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Sample records for relationship qspr models

  1. A modified scaled variable reduced coordinate (SVRC)-quantitative structure property relationship (QSPR) model for predicting liquid viscosity of pure organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seongmin; Park, Kiho; Yang, Dae Ryook [Korea University, Seoul (Korea, Republic of); Kwon, Yunkyung; Park, Taeyun [ChemEssen Inc., Seoul (Korea, Republic of)

    2017-10-15

    Liquid viscosity is an important physical property utilized in engineering designs for transportation and processing of fluids. However, the measurement of liquid viscosity is not always easy when the materials have toxicity and instability. In this study, a modified scaled variable reduced coordinate (SVRC)-quantitative structure property relationship (QSPR) model is suggested and analyzed in terms of its performance of prediction for liquid viscosity compared to the conventional SVRC-QSPR model and the other methods. The modification was conducted by changing the initial point from triple point to ambient temperature (293 K), and assuming that the liquid viscosity at critical temperature is 0 cP. The results reveal that the prediction performance of the modified SVRC-QSPR model is comparable to the other methods as showing 7.90% of mean absolute percentage error (MAPE) and 0.9838 of R{sup 2}. In terms of both the number of components and the performance of prediction, the modified SVRC-QSPR model is superior to the conventional SVRC-QSPR model. Also, the applicability of the model is improved since the condition of the end points of the modified model is not so restrictive as the conventional SVRC-QSPR model.

  2. A modified scaled variable reduced coordinate (SVRC)-quantitative structure property relationship (QSPR) model for predicting liquid viscosity of pure organic compounds

    International Nuclear Information System (INIS)

    Lee, Seongmin; Park, Kiho; Yang, Dae Ryook; Kwon, Yunkyung; Park, Taeyun

    2017-01-01

    Liquid viscosity is an important physical property utilized in engineering designs for transportation and processing of fluids. However, the measurement of liquid viscosity is not always easy when the materials have toxicity and instability. In this study, a modified scaled variable reduced coordinate (SVRC)-quantitative structure property relationship (QSPR) model is suggested and analyzed in terms of its performance of prediction for liquid viscosity compared to the conventional SVRC-QSPR model and the other methods. The modification was conducted by changing the initial point from triple point to ambient temperature (293 K), and assuming that the liquid viscosity at critical temperature is 0 cP. The results reveal that the prediction performance of the modified SVRC-QSPR model is comparable to the other methods as showing 7.90% of mean absolute percentage error (MAPE) and 0.9838 of R 2 . In terms of both the number of components and the performance of prediction, the modified SVRC-QSPR model is superior to the conventional SVRC-QSPR model. Also, the applicability of the model is improved since the condition of the end points of the modified model is not so restrictive as the conventional SVRC-QSPR model.

  3. Notes on quantitative structure-properties relationships (QSPR) (1): A discussion on a QSPR dimensionality paradox (QSPR DP) and its quantum resolution.

    Science.gov (United States)

    Carbó-Dorca, Ramon; Gallegos, Ana; Sánchez, Angel J

    2009-05-01

    Classical quantitative structure-properties relationship (QSPR) statistical techniques unavoidably present an inherent paradoxical computational context. They rely on the definition of a Gram matrix in descriptor spaces, which is used afterwards to reduce the original dimension via several possible kinds of algebraic manipulations. From there, effective models for the computation of unknown properties of known molecular structures are obtained. However, the reduced descriptor dimension causes linear dependence within the set of discrete vector molecular representations, leading to positive semi-definite Gram matrices in molecular spaces. To resolve this QSPR dimensionality paradox (QSPR DP) here is proposed to adopt as starting point the quantum QSPR (QQSPR) computational framework perspective, where density functions act as infinite dimensional descriptors. The fundamental QQSPR equation, deduced from employing quantum expectation value numerical evaluation, can be approximately solved in order to obtain models exempt of the QSPR DP. The substitution of the quantum similarity matrix by an empirical Gram matrix in molecular spaces, build up with the original non manipulated discrete molecular descriptor vectors, permits to obtain classical QSPR models with the same characteristics as in QQSPR, that is: possessing a certain degree of causality and explicitly independent of the descriptor dimension. 2008 Wiley Periodicals, Inc.

  4. Heterogeneous fenton degradation of azo dyes catalyzed by modified polyacrylonitrile fiber fe complexes: QSPR (quantitative structure peorperty relationship) study.

    Science.gov (United States)

    Li, Bing; Dong, Yongchun; Ding, Zhizhong

    2013-07-01

    The amidoximated polyacrylonitrile (PAN) fiber Fe complexes were prepared and used as the heterogeneous Fenton catalysts for the degradation of 28 anionic water soluble azo dyes in water under visible irradiation. The multiple linear regression (MLR) method was employed to develop the quantitative structure property relationship (QSPR) model equations for the decoloration and mineralization of azo dyes. Moreover, the predictive ability of the QSPR model equations was assessed using Leave-one-out (LOO) and cross-validation (CV) methods. Additionally, the effect of Fe content of catalyst and the sodium chloride in water on QSPR model equations were also investigated. The results indicated that the heterogeneous photo-Fenton degradation of the azo dyes with different structures was conducted in the presence of the amidoximated PAN fiber Fe complex. The QSPR model equations for the dye decoloration and mineralization were successfully developed using MLR technique. MW/S (molecular weight divided by the number of sulphonate groups) and NN=N (the number of azo linkage) are considered as the most important determining factor for the dye degradation and mineralization, and there is a significant negative correlation between MW/S or NN=N and degradation percentage or total organic carbon (TOC) removal. Moreover, LOO and CV analysis suggested that the obtained QSPR model equations have the better prediction ability. The variation in Fe content of catalyst and the addition of sodium chloride did not alter the nature of the QSPR model equations.

  5. Three-dimensional quantitative structure-property relationship (3D-QSPR) models for prediction of thermodynamic properties of polychlorinated biphenyls (PCBs): enthalpy of vaporization.

    Science.gov (United States)

    Puri, Swati; Chickos, James S; Welsh, William J

    2002-01-01

    Three-dimensional Quantitative Structure-Property Relationship (QSPR) models have been derived using Comparative Molecular Field Analysis (CoMFA) to correlate the vaporization enthalpies of a representative set of polychlorinated biphenyls (PCBs) at 298.15 K with their CoMFA-calculated physicochemical properties. Various alignment schemes, such as inertial, as is, and atom fit, were employed in this study. The CoMFA models were also developed using different partial charge formalisms, namely, electrostatic potential (ESP) charges and Gasteiger-Marsili (GM) charges. The most predictive model for vaporization enthalpy (Delta(vap)H(m)(298.15 K)), with atom fit alignment and Gasteiger-Marsili charges, yielded r2 values 0.852 (cross-validated) and 0.996 (conventional). The vaporization enthalpies of PCBs increased with the number of chlorine atoms and were found to be larger for the meta- and para-substituted isomers. This model was used to predict Delta(vap)H(m)(298.15 K) of the entire set of 209 PCB congeners.

  6. QSPR models based on molecular mechanics and quantum chemical calculations. 2. Thermodynamic properties of alkanes, alcohols, polyols, and ethers

    DEFF Research Database (Denmark)

    Dyekjær, Jane Dannow; Jonsdottir, Svava Osk

    2003-01-01

    Quantitative Structure-Property Relationship (QSPR) models for prediction of various thermodynamic properties of simple organic compounds have been developed. A number of new descriptors are proposed and used alongside with descriptors available within the Codessa program. An important feature...... for alkanes, alcohols, diols, ethers, and oxyalcohols, including cyclic alkanes and alcohols. Several good models, having good predictability, have been developed. To enhance the applicability of the QSPR models, simpler expressions for each descriptor have also been developed. This allows for the prediction...

  7. Quantitative Structure–Property Relationship (QSPR Models for a Local Quantum Descriptor: Investigation of the 4- and 3-Substituted-Cinnamic Acid Esterification

    Directory of Open Access Journals (Sweden)

    Cláudio E. Rodrigues-Santos

    2015-09-01

    Full Text Available In this work, the theoretical description of the 4- and 3-substituted-cinnamic acid esterification with different electron donating and electron withdrawing groups was performed at the B3LYP and M06-2X levels, as a two-step process: the O-protonation and the nucleophile attack by ethanol. In parallel, an experimental work devoted to the synthesis and characterization of the substituted-cinnamate esters has also been performed. In order to quantify the substituents effects, quantitative structure–property relationship (QSPR models based on the atomic charges, Fukui functions and the Frontier Effective-for-Reaction Molecular Orbitals (FERMO energies were investigated. In fact, the Fukui functions, ƒ+C and ƒ−O, indicated poor correlations for each individual step, and in contrast with the general literature, the O-protonation step is affected both by the FERMO energies and the O-charges of the carbonyl group. Since the process was shown to not be totally described by either charge- or frontier-orbitals, it is proposed to be frontier-charge-miscere controlled. Moreover, the observed trend for the experimental reaction yields suggests that the electron withdrawing groups favor the reaction and the same was observed for Step 2, which can thus be pointed out as the determining step.

  8. Geometry optimization method versus predictive ability in QSPR modeling for ionic liquids

    Science.gov (United States)

    Rybinska, Anna; Sosnowska, Anita; Barycki, Maciej; Puzyn, Tomasz

    2016-02-01

    Computational techniques, such as Quantitative Structure-Property Relationship (QSPR) modeling, are very useful in predicting physicochemical properties of various chemicals. Building QSPR models requires calculating molecular descriptors and the proper choice of the geometry optimization method, which will be dedicated to specific structure of tested compounds. Herein, we examine the influence of the ionic liquids' (ILs) geometry optimization methods on the predictive ability of QSPR models by comparing three models. The models were developed based on the same experimental data on density collected for 66 ionic liquids, but with employing molecular descriptors calculated from molecular geometries optimized at three different levels of the theory, namely: (1) semi-empirical (PM7), (2) ab initio (HF/6-311+G*) and (3) density functional theory (B3LYP/6-311+G*). The model in which the descriptors were calculated by using ab initio HF/6-311+G* method indicated the best predictivity capabilities ({{Q}}_{{EXT}}2 = 0.87). However, PM7-based model has comparable values of quality parameters ({{Q}}_{{EXT}}2 = 0.84). Obtained results indicate that semi-empirical methods (faster and less expensive regarding CPU time) can be successfully employed to geometry optimization in QSPR studies for ionic liquids.

  9. QSPR models based on molecular mechanics and quantum chemical calculations. 1. Construction of Boltzmann averaged descriptors for alkanes, alcohols, diols, ethers and cyclic compounds

    DEFF Research Database (Denmark)

    Dyekjær, Jane Dannow; Rasmussen, Kjeld; Jonsdottir, Svava Osk

    2002-01-01

    Values for nine descriptors for QSPR (quantitative structure-property relationships) modeling of physical properties of 96 alkanes, alcohols, ethers, diols, triols and cyclic alkanes and alcohols in conjunction with the program Codessa are presented. The descriptors are Boltzmann-averaged by sele......Values for nine descriptors for QSPR (quantitative structure-property relationships) modeling of physical properties of 96 alkanes, alcohols, ethers, diols, triols and cyclic alkanes and alcohols in conjunction with the program Codessa are presented. The descriptors are Boltzmann...

  10. CADASTER QSPR Models for Predictions of Melting and Boiling Points of Perfluorinated Chemicals.

    Science.gov (United States)

    Bhhatarai, Barun; Teetz, Wolfram; Liu, Tao; Öberg, Tomas; Jeliazkova, Nina; Kochev, Nikolay; Pukalov, Ognyan; Tetko, Igor V; Kovarich, Simona; Papa, Ester; Gramatica, Paola

    2011-03-14

    Quantitative structure property relationship (QSPR) studies on per- and polyfluorinated chemicals (PFCs) on melting point (MP) and boiling point (BP) are presented. The training and prediction chemicals used for developing and validating the models were selected from Syracuse PhysProp database and literatures. The available experimental data sets were split in two different ways: a) random selection on response value, and b) structural similarity verified by self-organizing-map (SOM), in order to propose reliable predictive models, developed only on the training sets and externally verified on the prediction sets. Individual linear and non-linear approaches based models developed by different CADASTER partners on 0D-2D Dragon descriptors, E-state descriptors and fragment based descriptors as well as consensus model and their predictions are presented. In addition, the predictive performance of the developed models was verified on a blind external validation set (EV-set) prepared using PERFORCE database on 15 MP and 25 BP data respectively. This database contains only long chain perfluoro-alkylated chemicals, particularly monitored by regulatory agencies like US-EPA and EU-REACH. QSPR models with internal and external validation on two different external prediction/validation sets and study of applicability-domain highlighting the robustness and high accuracy of the models are discussed. Finally, MPs for additional 303 PFCs and BPs for 271 PFCs were predicted for which experimental measurements are unknown. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. QSPR modeling of octanol/water partition coefficient for vitamins by optimal descriptors calculated with SMILES.

    Science.gov (United States)

    Toropov, A A; Toropova, A P; Raska, I

    2008-04-01

    Simplified molecular input line entry system (SMILES) has been utilized in constructing quantitative structure-property relationships (QSPR) for octanol/water partition coefficient of vitamins and organic compounds of different classes by optimal descriptors. Statistical characteristics of the best model (vitamins) are the following: n=17, R(2)=0.9841, s=0.634, F=931 (training set); n=7, R(2)=0.9928, s=0.773, F=690 (test set). Using this approach for modeling octanol/water partition coefficient for a set of organic compounds gives a model that is statistically characterized by n=69, R(2)=0.9872, s=0.156, F=5184 (training set) and n=70, R(2)=0.9841, s=0.179, F=4195 (test set).

  12. Current Mathematical Methods Used in QSAR/QSPR Studies

    Directory of Open Access Journals (Sweden)

    Peixun Liu

    2009-04-01

    Full Text Available This paper gives an overview of the mathematical methods currently used in quantitative structure-activity/property relationship (QASR/QSPR studies. Recently, the mathematical methods applied to the regression of QASR/QSPR models are developing very fast, and new methods, such as Gene Expression Programming (GEP, Project Pursuit Regression (PPR and Local Lazy Regression (LLR have appeared on the QASR/QSPR stage. At the same time, the earlier methods, including Multiple Linear Regression (MLR, Partial Least Squares (PLS, Neural Networks (NN, Support Vector Machine (SVM and so on, are being upgraded to improve their performance in QASR/QSPR studies. These new and upgraded methods and algorithms are described in detail, and their advantages and disadvantages are evaluated and discussed, to show their application potential in QASR/QSPR studies in the future.

  13. A Quantitative Structure-Property Relationship (QSPR Study of Aliphatic Alcohols by the Method of Dividing the Molecular Structure into Substructure

    Directory of Open Access Journals (Sweden)

    Bin Cheng

    2011-04-01

    Full Text Available A quantitative structure–property relationship (QSPR analysis of aliphatic alcohols is presented. Four physicochemical properties were studied: boiling point (BP, n-octanol–water partition coefficient (lg POW, water solubility (lg W and the chromatographic retention indices (RI on different polar stationary phases. In order to investigate the quantitative structure–property relationship of aliphatic alcohols, the molecular structure ROH is divided into two parts, R and OH to generate structural parameter. It was proposed that the property is affected by three main factors for aliphatic alcohols, alkyl group R, substituted group OH, and interaction between R and OH. On the basis of the polarizability effect index (PEI, previously developed by Cao, the novel molecular polarizability effect index (MPEI combined with odd-even index (OEI, the sum eigenvalues of bond-connecting matrix (SX1CH previously developed in our team, were used to predict the property of aliphatic alcohols. The sets of molecular descriptors were derived directly from the structure of the compounds based on graph theory. QSPR models were generated using only calculated descriptors and multiple linear regression techniques. These QSPR models showed high values of multiple correlation coefficient (R > 0.99 and Fisher-ratio statistics. The leave-one-out cross-validation demonstrated the final models to be statistically significant and reliable.

  14. Predictive QSPR Modelling for the Second Virial Coefficient of the Pure Organic Compounds.

    Science.gov (United States)

    Mokshyna, E; Polishchuk, P G; Nedostup, V I; Kuzmin, V E

    2015-01-01

    In this article we developed a system of the predictive models for the second virial coefficients of the pure compounds. Second virial coefficient is the property derived from the virial equation of state, and is of particular interest as it describes pair intermolecular interactions. The two-layer QSPR models were developed, which exploited the well-known physical equations and allowed us to include this information into traditional QSPR methodology. This shows some new perspectives for work with temperature-dependent properties. It was shown that 2D descriptors can be successfully used for modeling of complex thermodynamic properties like virial coefficients. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Considerations of nano-QSAR/QSPR models for nanopesticide risk assessment within the European legislative framework.

    Science.gov (United States)

    Villaverde, Juan José; Sevilla-Morán, Beatriz; López-Goti, Carmen; Alonso-Prados, José Luis; Sandín-España, Pilar

    2018-09-01

    The European market for pesticides is currently legislated through the well-developed Regulation (EC) No. 1107/2009. This regulation promotes the competitiveness of European agriculture, recognizing the necessity of safe pesticides for human and animal health and the environment to protect crops against pests, diseases and weeds. In this sense, nanotechnology can provide a tremendous opportunity to achieve a more rational use of pesticides. However, the lack of information regarding nanopesticides and their fate and behavior in the environment and their effects on human and animal health is inhibiting rapid nanopesticide incorporation into European Union agriculture. This review analyzes the recent state of knowledge on nanopesticide risk assessment, highlighting the challenges that need to be overcame to accelerate the arrival of these new tools for plant protection to European agricultural professionals. Novel nano-Quantitative Structure-Activity/Structure-Property Relationship (nano-QSAR/QSPR) tools for risk assessment are analyzed, including modeling methods and validation procedures towards the potential of these computational instruments to meet the current requirements for authorization of nanoformulations. Future trends on these issues, of pressing importance within the context of the current European pesticide legislative framework, are also discussed. Standard protocols to make high-quality and well-described datasets for the series of related but differently sized nanoparticles/nanopesticides are required. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. A primer on QSAR/QSPR modeling fundamental concepts

    CERN Document Server

    Roy, Kunal; Das, Rudra Narayan

    2015-01-01

    This brief goes back to basics and describes the Quantitative structure-activity/property relationships (QSARs/QSPRs) that represent predictive models derived from the application of statistical tools correlating biological activity (including therapeutic and toxic) and properties of chemicals (drugs/toxicants/environmental pollutants) with descriptors representative of molecular structure and/or properties. It explains how the sub-discipline of Cheminformatics is used for many applications such as risk assessment, toxicity prediction, property prediction and regulatory decisions apart from drug discovery and lead optimization. The authors also present, in basic terms, how QSARs and related chemometric tools are extensively involved in medicinal chemistry, environmental chemistry and agricultural chemistry for ranking of potential compounds and prioritizing experiments. At present, there is no standard or introductory publication available that introduces this important topic to students of chemistry and phar...

  17. QSPR models for predicting generator-column-derived octanol/water and octanol/air partition coefficients of polychlorinated biphenyls.

    Science.gov (United States)

    Yuan, Jintao; Yu, Shuling; Zhang, Ting; Yuan, Xuejie; Cao, Yunyuan; Yu, Xingchen; Yang, Xuan; Yao, Wu

    2016-06-01

    Octanol/water (K(OW)) and octanol/air (K(OA)) partition coefficients are two important physicochemical properties of organic substances. In current practice, K(OW) and K(OA) values of some polychlorinated biphenyls (PCBs) are measured using generator column method. Quantitative structure-property relationship (QSPR) models can serve as a valuable alternative method of replacing or reducing experimental steps in the determination of K(OW) and K(OA). In this paper, two different methods, i.e., multiple linear regression based on dragon descriptors and hologram quantitative structure-activity relationship, were used to predict generator-column-derived log K(OW) and log K(OA) values of PCBs. The predictive ability of the developed models was validated using a test set, and the performances of all generated models were compared with those of three previously reported models. All results indicated that the proposed models were robust and satisfactory and can thus be used as alternative models for the rapid assessment of the K(OW) and K(OA) of PCBs. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. General theory for multiple input-output perturbations in complex molecular systems. 1. Linear QSPR electronegativity models in physical, organic, and medicinal chemistry.

