDS-C16. Four studies examined discriminant validity, for the QIDS-SR16 alone. Eighteen studies had at least one author who was a co-author of the original QIDS16 study. Most studies were conducted in the USA (n = 26). The QIDS-SR16 and the QIDS-C16 are unidimensional rating scales with acceptable internal consistency. To justify the use of the QIDS16 scale in clinical practice, more research is needed on convergent and discriminant validity, and in populations outside the USA. PMID:25300442

  7. Development of a Modified Version of the Spinal Function Sort (M-SFS): A Mixed Method Approach.

    PubMed

    Janssen, Svenja; Trippolini, Maurizio A; Hilfiker, Roger; Oesch, Peter

    2016-09-01

    Purpose To develop a modified version of the spinal function sort (M-SFS) by measuring work-related self-efficacy beliefs in patients with chronic low back pain. Methods A mixed method design consisting of three different methods (M1-3) was performed. In semi-structured interviews participants were asked how often they performed the activities of the 50 SFS items in 1 week, and which spinal postures and movements were associated with their back pain (M1). Quantitative analysis of previously obtained SFS data investigated internal consistency, unidimensionality, item response, and floor and ceiling effect (M2). Experts rated the SFS items based on their relevance (M3). The findings from these methods were used within a final scoring system for item reduction. Results From semi-structured interviews with 17 participants, eight new items emerged (M1). Quantitative analysis of 565 data sets (M2) revealed very high internal consistency of all items (Cronbach's alpha = 0.98) indicating item redundancy; unidimensionality of the SFS was supported by principal component analysis; good item response was confirmed by Rasch analysis; and a floor effect of four items depicting very heavy material handling was found. Experts agreed on 8 out of the 50 SFS as relevant (M3). From the original SFS, 12 items met the predefined summary score of 9. Conclusions A modified version of the SFS with 20 items has been developed. Feasibility, reliability and validity of this modified version must be tested before it can be used in clinical practice. PMID:26499967

  8. [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

  9. 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

  10. Translation and validation of non-English versions of the Ankylosing Spondylitis Quality of Life (ASQOL) questionnaire

    PubMed Central

    Doward, Lynda C; McKenna, Stephen P; Meads, David M; Twiss, James; Revicki, Dennis; Wong, Robert L; Luo, Michelle P

    2007-01-01

    Background The Ankylosing Spondylitis Quality of Life (ASQOL) questionnaire is a unidimensional, disease-specific measure developed in the UK and the Netherlands. This study describes its adaptation into other languages. Methods The UK English ASQOL was translated into US English; Canadian French and English; French; German; Italian; Spanish; and Swedish (dual-panel methods). Cognitive debriefing interviews were conducted with AS patients. Psychometric/scaling properties were assessed using data from two Phase III studies of adalimumab. Baseline and Week-2 data were used to assess test-retest reliability. Validity was determined by correlation of ASQOL with SF-36 and BASFI and by discriminative ability of ASQOL based on disease severity. Item response theory (Rasch model) was used to test ASQOL's scaling properties. Results Cognitive debriefing showed the new ASQOL versions to be clear, relevant and comprehensive. Sample sizes varied, but were sufficient for: psychometric/scaling assessment for US English and Canadian English; psychometric but not scaling analyses for German; and preliminary evidence of these properties for the remaining languages. Test-retest reliability and Cronbach's alpha coefficients were high: US English (0.85, 0.85), Canadian English (0.87, 0.86), and German (0.77, 0.79). Correlations of ASQOL with SF-36 and BASFI for US English, Canadian English, and German measures were moderate, but ASQOL discriminated between patients based on perceived disease severities (p < 0.01). Results were comparable for the other languages. US English and Canadian English exhibited fit to the Rasch model (non-significant p-values: 0.54, 0.68), confirming unidimensionality. Conclusion The ASQOL was successfully translated into all eight languages. Psychometric properties were excellent for US English, Canadian English, and German, and extremely promising for the other languages. PMID:17274818

  11. 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

  12. 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

  13. 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

  14. 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

  15. [Reliability and factorial structure of a rating scale for amyotrophic lateral sclerosis].

