WorldWideScience

Sample records for all-atom structure validation

  1. MolProbity: More and better reference data for improved all-atom structure validation.

    Science.gov (United States)

    Williams, Christopher J; Headd, Jeffrey J; Moriarty, Nigel W; Prisant, Michael G; Videau, Lizbeth L; Deis, Lindsay N; Verma, Vishal; Keedy, Daniel A; Hintze, Bradley J; Chen, Vincent B; Jain, Swati; Lewis, Steven M; Arendall, W Bryan; Snoeyink, Jack; Adams, Paul D; Lovell, Simon C; Richardson, Jane S; Richardson, David C

    2018-01-01

    This paper describes the current update on macromolecular model validation services that are provided at the MolProbity website, emphasizing changes and additions since the previous review in 2010. There have been many infrastructure improvements, including rewrite of previous Java utilities to now use existing or newly written Python utilities in the open-source CCTBX portion of the Phenix software system. This improves long-term maintainability and enhances the thorough integration of MolProbity-style validation within Phenix. There is now a complete MolProbity mirror site at http://molprobity.manchester.ac.uk. GitHub serves our open-source code, reference datasets, and the resulting multi-dimensional distributions that define most validation criteria. Coordinate output after Asn/Gln/His "flip" correction is now more idealized, since the post-refinement step has apparently often been skipped in the past. Two distinct sets of heavy-atom-to-hydrogen distances and accompanying van der Waals radii have been researched and improved in accuracy, one for the electron-cloud-center positions suitable for X-ray crystallography and one for nuclear positions. New validations include messages at input about problem-causing format irregularities, updates of Ramachandran and rotamer criteria from the million quality-filtered residues in a new reference dataset, the CaBLAM Cα-CO virtual-angle analysis of backbone and secondary structure for cryoEM or low-resolution X-ray, and flagging of the very rare cis-nonProline and twisted peptides which have recently been greatly overused. Due to wide application of MolProbity validation and corrections by the research community, in Phenix, and at the worldwide Protein Data Bank, newly deposited structures have continued to improve greatly as measured by MolProbity's unique all-atom clashscore. © 2017 The Protein Society.

  2. MolProbity: all-atom structure validation for macromolecular crystallography

    International Nuclear Information System (INIS)

    Chen, Vincent B.; Arendall, W. Bryan III; Headd, Jeffrey J.; Keedy, Daniel A.; Immormino, Robert M.; Kapral, Gary J.; Murray, Laura W.; Richardson, Jane S.; Richardson, David C.

    2010-01-01

    MolProbity structure validation will diagnose most local errors in macromolecular crystal structures and help to guide their correction. MolProbity is a structure-validation web service that provides broad-spectrum solidly based evaluation of model quality at both the global and local levels for both proteins and nucleic acids. It relies heavily on the power and sensitivity provided by optimized hydrogen placement and all-atom contact analysis, complemented by updated versions of covalent-geometry and torsion-angle criteria. Some of the local corrections can be performed automatically in MolProbity and all of the diagnostics are presented in chart and graphical forms that help guide manual rebuilding. X-ray crystallography provides a wealth of biologically important molecular data in the form of atomic three-dimensional structures of proteins, nucleic acids and increasingly large complexes in multiple forms and states. Advances in automation, in everything from crystallization to data collection to phasing to model building to refinement, have made solving a structure using crystallography easier than ever. However, despite these improvements, local errors that can affect biological interpretation are widespread at low resolution and even high-resolution structures nearly all contain at least a few local errors such as Ramachandran outliers, flipped branched protein side chains and incorrect sugar puckers. It is critical both for the crystallographer and for the end user that there are easy and reliable methods to diagnose and correct these sorts of errors in structures. MolProbity is the authors’ contribution to helping solve this problem and this article reviews its general capabilities, reports on recent enhancements and usage, and presents evidence that the resulting improvements are now beneficially affecting the global database

  3. An All-Atom Force Field for Tertiary Structure Prediction of Helical Proteins

    Science.gov (United States)

    Herges, T.; Wenzel, W.

    2004-01-01

    We have developed an all-atom free-energy force field (PFF01) for protein tertiary structure prediction. PFF01 is based on physical interactions and was parameterized using experimental structures of a family of proteins believed to span a wide variety of possible folds. It contains empirical, although sequence-independent terms for hydrogen bonding. Its solvent-accessible surface area solvent model was first fit to transfer energies of small peptides. The parameters of the solvent model were then further optimized to stabilize the native structure of a single protein, the autonomously folding villin headpiece, against competing low-energy decoys. Here we validate the force field for five nonhomologous helical proteins with 20–60 amino acids. For each protein, decoys with 2–3 Å backbone root mean-square deviation and correct experimental Cβ–Cβ distance constraints emerge as those with the lowest energy. PMID:15507688

  4. Protein structure prediction by all-atom free-energy refinement

    Science.gov (United States)

    Verma, Abhinav; Wenzel, Wolfgang

    2007-01-01

    Background The reliable prediction of protein tertiary structure from the amino acid sequence remains challenging even for small proteins. We have developed an all-atom free-energy protein forcefield (PFF01) that we could use to fold several small proteins from completely extended conformations. Because the computational cost of de-novo folding studies rises steeply with system size, this approach is unsuitable for structure prediction purposes. We therefore investigate here a low-cost free-energy relaxation protocol for protein structure prediction that combines heuristic methods for model generation with all-atom free-energy relaxation in PFF01. Results We use PFF01 to rank and cluster the conformations for 32 proteins generated by ROSETTA. For 22/10 high-quality/low quality decoy sets we select near-native conformations with an average Cα root mean square deviation of 3.03 Å/6.04 Å. The protocol incorporates an inherent reliability indicator that succeeds for 78% of the decoy sets. In over 90% of these cases near-native conformations are selected from the decoy set. This success rate is rationalized by the quality of the decoys and the selectivity of the PFF01 forcefield, which ranks near-native conformations an average 3.06 standard deviations below that of the relaxed decoys (Z-score). Conclusion All-atom free-energy relaxation with PFF01 emerges as a powerful low-cost approach toward generic de-novo protein structure prediction. The approach can be applied to large all-atom decoy sets of any origin and requires no preexisting structural information to identify the native conformation. The study provides evidence that a large class of proteins may be foldable by PFF01. PMID:17371594

  5. A real-time all-atom structural search engine for proteins.

    Science.gov (United States)

    Gonzalez, Gabriel; Hannigan, Brett; DeGrado, William F

    2014-07-01

    Protein designers use a wide variety of software tools for de novo design, yet their repertoire still lacks a fast and interactive all-atom search engine. To solve this, we have built the Suns program: a real-time, atomic search engine integrated into the PyMOL molecular visualization system. Users build atomic-level structural search queries within PyMOL and receive a stream of search results aligned to their query within a few seconds. This instant feedback cycle enables a new "designability"-inspired approach to protein design where the designer searches for and interactively incorporates native-like fragments from proven protein structures. We demonstrate the use of Suns to interactively build protein motifs, tertiary interactions, and to identify scaffolds compatible with hot-spot residues. The official web site and installer are located at http://www.degradolab.org/suns/ and the source code is hosted at https://github.com/godotgildor/Suns (PyMOL plugin, BSD license), https://github.com/Gabriel439/suns-cmd (command line client, BSD license), and https://github.com/Gabriel439/suns-search (search engine server, GPLv2 license).

  6. NOMAD-Ref: visualization, deformation and refinement of macromolecular structures based on all-atom normal mode analysis.

    Science.gov (United States)

    Lindahl, Erik; Azuara, Cyril; Koehl, Patrice; Delarue, Marc

    2006-07-01

    Normal mode analysis (NMA) is an efficient way to study collective motions in biomolecules that bypasses the computational costs and many limitations associated with full dynamics simulations. The NOMAD-Ref web server presented here provides tools for online calculation of the normal modes of large molecules (up to 100,000 atoms) maintaining a full all-atom representation of their structures, as well as access to a number of programs that utilize these collective motions for deformation and refinement of biomolecular structures. Applications include the generation of sets of decoys with correct stereochemistry but arbitrary large amplitude movements, the quantification of the overlap between alternative conformations of a molecule, refinement of structures against experimental data, such as X-ray diffraction structure factors or Cryo-EM maps and optimization of docked complexes by modeling receptor/ligand flexibility through normal mode motions. The server can be accessed at the URL http://lorentz.immstr.pasteur.fr/nomad-ref.php.

  7. All-Atom Four-Body Knowledge-Based Statistical Potentials to Distinguish Native Protein Structures from Nonnative Folds

    Directory of Open Access Journals (Sweden)

    Majid Masso

    2017-01-01

    Full Text Available Recent advances in understanding protein folding have benefitted from coarse-grained representations of protein structures. Empirical energy functions derived from these techniques occasionally succeed in distinguishing native structures from their corresponding ensembles of nonnative folds or decoys which display varying degrees of structural dissimilarity to the native proteins. Here we utilized atomic coordinates of single protein chains, comprising a large diverse training set, to develop and evaluate twelve all-atom four-body statistical potentials obtained by exploring alternative values for a pair of inherent parameters. Delaunay tessellation was performed on the atomic coordinates of each protein to objectively identify all quadruplets of interacting atoms, and atomic potentials were generated via statistical analysis of the data and implementation of the inverted Boltzmann principle. Our potentials were evaluated using benchmarking datasets from Decoys-‘R’-Us, and comparisons were made with twelve other physics- and knowledge-based potentials. Ranking 3rd, our best potential tied CHARMM19 and surpassed AMBER force field potentials. We illustrate how a generalized version of our potential can be used to empirically calculate binding energies for target-ligand complexes, using HIV-1 protease-inhibitor complexes for a practical application. The combined results suggest an accurate and efficient atomic four-body statistical potential for protein structure prediction and assessment.

  8. Reconciling structural and thermodynamic predictions using all-atom and coarse-grain force fields: the case of charged oligo-arginine translocation into DMPC bilayers.

    Science.gov (United States)

    Hu, Yuan; Sinha, Sudipta Kumar; Patel, Sandeep

    2014-10-16

    Using the translocation of short, charged cationic oligo-arginine peptides (mono-, di-, and triarginine) from bulk aqueous solution into model DMPC bilayers, we explore the question of the similarity of thermodynamic and structural predictions obtained from molecular dynamics simulations using all-atom and Martini coarse-grain force fields. Specifically, we estimate potentials of mean force associated with translocation using standard all-atom (CHARMM36 lipid) and polarizable and nonpolarizable Martini force fields, as well as a series of modified Martini-based parameter sets. We find that we are able to reproduce qualitative features of potentials of mean force of single amino acid side chain analogues into model bilayers. In particular, modifications of peptide-water and peptide-membrane interactions allow prediction of free energy minima at the bilayer-water interface as obtained with all-atom force fields. In the case of oligo-arginine peptides, the modified parameter sets predict interfacial free energy minima as well as free energy barriers in almost quantitative agreement with all-atom force field based simulations. Interfacial free energy minima predicted by a modified coarse-grained parameter set are -2.51, -4.28, and -5.42 for mono-, di-, and triarginine; corresponding values from all-atom simulations are -0.83, -3.33, and -3.29, respectively, all in units of kcal/mol. We found that a stronger interaction between oligo-arginine and the membrane components and a weaker interaction between oligo-arginine and water are crucial for producing such minima in PMFs using the polarizable CG model. The difference between bulk aqueous and bilayer center states predicted by the modified coarse-grain force field are 11.71, 14.14, and 16.53 kcal/mol, and those by the all-atom model are 6.94, 8.64, and 12.80 kcal/mol; those are of almost the same order of magnitude. Our simulations also demonstrate a remarkable similarity in the structural aspects of the ensemble of

  9. All-Atom Multiscale Molecular Dynamics Theory and Simulation of Self-Assembly, Energy Transfer and Structural Transition in Nanosystems

    Science.gov (United States)

    Espinosa Duran, John Michael

    The study of nanosystems and their emergent properties requires the development of multiscale computational models, theories and methods that preserve atomic and femtosecond resolution, to reveal details that cannot be resolved experimentally today. Considering this, three long time scale phenomena were studied using molecular dynamics and multiscale methods: self-assembly of organic molecules on graphite, energy transfer in nanosystems, and structural transition in vault nanoparticles. Molecular dynamics simulations of the self-assembly of alkoxybenzonitriles with different tail lengths on graphite were performed to learn about intermolecular interactions and phases exhibited by self-organized materials. This is important for the design of ordered self-assembled organic photovoltaic materials with greater efficiency than the disordered blends. Simulations revealed surface dynamical behaviors that cannot be resolved experimentally today due to the lack of spatiotemporal resolution. Atom-resolved structures predicted by simulations agreed with scanning tunneling microscopy images and unit cell measurements. Then, a multiscale theory based on the energy density as a field variable is developed to study energy transfer in nanoscale systems. For applications like photothermal microscopy or cancer phototherapy is required to understand how the energy is transferred to/from nanosystems. This multiscale theory could be applied in this context and here is tested for cubic nanoparticles immersed in water for energy being transferred to/from the nanoparticle. The theory predicts the energy transfer dynamics and reveals phenomena that cannot be described by current phenomenological theories. Finally, temperature-triggered structural transitions were revealed for vault nanoparticles using molecular dynamics and multiscale simulations. Vault is a football-shaped supramolecular assembly very distinct from the commonly observed icosahedral viruses. It has very promising

  10. Structural Dynamics of Carbon Dots in Water and N, N-Dimethylformamide Probed by All-Atom Molecular Dynamics Simulations.

    Science.gov (United States)

    Paloncýová, Markéta; Langer, Michal; Otyepka, Michal

    2018-03-09

    Carbon dots (CDs), one of the youngest members of the carbon nanostructure family, are now widely experimentally studied for their tunable fluorescence properties, bleaching resistance, and biocompatibility. Their interaction with biomolecular systems has also been explored experimentally. However, many atomistic details still remain unresolved. Molecular dynamics (MD) simulations enabling atomistic and femtosecond resolutions simultaneously are a well-established tool of computational chemistry which can provide useful insights into investigated systems. Here we present a full procedure for performing MD simulations of CDs. We developed a builder for generating CDs of a desired size and with various oxygen-containing surface functional groups. Further, we analyzed the behavior of various CDs differing in size, surface functional groups, and degrees of functionalization by MD simulations. These simulations showed that surface functionalized CDs are stable in a water environment through the formation of an extensive hydrogen bonding network. We also analyzed the internal dynamics of individual layers of CDs and evaluated the role of surface functional groups on CD stability. We observed that carboxyl groups interconnected the neighboring layers and decreased the rate of internal rotations. Further, we monitored changes in the CD shape caused by an excess of charged carboxyl groups or carbonyl groups. In addition to simulations in water, we analyzed the behavior of CDs in the organic solvent DMF, which decreased the stability of pure CDs but increased the level of interlayer hydrogen bonding. We believe that the developed protocol, builder, and parameters will facilitate future studies addressing various aspects of structural features of CDs and nanocomposites containing CDs.

  11. An all-atom model of the chromatin fiber containing linker histones reveals a versatile structure tuned by the nucleosomal repeat length.

    Directory of Open Access Journals (Sweden)

    Hua Wong

    Full Text Available In the nucleus of eukaryotic cells, histone proteins organize the linear genome into a functional and hierarchical architecture. In this paper, we use the crystal structures of the nucleosome core particle, B-DNA and the globular domain of H5 linker histone to build the first all-atom model of compact chromatin fibers. In this 3D jigsaw puzzle, DNA bending is achieved by solving an inverse kinematics problem. Our model is based on recent electron microscopy measurements of reconstituted fiber dimensions. Strikingly, we find that the chromatin fiber containing linker histones is a polymorphic structure. We show that different fiber conformations are obtained by tuning the linker histone orientation at the nucleosomes entry/exit according to the nucleosomal repeat length. We propose that the observed in vivo quantization of nucleosomal repeat length could reflect nature's ability to use the DNA molecule's helical geometry in order to give chromatin versatile topological and mechanical properties.

  12. Structural Interpretation of the Large Slowdown of Water Dynamics at Stacked Phospholipid Membranes for Decreasing Hydration Level: All-Atom Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Carles Calero

    2016-04-01

    Full Text Available Hydration water determines the stability and function of phospholipid membranes as well as the interaction of membranes with other molecules. Experiments and simulations have shown that water dynamics slows down dramatically as the hydration decreases, suggesting that the interfacial water that dominates the average dynamics at low hydration is slower than water away from the membrane. Here, based on all-atom molecular dynamics simulations, we provide an interpretation of the slowdown of interfacial water in terms of the structure and dynamics of water–water and water–lipid hydrogen bonds (HBs. We calculate the rotational and translational slowdown of the dynamics of water confined in stacked phospholipid membranes at different levels of hydration, from completely hydrated to poorly hydrated membranes. For all hydrations, we analyze the distribution of HBs and find that water–lipids HBs last longer than water–water HBs and that at low hydration most of the water is in the interior of the membrane. We also show that water–water HBs become more persistent as the hydration is lowered. We attribute this effect (i to HBs between water molecules that form, in turn, persistent HBs with lipids; (ii to the hindering of the H-bonding switching between water molecules due to the lower water density at the interface; and (iii to the higher probability of water–lipid HBs as the hydration decreases. Our interpretation of the large dynamic slowdown in water under dehydration is potentially relevant in understanding membrane biophysics at different hydration levels.

  13. Development and application of a free energy force field for all atom protein folding

    International Nuclear Information System (INIS)

    Verma, A.

    2007-11-01

    Proteins are the workhorses of all cellular life. They constitute the building blocks and the machinery of all cells and typically function in specific three-dimensional conformations into which each protein folds. Currently over one million protein sequences are known, compared to about 40,000 structures deposited in the Protein Data Bank (the world-wide database of protein structures). Reliable theoretical methods for protein structure prediction could help to reduce the gap between sequence and structural databases and elucidate the biological information in structurally unresolved sequences. In this thesis we explore an approach for protein structure prediction and folding that is based on the Anfinsen's hypothesis that most proteins in their native state are in thermodynamic equilibrium with their environment. We have developed a free energy forcefield (PFF02) that locates the native conformation of many proteins from all structural classes at the global minimum of the free-energy model. We have validated the forcefield against a large decoy set (Rosetta). The average root mean square deviation (RMSD) for the lowest energy structure for the 32 proteins of the decoy set was only 2.14 Aa from the experimental conformation. We have successfully implemented and used stochastic optimization methods, such as the basin hopping technique and evolutionary algorithms for all atom protein structure prediction. The evolutionary algorithm performs exceptionally well on large supercomputational architectures, such as BlueGene and MareNostrum. Using the PFF02 forcefield, we were able to fold 13 proteins (12-56 amino acids), which include helix, sheet and mixed secondary structure. On average the predicted structure of these proteins deviated from their experimental conformation by only 2.89 Aa RMSD. (orig.)

  14. Folding of proteins with an all-atom Go-model.

    Science.gov (United States)

    Wu, L; Zhang, J; Qin, M; Liu, F; Wang, W

    2008-06-21

    The Go-like potential at a residual level has been successfully applied to the folding of proteins in many previous works. However, taking into consideration more detailed structural information in the atomic level, the definition of contacts used in these traditional Go-models may not be suitable for all-atom simulations. Here, in this work, we develop a rational definition of contacts considering the screening effect in the crowded intramolecular environment. In such a scheme, a large amount of screened atom pairs are excluded and the number of contacts is decreased compared to the case of the traditional definition. These contacts defined by such a new definition are compatible with the all-atom representation of protein structures. To verify the rationality of the new definition of contacts, the folding of proteins CI2 and SH3 is simulated by all-atom molecular dynamics simulations. A high folding cooperativity and good correlation of the simulated Phi-values with those obtained experimentally, especially for CI2, are found. This suggests that the all-atom Go-model is improved compared to the traditional Go-model. Based on the comparison of the Phi-values, the roles of side chains in the folding are discussed, and it is concluded that the side-chain structures are more important for local contacts in determining the transition state structures. Moreover, the relations between side chain and backbone orderings are also discussed.

  15. Structure validation in chemical crystallography

    Science.gov (United States)

    Spek, Anthony L.

    2009-01-01

    Automated structure validation was introduced in chemical crystallography about 12 years ago as a tool to assist practitioners with the exponential growth in crystal structure analyses. Validation has since evolved into an easy-to-use checkCIF/PLATON web-based IUCr service. The result of a crystal structure determination has to be supplied as a CIF-formatted computer-readable file. The checking software tests the data in the CIF for completeness, quality and consistency. In addition, the reported structure is checked for incomplete analysis, errors in the analysis and relevant issues to be verified. A validation report is generated in the form of a list of ALERTS on the issues to be corrected, checked or commented on. Structure validation has largely eliminated obvious problems with structure reports published in IUCr journals, such as refinement in a space group of too low symmetry. This paper reports on the current status of structure validation and possible future extensions. PMID:19171970

  16. Beyond Modeling: All-Atom Olfactory Receptor Model Simulations

    Directory of Open Access Journals (Sweden)

    Peter C Lai

    2012-05-01

    Full Text Available Olfactory receptors (ORs are a type of GTP-binding protein-coupled receptor (GPCR. These receptors are responsible for mediating the sense of smell through their interaction with odor ligands. OR-odorant interactions marks the first step in the process that leads to olfaction. Computational studies on model OR structures can validate experimental functional studies as well as generate focused and novel hypotheses for further bench investigation by providing a view of these interactions at the molecular level. Here we have shown the specific advantages of simulating the dynamic environment that is associated with OR-odorant interactions. We present a rigorous methodology that ranges from the creation of a computationally-derived model of an olfactory receptor to simulating the interactions between an OR and an odorant molecule. Given the ubiquitous occurrence of GPCRs in the membranes of cells, we anticipate that our OR-developed methodology will serve as a model for the computational structural biology of all GPCRs.

  17. Resolution-Adapted All-Atomic and Coarse-Grained Model for Biomolecular Simulations.

    Science.gov (United States)

    Shen, Lin; Hu, Hao

    2014-06-10

    We develop here an adaptive multiresolution method for the simulation of complex heterogeneous systems such as the protein molecules. The target molecular system is described with the atomistic structure while maintaining concurrently a mapping to the coarse-grained models. The theoretical model, or force field, used to describe the interactions between two sites is automatically adjusted in the simulation processes according to the interaction distance/strength. Therefore, all-atomic, coarse-grained, or mixed all-atomic and coarse-grained models would be used together to describe the interactions between a group of atoms and its surroundings. Because the choice of theory is made on the force field level while the sampling is always carried out in the atomic space, the new adaptive method preserves naturally the atomic structure and thermodynamic properties of the entire system throughout the simulation processes. The new method will be very useful in many biomolecular simulations where atomistic details are critically needed.

  18. Structural system identification: Structural dynamics model validation

    Energy Technology Data Exchange (ETDEWEB)

    Red-Horse, J.R.

    1997-04-01

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  19. Simulating the mechanism of antimicrobial lipopeptides with all-atom molecular dynamics.

    Science.gov (United States)

    Horn, Joshua N; Romo, Tod D; Grossfield, Alan

    2013-08-20

    The emergence of antibiotic resistant pathogens is one of the major medical concerns of the 21st century, prompting renewed interest in the development of novel antimicrobial compounds. Here we use microsecond-scale all-atom molecular dynamics simulations to characterize the structure, dynamics, and membrane-binding mechanism of a synthetic antimicrobial lipopeptide, C16-KGGK. Our simulations suggest that these lipopeptides prefer to aggregate in solution and alter the intrinsic order of the lipid bilayer upon binding. From these results and previous coarse-grained simulations, we have developed a simple model for the binding and insertion process for these lipopeptides.

  20. All-atom molecular dynamics simulation of a photosystem i/detergent complex.

    Science.gov (United States)

    Harris, Bradley J; Cheng, Xiaolin; Frymier, Paul

    2014-10-09

    All-atom molecular dynamics (MD) simulation was used to investigate the solution structure and dynamics of the photosynthetic pigment-protein complex photosystem I (PSI) from Thermosynechococcus elongatus embedded in a toroidal belt of n-dodecyl-β-d-maltoside (DDM) detergent. Evaluation of root-mean-square deviations (RMSDs) relative to the known crystal structure show that the protein complex surrounded by DDM molecules is stable during the 200 ns simulation time, and root-mean-square fluctuation (RMSF) analysis indicates that regions of high local mobility correspond to solvent-exposed regions such as turns in the transmembrane α-helices and flexible loops on the stromal and lumenal faces. Comparing the protein-detergent complex to a pure detergent micelle, the detergent surrounding the PSI trimer is found to be less densely packed but with more ordered detergent tails, contrary to what is seen in most lipid bilayer models. We also investigated any functional implications for the observed conformational dynamics and protein-detergent interactions, discovering interesting structural changes in the psaL subunits associated with maintaining the trimeric structure of the protein. Importantly, we find that the docking of soluble electron mediators such as cytochrome c6 and ferredoxin to PSI is not significantly impacted by the solubilization of PSI in detergent.

  1. Multiscale approach for the construction of equilibrated all-atom models of a poly(ethylene glycol)-based hydrogel.

    Science.gov (United States)

    Li, Xianfeng; Murthy, N Sanjeeva; Becker, Matthew L; Latour, Robert A

    2016-06-24

    A multiscale modeling approach is presented for the efficient construction of an equilibrated all-atom model of a cross-linked poly(ethylene glycol) (PEG)-based hydrogel using the all-atom polymer consistent force field (PCFF). The final equilibrated all-atom model was built with a systematic simulation toolset consisting of three consecutive parts: (1) building a global cross-linked PEG-chain network at experimentally determined cross-link density using an on-lattice Monte Carlo method based on the bond fluctuation model, (2) recovering the local molecular structure of the network by transitioning from the lattice model to an off-lattice coarse-grained (CG) model parameterized from PCFF, followed by equilibration using high performance molecular dynamics methods, and (3) recovering the atomistic structure of the network by reverse mapping from the equilibrated CG structure, hydrating the structure with explicitly represented water, followed by final equilibration using PCFF parameterization. The developed three-stage modeling approach has application to a wide range of other complex macromolecular hydrogel systems, including the integration of peptide, protein, and/or drug molecules as side-chains within the hydrogel network for the incorporation of bioactivity for tissue engineering, regenerative medicine, and drug delivery applications.

  2. Multiscale approach for the construction of equilibrated all-atom models of a poly(ethylene glycol)-based hydrogel

    Science.gov (United States)

    Li, Xianfeng; Murthy, N. Sanjeeva; Becker, Matthew L.; Latour, Robert A.

    2016-01-01

    A multiscale modeling approach is presented for the efficient construction of an equilibrated all-atom model of a cross-linked poly(ethylene glycol) (PEG)-based hydrogel using the all-atom polymer consistent force field (PCFF). The final equilibrated all-atom model was built with a systematic simulation toolset consisting of three consecutive parts: (1) building a global cross-linked PEG-chain network at experimentally determined cross-link density using an on-lattice Monte Carlo method based on the bond fluctuation model, (2) recovering the local molecular structure of the network by transitioning from the lattice model to an off-lattice coarse-grained (CG) model parameterized from PCFF, followed by equilibration using high performance molecular dynamics methods, and (3) recovering the atomistic structure of the network by reverse mapping from the equilibrated CG structure, hydrating the structure with explicitly represented water, followed by final equilibration using PCFF parameterization. The developed three-stage modeling approach has application to a wide range of other complex macromolecular hydrogel systems, including the integration of peptide, protein, and/or drug molecules as side-chains within the hydrogel network for the incorporation of bioactivity for tissue engineering, regenerative medicine, and drug delivery applications. PMID:27013229

  3. Refined OPLS all-atom force field for saturated phosphatidylcholine bilayers at full hydration.

    Science.gov (United States)

    Maciejewski, Arkadiusz; Pasenkiewicz-Gierula, Marta; Cramariuc, Oana; Vattulainen, Ilpo; Rog, Tomasz

    2014-05-01

    We report parametrization of dipalmitoyl-phosphatidylcholine (DPPC) in the framework of the Optimized Parameters for Liquid Simulations all-atom (OPLS-AA) force field. We chose DPPC as it is one of the most studied phospholipid species and thus has plenty of experimental data necessary for model validation, and it is also one of the highly important and abundant lipid types, e.g., in lung surfactant. Overall, PCs have not been previously parametrized in the OPLS-AA force field; thus, there is a need to derive its bonding and nonbonding parameters for both the polar and nonpolar parts of the molecule. In the present study, we determined the parameters for torsion angles in the phosphatidylcholine and glycerol moieties and in the acyl chains, as well the partial atomic charges. In these calculations, we used three methods: (1) Hartree-Fock (HF), (2) second order Møller-Plesset perturbation theory (MP2), and (3) density functional theory (DFT). We also tested the effect of the polar environment by using the polarizable continuum model (PCM), and for acyl chains the van der Waals parameters were also adjusted. In effect, six parameter sets were generated and tested on a DPPC bilayer. Out of these six sets, only one was found to be able to satisfactorily reproduce experimental data for the lipid bilayer. The successful DPPC model was obtained from MP2 calculations in an implicit polar environment (PCM).

  4. Bridging between NMA and Elastic Network Models: Preserving All-Atom Accuracy in Coarse-Grained Models.

    Directory of Open Access Journals (Sweden)

    Hyuntae Na

    2015-10-01

    Full Text Available Dynamics can provide deep insights into the functional mechanisms of proteins and protein complexes. For large protein complexes such as GroEL/GroES with more than 8,000 residues, obtaining a fine-grained all-atom description of its normal mode motions can be computationally prohibitive and is often unnecessary. For this reason, coarse-grained models have been used successfully. However, most existing coarse-grained models use extremely simple potentials to represent the interactions within the coarse-grained structures and as a result, the dynamics obtained for the coarse-grained structures may not always be fully realistic. There is a gap between the quality of the dynamics of the coarse-grained structures given by all-atom models and that by coarse-grained models. In this work, we resolve an important question in protein dynamics computations--how can we efficiently construct coarse-grained models whose description of the dynamics of the coarse-grained structures remains as accurate as that given by all-atom models? Our method takes advantage of the sparseness of the Hessian matrix and achieves a high efficiency with a novel iterative matrix projection approach. The result is highly significant since it can provide descriptions of normal mode motions at an all-atom level of accuracy even for the largest biomolecular complexes. The application of our method to GroEL/GroES offers new insights into the mechanism of this biologically important chaperonin, such as that the conformational transitions of this protein complex in its functional cycle are even more strongly connected to the first few lowest frequency modes than with other coarse-grained models.

  5. Structural Validation of the Holistic Wellness Assessment

    Science.gov (United States)

    Brown, Charlene; Applegate, E. Brooks; Yildiz, Mustafa

    2015-01-01

    The Holistic Wellness Assessment (HWA) is a relatively new assessment instrument based on an emergent transdisciplinary model of wellness. This study validated the factor structure identified via exploratory factor analysis (EFA), assessed test-retest reliability, and investigated concurrent validity of the HWA in three separate samples. The…

  6. A-site residues move independently from P-site residues in all-atom molecular dynamics simulations of the 70S bacterial ribosome.

    Directory of Open Access Journals (Sweden)

    Relly Brandman

    Full Text Available The ribosome is a large macromolecular machine, and correlated motion between residues is necessary for coordinating function across multiple protein and RNA chains. We ran two all-atom, explicit solvent molecular dynamics simulations of the bacterial ribosome and calculated correlated motion between residue pairs by using mutual information. Because of the short timescales of our simulation (ns, we expect that dynamics are largely local fluctuations around the crystal structure. We hypothesize that residues that show coupled dynamics are functionally related, even on longer timescales. We validate our model by showing that crystallographic B-factors correlate well with the entropy calculated as part of our mutual information calculations. We reveal that A-site residues move relatively independently from P-site residues, effectively insulating A-site functions from P-site functions during translation.

  7. All-Atom Molecular Dynamics Simulation of Protein Translocation through an α-Hemolysin Nanopore

    KAUST Repository

    Di Marino, Daniele

    2015-08-06

    © 2015 American Chemical Society. Nanopore sensing is attracting the attention of a large and varied scientific community. One of the main issues in nanopore sensing is how to associate the measured current signals to specific features of the molecule under investigation. This is particularly relevant when the translocating molecule is a protein and the pore is sufficiently narrow to necessarily involve unfolding of the translocating protein. Recent experimental results characterized the cotranslocational unfolding of Thioredoxin (Trx) passing through an α-hemolisin pore, providing evidence for the existence of a multistep process. In this study we report the results of all-atom molecular dynamics simulations of the same system. Our data indicate that Trx translocation involves two main barriers. The first one is an unfolding barrier associated with a translocation intermediate where the N-terminal region of Trx is stuck at the pore entrance in a conformation that strongly resembles the native one. After the abrupt unfolding of the N-terminal region, the Trx enters the α-hemolisin vestibule. During this stage, the constriction is occupied not only by the translocating residue but also by a hairpin-like structure forming a tangle in the constriction. The second barrier is associated with the disentangling of this region.

  8. Validation-driven protein-structure improvement

    NARCIS (Netherlands)

    Touw, W.G.

    2016-01-01

    High-quality protein structure models are essential for many Life Science applications, such as protein engineering, molecular dynamics, drug design, and homology modelling. The WHAT_CHECK model validation project and the PDB_REDO model optimisation project have shown that many structure models in

  9. Feature Extraction for Structural Dynamics Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles [Los Alamos National Laboratory; Nishio, Mayuko [Yokohama University; Hemez, Francois [Los Alamos National Laboratory; Stull, Chris [Los Alamos National Laboratory; Park, Gyuhae [Chonnam Univesity; Cornwell, Phil [Rose-Hulman Institute of Technology; Figueiredo, Eloi [Universidade Lusófona; Luscher, D. J. [Los Alamos National Laboratory; Worden, Keith [University of Sheffield

    2016-01-13

    As structural dynamics becomes increasingly non-modal, stochastic and nonlinear, finite element model-updating technology must adopt the broader notions of model validation and uncertainty quantification. For example, particular re-sampling procedures must be implemented to propagate uncertainty through a forward calculation, and non-modal features must be defined to analyze nonlinear data sets. The latter topic is the focus of this report, but first, some more general comments regarding the concept of model validation will be discussed.

  10. Explicit all-atom modeling of realistically sized ligand-capped nanocrystals

    KAUST Repository

    Kaushik, Ananth P.

    2012-01-01

    We present a study of an explicit all-atom representation of nanocrystals of experimentally relevant sizes (up to 6 nm), capped with alkyl chain ligands, in vacuum. We employ all-atom molecular dynamics simulation methods in concert with a well-tested intermolecular potential model, MM3 (molecular mechanics 3), for the studies presented here. These studies include determining the preferred conformation of an isolated single nanocrystal (NC), pairs of isolated NCs, and (presaging studies of superlattice arrays) unit cells of NC superlattices. We observe that very small NCs (3 nm) behave differently in a superlattice as compared to larger NCs (6 nm and above) due to the conformations adopted by the capping ligands on the NC surface. Short ligands adopt a uniform distribution of orientational preferences, including some that lie against the face of the nanocrystal. In contrast, longer ligands prefer to interdigitate. We also study the effect of changing ligand length and ligand coverage on the NCs on the preferred ligand configurations. Since explicit all-atom modeling constrains the maximum system size that can be studied, we discuss issues related to coarse-graining the representation of the ligands, including a comparison of two commonly used coarse-grained models. We find that care has to be exercised in the choice of coarse-grained model. The data provided by these realistically sized ligand-capped NCs, determined using explicit all-atom models, should serve as a reference standard for future models of coarse-graining ligands using united atom models, especially for self-assembly processes. © 2012 American Institute of Physics.

  11. Accelerating all-atom MD simulations of lipids using a modified virtual-sites technique

    DEFF Research Database (Denmark)

    Loubet, Bastien; Kopec, Wojciech; Khandelia, Himanshu

    2014-01-01

    of the virtual sites used in GROMACS while the other uses a new definition of the virtual sites of the CH2 groups. Our methods is tested on a DPPC (no unsaturated chain), a POPC (one unsaturated chain), and a DOPC (two unsaturated chains) lipid bilayers. We calculate various physical properties of the membrane......We present two new implementations of the virtual sites technique which completely suppresses the degrees of freedom of the hydrogen atoms in a lipid bilayer allowing for an increased time step of 5 fs in all-atom simulations of the CHARMM36 force field. One of our approaches uses the derivation...

  12. Rayleigh-Plesset equation of the bubble stable cavitation in water: A nonequilibrium all-atom molecular dynamics simulation study

    Science.gov (United States)

    Man, Viet Hoang; Li, Mai Suan; Derreumaux, Philippe; Nguyen, Phuong H.

    2018-03-01

    The Rayleigh-Plesset (RP) equation was derived from the first principles to describe the bubble cavitation in liquids in terms of macroscopic hydrodynamics. A number of nonequilibrium molecular dynamics studies have been carried out to validate this equation in describing the bubble inertial cavitation, but their results are contradictory and the applicability of the RP equation still remains to be examined, especially for the stable cavitation. In this work, we carry out nonequilibrium all-atom simulation to validate the applicability of the RP equation in the description of the stable cavitation of nano-sized bubbles in water. We show that although microscopic effects are not explicitly included, this equation still describes the dynamics of subnano-bubbles quite well as long as the contributions of various terms including inertial, surface tension, and viscosity are correctly taken into account. These terms are directly and inversely proportional to the amplitude and period of the cavitation, respectively. Thus, their contributions to the RP equation depend on these two parameters. This may explain the discrepancy between the current results obtained using different parameters. Finally, the accuracy of the RP equation in the current mathematical modeling studies of the ultrasound-induced blood-brain-barrier experiments is discussed in some detail.

  13. Quantum Mechanics/Molecular Mechanics Method Combined with Hybrid All-Atom and Coarse-Grained Model: Theory and Application on Redox Potential Calculations.

    Science.gov (United States)

    Shen, Lin; Yang, Weitao

    2016-04-12

    We developed a new multiresolution method that spans three levels of resolution with quantum mechanical, atomistic molecular mechanical, and coarse-grained models. The resolution-adapted all-atom and coarse-grained water model, in which an all-atom structural description of the entire system is maintained during the simulations, is combined with the ab initio quantum mechanics and molecular mechanics method. We apply this model to calculate the redox potentials of the aqueous ruthenium and iron complexes by using the fractional number of electrons approach and thermodynamic integration simulations. The redox potentials are recovered in excellent accordance with the experimental data. The speed-up of the hybrid all-atom and coarse-grained water model renders it computationally more attractive. The accuracy depends on the hybrid all-atom and coarse-grained water model used in the combined quantum mechanical and molecular mechanical method. We have used another multiresolution model, in which an atomic-level layer of water molecules around redox center is solvated in supramolecular coarse-grained waters for the redox potential calculations. Compared with the experimental data, this alternative multilayer model leads to less accurate results when used with the coarse-grained polarizable MARTINI water or big multipole water model for the coarse-grained layer.

  14. Multiscale approach for the construction of equilibrated all-atom models of a poly(ethylene glycol)-based hydrogel

    OpenAIRE

    Li, Xianfeng; Murthy, N. Sanjeeva; Becker, Matthew L.; Latour, Robert A.

    2016-01-01

    A multiscale modeling approach is presented for the efficient construction of an equilibrated all-atom model of a cross-linked poly(ethylene glycol) (PEG)-based hydrogel using the all-atom polymer consistent force field (PCFF). The final equilibrated all-atom model was built with a systematic simulation toolset consisting of three consecutive parts: (1) building a global cross-linked PEG-chain network at experimentally determined cross-link density using an on-lattice Monte Carlo method based...

  15. All-atom molecular dynamics calculation study of entire poliovirus empty capsids in solution

    Energy Technology Data Exchange (ETDEWEB)

    Andoh, Y.; Yoshii, N.; Yamada, A.; Kojima, H.; Mizutani, K.; Okazaki, S., E-mail: okazaki@apchem.nagoya-u.ac.jp [Department of Applied Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Fujimoto, K. [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Nakagawa, A. [Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871 (Japan); Nomoto, A. [Institute of Microbial Chemistry, Kamiosaki, Shinagawa-ku, Tokyo 141-0021 (Japan)

    2014-10-28

    Small viruses that belong, for example, to the Picornaviridae, such as poliovirus and foot-and-mouth disease virus, consist simply of capsid proteins and a single-stranded RNA (ssRNA) genome. The capsids are quite stable in solution to protect the genome from the environment. Here, based on long-time and large-scale 6.5 × 10{sup 6} all-atom molecular dynamics calculations for the Mahoney strain of poliovirus, we show microscopic properties of the viral capsids at a molecular level. First, we found equilibrium rapid exchange of water molecules across the capsid. The exchange rate is so high that all water molecules inside the capsid (about 200 000) can leave the capsid and be replaced by water molecules from the outside in about 25 μs. This explains the capsid's tolerance to high pressures and deactivation by exsiccation. In contrast, the capsid did not exchange ions, at least within the present simulation time of 200 ns. This implies that the capsid can function, in principle, as a semipermeable membrane. We also found that, similar to the xylem of trees, the pressure of the solution inside the capsid without the genome was negative. This is caused by coulombic interaction of the solution inside the capsid with the capsid excess charges. The negative pressure may be compensated by positive osmotic pressure by the solution-soluble ssRNA and the counter ions introduced into it.

  16. Preformed template fluctuations promote fibril formation: Insights from lattice and all-atom models

    Energy Technology Data Exchange (ETDEWEB)

    Kouza, Maksim, E-mail: mkouza@chem.uw.edu.pl; Kolinski, Andrzej [Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warszaw (Poland); Co, Nguyen Truong [Department of Physics, Institute of Technology, National University of HCM City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Institute for Computational Science and Technology, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City (Viet Nam); Nguyen, Phuong H. [Laboratoire de Biochimie Theorique, UPR 9080 CNRS, IBPC, Universite Paris 7, 13 rue Pierre et Marie Curie, 75005 Paris (France); Li, Mai Suan, E-mail: masli@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2015-04-14

    Fibril formation resulting from protein misfolding and aggregation is a hallmark of several neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. Despite the fact that the fibril formation process is very slow and thus poses a significant challenge for theoretical and experimental studies, a number of alternative pictures of molecular mechanisms of amyloid fibril formation have been recently proposed. What seems to be common for the majority of the proposed models is that fibril elongation involves the formation of pre-nucleus seeds prior to the creation of a critical nucleus. Once the size of the pre-nucleus seed reaches the critical nucleus size, its thermal fluctuations are expected to be small and the resulting nucleus provides a template for sequential (one-by-one) accommodation of added monomers. The effect of template fluctuations on fibril formation rates has not been explored either experimentally or theoretically so far. In this paper, we make the first attempt at solving this problem by two sets of simulations. To mimic small template fluctuations, in one set, monomers of the preformed template are kept fixed, while in the other set they are allowed to fluctuate. The kinetics of addition of a new peptide onto the template is explored using all-atom simulations with explicit water and the GROMOS96 43a1 force field and simple lattice models. Our result demonstrates that preformed template fluctuations can modulate protein aggregation rates and pathways. The association of a nascent monomer with the template obeys the kinetics partitioning mechanism where the intermediate state occurs in a fraction of routes to the protofibril. It was shown that template immobility greatly increases the time of incorporating a new peptide into the preformed template compared to the fluctuating template case. This observation has also been confirmed by simulation using lattice models and may be invoked to understand the role of template fluctuations in

  17. Validation of Structures in the Protein Data Bank.

    Science.gov (United States)

    Gore, Swanand; Sanz García, Eduardo; Hendrickx, Pieter M S; Gutmanas, Aleksandras; Westbrook, John D; Yang, Huanwang; Feng, Zukang; Baskaran, Kumaran; Berrisford, John M; Hudson, Brian P; Ikegawa, Yasuyo; Kobayashi, Naohiro; Lawson, Catherine L; Mading, Steve; Mak, Lora; Mukhopadhyay, Abhik; Oldfield, Thomas J; Patwardhan, Ardan; Peisach, Ezra; Sahni, Gaurav; Sekharan, Monica R; Sen, Sanchayita; Shao, Chenghua; Smart, Oliver S; Ulrich, Eldon L; Yamashita, Reiko; Quesada, Martha; Young, Jasmine Y; Nakamura, Haruki; Markley, John L; Berman, Helen M; Burley, Stephen K; Velankar, Sameer; Kleywegt, Gerard J

    2017-12-05

    The Worldwide PDB recently launched a deposition, biocuration, and validation tool: OneDep. At various stages of OneDep data processing, validation reports for three-dimensional structures of biological macromolecules are produced. These reports are based on recommendations of expert task forces representing crystallography, nuclear magnetic resonance, and cryoelectron microscopy communities. The reports provide useful metrics with which depositors can evaluate the quality of the experimental data, the structural model, and the fit between them. The validation module is also available as a stand-alone web server and as a programmatically accessible web service. A growing number of journals require the official wwPDB validation reports (produced at biocuration) to accompany manuscripts describing macromolecular structures. Upon public release of the structure, the validation report becomes part of the public PDB archive. Geometric quality scores for proteins in the PDB archive have improved over the past decade. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. What makes a crystal structure report valid?

    NARCIS (Netherlands)

    Spek, Anthony L.|info:eu-repo/dai/nl/156517566

    2018-01-01

    Single crystal X-ray crystallography has developed into a unique, highly automated and accessible tool to obtain detailed information on molecular structures. Proper archival makes that referees, readers and users of the results of reported crystal structures no longer need to depend solely on the

  19. A Structural Validation of the Schedule of Racist Events

    Science.gov (United States)

    Greer, Tawanda M.

    2010-01-01

    This study examined the structural validity of the Schedule of Racist Events (SRE), a brief inventory that assesses the frequency and stressfulness of racism in the lives of African Americans. The original three-factor structure of the SRE was examined, along with an alternative structure that was designed to test whether the SRE captured types of…

  20. Probing the folded state and mechanical unfolding pathways of T4 lysozyme using all-atom and coarse-grained molecular simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Wenjun, E-mail: wjzheng@buffalo.edu; Glenn, Paul [Department of Physics, University at Buffalo, Buffalo, New York 14260 (United States)

    2015-01-21

    The Bacteriophage T4 Lysozyme (T4L) is a prototype modular protein comprised of an N-terminal and a C-domain domain, which was extensively studied to understand the folding/unfolding mechanism of modular proteins. To offer detailed structural and dynamic insights to the folded-state stability and the mechanical unfolding behaviors of T4L, we have performed extensive equilibrium and steered molecular dynamics simulations of both the wild-type (WT) and a circular permutation (CP) variant of T4L using all-atom and coarse-grained force fields. Our all-atom and coarse-grained simulations of the folded state have consistently found greater stability of the C-domain than the N-domain in isolation, which is in agreement with past thermostatic studies of T4L. While the all-atom simulation cannot fully explain the mechanical unfolding behaviors of the WT and the CP variant observed in an optical tweezers study, the coarse-grained simulations based on the Go model or a modified elastic network model (mENM) are in qualitative agreement with the experimental finding of greater unfolding cooperativity in the WT than the CP variant. Interestingly, the two coarse-grained models predict different structural mechanisms for the observed change in cooperativity between the WT and the CP variant—while the Go model predicts minor modification of the unfolding pathways by circular permutation (i.e., preserving the general order that the N-domain unfolds before the C-domain), the mENM predicts a dramatic change in unfolding pathways (e.g., different order of N/C-domain unfolding in the WT and the CP variant). Based on our simulations, we have analyzed the limitations of and the key differences between these models and offered testable predictions for future experiments to resolve the structural mechanism for cooperative folding/unfolding of T4L.

  1. Validity and factor structure of the bodybuilding dependence scale

    OpenAIRE

    Smith, D; Hale, B

    2004-01-01

    Objectives: To investigate the factor structure, validity, and reliability of the bodybuilding dependence scale and to investigate differences in bodybuilding dependence between men and women and competitive and non-competitive bodybuilders.

  2. Validation of seismic soil-structure interaction

    International Nuclear Information System (INIS)

    Finn, Liam W.D.; Ledbetter, R.H.; Beratan, L.L.

    1988-01-01

    Simulated earthquake tests were conducted on centrifuged model structures embedded in dry and saturated sand foundations. Accelerations and pore water pressures were recorded at many locations during the test. Model responses were analyzed using the program TARA-3 which incorporates a procedure for nonlinear dynamic effective stress analysis. Computed and measured responses agreed quite closely. (author)

  3. CING: an integrated residue-based structure validation program suite

    International Nuclear Information System (INIS)

    Doreleijers, Jurgen F.; Sousa da Silva, Alan W.; Krieger, Elmar; Nabuurs, Sander B.; Spronk, Christian A. E. M.; Stevens, Tim J.; Vranken, Wim F.; Vriend, Gert; Vuister, Geerten W.

    2012-01-01

    We present a suite of programs, named CING for Common Interface for NMR Structure Generation that provides for a residue-based, integrated validation of the structural NMR ensemble in conjunction with the experimental restraints and other input data. External validation programs and new internal validation routines compare the NMR-derived models with empirical data, measured chemical shifts, distance- and dihedral restraints and the results are visualized in a dynamic Web 2.0 report. A red–orange–green score is used for residues and restraints to direct the user to those critiques that warrant further investigation. Overall green scores below ∼20 % accompanied by red scores over ∼50 % are strongly indicative of poorly modelled structures. The publically accessible, secure iCing webserver (https://nmr.le.ac.ukhttps://nmr.le.ac.uk) allows individual users to upload the NMR data and run a CING validation analysis.

  4. Hierarchical atom type definitions and extensible all-atom force fields.

    Science.gov (United States)

    Jin, Zhao; Yang, Chunwei; Cao, Fenglei; Li, Feng; Jing, Zhifeng; Chen, Long; Shen, Zhe; Xin, Liang; Tong, Sijia; Sun, Huai

    2016-03-15

    The extensibility of force field is a key to solve the missing parameter problem commonly found in force field applications. The extensibility of conventional force fields is traditionally managed in the parameterization procedure, which becomes impractical as the coverage of the force field increases above a threshold. A hierarchical atom-type definition (HAD) scheme is proposed to make extensible atom type definitions, which ensures that the force field developed based on the definitions are extensible. To demonstrate how HAD works and to prepare a foundation for future developments, two general force fields based on AMBER and DFF functional forms are parameterized for common organic molecules. The force field parameters are derived from the same set of quantum mechanical data and experimental liquid data using an automated parameterization tool, and validated by calculating molecular and liquid properties. The hydration free energies are calculated successfully by introducing a polarization scaling factor to the dispersion term between the solvent and solute molecules. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  5. An all-atom, active site exploration of antiviral drugs that target Flaviviridae polymerases

    Czech Academy of Sciences Publication Activity Database

    Valdés, James J.; Gil, V.A.; Butterill, Philip T.; Růžek, Daniel

    2016-01-01

    Roč. 97, OCT (2016), s. 2552-2565 ISSN 0022-1317 R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GB14-36098G; GA MZd(CZ) NV16-34238A EU Projects: European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : dependent RNA-polymerase * c virus polymerase * de-novo initiation * hepatitis C * allosteric inhibitors * nucleoside inhibitors * molecular dynamics * encephalitis virus * protein-structure * cluster- analysis Subject RIV: EE - Microbiology, Virology Impact factor: 2.838, year: 2016

  6. Cholesterol Protects the Oxidized Lipid Bilayer from Water Injury: An All-Atom Molecular Dynamics Study.

    Science.gov (United States)

    Owen, Michael C; Kulig, Waldemar; Rog, Tomasz; Vattulainen, Ilpo; Strodel, Birgit

    2018-03-17

    In an effort to delineate how cholesterol protects membrane structure under oxidative stress conditions, we monitored the changes to the structure of lipid bilayers comprising 30 mol% cholesterol and an increasing concentration of Class B oxidized 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) glycerophospholipids, namely, 1-palmitoyl-2-(9'-oxo-nonanoyl)-sn-glycero-3-phosphocholine (PoxnoPC), and 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC), using atomistic molecular dynamics simulations. Increasing the content of oxidized phospholipids (oxPLs) from 0 to 60 mol% oxPL resulted in a characteristic reduction in bilayer thickness and increase in area per lipid, thereby increasing the exposure of the membrane hydrophobic region to water. However, cholesterol was observed to help reduce water injury by moving into the bilayer core and forming more hydrogen bonds with the oxPLs. Cholesterol also resists altering its tilt angle, helping to maintain membrane integrity. Water that enters the 1-nm-thick core region remains part of the bulk water on either side of the bilayer, with relatively few water molecules able to traverse through the bilayer. In cholesterol-rich membranes, the bilayer does not form pores at concentrations of 60 mol% oxPL as was shown in previous simulations in the absence of cholesterol.

  7. Physical properties of the HIV-1 capsid from all-atom molecular dynamics simulations

    Science.gov (United States)

    Perilla, Juan R.; Schulten, Klaus

    2017-07-01

    Human immunodeficiency virus type 1 (HIV-1) infection is highly dependent on its capsid. The capsid is a large container, made of ~1,300 proteins with altogether 4 million atoms. Although the capsid proteins are all identical, they nevertheless arrange themselves into a largely asymmetric structure made of hexamers and pentamers. The large number of degrees of freedom and lack of symmetry pose a challenge to studying the chemical details of the HIV capsid. Simulations of over 64 million atoms for over 1 μs allow us to conduct a comprehensive study of the chemical-physical properties of an empty HIV-1 capsid, including its electrostatics, vibrational and acoustic properties, and the effects of solvent (ions and water) on the capsid. The simulations reveal critical details about the capsid with implications to biological function.

  8. All-atom simulation study of protein PTH(1-34) by using the Wang-Landau sampling method

    Science.gov (United States)

    Kim, Seung-Yeon; Kwak, Wooseop

    2014-12-01

    We perform simulations of the N-terminal 34-residue protein fragment PTH(1-34), consisting of 581 atoms, of the 84-residue human parathyroid hormone by using the all-atom ECEPP/3 force field and the Wang-Landau sampling method. Through a massive high-performance computation, the density of states and the partition function Z( T), as a continuous function of T, are obtained for PTH(1-34). From the continuous partition function Z( T), the partition function zeros of PTH(1-34) are evaluated for the first time. From both the specific heat and the partition function zeros, two characteristic transition temperatures are obtained for the all-atom protein PTH(1-34). The higher transition temperature T 1 and the lower transition temperature T 2 of PTH(1-34) can be interpreted as the collapse temperature T θ and the folding temperature T f , respectively.

  9. All-atom simulation study of protein PTH(1-34) by using the Wang-Landau sampling method

    International Nuclear Information System (INIS)

    Kim, Seung-Yeon; Kwak, Woo-Seop

    2014-01-01

    We perform simulations of the N-terminal 34-residue protein fragment PTH(1-34), consisting of 581 atoms, of the 84-residue human parathyroid hormone by using the all-atom ECEPP/3 force field and the Wang-Landau sampling method. Through a massive high-performance computation, the density of states and the partition function Z(T), as a continuous function of T, are obtained for PTH(1-34). From the continuous partition function Z(T), the partition function zeros of PTH(1-34) are evaluated for the first time. From both the specific heat and the partition function zeros, two characteristic transition temperatures are obtained for the all-atom protein PTH(1-34). The higher transition temperature T 1 and the lower transition temperature T 2 of PTH(1-34) can be interpreted as the collapse temperature T θ and the folding temperature T f , respectively.

  10. Analysis and validation of carbohydrate three-dimensional structures

    International Nuclear Information System (INIS)

    Lütteke, Thomas

    2009-01-01

    The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described. Knowledge of the three-dimensional structures of the carbohydrate molecules is indispensable for a full understanding of the molecular processes in which carbohydrates are involved, such as protein glycosylation or protein–carbohydrate interactions. The Protein Data Bank (PDB) is a valuable resource for three-dimensional structural information on glycoproteins and protein–carbohydrate complexes. Unfortunately, many carbohydrate moieties in the PDB contain inconsistencies or errors. This article gives an overview of the information that can be obtained from individual PDB entries and from statistical analyses of sets of three-dimensional structures, of typical problems that arise during the analysis of carbohydrate three-dimensional structures and of the validation tools that are currently available to scientists to evaluate the quality of these structures

  11. Structured Programming Series. Volume 15. Validation and Verification Study

    Science.gov (United States)

    1975-05-22

    System for FORTRAN," February 1975, pp 1-16. Gruenberger, F., "Program Testing and Validacion ," Datamation, July 1968, pp 39-47. Holland, J. G...by block rnmbor) Verification Validation Inspection Testing Certify Prove 20 ABSTRACT (■Conllnu» on nimm tldo II ntcofmry and Idonllly by...majority of software projects rely almost entirely on computer based testing as the method of verifying and validating software. Second, structured

  12. Experimental Validation of an Integrated Controls-Structures Design Methodology

    Science.gov (United States)

    Maghami, Peiman G.; Gupta, Sandeep; Elliot, Kenny B.; Walz, Joseph E.

    1996-01-01

    The first experimental validation of an integrated controls-structures design methodology for a class of large order, flexible space structures is described. Integrated redesign of the controls-structures-interaction evolutionary model, a laboratory testbed at NASA Langley, was described earlier. The redesigned structure was fabricated, assembled in the laboratory, and experimentally tested against the original structure. Experimental results indicate that the structure redesigned using the integrated design methodology requires significantly less average control power than the nominal structure with control-optimized designs, while maintaining the required line-of-sight pointing performance. Thus, the superiority of the integrated design methodology over the conventional design approach is experimentally demonstrated. Furthermore, amenability of the integrated design structure to other control strategies is evaluated, both analytically and experimentally. Using Linear-Quadratic-Guassian optimal dissipative controllers, it is observed that the redesigned structure leads to significantly improved performance with alternate controllers as well.

  13. Structural and Convergent Validity of the Homework Performance Questionnaire

    Science.gov (United States)

    Pendergast, Laura L.; Watkins, Marley W.; Canivez, Gary L.

    2014-01-01

    Homework is a requirement for most school-age children, but research on the benefits and drawbacks of homework is limited by lack of psychometrically sound measurement of homework performance. This study examined the structural and convergent validity of scores from the newly developed Homework Performance Questionnaire -- Teacher Scale (HPQ-T).…

  14. Structurally compliant rocket engine combustion chamber: Experimental and analytical validation

    Science.gov (United States)

    Jankovsky, Robert S.; Arya, Vinod K.; Kazaroff, John M.; Halford, Gary R.

    1994-03-01

    A new, structurally compliant rocket engine combustion chamber design has been validated through analysis and experiment. Subscale, tubular channel chambers have been cyclically tested and analytically evaluated. Cyclic lives were determined to have a potential for 1000 percent increase over those of rectangular channel designs, the current state of the art. Greater structural compliance in the circumferential direction gave rise to lower thermal strains during hot firing, resulting in lower thermal strain ratcheting and longer predicted fatigue lives. Thermal, structural, and durability analyses of the combustion chamber design, involving cyclic temperatures, strains, and low-cycle fatigue lives, have corroborated the experimental observations.

  15. All-atom normal-mode analysis reveals an RNA-induced allostery in a bacteriophage coat protein.

    Science.gov (United States)

    Dykeman, Eric C; Twarock, Reidun

    2010-03-01

    Assembly of the T=3 bacteriophage MS2 is initiated by the binding of a 19 nucleotide RNA stem loop from within the phage genome to a symmetric coat protein dimer. This binding event effects a folding of the FG loop in one of the protein subunits of the dimer and results in the formation of an asymmetric dimer. Since both the symmetric and asymmetric forms of the dimer are needed for the assembly of the protein container, this allosteric switch plays an important role in the life cycle of the phage. We provide here details of an all-atom normal-mode analysis of this allosteric effect. The results suggest that asymmetric contacts between the A -duplex RNA phosphodiester backbone of the stem loop with the EF loop in one coat protein subunit results in an increased dynamic behavior of its FG loop. The four lowest-frequency modes, which encompass motions predominantly on the FG loops, account for over 90% of the increased dynamic behavior due to a localization of the vibrational pattern on a single FG loop. Finally, we show that an analysis of the allosteric effect using an elastic network model fails to predict this localization effect, highlighting the importance of using an all-atom full force field method for this problem.

  16. All-atom simulation study of protein PTH(1-34) by using the Wang-Landau sampling method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung-Yeon [Korea National University of Transportation, Chungju (Korea, Republic of); Kwak, Woo-Seop [Chosun University, Gwangju (Korea, Republic of)

    2014-12-15

    We perform simulations of the N-terminal 34-residue protein fragment PTH(1-34), consisting of 581 atoms, of the 84-residue human parathyroid hormone by using the all-atom ECEPP/3 force field and the Wang-Landau sampling method. Through a massive high-performance computation, the density of states and the partition function Z(T), as a continuous function of T, are obtained for PTH(1-34). From the continuous partition function Z(T), the partition function zeros of PTH(1-34) are evaluated for the first time. From both the specific heat and the partition function zeros, two characteristic transition temperatures are obtained for the all-atom protein PTH(1-34). The higher transition temperature T{sub 1} and the lower transition temperature T{sub 2} of PTH(1-34) can be interpreted as the collapse temperature T{sub θ} and the folding temperature T{sub f} , respectively.

  17. The Selective Mutism Questionnaire: Measurement Structure and Validity

    Science.gov (United States)

    Letamendi, Andrea M.; Chavira, Denise A.; Hitchcock, Carla A.; Roesch, Scott C.; Shipon-Blum, Elisa; Stein, Murray B.; Roesch, Scott C.

    2010-01-01

    Objective To evaluate the factor structure, reliability, and validity of the 17-item Selective Mutism Questionnaire. Method Diagnostic interviews were administered via telephone to 102 parents of children identified with selective mutism (SM) and 43 parents of children without SM from varying U.S. geographic regions. Children were between the ages of 3 and 11 inclusive and comprised 58% girls and 42% boys. SM diagnoses were determined using the Anxiety Disorders Interview Schedule for Children - Parent Version (ADIS-C/P); SM severity was assessed using the 17-item Selective Mutism Questionnaire (SMQ); and behavioral and affective symptoms were assessed using the Child Behavior Checklist (CBCL). An exploratory factor analysis (EFA) was conducted to investigate the dimensionality of the SMQ and a modified parallel analysis procedure was used to confirm EFA results. Internal consistency, construct validity, and incremental validity were also examined. Results The EFA yielded a 13-item solution consisting of three factors: a) Social Situations Outside of School, b) School Situations, and c) Home and Family Situations. Internal consistency of SMQ factors and total scale ranged from moderate to high. Convergent and incremental validity were also well supported. Conclusions Measure structure findings are consistent with the 3-factor solution found in a previous psychometric evaluation of the SMQ. Results also suggest that the SMQ provides useful and unique information in the prediction of SM phenomenon beyond other child anxiety measures. PMID:18698268

  18. Digging into Lipid Membrane Permeation for Cardiac Ion Channel Blocker d-Sotalol with All-Atom Simulations

    Directory of Open Access Journals (Sweden)

    Kevin R. DeMarco

    2018-02-01

    Full Text Available Interactions of drug molecules with lipid membranes play crucial role in their accessibility of cellular targets and can be an important predictor of their therapeutic and safety profiles. Very little is known about spatial localization of various drugs in the lipid bilayers, their active form (ionization state or translocation rates and therefore potency to bind to different sites in membrane proteins. All-atom molecular simulations may help to map drug partitioning kinetics and thermodynamics, thus providing in-depth assessment of drug lipophilicity. As a proof of principle, we evaluated extensively lipid membrane partitioning of d-sotalol, well-known blocker of a cardiac potassium channel Kv11.1 encoded by the hERG gene, with reported substantial proclivity for arrhythmogenesis. We developed the positively charged (cationic and neutral d-sotalol models, compatible with the biomolecular CHARMM force field, and subjected them to all-atom molecular dynamics (MD simulations of drug partitioning through hydrated lipid membranes, aiming to elucidate thermodynamics and kinetics of their translocation and thus putative propensities for hydrophobic and aqueous hERG access. We found that only a neutral form of d-sotalol accumulates in the membrane interior and can move across the bilayer within millisecond time scale, and can be relevant to a lipophilic channel access. The computed water-membrane partitioning coefficient for this form is in good agreement with experiment. There is a large energetic barrier for a cationic form of the drug, dominant in water, to cross the membrane, resulting in slow membrane translocation kinetics. However, this form of the drug can be important for an aqueous access pathway through the intracellular gate of hERG. This route will likely occur after a neutral form of a drug crosses the membrane and subsequently re-protonates. Our study serves to demonstrate a first step toward a framework for multi-scale in silico safety

  19. Digging into Lipid Membrane Permeation for Cardiac Ion Channel Blocker d-Sotalol with All-Atom Simulations.

    Science.gov (United States)

    DeMarco, Kevin R; Bekker, Slava; Clancy, Colleen E; Noskov, Sergei Y; Vorobyov, Igor

    2018-01-01

    Interactions of drug molecules with lipid membranes play crucial role in their accessibility of cellular targets and can be an important predictor of their therapeutic and safety profiles. Very little is known about spatial localization of various drugs in the lipid bilayers, their active form (ionization state) or translocation rates and therefore potency to bind to different sites in membrane proteins. All-atom molecular simulations may help to map drug partitioning kinetics and thermodynamics, thus providing in-depth assessment of drug lipophilicity. As a proof of principle, we evaluated extensively lipid membrane partitioning of d-sotalol, well-known blocker of a cardiac potassium channel K v 11.1 encoded by the hERG gene, with reported substantial proclivity for arrhythmogenesis. We developed the positively charged (cationic) and neutral d-sotalol models, compatible with the biomolecular CHARMM force field, and subjected them to all-atom molecular dynamics (MD) simulations of drug partitioning through hydrated lipid membranes, aiming to elucidate thermodynamics and kinetics of their translocation and thus putative propensities for hydrophobic and aqueous hERG access. We found that only a neutral form of d-sotalol accumulates in the membrane interior and can move across the bilayer within millisecond time scale, and can be relevant to a lipophilic channel access. The computed water-membrane partitioning coefficient for this form is in good agreement with experiment. There is a large energetic barrier for a cationic form of the drug, dominant in water, to cross the membrane, resulting in slow membrane translocation kinetics. However, this form of the drug can be important for an aqueous access pathway through the intracellular gate of hERG. This route will likely occur after a neutral form of a drug crosses the membrane and subsequently re-protonates. Our study serves to demonstrate a first step toward a framework for multi-scale in silico safety pharmacology

  20. Comparison and validation of community structures in complex networks

    Science.gov (United States)

    Gustafsson, Mika; Hörnquist, Michael; Lombardi, Anna

    2006-07-01

    The issue of partitioning a network into communities has attracted a great deal of attention recently. Most authors seem to equate this issue with the one of finding the maximum value of the modularity, as defined by Newman. Since the problem formulated this way is believed to be NP-hard, most effort has gone into the construction of search algorithms, and less to the question of other measures of community structures, similarities between various partitionings and the validation with respect to external information. Here we concentrate on a class of computer generated networks and on three well-studied real networks which constitute a bench-mark for network studies; the karate club, the US college football teams and a gene network of yeast. We utilize some standard ways of clustering data (originally not designed for finding community structures in networks) and show that these classical methods sometimes outperform the newer ones. We discuss various measures of the strength of the modular structure, and show by examples features and drawbacks. Further, we compare different partitions by applying some graph-theoretic concepts of distance, which indicate that one of the quality measures of the degree of modularity corresponds quite well with the distance from the true partition. Finally, we introduce a way to validate the partitionings with respect to external data when the nodes are classified but the network structure is unknown. This is here possible since we know everything of the computer generated networks, as well as the historical answer to how the karate club and the football teams are partitioned in reality. The partitioning of the gene network is validated by use of the Gene Ontology database, where we show that a community in general corresponds to a biological process.

  1. Cross validation for the classical model of structured expert judgment

    International Nuclear Information System (INIS)

    Colson, Abigail R.; Cooke, Roger M.

    2017-01-01

    We update the 2008 TU Delft structured expert judgment database with data from 33 professionally contracted Classical Model studies conducted between 2006 and March 2015 to evaluate its performance relative to other expert aggregation models. We briefly review alternative mathematical aggregation schemes, including harmonic weighting, before focusing on linear pooling of expert judgments with equal weights and performance-based weights. Performance weighting outperforms equal weighting in all but 1 of the 33 studies in-sample. True out-of-sample validation is rarely possible for Classical Model studies, and cross validation techniques that split calibration questions into a training and test set are used instead. Performance weighting incurs an “out-of-sample penalty” and its statistical accuracy out-of-sample is lower than that of equal weighting. However, as a function of training set size, the statistical accuracy of performance-based combinations reaches 75% of the equal weight value when the training set includes 80% of calibration variables. At this point the training set is sufficiently powerful to resolve differences in individual expert performance. The information of performance-based combinations is double that of equal weighting when the training set is at least 50% of the set of calibration variables. Previous out-of-sample validation work used a Total Out-of-Sample Validity Index based on all splits of the calibration questions into training and test subsets, which is expensive to compute and includes small training sets of dubious value. As an alternative, we propose an Out-of-Sample Validity Index based on averaging the product of statistical accuracy and information over all training sets sized at 80% of the calibration set. Performance weighting outperforms equal weighting on this Out-of-Sample Validity Index in 26 of the 33 post-2006 studies; the probability of 26 or more successes on 33 trials if there were no difference between performance

  2. Nonequilibrium all-atom molecular dynamics simulation of the bubble cavitation and application to dissociate amyloid fibrils

    Science.gov (United States)

    Hoang Viet, Man; Derreumaux, Philippe; Nguyen, Phuong H.