    Science.gov (United States)

    González-Díaz, Humberto; Arrasate, Sonia; Gómez-SanJuan, Asier; Sotomayor, Nuria; Lete, Esther; Besada-Porto, Lina; Ruso, Juan M

    2013-01-01

    In general perturbation methods starts with a known exact solution of a problem and add "small" variation terms in order to approach to a solution for a related problem without known exact solution. Perturbation theory has been widely used in almost all areas of science. Bhor's quantum model, Heisenberg's matrix mechanincs, Feyman diagrams, and Poincare's chaos model or "butterfly effect" in complex systems are examples of perturbation theories. On the other hand, the study of Quantitative Structure-Property Relationships (QSPR) in molecular complex systems is an ideal area for the application of perturbation theory. There are several problems with exact experimental solutions (new chemical reactions, physicochemical properties, drug activity and distribution, metabolic networks, etc.) in public databases like CHEMBL. However, in all these cases, we have an even larger list of related problems without known solutions. We need to know the change in all these properties after a perturbation of initial boundary conditions. It means, when we test large sets of similar, but different, compounds and/or chemical reactions under the slightly different conditions (temperature, time, solvents, enzymes, assays, protein targets, tissues, partition systems, organisms, etc.). However, to the best of our knowledge, there is no QSPR general-purpose perturbation theory to solve this problem. In this work, firstly we review general aspects and applications of both perturbation theory and QSPR models. Secondly, we formulate a general-purpose perturbation theory for multiple-boundary QSPR problems. Last, we develop three new QSPR-Perturbation theory models. The first model classify correctly >100,000 pairs of intra-molecular carbolithiations with 75-95% of Accuracy (Ac), Sensitivity (Sn), and Specificity (Sp). The model predicts probabilities of variations in the yield and enantiomeric excess of reactions due to at least one perturbation in boundary conditions (solvent, temperature

  19. Multi-target QSPR modeling for simultaneous prediction of multiple gas-phase kinetic rate constants of diverse chemicals

    Science.gov (United States)

    Basant, Nikita; Gupta, Shikha

    2018-03-01

    The reactions of molecular ozone (O3), hydroxyl (•OH) and nitrate (NO3) radicals are among the major pathways of removal of volatile organic compounds (VOCs) in the atmospheric environment. The gas-phase kinetic rate constants (kO3, kOH, kNO3) are thus, important in assessing the ultimate fate and exposure risk of atmospheric VOCs. Experimental data for rate constants are not available for many emerging VOCs and the computational methods reported so far address a single target modeling only. In this study, we have developed a multi-target (mt) QSPR model for simultaneous prediction of multiple kinetic rate constants (kO3, kOH, kNO3) of diverse organic chemicals considering an experimental data set of VOCs for which values of all the three rate constants are available. The mt-QSPR model identified and used five descriptors related to the molecular size, degree of saturation and electron density in a molecule, which were mechanistically interpretable. These descriptors successfully predicted three rate constants simultaneously. The model yielded high correlations (R2 = 0.874-0.924) between the experimental and simultaneously predicted endpoint rate constant (kO3, kOH, kNO3) values in test arrays for all the three systems. The model also passed all the stringent statistical validation tests for external predictivity. The proposed multi-target QSPR model can be successfully used for predicting reactivity of new VOCs simultaneously for their exposure risk assessment.

  20. QSPR Models for Predicting Log Pliver Values for Volatile Organic Compounds Combining Statistical Methods and Domain Knowledge

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    Mónica F. Díaz

    2012-12-01

    Full Text Available Volatile organic compounds (VOCs are contained in a variety of chemicals that can be found in household products and may have undesirable effects on health. Thereby, it is important to model blood-to-liver partition coefficients (log Pliver for VOCs in a fast and inexpensive way. In this paper, we present two new quantitative structure-property relationship (QSPR models for the prediction of log Pliver, where we also propose a hybrid approach for the selection of the descriptors. This hybrid methodology combines a machine learning method with a manual selection based on expert knowledge. This allows obtaining a set of descriptors that is interpretable in physicochemical terms. Our regression models were trained using decision trees and neural networks and validated using an external test set. Results show high prediction accuracy compared to previous log Pliver models, and the descriptor selection approach provides a means to get a small set of descriptors that is in agreement with theoretical understanding of the target property.

  1. Characterization of Mixtures. Part 2: QSPR Models for Prediction of Excess Molar Volume and Liquid Density Using Neural Networks.

    Science.gov (United States)

    Ajmani, Subhash; Rogers, Stephen C; Barley, Mark H; Burgess, Andrew N; Livingstone, David J

    2010-09-17

    In our earlier work, we have demonstrated that it is possible to characterize binary mixtures using single component descriptors by applying various mixing rules. We also showed that these methods were successful in building predictive QSPR models to study various mixture properties of interest. Here in, we developed a QSPR model of an excess thermodynamic property of binary mixtures i.e. excess molar volume (V(E) ). In the present study, we use a set of mixture descriptors which we earlier designed to specifically account for intermolecular interactions between the components of a mixture and applied successfully to the prediction of infinite-dilution activity coefficients using neural networks (part 1 of this series). We obtain a significant QSPR model for the prediction of excess molar volume (V(E) ) using consensus neural networks and five mixture descriptors. We find that hydrogen bond and thermodynamic descriptors are the most important in determining excess molar volume (V(E) ), which is in line with the theory of intermolecular forces governing excess mixture properties. The results also suggest that the mixture descriptors utilized herein may be sufficient to model a wide variety of properties of binary and possibly even more complex mixtures. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Potentialities and limits of QSPR and molecular modeling in the design of the extraction solvents used in hydrometallurgy

    International Nuclear Information System (INIS)

    Cote, G.; Chagnes, A.

    2010-01-01

    Due to new challenges, new extraction solvents based on innovative extractants are needed in hydrometallurgy for specific tasks. Thus, the aim of the present paper is to discuss the potentialities and limits of QSPR and molecular modeling for identifying new extractants. QSPR methods may have useful applications in such a complex problem as the design of ligands for metal separation. Nevertheless, the degree of reliability of the predictions is still limited and, in the present state of the art, these techniques are likely more useful for optimization within a given family of extractants than to build in silico new reagents. The molecular modeling techniques provide binding energies between target metals and given ligands, as well as optimized chemical structures of the formed complexes. Thus, in principle, the information which can be deduced from the molecular modeling computations is richer than that provided by QSPR methods. Nevertheless, an effort should be made to establish more tangible links between the calculated binding energies and the physical parameters used by the hydrometallurgists, such as the complexation constants in aqueous phase (β MAn ) or better the extraction constants (K ex ). (author)

  3. Modeling adsorption of brominated, chlorinated and mixed bromo/chloro-dibenzo-p-dioxins on C60 fullerene using Nano-QSPR

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    Piotr Urbaszek

    2017-03-01

    Full Text Available Many technological implementations in the field of nanotechnology have involved carbon nanomaterials, including fullerenes such as the buckminsterfullerene, C60. The unprecedented properties of such organic nanomaterials (in particular their large surface area gained extensive attention for their potential use as organic pollutant sorbents. Sorption interactions can be very hazardous and useful at the same time. This work investigates the influence of halogenation by bromine and/or chlorine in dibenzo-p-dioxins on their sorption ability on the C60 fullerene surface. Halogenated dibenzo-p-dioxins (PXDDs, where X = Br or Cl are ever-present in the environment and accidently produced in many technological processes in only approximately known quantities. If all combinatorial Br and/or Cl dioxin substitution possibilities are present in the environment, the experimental characterization and investigation of sorbent effectiveness is more than difficult. In this work, we have developed a quantitative structure–property relationship (QSPR model (R2 = 0.998, predicting the adsorption energy [kcal/mol] for 1,701 PXDDs adsorbed on C60 (PXDD@C60. Based on the QSPR model reported herein, we concluded that the lowest energy PXDD@C60 complexes are those that the World Health Organization (WHO considers to be less dangerous with respect to the aryl hydrocarbon receptor (AhR toxicity mechanism. Therefore, the effectiveness of fullerenes as sorbent agents may be underestimated as sorption could be less effective for toxic congeners than previously believed.

  4. Ant colony optimization as a descriptor selection in QSPR modeling: Estimation of the λmax of anthraquinones-based dyes

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    Morteza Atabati

    2016-09-01

    Full Text Available Quantitative structure–property relationship (QSPR studies based on ant colony optimization (ACO were carried out for the prediction of λmax of 9,10-anthraquinone derivatives. ACO is a meta-heuristic algorithm, which is derived from the observation of real ants and proposed to feature selection. After optimization of 3D geometry of structures by the semi-empirical quantum-chemical calculation at AM1 level, different descriptors were calculated by the HyperChem and Dragon softwares (1514 descriptors. A major problem of QSPR is the high dimensionality of the descriptor space; therefore, descriptor selection is the most important step. In this paper, an ACO algorithm was used to select the best descriptors. Then selected descriptors were applied for model development using multiple linear regression. The average absolute relative deviation and correlation coefficient for the calibration set were obtained as 3.3% and 0.9591, respectively, while the average absolute relative deviation and correlation coefficient for the prediction set were obtained as 5.0% and 0.9526, respectively. The results showed that the applied procedure is suitable for prediction of λmax of 9,10-anthraquinone derivatives.

  5. Modeling the pH and temperature dependence of aqueousphase hydroxyl radical reaction rate constants of organic micropollutants using QSPR approach.

    Science.gov (United States)

    Gupta, Shikha; Basant, Nikita

    2017-11-01

    Designing of advanced oxidation process (AOP) requires knowledge of the aqueous phase hydroxyl radical ( ● OH) reactions rate constants (k OH ), which are strictly dependent upon the pH and temperature of the medium. In this study, pH- and temperature-dependent quantitative structure-property relationship (QSPR) models based on the decision tree boost (DTB) approach were developed for the prediction of k OH of diverse organic contaminants following the OECD guidelines. Experimental datasets (n = 958) pertaining to the k OH values of aqueous phase reactions at different pH (n = 470; 1.4 × 10 6 to 3.8 × 10 10  M -1  s -1 ) and temperature (n = 171; 1.0 × 10 7 to 2.6 × 10 10  M -1  s -1 ) were considered and molecular descriptors of the compounds were derived. The Sanderson scale electronegativity, topological polar surface area, number of double bonds, and halogen atoms in the molecule, in addition to the pH and temperature, were found to be the relevant predictors. The models were validated and their external predictivity was evaluated in terms of most stringent criteria parameters derived on the test data. High values of the coefficient of determination (R 2 ) and small root mean squared error (RMSE) in respective training (> 0.972, ≤ 0.12) and test (≥ 0.936, ≤ 0.16) sets indicated high generalization and predictivity of the developed QSPR model. Other statistical parameters derived from the training and test data also supported the robustness of the models and their suitability for screening new chemicals within the defined chemical space. The developed QSPR models provide a valuable tool for predicting the ● OH reaction rate constants of emerging new water contaminants for their susceptibility to AOPs.

  6. Major Source of Error in QSPR Prediction of Intrinsic Thermodynamic Solubility of Drugs: Solid vs Nonsolid State Contributions?

    Science.gov (United States)

    Abramov, Yuriy A

    2015-06-01

    The main purpose of this study is to define the major limiting factor in the accuracy of the quantitative structure-property relationship (QSPR) models of the thermodynamic intrinsic aqueous solubility of the drug-like compounds. For doing this, the thermodynamic intrinsic aqueous solubility property was suggested to be indirectly "measured" from the contributions of solid state, ΔGfus, and nonsolid state, ΔGmix, properties, which are estimated by the corresponding QSPR models. The QSPR models of ΔGfus and ΔGmix properties were built based on a set of drug-like compounds with available accurate measurements of fusion and thermodynamic solubility properties. For consistency ΔGfus and ΔGmix models were developed using similar algorithms and descriptor sets, and validated against the similar test compounds. Analysis of the relative performances of these two QSPR models clearly demonstrates that it is the solid state contribution which is the limiting factor in the accuracy and predictive power of the QSPR models of the thermodynamic intrinsic solubility. The performed analysis outlines a necessity of development of new descriptor sets for an accurate description of the long-range order (periodicity) phenomenon in the crystalline state. The proposed approach to the analysis of limitations and suggestions for improvement of QSPR-type models may be generalized to other applications in the pharmaceutical industry.

  7. Wavelet neural network modeling in QSPR for prediction of solubility of 25 anthraquinone dyes at different temperatures and pressures in supercritical carbon dioxide.

    Science.gov (United States)

    Tabaraki, R; Khayamian, T; Ensafi, A A

    2006-09-01

    A wavelet neural network (WNN) model in quantitative structure property relationship (QSPR) was developed for predicting solubility of 25 anthraquinone dyes in supercritical carbon dioxide over a wide range of pressures (70-770 bar) and temperatures (291-423 K). A large number of descriptors were calculated with Dragon software and a subset of calculated descriptors was selected from 18 classes of Dragon descriptors with a stepwise multiple linear regression (MLR) as a feature selection technique. Six calculated and two experimental descriptors, pressure and temperature, were selected as the most feasible descriptors. The selected descriptors were used as input nodes in a wavelet neural network (WNN) model. The wavelet neural network architecture and its parameters were optimized simultaneously. The data was randomly divided to the training, prediction and validation sets. The predictive ability of the model was evaluated using validation data set. The root mean squares error (RMSE) and mean absolute errors were 0.339 and 0.221, respectively, for the validation data set. The performance of the WNN model was also compared with artificial neural network (ANN) model and the results showed the superiority of the WNN over ANN model.

  8. Highly diverse, massive organic data as explored by a composite QSPR strategy: an advanced study of boiling point.

    Science.gov (United States)

    Ivanova, A A; Ivanov, A A; Oliferenko, A A; Palyulin, V A; Zefirov, N S

    2005-06-01

    An improved strategy of quantitative structure-property relationship (QSPR) studies of diverse and inhomogeneous organic datasets has been proposed. A molecular connectivity term was successively corrected for different structural features encoded in fragmental descriptors. The so-called solvation index 1chis (a weighted Randic index) was used as a "leading" variable and standardized molecular fragments were employed as "corrective" class-specific variables. Performance of the new approach was illustrated by modelling a dataset of experimental normal boiling points of 833 organic compounds belonging to 20 structural classes. Firstly, separate QSPR models were derived for each class and for eight groups of structurally similar classes. Finally, a general model formed by combining all the classes together was derived (r2=0.957, s=12.9degreesC). The strategy outlined can find application in QSPR analyses of massive, highly diverse databases of organic compounds.

  9. WHIM-3D-QSPR APPROACH FOR PREDICTING AQUEOUS SOLUBILITY OF CHLORINATED HYDROCARBONS

    Directory of Open Access Journals (Sweden)

    Oman Zuas

    2010-06-01

    Full Text Available The weighted holistic invariant molecular-three dimensional-quantitative structure property relationship (WHIM-3D-QSPR approach has been applied to the study of the aqueous solubility (- log Sw of chlorinated hydrocarbon compounds (CHC's. The obtained QSPR model is predictive and only requires four WHIM-3D descriptors in the calculation. The correlation equation of the model that is based on a training set of 50 CHC's compound has statistical parameters: standard coefficient correlation (R2 = 0.948; cross-validated correlation coefficients (Q2 = 0.935; Standard Error of Validation (SEV = 0.35; and average absolute error (AAE = 0.31. The application of the best model to a testing set of 50 CHC's demonstrates a reliable result with good predictability. Besides, it was possible to construct new model by applying WHIM-3D-QSPR approach without require any experimental physicochemical properties in the calculation of aqueous solubility.   Keywords: WHIM-3D; QSPR; aqueous solubility; - Log Sw, chlorinated hydrocarbons, CHC's

  10. Ant colony optimization as a descriptor selection in QSPR modeling: Estimation of the λmax of anthraquinones-based dyes

    OpenAIRE

    Morteza Atabati; Kobra Zarei; Azam Borhani

    2016-01-01

    Quantitative structure–property relationship (QSPR) studies based on ant colony optimization (ACO) were carried out for the prediction of λmax of 9,10-anthraquinone derivatives. ACO is a meta-heuristic algorithm, which is derived from the observation of real ants and proposed to feature selection. After optimization of 3D geometry of structures by the semi-empirical quantum-chemical calculation at AM1 level, different descriptors were calculated by the HyperChem and Dragon softwares (1514 des...

  11. QSPR models of n-octanol/water partition coefficients and aqueous solubility of halogenated methyl-phenyl ethers by DFT method.

    Science.gov (United States)

    Zeng, Xiao-Lan; Wang, Hong-Jun; Wang, Yan

    2012-02-01

    The possible molecular geometries of 134 halogenated methyl-phenyl ethers were optimized at B3LYP/6-31G(*) level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for predicting aqueous solubility (-lgS(w,l)) and n-octanol/water partition coefficient (lgK(ow)) of halogenated methyl-phenyl ethers. The two models achieved in this work both contain three variables: energy of the lowest unoccupied molecular orbital (E(LUMO)), most positive atomic partial charge in molecule (q(+)), and quadrupole moment (Q(yy) or Q(zz)), of which R values are 0.992 and 0.970 respectively, their standard errors of estimate in modeling (SD) are 0.132 and 0.178, respectively. The results of leave-one-out (LOO) cross-validation for training set and validation with external test sets both show that the models obtained exhibited optimum stability and good predictive power. We suggests that two QSPR models derived here can be used to predict S(w,l) and K(ow) accurately for non-tested halogenated methyl-phenyl ethers congeners. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. QSPR modeling of octanol/water partition coefficient of antineoplastic agents by balance of correlations.

    Science.gov (United States)

    Toropov, Andrey A; Toropova, Alla P; Raska, Ivan; Benfenati, Emilio

    2010-04-01

    Three different splits into the subtraining set (n = 22), the set of calibration (n = 21), and the test set (n = 12) of 55 antineoplastic agents have been examined. By the correlation balance of SMILES-based optimal descriptors quite satisfactory models for the octanol/water partition coefficient have been obtained on all three splits. The correlation balance is the optimization of a one-variable model with a target function that provides both the maximal values of the correlation coefficient for the subtraining and calibration set and the minimum of the difference between the above-mentioned correlation coefficients. Thus, the calibration set is a preliminary test set. Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.

  13. Excited-state properties from ground-state DFT descriptors: A QSPR approach for dyes.

    Science.gov (United States)

    Fayet, Guillaume; Jacquemin, Denis; Wathelet, Valérie; Perpète, Eric A; Rotureau, Patricia; Adamo, Carlo

    2010-02-26

    This work presents a quantitative structure-property relationship (QSPR)-based approach allowing an accurate prediction of the excited-state properties of organic dyes (anthraquinones and azobenzenes) from ground-state molecular descriptors, obtained within the (conceptual) density functional theory (DFT) framework. The ab initio computation of the descriptors was achieved at several levels of theory, so that the influence of the basis set size as well as of the modeling of environmental effects could be statistically quantified. It turns out that, for the entire data set, a statistically-robust four-variable multiple linear regression based on PCM-PBE0/6-31G calculations delivers a R(adj)(2) of 0.93 associated to predictive errors allowing for rapid and efficient dye design. All the selected descriptors are independent of the dye's family, an advantage over previously designed QSPR schemes. On top of that, the obtained accuracy is comparable to the one of the today's reference methods while exceeding the one of hardness-based fittings. QSPR relationships specific to both families of dyes have also been built up. This work paves the way towards reliable and computationally affordable color design for organic dyes. Copyright 2009 Elsevier Inc. All rights reserved.

  14. A QSPR STUDY OF NORMAL BOILING POINT OF ORGANIC COMPOUNDS (ALIPHATIC ALKANES USING MOLECULAR DESCRIPTORS

    Directory of Open Access Journals (Sweden)

    B. Souyei

    2013-12-01

    Full Text Available A quantitative structure–property relationship (QSPR study is carried out to develop correlations that relate the molecular structures of organic compounds (Aliphatic Alkanes to their normal boiling point (NBP and two correlations were proposed for constitutionals and connectivity indices Models. The correlations are simple in application with good accuracy, which provide an easy, direct and relatively accurate way to calculate NBP. Such calculation gives us a model that gives results in remarkable correlations with the descriptors of blokes constitutionals (CON, and connectivity indices (CI (R2 = 0.950, δ = 0.766 (R2 = 0.969, δ = 0.782 respectively.

  15. QSPR study of solvent quenching of the 5D 0 → 7F 2 emission of Eu(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) 3

    Science.gov (United States)

    Mercader, Andrew G.; Duchowicz, Pablo R.; Fernández, Francisco M.; Castro, Eduardo A.; Wolcan, Ezequiel

    2008-09-01

    We performed a predictive analysis, based on quantitative structure-property relationships (QSPR), of the luminescence lifetime ( τ) of Eu(fod) 3 in different solvents. The Eu(fod) 3 luminescent properties have been helpful as replacements for radioactivity, alternatives to standard fluorescent dyes and donors in energy transfer experiments, and are gaining expanding applications in wide variety of bioanalytical assays. Our best QSPR linear model constructed from 23 molecular structures combines four molecular descriptors, selected from more than a thousand geometrical, topological, quantum-mechanical and electronic types of descriptors.