    PubMed

    Oda, E; Ohashi, Y; Tashiro, K; Mizuno, Y; Kowa, H; Yanagisawa, N

    1996-11-01

    The Modified Norris Scale is a rating scale for amyotrophic lateral sclerosis (ALS), which consists of two parts, the Limb Norris Scale and the Norris Bulbar Scale. The Limb Scale has 21 items to evaluate extremity function and the Bulbar Scale has 13 items to evaluate bulbar function. Each item is rated in 4 ordinal categories. Considering the habitual difference, we translated the English scale into Japanese one with minor modification, and added more detailed explanations for all categories of each item. Then we examined reliability and factorial structure of the translated scale. The subjects were 23 patients with motor disturbance and each subject was rated twice by 2-4 neurologists. As a measure of reliability, the Kappa coefficient proposed by Cohen (1960) and Kraemer (1980) was calculated for each item and the intraclass correlation coefficient (ICC) was evaluated for total scores of each of two scales. To analyze the factorial structure, the factor analysis was carried out. The minimum and the maximum Kappa values were .70 and .97 for intra-rater reliability of the Limb Scale's items, .60 and .83 for inter-rater reliability of the Limb Scale's items, .41 and 1.00 for intra-rater reliability of the Bulbar Scale's items and .26 and .81 for inter-rater reliability of the Bulbar Scale's items, respectively. Concerning the factorial structure, the contribution of the first factor was 83.6% for the Limb Scale and that for the Bulbar Scale was 66.7%. This indicates unidimensionality of both Scales. The ICCs for the total scores were .97 (95%C.I. .95-.99) for the Limb Scale and .86 (.73-.93) for the Bulbar Scale, respectively. On the basis of these results, the Scale has unidimensionality and high reliability enough for practical use. PMID:8951891

  16. Recollection can be weak and familiarity can be strong.

    PubMed

    Ingram, Katherine M; Mickes, Laura; Wixted, John T

    2012-03-01

    The remember-know procedure is widely used to investigate recollection and familiarity in recognition memory, but almost all of the results obtained with that procedure can be readily accommodated by a unidimensional model based on signal-detection theory. The unidimensional model holds that remember judgments reflect strong memories (associated with high confidence, high accuracy, and fast reaction times), whereas know judgments reflect weaker memories (associated with lower confidence, lower accuracy, and slower reaction times). Although this is invariably true on average, a new 2-dimensional account (the continuous dual-process model) suggests that remember judgments made with low confidence should be associated with lower old-new accuracy but higher source accuracy than know judgments made with high confidence. We tested this prediction--and found evidence to support it--using a modified remember-know procedure in which participants were first asked to indicate a degree of recollection-based or familiarity-based confidence for each word presented on a recognition test and were then asked to recollect the color (red or blue) and screen location (top or bottom) associated with the word at study. For familiarity-based decisions, old-new accuracy increased with old-new confidence, but source accuracy did not (suggesting that stronger old-new memory was supported by higher degrees of familiarity). For recollection-based decisions, both old-new accuracy and source accuracy increased with old-new confidence (suggesting that stronger old-new memory was supported by higher degrees of recollection). These findings suggest that recollection and familiarity are continuous processes and that participants can indicate which process mainly contributed to their recognition decisions. PMID:21967320

  17. Number Concepts without Number Lines in an Indigenous Group of Papua New Guinea

    PubMed Central

    Núñez, Rafael; Cooperrider, Kensy; Wassmann, Jürg

    2012-01-01

    Background The generic concept of number line, which maps numbers to unidimensional space, is a fundamental concept in mathematics, but its cognitive origins are uncertain. Two defining criteria of the number line are that (i) there is a mapping of each individual number (or numerosity) under consideration onto a specific location on the line, and (ii) that the mapping defines a unidimensional space representing numbers with a metric — a distance function. It has been proposed that the number line is based on a spontaneous universal human intuition, rooted directly in brain evolution, that maps number magnitude to linear space with a metric. To date, no culture lacking this intuition has been documented. Methodology/Principal Findings By means of a number line task, we investigated the universality proposal with the Yupno of Papua New Guinea. Unschooled adults did exhibit a number-to-space mapping (criterion i) but, strikingly, despite having precise cardinal number concepts, they located numbers only on the endpoints, thus failing to use the extent of the line. The produced mapping was bi-categorical and metric-free, in violation of criterion ii. In contrast, Yupnos with scholastic experience used the extent of the segment according to known standards, but they did so not as evenly as western controls, exhibiting a bias towards the endpoints. Conclusions/Significance Results suggest that cardinal number concepts can exist independently from number line representations. They also suggest that the number line mapping, although ubiquitous in the modern world, is not universally spontaneous, but rather seems to be learned through — and continually reinforced by — specific cultural practices. PMID:22558193