    2016-11-01

    The cavitation of gas bubbles in liquids has been applied to different disciplines in life and natural sciences, and in technologies. To obtain an appropriate theoretical description of effects induced by the bubble cavitation, we develop an all-atom nonequilibrium molecular-dynamics simulation method to simulate bubbles undergoing harmonic oscillation in size. This allows us to understand the mechanism of the bubble cavitation-induced liquid shear stress on surrounding objects. The method is then employed to simulate an Aβ fibril model in the presence of bubbles, and the results show that the bubble expansion and contraction exert water pressure on the fibril. This yields to the deceleration and acceleration of the fibril kinetic energy, facilitating the conformational transition between local free energy minima, and leading to the dissociation of the fibril. Our work, which is a proof-of-concept, may open a new, efficient way to dissociate amyloid fibrils using the bubble cavitation technique, and new venues to investigate the complex phenomena associated with amyloidogenesis.

  3. Peptide insertion, positioning, and stabilization in a membrane: insight from an all-atom molecular dynamics simulation.

    Science.gov (United States)

    Babakhani, Arneh; Gorfe, Alemayehu A; Gullingsrud, Justin; Kim, Judy E; Andrew McCammon, J

    Peptide insertion, positioning, and stabilization in a model membrane are probed via an all-atom molecular dynamics (MD) simulation. One peptide (WL5) is simulated in each leaflet of a solvated dimyristoylglycero-3-phosphate (DMPC) membrane. Within the first 5 ns, the peptides spontaneously insert into the membrane and then stabilize during the remaining 70 ns of simulation time. In both leaflets, the peptides localize to the membrane interface, and this localization is attributed to the formation of peptide-lipid hydrogen bonds. We show that the single tryptophan residue in each peptide contributes significantly to these hydrogen bonds; specifically, the nitrogen heteroatom of the indole ring plays a critical role. The tilt angles of the indole rings relative to the membrane normal in the upper and lower leaflets are approximately 26 degrees and 54 degrees , respectively. The tilt angles of the entire peptide chain are 62 degrees and 74 degrees . The membrane induces conformations of the peptide that are characteristic of beta-sheets, and the peptide enhances the lipid ordering in the membrane. Finally, the diffusion rate of the peptides in the membrane plane is calculated (based on experimental peptide concentrations) to be approximately 6 A(2)/ns, thus suggesting a 500 ns time scale for intermolecular interactions.

  4. Predicting and validating protein interactions using network structure.

    Directory of Open Access Journals (Sweden)

    Pao-Yang Chen

    2008-07-01

    Full Text Available Protein interactions play a vital part in the function of a cell. As experimental techniques for detection and validation of protein interactions are time consuming, there is a need for computational methods for this task. Protein interactions appear to form a network with a relatively high degree of local clustering. In this paper we exploit this clustering by suggesting a score based on triplets of observed protein interactions. The score utilises both protein characteristics and network properties. Our score based on triplets is shown to complement existing techniques for predicting protein interactions, outperforming them on data sets which display a high degree of clustering. The predicted interactions score highly against test measures for accuracy. Compared to a similar score derived from pairwise interactions only, the triplet score displays higher sensitivity and specificity. By looking at specific examples, we show how an experimental set of interactions can be enriched and validated. As part of this work we also examine the effect of different prior databases upon the accuracy of prediction and find that the interactions from the same kingdom give better results than from across kingdoms, suggesting that there may be fundamental differences between the networks. These results all emphasize that network structure is important and helps in the accurate prediction of protein interactions. The protein interaction data set and the program used in our analysis, and a list of predictions and validations, are available at http://www.stats.ox.ac.uk/bioinfo/resources/PredictingInteractions.

  5. UCLA Loneliness Scale (Version 3): reliability, validity, and factor structure.

    Science.gov (United States)

    Russell, D W

    1996-02-01

    In this article I evaluated the psychometric properties of the UCLA Loneliness Scale (Version 3). Using data from prior studies of college students, nurses, teachers, and the elderly, analyses of the reliability, validity, and factor structure of this new version of the UCLA Loneliness Scale were conducted. Results indicated that the measure was highly reliable, both in terms of internal consistency (coefficient alpha ranging from .89 to .94) and test-retest reliability over a 1-year period (r = .73). Convergent validity for the scale was indicated by significant correlations with other measures of loneliness. Construct validity was supported by significant relations with measures of the adequacy of the individual's interpersonal relationships, and by correlations between loneliness and measures of health and well-being. Confirmatory factor analyses indicated that a model incorporating a global bipolar loneliness factor along with two method factor reflecting direction of item wording provided a very good fit to the data across samples. Implications of these results for future measurement research on loneliness are discussed.

  6. Fully automated antibody structure prediction using BIOVIA tools: Validation study.

    Directory of Open Access Journals (Sweden)

    Helen Kemmish

    Full Text Available We describe the methodology and results from our validation study of the fully automated antibody structure prediction tool available in the BIOVIA (formerly Accelrys protein modeling suite. Extending our previous study, we have validated the automated approach using a larger and more diverse data set (157 unique antibody Fv domains versus 11 in the previous study. In the current study, we explore the effect of varying several parameter settings in order to better understand their influence on the resulting model quality. Specifically, we investigated the dependence on different methods of framework model construction, antibody numbering schemes (Chothia, IMGT, Honegger and Kabat, the influence of compatibility of loop templates using canonical type filtering, wider exploration of model solution space, and others. Our results show that our recently introduced Top5 framework modeling method results in a small but significant improvement in model quality whereas the effect of other parameters is not significant. Our analysis provides improved guidelines of best practices for using our protocol to build antibody structures. We also identify some limitations of the current computational model which will enhance proper evaluation of model quality by users and suggests possible future enhancements.

  7. Using of Structural Equation Modeling Techniques in Cognitive Levels Validation

    Directory of Open Access Journals (Sweden)

    Natalija Curkovic

    2012-10-01

    Full Text Available When constructing knowledge tests, cognitive level is usually one of the dimensions comprising the test specifications with each item assigned to measure a particular level. Recently used taxonomies of the cognitive levels most often represent some modification of the original Bloom’s taxonomy. There are many concerns in current literature about existence of predefined cognitive levels. The aim of this article is to investigate can structural equation modeling techniques confirm existence of different cognitive levels. For the purpose of the research, a Croatian final high-school Mathematics exam was used (N = 9626. Confirmatory factor analysis and structural regression modeling were used to test three different models. Structural equation modeling techniques did not support existence of different cognitive levels in this case. There is more than one possible explanation for that finding. Some other techniques that take into account nonlinear behaviour of the items as well as qualitative techniques might be more useful for the purpose of the cognitive levels validation. Furthermore, it seems that cognitive levels were not efficient descriptors of the items and so improvements are needed in describing the cognitive skills measured by items.

  8. Fluid/structure interaction and TUF code validation

    International Nuclear Information System (INIS)

    Toong, T.

    1997-01-01

    In the course of analysis of Steam Generator (SG) divider plate integrity under Loss-Of-Coolant-Accident (LOCA) conditions, it became clear that the pressure differential across the divider plate is strongly affected by the ensuing movement of the divider plate. The effect of the divider plate movement on the thermal-hydraulics has been studied in detail at Ontario Hydro. In this paper, emphasis is placed on the fundamental physics involved in the phenomena. Two physics problems, which can be solved analytically, are presented in this paper, which may be used for code validation: 1) The first one relates to the fundamental physics of pressure wave propagation generated by the motion of the piston in a pipe, 2) The second one deals with a lumped volume (or node in simulation codes) with inlet and outlet pipes, which is representative of the bowl of a SG with the tubes and the nozzle as inlet and outlet. Fluid/structure interaction modeling for SG divider plate integrity study has been implemented in the TUF code at Ontario Hydro. The structure-to-fluid part of the coding is tested against these two physical problems. The results have demonstrated the code capability for simulations of fluid/structure interaction problems. (author)

  9. Validity and factor structure of the bodybuilding dependence scale.

    Science.gov (United States)

    Smith, D; Hale, B

    2004-04-01

    To investigate the factor structure, validity, and reliability of the bodybuilding dependence scale and to investigate differences in bodybuilding dependence between men and women and competitive and non-competitive bodybuilders. Seventy two male competitive bodybuilders, 63 female competitive bodybuilders, 87 male non-competitive bodybuilders, and 63 non-competitive female bodybuilders completed the bodybuilding dependence scale (BDS), the exercise dependence questionnaire (EDQ), and the muscle dysmorphia inventory (MDI). Confirmatory factor analysis of the BDS supported a three factor model of bodybuilding dependence, consisting of social dependence, training dependence, and mastery dependence (Q = 3.16, CFI = 0.98, SRMR = 0.04). Internal reliability of all three subscales was high (Cronbach's alpha = 0.92, 0.92, and 0.93 respectively). Significant (pbodybuilders scored significantly (pbodybuilders. However, there were no significant sex differences on any of the BDS subscales (p>0.05). The three factor BDS appears to be a reliable and valid measure of bodybuilding dependence. Symptoms of bodybuilding dependence are more prevalent in competitive bodybuilders than non-competitive ones, but there are no significant sex differences in bodybuilding dependence.

  10. Structural Health Monitoring 2007: Quantification, Validation, and Implementation

    Science.gov (United States)

    2008-07-01

    11.00 p, 1734 P~rkr.1It , Han-’Slill Slnl its for Slruclunlllnlllll MOllilorin WI",1est Nen.’orb 11:00-11:20 Vinod R. Challa . M.G Prasad and Frank T ...6th International Workshop on Structural Health Monitoring is "Quantification, Validation, and Implementation." Similar to the l’\\ T ))E community, the...ofTok\\’ll. J : Serdai’ IJckun. NASA. USA T ~o l’ur P I’UIlnd futu"" Pn>s ’" i"SII)1 09 OS -09:40 Jill D. Achc:obach. Nonhwe51ern Unt\\’ffJll • USA On t

  11. Validation of structural design of JHR fuel element

    International Nuclear Information System (INIS)

    Brisson, S.; Miras, G.; Le Bourdonnec, L.; Lemoine, P.; Anselmet, M.C.; Marelle, V.

    2010-01-01

    The validation of the structural design of the Jules Horowitz Reactor fuel element was made by the Finite Element Method, starting from the Computer Aided Design. The JHR fuel element is a cylindrical assembly of three sectors composed of eight rolled fuel plates. A roll-swaging process is used to join the fuel plates to three aluminium stiffeners. The hydraulic gap between each plate is 1.95 mm. The JHR fuel assembly is fastened at both ends to the upper and lower endfittings by riveting. The main stresses are essentially thermal loads, imposed on the fuel zone of the plates. These thermal loads result from the nuclear heat flux (W/cm 2 ). The mechanical loads are mainly hydraulic thrust forces. The average coolant velocity is 15 m/s. Seismic effects are also studied. The fuel assembly is entirely modelled by thin shells. The model takes into account asymmetric thermal loads which often appear in Research Reactors. The mechanics of the fuel plates vary in function of the burn up. These mechanical properties are derived from the data sets used in the MAIA code, and the validity of the structure is demonstrable at throughout the life of the fuel. Results concerning displacement are compared to functional criteria, while results concerning stress are compared to RCC-MX criteria. The results of this analysis show that the mechanical and geometrical integrity of the JHR fuel elements is respected for Operating Categories 1 and 2. This paper presents the methodology of this demonstration for the results obtained. (author)

  12. Membrane protein simulations with a united-atom lipid and all-atom protein model: lipid-protein interactions, side chain transfer free energies and model proteins

    International Nuclear Information System (INIS)

    Tieleman, D Peter; MacCallum, Justin L; Ash, Walter L; Kandt, Christian; Xu Zhitao; Monticelli, Luca

    2006-01-01

    We have reparameterized the dihedral parameters in a commonly used united-atom lipid force field so that they can be used with the all-atom OPLS force field for proteins implemented in the molecular dynamics simulation software GROMACS. Simulations with this new combination give stable trajectories and sensible behaviour of both lipids and protein. We have calculated the free energy of transfer of amino acid side chains between water and 'lipid-cyclohexane', made of lipid force field methylene groups, as a hydrophobic mimic of the membrane interior, for both the OPLS-AA and a modified OPLS-AA force field which gives better hydration free energies under simulation conditions close to those preferred for the lipid force field. The average error is 4.3 kJ mol -1 for water-'lipid-cyclohexane' compared to 3.2 kJ mol -1 for OPLS-AA cyclohexane and 2.4 kJ mol -1 for the modified OPLS-AA water-'lipid-cyclohexane'. We have also investigated the effect of different methods to combine parameters between the united-atom lipid force field and the united-atom protein force field ffgmx. In a widely used combination, the strength of interactions between hydrocarbon lipid tails and proteins is significantly overestimated, causing a decrease in the area per lipid and an increase in lipid ordering. Using straight combination rules improves the results. Combined, we suggest that using OPLS-AA together with the united-atom lipid force field implemented in GROMACS is a reasonable approach to membrane protein simulations. We also suggest that using partial volume information and free energies of transfer may help to improve the parameterization of lipid-protein interactions and point out the need for accurate experimental data to validate and improve force field descriptions of such interactions

  13. Validation and structural analysis of the kinematics concept test

    Science.gov (United States)

    Lichtenberger, A.; Wagner, C.; Hofer, S. I.; Stern, E.; Vaterlaus, A.

    2017-06-01

    The kinematics concept test (KCT) is a multiple-choice test designed to evaluate students' conceptual understanding of kinematics at the high school level. The test comprises 49 multiple-choice items about velocity and acceleration, which are based on seven kinematic concepts and which make use of three different representations. In the first part of this article we describe the development and the validation process of the KCT. We applied the KCT to 338 Swiss high school students who attended traditional teaching in kinematics. We analyzed the response data to provide the psychometric properties of the test. In the second part we present the results of a structural analysis of the test. An exploratory factor analysis of 664 student answers finally uncovered the seven kinematics concepts as factors. However, the analysis revealed a hierarchical structure of concepts. At the higher level, mathematical concepts group together, and then split up into physics concepts at the lower level. Furthermore, students who seem to understand a concept in one representation have difficulties transferring the concept to similar problems in another representation. Both results have implications for teaching kinematics. First, teaching mathematical concepts beforehand might be beneficial for learning kinematics. Second, instructions have to be designed to teach students the change between different representations.

  14. Validation and structural analysis of the kinematics concept test

    Directory of Open Access Journals (Sweden)

    A. Lichtenberger

    2017-04-01

    Full Text Available The kinematics concept test (KCT is a multiple-choice test designed to evaluate students’ conceptual understanding of kinematics at the high school level. The test comprises 49 multiple-choice items about velocity and acceleration, which are based on seven kinematic concepts and which make use of three different representations. In the first part of this article we describe the development and the validation process of the KCT. We applied the KCT to 338 Swiss high school students who attended traditional teaching in kinematics. We analyzed the response data to provide the psychometric properties of the test. In the second part we present the results of a structural analysis of the test. An exploratory factor analysis of 664 student answers finally uncovered the seven kinematics concepts as factors. However, the analysis revealed a hierarchical structure of concepts. At the higher level, mathematical concepts group together, and then split up into physics concepts at the lower level. Furthermore, students who seem to understand a concept in one representation have difficulties transferring the concept to similar problems in another representation. Both results have implications for teaching kinematics. First, teaching mathematical concepts beforehand might be beneficial for learning kinematics. Second, instructions have to be designed to teach students the change between different representations.

  15. Organizing the Confusion Surrounding Workaholism: New Structure, Measure, and Validation

    Directory of Open Access Journals (Sweden)

    Or Shkoler

    2017-10-01

    Full Text Available Since “workaholism” was coined, a considerable body of research was conducted to shed light on its essence. After at least 40 years of studying this important phenomenon, a large variety of definitions, conceptualizations, and measures emerged. In order to try and bring more integration and consensus to this construct, the current research was conducted in two phases. We aimed to formulate a theoretical definitional framework for workaholism, capitalizing upon the Facet Theory Approach. Two basic facets were hypothesized: A. Modalities of workaholism, with three elements: cognitive, emotional, and instrumental; and B. Resources of workaholism with two elements: time and effort. Based on this definitional framework, a structured questionnaire was conceived. In the first phase, the new measure was validated with an Israeli sample comparing two statistical procedures; Factor Analysis (FA and Smallest Space Analysis (SSA. In the second phase, we aimed to replicate the findings, and to contrast the newly-devised questionnaire with other extant workaholism measures, with a Romanian sample. Theoretical implications and future research suggestions are discussed.

  16. Two-step relaxation mode analysis with multiple evolution times applied to all-atom molecular dynamics protein simulation

    Science.gov (United States)

    Karasawa, N.; Mitsutake, A.; Takano, H.

    2017-12-01

    Proteins implement their functionalities when folded into specific three-dimensional structures, and their functions are related to the protein structures and dynamics. Previously, we applied a relaxation mode analysis (RMA) method to protein systems; this method approximately estimates the slow relaxation modes and times via simulation and enables investigation of the dynamic properties underlying the protein structural fluctuations. Recently, two-step RMA with multiple evolution times has been proposed and applied to a slightly complex homopolymer system, i.e., a single [n ] polycatenane. This method can be applied to more complex heteropolymer systems, i.e., protein systems, to estimate the relaxation modes and times more accurately. In two-step RMA, we first perform RMA and obtain rough estimates of the relaxation modes and times. Then, we apply RMA with multiple evolution times to a small number of the slowest relaxation modes obtained in the previous calculation. Herein, we apply this method to the results of principal component analysis (PCA). First, PCA is applied to a 2-μ s molecular dynamics simulation of hen egg-white lysozyme in aqueous solution. Then, the two-step RMA method with multiple evolution times is applied to the obtained principal components. The slow relaxation modes and corresponding relaxation times for the principal components are much improved by the second RMA.

  17. Studies of base pair sequence effects on DNA solvation based on all-atom molecular dynamics simulations.

    Science.gov (United States)

    Dixit, Surjit B; Mezei, Mihaly; Beveridge, David L

    2012-07-01

    Detailed analyses of the sequence-dependent solvation and ion atmosphere of DNA are presented based on molecular dynamics (MD) simulations on all the 136 unique tetranucleotide steps obtained by the ABC consortium using the AMBER suite of programs. Significant sequence effects on solvation and ion localization were observed in these simulations. The results were compared to essentially all known experimental data on the subject. Proximity analysis was employed to highlight the sequence dependent differences in solvation and ion localization properties in the grooves of DNA. Comparison of the MD-calculated DNA structure with canonical A- and B-forms supports the idea that the G/C-rich sequences are closer to canonical A- than B-form structures, while the reverse is true for the poly A sequences, with the exception of the alternating ATAT sequence. Analysis of hydration density maps reveals that the flexibility of solute molecule has a significant effect on the nature of observed hydration. Energetic analysis of solute-solvent interactions based on proximity analysis of solvent reveals that the GC or CG base pairs interact more strongly with water molecules in the minor groove of DNA that the AT or TA base pairs, while the interactions of the AT or TA pairs in the major groove are stronger than those of the GC or CG pairs. Computation of solvent-accessible surface area of the nucleotide units in the simulated trajectories reveals that the similarity with results derived from analysis of a database of crystallographic structures is excellent. The MD trajectories tend to follow Manning's counterion condensation theory, presenting a region of condensed counterions within a radius of about 17 A from the DNA surface independent of sequence. The GC and CG pairs tend to associate with cations in the major groove of the DNA structure to a greater extent than the AT and TA pairs. Cation association is more frequent in the minor groove of AT than the GC pairs. In general, the

  18. The Trait Emotional Intelligence Questionnaire: Internal Structure, Convergent, Criterion, and Incremental Validity in an Italian Sample

    Science.gov (United States)

    Andrei, Federica; Smith, Martin M.; Surcinelli, Paola; Baldaro, Bruno; Saklofske, Donald H.

    2016-01-01

    This study investigated the structure and validity of the Italian translation of the Trait Emotional Intelligence Questionnaire. Data were self-reported from 227 participants. Confirmatory factor analysis supported the four-factor structure of the scale. Hierarchical regressions also demonstrated its incremental validity beyond demographics, the…

  19. Constructing a Validity Argument for the Objective Structured Assessment of Technical Skills (OSATS): A Systematic Review of Validity Evidence

    Science.gov (United States)

    Hatala, Rose; Cook, David A.; Brydges, Ryan; Hawkins, Richard

    2015-01-01

    In order to construct and evaluate the validity argument for the Objective Structured Assessment of Technical Skills (OSATS), based on Kane's framework, we conducted a systematic review. We searched MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC, Web of Science, Scopus, and selected reference lists through February 2013. Working in duplicate, we selected…

  20. PrimeShip-ASSAS: Advanced Ship Structural Analysis and Validation System

    OpenAIRE

    Yasuharu, Tsutsui; Takuya, Yoneya; Toshiro, Koiwa; Toshiro, Arima; Shin-ichi, Yamashita; Abdul M., Rahim; Technical Investigation and Information Department; Technical Investigation and Information Department; Technical Investigation and Information Department; Research Institute; Technical Investigation and Information Department; Technical Investigation and Information Department

    1996-01-01

    The Society has been establishing a total assessment system for ship hull structures with the aim of realizing consistent hull structural assessment over the life cycle of ships. It comprises a comprehensive computer software system intended to support advanced ship structural design and assessment. This system called PrimeShip-ASSAS, the Advanced Ship Structural Analysis and Validation System, is outlined in this paper.

  1. Validation of Superelement Modelling of Complex Offshore Support Structures

    DEFF Research Database (Denmark)

    Wang, Shaofeng; Larsen, Torben J.; Hansen, Anders Melchior

    2016-01-01

    calculations consisting of up to thousands design load cases needs to be evaluated. However, even the simplest aero-elastic model of such structures has many more DOFs than monopile, resulting in excessive computation burden. In order to deal with this problem, the superelement method has been introduced...... for modelling such structures. One superelement method has been proven very promising in the previous project of Wave Loads [1] and a fundamental question in such DOFs reduction methods is which modes that are essential and which modes can be neglected. For the jacket structure, the introduction of a gravity...

  2. Validation of optimization strategies using the linear structured production chains

    Science.gov (United States)

    Kusiak, Jan; Morkisz, Paweł; Oprocha, Piotr; Pietrucha, Wojciech; Sztangret, Łukasz

    2017-06-01

    Different optimization strategies applied to sequence of several stages of production chains were validated in this paper. Two benchmark problems described by ordinary differential equations (ODEs) were considered. A water tank and a passive CR-RC filter were used as the exemplary objects described by the first and the second order differential equations, respectively. Considered in the work optimization problems serve as the validators of strategies elaborated by the Authors. However, the main goal of research is selection of the best strategy for optimization of two real metallurgical processes which will be investigated in an on-going projects. The first problem will be the oxidizing roasting process of zinc sulphide concentrate where the sulphur from the input concentrate should be eliminated and the minimal concentration of sulphide sulphur in the roasted products has to be achieved. Second problem will be the lead refining process consisting of three stages: roasting to the oxide, oxide reduction to metal and the oxidizing refining. Strategies, which appear the most effective in considered benchmark problems will be candidates for optimization of the mentioned above industrial processes.

  3. Vivaldi: Visualization and validation of biomacromolecular NMR structures from the PDB

    Science.gov (United States)

    Hendrickx, Pieter M S; Gutmanas, Aleksandras; Kleywegt, Gerard J

    2013-01-01

    We describe Vivaldi (VIsualization and VALidation DIsplay; http://pdbe.org/vivaldi), a web-based service for the analysis, visualization, and validation of NMR structures in the Protein Data Bank (PDB). Vivaldi provides access to model coordinates and several types of experimental NMR data using interactive visualization tools, augmented with structural annotations and model-validation information. The service presents information about the modeled NMR ensemble, validation of experimental chemical shifts, residual dipolar couplings, distance and dihedral angle constraints, as well as validation scores based on empirical knowledge and databases. Vivaldi was designed for both expert NMR spectroscopists and casual non-expert users who wish to obtain a better grasp of the information content and quality of NMR structures in the public archive. © Proteins 2013. © 2012 Wiley Periodicals, Inc. PMID:23180575

  4. The Tridimensional Personality Questionnaire: Structural Validity and Comparison with the Multidimensional Personality Questionnaire.

    Science.gov (United States)

    Waller, Niels G.; And Others

    1991-01-01

    The structural and external validity of the Tridimensional Personality Questionnaire (TPQ) and the relations among TPQ lower-order and higher-order scales and those of the Multidimensional Personality Questionnaire were examined. Results for 1,236 adults support the TPQ's validity but indicate its failure to operationalize portions of the…

  5. Theoretical temperature model with experimental validation for CLIC Accelerating Structures

    CERN Document Server

    AUTHOR|(CDS)2126138; Vamvakas, Alex; Alme, Johan

    Micron level stability of the Compact Linear Collider (CLIC) components is one of the main requirements to meet the luminosity goal for the future $48 \\,km$ long underground linear accelerator. The radio frequency (RF) power used for beam acceleration causes heat generation within the aligned structures, resulting in mechanical movements and structural deformations. A dedicated control of the air- and water- cooling system in the tunnel is therefore crucial to improve alignment accuracy. This thesis investigates the thermo-mechanical behavior of the CLIC Accelerating Structure (AS). In CLIC, the AS must be aligned to a precision of $10\\,\\mu m$. The thesis shows that a relatively simple theoretical model can be used within reasonable accuracy to predict the temperature response of an AS as a function of the applied RF power. During failure scenarios or maintenance interventions, the RF power is turned off resulting in no heat dissipation and decrease in the overall temperature of the components. The theoretica...

  6. Internal consistency, convergent validity, and structural validity of the Japanese version of the Physical Activity Self-Regulation scale (PASR-12) among Japanese workers: A validation study.

    Science.gov (United States)

    Watanabe, Kazuhiro; Kawakami, Norito; Adachi, Hidehiko; Inoue, Shigeru; Meyer, M Renee Umstattd

    2017-01-24

    Self-regulation for physical activity is considered as one of the most effective factors in promoting physical activity. However, there is no reliable and valid scale to measure it in Japanese. The purpose of this study was to investigate the internal consistency, convergent validity, and structural validity of the newly developed Japanese version of the 12-item Physical Activity Self-Regulation scale (PASR-12) among Japanese workers. A cross-sectional Internet-based survey recruiting 516 Japanese workers was conducted in Japan. The PASR-12 was translated according to the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) task force guidelines. Physical activity and self-efficacy for physical activity were measured as comparisons for convergent validity. We calculated Cronbach's alphas, and conducted correlational analyses and confirmatory factor analysis (CFA). Of 516 workers, 485 workers were eligible for all analyses. Cronbach's alpha for the scale scores ranged from 0.79 to 0.95. The scores of the total and 6 factor scales of the Japanese version of the PASR-12 had small-to-moderate positive correlations with the total physical activity and self-efficacy. Moreover, the 6-factor hypothesized model demonstrated excellent fit (χ2 (39) = 100.74, CFI = 0.973, RMSEA = 0.057). The Japanese version of the PASR-12 showed good reliability and factor-based and construct validity. Therefore, this scale could be applied to assess self-regulation for physical activity among Japanese workers.

  7. LBA-ECO TG-07 Forest Structure Measurements for GLAS Validation: Santarem 2004

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides the results of a GLAS (the Geoscience Laser Altimeter System) forest structure validation survey conducted in Santarem and Sao...

  8. LBA-ECO TG-07 Forest Structure Measurements for GLAS Validation: Santarem 2004

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides the results of a GLAS (the Geoscience Laser Altimeter System) forest structure validation survey conducted in Santarem and Sao Jorge, Para...

  9. Construct Validity of a Simple Laparoscopic Ovarian Cystectomy Model Using a Validated Objective Structured Assessment of Technical Skills.

    Science.gov (United States)

    Chahine, Elizabeth Britton; Han, Chan Hee; Auguste, Tamika

    To determine the construct validity and interrater reliability of a laparoscopic ovarian cystectomy simulator using a global rating scale. Prospective blinded observational study (Canadian Task Force classification II.3). Academic teaching hospital. A total of 26 postgraduate year (PGY) 1 to 4 gynecology and obstetrics residents were recruited (15 junior residents, postgraduate year PGY 1-2 and 11 senior residents, PGY 3-4). We developed a simple, low-cost laparoscopic ovarian cystectomy simulator and incorporated it into our simulation curriculum. The simulation was directed at junior residents with instruction and immediate feedback in a scheduled simulation session once during the academic year. At the end of the year resident skills assessment, all levels were recorded with video using this model to assess the construct validity between junior and senior residents. Resident performance was later evaluated and scored by 2 blinded, experienced laparoscopists using a validated Objective Structured Assessment of Technical Skills (OSATS). Each resident received a unique identification number and the simulated laparoscopic ovarian cystectomy procedure was filmed during the end of the year assessment. Two blinded raters evaluated the video of each resident with the modified Global Rating Scale (OSATS), using 5 of the 7 domains (respect for tissue, time and motion, instrument handling, flow of operation and knowledge of specific procedure). An average of the 2 ratings was computed for each domain, and comparisons were made using the Mann-Whitney U test. Interrater reliability was calculated using the Kendall tau β correlation coefficient. Construct validity was determined by comparing the rank scores of the junior to senior residents in each domain. Construct validity and interrater reliability was demonstrated in all of the measured domains except for respect for tissue. This simple, low-cost model can be used to teach important laparoscopic ovarian cystectomy skills

  10. Experimental validation of the interaction between combustion and structural vibration.

    NARCIS (Netherlands)

    Huls, R.A.; de Boer, Andries; Kok, Jacobus B.W.; van der Hoogt, Peter

    2005-01-01

    To decrease NOx emissions from combustion systems, lean premixed combustion is used. A disadvantage is the increase in sound pressure levels in the combustor, resulting in an increased excitation of the surrounding structure: the liner. This causes fatigue, which limits the life time of the

  11. Validating a Finite Element Model of a Structure Subjected to Mine Blast with Experimental Modal Analysis

    Science.gov (United States)

    2017-11-01

    FE finite element MAC modal assurance criteria SAE Society of Automotive Engineers SDIC stereo-digital image correlation SLAD Survivability...ARL-TR-8224 ● NOV 2017 US Army Research Laboratory Validating a Finite Element Model of a Structure Subjected to Mine Blast with...NOV 2017 US Army Research Laboratory Validating a Finite Element Model of a Structure Subjected to Mine Blast with Experimental Modal

  12. Validation of the measurement model concept for error structure identification

    International Nuclear Information System (INIS)

    Shukla, Pavan K.; Orazem, Mark E.; Crisalle, Oscar D.

    2004-01-01

    The development of different forms of measurement models for impedance has allowed examination of key assumptions on which the use of such models to assess error structure are based. The stochastic error structures obtained using the transfer-function and Voigt measurement models were identical, even when non-stationary phenomena caused some of the data to be inconsistent with the Kramers-Kronig relations. The suitability of the measurement model for assessment of consistency with the Kramers-Kronig relations, however, was found to be more sensitive to the confidence interval for the parameter estimates than to the number of parameters in the model. A tighter confidence interval was obtained for Voigt measurement model, which made the Voigt measurement model a more sensitive tool for identification of inconsistencies with the Kramers-Kronig relations

  13. Charge-leveling and proper treatment of long-range electrostatics in all-atom molecular dynamics at constant pH.

    Science.gov (United States)

    Wallace, Jason A; Shen, Jana K

    2012-11-14

    Recent development of constant pH molecular dynamics (CpHMD) methods has offered promise for adding pH-stat in molecular dynamics simulations. However, until now the working pH molecular dynamics (pHMD) implementations are dependent in part or whole on implicit-solvent models. Here we show that proper treatment of long-range electrostatics and maintaining charge neutrality of the system are critical for extending the continuous pHMD framework to the all-atom representation. The former is achieved here by adding forces to titration coordinates due to long-range electrostatics based on the generalized reaction field method, while the latter is made possible by a charge-leveling technique that couples proton titration with simultaneous ionization or neutralization of a co-ion in solution. We test the new method using the pH-replica-exchange CpHMD simulations of a series of aliphatic dicarboxylic acids with varying carbon chain length. The average absolute deviation from the experimental pK(a) values is merely 0.18 units. The results show that accounting for the forces due to extended electrostatics removes the large random noise in propagating titration coordinates, while maintaining charge neutrality of the system improves the accuracy in the calculated electrostatic interaction between ionizable sites. Thus, we believe that the way is paved for realizing pH-controlled all-atom molecular dynamics in the near future.

  14. Latent structure and construct validity of the reinforcement sensitivity questionnaire

    Directory of Open Access Journals (Sweden)

    Mitrović Dušanka

    2008-01-01

    Full Text Available The Revised reinforcement sensitivity theory contains three basic systems: Behavioral inhibition system (BAS, Behavioral activation system (BIS and the Fight/ Flight/ Freeze (FFF system. In this model, BIS is a system for detection of potential conflict or threat, and FFFS differs three basic patterns of reaction to actual or perceived danger. In Study 1, which was aimed at the examination of the latent structure of the RSQ, was conducted on a sample of 472 participants of both genders. The best - fitting model suggests that, at the top level of hierarchy, three dimensions exist, which are analogous to the BIS, BAS and FFF. The last dimension contains three subordinate dimensions, which represent the subsystems of the FFF. Study 2, in which 203 subjects participated, was aimed at examination of the relations between the dimensions of the Revised reinforcement sensitivity theory and dimensions of the PEN model. Confirmatory factor analyses of the RSQ and EPQ-R dimensions revealed that the best-fitting model comprised three latent dimensions, the first one being analogous to the BIS - Neuroticism, the second one to the BAS - Extraversion, and the third to the Aggressiveness- Psychoticism. The structure of the latent dimensions is in accordance with the expectations. The results state that fear and anxiety (which neurophysiological distinction is emphasized by Gray, are substantively similar on the behavioral level. Also, the results suggest that the Freeze dimension is probably closer to the BIS system than to the FFF.

  15. Network-centric fuzzy resource manager: structure and validation

    Science.gov (United States)

    Smith, James F., III; Firth, Zachary

    2003-07-01

    A fuzzy logic expert system has been developed that automatically allocates electronic attack resources on different platforms in real-time. This resource manager is made up of four trees, the isolated platform tree, the multi-platform tree that allows an individual platform to respond to a threat. The multi-platform tree allows a group of platforms to respond to a threat in a collaborative fashion. A genetic algorithm is used to optimize the resource manager. A genetic program is used to evolve optimal fuzzy decision tree topology. The non-uniqueness of the tree structure is considered. The superiority of a genetic program evolved tree compared to a tree written down exclusively based on expertise is discussed. Fuzzy membership functions related to four fuzzy concepts are given. Experiments designed to test these concepts in the expert system are discussed, as well as the resource manager's ability to: allow multiple platforms to self-organize without the benefit of a commander; to tolerate errors made by other systems; and to deal with multiple distinct enemy strategies.

  16. Modal strain energy-based structural health monitoring validation on rib stiffened composite panels

    NARCIS (Netherlands)

    Hwang, Joong Sun; Müller, J. Marcelo; Loendersloot, Richard; Tinga, Tiedo

    2017-01-01

    Structural Health Monitoring (SHM) techniques are emerging more and more in aerospace composite structure applications. Validation of the SHM techniques is one of the issues to be addressed yet. Moreover, cost-efficient and reproducible ways to compare SHM methods can be attractive for researchers

  17. Structural validation of the Self-Compassion Scale with a German general population sample

    NARCIS (Netherlands)

    Coroiu, A.; Kwakkenbos, C.M.C.; Moran, C.; Thombs, B.D.; Albani, C.; Bourkas, S.; Zenger, M.; Brahler, E.; Körner, A.

    2018-01-01

    Background: Published validation studies have reported different factor structures for the Self-Compassion Scale (SCS). The objective of this study was to assess the factor structure of the SCS in a large general population sample representative of the German population. Methods: A German population

  18. The Dynamic Similitude Design Method of Thin Walled Structures and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Zhong Luo

    2016-01-01

    Full Text Available For the applicability of dynamic similitude models of thin walled structures, such as engine blades, turbine discs, and cylindrical shells, the dynamic similitude design of typical thin walled structures is investigated. The governing equation of typical thin walled structures is firstly unified, which guides to establishing dynamic scaling laws of typical thin walled structures. Based on the governing equation, geometrically complete scaling law of the typical thin walled structure is derived. In order to determine accurate distorted scaling laws of typical thin walled structures, three principles are proposed and theoretically proved by combining the sensitivity analysis and governing equation. Taking the thin walled annular plate as an example, geometrically complete and distorted scaling laws can be obtained based on the principles of determining dynamic scaling laws. Furthermore, the previous five orders’ accurate distorted scaling laws of thin walled annular plates are presented and numerically validated. Finally, the effectiveness of the similitude design method is validated by experimental annular plates.

  19. Structure validation of the Josephin domain of ataxin-3: Conclusive evidence for an open conformation

    International Nuclear Information System (INIS)

    Nicastro, Giuseppe; Habeck, Michael; Masino, Laura; Svergun, Dmitri I.; Pastore, Annalisa

    2006-01-01

    The availability of new and fast tools in structure determination has led to a more than exponential growth of the number of structures solved per year. It is therefore increasingly essential to assess the accuracy of the new structures by reliable approaches able to assist validation. Here, we discuss a specific example in which the use of different complementary techniques, which include Bayesian methods and small angle scattering, resulted essential for validating the two currently available structures of the Josephin domain of ataxin-3, a protein involved in the ubiquitin/proteasome pathway and responsible for neurodegenerative spinocerebellar ataxia of type 3. Taken together, our results demonstrate that only one of the two structures is compatible with the experimental information. Based on the high precision of our refined structure, we show that Josephin contains an open cleft which could be directly implicated in the interaction with polyubiquitin chains and other partners

  20. The structural validity of the Experience of Work and Life Circumstances Questionnaire (WLQ

    Directory of Open Access Journals (Sweden)

    Pieter Schaap

    2016-09-01

    Full Text Available Orientation: Best practice frameworks suggest that an assessment practitioner’s choice of an assessment tool should be based on scientific evidence that underpins the appropriate and just use of the instrument. This is a context-specific validity study involving a classified psychological instrument against the background of South African regulatory frameworks and contemporary validity theory principles. Research purpose: The aim of the study was to explore the structural validity of the Experience of Work and Life Circumstances Questionnaire (WLQ administered to employees in the automotive assembly plant of a South African automotive manufacturing company. Motivation for the study: Although the WLQ has been used by registered health practitioners and numerous researchers, evidence to support the structural validity is lacking. This study, therefore, addressed the need for context-specific empirical support for the validity of score inferences in respect of employees in a South African automotive manufacturing plant. Research design, approach and method: The research was conducted using a convenience sample (N = 217 taken from the automotive manufacturing company where the instrument was used. Reliability and factor analyses were carried out to explore the structural validity of the WLQ. Main findings: The reliability of the WLQ appeared to be acceptable, and the assumptions made about unidimensionality were mostly confirmed. One of the proposed higher-order structural models of the said questionnaire administered to the sample group was confirmed, whereas the other one was partially confirmed. Practical/managerial implications: The conclusion reached was that preliminary empirical grounds existed for considering the continued use of the WLQ (with some suggested refinements by the relevant company, provided the process of accumulating a body of validity evidence continued. Contribution/value-add: This study identified some of the difficulties

  1. Construct validity of the reporter-interpreter-manager-educator structure for assessing students' patient encounter skills

    DEFF Research Database (Denmark)

    Tolsgaard, Martin G.; Arendrup, Henrick; Lindhardt, Bjarne O.

    2012-01-01

    PURPOSE: The aim of this study, done in Denmark, was to explore the construct validity of a Reporter-Interpreter-Manager-Educator (RIME)-structured scoring format for assessing patient encounter skills. METHOD: The authors developed a RIME-structured scoring form and explored its construct validity...... in a two-step procedure. The first step (implemented in 2009) was a randomized, controlled, experimental study in which the performance of three groups (16 fourth-year medical students, 16 sixth-year medical students, and 16 interns) was assessed in two simulated patient encounters. The second step.......In the observational study, the mean RIME score was higher (83.8 [SD 15.5]), and advanced RIME levels were frequently missing or scored "not relevant" by the clinician examiners. CONCLUSION: In an experimental setup, the RIME structure demonstrated construct validity in terms of reflecting progress in competence...

  2. The hierarchical structure and construct validity of the PID-5 trait measure in adolescence.

    Science.gov (United States)

    De Clercq, Barbara; De Fruyt, Filip; De Bolle, Marleen; Van Hiel, Alain; Markon, Kristian E; Krueger, Robert F

    2014-04-01

    The DSM-5 may be the first edition that enables a developmental perspective on personality disorders because of its proposal to include a trait assessment in the Axis II section. The current study explores the reliability, structure, and construct validity of the Personality Inventory for DSM-5 (PID-5; Krueger, Derringer, Markon, Watson, & Skodol, 2012) in adolescents, a measure that assesses the proposed DSM-5 traits. A community sample of Flemish adolescents (N = 434; 44.7% male) provided self-reports on the PID-5 and the Dimensional Personality Symptom Itempool (DIPSI; De Clercq, De Fruyt, Van Leeuwen, & Mervielde, 2006). Results indicate an acceptable reliability for the majority of the PID-5 facets and a tendency toward structural convergence of the adolescent PID-5 structure with the adult proposal. Convergent validity with age-specific facets of personality pathology was generally supported, but discriminant validity appeared to be low. Beyond the findings that support the applicability of the PID-5 in adolescents, developmental issues may be responsible for specific differences in the adolescent PID-5 structure, the rather poor discriminant validity of the PID-5, and the lower reliability of a small number of PID-5 facets. These results indicate that further research on the validity of the PID-5 in younger age groups is required. © 2013 Wiley Periodicals, Inc.

  3. The Factor Structure and Validity of the Persian Version of the Baumrind Parenting Style Inventory

    OpenAIRE

    اصغر مینائی; سپیده نیک زاد

    2017-01-01

    In this study, the factor structure and validity of the Persian version of the Baumrind parenting style inventory were evaluated among 576 mothers of elementary school students in Tehran who had been selected through multistage cluster sampling method. This study is, due to its subject and purposes a descriptive study based on psychometric methods. The factor structure of the inventory was tested by AMOS software based on the fitting and modification indicators in the confirmatory factor anal...

  4. Talin-driven inside-out activation mechanism of platelet αIIbβ3 integrin probed by multimicrosecond, all-atom molecular dynamics simulations

    Science.gov (United States)

    Coller, Barry S.; Filizola, Marta

    2016-01-01

    Platelet aggregation is the consequence of the binding of extracellular bivalent ligands such as fibrinogen and von Willebrand factor to the high affinity, active state of integrin αIIbβ3. This state is achieved through a so-called “inside-out” mechanism characterized by the membrane-assisted formation of a complex between the F2 and F3 subdomains of intracellular protein talin and the integrin β3 tail. Here, we present the results of multi-microsecond, all-atom molecular dynamics simulations carried on the complete transmembrane (TM) and C-terminal (CT) domains of αIIbβ3 integrin in an explicit lipid-water environment, and in the presence or absence of the talin-1 F2 and F3 subdomains. These large-scale simulations provide unprecedented molecular-level insights into the talin-driven inside-out activation of αIIbβ3 integrin. Specifically, they suggest a preferred conformation of the complete αIIbβ3 TM/CT domains in a lipid-water environment, and testable hypotheses of key intermolecular interactions between αIIbβ3 integrin and the F2/F3 domains of talin-1. Notably, not only do these simulations give support to a stable left-handed reverse turn conformation of the αIIb juxtamembrane motif rather than a helical turn, but they raise the question as to whether TM helix separation is required for talin-driven integrin activation. PMID:24677266

  5. The tilt-dependent potential of mean force of a pair of DNA oligomers from all-atom molecular dynamics simulations

    International Nuclear Information System (INIS)

    Cortini, Ruggero; Cheng, Xiaolin

    2017-01-01

    Electrostatic interactions between DNA molecules have been extensively studied experimentally and theoretically, but several aspects (e.g. its role in determining the pitch of the cholesteric DNA phase) still remain unclear. Here, we performed large-scale all-atom molecular dynamics simulations in explicit water and 150 mM sodium chloride, to reconstruct the potential of mean force (PMF) of two DNA oligomers 24 base pairs long as a function of their interaxial angle and intermolecular distance. We find that the potential of mean force is dominated by total DNA charge, and not by the helical geometry of its charged groups. The theory of homogeneously charged cylinders fits well all our simulation data, and the fit yields the optimal value of the total compensated charge on DNA to ≈65% of its total fixed charge (arising from the phosphorous atoms), close to the value expected from Manning's theory of ion condensation. The PMF calculated from our simulations does not show a significant dependence on the handedness of the angle between the two DNA molecules, or its size is on the order of 1k B T. Thermal noise for molecules of the studied length seems to mask the effect of detailed helical charge patterns of DNA. The fact that in monovalent salt the effective interaction between two DNA molecules is independent on the handedness of the tilt may suggest that alternative mechanisms are required to understand the cholesteric phase of DNA.

  6. C6 Coefficients and Dipole Polarizabilities for All Atoms and Many Ions in Rows 1-6 of the Periodic Table.

    Science.gov (United States)

    Gould, Tim; Bučko, Tomáš

    2016-08-09

    Using time-dependent density functional theory (TDDFT) with exchange kernels, we calculate and test imaginary frequency-dependent dipole polarizabilities for all atoms and many ions in rows 1-6 of the periodic table. These are then integrated over frequency to produce C6 coefficients. Results are presented under different models: straight TDDFT calculations using two different kernels; "benchmark" TDDFT calculations corrected by more accurate quantum chemical and experimental data; and "benchmark" TDDFT with frozen orbital anions. Parametrizations are presented for 411+ atoms and ions, allowing results to be easily used by other researchers. A curious relationship, C6,XY ∝ [αX(0)αY(0)](0.73), is found between C6 coefficients and static polarizabilities α(0). The relationship C6,XY = 2C6,XC6,Y/[(αX/αY)C6,Y + (αY/αX)C6,X] is tested and found to work well (30% errors) in a small fraction of cases.

  7. Validity of a structured method of selecting abstracts for a plastic surgical scientific meeting

    NARCIS (Netherlands)

    van der Steen, LPE; Hage, JJ; Kon, M; Monstrey, SJ

    In 1999, the European Association of Plastic Surgeons accepted a structured method to assess and select the abstracts that are submitted for its yearly scientific meeting. The two criteria used to evaluate whether such a selection method is accurate were reliability and validity. The authors

  8. The Reliability, Validity, and Usefulness of the Objective Structured Clinical Examination (OSCE) in Dental Education

    Science.gov (United States)

    Graham, Roseanna

    2010-01-01

    This study evaluated the reliability, validity, and educational usefulness of a comprehensive, multidisciplinary Objective Structured Clinical Examination (OSCE) in dental education. The OSCE was administered to dental students at the Columbia University College of Dental Medicine (CDM) before they entered clinical training. Participants in this…

  9. Validation of the interface-GMRES(R) solution method for fluid-structure interactions

    NARCIS (Netherlands)

    Michler, C.; Van Brummelen, E.H.; In 't Groen, R.; De Borst, R.

    2006-01-01

    The numerical solution of fluid-structure interactions with the customary subiteration method incurs numerous deficiencies. We validate a recently proposed solution method based on the conjugation of subiteration with a Newton-Krylov method, and demonstrate its superiority and beneficial

  10. Experimental validation for calcul methods of structures having shock non-linearity

    International Nuclear Information System (INIS)

    Brochard, D.; Buland, P.

    1987-01-01

    For the seismic analysis of non-linear structures, numerical methods have been developed which need to be validated on experimental results. The aim of this paper is to present the design method of a test program which results will be used for this purpose. Some applications to nuclear components will illustrate this presentation [fr

  11. The Reliability, Validity, and Evaluation of the Objective Structured Clinical Examination in Podiatry (Chiropody).

    Science.gov (United States)

    Woodburn, Jim; Sutcliffe, Nick

    1996-01-01

    The Objective Structured Clinical Examination (OSCE), initially developed for undergraduate medical education, has been adapted for assessment of clinical skills in podiatry students. A 12-month pilot study found the test had relatively low levels of reliability, high construct and criterion validity, and good stability of performance over time.…

  12. Implicit structural inversion of gravity data using linear programming, a validation study

    NARCIS (Netherlands)

    Zon, A.T. van; Roy Chowdhury, K.

    2010-01-01

    In this study, a regional scale gravity data set has been inverted to infer the structure (topography) of the top of the basement underlying sub-horizontal strata. We apply our method to this real data set for further proof of concept, validation and benchmarking against results from an earlier

  13. Contribution to the validation of thermal ratchetting prevision methods in metallic structures; Contribution a la validation des methodes de prevision du rochet thermique dans les structures metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Rakotovelo, A.M

    1998-03-01

    This work concerns the steady state assessment in the metallic structures subjected to thermomechanical cyclic loadings in biaxial stress state. The effect of the short time mechanical overloads is also investigated. The first chapter is devoted to a bibliographic research concerning the behaviour of the materials and the structures in the cyclic plasticity. Some works relate to the experimental aspect as well as the numerical one for the steady state assessment of such structures are presented. The experimental part of the study is presented in the second chapter. The experimental device was carried out in order to prescribe tension and torsion forces combined with cyclic thermal loading. Some tests was then carried out, among these tests certain include some overloads in tension or torsion. The last chapter describes the numerical calculations using different models (linear isotropic hardening, linear kinematic hardening and elasto-viscoplastic Chaboche's model) and the application of some simplified methods for the ratchetting assessment in the structures. We have considered two categories of methods. The first one is based on an elastic analysis (Bree's diagram, 3 Sm rule, efficiency rule) and the second one combines elastic analysis and elastoplastic analysis of the first cycle (Gatt's and Taleb's methods). The results of this study have enabled: to validate in the biaxial stress state an expression which takes into account the effect of mechanical short time overloads; to test the performances of considered models to describe the evolution of the structure during the first cycle and to take into account the effect of short time overloads. Among the considered models, the elastoplastic Chaboche's model seems to be the most accurate to describe the structure's behaviour during the first cycles; to validate some simplified methods. Certain methods based only on elastic analysis (Bee's diagram and efficiency rule) seem not

  14. Structural Validity of the WISC-IV for Students With Learning Disabilities.

    Science.gov (United States)

    Styck, Kara M; Watkins, Marley W

    2016-01-01

    The structural validity of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was evaluated using confirmatory factor analysis for a clinical sample of 1,537 students diagnosed with specific learning disabilities (SLD) by school psychologists in two large southwestern school districts. Results indicated that a bifactor model consisting of four first-order domain specific factors and a general intelligence breadth factor fit the data best. Consequently, the structural validity of the WISC-IV for students with SLD was supported by the results of the present study. The general intelligence factor contributed the most information, accounting for 48% of the common variance. Given this structure, it was recommended that score interpretation should emphasize the Full-Scale IQ score because of the marginal contributions of the first-order domain-specific factors and their low precision of measurement independent of the general factor. © Hammill Institute on Disabilities 2014.

  15. Three-factor structure for Epistemic Belief Inventory: A cross-validation study.

    Directory of Open Access Journals (Sweden)

    Francisco Leal-Soto

    Full Text Available Research on epistemic beliefs has been hampered by lack of validated models and measurement instruments. The most widely used instrument is the Epistemological Questionnaire, which has been criticized for validity, and it has been proposed a new instrument based in the Epistemological Questionnaire: the Epistemic Belief Inventory. The Spanish-language version of Epistemic Belief Inventory was applied to 1,785 Chilean high school students. Exploratory and confirmatory factor analyses in independent subsamples were performed. A three factor structure emerged and was confirmed. Reliability was comparable to other studies, and the factor structure was invariant among randomized subsamples. The structure that was found does not replicate the one proposed originally, but results are interpreted in light of embedded systemic model of epistemological beliefs.

  16. ProTSAV: A protein tertiary structure analysis and validation server.

    Science.gov (United States)

    Singh, Ankita; Kaushik, Rahul; Mishra, Avinash; Shanker, Asheesh; Jayaram, B

    2016-01-01

    Quality assessment of predicted model structures of proteins is as important as the protein tertiary structure prediction. A highly efficient quality assessment of predicted model structures directs further research on function. Here we present a new server ProTSAV, capable of evaluating predicted model structures based on some popular online servers and standalone tools. ProTSAV furnishes the user with a single quality score in case of individual protein structure along with a graphical representation and ranking in case of multiple protein structure assessment. The server is validated on ~64,446 protein structures including experimental structures from RCSB and predicted model structures for CASP targets and from public decoy sets. ProTSAV succeeds in predicting quality of protein structures with a specificity of 100% and a sensitivity of 98% on experimentally solved structures and achieves a specificity of 88%and a sensitivity of 91% on predicted protein structures of CASP11 targets under 2Å.The server overcomes the limitations of any single server/method and is seen to be robust in helping in quality assessment. ProTSAV is freely available at http://www.scfbio-iitd.res.in/software/proteomics/protsav.jsp. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Validation of the Transient Structural Response of a Threaded Assembly: Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Doebling, Scott W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Robertson, Amy N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maupin, Ryan D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schultze, John F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cundy, Amanda L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hylok, Jeff E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2004-04-01

    This report explores the application of model validation techniques in structural dynamics. The problem of interest is the propagation of an explosive-driven mechanical shock through a complex threaded joint. The study serves the purpose of assessing whether validating a large-size computational model is feasible, which unit experiments are required, and where the main sources of uncertainty reside. The results documented here are preliminary, and the analyses are exploratory in nature. The results obtained to date reveal several deficiencies of the analysis, to be rectified in future work.

  18. Structural refinement and prediction of potential CCR2 antagonists through validated multi-QSAR modeling studies.

    Science.gov (United States)

    Amin, Sk Abdul; Adhikari, Nilanjan; Baidya, Sandip Kumar; Gayen, Shovanlal; Jha, Tarun

    2018-01-03

    Chemokines trigger numerous inflammatory responses and modulate the immune system. The interaction between monocyte chemoattractant protein-1 and chemokine receptor 2 (CCR2) may be the cause of atherosclerosis, obesity, and insulin resistance. However, CCR2 is also implicated in other inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, asthma, and neuropathic pain. Therefore, there is a paramount importance of designing potent and selective CCR2 antagonists despite a number of drug candidates failed in clinical trials. In this article, 83 CCR2 antagonists by Jhonson and Jhonson Pharmaceuticals have been considered for robust validated multi-QSAR modeling studies to get an idea about the structural and pharmacophoric requirements for designing more potent CCR2 antagonists. All these QSAR models were validated and statistically reliable. Observations resulted from different modeling studies correlated and validated results of other ones. Finally, depending on these QSAR observations, some new molecules were proposed that may exhibit higher activity against CCR2.

  19. [French version of structured interviews for the Glasgow Outcome Scale: guidelines and first studies of validation].

    Science.gov (United States)

    Fayol, P; Carrière, H; Habonimana, D; Preux, P-M; Dumond, J-J

    2004-05-01

    The Glasgow Outcome Scale (GOS) is the most widely used outcome measure after traumatic brain injury. The GOS's reliability is improved by a structured interview. The two aims of this paper were to present a French version of the structured interview for the five-point Glasgow Outcome Scale and the extended eight-point GOS (GOSE) and to study their validity. The French version was developed using back-translation. Concurrent validity was studied by comparison with GOS/GOSE without structured interview. Inter-rater reliability was studied by comparison between assignments made by untrained head injury observers and trained head injury observers. Strength of agreement between ratings was assessed using the Kappa statistic. The French version and the guidelines for their use are given in the Appendix. Ratings were made for 25 brain injured patients and 25 relatives. Concurrent validity was good and inter-rater reliability was excellent. Using the structured interview for the GOS will give a more reliable assessment of the outcome of brain injured patients by French-speaking rehabilitation teams and a more precise assessment with the extended GOS.

  20. A mobile sensing system for structural health monitoring: design and validation

    International Nuclear Information System (INIS)

    Zhu, Dapeng; Yi, Xiaohua; Wang, Yang; Lee, Kok-Meng; Guo, Jiajie

    2010-01-01

    This paper describes a new approach using mobile sensor networks for structural health monitoring. Compared with static sensors, mobile sensor networks offer flexible system architectures with adaptive spatial resolutions. The paper first describes the design of a mobile sensing node that is capable of maneuvering on structures built with ferromagnetic materials. The mobile sensing node can also attach/detach an accelerometer onto/from the structural surface. The performance of the prototype mobile sensor network has been validated through laboratory experiments. Two mobile sensing nodes are adopted for navigating on a steel portal frame and providing dense acceleration measurements. Transmissibility function analysis is conducted to identify structural damage using data collected by the mobile sensing nodes. This preliminary work is expected to spawn transformative changes in the use of mobile sensors for future structural health monitoring

  1. The Factor Structure and Validity of the Persian Version of the Baumrind Parenting Style Inventory

    Directory of Open Access Journals (Sweden)

    اصغر مینائی

    2017-06-01

    Full Text Available In this study, the factor structure and validity of the Persian version of the Baumrind parenting style inventory were evaluated among 576 mothers of elementary school students in Tehran who had been selected through multistage cluster sampling method. This study is, due to its subject and purposes a descriptive study based on psychometric methods. The factor structure of the inventory was tested by AMOS software based on the fitting and modification indicators in the confirmatory factor analysis. The results showed that all items of the parenting style inventory except the items of 24, 8, 13, 18, assess the previously determined factors of the inventory, and that the inventory’s questions have a relatively good validity. Also, stratified alpha was used to calculate the reliability of the whole inventory, and Guttman coefficient was utilized to calculate the reliability of subscales. The outcomes indicated that the inventory and its subscales possess a relatively good reliability.

  2. Aggressive Attitudes in Middle Schools: A Factor Structure and Criterion-Related Validity Study.

    Science.gov (United States)

    Huang, Francis L; Cornell, Dewey G; Konold, Timothy R

    2015-08-01

    Student attitudes toward aggression have been linked to individual aggressive behavior, but the relationship between school-wide normative beliefs about aggression and aggressive behavior poses some important measurement challenges that have not been adequately examined. The current study investigated the factor structure, measurement invariance, and criterion-related validity of a six-item Aggressive Attitudes scale using a large sample of seventh- and eighth-grade students (n = 39,364) from 423 schools. Analytic procedures accounted for the frequently ignored modeling problems of clustered and ordinal data to provide more reliable and accurate model estimates and standard errors. The resulting second-order factor structure of the Aggressive Attitudes scale demonstrated measurement invariance across gender, grade, and race/ethnicity groups. Criterion-related validity was supported with eight student- and school-level indices of aggressive behavior. © The Author(s) 2014.

  3. Validation of Temperature Histories for Structural Steel Welds Using Estimated Heat-Affected-Zone Edges

    Science.gov (United States)

    2016-10-12

    possibly not convenient. A classification of steels that can be characterized for quantitative estimation of solidification and HAZ edge boundaries is...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6394--16-9690 Validation of Temperature Histories for Structural Steel Welds Using...SECURITY CLASSIFICATION OF: a. REPORT 19a. NAME OF RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (include area code) b. ABSTRACT c. THIS PAGE 18. NUMBER OF

  4. Validation of an employee satisfaction model: A structural equation model approach

    OpenAIRE

    Ophillia Ledimo; Nico Martins

    2015-01-01

    The purpose of this study was to validate an employee satisfaction model and to determine the relationships between the different dimensions of the concept, using the structural equation modelling approach (SEM). A cross-sectional quantitative survey design was used to collect data from a random sample of (n=759) permanent employees of a parastatal organisation. Data was collected using the Employee Satisfaction Survey (ESS) to measure employee satisfaction dimensions. Following the steps of ...

  5. The Structure of Preschoolers' Emotion Knowledge: Model Equivalence and Validity Using a Structural Equation Modeling Approach

    Science.gov (United States)

    Bassett, Hideko Hamada; Denham, Susanne; Mincic, Melissa; Graling, Kelly

    2012-01-01

    Research Findings: A theory-based 2-factor structure of preschoolers' emotion knowledge (i.e., recognition of emotional expression and understanding of emotion-eliciting situations) was tested using confirmatory factor analysis. Compared to 1- and 3-factor models, the 2-factor model showed a better fit to the data. The model was found to be…

  6. Structurally-compliant rocket engine combustion chamber: Experimental/analytical validation

    Science.gov (United States)

    Jankovsky, R. S.; Kazaroff, J. M.; Galford, G. R.; Arya, V. K.

    1993-11-01

    A new, structurally-compliant rocket engine combustion chamber design has been validated through analysis and experiment. Subscale, tubular channel chambers have been cyclically tested, and analytically evaluated. Cyclic lives were determined to have a potential for 1000 percent increase in life over that of rectangular channel designs, the current state-of-the-art. Greater structural compliance in the circumferential direction gives rise to lower thermal strains during hot firing, resulting in lower thermal strain ratcheting and longer predicted fatigue lives. Thermal/durability analyses of the combustion chamber design, involving cyclic temperatures, strains, and low-cycle fatigue lives have corroborated the experimental observations.

  7. Methodologies for Verification and Validation of Space Launch System (SLS) Structural Dynamic Models: Appendices

    Science.gov (United States)

    Coppolino, Robert N.

    2018-01-01

    Verification and validation (V&V) is a highly challenging undertaking for SLS structural dynamics models due to the magnitude and complexity of SLS subassemblies and subassemblies. Responses to challenges associated with V&V of Space Launch System (SLS) structural dynamics models are presented in Volume I of this paper. Four methodologies addressing specific requirements for V&V are discussed. (1) Residual Mode Augmentation (RMA). (2) Modified Guyan Reduction (MGR) and Harmonic Reduction (HR, introduced in 1976). (3) Mode Consolidation (MC). Finally, (4) Experimental Mode Verification (EMV). This document contains the appendices to Volume I.

  8. Protein structure validation by generalized linear model root-mean-square deviation prediction.

    Science.gov (United States)

    Bagaria, Anurag; Jaravine, Victor; Huang, Yuanpeng J; Montelione, Gaetano T; Güntert, Peter

    2012-02-01

    Large-scale initiatives for obtaining spatial protein structures by experimental or computational means have accentuated the need for the critical assessment of protein structure determination and prediction methods. These include blind test projects such as the critical assessment of protein structure prediction (CASP) and the critical assessment of protein structure determination by nuclear magnetic resonance (CASD-NMR). An important aim is to establish structure validation criteria that can reliably assess the accuracy of a new protein structure. Various quality measures derived from the coordinates have been proposed. A universal structural quality assessment method should combine multiple individual scores in a meaningful way, which is challenging because of their different measurement units. Here, we present a method based on a generalized linear model (GLM) that combines diverse protein structure quality scores into a single quantity with intuitive meaning, namely the predicted coordinate root-mean-square deviation (RMSD) value between the present structure and the (unavailable) "true" structure (GLM-RMSD). For two sets of structural models from the CASD-NMR and CASP projects, this GLM-RMSD value was compared with the actual accuracy given by the RMSD value to the corresponding, experimentally determined reference structure from the Protein Data Bank (PDB). The correlation coefficients between actual (model vs. reference from PDB) and predicted (model vs. "true") heavy-atom RMSDs were 0.69 and 0.76, for the two datasets from CASD-NMR and CASP, respectively, which is considerably higher than those for the individual scores (-0.24 to 0.68). The GLM-RMSD can thus predict the accuracy of protein structures more reliably than individual coordinate-based quality scores. Copyright © 2011 The Protein Society.

  9. Assessing the diagnostic validity of a structured psychiatric interview in a first-admission hospital sample

    DEFF Research Database (Denmark)

    Nordgaard, Julie; Revsbech, Rasmus; Sæbye, Ditte

    2012-01-01

    The use of structured psychiatric interviews performed by non-clinicians is frequent for research purposes and is becoming increasingly common in clini-cal practice. The validity of such interviews has rarely been evaluated empirically. In this study of a sample of 100 diagnostically heterogeneous......, first-admitted inpatients, the results of an assessment with the Structured Clinical Interview for DSM-IV (SCID), yielding a DSM-IV diagnosis and performed by a trained non-clinician, were compared with a consensus lifetime best diagnostic estimate (DSM-IV) by two experienced research clinicians, based...... on multiple sources of information, which included videotaped comprehensive semi-structured narrative interviews. The overall kappa agreement was 0.18. The sensitivity and specificity for the diagnosis of schizophrenia by SCID were 19% and 100%, respectively. It is concluded that structured interviews...

  10. Full-Scale Structural and NDI Validation Tests of Bonded Composite Doublers for Commercial Aircraft Applications

    Energy Technology Data Exchange (ETDEWEB)

    Roach, D.; Walkington, P.

    1999-02-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single Boron-Epoxy composite doubler to the damaged structure. Most of the concerns surrounding composite doubler technology pertain to long-term survivability, especially in the presence of non-optimum installations, and the validation of appropriate inspection procedures. This report focuses on a series of full-scale structural and nondestructive inspection (NDI) tests that were conducted to investigate the performance of Boron-Epoxy composite doublers. Full-scale tests were conducted on fuselage panels cut from retired aircraft. These full-scale tests studied stress reductions, crack mitigation, and load transfer capabilities of composite doublers using simulated flight conditions of cabin pressure and axial stress. Also, structures which modeled key aspects of aircraft structure repairs were subjected to extreme tension, shear and bending loads to examine the composite laminate's resistance to disbond and delamination flaws. Several of the structures were loaded to failure in order to determine doubler design margins. Nondestructive inspections were conducted throughout the test series in order to validate appropriate techniques on actual aircraft structure. The test results showed that a properly designed and installed composite doubler is able to enhance fatigue life, transfer load away from damaged structure, and avoid the introduction of new stress risers (i.e. eliminate global reduction in the fatigue life of the structure). Comparisons with test data obtained prior to the doubler installation revealed that stresses in the parent material can be reduced 30%--60% through the use of the composite doubler. Tests to failure demonstrated that the bondline is able to transfer plastic strains into the doubler and that

  11. Validating metal binding sites in macromolecule structures using the CheckMyMetal web server

    Science.gov (United States)

    Zheng, Heping; Chordia, Mahendra D.; Cooper, David R.; Chruszcz, Maksymilian; Müller, Peter; Sheldrick, George M.

    2015-01-01

    Metals play vital roles in both the mechanism and architecture of biological macromolecules. Yet structures of metal-containing macromolecules where metals are misidentified and/or suboptimally modeled are abundant in the Protein Data Bank (PDB). This shows the need for a diagnostic tool to identify and correct such modeling problems with metal binding environments. The "CheckMyMetal" (CMM) web server (http://csgid.org/csgid/metal_sites/) is a sophisticated, user-friendly web-based method to evaluate metal binding sites in macromolecular structures in respect to 7350 metal binding sites observed in a benchmark dataset of 2304 high resolution crystal structures. The protocol outlines how the CMM server can be used to detect geometric and other irregularities in the structures of metal binding sites and alert researchers to potential errors in metal assignment. The protocol also gives practical guidelines for correcting problematic sites by modifying the metal binding environment and/or redefining metal identity in the PDB file. Several examples where this has led to meaningful results are described in the anticipated results section. CMM was designed for a broad audience—biomedical researchers studying metal-containing proteins and nucleic acids—but is equally well suited for structural biologists to validate new structures during modeling or refinement. The CMM server takes the coordinates of a metal-containing macromolecule structure in the PDB format as input and responds within a few seconds for a typical protein structure modeled with a few hundred amino acids. PMID:24356774

  12. A Structured Clinical Interview for Kleptomania (SCI-K): preliminary validity and reliability testing.

    Science.gov (United States)

    Grant, Jon E; Kim, Suck Won; McCabe, James S

    2006-06-01

    Kleptomania presents difficulties in diagnosis for clinicians. This study aimed to develop and test a DSM-IV-based diagnostic instrument for kleptomania. To assess for current kleptomania the Structured Clinical Interview for Kleptomania (SCI-K) was administered to 112 consecutive subjects requesting psychiatric outpatient treatment for a variety of disorders. Reliability and validity were determined. Classification accuracy was examined using the longitudinal course of illness. The SCI-K demonstrated excellent test-retest (Phi coefficient = 0.956 (95% CI = 0.937, 0.970)) and inter-rater reliability (phi coefficient = 0.718 (95% CI = 0.506, 0.848)) in the diagnosis of kleptomania. Concurrent validity was observed with a self-report measure using DSM-IV kleptomania criteria (phi coefficient = 0.769 (95% CI = 0.653, 0.850)). Discriminant validity was observed with a measure of depression (point biserial coefficient = -0.020 (95% CI = -0.205, 0.166)). The SCI-K demonstrated both high sensitivity and specificity based on longitudinal assessment. The SCI-K demonstrated excellent reliability and validity in diagnosing kleptomania in subjects presenting with various psychiatric problems. These findings require replication in larger groups, including non-psychiatric populations, to examine their generalizability. Copyright (c) 2006 John Wiley & Sons, Ltd.

  13. Validation of a fluid-structure interaction numerical model for predicting flow transients in arteries.

    Science.gov (United States)

    Kanyanta, V; Ivankovic, A; Karac, A

    2009-08-07

    Fluid-structure interaction (FSI) numerical models are now widely used in predicting blood flow transients. This is because of the importance of the interaction between the flowing blood and the deforming arterial wall to blood flow behaviour. Unfortunately, most of these FSI models lack rigorous validation and, thus, cannot guarantee the accuracy of their predictions. This paper presents the comprehensive validation of a two-way coupled FSI numerical model, developed to predict flow transients in compliant conduits such as arteries. The model is validated using analytical solutions and experiments conducted on polyurethane mock artery. Flow parameters such as pressure and axial stress (and precursor) wave speeds, wall deformations and oscillating frequency, fluid velocity and Poisson coupling effects, were used as the basis of this validation. Results show very good comparison between numerical predictions, analytical solutions and experimental data. The agreement between the three approaches is generally over 95%. The model also shows accurate prediction of Poisson coupling effects in unsteady flows through flexible pipes, which up to this stage have only being predicted analytically. Therefore, this numerical model can accurately predict flow transients in compliant vessels such as arteries.