  16. QSPR Study of the Retention/release Property of Odorant Molecules in Water Using Statistical Methods

    Directory of Open Access Journals (Sweden)

    Assia Belhassan

    2017-10-01

    Full Text Available An integrated approach physicochemistry and structures property relationships has been carried out to study the odorant molecules retention/release phenomenon in the water. This study aimed to identify the molecular properties (molecular descriptors that govern this phenomenon assuming that modifying the structure leads automatically to a change in the retention/release property of odorant molecules. ACD/ChemSketch, MarvinSketch, and ChemOffice programs were used to calculate several molecular descriptors of 51 odorant molecules (15 alcohols, 11 aldehydes, 9 ketones and 16 esters. A total of 37 molecules (2/3 of the data set were placed in the training set to build the QSPR models, whereas the remaining, 14 molecules (1/3 of the data set constitute the test set. The best descriptors were selected to establish the quantitative structure property relationship (QSPR of the retention/release property of odorant molecules in water using multiple linear regression (MLR, multiple non-linear regression (MNLR and an artificial neural network (ANN methods. We propose a quantitative model according to these analyses. The models were used to predict the retention/release property of the test set compounds, and agreement between the experimental and predicted values was verified. The descriptors showed by QSPR study are used for study and designing of new compounds. The statistical results indicate that the predicted values are in good agreement with the experimental results. To validate the predictive power of the resulting models, external validation multiple correlation coefficient was calculated and has both in addition to a performant prediction power, a favorable estimation of stability. DOI: http://dx.doi.org/10.17807/orbital.v9i4.978 

  17. Application of the QSPR approach to the boiling points of azeotropes.

    Science.gov (United States)

    Katritzky, Alan R; Stoyanova-Slavova, Iva B; Tämm, Kaido; Tamm, Tarmo; Karelson, Mati

    2011-04-21

    CODESSA Pro derivative descriptors were calculated for a data set of 426 azeotropic mixtures by the centroid approximation and the weighted-contribution-factor approximation. The two approximations produced almost identical four-descriptor QSPR models relating the structural characteristic of the individual components of azeotropes to the azeotropic boiling points. These models were supported by internal and external validations. The descriptors contributing to the QSPR models are directly related to the three components of the enthalpy (heat) of vaporization.

  18. QSPR using MOLGEN-QSPR: the challenge of fluoroalkane boiling points.

    Science.gov (United States)

    Rücker, Christoph; Meringer, Markus; Kerber, Adalbert

    2005-01-01

    By means of the new software MOLGEN-QSPR, a multilinear regression model for the boiling points of lower fluoroalkanes is established. The model is based exclusively on simple descriptors derived directly from molecular structure and nevertheless describes a broader set of data more precisely than previous attempts that used either more demanding (quantum chemical) descriptors or more demanding (nonlinear) statistical methods such as neural networks. The model's internal consistency was confirmed by leave-one-out cross-validation. The model was used to predict all unknown boiling points of fluorobutanes, and the quality of predictions was estimated by means of comparison with boiling point predictions for fluoropentanes.

  19. Rational Formulation of Alternative Fuels using QSPR Methods: Application to Jet Fuels Développement d’un outil d’aide à la formulation des carburants alternatifs utilisant des méthodes QSPR (Quantitative Structure Property Relationship: application aux carburéacteurs

    Directory of Open Access Journals (Sweden)

    Saldana D.A.

    2013-06-01

    Full Text Available Alternative fuels are a promising solution for road transport but also for aircraft. In the aviation field, a huge amount of work has been done in the past years with the approval to use up to 50 % by volume of SPK (Synthetic Paraffinic Kerosene in blends with conventional fossil Jet A-1. SPK are Fischer-Tropsch (FT fuels but also Hydroprocessed Esters and Fatty Acids (HEFA. However, these alternative fuels can have different chemical properties depending on the process used for their production. These properties include normal to iso paraffin ratio, carbon chain length and level of branching. R&D studies of alternative fuels are based on the evaluation of products coming from identified production processes. However, it appears that a better way of studying them could be firstly to determine the best chemical composition regarding aviation problems and secondly to find the best process and finishing process in order to obtain such a product. The objective of this work is to design a tool that aims to guide the future formulation of alternative fuels for aviation through the prediction of targeted physical properties. Thus, it is proposed to apply a methodology that identifies relationships between the structure and properties of a molecule (QSPR for Quantitative Structure Property Relationship, with the aim of establishing predictive models. These models will be built for hydrocarbons (normal and iso paraffins, naphthenes, aromatics, etc. and oxygenated compounds (esters and alcohols. For aviation, oxygenated compounds are not considered as a drop-in fuel. It could be seen as a disruptive solution in a long term view. There are concerns with oxygenates in aviation that are covered in this paper such as the flash point but others such as the energetic content, the water affinity that are not taken into account in this paper. The properties currently studied are flash point, cetane number, density and viscosity. The data sets will contain data

  20. Advances in QSPR/QSTR models of ionic liquids for the design of greener solvents of the future.

    Science.gov (United States)

    Das, Rudra Narayan; Roy, Kunal

    2013-02-01

    In order to protect the life of all creatures living in the environment, the toxicity arising from various hazardous chemicals must be controlled. This imposes a serious responsibility on different chemical, pharmaceutical, and other biological industries to produce less harmful chemicals. Among various international initiatives on harmful aspects of chemicals, the 'Green Chemistry' ideology appears to be one of the most highlighted concepts that focus on the use of eco-friendly chemicals. Ionic liquids are a comparatively new addition to the huge garrison of chemical compounds released from the industry. Extensive research on ionic liquids in the past decade has shown them to be highly useful chemicals with a good degree of thermal and chemical stability, appreciable task specificity and minimal environmental release resulting in a notion of 'green chemical'. However, studies have also shown that ionic liquids are not intrinsically non-toxic agents and can pose severe degree of toxicity as well as the risk of bioaccumulation depending upon their structural components. Moreover, ionic liquids possess issues of waste generation during synthesis as well as separation problems. Predictive quantitative structure-activity relationship (QSAR) models constitute a rational opportunity to explore the structural attributes of ionic liquids towards various physicochemical and toxicological endpoints and thereby leading to the design of environmentally more benevolent analogues with higher process selectivity. Such studies on ionic liquids have been less extensive compared to other industrial chemicals. The present review attempts to summarize different QSAR studies performed on these chemicals and also highlights the safety, health and environmental issues along with the application specificity on the dogma of 'green chemistry'.

  1. Prediction of boiling points of organic compounds by QSPR tools.

    Science.gov (United States)

    Dai, Yi-min; Zhu, Zhi-ping; Cao, Zhong; Zhang, Yue-fei; Zeng, Ju-lan; Li, Xun

    2013-07-01

    The novel electro-negativity topological descriptors of YC, WC were derived from molecular structure by equilibrium electro-negativity of atom and relative bond length of molecule. The quantitative structure-property relationships (QSPR) between descriptors of YC, WC as well as path number parameter P3 and the normal boiling points of 80 alkanes, 65 unsaturated hydrocarbons and 70 alcohols were obtained separately. The high-quality prediction models were evidenced by coefficient of determination (R(2)), the standard error (S), average absolute errors (AAE) and predictive parameters (Qext(2),RCV(2),Rm(2)). According to the regression equations, the influences of the length of carbon backbone, the size, the degree of branching of a molecule and the role of functional groups on the normal boiling point were analyzed. Comparison results with reference models demonstrated that novel topological descriptors based on the equilibrium electro-negativity of atom and the relative bond length were useful molecular descriptors for predicting the normal boiling points of organic compounds. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Random Forest Approach to QSPR Study of Fluorescence Properties Combining Quantum Chemical Descriptors and Solvent Conditions.

    Science.gov (United States)

    Chen, Chia-Hsiu; Tanaka, Kenichi; Funatsu, Kimito

    2018-04-22

    The Quantitative Structure - Property Relationship (QSPR) approach was performed to study the fluorescence absorption wavelengths and emission wavelengths of 413 fluorescent dyes in different solvent conditions. The dyes included the chromophore derivatives of cyanine, xanthene, coumarin, pyrene, naphthalene, anthracene and etc., with the wavelength ranging from 250 nm to 800 nm. An ensemble method, random forest (RF), was employed to construct nonlinear prediction models compared with the results of linear partial least squares and nonlinear support vector machine regression models. Quantum chemical descriptors derived from density functional theory method and solvent information were also used by constructing models. The best prediction results were obtained from RF model, with the squared correlation coefficients [Formula: see text] of 0.940 and 0.905 for λ abs and λ em , respectively. The descriptors used in the models were discussed in detail in this report by comparing the feature importance of RF.

  3. QSPR studies for predicting polarity parameter of organic compounds in methanol using support vector machine and enhanced replacement method.

    Science.gov (United States)

    Golmohammadi, H; Dashtbozorgi, Z

    2016-12-01

    In the present work, enhanced replacement method (ERM) and support vector machine (SVM) were used for quantitative structure-property relationship (QSPR) studies of polarity parameter (p) of various organic compounds in methanol in reversed phase liquid chromatography based on molecular descriptors calculated from the optimized structures. Diverse kinds of molecular descriptors were calculated to encode the molecular structures of compounds, such as geometric, thermodynamic, electrostatic and quantum mechanical descriptors. The variable selection method of ERM was employed to select an optimum subset of descriptors. The five descriptors selected using ERM were used as inputs of SVM to predict the polarity parameter of organic compounds in methanol. The coefficient of determination, r 2 , between experimental and predicted polarity parameters for the prediction set by ERM and SVM were 0.952 and 0.982, respectively. Acceptable results specified that the ERM approach is a very effective method for variable selection and the predictive aptitude of the SVM model is superior to those obtained by ERM. The obtained results demonstrate that SVM can be used as a substitute influential modeling tool for QSPR studies.

  4. QSAR, QSPR and QSRR in Terms of 3-D-MoRSE Descriptors for In Silico Screening of Clofibric Acid Analogues.

    Science.gov (United States)

    Di Tullio, Maurizio; Maccallini, Cristina; Ammazzalorso, Alessandra; Giampietro, Letizia; Amoroso, Rosa; De Filippis, Barbara; Fantacuzzi, Marialuigia; Wiczling, Paweł; Kaliszan, Roman

    2012-07-01

    A series of 27 analogues of clofibric acid, mostly heteroarylalkanoic derivatives, have been analyzed by a novel high-throughput reversed-phase HPLC method employing combined gradient of eluent's pH and organic modifier content. The such determined hydrophobicity (lipophilicity) parameters, log kw , and acidity constants, pKa , were subjected to multiple regression analysis to get a QSRR (Quantitative StructureRetention Relationships) and a QSPR (Quantitative Structure-Property Relationships) equation, respectively, describing these pharmacokinetics-determining physicochemical parameters in terms of the calculation chemistry derived structural descriptors. The previously determined in vitro log EC50 values - transactivation activity towards PPARα (human Peroxisome Proliferator-Activated Receptor α) - have also been described in a QSAR (Quantitative StructureActivity Relationships) equation in terms of the 3-D-MoRSE descriptors (3D-Molecule Representation of Structures based on Electron diffraction descriptors). The QSAR model derived can serve for an a priori prediction of bioactivity in vitro of any designed analogue, whereas the QSRR and the QSPR models can be used to evaluate lipophilicity and acidity, respectively, of the compounds, and hence to rational guide selection of structures of proper pharmacokinetics. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. QSPR study of the retention/release property of odorant molecules in pectin gels using statistical methods

    Directory of Open Access Journals (Sweden)

    Assia Belhassan

    2017-11-01

    Full Text Available The ACD/ChemSketch, MarvinSketch, and ChemOffice programmes were used to calculate several molecular descriptors of 51 odorant molecules (15 alcohols, 11 aldehydes, 9 ketones and 16 esters. The best descriptors were selected to establish the Quantitative Structure-Property Relationship (QSPR of the retention/release property of odorant molecules in pectin gels using Principal Components Analysis (PCA, Multiple Linear Regression (MLR, Multiple Non-linear Regression (MNLR and Artificial Neural Network (ANN methods We propose a quantitative model based on these analyses. PCA has been used to select descriptors that exhibit high correlation with the retention/release property. The MLR method yielded correlation coefficients of 0.960 and 0.958 for PG-0.4 (pectin concentration: 0.4% w/w and PG-0.8 (pectin concentration: 0.8% w/w media, respectively. Internal and external validations were used to determine the statistical quality of the QSPR of the two MLR models. The MNLR method, considering the relevant descriptors obtained from the MLR, yielded correlation coefficients of 0.978 and 0.975 for PG-0.4 and PG-0.8 media, respectively. The applicability domain of MLR models was investigated using simple and leverage approaches to detect outliers and outside compounds. The effects of different descriptors on the retention/release property are described, and these descriptors were used to study and design new compounds with higher and lower values of the property than the existing ones. Keywords: Odorant Molecules, Retention/Release, Pectin Gels, Quantitative Structure Property Relationship, Multiple Linear Regression, Artificial Neural Network

  6. A 2D-QSPR approach to predict blood-brain barrier penetration of drugs acting on the central nervous system

    Directory of Open Access Journals (Sweden)

    Matheus Malta de Sá

    2010-12-01

    Full Text Available Drugs acting on the central nervous system (CNS have to cross the blood-brain barrier (BBB in order to perform their pharmacological actions. Passive BBB diffusion can be partially expressed by the blood/brain partition coefficient (logBB. As the experimental evaluation of logBB is time and cost consuming, theoretical methods such as quantitative structure-property relationships (QSPR can be useful to predict logBB values. In this study, a 2D-QSPR approach was applied to a set of 28 drugs acting on the CNS, using the logBB property as biological data. The best QSPR model [n = 21, r = 0.94 (r² = 0.88, s = 0.28, and Q² = 0.82] presented three molecular descriptors: calculated n-octanol/water partition coefficient (ClogP, polar surface area (PSA, and polarizability (α. Six out of the seven compounds from the test set were well predicted, which corresponds to good external predictability (85.7%. These findings can be helpful to guide future approaches regarding those molecular descriptors which must be considered for estimating the logBB property, and also for predicting the BBB crossing ability for molecules structurally related to the investigated set.Fármacos que atuam no sistema nervoso central (SNC devem atravessar a barreira hematoencefálica (BHE para exercerem suas ações farmacológicas. A difusão passiva através da BHE pode ser parcialmente expressa pelo coeficiente de partição entre os compartimentos encefálico e sanguíneo (logBB, brain/blood partition coefficient. Considerando-se que a avaliação experimental de logBB é dispendiosa e demorada, métodos teóricos como estudos das relações entre estrutura química e propriedade (QSPR, Quantitative Structure-Property Relationships podem ser utilizados na previsão dos valores de logBB. Neste estudo, uma abordagem de QSPR-2D foi aplicada a um conjunto de 28 moléculas com ação central, usando logBB como propriedade biológica. O melhor modelo de QSPR [n = 21, r = 0,94 (r

  7. Quantitative relationships for the prediction of the vapor pressure of some hydrocarbons from the van der Waals molecular surface

    Directory of Open Access Journals (Sweden)

    Olariu Tudor

    2015-01-01

    Full Text Available A quantitative structure - property relationship (QSPR modeling of vapor pressure at 298.15 K, expressed as log (VP / Pa was performed for a series of 84 hydrocarbons (63 alkanes and 21 cycloalkanes using the van der Waals (vdW surface area, SW/Å2, calculated by the Monte Carlo method, as the molecular descriptor. The QSPR model developed from the subset of 63 alkanes (C1-C16, deemed as the training set, was successfully used for the prediction of the log (VP / Pa values of the 21 cycloalkanes, which was the external prediction (test subset. A QSPR model was also developed for a series composed of all 84 hydrocarbons. Both QSPR models were statistically tested for their ability to fit the data and for prediction. The results showed that the vdW molecular surface used as molecular descriptor (MD explains the variance of the majority of the log (VP / Pa values in this series of 84 hydrocarbons. This MD describes very well the intermolecular forces that hold neutral molecules together. The clear physical meaning of the molecular surface values, SW/Å2, could explain the success of the QSPR models obtained with a single structural molecular descriptor.

  8. Prediction of the maximum absorption wavelength of azobenzene dyes by QSPR tools

    Science.gov (United States)

    Xu, Xuan; Luan, Feng; Liu, Huitao; Cheng, Jianbo; Zhang, Xiaoyun

    2011-12-01

    The maximum absorption wavelength ( λmax) of a large data set of 191 azobenzene dyes was predicted by quantitative structure-property relationship (QSPR) tools. The λmax was correlated with the 4 molecular descriptors calculated from the structure of the dyes alone. The multiple linear regression method (MLR) and the non-linear radial basis function neural network (RBFNN) method were applied to develop the models. The statistical parameters provided by the MLR model were R2 = 0.893, Radj2=0.893, qLOO2=0.884, F = 1214.871, RMS = 11.6430 for the training set; and R2 = 0.849, Radj2=0.845, qext2=0.846, F = 207.812, RMS = 14.0919 for the external test set. The RBFNN model gave even improved statistical results: R2 = 0.920, Radj2=0.919, qLOO2=0.898, F = 1664.074, RMS = 9.9215 for the training set, and R2 = 0.895, Radj2=0.892, qext2=0.895, F = 314.256, RMS = 11.6427 for the external test set. This theoretical method provides a simple, precise and an alternative method to obtain λmax of azobenzene dyes.

  9. Solvent Extraction and QSPR of Catecholamines with a Bis(2-ethlhexyl) Hydrogen Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizuka, Kazuharu.; Fujimoto, Yuko.; Ota, Keisuke.; Inoue, Katsutoshi. [Saga University, Saga (Japan). Dept. of Applied Chemistry

    1999-02-01

    In order to develop an effective separation recess for catecholamine (CA), a basic investigation on solvent extraction of dopamine (DA), adrenaline (Ad) and noradrenaline (NA) from hydrochloric acid solution and their stripping is conducted at 30 degree C employing bis(2-ethylhexyl) hydrogen phosphate (D2EHPA) in chloroform, n-hexane and toluene as the organic diluents. From the dependencies of the distribution ratios on the concentrations of reactant species, i.e. CA, hydrogen ion and D2EHPA, it is elucidated that CA (RNH{sub 2}) is extracted with D2EHPA (HR`) according to the ion exchange mechanism, as the complex type, RNH{sub 3}R` (HR`){sub 3}, and the equilibrium constants (K{sub ex,CA}) for the extraction reactions are also evaluated. The quantitative structure property relationship (QSPR) of K{sub ex,CA} values for each organic diluent is discussed using molecular modeling with semi-empirical molecular orbital calculations considering the solvent effect. (author)

  10. Diprotonation process of meso-tetraphenylporphyrin derivatives designed for Photodynamic Therapy of cancers: From Multivariate Curve Resolution to predictive QSPR modeling

    Energy Technology Data Exchange (ETDEWEB)

    Chauvin, Benoit, E-mail: benoit.chauvin@u-psud.fr [Univ. Paris-Sud, EA 4041, IFR 141, Faculte de Pharmacie, F-92296 Chatenay-Malabry (France); Institut Curie, UMR 176 CNRS, Centre Universitaire, Univ Paris-Sud, F-91405 Orsay (France); Kasselouri, Athena; Chaminade, Pierre; Quiameso, Rita [Univ. Paris-Sud, EA 4041, IFR 141, Faculte de Pharmacie, F-92296 Chatenay-Malabry (France); Nicolis, Ioannis [Laboratoire de Biomathematiques et Informatique, Departement de Sante publique et biostatistiques et EA 4466, Faculte de Pharmacie, Universite Paris Descartes, 4, avenue de l' Observatoire, 75270 Paris cedex 06 (France); Maillard, Philippe [Institut Curie, UMR 176 CNRS, Centre Universitaire, Univ Paris-Sud, F-91405 Orsay (France); Prognon, Patrice [Univ. Paris-Sud, EA 4041, IFR 141, Faculte de Pharmacie, F-92296 Chatenay-Malabry (France)

    2011-10-31

    Highlights: {yields} Diprotonation of 17 meso-tetraphenylporphyrin derivatives. {yields} MCR-ALS resolution of multi-component mixtures. {yields} Determination of stepwise protonation constants. {yields} Prediction of protonation constants from ET-State indices. - Abstract: Tetrapyrrole rings possess four nitrogen atoms, two of which act as Broendsted bases in acidic media. The two protonation steps occur on a close pH range, particularly in the case of meso-tetraphenylporphyrin (TPP) derivatives. If the cause of this phenomenon is well known - a protonation-induced distortion of the porphyrin ring - data on stepwise protonation constants and on electronic absorption spectra of monoprotonated TPPs are sparse. A multivariate approach has been systematically applied to a series of glycoconjugated and hydroxylated TPPs, potential anticancer drugs usable in Photodynamic Therapy. The dual purpose was determination of protonation constants and linking substitution with basicity. Hard-modeling version of MCR-ALS (Multivariate Curve Resolution Alternating Least Squares) has given access to spectra and distribution profile of pure components. Spectra of monoprotonated species (H{sub 3}TPP{sup +}) in solution resemble those of diprotonated species (H{sub 4}TPP{sup 2+}), mainly differing by a slight blue-shift of bands. Overlap of H{sub 3}TPP{sup +} and H{sub 4}TPP{sup 2+} spectra reinforces the difficulty to evidence an intermediate form only present in low relative abundance. Depending on macrocycle substitution, pK values ranged from 3.5 {+-} 0.1 to 5.1 {+-} 0.1 for the first protonation and from 3.2 {+-} 0.2 to 4.9 {+-} 0.1 for the second one. Inner nitrogens' basicity is affected by position, number and nature of peripheral substituents depending on their electrodonating character. pK values have been used to establish a predictive Multiple Linear Regression (MLR) model, relying on atom-type electrotopological indices. This model accurately describes our results and

  11. The Interplay between QSAR/QSPR Studiesand Partial Order Ranking and Formal Concept Analyses

    Directory of Open Access Journals (Sweden)

    Lars Carlsen

    2009-04-01

    Full Text Available The often observed scarcity of physical-chemical and well as toxicological data hampers the assessment of potentially hazardous chemicals released to the environment. In such cases Quantitative Structure-Activity Relationships/Quantitative Structure-Property Relationships (QSAR/QSPR constitute an obvious alternative for rapidly, effectively and inexpensively generatng missing experimental values. However, typically further treatment of the data appears necessary, e.g., to elucidate the possible relations between the single compounds as well as implications and associations between the various parameters used for the combined characterization of the compounds under investigation. In the present paper the application of QSAR/QSPR in combination with Partial Order Ranking (POR methodologies will be reviewed and new aspects using Formal Concept Analysis (FCA will be introduced. Where POR constitutes an attractive method for, e.g., prioritizing a series of chemical substances based on a simultaneous inclusion of a range of parameters, FCA gives important information on the implications associations between the parameters. The combined approach thus constitutes an attractive method to a preliminary assessment of the impact on environmental and human health by primary pollutants or possibly by a primary pollutant well as a possible suite of transformation subsequent products that may be both persistent in and bioaccumulating and toxic.The present review focus on the environmental – and human health impact by residuals of the rocket fuel 1,1-dimethyl- hydrazine (heptyl and its transformation products as an illustrative example.