  18. Wiener spectrum of radiographic systems: comparison of different evaluation methods.

    PubMed

    Bregant, P; De Denaro, M; De Guarrini, F; Borasi, G

    1997-05-01

    The noise power spectrum, or Wiener spectrum, of the radiographic mottle is a fundamental quantity in film-screen image quality evaluation. In this paper, using a high-quality computerized microdensitometer, two different acquisition and calculation methods for noise evaluation are compared. The first one is the classic (unidimensional) method used in film noise evaluation: a long and narrow slit (10 x 400 microns2) is used to delimit the microdensitometer light beam and the transmission data are collected by scanning the sample in a rectilinear pattern. A section of the two-dimensional Wiener spectrum is thus obtained. The second (two-dimensional) method is similar to that used in digital image noise evaluation: a square slit is used on the microdensitometer window and data are collected by scanning the sample on a square pattern. To evaluate the effect of different sampling frequencies, our data were acquired both selecting a 50 x 50 microns2 square slit and a 20 x 20 microns2 square slit. The two-dimensional Wiener spectrum thus obtained is then reduced to a unidimensional function. The measurements were made on two different films (Kodak Ortho G e Kodak T-MAT G) exposed with the same screen (Kodak Lanex Regular). These films have the same sensitivity but a different emulsion structure. One film (Ortho G) is made of irregular halide silver grains and the other (T-MAT G) of tabular grains. A satisfactory agreement between the two procedures was found which makes the comparison of data from the laboratories using microdensitometers and those using TV-grabbing system for film-screen evaluation meaningful. PMID:9251741

  19. 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

  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. Asymmetric friction of nonmotor MAPs can lead to their directional motion in active microtubule networks.

    PubMed

    Forth, Scott; Hsia, Kuo-Chiang; Shimamoto, Yuta; Kapoor, Tarun M

    2014-04-10

    Diverse cellular processes require microtubules to be organized into distinct structures, such as asters or bundles. Within these dynamic motifs, microtubule-associated proteins (MAPs) are frequently under load, but how force modulates these proteins' function is poorly understood. Here, we combine optical trapping with TIRF-based microscopy to measure the force dependence of microtubule interaction for three nonmotor MAPs (NuMA, PRC1, and EB1) required for cell division. We find that frictional forces increase nonlinearly with MAP velocity across microtubules and depend on filament polarity, with NuMA's friction being lower when moving toward minus ends, EB1's lower toward plus ends, and PRC1's exhibiting no directional preference. Mathematical models predict, and experiments confirm, that MAPs with asymmetric friction can move directionally within actively moving microtubule pairs they crosslink. Our findings reveal how nonmotor MAPs can generate frictional resistance in dynamic cytoskeletal networks via micromechanical adaptations whose anisotropy may be optimized for MAP localization and function within cellular structures. PMID:24725408

  3. 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

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

    PubMed

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

    2013-05-01

    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

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 'Two cultures' turns 50

    NASA Astrophysics Data System (ADS)

    Crease, Robert P.

    2009-05-01

    Half a century ago this month, the physicist and author Charles Percy Snow (1905-1980) delivered the annual Rede Lecture in the Senate House of the University of Cambridge. (Usually referred to as C P Snow, he was later made a life peer and enjoyed appearing in the House of Lords as Baron Snow, despite being a self-professed socialist.) Its title - "The Two Cultures" - referred to a gulf Snow diagnosed between "literary intellectuals" and "natural scientists", and it elaborated themes he had mentioned in the New Statesman three years earlier. The talk was published in Encounter in June and July 1959, and then as a book.