  14. The validity and clinical utility of structured diagnoses of antisocial personality disorder with forensic patients.

    Science.gov (United States)

    Marin-Avellan, Luisa E; McGauley, Gillian A; Campbell, Colin D; Fonagy, Peter

    2014-08-01

    Current DSM-based instruments for personality disorders (PDs) limit the investigation of the course and outcome of treatment of these disorders. This study examined the validity of the Shedler-Westen Assessment Procedure-200 (SWAP-200) and the Structured Clinical Interview for DSM-IV Axis II PD (SCID-II) in a sample of forensic PD patients. Results based on 66 participants indicated that the SWAP-200 Q-factors reduced the frequency of diagnostic comorbidity of PD categories by half compared with the SCID-II. Only the SWAP-200's Antisocial PD category showed good convergent and discriminant validity with respect to other instruments describing aspects of PD. The validity of the cutoff score for severe antisocial PD was confirmed, and this category predicted severe incidents in the hospital at 1 year of follow-up. A violence risk scale was constructed, which differentiated violent and nonviolent offenders. The results support the validity of the SWAP-200 and its potential clinical utility with forensic PD patients.

  15. Structural validity and reliability of the healthcare professionals' economic reasoning questionnaire

    Directory of Open Access Journals (Sweden)

    Vuković Mira H.

    2015-01-01

    Full Text Available Introduction: The structure of healthcare professionals' economic reasoning (HPER is still unknown. The aim: The structural validity and the reliability of the HPER questionnaire were evaluated. Methods: The psychometric study about evaluation of the HPER factors was conducted. The healthcare professionals (physicians, dentists, pharmacists that are employed in healthcare state sector of Republic of Serbia were interviewed. The HPER Questionnaire contained 29 preliminary items. Its structure was evaluated by Principal Component Analysis for categorial and ordinal data. Results: The 9 items that defined seven HPER factors were extracted: (1 the negligence of the cost of quality by the administration and financier; (2 the consideration of the market price and healthcare benefit; (3 market orientation considering patient's requests; (4 the recognition of inadequate resource alocations by non-medical administrative authority; (5 the attitude about redirecting the profit from state to private healthcare sector; (6 the recognition of the unjustified spending by the healthcare professionals and (7 the relationship physician/patient. Conclusion: The HPER-9 Questionnaire has high structural validity and reliability in the HPER measurement.

  16. Validation of diffusion tensor MRI measurements of cardiac microstructure with structure tensor synchrotron radiation imaging.

    Science.gov (United States)

    Teh, Irvin; McClymont, Darryl; Zdora, Marie-Christine; Whittington, Hannah J; Davidoiu, Valentina; Lee, Jack; Lygate, Craig A; Rau, Christoph; Zanette, Irene; Schneider, Jürgen E

    2017-03-10

    Diffusion tensor imaging (DTI) is widely used to assess tissue microstructure non-invasively. Cardiac DTI enables inference of cell and sheetlet orientations, which are altered under pathological conditions. However, DTI is affected by many factors, therefore robust validation is critical. Existing histological validation is intrinsically flawed, since it requires further tissue processing leading to sample distortion, is routinely limited in field-of-view and requires reconstruction of three-dimensional volumes from two-dimensional images. In contrast, synchrotron radiation imaging (SRI) data enables imaging of the heart in 3D without further preparation following DTI. The objective of the study was to validate DTI measurements based on structure tensor analysis of SRI data. One isolated, fixed rat heart was imaged ex vivo with DTI and X-ray phase contrast SRI, and reconstructed at 100 μm and 3.6 μm isotropic resolution respectively. Structure tensors were determined from the SRI data and registered to the DTI data. Excellent agreement in helix angles (HA) and transverse angles (TA) was observed between the DTI and structure tensor synchrotron radiation imaging (STSRI) data, where HA DTI-STSRI  = -1.4° ± 23.2° and TA DTI-STSRI  = -1.4° ± 35.0° (mean ± 1.96 standard deviation across all voxels in the left ventricle). STSRI confirmed that the primary eigenvector of the diffusion tensor corresponds with the cardiomyocyte long-axis across the whole myocardium. We have used STSRI as a novel and high-resolution gold standard for the validation of DTI, allowing like-with-like comparison of three-dimensional tissue structures in the same intact heart free of distortion. This represents a critical step forward in independently verifying the structural basis and informing the interpretation of cardiac DTI data, thereby supporting the further development and adoption of DTI in structure-based electro-mechanical modelling and routine clinical

  17. Examining the Reliability, Validity and Factor Structure of the DRS-15 with College Athletes

    Directory of Open Access Journals (Sweden)

    Leilani Madrigal

    2016-07-01

    Full Text Available Hardiness, comprising feelings of commitment, control and challenge, is most frequently measured with the Dispositional Resiliency Scale (DRS, but little work has been done with the brief 15-item version.To examine the factor structure, reliability, validity, and item functioning for gender invariance of the 15-item DRS with 525 collegiate athletes from a wide range of sports. Convergent and divergent validity were examined through relationships with mental toughness, grit and competitive anxiety. Participants completed measures of mental toughness, optimism, grit, competitive anxiety, and the DRS-15.Confirmatory Factor Analysis revealed a poor fit for the three-factor hardiness model, and subsequent exploratory factor analysis yielded a four-factor model with better fit than the three-factor structure. Additionally, several items appear to be biased towards males or females. The fourth factor may be unique to the collegiate athlete population, and related to perceived lack of control in future life directions. Convergent and divergent validity were supported through correlations of DRS scores with related measures.The four-factor model should be tested with different samples to determine if these changes should be adapted when using the DRS-15 in collegiate athletics or other settings.

  18. Estimation of spatial covariance structures by adjoint state maximum likelihood cross-validation: 1. Theory

    Science.gov (United States)

    Samper, F. Javier; Neuman, Shlomo P.

    1989-03-01

    This series of three papers describes a cross-validation method to estimate the spatial covariance structure of intrinsic or nonintrinsic random functions from point or spatially averaged data that may be corrupted by noise. Any number of relevant parameters, including nugget effect, can be estimated. The theory, described in this paper, is based on a maximum likelihood approach which treats the cross-validation errors as Gaussian. Various a posteriori statistical tests are used to verify this hypothesis and to show that in many cases, correlation between these errors is weak. The log likelihood criterion is optimized through a combination of conjugate gradient algorithms. An adjoint state theory is used to efficiently calculate the gradient of the estimation criterion, optimize the step size downgradient, and compute a lower bound for the covariance matrix of the estimation errors. Issues related to the identifiability, stability, and uniqueness of the resulting adjoint state maximum likelihood cross-validation (ASMLCV) method are discussed. This paper also describes the manner in which ASMLCV allows one to use model structure identification criteria to select the best covariance model among a given set of alternatives. Practical aspects of ASMLCV and its application to synthetic data are presented in paper 2 (Samper and Neuman, this issue (a)). Applications to real hydrogeological data (transmissivities and groundwater levels) have been presented elsewhere, while hydrochemical and isotopic data are analyzed by ASMLCV in paper 3 (Samper and Neuman, this issue (b)).

  19. 3D structure tensor analysis of light microscopy data for validating diffusion MRI.

    Science.gov (United States)

    Khan, Ahmad Raza; Cornea, Anda; Leigland, Lindsey A; Kohama, Steven G; Jespersen, Sune Nørhøj; Kroenke, Christopher D

    2015-05-01

    Diffusion magnetic resonance imaging (d-MRI) is a powerful non-invasive and non-destructive technique for characterizing brain tissue on the microscopic scale. However, the lack of validation of d-MRI by independent experimental means poses an obstacle to accurate interpretation of data acquired using this method. Recently, structure tensor analysis has been applied to light microscopy images, and this technique holds promise to be a powerful validation strategy for d-MRI. Advantages of this approach include its similarity to d-MRI in terms of averaging the effects of a large number of cellular structures, and its simplicity, which enables it to be implemented in a high-throughput manner. However, a drawback of previous implementations of this technique arises from it being restricted to 2D. As a result, structure tensor analyses have been limited to tissue sectioned in a direction orthogonal to the direction of interest. Here we describe the analytical framework for extending structure tensor analysis to 3D, and utilize the results to analyze serial image "stacks" acquired with confocal microscopy of rhesus macaque hippocampal tissue. Implementation of 3D structure tensor procedures requires removal of sources of anisotropy introduced in tissue preparation and confocal imaging. This is accomplished with image processing steps to mitigate the effects of anisotropic tissue shrinkage, and the effects of anisotropy in the point spread function (PSF). In order to address the latter confound, we describe procedures for measuring the dependence of PSF anisotropy on distance from the microscope objective within tissue. Prior to microscopy, ex vivo d-MRI measurements performed on the hippocampal tissue revealed three regions of tissue with mutually orthogonal directions of least restricted diffusion that correspond to CA1, alveus and inferior longitudinal fasciculus. We demonstrate the ability of 3D structure tensor analysis to identify structure tensor orientations that

  20. Design, Manufacturing and Experimental Validation of Optical Fiber Sensors Based Devices for Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Angela CORICCIATI

    2016-06-01

    Full Text Available The use of optical fiber sensors is a promising and rising technique used for Structural Health Monitoring (SHM, because permit to monitor continuously the strain and the temperature of the structure where they are applied. In the present paper three different types of smart devices, that are composite materials with an optical fiber sensor embedded inside them during the manufacturing process, are described: Smart Patch, Smart Rebar and Smart Textile, which are respectively a plate for local exterior intervention, a rod for shear and flexural interior reinforcement and a textile for an external whole application. In addition to the monitoring aim, the possible additional function of these devices could be the reinforcement of the structures where they are applied. In the present work, after technology manufacturing description, the experimental laboratory characterization of each device is discussed. At last, smart devices application on medium scale masonry walls and their validation by mechanical tests is described.

  1. Interrater reliability and discriminative validity of the structural elements of the Ayres Sensory Integration Fidelity Measure.

    Science.gov (United States)

    May-Benson, Teresa A; Roley, Susanne Smith; Mailloux, Zoe; Parham, L Diane; Koomar, Jane; Schaaf, Roseann C; Jaarsveld, Annamarie Van; Cohn, Ellen

    2014-01-01

    This study examined the reliability and validity of the structural section of the Ayres Sensory Integration® Fidelity Measure© (ASIFM), which provides a method for monitoring the extent to which an intervention was implemented as conceptualized in studies of occupational therapy using sensory integration intervention methods (OT-SI). We examined the structural elements of the measure, including content of assessment reports, availability of specific equipment and adequate space, safety monitoring, and integration of communication with parents and other team members, such as collaborative goal setting with parents or family and teacher education, into the intervention program. Analysis of self-report ratings by 259 occupational therapists from 185 different facilities indicated that the structural section of the ASIFM has acceptable interrater reliability (r ≥ .82) and significantly differentiates between settings in which therapists reportedly do and do not practice OT-SI (p < .001). Copyright © 2014 by the American Occupational Therapy Association, Inc.

  2. Portuguese validation of the Short Health Anxiety Inventory: Factor structure, reliability, and factor invariance.

    Science.gov (United States)

    Morales, Alexandra; Reis, Sibília; Espada, José P; Orgilés, Mireia

    2016-09-01

    The Short Health Anxiety Inventory is a brief instrument to assess health anxiety widely used across countries; however, no validated version is available for Portuguese-speaking population. Factorial structure, reliability, and equivalency factor with the Spanish version were analyzed with Portuguese adolescents aged 14-18 years. A Portuguese adolescent cohort ( N = 629) and a comparative Spanish adolescent cohort ( N = 1502) were evaluated. The original two-factor version was the best fitting model for the Portuguese version. The reliability was excellent. Complete measurement invariance across both countries was supported. The Portuguese version of the Short Health Anxiety Inventory is a valid screening inventory to assess health anxiety in adolescents.

  3. Synthesis, crystal structure and charge-distribution validation of β-Na4Cu(MoO43 adopting the alluadite structure-type

    Directory of Open Access Journals (Sweden)

    Wassim Dridi

    2016-08-01

    Full Text Available Single crystals of a new variety of tetrasodium copper(II tris[molybdate(VI], Na4Cu(MoO43, have been synthesized by solid-state reactions and characterized by single-crystal X-ray diffraction. This alluaudite structure-type is characterized by the presence of infinite layers of composition (Cu/Na2Mo3O14 parallel to the (100 plane, which are linked by MoO4 tetrahedra, forming a three-dimensional framework containing two types of hexagonal channels in which Na+ cations reside. The Cu2+ and Na2+ cations are located at the same general site with occupancies of 0.5. All atoms are on general positions except for one Mo, two Na (site symmetry 2 and another Na (site symmetry -1 atom. One O atom is split into two separate positions with occupancies of 0.5. The title compound is isotypic with Na5Sc(MoO44 and Na3In2As3O12. The structure model is supported by bond-valence-sum (BVS and charge-distribution CHARDI methods. β-Na4Cu(MoO43 is compared and discussed with the K4Cu(MoO43 and α-Na4Cu(MoO43 structures.

  4. DEVELOPMENT AND VALIDATION OF NUMERICAL METHOD FOR STRENGTH ANALYSIS OF LATTICE COMPOSITE FUSELAGE STRUCTURES

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available Lattice composite fuselage structures are developed as an alternative to conventional composite structures based on laminated skin and stiffeners. Structure layout of lattice structures allows to realize advantages of current composite materials to a maximal extent, at the same time minimizing their main shortcomings, that allows to provide higher weight efficiency for these structures in comparison with conventional analogues.Development and creation of lattice composite structures requires development of novel methods of strength anal- ysis, as conventional methods, as a rule, are aiming to strength analysis of thin-walled elements and do not allow to get confident estimation of local strength of high-loaded unidirectional composite ribs.In the present work the method of operative strength analysis of lattice composite structure is presented, based onspecialized FE-models of unidirectional composite ribs and their intersections. In the frames of the method, every rib is modeled by a caisson structure, consisting of arbitrary number of flanges and webs, modeled by membrane finite elements. Parameters of flanges and webs are calculated automatically from the condition of stiffness characteristics equality of real rib and the model. This method allows to perform local strength analysis of high-loaded ribs of lattice structure without use of here-dimensional finite elements, that allows to shorten time of calculations and sufficiently simplify the procedure of analysis of results of calculations.For validation of the suggested method, the results of experimental investigations of full-scale prototype of shell of lattice composite fuselage section have been used. The prototype of the lattice section was manufactured in CRISM and tested in TsAGI within the frames of a number of Russian and International scientific projects. The results of validation have shown that the suggested method allows to provide high operability of strength analysis, keeping

  5. Impact of Cross-Axis Structural Dynamics on Validation of Linear Models for Space Launch System

    Science.gov (United States)

    Pei, Jing; Derry, Stephen D.; Zhou Zhiqiang; Newsom, Jerry R.

    2014-01-01

    A feasibility study was performed to examine the advisability of incorporating a set of Programmed Test Inputs (PTIs) during the Space Launch System (SLS) vehicle flight. The intent of these inputs is to provide validation to the preflight models for control system stability margins, aerodynamics, and structural dynamics. During October 2009, Ares I-X program was successful in carrying out a series of PTI maneuvers which provided a significant amount of valuable data for post-flight analysis. The resulting data comparisons showed excellent agreement with the preflight linear models across the frequency spectrum of interest. However unlike Ares I-X, the structural dynamics associated with the SLS boost phase configuration are far more complex and highly coupled in all three axes. This presents a challenge when implementing this similar system identification technique to SLS. Preliminary simulation results show noticeable mismatches between PTI validation and analytical linear models in the frequency range of the structural dynamics. An alternate approach was examined which demonstrates the potential for better overall characterization of the system frequency response as well as robustness of the control design.

  6. Longitudinal Validation of General and Specific Structural Features of Personality Pathology

    Science.gov (United States)

    Wright, Aidan G.C.; Hopwood, Christopher J.; Skodol, Andrew E.; Morey, Leslie C.

    2016-01-01

    Theorists have long argued that personality disorder (PD) is best understood in terms of general impairments shared across the disorders as well as more specific instantiations of pathology. A model based on this theoretical structure was proposed as part of the DSM-5 revision process. However, only recently has this structure been subjected to formal quantitative evaluation, with little in the way of validation efforts via external correlates or prospective longitudinal prediction. We used the Collaborative Longitudinal Study of Personality Disorders dataset to: (1) estimate structural models that parse general from specific variance in personality disorder features, (2) examine patterns of growth in general and specific features over the course of 10 years, and (3) establish concurrent and dynamic longitudinal associations in PD features and a host of external validators including basic personality traits and psychosocial functioning scales. We found that general PD exhibited much lower absolute stability and was most strongly related to broad markers of psychosocial functioning, concurrently and longitudinally, whereas specific features had much higher mean stability and exhibited more circumscribed associations with functioning. However, both general and specific factors showed recognizable associations with normative and pathological traits. These results can inform efforts to refine the conceptualization and diagnosis of personality pathology. PMID:27819472

  7. Development and validation of a strain-based Structural Health Monitoring system

    Science.gov (United States)

    Katsikeros, Ch. E.; Labeas, G. N.

    2009-02-01

    An innovative Structural Health Monitoring (SHM) methodology, based on structural strain measurements, which are processed by a back-propagation feed-forward Artificial Neural Network (ANN), is proposed. The demonstration of the SHM methodology and the identification of its capabilities and drawbacks are performed by applying the method in the prediction of fatigue damage states of a typical aircraft cracked lap-joint structure. An ANN of suitable architecture is developed and trained by numerically generated strain data sets, which have been preprocessed by Fast Fourier Transformation (FFT) for the extraction of the Fourier Descriptors (FDs). The Finite Element (FE) substructuring technique is implemented in the stress and strain analysis of the lap-joint structure, due to its efficiency in the calculation of the numerous strain data, which are necessary for the ANN training. The trained network is successfully validated, as it is proven capable to accurately predict crack positions and lengths of a lap-joint structure, which is damaged by fatigue cracks of unknown location and extent. The proposed methodology is applicable to the identification of more complex types of damage or to other critical structural locations, as its basic concept is generic.

  8. Finite element model validation of bridge based on structural health monitoring—Part II: Uncertainty propagation and model validation

    Directory of Open Access Journals (Sweden)

    Xiaosong Lin

    2015-08-01

    Full Text Available Because of uncertainties involved in modeling, construction, and measurement systems, the assessment of the FE model validation must be conducted based on stochastic measurements to provide designers with confidence for further applications. In this study, based on the updated model using response surface methodology, a practical model validation methodology via uncertainty propagation is presented. Several criteria of testing/analysis correlation are introduced, and the sources of model and testing uncertainties are also discussed. After that, Monte Carlo stochastic finite element (FE method is employed to perform the uncertainty quantification and propagation. The proposed methodology is illustrated with the examination of the validity of a large-span prestressed concrete continuous rigid frame bridge monitored under operational conditions. It can be concluded that the calculated frequencies and vibration modes of the updated FE model of Xiabaishi Bridge are consistent with the measured ones. The relative errors of each frequency are all less than 3.7%. Meanwhile, the overlap ratio indexes of each frequency are all more than 75%; The MAC values of each calculated vibration frequency are all more than 90%. The model of Xiabaishi Bridge is valid in the whole operation space including experimental design space, and its confidence level is upper than 95%. The validated FE model of Xiabaishi Bridge can reflect the current condition of Xiabaishi Bridge, and also can be used as basis of bridge health monitoring, damage identification and safety assessment.

  9. Construct validity of the reporter-interpreter-manager-educator structure for assessing students' patient encounter skills.

    Science.gov (United States)

    Tolsgaard, Martin G; Arendrup, Henrick; Lindhardt, Bjarne O; Hillingsø, Jens G; Stoltenberg, Michael; Ringsted, Charlotte

    2012-06-01

    The aim of this study, done in Denmark, was to explore the construct validity of a Reporter-Interpreter-Manager-Educator (RIME)-structured scoring format for assessing patient encounter skills. The authors developed a RIME-structured scoring form and explored its construct validity in a two-step procedure. The first step (implemented in 2009) was a randomized, controlled, experimental study in which the performance of three groups (16 fourth-year medical students, 16 sixth-year medical students, and 16 interns) was assessed in two simulated patient encounters. The second step (carried out during 2009-2010) was an observational study of patient encounter skills where clinician examiners used the scoring form in end-of-clerkship oral examinations of three consecutive cohorts of a total of 547 fourth-year medical students. In the experimental study, RIME scores showed significant difference between the three groups-fourth-year students, mean 41.7 (standard deviation [SD] 11.0); sixth-year students, mean 48.2 (SD 10.9); and interns, mean 61.9 (SD 8.5), one-way ANOVA, P < .0001-and showed a progression over the four RIME elements with participants' increasing competence.In the observational study, the mean RIME score was higher (83.8 [SD 15.5]), and advanced RIME levels were frequently missing or scored "not relevant" by the clinician examiners. In an experimental setup, the RIME structure demonstrated construct validity in terms of reflecting progress in competence in managing patient encounters when assessed according to an advanced criterion. However, clinician examiners may tacitly score the elements according to what can be expected at a certain level of student experience.

  10. Development and validation of a structured observation scale to measure responsiveness of physicians in rural Bangladesh.

    Science.gov (United States)

    Joarder, Taufique; Mahmud, Ilias; Sarker, Malabika; George, Asha; Rao, Krishna Dipankar

    2017-11-21

    Responsiveness of physicians is the social actions that physicians do to meet the legitimate expectations of service seekers. Since there is no such scale, this study aimed at developing one for measuring responsiveness of physicians in rural Bangladesh, by structured observation method. Data were collected from Khulna division of Bangladesh, through structured observation of 393 patient-consultations with physicians. The structured observation tool consisted of 64 items, with four Likert type response categories, each anchored with a defined scenario. Inter-rater reliability was assessed by same three raters observing 30 consultations. Data were analyzed by exploratory factor analysis (EFA), followed by assessment of internal consistency by ordinal alpha coefficient, inter-rater reliability by intra-class correlation coefficient (ICC), concurrent validity by correlating responsiveness score with waiting time, and known group validity by comparing public and private sector physicians. After removing items with more than 50% missing values, 45 items were considered for EFA. Parallel analysis suggested a 5-factor model. Nine items were removed from the list owing to Scale (ROP-Scale). The five factors were named as 1) Friendliness, 2) Respecting, 3) Informing and guiding, 4) Gaining trust, and 5) Financial sensitivity. Inter-rater reliability was high, with an ICC of 0.64 for individual rater's reliability and 0.84 for average reliability scores. Positive correlation with waiting time (0.51), and higher score of private sector by 0.18 point denote concurrent, and known group validity, respectively. The ROP-Scale consists of 34 items grouped under five factors. One can apply this with confidence in comparable settings, as this scale demonstrated high internal consistency and inter-rater reliability. More research is needed to test this scale in other settings and with other types of providers.

  11. Factor structure of the Parent Emotional Reaction Questionnaire: analysis and validation

    Directory of Open Access Journals (Sweden)

    Tonje Holt

    2015-09-01

    Full Text Available Background: Although many children experience violence and abuse each year, there is a lack of instruments measuring parents’ emotional reactions to these events. One instrument, the Parent Emotional Reaction Questionnaire (PERQ, allows researchers and clinicians to survey a broad spectrum of parents’ feelings directly related to their children's traumatic experiences. The objectives of this study were: (1 to examine the factor structure and the internal consistency of the PERQ; (2 to evaluate the discriminant validity of the instrument; and (3 to measure whether potential subscales are sensitive to change. Method: A Norwegian sample of 120 primary caregivers of a clinical sample of 120 traumatized children and youths (M age=14.7, SD=2.2; 79.8% girls were asked to report their emotional reactions to their child's self-reported worst trauma. Exploratory factor analysis was used to explore the underlying factor structure of the data. Results: The analysis of the PERQ showed a three-factor structure, conceptualized as PERQdistress, PERQshame, and PERQguilt. The internal consistencies of all three subscales were satisfactory. The correlations between the PERQ subscales and two other parental measurements revealed small to moderate effect sizes, supporting the discriminant validity of the PERQ subscales. The differences in sum scores of the PERQ subscales before and after a therapeutic intervention suggest that all of the subscales were sensitive to change. Conclusions: Study findings support the validity of conceptualizing the PERQ as three separate subscales that capture clinically meaningful features of parents’ feelings after their children have experienced trauma. However, the subscales need to be further evaluated using a larger sample size and a confirmatory factor analytic approach.

  12. Factor structure of the Parent Emotional Reaction Questionnaire: analysis and validation.

    Science.gov (United States)

    Holt, Tonje; Cohen, Judith A; Mannarino, Anthony

    2015-01-01

    Although many children experience violence and abuse each year, there is a lack of instruments measuring parents' emotional reactions to these events. One instrument, the Parent Emotional Reaction Questionnaire (PERQ), allows researchers and clinicians to survey a broad spectrum of parents' feelings directly related to their children's traumatic experiences. The objectives of this study were: (1) to examine the factor structure and the internal consistency of the PERQ; (2) to evaluate the discriminant validity of the instrument; and (3) to measure whether potential subscales are sensitive to change. A Norwegian sample of 120 primary caregivers of a clinical sample of 120 traumatized children and youths (M age=14.7, SD=2.2; 79.8% girls) were asked to report their emotional reactions to their child's self-reported worst trauma. Exploratory factor analysis was used to explore the underlying factor structure of the data. The analysis of the PERQ showed a three-factor structure, conceptualized as PERQdistress, PERQshame, and PERQguilt. The internal consistencies of all three subscales were satisfactory. The correlations between the PERQ subscales and two other parental measurements revealed small to moderate effect sizes, supporting the discriminant validity of the PERQ subscales. The differences in sum scores of the PERQ subscales before and after a therapeutic intervention suggest that all of the subscales were sensitive to change. Study findings support the validity of conceptualizing the PERQ as three separate subscales that capture clinically meaningful features of parents' feelings after their children have experienced trauma. However, the subscales need to be further evaluated using a larger sample size and a confirmatory factor analytic approach.

  13. Demonstration and Validation of Two Coat High Performance Coating System for Steel Structures in Corrosive Environments

    Science.gov (United States)

    2016-12-01

    Corrosion and anti-corrosives, Storage tanks, Steel —Corrosion, Military bases, Fort Bragg (N.C.) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...System for Steel Structures in Corrosive Environments Final Report on Project F12-AR06 Co ns tr uc tio n En gi ne er in g R es ea rc h La bo ra...Prevention and Control Program ERDC/CERL TR-16-27 December 2016 Demonstration and Validation of Two-Coat High- Performance Coating System for Steel

  14. Assessing factor structure and convergent validity of the work regulatory focus scale.

    Science.gov (United States)

    Akhtar, Syed; Lee, Jenny S Y

    2014-08-01

    This study assessed the factor structure of the Work Regulatory Focus Scale, which includes work-related prevention and promotion as dimensions of regulatory focus. To examine the concurrent validity, these dimensions were correlated with the prevention and promotion subscales of the Chronic Regulatory Focus Questionnaire. Using computer-assisted telephone interviews, data were collected from 237 full-time working people in Hong Kong, with a response rate of 72.9%. A confirmatory factor analysis indicated that the two-factor model of the Work Regulatory Focus Scale fit the data adequately. Fit indices improved after two of the items with low factor loadings on the promotion focus dimension were excluded from the analysis, which left 10 items in the scale. Pearson correlations between work-related regulatory focus subscales and chronic regulatory focus subscales were low but significant (range, .19-.39). The mean score differences between regulatory focus subscales were mostly in the expected direction, providing convergent validity evidence. The implications of these findings and suggestions for future research on the validity of the scale were discussed.

  15. Creating a Test-Validated Finite-Element Model of the X-56A Aircraft Structure

    Science.gov (United States)

    Pak, Chan-Gi; Truong, Samson

    2014-01-01

    Small modeling errors in a finite-element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of the X-56A Multi-Utility Technology Testbed aircraft is the flight demonstration of active flutter suppression and, therefore, in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of the X-56A aircraft. The ground-vibration test-validated structural dynamic finite-element model of the X-56A aircraft is created in this study. The structural dynamic finite-element model of the X-56A aircraft is improved using a model-tuning tool. In this study, two different weight configurations of the X-56A aircraft have been improved in a single optimization run. Frequency and the cross-orthogonality (mode shape) matrix were the primary focus for improvement, whereas other properties such as c.g. location, total weight, and off-diagonal terms of the mass orthogonality matrix were used as constraints. The end result was an improved structural dynamic finite-element model configuration for the X-56A aircraft. Improved frequencies and mode shapes in this study increased average flutter speeds of the X-56A aircraft by 7.6% compared to the baseline model.

  16. The reliability, validity, and usefulness of the Objective Structured Clinical Examination (OSCE) in dental education

    Science.gov (United States)

    Graham, Roseanna

    This study evaluated the reliability, validity, and educational usefulness of a comprehensive, multidisciplinary Objective Structured Clinical Examination (OSCE) in dental education. The OSCE was administered to dental students at the Columbia University College of Dental Medicine (CDM) before they entered clinical training. Participants in this study included CDM's class of 2010 which consisted of 78 students. The overall reliability of the examination was measured via calculation of Cronbach's alpha. Content validity was examined through evaluation of the OSCE by three experienced clinical faculty members. Predictive validity was evaluated by correlating student grades on the OSCE to future clinical performance as measured by number of clinical points achieved during the third year of training. Student perceptions regarding the educational usefulness of the examination were evaluated through a 12-question Liken-type survey and focus group interviews analyzed using a phenomenological approach. Findings of the study indicated the OSCE was a highly reliable examination (alpha=0.86) with high content validity and a moderately high correlation to future clinical performance (r=.614, ppoint Likert scale (1=strongly disagree and 5=strongly agree). They reported that the exam required the ability to think critically and problem-solve (4.0 +/- 0.85), assessed clinically relevant skills (4.59 +/- 0.69), helped identify clinical weaknesses (4.16 +/- 0.90), and was a learning experience (4.58 +/- 0.84). Findings from the qualitative portion of the study identified four main themes including the student perception that the OSCE is a unique assessment experience that required integration and application of knowledge. Recommendations for the use of the OSCE to improve clinical teaching and the implications of this study relating to the expanded use of the OSCE in dental education are discussed.

  17. Validity and reliability of the Structured Clinical Interview for Depersonalization–Derealization Spectrum (SCI-DER

    Directory of Open Access Journals (Sweden)

    Marco Mula

    2008-08-01

    Full Text Available Marco Mula, Stefano Pini, Simona Calugi, Matteo Preve, Matteo Masini, Ilaria Giovannini, Ciro Conversano, Paola Rucci, Giovanni B CassanoDepartment of Psychiatry, Neurobiology, Pharmacology and Biotechnologies, University of Pisa, ItalyAbstract: This study evaluates the validity and reliability of a new instrument developed to assess symptoms of depersonalization: the Structured Clinical Interview for the Depersonalization-Derealization Spectrum (SCI-DER. The instrument is based on a spectrum model that emphasizes soft-signs, sub-threshold syndromes as well as clinical and subsyndromal manifestations. Items of the interview include, in addition to DSM-IV criteria for depersonalization, a number of features derived from clinical experience and from a review of phenomenological descriptions. Study participants included 258 consecutive patients with mood and anxiety disorders, 16.7% bipolar I disorder, 18.6% bipolar II disorder, 32.9% major depression, 22.1% panic disorder, 4.7% obsessive compulsive disorder, and 1.5% generalized anxiety disorder; 2.7% patients were also diagnosed with depersonalization disorder. A comparison group of 42 unselected controls was enrolled at the same site. The SCI-DER showed excellent reliability and good concurrent validity with the Dissociative Experiences Scale. It significantly discriminated subjects with any diagnosis of mood and anxiety disorders from controls and subjects with depersonalization disorder from controls. The hypothesized structure of the instrument was confirmed empirically.Keywords: depersonalization, derealization, mood disorders, anxiety disorders

  18. Factor structure and construct validity of the temporal experience of pleasure scales.

    Science.gov (United States)

    Ho, Paul M; Cooper, Andrew J; Hall, Phillip J; Smillie, Luke D

    2015-01-01

    Feelings of pleasure felt in the moment of goal attainment (consummatory pleasure) are thought to be dissociable from feelings of desire connected with the motivated approach of goals (anticipatory pleasure). The Temporal Experience of Pleasure Scales (TEPS; Gard, Gard, Kring, & John, 2006) was developed to assess individual differences in these distinct processes. Recently, an independent evaluation of the psychometric characteristics of a Chinese-translated TEPS suggested a more complex factor structure (Chan et al., 2012). This study aimed to reexamine the factor structure and convergent and divergent validity of the TEPS in two previously unexamined multiethnic samples. University students in the United Kingdom (N = 294) completed the TEPS and university students in Australia (N = 295) completed the TEPS as well as a battery of conceptually related questionnaires. A confirmatory factor analysis of Gard et al.'s (2006) 2-factor model produced inadequate fit, which model-modification indexes suggested might be due to item cross-loadings. This issue was examined further using an exploratory factor analysis, which revealed a clear 2-factor solution despite cross-loadings among some items. Finally, mixed evidence for convergent-divergent validity was obtained, in terms of relationships between the TEPS and measures of anhedonia, approach-motivation, and positive emotion.

  19. Development and validation of a quantitative structure-activity relationship for chronic narcosis to fish.

    Science.gov (United States)

    Claeys, Lieve; Iaccino, Federica; Janssen, Colin R; Van Sprang, Patrick; Verdonck, Frederik

    2013-10-01

    Vertebrate testing under the European Union's regulation on Registration, Evaluation, Authorisation and Restriction of Chemical substances (REACH) is discouraged, and the use of alternative nontesting approaches such as quantitative structure-activity relationships (QSARs) is encouraged. However, robust QSARs predicting chronic ecotoxicity of organic compounds to fish are not available. The Ecological Structure Activity Relationships (ECOSAR) Class Program is a computerized predictive system that estimates the acute and chronic toxicity of organic compounds for several chemical classes based on their log octanol-water partition coefficient (K(OW)). For those chemical classes for which chronic training data sets are lacking, acute to chronic ratios are used to predict chronic toxicity to aquatic organisms. Although ECOSAR reaches a high score against the Organisation for Economic Co-operation and Development (OECD) principles for QSAR validation, the chronic QSARs in ECOSAR are not fully compliant with OECD criteria in the framework of REACH or CLP (classification, labeling, and packaging) regulation. The objective of the present study was to develop a chronic ecotoxicity QSAR for fish for compounds acting via nonpolar and polar narcosis. These QSARs were built using a database of quality screened toxicity values, considering only chronic exposure durations and relevant end points. After statistical multivariate diagnostic analysis, literature-based, mechanistically relevant descriptors were selected to develop a multivariate regression model. Finally, these QSARs were tested for their acceptance for regulatory purposes and were found to be compliant with the OECD principles for the validation of a QSAR. © 2013 SETAC.

  20. Validation of New Process Models for Large Injection-Molded Long-Fiber Thermoplastic Composite Structures

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Jin, Xiaoshi; Wang, Jin; Kunc, Vlastimil; Tucker III, Charles L.

    2012-02-23

    This report describes the work conducted under the CRADA Nr. PNNL/304 between Battelle PNNL and Autodesk whose objective is to validate the new process models developed under the previous CRADA for large injection-molded LFT composite structures. To this end, the ARD-RSC and fiber length attrition models implemented in the 2013 research version of Moldflow was used to simulate the injection molding of 600-mm x 600-mm x 3-mm plaques from 40% glass/polypropylene (Dow Chemical DLGF9411.00) and 40% glass/polyamide 6,6 (DuPont Zytel 75LG40HSL BK031) materials. The injection molding was performed by Injection Technologies, Inc. at Windsor, Ontario (under a subcontract by Oak Ridge National Laboratory, ORNL) using the mold offered by the Automotive Composite Consortium (ACC). Two fill speeds under the same back pressure were used to produce plaques under slow-fill and fast-fill conditions. Also, two gating options were used to achieve the following desired flow patterns: flows in edge-gated plaques and in center-gated plaques. After molding, ORNL performed measurements of fiber orientation and length distributions for process model validations. The structure of this report is as follows. After the Introduction (Section 1), Section 2 provides a summary of the ARD-RSC and fiber length attrition models. A summary of model implementations in the latest research version of Moldflow is given in Section 3. Section 4 provides the key processing conditions and parameters for molding of the ACC plaques. The validations of the ARD-RSC and fiber length attrition models are presented and discussed in Section 5. The conclusions will be drawn in Section 6.

  1. Brazilian Portuguese version of the Revised Fibromyalgia Impact Questionnaire (FIQR-Br): cross-cultural validation, reliability, and construct and structural validation.

    Science.gov (United States)

    Lupi, Jaqueline Basilio; Carvalho de Abreu, Daniela Cristina; Ferreira, Mariana Candido; Oliveira, Renê Donizeti Ribeiro de; Chaves, Thais Cristina

    2017-08-01

    This study aimed to culturally adapt and validate the Revised Fibromyalgia Impact Questionnaire (FIQR) to Brazilian Portuguese, by the use of analysis of internal consistency, reliability, and construct and structural validity. A total of 100 female patients with fibromyalgia participated in the validation process of the Brazilian Portuguese version of the FIQR (FIQR-Br).The intraclass correlation coefficient (ICC) was used for statistical analysis of reliability (test-retest), Cronbach's alpha for internal consistency, Pearson's rank correlation for construct validity, and confirmatory factor analysis (CFA) for structural validity. It was verified excellent levels of reliability, with ICC greater than 0.75 for all questions and domains of the FIQR-Br. For internal consistency, alpha values greater than 0.70 for the items and domains of the questionnaire were observed. Moderate (0.40  0.70) correlations were observed for the scores of domains and total score between the FIQR-Br and FIQ-Br. The structure of the three domains of the FIQR-Br was confirmed by CFA. The results of this study suggest that that the FIQR-Br is a reliable and valid instrument for assessing fibromyalgia-related impact, and supports its use in clinical settings and research. The structure of the three domains of the FIQR-Br was also confirmed. Implications for Rehabilitation Fibromyalgia is a chronic musculoskeletal disorder characterized by widespread and diffuse pain, fatigue, sleep disturbances, and depression. The disease significantly impairs patients' quality of life and can be highly disabling. To be used in multicenter research efforts, the Revised Fibromyalgia Impact Questionnaire (FIQR) must be cross-culturally validated and psychometrically tested. This paper will make available a new version of the FIQR-Br since another version already exists, but there are concerns about its measurement properties. The availability of an instrument adapted to and validated for Brazilian

  2. Experimental validation of cost-effective vision-based structural health monitoring

    Science.gov (United States)

    Feng, Dongming; Feng, Maria Q.

    2017-05-01

    Monitoring structural displacement responses can provide quantitative information for both structural safety evaluations and maintenance purposes. To overcome the limitations of conventional displacement sensors, advanced noncontact vision-based systems offer a promising alternative. This study validates the potentials of the vision displacement sensor for cost-effective structural health monitoring. The results of laboratory experiments on simply-supported beam structures demonstrate the high accuracy of the vision sensor for dense full-field displacement measurements. The identified natural frequencies and mode shapes from measurements by using one camera match well with those from an array of accelerometers. Moreover, the smoother mode shapes make possible the noncontact damage detection based on the conventional mode shape curvature index. This study also discusses the issues concerning the practical applications of the vision displacement sensors, such as the scaling factor determination, measurement with small camera tilt angles, tradeoffs between the measurement resolution and measurement points or field of view, etc. Furthermore, the remote, real-time and multi-point measurement capacities of the vision sensor are confirmed through field tests of Manhattan Bridge during train passing.

  3. Fluid-structure interaction in non-rigid pipeline systems - large scale validation experiments

    International Nuclear Information System (INIS)

    Heinsbroek, A.G.T.J.; Kruisbrink, A.C.H.

    1993-01-01

    The fluid-structure interaction computer code FLUSTRIN, developed by DELFT HYDRAULICS, enables the user to determine dynamic fluid pressures, structural stresses and displacements in a liquid-filled pipeline system under transient conditions. As such, the code is a useful tool to process and mechanical engineers in the safe design and operation of pipeline systems in nuclear power plants. To validate FLUSTRIN, experiments have been performed in a large scale 3D test facility. The test facility consists of a flexible pipeline system which is suspended by wires, bearings and anchors. Pressure surges, which excite the system, are generated by a fast acting shut-off valve. Dynamic pressures, structural displacements and strains (in total 70 signals) have been measured under well determined initial and boundary conditions. The experiments have been simulated with FLUSTRIN, which solves the acoustic equations using the method of characteristics (fluid) and the finite element method (structure). The agreement between experiments and simulations is shown to be good: frequencies, amplitudes and wave phenomena are well predicted by the numerical simulations. It is demonstrated that an uncoupled water hammer computation would render unreliable and useless results. (author)

  4. Experimental validation of tape springs to be used as thin-walled space structures

    Science.gov (United States)

    Oberst, S.; Tuttle, S. L.; Griffin, D.; Lambert, A.; Boyce, R. R.

    2018-04-01

    With the advent of standardised launch geometries and off-the-shelf payloads, space programs utilising nano-satellite platforms are growing worldwide. Thin-walled, flexible and self-deployable structures are commonly used for antennae, instrument booms or solar panels owing to their lightweight, ideal packaging characteristics and near zero energy consumption. However their behaviour in space, in particular in Low Earth Orbits with continually changing environmental conditions, raises many questions. Accurate numerical models, which are often not available due to the difficulty of experimental testing under 1g-conditions, are needed to answer these questions. In this study, we present on-earth experimental validations, as a starting point to study the response of a tape spring as a representative of thin-walled flexible structures under static and vibrational loading. Material parameters of tape springs in a singly (straight, open cylinder) and a doubly curved design, are compared to each other by combining finite element calculations, with experimental laser vibrometry within a single and multi-stage model updating approach. While the determination of the Young's modulus is unproblematic, the damping is found to be inversely proportional to deployment length. With updated material properties the buckling instability margin is calculated using different slenderness ratios. Results indicate a high sensitivity of thin-walled structures to miniscule perturbations, which makes proper experimental testing a key requirement for stability prediction on thin-elastic space structures. The doubly curved tape spring provides closer agreement with experimental results than a straight tape spring design.

  5. Prediction of proton chemical shifts in RNA - Their use in structure refinement and validation

    International Nuclear Information System (INIS)

    Cromsigt, Jenny A.M.T.C.; Hilbers, Cees W.; Wijmenga, Sybren S.

    2001-01-01

    An analysis is presented of experimental versus calculated chemical shifts of the non-exchangeable protons for 28 RNA structures deposited in the Protein Data Bank, covering a wide range of structural building blocks. We have used existing models for ring-current and magnetic-anisotropy contributions to calculate the proton chemical shifts from the structures. Two different parameter sets were tried: (i) parameters derived by Ribas-Prado and Giessner-Prettre (GP set) [(1981) J. Mol. Struct.,76, 81-92.]; (ii) parameters derived by Case [(1995) J. Biomol. NMR, 6, 341-346]. Both sets lead to similar results. The detailed analysis was carried using the GP set. The root-mean-square-deviation between the predicted and observed chemical shifts of the complete database is 0.16 ppm with a Pearson correlation coefficient of 0.79. For protons in the usually well-defined A-helix environment these numbers are, 0.08 ppm and 0.96, respectively. As a result of this good correspondence, a reliable analysis could be made of the structural dependencies of the 1 H chemical shifts revealing their physical origin. For example, a down-field shift of either H2' or H3' or both indicates a high-syn/syn χ-angle. In an A-helix it is essentially the 5'-neighbor that affects the chemical shifts of H5, H6 and H8 protons. The H5, H6 and H8 resonances can therefore be assigned in an A-helix on the basis of their observed chemical shifts. In general, the chemical shifts were found to be quite sensitive to structural changes. We therefore propose that a comparison between calculated and observed 1 H chemical shifts is a good tool for validation and refinement of structures derived from NOEs and J-couplings

  6. Development and validation of a structured observation scale to measure responsiveness of physicians in rural Bangladesh

    Directory of Open Access Journals (Sweden)

    Taufique Joarder

    2017-11-01

    Full Text Available Abstract Background Responsiveness of physicians is the social actions that physicians do to meet the legitimate expectations of service seekers. Since there is no such scale, this study aimed at developing one for measuring responsiveness of physicians in rural Bangladesh, by structured observation method. Methods Data were collected from Khulna division of Bangladesh, through structured observation of 393 patient-consultations with physicians. The structured observation tool consisted of 64 items, with four Likert type response categories, each anchored with a defined scenario. Inter-rater reliability was assessed by same three raters observing 30 consultations. Data were analyzed by exploratory factor analysis (EFA, followed by assessment of internal consistency by ordinal alpha coefficient, inter-rater reliability by intra-class correlation coefficient (ICC, concurrent validity by correlating responsiveness score with waiting time, and known group validity by comparing public and private sector physicians. Results After removing items with more than 50% missing values, 45 items were considered for EFA. Parallel analysis suggested a 5-factor model. Nine items were removed from the list owing to < 0.50 communality, <0.32 loading in un-rotated matrix, and <0.30 on any factor in rotated matrix. Since 34 items (i.e., the number of remaining items after removing nine items by EFA were loaded neatly under five factors, explained 61.38% of common variance, and demonstrated high internal consistency with coefficient of 0.91, this was adopted as the Responsiveness of Physicians Scale (ROP-Scale. The five factors were named as 1 Friendliness, 2 Respecting, 3 Informing and guiding, 4 Gaining trust, and 5 Financial sensitivity. Inter-rater reliability was high, with an ICC of 0.64 for individual rater’s reliability and 0.84 for average reliability scores. Positive correlation with waiting time (0.51, and higher score of private sector by 0.18 point

  7. Construct validity of the WISC-IV with a referred sample: direct versus indirect hierarchical structures.

    Science.gov (United States)

    Canivez, Gary L

    2014-03-01

    The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) is one of the most frequently used intelligence tests in clinical assessments of children with learning difficulties. Construct validity studies of the WISC-IV have generally supported the higher order structure with four correlated first-order factors and one higher-order general intelligence factor, but recent studies have supported an alternate model in which general intelligence is conceptualized as a breadth factor rather than a superordinate factor (M. W. Watkins, 2010, Structure of the Wechsler Intelligence Scale for Children-Fourth Edition among a national sample of referred students, Psychological Assessment, Vol. 22, pp. 782-787; M. W. Watkins, G. L. Canivez, T. James, K. & R. Good, in press, Construct validity of the WISC-IVUK with a large referred Irish sample, International Journal of School and Educational Psychology). WISC-IV core subtest data obtained from evaluations to assess learning difficulties in 345 children (224 boys, 121 girls) were examined. One through four, first order factor models and indirect versus direct hierarchical models were compared using confirmatory factor analyses. The correlated four-factor Wechsler model provided good fit to these data, but the direct hierarchical model showed statistically significant improvement over the indirect hierarchical model and correlated four-factor model. The direct hierarchical model was judged the best explanation of the WISC-IV factor structure, with the general factor accounting for 71.6% of the common variance while the first order factors accounted for 2.4-10.3% of the common variance. Thus, the results with the present sample of referred children were similar to those from other investigations (G. E. Gignac, 2005, Revisiting the factor structure of the WAIS-R: Insights through nested factor modeling, Assessment, Vol. 12, pp. 320-329; G. E. Gignac, 2006, The WAIS-III as a nested factors model: A useful alternative to

  8. Manufacturing monitoring and mock-ups validation of the WEST divertor structure and coils

    Energy Technology Data Exchange (ETDEWEB)

    Doceul, Louis, E-mail: louis.doceul@cea.fr [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Bucalossi, Jérôme; Decool, Patrick; Dougnac, Hubert; Ferlay, Fabien; Gargiulo, Laurent; Keller, Delphine; Larroque, Sébastien; Lipa, Manfred; Martino, Patrick; Pilia, Arnaud; Poli, Serge [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Portafaix, Christophe [ITER Organization, Route de Vinon-sur-Verdon, 13115 Saint-Paul-lez-Durance (France); Saille, Alain [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Salami, Michael [AVANTIS Engineering Groupe, ZI de l’Aiguille, 46100 Figeac (France); Samaille, Frank; Soler, Bernard; Thouvenin, Didier; Verger, Jean-Marc [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Voyard, Olivier [CNIM, ZI de Brégaillon, 83500 La Seyne-sur-Mer (France); and others

    2015-10-15

    Highlights: • The mechanical design and integration of the divertor structure have been performed. • The design of the casing and the winding-pack has been optimized. • The coil assembly process has been assessed. • The realization of a coil mock-up scale one is scheduled. - Abstract: In order to fully validate “ITER-like” actively water cooled tungsten plasma facing units, the implementation of an axisymmetric divertor structure in the Tokamak Tore-Supra has been studied. With this major upgrade, the so-called WEST (Tungsten Environment in Steady state Tokamak), Tore-Supra will be able to address the issues of long plasma discharges using a tungsten divertor based on monoblock targets. The divertor structure and coils assembly are made up of two stainless steel casings containing a copper winding pack cooled by a pressurized hot water circuit (up to 180 °C, 4 MPa) in which a total divertor current of up to 16 × 13 kA is circulating in steady state. The conductor is electrically insulated and wedged inside the casing in order to be mechanically protected. The divertor which is designed to perform steady state plasma operation (up to 1000 s), must sustain harsh environmental conditions in terms of ultra light vacuum conditions, electromagnetical loads and electrical insulation (5 kV ground voltage) under high temperature (180 °C). Therefore, a feasibility study of such a complex structure has been performed. It implied activities on a scale one dummy coil, such as installation, assembly issues and representative tests (electric, thermal and hydraulic). The manufacturing of the divertor structure, which is a large assembly of 4-m diameter representing a total weight of around 20 tonnes, started in the second half of 2013 and is expected to be delivered by the end of 2014. The paper will illustrate the technical developments and tests performed during 2013 and beginning of 2014 in order to fully validate the design concept before the industrial phase

  9. Objective Structured Clinical Examinations Provide Valid Clinical Skills Assessment in Emergency Medicine Education

    Directory of Open Access Journals (Sweden)

    Wallenstein, Joshua

    2014-12-01

    Full Text Available Introduction: Evaluation of emergency medicine (EM learners based on observed performance in the emergency department (ED is limited by factors such as reproducibility and patient safety. EM educators depend on standardized and reproducible assessments such as the objective structured clinical examination (OSCE. The validity of the OSCE as an evaluation tool in EM education has not been previously studied. The objective was to assess the validity of a novel management-focused OSCE as an evaluation instrument in EM education through demonstration of performance correlation with established assessment methods and case item analysis. Methods: We conducted a prospective cohort study of fourth-year medical students enrolled in a required EM clerkship. Students enrolled in the clerkship completed a five-station EM OSCE. We used Pearson’s coefficient to correlate OSCE performance with performance in the ED based on completed faculty evaluations. Indices of difficulty and discrimination were computed for each scoring item. Results: We found a moderate and statistically-significant correlation between OSCE score and ED performance score [r(239 =0.40, p<0.001]. Of the 34 OSCE testing items the mean index of difficulty was 63.0 (SD =23.0 and the mean index of discrimination was 0.52 (SD =0.21. Conclusion: Student performance on the OSCE correlated with their observed performance in the ED, and indices of difficulty and differentiation demonstrated alignment with published best-practice testing standards. This evidence, along with other attributes of the OSCE, attest to its validity. Our OSCE can be further improved by modifying testing items that performed poorly and by examining and maximizing the inter-rater reliability of our evaluation instrument. [West J Emerg Med. 2015;16(1:121–126.

  10. Validation of a 2-D semi-coupled numerical model for fluid-structure-seabed interaction

    Science.gov (United States)

    Ye, Jianhong; Jeng, Dongsheng; Wang, Ren; Zhu, Changqi

    2013-10-01

    A 2-D semi-coupled model PORO-WSSI 2D (also be referred as FSSI-CAS 2D) for the Fluid-Structure-Seabed Interaction (FSSI) has been developed by employing RANS equations for wave motion in fluid domain, VARANS equations for porous flow in porous structures; and taking the dynamic Biot's equations (known as "u - p" approximation) for soil as the governing equations. The finite difference two-step projection method and the forward time difference method are adopted to solve the RANS, VARANS equations; and the finite element method is adopted to solve the "u - p" approximation. A data exchange port is developed to couple the RANS, VARANS equations and the dynamic Biot's equations together. The analytical solution proposed by Hsu and Jeng (1994) and some experiments conducted in wave flume or geotechnical centrifuge in which various waves involved are used to validate the developed semi-coupled numerical model. The sandy bed involved in these experiments is poro-elastic or poro-elastoplastic. The inclusion of the interaction between fluid, marine structures and poro-elastoplastic seabed foundation is a special point and highlight in this paper, which is essentially different with other previous coupled models The excellent agreement between the numerical results and the experiment data indicates that the developed coupled model is highly reliablefor the FSSI problem.

  11. Methodologies for Verification and Validation of Space Launch System (SLS) Structural Dynamic Models

    Science.gov (United States)

    Coppolino, Robert N.

    2018-01-01

    Responses to challenges associated with verification and validation (V&V) of Space Launch System (SLS) structural dynamics models are presented in this paper. Four methodologies addressing specific requirements for V&V are discussed. (1) Residual Mode Augmentation (RMA), which has gained acceptance by various principals in the NASA community, defines efficient and accurate FEM modal sensitivity models that are useful in test-analysis correlation and reconciliation and parametric uncertainty studies. (2) Modified Guyan Reduction (MGR) and Harmonic Reduction (HR, introduced in 1976), developed to remedy difficulties encountered with the widely used Classical Guyan Reduction (CGR) method, are presented. MGR and HR are particularly relevant for estimation of "body dominant" target modes of shell-type SLS assemblies that have numerous "body", "breathing" and local component constituents. Realities associated with configuration features and "imperfections" cause "body" and "breathing" mode characteristics to mix resulting in a lack of clarity in the understanding and correlation of FEM- and test-derived modal data. (3) Mode Consolidation (MC) is a newly introduced procedure designed to effectively "de-feature" FEM and experimental modes of detailed structural shell assemblies for unambiguous estimation of "body" dominant target modes. Finally, (4) Experimental Mode Verification (EMV) is a procedure that addresses ambiguities associated with experimental modal analysis of complex structural systems. Specifically, EMV directly separates well-defined modal data from spurious and poorly excited modal data employing newly introduced graphical and coherence metrics.

  12. Structure and Validity of Affect Knowledge Test (AKT) in a Sample of Italian Preschoolers.

    Science.gov (United States)

    Sette, Stefania; Bassett, Hideko H; Baumgartner, Emma; Denham, Susanne A

    2015-01-01

    The authors' main goals were to examine whether the Affect Knowledge Test's (AKT) factor structure would be represented by a two-factor model (i.e., emotion recognition and situation knowledge) or by a one-factor model in Italian preschoolers (N = 164; M = 4.24 years, SD = 1.09 years). The concurrent validity of the AKT was further examined using measures of social competence. The findings replicated a model of emotion knowledge, with emotion recognition and situation knowledge as distinct but interrelated factors. Gender and age differences showed that older children and girls displayed higher scores in situation knowledge than younger children and boys. Additionally, our validity model of the AKT demonstrated that emotion recognition preceded situation knowledge, which in turn was positively related to children's sensitive or cooperative behaviors and negatively associated with anxious or withdrawn behaviors. Our results suggest that the use of the AKT may help the teachers to evaluate children's level on emotional knowledge that in turn might impact on children's positive social relationships within classroom in Italy.

  13. Psychometrics and life history strategy: the structure and validity of the High K Strategy Scale.

    Science.gov (United States)

    Copping, Lee T; Campbell, Anne; Muncer, Steven

    2014-03-22

    In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006) was distributed to a large British sample (n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

  14. Development and validation of a structured query language implementation of the Elixhauser comorbidity index.

    Science.gov (United States)

    Epstein, Richard H; Dexter, Franklin

    2017-07-01

    Comorbidity adjustment is often performed during outcomes and health care resource utilization research. Our goal was to develop an efficient algorithm in structured query language (SQL) to determine the Elixhauser comorbidity index. We wrote an SQL algorithm to calculate the Elixhauser comorbidities from Diagnosis Related Group and International Classification of Diseases (ICD) codes. Validation was by comparison to expected comorbidities from combinations of these codes and to the 2013 Nationwide Readmissions Database (NRD). The SQL algorithm matched perfectly with expected comorbidities for all combinations of ICD-9 or ICD-10, and Diagnosis Related Groups. Of 13 585 859 evaluable NRD records, the algorithm matched 100% of the listed comorbidities. Processing time was ∼0.05 ms/record. The SQL Elixhauser code was efficient and computationally identical to the SAS algorithm used for the NRD. This algorithm may be useful where preprocessing of large datasets in a relational database environment and comorbidity determination is desired before statistical analysis. A validated SQL procedure to calculate Elixhauser comorbidities and the van Walraven index from ICD-9 or ICD-10 discharge diagnosis codes has been published. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  15. Validation of a Seven-Factor Structure for the Motives for Playing Drinking Games Measure.

    Science.gov (United States)

    Zamboanga, Byron L; Audley, Shannon; Olthuis, Janine V; Blumenthal, Heidemarie; Tomaso, Cara C; Bui, Ngoc; Borsari, Brian

    2017-04-01

    Playing drinking games can be characterized as a high-risk drinking activity because games are typically designed to promote heavy alcohol consumption. While research suggests that young adults are motivated to play drinking games for a variety of reasons (e.g., for thrills/fun, for the competition), the Motives for Playing Drinking Games measure has received limited empirical attention. We examined the psychometric properties of this measure with a confirmation sample of young adults recruited from Amazon's MTurk ( N = 1,809, ages 18-25 years, 47% men; 41% not currently enrolled in college) and a validation sample of college students ( N = 671; ages 18-23 years; 26% men). Contrary to the 8-factor model obtained by Johnson and Sheets in a study published in 2004, examination of the factor structure with our confirmation sample yielded a revised 7-factor model that was invariant across race/ethnicity and college student status. This model was also validated with the college student sample. In the confirmation sample, enhancement/thrills and sexual pursuit motives for playing drinking games were positively associated with gaming frequency/consumption and negative gaming consequences. Furthermore, conformity motives for playing drinking games were positively associated with negative gaming consequences, while competition motives were positively associated with gaming frequency. These findings have significant implications for research and prevention/intervention efforts.

  16. [Evaluation of Significant Autobiographical Memories Scale: Design and structural validation at an exploratory level].

    Science.gov (United States)

    Lolich, María; Azzollini, Susana

    2016-11-01

    Personal memories are multimodal cognitive representations. Nowadays, psychometric instruments which aim to assess signifcant memories phenomenological features are scarce. Consequently, the Evaluation of Signifcant Autobiographical Memories Scale was constructed and structural validated at an exploratory level. A total of 404 individuals from Buenos Aires city (Argentina) participated in the research. Initially, an expert judgment and a pilot study administration were carried out. Next, a homogeneity and a principal components analysis were implemented. To assess the scale reliability, Cronbach's alphas coefficients were analyzed. The fnal version has 30 Likert response items gathered in 8 dimensions. Satisfactory psychometric proprieties were obtained - internal consistency of .892 and a total explained variance of 65.78%. The scale provides two main scores regarding the total quantity and intensity of the phenomenological components as well as a partial score per each dimension. It is stated that the test will prove to be useful in the research feld as well as in the clinical area.

  17. Validity of internal structure of the Competitive State Anxiety Inventory in a Brazilian sample

    Directory of Open Access Journals (Sweden)

    Daniel Bartholomeu

    2014-06-01

    Full Text Available This study investigated internal structure validity of the CSAI-2. The sample comprised 172 in Brazilian athletes, both sexes and ages ranging from 14 to 58 years. The athletes attended to the following sports: basketball, soccer, handball, volleyball and jiu-jitsu. The CSAI-2 was collectively applied before training. Initially a confirmatory factor analysis was done, but the data did not fit the model. Then, an exploratory factor analysis was conducted and, although the parallel analysis pointed out the adequacy of a two factor model, the three factor model was the one that best explained the test's theory, with some items excluded from the analysis. The factor's precision was taken by means of Cronbach's alpha and item-total correlation index and showed good results.

  18. EMOTIONAL CREATIVITY INVENTORY: FACTOR STRUCTURE, RELIABILITY AND VALIDITY IN A GEORGIAN-SPEAKING POPULATION

    Directory of Open Access Journals (Sweden)

    Khatuna Martsksvishvili

    2017-12-01

    Full Text Available The concept of emotional creativity is based on a social constructivist theory of emotion and refers to an individual’s ability to experience and express novel, sincere, and effective mixtures of emotions. The present research examines the psychometric properties of the Georgian version of Emotional Creativity Inventory (G-ECI; Averill, 1999. 834 individuals across five studies completed the G-ECI. Results from exploratory factor analysis indicate that the factor structure of the original ECI broadly replicates in the Georgian translation. The Cronbach’s alpha reliabilities of the G-ECI scales are mostly acceptable. There are significant gender differences. Examining the construct validity of G-ECI with other constructs (namely, with emotional intelligence, creativity and flow showed the expected relationships. In conclusion, the Georgian version of the emotional creativity inventory seems well suited for future research purposes.

  19. Structural validity of the Pittsburgh Sleep Quality Index in Chinese undergraduate students: A confirmatory factor analysis

    Directory of Open Access Journals (Sweden)

    Suran Guo

    2016-08-01

    Full Text Available The purpose of this study was to examine the structural validity of the Pittsburgh Sleep Quality Index (PSQI in Chinese undergraduate students. A cross-sectional questionnaire survey with 631 Chinese undergraduate students was conducted, and the questionnaire package included a measure of demographic characteristics, Pittsburgh Sleep Quality Index (PSQI, Chinese editions of Center for Epidemiologic Studies-Depression, State- Trait Anxiety Inventory, Rumination Response Scale, and Perceived Social Support Scale. Results showed that the item use of sleep medicine was not suitable for use with this population, that a two-factor model provided the best fit to the data as assessed through confirmatory factor analysis, and that other indices were consistently correlated with the sleep quality but not the sleep efficiency factor.

  20. Reliability and content validity of the Disability Assessment Structured Interview (DASI) : A tool to assess functional limitations in claimants

    NARCIS (Netherlands)

    Spanjer, Jerry; Krol, Boudien; Brouwer, Sandra; Popping, R.; Groothoff, J.W.; Van der Klink, J.J.L.

    Objective The aim of this study is to investigate the reliability and validity of the Disability Assessment Structured Interview (DASI). The DASI is a semi-structured interview for assessing long-term functional limitations concerning the work disability assessment of claimants. Methods A randomized

  1. Factorial Structure and Preliminary Validation of the Schema Mode Inventory for Eating Disorders (SMI-ED

    Directory of Open Access Journals (Sweden)

    Susan G. Simpson

    2018-04-01

    Full Text Available Objective: The aim of this study was to examine the psychometric properties and factorial structure of the Schema Mode Inventory for Eating Disorders (SMI-ED in a disordered eating population.Method: 573 participants with disordered eating patterns as measured by the Eating Disorder Examination Questionnaire (EDE-Q completed the 190-item adapted version of the Schema Mode Inventory (SMI. The new SMI-ED was developed by clinicians/researchers specializing in the treatment of eating disorders, through combining items from the original SMI with a set of additional questions specifically representative of the eating disorder population. Psychometric testing included Confirmatory Factor Analysis (CFA and internal consistency (Cronbach's α. Multivariate Analyses of Covariance (MANCOVA was also run to test statistical differences between the EDE-Q subscales on the SMI-ED modes, while controlling for possible confounding variables.Results: Factorial analysis confirmed an acceptable 16-related-factors solution for the SMI-ED, thus providing preliminary evidence for the adequate validity of the new measure based on internal structure. Concurrent validity was also established through moderate to high correlations on the modes most relevant to eating disorders with EDE-Q subscales. This study represents the first step in creating a psychometrically sound instrument for measuring schema modes in eating disorders, and provides greater insight into the relevant schema modes within this population.Conclusion: This research represents an important preliminary step toward understanding and labeling the schema mode model for this clinical group. Findings from the psychometric evaluation of SMI-ED suggest that this is a useful tool which may further assist in the measurement and conceptualization of schema modes in this population.

  2. Effects of forcefield and sampling method in all-atom simulations of inherently disordered proteins: Application to conformational preferences of human amylin.

    Directory of Open Access Journals (Sweden)

    Enxi Peng

    Full Text Available Although several computational modelling studies have investigated the conformational behaviour of inherently disordered protein (IDP amylin, discrepancies in identifying its preferred solution conformations still exist between various forcefields and sampling methods used. Human islet amyloid polypeptide has long been a subject of research, both experimentally and theoretically, as the aggregation of this protein is believed to be the lead cause of type-II diabetes. In this work, we present a systematic forcefield assessment using one of the most advanced non-biased sampling techniques, Replica Exchange with Solute Tempering (REST2, by comparing the secondary structure preferences of monomeric amylin in solution. This study also aims to determine the ability of common forcefields to sample a transition of the protein from a helical membrane bound conformation into the disordered solution state of amylin. Our results demonstrated that the CHARMM22* forcefield showed the best ability to sample multiple conformational states inherent for amylin. It is revealed that REST2 yielded results qualitatively consistent with experiments and in quantitative agreement with other sampling methods, however far more computationally efficiently and without any bias. Therefore, combining an unbiased sampling technique such as REST2 with a vigorous forcefield testing could be suggested as an important step in developing an efficient and robust strategy for simulating IDPs.

  3. An all-atom knowledge-based energy function for protein-DNA threading, docking decoy discrimination, and prediction of transcription-factor binding profiles

    Science.gov (United States)

    Xu, Beisi; Yang, Yuedong; Liang, Haojun; Zhou, Yaoqi

    2009-01-01

    How to make an accurate representation of protein-DNA interactions by an energy function is a long-standing unsolved problem in structural biology. Here, we modified a statistical potential based on the distance-scaled, finite ideal-gas reference state (DFIRE) so that it is optimized for protein-DNA interactions. The changes include a volume-fraction correction to account for unmixable atom types in proteins and DNA in addition to the usage of a low-count correction, residue/base-specific atom types, and a shorter cutoff distance for protein-DNA interactions. The new statistical energy functions are tested in threading and docking decoy discriminations and prediction of protein-DNA binding affinities and transcription-factor binding profiles. Results indicate that new proposed energy functions are among the best in existing energy functions for protein-DNA interactions. The new energy functions are available as a web-server called DDNA 2.0 at http://sparks.informatics.iupui.edu. The server version was trained by the entire 212 protein-DNA complexes. PMID:19274740

  4. Reliability, Validity and Factor Structure of the 12-Item General Health Questionnaire among General Population

    Science.gov (United States)

    Petkovska, Miodraga Stefanovska; Bojadziev, Marjan I.; Stefanovska, Vesna Velikj

    2015-01-01

    AIM: The aim of the study is to analyze the internal consistency; validity and factor structure of the twelve item General Health Questionnaire for the Macedonian general population. MATERIAL AND METHODS: Data came from nationally representative sample of 1603 randomly selected Macedonians all aged 18 years or older. RESULTS: The mean GHQ score in the general sample was found to be 7.9 (SD = 4.3). The results revealed a higher GHQ score among women (M = 8.91, SD = 4.5) compared to men (M = 6.89; SD = 4.2). The participants from the rural areas obtained a lower GHQ score (M = 7.55, SD = 3.8) compared to participants coming from the urban areas (M = 9.37, SD = 4.1). The principal component analysis with oblique rotation (direct oblimin) with maximum likelihood procedure solution was performed and the results yielded a three factor solution which jointly accounted for 57.17% of the total variance: Factor I named social management (items 1, 3, 4, 6, 7 and 8); Factor II stress (items 2, 5 and 9) and Factor III named self-confidence (items 10, 11 and 12). Its factor structure is in line with representative research from other population groups. CONCLUSION: The GHQ-12 can be used effectively for assessment of the overall psychological well-being and detection of non-psychotic psychiatric problems among the Macedonian population. PMID:27275274

  5. Psychometric properties and structural validity of the short version of the personality beliefs questionnaire (PBQ-SF)

    OpenAIRE

    Manrique Hernández, Rubén Darío; Universidad San Buenaventura; Moratto Vasquez, Nadia Semenova; Universidad CES

    2015-01-01

    The Personality Belief Questionnaire- Short Form (PBQ-SF) is an assessment instrument of personality beliefs based on the cognitive theory that states that these are characterized by a specific pattern of dysfunctional thoughts. The objective of this study was to establish the psychometric properties and structural validity of the PBQ-SF questionnaire in Colombian adults from 18 to 35 years old. To carry out the above and with permission of the author the validation process was initiated foll...

  6. Structural exploration for the refinement of anticancer matrix metalloproteinase-2 inhibitor designing approaches through robust validated multi-QSARs

    Science.gov (United States)

    Adhikari, Nilanjan; Amin, Sk. Abdul; Saha, Achintya; Jha, Tarun

    2018-03-01

    Matrix metalloproteinase-2 (MMP-2) is a promising pharmacological target for designing potential anticancer drugs. MMP-2 plays critical functions in apoptosis by cleaving the DNA repair enzyme namely poly (ADP-ribose) polymerase (PARP). Moreover, MMP-2 expression triggers the vascular endothelial growth factor (VEGF) having a positive influence on tumor size, invasion, and angiogenesis. Therefore, it is an urgent need to develop potential MMP-2 inhibitors without any toxicity but better pharmacokinetic property. In this article, robust validated multi-quantitative structure-activity relationship (QSAR) modeling approaches were attempted on a dataset of 222 MMP-2 inhibitors to explore the important structural and pharmacophoric requirements for higher MMP-2 inhibition. Different validated regression and classification-based QSARs, pharmacophore mapping and 3D-QSAR techniques were performed. These results were challenged and subjected to further validation to explain 24 in house MMP-2 inhibitors to judge the reliability of these models further. All these models were individually validated internally as well as externally and were supported and validated by each other. These results were further justified by molecular docking analysis. Modeling techniques adopted here not only helps to explore the necessary structural and pharmacophoric requirements but also for the overall validation and refinement techniques for designing potential MMP-2 inhibitors.