  12. QSPR study of absorption maxima of organic dyes for dye-sensitized solar cells based on 3D descriptors

    Science.gov (United States)

    Xu, Jie; Zhang, Hui; Wang, Lei; Liang, Guijie; Wang, Luoxin; Shen, Xiaolin; Xu, Weilin

    2010-07-01

    A quantitative structure-property relationship (QSPR) study was performed for the prediction of the absorption maxima ( λmax) of organic dyes for dye-sensitized solar cells (DSSCs). The entire set of 70 dyes was divided into a training set of 53 dyes and a test set of 17 dyes according to Kennard and Stones algorithm. Three-dimensional (3D) descriptors were calculated to represent the dye molecules. A ten-descriptor model, with a squared correlation coefficient ( R2) of 0.9543 and a standard error of estimation ( s) of 14.7 nm, was produced by using the stepwise multilinear regression analysis (MLRA) on the training set. The reliability of the proposed model was further illustrated using various evaluation techniques: leave-one-out cross-validation procedure, randomization tests, and validation through the external test set. All descriptors involved in the model were derived solely from the chemical structure of the dye molecules, which makes the model very useful to estimate the λmax of dyes before they are actually synthesized.

  13. 3D-QSPR Method of Computational Technique Applied on Red Reactive Dyes by Using CoMFA Strategy

    Directory of Open Access Journals (Sweden)

    Shahnaz Perveen

    2011-12-01

    Full Text Available Cellulose fiber is a tremendous natural resource that has broad application in various productions including the textile industry. The dyes, which are commonly used for cellulose printing, are “reactive dyes” because of their high wet fastness and brilliant colors. The interaction of various dyes with the cellulose fiber depends upon the physiochemical properties that are governed by specific features of the dye molecule. The binding pattern of the reactive dye with cellulose fiber is called the ligand-receptor concept. In the current study, the three dimensional quantitative structure property relationship (3D-QSPR technique was applied to understand the red reactive dyes interactions with the cellulose by the Comparative Molecular Field Analysis (CoMFA method. This method was successfully utilized to predict a reliable model. The predicted model gives satisfactory statistical results and in the light of these, it was further analyzed. Additionally, the graphical outcomes (contour maps help us to understand the modification pattern and to correlate the structural changes with respect to the absorptivity. Furthermore, the final selected model has potential to assist in understanding the charachteristics of the external test set. The study could be helpful to design new reactive dyes with better affinity and selectivity for the cellulose fiber.

  14. 3D-QSPR method of computational technique applied on red reactive dyes by using CoMFA strategy.

    Science.gov (United States)

    Mahmood, Uzma; Rashid, Sitara; Ali, S Ishrat; Parveen, Rasheeda; Zaheer-Ul-Haq; Ambreen, Nida; Khan, Khalid Mohammed; Perveen, Shahnaz; Voelter, Wolfgang

    2011-01-01

    Cellulose fiber is a tremendous natural resource that has broad application in various productions including the textile industry. The dyes, which are commonly used for cellulose printing, are "reactive dyes" because of their high wet fastness and brilliant colors. The interaction of various dyes with the cellulose fiber depends upon the physiochemical properties that are governed by specific features of the dye molecule. The binding pattern of the reactive dye with cellulose fiber is called the ligand-receptor concept. In the current study, the three dimensional quantitative structure property relationship (3D-QSPR) technique was applied to understand the red reactive dyes interactions with the cellulose by the Comparative Molecular Field Analysis (CoMFA) method. This method was successfully utilized to predict a reliable model. The predicted model gives satisfactory statistical results and in the light of these, it was further analyzed. Additionally, the graphical outcomes (contour maps) help us to understand the modification pattern and to correlate the structural changes with respect to the absorptivity. Furthermore, the final selected model has potential to assist in understanding the characteristics of the external test set. The study could be helpful to design new reactive dyes with better affinity and selectivity for the cellulose fiber.

  15. 2D Quantitative Structure-Property Relationship Study of Mycotoxins by Multiple Linear Regression and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Fereshteh Shiri

    2010-08-01

    Full Text Available In the present work, support vector machines (SVMs and multiple linear regression (MLR techniques were used for quantitative structure–property relationship (QSPR studies of retention time (tR in standardized liquid chromatography–UV–mass spectrometry of 67 mycotoxins (aflatoxins, trichothecenes, roquefortines and ochratoxins based on molecular descriptors calculated from the optimized 3D structures. By applying missing value, zero and multicollinearity tests with a cutoff value of 0.95, and genetic algorithm method of variable selection, the most relevant descriptors were selected to build QSPR models. MLRand SVMs methods were employed to build QSPR models. The robustness of the QSPR models was characterized by the statistical validation and applicability domain (AD. The prediction results from the MLR and SVM models are in good agreement with the experimental values. The correlation and predictability measure by r2 and q2 are 0.931 and 0.932, repectively, for SVM and 0.923 and 0.915, respectively, for MLR. The applicability domain of the model was investigated using William’s plot. The effects of different descriptors on the retention times are described.

  16. Field determination and QSPR prediction of equilibrium-status soil/vegetation partition coefficient of PCDD/Fs.

    Science.gov (United States)

    Li, Li; Wang, Qiang; Qiu, Xinghua; Dong, Yian; Jia, Shenglan; Hu, Jianxin

    2014-07-15

    Characterizing pseudo equilibrium-status soil/vegetation partition coefficient KSV, the quotient of respective concentrations in soil and vegetation of a certain substance at remote background areas, is essential in ecological risk assessment, however few previous attempts have been made for field determination and developing validated and reproducible structure-based estimates. In this study, KSV was calculated based on measurements of seventeen 2,3,7,8-substituted PCDD/F congeners in soil and moss (Dicranum angustum), and rouzi grass (Thylacospermum caespitosum) of two background sites, Ny-Ålesund of the Arctic and Zhangmu-Nyalam region of the Tibet Plateau, respectively. By both fugacity modeling and stepwise regression of field data, the air-water partition coefficient (KAW) and aqueous solubility (SW) were identified as the influential physicochemical properties. Furthermore, validated quantitative structure-property relationship (QSPR) model was developed to extrapolate the KSV prediction to all 210 PCDD/F congeners. Molecular polarizability, molecular size and molecular energy demonstrated leading effects on KSV. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. PREDICTING THE BOILING POINT OF PCDD/Fs BY THE QSPR METHOD BASED ON THE MOLECULAR DISTANCE-EDGE VECTOR INDEX

    Directory of Open Access Journals (Sweden)

    Long Jiao

    2015-05-01

    Full Text Available The quantitative structure property relationship (QSPR for the boiling point (Tb of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs was investigated. The molecular distance-edge vector (MDEV index was used as the structural descriptor. The quantitative relationship between the MDEV index and Tb was modeled by using multivariate linear regression (MLR and artificial neural network (ANN, respectively. Leave-one-out cross validation and external validation were carried out to assess the prediction performance of the models developed. For the MLR method, the prediction root mean square relative error (RMSRE of leave-one-out cross validation and external validation was 1.77 and 1.23, respectively. For the ANN method, the prediction RMSRE of leave-one-out cross validation and external validation was 1.65 and 1.16, respectively. A quantitative relationship between the MDEV index and Tb of PCDD/Fs was demonstrated. Both MLR and ANN are practicable for modeling this relationship. The MLR model and ANN model developed can be used to predict the Tb of PCDD/Fs. Thus, the Tb of each PCDD/F was predicted by the developed models.

  18. Computational modeling of human oral bioavailability: what will be next?

    Science.gov (United States)

    Cabrera-Pérez, Miguel Ángel; Pham-The, Hai

    2018-06-01

    The oral route is the most convenient way of administrating drugs. Therefore, accurate determination of oral bioavailability is paramount during drug discovery and development. Quantitative structure-property relationship (QSPR), rule-of-thumb (RoT) and physiologically based-pharmacokinetic (PBPK) approaches are promising alternatives to the early oral bioavailability prediction. Areas covered: The authors give insight into the factors affecting bioavailability, the fundamental theoretical framework and the practical aspects of computational methods for predicting this property. They also give their perspectives on future computational models for estimating oral bioavailability. Expert opinion: Oral bioavailability is a multi-factorial pharmacokinetic property with its accurate prediction challenging. For RoT and QSPR modeling, the reliability of datasets, the significance of molecular descriptor families and the diversity of chemometric tools used are important factors that define model predictability and interpretability. Likewise, for PBPK modeling the integrity of the pharmacokinetic data, the number of input parameters, the complexity of statistical analysis and the software packages used are relevant factors in bioavailability prediction. Although these approaches have been utilized independently, the tendency to use hybrid QSPR-PBPK approaches together with the exploration of ensemble and deep-learning systems for QSPR modeling of oral bioavailability has opened new avenues for development promising tools for oral bioavailability prediction.

  19. A New Variable Selection Method Based on Mutual Information Maximization by Replacing Collinear Variables for Nonlinear Quantitative Structure-Property Relationship Models

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Jahan B.; Zolfonoun, Ehsan [Toosi University of Technology, Tehran (Korea, Republic of)

    2012-05-15

    Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms.

  20. A New Variable Selection Method Based on Mutual Information Maximization by Replacing Collinear Variables for Nonlinear Quantitative Structure-Property Relationship Models

    International Nuclear Information System (INIS)

    Ghasemi, Jahan B.; Zolfonoun, Ehsan

    2012-01-01

    Selection of the most informative molecular descriptors from the original data set is a key step for development of quantitative structure activity/property relationship models. Recently, mutual information (MI) has gained increasing attention in feature selection problems. This paper presents an effective mutual information-based feature selection approach, named mutual information maximization by replacing collinear variables (MIMRCV), for nonlinear quantitative structure-property relationship models. The proposed variable selection method was applied to three different QSPR datasets, soil degradation half-life of 47 organophosphorus pesticides, GC-MS retention times of 85 volatile organic compounds, and water-to-micellar cetyltrimethylammonium bromide partition coefficients of 62 organic compounds.The obtained results revealed that using MIMRCV as feature selection method improves the predictive quality of the developed models compared to conventional MI based variable selection algorithms

  1. Power Conversion Efficiency of Arylamine Organic Dyes for Dye-Sensitized Solar Cells (DSSCs Explicit to Cobalt Electrolyte: Understanding the Structural Attributes Using a Direct QSPR Approach

    Directory of Open Access Journals (Sweden)

    Supratik Kar

    2016-12-01

    Full Text Available Post silicon solar cell era involves light-absorbing dyes for dye-sensitized solar systems (DSSCs. Therefore, there is great interest in the design of competent organic dyes for DSSCs with high power conversion efficiency (PCE to bypass some of the disadvantages of silicon-based solar cell technologies, such as high cost, heavy weight, limited silicon resources, and production methods that lead to high environmental pollution. The DSSC has the unique feature of a distance-dependent electron transfer step. This depends on the relative position of the sensitized organic dye in the metal oxide composite system. In the present work, we developed quantitative structure-property relationship (QSPR models to set up the quantitative relationship between the overall PCE and quantum chemical molecular descriptors. They were calculated from density functional theory (DFT and time-dependent DFT (TD-DFT methods as well as from DRAGON software. This allows for understanding the basic electron transfer mechanism along with the structural attributes of arylamine-organic dye sensitizers for the DSSCs explicit to cobalt electrolyte. The identified properties and structural fragments are particularly valuable for guiding time-saving synthetic efforts for development of efficient arylamine organic dyes with improved power conversion efficiency.

  2. Quantitative Structure-Retention Relationships (QSRR) for Chromatographic Separation of Disazo and Trisazo 4,4'-Diaminobenzanilide-based Dyes

    OpenAIRE

    Funar-Timofei, Simona; Fabian, Walter M. F.; Simu, Georgeta M.; Suzukic, Takahiro

    2006-01-01

    For a series of 23 disazo and trisazo 4,4'-diaminobenzanilide-based direct dye molecules, thechromatographic mobilities, extrapolated to modifier-free conditions (RM0 values), were determinedfrom reverse-phase thin-layer chromatography (RP-TLC) experiments. Traditional and rational QSAR/QSPR modelling techniques have been applied to find a quantitative structure-retention relationship (QSRR) for the dyes. Molecular dye structures were energy minimized by both molecular mechanics and quantum c...

  3. Development of Quantitative Structure-Property Relationship Models for Self-Emulsifying Drug Delivery System of 2-Aryl Propionic Acid NSAIDs

    Directory of Open Access Journals (Sweden)

    Chen-Wen Li

    2011-01-01

    Full Text Available We developed the quantative structure-property relationships (QSPRs models to correlate the molecular structures of surfactant, cosurfactant, oil, and drug with the solubility of poorly water-soluble 2-aryl propionic acid nonsteroidal anti-inflammatory drugs (2-APA-NSAIDs in self-emulsifying drug delivery systems (SEDDSs. The compositions were encoded with electronic, geometrical, topological, and quantum chemical descriptors. To obtain reliable predictions, we used multiple linear regression (MLR and artificial neural network (ANN methods for model development. The obtained equations were validated using a test set of 42 formulations and showed a great predictive power, and linear models were found to be better than nonlinear ones. The obtained QSPR models would greatly facilitate fast screening for the optimal formulations of SEDDS at the early stage of drug development and minimize experimental effort.

  4. Rationalizing fragment based drug discovery for BACE1: insights from FB-QSAR, FB-QSSR, multi objective (MO-QSPR) and MIF studies.

    Science.gov (United States)

    Manoharan, Prabu; Vijayan, R S K; Ghoshal, Nanda

    2010-10-01

    The ability to identify fragments that interact with a biological target is a key step in FBDD. To date, the concept of fragment based drug design (FBDD) is increasingly driven by bio-physical methods. To expand the boundaries of QSAR paradigm, and to rationalize FBDD using In silico approach, we propose a fragment based QSAR methodology referred here in as FB-QSAR. The FB-QSAR methodology was validated on a dataset consisting of 52 Hydroxy ethylamine (HEA) inhibitors, disclosed by GlaxoSmithKline Pharmaceuticals as potential anti-Alzheimer agents. To address the issue of target selectivity, a major confounding factor in the development of selective BACE1 inhibitors, FB-QSSR models were developed using the reported off target activity values. A heat map constructed, based on the activity and selectivity profile of the individual R-group fragments, and was in turn used to identify superior R-group fragments. Further, simultaneous optimization of multiple properties, an issue encountered in real-world drug discovery scenario, and often overlooked in QSAR approaches, was addressed using a Multi Objective (MO-QSPR) method that balances properties, based on the defined objectives. MO-QSPR was implemented using Derringer and Suich desirability algorithm to identify the optimal level of independent variables (X) that could confer a trade-off between selectivity and activity. The results obtained from FB-QSAR were further substantiated using MIF (Molecular Interaction Fields) studies. To exemplify the potentials of FB-QSAR and MO-QSPR in a pragmatic fashion, the insights gleaned from the MO-QSPR study was reverse engineered using Inverse-QSAR in a combinatorial fashion to enumerate some prospective novel, potent and selective BACE1 inhibitors.

  5. Rationalizing fragment based drug discovery for BACE1: insights from FB-QSAR, FB-QSSR, multi objective (MO-QSPR) and MIF studies

    Science.gov (United States)

    Manoharan, Prabu; Vijayan, R. S. K.; Ghoshal, Nanda

    2010-10-01

    The ability to identify fragments that interact with a biological target is a key step in FBDD. To date, the concept of fragment based drug design (FBDD) is increasingly driven by bio-physical methods. To expand the boundaries of QSAR paradigm, and to rationalize FBDD using In silico approach, we propose a fragment based QSAR methodology referred here in as FB-QSAR. The FB-QSAR methodology was validated on a dataset consisting of 52 Hydroxy ethylamine (HEA) inhibitors, disclosed by GlaxoSmithKline Pharmaceuticals as potential anti-Alzheimer agents. To address the issue of target selectivity, a major confounding factor in the development of selective BACE1 inhibitors, FB-QSSR models were developed using the reported off target activity values. A heat map constructed, based on the activity and selectivity profile of the individual R-group fragments, and was in turn used to identify superior R-group fragments. Further, simultaneous optimization of multiple properties, an issue encountered in real-world drug discovery scenario, and often overlooked in QSAR approaches, was addressed using a Multi Objective (MO-QSPR) method that balances properties, based on the defined objectives. MO-QSPR was implemented using Derringer and Suich desirability algorithm to identify the optimal level of independent variables ( X) that could confer a trade-off between selectivity and activity. The results obtained from FB-QSAR were further substantiated using MIF (Molecular Interaction Fields) studies. To exemplify the potentials of FB-QSAR and MO-QSPR in a pragmatic fashion, the insights gleaned from the MO-QSPR study was reverse engineered using Inverse-QSAR in a combinatorial fashion to enumerate some prospective novel, potent and selective BACE1 inhibitors.

  6. THREE-DIMENSIONAL QUANTITATIVE STRUCTURE-PROPERTY RELATIONSHIP (3D-QSPR) MODELS FOR PREDICTION OF THERMODYNAMIC PROPERTIES OF POLYCHLORINATED BIPHENYLS (PCBS): ENTHALPY OF VAPORIZATION. (R826133)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  7. An approach to the interpretation of backpropagation neural network models in QSAR studies.

    Science.gov (United States)

    Baskin, I I; Ait, A O; Halberstam, N M; Palyulin, V A; Zefirov, N S

    2002-03-01

    An approach to the interpretation of backpropagation neural network models for quantitative structure-activity and structure-property relationships (QSAR/QSPR) studies is proposed. The method is based on analyzing the first and second moments of distribution of the values of the first and the second partial derivatives of neural network outputs with respect to inputs calculated at data points. The use of such statistics makes it possible not only to obtain actually the same characteristics as for the case of traditional "interpretable" statistical methods, such as the linear regression analysis, but also to reveal important additional information regarding the non-linear character of QSAR/QSPR relationships. The approach is illustrated by an example of interpreting a backpropagation neural network model for predicting position of the long-wave absorption band of cyane dyes.

  8. Computational models for structure-hydrophobicity relationships of 4-carboxyl-2,6-dinitrophenyl azo hydroxynaphthalenes.

    Science.gov (United States)

    Idowu, Olakunle S; Adegoke, Olajire A; Idowu, Abiola; Olaniyi, Ajibola A

    2007-01-01

    Some phenyl azo hydroxynaphthalene dyes (e.g., sunset yellow) are certified as approved colorants for food, cosmetics, and drug formulations. The hydrophobicity of 4 newly synthesized azo dyes of the phenyl azo hydroxynaphthalene class was investigated, as a training set, with the goal of developing models for quantitative structure-property relationships (QSPR). Retention behavior of the molecules reversed-phase thin-layer chromatography (RPTLC) was investigated using liquid paraffin-coated silica gel as the stationary phase. Mobile phases consisted of aqueous mixtures of methanol, acetone, and dimethylformamide (DMF). Basic hydrophobicity parameter (Rmw), specific hydrophobic surface area (S), and isocratic chromatographic hydrophobicity index (phio) were computed from the chromatographic data. The hydrophobicity index (Rm) decreased linearly with increasing concentration of organic modifiers. Extrapolated Rmw values obtained by using DMF and acetone differ significantly from the value obtained by using methanol as organic modifier [P dyes and may also play useful roles in computer-assisted molecular discovery of nontoxic azo dyes.

  9. Advances in the replacement and enhanced replacement method in QSAR and QSPR theories.

    Science.gov (United States)

    Mercader, Andrew G; Duchowicz, Pablo R; Fernández, Francisco M; Castro, Eduardo A

    2011-07-25

    The selection of an optimal set of molecular descriptors from a much greater pool of such regression variables is a crucial step in the development of QSAR and QSPR models. The aim of this work is to further improve this important selection process. For this reason three different alternatives for the initial steps of our recently developed enhanced replacement method (ERM) and replacement method (RM) are proposed. These approaches had previously proven to yield near optimal results with a much smaller number of linear regressions than the full search. The algorithms were tested on four different experimental data sets, formed by collections of 116, 200, 78, and 100 experimental records from different compounds and 1268, 1338, 1187, and 1306 molecular descriptors, respectively. The comparisons showed that one of the new alternatives further improves the ERM, which has shown to be superior to genetic algorithms for the selection of an optimal set of molecular descriptors from a much greater pool. The new proposed alternative also improves the simpler and the lower computational demand algorithm RM.