  10. 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

  11. The German version of the Individualized Care Scale – assessing validity and reliability

    PubMed Central

    Köberich, Stefan; Suhonen, Riitta; Feuchtinger, Johanna; Farin, Erik

    2015-01-01

    Aim To assess validity and reliability of the German version of the Individualized Care Scale (ICS). Background Individualized nursing care plays a pivotal role in establishing patient-centered care. To assess individualized nursing care and to compare it in different settings and countries, valid and reliable instruments are needed. No psychometric-tested instrument for comparing individualized nursing care with other countries is available in Germany. Design Cross-sectional study. Methods Data were collected between September 2013 and June 2014 from 606 patients in 20 wards in five hospitals across Germany. Unidimensionality of the ICS scales ICSA (patients’ views on how individuality is supported through nursing interventions) and ICSB (patients’ perceptions of individualized nursing care) was analyzed by confirmatory factor analysis. Internal consistency was assessed by calculating Cronbach’s alpha. The Smoliner Scale (patients’ perceptions of the decision-making process in nursing care) and results from participating hospitals’ assessment of the nursing care delivery systems were used to assess known-groups validity and concurrent validity. Results Fit indices of confirmatory factor analysis indicate unidimensionality of the ICSA (Comparative Fit Index: 0.92; Tucker-Lewis Index: 0.902; root mean square error of approximation: 0.09; standardized root mean square residual: 0.05) and the ICSB (Comparative Fit Index: 0.91; Tucker-Lewis Index: 0.89; root mean square error of approximation: 0.09; standardized root mean square residual: 0.05). Internal consistency using Cronbach’s alpha was 0.95 (95% confidence interval: 0.94–0.95) for ICSA and 0.93 (95% confidence interval: 0.92–0.94) for the ICSB. Concurrent validity was established by a significant relationship between the Smoliner Scale and ICSA (r=0.66; P<0.01) and ICSB (r=0.72; P<0.01). Known-groups validity was approved by ICSA/ICSB score differences related to nursing care delivery systems and

  12. 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

  13. 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

  14. Precision intrauterine contraception may significantly increase continuation of use: a review of long-term clinical experience with frameless copper-releasing intrauterine contraception devices

    PubMed Central

    Wildemeersch, Dirk; Pett, Ansgar; Jandi, Sohela; Hasskamp, Thomas; Rowe, Patrick; Vrijens, Marc

    2013-01-01

    Objective The purpose of this paper is to review the experience with the frameless, anchored, GyneFix copper-releasing intrauterine contraceptive devices (IUCDs/IUDs) (Contrel Europe, Belgium), and to demonstrate their high acceptability and low rate of discontinuation of use, which could contribute to current efforts that aim to reduce radically the high number of unintended pregnancies and induced abortions, particularly in young women. Materials and methods This paper is based on studies that examined the differences in uterine volume and cavity size, related to age and parity, and on original clinical research data and practical experience with frameless copper IUDs, as well as on literature data on the IUD–endometrial cavity relationship of conventional IUDs, with special reference to side effects and user discontinuation. Results The mean transverse diameter in nulliparous and parous women is significantly less than the length of the transverse arm of the TCu380A IUD (ParaGard, Duramed, NY, USA) or the levonorgestrel intrauterine system (Mirena, Bayer, Germany). Small, frameless, flexible, and unidimensional copper IUDs appear to be well tolerated, with less impact on menstrual bleeding, resulting in low discontinuation rates when compared with standard-size conventional IUDs, which often result in increased expulsion rates, complaints of pain and erratic or increased menstrual bleeding, and subsequent high rates of discontinuation, particularly in young women. Conclusion The unidimensional GyneFix IUDs fit the majority of uterine cavities. An IUD that fits is likely to result in increased tolerance and continued use of the method. As this would appeal to women, the logical result should be greater use of the method and fewer unintended pregnancies and induced abortions. Recommending the standard TCu380A (ParaGard) IUD or the Mirena levonorgestrel intrauterine system, primarily developed for use in parous women, for general use in nulliparous and adolescent

  15. 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

  16. 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

  17. Mokken scale analysis of mental health and well-being questionnaire item responses: a non-parametric IRT method in empirical research for applied health researchers

    PubMed Central

    2012-01-01

    Background Mokken scaling techniques are a useful tool for researchers who wish to construct unidimensional tests or use questionnaires that comprise multiple binary or polytomous items. The stochastic cumulative scaling model offered by this approach is ideally suited when the intention is to score an underlying latent trait by simple addition of the item response values. In our experience, the Mokken model appears to be less well-known than for example the (related) Rasch model, but is seeing increasing use in contemporary clinical research and public health. Mokken's method is a generalisation of Guttman scaling that can assist in the determination of the dimensionality of tests or scales, and enables consideration of reliability, without reliance on Cronbach's alpha. This paper provides a practical guide to the application and interpretation of this non-parametric item response theory method in empirical research with health and well-being questionnaires. Methods Scalability of data from 1) a cross-sectional health survey (the Scottish Health Education Population Survey) and 2) a general population birth cohort study (the National Child Development Study) illustrate the method and modeling steps for dichotomous and polytomous items respectively. The questionnaire data analyzed comprise responses to the 12 item General Health Questionnaire, under the binary recoding recommended for screening applications, and the ordinal/polytomous responses to the Warwick-Edinburgh Mental Well-being Scale. Results and conclusions After an initial analysis example in which we select items by phrasing (six positive versus six negatively worded items) we show that all items from the 12-item General Health Questionnaire (GHQ-12) – when binary scored – were scalable according to the double monotonicity model, in two short scales comprising six items each (Bech’s “well-being” and “distress” clinical scales). An illustration of ordinal item analysis confirmed that all 14