  7. [Factor structure validity of the social capital scale used at baseline in the ELSA-Brasil study].

    Science.gov (United States)

    Souto, Ester Paiva; Vasconcelos, Ana Glória Godoi; Chor, Dora; Reichenheim, Michael E; Griep, Rosane Härter

    2016-07-21

    This study aims to analyze the factor structure of the Brazilian version of the Resource Generator (RG) scale, using baseline data from the Brazilian Longitudinal Health Study in Adults (ELSA-Brasil). Cross-validation was performed in three random subsamples. Exploratory factor analysis using exploratory structural equation models was conducted in the first two subsamples to diagnose the factor structure, and confirmatory factor analysis was used in the third to corroborate the model defined by the exploratory analyses. Based on the 31 initial items, the model with the best fit included 25 items distributed across three dimensions. They all presented satisfactory convergent validity (values greater than 0.50 for the extracted variance) and precision (values greater than 0.70 for compound reliability). All factor correlations were below 0.85, indicating full discriminative factor validity. The RG scale presents acceptable psychometric properties and can be used in populations with similar characteristics.

  8. The Validity, Reliability and Factorial Structure of the Turkish Version of the Tromso Social Intelligence Scale

    Science.gov (United States)

    Dogan, Tayfun; Cetin, Bayram

    2009-01-01

    The purpose of the present study was to investigate the reliability and validity of the Turkish version of the Tromso Social Intelligence Scale (TSIS) developed by Silvera, Martinussen, and Dahl (2001). 719 students from Sakarya University participated in the study. Construct validity and criterion related validity and reliability were assessed.…

  9. Contribution of the JRC to test and validate innovation systems for earthquake protection and control of vibration of structures

    International Nuclear Information System (INIS)

    Renda, Vito

    2002-01-01

    The mission of JRC is to provide scientific and technical support for the conception, development and monitoring of EU policies. The task of IPSC is to provide cyber-security and fight against the fraud; natural, technological and economic risks; humanitarian security, non-proliferation and nuclear safeguards. The Structural mechanics laboratory supplies pseudo-dynamic testing of full/large scale models and structures. Earthquake simulation is provided by two complementary approaches: shaking table, and reaction wall. The main objectives of the large scale testing are: to calibrate analytical models suitable for different classes of structures; to validate rules of norms and standards; and to contribute to the development of innovative technologies for the protection of structures of both civil and architectural interest. Seismic isolation program deals with validation of the pseudo-dynamic method for testing large models of base isolated structures

  10. The Health Behavior Checklist: Factor structure in community samples and validity of a revised good health practices scale.

    Science.gov (United States)

    Hampson, Sarah E; Edmonds, Grant W; Goldberg, Lewis R

    2017-01-01

    This study examined the factor structure and predictive validity of the commonly used multidimensional Health Behavior Checklist. A three-factor structure was found in two community samples that included men and women. The new 16-item Good Health Practices scale and the original Wellness Maintenance scale were the only Health Behavior Checklist scales to be related to cardiovascular and metabolic risk factors. While the other Health Behavior Checklist scales require further validation, the Good Health Practices scale could be used where more objective or longer measures are not feasible.

  11. Headache symptoms from migraine patients with and without aura through structure-validated self-reports.

    Science.gov (United States)

    Wang, Jiawei; Zhang, Bingren; Shen, Chanchan; Zhang, Jinhua; Wang, Wei

    2017-10-12

    Headache symptoms self-reported by migraine patients are largely congruent with the clinician-used diagnostic criteria, but not always so. Patients' self-reports of headache symptoms might offer additional clues to characterize migraine with (MA) and without (MO) aura more precisely. Firstly, we invited 324 participants with a life-long headache attack to answer an item-matrix measuring symptoms of primary headaches, then we performed both exploratory and confirmatory factor analyses to their answers and refined a headache symptom questionnaire. Secondly, we applied this questionnaire to 28 MA and 52 MO patients. In participants with a life-long headache, we refined a 27-item, structure-validated headache symptom questionnaire, with four factors (scales) namely the Somatic /Aura Symptoms, Gastrointestinal and Autonomic Symptoms, Tightness and Location Features, and Prodromal/Aggravating Symptoms. Further, we found that MA patients reported higher than did MO patients on the Somatic/Aura Symptoms and Tightness and Location Features scales. Compared to MO, MA was conferred with more prominent tightness and location features besides its higher somatic or aura symptoms. Patients' self-reports of headache symptoms might offer more clues to distinguish two types of migraine besides their clinician-defined criteria.

  12. Reliability and Validity of the Child and Adolescent Behavior Assessment (CABA): A Brief Structured Scale.

    Science.gov (United States)

    Morin, Amanda Leigh; Miller, Stacy Jo; Smith, Johan R; Johnson, Karen E

    2017-04-01

    Use of valid, affordable, accessible, and brief measures facilitates the assessment of mental health outcomes. The Child and Adolescent Behavior Assessment Scale, a brief, structured scale, assesses problem behavior through patient and/or informant report. The purpose of this paper is to illustrate the scale's psychometric properties. In the cross-sectional study presented, a large national sample of youth (aged 5-18) admitted for psychiatric treatment (N = 32,689) was examined. The two major domains of problem behavior assessed were Internalizing and Externalizing. Reliability was good to excellent with alpha levels ranging from 0.874 to 0.917. Additional items measured Risk Behavior (α = 0.648). Subscale total scores correlated well with the Brief Psychiatric Rating Scale for Children, 9-item version (BPRS-C-9). Exploratory and confirmatory factor analyses supported the three-factor, multidimensional model of problem behavior as satisfactory for child and adolescent use, although further research is required to refine some items for clarity and improved model fit.

  13. Vocalist - an international programme for the validation of constraint based methodology in structural integrity

    International Nuclear Information System (INIS)

    Lidbury, D.; Bass, R.; Gilles, Ph.; Connors, D.; Eisele, U.; Keim, E.; Keinanen, H.; Marie, St.; Nagel, G.; Taylor, N.; Wadier, Y.

    2001-01-01

    The pattern of crack-tip stresses and strains causing plastic flow and fracture in components is different to that in test specimens. This gives rise to the so-called constraint effect. Crack-tip constraint in components is generally lower than in test specimens. Effective toughness is correspondingly higher. The fracture toughness measured on test specimens is thus likely to underestimate that exhibited by cracks in components. A 36-month programme was initiated in October 2000 as part of the Fifth Framework of the European Atomic Energy Community (EURATOM), with the objective of achieving (i) an improved defect assessment methodology for predicting safety margins; (ii) improved lifetime management arguments. The programme VOCALIST (Validation of Constraint Based Methodology in Structural Integrity) is one of a 'cluster' of Fifth Framework projects in the area of Plant Life Management (Nuclear Fission). VOCALIST is also an associated project of NESC (Network for Evaluating Steel Components). The present paper describes the aims and objectives of VOCALIST, its interactions with NESC, and gives details of its various Work Packages. (authors)

  14. The Tridimensional Structure of Sociosexuality: Spanish Validation of the Revised Sociosexual Orientation Inventory.

    Science.gov (United States)

    Barrada, Juan R; Castro, Ángel; Correa, Ana Belén; Ruiz-Gómez, Paula

    2018-02-17

    Casual sex has become a common experience for many university students. Therefore, it is necessary to have instruments and studies that analyze youth's orientation toward sociosexuality. The SOI-R assesses sociosexual behavior, attitudes toward sociosexuality, and the desire for relationships without commitment with just nine items. The goal of this study was to validate the Spanish version of the SOI-R, to improve the scale, and to contribute evidence of the utility of the Sociosexual Desire subscale. Participants were 839 heterosexual university students of both sexes, aged between 18 and 26, who completed a battery of online questionnaires. The internal structure of the SOI-R revealed the three proposed theoretical dimensions, with medium to low relationships between factors. The instrument has measurement invariance with regards to sex and age. The Spanish version of the SOI-R had adequate levels of reliability. The modification of the first item of the scale is suggested, as well as the relevance of assessing sociosexual desire as an independent construct. The relation between sociosexuality and other sociodemographic and psychosocial variables was also analyzed. The discussion highlights the need for research to determine youth's sociosexual orientation and patterns of casual sex.

  15. Parents' and Adolescents' Perspectives on Parenting: Evaluating Conceptual Structure, Measurement Invariance, and Criterion Validity.

    Science.gov (United States)

    Janssens, Annelies; Goossens, Luc; Van Den Noortgate, Wim; Colpin, Hilde; Verschueren, Karine; Van Leeuwen, Karla

    2015-08-01

    Uncertainty persists regarding adequate measurement of parenting behavior during early adolescence. The present study aimed to clarify the conceptual structure of parenting by evaluating three different models that include support, psychological control, and various types of behavioral control (i.e., proactive, punitive, and harsh punitive control). Furthermore, we examined measurement invariance of parenting ratings by 1,111 Flemish adolescents from Grade 7 till 9, their mother, and father. Finally, criterion validity of parenting ratings was estimated in relation to adolescent problem behavior. Results supported a five-factor parenting model indicating multiple aspects of behavioral control, with punitive and harsh punitive control as more intrusive forms and proactive control as a more supportive form. Similar constructs were measured for adolescents, mothers, and fathers (i.e., configural and metric invariance), however on a different scale (i.e., scalar noninvariance). Future research and clinical practices should acknowledge these findings in order to fully grasp the parenting process. © The Author(s) 2014.

  16. Development and Validation of Quantitative Structure-Activity Relationship Models for Compounds Acting on Serotoninergic Receptors

    Directory of Open Access Journals (Sweden)

    Grażyna Żydek

    2012-01-01

    Full Text Available A quantitative structure-activity relationship (QSAR study has been made on 20 compounds with serotonin (5-HT receptor affinity. Thin-layer chromatographic (TLC data and physicochemical parameters were applied in this study. RP2 TLC 60F254 plates (silanized impregnated with solutions of propionic acid, ethylbenzene, 4-ethylphenol, and propionamide (used as analogues of the key receptor amino acids and their mixtures (denoted as S1–S7 biochromatographic models were used in two developing phases as a model of drug-5-HT receptor interaction. The semiempirical method AM1 (HyperChem v. 7.0 program and ACD/Labs v. 8.0 program were employed to calculate a set of physicochemical parameters for the investigated compounds. Correlation and multiple linear regression analysis were used to search for the best QSAR equations. The correlations obtained for the compounds studied represent their interactions with the proposed biochromatographic models. The good multivariate relationships (R2=0.78–0.84 obtained by means of regression analysis can be used for predicting the quantitative effect of biological activity of different compounds with 5-HT receptor affinity. “Leave-one-out” (LOO and “leave-N-out” (LNO cross-validation methods were used to judge the predictive power of final regression equations.

  17. Validation of an employee satisfaction model: A structural equation model approach

    Directory of Open Access Journals (Sweden)

    Ophillia Ledimo

    2015-01-01

    Full Text Available The purpose of this study was to validate an employee satisfaction model and to determine the relationships between the different dimensions of the concept, using the structural equation modelling approach (SEM. A cross-sectional quantitative survey design was used to collect data from a random sample of (n=759 permanent employees of a parastatal organisation. Data was collected using the Employee Satisfaction Survey (ESS to measure employee satisfaction dimensions. Following the steps of SEM analysis, the three domains and latent variables of employee satisfaction were specified as organisational strategy, policies and procedures, and outcomes. Confirmatory factor analysis of the latent variables was conducted, and the path coefficients of the latent variables of the employee satisfaction model indicated a satisfactory fit for all these variables. The goodness-of-fit measure of the model indicated both absolute and incremental goodness-of-fit; confirming the relationships between the latent and manifest variables. It also indicated that the latent variables, organisational strategy, policies and procedures, and outcomes, are the main indicators of employee satisfaction. This study adds to the knowledge base on employee satisfaction and makes recommendations for future research.

  18. Reliability and Validity of Objective Structured Clinical Examination for Residents of Obstetrics and Gynecology at Kermanshah University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    Nasrin Jalilian

    2012-11-01

    Full Text Available Introduction: Objective structured clinical examination (OSCE is used for the evaluation of the clinical competence in medicine for which it is essential to measure validity and reliability. This study aimed to investigate the validity and reliability of OSCE for residents of obstetrics and gynecology at Kermanshah University of Medical Sciences in 2011.Methods: A descriptive-correlation study was designed and the data of OSCE for obstetrics and gynecology were collected via learning behavior checklists in method stations and multiple choice questions in question stations. The data were analyzed through Pearson correlation coefficient and Cronbach's alpha, using SPSS software (version 16. To determine the criterion validity, correlation of OSCE scores with scores of resident promotion test, direct observation of procedural skills, and theoretical knowledge was determined; for reliability, however, Cronbach's alpha was used. Total sample consisted of 25 participants taking part in 14 stations. P value of less than 0.05 was considered as significant.Results: The mean OSCE scores was 22.66 (±6.85. Criterion validity of the stations with resident promotion theoretical test, first theoretical knowledge test, second theoretical knowledge, and direct observation of procedural skills (DOPS was 0.97, 0.74, 0.49, and 0.79, respectively. In question stations, criterion validity was 0.15, and total validity of OSCE was 0.77.Conclusion: Findings of the present study indicated acceptable validity and reliability of OSCE for residents of obstetrics and gynecology.

  19. Experimentally validated structural vibration frequencies’ prediction from frictional temperature signatures using numerical simulation: A case of laced cantilever beam-like structures

    Directory of Open Access Journals (Sweden)

    Stephen M Talai

    2016-12-01

    Full Text Available This article pertains to the prediction of structural vibration frequencies from frictional temperature evolution through numerical simulation. To achieve this, a finite element analysis was carried on AISI 304 steel cantilever beam-like structures coupled with a lacing wire using the commercial software ABAQUS/CAE. The coupled temperature–displacement transient analysis simulated the frictional thermal generation. Furthermore, an experimental analysis was carried out with infrared cameras capturing the interfacial thermal images while the beams were subjected to forced excitation, thus validating the finite element analysis results. The analysed vibration frequencies using a MATLAB fast Fourier transform algorithm confirmed the validity of its prediction from the frictional temperature time domain waveform. This finding has a great significance to the mechanical and aerospace engineering communities for the effective structural health monitoring of dynamic structures online using infrared thermography, thus reducing the downtime and maintenance cost, leading to increased efficiency.

  20. Circumplex Structure and Personality Disorder Correlates of the Interpersonal Problems Model (IIP-C): Construct Validity and Clinical Implications

    Science.gov (United States)

    Monsen, Jon T.; Hagtvet, Knut A.; Havik, Odd E.; Eilertsen, Dag E.

    2006-01-01

    This study assessed the construct validity of the circumplex model of the Inventory of Interpersonal Problems (IIP-C) in Norwegian clinical and nonclinical samples. Structure was examined by evaluating the fit of the circumplex model to data obtained by the IIP-C. Observer-rated personality disorder criteria (DSM-IV, Axis II) were used as external…

  1. Construct Validity of an Objective Structured Clinical Examination (OSCE) in Psychiatry: Associations with the Clinical Skills Examination and Other Indicators

    Science.gov (United States)

    Park, Robin S.; Chibnall, John T.; Blaskiewicz, Robert J.; Furman, Gail E.; Powell, Jill K.; Mohr, Clinton J.

    2004-01-01

    Objective: The construct validity of checklist and global process scores for an objective structured clinical examination (OSCE) in psychiatry was assessed. Multiple regression analysis was used to predict psychiatry OSCE scores from the clinical skills examination, an obstetrics/gynecology (OB/GYN) OSCE, and the National Board of Medical…

  2. Structural validity of the Dutch-language version of the WAIS-III in a psychiatric sample

    NARCIS (Netherlands)

    Heijden, P. van der; Bos, P. van den; Mol, B.; Kessels, R.P.C.

    2013-01-01

    The Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV; Wechsler, 2008 ) no longer provides the "traditional" Verbal IQ and Performance IQ deviation scores. In the current study, we investigated the structural validity of these scores in the scale's predecessor, the WAIS-Third Edition

  3. Structural Validity of the Dutch-Language Version of the WAIS-III in a Psychiatric Sample

    NARCIS (Netherlands)

    Heijden, P.T. van der; Bos, P. van den; Mol, B.A.W.; Kessels, R.P.C.

    2013-01-01

    The Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV; Wechsler, 2008) no longer provides the traditional Verbal IQ and Performance IQ deviation scores. In the current study, we investigated the structural validity of these scores in the scale's predecessor, the WAIS-Third Edition (WAIS-III;

  4. Using Structural Equation Modeling to Validate Online Game Players' Motivations Relative to Self-Concept and Life Adaptation

    Science.gov (United States)

    Yang, Shu Ching; Huang, Chiao Ling

    2013-01-01

    This study aimed to validate a systematic instrument to measure online players' motivations for playing online games (MPOG) and examine how the interplay of differential motivations impacts young gamers' self-concept and life adaptation. Confirmatory factor analysis determined that a hierarchical model with a two-factor structure of…

  5. Discriminant and concurrent validity of a simplified DSM-based structured diagnostic instrument for the assessment of autism spectrum disorders in youth and young adults

    OpenAIRE

    Joshi, Gagan; Petty, Carter R; Fried, Ronna; Wozniak, Janet; Micco, Jamie A; Henin, Aude; Doyle, Robert; Galdo, Maribel; Kotarski, Meghan; Caruso, Janet; Meller, Benjamin; Faraone, Stephen V; Biederman, Joseph

    2011-01-01

    Abstract Background To evaluate the concurrent and discriminant validity of a brief DSM-based structured diagnostic interview for referred individuals with autism spectrum disorders (ASDs). Methods To test concurrent validity, we assessed the structured interview's agreement in 123 youth with the expert clinician assessment and the Social Responsiveness Scale (SRS). Discriminant validity was examined using 1563 clinic-referred youth. Results The structured diagnostic interview and SRS were hi...

  6. Convergence among Data Sources, Response Bias, and Reliability and Validity of a Structured Job Analysis Questionnaire.

    Science.gov (United States)

    Smith, Jack E.; Hakel, Milton D.

    1979-01-01

    Examined are questions pertinent to the use of the Position Analysis Questionnaire: Who can use the PAQ reliably and validly? Must one rely on trained job analysts? Can people having no direct contact with the job use the PAQ reliably and validly? Do response biases influence PAQ responses? (Author/KC)

  7. "MASSIVE" brain dataset: Multiple acquisitions for standardization of structural imaging validation and evaluation.

    Science.gov (United States)

    Froeling, Martijn; Tax, Chantal M W; Vos, Sjoerd B; Luijten, Peter R; Leemans, Alexander

    2017-05-01

    In this work, we present the MASSIVE (Multiple Acquisitions for Standardization of Structural Imaging Validation and Evaluation) brain dataset of a single healthy subject, which is intended to facilitate diffusion MRI (dMRI) modeling and methodology development. MRI data of one healthy subject (female, 25 years) were acquired on a clinical 3 Tesla system (Philips Achieva) with an eight-channel head coil. In total, the subject was scanned on 18 different occasions with a total acquisition time of 22.5 h. The dMRI data were acquired with an isotropic resolution of 2.5 mm 3 and distributed over five shells with b-values up to 4000 s/mm 2 and two Cartesian grids with b-values up to 9000 s/mm 2 . The final dataset consists of 8000 dMRI volumes, corresponding B 0 field maps and noise maps for subsets of the dMRI scans, and ten three-dimensional FLAIR, T 1 -, and T 2 -weighted scans. The average signal-to-noise-ratio of the non-diffusion-weighted images was roughly 35. This unique set of in vivo MRI data will provide a robust framework to evaluate novel diffusion processing techniques and to reliably compare different approaches for diffusion modeling. The MASSIVE dataset is made publically available (both unprocessed and processed) on www.massive-data.org. Magn Reson Med 77:1797-1809, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  8. Adaptation of the Body Image after Breast Cancer Questionnaire in the Polish context: factorial structure and validity of the scale

    Directory of Open Access Journals (Sweden)

    Romuald Derbis

    2016-01-01

    Full Text Available Background Valid assessment of body image is salient in therapy and rehabilitation of women suffering from breast cancer. Adequate instruments are still lacking in this domain. To overcome this limitation two aims were formulated in the study. First, we tested the factorial structure of the Body Image after Breast Cancer Questionnaire (BIBCQ developed by Baxter (1998 in Canada, in the Polish context. Then, we tested the construct validity of the scale. The scale is based on a multidimensional concept of the body image of chronically ill individuals proposed by Vamos (1993. Participants and procedure A group of 270 women at the mean age of 55 (range of 23-81 with breast cancer who underwent conservation, mastectomy, or lumpectomy surgery was sampled in the Amazonki community. Results Confirmatory factor analysis was used to test the factorial structure of the instrument. To test the convergent validity, scales assessing body self, body image, self-esteem, and depression were used. Divergent validity was analyzed in the context of the social desirability construct. Discriminant validity was based on comparisons between women who had undergone lumpectomy or mastectomy surgery. The results showed that within two out of six subscales proposed by Baxter, two additional subscales had to be distinguished. However, some differences in comparisons with previous validation studies were also found. Conclusions The BIBCQ scale was found to be a valid multidimensional tool of body image assessment in the Polish context. The results are discussed in terms of cross-cultural differences in body image perception in breast cancer patients and guidelines for the scale’s implementation in the Polish context.

  9. The Structured Observation of Motor Performance in Infants has convergent and discriminant validity in preterm and term infants.

    Science.gov (United States)

    Montgomery, Cecilia; Hellström Westas, Lena; Strand Brodd, Katarina; Sonnander, Karin; Persson, Kristina

    2017-05-01

    Methods are needed to evaluate the level of early motor development and quality of motor performance in infants. We examined the convergent and discriminant validity of the Structured Observation of Motor Performance in Infants (SOMP-I) for evaluating the level of motor development and quality of motor performance in preterm and term infants. A regional cohort of 111 preterm infants with a gestational age of validity was analysed with a mixed model analysis of the motor performance over time. Discriminant validity was analysed with the Mann-Whitney U-test in groups with different neonatal characteristics. Convergent validity was supported, as the level of motor development increased with age and the quality of motor performance improved over time. The method discriminated for both level and quality between the preterm and the term infants. The preterm infants demonstrated different quality deficits regardless of the level of motor development. Convergent validity and discriminant validity of the SOMP-I were supported in preterm and term infants and facilitates early identification of infants with atypical motor development. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  10. Validation of HFCS-I on Calculation of High-Frequency Parameters of Helical Slow-Wave Structures

    Science.gov (United States)

    Zhu, Xiaofang; Yang, Zhonghai; Li, Bin; Li, Jianqing; Xu, Li

    2010-02-01

    To validate HFCS-I, a newly developed design tool for high frequency circuits of microwave tubes, the high-frequency parameters (including dispersion, interaction impedance and attenuation constant) of a typical helical slow-wave structure (SWS) for millimetre wave travelling-wave tube are calculated by HFCS-I and MAFIA. Both the direct calculation method and the Non-Resonant Perturbation (NRP) technique are adopted to get the interaction impedance. The obtained high-frequency parameters from HFCS-I and MAFIA are compared in detail and the consistency has proved the reliability and validity of HFCS-I.

  11. Effective electron-density map improvement and structure validation on a Linux multi-CPU web cluster: The TB Structural Genomics Consortium Bias Removal Web Service.

    Science.gov (United States)

    Reddy, Vinod; Swanson, Stanley M; Segelke, Brent; Kantardjieff, Katherine A; Sacchettini, James C; Rupp, Bernhard

    2003-12-01

    Anticipating a continuing increase in the number of structures solved by molecular replacement in high-throughput crystallography and drug-discovery programs, a user-friendly web service for automated molecular replacement, map improvement, bias removal and real-space correlation structure validation has been implemented. The service is based on an efficient bias-removal protocol, Shake&wARP, and implemented using EPMR and the CCP4 suite of programs, combined with various shell scripts and Fortran90 routines. The service returns improved maps, converted data files and real-space correlation and B-factor plots. User data are uploaded through a web interface and the CPU-intensive iteration cycles are executed on a low-cost Linux multi-CPU cluster using the Condor job-queuing package. Examples of map improvement at various resolutions are provided and include model completion and reconstruction of absent parts, sequence correction, and ligand validation in drug-target structures.

  12. On-orbit validation system for space structure composite actuators, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project delivers an On-orbit Validation System (OVS) that provides performance and durability data for Macro Fiber Composite (MFC) active piezocomposite...

  13. Factor structure and construct validity of the Generalized Anxiety Disorder 7-item (GAD-7 among Portuguese college students

    Directory of Open Access Journals (Sweden)

    Ana Bártolo

    2017-09-01

    Full Text Available Abstract: The Generalized Anxiety Disorder 7-item (GAD-7 scale has been presented as a reliable and valid measure to assess generalized anxiety symptoms in several clinical settings and among the general population. However, some researches did not support the original one-dimensional structure of the GAD-7 tool. Our main aim was to examine the factor structure of GAD-7 comparing the one-factor model fit with a two-factor model (3 somatic nature symptoms and 4 cognitive-emotional nature symptoms in a sample of college students. This validation study with data collected cross-sectionally included 1,031 Portuguese college students attending courses in the six schools of the Polytechnic Institute of Coimbra, Coimbra, Portugal. Measures included the GAD-7, Hospital Anxiety and Depression Scale (HADS and the University Student Risk Behaviors Questionnaire. Confirmatory factor analysis (CFA procedures confirmed that neither factor structure was well fitting. Thus, a modified single factor model allowing the error terms of items associated with relaxing difficulties and irritability to covary was an appropriate solution. Additionally, this factor structure revealed configural and metric invariance across gender. A good convergent validity was found by correlating global anxiety and depression. However, this measure showed a weak association with consumption behaviors. Our results are relevant to clinical practice, since the comprehensive approach to GAD-7 contributes to knowing generalized anxiety symptoms trajectory and their correlates within the university setting.

  14. The hierarchical structure of common mental disorders: Connecting multiple levels of comorbidity, bifactor models, and predictive validity.

    Science.gov (United States)

    Kim, Hyunsik; Eaton, Nicholas R

    2015-11-01

    Studies of mental disorder comorbidity have produced an unsynthesized literature with multiple competing transdiagnostic models. The current study attempted to (a) integrate these models into an overarching comorbidity hierarchy, (b) link the resulting transdiagnostic factors to the bifactor model of psychopathology, and (c) investigate predictive validity of transdiagnostic factors for important future outcomes. A series of exploratory structural equation models (ESEMs) was conducted on 12 common mental disorders from a large, 2-wave nationally representative sample, using the bass-ackwards method to explore the hierarchical structure of transdiagnostic comorbidity factors. These Wave 1 factors were then linked with the bifactor model and with mental disorders at Wave 2. Results indicated that common mental disorder comorbidity was structured into an interpretable hierarchy. Connections between the hierarchy's general factor of psychopathology (denoted p), internalizing, and distress were very strong; these factors also linked strongly with the bifactor model's p factor. Predictive validity analyses prospectively predicting subsequent diagnoses indicated that, overall: (a) transdiagnostic factors outperformed disorder-specific variance; (b) within hierarchy levels, transdiagnostic factors where disorders optimally loaded outperformed other transdiagnostic factors, but this differed by disorder type; and (c) between hierarchy levels, transdiagnostic factors where disorders optimally loaded showed similar predictive validity. We discuss implications for hierarchical structure modeling, the integration of multiple competing comorbidity models, and benefits of transdiagnostic factors for understanding the continuity of mental disorders over time. (c) 2015 APA, all rights reserved).

  15. Validation and implementation of sandwich structure bottom plate to rib weld joint in the base section of ITER Cryostat

    Energy Technology Data Exchange (ETDEWEB)

    Prajapati, Rajnikant, E-mail: rajnikant@iter-india.org [ITER-India, Institute For Plasma Research, A-29, GIDC Electronics Estate, Sector-25, Gandhinagar 382016 (India); Bhardwaj, Anil K.; Gupta, Girish; Joshi, Vaibhav; Patel, Mitul; Bhavsar, Jagrut; More, Vipul; Jindal, Mukesh; Bhattacharya, Avik; Jogi, Gaurav; Palaliya, Amit; Jha, Saroj; Pandey, Manish [ITER-India, Institute For Plasma Research, A-29, GIDC Electronics Estate, Sector-25, Gandhinagar 382016 (India); Jadhav, Pandurang; Desai, Hemal [Larsen & Toubro Limited, Heavy Engineering, Hazira Manufacturing Complex, Gujarat (India)

    2016-11-01

    Highlights: • ITER Cryostat base section sandwich structure bottom plate to rib weld joint is qualified through mock-up. • Established welding sequence was successfully implemented on all six sectors of cryostat base section. • Each layer liquid penetrant examination has been carried out for these weld joints and found satisfactory. - Abstract: Cryostat is a large stainless steel vacuum vessel providing vacuum environment to ITER machine components. The cryostat is ∼30 m in diameter and ∼30 m in height having variable thickness from 25 mm to 180 mm. Sandwich structure of cryostat base section withstands vacuum loading and limits the deformation under service conditions. Sandwich structure consists of top and bottom plates internally strengthened with radial and circular ribs. In current work, sandwich structure bottom plate to rib weld joint has been designed with full penetration joint as per ITER Vacuum Handbook requirement considering nondestructive examinations and welding feasibility. Since this joint was outside the scope of ASME Section VIII Div. 2, it was decided to validate through mock-up of bottom plate to rib joint. Welding sequence was established to control the distortion. Tensile test, macro-structural examination and layer by layer LPE were carried out for validation of this weld joint. However possibility of ultrasonic examination method was also investigated. The test results from the welded joint mock-up were found to confirm all code and specification requirements. The same was implemented in first sector (0–60°) of base section sandwich structure.

  16. [The Establishment and Examination of the Reliability, Validity, Discrimination, and Difficulty of Nursing Objective Structured Clinical Examination (OSCE)].

    Science.gov (United States)

    Huang, Hsiang-Ping; Chao, Li-Fen; Wang, Yu-Hsin; Liu, Ying-Mei; Ni, Lee-Fen; Jane, Sui-Whi

    2017-12-01

    The objective structured clinical examination (OSCE) is one of the evaluation strategies used to examine the clinical competence of nursing students. More attention needs to be paid to establishing an examination that is based on the standardized protocol and on reliability and validity. The aims of this study were to develop an OSCE that is based on a standardized protocol and to analyze the content validity and predictive validity, inter-rater consistency, internal consistency, item-to-total correlation, and the degree of discrimination and difficulty of this OSCE. Based on the blueprint for OSCEs that use an 8-station format, this study used a descriptive, cross-sectional design and a sample population of 207 senior students who were preparing for their last-mile practicum at a nursing technology university in northern Taiwan. The study period lasted from September 2015 to October 2016. Furthermore, the validity, reliability, degree of discrimination, and difficulty of the OSCE were examined. An OSCE with an eight-station format was developed. The content validity index (CVI) was .85-1.0, inter-rater reliability was .80-1.0, Cronbach' alpha internal consistency was .53-.82, and item-to-total correlation was .36-.63. In addition, the level of difficulty of the OSCE was easy to moderate and the discrimination of the OSCE ranged from fair to excellent. Meanwhile, the OSCE scores of the participants appeared to be a valid predictor of scores on the last mile practicum. According to the standardized protocol of OSCE development, an 8- station nursing OSCE format is reliable and valid, providing fair levels of difficulty and discrimination. The developed OSCE may be applied to evaluate the clinical competence of nursing students prior to beginning their last mile practicum. The results from the present study may provide a reference for nursing educators who are responsible for developing OSCE evaluation strategies.

  17. The DUNDRUM-1 structured professional judgment for triage to appropriate levels of therapeutic security: retrospective-cohort validation study.

    LENUS (Irish Health Repository)

    Flynn, Grainne

    2011-01-01

    The assessment of those presenting to prison in-reach and court diversion services and those referred for admission to mental health services is a triage decision, allocating the patient to the appropriate level of therapeutic security. This is a critical clinical decision. We set out to improve on unstructured clinical judgement. We collated qualitative information and devised an 11 item structured professional judgment instrument for this purpose then tested for validity.

  18. Using Objective Structured Clinical Examination (OSCE) in undergraduate psychiatric nursing education: is it reliable and valid?

    Science.gov (United States)

    Selim, Abeer A; Ramadan, Fatma H; El-Gueneidy, Mervat M; Gaafer, Maha M

    2012-04-01

    While there is widespread use of OSCE in general nursing specialties, psychiatric nursing has been slow to adopt this evaluation method and it has only recently been introduced to psychiatric nursing education. The main aim of the present study is to test the first application, validity and reliability of the OSCE in undergraduate psychiatric nursing education. OSCE was developed to assess undergraduate psychiatric nursing students' clinical skills. The students' evaluation of the OSCE process was obtained after the completion of each OSCE circuit. The psychiatric nursing OSCE proved to be a reliable and valid method in assessing psychiatric nursing clinical competencies. In general, the students perceived OSCE as a positive experience and stressful on the other hand. OSCE is a reliable and valid method of assessing the students' psychiatric nursing competency skills. It has been shown to have many advantages over traditional methods of assessment and has the ability to objectively assess psychiatric nursing skills. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Protein structure validation and identification from unassigned residual dipolar coupling data using 2D-PDPA.

    Science.gov (United States)

    Fahim, Arjang; Mukhopadhyay, Rishi; Yandle, Ryan; Prestegard, James H; Valafar, Homayoun

    2013-08-22

    More than 90% of protein structures submitted to the PDB each year are homologous to some previously characterized protein structure. The extensive resources that are required for structural characterization of proteins can be justified for the 10% of the novel structures, but not for the remaining 90%. This report presents the 2D-PDPA method, which utilizes unassigned residual dipolar coupling in order to address the economics of structure determination of routine proteins by reducing the data acquisition and processing time. 2D-PDPA has been demonstrated to successfully identify the correct structure of an array of proteins that range from 46 to 445 residues in size from a library of 619 decoy structures by using unassigned simulated RDC data. When using experimental data, 2D-PDPA successfully identified the correct NMR structures from the same library of decoy structures. In addition, the most homologous X-ray structure was also identified as the second best structural candidate. Finally, success of 2D-PDPA in identifying and evaluating the most appropriate structure from a set of computationally predicted structures in the case of a previously uncharacterized protein Pf2048.1 has been demonstrated. This protein exhibits less than 20% sequence identity to any protein with known structure and therefore presents a compelling and practical application of our proposed work.

  20. Protein Structure Validation and Identification from Unassigned Residual Dipolar Coupling Data Using 2D-PDPA

    Science.gov (United States)

    Fahim, Arjang; Mukhopadhyay, Rishi; Yandle, Ryan; Prestegard, James H.; Valafar, Homayoun

    2014-01-01

    More than 90% of protein structures submitted to the PDB each year are homologous to some previously characterized protein structure. The extensive resources that are required for structural characterization of proteins can be justified for the 10% of the novel structures, but not for the remaining 90%. This report presents the 2D-PDPA method, which utilizes unassigned residual dipolar coupling in order to address the economics of structure determination of routine proteins by reducing the data acquisition and processing time. 2D-PDPA has been demonstrated to successfully identify the correct structure of an array of proteins that range from 46 to 445 residues in size from a library of 619 decoy structures by using unassigned simulated RDC data. When using experimental data, 2D-PDPA successfully identified the correct NMR structures from the same library of decoy structures. In addition, the most homologous X-ray structure was also identified as the second best structural candidate. Finally, success of 2D-PDPA in identifying and evaluating the most appropriate structure from a set of computationally predicted structures in the case of a previously uncharacterized protein Pf2048.1 has been demonstrated. This protein exhibits less than 20% sequence identity to any protein with known structure and therefore presents a compelling and practical application of our proposed work. PMID:23973992

  1. Structural and discriminant validity of the tripartite model of mental well-being: differential relationships with the big five traits.

    Science.gov (United States)

    Joshanloo, Mohsen

    2017-09-04

    The tripartite model of mental well-being offers a comprehensive account of the nature of mental well-being. According to this model, mental well-being is composed of three distinct yet related dimensions of subjective (hedonic), psychological and social well-being. The present study investigated the structural and discriminant validity of the three well-being factors. A large American sample (N = 2732) was used. Data were analyzed using both Confirmatory Factor Analysis (CFA) and Exploratory Structural Equation Modeling (ESEM). It was found that the well-being variables loaded on three separate factors, indicating that the tripartite model was consistent with the data. Discriminant validity was further evidenced by moderate correlations between the latent factors, and differential relationships with the Big Five personality traits. ESEM proved to be a more appropriate approach for analyzing the data given the presence of cross-loadings. These results support adequate structural and discriminant validity for the dimensions of the tripartite model.

  2. A Multiscale Finite Element Model Validation Method of Composite Cable-Stayed Bridge Based on Structural Health Monitoring System

    Directory of Open Access Journals (Sweden)

    Rumian Zhong

    2015-01-01

    Full Text Available A two-step response surface method for multiscale finite element model (FEM updating and validation is presented with respect to Guanhe Bridge, a composite cable-stayed bridge in the National Highway number G15, in China. Firstly, the state equations of both multiscale and single-scale FEM are established based on the basic equation in structural dynamic mechanics to update the multiscale coupling parameters and structural parameters. Secondly, based on the measured data from the structural health monitoring (SHM system, a Monte Carlo simulation is employed to analyze the uncertainty quantification and transmission, where the uncertainties of the multiscale FEM and measured data were considered. The results indicate that the relative errors between the calculated and measured frequencies are less than 2%, and the overlap ratio indexes of each modal frequency are larger than 80% without the average absolute value of relative errors. These demonstrate that the proposed method can be applied to validate the multiscale FEM, and the validated FEM can reflect the current conditions of the real bridge; thus it can be used as the basis for bridge health monitoring, damage prognosis (DP, and safety prognosis (SP.

  3. Toward validation of a structural approach to conceptualizing psychopathology: A special section of the Journal of Abnormal Psychology.

    Science.gov (United States)

    Krueger, Robert F; Tackett, Jennifer L; MacDonald, Angus

    2016-11-01

    Traditionally, psychopathology has been conceptualized in terms of polythetic categories derived from committee deliberations and enshrined in authoritative psychiatric nosologies-most notably the Diagnostic and Statistical Manual of Mental Disorders (DSM; American Psychiatric Association [APA], 2013). As the limitations of this form of classification have become evident, empirical data have been increasingly relied upon to investigate the structure of psychopathology. These efforts have borne fruit in terms of an increasingly consistent set of psychopathological constructs closely connected with similar personality constructs. However, the work of validating these constructs using convergent sources of data is an ongoing enterprise. This special section collects several new efforts to use structural approaches to study the validity of this empirically based organizational scheme for psychopathology. Inasmuch as a structural approach reflects the natural organization of psychopathology, it has great potential to facilitate comprehensive organization of information on the correlates of psychopathology, providing evidence for the convergent and discriminant validity of an empirical approach to classification. Here, we highlight several themes that emerge from this burgeoning literature. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. The 12-Item General Health Questionnaire (GHQ-12): Reliability,external validity and factor structure in the Spanish population

    OpenAIRE

    Sánchez López, María Pilar; Dresch, Virginia

    2008-01-01

    The purpose of this study was to analyze the internal consistency and the external and structure validity of the 12-Item General Health Questionnaire (GHQ-12) in the Spanish general population. A stratified sample of 1001 subjects, ages between 25 and 65 years, taken from the general Spanish population was employed. The GHQ-12 and the Inventory of Situations and Responses of Anxiety-ISRA were administered. A Cronbach’s alpha of .76 (Standardized Alpha: .78) and a 3-factor structure (with obli...

  5. Creating a Test Validated Structural Dynamic Finite Element Model of the Multi-Utility Technology Test Bed Aircraft

    Science.gov (United States)

    Pak, Chan-Gi; Truong, Samson S.

    2014-01-01

    Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of Multi Utility Technology Test Bed, X-56A, aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of X-56A. The ground vibration test validated structural dynamic finite element model of the X-56A is created in this study. The structural dynamic finite element model of the X-56A is improved using a model tuning tool. In this study, two different weight configurations of the X-56A have been improved in a single optimization run.

  6. Construct Validity and Reliability of Structured Assessment of endoVascular Expertise in a Simulated Setting

    DEFF Research Database (Denmark)

    Bech, B; Lönn, L; Falkenberg, M

    2011-01-01

    with clinical experience (R = -0.53, P fluoroscopy time and amount of contrast fluid did not correlate. Conclusions The construct validity and reliability of assessment with the SAVE scale was high when applied to performances in a simulation setting with advanced realism. No ceiling effect...

  7. Proton affinities of anionic bases: Trends across the periodic table, structural effects, and DFT validation

    NARCIS (Netherlands)

    Swart, M.; Bickelhaupt, F.M.

    2006-01-01

    We have carried out an extensive exploration of the gas-phase basicity of archetypal anionic bases across the periodic system using the generalized gradient approximation of density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing proton

  8. Validation of standardized and structured EHR data in the dual model approach.

    Science.gov (United States)

    Rinner, Christoph; Duftschmid, Georg

    2009-01-01

    We present a W3C XML Schema-based method to validate standardized EHR data against semantic constraints that build the knowledge layer within the dual model approach. The approach was tested with three EN/ISO13606 archetypes and an HL7 CDA implementation guide for diabetes therapies.

  9. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Directory of Open Access Journals (Sweden)

    G F Pereira

    Full Text Available In a fibre-reinforced polymer (FRP structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP, the structural health monitoring technology (fibre Bragg gratings to detect delamination, and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model.

  10. Conformational Analysis of the DFG-Out Kinase Motif and Biochemical Profiling of Structurally Validated Type II Inhibitors

    Science.gov (United States)

    2015-01-01

    Structural coverage of the human kinome has been steadily increasing over time. The structures provide valuable insights into the molecular basis of kinase function and also provide a foundation for understanding the mechanisms of kinase inhibitors. There are a large number of kinase structures in the PDB for which the Asp and Phe of the DFG motif on the activation loop swap positions, resulting in the formation of a new allosteric pocket. We refer to these structures as “classical DFG-out” conformations in order to distinguish them from conformations that have also been referred to as DFG-out in the literature but that do not have a fully formed allosteric pocket. We have completed a structural analysis of almost 200 small molecule inhibitors bound to classical DFG-out conformations; we find that they are recognized by both type I and type II inhibitors. In contrast, we find that nonclassical DFG-out conformations strongly select against type II inhibitors because these structures have not formed a large enough allosteric pocket to accommodate this type of binding mode. In the course of this study we discovered that the number of structurally validated type II inhibitors that can be found in the PDB and that are also represented in publicly available biochemical profiling studies of kinase inhibitors is very small. We have obtained new profiling results for several additional structurally validated type II inhibitors identified through our conformational analysis. Although the available profiling data for type II inhibitors is still much smaller than for type I inhibitors, a comparison of the two data sets supports the conclusion that type II inhibitors are more selective than type I. We comment on the possible contribution of the DFG-in to DFG-out conformational reorganization to the selectivity. PMID:25478866

  11. Experimental validation of 3D printed material behaviors and their influence on the structural topology design

    Science.gov (United States)

    Yang, Kai Ke; Zhu, Ji Hong; Wang, Chuang; Jia, Dong Sheng; Song, Long Long; Zhang, Wei Hong

    2018-02-01

    The purpose of this paper is to investigate the structures achieved by topology optimization and their fabrications by 3D printing considering the particular features of material microstructures and macro mechanical performances. Combining Digital Image Correlation and Optical Microscope, this paper experimentally explored the anisotropies of stiffness and strength existing in the 3D printed polymer material using Stereolithography (SLA) and titanium material using Selective Laser Melting (SLM). The standard specimens and typical structures obtained by topology optimization were fabricated along different building directions. On the one hand, the experimental results of these SLA produced structures showed stable properties and obviously anisotropic rules in stiffness, ultimate strengths and places of fractures. Further structural designs were performed using topology optimization when the particular mechanical behaviors of SLA printed materials were considered, which resulted in better structural performances compared to the optimized designs using `ideal' isotropic material model. On the other hand, this paper tested the mechanical behaviors of SLM printed multiscale lattice structures which were fabricated using the same metal powder and the same machine. The structural stiffness values are generally similar while the strength behaviors show a difference, which are mainly due to the irregular surface quality of the tiny structural branches of the lattice. The above evidences clearly show that the consideration of the particular behaviors of 3D printed materials is therefore indispensable for structural design and optimization in order to improve the structural performance and strengthen their practical significance.

  12. Factor Structure, Factorial Invariance, and Validity of the Multidimensional Shame-Related Response Inventory-21 (MSRI-21)

    Science.gov (United States)

    Garcia, Antonio F.; Acosta, Melina; Pirani, Saifa; Edwards, Daniel; Osman, Augustine

    2017-01-01

    We describe 2 studies designed to evaluate scores on the Multidimensional Shame-related Response Inventory-21 (MSRI-21), a recently developed instrument that measures affective and behavioral responses to shame. The inventory assesses shame-related responses in 3 categories: negative self-evaluation, fear of social consequences, and maladaptive behavior tendency. For Study 1, (N = 743) undergraduates completed the MSRI-21. Confirmatory factor analysis supported the validity of the MSRI-21 3-factor structure. Latent variable modeling of coefficient-α provided strong evidence for the internal consistency of scores on each scale. In Study 2, (N = 540) undergraduates completed the instrument along with 5 concurrent measures chosen for clinical significance. Achievement of factorial invariance supported the use of MSRI-21 scale scores to make valid mean comparisons across gender. In addition, MSRI-21 scale scores were associated as expected with scores on measures of self-harm, suicide, and other risk factors. Taken together, results of 2 studies support the internal consistency reliability, factorial validity, factorial invariance, and convergent validity of scores on the MSRI-21. Further work is needed to assess the temporal stability of the MSRI-21 scale scores, invariance across clinical status and other groupings, item-level measurement properties, and viability in highly symptomatic samples. PMID:28182490

  13. Factor structure, reliability, and validity of the Levenson's Locus of Control Scale in Iranian infertile people.

    Science.gov (United States)

    Maroufizadeh, Saman; Omani Samani, Reza; Amini, Payam; Navid, Behnaz

    2016-09-01

    This study examined psychometric properties of the Levenson's Locus of Control Scale among Iranian infertile patients. In all, 312 infertile patients completed the Levenson's Locus of Control Scale and Hospital Anxiety and Depression Scale. The confirmatory factor analysis indicated that the original three-factor model of Levenson's Locus of Control Scale was adequate ( χ 2 / df = 2.139; goodness-of-fit index = 0.88; root mean square error of approximation = 0.061; and standardized root mean square residual = 0.076). The Cronbach's alpha of the subscales ranged from 0.56 to 0.67. The Levenson's Locus of Control Scale subscales significantly correlated with anxiety and depression, showing an acceptable convergent validity. In conclusion, the Levenson's Locus of Control Scale has adequate reliability and validity and can be used to measure locus of control orientation in Iranian infertile patients.

  14. The 12-Item General Health Questionnaire (GHQ-12): reliability, external validity and factor structure in the Spanish population.

    Science.gov (United States)

    Sánchez-López, María del Pilar; Dresch, Virginia

    2008-11-01

    The purpose of this study was to analyze the internal consistency and the external and structure validity of the 12-Item General Health Questionnaire (GHQ-12) in the Spanish general population. A stratified sample of 1001 subjects, ages between 25 and 65 years, taken from the general Spanish population was employed. The GHQ-12 and the Inventory of Situations and Responses of Anxiety-ISRA were administered. A Cronbach's alpha of .76 (Standardized Alpha: .78) and a 3-factor structure (with oblique rotation and maximum likelihood procedure) were obtained. External validity of Factor I (Successful Coping) with the ISRA is very robust (.82; Factor II, .70; Factor III, .75). The GHQ-12 shows adequate reliability and validity in the Spanish population. Therefore, the GHQ-12 can be used with efficacy to assess people's overall psychological well-being and to detect non-psychotic psychiatric problems. Additionally, our results confirm that the GHQ-12 can best be thought of as a multidimensional scale that assesses several distinct aspects of distress, rather than just a unitary screening measure.

  15. Construct validity of the Chinese version of the Self-care of Heart Failure Index determined using structural equation modeling.

    Science.gov (United States)

    Kang, Xiaofeng; Dennison Himmelfarb, Cheryl R; Li, Zheng; Zhang, Jian; Lv, Rong; Guo, Jinyu

    2015-01-01

    The Self-care of Heart Failure Index (SCHFI) is an empirically tested instrument for measuring the self-care of patients with heart failure. The aim of this study was to develop a simplified Chinese version of the SCHFI and provide evidence for its construct validity. A total of 182 Chinese with heart failure were surveyed. A 2-step structural equation modeling procedure was applied to test construct validity. Factor analysis showed 3 factors explaining 43% of the variance. Structural equation model confirmed that self-care maintenance, self-care management, and self-care confidence are indeed indicators of self-care, and self-care confidence was a positive and equally strong predictor of self-care maintenance and self-care management. Moreover, self-care scores were correlated with the Partners in Health Scale, indicating satisfactory concurrent validity. The Chinese version of the SCHFI is a theory-based instrument for assessing self-care of Chinese patients with heart failure.

  16. Self-Compassion Scale: IRT Psychometric Analysis, Validation, and Factor Structure – Slovak Translation

    Directory of Open Access Journals (Sweden)

    Júlia Halamová

    2018-01-01

    Full Text Available The present study verifies the psychometric properties of the Slovak version of the Self-Compassion Scale through item response theory, factor-analysis, validity analyses and norm development. The surveyed sample consisted of 1,181 participants (34% men and 66% women with a mean age of 30.30 years (SD = 12.40. Two general factors (Self-compassionate responding and Self-uncompassionate responding were identified, whereas there was no support for a single general factor of the scale and six subscales. The results of the factor analysis were supported by an independent sample of 676 participants. Therefore, the use of total score for the whole scale would be inappropriate. In Slovak language the Self-Compassion Scale should be used in the form of two general subscales (Self-compassionate responding and Self-uncompassionate responding. In line with our theoretical assumptions, we obtained relatively high Spearman’s correlation coefficients between the Self-Compassion Scale and related external variables, demonstrating construct validity for the scale. To sum up, the Slovak translation of The Self-Compassion Scale is a reliable and valid instrument that measures Self-compassionate responding and Self-uncompassionate responding.

  17. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics...... a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored...... instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model....

  18. EcoSmart Fire as structure ignition model in wildland urban interface: predictions and validations

    Science.gov (United States)

    Mark A. Dietenberger; Charles R. Boardman

    2016-01-01

    EcoSmartFire is a Windows program that models heat damage and piloted ignition of structures from radiant exposure to discrete landscaped tree fires. It calculates the radiant heat transfer from cylindrical shaped fires to the walls and roof of the structure while accounting for radiation shadowing, attenuation, and ground reflections. Tests of litter burn, a 0.6 m...

  19. Validation of Clay Modeling as a Learning Tool for the Periventricular Structures of the Human Brain

    Science.gov (United States)

    Akle, Veronica; Peña-Silva, Ricardo A.; Valencia, Diego M.; Rincón-Perez, Carlos W.

    2018-01-01

    Visualizing anatomical structures and functional processes in three dimensions (3D) are important skills for medical students. However, contemplating 3D structures mentally and interpreting biomedical images can be challenging. This study examines the impact of a new pedagogical approach to teaching neuroanatomy, specifically how building a…

  20. Guessing unknown and disordered solvent molecules with squeeze in the structure validation platon

    International Nuclear Information System (INIS)

    Weng, S.

    2014-01-01

    This report describes the assignment of the nature and number of solvent molecules in the refinement of several solvated crystal structures without a prior knowledge of the solvent system used for crystallization for the cases when the solvent molecule cannot be properly modeled. The solvent molecules can be assigned even for twinned crystal structures. (author)

  1. Psychometric Properties and Structural Validity of the Short Version of the Personality Beliefs Questionnaire (PBQ-SF

    Directory of Open Access Journals (Sweden)

    Rubén Darío Manrique Hernández

    2016-06-01

    Full Text Available The Personality Belief Questionnaire- Short Form (PBQ-SF is an assessment instrument of personality beliefs based on the cognitive theory that states that these are characterized by a specific pattern of dysfunctional thoughts. The objective of this study was to establish the psychometric properties and structural validity of the PBQ-SF questionnaire in Colombian adults from 18 to 35 years old. To carry out the above and with permission of the author the validation process was initiated following a thorough and rigorous process that led to a final version of the PBQ-SF applied to 1423 persons born in Colombia and living in nine Colombian cities. Analysis of internal consistency among the items (Cronbach´s alpha, confirmatory factor analysis and calculus of goodness of fit estimators were performed. It was found that the Internal consistency of the domains varied from 0,65 for avoidant disorder up to 0,83 for paranoid disorder.

  2. The factor structure and construct validity of the inventory of callous-unemotional traits in Chinese undergraduate students.

    Science.gov (United States)

    Wang, Meng-Cheng; Gao, Yu; Deng, Jiaxin; Lai, Hongyu; Deng, Qiaowen; Armour, Cherie

    2017-01-01

    The current study assesses the factor structure and construct validity of the self-reported Inventory of Callous-Unemotional Traits (ICU) in 637 Chinese community adults (mean age = 25.98, SD = 5.79). A series of theoretical models proposed in previous studies were tested through confirmatory factor analyses. Results indicated that a shortened form that consists of 11 items (ICU-11) to assess callousness and uncaring factors has excellent overall fit. Additionally, correlations with a wide range of external variables demonstrated that this shortened form has similar construct validity compared to the original ICU. In conclusion, our findings suggest that the ICU-11 may be a promising self-report tool that could be a good substitute for the original form to assess callous-uncaring traits in adults.

  3. The factor structure and construct validity of the inventory of callous-unemotional traits in Chinese undergraduate students.

    Directory of Open Access Journals (Sweden)

    Meng-Cheng Wang

    Full Text Available The current study assesses the factor structure and construct validity of the self-reported Inventory of Callous-Unemotional Traits (ICU in 637 Chinese community adults (mean age = 25.98, SD = 5.79. A series of theoretical models proposed in previous studies were tested through confirmatory factor analyses. Results indicated that a shortened form that consists of 11 items (ICU-11 to assess callousness and uncaring factors has excellent overall fit. Additionally, correlations with a wide range of external variables demonstrated that this shortened form has similar construct validity compared to the original ICU. In conclusion, our findings suggest that the ICU-11 may be a promising self-report tool that could be a good substitute for the original form to assess callous-uncaring traits in adults.

  4. Validation of a numerical 3-D fluid-structure interaction model for a prosthetic valve based on experimental PIV measurements.

    Science.gov (United States)

    Guivier-Curien, Carine; Deplano, Valérie; Bertrand, Eric

    2009-10-01

    A numerical 3-D fluid-structure interaction (FSI) model of a prosthetic aortic valve was developed, based on a commercial computational fluid dynamics (CFD) software program using an Arbitrary Eulerian Lagrangian (ALE) formulation. To make sure of the validity of this numerical model, an equivalent experimental model accounting for both the geometrical features and the hydrodynamic conditions was also developed. The leaflet and the flow behaviours around the bileaflet valve were investigated numerically and experimentally by performing particle image velocimetry (PIV) measurements. Through quantitative and qualitative comparisons, it was shown that the leaflet behaviour and the velocity fields were similar in both models. The present study allows the validation of a fully coupled 3-D FSI numerical model. The promising numerical tool could be therefore used to investigate clinical issues involving the aortic valve.

  5. Is structured observation a valid technique to measure handwashing behavior? Use of acceleration sensors embedded in soap to assess reactivity to structured observation.

    Science.gov (United States)

    Ram, Pavani K; Halder, Amal K; Granger, Stewart P; Jones, Therese; Hall, Peter; Hitchcock, David; Wright, Richard; Nygren, Benjamin; Islam, M Sirajul; Molyneaux, John W; Luby, Stephen P

    2010-11-01

    Structured observation is often used to evaluate handwashing behavior. We assessed reactivity to structured observation in rural Bangladesh by distributing soap containing acceleration sensors and performing structured observation 4 days later. Sensors recorded the number of times soap was moved. In 45 participating households, the median number of sensor soap movements during the 5-hour time block on pre-observation days was 3.7 (range 0.3-10.6). During the structured observation, the median number of sensor soap movements was 5.0 (range 0-18.0), a 35% increase, P = 0.0004. Compared with the same 5-hour time block on pre-observation days, the number of sensor soap movements increased during structured observation by ≥ 20% in 62% of households, and by ≥ 100% in 22% of households. The increase in sensor soap movements during structured observation, compared with pre-observation days, indicates substantial reactivity to the presence of the observer. These findings call into question the validity of structured observation for measurement of handwashing behavior.

  6. Ab initio structural modeling of and experimental validation for Chlamydia trachomatis protein CT296 reveal structural similarity to Fe(II) 2-oxoglutarate-dependent enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Kemege, Kyle E.; Hickey, John M.; Lovell, Scott; Battaile, Kevin P.; Zhang, Yang; Hefty, P. Scott (Michigan); (Kansas); (HWMRI)

    2012-02-13

    Chlamydia trachomatis is a medically important pathogen that encodes a relatively high percentage of proteins with unknown function. The three-dimensional structure of a protein can be very informative regarding the protein's functional characteristics; however, determining protein structures experimentally can be very challenging. Computational methods that model protein structures with sufficient accuracy to facilitate functional studies have had notable successes. To evaluate the accuracy and potential impact of computational protein structure modeling of hypothetical proteins encoded by Chlamydia, a successful computational method termed I-TASSER was utilized to model the three-dimensional structure of a hypothetical protein encoded by open reading frame (ORF) CT296. CT296 has been reported to exhibit functional properties of a divalent cation transcription repressor (DcrA), with similarity to the Escherichia coli iron-responsive transcriptional repressor, Fur. Unexpectedly, the I-TASSER model of CT296 exhibited no structural similarity to any DNA-interacting proteins or motifs. To validate the I-TASSER-generated model, the structure of CT296 was solved experimentally using X-ray crystallography. Impressively, the ab initio I-TASSER-generated model closely matched (2.72-{angstrom} C{alpha} root mean square deviation [RMSD]) the high-resolution (1.8-{angstrom}) crystal structure of CT296. Modeled and experimentally determined structures of CT296 share structural characteristics of non-heme Fe(II) 2-oxoglutarate-dependent enzymes, although key enzymatic residues are not conserved, suggesting a unique biochemical process is likely associated with CT296 function. Additionally, functional analyses did not support prior reports that CT296 has properties shared with divalent cation repressors such as Fur.

  7. Verification and Validation of Numerical Models for Air/Water Flow on Coastal and Navigation Fluid-Structure Interaction Applications

    Science.gov (United States)

    Kees, C. E.; Farthing, M.; Dimakopoulos, A.; DeLataillade, T.

    2015-12-01

    Performance analysis and optimization of coastal and navigation structures is becoming feasible due to recent improvements in numerical methods for multiphase flows and the steady increase in capacity and availability of high performance computing resources. Now that the concept of fully three-dimensional air/water flow modelling for real world engineering analysis is achieving acceptance by the wider engineering community, it is critical to expand careful comparative studies on verification,validation, benchmarking, and uncertainty quantification for the variety of competing numerical methods that are continuing to evolve. Furthermore, uncertainty still remains about the relevance of secondary processes such as surface tension, air compressibility, air entrainment, and solid phase (structure) modelling so that questions about continuum mechanical theory and mathematical analysis of multiphase flow are still required. Two of the most popular and practical numerical approaches for large-scale engineering analysis are the Volume-Of-Fluid (VOF) and Level Set (LS) approaches. In this work we will present a publically available verification and validation test set for air-water-structure interaction problems as well as computational and physical model results including a hybrid VOF-LS method, traditional VOF methods, and Smoothed Particle Hydrodynamics (SPH) results. The test set repository and test problem formats will also be presented in order to facilitate future comparative studies and reproduction of scientific results.

  8. Investigating structure and function in the healthy human brain: validity of acute versus chronic lesion-symptom mapping.

    Science.gov (United States)

    Karnath, Hans-Otto; Rennig, Johannes

    2017-07-01

    Modern voxel-based lesion-symptom mapping (VLSM) analyses techniques provide powerful tools to examine the relationship between structure and function of the healthy human brain. However, there is still uncertainty on the type of and the appropriate time point of imaging and of behavioral testing for such analyses. Here we tested the validity of the three most common combinations of structural imaging data and behavioral scores used in VLSM analyses. Given the established knowledge about the neural substrate of the primary motor system in humans, we asked the mundane question of where the motor system is represented in the normal human brain, analyzing individual arm motor function of 60 unselected stroke patients. Only the combination of acute behavioral scores and acute structural imaging precisely identified the principal brain area for the emergence of hemiparesis after stroke, i.e., the corticospinal tract (CST). In contrast, VLSM analyses based on chronic behavior-in combination with either chronic or acute imaging-required the exclusion of patients who had recovered from an initial paresis to reveal valid anatomical results. Thus, if the primary research aim of a VLSM lesion analysis is to uncover the neural substrates of a certain function in the healthy human brain and if no longitudinal designs with repeated evaluations are planned, the combination of acute imaging and behavior represents the ideal dataset.

  9. [Validation of the structure and resources of nosocomial infection control team in hospitals ascribed to VINCat program in Catalonia, Spain].

    Science.gov (United States)

    Limón, Enrique; Pujol, Miquel; Gudiol, Francesc

    2014-07-01

    The main objective of this study was to validate the structure of the infection control team (ICT) in the hospitals adhered to VINCat program and secondary objective was to establish the consistency of resources of each center with the requirements established by the program. Qualitative research consisting of an ethnographic study using participant observation during the years 2008-2010. The centers were stratified in three groups by complexity and beds. The instrument was a semistructured interview to members of the ICT. The transcription of the interview was sent to informants for validation. In November 2010 a questionnaire regarding human resources and number hours dedicated to the ICT was sent. During 2008-2010, 65 centers had been adhered to VINCat program. In 2010, the ICT of Group I hospitals had a mean of two physician, one in full-time and one nurse for every 230 beds. In Group II, one physician part-time and one nurse per 180 beds and in Group III a physician and a nurse for every 98 beds, both part-time. In 2010, all hospitals had a structured ICT, an operative infection committee, and a hospital member representing the center at the program as well as enough electronic resources. The hospitals participating in the program have now VINCat an adequate surveillance structure and meet the minimum technical and human resources required to provide high-quality data. However human resources are not guaranteed. Copyright © 2014. Published by Elsevier Espana.

  10. Adaptive pressure-controlled cellular structures for shape morphing: II. Numerical and experimental validation

    International Nuclear Information System (INIS)

    Luo, Quantian; Tong, Liyong

    2013-01-01

    This part presents finite element analysis to verify the present formulations on mechanics of the pressurized cellular structures derived in Part I and experimental testing for a pressurized cellular actuator to demonstrate feasibility and realization of the proposed pressurized cellular structures. Linear and nonlinear finite element analyses are implemented in a commercial finite element analysis package and the numerical results are compared with those of the novel formulations given in Part I. A pressurized cellular structure specimen with 3 cells is fabricated and tested. The fabricated 3-cell cellular structure is capable of yielding a free actuation strain of around 24%. The measured pressure-induced displacement and blocking force compare favorably with the numerical results predicted by the finite element analysis and analytical formulations. (paper)

  11. New tools and new ideas for HR practitioners. Structural and predictive validity of weighted satisfaction questionnaire

    Directory of Open Access Journals (Sweden)

    Lorenzo Revuelto Taboada

    2012-12-01

    Full Text Available One of the fundamental tasks for an Human Resource Management (HRM practitioner consists in designing a reward system that can be broadly understood and can influence the attitudes and, subsequently, the behavior of individuals to permit achievement of organizational objectives. To do so, appropriate tools are necessary to allow key actions to be identified in terms of motivating employees; thereby, avoiding opportunistic costs derived from allocating resources needed to close the gap in employee satisfaction, with regard to non-priority factors for workers in satisfying their own personal needs. This article, thus, presents a dual assessment scale consisting of 44 items, categorized into six dimensions, which firstly evaluates the importance of motivation and, secondly, the level of satisfaction with the current situation for each of the 44 factors considered. Using a sample of 801 individuals, we analyzedthe internal consistency, face validity, and predictive validity of the measuring scales, obtaining a series of results that were, to say the least, promising

  12. Multilevel Factor Structure and Concurrent Validity of the Teacher Version of the Authoritative School Climate Survey.

    Science.gov (United States)

    Huang, Francis L; Cornell, Dewey G; Konold, Timothy; Meyer, Joseph P; Lacey, Anna; Nekvasil, Erin K; Heilbrun, Anna; Shukla, Kathan D

    2015-12-01

    School climate is well recognized as an important influence on student behavior and adjustment to school, but there is a need for theory-guided measures that make use of teacher perspectives. Authoritative school climate theory hypothesizes that a positive school climate is characterized by high levels of disciplinary structure and student support. A teacher version of the Authoritative School Climate Survey (ASCS) was administered to a statewide sample of 9099 7th- and 8th-grade teachers from 366 schools. The study used exploratory and multilevel confirmatory factor analyses (MCFA) that accounted for the nested data structure and allowed for the modeling of the factor structures at 2 levels. Multilevel confirmatory factor analyses conducted on both an exploratory (N = 4422) and a confirmatory sample (N = 4677) showed good support for the factor structures investigated. Factor correlations at 2 levels indicated that schools with greater levels of disciplinary structure and student support had higher student engagement, less teasing and bullying, and lower student aggression toward teachers. The teacher version of the ASCS can be used to assess 2 key domains of school climate and associated measures of student engagement and aggression toward peers and teachers. © 2015, American School Health Association.

  13. A Quantitative Structure Activity Relationship for acute oral toxicity of pesticides on rats: Validation, domain of application and prediction.

    Science.gov (United States)

    Hamadache, Mabrouk; Benkortbi, Othmane; Hanini, Salah; Amrane, Abdeltif; Khaouane, Latifa; Si Moussa, Cherif

    2016-02-13

    Quantitative Structure Activity Relationship (QSAR) models are expected to play an important role in the risk assessment of chemicals on humans and the environment. In this study, we developed a validated QSAR model to predict acute oral toxicity of 329 pesticides to rats because a few QSAR models have been devoted to predict the Lethal Dose 50 (LD50) of pesticides on rats. This QSAR model is based on 17 molecular descriptors, and is robust, externally predictive and characterized by a good applicability domain. The best results were obtained with a 17/9/1 Artificial Neural Network model trained with the Quasi Newton back propagation (BFGS) algorithm. The prediction accuracy for the external validation set was estimated by the Q(2)ext and the root mean square error (RMS) which are equal to 0.948 and 0.201, respectively. 98.6% of external validation set is correctly predicted and the present model proved to be superior to models previously published. Accordingly, the model developed in this study provides excellent predictions and can be used to predict the acute oral toxicity of pesticides, particularly for those that have not been tested as well as new pesticides. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. THE SPANISH VERSION OF THE CRIMINAL SENTIMENT SCALE MODIFIED (CSS-M: FACTOR STRUCTURE, RELIABILITY, AND VALIDITY

    Directory of Open Access Journals (Sweden)

    Víctor Company Martínez

    2015-07-01

    Full Text Available The purpose of this study was to translate and validate the Criminal Sentiment Scale Modified (CSS-M, which measures the criminal attitudes into Spanish. Despite the large body of research proving their importance as one of the best predictors of criminal conduct, only a few measures have been psychometrically developed and validated, and none of them are available in the Spanish language. A sample of 153 male inmates from Penitentiary Brians I of the Catalan Prison Service (Spain participated voluntarily in the study (73.9% of Spanish nationality, mean age = 37.3 completed the final version of the Spanish adaptation. An exploratory factor analysis (EFA and a confirmatory factor analysis (CFA were conducted with all the scales simultaneously, showing that the underlying structure of the CSS-M was best explained by a two-factor solution: Sentiments toward the establishment and Criminality self-benefits. Moreover, a set of analyses of variance (ANOVA was also performed, validating the scale well. According to the results of the study, it was concluded that the Spanish version of the CSS-M has satisfactory psychometric properties, enabling its potential usefulness within the legal field of Spanish-speaking countries as a key element in crime prevention.

  15. The Smoking Consequences Questionnaire: Factor structure and predictive validity among Spanish-speaking Latino smokers in the United States.

    Science.gov (United States)

    Vidrine, Jennifer Irvin; Vidrine, Damon J; Costello, Tracy J; Mazas, Carlos; Cofta-Woerpel, Ludmila; Mejia, Luz Maria; Wetter, David W

    2009-11-01

    Much of the existing research on smoking outcome expectancies has been guided by the Smoking Consequences Questionnaire (SCQ ). Although the original version of the SCQ has been modified over time for use in different populations, none of the existing versions have been evaluated for use among Spanish-speaking Latino smokers in the United States. The present study evaluated the factor structure and predictive validity of the 3 previously validated versions of the SCQ--the original, the SCQ-Adult, and the SCQ-Spanish, which was developed with Spanish-speaking smokers in Spain--among Spanish-speaking Latino smokers in Texas. The SCQ-Spanish represented the least complex solution. Each of the SCQ-Spanish scales had good internal consistency, and the predictive validity of the SCQ-Spanish was partially supported. Nearly all the SCQ-Spanish scales predicted withdrawal severity even after controlling for demographics and dependence. Boredom Reduction predicted smoking relapse across the 5- and 12-week follow-up assessments in a multivariate model that also controlled for demographics and dependence. Our results support use of the SCQ-Spanish with Spanish-speaking Latino smokers in the United States.