  10. Information Systems Outsourcing Relationship Model

    Directory of Open Access Journals (Sweden)

    Richard Flemming

    2007-09-01

    Full Text Available Increasing attention is being paid to what determines the success of an information systems outsourcing arrangement. The current research aims to provide an improved understanding of the factors influencing the outcome of an information systems outsourcing relationship and to provide a preliminary validation of an extended outsourcing relationship model by interviews with information systems outsourcing professionals in both the client and vendor of a major Australian outsourcing relationship. It also investigates whether the client and the vendor perceive the relationship differently and if so, how they perceive it differently and whether the two perspectives are interrelated.

  11. Modeling the Dispersibility of Single Walled Carbon Nanotubes in Organic Solvents by Quantitative Structure-Activity Relationship Approach

    Science.gov (United States)

    Yilmaz, Hayriye; Rasulev, Bakhtiyor; Leszczynski, Jerzy

    2015-01-01

    The knowledge of physico-chemical properties of carbon nanotubes, including behavior in organic solvents is very important for design, manufacturing and utilizing of their counterparts with improved properties. In the present study a quantitative structure-activity/property relationship (QSAR/QSPR) approach was applied to predict the dispersibility of single walled carbon nanotubes (SWNTs) in various organic solvents. A number of additive descriptors and quantum-chemical descriptors were calculated and utilized to build QSAR models. The best predictability is shown by a 4-variable model. The model showed statistically good results (R2training = 0.797, Q2 = 0.665, R2test = 0.807), with high internal and external correlation coefficients. Presence of the X0Av descriptor and its negative term suggest that small size solvents have better SWCNTs solubility. Mass weighted descriptor ATS6m also indicates that heavier solvents (and small in size) most probably are better solvents for SWCNTs. The presence of the Dipole Z descriptor indicates that higher polarizability of the solvent molecule increases the solubility. The developed model and contributed descriptors can help to understand the mechanism of the dispersion process and predictorganic solvents that improve the dispersibility of SWNTs. PMID:28347035

  12. Towards the Development of Global Nano-Quantitative Structure–Property Relationship Models: Zeta Potentials of Metal Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Andrey A. Toropov

    2018-04-01

    Full Text Available Zeta potential indirectly reflects a charge of the surface of nanoparticles in solutions and could be used to represent the stability of the colloidal solution. As processes of synthesis, testing and evaluation of new nanomaterials are expensive and time-consuming, so it would be helpful to estimate an approximate range of properties for untested nanomaterials using computational modeling. We collected the largest dataset of zeta potential measurements of bare metal oxide nanoparticles in water (87 data points. The dataset was used to develop quantitative structure–property relationship (QSPR models. Essential features of nanoparticles were represented using a modified simplified molecular input line entry system (SMILES. SMILES strings reflected the size-dependent behavior of zeta potentials, as the considered quasi-SMILES modification included information about both chemical composition and the size of the nanoparticles. Three mathematical models were generated using the Monte Carlo method, and their statistical quality was evaluated (R2 for the training set varied from 0.71 to 0.87; for the validation set, from 0.67 to 0.82; root mean square errors for both training and validation sets ranged from 11.3 to 17.2 mV. The developed models were analyzed and linked to aggregation effects in aqueous solutions.

  13. Modeling the Dispersibility of Single Walled Carbon Nanotubes in Organic Solvents by Quantitative Structure-Activity Relationship Approach

    Directory of Open Access Journals (Sweden)

    Hayriye Yilmaz

    2015-05-01

    Full Text Available The knowledge of physico-chemical properties of carbon nanotubes, including behavior in organic solvents is very important for design, manufacturing and utilizing of their counterparts with improved properties. In the present study a quantitative structure-activity/property relationship (QSAR/QSPR approach was applied to predict the dispersibility of single walled carbon nanotubes (SWNTs in various organic solvents. A number of additive descriptors and quantum-chemical descriptors were calculated and utilized to build QSAR models. The best predictability is shown by a 4-variable model. The model showed statistically good results (R2training = 0.797, Q2 = 0.665, R2test = 0.807, with high internal and external correlation coefficients. Presence of the X0Av descriptor and its negative term suggest that small size solvents have better SWCNTs solubility. Mass weighted descriptor ATS6m also indicates that heavier solvents (and small in size most probably are better solvents for SWCNTs. The presence of the Dipole Z descriptor indicates that higher polarizability of the solvent molecule increases the solubility. The developed model and contributed descriptors can help to understand the mechanism of the dispersion process and predictorganic solvents that improve the dispersibility of SWNTs.

  14. Estimating persistence of brominated and chlorinated organic pollutants in air, water, soil, and sediments with the QSPR-based classification scheme.

    Science.gov (United States)

    Puzyn, T; Haranczyk, M; Suzuki, N; Sakurai, T

    2011-02-01

    We have estimated degradation half-lives of both brominated and chlorinated dibenzo-p-dioxins (PBDDs and PCDDs), furans (PBDFs and PCDFs), biphenyls (PBBs and PCBs), naphthalenes (PBNs and PCNs), diphenyl ethers (PBDEs and PCDEs) as well as selected unsubstituted polycyclic aromatic hydrocarbons (PAHs) in air, surface water, surface soil, and sediments (in total of 1,431 compounds in four compartments). Next, we compared the persistence between chloro- (relatively well-studied) and bromo- (less studied) analogs. The predictions have been performed based on the quantitative structure-property relationship (QSPR) scheme with use of k-nearest neighbors (kNN) classifier and the semi-quantitative system of persistence classes. The classification models utilized principal components derived from the principal component analysis of a set of 24 constitutional and quantum mechanical descriptors as input variables. Accuracies of classification (based on an external validation) were 86, 85, 87, and 75% for air, surface water, surface soil, and sediments, respectively. The persistence of all chlorinated species increased with increasing halogenation degree. In the case of brominated organic pollutants (Br-OPs), the trend was the same for air and sediments. However, we noticed that the opposite trend for persistence in surface water and soil. The results suggest that, due to high photoreactivity of C-Br chemical bonds, photolytic processes occurring in surface water and soil are able to play significant role in transforming and removing Br-OPs from these compartments. This contribution is the first attempt of classifying together Br-OPs and Cl-OPs according to their persistence, in particular, environmental compartments.

  15. Spaghetti Bridges: Modeling Linear Relationships

    Science.gov (United States)

    Kroon, Cindy D.

    2016-01-01

    Mathematics and science are natural partners. One of many examples of this partnership occurs when scientific observations are made, thus providing data that can be used for mathematical modeling. Developing mathematical relationships elucidates such scientific principles. This activity describes a data-collection activity in which students employ…

  16. Event-based criteria in GT-STAF information indices: theory, exploratory diversity analysis and QSPR applications.

    Science.gov (United States)

    Barigye, S J; Marrero-Ponce, Y; Martínez López, Y; Martínez Santiago, O; Torrens, F; García Domenech, R; Galvez, J

    2013-01-01

    Versatile event-based approaches for the definition of novel information theory-based indices (IFIs) are presented. An event in this context is the criterion followed in the "discovery" of molecular substructures, which in turn serve as basis for the construction of the generalized incidence and relations frequency matrices, Q and F, respectively. From the resultant F, Shannon's, mutual, conditional and joint entropy-based IFIs are computed. In previous reports, an event named connected subgraphs was presented. The present study is an extension of this notion, in which we introduce other events, namely: terminal paths, vertex path incidence, quantum subgraphs, walks of length k, Sach's subgraphs, MACCs, E-state and substructure fingerprints and, finally, Ghose and Crippen atom-types for hydrophobicity and refractivity. Moreover, we define magnitude-based IFIs, introducing the use of the magnitude criterion in the definition of mutual, conditional and joint entropy-based IFIs. We also discuss the use of information-theoretic parameters as a measure of the dissimilarity of codified structural information of molecules. Finally, a comparison of the statistics for QSPR models obtained with the proposed IFIs and DRAGON's molecular descriptors for two physicochemical properties log P and log K of 34 derivatives of 2-furylethylenes demonstrates similar to better predictive ability than the latter.

  17. The application of feature selection to the development of Gaussian process models for percutaneous absorption.

    Science.gov (United States)

    Lam, Lun Tak; Sun, Yi; Davey, Neil; Adams, Rod; Prapopoulou, Maria; Brown, Marc B; Moss, Gary P

    2010-06-01

    The aim was to employ Gaussian processes to assess mathematically the nature of a skin permeability dataset and to employ these methods, particularly feature selection, to determine the key physicochemical descriptors which exert the most significant influence on percutaneous absorption, and to compare such models with established existing models. Gaussian processes, including automatic relevance detection (GPRARD) methods, were employed to develop models of percutaneous absorption that identified key physicochemical descriptors of percutaneous absorption. Using MatLab software, the statistical performance of these models was compared with single linear networks (SLN) and quantitative structure-permeability relationships (QSPRs). Feature selection methods were used to examine in more detail the physicochemical parameters used in this study. A range of statistical measures to determine model quality were used. The inherently nonlinear nature of the skin data set was confirmed. The Gaussian process regression (GPR) methods yielded predictive models that offered statistically significant improvements over SLN and QSPR models with regard to predictivity (where the rank order was: GPR > SLN > QSPR). Feature selection analysis determined that the best GPR models were those that contained log P, melting point and the number of hydrogen bond donor groups as significant descriptors. Further statistical analysis also found that great synergy existed between certain parameters. It suggested that a number of the descriptors employed were effectively interchangeable, thus questioning the use of models where discrete variables are output, usually in the form of an equation. The use of a nonlinear GPR method produced models with significantly improved predictivity, compared with SLN or QSPR models. Feature selection methods were able to provide important mechanistic information. However, it was also shown that significant synergy existed between certain parameters, and as such it

  18. Self-Models and Relationship Threat

    Directory of Open Access Journals (Sweden)

    Máire B. Ford

    2015-07-01

    Full Text Available This study investigated a key claim of risk regulation theory, namely, that psychological internalizing of a relationship threat will serve as a mediator of the link between self-models (self-esteem and attachment anxiety and relationship responses (moving closer to a partner vs. distancing from a partner. Participants (N = 101 received feedback that threatened their current romantic relationship (or no feedback and then completed measures of internal–external focus, relationship closeness–distancing, and acceptance–rejection of the feedback. Results showed that participants with negative self-models responded to the relationship threat by becoming more internally focused and by distancing from their partners, whereas those with positive self-models became more externally focused and moved closer to their partners. Mediation analyses indicated that the link between self-models and relationship closeness–distancing was partially explained by internal focus.

  19. Quantitative structure-property relationships for octanol-water partition coefficients of polybrominated diphenyl ethers.

    Science.gov (United States)

    Li, Linnan; Xie, Shaodong; Cai, Hao; Bai, Xuetao; Xue, Zhao

    2008-08-01

    Theoretical molecular descriptors were tested against logK(OW) values for polybrominated diphenyl ethers (PBDEs) using the Partial Least-Squares Regression method which can be used to analyze data with many variables and few observations. A quantitative structure-property relationship (QSPR) model was successfully developed with a high cross-validated value (Q(cum)(2)) of 0.961, indicating a good predictive ability and stability of the model. The predictive power of the QSPR model was further cross-validated. The values of logK(OW) for PBDEs are mainly governed by molecular surface area, energy of the lowest unoccupied molecular orbital and the net atomic charges on the oxygen atom. All these descriptors have been discussed to interpret the partitioning mechanism of PBDE chemicals. The bulk property of the molecules represented by molecular surface area is the leading factor, and K(OW) values increase with the increase of molecular surface area. Higher energy of the lowest unoccupied molecular orbital and higher net atomic charge on the oxygen atom of PBDEs result in smaller K(OW). The energy of the lowest unoccupied molecular orbital and the net atomic charge on PBDEs oxygen also play important roles in affecting the partition of PBDEs between octanol and water by influencing the interactions between PBDEs and solvent molecules.

  20. Relationships between models of concurrency

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Sassone, Vladimiro; Winskel, Glynn

    1994-01-01

    Models for concurrency can be classified with respect to the three relevant parameters: behaviour/system, interleaving/noninterleaving, linear/branching time. When modelling a process, a choice concerning such parameters corresponds to choosing the level of abstraction of the resulting semantics....

  1. Quantitative structure-property relationship study of n-octanol-water partition coefficients of some of diverse drugs using multiple linear regression

    International Nuclear Information System (INIS)

    Ghasemi, Jahanbakhsh; Saaidpour, Saadi

    2007-01-01

    A quantitative structure-property relationship (QSPR) study was performed to develop models those relate the structures of 150 drug organic compounds to their n-octanol-water partition coefficients (log P o/w ). Molecular descriptors derived solely from 3D structures of the molecular drugs. A genetic algorithm was also applied as a variable selection tool in QSPR analysis. The models were constructed using 110 molecules as training set, and predictive ability tested using 40 compounds. Modeling of log P o/w of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR). Four descriptors for these compounds molecular volume (MV) (geometrical), hydrophilic-lipophilic balance (HLB) (constitutional), hydrogen bond forming ability (HB) (electronic) and polar surface area (PSA) (electrostatic) are taken as inputs for the model. The use of descriptors calculated only from molecular structure eliminates the need for experimental determination of properties for use in the correlation and allows for the estimation of log P o/w for molecules not yet synthesized. Application of the developed model to a testing set of 40 drug organic compounds demonstrates that the model is reliable with good predictive accuracy and simple formulation. The prediction results are in good agreement with the experimental value. The root mean square error of prediction (RMSEP) and square correlation coefficient (R 2 ) for MLR model were 0.22 and 0.99 for the prediction set log P o/w

  2. Designing Customer Relationship Management Model in Hospital

    OpenAIRE

    Mohammad Abbaszadeh; Roohollah Askari; Morad Alizadeh; Mohammad Amin Bahrami

    2017-01-01

    Background: Customer relationship management is a modern marketing concept which is also considered as a successful business strategy. The present study aimed to design a customer relationship management model in the hospital. Methods: The study is an applied research performed in 2 phases of 1) texts investigation and 2) the experts' opinions to achieve consensus. Data were analyzed using SPSS 18 software along with descriptive statistics. Results: The designed model included areas of ...

  3. Quantitative structure-property relationships of electroluminescent ...

    Indian Academy of Sciences (India)

    Thus, support vector machine is a good method to build QSPR models to predict the ... For high-quality OLED dis- ... it provides a guide to the development process and speeds up ... The free software ChemSketch 12.0 was used to draw 2-D.

  4. Adaptive regression for modeling nonlinear relationships

    CERN Document Server

    Knafl, George J

    2016-01-01

    This book presents methods for investigating whether relationships are linear or nonlinear and for adaptively fitting appropriate models when they are nonlinear. Data analysts will learn how to incorporate nonlinearity in one or more predictor variables into regression models for different types of outcome variables. Such nonlinear dependence is often not considered in applied research, yet nonlinear relationships are common and so need to be addressed. A standard linear analysis can produce misleading conclusions, while a nonlinear analysis can provide novel insights into data, not otherwise possible. A variety of examples of the benefits of modeling nonlinear relationships are presented throughout the book. Methods are covered using what are called fractional polynomials based on real-valued power transformations of primary predictor variables combined with model selection based on likelihood cross-validation. The book covers how to formulate and conduct such adaptive fractional polynomial modeling in the s...

  5. Excited States and Photodebromination of Selected Polybrominated Diphenyl Ethers: Computational and Quantitative Structure—Property Relationship Studies

    Directory of Open Access Journals (Sweden)

    Jin Luo

    2015-01-01

    Full Text Available This paper presents a density functional theory (DFT/time-dependent DFT (TD-DFT study on the lowest lying singlet and triplet excited states of 20 selected polybrominateddiphenyl ether (PBDE congeners, with the solvation effect included in the calculations using the polarized continuum model (PCM. The results obtained showed that for most of the brominated diphenyl ether (BDE congeners, the lowest singlet excited state was initiated by the electron transfer from HOMO to LUMO, involving a π–σ* excitation. In triplet excited states, structure of the BDE congeners differed notably from that of the BDE ground states with one of the specific C–Br bonds bending off the aromatic plane. In addition, the partial least squares regression (PLSR, principal component analysis-multiple linear regression analysis (PCA-MLR, and back propagation artificial neural network (BP-ANN approaches were employed for a quantitative structure-property relationship (QSPR study. Based on the previously reported kinetic data for the debromination by ultraviolet (UV and sunlight, obtained QSPR models exhibited a reasonable evaluation of the photodebromination reactivity even when the BDE congeners had same degree of bromination, albeit different patterns of bromination.

  6. Adsorption of s-triazines onto polybenzimidazole: A quantitative structure-property relationship investigation

    Energy Technology Data Exchange (ETDEWEB)

    D' Archivio, Angelo Antonio, E-mail: angeloantonio.darchivio@univaq.it [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi dell' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy); Incani, Angela; Mazzeo, Pietro; Ruggieri, Fabrizio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi dell' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)

    2009-09-21

    The adsorption of 25 symmetric triazines (s-triazines) on polybenzimidazole (PBI) beads is investigated under equilibrium (batch) conditions. The observed adsorption isotherms of the selected compounds are accurately described by the Freundlich model, while the agreement between the Langmuir model and the experimental data is moderately worse, which seems to reflect the heterogeneous meso- and micro-porosity of PBI and polydispersion in the interaction mechanism. Methylthio- and methoxytriazines exhibit a greater adsorption tendency as compared with chlorotriazines, moreover, progressive dealkylation of amino groups results in a progressive increase of triazine uptake on PBI. Based on these evidences, the adsorption mechanism seems to be governed by a combination of {pi}-{pi} and hydrogen-bonding interactions. Genetic algorithm (GA) variable selection and multilinear regression (MLR) are combined in order to describe the effect of triazine structure on the extraction performance of PBI according to the quantitative structure-property relationship (QSPR) method. q{sub max}, the amount of triazine adsorbed per weight unit of PBI assuming homogeneous monolayer (Langmuir) mechanism, exhibits a great variability within the set of investigated triazines and is the quantity here modelled by QSPR. On the other hand, the Freundlich constant, K{sub F}, which expresses the adsorption efficiency under multilayer heterogeneous conditions, even if markedly increases passing from chloro- to methylthio- or methoxytriazines, is less noticeably affected by the fine details of the adsorbate structure, as the number or nature of alkyl fragments bound to the amino groups. To quantitatively relate q{sub max} with the triazine structure GA-MLR analysis is performed on the set of 1664 theoretical molecular descriptors provided by the software Dragon. Finally, a four-dimensional QSPR model is selected based on leave-one-out cross-validation and its prediction ability is further tested on

  7. Adsorption of s-triazines onto polybenzimidazole: A quantitative structure-property relationship investigation

    International Nuclear Information System (INIS)

    D'Archivio, Angelo Antonio; Incani, Angela; Mazzeo, Pietro; Ruggieri, Fabrizio

    2009-01-01

    The adsorption of 25 symmetric triazines (s-triazines) on polybenzimidazole (PBI) beads is investigated under equilibrium (batch) conditions. The observed adsorption isotherms of the selected compounds are accurately described by the Freundlich model, while the agreement between the Langmuir model and the experimental data is moderately worse, which seems to reflect the heterogeneous meso- and micro-porosity of PBI and polydispersion in the interaction mechanism. Methylthio- and methoxytriazines exhibit a greater adsorption tendency as compared with chlorotriazines, moreover, progressive dealkylation of amino groups results in a progressive increase of triazine uptake on PBI. Based on these evidences, the adsorption mechanism seems to be governed by a combination of π-π and hydrogen-bonding interactions. Genetic algorithm (GA) variable selection and multilinear regression (MLR) are combined in order to describe the effect of triazine structure on the extraction performance of PBI according to the quantitative structure-property relationship (QSPR) method. q max , the amount of triazine adsorbed per weight unit of PBI assuming homogeneous monolayer (Langmuir) mechanism, exhibits a great variability within the set of investigated triazines and is the quantity here modelled by QSPR. On the other hand, the Freundlich constant, K F , which expresses the adsorption efficiency under multilayer heterogeneous conditions, even if markedly increases passing from chloro- to methylthio- or methoxytriazines, is less noticeably affected by the fine details of the adsorbate structure, as the number or nature of alkyl fragments bound to the amino groups. To quantitatively relate q max with the triazine structure GA-MLR analysis is performed on the set of 1664 theoretical molecular descriptors provided by the software Dragon. Finally, a four-dimensional QSPR model is selected based on leave-one-out cross-validation and its prediction ability is further tested on four

  8. Cheminformatics Modeling of Amine Solutions for Assessing their CO2 Absorption Properties.

    Science.gov (United States)

    Kuenemann, Melaine A; Fourches, Denis

    2017-07-01

    As stricter regulations on CO 2 emissions are adopted worldwide, identifying efficient chemical processes to capture and recycle CO 2 is of critical importance for industry. The most common process known as amine scrubbing suffers from the lack of available amine solutions capable of capturing CO 2 efficiently. Tertiary amines characterized by low heats of reaction are considered good candidates but their absorption properties can significantly differ from one analogue to another despite high structural similarity. Herein, after collecting and curating experimental data from the literature, we have built a modeling set of 41 amine structures with their absorption properties. Then we analyzed their chemical composition using molecular descriptors and non-supervised clustering. Furthermore, we developed a series of quantitative structure-property relationships (QSPR) to assess amines' CO 2 absorption properties from their structural characteristics. These models afforded reasonable prediction performances (e. g., Q 2 LOO =0.63 for CO 2 absorption amount) even though they are solely based on 2D chemical descriptors and individual machine learning techniques (random forest and neural network). Overall, we believe the chemical analysis and the series of QSPR models presented in this proof-of-concept study represent new knowledge and innovative tools that could be very useful for screening and prioritizing hypothetical amines to be synthesized and tested experimentally for their CO 2 absorption properties. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Scaling and constitutive relationships in downcomer modeling

    International Nuclear Information System (INIS)

    Daly, B.J.; Harlow, F.H.