  18. 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

  19. Clomp

    Energy Science and Technology Software Center (ESTSC)

    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

  20. Going vertical: functional role and working principles of the protein Inscuteable in asymmetric cell divisions.

    PubMed

    Culurgioni, Simone; Mapelli, Marina

    2013-11-01

    Coordinating mitotic spindle dynamics with cortical polarity is essential for stem cell asymmetric divisions. Over the years, the protein Inscuteable (Insc) has emerged as a key element determining the spindle orientation in asymmetric mitoses. Its overexpression increases differentiative divisions in systems as diverse as mouse keratinocytes and radial glial cells. To date, the molecular explanation to account for this phenotype envisioned Insc as an adaptor molecule bridging between the polarity proteins Par3:Par6:aPKC and the spindle pulling machines assembled on NuMA:LGN:Gαi. However, recent biochemical and structural data revealed that Insc and NuMA are competitive interactors of LGN, challenging the simplistic idea of a single apical macromolecular complex, and demanding a revision of the actual working principles of Insc. PMID:23516018

  1. 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.

  2. Human Papillomavirus Type 16 E7 oncoprotein engages but does not abrogate the mitotic spindle assembly checkpoint

    PubMed Central

    Yu, Yueyang; Munger, Karl

    2012-01-01

    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. PMID:22748180

  3. 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.

  4. 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.

  5. 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.

  6. Clomp

    SciTech Connect

    Gylenhaal, J.; Bronevetsky, G.

    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 large 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.

  7. Performance benchmark of LHCb code on state-of-the-art x86 architectures

    NASA Astrophysics Data System (ADS)

    Campora Perez, D. H.; Neufeld, N.; Schwemmer, R.

    2015-12-01

    For Run 2 of the LHC, LHCb is replacing a significant part of its event filter farm with new compute nodes. For the evaluation of the best performing solution, we have developed a method to convert our high level trigger application into a stand-alone, bootable benchmark image. With additional instrumentation we turned it into a self-optimising benchmark which explores techniques such as late forking, NUMA balancing and optimal number of threads, i.e. it automatically optimises box-level performance. We have run this procedure on a wide range of Haswell-E CPUs and numerous other architectures from both Intel and AMD, including also the latest Intel micro-blade servers. We present results in terms of performance, power consumption, overheads and relative cost.

  8. 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.

  9. 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

  10. Assessment of Autoantibodies to Meningioma in a Population-based Study

    PubMed Central

    Wiemels, Joseph L.; Bracci, Paige M.; Wrensch, Margaret; Schildkraut, Joellen; Bondy, Melissa; Pfefferle, Jon; Zhou, Mi; Sison, Jennette; Calvocoressi, Lisa; Claus, Elizabeth B.

    2013-01-01

    Meningioma is an intracranial tumor with few confirmed risk factors. Recent research points to an impact on meningioma risk from factors related to immune function and development, such as allergy, immunoglobulin E, and Varicella infection status. To further explore an association with immune function, the authors assessed individual seroreactivity to meningioma tumor-associated antigens among participants enrolled in a multicenter, population-based US case-control study of meningioma (2006–2009). Serum samples from cases (n = 349) and controls (n = 348) were screened for autoantibody reactivity to 3 proteins identified in previous studies: enolase 1 (ENO1), NK-tumor recognition protein (NKTR), and nuclear mitotic apparatus protein 1 (NUMA1). Case-control differences were not strong overall (adjusted odds ratio (OR)ENO1 (continuous) = 1.1, 95% confidence interval (CI): 0.6, 1.9 (Ptrend = 0.3); adjusted ORNKTR (continuous) = 1.3, 95% CI: 0.7, 2.4 (Ptrend = 0.02); and adjusted ORNUMA1 (continuous) = 1.1, 95% CI: 0.7, 1.8 (Ptrend = 0.06)); however, antibodies to NKTR and NUMA1 were detected at higher levels in cases than in controls, particularly among men (for men, adjusted ORENO1 (continuous) = 1.6, 95% CI: 0.5, 4.7 (Ptrend = 0.24); adjusted ORNKTR (continuous) = 4.3, 95% CI: 1.2, 15 (Ptrend = 0.009); and adjusted ORNUMA1 (continuous) = 3.6, 95% CI: 1.1, 11 (Ptrend = 0.006)). These results indicate that men with meningioma commonly react with a serologic antimeningioma response; if supported by further research, this finding suggests a distinctive etiology for meningioma in men. PMID:23221727