  16. Validation of metal-binding sites in macromolecular structures with the CheckMyMetal web server.

    Science.gov (United States)

    Zheng, Heping; Chordia, Mahendra D; Cooper, David R; Chruszcz, Maksymilian; Müller, Peter; Sheldrick, George M; Minor, Wladek

    2014-01-01

    Metals have vital roles in both the mechanism and architecture of biological macromolecules. Yet structures of metal-containing macromolecules in which metals are misidentified and/or suboptimally modeled are abundant in the Protein Data Bank (PDB). This shows the need for a diagnostic tool to identify and correct such modeling problems with metal-binding environments. The CheckMyMetal (CMM) web server (http://csgid.org/csgid/metal_sites/) is a sophisticated, user-friendly web-based method to evaluate metal-binding sites in macromolecular structures using parameters derived from 7,350 metal-binding sites observed in a benchmark data set of 2,304 high-resolution crystal structures. The protocol outlines how the CMM server can be used to detect geometric and other irregularities in the structures of metal-binding sites, as well as how it can alert researchers to potential errors in metal assignment. The protocol also gives practical guidelines for correcting problematic sites by modifying the metal-binding environment and/or redefining metal identity in the PDB file. Several examples where this has led to meaningful results are described in the ANTICIPATED RESULTS section. CMM was designed for a broad audience--biomedical researchers studying metal-containing proteins and nucleic acids--but it is equally well suited for structural biologists validating new structures during modeling or refinement. The CMM server takes the coordinates of a metal-containing macromolecule structure in the PDB format as input and responds within a few seconds for a typical protein structure with 2-5 metal sites and a few hundred amino acids.

  17. Safety behaviours in eating disorders: factor structure and clinical validation of the brief safety behaviours scale.

    Science.gov (United States)

    Waller, Glenn; Kyriacou Marcoulides, Olivia

    2013-05-01

    This study examined the utility of a transdiagnostic measure of safety behaviours [Brief Safety Behaviours Scale (BSBS)] in eating disorders. Prior to treatment, a group of 102 women with eating disorders completed the BSBS and well-validated measures of eating pathology, anxiety and intolerance of uncertainty. The BSBS had three factors, suggesting that avoidant, checking and social safety behaviours are distinct constructs in the eating disorders. This three-scale scoring system showed greater clinical precision in correlations with eating pathology than the original two-scale version. The pattern of safety behaviours in the eating disorders is more specific than had previously been shown in other clinical samples. While it is important to consider eating-related safety behaviours in the eating disorders (e.g. restriction, body checking), it is also necessary to consider the role of generic safety behaviours when assessing, formulating and treating eating disorders. Copyright © 2012 John Wiley & Sons, Ltd and Eating Disorders Association.

  18. Structural Design of the DTU-ESA MM-Wave Validation Standard Antenna

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter; Markussen, Christen Malte

    2015-01-01

    in the range of temperatures 20±5°C under arbitrary orientation in the gravity field. The antenna has a characteristic length of approximately 500mm. And in order to obtain very low measuring error, the allowable deformations of the reflector and feeds are down to 2.5μm. The antenna is modelled structurally...... using the commercial finite element package MSC.Patran with MSC.MARC as solver. The solid parts of the antenna are meshed with 10-noded tetrahedral elements, which have quadratic shape functions and the entire model has approximately 325.000 elements. The individual solid part of the antenna...... is connected via a glued contact formulation in MSC.MARC. Because of the size and the complexity of the model a computer cluster is applied to solve the analyses. This paper describes the structural solution to meet these extremely strict stability requirements and the structural analyses done in order...

  19. Simulation of High Velocity Impact on Composite Structures - Model Implementation and Validation

    Science.gov (United States)

    Schueler, Dominik; Toso-Pentecôte, Nathalie; Voggenreiter, Heinz

    2016-08-01

    High velocity impact on composite aircraft structures leads to the formation of flexural waves that can cause severe damage to the structure. Damage and failure can occur within the plies and/or in the resin rich interface layers between adjacent plies. In the present paper a modelling methodology is documented that captures intra- and inter-laminar damage and their interrelations by use of shell element layers representing sub-laminates that are connected with cohesive interface layers to simulate delamination. This approach allows the simulation of large structures while still capturing the governing damage mechanisms and their interactions. The paper describes numerical algorithms for the implementation of a Ladevèze continuum damage model for the ply and methods to derive input parameters for the cohesive zone model. By comparison with experimental results from gas gun impact tests the potential and limitations of the modelling approach are discussed.

  20. Generation and structural validation of a library of diverse xyloglucan-derived oligosaccharides, including an update on xyloglucan nomenclature.

    Science.gov (United States)

    Tuomivaara, Sami T; Yaoi, Katsuro; O'Neill, Malcolm A; York, William S

    2015-01-30

    Xyloglucans are structurally complex plant cell wall polysaccharides that are involved in cell growth and expansion, energy metabolism, and signaling. Determining the structure-function relationships of xyloglucans would benefit from the availability of a comprehensive and structurally diverse collection of rigorously characterized xyloglucan oligosaccharides. Here, we present a workflow for the semi-preparative scale generation and purification of neutral and acidic xyloglucan oligosaccharides using a combination of enzymatic and chemical treatments and size-exclusion chromatography. Twenty-six of these oligosaccharides were purified to near homogeneity and their structures validated using a combination of matrix-assisted laser desorption/ionization mass spectrometry, high-performance anion exchange chromatography, and 1H nuclear magnetic resonance spectroscopy. Mass spectrometry and analytical chromatography were compared as methods for xyloglucan oligosaccharide quantification. 1H chemical shifts were assigned using two-dimensional correlation spectroscopy. A comprehensive update of the nomenclature describing xyloglucan side-chain structures is provided for reference. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Validation of ultrasonography in detecting structural disease of the urogenital tract of the koala, Phascolarctos cinereus.

    Science.gov (United States)

    Marschner, C; Flanagan, C; Higgins, D P; Krockenberger, M B

    2014-05-01

    A retrospective review of case records of ultrasonography and necropsy outcomes of 62 koalas was used to investigate the accuracy of ultrasonography in assessing koala urogenital tract structural disease at the Port Macquarie Koala Hospital. The results showed high concordance, supporting ultrasonography as an effective tool for evaluating structural disease of the koala urogenital tract, most commonly seen with chlamydiosis. The study also illustrates the advances benefiting animal welfare that can be made by wildlife carer groups through using a scientific, evidence-based approach. © 2014 Australian Veterinary Association.

  2. Protein Structure Validation and Refinement Using Chemical Shifts Derived from Quantum Mechanics

    DEFF Research Database (Denmark)

    Bratholm, Lars Andersen

    to within 3 A. Furthermore, a fast quantum mechanics based chemical shift predictor was developed together with methodology for using chemical shifts in structure simulations. The developed predictor was used for renement of several protein structures and for reducing the computational cost of quantum...... mechanics / molecular mechanics (QM/MM) computations of chemical shieldings. Several improvements to the predictor is ongoing, where among other things, kernel based machine learning techniques have successfully been used to improve the quantum mechanical level of theory used in the predictions....

  3. Development and preliminary validation of the spondyloarthritis research consortium of Canada magnetic resonance imaging sacroiliac joint structural score

    DEFF Research Database (Denmark)

    Maksymowych, Walter P; Wichuk, Stephanie; Chiowchanwisawakit, Praveena

    2015-01-01

    to excellent for ankylosis (ICC 0.79-0.98), consistently good for fat metaplasia (ICC 0.71-0.78), moderate to good for erosion (ICC 0.58-0.62), and fair to good for backfill (ICC 0.35-0.66). Reliability for change scores was moderate to good for all structural lesions despite the relatively small changes...... in scores, and was highest for fat metaplasia when both ICC and SDC values were compared. CONCLUSION: The new SPARCC MRI SSS method can detect structural changes in the SIJ with acceptable reliability over a 1-2-year timeframe, and should be further validated in patients with SpA......., and either 2-year (exercises 1 and 2) or 1-year (exercise 3) scans from 147 patients with SpA assessed blinded to timepoint. Interobserver reliability was assessed by intraclass correlation coefficient (ICC) and smallest detectable change (SDC). RESULTS: Interobserver reliability for status score was good...

  4. Discriminant and concurrent validity of a simplified DSM-based structured diagnostic instrument for the assessment of autism spectrum disorders in youth and young adults

    Directory of Open Access Journals (Sweden)

    Joshi Gagan

    2011-12-01

    Full Text Available Abstract Background To evaluate the concurrent and discriminant validity of a brief DSM-based structured diagnostic interview for referred individuals with autism spectrum disorders (ASDs. Methods To test concurrent validity, we assessed the structured interview's agreement in 123 youth with the expert clinician assessment and the Social Responsiveness Scale (SRS. Discriminant validity was examined using 1563 clinic-referred youth. Results The structured diagnostic interview and SRS were highly sensitive indicators of the expert clinician assessment. Equally strong was the agreement between the structured interview and SRS. We found evidence for high specificity for the structured interview. Conclusions A simplified DSM-based ASD structured diagnostic interview could serve as a useful diagnostic aid in the assessment of subjects with ASDs in clinical and research settings.

  5. The PANAS Structure Revisited: On the Validity of a Bifactor Model in Community and Forensic Samples

    Science.gov (United States)

    Leue, Anja; Beauducel, Andre

    2011-01-01

    The Positive and Negative Affect Schedule (PANAS) is a widely used inventory for the assessment of affect in psychology and other applied sciences. Despite its popularity, the structure of the PANAS is still under debate. On the one hand, there is evidence of the traditional 2-factor model with Positive Affect (PA) and Negative Affect (NA) as…

  6. Delaware School Climate Survey--Student: Its Factor Structure, Concurrent Validity, and Reliability

    Science.gov (United States)

    Bear, George G.; Gaskins, Clare; Blank, Jessica; Chen, Fang Fang

    2011-01-01

    The Delaware School Climate Survey-Student (DSCS-S) was developed to provide schools with a brief and psychometrically sound student survey for assessing school climate, particularly the dimensions of social support and structure. Confirmatory factor analyses, conducted on a sample of 11,780 students in 85 schools, showed that a bifactor model…

  7. The Relationship of Bureaucratic Structure to School Climate: An Exploratory Factor Analysis of Construct Validity

    Science.gov (United States)

    Lennon, Patricia A.

    2010-01-01

    This researcher examined the relationship of bureaucratic structure to school climate by means of an exploratory factor analysis of a measure of bureaucracy developed by Hoy and Sweetland (2000) and the four dimensional measure of climate developed by Hoy, Smith, and Sweetland (2002). Since there had been no other empirical studies whose authors…

  8. Multilevel Factor Structure and Concurrent Validity of the Teacher Version of the Authoritative School Climate Survey

    Science.gov (United States)

    Huang, Francis L.; Cornell, Dewey G.; Konold, Timothy; Meyer, Joseph P.; Lacey, Anna; Nekvasil, Erin K.; Heilbrun, Anna; Shukla, Kathan D.

    2015-01-01

    Background: School climate is well recognized as an important influence on student behavior and adjustment to school, but there is a need for theory-guided measures that make use of teacher perspectives. Authoritative school climate theory hypothesizes that a positive school climate is characterized by high levels of disciplinary structure and…

  9. Childhood Trauma Questionnaire: factor structure, measurement invariance, and validity across emotional disorders

    NARCIS (Netherlands)

    Spinhoven, P.; Penninx, B.W.; Hickendorff, M.; van Hemert, A.M.; Bernstein, D.P.; Elzinga, B.M.

    2014-01-01

    To study the psychometric properties of the Childhood Trauma Questionnaire-Short Form (CTQ-SF), we determined its dimensional structure, measurement invariance across presence of emotional disorders, the association of the CTQ-SF with an analogous interview-based measure (CTI) across presence of

  10. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics

    DEFF Research Database (Denmark)

    Christensen, Anders Steen; Linnet, Troels Emtekær; Borg, Mikael

    2013-01-01

    We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts - sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM) calculations and reproduces high level...

  11. The Student Perception of University Support and Structure Scale: Development and Validation

    Science.gov (United States)

    Wintre, Maxine G.; Gates, Shawn K. E.; Pancer, W. Mark; Pratt, Michael S.; Polivy, Janet; Birnie-Lefcovitch, S.; Adams, Gerald

    2009-01-01

    A new scale, the Student Perception of University Support and Structure Scale (SPUSS), was developed for research on the transition to university. The scale was based on concepts derived from Baumrind's (1971) theory of parenting styles. Data were obtained from two separate cohorts of freshmen (n=759 and 397) attending six Canadian universities of…

  12. FEM validation of a double porosity elastic model for consolidation of structurally complex clayey soils

    Science.gov (United States)

    Callari, C.; Federico, F.

    2000-04-01

    Laboratory consolidation of structured clayey soils is analysed in this paper. The research is carried out by two different methods. The first one treats the soil as an isotropic homogeneous equivalent Double Porosity (DP) medium. The second method rests on the extensive application of the Finite Element Method (FEM) to combinations of different soils, composing 2D or fully 3D ordered structured media that schematically discretize the complex material. Two reference problems, representing typical situations of 1D laboratory consolidation of structured soils, are considered. For each problem, solution is obtained through integration of the equations governing the consolidation of the DP medium as well as via FEM applied to the ordered schemes composed of different materials. The presence of conventional experimental devices to ensure the drainage of the sample is taken into account through appropriate boundary conditions. Comparison of FEM results with theoretical results clearly points out the ability of the DP model to represent consolidation processes of structurally complex soils. Limits of applicability of the DP model may arise when the rate of fluid exchange between the two porous systems is represented through oversimplified relations. Results of computations, obtained having assigned reasonable values to the meso-structural and to the experimental apparatus parameters, point out that a partially efficient drainage apparatus strongly influences the distribution along the sample and the time evolution of the interstitial water pressure acting in both systems of pores. Data of consolidation tests in a Rowe's cell on samples of artificially fissured clays reported in the literature are compared with the analytical and numerical results showing a significant agreement.

  13. Brazilian version of the Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R: adaptation and validation process

    Directory of Open Access Journals (Sweden)

    Jessica Camargo

    2013-12-01

    Full Text Available BACKGROUND: Posttraumatic stress disorder (PTSD contemplates the impact of acute traumatic events, but the literature indicates that this is not true for chronic exposure to stress. In this sense, the category disorders of extreme stress not otherwise specified (DESNOS has been proposed to characterize the behavior and cognitive alterations derived from exposure to continuous early life stress. The Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R was developed to investigate and measure DESNOS. Considering the lack of instruments designed to assess DESNOS, especially in Brazil, the aim of this study was to translate, adapt, and validate the contents of SIDES-R to Brazilian Portuguese (SIDES-R-BR. METHOD: The original interview was subjected to translation, back-translation, semantic equivalence and conceptual correspondence analyses by naive and specialized judges, respectively, an acceptability trial, and inter-rater validity analysis. RESULTS: The interview underwent semantic and structural adaptations considering the Brazilian culture. The final version, SIDES-R-BR, showed a mean understanding score of 4.98 on a 5-point verbal rating scale, in addition to a kappa coefficient of 0.853. CONCLUSION: SIDES-R-BR may be a useful tool in the investigation of DESNOS and contributes a valuable input to clinical research in Brazil. The availability of the instrument allows to test symptoms with adequate reliability, as verified by the kappa coefficient and translation steps.

  14. Factor Structure, Reliability, and Validity of the Japanese Version of the Disgust Propensity and Sensitivity Scale-Revised.

    Science.gov (United States)

    Iwasa, Kazunori; Tanaka, Tsunehiko; Yamada, Yuki

    2016-01-01

    The Disgust Propensity and Sensitivity Scale-Revised is one of the most widely used measures of individual differences for the emotion of disgust. It consists of 2 subscales: disgust propensity and disgust sensitivity. This study examined the factor structure, reliability, and validity of the Japanese version of the revised Disgust Propensity and Sensitivity Scale. Japanese participants (N = 1067) completed the scale as well as the Padua Inventory, Anxiety Sensitivity Index, State-Trait Anxiety Inventory, and Positive and Negative Affective Schedule. The participants were divided into 3 samples: Sample 1 (n = 481, mean age = 23.05, 186 males and 295 females); Sample 2 (n = 492, mean age = 20.27, 243 males and 249 females); and Sample 3 (n = 94, mean age = 22.68, 35 males and 58 females). We combined Samples 1 and 2 (n = 973, mean age = 21.66, 429 males and 544 females), and then created 2 subsamples to ensure the mutual independence of the samples used for two different factor analyses: subsample 1 (n = 486, mean age = 21.86, 199 male and 287 female) for exploratory factor analysis and subsample 2 (n = 487, mean age = 21.40, 230 male and 257 female) for confirmatory factor analysis. We examined test-retest reliability using Sample 3, and construct validity using Samples 1, 2, and the combined sample. Exploratory and confirmatory factor analyses revealed that the item-factor structure of the Japanese Disgust Propensity and Sensitivity Scale-Revised was identical to the English version. Moreover, the scale showed good internal consistency, test-retest reliability, and construct validity for empirical support as provided by correlational analyses. Results revealed adequate psychometric properties of the scale. This study provided the first examples of empirical support for the DPSS-R-J.

  15. Assessing psychological distress in patients with skin diseases: reliability, validity and factor structure of the GHQ-12.

    Science.gov (United States)

    Picardi, A; Abeni, D; Pasquini, P

    2001-09-01

    We studied reliability, validity and factor structure of the 12-item General Health Questionnaire (GHQ-12) in dermatological patients. Subjects attending a dermatological outpatient clinic were administered the GHQ-12 and the Skindex-29. A random subsample was mailed another copy of the questionnaires to be completed within 1 week. A total of 2,579 subjects completed the GHQ-12. The internal consistency of the GHQ-12 was high (Cronbach's alpha = 0.88). Test-retest reliability on 137 subjects was also fairly satisfactory (intraclass correlation coefficient = 0.72), notwithstanding a re-test artefact probably related to reassurance from the physician. Evidence of construct validity was provided by the pattern of correlation between scores on the GHQ-12 and on the scales of Skindex-29, which were as hypothesized. Also, GHQ-12 scores of patients in different clinical groups varied as hypothesized, with patients affected by inflammatory skin diseases scoring significantly higher than patients with isolated skin lesions. We obtained both a two-factor and a three-factor solution: the latter seemed theoretically more appropriate, although the first may have practical advantages. A 'social dysfunction' factor emerged in both analyses, while the other items loaded on a 'general dysphoria' factor or on two separate factors interpreted as 'anxiety' and 'loss of self-esteem'. The GHQ-12 is a reliable and valid instrument with a factor structure that is quite stable across different samples as well as across diverse cultures. Its brevity and easiness of completion make it a useful tool to assess psychological distress in dermatological patients.

  16. Predictive validity of the structured assessment of violence risk in youth: A 4-year follow-up.

    Science.gov (United States)

    Gammelgård, Monica; Koivisto, Anna-Maija; Eronen, Markku; Kaltiala-Heino, Riittakerttu

    2015-07-01

    Structured violence risk assessment is an essential part of treatment planning for violent young people. The Structured Assessment of Violence Risk in Youth (SAVRY) has been shown to have good reliability and validity in a range of settings but has hardly been studied in adolescent mental health services. This study aimed to evaluate the long-term predictive validity of the SAVRY in adolescent psychiatry settings. In a prospective study, 200 SAVRY assessments of adolescents were acquired from psychiatric, forensic and correctional settings. Re-offending records from the Finnish National Crime Register were collected. Receiver operating curve statistics were applied. High SAVRY total and individual subscale scores and low values on the protective factor subscale were significantly associated with subsequent adverse outcomes, but the predictive value of the total score was weak. At the risk item level, those indicating antisocial lifestyle, absence of social support and pro-social involvement were strong indicators of subsequent criminal convictions, with or without violence. The SAVRY summary risk rating was the best indicator of likelihood of being convicted of a violent crime. After allowing for sex, age, psychiatric diagnosis and treatment setting, for example, conviction for a violent crime was over nine times more likely among those young people given high SAVRY summary risk ratings. The SAVRY is a valid and useful method for assessing both short-term and long-term risks of violent and non-violent crime by young people in psychiatric as well as criminal justice settings, adding to a traditional risk-centred assessment approach by also indicating where future preventive treatment efforts should be targeted. The next steps should be to evaluate its role in everyday clinical practice when using the knowledge generated to inform and monitor management and treatment strategies. Copyright © 2014 John Wiley & Sons, Ltd.

  17. Structural damage identification in wind turbine blades using piezoelectric active sensing with ultrasonic validation

    Energy Technology Data Exchange (ETDEWEB)

    Claytor, Thomas N [Los Alamos National Laboratory; Ammerman, Curtt N [Los Alamos National Laboratory; Park, Gyu Hae [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory; Atterbury, Marie K [Los Alamos National Laboratory

    2010-01-01

    This paper gives a brief overview of a new project at LANL in structural damage identification for wind turbines. This project makes use of modeling capabilities and sensing technology to understand realistic blade loading on large turbine blades, with the goal of developing the technology needed to automatically detect early damage. Several structural health monitoring (SHM) techniques using piezoelectric active materials are being investigated for the development of wireless, low power sensors that interrogate sections of the wind turbine blade using Lamb wave propagation data, frequency response functions (FRFs), and time-series analysis methods. The modeling and sensor research will be compared with extensive experimental testing, including wind tunnel experiments, load and fatigue tests, and ultrasonic scans - on small- to mid-scale turbine blades. Furthermore, this study will investigate the effect of local damage on the global response of the blade by monitoring low-frequency response changes.

  18. Validation of spectral methods for the seismic analysis of multi-supported structures

    International Nuclear Information System (INIS)

    Viola, B.

    1999-01-01

    There are many methodologies for the seismic analysis of buildings. When a seism occurs, structures such piping systems in nuclear power plants are subjected to motions that may be different at each support point. Therefore it is necessary to develop methods that take into account the multi-supported effect. In a first time, a bibliography analysis on the different methods that exist has been carried out. The aim was to find a particular method applicable to the study of piping systems. The second step of this work consisted in developing a program that may be used to test and make comparisons on different selected methods. So spectral methods have the advantage to give an estimation of the maximum values for strain in the structure, in reduced calculation time. The time history analysis is used as the reference for the tests. (author)

  19. Beyond Description in Interpersonal Construct Validation: Methodological Advances in the Circumplex Structural Summary Approach.

    Science.gov (United States)

    Zimmermann, Johannes; Wright, Aidan G C

    2017-01-01

    The interpersonal circumplex is a well-established structural model that organizes interpersonal functioning within the two-dimensional space marked by dominance and affiliation. The structural summary method (SSM) was developed to evaluate the interpersonal nature of other constructs and measures outside the interpersonal circumplex. To date, this method has been primarily descriptive, providing no way to draw inferences when comparing SSM parameters across constructs or groups. We describe a newly developed resampling-based method for deriving confidence intervals, which allows for SSM parameter comparisons. In a series of five studies, we evaluated the accuracy of the approach across a wide range of possible sample sizes and parameter values, and demonstrated its utility for posing theoretical questions on the interpersonal nature of relevant constructs (e.g., personality disorders) using real-world data. As a result, the SSM is strengthened for its intended purpose of construct evaluation and theory building. © The Author(s) 2015.

  20. Experiments to Populate and Validate a Processing Model for Polyurethane Foam: Additional Data for Structural Foams

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Rekha R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Celina, Mathias C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Giron, Nicholas Henry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Russick, Edward M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150°C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.

  1. Validation of network communicability metrics for the analysis of brain structural networks.

    Directory of Open Access Journals (Sweden)

    Jennifer Andreotti

    Full Text Available Computational network analysis provides new methods to analyze the brain's structural organization based on diffusion imaging tractography data. Networks are characterized by global and local metrics that have recently given promising insights into diagnosis and the further understanding of psychiatric and neurologic disorders. Most of these metrics are based on the idea that information in a network flows along the shortest paths. In contrast to this notion, communicability is a broader measure of connectivity which assumes that information could flow along all possible paths between two nodes. In our work, the features of network metrics related to communicability were explored for the first time in the healthy structural brain network. In addition, the sensitivity of such metrics was analysed using simulated lesions to specific nodes and network connections. Results showed advantages of communicability over conventional metrics in detecting densely connected nodes as well as subsets of nodes vulnerable to lesions. In addition, communicability centrality was shown to be widely affected by the lesions and the changes were negatively correlated with the distance from lesion site. In summary, our analysis suggests that communicability metrics that may provide an insight into the integrative properties of the structural brain network and that these metrics may be useful for the analysis of brain networks in the presence of lesions. Nevertheless, the interpretation of communicability is not straightforward; hence these metrics should be used as a supplement to the more standard connectivity network metrics.

  2. Validation of the factor structure of the Greek adaptation of the Sociocultural Attitudes Towards Appearance Questionnaire (SATAQ-3).

    Science.gov (United States)

    Argyrides, Marios; Kkeli, Natalie; Kendeou, Panayiota

    2014-06-01

    The current study aimed to confirm the factor structure and reliability of the newly translated Greek version of the Sociocultural Attitudes Towards Appearance Questionnaire-3 (SATAQ-3) among 1753 Greek-Cypriot high school students. Results of the structural equation modeling indicated a very good fit with the original four-factor structure of the SATAQ-3 for both males and females. The Cronbach's alpha coefficients for the four subscales were .92 for 'Internalization-General', .82 for 'Internalization-Athlete', .94 for 'Pressure' and .88 for 'Information'. Further analyses showed no significant differences between BMI categories with respect to the Internalization-General, Internalization-Athlete and Information factors but there were significant differences on the Pressure factor. The findings of the current study support the existence of the original four-factor structure of the SATAQ-3. The validity and reliability results of the Greek version of the SATAQ-3 support its use in Greek-speaking countries or populations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. The Readiness to Change for Bariatric Surgery Assessment Tool: Validity, Factor Structure, and Reliability.

    Science.gov (United States)

    Carlson, Susan M S

    2017-11-01

    Currently, there is no guideline or standard of practice for performing the psychiatric/psychological evaluation that is a requirement for approval for bariatric surgery. The Readiness to Change for Bariatric Surgery Assessment Tool (RCB-SAT) establishes a means for psychiatric evaluators to objectively assess the patient's cognition, beliefs, and motivation around the bariatric diet and lifestyle changes. Development of a clinical decision-making tool for assessing readiness to change in bariatric patients will be useful regarding The Strategic Plan for NIH Obesity Research. The strategic plan outlines 6 overarching themes, with the last 3 centering around creation of such a clinical decision-making tool to assess a bariatric patient's readiness to change: evaluate promising strategies for obesity prevention and treatment in realworld settings and diverse populations, harness technology and tools to advance obesity research and improve health care delivery, and facilitate integration of research results into community programs and medical practice (National Institutes of Health, 2011). The pilot tool was administered to 153 potential bariatric patients, with 61 patients completing the survey a second time. Face and content validity of the items were established through an expert review process. Principle axis factoring by means of varimax rotation with Kaiser normalization identified 15 items loading on 3 factors associated with Prochaska and DiClemente's transtheoretical model of health behavior change: precontemplation, contemplation, and action (DiClemente & Prochaska, 1998). Test-retest reliability was also established for the tool. The proposed RCB-SAT demonstrates potential for assessing a patient's readiness to change regarding the bariatric diet and lifestyle.

  4. Optimization and Validation of Rotating Current Excitation with GMR Array Sensors for Riveted Structures Inspection

    Directory of Open Access Journals (Sweden)

    Chaofeng Ye

    2016-09-01

    Full Text Available In eddy current non-destructive testing of a multi-layered riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. However, when used with linear array sensors, the exciting magnetic flux density ( B x of the orthogonal coils is not uniform over the sensor region, resulting in an output signal magnitude that depends on the relative location of the defect to the sensor array. In this paper, the rotating excitation coil is optimized to achieve a uniform B x field in the sensor array area and minimize the probe size. The current density distribution of the coil is optimized using the polynomial approximation method. A non-uniform coil design is derived from the optimized current density distribution. Simulation results, using both an optimized coil and a conventional coil, are generated using the finite element method (FEM model. The signal magnitude for an optimized coil is seen to be more robust with respect to offset of defects from the coil center. A novel multilayer coil structure, fabricated on a multi-layer printed circuit board, is used to build the optimized coil. A prototype probe with the optimized coil and 32 giant magnetoresistive (GMR sensors is built and tested on a two-layer riveted aluminum sample. Experimental results show that the optimized probe has better defect detection capability compared with a conventional non-optimized coil.

  5. Analysis of foot structural damage in rheumatoid arthritis: clinical evaluation by validated measures and serological correlations

    Directory of Open Access Journals (Sweden)

    E. Bartoloni Bocci

    2011-06-01

    Full Text Available Objective: To examine foot involvement in rheumatoid arthritis (RA and to characterize structural alterations in patients with anti-cyclic citrullinated peptide (CCP antibody-positive and -negative disease. Methods: Seventy-eight patients with RA with foot pain were consecutively enrolled. The Manchester Hallux Valgus (MHV rating scale was used to evaluate the hallux valgus deformity degree. The Foot Posture Index (FPI6, a novel, foot-specific outcome measure, was adopted in order to quantify variation in the position of the foot. The findings were correlated with disease duration and presence or absence of anti-CCP antibodies. Results: About 84.6% patients had different degrees of hallux valgus and 65.4% subjects had a pronated foot. These two foot alterations were prevalently found in patients with long-standing disease and circulating anti-CCP antibodies. On the contrary, RA patients without anti-CCP and early disease essentially displayed a supinated foot without relevant hallux valgus deformity. Conclusion: Our findings allowed to identify different anatomic foot alterations in RA patients according to disease duration and negative prognostic factors such as anti-CCP antibodies. Our findings support the role of an accurate analysis of foot structural damage and may suggest the usefulness of a correct plantar orthosis prescription also in early phases of the disease.

  6. Damage Theory Validation

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    This report contains a series of validation examples for the theoretical model implemented in the computer program DAMAGE. note that the validation examples are for assembled structures.......This report contains a series of validation examples for the theoretical model implemented in the computer program DAMAGE. note that the validation examples are for assembled structures....

  7. Validation of quantitative structure-activity relationship (QSAR) model for photosensitizer activity prediction.

    Science.gov (United States)

    Frimayanti, Neni; Yam, Mun Li; Lee, Hong Boon; Othman, Rozana; Zain, Sharifuddin M; Rahman, Noorsaadah Abd

    2011-01-01

    Photodynamic therapy is a relatively new treatment method for cancer which utilizes a combination of oxygen, a photosensitizer and light to generate reactive singlet oxygen that eradicates tumors via direct cell-killing, vasculature damage and engagement of the immune system. Most of photosensitizers that are in clinical and pre-clinical assessments, or those that are already approved for clinical use, are mainly based on cyclic tetrapyrroles. In an attempt to discover new effective photosensitizers, we report the use of the quantitative structure-activity relationship (QSAR) method to develop a model that could correlate the structural features of cyclic tetrapyrrole-based compounds with their photodynamic therapy (PDT) activity. In this study, a set of 36 porphyrin derivatives was used in the model development where 24 of these compounds were in the training set and the remaining 12 compounds were in the test set. The development of the QSAR model involved the use of the multiple linear regression analysis (MLRA) method. Based on the method, r(2) value, r(2) (CV) value and r(2) prediction value of 0.87, 0.71 and 0.70 were obtained. The QSAR model was also employed to predict the experimental compounds in an external test set. This external test set comprises 20 porphyrin-based compounds with experimental IC(50) values ranging from 0.39 μM to 7.04 μM. Thus the model showed good correlative and predictive ability, with a predictive correlation coefficient (r(2) prediction for external test set) of 0.52. The developed QSAR model was used to discover some compounds as new lead photosensitizers from this external test set.

  8. Validation of Quantitative Structure-Activity Relationship (QSAR) Model for Photosensitizer Activity Prediction

    Science.gov (United States)

    Frimayanti, Neni; Yam, Mun Li; Lee, Hong Boon; Othman, Rozana; Zain, Sharifuddin M.; Rahman, Noorsaadah Abd.

    2011-01-01

    Photodynamic therapy is a relatively new treatment method for cancer which utilizes a combination of oxygen, a photosensitizer and light to generate reactive singlet oxygen that eradicates tumors via direct cell-killing, vasculature damage and engagement of the immune system. Most of photosensitizers that are in clinical and pre-clinical assessments, or those that are already approved for clinical use, are mainly based on cyclic tetrapyrroles. In an attempt to discover new effective photosensitizers, we report the use of the quantitative structure-activity relationship (QSAR) method to develop a model that could correlate the structural features of cyclic tetrapyrrole-based compounds with their photodynamic therapy (PDT) activity. In this study, a set of 36 porphyrin derivatives was used in the model development where 24 of these compounds were in the training set and the remaining 12 compounds were in the test set. The development of the QSAR model involved the use of the multiple linear regression analysis (MLRA) method. Based on the method, r2 value, r2 (CV) value and r2 prediction value of 0.87, 0.71 and 0.70 were obtained. The QSAR model was also employed to predict the experimental compounds in an external test set. This external test set comprises 20 porphyrin-based compounds with experimental IC50 values ranging from 0.39 μM to 7.04 μM. Thus the model showed good correlative and predictive ability, with a predictive correlation coefficient (r2 prediction for external test set) of 0.52. The developed QSAR model was used to discover some compounds as new lead photosensitizers from this external test set. PMID:22272096

  9. Fourth Smissman Award Address. The long search for valid structure-action relationships in drugs.

    Science.gov (United States)

    Albert, A

    1982-01-01

    In 1869, Crum Brown discovered the first structure-activity link by showing that alkaloids, even convulsive ones, were converted by N-methylation to muscle relaxants resembling curarine (itself a quaternary amine). This led to an attempt to link every type of drug action to its own cluster of atoms. This quest was jolted when Loewi (1926) found that a quaternary amine (acetylcholine) was the principal activator of muscle! Suddenly it was seen that a chemical group could be either an agonist or antagonist, depending on its molecular setting. That the agonists were smaller molecules suggested operation of a steric factor. Moreover, Cushny (1926) had focused attention on optical enantiomers: usually only one member of each pair had biological activity, although both were identical in all other properties. The stage was now set for physical properties to play the leading role in relating structure to activity. People recalled the demonstration by Overton and Meyer (1900) that the depressant action of a drug was linked to its lipophilicity. Unhappily, further physical correlations were slow to appear. My colleagues and I, who had been studying (from 1941) the antimicrobial action of aminoacridines and hydroxyquinolines, established quantitatively the role of ionization and chelation (two electronic influences) in the action of drugs. Today most people would agree that the most important properties in determining the action of drugs are not some particular nucleus or substituent but a trio of physical properties: lipophilicity, electron distribution, and shape. Although these properties govern the activity of drugs, their selectivity is due, as I have long maintained, to another trio of properties, namely, comparative distribution (not necessarily lipophilic), comparative biochemistry, and comparative cytology.

  10. Structural Analysis of an Inflation-Deployed Solar Sail With Experimental Validation

    Science.gov (United States)

    Sleight, David W.; Michii, Yuki; Lichodziejewski, David; Derbes, Billy; Mann, Troy O.

    2005-01-01

    Under the direction of the NASA In-Space Propulsion Technology Office, the team of L Garde, NASA Jet Propulsion Laboratory, Ball Aerospace, and NASA Langley Research Center has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. Prior to a flight experiment of a full-scale solar sail, a comprehensive phased test plan is currently being implemented to advance the technology readiness level of the solar sail design. These tests consist of solar sail component, subsystem, and sub-scale system ground tests that simulate the vacuum and thermal conditions of the space environment. Recently, two solar sail test articles, a 7.4-m beam assembly subsystem test article and a 10-m four-quadrant solar sail system test article, were tested in vacuum conditions with a gravity-offload system to mitigate the effects of gravity. This paper presents the structural analyses simulating the ground tests and the correlation of the analyses with the test results. For programmatic risk reduction, a two-prong analysis approach was undertaken in which two separate teams independently developed computational models of the solar sail test articles using the finite element analysis software packages: NEiNastran and ABAQUS. This paper compares the pre-test and post-test analysis predictions from both software packages with the test data including load-deflection curves from static load tests, and vibration frequencies and mode shapes from structural dynamics tests. The analysis predictions were in reasonable agreement with the test data. Factors that precluded better correlation of the analyses and the tests were uncertainties in the material properties, test conditions, and modeling assumptions used in the analyses.

  11. Attentional Control Scale for Children: Factor Structure and Concurrent Validity Among Children and Adolescents Referred for Anxiety Disorders.

    Science.gov (United States)

    Melendez, Raquel; Bechor, Michele; Rey, Yasmin; Pettit, Jeremy W; Silverman, Wendy K

    2017-04-01

    The present study examined the factor structure and concurrent validity of the Attentional Control Scale for Children (ACS-C; Muris, de Jong, & Engelen, 2004), a youth self-rating scale of attentional control. A multisource assessment approach was used with 186 children and adolescents referred to an anxiety disorders specialty clinic. Exploratory factor analysis yielded a 2-factor structure with internally consistent and moderately correlated subscales of Attentional Focusing and Attentional Shifting. Total ACS-C and subscale scores demonstrated significant associations with youth and parent ratings of youth anxiety symptoms, youth self ratings of depressive symptoms, and youth diagnosis of attention deficit-hyperactivity disorder. These findings support use of the ACS-C as a self-rating scale of attentional control among referred youth. Future research is encouraged to examine retest reliability of the ACS-C and to evaluate whether its internal structure could be enhanced by removing or modifying items that performed poorly. © 2016 Wiley Periodicals, Inc.

  12. Original article Reliability, factor structure, and construct validity of the Polish version of the sport imagery ability measure

    Directory of Open Access Journals (Sweden)

    Dagmara Budnik-Przybylska

    2014-12-01

    Full Text Available Background An important component of mental training in sport is the utilization of positive imagery. The “human brain cannot distinguish between an imagined experience and a real experience. The same areas of the brain light up in an imagined experience or imagined performance as in a real experience or performance. For that reason, positive performance imagery has enormous potential” (Orlick, 2008, p. 101. Imagery “has been described as a centre pillar of applied sport psychology” research (Morris, Spittle, & Perry, 2004, p. 344. The aim of the present study was to examine reliability and validity characteristics of the Polish language version of the Sport Imagery Ability Measure (SIAM. Participants and procedure Polish athletes (N = 316 from a range of sports and competitive levels completed the 48 item SIAM. The participants (163 male, 153 female were aged between 12 and 57 years (M = 22.15, SD = 8.25. Results Results indicated that the SIAM had sound internal consistency and maintained good stability over a 3-week period. Confirmatory factor analysis demonstrated that the a priori 3-factor structure of the SIAM resulted in a set of acceptable and poor fit indices (CFI = .91, NFI = .90, RMSEA = .12. Finally, differences in athletes’ imagery abilities were examined in relation to competitive level, gender, and age. Conclusions Overall, results generally supported the reliability and construct validity of the Polish version of the SIAM.

  13. A structural validation of an inventory based on the Abridged Five Factor Circumplex Model (AB5C).

    Science.gov (United States)

    Backstrom, Martin; Larsson, Magnus R; Maddux, Rachel E

    2009-09-01

    We investigated the structural validity of an inventory from the International Personality Item Pool (Goldberg et al., 2006) that is based on the Abridged Five Factor Circumplex (AB5C) model. In a Swedish sample of 1,080 subjects using confirmatory factor analysis, we found that the majority of investigated facets had a primary loading on 1 of the 5 personality factors and a secondary loading on another factor. These results provide overall support for the inventory and indirect support for the AB5C model. Some of the problems detected in the inventory appear to be rooted at the item level and may be a result of how the AB5C is operationalized. Thus, the inventory still requires some refinement and is not in its final stage of development. Nevertheless, our preliminary results are very promising, and we believe the AB5C model deserves renewed attention in trait psychology.

  14. Constitutive Theories for Woven Composite Structures Subjected to Shock Loading; Experimental Validation Using a Conical Shock Tube

    Directory of Open Access Journals (Sweden)

    David R. Hufner

    2012-01-01

    Full Text Available Woven polymer-based composites are currently used in a wide range of marine applications. These materials often exhibit highly nonlinear, rate dependent, anisotropic behavior under shock loadings. Correlation to transient response data, beyond an initial peak, is often difficult. The state of damage evolves throughout the time history and the unloading response varies based on the amount, and nature of, the accumulated damage. Constitutive theories that address the loading and unloading responses have been developed and integrated with each other. A complete theory, applicable to transient dynamic analysis, is presented. The model is implemented within the commercial finite element code, Abaqus, in the form of a user material subroutine. In this study, the conical shock tube is used to experimentally reproduce the high strain rates and fluid structure interactions typical of underwater shock loadings. The conical shock tube data is used to validate analytical model predictions. Simulation results are in good agreement with test data.

  15. Experiment for validation of fluid-structure interaction models and algorithms.

    Science.gov (United States)

    Hessenthaler, A; Gaddum, N R; Holub, O; Sinkus, R; Röhrle, O; Nordsletten, D

    2017-09-01

    In this paper a fluid-structure interaction (FSI) experiment is presented. The aim of this experiment is to provide a challenging yet easy-to-setup FSI test case that addresses the need for rigorous testing of FSI algorithms and modeling frameworks. Steady-state and periodic steady-state test cases with constant and periodic inflow were established. Focus of the experiment is on biomedical engineering applications with flow being in the laminar regime with Reynolds numbers 1283 and 651. Flow and solid domains were defined using computer-aided design (CAD) tools. The experimental design aimed at providing a straightforward boundary condition definition. Material parameters and mechanical response of a moderately viscous Newtonian fluid and a nonlinear incompressible solid were experimentally determined. A comprehensive data set was acquired by using magnetic resonance imaging to record the interaction between the fluid and the solid, quantifying flow and solid motion. Copyright © 2016 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.

  16. Design and laboratory validation of a structural element instrumented with multiplexed interferometric fiber optic sensors

    Science.gov (United States)

    Zonta, Daniele; Pozzi, Matteo; Wu, Huayong; Inaudi, Daniele

    2008-03-01

    This paper introduces a concept of smart structural elements for the real-time condition monitoring of bridges. These are prefabricated reinforced concrete elements embedding a permanent sensing system and capable of self-diagnosis when in operation. The real-time assessment is automatically controlled by a numerical algorithm founded on Bayesian logic: the method assigns a probability to each possible damage scenario, and estimates the statistical distribution of the damage parameters involved (such as location and extent). To verify the effectiveness of the technology, we produced and tested in the laboratory a reduced-scale smart beam prototype. The specimen is 3.8 m long and has cross-section 0.3 by 0.5m, and has been prestressed using a Dywidag bar, in such a way as to control the preload level. The sensor system includes a multiplexed version of SOFO interferometric sensors mounted on a composite bar, along with a number of traditional metal-foil strain gauges. The method allowed clear recognition of increasing fault states, simulated on the beam by gradually reducing the prestress level.

  17. Development and experimental validation of computational methods to simulate abnormal thermal and structural environments

    International Nuclear Information System (INIS)

    Moya, J.L.; Skocypec, R.D.; Thomas, R.K.

    1993-01-01

    Over the past 40 years, Sandia National Laboratories (SNL) has been actively engaged in research to improve the ability to accurately predict the response of engineered systems to abnormal thermal and structural environments. These engineered systems contain very hazardous materials. Assessing the degree of safety/risk afforded the public and environment by these engineered systems, therefore, is of upmost importance. The ability to accurately predict the response of these systems to accidents (to abnormal environments) is required to assess the degree of safety. Before the effect of the abnormal environment on these systems can be determined, it is necessary to ascertain the nature of the environment. Ascertaining the nature of the environment, in turn, requires the ability to physically characterize and numerically simulate the abnormal environment. Historically, SNL has demonstrated the level of safety provided by these engineered systems by either of two approaches: (1) a purely regulatory approach, or (2) by a Probabilistic Risk Assessment (PRA). This paper will address the latter of the two approaches

  18. Validation of a structured questionnaire for COPD and prevalence of COPD in rural area of Mysore: A pilot study

    Directory of Open Access Journals (Sweden)

    Mahesh P

    2009-01-01

    Full Text Available Background: The prevalence of chronic obstructive pulmonary disease (COPD is increasing in India and there is a need to study the prevalence of COPD, particularly in the rural areas, which may be most affected due to their lifestyle. Materials and Methods: First stage: Validation of the questionnaire-105 consecutive patients underwent administration of the structured questionnaire and spirometry was used as a gold standard for the diagnosis of COPD. Second stage: Adults above 40 years (n = 900 in two villages of Mysore district were administered with the validated questionnaire, Knowledge and Attitude questionnaire and Fagerstorm questionnaire, to assess nicotine dependency. Results: The questionnaire was found to have a sensitivity of 62.5% and specificity of 87.6% to diagnose COPD. Of the total 900 adults surveyed (Males: 453, Females: 447, the total prevalence of COPD was 7.1%. Males had a higher prevalence (11.1% compared to females (4.5%. The prevalence of smoking was very high among men at 71.9% and all the women were nonsmokers. The prevalence of COPD was 14.7% in smokers, 19.3% had mild to moderate nicotine dependency and 12.8% were highly dependent. Of the women exposed to regular biomass fuels, the prevalence of COPD was 3.9%, which increased to 4.8% on addition of regular passive smoking. In smoking, male gender and age were significantly associated with COPD ( P < 0.05. Conclusion: The structured questionnaire is a useful tool for the screening of COPD in field studies. Smoking and biomass fuel exposure are important risk factors for COPD.

  19. Three-dimensional velocity model of crustal structure in the southern Korean Peninsula and its full-waveform validations

    Science.gov (United States)

    Rhie, J.; Kim, S.; Woo, J. U.; Song, J. H.

    2016-12-01

    To obtain a high-resolution crustal three-dimensional (3-D) model, we incorporate multiple regional ambient noise datasets in different scales, which consist of 150 accelerometer stations (1-6 s group velocity), 37 regional broadband stations (5-30 s group and phase velocity), and longer period phase velocity maps from previous study (25-40 s phase velocity). A 3-D structure of shear wave velocity is constrained by integrating one-dimensional depth profiles from inversions of surface wave dispersions. The model estimation is carried out thoroughly in a trans-dimensional and hierarchical Bayesian inversion framework, such that the resulting model is less biased by arbitrary assumptions in the inversion process. To obtain P-wave velocity structure, then, a previous estimation of the variation of Vp/Vs ratio is applied. A 1-D velocity model will be replaced by this new 3-D model for determining accurate hypocenters and source processes of local earthquakes in the region. In addition, the new model will make more reliable seismic hazard analysis for scenario earthquakes possible. Before adopting the new model for various applications, it is necessary to validate it. To verify the validity of the model, full-waveform simulations for recent local earthquakes are performed. Two well observed moderate earthquakes occurred at NE and SW of the southern Korean Peninsula are considered for waveform simulations. The comparison between synthetic and observed waveforms shows that the new model reasonably well represents the seismic wave propagation characteristics in the southern Korean Peninsula.

  20. Validation of Material Models For Automotive Carbon Fiber Composite Structures Via Physical And Crash Testing (VMM Composites Project)

    Energy Technology Data Exchange (ETDEWEB)

    Coppola, Anthony [General Motors Company, Flint, MI (United States); Faruque, Omar [Ford Motor Company, Dearborn, MI (United States); Truskin, James F [FCA US LLC, Auburn Hills, MI (United States); Board, Derek [Ford Motor Company, Dearborn, MI (United States); Jones, Martin [Ford Motor Company, Dearborn, MI (United States); Tao, Jian [FCA US LLC, Auburn Hills, MI (United States); Chen, Yijung [Ford Motor Company, Dearborn, MI (United States); Mehta, Manish [M-Tech International LLC, Dubai (United Arab Emirates)

    2017-09-27

    As automotive fuel economy requirements increase, the push for reducing overall vehicle weight will likely include the consideration of materials that have not previously been part of mainstream vehicle design and manufacturing, including carbon fiber composites. Vehicle manufacturers currently rely on computer-aided engineering (CAE) methods as part of the design and development process, so going forward, the ability to accurately and predictably model carbon fiber composites will be necessary. If composites are to be used for structural components, this need applies to both, crash and quasi-static modeling. This final report covers the results of a five-year, $6.89M, 50% cost-shared research project between Department of Energy (DOE) and the US Advanced Materials Partnership (USAMP) under Cooperative Agreement DE-EE-0005661 known as “Validation of Material Models for Automotive Carbon Fiber Composite Structures Via Physical and Crash Testing (VMM).” The objective of the VMM Composites Project was to validate and assess the ability of physics-based material models to predict crash performance of automotive primary load-carrying carbon fiber composite structures. Simulation material models that were evaluated included micro-mechanics based meso-scale models developed by the University of Michigan (UM) and micro-plane models by Northwestern University (NWU) under previous collaborations with the DOE and Automotive Composites Consortium/USAMP, as well as five commercial crash codes: LS-DYNA, RADIOSS, VPS/PAM-CRASH, Abaqus, and GENOA-MCQ. CAE predictions obtained from seven organizations were compared with experimental results from quasi-static testing and dynamic crash testing of a thermoset carbon fiber composite front-bumper and crush-can (FBCC) system gathered under multiple loading conditions. This FBCC design was developed to demonstrate progressive crush, virtual simulation, tooling, fabrication, assembly, non-destructive evaluation and crash testing

  1. Validation of seismic soil-structure interaction analysis methods: EPRI [Electric Power Research Institute]/NRC [Nuclear Regulatory Commission] cooperation in Lotung, Taiwan, experiments

    International Nuclear Information System (INIS)

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Tang, Y.K.; Kassawara, R.P.

    1986-01-01

    The cooperative program between NRC/ANL and EPRI on the validation of soil-structure interaction analysis methods with actual seismic response data is described. A large scale-model of a containment building has been built by EPRI/Taipower in a highly seismic region of Taiwan. Vibration tests were performed, first on the basemat before the superstructure was built and then on the completed structure. Since its completion, the structure has experienced many earthquakes. The site and structural response to these earthquakes have been recorded with field (surface and downhole) and structural instrumentation. The validation program involves blind predictions of site and structural response during vibration tests and a selected seismic event, and subsequent comparison between the predictions and measurements. The predictive calculations are in progress. The results of the correlation are expected to lead to the evaluation of the methods as to their conservatisms and sensitivities

  2. Numerical and Experimental Validation of the Optimization Methodologies for a Wing-Tip Structure Equipped with Conventional and Morphing Ailerons =

    Science.gov (United States)

    Koreanschi, Andreea

    In order to answer the problem of 'how to reduce the aerospace industry's environment footprint?' new morphing technologies were developed. These technologies were aimed at reducing the aircraft's fuel consumption through reduction of the wing drag. The morphing concept used in the present research consists of replacing the conventional aluminium upper surface of the wing with a flexible composite skin for morphing abilities. For the ATR-42 'Morphing wing' project, the wing models were manufactured entirely from composite materials and the morphing region was optimized for flexibility. In this project two rigid wing models and an active morphing wing model were designed, manufactured and wind tunnel tested. For the CRIAQ MDO 505 project, a full scale wing-tip equipped with two types of ailerons, conventional and morphing, was designed, optimized, manufactured, bench and wind tunnel tested. The morphing concept was applied on a real wing internal structure and incorporated aerodynamic, structural and control constraints specific to a multidisciplinary approach. Numerical optimization, aerodynamic analysis and experimental validation were performed for both the CRIAQ MDO 505 full scale wing-tip demonstrator and the ATR-42 reduced scale wing models. In order to improve the aerodynamic performances of the ATR-42 and CRIAQ MDO 505 wing airfoils, three global optimization algorithms were developed, tested and compared. The three algorithms were: the genetic algorithm, the artificial bee colony and the gradient descent. The algorithms were coupled with the two-dimensional aerodynamic solver XFoil. XFoil is known for its rapid convergence, robustness and use of the semi-empirical e n method for determining the position of the flow transition from laminar to turbulent. Based on the performance comparison between the algorithms, the genetic algorithm was chosen for the optimization of the ATR-42 and CRIAQ MDO 505 wing airfoils. The optimization algorithm was improved during

  3. Control Structure Impact on the Flying Performance of the Multi-Rotor VTOL Platform - Design, Analysis and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Roman Czyba

    2013-01-01

    Full Text Available The aim of this research is to examine the different control strategies for the unmanned aerial vehicles (UAV. The control task is formulated as an angular stabilization of the four rotor platform, and also as a tracking problem of chosen state variables. The PID algorithm has been considered in three structures in respect of the optimal control signal applied to the actuators. For better performance of the quadrotor in hover mode the cascade control system has been proposed. The simulation results of attitude control with different PID controller architectures are presented, and confirm the effectiveness of the proposed control structure and theoretical expectations. Moreover, the design and the practical realization of the control architecture on the experimental aerial vehicle are described. The fast prototyping method together with Matlab/Simulink software and DAQ hardware are used for both evolution and validation of control algorithms. The capacity of the attitude stabilization system is important in the development process of more advanced functionality of autonomous flying vehicles; therefore it needs to be highlighted and taken into careful consideration.

  4. The Nature of Coping in Treatment for Marijuana Dependence: Latent Structure and Validation of the Coping Strategies Scale

    Science.gov (United States)

    Litt, Mark D.; Kadden, Ronald M; Tennen, Howard

    2012-01-01

    The Coping Strategies Scale (CSS) was designed to assess adaptive changes in substance-use specific coping that result from treatment. The present study sought to examine the latent structure of the CSS in the hope that it might shed light on the coping processes of drug users, and guide the development of a brief version of the CSS. Respondents on the CSS were 751 men and women treated in three clinical trials for marijuana dependence. Posttreatment CSS data were analyzed to determine the nature of coping responses in patients who have been trained to use specific strategies to deal with substance use disorders. Exploratory factor analysis yielded two factors, categorized as problem-focused and emotion-focused coping, but confirmatory factor analysis did not support this structure. When infrequently endorsed items were removed, however, confirmatory factor analysis revealed a good fit to the data. Contrary to expectations, practical strategies that often form the basis for coping skills training, such as avoiding those who smoke, were not frequently endorsed. Problem focused items reflected cognitive commitments to change. Emotion-focused items included cognitive reinterpretations of emotions, to help manage emotional reactions. Brief versions of the CSS based on these factors showed good convergent and discriminant validity. The CSS, and the brief versions of the CSS, may prove useful in future treatment trials to evaluate effects of treatment on coping skills acquisition and utilization in substance dependent individuals. PMID:22082345

  5. Validity of active fault identification through magnetic anomalous using earthquake mechanism, microgravity and topography structure analysis in Cisolok area

    Science.gov (United States)

    Setyonegoro, Wiko; Kurniawan, Telly; Ahadi, Suaidi; Rohadi, Supriyanto; Hardy, Thomas; Prayogo, Angga S.

    2017-07-01

    Research was conducted to determine the value of the magnetic anomalies to identify anomalous value standard fault, down or up with the type of Meratus trending northeast-southwest Cisolok, Sukabumi. Data collection was performed by setting the measurement grid at intervals of 5 meters distance measurement using a Precision Proton Magnetometer (PPM) -GSM-19T. To identification the active fault using magnetic is needed another parameter. The purpose of this study is to identification active fault using magnetic Anomaly in related with subsurface structure through the validation analysis of earthquake mechanism, microgravity and with Topography Structure in Java Island. Qualitative interpretation is done by analyzing the residual anomaly that has been reduced to the pole while the quantitative interpretation is done by analyzing the pattern of residual anomalies through computation. The results of quantitative interpretation, an anomalous value reduction to the pole magnetic field is at -700 nT to 700 nT while the results of the qualitative interpretation of the modeling of the path AA', BB' and CC' shows the magnetic anomaly at coordinates liquefaction resources with a value of 1028.04, 1416.21, - 1565, -1686.91. The measurement results obtained in Cisolok magnetic anomalies that indicate a high content of alumina (Al) and iron (Fe) which be identified appears through the fault gap towards the northeast through Rajamandala Lembang Fault related to the mechanism in the form of a normal fault with slip rate of 2 mm / year.

  6. Retrospective Validation of a Structure-Based Virtual Screening Protocol to Identify Ligands for Estrogen Receptor Alpha and Its Application to Identify the Alpha-Mangostin Binding Pose

    OpenAIRE

    Agustina Setiawati; Florentinus Dika Octa Riswanto; Sri Hartati Yuliani; Enade Perdana Istyastono

    2014-01-01

    The publicly available enhanced data of ligands and decoys for estrogen receptor alpha (ERα) which were recently published has made the retrospective validation of a structure-based virtual screening (SBVS) protocol to identify ligands for ERα possible. In this article, we present the retrospective validation of an SBVS protocol using PLANTS molecular docking software version 1.2 (PLANTS1.2) as the backbone software. The protocol shows better enrichment factor at 1% false positives (EF1%) val...

  7. Advanced approach to the local structure reconstruction and theory validation on the example of the W L3-edge extended x-ray absorption fine structure of tungsten

    Science.gov (United States)

    Jonane, Inga; Anspoks, Andris; Kuzmin, Alexei

    2018-02-01

    Atomistic simulations of the experimental W L3-edge extended x-ray absorption fine structure (EXAFS) of bcc tungsten at T = 300 K were performed using classical molecular dynamics (MD) and reverse Monte Carlo (RMC) methods. The MD-EXAFS method based on the results of MD simulations allowed us to access the structural information, encoded in EXAFS, beyond the first coordination shell and to validate the accuracy of two interaction potential models—the embedded atom model potential and the second nearest-neighbor modified embedded atom method potential. The RMC-EXAFS method was used for more elaborate analysis of the EXAFS data giving access to thermal disorder effects. The results of both methods suggest that the correlation in atomic motion in bcc tungsten becomes negligible above 8 Å. This fact allowed us to use the EXAFS data to determine not only mean-square relative displacements of atomic W–W pair motion but also mean-square displacements of individual tungsten atoms, which are usually accessible from diffraction data only.

  8. Design and experimental validation of a generic model for combinatorial assembly of DNA tiles into 1D-structures.

    Science.gov (United States)

    Laisne, Aude; Lesniewska, Eric; Pompon, Denis

    2011-06-01

    Quantitative modeling of the self-assembly of DNA tiles leading either to defined end-products or distribution of biopolymers is of practical importance for biotechnology and synthetic biology. The combinatorial process describing tile assembly was implemented into a generic algorithm allowing quantitative description of the population of significant species accumulating during the reaction course. Experimental formation and characterization by optical and electrophoresis approaches of copolymers resulting from the self-assembly of a limited number of half-complementary tiles were used to define and validate generic rules allowing definition of model parameters. Factors controlling the structure and the dynamic of the oligomer population were evidenced for assemblies leading or not to defined end-products. Primary parameters were experimentally determined using rapid mixing experiments. Adjustment of simulations to experimental profiles allowed definition of generic rules for calculation of secondary parameters that take into account macro- and microenvironment of individual hybridization steps. In the case of copolymers, accurate simulation of experimental profiles was achieved for formation of linear assemblies. Overall length of species and structure of the DNA regions flanking the hybridization sites are critical parameters for which calculation rules were defined. The computational approach quantitatively predicted the parameters affecting time-course and distribution of accumulating products for different experimental designs. The computational and parameter evaluation procedures designed for the assembly of DNA tiles into large 1D-structures are more generally applicable for the construction of non-DNA polymers by extremities-specific recognition of molecular blocks. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. SU-E-J-52: Validation of 3D Structure Projection Onto 2D DRR in Commercial Treatment Planning Systems.

    Science.gov (United States)

    Zhang, L; Court, L; Balter, P; Dong, L

    2012-06-01

    The use of structure overlay on setup DRRs can aid the image alignment procedure for daily image-guided setup procedures. However, the accuracy of a 3D region-of-interest (ROI) projected on a 2D digitally reconstructed radiograph (DRR) has rarely been evaluated quantitatively. The goal of this study is to test the accuracy of two commercial treatment planning systems (TPS) in producing overlay structures on setup DRRs. We designed a novel method to identify landmarks which were on the boundary of the projected ROI on a DRR. The 3D ROIvolume is composed of a stack of 2D curves. We first mathematically project each 2D curve onto a beams-eye-view (BEV) plane. Next, we detectthe boundary points of the projected curves. Those boundary points serve aslandmarks. Finally, we project the binary mask of the 3D ROI volume using ray tracing method onto the BEV plane. This projected binary mask is used to exclude the false landmarks. Once those landmarks are detected, wecompute the distance between the landmarks and ROI outlines from the TPS. We applied our validation method to 13 ROIs from a lung patient and 4 simulated ROIs on 2 BEV DRRs for two different TPS (Eclipse and Pinnacle). Average distance between the landmarks and ROIoutlines was 0.5mm for both Eclipse and Pinnacle approaches, which is close to the pixel resolution of the DRR. The maximum distance andaverage maximum distance was 2mm and 1 mm, respectively, for both TPS.The maximum distance occurred at points where the ROI curve has a sharpchange between slices. The accuracy of Eclipse and Pinnacle ROI projection method seems to be acceptable to within 1mm althoughprojection error can be as large as 2mm when structure shape has a sharp variation from one slice to the next. © 2012 American Association of Physicists in Medicine.

  10. Validation of the Penn Inventory of Scrupulosity (PIOS) in scrupulous and nonscrupulous patients: Revision of factor structure and psychometrics.

    Science.gov (United States)

    Huppert, Jonathan D; Fradkin, Isaac

    2016-06-01

    Scrupulosity, or obsessive-compulsive symptoms related to religiosity or religion, is a common presentation of obsessive compulsive disorder (OCD), and it is important to elucidate its phenomenology and measurement. Today, the most widespread questionnaire for the assessment of scrupulosity is the Penn Inventory of Scrupulosity (PIOS). The current study examines the psychometric properties of the PIOS in outpatient, treatment-seeking patients. Results of a confirmatory factor analysis suggested an unsatisfactory fit for previously suggested factor structures. A follow-up exploratory factor analysis suggested that a bifactor model was the most suitable solution. In addition, the scores of the PIOS and its revised subscales were found to have moderate-good concurrent validity; however, its scores discriminated poorly between patients with scrupulous obsessions and patients with OCD and other repugnant obsessions. Group differences and receiver operating characteristics (ROC) analyses both indicated that the PIOS is more suitable in discriminating scrupulous obsessions in Christian patients but not in other religious groups (i.e., Jews, nonreligious patients). Additional analyses revealed that the co-occurrence of scrupulous and other repugnant obsessions is also moderated by religious affiliation. These results raise questions in terms of grouping scrupulosity with other repugnant obsessions and suggest for the need of culturally sensitive instruments of scrupulosity. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Validity of the independent-processes approximation for resonance structures in electron-ion scattering cross sections

    International Nuclear Information System (INIS)

    Badnell, N.R.; Pindzola, M.S.; Griffin, D.C.

    1991-01-01

    The total inelastic cross section for electron-ion scattering may be found in the independent-processes approximation by adding the resonant cross section to the nonresonant background cross section. We study the validity of this approximation for electron excitation of multiply charged ions. The resonant-excitation cross section is calculated independently using distorted waves for various Li-like and Na-like ions using (N+1)-electron atomic-structure methods previously developed for the calculation of dielectronic-recombination cross sections. To check the effects of interference between the two scattering processes, we also carry out detailed close-coupling calculations for the same atomic ions using the R-matrix method. For low ionization stages, interference effects manifest themselves sometimes as strong window features in the close-coupling cross section, which are not present in the independent-processes cross section. For higher ionization stages, however, the resonance features found in the independent-processes approximation are found to be in good agreement with the close-coupling results

  12. Emotional Responses to Suicidal Patients: Factor Structure, Construct, and Predictive Validity of the Therapist Response Questionnaire-Suicide Form

    Directory of Open Access Journals (Sweden)

    Shira Barzilay

    2018-04-01

    3-factor structure. It demonstrates construct validity for assessing distinct suicide-related countertransference to psychiatric outpatients. Mental health professionals’ emotional responses to their patients are concurrently indicative and prospectively predictive of suicidal thoughts and behaviors. Thus, the TRQ-SF is a useful tool for the study of countertransference in the treatment of suicidal patients and may help clinicians make diagnostic and therapeutic use of their own responses to improve assessment and intervention for individual suicidal patients.

  13. Multilevel Factor Structure, Concurrent Validity, and Test-Retest Reliability of the High School Teacher Version of the Authoritative School Climate Survey

    Science.gov (United States)

    Huang, Francis L.; Cornell, Dewey G.

    2016-01-01

    Although school climate has long been recognized as an important factor in the school improvement process, there are few psychometrically supported measures based on teacher perspectives. The current study replicated and extended the factor structure, concurrent validity, and test-retest reliability of the teacher version of the Authoritative…

  14. Making the Transition from Diagnosis to Treatment-Planning: Validity, Reliability and Factor Structure of the Autism Spectrum Disorder Behaviour Checklist

    Science.gov (United States)

    Bitsika, Vicki; Sharpley, Christopher F.

    2018-01-01

    The validity, reliability and factor structure of the Autism Spectrum Disorder Behaviour Checklist-Revised (ASDBC-R) were measured in a sample of 140 boys with Autism Spectrum Disorder (ASD) aged between 6 and 18 years. Internal consistency (Cronbach's alpha) was satisfactory and the ASDBC-R significantly correlated with the Social Responsiveness…

  15. Modeling validation to structural flaws in the foundations of oil tanks; Validacao de modelagem para estudo de alteracoes estruturais em fundacoes de tanques de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Couto, Larissa Goncalves; Leite, Sandro Passos, E-mail: leite_sp@ig.com.br [Fundacao Tecnico-Educacional Souza Marques, Rio de Janeiro, RJ (Brazil). Faculdade de Engenharia; Pereira, Walsan Wagner [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    This paper presents the modeling of an experiment used to study the application of backscattered neutrons in the identification of structural flaws in the foundations of oil tanks. This modeling was a preliminary validation procedure of the method of calculation, performed with the radiation transport code MCNP, to study the application of backscattered neutrons as inspection tool. (author)

  16. Validation of the National Institutes of Health Stroke Scale, modified Rankin Scale and Barthel Index in Brazil: the role of cultural adaptation and structured interviewing.

    Science.gov (United States)

    Cincura, Carolina; Pontes-Neto, Octavio M; Neville, Iuri S; Mendes, Henrique F; Menezes, Daniela F; Mariano, Débora C; Pereira, Issana F; Teixeira, Larissa A; Jesus, Pedro A P; de Queiroz, Danilo C L; Pereira, Davidson F; Pinto, Elen; Leite, João P; Lopes, Antonio A; Oliveira-Filho, Jamary

    2009-01-01

    We aimed to validate three widely used scales in stroke research in a multiethnic Brazilian population. The National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and Barthel Index (BI) were translated, culturally adapted and applied by two independent investigators. The mRS was applied with or without a previously validated structured interview. Interobserver agreement (kappa statistics) and intraclass correlation coefficients were calculated. 84 patients underwent mRS (56 with and 28 without a structured interview), 57 BI and 62 NIHSS scoring. Intraclass correlation coefficient was 0.902 for NIHSS and 0.967 for BI. For BI, interobserver agreement was good (kappa = 0.70). For mRS, the structured interview improved interobserver agreement (kappa = 0.34 without a structured interview; 0.75 with a structured interview). The NIHSS, BI and mRS show good validity when translated and culturally adapted. Using a structured interview for the mRS improves interobserver concordance rates. Copyright (c) 2008 S. Karger AG, Basel.

  17. A validation of the Experiences in Close Relationships-Relationship Structures scale (ECR-RS) in adolescents

    DEFF Research Database (Denmark)

    Elklit, Ask; Feddern, Dagmar

    2014-01-01

    , exhibiting satisfactory construct validity, including factor-specific links to the model of adult attachment (Bartholomew & Horowitz, 1991), and independent factor discrimination between subgroups. A robust validation supports the application of the ECR-RS to assessing relationship-specific adolescent...

  18. The Theory of Planned Behavior (TPB) and Pre-Service Teachers' Technology Acceptance: A Validation Study Using Structural Equation Modeling

    Science.gov (United States)

    Teo, Timothy; Tan, Lynde

    2012-01-01

    This study applies the theory of planned behavior (TPB), a theory that is commonly used in commercial settings, to the educational context to explain pre-service teachers' technology acceptance. It is also interested in examining its validity when used for this purpose. It has found evidence that the TPB is a valid model to explain pre-service…

  19. Extended criteria and predictors in college admission: Exploring the structure of study success and investigating the validity of domain knowledge

    Directory of Open Access Journals (Sweden)

    OLGA KUNINA

    2007-06-01

    Full Text Available The utility of aptitude tests and intelligence measures in the prediction of the success in college is one of the empirically best supported results in ability research. However, the structure of the criterion “study success” has not been appropriately investigated so far. Moreover, it remains unclear which aspect of intelligence – fluid intelligence or crystallized intelligence – has the major impact on the prediction. In three studies we have investigated the dimensionality of the criterion achievements as well as the relative contributions of competing ability predictors. In the first study, the dimensionality of college grades was explored in a sample of 629 alumni. A measurement model with two correlated latent factors distinguishing undergraduate college grades on the one hand from graduate college grades on the other hand had the best fit to the data. In the second study, a group of 179 graduate students completed a Psychology knowledge test and provided available college grades in undergraduate studies. A model separating a general latent factor for Psychology knowledge from a nested method factor for college grades, and a second nested factor for “experimental orientation” had the best fit to the data. In the third study the predictive power of domain specific knowledge tests in Mathematics, English, and Biology was investigated. A sample of 387 undergraduate students in this prospective study additionally completed a compilation of fluid intelligence tests. The results of this study indicate as expected that: a ability measures are incrementally predictive over school grades in predicting exam grades; and b that knowledge tests from relevant domains were incrementally predictive over fluid intelligence. The results of these studies suggest that criteria for college admission tests deserve and warrant more attention, and that domain specific ability indicators can contribute to the predictive validity of established

  20. The Causes of School Failure in Secondary School Students: Validation of a Psychosocial Model with Structural Equations.