    1978-12-01

    Constitutive relationships to describe mass and momentum exchange in multiphase flow in a pressurized water reactor downcomer are presented. Momentum exchange between the phases is described by the product of the flux of momentum available for exchange and the effective area for interaction. The exchange of mass through condensation is assumed to occur along a distinct condensation boundary separating steam at saturation temperature from water in which the temperature falls off roughly linearly with distance from the boundary. Because of the abundance of nucleation sites in a typical churning flow in a downcomer, we propose an equilibrium evaporation process that produces sufficient steam per unit time to keep the water perpetually cooled to the saturation temperature. The transport equations, constitutive models, and boundary conditions used in the K-TIF numerical method are nondimensionalized to obtain scaling relationships for two-phase flow in the downcomer. The results indicate that, subject to idealized thermodynamic and hydraulic constraints, exact mathematical scaling can be achieved. Experiments are proposed to isolate the effects of parameters that contribute to mass, momentum, and energy exchange between the phases

  10. A quantitative structure- property relationship of gas chromatographic/mass spectrometric retention data of 85 volatile organic compounds as air pollutant materials by multivariate methods

    Directory of Open Access Journals (Sweden)

    Sarkhosh Maryam

    2012-05-01

    Full Text Available Abstract A quantitative structure-property relationship (QSPR study is suggested for the prediction of retention times of volatile organic compounds. Various kinds of molecular descriptors were calculated to represent the molecular structure of compounds. Modeling of retention times of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR and artificial neural network (ANN. The stepwise regression was used for the selection of the variables which gives the best-fitted models. After variable selection ANN, MLR methods were used with leave-one-out cross validation for building the regression models. The prediction results are in very good agreement with the experimental values. MLR as the linear regression method shows good ability in the prediction of the retention times of the prediction set. This provided a new and effective method for predicting the chromatography retention index for the volatile organic compounds.

  11. Comparing estimates of genetic variance across different relationship models.

    Science.gov (United States)

    Legarra, Andres

    2016-02-01

    Use of relationships between individuals to estimate genetic variances and heritabilities via mixed models is standard practice in human, plant and livestock genetics. Different models or information for relationships may give different estimates of genetic variances. However, comparing these estimates across different relationship models is not straightforward as the implied base populations differ between relationship models. In this work, I present a method to compare estimates of variance components across different relationship models. I suggest referring genetic variances obtained using different relationship models to the same reference population, usually a set of individuals in the population. Expected genetic variance of this population is the estimated variance component from the mixed model times a statistic, Dk, which is the average self-relationship minus the average (self- and across-) relationship. For most typical models of relationships, Dk is close to 1. However, this is not true for very deep pedigrees, for identity-by-state relationships, or for non-parametric kernels, which tend to overestimate the genetic variance and the heritability. Using mice data, I show that heritabilities from identity-by-state and kernel-based relationships are overestimated. Weighting these estimates by Dk scales them to a base comparable to genomic or pedigree relationships, avoiding wrong comparisons, for instance, "missing heritabilities". Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Modeling rainfall-runoff relationship using multivariate GARCH model

    Science.gov (United States)

    Modarres, R.; Ouarda, T. B. M. J.

    2013-08-01

    The traditional hydrologic time series approaches are used for modeling, simulating and forecasting conditional mean of hydrologic variables but neglect their time varying variance or the second order moment. This paper introduces the multivariate Generalized Autoregressive Conditional Heteroscedasticity (MGARCH) modeling approach to show how the variance-covariance relationship between hydrologic variables varies in time. These approaches are also useful to estimate the dynamic conditional correlation between hydrologic variables. To illustrate the novelty and usefulness of MGARCH models in hydrology, two major types of MGARCH models, the bivariate diagonal VECH and constant conditional correlation (CCC) models are applied to show the variance-covariance structure and cdynamic correlation in a rainfall-runoff process. The bivariate diagonal VECH-GARCH(1,1) and CCC-GARCH(1,1) models indicated both short-run and long-run persistency in the conditional variance-covariance matrix of the rainfall-runoff process. The conditional variance of rainfall appears to have a stronger persistency, especially long-run persistency, than the conditional variance of streamflow which shows a short-lived drastic increasing pattern and a stronger short-run persistency. The conditional covariance and conditional correlation coefficients have different features for each bivariate rainfall-runoff process with different degrees of stationarity and dynamic nonlinearity. The spatial and temporal pattern of variance-covariance features may reflect the signature of different physical and hydrological variables such as drainage area, topography, soil moisture and ground water fluctuations on the strength, stationarity and nonlinearity of the conditional variance-covariance for a rainfall-runoff process.

  13. Models for risk assessment of reactive chemicals in aquatic toxicology

    NARCIS (Netherlands)

    Freidig, Andreas Peter

    2000-01-01

    A quantitative structure property relationship (QSPR) for a,b-unsaturated carboxylates (mainly acrylates and methacrylates) was established in chapter 2. Chemical reaction rate constants were measured for 12 different chemicals with three different nucleophiles, namely H 2 O, OH - and glutathione

  14. A curious relationship between Potts glass models

    Science.gov (United States)

    Yamaguchi, Chiaki

    2015-08-01

    A Potts glass model proposed by Nishimori and Stephen [H. Nishimori, M.J. Stephen, Phys. Rev. B 27, 5644 (1983)] is analyzed by means of the replica mean field theory. This model is a discrete model, has a gauge symmetry, and is called the Potts gauge glass model. By comparing the present results with the results of the conventional Potts glass model, we find the coincidences and differences between the models. We find a coincidence that the property for the Potts glass phase in this model is coincident with that in the conventional model at the mean field level. We find a difference that, unlike in the case of the conventional p-state Potts glass model, this system for large p does not become ferromagnetic at low temperature under a concentration of ferromagnetic interaction. The present results support the act of numerically investigating the present model for study of the Potts glass phase in finite dimensions.

  15. Inclusion of Switching Behaviour into Relationship Marketing Model

    DEFF Research Database (Denmark)

    Alnaimi, Husam; Jones, Richard; Perkins, Helen

    2011-01-01

    Relationship marketing authors have attempted to develop distinct models suitable for investigating relationship marketing in different contexts. However, there is no agreement as yet about the antecedents that best capture the characteristics of the relational exchange that influences relationship...... marketing. Maintaining a long-term relationship with a customer is one of the fundamental factors determining the value that the customer provides to the company. A serious threat to achieving a long-term relationship is the customer’s switching behaviour. This study develops a theoretical model...... of relationship marketing, which includes customers’ switching behaviour (switchers and stayers), as a vital construct to understand the relationship development process between customers and service providers. Also, hypotheses to specify the association between the underlying models’ constructs were presented...

  16. Information retrieval models foundations and relationships

    CERN Document Server

    Roelleke, Thomas

    2013-01-01

    Information Retrieval (IR) models are a core component of IR research and IR systems. The past decade brought a consolidation of the family of IR models, which by 2000 consisted of relatively isolated views on TF-IDF (Term-Frequency times Inverse-Document-Frequency) as the weighting scheme in the vector-space model (VSM), the probabilistic relevance framework (PRF), the binary independence retrieval (BIR) model, BM25 (Best-Match Version 25, the main instantiation of the PRF/BIR), and language modelling (LM). Also, the early 2000s saw the arrival of divergence from randomness (DFR).Regarding in

  17. Internal Representational Models of Attachment Relationships.

    Science.gov (United States)

    Crittenden, Patricia M.

    This paper outlines several properties of internal representational models (IRMs) and offers terminology that may help to differentiate the models. Properties of IRMs include focus, memory systems, content, cognitive function, "metastructure," quality of attachment, behavioral strategies, and attitude toward attachment. An IRM focuses on…

  18. Modeling the binding affinity of structurally diverse industrial chemicals to carbon using the artificial intelligence approaches.

    Science.gov (United States)

    Gupta, Shikha; Basant, Nikita; Rai, Premanjali; Singh, Kunwar P

    2015-11-01

    Binding affinity of chemical to carbon is an important characteristic as it finds vast industrial applications. Experimental determination of the adsorption capacity of diverse chemicals onto carbon is both time and resource intensive, and development of computational approaches has widely been advocated. In this study, artificial intelligence (AI)-based ten different qualitative and quantitative structure-property relationship (QSPR) models (MLPN, RBFN, PNN/GRNN, CCN, SVM, GEP, GMDH, SDT, DTF, DTB) were established for the prediction of the adsorption capacity of structurally diverse chemicals to activated carbon following the OECD guidelines. Structural diversity of the chemicals and nonlinear dependence in the data were evaluated using the Tanimoto similarity index and Brock-Dechert-Scheinkman statistics. The generalization and prediction abilities of the constructed models were established through rigorous internal and external validation procedures performed employing a wide series of statistical checks. In complete dataset, the qualitative models rendered classification accuracies between 97.04 and 99.93%, while the quantitative models yielded correlation (R(2)) values of 0.877-0.977 between the measured and the predicted endpoint values. The quantitative prediction accuracies for the higher molecular weight (MW) compounds (class 4) were relatively better than those for the low MW compounds. Both in the qualitative and quantitative models, the Polarizability was the most influential descriptor. Structural alerts responsible for the extreme adsorption behavior of the compounds were identified. Higher number of carbon and presence of higher halogens in a molecule rendered higher binding affinity. Proposed QSPR models performed well and outperformed the previous reports. A relatively better performance of the ensemble learning models (DTF, DTB) may be attributed to the strengths of the bagging and boosting algorithms which enhance the predictive accuracies. The

  19. modelling relationship between rainfall variability and yields

    African Journals Online (AJOL)

    , S. and ... factors to rice yield. Adebayo and Adebayo (1997) developed double log multiple regression model to predict rice yield in Adamawa State, Nigeria. The general form of .... the second are the crop yield/values for millet and sorghum ...

  20. Personality, relationship conflict, and teamwork-related mental models

    NARCIS (Netherlands)

    Vîrgă, D.; Curseu, P.L.; Maricuţoiu, L.; Sava, S.A.; Macsinga, I.; Măgurean, S.

    2014-01-01

    This study seeks to explore whether neuroticism, agreeableness, and conscientiousness moderate the influence of relationship conflict experienced in groups on changes in group members' evaluative cognitions related to teamwork quality (teamwork-related mental models). Data from 216 students, nested

  1. Game Theory and its Relationship with Linear Programming Models ...

    African Journals Online (AJOL)

    Game Theory and its Relationship with Linear Programming Models. ... This paper shows that game theory and linear programming problem are closely related subjects since any computing method devised for ... AJOL African Journals Online.

  2. Event-Entity-Relationship Modeling in Data Warehouse Environments

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    We use the event-entity-relationship model (EVER) to illustrate the use of entity-based modeling languages for conceptual schema design in data warehouse environments. EVER is a general-purpose information modeling language that supports the specification of both general schema structures and multi...

  3. Constitutive relationships and models in continuum theories of multiphase flows

    International Nuclear Information System (INIS)

    Decker, R.

    1989-09-01

    In April, 1989, a workshop on constitutive relationships and models in continuum theories of multiphase flows was held at NASA's Marshall Space Flight Center. Topics of constitutive relationships for the partial or per phase stresses, including the concept of solid phase pressure are discussed. Models used for the exchange of mass, momentum, and energy between the phases in a multiphase flow are also discussed. The program, abstracts, and texts of the presentations from the workshop are included

  4. Relationship Management: Towards a Holistic model

    DEFF Research Database (Denmark)

    Andersen, Poul Houman

    2006-01-01

     This contribution provides a ground plan for managing the networked enterprise as a central aspect in 21st century organizations. It builds upon and synthesizes parts of the literature, but provides novel insights from this synthesis as well, using a model, that links three generic network...... management tasks with three levels of management, identifying 9 focus areas. Rather than distinguishing between the management of external and internal resources, integration of external and internal resources are in focus, meaning that all managerial tasks hold consequences both internally and externally...

  5. Grid-based Continual Analysis of Molecular Interior for Drug Discovery, QSAR and QSPR.

    Science.gov (United States)

    Potemkin, Andrey V; Grishina, Maria A; Potemkin, Vladimir A

    2017-01-01

    In 1979, R.D.Cramer and M.Milne made a first realization of 3D comparison of molecules by aligning them in space and by mapping their molecular fields to a 3D grid. Further, this approach was developed as the DYLOMMS (Dynamic Lattice- Oriented Molecular Modelling System) approach. In 1984, H.Wold and S.Wold proposed the use of partial least squares (PLS) analysis, instead of principal component analysis, to correlate the field values with biological activities. Then, in 1988, the method which was called CoMFA (Comparative Molecular Field Analysis) was introduced and the appropriate software became commercially available. Since 1988, a lot of 3D QSAR methods, algorithms and their modifications are introduced for solving of virtual drug discovery problems (e.g., CoMSIA, CoMMA, HINT, HASL, GOLPE, GRID, PARM, Raptor, BiS, CiS, ConGO,). All the methods can be divided into two groups (classes):1. Methods studying the exterior of molecules; 2) Methods studying the interior of molecules. A series of grid-based computational technologies for Continual Molecular Interior analysis (CoMIn) are invented in the current paper. The grid-based analysis is fulfilled by means of a lattice construction analogously to many other grid-based methods. The further continual elucidation of molecular structure is performed in various ways. (i) In terms of intermolecular interactions potentials. This can be represented as a superposition of Coulomb, Van der Waals interactions and hydrogen bonds. All the potentials are well known continual functions and their values can be determined in all lattice points for a molecule. (ii) In the terms of quantum functions such as electron density distribution, Laplacian and Hamiltonian of electron density distribution, potential energy distribution, the highest occupied and the lowest unoccupied molecular orbitals distribution and their superposition. To reduce time of calculations using quantum methods based on the first principles, an original quantum

  6. Relationships between water table and model simulated ET

    Science.gov (United States)

    Prem B. Parajuli; Gretchen F. Sassenrath; Ying Ouyang

    2013-01-01

    This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km2) within the Yazoo River Basin...

  7. [RELATIONSHIP BETWEEN JUNIOR AND SENIOR DOCTORS: A BUBERIAN MODEL].

    Science.gov (United States)

    Pougnet, Richard; Pougnet, Laurence

    2016-01-01

    Doctors in training work in services under the supervision of senior doctors. These professional relationships may lead to frustrations, or ill-being at work. Indeed doctors are often very busy with care and can hardly communicate. The purpose of this article is to propose ways to think in its ethical dimension this relationship, by learning from Martin Buber's ideas. He thought a philosophy of relationship in two word pairs: I-Thou and I-It. This thought can be useful in the context of the médical relationship and mentorship. Indeed we can see our colleague as a person or only as a caregiver. We offer a relationship model according to buberian thought, between junior and senior doctor caring about the same patients.

  8. Personality, Relationship Conflict, and Teamwork-Related Mental Models

    Science.gov (United States)

    Vîrgă, Delia; CurŞeu, Petru Lucian; Maricuţoiu, Laurenţiu; Sava, Florin A.; Macsinga, Irina; Măgurean, Silvia

    2014-01-01

    This study seeks to explore whether neuroticism, agreeableness, and conscientiousness moderate the influence of relationship conflict experienced in groups on changes in group members' evaluative cognitions related to teamwork quality (teamwork-related mental models). Data from 216 students, nested in 48 groups were analyzed using a multilevel modeling approach. Our results show that the experience of relationship conflict leads to a negative shift from the pre-task to the post-task teamwork-related mental models. Moreover, the results indicate that conscientiousness buffered the negative association between relationship conflict and the change in teamwork-related mental models. Our results did not support the hypothesized moderating effect of agreeableness and show that the detrimental effect of relationship conflict on the shift in teamwork-related mental models is accentuated for group members scoring low rather than high on neuroticism. These findings open new research venues for exploring the association between personality, coping styles and change in teamwork-related mental models. PMID:25372143

  9. Personality, relationship conflict, and teamwork-related mental models.

    Directory of Open Access Journals (Sweden)

    Delia Vîrgă

    Full Text Available This study seeks to explore whether neuroticism, agreeableness, and conscientiousness moderate the influence of relationship conflict experienced in groups on changes in group members' evaluative cognitions related to teamwork quality (teamwork-related mental models. Data from 216 students, nested in 48 groups were analyzed using a multilevel modeling approach. Our results show that the experience of relationship conflict leads to a negative shift from the pre-task to the post-task teamwork-related mental models. Moreover, the results indicate that conscientiousness buffered the negative association between relationship conflict and the change in teamwork-related mental models. Our results did not support the hypothesized moderating effect of agreeableness and show that the detrimental effect of relationship conflict on the shift in teamwork-related mental models is accentuated for group members scoring low rather than high on neuroticism. These findings open new research venues for exploring the association between personality, coping styles and change in teamwork-related mental models.

  10. Personality, relationship conflict, and teamwork-related mental models.

    Science.gov (United States)

    Vîrgă, Delia; Curşeu, Petru Lucian; CurŞeu, Petru Lucian; Maricuţoiu, Laurenţiu; Sava, Florin A; Macsinga, Irina; Măgurean, Silvia

    2014-01-01

    This study seeks to explore whether neuroticism, agreeableness, and conscientiousness moderate the influence of relationship conflict experienced in groups on changes in group members' evaluative cognitions related to teamwork quality (teamwork-related mental models). Data from 216 students, nested in 48 groups were analyzed using a multilevel modeling approach. Our results show that the experience of relationship conflict leads to a negative shift from the pre-task to the post-task teamwork-related mental models. Moreover, the results indicate that conscientiousness buffered the negative association between relationship conflict and the change in teamwork-related mental models. Our results did not support the hypothesized moderating effect of agreeableness and show that the detrimental effect of relationship conflict on the shift in teamwork-related mental models is accentuated for group members scoring low rather than high on neuroticism. These findings open new research venues for exploring the association between personality, coping styles and change in teamwork-related mental models.

  11. Event-Entity-Relationship Modeling in Data Warehouse Environments

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    We use the event-entity-relationship model (EVER) to illustrate the use of entity-based modeling languages for conceptual schema design in data warehouse environments. EVER is a general-purpose information modeling language that supports the specification of both general schema structures and multi......-dimensional schemes that are customized to serve specific information needs. EVER is based on an event concept that is very well suited for multi-dimensional modeling because measurement data often represent events in multi-dimensional databases...

  12. Simulating pattern-process relationships to validate landscape genetic models

    Science.gov (United States)

    A. J. Shirk; S. A. Cushman; E. L. Landguth

    2012-01-01

    Landscapes may resist gene flow and thereby give rise to a pattern of genetic isolation within a population. The mechanism by which a landscape resists gene flow can be inferred by evaluating the relationship between landscape models and an observed pattern of genetic isolation. This approach risks false inferences because researchers can never feasibly test all...

  13. Modeling the Relationships between Subdimensions of Environmental Literacy

    Science.gov (United States)

    Genc, Murat; Akilli, Mustafa

    2016-01-01

    The aim of this study is to demonstrate the relationships between subdimensions of environmental literacy using Structural Equation Modeling (SEM). The study was conducted by the analysis of students' answers to questionnaires data using SEM. Initially, Kaiser-Meyer-Olkin and Bartlett's tests were done to test appropriateness of subdimensions to…

  14. QUANTITATIVE ANALYSIS OF RELATIONSHIP STRUCTURE AND ANIONIC SURFACTANT MICELLE CONCENTRATION CRITIC WITH SEMIEMPIRIS AM1

    Directory of Open Access Journals (Sweden)

    Eva Vaulina Yulistia Delsy

    2017-05-01

    Full Text Available This research determines the mathematical equation which calculate the Concentration Micelle Critic theoretical anionic surfactant. The research was conducted the depiction of each surfactant anionic three-dimensional compound models, followed by optimizing the model structure anionic surfactant by using AM1 calculation method. Furthermore the calculation of descriptors (QSPR method, then it was analyzed statistically using Multiple Linear Regression (MLR. The results of statistical calculations showed that to calculate the theoretical CMC anionic surfactant can use the QSPR equation: log CMC = 4.157+0.118qC1+7.698qC2+0.425α–0.010µ-0.129RD–0.138 log P+0.021BM–0.034Avdw, n = 100 ; r = 0.927 ; r2 = 0.860 ; SE = 0.352 ; F= 30.888 ; PRESS = 23.506

  15. Modeling process-structure-property relationships for additive manufacturing

    Science.gov (United States)

    Yan, Wentao; Lin, Stephen; Kafka, Orion L.; Yu, Cheng; Liu, Zeliang; Lian, Yanping; Wolff, Sarah; Cao, Jian; Wagner, Gregory J.; Liu, Wing Kam

    2018-02-01

    This paper presents our latest work on comprehensive modeling of process-structure-property relationships for additive manufacturing (AM) materials, including using data-mining techniques to close the cycle of design-predict-optimize. To illustrate the processstructure relationship, the multi-scale multi-physics process modeling starts from the micro-scale to establish a mechanistic heat source model, to the meso-scale models of individual powder particle evolution, and finally to the macro-scale model to simulate the fabrication process of a complex product. To link structure and properties, a highefficiency mechanistic model, self-consistent clustering analyses, is developed to capture a variety of material response. The model incorporates factors such as voids, phase composition, inclusions, and grain structures, which are the differentiating features of AM metals. Furthermore, we propose data-mining as an effective solution for novel rapid design and optimization, which is motivated by the numerous influencing factors in the AM process. We believe this paper will provide a roadmap to advance AM fundamental understanding and guide the monitoring and advanced diagnostics of AM processing.