  11. Long-Term (Postnatal Day 70) Outcome and Safety of Intratracheal Transplantation of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Neonatal Hyperoxic Lung Injury

    PubMed Central

    Ahn, So Yoon; Chang, Yun Sil; Kim, Soo Yoon; Sung, Dong Kyung; Kim, Eun Sun; Rime, So Yub; Yu, Wook Joon; Choi, Soo Jin; Oh, Won Il

    2013-01-01

    Purpose This study was performed to evaluate the long-term effects and safety of intratracheal (IT) transplantation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in neonatal hyperoxic lung injury at postnatal day (P)70 in a rat model. Materials and Methods Newborn Sprague Dawley rat pups were subjected to 14 days of hyperoxia (90% oxygen) within 10 hours after birth and allowed to recover at room air until sacrificed at P70. In the transplantation groups, hUCB-MSCs (5×105) were administered intratracheally at P5. At P70, various organs including the heart, lung, liver, and spleen were histologically examined, and the harvested lungs were assessed for morphometric analyses of alveolarization. ED-1, von Willebrand factor, and human-specific nuclear mitotic apparatus protein (NuMA) staining in the lungs and the hematologic profile of blood were evaluated. Results Impaired alveolar and vascular growth, which evidenced by an increased mean linear intercept and decreased amount of von Willebrand factor, respectively, and the hyperoxia-induced inflammatory responses, as evidenced by inflammatory foci and ED-1 positive alveolar macrophages, were attenuated in the P70 rat lungs by IT transplantation of hUCB-MSCs. Although rare, donor cells with human specific NuMA staining were persistently present in the P70 rat lungs. There were no gross or microscopic abnormal findings in the heart, liver, or spleen, related to the MSCs transplantation. Conclusion The protective and beneficial effects of IT transplantation of hUCB-MSCs in neonatal hyperoxic lung injuries were sustained for a prolonged recovery period without any long-term adverse effects up to P70. PMID:23364976

  12. 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.

  13. 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

  14. 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

  15. Assessing Psychological Well-Being: Self-Report Instruments for the NIH Toolbox

    PubMed Central

    Salsman, John M.; Lai, Jin-Shei; Hendrie, Hugh C.; Butt, Zeeshan; Zill, Nicholas; Pilkonis, Paul A.; Peterson, Christopher; Stoney, Catherine M.; Brouwers, Pim; Cella, David

    2013-01-01

    Objective Psychological well-being (PWB) has a significant relationship with physical and mental health. As part of the NIH Toolbox for the Assessment of Neurological and Behavioral Function, we developed self-report item banks and short forms to assess PWB. Study Design and Setting Expert feedback and literature review informed the selection of PWB concepts and the development of item pools for Positive Affect, Life Satisfaction, and Meaning and Purpose. Items were tested with a community-dwelling U.S. internet panel sample of adults aged 18 and above (N=552). Classical and item response theory (IRT) approaches were used to evaluate unidimensionality, fit of items to the overall measure, and calibrations of those items, including differential item function (DIF). Results IRT-calibrated item banks were produced for Positive Affect (34 items), Life Satisfaction (16 items), and Meaning and Purpose (18 items). Their psychometric properties were supported based on results of factor analysis, fit statistics, and DIF evaluation. All banks measured the concepts precisely (reliability ≥0.90) for more than 98% of participants. Conclusion These adult scales and item banks for PWB provide the flexibility, efficiency, and precision necessary to promote future epidemiological, observational, and intervention research on the relationship of PWB with physical and mental health. PMID:23771709