    Science.gov (United States)

    Chacón Fuertes, Fernando; Huertas Hurtado, Carlos A

    2017-11-20

    The objective of the study was to determine the causal effects of school failure (SF) among secondary school students, belonging to five public schools within the region of Girardota, Colombia, through the validation of a psychosocial model with structural equations. A total of 319 students, 25% more males, enrolled in classes between 6th and 11th year, with an average age of 14 years. Furthermore, 265 parents and 200 teachers were also included in the sample. Participants answered the questions raised in 9 instruments. Of the total number of students, 63.8% were surveyed. The instruments were subjected to a pilot test and to the judgment of experts. In order to reduce the amount of data, exploratory and confirmatory factorial analyses were used. Other techniques of multivariate analysis such as decision trees and linear regressions were also used in order to previously evaluate the relationships between the independent variables (IV) and the dependent variable (DV). Afterwards, the Full SEM was calculated, yielding a model consisting of 34 variables (10 latent and 24 observable), with the following indexes of goodness of fit: CMIN/DF = 1.146, p = .058, IFI = 0.974, TLI = .970, CFI = .974, RMSEA = .027 and PCLOSE = 0.998. Theoretically, the model confirms the predictive value of the selected variables, with respect to school failure. The results are applicable to both the design of educational policies and the direct intervention in the classroom. In both contexts, strategies can be developed that reduce factors that negatively affect school performance, actively linking students, teachers and parents.

  1. Development and validation of a bedside risk score for MRSA among patients hospitalized with complicated skin and skin structure infections

    Directory of Open Access Journals (Sweden)

    Zilberberg Marya D

    2012-07-01

    Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA is a frequent cause of complicated skin and skin structure infections (cSSSI. Patients with MRSA require different empiric treatment than those with non-MRSA infections, yet no accurate tools exist to aid in stratifying the risk for a MRSA cSSSI. We sought to develop a simple bedside decision rule to tailor empiric coverage more accurately. Methods We conducted a large multicenter (N=62 hospitals retrospective cohort study in a US-based database between April 2005 and March 2009. All adult initial admissions with ICD-9-CM codes specific to cSSSI were included. Patients admitted with MRSA vs. non-MRSA were compared with regard to baseline demographic, clinical and hospital characteristics. We developed and validated a model to predict the risk of MRSA, and compared its performance via sensitivity, specificity and other classification statistics to the healthcare-associated (HCA infection risk factors. Results Of the 7,183 patients with cSSSI, 2,387 (33.2% had MRSA. Factors discriminating MRSA from non-MRSA were age, African-American race, no evidence of diabetes mellitus, cancer or renal dysfunction, and prior history of cardiac dysrhythmia. The score ranging from 0 to 8 points exhibited a consistent dose–response relationship. A MRSA score of 5 or higher was superior to the HCA classification in all characteristics, while that of 4 or higher was superior on all metrics except specificity. Conclusions MRSA is present in 1/3 of all hospitalized cSSSI. A simple bedside risk score can help discriminate the risk for MRSA vs. other pathogens with improved accuracy compared to the HCA definition.

  2. Cross-validation of the structure of a transiently formed and low populated FF domain folding intermediate determined by relaxation dispersion NMR and CS-Rosetta.

    Science.gov (United States)

    Barette, Julia; Velyvis, Algirdas; Religa, Tomasz L; Korzhnev, Dmitry M; Kay, Lewis E

    2012-06-14

    We have recently reported the atomic resolution structure of a low populated and transiently formed on-pathway folding intermediate of the FF domain from human HYPA/FBP11 [Korzhnev, D. M.; Religa, T. L.; Banachewicz, W.; Fersht, A. R.; Kay, L.E. Science 2011, 329, 1312-1316]. The structure was determined on the basis of backbone chemical shift and bond vector orientation restraints of the invisible intermediate state measured using relaxation dispersion nuclear magnetic resonance (NMR) spectroscopy that were subsequently input into the database structure determination program, CS-Rosetta. As a cross-validation of the structure so produced, we present here the solution structure of a mimic of the folding intermediate that is highly populated in solution, obtained from the wild-type domain by mutagenesis that destabilizes the native state. The relaxation dispersion/CS-Rosetta structures of the intermediate are within 2 Å of those of the mimic, with the nonnative interactions in the intermediate also observed in the mimic. This strongly confirms the structure of the FF domain folding intermediate, in particular, and validates the use of relaxation dispersion derived restraints in structural studies of invisible excited states, in general.

  3. Parameter Optimization and Field Validation of the Functional–Structural Model GREENLAB for Maize at Different Population Densities

    Science.gov (United States)

    Ma, Yuntao; Wen, Meiping; Guo, Yan; Li, Baoguo; Cournède, Paul-Henry; de Reffye, Philippe

    2008-01-01

    Background and Aims Plant population density (PPD) influences plant growth greatly. Functional–structural plant models such as GREENLAB can be used to simulate plant development and growth and PPD effects on plant functioning and architectural behaviour can be investigated. This study aims to evaluate the ability of GREENLAB to predict maize growth and development at different PPDs. Methods Two field experiments were conducted on irrigated fields in the North China Plain with a block design of four replications. Each experiment included three PPDs: 2·8, 5·6 and 11·1 plants m−2. Detailed observations were made on the dimensions and fresh biomass of above-ground plant organs for each phytomer throughout the seasons. Growth stage-specific target files (a description of plant organ weight and dimension according to plant topological structure) were established from the measured data required for GREENLAB parameterization. Parameter optimization was conducted using a generalized least square method for the entire growth cycles for all PPDs and years. Data from in situ plant digitization were used to establish geometrical symbol files for organs that were then applied to translate model output directly into 3-D representation for each time step of the model execution. Key Results The analysis indicated that the parameter values of organ sink variation function, and the values of most of the relative sink strength parameters varied little among years and PPDs, but the biomass production parameter, computed plant projection surface and internode relative sink strength varied with PPD. Simulations of maize plant growth based on the fitted parameters were reasonably good as indicated by the linearity and slopes similar to unity for the comparison of simulated and observed values. Based on the parameter values fitted from different PPDs, shoot (including vegetative and reproductive parts of the plant) and cob fresh biomass for other PPDs were simulated. Three

  4. Factor Structure and Initial Validation of a Multidimensional Measure of Difficulties in the Regulation of Positive Emotions: The DERS-Positive.

    Science.gov (United States)

    Weiss, Nicole H; Gratz, Kim L; Lavender, Jason M

    2015-05-01

    Emotion regulation difficulties are a transdiagnostic construct relevant to numerous clinical difficulties. Although the Difficulties in Emotion Regulation Scale (DERS) is a multidimensional measure of maladaptive ways of responding to emotions, it focuses on difficulties with the regulation of negative emotions and does not assess emotion dysregulation in the form of problematic responding to positive emotions. The aim of this study was to develop and validate a measure of clinically relevant difficulties in the regulation of positive emotions (DERS-Positive). Findings revealed a three-factor structure and supported the internal consistency and construct validity of the total and subscale scores. © The Author(s) 2015.

  5. Neighbourhood social and built environment factors and falls in community-dwelling canadian older adults: A validation study and exploration of structural confounding

    Directory of Open Access Journals (Sweden)

    Afshin Vafaei

    2016-12-01

    Full Text Available Older persons are vulnerable to the ill effects of their social and built environment due to age-related limitations in mobility and bio-psychological vulnerability. Falls are common in older adults and result from complex interactions between individual, social, and contextual determinants. We addressed two methodological issues of neighbourhood-health and social epidemiological studies in this analysis: (1 validity of measures of neighbourhood contexts, and (2 structural confounding resulting from social sorting mechanisms. Baseline data from International Mobility in Aging Study were used. Samples included community-dwelling Canadians older than 65 living in Kingston (Ontario and St-Hyacinthe (Quebec. We performed factor analysis and ecometric analysis to assess the validity of measures of neighbourhood social capital, socioeconomic status, and the built environment and stratified tabular analyses to explore structural confounding. The scales all demonstrated good psychometric and ecometric properties. There was an evidence of the existence of structural confounding in this sample of Canadian older adults as some combinations of strata for the three neighbourhood measures had no population. This limits causal inference in studying relationships between neighbourhood factors and falls and should be taken into account in aetiological aging research. Keywords: Ecometric analysis, Falls, Social and built environment, Neighbourhoods, Older adults, Social Capital, Structural confounding, Validity

  6. Computational analysis of Amsacrine resistance in human topoisomerase II alpha mutants (R487K and E571K) using homology modeling, docking and all-atom molecular dynamics simulation in explicit solvent.

    Science.gov (United States)

    Sader, Safaa; Wu, Chun

    2017-03-01

    Amsacrine is an effective topoisomerase II enzyme inhibitor in acute lymphatic leukemia. Previous experimental studies have successfully identified two important mutations (R487K and E571K) conferring 100 and 25 fold resistance to Amsacrine respectively. Although the reduction of the cleavage ligand-DNA-protein ternary complex has been well thought as the major cause of drug resistance, the detailed energetic, structural and dynamic mechanisms remain to be elusive. In this study, we constructed human topoisomerase II alpha (hTop2α) homology model docked with Amsacrine based on crystal structure of human Top2β in complex with etoposide. This wild type complex was used to build the ternary complex with R487K and E571K mutants. Three 500ns molecular dynamics simulations were performed on complex systems of wild type and two mutants. The detailed energetic, structural and dynamic analysis were performed on the simulation data. Our binding data indicated a significant impairment of Amsacrine binding energy in the two mutants compared with the wild type. The order of weakening (R487K>E571K) was in agreement with the order of experimental drug resistance fold (R489K>E571K). Our binding energy decomposition further indicated that weakening of the ligand-protein interaction rather than the ligand-DNA interaction was the major contributor of the binding energy difference between R487K and E571K. In addition, key residues contributing to the binding energy (ΔG) or the decrease of the binding energy (ΔΔG) were identified through the energy decomposition analysis. The change in ligand binding pose, dynamics of protein, DNA and ligand upon the mutations were thoroughly analyzed and discussed. Deciphering the molecular basis of drug resistance is crucial to overcome drug resistance using rational drug design. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Partial validation of a French version of the ADHD-rating scale IV on a French population of children with ADHD and epilepsy. Factorial structure, reliability, and responsiveness.

    Science.gov (United States)

    Mercier, Catherine; Roche, Sylvain; Gaillard, Ségolène; Kassai, Behrouz; Arzimanoglou, Alexis; Herbillon, Vania; Roy, Pascal; Rheims, Sylvain

    2016-05-01

    Attention deficit hyperactivity disorder (ADHD) is a well-known comorbidity in children with epilepsy. In English-speaking countries, the scores of the original ADHD-rating scale IV are currently used as main outcomes in various clinical trials in children with epilepsy. In French-speaking countries, several French versions are in use though none has been fully validated yet. We sought here for a partial validation of a French version of the ADHD-RS IV regarding construct validity, internal consistency (i.e., scale reliability), item reliability, and responsiveness in a group of French children with ADHD and epilepsy. The study involved 167 children aged 6-15years in 10 French neuropediatric units. The factorial structure and item reliability were assessed with a confirmatory factorial analysis for ordered categorical variables. The dimensions' internal consistency was assessed with Guttman's lambda 6 coefficient. The responsiveness was assessed by the change in score under methylphenidate and in comparison with a control group. The results confirmed the original two-dimensional factorial structure (inattention, hyperactivity/impulsivity) and showed a satisfactory reliability of most items, a good dimension internal consistency, and a good responsiveness of the total score and the two subscores. The studied French version of the ADHD-RS IV is thus validated regarding construct validity, reliability, and responsiveness. It can now be used in French-speaking countries in clinical trials of treatments involving children with ADHD and epilepsy. The full validation requires further investigations. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. An evaluation of the structural validity of the shoulder pain and disability index (SPADI) using the Rasch model.

    Science.gov (United States)

    Jerosch-Herold, Christina; Chester, Rachel; Shepstone, Lee; Vincent, Joshua I; MacDermid, Joy C

    2018-02-01

    The shoulder pain and disability index (SPADI) has been extensively evaluated for its psychometric properties using classical test theory (CTT). The purpose of this study was to evaluate its structural validity using Rasch model analysis. Responses to the SPADI from 1030 patients referred for physiotherapy with shoulder pain and enrolled in a prospective cohort study were available for Rasch model analysis. Overall fit, individual person and item fit, response format, dependence, unidimensionality, targeting, reliability and differential item functioning (DIF) were examined. The SPADI pain subscale initially demonstrated a misfit due to DIF by age and gender. After iterative analysis it showed good fit to the Rasch model with acceptable targeting and unidimensionality (overall fit Chi-square statistic 57.2, p = 0.1; mean item fit residual 0.19 (1.5) and mean person fit residual 0.44 (1.1); person separation index (PSI) of 0.83. The disability subscale however shows significant misfit due to uniform DIF even after iterative analyses were used to explore different solutions to the sources of misfit (overall fit (Chi-square statistic 57.2, p = 0.1); mean item fit residual 0.54 (1.26) and mean person fit residual 0.38 (1.0); PSI 0.84). Rasch Model analysis of the SPADI has identified some strengths and limitations not previously observed using CTT methods. The SPADI should be treated as two separate subscales. The SPADI is a widely used outcome measure in clinical practice and research; however, the scores derived from it must be interpreted with caution. The pain subscale fits the Rasch model expectations well. The disability subscale does not fit the Rasch model and its current format does not meet the criteria for true interval-level measurement required for use as a primary endpoint in clinical trials. Clinicians should therefore exercise caution when interpreting score changes on the disability subscale and attempt to compare their scores to age- and sex

  9. The DUNDRUM-1 structured professional judgment for triage to appropriate levels of therapeutic security: retrospective-cohort validation study

    Directory of Open Access Journals (Sweden)

    O'Neill Conor

    2011-03-01

    Full Text Available Abstract Background The assessment of those presenting to prison in-reach and court diversion services and those referred for admission to mental health services is a triage decision, allocating the patient to the appropriate level of therapeutic security. This is a critical clinical decision. We set out to improve on unstructured clinical judgement. We collated qualitative information and devised an 11 item structured professional judgment instrument for this purpose then tested for validity. Methods All those assessed following screening over a three month period at a busy remand committals prison (n = 246 were rated in a retrospective cohort design blind to outcome. Similarly, all those admitted to a mental health service from the same prison in-reach service over an overlapping two year period were rated blind to outcome (n = 100. Results The 11 item scale had good internal consistency (Cronbach's alpha = 0.95 and inter-rater reliability. The scale score did not correlate with the HCR-20 'historical' score. For the three month sample, the receiver operating characteristic area under the curve (AUC for those admitted to hospital was 0.893 (95% confidence interval 0.843 to 0.943. For the two year sample, AUC distinguished at each level between those admitted to open wards, low secure units or a medium/high secure service. Open wards v low secure units AUC = 0.805 (95% CI 0.680 to 0.930; low secure v medium/high secure AUC = 0.866, (95% CI 0.784 to 0.949. Item to outcome correlations were significant for all 11 items. Conclusions The DUNDRUM-1 triage security scale and its items performed to criterion levels when tested against the real world outcome. This instrument can be used to ensure consistency in decision making when deciding who to admit to secure forensic hospitals. It can also be used to benchmark admission thresholds between services and jurisdictions. In this study we found some divergence between assessed need and actual placement

  10. Validity of semi-quantitative scale for brain MRI in unilateral cerebral palsy due to periventricular white matter lesions: Relationship with hand sensorimotor function and structural connectivity.

    Science.gov (United States)

    Fiori, Simona; Guzzetta, Andrea; Pannek, Kerstin; Ware, Robert S; Rossi, Giuseppe; Klingels, Katrijn; Feys, Hilde; Coulthard, Alan; Cioni, Giovanni; Rose, Stephen; Boyd, Roslyn N

    2015-01-01

    To provide first evidence of construct validity of a semi-quantitative scale for brain structural MRI (sqMRI scale) in children with unilateral cerebral palsy (UCP) secondary to periventricular white matter (PWM) lesions, by examining the relationship with hand sensorimotor function and whole brain structural connectivity. Cross-sectional study of 50 children with UCP due to PWM lesions using 3 T (MRI), diffusion MRI and assessment of hand sensorimotor function. We explored the relationship of lobar, hemispheric and global scores on the sqMRI scale, with fractional anisotropy (FA), as a measure of brain white matter microstructure, and with hand sensorimotor measures (Assisting Hand Assessment, AHA; Jebsen-Taylor Test for Hand Function, JTTHF; Melbourne Assessment of Unilateral Upper Limb Function, MUUL; stereognosis; 2-point discrimination). Lobar and hemispheric scores on the sqMRI scale contralateral to the clinical side of hemiplegia correlated with sensorimotor paretic hand function measures and FA of a number of brain structural connections, including connections of brain areas involved in motor control (postcentral, precentral and paracentral gyri in the parietal lobe). More severe lesions correlated with lower sensorimotor performance, with the posterior limb of internal capsule score being the strongest contributor to impaired hand function. The sqMRI scale demonstrates first evidence of construct validity against impaired motor and sensory function measures and brain structural connectivity in a cohort of children with UCP due to PWM lesions. More severe lesions correlated with poorer paretic hand sensorimotor function and impaired structural connectivity in the hemisphere contralateral to the clinical side of hemiplegia. The quantitative structural MRI scoring may be a useful clinical tool for studying brain structure-function relationships but requires further validation in other populations of CP.

  11. Examining construct and predictive validity of the Health-IT Usability Evaluation Scale: confirmatory factor analysis and structural equation modeling results

    Science.gov (United States)

    Yen, Po-Yin; Sousa, Karen H; Bakken, Suzanne

    2014-01-01

    Background In a previous study, we developed the Health Information Technology Usability Evaluation Scale (Health-ITUES), which is designed to support customization at the item level. Such customization matches the specific tasks/expectations of a health IT system while retaining comparability at the construct level, and provides evidence of its factorial validity and internal consistency reliability through exploratory factor analysis. Objective In this study, we advanced the development of Health-ITUES to examine its construct validity and predictive validity. Methods The health IT system studied was a web-based communication system that supported nurse staffing and scheduling. Using Health-ITUES, we conducted a cross-sectional study to evaluate users’ perception toward the web-based communication system after system implementation. We examined Health-ITUES's construct validity through first and second order confirmatory factor analysis (CFA), and its predictive validity via structural equation modeling (SEM). Results The sample comprised 541 staff nurses in two healthcare organizations. The CFA (n=165) showed that a general usability factor accounted for 78.1%, 93.4%, 51.0%, and 39.9% of the explained variance in ‘Quality of Work Life’, ‘Perceived Usefulness’, ‘Perceived Ease of Use’, and ‘User Control’, respectively. The SEM (n=541) supported the predictive validity of Health-ITUES, explaining 64% of the variance in intention for system use. Conclusions The results of CFA and SEM provide additional evidence for the construct and predictive validity of Health-ITUES. The customizability of Health-ITUES has the potential to support comparisons at the construct level, while allowing variation at the item level. We also illustrate application of Health-ITUES across stages of system development. PMID:24567081

  12. STRUCTURE AND VALIDATION OF A CONTEXTUAL QUALITY OF LIFE SCALE FOR PEOPLE WITH INTELLECTUAL DISABILITIES IN SOCIAL SERVICES: AN ORGANIZATION-ORIENTED MEASURE FROM AN EXTERNAL PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Carolina Moliner

    2013-09-01

    Full Text Available The aim of this study is to develop and validate a scale on the Quality of Life (QoL of people with intellectual disabilities as assessed by family members (external perspective. The instrument measures improvement in QoL due to actions by organizations delivering services to individuals with intellectual disabilities (organization-oriented measure. In order to design the items for the scale, focus groups were set up with professionals dedicated to attending to individuals with intellectual disabilities. An initial scale of 20 items was constructed by consensus. A total of 1195 family members answered the questionnaire. In order to assess the structure of the scale, EFA recommended deleting 3 overlapping items. The final scale consisted of 17 items (α=95 and was composed of four main dimensions: self-determination (SD, social inclusion (SI, rights (RI and overall improvement (OI, which explained 74.83% of the variance. Finally, the consistency and validity were assessed. Convergent validity and discriminant validity were satisfactory. Moreover, CFA confirmed the structure of the scale. Main conclusions, limitations and practical implications are discussed.

  13. The 13-Item Sense of Coherence Scale in Dutch-Speaking Adolescents and Young Adults: Structural Validity, Age Trends, and Chronic Disease

    Directory of Open Access Journals (Sweden)

    Koen Luyckx

    2012-12-01

    Full Text Available The present study focused on the structural validity of the Dutch 13-item sense of coherence (SOC scale, examined age trends in SOC in adolescence and young adulthood, and investigated the potential impact of chronic disease on SOC. Eight samples of Belgian high school students, college students, and young adult employees were used (total 'N' = 2,781; 380 of them aged 14-18 years were diagnosed with congenital heart disease. The SOC-13 scale proved to be structurally valid, as configural, metric, and scalar invariance was established. In line with salutogenic theory, SOC was found to increase with age through the teens and twenties. Relatedly, whereas high school and college students did not differ on mean SOC scores, employed young adults scored significantly higher. Having congenital heart disease was associated with higher levels of SOC in 14-18 year olds: they displayed similarly high scores on SOC as healthy individuals in their late twenties.

  14. Magnetic Decoupling Design and Experimental Validation of a Radial-Radial Flux Compound-Structure Permanent-Magnet Synchronous Machine for HEVs

    Directory of Open Access Journals (Sweden)

    Zhiyi Song

    2012-10-01

    Full Text Available The radial-radial flux compound-structure permanent-magnet synchronous machine (CS-PMSM, integrated by two concentrically arranged permanent-magnet electric machines, is an electromagnetic power-splitting device for hybrid electric vehicles (HEVs. As the two electric machines share a rotor as structural and magnetic common part, their magnetic paths are coupled, leading to possible mutual magnetic-field interference and complex control. In this paper, a design method to ensure magnetic decoupling with minimum yoke thickness of the common rotor is investigated. A prototype machine is designed based on the proposed method, and the feasibility of magnetic decoupling and independent control is validated by experimental tests of mutual influence. The CS-PMSM is tested by a designed driving cycle, and functions to act as starter motor, generator and to help the internal combustion engine (ICE operate at optimum efficiency are validated.

  15. The Impact of Structural Break(s on the Validity of Purchasing Power Parity in Turkey: Evidence from Zivot-Andrews and Lagrange Multiplier Unit Root Tests

    Directory of Open Access Journals (Sweden)

    Hakan Kum

    2012-01-01

    Full Text Available This study examines the validity of the purchasing power parity (PPP in Turkey for annual data from 1953 to 2009. While results from both the ADF unit root and the DF-GLS unit root test indicate mixed results, PPP holds for Turkey with the presence of structural breaks which are obtained by Zivot and Andrews and Lagrange Multiplier unit root tests.

  16. Finite element model validation of bridge based on structural health monitoring—Part I: Response surface-based finite element model updating

    Directory of Open Access Journals (Sweden)

    Zhouhong Zong

    2015-08-01

    Full Text Available In the engineering practice, merging statistical analysis into structural evaluation and assessment is a tendency in the future. As a combination of mathematical and statistical techniques, response surface (RS methodology has been successfully applied to design optimization, response prediction and model validation. With the aid of RS methodology, these two serial papers present a finite element (FE model updating and validation method for bridge structures based on structural health monitoring. The key issues to implement such a model updating are discussed in this paper, such as design of experiment, parameter screening, construction of high-order polynomial response surface model, optimization methods and precision inspection of RS model. The proposed procedure is illustrated by a prestressed concrete continuous rigid-frame bridge monitored under operational conditions. The results from the updated FE model have been compared with those obtained from online health monitoring system. The real application to a full-size bridge has demonstrated that the FE model updating process is efficient and convenient. The updated FE model can relatively reflect the actual condition of Xiabaishi Bridge in the design space of parameters and can be further applied to FE model validation and damage identification.

  17. Structural Validity of the MACI Psychopathy and Narcissism Scales: Evidence of Multidimensionality and Implications for Use in Research and Screening

    Science.gov (United States)

    Penney, Stephanie R.; Moretti, Marlene M.; Da Silva, Kimberley S.

    2008-01-01

    This study investigated the psychometric properties and predictive validity of three self-report scales (the Psychopathy Content Scale, the Psychopathy-16 scale, and the Egotistic scale) derived from the Millon Adolescent Clinical Inventory (MACI) to screen for the presence of psychopathic and narcissistic personality characteristics. Exploratory…

  18. Proton affinities of maingroup-element hydrides and noble gases: trends across the periodic table, structural effects, and DFT validation

    NARCIS (Netherlands)

    Swart, M.; Rosler, E.; Bickelhaupt, F.M.

    2006-01-01

    We have carried out an extensive exploration of the gas-phase basicity of archetypal neutral bases across the periodic system using the generalized gradient approximation (GGA) of the density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing

  19. Construct validity evidence for the Male Role Norms Inventory-Short Form: A structural equation modeling approach using the bifactor model.

    Science.gov (United States)

    Levant, Ronald F; Hall, Rosalie J; Weigold, Ingrid K; McCurdy, Eric R

    2016-10-01

    The construct validity of the Male Role Norms Inventory-Short Form (MRNI-SF) was assessed using a latent variable approach implemented with structural equation modeling (SEM). The MRNI-SF was specified as having a bifactor structure, and validation scales were also specified as latent variables. The latent variable approach had the advantages of separating effects of general and specific factors and controlling for some sources of measurement error. Data (N = 484) were from a diverse sample (38.8% men of color, 22.3% men of diverse sexualities) of community-dwelling and college men who responded to an online survey. The construct validity of the MRNI-SF General Traditional Masculinity Ideology factor was supported for all 4 of the proposed latent correlations with: (a) Male Role Attitudes Scale; (b) general factor of Conformity to Masculine Norms Inventory-46; (c) higher-order factor of Gender Role Conflict Scale; and (d) Personal Attributes Questionnaire-Masculinity Scale. Significant correlations with relevant other latent factors provided concurrent validity evidence for the MRNI-SF specific factors of Negativity toward Sexual Minorities, Importance of Sex, Restrictive Emotionality, and Toughness, with all 8 of the hypothesized relationships supported. However, 3 relationships concerning Dominance were not supported. (The construct validity of the remaining 2 MRNI-SF specific factors-Avoidance of Femininity and Self-Reliance through Mechanical Skills was not assessed.) Comparisons were made, and meaningful differences noted, between the latent correlations emphasized in this study and their raw variable counterparts. Results are discussed in terms of the advantages of an SEM approach and the unique characteristics of the bifactor model. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. Validation of molecular crystal structures from powder diffraction data with dispersion-corrected density functional theory (DFT-D).

    Science.gov (United States)

    van de Streek, Jacco; Neumann, Marcus A

    2014-12-01

    In 2010 we energy-minimized 225 high-quality single-crystal (SX) structures with dispersion-corrected density functional theory (DFT-D) to establish a quantitative benchmark. For the current paper, 215 organic crystal structures determined from X-ray powder diffraction (XRPD) data and published in an IUCr journal were energy-minimized with DFT-D and compared to the SX benchmark. The on average slightly less accurate atomic coordinates of XRPD structures do lead to systematically higher root mean square Cartesian displacement (RMSCD) values upon energy minimization than for SX structures, but the RMSCD value is still a good indicator for the detection of structures that deserve a closer look. The upper RMSCD limit for a correct structure must be increased from 0.25 Å for SX structures to 0.35 Å for XRPD structures; the grey area must be extended from 0.30 to 0.40 Å. Based on the energy minimizations, three structures are re-refined to give more precise atomic coordinates. For six structures our calculations provide the missing positions for the H atoms, for five structures they provide corrected positions for some H atoms. Seven crystal structures showed a minor error for a non-H atom. For five structures the energy minimizations suggest a higher space-group symmetry. For the 225 SX structures, the only deviations observed upon energy minimization were three minor H-atom related issues. Preferred orientation is the most important cause of problems. A preferred-orientation correction is the only correction where the experimental data are modified to fit the model. We conclude that molecular crystal structures determined from powder diffraction data that are published in IUCr journals are of high quality, with less than 4% containing an error in a non-H atom.

  1. Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.; Parsons, B.K.; Althof, J.A.

    1988-10-01

    The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations. 33 refs., 69 figs., 38 tabs.

  2. The Psychometric Properties of the Center for Epidemiologic Studies Depression Scale in Chinese Primary Care Patients: Factor Structure, Construct Validity, Reliability, Sensitivity and Responsiveness.

    Science.gov (United States)

    Chin, Weng Yee; Choi, Edmond P H; Chan, Kit T Y; Wong, Carlos K H

    2015-01-01

    The Center for Epidemiologic Studies Depression Scale (CES-D) is a commonly used instrument to measure depressive symptomatology. Despite this, the evidence for its psychometric properties remains poorly established in Chinese populations. The aim of this study was to validate the use of the CES-D in Chinese primary care patients by examining factor structure, construct validity, reliability, sensitivity and responsiveness. The psychometric properties were assessed amongst a sample of 3686 Chinese adult primary care patients in Hong Kong. Three competing factor structure models were examined using confirmatory factor analysis. The original CES-D four-structure model had adequate fit, however the data was better fit into a bi-factor model. For the internal construct validity, corrected item-total correlations were 0.4 for most items. The convergent validity was assessed by examining the correlations between the CES-D, the Patient Health Questionnaire 9 (PHQ-9) and the Short Form-12 Health Survey (version 2) Mental Component Summary (SF-12 v2 MCS). The CES-D had a strong correlation with the PHQ-9 (coefficient: 0.78) and SF-12 v2 MCS (coefficient: -0.75). Internal consistency was assessed by McDonald's omega hierarchical (ωH). The ωH value for the general depression factor was 0.855. The ωH values for "somatic", "depressed affect", "positive affect" and "interpersonal problems" were 0.434, 0.038, 0.738 and 0.730, respectively. For the two-week test-retest reliability, the intraclass correlation coefficient was 0.91. The CES-D was sensitive in detecting differences between known groups, with the AUC >0.7. Internal responsiveness of the CES-D to detect positive and negative changes was satisfactory (with p value size statistics >0.2). The CES-D was externally responsive, with the AUC>0.7. The CES-D appears to be a valid, reliable, sensitive and responsive instrument for screening and monitoring depressive symptoms in adult Chinese primary care patients. In its

  3. The Psychometric Properties of the Center for Epidemiologic Studies Depression Scale in Chinese Primary Care Patients: Factor Structure, Construct Validity, Reliability, Sensitivity and Responsiveness.

    Directory of Open Access Journals (Sweden)

    Weng Yee Chin

    Full Text Available The Center for Epidemiologic Studies Depression Scale (CES-D is a commonly used instrument to measure depressive symptomatology. Despite this, the evidence for its psychometric properties remains poorly established in Chinese populations. The aim of this study was to validate the use of the CES-D in Chinese primary care patients by examining factor structure, construct validity, reliability, sensitivity and responsiveness.The psychometric properties were assessed amongst a sample of 3686 Chinese adult primary care patients in Hong Kong. Three competing factor structure models were examined using confirmatory factor analysis. The original CES-D four-structure model had adequate fit, however the data was better fit into a bi-factor model. For the internal construct validity, corrected item-total correlations were 0.4 for most items. The convergent validity was assessed by examining the correlations between the CES-D, the Patient Health Questionnaire 9 (PHQ-9 and the Short Form-12 Health Survey (version 2 Mental Component Summary (SF-12 v2 MCS. The CES-D had a strong correlation with the PHQ-9 (coefficient: 0.78 and SF-12 v2 MCS (coefficient: -0.75. Internal consistency was assessed by McDonald's omega hierarchical (ωH. The ωH value for the general depression factor was 0.855. The ωH values for "somatic", "depressed affect", "positive affect" and "interpersonal problems" were 0.434, 0.038, 0.738 and 0.730, respectively. For the two-week test-retest reliability, the intraclass correlation coefficient was 0.91. The CES-D was sensitive in detecting differences between known groups, with the AUC >0.7. Internal responsiveness of the CES-D to detect positive and negative changes was satisfactory (with p value 0.2. The CES-D was externally responsive, with the AUC>0.7.The CES-D appears to be a valid, reliable, sensitive and responsive instrument for screening and monitoring depressive symptoms in adult Chinese primary care patients. In its original

  4. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples.

    Science.gov (United States)

    Zheng, Lijun; Goldberg, Lewis R; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2008-11-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject samples. The reliabilities of the five factors were quite high except for the 50-item measure of Agreeableness. The part-whole correlations between the 100-item and 50-item factors were high, as were the factor congruence coefficients between the heterosexual and the homosexual samples. Both versions of the IPIP Big-Five factor markers were strongly correlated with the scales from the Big Five Inventory (BFI: John, Donahue & Kentle, 1991), thus providing some concurrent validation in a Chinese context.

  5. Validation of molecular crystal structures from powder diffraction data with dispersion-corrected density functional theory (DFT-D)

    DEFF Research Database (Denmark)

    van de Streek, Jacco; Neumann, Marcus A

    2014-01-01

    In 2010 we energy-minimized 225 high-quality single-crystal (SX) structures with dispersion-corrected density functional theory (DFT-D) to establish a quantitative benchmark. For the current paper, 215 organic crystal structures determined from X-ray powder diffraction (XRPD) data and published...

  6. Validity and reliability of a structured interview for early detection and risk assessment of parenting and developmental problems in young children: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    van Stel Henk F

    2012-06-01

    Full Text Available Abstract Background Preventive child health care is well suited for the early detection of parenting and developmental problems. However, as far as the younger age group is concerned, there are no validated early detection instruments which cover both the child and its environment. Therefore, we have developed a broad-scope structured interview which assesses parents’ concerns and their need for support, using both the parental perspective and the experience of the child health care nurse: the Structured Problem Analysis of Raising Kids (SPARK. This study reports the psychometric characteristics of the SPARK. Method A cross-sectional study of 2012 18-month-old children, living in Zeeland, a province of the Netherlands. Inter-rater reliability was assessed in 67 children. Convergent validity was assessed by comparing SPARK-domains with domains in self-report questionnaires on child development and parenting stress. Discriminative validity was assessed by comparing different outcomes of the SPARK between groups with different levels of socio-economic status and by performing an extreme-groups comparison. The user experience of both parents and nurses was assessed with the aid of an online survey. Results The response rate was 92.1% for the SPARK. Self-report questionnaires were returned in the case of 66.9% of the remaining 1721 children. There was selective non-reporting: 33.1% of the questionnaires were not returned, covering 65.2% of the children with a high-risk label according to the SPARK (p  Conclusion The SPARK discriminates between children with a high, increased and low risk of parenting and developmental problems. It does so in a reliable way, but more research is needed on aspects of validity and in other populations.

  7. Validating the cross-cultural factor structure and invariance property of the Insomnia Severity Index: evidence based on ordinal EFA and CFA.

    Science.gov (United States)

    Chen, Po-Yi; Yang, Chien-Ming; Morin, Charles M

    2015-05-01

    The purpose of this study is to examine the factor structure of the Insomnia Severity Index (ISI) across samples recruited from different countries. We tried to identify the most appropriate factor model for the ISI and further examined the measurement invariance property of the ISI across samples from different countries. Our analyses included one data set collected from a Taiwanese sample and two data sets obtained from samples in Hong Kong and Canada. The data set collected in Taiwan was analyzed with ordinal exploratory factor analysis (EFA) to obtain the appropriate factor model for the ISI. After that, we conducted a series of confirmatory factor analyses (CFAs), which is a special case of the structural equation model (SEM) that concerns the parameters in the measurement model, to the statistics collected in Canada and Hong Kong. The purposes of these CFA were to cross-validate the result obtained from EFA and further examine the cross-cultural measurement invariance of the ISI. The three-factor model outperforms other models in terms of global fit indices in Taiwan's population. Its external validity is also supported by confirmatory factor analyses. Furthermore, the measurement invariance analyses show that the strong invariance property between the samples from different cultures holds, providing evidence that the ISI results obtained in different cultures are comparable. The factorial validity of the ISI is stable in different populations. More importantly, its invariance property across cultures suggests that the ISI is a valid measure of the insomnia severity construct across countries. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Factor Structure, Validity, Reliability and Normalization of the Adult Attention Deficit/Hyperactivity Disorder Scale in Iranian Sample

    Directory of Open Access Journals (Sweden)

    Nafiseh Tabatabaei

    2016-08-01

    Full Text Available Background and Objectives: Researches on attention deficit and hyperactivity disorder indicated that this common disorder would not be resolved with age and continues into adulthood. This study was carried out with the objective of validation and normalization of diagnostic scale of adult attention deficit/hyperactivity disorder scale in Iranian sample. Methods: This study was performed as a psychometric study on the patients (1400 to 1600 cases referred to two psychiatry and neurology clinics in Tehran in the autumn and winter of 2014. Among these patients, 301 persons were selected by purposeful non-random sampling according to the sample size formula based on ratio or two-value variable (patient and non-patient and related questionnaire was administered to them. Cronbach's alpha, Spearman- Brown, and Guttmann’s coefficients was used to evaluate concurrent validity and reliability and exploratory and confirmatory factor analysis in order to assess the construct validity. Results: In this study, Cronbach's alpha of the total scale was 0.88 and for the subscales of inattention, hyperactivity, and impulsivity were 0.82, 0.72, 0.67, respectively. The correlation coefficients between the mentioned scale and adult attention deficit/hyperactivity questionnaire (Wender Utah was obtained 0.59, and between the subscales and the Wender Utah questionnaire, were 0.56, 0.49, and 0.40, respectively, which all three were significant (p<0/01. Confirmatory factor analysis results showed that this scale has three factors and two goodness-of-fit indices. Conclusion: The results of this study revealed that specialists can diagnose and treat the patients using this diagnostic scale.

  9. The Brazilian Portuguese version of the revised Maastricht Upper Extremity Questionnaire (MUEQ-Br revised): translation, cross-cultural adaptation, reliability, and structural validation.

    Science.gov (United States)

    Turci, Aline Mendonça; Bevilaqua-Grossi, Débora; Pinheiro, Carina Ferreira; Bragatto, Marcela Mendes; Chaves, Thais Cristina

    2015-02-25

    Complaints of the arm, neck, and shoulders (CANS) have a multifactorial etiology, and, therefore, their assessment should consider both work-related ergonomic and psychosocial aspects. The Maastricht Upper Extremity Questionnaire (MUEQ) is one of a few specific tools available to evaluate the nature and occurrence of CANS in computer-office workers and the impact of psychosocial and ergonomic aspects on work conditions. The purpose of the present study was to perform a translation and cross-cultural adaptation of the MUEQ to Brazilian Portuguese and verify the reliability, internal consistency, and structural validity of the MUEQ in Brazilian computer-office workers. The cross-cultural adaptation consisted of five stages (forward translation of the MUEQ to Brazilian Portuguese, synthesis of the translation, back-translation, expert committee meeting, and the pre-final-version test). In the pre-final-version test, 55 computer-office workers participated. For reproducibility, a sample of 50 workers completed the questionnaire twice within a one-week interval. A sample of 386 workers from the University of São Paulo (mean age = 37.44 years; 95% confidence interval: 36.50-38.38; 216 women and 170 men) participated on the structural validation and internal consistency analysis. Intraclass correlation coefficient was used for the statistical analysis of reproducibility, Cronbach's alpha was used for internal consistency, and confirmatory factor analysis was used for structural validity. The calculation of internal consistency, reproducibility, and cross validation provided evidence of reliability and lack of redundancy. The psychometric properties of the modified MUEQ-Br revised were assessed using confirmatory factor analysis, which revealed 6 factors and 41 questions. For this model, the comparative fit index (CFI), goodness-of-fit index (GFI), and non-normed fit index (NNFI) each achieved 0.90, and the consistent Akaike information criterion (CAIC), chi

  10. Factor Structure and Predictive Validity of a Homework Motivation Measure for Use With Middle School Students With Attention-Deficit/Hyperactivity Disorder (ADHD).

    Science.gov (United States)

    Langberg, Joshua M; Smith, Zoe R; Dvorsky, Melissa R; Molitor, Stephen J; Bourchtein, Elizaveta; Eddy, Laura D; Eadeh, Hana-May; Oddo, Lauren E

    2017-08-31

    Many students with attention-deficit/hyperactivity disorder (ADHD) exhibit deficits in motivation to pursue long-term goals. Students with ADHD have particular difficulty with motivation to complete homework-related tasks and often fail to complete assignments. Although these problems are common and may impact academic performance, no homework-motivation measures have been validated for use with students with ADHD. The primary goal of the present study was to evaluate the factor structure and predictive validity of a homework-motivation measure based upon the expectancy-value theory of achievement motivation. A sample of 285 middle school students with ADHD completed the measure, and confirmatory factor analysis was used to evaluate the proposed factor structure and associations with parent and teacher ratings of homework performance. A 2-factor structure emerged, and model fit was excellent. Further, student-rated ability-expectancy beliefs demonstrated significant associations with parent-rated homework problems and performance and with teacher-rated homework performance and percentage of assignments turned in above and beyond ADHD symptoms. Future directions for studying the importance of motivation in students with ADHD are provided, with particular attention to the role that reward sensitivity may play in motivation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Quantitative Structure-Use Relationship Model thresholds for Model Validation, Domain of Applicability, and Candidate Alternative Selection

    Data.gov (United States)

    U.S. Environmental Protection Agency — This file contains value of the model training set confusion matrix, domain of applicability evaluation based on training set to predicted chemicals structural...

  12. Structural damage detection based on stochastic subspace identification and statistical pattern recognition: II. Experimental validation under varying temperature

    Science.gov (United States)

    Lin, Y. Q.; Ren, W. X.; Fang, S. E.

    2011-11-01

    Although most vibration-based damage detection methods can acquire satisfactory verification on analytical or numerical structures, most of them may encounter problems when applied to real-world structures under varying environments. The damage detection methods that directly extract damage features from the periodically sampled dynamic time history response measurements are desirable but relevant research and field application verification are still lacking. In this second part of a two-part paper, the robustness and performance of the statistics-based damage index using the forward innovation model by stochastic subspace identification of a vibrating structure proposed in the first part have been investigated against two prestressed reinforced concrete (RC) beams tested in the laboratory and a full-scale RC arch bridge tested in the field under varying environments. Experimental verification is focused on temperature effects. It is demonstrated that the proposed statistics-based damage index is insensitive to temperature variations but sensitive to the structural deterioration or state alteration. This makes it possible to detect the structural damage for the real-scale structures experiencing ambient excitations and varying environmental conditions.

  13. The 13-Item Sense of Coherence Scale in Dutch-Speaking Adolescents and Young Adults: Structural Validity, Age Trends, and Chronic Disease

    OpenAIRE

    Koen Luyckx; Eva Goossens; Silke Apers; Jessica Rassart; Theo Klimstra; Jessie Dezutter; Philip Moons

    2012-01-01

    The present study focused on the structural validity of the Dutch version of the 13-item sense of coherence (SOC) scale, examined age trends in SOC in adolescence and young adulthood (ages 14-30 years), and investigated the potential impact of chronic disease on SOC. Eight samples of Belgian high school students, college students, and young adult employees collected between 2005 - 2010 were used (total N = 2,781); 380 of these individuals aged 14-18 years were diagnosed with congenital heart ...

  14. Structures' validation profiles in Transmission of Imaging and Data (TRIAD) for automated National Clinical Trials Network (NCTN) clinical trial digital data quality assurance.

    Science.gov (United States)

    Giaddui, Tawfik; Yu, Jialu; Manfredi, Denise; Linnemann, Nancy; Hunter, Joanne; O'Meara, Elizabeth; Galvin, James; Bialecki, Brian; Xiao, Ying

    2016-01-01

    Transmission of Imaging and Data (TRIAD) is a standard-based system built by the American College of Radiology to provide the seamless exchange of images and data for accreditation of clinical trials and registries. Scripts of structures' names validation profiles created in TRIAD are used in the automated submission process. It is essential for users to understand the logistics of these scripts for successful submission of radiation therapy cases with less iteration. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  15. Validation by numerical simulation of the behaviour of protective structures of machinery cabins subjected to standardized shocks

    Science.gov (United States)

    Dumitrache, P.; Goanţă, A. M.

    2017-08-01

    The ability of the cabins to insure the operator protection in the case of the shock loading that appears at the roll-over of the machine or when the cab is struck by the falling objects, it’s one of the most important performance criterions that it must comply by the machines and the mobile equipments. The experimental method provides the most accurate information on the behaviour of protective structures, but generates high costs due to experimental installations and structures which may be compromised during the experiments. In these circumstances, numerical simulation of the actual problem (mechanical shock applied to a strength structure) is a perfectly viable alternative, given that the hardware and software current performances provides the necessary support to obtain results with an acceptable level of accuracy. In this context, the paper proposes using FEA platforms for virtual testing of the actual strength structures of the cabins using their finite element models based on 3D models generated in CAD environments. In addition to the economic advantage above mentioned, although the results obtained by simulation using the finite element method are affected by a number of simplifying assumptions, the adequate modelling of the phenomenon can be a successful support in the design process of structures to meet safety performance criteria imposed by current standards. In the first section of the paper is presented the general context of the security performance requirements imposed by current standards on the cabins strength structures. The following section of the paper is dedicated to the peculiarities of finite element modelling in problems that impose simulation of the behaviour of structures subjected to shock loading. The final section of the paper is dedicated to a case study and to the future objectives.

  16. Vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitors: development and validation of predictive 3-D QSAR models through extensive ligand- and structure-based approaches

    Science.gov (United States)

    Ragno, Rino; Ballante, Flavio; Pirolli, Adele; Wickersham, Richard B.; Patsilinakos, Alexandros; Hesse, Stéphanie; Perspicace, Enrico; Kirsch, Gilbert

    2015-08-01

    Vascular endothelial growth factor receptor-2, (VEGFR-2), is a key element in angiogenesis, the process by which new blood vessels are formed, and is thus an important pharmaceutical target. Here, 3-D quantitative structure-activity relationship (3-D QSAR) were used to build a quantitative screening and pharmacophore model of the VEGFR-2 receptors for design of inhibitors with improved activities. Most of available experimental data information has been used as training set to derive optimized and fully cross-validated eight mono-probe and a multi-probe quantitative models. Notable is the use of 262 molecules, aligned following both structure-based and ligand-based protocols, as external test set confirming the 3-D QSAR models' predictive capability and their usefulness in design new VEGFR-2 inhibitors. From a survey on literature, this is the first generation of a wide-ranging computational medicinal chemistry application on VEGFR2 inhibitors.

  17. The Eating Disorder Assessment for DSM-5 (EDA-5): Development and Validation of a Structured Interview for Feeding and Eating Disorders

    Science.gov (United States)

    Sysko, Robyn; Glasofer, Deborah R.; Hildebrandt, Tom; Klimek, Patrycja; Mitchell, James E.; Berg, Kelly C.; Peterson, Carol B.; Wonderlich, Stephen A.; Walsh, B. Timothy

    2016-01-01

    Objective Existing measures for DSM-IV eating disorder diagnoses have notable limitations, and there are important differences between DSM-IV and DSM-5 feeding and eating disorders. This study developed and validated a new semi-structured interview, the Eating Disorders Assessment for DSM-5 (EDA-5). Method Two studies evaluated the utility of the EDA-5. Study 1 compared the diagnostic validity of the EDA-5 to the Eating Disorder Examination (EDE) and evaluated the test-retest reliability of the new measure. Study 2 compared the diagnostic validity of an EDA-5 electronic application (“app”) to clinician interview and self-report assessments. Results In Study 1, the kappa for EDE and EDA-5 eating disorder diagnoses was 0.74 across all diagnoses (n= 64), with a range of κ=0.65 for Other Specified Feeding or Eating Disorder (OSFED)/Unspecified Feeding or Eating Disorder (USFED) to κ=0.90 for Binge Eating Disorder (BED). The EDA-5 test-retest kappa coefficient was 0.87 across diagnoses. For Study 2, clinical interview versus “app” conditions revealed a kappa of 0.83 for all eating disorder diagnoses (n=71). Across individual diagnostic categories, kappas ranged from 0.56 for OSFED/USFED to 0.94 for BN. Discussion High rates of agreement were found between diagnoses by EDA-5 and the EDE, and EDA-5 and clinical interviews. As this study supports the validity of the EDA-5 to generate DSM-5 eating disorders and the reliability of these diagnoses, the EDA-5 may be an option for the assessment of Anorexia Nervosa, Bulimia Nervosa, and BED. Additional research is needed to evaluate the utility of the EDA-5 in assessing DSM-5 feeding disorders. PMID:25639562

  18. Reliability, factor structure, and validity of the German version of the Trauma Symptom Checklist for Children in a sample of adolescents

    Directory of Open Access Journals (Sweden)

    Simone Matulis

    2015-10-01

    Full Text Available Background: The Trauma Symptom Checklist for Children (TSC-C is the most widely used self-report scale to assess trauma-related symptoms in children and adolescents on six clinical scales. The purpose of the present study was to develop a German version of the TSC-C and to investigate its psychometric properties, such as factor structure, reliability, and validity, in a sample of German adolescents. Method: A normative sample of N=583 and a clinical sample of N=41 adolescents with a history of physical or sexual abuse aged between 13 and 21 years participated in the study. Results: The Confirmatory Factor Analysis on the six-factor model (anger, anxiety, depression, dissociation, posttraumatic stress, and sexual concerns with the subdimensions preoccupation and distress revealed acceptable to good fit statistics in the normative sample. One item had to be excluded from the German version of the TSC-C because the factor loading was too low. All clinical scales presented acceptable to good reliability, with Cronbach's α's ranging from .80 to .86 in the normative sample and from .72 to .87 in the clinical sample. Concurrent validity was also demonstrated by the high correlations between the TSC-C scales and instruments measuring similar psychopathology. TSC-C scores reliably differentiated between adolescents with trauma history and those without trauma history, indicating discriminative validity. Conclusions: In conclusion, the German version of the TSC-C is a reliable and valid instrument for assessing trauma-related symptoms on six different scales in adolescents aged between 13 and 21 years.

  19. Validation of a structured questionnaire as an instrument to measure chronic pain in dogs on the basis of effects on health-related quality of life.

    Science.gov (United States)

    Wiseman-Orr, M Lesley; Scott, E Marian; Reid, Jacqueline; Nolan, Andrea M

    2006-11-01

    To validate the use of a novel questionnaire as an instrument for measurement of chronic pain in dogs through its impact on health-related quality of life (HRQL). 108 dogs with chronic degenerative joint disease and 26 healthy dogs. Questionnaire responses were subjected to factor analysis (FA) and questionnaire scores to discriminant analysis to evaluate construct validity. Questionnaire scores were used to explore the potential of this instrument for minimizing respondent bias and for evaluative purposes. FA results revealed a sensible factor structure accounting for 65% of the variance in data, with factors identifiable as domains of HRQL in dogs affected by chronic pain. Further evidence for construct validity was provided when questionnaire scores were used to discriminate, on the basis of 218 questionnaires, between dogs with clinician-awarded pain scores of 0 and dogs with pain scores >or= 1 (88% discrimination, with 95% of no-pain group dogs and 87% of some-pain group dogs correctly categorized). Use of the questionnaire provided minimized respondent bias. Validation of the questionnaire as an instrument for discriminative and evaluative measurements of orthopedic chronic pain through its impact on HRQL in dogs was provided. Use of the questionnaire, with further testing and refinement, may support improved clinical decision making, facilitate development of evidence-based therapeutic options for chronic diseases, and help veterinarians and owners define humane end points in dogs. Information gained here may provide improved measurements of clinical change in animal studies that use dogs with naturally occurring chronic pain to evaluate novel human treatment protocols.

  20. The Construct Validity of Scores on the Ways of Coping Questionnaire: Confirmatory Analysis of Alternative Factor Structures.

    Science.gov (United States)

    Edwards, Jeffrey R.; O'Neill, Regina M.

    1998-01-01

    Confirmatory factor analysis was used to evaluate alternative factor structures, based on previous exploratory factor analyses and coping dimensions derived from the theory of R. Lazarus, for the Ways of Coping Questionnaire (S. Folkman and R. Lazarus, 1988). Results from responses of 654 college graduates provide little support for the factor…

  1. Complementary numerical–experimental benchmarking for shape optimization and validation of structures subjected to wave and current forces

    DEFF Research Database (Denmark)

    Markus, D.; Ferri, Francesco; Wüchner, R.

    2015-01-01

    load cases. The experiments are carried out in a recirculating wave–current flume while the numerical simulations are based on Computational Fluid Dynamics (CFD). Data is also provided to analyze the effect of wave–current interaction on structural loads. Furthermore, a reference study is carried out...

  2. Validation of Accelerometer-Based Energy Expenditure Prediction Models in Structured and Simulated Free-Living Settings

    Science.gov (United States)

    Montoye, Alexander H. K.; Conger, Scott A.; Connolly, Christopher P.; Imboden, Mary T.; Nelson, M. Benjamin; Bock, Josh M.; Kaminsky, Leonard A.

    2017-01-01

    This study compared accuracy of energy expenditure (EE) prediction models from accelerometer data collected in structured and simulated free-living settings. Twenty-four adults (mean age 45.8 years, 50% female) performed two sessions of 11 to 21 activities, wearing four ActiGraph GT9X Link activity monitors (right hip, ankle, both wrists) and a…

  3. Validation of the structure-function correlation report from the heidelberg edge perimeter and spectral-domain optical coherence tomography.

    Science.gov (United States)

    Cui, Qi N; Fudemberg, Scott J; Resende, Arthur F; Vu, Thuy-Anh; Zhou, Chen; Rahmatnejad, Kamran; Hark, Lisa A; Myers, Jonathan S; Katz, L Jay; Waisbourd, Michael

    2018-02-02

    To compare the diagnostic assessment of glaucoma specialists with an automated structure-function correlation report combining visual field (VF) and spectral-domain optical coherence tomography (SD-OCT) imagining in subjects with glaucoma. This prospective, cross-sectional study was conducted at Wills Eye Hospital, Philadelphia, PA, USA. Subjects with glaucoma received ophthalmic examination, VF testing, and SD-OCT imaging. An automated report was generated describing structure-function correlations between the two structural elements [retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (MRW)] and VF sectors. Three glaucoma specialists masked to the automated report and to each other identified clinically significant structure-function correlations between the VF and SD-OCT reports. Raw agreement and chance-corrected agreement (kappa statistics) between the automated report and the clinical assessments were compared. A total of 53 eyes from 45 subjects with glaucoma were included in this study. The overall agreement between the automated report and clinical assessment comparing MRW and VF was good at 74.8% with a kappa of 0.62 (95% CI 0.55-0.69). Agreements for the six different MRW sections were moderate to good with kappa values ranging from 0.54 to 0.69. For mean RNFL thickness and VF comparisons, agreement between the automated report and clinical assessment was 75.4% with a kappa of 0.62 (95% CI 0.54-0.70). For different RNFL sectors, kappa values ranged from 0.47 (moderate agreement) to 0.80 (good agreement). This study suggests that the automated structure-function report combining results from the SD-OCT and the HEP may assist in the evaluation and management of glaucoma.

  4. Validation of the factor structure of the Greek adaptation of the Situational Inventory of Body-Image Dysphoria-Short Form (SIBID-S).

    Science.gov (United States)

    Argyrides, Marios; Kkeli, Natalie

    2015-12-01

    Body image is a psychological construct that refers to one's perceptions, feelings, and thoughts towards one's body and appearance. The intensity and frequency of dysphoric body-image emotions depend upon situational events (i.e., situations involving body exposure, social comparisons, wearing certain clothing, looking in the mirror, and so forth). The Situational Inventory of Body-Image Dysphoria-Short Form (SIBID-S; Cash, Manual for the situational inventory of body-image dysphoria, 2000) was originally developed to assess one's negative body-image emotions in certain situational events. The current study aimed to confirm the factor structure and reliability of the newly translated Greek version of the SIBID-S. Participants consisted of a convenient sample of 2664 high school students (1119 males, 1545 females) who answered the measures of interest. Results indicated that the original one-factor structure of the SIBID-S was retained and fitted very well with the original model for both males and females. In addition, the Greek version had satisfactory reliability and convergent validity coefficients. Gender differences were also noted. The Greek SIBID-S has very good validity and reliability data and will serve as a useful measure of body-image dysphoria enabling research with the Greek-speaking population as well as cross-cultural research.

  5. Postpartum Bonding Disorder: Factor Structure, Validity, Reliability and a Model Comparison of the Postnatal Bonding Questionnaire in Japanese Mothers of Infants

    Directory of Open Access Journals (Sweden)

    Yukiko Ohashi

    2016-08-01

    Full Text Available Negative attitudes of mothers towards their infant is conceptualized as postpartum bonding disorder, which leads to serious health problems in perinatal health care. However, its measurement still remains to be standardized. Our aim was to examine and confirm the psychometric properties of the Postnatal Bonding Questionnaire (PBQ in Japanese mothers. We distributed a set of questionnaires to community mothers and studied 392 mothers who returned the questionnaires at 1 month after childbirth. Our model was compared with three other models derived from previous studies. In a randomly halved sample, an exploratory factor analysis yielded a three-factor structure: Anger and Restrictedness, Lack of Affection, and Rejection and Fear. This factor structure was cross-validated by a confirmatory factor analysis using the other halved sample. The three subscales showed satisfactory internal consistency. The three PBQ subscale scores were correlated with depression and psychological abuse scores. Their test–retest reliability between day 5 and 1 month after childbirth was measured by intraclass correlation coefficients between 0.76 and 0.83. The Akaike Information Criteria of our model was better than the original four-factor model of Brockington. The present study indicates that the PBQ is a reliable and valid measure of bonding difficulties of Japanese mothers with neonates.

  6. Assessment of Dysfunctional Cognitions in Binge-Eating Disorder: Factor Structure and Validity of the Mizes Anorectic Cognitions Questionnaire-Revised (MAC-R).

    Science.gov (United States)

    Carrard, Isabelle; Rothen, Stephane; Kruseman, Maaike; Khazaal, Yasser

    2017-01-01

    Background: Dysfunctional cognitions regarding weight and shape and their implications for self-esteem are considered core features of anorexia nervosa and bulimia nervosa. However, they have also been associated with the severity of binge eating disorder (BED). Therefore, they should be screened with appropriate instruments to tailor treatment to individual patient needs. The Mizes Anorectic Cognitions-Revised (MAC-R) is a self-report questionnaire that lists dysfunctional cognitions related to three hypothesized core beliefs typical of the psychopathology of eating disorders: weight and eating as the basis of approval from others; the belief that rigid self-control is fundamental to self-worth; and the rigidity of weight- and eating-regulation efforts. Objectives: The goal of the study was to confirm the factor structure and to assess the validity of the MAC-R among a sample that met full-threshold and subthreshold criteria for BED. Methods: We used data of women meeting full-threshold ( n = 94) and subthreshold ( n = 22) criteria for BED to conduct confirmatory factor analyses and to compute Spearman's correlations, in order to assess factorial, convergent, and discriminant validity. Results: Two models having a structure of three factors with or without a total score proved to be acceptable. The MAC-R total score was correlated with questionnaires assessing dimensions related to eating disorder psychopathology, adding to the validity of the questionnaire. Conclusion: These results were similar to those found in studies on the psychometric properties of the MAC among samples with anorexia nervosa or bulimia nervosa, encouraging the use of the MAC-R as a research or clinical tool in order to further document the core beliefs underlying BED.

  7. Proton affinities of maingroup-element hydrides and noble gases: trends across the periodic table, structural effects, and DFT validation.

    Science.gov (United States)

    Swart, Marcel; Rösler, Ernst; Bickelhaupt, F Matthias

    2006-10-01

    We have carried out an extensive exploration of the gas-phase basicity of archetypal neutral bases across the periodic system using the generalized gradient approximation (GGA) of the density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing proton affinities and related thermochemical quantities: BP86/QZ4P//BP86/TZ2P is shown to yield a mean absolute deviation of 2.0 kcal/mol for the proton affinity at 298 K with respect to experiment, and 1.2 kcal/mol with high-level ab initio benchmark data. The main purpose of this work is to provide the proton affinities (and corresponding entropies) at 298 K of the neutral bases constituted by all maingroup-element hydrides of groups 15-17 and the noble gases, that is, group 18, and periods 1-6. We have also studied the effect of step-wise methylation of the protophilic center of the second- and third-period bases. Copyright 2006 Wiley Periodicals, Inc.

  8. Proton Affinities of Anionic Bases:  Trends Across the Periodic Table, Structural Effects, and DFT Validation.

    Science.gov (United States)

    Swart, Marcel; Bickelhaupt, F Matthias

    2006-03-01

    We have carried out an extensive exploration of the gas-phase basicity of archetypal anionic bases across the periodic system using the generalized gradient approximation of density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing proton affinities and related thermochemical quantities:  BP86/QZ4P//BP86/TZ2P is shown to yield a mean absolute deviation of 1.6 kcal/mol for the proton affinity at 0 K with respect to high-level ab initio benchmark data. The main purpose of this work is to provide the proton affinities (and corresponding entropies) at 298 K of the anionic conjugate bases of all main-group-element hydrides of groups 14-17 and periods 2-6. We have also studied the effect of stepwise methylation of the protophilic center of the second- and third-period bases.

  9. Nonlinear modeling and validation of air spring effects in a sealed tuned liquid column damper for structural control

    Science.gov (United States)

    Bhattacharyya, Soumi; Ghosh, Aparna (Dey); Basu, Biswajit

    2017-12-01

    The present study focuses on an experimental investigation of nonlinear air spring effects in a passive sealed Tuned Liquid Column Damper (TLCD). The aim is to quantify the polytropic process representing the pressure-volume variation in a sealed air column and examine the extent of stiffness nonlinearity present in the system. This is accomplished by measuring pressure data using pressure transducers and liquid elevations using wave gauges. The mathematical model of the sealed TLCD considering the pressure-volume relation in the sealed air column as an isentropic process is presented and validated with the experimental results. The expressions for nonlinear and linearized air spring stiffness and linearized natural frequency of the damper are presented. The effect of linearization of the air spring stiffness on damper performance is examined and found to be acceptable under certain conditions. It is seen that though the passive sealed TLCD is intrinsically nonlinear, both in damping and in stiffness, the effect of the stiffness nonlinearity is small and the system possesses a natural frequency which may be effectively used for the purpose of tuning. Finally, the variation of the damper frequency due to change in different design parameters is presented to demonstrate the options to utilize this damper in the high frequency range where the conventional open TLCD is not applicable.

  10. Explicating Validity

    Science.gov (United States)

    Kane, Michael T.

    2016-01-01

    How we choose to use a term depends on what we want to do with it. If "validity" is to be used to support a score interpretation, validation would require an analysis of the plausibility of that interpretation. If validity is to be used to support score uses, validation would require an analysis of the appropriateness of the proposed…

  11. A general psychopathology factor (P factor) in children: Structural model analysis and external validation through familial risk and child global executive function.

    Science.gov (United States)

    Martel, Michelle M; Pan, Pedro M; Hoffmann, Maurício S; Gadelha, Ary; do Rosário, Maria C; Mari, Jair J; Manfro, Gisele G; Miguel, Eurípedes C; Paus, Tomás; Bressan, Rodrigo A; Rohde, Luis A; Salum, Giovanni A

    2017-01-01

    High rates of comorbidities and poor validity of disorder diagnostic criteria for mental disorders hamper advances in mental health research. Recent work has suggested the utility of continuous cross-cutting dimensions, including general psychopathology and specific factors of externalizing and internalizing (e.g., distress and fear) syndromes. The current study evaluated the reliability of competing structural models of psychopathology and examined external validity of the best fitting model on the basis of family risk and child global executive function (EF). A community sample of 8,012 families from Brazil with children ages 6-12 years completed structured interviews about the child and parental psychiatric syndromes, and a subsample of 2,395 children completed tasks assessing EF (i.e., working memory, inhibitory control, and time processing). Confirmatory factor analyses tested a series of structural models of psychopathology in both parents and children. The model with a general psychopathology factor ("P factor") with 3 specific factors (fear, distress, and externalizing) exhibited the best fit. The general P factor accounted for most of the variance in all models, with little residual variance explained by each of the 3 specific factors. In addition, associations between child and parental factors were mainly significant for the P factors and nonsignificant for the specific factors from the respective models. Likewise, the child P factor-but not the specific factors-was significantly associated with global child EF. Overall, our results provide support for a latent overarching P factor characterizing child psychopathology, supported by familial associations and child EF. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Factor Structure and Validity of the Body Parts Satisfaction Scale: Results from the 1972 Psychology Today Survey

    Directory of Open Access Journals (Sweden)

    David Frederick

    2014-07-01

    Full Text Available In 1972, the first major national study on body image was conducted under the auspices of Psychology Today. Body image was assessed with the Body Parts Satisfaction Scale, which examined the dissatisfaction people experienced with 24 aspects of their bodies. Despite the continued reliance on this scale and reference to the study, data on the factor structure of this measure in a sample of adults have never been published, and citations of the original scale have relied on an unpublished manuscript (Bohrnstedt, 1977. An exploratory factor analysis conducted on 2,013 adults revealed factors for men (Face, Sex Organ, Height, Lower Body, Mid Torso, Upper Torso, Height and women (Face, Sex Organ, Height, Lower Torso, Mid Torso, Extremities, Breast. The factors were weakly to moderately intercorrelated, suggesting the scale can be analyzed by items, by subscales, or by total score. People who reported more dissatisfaction with their body also tended to report lower self-esteem and less comfort interacting with members of the other sex. The analyses provide a useful comparison point for researchers looking to examine gender differences in dissatisfaction with specific aspects of the body, as well as the factor structures linking these items.

  13. Numerical modeling and experimental validation of the acoustic transmission of aircraft's double-wall structures including sound package

    Science.gov (United States)

    Rhazi, Dilal

    In the field of aeronautics, reducing the harmful effects of acoustics constitutes a major concern at the international level and justifies the call for further research, particularly in Canada where aeronautics is a key economic sector, which operates in a context of global competition. Aircraft sidewall structure is usually of a double wall construction with a curved ribbed metallic skin and a lightweight composite or sandwich trim separated by a cavity filled with a noise control treatment. The latter is of a great importance in the transport industry, and continues to be of interest in many engineering applications. However, the insertion loss noise control treatment depends on the excitation of the supporting structure. In particular, Turbulent Boundary Layer is of interest to several industries. This excitation is difficult to simulate in laboratory conditions, given the prohibiting costs and difficulties associated with wind tunnel and in-flight tests. Numerical simulation is the only practical way to predict the response to such excitations and to analyze effects of design changes to the response to such excitation. Another kinds of excitations encountered in industrial are monopole, rain on the Roof and diffuse acoustic field. Deterministic methods can calculate in each point the spectral response of the system. Most known are numerical methods such as finite elements and boundary elements methods. These methods generally apply to the low frequency where modal behavior of the structure dominates. However, the high limit of calculation in frequency of these methods cannot be defined in a strict way because it is related to the capacity of data processing and to the nature of the studied mechanical system. With these challenges in mind, and with limitations of the main numerical codes on the market, the manufacturers have expressed the need for simple models immediately available as early as the stage of preliminary drafts. This thesis represents an attempt

  14. The Reliability, Validity, and Factorial Structure of the Collett-Lester Fear of Death Scale in a Sample of Iranian Nurses

    Directory of Open Access Journals (Sweden)

    Mahboubeh Dadfar

    2016-07-01

    Full Text Available The fear of death is an emotional reaction involving subjective feelings of unpleasantness and concern based on contemplation or anticipation of any of the several facts related to death. A cross-sectional study was conducted to investigate reliability, validity, and factorial structure of the Farsi version of Collett-Lester Fear of Death Scale (CLFDS in 106 Iranian nurses from two hospitals at Tehran city, Iran. They were selected using a convenience sampling method, and completed the Collett-Lester Fear of Death Scale (CLFDS, the Death Concern Scale (DCS, the Death Anxiety Scale (DAS, the Reasons for Death Fear Scale (RDFS, the Death Depression Scale (DDS, and the Death Obsession Scale (DOS. The Cronbach alpha coefficient for the CLFDS was 0.94, the Spearman-Brown coefficient 0.83, the Guttman Split-Half coefficient 0.83, and two-week test-retest reliability 0.58. Cronbach alpha coefficients for the four subscales of the CLFDS were 0.79 for Your own death, 0.90 for Your own dying, 0.75 for The death of others, and 0.90 for The dying of others. The CLFDS correlated 0.51 with the DCS, 0.38 with the DAS, 0.39 with the RDFS, 0.39 with the DDS, and 0.46 with the DOS, significant at the .01 level and indicating good construct and criterion-related validity. The results of the factor analysis of the CLFDS items identified 7 factors, four of which had 4 or more items loaded on them and matching the labels of the four subscales The CLFDS, therefore, appears to have good validity and reliability, and it can be used in clinical, educational, and research settings.

  15. The joint WAIS-III and WMS-III factor structure: development and cross-validation of a six-factor model of cognitive functioning.

    Science.gov (United States)

    Tulsky, David S; Price, Larry R

    2003-06-01

    During the standardization of the Wechsler Adult Intelligence Scale (3rd ed.; WAIS-III) and the Wechsler Memory Scale (3rd ed.; WMS-III) the participants in the normative study completed both scales. This "co-norming" methodology set the stage for full integration of the 2 tests and the development of an expanded structure of cognitive functioning. Until now, however, the WAIS-III and WMS-III had not been examined together in a factor analytic study. This article presents a series of confirmatory factor analyses to determine the joint WAIS-III and WMS-III factor structure. Using a structural equation modeling approach, a 6-factor model that included verbal, perceptual, processing speed, working memory, auditory memory, and visual memory constructs provided the best model fit to the data. Allowing select subtests to load simultaneously on 2 factors improved model fit and indicated that some subtests are multifaceted. The results were then replicated in a large cross-validation sample (N = 858).