  16. Derivatives in discrete mathematics: a novel graph-theoretical invariant for generating new 2/3D molecular descriptors. I. Theory and QSPR application.

    Science.gov (United States)

    Marrero-Ponce, Yovani; Santiago, Oscar Martínez; López, Yoan Martínez; Barigye, Stephen J; Torrens, Francisco

    2012-11-01

    among different atoms, an atomic weighting scheme (atom-type labels) is used in the formation of the matrix Q or in LOVIs state. The obtained indices were utilized to describe the partition coefficient (Log P) and the reactivity index (Log K) of the 34 derivatives of 2-furylethylenes. In all the cases, our MDs showed better statistical results than those previously obtained using some of the most used families of MDs in chemometric practice. Therefore, it has been demonstrated to that the proposed MDs are useful in molecular design and permit obtaining easier and robust mathematical models than the majority of those reported in the literature. All this range of mentioned possibilities open "the doors" to the creation of a new family of MDs, using the graph derivative, and avail a new tool for QSAR/QSPR and molecular diversity/similarity studies.

  17. OPERA models for predicting physicochemical properties and environmental fate endpoints.

    Science.gov (United States)

    Mansouri, Kamel; Grulke, Chris M; Judson, Richard S; Williams, Antony J

    2018-03-08

    The collection of chemical structure information and associated experimental data for quantitative structure-activity/property relationship (QSAR/QSPR) modeling is facilitated by an increasing number of public databases containing large amounts of useful data. However, the performance of QSAR models highly depends on the quality of the data and modeling methodology used. This study aims to develop robust QSAR/QSPR models for chemical properties of environmental interest that can be used for regulatory purposes. This study primarily uses data from the publicly available PHYSPROP database consisting of a set of 13 common physicochemical and environmental fate properties. These datasets have undergone extensive curation using an automated workflow to select only high-quality data, and the chemical structures were standardized prior to calculation of the molecular descriptors. The modeling procedure was developed based on the five Organization for Economic Cooperation and Development (OECD) principles for QSAR models. A weighted k-nearest neighbor approach was adopted using a minimum number of required descriptors calculated using PaDEL, an open-source software. The genetic algorithms selected only the most pertinent and mechanistically interpretable descriptors (2-15, with an average of 11 descriptors). The sizes of the modeled datasets varied from 150 chemicals for biodegradability half-life to 14,050 chemicals for logP, with an average of 3222 chemicals across all endpoints. The optimal models were built on randomly selected training sets (75%) and validated using fivefold cross-validation (CV) and test sets (25%). The CV Q 2 of the models varied from 0.72 to 0.95, with an average of 0.86 and an R 2 test value from 0.71 to 0.96, with an average of 0.82. Modeling and performance details are described in QSAR model reporting format and were validated by the European Commission's Joint Research Center to be OECD compliant. All models are freely available as an open

  18. Model Pengukuran Kinerja Customer Relationship Management dalam Industri Perbankan

    Directory of Open Access Journals (Sweden)

    Freddy Simbolon

    2014-05-01

    Full Text Available High competition in the banking industry requires the banking industry to properly manage relationships with customers, as it is known as Customer Relationship Management (CRM. CRM applications will become effective when supported by information technology. Investment in information technology is not a small investment, because the higher the information technology, the greater the value of the investment. This study aims to obtain a model of CRM performance measurement in the banking industry efficiently and effective. The method in this study uses descriptive analytical method, while the results obtained in this study is a CRM Scorecard. CRM Scorecard is one of the approach models that correctly measure the performance of CRM, which is based on information technology. Through CRM Scorecard approach, information technology investment in CRM is no longer seen as a cost center, but seen to be a profit center, because the company can manage customers efficiently and effectively in order to enhance shareholder value in the future.

  19. Relationship Marketing results: proposition of a cognitive mapping model

    Directory of Open Access Journals (Sweden)

    Iná Futino Barreto

    2015-12-01

    Full Text Available Objective - This research sought to develop a cognitive model that expresses how marketing professionals understand the relationship between the constructs that define relationship marketing (RM. It also tried to understand, using the obtained model, how objectives in this field are achieved. Design/methodology/approach – Through cognitive mapping, we traced 35 individual mental maps, highlighting how each respondent understands the interactions between RM elements. Based on the views of these individuals, we established an aggregate mental map. Theoretical foundation – The topic is based on a literature review that explores the RM concept and its main elements. Based on this review, we listed eleven main constructs. Findings – We established an aggregate mental map that represents the RM structural model. Model analysis identified that CLV is understood as the final result of RM. We also observed that the impact of most of the RM elements on CLV is brokered by loyalty. Personalization and quality, on the other hand, proved to be process input elements, and are the ones that most strongly impact others. Finally, we highlight that elements that punish customers are much less effective than elements that benefit them. Contributions - The model was able to insert core elements of RM, but absent from most formal models: CLV and customization. The analysis allowed us to understand the interactions between the RM elements and how the end result of RM (CLV is formed. This understanding improves knowledge on the subject and helps guide, assess and correct actions.

  20. Incentive Model Based on Cooperative Relationship in Sustainable Construction Projects

    Directory of Open Access Journals (Sweden)

    Guangdong Wu

    2017-07-01

    Full Text Available Considering the cooperative relationship between owners and contractors in sustainable construction projects, as well as the synergistic effects created by cooperative behaviors, a cooperative incentive model was developed using game theory. The model was formulated and analyzed under both non-moral hazard and moral hazard situations. Then, a numerical simulation and example were proposed to verify the conclusions derived from the model. The results showed that the synergistic effect increases the input intensity of one party’s resource transfer into the increase of marginal utility of the other party, thus the owner and contractor are willing to enhance their levels of effort. One party’s optimal benefit allocation coefficient is positively affected by its own output efficiency, and negatively affected by the other party’s output efficiency. The effort level and expected benefits of the owner and contractor can be improved by enhancing the cooperative relationship between the two parties, as well as enhancing the net benefits of a sustainable construction project. The synergistic effect cannot lower the negative effect of moral hazard behaviors during the implementation of sustainable construction projects. Conversely, the higher levels of the cooperative relationship, the wider the gaps amongst the optimal values under both non-moral hazard and moral hazard situations for the levels of effort, expected benefits and net project benefits. Since few studies to date have emphasized the effects of cooperative relationship on sustainable construction projects, this study constructed a game-based incentive model to bridge the gaps. This study contributes significant theoretical and practical insights into the management of cooperation amongst stakeholders, and into the enhancement of the overall benefits of sustainable construction projects.

  1. Some hybrid models applicable to dose-response relationships

    International Nuclear Information System (INIS)

    Kumazawa, Shigeru

    1992-01-01

    A new type of models of dose-response relationships has been studied as an initial stage to explore a reliable extrapolation of the relationships decided by high dose data to the range of low dose covered by radiation protection. The approach is to use a 'hybrid scale' of linear and logarithmic scales; the first model is that the normalized surviving fraction (ρ S > 0) in a hybrid scale decreases linearly with dose in a linear scale, and the second is that the induction in a log scale increases linearly with the normalized dose (τ D > 0) in a hybrid scale. The hybrid scale may reflect an overall effectiveness of a complex system against adverse events caused by various agents. Some data of leukemia in the atomic bomb survivors and of rodent experiments were used to show the applicability of hybrid scale models. The results proved that proposed models fit these data not less than the popular linear-quadratic models, providing the possible interpretation of shapes of dose-response curves, e.g. shouldered survival curves varied by recovery time. (author)

  2. Selecting an optimal mixed products using grey relationship model

    Directory of Open Access Journals (Sweden)

    Farshad Faezy Razi

    2013-06-01

    Full Text Available This paper presents an integrated supplier selection and inventory management using grey relationship model (GRM as well as multi-objective decision making process. The proposed model of this paper first ranks different suppliers based on GRM technique and then determines the optimum level of inventory by considering different objectives. To show the implementation of the proposed model, we use some benchmark data presented by Talluri and Baker [Talluri, S., & Baker, R. C. (2002. A multi-phase mathematical programming approach for effective supply chain design. European Journal of Operational Research, 141(3, 544-558.]. The preliminary results indicate that the proposed model of this paper is capable of handling different criteria for supplier selection.

  3. Military-related posttraumatic stress disorder and intimate relationship behaviors: a developing dyadic relationship model.

    Science.gov (United States)

    Gerlock, April A; Grimesey, Jackie; Sayre, George

    2014-07-01

    The protracted conflict in Iraq and Afghanistan and an all-volunteer military has resulted in multiple war zone deployments for many service members. While quick redeployment turnaround has left little time for readjustment for either the service member or family, dealing with the long-term sequelae of combat exposure often leaves families and intimate partners ill-prepared for years after deployments. Using a modified grounded theory approach, digitally recorded couple interviews of 23 couples were purposefully selected from a larger sample of 441 couples to better understand the impact of war zone deployment on the couple. The veteran sample was recruited from a randomly selected cohort of men in treatment for posttraumatic stress disorder (PTSD). Overall, it was found when veterans experiencing deployment-related PTSD reenter or start new intimate relationships they may bring with them a unique cluster of interrelated issues which include PTSD symptoms, physical impairment, high rates of alcohol and/or drug abuse, and psychological and physical aggression. These factors contributed to a dynamic of exacerbating conflict. How these couples approached relationship qualities of mutuality, balanced locus of control and weakness tolerance across six axes of caregiving, disability, responsibility, trauma, communication, and community impacted the couple's capacity to communicate and resolve conflict. This dyadic relationship model is used to help inform implications for clinical practice. © 2013 American Association for Marriage and Family Therapy.

  4. The Relationship Between Resilience and Internet Addiction: A Multiple Mediation Model Through Peer Relationship and Depression.

    Science.gov (United States)

    Zhou, Pingyan; Zhang, Cai; Liu, Jian; Wang, Zhe

    2017-10-01

    Heavy use of the Internet may lead to profound academic problems in elementary students, such as poor grades, academic probation, and even expulsion from school. It is of great concern that Internet addiction problems in elementary school students have increased sharply in recent years. In this study, 58,756 elementary school students from the Henan province of China completed four questionnaires to explore the mechanisms of Internet addiction. The results showed that resilience was negatively correlated with Internet addiction. There were three mediational paths in the model: (a) the mediational path through peer relationship with an effect size of 50.0 percent, (b) the mediational path through depression with an effect size of 15.6 percent, (c) the mediational path through peer relationship and depression with an effect size of 13.7 percent. The total mediational effect size was 79.27 percent. The effect size through peer relationship was the strongest among the three mediation paths. The current findings suggest that resilience is a predictor of Internet addiction. Improving children's resilience (such as toughness, emotional control, and problem solving) can be an effective way to reduce Internet addiction behavior. The current findings provide useful information for early detection and intervention for Internet addiction.

  5. HydroCube: an entity-relationship hydrogeological data model

    Science.gov (United States)

    Wojda, Piotr; Brouyère, Serge; Derouane, Johan; Dassargues, Alain

    2010-12-01

    Managing, handling and accessing hydrogeological information depends heavily on the applied hydrogeological data models, which differ between institutions and countries. The effective dissemination of hydrogeological information requires the convergence of such models to make hydrogeological information accessible to multiple users such as universities, water suppliers, and administration and research organisations. Furthermore, because hydrogeological studies are complex, they require a wide variety of high-quality hydrogeological data with appropriate metadata in clearly designed and coherent structures. A need exists, therefore, to develop and implement hydrogeological data models that cover, as much as possible, the full hydrogeological domain. A new data model, called HydroCube, was developed for the Walloon Region in Belgium in 2005. The HydroCube model presents an innovative holistic project-based approach which covers a full set of hydrogeological concepts and features, allowing for effective hydrogeological project management. The model stores data relating to the project locality, hydrogeological equipment, and related observations and measurements. In particular, it focuses on specialized hydrogeological field experiments such as pumping and tracer tests. This logical data model uses entity-relationship diagrams and it has been implemented in the Microsoft Access environment. It has been enriched with a fully functional user interface.

  6. Modeling of microstructure property relationships in titanium-aluminum-vanadium

    Science.gov (United States)

    Tiley, Jaimie Scott

    Fuzzy logic neural network models were developed to predict the room temperature tensile behavior of Ti-6Al-4V. This involved the development of a database relating microstructure to properties. This necessitated establishing heat treatment processes to develop microstructural features, mechanical testing of samples, creating rigorous stereology procedures, developing numerical models to predict mechanical behavior, and determining trends and inter-relationships relating microstructural features to mechanical properties. Microstructural features were developed using a Gleeble(TM) 1500 Thermal-mechanical simulator. Samples were obtained from mill annealed plate material and both alpha + beta forged and beta forged materials. A total of 72 samples were beta solutionized and heat treated using different heating and cooling conditions. Rigorous stereology procedures were developed to characterize the important microstructural features. The features included Widmanstatten alpha lath thickness, volume fraction of total alpha, volume fraction of Widmanstatten alpha, grain boundary alpha thickness, mean edge length, colony scale factor, and prior beta grain size factor. Chemical composition was also determined using standard chemical analysis and microscopy techniques. The samples were tested for yield strength, ultimate tensile strength, and elongation at room temperature. Results from the tests and the characterization were used to develop fuzzy logic neural network models to predict the mechanical behaviors and develop relationships between the microstructural features (using CubiCalc RTC(TM)). Results were compared to standard multi-variable regression models. The fuzzy logic neural network models were able to predict the yield, and ultimate tensile strength, within acceptable error ranges with a limited number of input data samples. The models also predicted the elongation values but with larger errors. Of particular importance, the models identified the importance of

  7. Externally predictive quantitative modeling of supercooled liquid vapor pressure of polychlorinated-naphthalenes through electron-correlation based quantum-mechanical descriptors.

    Science.gov (United States)

    Vikas; Chayawan

    2014-01-01

    For predicting physico-chemical properties related to environmental fate of molecules, quantitative structure-property relationships (QSPRs) are valuable tools in environmental chemistry. For developing a QSPR, molecular descriptors computed through quantum-mechanical methods are generally employed. The accuracy of a quantum-mechanical method, however, rests on the amount of electron-correlation estimated by the method. In this work, single-descriptor QSPRs for supercooled liquid vapor pressure of chloronaphthalenes and polychlorinated-naphthalenes are developed using molecular descriptors based on the electron-correlation contribution of the quantum-mechanical descriptor. The quantum-mechanical descriptors for which the electron-correlation contribution is analyzed include total-energy, mean polarizability, dipole moment, frontier orbital (HOMO/LUMO) energy, and density-functional theory (DFT) based descriptors, namely, absolute electronegativity, chemical hardness, and electrophilicity index. A total of 40 single-descriptor QSPRs were developed using molecular descriptors computed with advanced semi-empirical (SE) methods, namely, RM1, PM7, and ab intio methods, namely, Hartree-Fock and DFT. The developed QSPRs are validated using state-of-the-art external validation procedures employing an external prediction set. From the comparison of external predictivity of the models, it is observed that the single-descriptor QSPRs developed using total energy and correlation energy are found to be far more robust and predictive than those developed using commonly employed descriptors such as HOMO/LUMO energy and dipole moment. The work proposes that if real external predictivity of a QSPR model is desired to be explored, particularly, in terms of intra-molecular interactions, correlation-energy serves as a more appropriate descriptor than the polarizability. However, for developing QSPRs, computationally inexpensive advanced SE methods such as PM7 can be more reliable than

  8. Relationship model and supporting activities of JIT, TQM and TPM

    Directory of Open Access Journals (Sweden)

    Nuttapon SaeTong

    2011-02-01

    Full Text Available This paper gives a relationship model and supporting activities of Just-in-time (JIT, Total Quality Management (TQM,and Total Productive Maintenance (TPM. By reviewing the concepts, 5S, Kaizen, preventive maintenance, Kanban, visualcontrol, Poka-Yoke, and Quality Control tools are the main supporting activities. Based on the analysis, 5S, preventive maintenance,and Kaizen are the foundation of the three concepts. QC tools are required activities for implementing TQM, whereasPoka-Yoke and visual control are necessary activities for implementing TPM. After successfully implementing TQM andTPM, Kanban is needed for JIT.

  9. Perancangan Model Basis Data Sistem Operasional Berbasiskan Customer Relationship Management

    Directory of Open Access Journals (Sweden)

    Tanty Oktavia

    2013-12-01

    Full Text Available Data is a very important asset for a company since it describes the company’s running processes. Database as a part of the information system components provides a big influence in helping data integration in a company. Therefore, we need a system which can facilitate the availability of data to be processed and used as needed, This study takes a company engaged in the sale of bike and spare parts, namely PT TDI, as the object of the study. At this time, PT TDI uses an integrated system in helping the company's operations. Along with thevision and mission, PT TDI intends to build a new operating system by applying the concept of Customer Relationship Management (CRM which is believed to assist the company in maintaining relationships with customers using web-based platform. It aims to facilitate interaction with customers so that it can be done anytime and anywhere. This study implements the database design life cycle adjusted to the component aspects of CRM. The result achieved is a model that combines database CRM systems that can help companies improve relationships with customers.

  10. The coach-athlete relationship: a motivational model.

    Science.gov (United States)

    Mageau, Geneviève A; Vallerand, Robert J

    2003-11-01

    The aim of this paper is to present a motivational model of the coach-athlete relationship that describes how coaches may influence athletes' motivation. In line with cognitive evaluation theory (Deci and Ryan, 1980, 1985) and the hierarchical model of intrinsic and extrinsic motivation (Vallerand, 1997, 2000), a motivational sequence is proposed where coaches' personal orientation towards coaching, the context within which they operate, and their perceptions of their athletes' behaviour and motivation influence coaches' behaviours. Also, coaches' behaviours in the form of autonomy-supportive behaviours, provision of structure and involvement have a beneficial impact on athletes' needs for autonomy, competence and relatedness, which, in turn, nurture athletes' intrinsic motivation and self-determined types of extrinsic motivation. Here, we first review coaches' autonomy-supportive behaviours. We then describe the psychological processes through which coaching behaviours have a positive influence on athletes' intrinsic and self-determined extrinsic motivation. Finally, we identify social and personality processes that determine coaching behaviours.

  11. Quantitative structure--property relationships for enhancing predictions of synthetic organic chemical removal from drinking water by granular activated carbon.

    Science.gov (United States)

    Magnuson, Matthew L; Speth, Thomas F

    2005-10-01

    Granular activated carbon is a frequently explored technology for removing synthetic organic contaminants from drinking water sources. The success of this technology relies on a number of factors based not only on the adsorptive properties of the contaminant but also on properties of the water itself, notably the presence of substances in the water which compete for adsorption sites. Because it is impractical to perform field-scale evaluations for all possible contaminants, the pore surface diffusion model (PSDM) has been developed and used to predict activated carbon column performance using single-solute isotherm data as inputs. Many assumptions are built into this model to account for kinetics of adsorption and competition for adsorption sites. This work further evaluates and expands this model, through the use of quantitative structure-property relationships (QSPRs) to predict the effect of natural organic matter fouling on activated carbon adsorption of specific contaminants. The QSPRs developed are based on a combination of calculated topographical indices and quantum chemical parameters. The QSPRs were evaluated in terms of their statistical predictive ability,the physical significance of the descriptors, and by comparison with field data. The QSPR-enhanced PSDM was judged to give results better than what could previously be obtained.

  12. How an Evolution View of Workplace Mentoring Relationships Helps Avoid Negative Experiences: The Developmental Relationship Mentoring Model in Action

    Science.gov (United States)

    Washington, Rhianon; Cox, Elaine

    2016-01-01

    In this paper, we explore how the use of a specific mentoring model focusing on the evolution of the relationship between mentor and mentee, may influence the incidence of failure. In our research we employed a case study methodology to examine a regional public service mentoring scheme in the UK where a developmental relationship mentoring model…

  13. A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

    Science.gov (United States)

    Luong, Ming; Stevens, Jeff

    2015-01-01

    The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

  14. Examining Asymmetrical Relationships of Organizational Learning Antecedents: A Theoretical Model

    Directory of Open Access Journals (Sweden)

    Ery Tri Djatmika

    2016-02-01

    Full Text Available Global era is characterized by highly competitive advantage market demand. Responding to the challenge of rapid environmental changes, organizational learning is becoming a strategic way and solution to empower people themselves within the organization in order to create a novelty as valuable positioning source. For research purposes, determining the influential antecedents that affect organizational learning is vital to understand research-based solutions given for practical implications. Accordingly, identification of variables examined by asymmetrical relationships is critical to establish. Possible antecedent variables come from organizational and personal point of views. It is also possible to include a moderating one. A proposed theoretical model of asymmetrical effects of organizational learning and its antecedents is discussed in this article.