  16. In vivo oxygen transport in the normal rabbit femoral arterial wall.

    PubMed Central

    Crawford, D W; Back, L H; Cole, M A

    1980-01-01

    In vivo measurements of tissue oxygen tension were made at 10-micrometer intervals through functioning in situ rabbit femoral arterial walls, using inhalation anesthesia and recessed microcathodes with approximately 4-micrometer external diameters. External environment was controlled with a superfusion well at 30 torr PO2, 35 torr PCO2. Blood pressure, gas tension levels, and blood pH were held within the normal range. Radial PO2 measurements closely fit a mathematical model for unidimensional diffusion into a thick-walled artery with uniform oxygen consumption, and the distances traversed fit measured dimensions of quick-frozen in vivo sections. Using standard values of diffusion and solubility coefficients, mean calculated medial oxygen consumption was 99 nl0/ml-s. Mural oxygen consumption appeared to be related linearly to mean tangential wall stress. Differences in experimental design and technique were compared with previous in vivo and in vitro measurements of wall oxygenation, and largely account for the varying results obtained. Control of environment external to the artery, and maintenance of normally flowing blood in the lumen in vivo appeared critical to an understanding of mural oxygenation in life. If the conditions of this experiment prevailed in arteries with thicker avascular layers, PO2 could have been 20 torr at approximately 156 micrometer and 10 torr at 168 micrometer from blood (average values). Images PMID:7410554

  17. 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

  18. Psychometric Properties of Creative Self-Efficacy Inventory Among Distinguished Students in Saudi Arabian Universities.

    PubMed

    Alotaibi, Khaled N

    2016-06-01

    This study examined the psychometric properties of the Arabic version of Abbott's Creative Self-Efficacy inventory. Saudi honors students (157 men vs. 163 women) participated. These students are undergraduates (M age = 19.5 year, SD = 1.9) who complete 30 credit hours with a grade point average of no less than 4.5 out of 5. The results showed that the internal consistency (α = .87) and the test-retest reliabilities (r = .73) were satisfactory. The study sample was separated into two subsamples. The data from the first subsample (n = 60) were used to conduct an exploratory factor analysis, whereas the data from the second subsample (n = 260) were used to perform a confirmatory factor analysis. The results of exploratory factor analysis and confirmatory factor analysis indicated that creative self-efficacy was not a unidimensional construct but consisted of two factors labeled "creative thinking self-efficacy" and "creative performance self-efficacy." As expected, this two-factor model fit the data adequately, supporting prior research that treated creative self-efficacy as multidimensional construct. PMID:27140651

  19. From the inverted pendulum to the periodic interface modes

    NASA Astrophysics Data System (ADS)

    Combe, Nicolas

    2013-01-01

    The physics of the spatial propagation of monochromatic waves in periodic media is related to the temporal evolution of the parametric oscillators. We transpose the possibility that a parametric pendulum oscillates in the vicinity of its unstable equilibrium position to the case of monochromatic waves in a lossless unidimensional periodic medium. We develop this concept, that can formally applies to any kind of waves, to the case of longitudinal elastic wave. Our analysis yields us to study the propagation of monochromatic waves in a periodic structure involving two main periods. We evidence a class of phonons we refer to as periodic interface modes that propagate in these structures. These modes are similar to the optical Tamm states exhibited in photonic crystals. Our analysis is based on both a formal and an analytical approach. The application of the concept to the case of phonons in an experimentally realizable structure is given. We finally show how to control the frequencies of these phonons from the engineering of the periodic structure.

  20. Transport across the tropical tropopause layer and convection

    NASA Astrophysics Data System (ADS)

    Tissier, Ann-Sophie; Legras, Bernard; Tzella, Alexandra

    2015-04-01

    We investigate how air parcels detrained from convective sources enter the TTL. The approach is based on the comparison of unidimensional trajectories and Lagrangian backward and forward trajectories, using TRACZILLA and ERA-Interim. Backward trajectories are launched at 380K and run until they hit a deep convective cloud. Forward trajectories are launched at the top of high convective clouds identified by brightness temperature from CLAUS dataset. 1D trajectories are computed using Gardiner's method. Results show that the warm pool region during winter and the Bay of Bengal / Sea of China during summer are the prevalent sources as already identified in many previous studies and we quantify the respective role of the various regions. We show that the 1D model explains qualitatively and often quantitatively the 3d results. We also show that in spite of generating very high convection, Africa is quite ineffective as providing air that remains in the TTL while on the opposite the Tibetan Plateau is the most effective region in this respect although its total contribution is minor. Finally, we compare ERA-Interim, JRA-55 and MERRA reanalysis and find large similarities between the two formers.