  16. One DOF mechanism for the mechanical harvest of vines in an arbor structure and the validation of the acceleration of grape berry harvesting

    Science.gov (United States)

    Penisi, Osvaldo; Bocca, José; Aguilar, Horacio; Bocca, Pedro

    2015-09-01

    In the mechanized harvest of vines, grape berries are detached through the vibration to the structure supporting the clusters. According to the kind of guide selected, the clusters require one or two vibration directions in the structure. For guiding in parral structures, vibration is necessary in two directions or planes: One perpendicular to the other. The guide branches producing the clusters develop in these planes, and the guiding is called H-guiding. Mechanism theory indicates that a mechanism has as many degrees of freedom as its actuators, and an actuator is needed to achieve a certain vibration. Having the smallest number of possible actuators is beneficial in reducing moving parts and achieving more compact and easily controllable mechanisms. In this case, a single degree-of-freedom mechanism is proposed. It is capable of generating vibrations on two planes: One perpendicular to the other. This mechanism is the sum of two link mechanisms on perpendicular planes with a common outlet located at the output rod of the mechanism where the actuator is found. As the distance between the soil and the elements containing the clusters is not constant, a system has been designed to measure the accelerations at the bars and the rocker to validate the acceleration values that detach the grape berries in a prototype in a lab experiment, to ensure that the acceleration needed for pulling the grape berries are produced at any contact point of the bar.

  17. Retrospective Validation of a Structure-Based Virtual Screening Protocol to Identify Ligands for Estrogen Receptor Alpha and Its Application to Identify the Alpha-Mangostin Binding Pose

    Directory of Open Access Journals (Sweden)

    Agustina Setiawati

    2014-07-01

    Full Text Available The publicly available enhanced data of ligands and decoys for estrogen receptor alpha (ERα which were recently published has made the retrospective validation of a structure-based virtual screening (SBVS protocol to identify ligands for ERα possible. In this article, we present the retrospective validation of an SBVS protocol using PLANTS molecular docking software version 1.2 (PLANTS1.2 as the backbone software. The protocol shows better enrichment factor at 1% false positives (EF1% value and the Area Under Curve (AUC value of the Receiver Operator Characteristic (ROC compared to the original published protocol. Moreover, in all 1000 iterative attempts the protocol could reproduce the co-crystal pose of 4-hydroxitamoxifen in ERα binding pocket. It shows that the protocol is not only able to identify potent ligands for ERα but also able to be employed in examining binding pose of known ligand. Thence, the protocol was successfully employed to examine the binding poses of α-mangostin, an ERα ligand found in the Garcinia mangostana, L. pericarp.

  18. The French Version of the Screen for Child Anxiety Related Emotional Disorders-Revised (Scared-R: Factor Structure, Convergent and Divergent Validity in a Sample of Teenagers

    Directory of Open Access Journals (Sweden)

    Martine Bouvard

    2013-06-01

    Full Text Available The principal objective of this study is to provide data on the French version of the SCARED-R. This article investigates the factor structure of the French version of the Screen for Child Anxiety Related Emotional Disorders-Revised (SCARED-R and its convergent and divergent validity. 704 normal adolescents aged 10 to 19 years completed the questionnaires in their classrooms. A sub-sample of 595 adolescents also completed an anxiety questionnaire (the French version of the Fear Survey Schedule for Children-Revised, FSSC-R and a depression questionnaire (the French version of the Center for Epidemiological Studies Depression Scale, CES-D. Confirmatory factor analysis of the SCARED-R suggested reasonable fit for the 9-factor model. The comparison of the convergent and divergent validity revealed that the SCARED-R total score and five SCARED-R subscales (SAD, Social Phobia and the three Specific Phobias correlated more strongly with anxiety than depression. The other SCARED-R subscales (GAD, Panic Disorder, OCD and PTSD are positively related to levels of anxiety and depression. Altogether, the French version of the SCARED-R showed reasonable psychometric properties.

  19. Measuring trauma and stressful events in childhood and adolescence among patients with first-episode psychosis: initial factor structure, reliability, and validity of the Trauma Experiences Checklist.

    Science.gov (United States)

    Cristofaro, Sarah L; Cleary, Sean D; Ramsay Wan, Claire; Broussard, Beth; Chapman, Colby; Haggard, Patrick J; Jananeh, Sara; Myers, Neely L; Compton, Michael T

    2013-12-15

    Past trauma and stressful events, especially in childhood and adolescence, are common among individuals with serious mental illnesses like schizophrenia. Traumatic experiences are thought to be a socio-environmental risk factor not only for poorer outcomes, but also potentially for the onset of these disorders. Because improved measurement tools are needed, we developed and studied, among 205 first-episode psychosis patients, the factor structure, internal consistency reliability, and initial validity of the Trauma Experiences Checklist (TEC), our measure of trauma and stressful events during childhood/adolescence. We assessed validity of subscales using correlations with Childhood Trauma Questionnaire-Short Form, Parental Harsh Discipline, Violence Exposure, and TEC-Informant Version scores. Exploratory factor analysis resulted in two internally consistent subscales (Cronbach's α=0.79 and 0.80, respectively), interpersonal abuse and family stress, and violence, death, and legal involvement. Scores from the former subscale were substantially associated with CTQ-SF physical, emotional, and sexual abuse (r=0.42-0.57, all pchildhood and adolescence. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Psychometric properties of the 25-item Work Limitations Questionnaire in Japan: factor structure, validity, and reliability in information and communication technology company employees.

    Science.gov (United States)

    Kono, Yuko; Matsushima, Eisuke; Uji, Masayo

    2014-02-01

    The 25-item Work Limitations Questionnaire (WLQ-25) measures presenteeism but has not been sufficiently validated in a Japanese population. A total of 451 employees from four information technology companies in Tokyo completed the WLQ-25 and questionnaires of other variables on two occasions, 2 weeks apart. The WLQ-25 yielded a two-factor structure: Cognitive Demand and Physical Demand. These subscales showed good internal consistency, and both were associated with adverse working conditions, greater perceived job strain, lower skill use, poorer workplace social support, and less satisfactory psychological adjustment. Intraclass correlation coefficients of the two WLQ-25 subscales between time 1 and time 2 were 0.78 and 0.55, respectively. This study suggests acceptable psychometric properties of the WLQ-25 in Japan.

  1. Structure, reliability, and validity of the revised child anxiety and depression scale (RCADS) in a multi-ethnic urban sample of Dutch children.

    Science.gov (United States)

    Kösters, Mia P; Chinapaw, Mai J M; Zwaanswijk, Marieke; van der Wal, Marcel F; Koot, Hans M

    2015-06-23

    Although anxiety and, to a lesser extent, depression are highly prevalent in children, these problems are, difficult to identify. The Revised Anxiety and Depression Scale (RCADS) assesses self-reported symptoms of anxiety and depression in youth. The present study examined the factor structure, internal consistency, short-term stability, and validity including sensitivity to change of the RCADS in a multi-ethnic urban sample of 3636 Dutch children aged 8 to 13 years old. Results indicate that the RCADS is a reliable and valid instrument. The original 6-factor structure was replicated to a fair extent in the present study (RMSEA = 0.048) and internal consistency was good (αs = 0.70-0.96). ICCs for short-term stability were 0.76 to 0.86. Girls and children who indicated wishing to participate in a program targeting anxiety and depression had higher RCADS scores. Sensitivity to change analyses showed that the RCADS can detect changes in anxiety and depression symptoms in children who participated in a preventive intervention. The study showed low agreement between teacher and self-reported internalizing problems, even for children scoring above the 90(th) percentile of the RCADS, indicating a high level of problems, emphasizing the need to also take child reports into account when screening for anxiety and depression in children. This study shows that the RCADS can yield reliable data on a diversity of anxiety disorders and depression in urban children aged 8-13 from very diverse ethnic backgrounds. Netherlands Trial Register: NTR2397 . Registered 30 June 2010.

  2. Exploring RNA structure by integrative molecular modelling

    DEFF Research Database (Denmark)

    Masquida, Benoît; Beckert, Bertrand; Jossinet, Fabrice

    2010-01-01

    on interactive all-atom molecular modelling relies on the observation that specific structural motifs are recurrently found in RNA sequences. Once identified by a combination of comparative sequence analysis and biochemical data, the motifs composing the secondary structure of a given RNA can be extruded...

  3. Simple quasi-analytical holonomic homogenization model for the non-linear analysis of in-plane loaded masonry panels: Part 2, structural implementation and validation

    Science.gov (United States)

    Milani, G.; Bertolesi, E.

    2017-07-01

    The simple quasi analytical holonomic homogenization approach for the non-linear analysis of in-plane loaded masonry presented in Part 1 is here implemented at a structural leveland validated. For such implementation, a Rigid Body and Spring Mass model (RBSM) is adopted, relying into a numerical modelling constituted by rigid elements interconnected by homogenized inelastic normal and shear springs placed at the interfaces between adjoining elements. Such approach is also known as HRBSM. The inherit advantage is that it is not necessary to solve a homogenization problem at each load step in each Gauss point, and a direct implementation into a commercial software by means of an external user supplied subroutine is straightforward. In order to have an insight into the capabilities of the present approach to reasonably reproduce masonry behavior at a structural level, non-linear static analyses are conducted on a shear wall, for which experimental and numerical data are available in the technical literature. Quite accurate results are obtained with a very limited computational effort.

  4. SMILE: A european R and D programme for the validation of the warm pre-stress effect in a reactor pressure vessel structural integrity assessment

    International Nuclear Information System (INIS)

    Moinereau, Dominique; Bezdikian, Georges; Lidbury, David

    2003-01-01

    The reactor pressure vessel (RPV) is an essential component liable to limit the lifetime duration of nuclear PWR power plants. The structural integrity assessment of RPV subjected to pressurized thermal shock (PTS) transients made at an European level generally doesn't take into account the potential beneficial effect of the load history (warm pre-stress WPS). A 3-year European Research and Development programme (SMILE) started in January 2002 as part of the Fifth Framework Programme of the European Atomic Energy Community (EURATOM). The SMILE project is one of a 'cluster' of Fifth Framework projects in the area of Plant Life Management. It aims to give sufficient elements to model and to validate the beneficial WPS effect in a RPV structural integrity assessment. Finally, this project aims to harmonize the different approaches to lay the basis for European codes and standards regarding the inclusion of the warm pre-stress (WPS) effect in the RPV assessments. The present paper describes the aims and objectives of SMILE project, its interactions with European NESC network (Network for Evaluating Steel Components) and other European projects, and give details of its various work-packages. Finally, the on going progress of the project is reviewed. (author)

  5. THE PRENATAL PARENTAL REFLECTIVE FUNCTIONING QUESTIONNAIRE: EXPLORING FACTOR STRUCTURE AND CONSTRUCT VALIDITY OF A NEW MEASURE IN THE FINN BRAIN BIRTH COHORT PILOT STUDY.

    Science.gov (United States)

    Pajulo, Marjukka; Tolvanen, Mimmi; Karlsson, Linnea; Halme-Chowdhury, Elina; Öst, Camilla; Luyten, Patrick; Mayes, Linda; Karlsson, Hasse

    2015-01-01

    Parental reflective functioning (PRF) is the capacity to focus on experience and feelings in oneself and in the child. Individual differences in PRF reportedly affect child attachment and socioemotional development. In this study, we report work on developing a questionnaire to assess PRF during pregnancy (Prenatal Parental Reflective Functioning Questionnaire; P-PRFQ). The factor structure of the 33-item version of the P-PRFQ was explored using pilot study data from the Finn Brain Birth Cohort Study (n = 124 mothers, n = 82 fathers). Construct validity was assessed against the Pregnancy Interview (PI; A. Slade, L. Grunebaum, L. Huganir, & M. Reeves, 1987, 2002, 2011) in a subsample of 29 mothers from the same pilot sample. Exploratory and confirmatory factor analysis resulted in a 14-item P-PRFQ, with three factors which seem to capture relevant aspects of prenatal parental mentalization-F1: "Opacity of mental states," F2: "Reflecting on the fetus-child," and F3: "The dynamic nature of the mental states." Functioning of the factor structure was further tested in the large cohort with 600 mothers and 600 fathers. Correlations with the PI result were high, both regarding total and factor scores of the P-PRFQ. Cost-effective tools to assess key areas of early parenting are needed for both research and clinical purposes. The 14-item P-PRFQ seems to be an applicable and promising new tool for assessing very early parental mentalizing capacity. © 2015 Michigan Association for Infant Mental Health.

  6. Assessing early communication behaviours: structure and validity of the Communication and Symbolic Behaviour Scales-Developmental Profile (CSBS-DP) in 12-month-old infants.

    Science.gov (United States)

    Eadie, Patricia Ann; Ukoumunne, Obioha; Skeat, Jemma; Prior, Margot Ruth; Bavin, Edith; Bretherton, Lesley; Reilly, Sheena

    2010-01-01

    Parent report instruments are frequently used for the identification of both 'at-risk' children and to support the diagnosis of communication delay. Whilst the evidence is strong for the accuracy of parent report of vocabulary between 2 and 3 years, there are fewer studies that have considered the ability of parents to report on early communication behaviours in 12-month-old infants. To investigate the validity of the underlying structure of the Communication and Symbolic Behaviour Scales-Developmental Profile (CSBS-DP) for each of the direct observation and parent reports of communication behaviour in infants at 12 months of age. Participants were 1725 infants, already participating in a longitudinal study of language development, whose parents completed the Infant-Toddler Checklist from the CSBS-DP. Seven hundred and twenty-eight (728) of these infants also completed the Behaviour Sample from the CSBS-DP. The structure of the CSBS-DP was examined using confirmatory factor analyses (CFA) of the Behaviour Sample and the Infant-Toddler Checklist. Correlations between the Infant-Toddler Checklist and the Behaviour Sample on the total, composite, and subscale scores were also calculated. Confirmatory factor analysis of the CSBS-DP Behaviour Sample replicated previous work conducted during the development of the instrument, but on a larger and younger cohort of Australian infants. The data provided support for at least three factors, broadly representing Social, Speech, and Symbolic communication skills, with some evidence that the speech factor could be further split into sub-factors representing Sounds and Words. There was support for a three-factor structure for the Infant-Toddler Checklist. Moderate correlations were found between results from the Behaviour Sample and the Infant-Toddler Checklist. As measures of early communication skill for young infants, the CSBS-DP Behaviour Sample and the Infant-Toddler Checklist are valid clinical tools for measuring

  7. Structural validity of a 16-item abridged version of the Cervantes Health-Related Quality of Life scale for menopause: the Cervantes Short-Form Scale.

    Science.gov (United States)

    Coronado, Pluvio J; Borrego, Rafael Sánchez; Palacios, Santiago; Ruiz, Miguel A; Rejas, Javier

    2015-03-01

    The Cervantes Scale is a specific health-related quality of life questionnaire that was originally developed in Spanish to be used in Spain for women through and beyond menopause. It contains 31 items and is time-consuming. The aim of this study was to produce an abridged version with the same dimensional structure and with similar psychometric properties. A representative sample of 516 postmenopausal women (mean [SD] age, 57 [4.31] y) seen in outpatient gynecology clinics and extracted from an observational cross-sectional study was used. Item analysis, internal consistency reliability, item-total and item-dimension correlations, and item correlation with the 12-item Medical Outcomes Study Short Form Health Survey Version 2.0 were studied. Dimensional and full-model confirmatory factor analyses were used to check structure stability. A threefold cross-validation method was used to obtain stable estimates by means of multigroup analysis. The scale was reduced to a 16-item version, the Cervantes Short-Form Scale, containing four main dimensions (Menopause and Health, Psychological, Sexuality, and Couple Relations), with the first dimension composed of three subdimensions (Vasomotor Symptoms, Health, and Aging). Goodness-of-fit statistics were better than those of the extended version (χ(2)/df = 2.493; adjusted goodness-of-fit index, 0.802; parsimony comparative fit index, 0.749; root mean standard error of approximation, 0.054). Internal consistency was good (Cronbach's α = 0.880). Correlations between the extended and the reduced dimensions were high and significant in all cases (P < 0.001; r values ranged from 0.90 for Sexuality to 0.969 for Vasomotor Symptoms). The Cervantes Scale can be reduced to a 16-item abridged version (Cervantes Short-Form Scale) that maintains the original dimensional structure and psychometric properties. At 51% of the original length, this version can be administered faster, making it especially suitable for routine medical practice.

  8. Antisocial Personality Disorder Subscale (Chinese Version) of the Structured Clinical Interview for the DSM-IV Axis II disorders: validation study in Cantonese-speaking Hong Kong Chinese.

    Science.gov (United States)

    Tang, D Y Y; Liu, A C Y; Leung, M H T; Siu, B W M

    2013-06-01

    OBJECTIVE. Antisocial personality disorder (ASPD) is a risk factor for violence and is associated with poor treatment response when it is a co-morbid condition with substance abuse. It is an under-recognised clinical entity in the local Hong Kong setting, for which there are only a few available Chinese-language diagnostic instruments. None has been tested for its psychometric properties in the Cantonese-speaking population in Hong Kong. This study therefore aimed to assess the reliability and validity of the Chinese version of the ASPD subscale of the Structured Clinical Interview for the DSM-IV Axis II Disorders (SCID-II) in Hong Kong Chinese. METHODS. This assessment tool was modified according to dialectal differences between Mainland China and Hong Kong. Inpatients in Castle Peak Hospital, Hong Kong, who were designated for priority follow-up based on their assessed propensity for violence and who fulfilled the inclusion criteria for the study, were recruited. To assess the level of agreement, best-estimate diagnosis made by a multidisciplinary team was compared with diagnostic status determined by the SCID-II ASPD subscale. The internal consistency, sensitivity, and specificity of the subscale were also calculated. RESULTS. The internal consistency of the subscale was acceptable at 0.79, whereas the test-retest reliability and inter-rater reliability showed an excellent and good agreement of 0.90 and 0.86, respectively. Best-estimate clinical diagnosis-SCID diagnosis agreement was acceptable at 0.76. The sensitivity, specificity, positive and negative predictive values were 0.91, 0.86, 0.83, and 0.93, respectively. CONCLUSION. The Chinese version of the SCID-II ASPD subscale is reliable and valid for diagnosing ASPD in a Cantonese-speaking clinical population.

  9. Investigation of V and V process for thermal fatigue issue in a sodium cooled fast reactor – Application of uncertainty quantification scheme in verification and validation with fluid-structure thermal interaction problem in T-junction piping system

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Masaaki, E-mail: tanaka.masaaki@jaea.go.jp

    2014-11-15

    Highlights: • Outline of numerical simulation code MUGTHES for fluid-structure thermal interaction was described. • The grid convergence index (GCI) method was applied according to the ASME V and V-20 guide. • Uncertainty of MUGTHES can be successfully quantified for thermal-hydraulic problems and unsteady heat conduction problems in the structure. • Validation for fluid-structure thermal interaction problem in a T-junction piping system was well conducted. - Abstract: Thermal fatigue caused by thermal mixing phenomena is one of the most important issues in design and safety assessment of fast breeder reactors. A numerical simulation code MUGTHES consisting of two calculation modules for unsteady thermal-hydraulics analysis and unsteady heat conduction analysis in structure has been developed to predict thermal mixing phenomena and to estimate thermal response of structure under the thermal interaction between fluid and structure fields. Although verification and validation (V and V) of MUGTHES has been required, actual procedure for uncertainty quantification is not fixed yet. In order to specify an actual procedure of V and V, uncertainty quantifications with the grid convergence index (GCI) estimation according to the existing guidelines were conducted in fundamental laminar flow problems for the thermal-hydraulics analysis module, and also uncertainty for the structure heat conduction analysis module and conjugate heat transfer model was quantified in comparison with the theoretical solutions of unsteady heat conduction problems. After the verification, MUGTHES was validated for a practical fluid-structure thermal interaction problem in T-junction piping system compared with measured results of velocity and temperatures of fluid and structure. Through the numerical simulations in the verification and validation, uncertainty of the code was successfully estimated and applicability of the code to the thermal fatigue issue was confirmed.

  10. Investigation of V and V process for thermal fatigue issue in a sodium cooled fast reactor – Application of uncertainty quantification scheme in verification and validation with fluid-structure thermal interaction problem in T-junction piping system

    International Nuclear Information System (INIS)

    Tanaka, Masaaki

    2014-01-01

    Highlights: • Outline of numerical simulation code MUGTHES for fluid-structure thermal interaction was described. • The grid convergence index (GCI) method was applied according to the ASME V and V-20 guide. • Uncertainty of MUGTHES can be successfully quantified for thermal-hydraulic problems and unsteady heat conduction problems in the structure. • Validation for fluid-structure thermal interaction problem in a T-junction piping system was well conducted. - Abstract: Thermal fatigue caused by thermal mixing phenomena is one of the most important issues in design and safety assessment of fast breeder reactors. A numerical simulation code MUGTHES consisting of two calculation modules for unsteady thermal-hydraulics analysis and unsteady heat conduction analysis in structure has been developed to predict thermal mixing phenomena and to estimate thermal response of structure under the thermal interaction between fluid and structure fields. Although verification and validation (V and V) of MUGTHES has been required, actual procedure for uncertainty quantification is not fixed yet. In order to specify an actual procedure of V and V, uncertainty quantifications with the grid convergence index (GCI) estimation according to the existing guidelines were conducted in fundamental laminar flow problems for the thermal-hydraulics analysis module, and also uncertainty for the structure heat conduction analysis module and conjugate heat transfer model was quantified in comparison with the theoretical solutions of unsteady heat conduction problems. After the verification, MUGTHES was validated for a practical fluid-structure thermal interaction problem in T-junction piping system compared with measured results of velocity and temperatures of fluid and structure. Through the numerical simulations in the verification and validation, uncertainty of the code was successfully estimated and applicability of the code to the thermal fatigue issue was confirmed

  11. Exploring the feasibility of a meta-structure for DSM-V and ICD-11: could it improve utility and validity?

    Science.gov (United States)

    Andrews, G; Goldberg, D P; Krueger, R F; Carpenter, W T; Hyman, S E; Sachdev, P; Pine, D S

    2009-12-01

    The organization of mental disorders into 16 DSM-IV and 10 ICD-10 chapters is complex and based on clinical presentation. We explored the feasibility of a more parsimonious meta-structure based on both risk factors and clinical factors. Most DSM-IV disorders were allocated to one of five clusters as a starting premise. Teams of experts then reviewed the literature to determine within-cluster similarities on 11 predetermined validating criteria. Disorders were included and excluded as determined by the available data. These data are intended to inform the grouping of disorders in the DSM-V and ICD-11 processes. The final clusters were neurocognitive (identified principally by neural substrate abnormalities), neurodevelopmental (identified principally by early and continuing cognitive deficits), psychosis (identified principally by clinical features and biomarkers for information processing deficits), emotional (identified principally by the temperamental antecedent of negative emotionality), and externalizing (identified principally by the temperamental antecedent of disinhibition). Large groups of disorders were found to share risk factors and also clinical picture. There could be advantages for clinical practice, public administration and research from the adoption of such an organizing principle.

  12. The DUNDRUM Quartet: validation of structured professional judgement instruments DUNDRUM-3 assessment of programme completion and DUNDRUM-4 assessment of recovery in forensic mental health services

    Directory of Open Access Journals (Sweden)

    McDonnell Kim

    2011-07-01

    Full Text Available Abstract Background Moving a forensic mental health patient from one level of therapeutic security to a lower level or to the community is influenced by more than risk assessment and risk management. We set out to construct and validate structured professional judgement instruments for consistency and transparency in decision making Methods Two instruments were developed, the seven-item DUNDRUM-3 programme completion instrument and the six item DUNDRUM-4 recovery instrument. These were assessed for all 95 forensic patients at Ireland's only forensic mental health hospital. Results The two instruments had good internal consistency (Cronbach's alpha 0.911 and 0.887. Scores distinguished those allowed no leave or accompanied leave from those with unaccompanied leave (ANOVA F = 38.1 and 50.3 respectively, p Conclusions The DUNDRUM-3 programme completion items distinguished significantly between levels of therapeutic security while the DUNDRUM-4 recovery items consistently distinguished those given unaccompanied leave outside the hospital and those in the lowest levels of therapeutic security. This data forms the basis for a prospective study of outcomes now underway.

  13. Rasch Model Analysis Gives New Insights Into the Structural Validity of the QuickDASH in Patients With Musculoskeletal Shoulder Pain.

    Science.gov (United States)

    Jerosch-Herold, Christina; Chester, Rachel; Shepstone, Lee

    2017-09-01

    Study Design Cross-sectional secondary analysis of a prospective cohort study. Background The shortened version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) is a widely used outcome measure that has been extensively evaluated using classical test theory. Rasch model analysis can identify strengths and weaknesses of rating scales and goes beyond classical test theory approaches. It uses a mathematical model to test the fit between the observed data and expected responses and converts ordinal-level scores into interval-level measurement. Objective To test the structural validity of the QuickDASH using Rasch analysis. Methods A prospective cohort study of 1030 patients with shoulder pain provided baseline data. Rasch analysis was conducted to (1) assess how the QuickDASH fits the Rasch model, (2) identify sources of misfit, and (3) explore potential solutions to these. Results There was evidence of multidimensionality and significant misfit to the Rasch model (χ 2 = 331.09, PSports Phys Ther 2017;47(9):664-672. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7288.

  14. Study of the structure and dynamics of poly(vinyl pyrrolidone) by molecular dynamics simulations validated by quasielastic neutron scattering and x-ray diffraction experiments.

    Science.gov (United States)

    Busselez, Rémi; Arbe, Arantxa; Alvarez, Fernando; Colmenero, Juan; Frick, Bernhard

    2011-02-07

    Quasielastic neutron scattering, x-ray diffraction measurements, and fully atomistic molecular dynamics simulations have been performed on poly(vinylpyrrolidone) homopolymer above its glass transition temperature. A "prepeak" appears in the x-ray diffraction pattern that shows the typical features of a first amorphous halo. From an effective description of the experimentally accessed incoherent scattering function of hydrogens in terms of a stretched exponential function, we observe enhanced stretching and a momentum-transfer dependence of the characteristic time different from that usually reported for more simple polymers (main-chain polymers or polymers with small side groups). The comparison with both kinds of experimental results has validated the simulations. The analysis of the simulated structure factor points to a nanosegregation of side groups (SG) and main-chains (MC). The detailed insight provided by the simulations on the atomic trajectories reveals a partial and spatially localized decoupling of MC and SG dynamics at length scales between the average SG-SG distance and the characteristic length of the backbone interchain correlations. Anomalous behavior in correlators calculated for the SG subsystem are found, like e.g., logarithmiclike decays of the density-density correlation function. They might be a consequence of the existing large dynamic asymmetry between SG and MC subsystems. Our results suggest that, as the SGs are spatially extended and chemically different from the backbone, they form transient nanosegregated domains. The dynamics of these domains show similar behavior to that found in other systems displaying large dynamic asymmetry.

  15. The DUNDRUM Quartet: validation of structured professional judgement instruments DUNDRUM-3 assessment of programme completion and DUNDRUM-4 assessment of recovery in forensic mental health services.

    LENUS (Irish Health Repository)

    O'Dwyer, Sarah

    2011-07-03

    Abstract Background Moving a forensic mental health patient from one level of therapeutic security to a lower level or to the community is influenced by more than risk assessment and risk management. We set out to construct and validate structured professional judgement instruments for consistency and transparency in decision making Methods Two instruments were developed, the seven-item DUNDRUM-3 programme completion instrument and the six item DUNDRUM-4 recovery instrument. These were assessed for all 95 forensic patients at Ireland\\'s only forensic mental health hospital. Results The two instruments had good internal consistency (Cronbach\\'s alpha 0.911 and 0.887). Scores distinguished those allowed no leave or accompanied leave from those with unaccompanied leave (ANOVA F = 38.1 and 50.3 respectively, p < 0.001). Scores also distinguished those in acute\\/high security units from those in medium or in low secure\\/pre-discharge units. Each individual item distinguished these levels of need significantly. The DUNDRUM-3 and DUNDRUM-4 correlated moderately with measures of dynamic risk and with the CANFOR staff rated unmet need (Spearman r = 0.5, p < 0.001). Conclusions The DUNDRUM-3 programme completion items distinguished significantly between levels of therapeutic security while the DUNDRUM-4 recovery items consistently distinguished those given unaccompanied leave outside the hospital and those in the lowest levels of therapeutic security. This data forms the basis for a prospective study of outcomes now underway.

  16. Reliability and validity of the Turkish version of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D): a preliminary study.

    Science.gov (United States)

    Kundakçi, Turgut; Sar, Vedat; Kiziltan, Emre; Yargiç, Ilhan L; Tutkun, Hamdi

    2014-01-01

    A total of 34 consecutive patients with dissociative identity disorder or dissociative disorder not otherwise specified were evaluated using the Turkish version of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). They were compared with a matched control group composed of 34 patients who had a nondissociative psychiatric disorder. Interrater reliability was evaluated by 3 clinicians who assessed videotaped interviews conducted with 5 dissociative and 5 nondissociative patients. All subjects who were previously diagnosed by clinicians as having a dissociative disorder were identified as positive, and all subjects who were previously diagnosed as not having a dissociative disorder were identified as negative. The scores of the main symptom clusters and the total score of the SCID-D differentiated dissociative patients from the nondissociative group. There were strong correlations between the SCID-D and the Dissociative Experiences Scale total and subscale scores. These results are promising for the validity and reliability of the Turkish version of the SCID-D. However, as the present study was conducted on a predominantly female sample with very severe dissociation, these findings should not be generalized to male patients, to dissociative disorders other than dissociative identity disorder, or to broader clinical or nonclinical populations.

  17. xMDFF: molecular dynamics flexible fitting of low-resolution X-ray structures

    International Nuclear Information System (INIS)

    McGreevy, Ryan; Singharoy, Abhishek; Li, Qufei; Zhang, Jingfen; Xu, Dong; Perozo, Eduardo; Schulten, Klaus

    2014-01-01

    A new real-space refinement method for low-resolution X-ray crystallography is presented. The method is based on the molecular dynamics flexible fitting protocol targeted at addressing large-scale deformations of the search model to achieve refinement with minimal manual intervention. An explanation of the method is provided, augmented by results from the refinement of both synthetic and experimental low-resolution data, including an independent electrophysiological verification of the xMDFF-refined crystal structure of a voltage-sensor protein. X-ray crystallography remains the most dominant method for solving atomic structures. However, for relatively large systems, the availability of only medium-to-low-resolution diffraction data often limits the determination of all-atom details. A new molecular dynamics flexible fitting (MDFF)-based approach, xMDFF, for determining structures from such low-resolution crystallographic data is reported. xMDFF employs a real-space refinement scheme that flexibly fits atomic models into an iteratively updating electron-density map. It addresses significant large-scale deformations of the initial model to fit the low-resolution density, as tested with synthetic low-resolution maps of d-ribose-binding protein. xMDFF has been successfully applied to re-refine six low-resolution protein structures of varying sizes that had already been submitted to the Protein Data Bank. Finally, via systematic refinement of a series of data from 3.6 to 7 Å resolution, xMDFF refinements together with electrophysiology experiments were used to validate the first all-atom structure of the voltage-sensing protein Ci-VSP

  18. A simulation environment for validating ultrasonic blood flow and vessel wall imaging based on fluid-structure interaction simulations: ultrasonic assessment of arterial distension and wall shear rate.

    Science.gov (United States)

    Swillens, Abigail; Degroote, Joris; Vierendeels, Jan; Lovstakken, Lasse; Segers, Patrick

    2010-08-01

    Ultrasound (US) is a commonly used vascular imaging tool when screening for patients at high cardiovascular risk. However, current blood flow and vessel wall imaging methods are hampered by several limitations. When optimizing and developing new ultrasound modalities, proper validation is required before clinical implementation. Therefore, the authors present a simulation environment integrating ultrasound and fluid-structure interaction (FSI) simulations, allowing construction of synthetic ultrasound images based on physiologically realistic behavior of an artery. To demonstrate the potential of the model for vascular ultrasound research, the authors studied clinically relevant imaging modalities of arterial function related to both vessel wall deformation and arterial hemodynamics: Arterial distension (related to arterial stiffness) and wall shear rate (related to the development of atherosclerosis) imaging. An in-house code ("TANGO") was developed to strongly couple the flow solver FLUENT and structural solver ABAQUS using an interface quasi-Newton technique. FIELD II was used to model realistic transducer and scan settings. The input to the FSI-US model is a scatterer phantom on which the US waves reflect, with the scatterer displacement derived from the FSI flow and displacement fields. The authors applied the simulation tool to a 3D straight tube, representative of the common carotid artery (length: 5 cm; and inner and outer radius: 3 and 4 mm). A mass flow inlet boundary condition, based on flow measured in a healthy subject, was applied. A downstream pressure condition, based on a noninvasively measured pressure waveform, was chosen and scaled to simulate three different degrees of arterial distension (1%, 4%, and 9%). The RF data from the FSI-US coupling were further processed for arterial wall and flow imaging. Using an available wall tracking algorithm, arterial distensibility was assessed. Using an autocorrelation estimator, blood velocity and shear

  19. Testing of the preliminary OMERACT validation criteria for a biomarker to be regarded as reflecting structural damage endpoints in rheumatoid arthritis clinical trials: the example of C-reactive protein

    NARCIS (Netherlands)

    Keeling, Stephanie O.; Landewe, Robert; van der Heijde, Desiree; Bathon, Joan; Boers, Maarten; Garnero, Patrick; Geusens, Piet; El-Gabalawy, Hani; Inman, Robert D.; Kraus, Virginia B.; Kvien, Tore K.; Mease, Philip J.; Ostergaard, Mikkel; Ritchlin, Chris; Syversen, Silje W.; Maksymowych, Walter P.

    2007-01-01

    A list of 14 criteria for guiding the validation of a soluble biomarker as reflecting structural damage endpoints in rheumatoid arthritis (RA) clinical trials was drafted by an international working group after a Delphi consensus exercise. C-reactive protein (CRP), a soluble biomarker extensively

  20. The Structured Interview & Scoring Tool-Massachusetts Alzheimer's Disease Research Center (SIST-M): development, reliability, and cross-sectional validation of a brief structured clinical dementia rating interview.

    Science.gov (United States)

    Okereke, Olivia I; Copeland, Maura; Hyman, Bradley T; Wanggaard, Taylor; Albert, Marilyn S; Blacker, Deborah

    2011-03-01

    The Clinical Dementia Rating (CDR) and CDR Sum-of-Boxes can be used to grade mild but clinically important cognitive symptoms of Alzheimer disease. However, sensitive clinical interview formats are lengthy. To develop a brief instrument for obtaining CDR scores and to assess its reliability and cross-sectional validity. Using legacy data from expanded interviews conducted among 347 community-dwelling older adults in a longitudinal study, we identified 60 questions (from a possible 131) about cognitive functioning in daily life using clinical judgment, inter-item correlations, and principal components analysis. Items were selected in 1 cohort (n=147), and a computer algorithm for generating CDR scores was developed in this same cohort and re-run in a replication cohort (n=200) to evaluate how well the 60 items retained information from the original 131 items. Short interviews based on the 60 items were then administered to 50 consecutively recruited older individuals, with no symptoms or mild cognitive symptoms, at an Alzheimer's Disease Research Center. Clinical Dementia Rating scores based on short interviews were compared with those from independent long interviews. In the replication cohort, agreement between short and long CDR interviews ranged from κ=0.65 to 0.79, with κ=0.76 for Memory, κ=0.77 for global CDR, and intraclass correlation coefficient for CDR Sum-of-Boxes=0.89. In the cross-sectional validation, short interview scores were slightly lower than those from long interviews, but good agreement was observed for global CDR and Memory (κ≥0.70) as well as for CDR Sum-of-Boxes (intraclass correlation coefficient=0.73). The Structured Interview & Scoring Tool-Massachusetts Alzheimer's Disease Research Center is a brief, reliable, and sensitive instrument for obtaining CDR scores in persons with symptoms along the spectrum of mild cognitive change.

  1. Predictive validity of measurements of clinical competence using the team objective structured bedside assessment (TOSBA): assessing the clinical competence of final year medical students.

    LENUS (Irish Health Repository)

    Meagher, Frances M

    2009-11-01

    The importance of valid and reliable assessment of student competence and performance is gaining increased recognition. Provision of valid patient-based formative assessment is an increasing challenge for clinical teachers in a busy hospital setting. A formative assessment tool that reliably predicts performance in the summative setting would be of value to both students and teachers.

  2. Validity of the Brief Symptom Inventory-18 (BSI-18) for identifying depression and anxiety in young adult cancer survivors: Comparison with a Structured Clinical Diagnostic Interview.

    Science.gov (United States)

    Recklitis, Christopher J; Blackmon, Jaime E; Chang, Grace

    2017-10-01

    The Brief Symptom Inventory-18 (BSI-18) is widely used to assess psychological symptoms in cancer survivors, but the validity of conventional BSI-18 cut-off scores in this population has been questioned. This study assessed the accuracy of the BSI-18 for identifying significant anxiety and depression in young adult cancer survivors (YACS), by comparing it with a "gold standard" diagnostic interview measure. Two hundred fifty YACS, age 18-40 completed the BSI-18 and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; SCID) interview assessing anxiety and depressive disorders. BSI-18 results were compared with SCID criteria using receiver operating characteristics (ROC) analyses. Forty four participants (17.7%) met criteria for ≥1 SCID diagnoses, and an additional 20 (8.0%) met criteria for clinically significant SCID symptoms without a diagnosis. General concordance between the BSI-18 GSI scale and SCID diagnosis was good (AUC = 0.848), but the 2 most widely used BSI-18 case rules failed to identify a majority of survivors with SCID diagnoses, and no alternative BSI-18 cut-off scores met study criteria for clinical screening. Analyses aimed at identifying survivors with significant SCID symptoms or a SCID diagnosis had similar results, as did analyses examining depression and anxiety separately. The BSI-18 shows good overall concordance with a psychiatric interview, but recommended cut-off scores fail to identify a majority of YACS with psychiatric diagnosis. Clinicians should not rely on the BSI-18 alone as a screening measure for YACS. Alternative BSI-18 scoring algorithms optimized for detecting psychiatric symptoms in YACS may be an important step to address this limitation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Developing and validating predictive decision tree models from mining chemical structural fingerprints and high–throughput screening data in PubChem

    Directory of Open Access Journals (Sweden)

    Bryant Stephen H

    2008-09-01

    Full Text Available Abstract Background Recent advances in high-throughput screening (HTS techniques and readily available compound libraries generated using combinatorial chemistry or derived from natural products enable the testing of millions of compounds in a matter of days. Due to the amount of information produced by HTS assays, it is a very challenging task to mine the HTS data for potential interest in drug development research. Computational approaches for the analysis of HTS results face great challenges due to the large quantity of information and significant amounts of erroneous data produced. Results In this study, Decision Trees (DT based models were developed to discriminate compound bioactivities by using their chemical structure fingerprints provided in the PubChem system http://pubchem.ncbi.nlm.nih.gov. The DT models were examined for filtering biological activity data contained in four assays deposited in the PubChem Bioassay Database including assays tested for 5HT1a agonists, antagonists, and HIV-1 RT-RNase H inhibitors. The 10-fold Cross Validation (CV sensitivity, specificity and Matthews Correlation Coefficient (MCC for the models are 57.2~80.5%, 97.3~99.0%, 0.4~0.5 respectively. A further evaluation was also performed for DT models built for two independent bioassays, where inhibitors for the same HIV RNase target were screened using different compound libraries, this experiment yields enrichment factor of 4.4 and 9.7. Conclusion Our results suggest that the designed DT models can be used as a virtual screening technique as well as a complement to traditional approaches for hits selection.

  4. Developing and validating predictive decision tree models from mining chemical structural fingerprints and high-throughput screening data in PubChem.

    Science.gov (United States)

    Han, Lianyi; Wang, Yanli; Bryant, Stephen H

    2008-09-25

    Recent advances in high-throughput screening (HTS) techniques and readily available compound libraries generated using combinatorial chemistry or derived from natural products enable the testing of millions of compounds in a matter of days. Due to the amount of information produced by HTS assays, it is a very challenging task to mine the HTS data for potential interest in drug development research. Computational approaches for the analysis of HTS results face great challenges due to the large quantity of information and significant amounts of erroneous data produced. In this study, Decision Trees (DT) based models were developed to discriminate compound bioactivities by using their chemical structure fingerprints provided in the PubChem system http://pubchem.ncbi.nlm.nih.gov. The DT models were examined for filtering biological activity data contained in four assays deposited in the PubChem Bioassay Database including assays tested for 5HT1a agonists, antagonists, and HIV-1 RT-RNase H inhibitors. The 10-fold Cross Validation (CV) sensitivity, specificity and Matthews Correlation Coefficient (MCC) for the models are 57.2 approximately 80.5%, 97.3 approximately 99.0%, 0.4 approximately 0.5 respectively. A further evaluation was also performed for DT models built for two independent bioassays, where inhibitors for the same HIV RNase target were screened using different compound libraries, this experiment yields enrichment factor of 4.4 and 9.7. Our results suggest that the designed DT models can be used as a virtual screening technique as well as a complement to traditional approaches for hits selection.

  5. Atomistic structural ensemble refinement reveals non-native structure stabilizes a sub-millisecond folding intermediate of CheY

    International Nuclear Information System (INIS)

    Shi, Jade; Schwantes, Christian; Bilsel, Osman

    2017-01-01

    The dynamics of globular proteins can be described in terms of transitions between a folded native state and less-populated intermediates, or excited states, which can play critical roles in both protein folding and function. Excited states are by definition transient species, and therefore are difficult to characterize using current experimental techniques. We report an atomistic model of the excited state ensemble of a stabilized mutant of an extensively studied flavodoxin fold protein CheY. We employed a hybrid simulation and experimental approach in which an aggregate 42 milliseconds of all-atom molecular dynamics were used as an informative prior for the structure of the excited state ensemble. The resulting prior was then refined against small-angle X-ray scattering (SAXS) data employing an established method (EROS). The most striking feature of the resulting excited state ensemble was an unstructured N-terminus stabilized by non-native contacts in a conformation that is topologically simpler than the native state. We then predict incisive single molecule FRET experiments, using these results, as a means of model validation. Our study demonstrates the paradigm of uniting simulation and experiment in a statistical model to study the structure of protein excited states and rationally design validating experiments.

  6. Atomistic structural ensemble refinement reveals non-native structure stabilizes a sub-millisecond folding intermediate of CheY

    Science.gov (United States)

    Shi, Jade; Nobrega, R. Paul; Schwantes, Christian; Kathuria, Sagar V.; Bilsel, Osman; Matthews, C. Robert; Lane, T. J.; Pande, Vijay S.

    2017-03-01

    The dynamics of globular proteins can be described in terms of transitions between a folded native state and less-populated intermediates, or excited states, which can play critical roles in both protein folding and function. Excited states are by definition transient species, and therefore are difficult to characterize using current experimental techniques. Here, we report an atomistic model of the excited state ensemble of a stabilized mutant of an extensively studied flavodoxin fold protein CheY. We employed a hybrid simulation and experimental approach in which an aggregate 42 milliseconds of all-atom molecular dynamics were used as an informative prior for the structure of the excited state ensemble. This prior was then refined against small-angle X-ray scattering (SAXS) data employing an established method (EROS). The most striking feature of the resulting excited state ensemble was an unstructured N-terminus stabilized by non-native contacts in a conformation that is topologically simpler than the native state. Using these results, we then predict incisive single molecule FRET experiments as a means of model validation. This study demonstrates the paradigm of uniting simulation and experiment in a statistical model to study the structure of protein excited states and rationally design validating experiments.

  7. Validated dynamic flow model

    DEFF Research Database (Denmark)

    Knudsen, Torben

    2011-01-01

    model structure suggested by University of Lund the WP4 leader. This particular model structure has the advantages that it fits better into the control design frame work used by WP3-4 compared to the model structures previously developed in WP2. The different model structures are first summarised....... Then issues dealing with optimal experimental design is considered. Finally the parameters are estimated in the chosen static and dynamic models and a validation is performed. Two of the static models, one of them the additive model, explains the data well. In case of dynamic models the suggested additive...

  8. High-resolution noise substitution to measure overfitting and validate resolution in 3D structure determination by single particle electron cryomicroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shaoxia; McMullan, Greg; Faruqi, Abdul R.; Murshudov, Garib N.; Short, Judith M.; Scheres, Sjors H.W.; Henderson, Richard, E-mail: rh15@mrc-lmb.cam.ac.uk

    2013-12-15

    unbiased FSC from the two curves, even when a substantial amount of overfitting is present. The approach is software independent. The user is therefore completely free to use any established method or novel combination of methods, provided the HR-noise test is carried out in parallel. Applying this procedure to cryoEM images of beta-galactosidase shows how overfitting varies greatly depending on the procedure, but in the best case shows no overfitting and a resolution of ∼6 Å. (382 words) - Highlights: • A new method to validate 3D cryoEM maps of biological structures is described. • High-resolution noise substitution is a tool to measure the amount of overfitting of noise in single particle cryoEM. • A reliable, unbiased resolution estimation can be obtained even when some overfitting is present. • Structure of beta-galactosidase at ∼6 Å resolution is determined by cryoEM.

  9. Validation philosophy

    International Nuclear Information System (INIS)

    Vornehm, D.

    1994-01-01

    To determine when a set of calculations falls within an umbrella of an existing validation documentation, it is necessary to generate a quantitative definition of range of applicability (our definition is only qualitative) for two reasons: (1) the current trend in our regulatory environment will soon make it impossible to support the legitimacy of a validation without quantitative guidelines; and (2) in my opinion, the lack of support by DOE for further critical experiment work is directly tied to our inability to draw a quantitative open-quotes line-in-the-sandclose quotes beyond which we will not use computer-generated values

  10. The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

    Science.gov (United States)

    Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

    2014-01-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identifying a core atom set, and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an “Expanded FindCore” atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines “expanded core atom sets” that match an expert’s intuition of which parts of the structure are sufficiently well-defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  11. Burnout and depressive symptoms in teachers: Factor structure and construct validity of the Maslach Burnout inventory-educators survey among elementary and secondary school teachers in Hungary.

    Science.gov (United States)

    Szigeti, Réka; Balázs, Noémi; Bikfalvi, Réka; Urbán, Róbert

    2017-12-01

    This study validated the Hungarian version of the Maslach Burnout Inventory-Educators Survey on a sample of n = 211 elementary and secondary teachers. To test factorial validity, we ran a series of confirmatory analysis with eight models. The best fitting model was the bifactor model with general burnout and three specific factors: emotional exhaustion, depersonalization, and personal accomplishment. Analyzing the covariates revealed that gender and age were not associated with burnout, but depressive symptoms and overcommitment had a significant relationship with general burnout, and overcommitment was related to emotional exhaustion as well. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Testing of the OMERACT 8 draft validation criteria for a soluble biomarker reflecting structural damage in rheumatoid arthritis: a systematic literature search on 5 candidate biomarkers

    DEFF Research Database (Denmark)

    Syversen, Silje W; Landewe, Robert; van der Heijde, Désirée

    2009-01-01

    OBJECTIVE: To test the OMERACT 8 draft validation criteria for soluble biomarkers by assessing the strength of literature evidence in support of 5 candidate biomarkers. METHODS: A systematic literature search was conducted on the 5 soluble biomarkers RANKL, osteoprotegerin (OPG), matrix metallopr......OBJECTIVE: To test the OMERACT 8 draft validation criteria for soluble biomarkers by assessing the strength of literature evidence in support of 5 candidate biomarkers. METHODS: A systematic literature search was conducted on the 5 soluble biomarkers RANKL, osteoprotegerin (OPG), matrix...

  13. Structure and conformational dynamics of scaffolded DNA origami nanoparticles.

    Science.gov (United States)

    Pan, Keyao; Bricker, William P; Ratanalert, Sakul; Bathe, Mark

    2017-06-20

    Synthetic DNA is a highly programmable nanoscale material that can be designed to self-assemble into 3D structures that are fully determined by underlying Watson-Crick base pairing. The double crossover (DX) design motif has demonstrated versatility in synthesizing arbitrary DNA nanoparticles on the 5-100 nm scale for diverse applications in biotechnology. Prior computational investigations of these assemblies include all-atom and coarse-grained modeling, but modeling their conformational dynamics remains challenging due to their long relaxation times and associated computational cost. We apply all-atom molecular dynamics and coarse-grained finite element modeling to DX-based nanoparticles to elucidate their fine-scale and global conformational structure and dynamics. We use our coarse-grained model with a set of secondary structural motifs to predict the equilibrium solution structures of 45 DX-based DNA origami nanoparticles including a tetrahedron, octahedron, icosahedron, cuboctahedron and reinforced cube. Coarse-grained models are compared with 3D cryo-electron microscopy density maps for these five DNA nanoparticles and with all-atom molecular dynamics simulations for the tetrahedron and octahedron. Our results elucidate non-intuitive atomic-level structural details of DX-based DNA nanoparticles, and offer a general framework for efficient computational prediction of global and local structural and mechanical properties of DX-based assemblies that are inaccessible to all-atom based models alone. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  14. Alignment validation

    Energy Technology Data Exchange (ETDEWEB)

    ALICE; ATLAS; CMS; LHCb; Golling, Tobias

    2008-09-06

    The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.

  15. SANSMIC Validation.

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Paula D.; Rudeen, David Keith; Lord, David L.

    2014-08-01

    SANSMIC is solution mining software that was developed and utilized by SNL in its role as geotechnical advisor to the US DOE SPR for planning purposes. Three SANSMIC leach modes - withdrawal, direct, and reverse leach - have been revalidated with multiple test cases for each mode. The withdrawal mode was validated using high quality data from recent leach activity while the direct and reverse modes utilized data from historical cavern completion reports. Withdrawal results compared very well with observed data, including the location and size of shelves due to string breaks with relative leached volume differences ranging from 6 - 10% and relative radius differences from 1.5 - 3%. Profile comparisons for the direct mode were very good with relative leached volume differences ranging from 6 - 12% and relative radius differences from 5 - 7%. First, second, and third reverse configurations were simulated in order to validate SANSMIC over a range of relative hanging string and OBI locations. The first-reverse was simulated reasonably well with relative leached volume differences ranging from 1 - 9% and relative radius differences from 5 - 12%. The second-reverse mode showed the largest discrepancies in leach profile. Leached volume differences ranged from 8 - 12% and relative radius differences from 1 - 10%. In the third-reverse, relative leached volume differences ranged from 10 - 13% and relative radius differences were %7E4 %. Comparisons to historical reports were quite good, indicating that SANSMIC is essentially the same as documented and validated in the early 1980's.

  16. Structural heterogeneity in familial Alzheimer's disease mutants of amyloid-beta peptides.

    Science.gov (United States)

    Chong, Song-Ho; Yim, Janghyun; Ham, Sihyun

    2013-05-01

    Alzheimer's disease is a neurodegenerative disorder characterized by progressive deposition of amyloid-beta (Aβ) peptides in brain parenchyma and cerebral blood vessels. Several pathogenic familial mutations of Aβ peptides have been identified that exhibit enhanced neurotoxicity and aggregative ability. However, knowledge of the structural characteristics of those Aβ mutants is still limited. Here, we report multiple all-atom molecular dynamics simulations of the wild-type 42-residue Aβ peptide (Aβ42) and its Flemish (A21G), Arctic (E22G), Dutch (E22Q), Italian (E22K), and Iowa (D23N) familial mutants in explicit water. After validating our simulations by comparison with available experimental data, we examined common/different features in the secondary and tertiary structures of the wild-type and five familial mutants of Aβ42. We found that Aβ42 peptides display quite heterogeneous secondary and tertiary structure ensembles. Such structural heterogeneity in the monomeric state would facilitate interconversions between various secondary structures during the formation of a β-sheet-rich amyloid fibril, and may also serve as a structural basis of the amyloid polymorphism.

  17. Adaptation of the Boundary Violations Scale Developed Based on Structural Family Therapy to the Turkish Context: A Study of Validity and Reliability

    Science.gov (United States)

    Avci, Rasit; Çolakkadioglu, Oguzhan; Öz, Aysegül Sükran; Akbas, Turan

    2015-01-01

    The purpose of this study was to adapt "The Boundary Violations Scale" (Madden et al., 2002), which was created to measure the intergenerational boundary violations in families from the perspective of children, to Turkish and to test the validity and reliability of the Turkish version of this instrument. This instrument was developed…

  18. Reappraisal of OMERACT 8 draft validation criteria for a soluble biomarker reflecting structural damage endpoints in rheumatoid arthritis, psoriatic arthritis, and spondyloarthritis

    DEFF Research Database (Denmark)

    Maksymowych, Walter P; Landewé, Robert; Tak, Paul-Peter

    2009-01-01

    and the principle objectives of the validation process were clarified at a meeting of the working group in London, December 2007. A new framework was proposed after the following steps were conducted: (A) A systematic review of the literature focusing on the draft criteria and a preselected group of biomarkers (MMP...

  19. The eating disorder assessment for DSM-5 (EDA-5): Development and validation of a structured interview for feeding and eating disorders.

    Science.gov (United States)

    Sysko, Robyn; Glasofer, Deborah R; Hildebrandt, Tom; Klimek, Patrycja; Mitchell, James E; Berg, Kelly C; Peterson, Carol B; Wonderlich, Stephen A; Walsh, B Timothy

    2015-07-01

    Existing measures for DSM-IV eating disorder diagnoses have notable limitations, and there are important differences between DSM-IV and DSM-5 feeding and eating disorders. This study developed and validated a new semistructured interview, the Eating Disorders Assessment for DSM-5 (EDA-5). Two studies evaluated the utility of the EDA-5. Study 1 compared the diagnostic validity of the EDA-5 with the Eating Disorder Examination (EDE) and evaluated the test-retest reliability of the new measure. Study 2 compared the diagnostic validity of an EDA-5 electronic application ("App") with clinician interview and self-reported assessments. In Study 1, the kappa for EDE and EDA-5 eating disorder diagnoses was 0.74 across all diagnoses (n = 64), with a range of κ = 0.65 for other specified feeding or eating disorder/unspecified feeding or eating disorder to κ = 0.90 for binge eating disorder. The EDA-5 test-retest kappa coefficient was 0.87 across diagnoses. For Study 2, clinical interview versus App conditions revealed a kappa of 0.83 for all eating disorder diagnoses (n = 71). Across individual diagnostic categories, kappas ranged from 0.56 for other specified feeding or eating disorder/unspecified feeding or eating disorder to 0.94 for BN. High rates of agreement were found between diagnoses by EDA-5 and the EDE, and EDA-5 and clinical interviews. Because this study supports the validity of the EDA-5 to generate DSM-5 eating disorders and the reliability of these diagnoses, the EDA-5 may be an option for the assessment of anorexia nervosa, bulimia nervosa, and binge eating disorder. Additional research is needed to evaluate the utility of the EDA-5 in assessing DSM-5 feeding disorders. © 2015 Wiley Periodicals, Inc.

  20. Reliability and Concurrent Validation of the IPIP Big-Five Factor Markers in China: Consistencies in Factor Structure between Internet-Obtained Heterosexual and Homosexual Samples

    OpenAIRE

    Zheng, Lijun; Goldberg, Lewis R.; Zheng, Yong; Zhao, Yufang; Tang, Yonglong; Liu, Li

    2008-01-01

    Previous studies have suggested the cross-cultural generalizability of a 5-factor structure for personality traits. In this article, we analyzed the utility of 2 versions (100-item and 50-item) of the IPIP Big-Five factor markers in both heterosexual (N = 633) and homosexual (N = 437) samples in China. Factor analysis within versions showed that both versions of these IPIP measures showed clear 5-factor orthogonal structures that were nearly identical to the American structure in both subject...

  1. Cross-validation of the factorial structure of the Neighborhood Environment Walkability Scale (NEWS and its abbreviated form (NEWS-A

    Directory of Open Access Journals (Sweden)

    Cerin Ester

    2009-06-01

    Full Text Available Abstract Background The Neighborhood Environment Walkability Scale (NEWS and its abbreviated form (NEWS-A assess perceived environmental attributes believed to influence physical activity. A multilevel confirmatory factor analysis (MCFA conducted on a sample from Seattle, WA showed that, at the respondent level, the factor-analyzable items of the NEWS and NEWS-A measured 11 and 10 constructs of perceived neighborhood environment, respectively. At the census blockgroup (used by the US Census Bureau as a subunit of census tracts level, the MCFA yielded five factors for both NEWS and NEWS-A. The aim of this study was to cross-validate the individual- and blockgroup-level measurement models of the NEWS and NEWS-A in a geographical location and population different from those used in the original validation study. Methods A sample of 912 adults was recruited from 16 selected neighborhoods (116 census blockgroups in the Baltimore, MD region. Neighborhoods were stratified according to their socio-economic status and transport-related walkability level measured using Geographic Information Systems. Participants self-completed the NEWS. MCFA was used to cross-validate the individual- and blockgroup-level measurement models of the NEWS and NEWS-A. Results The data provided sufficient support for the factorial validity of the original individual-level measurement models, which consisted of 11 (NEWS and 10 (NEWS-A correlated factors. The original blockgroup-level measurement model of the NEWS and NEWS-A showed poor fit to the data and required substantial modifications. These included the combining of aspects of building aesthetics with safety from crime into one factor; the separation of natural aesthetics and building aesthetics into two factors; and for the NEWS-A, the separation of presence of sidewalks/walking routes from other infrastructure for walking. Conclusion This study provided support for the generalizability of the individual

  2. Clinical validity of MR based program for analysis of fluid/brain index of posterior cranial fossa structures in patients with spinocerebellar ataxia

    International Nuclear Information System (INIS)

    Boguslawska, R.; Lechowicz, W.

    2008-01-01

    Spinocerebellar ataxia type 1 (SCA1) and type 2 (SCA2) belong to the group of neurodegenerative disorders of autosomal dominant inheritance, genetically and clinically heterogeneous, caused by CAG trinucleotide repeat expansion, which leads to productions of protein carrying the abnormal polyglutamine chain (polyQ). Molecular abnormalities cause degenerative changes - atrophy of posterior cranial fossa structures. The clinical symptoms typical of this disorder include progressive gait and limb ataxia, dysarthria, occulomotor disturbances, pyramidal tract and peripheral nerves involvement. The aim of the study is to evaluate the usefulness of a computer program prepared in our department for volumetric measurements of posterior cranial fossa structures (the pons, vermis and cerebellar hemispheres) in a group of SCA patients. MR examinations of 22 patients suffering from SCA were used to calculate the value of fluid/brain index of posterior cranial fossa structures and compared with the results of group of 10 healthy volunteers. The degree of atrophy of posterior cranial fossa structures can be objectively evaluated by special volumetric measurements. We found fluid/brain index (FBI) of posterior cranial fossa structures in group of SCA patients to vary from 0.1411 to 0.3929 (mean 0.2456 SD±0.601). 1. MR-based calculation of fluid/brain index of posterior fossa structures is a valuable tool for morphological assessment of SCA-related changes in brain structures. 2. The presented software enables objective evaluation of the course and stage of posterior fossa structures atrophy. 3. Our self-made computer program to calculate the fluid/brain index of posterior cranial fossa structures is easy to use on a personal computer- it is a good tool in everyday radiological practice. (author)

  3. A Stability-Indicating HPLC-DAD Method for Determination of Stiripentol: Development, Validation, Kinetics, Structure Elucidation and Application to Commercial Dosage Form

    Directory of Open Access Journals (Sweden)

    Hany W. Darwish

    2014-01-01

    Full Text Available A rapid, simple, sensitive, and accurate isocratic reversed-phase stability-indicating high performance liquid chromatography method has been developed and validated for the determination of stiripentol and its degradation product in its bulk form and pharmaceutical dosage form. Chromatographic separation was achieved on a Symmetry C18 column and quantification was achieved using photodiode array detector (DAD. The method was validated in accordance with the ICH requirements showing specificity, linearity (r2=0.9996, range of 1–25 μg/mL, precision (relative standard deviation lower than 2%, accuracy (mean recovery 100.08±1.73, limits of detection and quantitation (LOD = 0.024 and LOQ = 0.081 μg/mL, and robustness. Stiripentol was subjected to various stress conditions and it has shown marked stability under alkaline hydrolytic stress conditions, thermal, oxidative, and photolytic conditions. Stiripentol degraded only under acidic conditions, forming a single degradation product which was well resolved from the pure drug with significantly different retention time values. This degradation product was characterized by 1H-NMR and 13C-NMR spectroscopy as well as ion trap mass spectrometry. The results demonstrated that the method would have a great value when applied in quality control and stability studies for stiripentol.

  4. The General Assessment of Personality Disorder (GAPD): factor structure, incremental validity of self-pathology, and relations to DSM-IV personality disorders.

    Science.gov (United States)

    Hentschel, Annett G; Livesley, W John

    2013-01-01

    Recent developments in the classification of personality disorder, especially moves toward more dimensional systems, create the need to assess general personality disorder apart from individual differences in personality pathology. The General Assessment of Personality Disorder (GAPD) is a self-report questionnaire designed to evaluate general personality disorder. The measure evaluates 2 major components of disordered personality: self or identity problems and interpersonal dysfunction. This study explores whether there is a single factor reflecting general personality pathology as proposed by the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), whether self-pathology has incremental validity over interpersonal pathology as measured by GAPD, and whether GAPD scales relate significantly to Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]) personality disorders. Based on responses from a German psychiatric sample of 149 participants, parallel analysis yielded a 1-factor model. Self Pathology scales of the GAPD increased the predictive validity of the Interpersonal Pathology scales of the GAPD. The GAPD scales showed a moderate to high correlation for 9 of 12 DSM-IV personality disorders.

  5. Testing of the preliminary OMERACT validation criteria for a biomarker to be regarded as reflecting structural damage endpoints in rheumatoid arthritis clinical trials: the example of C-reactive protein

    DEFF Research Database (Denmark)

    Keeling, Stephanie O; Landewe, Robert; van der Heijde, Desiree

    2007-01-01

    OBJECTIVE: A list of 14 criteria for guiding the validation of a soluble biomarker as reflecting structural damage endpoints in rheumatoid arthritis (RA) clinical trials was drafted by an international working group after a Delphi consensus exercise. C-reactive protein (CRP), a soluble biomarker...... in a special interest soluble biomarker group at OMERACT 8. Participants at OMERACT 8 were asked to rate the strength of evidence and the strength of the recommendation in support of each individual criterion on a 0-10 numerical rating scale. Working group members not present at OMERACT voted by a Web...

  6. Chinese version of the Responses to Positive Affect Questionnaire: testing the factor structure, reliability, and validity in a college student sample.

    Science.gov (United States)

    Yang, Hongfei; Guo, Wenjing

    2014-10-01

    This study tested the psychometrics of the Chinese version of the Responses to Positive Affect Questionnaire among 915 Chinese college students with an average age of 20.3 yr. (SD = 1.6). The original three-factor model with the factors dampening, emotion-focused positive rumination, and self-focused rumination was supported using exploratory and confirmatory factor analyses. All subscales showed good internal reliability, as well as evidence for convergent and incremental validity with measures of ego-resiliency, life satisfaction, and mental health symptoms. Finally, a series of hierarchical regression analyses indicated that the three subscales, especially dampening, accounted for additional unique variance in psychological adjustment above and beyond resilience. These findings generally suggested that the Chinese Responses to Positive Affect Questionnaire possesses acceptable psychometric properties. Implications for counseling, limitations, and suggestions for future study were presented.

  7. Usage and validation of a fluid structure interaction methodology for the study of different suction valve parameters of a hermetic reciprocating compressor

    Directory of Open Access Journals (Sweden)

    W Lang

    2016-09-01

    Full Text Available The dynamics of the flatter valves inside a hermetic reciprocating compressor used in household appliances is the most important factor concerning the gas dynamic behaviour of such a compressor. Hence for a good valve design and for a reliable simulation of the compressor the ability to predict the movement of the valves is indispensable. The present paper describes a methodology which allows the prediction of the valve dynamics. For the validation of the methodology the simulation results of the suction valve dynamics have been compared with experimental data obtained out of measurements with a Laser-Doppler-Vibrometer. Furthermore the method has been used for the variation of some suction valve parameters and their influence onto the overall compressor performance has been shown. The whole methodology has been implemented into a commercial available CFD code (FLUENT as a user defined function (UDF.

  8. Understanding latent structures of clinical information logistics: A bottom-up approach for model building and validating the workflow composite score.

    Science.gov (United States)

    Esdar, Moritz; Hübner, Ursula; Liebe, Jan-David; Hüsers, Jens; Thye, Johannes

    2017-01-01

    Clinical information logistics is a construct that aims to describe and explain various phenomena of information provision to drive clinical processes. It can be measured by the workflow composite score, an aggregated indicator of the degree of IT support in clinical processes. This study primarily aimed to investigate the yet unknown empirical patterns constituting this construct. The second goal was to derive a data-driven weighting scheme for the constituents of the workflow composite score and to contrast this scheme with a literature based, top-down procedure. This approach should finally test the validity and robustness of the workflow composite score. Based on secondary data from 183 German hospitals, a tiered factor analytic approach (confirmatory and subsequent exploratory factor analysis) was pursued. A weighting scheme, which was based on factor loadings obtained in the analyses, was put into practice. We were able to identify five statistically significant factors of clinical information logistics that accounted for 63% of the overall variance. These factors were "flow of data and information", "mobility", "clinical decision support and patient safety", "electronic patient record" and "integration and distribution". The system of weights derived from the factor loadings resulted in values for the workflow composite score that differed only slightly from the score values that had been previously published based on a top-down approach. Our findings give insight into the internal composition of clinical information logistics both in terms of factors and weights. They also allowed us to propose a coherent model of clinical information logistics from a technical perspective that joins empirical findings with theoretical knowledge. Despite the new scheme of weights applied to the calculation of the workflow composite score, the score behaved robustly, which is yet another hint of its validity and therefore its usefulness. Copyright © 2016 Elsevier Ireland

  9. Factor structure and invariance test of the alcohol use disorder identification test (AUDIT): Comparison and further validation in a U.S. and Philippines college student sample.

    Science.gov (United States)

    Tuliao, Antover P; Landoy, Bernice Vania N; McChargue, Dennis E

    2016-01-01

    The Alcohol Use Disorder Identification Test's factor structure varies depending on population and culture. Because of this inconsistency, this article examined the factor structure of the test and conducted a factorial invariance test between a U.S. and a Philippines college sample. Confirmatory factor analyses indicated that a three-factor solution outperforms the one- and two-factor solution in both samples. Factorial invariance analyses further supports the confirmatory findings by showing that factor loadings were generally invariant across groups; however, item intercepts show non-invariance. Country differences between factors show that Filipino consumption factor mean scores were significantly lower than their U.S. counterparts.

  10. Extending Structural Analyses of the Rosenberg Self-Esteem Scale to Consider Criterion-Related Validity: Can Composite Self-Esteem Scores Be Good Enough?

    Science.gov (United States)

    Donnellan, M Brent; Ackerman, Robert A; Brecheen, Courtney

    2016-01-01

    Although the Rosenberg Self-Esteem Scale (RSES) is the most widely used measure of global self-esteem in the literature, there are ongoing disagreements about its factor structure. This methodological debate informs how the measure should be used in substantive research. Using a sample of 1,127 college students, we test the overall fit of previously specified models for the RSES, including a newly proposed bifactor solution (McKay, Boduszek, & Harvey, 2014 ). We extend previous work by evaluating how various latent factors from these structural models are related to a set of criterion variables frequently studied in the self-esteem literature. A strict unidimensional model poorly fit the data, whereas models that accounted for correlations between negatively and positively keyed items tended to fit better. However, global factors from viable structural models had similar levels of association with criterion variables and with the pattern of results obtained with a composite global self-esteem variable calculated from observed scores. Thus, we did not find compelling evidence that different structural models had substantive implications, thereby reducing (but not eliminating) concerns about the integrity of the self-esteem literature based on overall composite scores for the RSES.

  11. The Structure of Self-Serving Cognitive Distortions: A Validation of the "How I Think" Questionnaire in a Sample of Italian Adolescents

    Science.gov (United States)

    Bacchini, Dario; De Angelis, Grazia; Affuso, Gaetana; Brugman, Daniel

    2016-01-01

    This study aims to investigate the structure of self-serving cognitive distortions (CD), evaluating the psychometric properties of the How I Think Questionnaire in a sample of Italian adolescents. A confirmatory factor analysis supported the distinction between four categories of CD and the use of a single second-order dimension of CD. Reliability…

  12. Methodology for testing and validating knowledge bases

    Science.gov (United States)

    Krishnamurthy, C.; Padalkar, S.; Sztipanovits, J.; Purves, B. R.

    1987-01-01

    A test and validation toolset developed for artificial intelligence programs is described. The basic premises of this method are: (1) knowledge bases have a strongly declarative character and represent mostly structural information about different domains, (2) the conditions for integrity, consistency, and correctness can be transformed into structural properties of knowledge bases, and (3) structural information and structural properties can be uniformly represented by graphs and checked by graph algorithms. The interactive test and validation environment have been implemented on a SUN workstation.

  13. Brief report: The Identity Style Inventory (ISI-3) and the Utrecht-Management of Identity Commitments Scale (U-MICS): factor structure, reliability, and convergent validity in French-speaking university students.

    Science.gov (United States)

    Zimmermann, Grégoire; Mahaim, Elodie Biermann; Mantzouranis, Gregory; Genoud, Philippe A; Crocetti, Elisabetta

    2012-04-01

    The purpose of this study was to evaluate the factor structure and the reliability of the French versions of the Identity Style Inventory (ISI-3) and the Utrecht-Management of Identity Commitments Scale (U-MICS) in a sample of college students (N = 457, 18-25 years old). Confirmatory factor analyses confirmed the hypothesized three-factor solution of the ISI-3 identity styles (i.e. informational, normative, and diffuse-avoidant styles), the one-factor solution of the ISI-3 identity commitment, and the three-factor structure of the U-MICS (i.e. commitment, in-depth exploration, and reconsideration of commitment). Additionally, theoretically consistent and meaningful associations among the ISI-3, U-MICS, and Ego Identity Process Questionnaire (EIPQ) confirmed convergent validity. Overall, the results of the present study indicate that the French versions of the ISI-3 and UMICS are useful instruments for assessing identity styles and processes, and provide additional support to the cross-cultural validity of these tools. Copyright © 2010 The Association for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  14. Multi-institutional quantitative evaluation and clinical validation of Smart Probabilistic Image Contouring Engine (SPICE) autosegmentation of target structures and normal tissues on computer tomography images in the head and neck, thorax, liver, and male pelvis areas.

    Science.gov (United States)

    Zhu, Mingyao; Bzdusek, Karl; Brink, Carsten; Eriksen, Jesper Grau; Hansen, Olfred; Jensen, Helle Anita; Gay, Hiram A; Thorstad, Wade; Widder, Joachim; Brouwer, Charlotte L; Steenbakkers, Roel J H M; Vanhauten, Hubertus A M; Cao, Jeffrey Q; McBrayne, Gail; Patel, Salil H; Cannon, Donald M; Hardcastle, Nicholas; Tomé, Wolfgang A; Guckenberg, Matthias; Parikh, Parag J

    2013-11-15

    Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE). CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independent institutions were autosegmented using SPICE and computational times were recorded. The number of structures autocontoured were 25 for the HN, 7 for the thorax, 3 for the liver, and 6 for the male pelvis regions. Using the clinical contours as reference, autocontours of 22 selected structures were quantitatively evaluated using Dice Similarity Coefficient (DSC) and Mean Slice-wise Hausdorff Distance (MSHD). All 40 autocontours were evaluated by a radiation oncologist from the institution that treated the patients. The mean computational times to autosegment all the structures using SPICE were 3.1 to 11.1 minutes per patient. For the HN region, the mean DSC was >0.70 for all evaluated structures, and the MSHD ranged from 3.2 to 10.0 mm. For the thorax region, the mean DSC was 0.95 for the lungs and 0.90 for the heart, and the MSHD ranged from 2.8 to 12.8 mm. For the liver region, the mean DSC was >0.92 for all structures, and the MSHD ranged from 5.2 to 15.9 mm. For the male pelvis region, the mean DSC was >0.76 for all structures, and the MSHD ranged from 4.8 to 10.5 mm. Out of the 40 autocontoured structures reviews by experts, 25 were scored useful as autocontoured or with minor edits for at least 90% of the patients and 33 were scored useful autocontoured or with minor edits for at least 80% of the patients. Compared with manual contouring, autosegmentation using SPICE for the HN, thorax, liver, and male pelvis regions is efficient and shows significant promise for clinical utility. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Structure-based design, synthesis and validation of CD4-mimetic small molecule inhibitors of HIV-1 entry: conversion of a viral entry agonist to an antagonist.

    Science.gov (United States)

    Courter, Joel R; Madani, Navid; Sodroski, Joseph; Schön, Arne; Freire, Ernesto; Kwong, Peter D; Hendrickson, Wayne A; Chaiken, Irwin M; LaLonde, Judith M; Smith, Amos B

    2014-04-15

    This Account provides an overview of a multidisciplinary consortium focused on structure-based strategies to devise small molecule antagonists of HIV-1 entry into human T-cells, which if successful would hold considerable promise for the development of prophylactic modalities to prevent HIV transmission and thereby alter the course of the AIDS pandemic. Entry of the human immunodeficiency virus (HIV) into target T-cells entails an interaction between CD4 on the host T-cell and gp120, a component of the trimeric envelope glycoprotein spike on the virion surface. The resultant interaction initiates a series of conformational changes within the envelope spike that permits binding to a chemokine receptor, formation of the gp41 fusion complex, and cell entry. A hydrophobic cavity at the CD4-gp120 interface, defined by X-ray crystallography, provided an initial site for small molecule antagonist design. This site however has evolved to facilitate viral entry. As such, the binding of prospective small molecule inhibitors within this gp120 cavity can inadvertently trigger an allosteric entry signal. Structural characterization of the CD4-gp120 interface, which provided the foundation for small molecule structure-based inhibitor design, will be presented first. An integrated approach combining biochemical, virological, structural, computational, and synthetic studies, along with a detailed analysis of ligand binding energetics, revealed that modestly active small molecule inhibitors of HIV entry can also promote viral entry into cells lacking the CD4 receptor protein; these competitive inhibitors were termed small molecule CD4 mimetics. Related congeners were subsequently identified with both improved binding affinity and more potent viral entry inhibition. Further assessment of the affinity-enhanced small molecule CD4 mimetics demonstrated that premature initiation of conformational change within the viral envelope spike, prior to cell encounter, can lead to irreversible

  16. Are patients reliable when self-reporting medication use? Validation of structured drug interviews and home visits by drug analysis and prescription data in acutely hospitalized patients

    DEFF Research Database (Denmark)

    Glintborg, Bente; Hillestrøm, Peter René; Olsen, Lenette Holm

    2007-01-01

    inspected, and patients were interviewed about their drug use. Additional blood samples were drawn for drug analysis. The median age of included patients was 72 years, and 298 patients (60%) were women. Patients reported use of 3 (median) prescription-only medications (range, 0-14) during the structured...... interview. The congruence between self-report and drug analysis was high for all 5 drugs measured (all kappa >0.8). However, 9 patients (2%) reported use of drugs that were not detected in their blood samples. In 29 patients (6%), the blood samples contained drugs not reported during the structured...... to an acute medical department at a Danish university hospital were interviewed on the day of admission about their recent medication use. Blood samples drawn immediately after admission were screened for contents of 5 drugs (digoxin, bendroflumethiazide, amlodipine, simvastatin, glimepiride), and the results...

  17. Optimized set of two-dimensional experiments for fast sequential assignment, secondary structure determination, and backbone fold validation of 13C/15N-labelled proteins

    International Nuclear Information System (INIS)

    Bersch, Beate; Rossy, Emmanuel; Coves, Jacques; Brutscher, Bernhard

    2003-01-01

    NMR experiments are presented which allow backbone resonance assignment, secondary structure identification, and in favorable cases also molecular fold topology determination from a series of two-dimensional 1 H- 15 N HSQC-like spectra. The 1 H- 15 N correlation peaks are frequency shifted by an amount ± ω X along the 15 N dimension, where ω X is the C α , C β , or H α frequency of the same or the preceding residue. Because of the low dimensionality (2D) of the experiments, high-resolution spectra are obtained in a short overall experimental time. The whole series of seven experiments can be performed in typically less than one day. This approach significantly reduces experimental time when compared to the standard 3D-based methods. The here presented methodology is thus especially appealing in the context of high-throughput NMR studies of protein structure, dynamics or molecular interfaces

  18. Are patients reliable when self-reporting medication use? Validation of structured drug interviews and home visits by drug analysis and prescription data in acutely hospitalized patients

    DEFF Research Database (Denmark)

    Glintborg, Bente; Hillestrøm, Peter René; Olsen, Lenette Holm

    2007-01-01

    to an acute medical department at a Danish university hospital were interviewed on the day of admission about their recent medication use. Blood samples drawn immediately after admission were screened for contents of 5 drugs (digoxin, bendroflumethiazide, amlodipine, simvastatin, glimepiride), and the results...... inspected, and patients were interviewed about their drug use. Additional blood samples were drawn for drug analysis. The median age of included patients was 72 years, and 298 patients (60%) were women. Patients reported use of 3 (median) prescription-only medications (range, 0-14) during the structured...... interview. The congruence between self-report and drug analysis was high for all 5 drugs measured (all kappa >0.8). However, 9 patients (2%) reported use of drugs that were not detected in their blood samples. In 29 patients (6%), the blood samples contained drugs not reported during the structured...

  19. Validation of missed space-group symmetry in X-ray powder diffraction structures with dispersion-corrected density functional theory

    DEFF Research Database (Denmark)

    Hempler, Daniela; Schmidt, Martin U.; Van De Streek, Jacco

    2017-01-01

    More than 600 molecular crystal structures with correct, incorrect and uncertain space-group symmetry were energy-minimized with dispersion-corrected density functional theory (DFT-D, PBE-D3). For the purpose of determining the correct space-group symmetry the required tolerance on the atomic...... with missed symmetry were investigated by dispersion-corrected density functional theory. In 98.5% of the cases the correct space group is found....

  20. Perceived parental rearing style in childhood: internal structure and concurrent validity on the Egna Minnen Beträffande Uppfostran--Child Version in clinical settings.

    Science.gov (United States)

    Penelo, Eva; Viladrich, Carme; Domènech, Josep M

    2010-01-01

    We provide the first validation data of the Spanish version of the Egna Minnen Beträffande Uppfostran--Child Version (EMBU-C) in a clinical context. The EMBU-C is a 41-item self-report questionnaire that assesses perceived parental rearing style in children, comprising 4 subscales (rejection, emotional warmth, control attempts/overprotection, and favoring subjects). The test was administered to a clinical sample of 174 Spanish psychiatric outpatients aged 8 to 12. Confirmatory factor analyses were performed, analyzing the children's reports about their parents' rearing style. The results were almost equivalent for father's and mother's ratings. Confirmatory factor analysis yielded an acceptable fit to data of the 3-factor model when removing the items of the favoring subjects scale (root mean squared error of approximation .73), whereas control attempts scale showed lower values, as in previous studies. The influence of sex (of children and parents) on scale scores was inappreciable and children tended to perceive their parents as progressively less warm as they grew older. As predicted, the scores for rejection and emotional warmth were related to bad relationships with parents, absence of family support, harsh discipline, and lack of parental supervision. The Spanish version of EMBU-C can be used with psychometric guarantees to identify rearing style in psychiatric outpatients because evidences of quality in this setting match those obtained in community samples. Copyright 2010 Elsevier Inc. All rights reserved.

  1. Design Validation of a {sup 10}B{sub 4}C Coated RSP with Multi-layered structure for Homeland Security

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su Hyun; Kim, Jong Yul; Lee, Joo Hyun; Moon, Mung Kook [KAERI, Daejeon (Korea, Republic of); Lim, Chang Hwy [Korea Research Institute of Ships and Ocean Engineering, Daejeon (Korea, Republic of); Lim, Ki Seo [Myongji University, Yongin (Korea, Republic of)

    2016-05-15

    It is a national priority to prevent radiological threats including radiological terrorism and smuggling nuclear material and devices. For this purpose, many governments and relevant organizations have been exploiting radiation detection technology. Especially, radiation portal monitor (RPM) is a widely used type of radiation detectors when it comes to homeland security and commonly deployed at strategic sites like airports and ports. In the most cases, they could be divided into two types of primary screening and secondary screening. In the latter case, hand-held detectors are mainly used for a closer inspection. On the other hand, RPMs for the primary screening, our concern, are stationary mounted type and comprise gamma-ray detector and neutron detector in many cases. The expected performance of the design of a RSP(Radiation Sensor Panel) has been demonstrated. According to the results of the simulation, three RSPs should be needed to meet the criterion mentioned in subsection 2.1. The design still can be validated when taking into account that the geometrical acceptance will be increased since it has been planned that the RPM is going to installed with four RSPs.

  2. Validation of tautomeric and protomeric binding modes by free energy calculations. A case study for the structure based optimization of d-amino acid oxidase inhibitors

    Science.gov (United States)

    Orgován, Zoltán; Ferenczy, György G.; Steinbrecher, Thomas; Szilágyi, Bence; Bajusz, Dávid; Keserű, György M.

    2018-02-01

    Optimization of fragment size d-amino acid oxidase (DAAO) inhibitors was investigated using a combination of computational and experimental methods. Retrospective free energy perturbation (FEP) calculations were performed for benzo[d]isoxazole derivatives, a series of known inhibitors with two potential binding modes derived from X-ray structures of other DAAO inhibitors. The good agreement between experimental and computed binding free energies in only one of the hypothesized binding modes strongly support this bioactive conformation. Then, a series of 1-H-indazol-3-ol derivatives formerly not described as DAAO inhibitors was investigated. Binding geometries could be reliably identified by structural similarity to benzo[d]isoxazole and other well characterized series and FEP calculations were performed for several tautomers of the deprotonated and protonated compounds since all these forms are potentially present owing to the experimental pKa values of representative compounds in the series. Deprotonated compounds are proposed to be the most important bound species owing to the significantly better agreement between their calculated and measured affinities compared to the protonated forms. FEP calculations were also used for the prediction of the affinities of compounds not previously tested as DAAO inhibitors and for a comparative structure-activity relationship study of the benzo[d]isoxazole and indazole series. Selected indazole derivatives were synthesized and their measured binding affinity towards DAAO was in good agreement with FEP predictions.

  3. Examining the factorial structure, measurement invariance and convergent and discriminant validity of a novel self-report measure of work ability: work ability--personal radar.

    Science.gov (United States)

    Ilmarinen, Ville; Ilmarinen, Juhani; Huuhtanen, Pekka; Louhevaara, Veikko; Näsman, Ove

    2015-01-01

    For identification of groups and domains for work ability promotion, brief self-report measure, work ability - personal radar (WA-PR), based on the 'the house of work ability' model is presented and psychometrically evaluated in the structural equation framework using data from technological sector (N = 3754). The house model had acceptable fit to the data. In addition, factor loadings in the model were invariant across groups, demonstrating metric invariance of the WA-PR. Scalar invariance of WA-PR was fully demonstrated across men and women, and partially demonstrated across age and employee groups. Comparisons between groups revealed lower levels of health and functional capacity, but higher levels of four other WA-PR dimensions in older employees. In addition, all house structures showed convergence with alternative work ability measures. WA-PR demonstrated potential for effective measurement of multiple work ability dimensions from employees' perspective. It provides means for efficient location of relevant domains and focus groups for work ability promotion. A novel approach to multidimensional work ability measurement was developed to tackle the challenges of work ability promotion. The properties of the instrument were psychometrically evaluated in structural equation modelling framework. Instrument demonstrated potential for locating relevant domains and focus groups for work ability promotions at workplaces and organisations.

  4. The Use of the Risky Sex Scale among Adolescents Receiving Treatment Services for Substance Use Problems: Factor Structure and Predictive Validity

    Science.gov (United States)

    Tubman, Jonathan G.; Des Rosiers, Sabrina E.; Schwartz, Seth J.; O'Hare, Thomas

    2015-01-01

    The present study evaluated the use of the Risky Sex Scale (RSS; O'Hare, 2001) among youth in outpatient treatment for substance use problems. An ethnically diverse sample of 394 adolescents (280 males; Mage = 16.33 years, SDage = 1.15) was recruited from two treatment sites. The study was guided by two aims. First, a confirmatory factor analysis was conducted on RSS item responses. Findings replicated the factor structure identified in previous studies of undergraduate students cited for campus alcohol violations. Second, structural equation modeling (SEM) was used to document associations between RSS subscales and self-reported substance use and sexual risk behaviors. The Risky Sex Expectancies (RSE) subscale was significantly associated with co-occurring alcohol use and sex, alcohol use at last intercourse, and alcohol use during the prior 30 days. The Risky Sex Behaviors (RSB) subscale was significantly associated with cooccurring drug use and sex, condom use at last intercourse and unprotected intercourse during the prior 30 days. The factor structure of the RSS was consistent across age group (12-16 and 16- 18) and across gender, and the links between the RSS subscales and health risk behaviors varied somewhat by gender but not by age group. These findings suggest that the RSS is an appropriate brief screening tool for predicting health risk behaviors among adolescents in substance abuse treatment. PMID:22425202

  5. Personality structure among prisoners: how valid is the five-factor model, and can it offer support for Eysenck's theory of criminality?

    Science.gov (United States)

    Ireland, Jane L; Ireland, Carol A

    2011-02-01

    Research with offenders has tended to use a categorical system of diagnosis or a three-factor model. There is growing evidence among non-offending groups that a five-factor model (FFM), which is more holistic and emphasises strengths as well as limitations, may be more clinically useful. The purpose of this study was to test the validity of the FFM of personality in a sample of adult male prisoners. It was predicted that they would show higher scores for extraversion (E) and lower scores for emotional stability (ES) [the equivalent of higher neuroticism (N)], that E would be predicted by prison experience and age and that the FFM would be confirmed as a better fit to the data over Eysenck's three-factor [P(psychoticism)EN] model. Two independent samples of adult male prisoners were asked to complete the International Personality Item Pool while locked in their cells over the lunchtime period. Parallel and confirmatory factor analyses were used to test the hypotheses. There was a 65 and 75% response rate across the independent samples, resulting in samples of 259 and 183, respectively. Overall, more positive personality traits were evidenced across both samples. E was not predicted by prison experience or age, with increased ES related to increased age in only one sample. The best-fitting model comprised five factors, but represented a variant of the FFM. The value of applying broad conceptualisations of personality to special samples is discussed, with the importance of accounting for positive, as well as negative, traits acknowledged. The presence of increased positive traits in comparison to negative traits is not in keeping with Eysenck's original personality theory of criminal behaviour, with the study highlighting value in accounting more for environmental factors. Copyright © 2010 John Wiley & Sons, Ltd.

  6. Structural basis for species specific inhibition of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1: computational study and biological validation.

    Directory of Open Access Journals (Sweden)

    Tobias Klein

    Full Text Available 17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1 catalyzes the reduction of estrone to estradiol, which is the most potent estrogen in humans. Inhibition of 17β-HSD1 and thereby reducing the intracellular estradiol concentration is thus a promising approach for the treatment of estrogen dependent diseases. In the past, several steroidal and non-steroidal inhibitors of 17β-HSD1 have been described but so far there is no cocrystal structure of the latter in complex with 17β-HSD1. However, a distinct knowledge of active site topologies and protein-ligand interactions is a prerequisite for structure-based drug design and optimization. An elegant strategy to enhance this knowledge is to compare inhibition values obtained for one compound toward ortholog proteins from various species, which are highly conserved in sequence and differ only in few residues. In this study the inhibitory potencies of selected members of different non-steroidal inhibitor classes toward marmoset 17β-HSD1 were determined and the data were compared with the values obtained for the human enzyme. A species specific inhibition profile was observed in the class of the (hydroxyphenylnaphthols. Using a combination of computational methods, including homology modelling, molecular docking, MD simulation, and binding energy calculation, a reasonable model of the three-dimensional structure of marmoset 17β-HSD1 was developed and inhibition data were rationalized on the structural basis. In marmoset 17β-HSD1, residues 190 to 196 form a small α-helix, which induces conformational changes compared to the human enzyme. The docking poses suggest these conformational changes as determinants for species specificity and energy decomposition analysis highlighted the outstanding role of Asn152 as interaction partner for inhibitor binding. In summary, this strategy of comparing the biological activities of inhibitors toward highly conserved ortholog proteins might be an alternative to

  7. Validation of the k-filtering technique for a signal composed of random-phase plane waves and non-random coherent structures

    Directory of Open Access Journals (Sweden)

    O. W. Roberts

    2014-12-01

    Full Text Available Recent observations of astrophysical magnetic fields have shown the presence of fluctuations being wave-like (propagating in the plasma frame and those described as being structure-like (advected by the plasma bulk velocity. Typically with single-spacecraft missions it is impossible to differentiate between these two fluctuations, due to the inherent spatio-temporal ambiguity associated with a single point measurement. However missions such as Cluster which contain multiple spacecraft have allowed for temporal and spatial changes to be resolved, using techniques such as k filtering. While this technique does not assume Taylor's hypothesis it requires both weak stationarity of the time series and that the fluctuations can be described by a superposition of plane waves with random phases. In this paper we test whether the method can cope with a synthetic signal which is composed of a combination of non-random-phase coherent structures with a mean radius d and a mean separation λ, as well as plane waves with random phase.

  8. The Skin Cancer Objective Structured Clinical Examination (SCOSCE): A multi-institutional collaboration to develop and validate a clinical skills assessment for melanoma.

    Science.gov (United States)

    Garg, Amit; Biello, Katie; Hoot, Joyce W; Reddy, Shalini B; Wilson, Lindsay; George, Paul; Robinson-Bostom, Leslie; Belazarian, Leah; Domingues, Erik; Powers, Jennifer; Jacob, Reza; Powers, Michael; Besen, Justin; Geller, Alan C

    2015-12-01

    Assessing medical students on core skills related to melanoma detection is challenging in the absence of a well-developed instrument. We sought to develop an objective structured clinical examination for the detection and evaluation of melanoma among medical students. This was a prospective cohort analysis of student and objective rater agreement on performance of clinical skills and assessment of differences in performance across 3 schools. Kappa coefficients indicated excellent agreement for 3 of 5 core skills including commenting on the presence of the moulage (k = 0.87, 95% confidence interval 0.77-0.96), obtaining a history for the moulage (k = 0.84, 95% confidence interval 0.74-0.94), and making a clinical impression (k = 0.80, 95% confidence interval 0.68-0.92). There were no differences in performance across schools with respect to 3 of 5 core skills: commenting on the presence of the moulage (P = .15), initiating a history (P = .53), and managing the suspicious lesion (P value range .07-.17). Overall, 54.2% and 44.7% of students commented on the presence of the moulage and achieved maximum performance of core skills, respectively, with no difference in performance across schools. Limitations include overall sample size of students and schools. The Skin Cancer Objective Structured Clinical Examination represents a potentially important instrument to measure students' performance on the optimal step-by-step evaluation of a melanoma. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  9. Retinal Ligand Mobility Explains Internal Hydration and Reconciles Active Rhodopsin Structures

    Science.gov (United States)

    Leioatts, Nicholas; Mertz, Blake; Martínez-Mayorga, Karina; Romo, Tod D.; Pitman, Michael C.; Feller, Scott E.; Grossfield, Alan; Brown, Michael F.

    2014-01-01

    Rhodopsin, the mammalian dim-light receptor, is one of the best-characterized G-protein-coupled receptors, a pharmaceutically important class of membrane proteins that has garnered a great deal of attention because of the recent availability of structural information. Yet the mechanism of rhodopsin activation is not fully understood. Here, we use microsecond-scale all-atom molecular dynamics simulations, validated by solid-state 2H nuclear magnetic resonance spectroscopy, to understand the transition between the dark and metarhodopsin I (Meta I) states. Our analysis of these simulations reveals striking differences in ligand flexibility between the two states. Retinal is much more dynamic in Meta I, adopting an elongated conformation similar to that seen in the recent activelike crystal structures. Surprisingly, this elongation corresponds to both a dramatic influx of bulk water into the hydrophobic core of the protein and a concerted transition in the highly conserved Trp2656.48 residue. In addition, enhanced ligand flexibility upon light activation provides an explanation for the different retinal orientations observed in X-ray crystal structures of active rhodopsin. PMID:24328554

  10. Bayesian refinement of protein structures and ensembles against SAXS data using molecular dynamics.

    Science.gov (United States)

    Shevchuk, Roman; Hub, Jochen S

    2017-10-01

    Small-angle X-ray scattering is an increasingly popular technique used to detect protein structures and ensembles in solution. However, the refinement of structures and ensembles against SAXS data is often ambiguous due to the low information content of SAXS data, unknown systematic errors, and unknown scattering contributions from the solvent. We offer a solution to such problems by combining Bayesian inference with all-atom molecular dynamics simulations and explicit-solvent SAXS calculations. The Bayesian formulation correctly weights the SAXS data versus prior physical knowledge, it quantifies the precision or ambiguity of fitted structures and ensembles, and it accounts for unknown systematic errors due to poor buffer matching. The method further provides a probabilistic criterion for identifying the number of states required to explain the SAXS data. The method is validated by refining ensembles of a periplasmic binding protein against calculated SAXS curves. Subsequently, we derive the solution ensembles of the eukaryotic chaperone heat shock protein 90 (Hsp90) against experimental SAXS data. We find that the SAXS data of the apo state of Hsp90 is compatible with a single wide-open conformation, whereas the SAXS data of Hsp90 bound to ATP or to an ATP-analogue strongly suggest heterogenous ensembles of a closed and a wide-open state.

  11. Lower Length Scale Characterization and Validation of Formation and Stability of Helium Bubbles in Nano-structured Ferritic Alloys under Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Huijuan [Clemson Univ., SC (United States); Yun, Di [Argonne National Lab. (ANL), Argonne, IL (United States); Hoelzer, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC)

    2018-01-30

    In order to extend the operating license of current light water reactors (LWRs) in the United States and other countries to as many as 80 years or longer, it is demanding to identify potential materials for many of the internal structural components and fasteners. We proposed that 14YWT iron alloy can be adopted in such applications with its excellent material properties, such as high-temperature strength, low creep rate, and high irradiation resistance. Application with 14YWT would improve the void/helium swelling characteristics of the LWR fuels, extend the burn-up limits with the tolerant temperature up to 800oC and reduce the hydrogen production. One key feature of 14YWT material property enhancement is the ultrafine high density of 2-4nm Y-Ti-O enriched nanoclusters (NCs) within the 14YWT iron matrix. The NCs can effectively pin the ultra-fine grain boundaries and dislocations, which significantly enhance mechanical properties of the alloy. Moreover, these nanoclusters remain stable with no coarsening after a large dose of ion irradiation. After ion irradiation, the helium bubbles are observed extremely uniform in size (1nm) and quite homogeneously distributed within the 14YWT matrix, which indicates that the microstructure of 14YWT remains remarkably tolerance to radiation damage. However, there is a lack of understanding of 14YWT both theoretically and experimentally in order to understand the mechanism behind the material property enhancement and to further develop and design a new generation of advanced structural material for current LWR applications and future fusion applications.

  12. Target-specific support vector machine scoring in structure-based virtual screening: computational validation, in vitro testing in kinases, and effects on lung cancer cell proliferation.

    Science.gov (United States)

    Li, Liwei; Khanna, May; Jo, Inha; Wang, Fang; Ashpole, Nicole M; Hudmon, Andy; Meroueh, Samy O

    2011-04-25

    We assess the performance of our previously reported structure-based support vector machine target-specific scoring function across 41 targets, 40 among them from the Directory of Useful Decoys (DUD). The area under the curve of receiver operating characteristic plots (ROC-AUC) revealed that scoring with SVM-SP resulted in consistently better enrichment over all target families, outperforming Glide and other scoring functions, most notably among kinases. In addition, SVM-SP performance showed little variation among protein classes, exhibited excellent performance in a test case using a homology model, and in some cases showed high enrichment even with few structures used to train a model. We put SVM-SP to the test by virtual screening 1125 compounds against two kinases, EGFR and CaMKII. Among the top 25 EGFR compounds, three compounds (1-3) inhibited kinase activity in vitro with IC₅₀ of 58, 2, and 10 μM. In cell cultures, compounds 1-3 inhibited nonsmall cell lung carcinoma (H1299) cancer cell proliferation with similar IC₅₀ values for compound 3. For CaMKII, one compound inhibited kinase activity in a dose-dependent manner among 20 tested with an IC₅₀ of 48 μM. These results are encouraging given that our in-house library consists of compounds that emerged from virtual screening of other targets with pockets that are different from typical ATP binding sites found in kinases. In light of the importance of kinases in chemical biology, these findings could have implications in future efforts to identify chemical probes of kinases within the human kinome.

  13. Evaluation of fluid-coupled seismic buckling strength for FBRs' reactor vessel wall protective structures. Validation of the applicability of the finite element procedures for dynamic buckling analyses of a fluid-filled thin cylindrical shell by dynamic buckling tests

    International Nuclear Information System (INIS)

    Toyoda, Yukihiro; Matsuura, Shinichi

    1997-01-01

    The demonstration FBRs' reactor vessel wall protective structures, which are composed of thin shell structures, may fail by dynamic buckling due to seismically induced hydrodynamic effects. In order to clarify the dynamic buckling characteristics of the shells, numerical analysis can be a useful tool. However, it generally takes an enormous amount of computational time to execute dynamic buckling analysis by the finite element method. Therefore, one of the authors has developed an elastic-plastic large displacement analysis computer program for shells of revolution with high efficiency. The objectives of this study are to investigate the buckling behaviour of a partially liquid-filled cantilevered thin cylindrical shell subjected to harmonic excitation, and to validate the applicability of the improved computer program which has the capability of elastic-plastic dynamic buckling analysis including fluid-structure interaction. Numerical simulations were performed using the computer program under the conditions corresponding to shaking table tests of the tank. It is confirmed that the dynamic buckling analyses of the liquid-filled thin shell are possible by using the computer program within reasonable computational time. (author)

  14. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars. Part 1. Model structure, simulation of bounded rationality, and model validation

    International Nuclear Information System (INIS)

    Mueller, Michel G.; Haan, Peter de

    2009-01-01

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated. (author)

  15. Coarse-grained/molecular mechanics of the TAS2R38 bitter taste receptor: experimentally-validated detailed structural prediction of agonist binding.

    Directory of Open Access Journals (Sweden)

    Alessandro Marchiori

    Full Text Available Bitter molecules in humans are detected by ∼25 G protein-coupled receptors (GPCRs. The lack of atomic resolution structure for any of them is complicating an in depth understanding of the molecular mechanisms underlying bitter taste perception. Here, we investigate the molecular determinants of the interaction of the TAS2R38 bitter taste receptor with its agonists phenylthiocarbamide (PTC and propylthiouracil (PROP. We use the recently developed hybrid Molecular Mechanics/Coarse Grained (MM/CG method tailored specifically for GPCRs. The method, through an extensive exploration of the conformational space in the binding pocket, allows the identification of several residues important for agonist binding that would have been very difficult to capture from the standard bioinformatics/docking approach. Our calculations suggest that both agonists bind to Asn103, Phe197, Phe264 and Trp201, whilst they do not interact with the so-called extra cellular loop 2, involved in cis-retinal binding in the GPCR rhodopsin. These predictions are consistent with data sets based on more than 20 site-directed mutagenesis and functional calcium imaging experiments of TAS2R38. The method could be readily used for other GPCRs for which experimental information is currently lacking.

  16. Death Anxiety, Reliability, Validity, and Factorial Structure of the Farsi Form of the Arabic Scale of Death Anxiety in Iranian Old-Aged Persons

    Directory of Open Access Journals (Sweden)

    Mahboubeh Dadfar

    2016-01-01

    Full Text Available The present study is aimed at examining the level of death anxiety and the sex-related differences among old-aged Iranian individuals sample to compare the old-aged persons with young college students and to explore the psychometric properties of the Arabic Scale of Death Anxiety (ASDA factors in old-aged sample. A sample of 146 volunteer Iranian individuals took part in the study. The mean ages were 68.58 (SD = 7.10, men 68.81 (SD = 7.44 and women 68.28 (SD = 6.76, respectively. The mean score of the ASDA was 51.09 (SD = 20.19. Cronbach’s alpha of the ASDA was found to be high (0.94; and Spearman-Brown coefficient was 0.92. Women had a significantly higher mean total score on the ASDA. Old-aged individuals had a significantly higher mean ASDA total score than younger college students (M age = 25.77. The factor analysis of the ASDA items yielded three factors accounting for 67.88% of the total variance labeled (F1 fear of dead people and tombs; (F2 fear of lethal disease and postmortem events; and (F3 death fear. These factors were highly replicable with previous factors extracted from a middle-aged Kuwaiti sample. On the basis of the present results, there are the following three general conclusions: death anxiety is not significantly correlated with age; the sex-related differences on death anxiety are striking in the Iranian samples; and the ASDA has a highly replicable factor structure among two Iranian and Arab countries.

  17. Structural Validity of the Mini-Balance Evaluation Systems Test (Mini-BESTest) in People With Mild to Moderate Parkinson Disease.

    Science.gov (United States)

    Benka Wallén, Martin; Sorjonen, Kimmo; Löfgren, Niklas; Franzén, Erika

    2016-11-01

    The Mini-Balance Evaluation Systems Test (Mini-BESTest) is a clinical balance test comprising 14 items assumed to reflect the unidimensional construct "dynamic balance." The study objective was to examine the dimensionality of the test and the properties of each item and their interrelationships in elderly people with mild to moderate Parkinson disease (PD). This was a cross-sectional study in a laboratory setting. A total of 112 participants (mean age=73 years) with idiopathic PD (Hoehn and Yahr stages 1-3) were assessed by physical therapists. Local independence among items was examined with Rasch modeling. Unidimensionality was tested by running a principal component analysis on the residuals. An exploratory factor analysis was used to examine the structure of the test, and a confirmatory factor analysis was used to evaluate the fit of the derived model. The first residual component of the principal component analysis, with an eigenvalue of greater than 2, superseded the assumption of unidimensionality. After the omission of item 7 because of convergence problems, the exploratory factor analysis suggested that a 3-factor solution best fit the data. A confirmatory factor analysis demonstrated acceptable fit of the final model, although item 14 loaded poorly on its factor. The sample size was on the lower end of what is generally recommended. This study could not confirm that the Mini-BESTest is unidimensional. Gait items were dispersed over all factors, indicating that they may reflect different constructs. Nonetheless, as there arguably is no clinical balance test superior to the Mini-BESTest today, we recommend using the total score for assessing gross balance in this population and individual items to identify specific weaknesses. Moreover, dual tasks should be assessed separately because they are an important aspect of balance control in people with PD, reflected in only one item of the test. © 2016 American Physical Therapy Association.

  18. Validación de un cuestionario de contexto para evaluar sistemas educativos con Modelos de Ecuaciones Estructurales. [Validation of a context questionnaire for the evaluation of educational systems with Structural Equations Modeling].

    Directory of Open Access Journals (Sweden)

    González-Montesinos, Manuel-Jorge

    2010-12-01

    Full Text Available This work shows the use of Structural Equations Modeling (SEM methodology to validate the conceptual structure of context questionnaires employed in national and international studies that evaluate the educational achievement of students. Unfortunately, evaluation agencies do not assign the same amount of technical resources to context questionnaires as those allotted to achievement tests, consequently the former are rarely subject to validity studies. In order to show the use of SEM methodology, a questionnaire was selected, which was employed by the National Institute for the Evaluation of Education to investigate the background factors associated with educational achievement of elementary school students in the third grade. It was administered to a national representative sample of 55,312 students. This questionnaire is analyzed according to SEM procedures of confirmatory factor analysis (CFA. The obtained results provide evidence for the constructive validity of this tool. Este trabajo tiene el propósito de mostrar el uso de la metodología de Modelos de Ecuaciones Estructurales (SEM para validar la estructura conceptual de cuestionarios de contexto que se utilizan en los estudios nacionales e internacionales para evaluar el logro educativo de los escolares. Desgraciadamente, los organismos evaluadores no destinan los mismos recursos técnicos a los cuestionarios de contexto que a las pruebas de aprendizaje, por lo que rara vez los primeros son sujetos a estudios de validez. Para mostrar el uso de la metodología SEM, se seleccionó el cuestionario dirigido a alumnos que utilizó el Instituto Nacional para la Evaluación de la Educación (INEE para conocer los factores de contexto asociados el logro educativo de los estudiantes de tercero de primaria, el que se aplicó a una muestra representativa nacional de 55, 312 alumnos. A dicho instrumento se le aplican los supuestos y procedimientos del análisis factorial confirmatorio (AFC y se

  19. Structure of solid monolayers and multilayers of n-hexane on graphite

    Indian Academy of Sciences (India)

    Unknown

    We present all-atom molecular dynamics simulations of n-hexane on the basal plane of graphite at ... lie parallel to the graphite surface at the multilayer coverage, while a few molecules are observed to attain ... structure of the first adsorbed layer has also been observed recently in neutron scattering studies of other even ...

  20. Multi-institutional Quantitative Evaluation and Clinical Validation of Smart Probabilistic Image Contouring Engine (SPICE) Autosegmentation of Target Structures and Normal Tissues on Computer Tomography Images in the Head and Neck, Thorax, Liver, and Male Pelvis Areas

    DEFF Research Database (Denmark)

    Zhu, Mingyao; Bzdusek, Karl; Brink, Carsten

    2013-01-01

    Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE).......Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE)....

  1. Description of the Sandia Validation Metrics Project

    International Nuclear Information System (INIS)

    TRUCANO, TIMOTHY G.; EASTERLING, ROBERT G.; DOWDING, KEVIN J.; PAEZ, THOMAS L.; URBINA, ANGEL; ROMERO, VICENTE J.; RUTHERFORD, BRIAN M.; HILLS, RICHARD GUY

    2001-01-01

    This report describes the underlying principles and goals of the Sandia ASCI Verification and Validation Program Validation Metrics Project. It also gives a technical description of two case studies, one in structural dynamics and the other in thermomechanics, that serve to focus the technical work of the project in Fiscal Year 2001

  2. Preliminary Assessment of ATR-C Capabilities to Provide Integral Benchmark Data for Key Structural/Matrix Materials that May be Used for Nuclear Data Testing and Analytical Methods Validation

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess

    2009-03-01

    The purpose of this research is to provide a fundamental computational investigation into the possible integration of experimental activities with the Advanced Test Reactor Critical (ATR-C) facility with the development of benchmark experiments. Criticality benchmarks performed in the ATR-C could provide integral data for key matrix and structural materials used in nuclear systems. Results would then be utilized in the improvement of nuclear data libraries and as a means for analytical methods validation. It is proposed that experiments consisting of well-characterized quantities of materials be placed in the Northwest flux trap position of the ATR-C. The reactivity worth of the material could be determined and computationally analyzed through comprehensive benchmark activities including uncertainty analyses. Experiments were modeled in the available benchmark model of the ATR using MCNP5 with the ENDF/B-VII.0 cross section library. A single bar (9.5 cm long, 0.5 cm wide, and 121.92 cm high) of each material could provide sufficient reactivity difference in the core geometry for computational modeling and analysis. However, to provide increased opportunity for the validation of computational models, additional bars of material placed in the flux trap would increase the effective reactivity up to a limit of 1$ insertion. For simplicity in assembly manufacture, approximately four bars of material could provide a means for additional experimental benchmark configurations, except in the case of strong neutron absorbers and many materials providing positive reactivity. Future tasks include the cost analysis and development of the experimental assemblies, including means for the characterization of the neutron flux and spectral indices. Oscillation techniques may also serve to provide additional means for experimentation and validation of computational methods and acquisition of integral data for improving neutron cross sections. Further assessment of oscillation

  3. Preliminary Assessment of ATR-C Capabilities to Provide Integral Benchmark Data for Key Structural/Matrix Materials that May be Used for Nuclear Data Testing and Analytical Methods Validation

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess

    2009-07-01

    The purpose of this document is to identify some suggested types of experiments that can be performed in the Advanced Test Reactor Critical (ATR-C) facility. A fundamental computational investigation is provided to demonstrate possible integration of experimental activities in the ATR-C with the development of benchmark experiments. Criticality benchmarks performed in the ATR-C could provide integral data for key matrix and structural materials used in nuclear systems. Results would then be utilized in the improvement of nuclear data libraries and as a means for analytical methods validation. It is proposed that experiments consisting of well-characterized quantities of materials be placed in the Northwest flux trap position of the ATR-C. The reactivity worth of the material could be determined and computationally analyzed through comprehensive benchmark activities including uncertainty analyses. Experiments were modeled in the available benchmark model of the ATR using MCNP5 with the ENDF/B-VII.0 cross section library. A single bar (9.5 cm long, 0.5 cm wide, and 121.92 cm high) of each material could provide sufficient reactivity difference in the core geometry for computational modeling and analysis. However, to provide increased opportunity for the validation of computational models, additional bars of material placed in the flux trap would increase the effective reactivity up to a limit of 1$ insertion. For simplicity in assembly manufacture, approximately four bars of material could provide a means for additional experimental benchmark configurations, except in the case of strong neutron absorbers and many materials providing positive reactivity. Future tasks include the cost analysis and development of the experimental assemblies, including means for the characterization of the neutron flux and spectral indices. Oscillation techniques may also serve to provide additional means for experimentation and validation of computational methods and acquisition of

  4. Selective Mutism Questionnaire: Measurement Structure and Validity

    Science.gov (United States)

    Letamendi, Andrea M.; Chavira, Denise A.; Hitchcock, Carla A.; Roesch, Scott C.; Shipon-Blum, Elisa; Stein, Murray B.

    2008-01-01

    The psychometric properties of the Selective Mutism Questionnaire (SMQ) are evaluated using a clinical sample of children with selective mutism (SM). The study shows that SMQ is useful in determining the severity of a child's nonspeaking behaviors, the scope of these behaviors and necessary follow up assessment.

  5. Construct validity and factor structure of the pittsburgh sleep quality index and epworth sleepiness scale in a multi-national study of African, South East Asian and South American college students.

    Directory of Open Access Journals (Sweden)

    Bizu Gelaye

    Full Text Available The Pittsburgh Sleep Quality Index (PSQI and the Epworth Sleepiness Scale (ESS are questionnaires used to assess sleep quality and excessive daytime sleepiness in clinical and population-based studies. The present study aimed to evaluate the construct validity and factor structure of the PSQI and ESS questionnaires among young adults in four countries (Chile, Ethiopia, Peru and Thailand.A cross-sectional study was conducted among 8,481 undergraduate students. Students were invited to complete a self-administered questionnaire that collected information about lifestyle, demographic, and sleep characteristics. In each country, the construct validity and factorial structures of PSQI and ESS questionnaires were tested through exploratory and confirmatory factor analyses (EFA and CFA.The largest component-total correlation coefficient for sleep quality as assessed using PSQI was noted in Chile (r = 0.71 while the smallest component-total correlation coefficient was noted for sleep medication use in Peru (r = 0.28. The largest component-total correlation coefficient for excessive daytime sleepiness as assessed using ESS was found for item 1 (sitting/reading in Chile (r = 0.65 while the lowest item-total correlation was observed for item 6 (sitting and talking to someone in Thailand (r = 0.35. Using both EFA and CFA a two-factor model was found for PSQI questionnaire in Chile, Ethiopia and Thailand while a three-factor model was found for Peru. For the ESS questionnaire, we noted two factors for all four countries.Overall, we documented cross-cultural comparability of sleep quality and excessive daytime sleepiness measures using the PSQI and ESS questionnaires among Asian, South American and African young adults. Although both the PSQI and ESS were originally developed as single-factor questionnaires, the results of our EFA and CFA revealed the multi- dimensionality of the scales suggesting limited usefulness of the global PSQI and ESS

  6. Validación estructural del Wong-Law Emotional Intelligence Scale (WLEIS: estudio preliminar en adultos / Structural validation of the Wong-Law Emotional Intelligence Scale (WLEIS: preliminary study in adults

    Directory of Open Access Journals (Sweden)

    César Merino Soto

    2016-06-01

    structure validity of the WLEIS in Peruvian adults. There were 120 participants (72 women between 17 and 59 years old who responded to the questionnaire mediated by the internet. The internal structure was analyzed using structural equations methodology. A satisfactory structure of 4 factors and high factorial loads of items was found. The inter-factorial correlations were high or moderately high – and the internal consistency was good. It is concluded that the first results are acceptable – to assume that the Wong-Law model is also apparently generalizable.

  7. Mixed DPPC/POPC Monolayers: All-atom Molecular Dynamics Simulations and Langmuir Monolayer Experiments

    Czech Academy of Sciences Publication Activity Database

    Olžyńska, Agnieszka; Zubek, M.; Roeselová, Martina; Korchowiec, J.; Cwiklik, Lukasz

    2016-01-01

    Roč. 1858, č. 12 (2016), s. 3120-3130 ISSN 0005-2736 R&D Projects: GA ČR GA15-14292S Institutional support: RVO:61388955 ; RVO:61388963 Keywords : phospholipid monolayers * Lung surfactant * molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.498, year: 2016

  8. Refined OPLS All-Atom Force Field for Saturated Phosphatidylcholine Bilayers at Full Hydration

    DEFF Research Database (Denmark)

    Maciejewski, A.; Pasenkiewicz-Gierula, M.; Cramariuc, O.

    2014-01-01

    ) density functional theory (DFT). We also tested the effect of the polar environment by using the polarizable continuum model (PCM), and for acyl chains the van der Waals parameters were also adjusted. In effect, six parameter sets were generated and tested on a DPPC bilayer. Out of these six sets, only...... one was found to be able to satisfactorily reproduce experimental data for the lipid bilayer. The successful DPPC model was obtained from MP2 calculations in an implicit polar environment (PCM)....

  9. Reparameterization of all-atom dipalmitoylphosphatidylcholine lipid parameters enables simulation of fluid bilayers at zero tension

    DEFF Research Database (Denmark)

    Sonne, Jacob; Jensen, M.Ø.; Hansen, Flemming Yssing

    2007-01-01

    lipid of 60.4 ± 0.1 Å2. Compared to the 48 Å2, the new value of 60.4 Å2 is in fair agreement with the experimental value of 64 Å2. In addition, the simulated order parameter profile and electron density profile are in satisfactory agreement with experimental data. Thus, the biologically more interesting...

  10. Principles of Proper Validation

    DEFF Research Database (Denmark)

    Esbensen, Kim; Geladi, Paul

    2010-01-01

    Validation in chemometrics is presented using the exemplar context of multivariate calibration/prediction. A phenomenological analysis of common validation practices in data analysis and chemometrics leads to formulation of a set of generic Principles of Proper Validation (PPV), which is based...

  11. A critical comparison of coarse-grained structure-based approaches and atomic models of protein folding.

    Science.gov (United States)

    Hu, Jie; Chen, Tao; Wang, Moye; Chan, Hue Sun; Zhang, Zhuqing

    2017-05-31

    Structure-based coarse-grained Gō-like models have been used extensively in deciphering protein folding mechanisms because of their simplicity and tractability. Meanwhile, explicit-solvent molecular dynamics (MD) simulations with physics-based all-atom force fields have been applied successfully to simulate folding/unfolding transitions for several small, fast-folding proteins. To explore the degree to which coarse-grained Gō-like models and their extensions to incorporate nonnative interactions are capable of producing folding processes similar to those in all-atom MD simulations, here we systematically compare the computed unfolded states, transition states, and transition paths obtained using coarse-grained models and all-atom explicit-solvent MD simulations. The conformations in the unfolded state in common Gō models are more extended, and are thus more in line with experiment, than those from all-atom MD simulations. Nevertheless, the structural features of transition states obtained by the two types of models are largely similar. In contrast, the folding transition paths are significantly more sensitive to modeling details. In particular, when common Gō-like models are augmented with nonnative interactions, the predicted dimensions of the unfolded conformations become similar to those computed using all-atom MD. With this connection, the large deviations of all-atom MD from simple diffusion theory are likely caused in part by the presence of significant nonnative effects in folding processes modelled by current atomic force fields. The ramifications of our findings to the application of coarse-grained modeling to more complex biomolecular systems are discussed.

  12. Validity in qualitative research.

    Science.gov (United States)

    Whittemore, R; Chase, S K; Mandle, C L

    2001-07-01

    Much contemporary dialogue has centered on the difficulty of establishing validity criteria in qualitative research. Developing validity standards in qualitative research is challenging because of the necessity to incorporate rigor and subjectivity as well as creativity into the scientific process. This article explores the extant issues related to the science and art of qualitative research and proposes a synthesis of contemporary viewpoints. A distinction between primary and secondary validity criteria in qualitative research is made with credibility, authenticity, criticality, and integrity identified as primary validity criteria and explicitness, vividness, creativity, thoroughness, congruence, and sensitivity identified as secondary validity criteria.

  13. New Force Field Model for Propylene Glycol: Insight to Local Structure and Dynamics.

    Science.gov (United States)

    Ferreira, Elisabete S C; Voroshylova, Iuliia V; Koverga, Volodymyr A; Pereira, Carlos M; Cordeiro, M Natália D S

    2017-12-07

    In this work we developed a new force field model (FFM) for propylene glycol (PG) based on the OPLS all-atom potential. The OPLS potential was refined using quantum chemical calculations, taking into account the densities and self-diffusion coefficients. The validation of this new FFM was carried out based on a wide range of physicochemical properties, such as density, enthalpy of vaporization, self-diffusion coefficients, isothermal compressibility, surface tension, and shear viscosity. The molecular dynamics (MD) simulations were performed over a large range of temperatures (293.15-373.15 K). The comparison with other force field models, such as OPLS, CHARMM27, and GAFF, revealed a large improvement of the results, allowing a better agreement with experimental data. Specific structural properties (radial distribution functions, hydrogen bonding and spatial distribution functions) were then analyzed in order to support the adequacy of the proposed FFM. Pure propylene glycol forms a continuous phase, displaying no microstructures. It is shown that the developed FFM gives rise to suitable results not only for pure propylene glycol but also for mixtures by testing its behavior for a 50 mol % aqueous propylene glycol solution. Furthermore, it is demonstrated that the addition of water to the PG phase produces a homogeneous solution and that the hydration interactions prevail over the propylene glycol self-association interactions.

  14. Novel computational methodologies for structural modeling of spacious ligand binding sites of G-protein-coupled receptors: development and application to human leukotriene B4 receptor.

    Science.gov (United States)

    Ishino, Yoko; Harada, Takanori

    2012-01-01

    This paper describes a novel method to predict the activated structures of G-protein-coupled receptors (GPCRs) with high accuracy, while aiming for the use of the predicted 3D structures in in silico virtual screening in the future. We propose a new method for modeling GPCR thermal fluctuations, where conformation changes of the proteins are modeled by combining fluctuations on multiple time scales. The core idea of the method is that a molecular dynamics simulation is used to calculate average 3D coordinates of all atoms of a GPCR protein against heat fluctuation on the picosecond or nanosecond time scale, and then evolutionary computation including receptor-ligand docking simulations functions to determine the rotation angle of each helix of a GPCR protein as a movement on a longer time scale. The method was validated using human leukotriene B4 receptor BLT1 as a sample GPCR. Our study demonstrated that the proposed method was able to derive the appropriate 3D structure of the active-state GPCR which docks with its agonists.

  15. Novel Computational Methodologies for Structural Modeling of Spacious Ligand Binding Sites of G-Protein-Coupled Receptors: Development and Application to Human Leukotriene B4 Receptor

    Directory of Open Access Journals (Sweden)

    Yoko Ishino

    2012-01-01

    Full Text Available This paper describes a novel method to predict the activated structures of G-protein-coupled receptors (GPCRs with high accuracy, while aiming for the use of the predicted 3D structures in in silico virtual screening in the future. We propose a new method for modeling GPCR thermal fluctuations, where conformation changes of the proteins are modeled by combining fluctuations on multiple time scales. The core idea of the method is that a molecular dynamics simulation is used to calculate average 3D coordinates of all atoms of a GPCR protein against heat fluctuation on the picosecond or nanosecond time scale, and then evolutionary computation including receptor-ligand docking simulations functions to determine the rotation angle of each helix of a GPCR protein as a movement on a longer time scale. The method was validated using human leukotriene B4 receptor BLT1 as a sample GPCR. Our study demonstrated that the proposed method was able to derive the appropriate 3D structure of the active-state GPCR which docks with its agonists.

  16. Self-Assembly of Nanocomponents into Composite Structures: Derivation and Simulation of Langevin Equations

    OpenAIRE

    Pankavich, Stephen; Shreif, Zeina; Miao, Yinglong; Ortoleva, Peter

    2010-01-01

    The kinetics of the self-assembly of nanocomponents into a virus, nanocapsule, or other composite structure is analyzed via a multiscale approach. The objective is to achieve predictability and to preserve key atomic-scale features that underlie the formation and stability of the composite structures. We start with an all-atom description, the Liouville equation, and the order parameters characterizing nanoscale features of the system. An equation of Smoluchowski type for the stochastic dynam...

  17. Robust Object Tracking Using Valid Fragments Selection.

    Science.gov (United States)

    Zheng, Jin; Li, Bo; Tian, Peng; Luo, Gang

    Local features are widely used in visual tracking to improve robustness in cases of partial occlusion, deformation and rotation. This paper proposes a local fragment-based object tracking algorithm. Unlike many existing fragment-based algorithms that allocate the weights to each fragment, this method firstly defines discrimination and uniqueness for local fragment, and builds an automatic pre-selection of useful fragments for tracking. Then, a Harris-SIFT filter is used to choose the current valid fragments, excluding occluded or highly deformed fragments. Based on those valid fragments, fragment-based color histogram provides a structured and effective description for the object. Finally, the object is tracked using a valid fragment template combining the displacement constraint and similarity of each valid fragment. The object template is updated by fusing feature similarity and valid fragments, which is scale-adaptive and robust to partial occlusion. The experimental results show that the proposed algorithm is accurate and robust in challenging scenarios.

  18. Atomic Reference Data for Electronic Structure Calculations

    CERN Document Server

    Kotochigova, S; Shirley, E L

    We have generated data for atomic electronic structure calculations, to provide a standard reference for results of specified accuracy under commonly used approximations. Results are presented here for total energies and orbital energy eigenvalues for all atoms from H to U, at microHartree accuracy in the total energy, as computed in the local-density approximation (LDA) the local-spin-density approximation (LSD); the relativistic local-density approximation (RLDA); and scalar-relativistic local-density approximation (ScRLDA).

  19. Validation of simulation models

    DEFF Research Database (Denmark)

    Rehman, Muniza; Pedersen, Stig Andur

    2012-01-01

    In philosophy of science, the interest for computational models and simulations has increased heavily during the past decades. Different positions regarding the validity of models have emerged but the views have not succeeded in capturing the diversity of validation methods. The wide variety...

  20. An SAT® Validity Primer

    Science.gov (United States)

    Shaw, Emily J.

    2015-01-01

    This primer should provide the reader with a deeper understanding of the concept of test validity and will present the recent available validity evidence on the relationship between SAT® scores and important college outcomes. In addition, the content examined on the SAT will be discussed as well as the fundamental attention paid to the fairness of…

  1. Model Validation Status Review

    International Nuclear Information System (INIS)

    E.L. Hardin

    2001-01-01

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M and O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  2. Model Validation Status Review

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2001-11-28

    The primary objective for the Model Validation Status Review was to perform a one-time evaluation of model validation associated with the analysis/model reports (AMRs) containing model input to total-system performance assessment (TSPA) for the Yucca Mountain site recommendation (SR). This review was performed in response to Corrective Action Request BSC-01-C-01 (Clark 2001, Krisha 2001) pursuant to Quality Assurance review findings of an adverse trend in model validation deficiency. The review findings in this report provide the following information which defines the extent of model validation deficiency and the corrective action needed: (1) AMRs that contain or support models are identified, and conversely, for each model the supporting documentation is identified. (2) The use for each model is determined based on whether the output is used directly for TSPA-SR, or for screening (exclusion) of features, events, and processes (FEPs), and the nature of the model output. (3) Two approaches are used to evaluate the extent to which the validation for each model is compliant with AP-3.10Q (Analyses and Models). The approaches differ in regard to whether model validation is achieved within individual AMRs as originally intended, or whether model validation could be readily achieved by incorporating information from other sources. (4) Recommendations are presented for changes to the AMRs, and additional model development activities or data collection, that will remedy model validation review findings, in support of licensing activities. The Model Validation Status Review emphasized those AMRs that support TSPA-SR (CRWMS M&O 2000bl and 2000bm). A series of workshops and teleconferences was held to discuss and integrate the review findings. The review encompassed 125 AMRs (Table 1) plus certain other supporting documents and data needed to assess model validity. The AMRs were grouped in 21 model areas representing the modeling of processes affecting the natural and

  3. Validity in Qualitative Evaluation

    Directory of Open Access Journals (Sweden)

    Vasco Lub

    2015-12-01

    Full Text Available This article provides a discussion on the question of validity in qualitative evaluation. Although validity in qualitative inquiry has been widely reflected upon in the methodological literature (and is still often subject of debate, the link with evaluation research is underexplored. Elaborating on epistemological and theoretical conceptualizations by Guba and Lincoln and Creswell and Miller, the article explores aspects of validity of qualitative research with the explicit objective of connecting them with aspects of evaluation in social policy. It argues that different purposes of qualitative evaluations can be linked with different scientific paradigms and perspectives, thus transcending unproductive paradigmatic divisions as well as providing a flexible yet rigorous validity framework for researchers and reviewers of qualitative evaluations.

  4. Verification and validation benchmarks.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-02-01

    Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of

  5. Cross validation in LULOO

    DEFF Research Database (Denmark)

    Sørensen, Paul Haase; Nørgård, Peter Magnus; Hansen, Lars Kai

    1996-01-01

    The leave-one-out cross-validation scheme for generalization assessment of neural network models is computationally expensive due to replicated training sessions. Linear unlearning of examples has recently been suggested as an approach to approximative cross-validation. Here we briefly review the...... the linear unlearning scheme, dubbed LULOO, and we illustrate it on a systemidentification example. Further, we address the possibility of extracting confidence information (error bars) from the LULOO ensemble....

  6. Verification and validation benchmarks

    International Nuclear Information System (INIS)

    Oberkampf, William L.; Trucano, Timothy G.

    2008-01-01

    Verification and validation (V and V) are the primary means to assess the accuracy and reliability of computational simulations. V and V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V and V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the

  7. HEDR model validation plan

    International Nuclear Information System (INIS)

    Napier, B.A.; Gilbert, R.O.; Simpson, J.C.; Ramsdell, J.V. Jr.; Thiede, M.E.; Walters, W.H.

    1993-06-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computational ''tools'' for estimating the possible radiation dose that individuals may have received from past Hanford Site operations. This document describes the planned activities to ''validate'' these tools. In the sense of the HEDR Project, ''validation'' is a process carried out by comparing computational model predictions with field observations and experimental measurements that are independent of those used to develop the model

  8. Worldwide Protein Data Bank validation information: usage and trends.

    Science.gov (United States)

    Smart, Oliver S; Horský, Vladimír; Gore, Swanand; Svobodová Vařeková, Radka; Bendová, Veronika; Kleywegt, Gerard J; Velankar, Sameer

    2018-03-01

    Realising the importance of assessing the quality of the biomolecular structures deposited in the Protein Data Bank (PDB), the Worldwide Protein Data Bank (wwPDB) partners established Validation Task Forces to obtain advice on the methods and standards to be used to validate structures determined by X-ray crystallography, nuclear magnetic resonance spectroscopy and three-dimensional electron cryo-microscopy. The resulting wwPDB validation pipeline is an integral part of the wwPDB OneDep deposition, biocuration and validation system. The wwPDB Validation Service webserver (https://validate.wwpdb.org) can be used to perform checks prior to deposition. Here, it is shown how validation metrics can be combined to produce an overall score that allows the ranking of macromolecular structures and domains in search results. The ValTrends DB database provides users with a convenient way to access and analyse validation information and other properties of X-ray crystal structures in the PDB, including investigating trends in and correlations between different structure properties and validation metrics.

  9. Validation tools for image segmentation

    Science.gov (United States)

    Padfield, Dirk; Ross, James

    2009-02-01

    A large variety of image analysis tasks require the segmentation of various regions in an image. For example, segmentation is required to generate accurate models of brain pathology that are important components of modern diagnosis and therapy. While the manual delineation of such structures gives accurate information, the automatic segmentation of regions such as the brain and tumors from such images greatly enhances the speed and repeatability of quantifying such structures. The ubiquitous need for such algorithms has lead to a wide range of image segmentation algorithms with various assumptions, parameters, and robustness. The evaluation of such algorithms is an important step in determining their effectiveness. Therefore, rather than developing new segmentation algorithms, we here describe validation methods for segmentation algorithms. Using similarity metrics comparing the automatic to manual segmentations, we demonstrate methods for optimizing the parameter settings for individual cases and across a collection of datasets using the Design of Experiment framework. We then employ statistical analysis methods to compare the effectiveness of various algorithms. We investigate several region-growing algorithms from the Insight Toolkit and compare their accuracy to that of a separate statistical segmentation algorithm. The segmentation algorithms are used with their optimized parameters to automatically segment the brain and tumor regions in MRI images of 10 patients. The validation tools indicate that none of the ITK algorithms studied are able to outperform with statistical significance the statistical segmentation algorithm although they perform reasonably well considering their simplicity.

  10. Validity and reliability of the Structured Clinical Interview for Mood Spectrum: Brazilian version (SCIMOODS-VB Validade e confiabilidade da versão brasileira da Entrevista Clínica Estruturada para o Espectro do Humor (SCIMOODS-VB

    Directory of Open Access Journals (Sweden)

    Roberto Ratzke

    2011-03-01

    Full Text Available OBJECTIVE: The aim of this study was to translate the Structured Clinical Interview for Mood Spectrum into Brazilian Portuguese, measuring its reliability, validity, and defining scores for bipolar disorders. METHOD: Questionnaire was translated (into Brazilian Portuguese and back-translated into English. Sample consisted of 47 subjects with bipolar disorder, 47 with major depressive disorder, 18 with schizophrenia and 22 controls. Inter-rater reliability was tested in 20 subjects with bipolar disorder and MDD. Internal consistency was measured using the Kuder Richardson formula. Forward stepwise discriminant analysis was performed. Scores were compared between groups; manic (M, depressive (D and total (T threshold scores were calculated through receiver operating characteristic (ROC curves. RESULTS: Kuder Richardson coefficients were between 0.86 and 0.94. Intraclass correlation coefficient was 0.96 (CI 95 % 0.93-0.97. Subjects with bipolar disorder had higher M and T, and similar D scores, when compared to major depressive disorder (ANOVA, p OBJETIVO: Traduzir e validar para o português a Entrevista Clínica Estruturada para Distúrbios do Humor, mensurando sua validade, confiabilidade, bem como definindo os escores para transtornos bipolares. MÉTODO: A entrevista foi traduzida (para o português e novamente traduzida para o inglês. A amostra incluiu 47 indivíduos com transtornos bipolares, 47 com transtorno depressivo maior, 18 com esquizofrenia e 22 controles. A confiabilidade entre avaliadores foi testada em 20 indivíduos com transtornos bipolares e transtorno depressivo maior. A consistência interna foi mensurada por meio da fórmula de Kuder Richardson. Análise discriminante foi realizada. Escores dos diversos grupos foram comparados; limiares para mania (M, depressão (D e valores totais foram calculados usando curvas de "receiver operating characteristic" (ROC. RESULTADOS: Coeficientes de Kuder Richardson ficaram entre 0,86 e 0

  11. Crystal structure of Ca12Al14O32Cl2 and luminescence properties of Ca12Al14O32Cl2:Eu2+

    International Nuclear Information System (INIS)

    Iwata, Tomoyuki; Haniuda, Masahide; Fukuda, Koichiro

    2008-01-01

    The crystal structure of Ca 12 Al 14 O 32 Cl 2 was determined from laboratory X-ray powder diffraction data (CuKα 1 ) using the Rietveld method, with the anisotropic displacement parameters being assigned for all atoms. The crystal structure is cubic (space group I4-bar 3d, Z=2) with lattice dimensions a=1.200950(5) nm and V=1.73211(1) nm 3 . The reliability indices calculated from the Rietveld method were R wp =8.48% (S=1.21), R p =6.05%, R B =1.27% and R F =1.01%. The validity of the structural model was verified by the three-dimensional electron density distribution, the structural bias of which was reduced as much as possible using the maximum-entropy methods-based pattern fitting (MPF). The reliability indices calculated from the MPF were R B =0.75% and R F =0.56%. In the structural model there are one Ca site, two Al sites, two O sites and one Cl site. This compound is isomorphous with Ca 12 Al 10.6 Si 3.4 O 32 Cl 5.4 . Europium-doped sample Ca 12 Al 14 O 32 Cl 2 :Eu 2+ was prepared and the photoluminescence properties were presented. The excitation spectrum consisted of two wide bands, which were located at about 268 and 324 nm. The emission spectrum, when excited at 324 nm, resulted in indigo light with a peak at about 442 nm. - Graphical abstract: A portion of the crystal structure of Ca 12 Al 14 O 32 Cl 2 showing eight-membered AlO 4 rings and Ca-Cl-Ca unit

  12. Containment Code Validation Matrix

    International Nuclear Information System (INIS)

    Chin, Yu-Shan; Mathew, P.M.; Glowa, Glenn; Dickson, Ray; Liang, Zhe; Leitch, Brian; Barber, Duncan; Vasic, Aleks; Bentaib, Ahmed; Journeau, Christophe; Malet, Jeanne; Studer, Etienne; Meynet, Nicolas; Piluso, Pascal; Gelain, Thomas; Michielsen, Nathalie; Peillon, Samuel; Porcheron, Emmanuel; Albiol, Thierry; Clement, Bernard; Sonnenkalb, Martin; Klein-Hessling, Walter; Arndt, Siegfried; Weber, Gunter; Yanez, Jorge; Kotchourko, Alexei; Kuznetsov, Mike; Sangiorgi, Marco; Fontanet, Joan; Herranz, Luis; Garcia De La Rua, Carmen; Santiago, Aleza Enciso; Andreani, Michele; Paladino, Domenico; Dreier, Joerg; Lee, Richard; Amri, Abdallah

    2014-01-01

    The Committee on the Safety of Nuclear Installations (CSNI) formed the CCVM (Containment Code Validation Matrix) task group in 2002. The objective of this group was to define a basic set of available experiments for code validation, covering the range of containment (ex-vessel) phenomena expected in the course of light and heavy water reactor design basis accidents and beyond design basis accidents/severe accidents. It was to consider phenomena relevant to pressurised heavy water reactor (PHWR), pressurised water reactor (PWR) and boiling water reactor (BWR) designs of Western origin as well as of Eastern European VVER types. This work would complement the two existing CSNI validation matrices for thermal hydraulic code validation (NEA/CSNI/R(1993)14) and In-vessel core degradation (NEA/CSNI/R(2001)21). The report initially provides a brief overview of the main features of a PWR, BWR, CANDU and VVER reactors. It also provides an overview of the ex-vessel corium retention (core catcher). It then provides a general overview of the accident progression for light water and heavy water reactors. The main focus is to capture most of the phenomena and safety systems employed in these reactor types and to highlight the differences. This CCVM contains a description of 127 phenomena, broken down into 6 categories: - Containment Thermal-hydraulics Phenomena; - Hydrogen Behaviour (Combustion, Mitigation and Generation) Phenomena; - Aerosol and Fission Product Behaviour Phenomena; - Iodine Chemistry Phenomena; - Core Melt Distribution and Behaviour in Containment Phenomena; - Systems Phenomena. A synopsis is provided for each phenomenon, including a description, references for further information, significance for DBA and SA/BDBA and a list of experiments that may be used for code validation. The report identified 213 experiments, broken down into the same six categories (as done for the phenomena). An experiment synopsis is provided for each test. Along with a test description

  13. Validation of Serious Games

    Directory of Open Access Journals (Sweden)

    Katinka van der Kooij

    2015-09-01

    Full Text Available The application of games for behavioral change has seen a surge in popularity but evidence on the efficacy of these games is contradictory. Anecdotal findings seem to confirm their motivational value whereas most quantitative findings from randomized controlled trials (RCT are negative or difficult to interpret. One cause for the contradictory evidence could be that the standard RCT validation methods are not sensitive to serious games’ effects. To be able to adapt validation methods to the properties of serious games we need a framework that can connect properties of serious game design to the factors that influence the quality of quantitative research outcomes. The Persuasive Game Design model [1] is particularly suitable for this aim as it encompasses the full circle from game design to behavioral change effects on the user. We therefore use this model to connect game design features, such as the gamification method and the intended transfer effect, to factors that determine the conclusion validity of an RCT. In this paper we will apply this model to develop guidelines for setting up validation methods for serious games. This way, we offer game designers and researchers handles on how to develop tailor-made validation methods.

  14. Validation of the regional authority index

    NARCIS (Netherlands)

    Schakel, A.H.

    2008-01-01

    This article validates the Regional Authority Index (RAI) with seven widely used decentralization indices in the literature. A principal axis analysis reveals a common structure. The major source of disagreement between the RAI and the other indices stems from the fact that the RAI does not include

  15. Validation of the organizational culture assessment instrument.

    Directory of Open Access Journals (Sweden)

    Brody Heritage

    Full Text Available Organizational culture is a commonly studied area in industrial/organizational psychology due to its important role in workplace behaviour, cognitions, and outcomes. Jung et al.'s [1] review of the psychometric properties of organizational culture measurement instruments noted many instruments have limited validation data despite frequent use in both theoretical and applied situations. The Organizational Culture Assessment Instrument (OCAI has had conflicting data regarding its psychometric properties, particularly regarding its factor structure. Our study examined the factor structure and criterion validity of the OCAI using robust analysis methods on data gathered from 328 (females = 226, males = 102 Australian employees. Confirmatory factor analysis supported a four factor structure of the OCAI for both ideal and current organizational culture perspectives. Current organizational culture data demonstrated expected reciprocally-opposed relationships between three of the four OCAI factors and the outcome variable of job satisfaction but ideal culture data did not, thus indicating possible weak criterion validity when the OCAI is used to assess ideal culture. Based on the mixed evidence regarding the measure's properties, further examination of the factor structure and broad validity of the measure is encouraged.

  16. Validation of the Organizational Culture Assessment Instrument

    Science.gov (United States)

    Heritage, Brody; Pollock, Clare; Roberts, Lynne

    2014-01-01

    Organizational culture is a commonly studied area in industrial/organizational psychology due to its important role in workplace behaviour, cognitions, and outcomes. Jung et al.'s [1] review of the psychometric properties of organizational culture measurement instruments noted many instruments have limited validation data despite frequent use in b