  15. Modeling the Contested Relationship between Analects, Mencius, and Xunzi

    DEFF Research Database (Denmark)

    Nichols, Ryan; Slingerland, Edward; Nielbo, Kristoffer Laigaard

    2018-01-01

    the other two; and explains topics that intersect all three texts. The authors’ results confirm many scholarly opinions derived from close-reading methods, suggest a reappraisal of Xunzi’s shared semantic content with Analects, and yield several actionable research questions for traditional scholarship......This article presents preliminary findings from a multi-year, multi-disciplinary text analysis project using an ancient and medieval Chinese corpus of over five million characters in works that date from the earliest received texts to the Song dynasty. It describes “distant reading” methods...... in the humanities and the authors’ corpus; introduces topic-modeling procedures; answers questions about the authors’ data; discusses complementary relationships between machine learning and human expertise; explains topics represented in Analects, Mencius, and Xunzi that set each of those texts apart from...

  16. Using structural equation modeling to investigate relationships among ecological variables

    Science.gov (United States)

    Malaeb, Z.A.; Kevin, Summers J.; Pugesek, B.H.

    2000-01-01

    Structural equation modeling is an advanced multivariate statistical process with which a researcher can construct theoretical concepts, test their measurement reliability, hypothesize and test a theory about their relationships, take into account measurement errors, and consider both direct and indirect effects of variables on one another. Latent variables are theoretical concepts that unite phenomena under a single term, e.g., ecosystem health, environmental condition, and pollution (Bollen, 1989). Latent variables are not measured directly but can be expressed in terms of one or more directly measurable variables called indicators. For some researchers, defining, constructing, and examining the validity of latent variables may be the end task of itself. For others, testing hypothesized relationships of latent variables may be of interest. We analyzed the correlation matrix of eleven environmental variables from the U.S. Environmental Protection Agency's (USEPA) Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) using methods of structural equation modeling. We hypothesized and tested a conceptual model to characterize the interdependencies between four latent variables-sediment contamination, natural variability, biodiversity, and growth potential. In particular, we were interested in measuring the direct, indirect, and total effects of sediment contamination and natural variability on biodiversity and growth potential. The model fit the data well and accounted for 81% of the variability in biodiversity and 69% of the variability in growth potential. It revealed a positive total effect of natural variability on growth potential that otherwise would have been judged negative had we not considered indirect effects. That is, natural variability had a negative direct effect on growth potential of magnitude -0.3251 and a positive indirect effect mediated through biodiversity of magnitude 0.4509, yielding a net positive total effect of 0

  17. Doctor-patient relationships in general practice--a different model.

    Science.gov (United States)

    Kushner, T

    1981-09-01

    Philosophical concerns cannot be excluded from even a cursory examination of the physician-patient relationship. Two possible alternatives for determining what this relationship entails are the teleological (outcome) approach vs the deontological (process) one. Traditionally, this relationship has been structured around the 'clinical model' which views the physician-patient relationship in teleological terms. Data on the actual content of general medical practice indicate the advisability of reassessing this relationship, and suggest that the 'clinical model' may be too limiting, and that a more appropriate basis for the physician-patient relationship is one described in this paper as the 'relational model'.

  18. Linear Equating for the NEAT Design: Parameter Substitution Models and Chained Linear Relationship Models

    Science.gov (United States)

    Kane, Michael T.; Mroch, Andrew A.; Suh, Youngsuk; Ripkey, Douglas R.

    2009-01-01

    This paper analyzes five linear equating models for the "nonequivalent groups with anchor test" (NEAT) design with internal anchors (i.e., the anchor test is part of the full test). The analysis employs a two-dimensional framework. The first dimension contrasts two general approaches to developing the equating relationship. Under a "parameter…

  19. Building Customer Relationships: A Model for Vocational Education and Training Delivery.

    Science.gov (United States)

    Jarratt, Denise G.; Murphy, Tom; Lowry, Diannah

    1997-01-01

    Review of the theory of relational marketing and interviews with training providers identified a training delivery model that includes elements of trust and commitment, investment by relationship partners, and knowledge exchange, supporting relationship longevity. (SK)

  20. Synthesised model of market orientation-business performance relationship

    Directory of Open Access Journals (Sweden)

    G. Nwokah

    2006-12-01

    Full Text Available Purpose: The purpose of this paper is to assess the impact of market orientation on the performance of the organisation. While much empirical works have centered on market orientation, the generalisability of its impact on performance of the Food and Beverages organisations in the Nigeria context has been under-researched. Design/Methodology/Approach: The study adopted a triangulation methodology (quantitative and qualitative approach. Data was collected from key informants using a research instrument. Returned instruments were analyzed using nonparametric correlation through the use of the Statistical Package for Social Sciences (SPSS version 10. Findings: The study validated the earlier instruments but did not find any strong association between market orientation and business performance in the Nigerian context using the food and beverages organisations for the study. The reasons underlying the weak relationship between market orientation and business performance of the Food and Beverages organisations is government policies, new product development, diversification, innovation and devaluation of the Nigerian currency. One important finding of this study is that market orientation leads to business performance through some moderating variables. Implications: The study recommends that Nigerian Government should ensure a stable economy and make economic policies that will enhance existing business development in the country. Also, organisations should have performance measurement systems to detect the impact of investment on market orientation with the aim of knowing how the organisation works. Originality/Value: This study significantly refines the body of knowledge concerning the impact of market orientation on the performance of the organisation, and thereby offers a model of market orientation and business performance in the Nigerian context for marketing scholars and practitioners. This model will, no doubt, contribute to the body of

  1. Accessing Data Bases Through Interface Views Using a Unified Graph-Oriented Entity-Relationship Model

    DEFF Research Database (Denmark)

    Kraft, Peter; Sørensen, Jens Otto

    Interface Abstract: The paper describes an Entity Relationship (ER) model with a diagrammed schema and extensions modeled into a graph. The semantics of schema symbols are fundamentally simple implying a unified model where given conceptualizations of environments are diagrammed uniquely. By the ......Interface Abstract: The paper describes an Entity Relationship (ER) model with a diagrammed schema and extensions modeled into a graph. The semantics of schema symbols are fundamentally simple implying a unified model where given conceptualizations of environments are diagrammed uniquely...... with a unified graphic model is more efficient and less error-prone than working with more complex ER models and models based on lexical description. Key terms: Entity-relationship model, path expressions, entity-relationship language, derived interface view, view updates, graphical models....

  2. Forest evaporation models: Relationships between stand growth and evaporation

    CSIR Research Space (South Africa)

    Le Maitre, David C

    1997-06-01

    Full Text Available The relationships between forest stand structure, growth and evaporation were analysed to determine whether forest evaporation can be estimated from stand growth data. This approach permits rapid assessment of the potential impacts of afforestation...

  3. Remaining in an Abusive Relationship: An Investment Model Analysis of Nonvoluntary Dependence.

    Science.gov (United States)

    Rusbult, Caryl E.; Martz, John M.

    1995-01-01

    Analyzes the nature of interdependence in ongoing relationships, using an investment model to understand decisions to remain in abusive relationships. Found that feelings of commitment were greater among women who had poorer-quality economic alternatives, were more heavily invested in their relationship, and who experienced less dissatisfaction…

  4. Robust modelling of solubility in supercritical carbon dioxide using Bayesian methods.

    Science.gov (United States)

    Tarasova, Anna; Burden, Frank; Gasteiger, Johann; Winkler, David A

    2010-04-01

    Two sparse Bayesian methods were used to derive predictive models of solubility of organic dyes and polycyclic aromatic compounds in supercritical carbon dioxide (scCO(2)), over a wide range of temperatures (285.9-423.2K) and pressures (60-1400 bar): a multiple linear regression employing an expectation maximization algorithm and a sparse prior (MLREM) method and a non-linear Bayesian Regularized Artificial Neural Network with a Laplacian Prior (BRANNLP). A randomly selected test set was used to estimate the predictive ability of the models. The MLREM method resulted in a model of similar predictivity to the less sparse MLR method, while the non-linear BRANNLP method created models of substantially better predictivity than either the MLREM or MLR based models. The BRANNLP method simultaneously generated context-relevant subsets of descriptors and a robust, non-linear quantitative structure-property relationship (QSPR) model for the compound solubility in scCO(2). The differences between linear and non-linear descriptor selection methods are discussed. (c) 2009 Elsevier Inc. All rights reserved.

  5. Geometrical Modeling of Woven Fabrics Weavability-Limit New Relationships

    Directory of Open Access Journals (Sweden)

    Dalal Mohamed

    2017-03-01

    Full Text Available The weavability limit and tightness for 2D and 3D woven fabrics is an important factor and depends on many geometric parameters. Based on a comprehensive review of the literature on textile fabric construction and property, and related research on fabric geometry, a study of the weavability limit and tightness relationships of 2D and 3D woven fabrics was undertaken. Experiments were conducted on a representative number of polyester and cotton woven fabrics which have been woven in our workshop, using three machines endowed with different insertion systems (rapier, projectiles and air jet. Afterwards, these woven fabrics have been analyzed in the laboratory to determine their physical and mechanical characteristics using air permeability-meter and KES-F KAWABATA Evaluation System for Fabrics. In this study, the current Booten’s weavability limit and tightness relationships based on Ashenhurst’s, Peirce’s, Love’s, Russell’s, Galuszynskl’s theory and maximum-weavability is reviewed and modified as new relationships to expand their use to general cases (2D and 3D woven fabrics, all fiber materiel, all yarns etc…. The theoretical relationships were examined and found to agree with experimental results. It was concluded that the weavability limit and tightness relationships are useful tools for weavers in predicting whether a proposed fabric construction was weavable and also in predicting and explaining their physical and mechanical properties.

  6. Inequity in work and intimate relationships: a Spillover-Crossover model.

    Science.gov (United States)

    Bakker, Arnold B; Petrou, Paraskevas; Tsaousis, Ioannis

    2012-01-01

    This study among 267 Greek teachers and their partners tested and expanded the recently proposed Spillover-Crossover model (SCM) of well-being. Accordingly, experiences built up at work spill over to the home domain, and then influence the partner. The authors integrated equity theory in the model by formulating hypotheses about exchange in interpersonal relationships. Structural equation modeling analyses supported the spillover hypothesis that teachers who lose their work engagement as a result of an inequitable relationship with their students invest less in the relationship with their partner. In addition, the results supported the crossover hypothesis that teachers' relationship investments, in turn, show a negative relationship with inequity in the intimate relationship as perceived by the partner; and inequity in the intimate relationship contributed to partner depression. The findings are discussed in light of the SCM of well-being.

  7. QSPR Calculation of Normal Boiling Points of Organic Molecules Based on the Use of Correlation Weighting of Atomic Orbitals with Extended Connectivity of Zero- and First-Order Graphs of Atomic Orbitals

    Directory of Open Access Journals (Sweden)

    Eduardo A. Castro

    2004-12-01

    Full Text Available We report the results of a calculation of the normal boiling points of a representative set of 200 organic molecules through the application of QSPR theory. For this purpose we have used a particular set of flexible molecular descriptors, the so called Correlation Weighting of Atomic Orbitals with Extended Connectivity of Zero- and First-Order Graphs of Atomic Orbitals. Although in general the results show suitable behavior to predict this physical chemistry property, the existence of some deviant behaviors points to a need to complement this index with some other sort of molecular descriptors. Some possible extensions of this study are discussed.

  8. The relationship between structural and functional connectivity: graph theoretical analysis of an EEG neural mass model

    NARCIS (Netherlands)

    Ponten, S.C.; Daffertshofer, A.; Hillebrand, A.; Stam, C.J.

    2010-01-01

    We investigated the relationship between structural network properties and both synchronization strength and functional characteristics in a combined neural mass and graph theoretical model of the electroencephalogram (EEG). Thirty-two neural mass models (NMMs), each representing the lump activity

  9. Team Risk Management: A New Model for Customer-Supplier Relationships

    Science.gov (United States)

    1994-07-01

    Management : A New Model for Customer - Supplier Relationships Ronald P. Higuera "Audrey J. Dorofee Julie A. Walker Ray C. Williams July 1994 ""•// 94...N/A N/A N/A 11. TITLE (Include Secuity Claaaificatioa) Team Risk Management : A New Model for Customer -Supplier Relationships 12. PERSONAL AUTHOR(S...by block number) FIELD GROUP SUB. GR. Customer - Supplier Relationships Risk Team Risk Management 19. ABSTRACT (cominus on = if necesaryd id’y by block

  10. Using fuzzy models to migrate from customer relationship management (CRM) to customer experience management (CEM)

    OpenAIRE

    Dr. Anna Maria Gil-Lafuente; Carolina Luis-Bassa

    2011-01-01

    Relationship Marketing has made rapid progress during the last ten years. Since the development of the customer-centric model, reinforced by the emergence of CRM (Customer Relationship Management) strategies, companies have focused on finding models and tools that allow them to get to know better their clients. The management of customer relationship with the company has evolved from seeking the customer satisfaction to seek customer loyalty, and later on to create a brand advocate consumer f...

  11. Structure-retention and mobile phase-retention relationships for reversed-phase high-performance liquid chromatography of several hydroxythioxanthone derivatives in binary acetonitrile-water mixtures

    International Nuclear Information System (INIS)

    Amiri, Ali Asghar; Hemmateenejad, Bahram; Safavi, Afsaneh; Sharghi, Hashem; Beni, Ali Reza Salimi; Shamsipur, Mojtaba

    2007-01-01

    The reversed-phase high-performance liquid chromatographic (RP-HPLC) behavior of some newly synthesized hydroxythioxanthone derivatives using binary acetonitrile-water mixtures as mobile phase has been examined. First, the variation in the retention time of each molecule as a function of mobile phase properties was studied by Kamlet-Taft solvatochromic equations. Then, the influences of molecular structure of the hydroxythioxanthone derivatives on their retention time in various mobile phase mixtures were investigated by quantitative structure-property relationship (QSPR) analysis. Finally, a unified model containing both the molecular structure parameters and mobile phase properties was developed to describe the chromatographic behavior of the systems studied. Among the solvent properties, polarity/polarizability parameter (π * ) and hydrogen-bond basicity (β), and among the solute properties, the most positive local charge (MPC), the sum of positive charges on hydrogen atoms contributing in hydrogen bonding (SPCH) and lipophilicity index (log P) were identified as controlling factors in the RP-HPLC behavior of hydroxythioxanthone derivatives in actonitrile-water binary solvents

  12. Adolescents' working models and styles for relationships with parents, friends, and romantic partners.

    Science.gov (United States)

    Furman, Wyndol; Simon, Valerie A; Shaffer, Laura; Bouchey, Heather A

    2002-01-01

    This study examined the links among adolescents' representations of their relationships with parents, friends, and romantic partners. Sixty-eight adolescents were interviewed three times to assess their working models for each of these types of relationships. Working models of friendships were related to working models of relationships with parents and romantic partners. Working models of relationships with parents and romantic partners were inconsistently related. A similar pattern of results was obtained for self-report measures of relational styles for the three types of relationships. Perceived experiences were also related. Specifically, support in relationships with parents tended to be related to support in romantic relationships and friendships, but the latter two were unrelated. On the other hand, self and other controlling behaviors in friendships were related to corresponding behaviors in romantic relationships. Negative interactions in the three types of relationships also tended to be related. Taken together, the findings indicate that the representations of the three types of relationships are distinct, yet related. Discussion focuses on the nature of the links among the three.

  13. Relationship Model of Personality, Communication, Student Engagement, and Learning Satisfaction

    Directory of Open Access Journals (Sweden)

    Dorothea Ariani

    2015-12-01

    Full Text Available This study aims to examine the engagement as a mediating variable of the relationship between personality and communication with satisfaction. This study was conducted at business school in Indonesia with 307 students who are still active as a respondent. Survey research was conducted over four months by questionnaire that has been well-established that was taken and modified from previous studies. The results of this study indicate that student engagement mediates the relationship between personality and communication as independent variables and satisfaction as the dependent variable. Extroversion personality and communication significantly positive effect on student engagement in all three dimensions (vigor, dedication, and absorption. In addition, this study also showed that engagement and satisfaction are two different variables, but correlated, and there was no difference in terms of gender differences involvement.

  14. Modelling the relationship between antiretroviral treatment and HIV ...

    African Journals Online (AJOL)

    This paper shows how two publicly available epidemiological modelling packages, namely the Spectrum AIDS Impact Model and the ASSA2003 AIDS and Demographic Model, predict very different impacts from rolling out highly active antiretroviral treatment (HAART) on new HIV infections. Using South Africa as a case ...

  15. Identifying and Evaluating the Relationships that Control a Land Surface Model's Hydrological Behavior

    Science.gov (United States)

    Koster, Randal D.; Mahanama, Sarith P.

    2012-01-01

    The inherent soil moisture-evaporation relationships used in today 's land surface models (LSMs) arguably reflect a lot of guesswork given the lack of contemporaneous evaporation and soil moisture observations at the spatial scales represented by regional and global models. The inherent soil moisture-runoff relationships used in the LSMs are also of uncertain accuracy. Evaluating these relationships is difficult but crucial given that they have a major impact on how the land component contributes to hydrological and meteorological variability within the climate system. The relationships, it turns out, can be examined efficiently and effectively with a simple water balance model framework. The simple water balance model, driven with multi-decadal observations covering the conterminous United States, shows how different prescribed relationships lead to different manifestations of hydrological variability, some of which can be compared directly to observations. Through the testing of a wide suite of relationships, the simple model provides estimates for the underlying relationships that operate in nature and that should be operating in LSMs. We examine the relationships currently used in a number of different LSMs in the context of the simple water balance model results and make recommendations for potential first-order improvements to these LSMs.

  16. DESIGNING A MODEL OF CUSTOMER RELATIONSHIP MANAGEMENT FOR A MOBILE PHONE COMPANY

    Directory of Open Access Journals (Sweden)

    BRUTU MĂDĂLINA

    2015-07-01

    Full Text Available Customer relationship management refers to establishing, maintaining, developing and optimizing the relations between an organization and its customers and focuses on understanding and meeting its customers’ wishes and demands, the core items of the business strategy of any performant company. This paper aims at designing and testing a model of customer relationship management applicable within a mobile phone company. Starting from this purpose, the main objectives of the research were: presenting the concept of customer relationship management; the importance of companies’ orientation to the market; identifying a model of customer relationship management and, not least, analyzing the efficiency of this model. The results lead to the conclusion that the model of customer relationship management is extremely effective in the mobile phone industry, bringing significant profits.

  17. Negative childhood experiences and adult love relationships: the role of internal working models of attachment.

    Science.gov (United States)

    McCarthy, Gerard; Maughan, Barbara

    2010-09-01

    This study investigated links between internal working models of attachment and the quality of adult love relationships in a high risk sample of women (n = 34), all of whom reported negative parenting in childhood. Half of the sample was identified as having a history of satisfying adult love relationships, while the remainder had experienced ongoing adult relationship problems. Measures of internal working models of attachment were made using the Adult Attachment Interview (AAI). A strong association was found between attachment classifications and the quality of adult love relationships. In addition, women with satisfying love relationships demonstrated significantly higher coherence of mind ratings than those with poor relationship histories. Insecure working models of attachment were associated with problems in adult love relationships. Although secure/autonomous attachment status was linked to optimal adult relationship outcomes, some women with a history of satisfying love relationships had insecure working models of attachment. These results suggest that the ways that adults process early experiences may influence later psychosocial functioning.

  18. A conceptual model for ethical business decision-making under the influence of personal relationships

    OpenAIRE

    Davidrajuh, Reggie

    2008-01-01

    This paper proposes a conceptual model for ethical business decision-making. The purpose of this model is to explore the ethical implications of personal relationship in business exchanges. Firstly, this paper introduces personal relationship in business exchanges. Secondly, three normative theories of ethics that are relevant to the business environment are presented. Thirdly, a literature study on the existing models and frameworks for ethical business decision-making is pres...

  19. Rain storm models and the relationship between their parameters

    NARCIS (Netherlands)

    Stol, P.T.

    1977-01-01

    Rainfall interstation correlation functions can be obtained with the aid of analytic rainfall or storm models. Since alternative storm models have different mathematical formulas, comparison should be based on equallity of parameters like storm diameter, mean rainfall amount, storm maximum or total

  20. Exploring the Relationship between Mathematical Modelling and Classroom Discourse

    Science.gov (United States)

    Redmond, Trevor; Sheehy, Joanne; Brown, Raymond

    2010-01-01

    This paper explores the notion that the discourse of the mathematics classroom impacts on the practices that students engage when modelling mathematics. Using excerpts of a Year 12 student's report on modelling Newton's law of cooling, this paper argues that when students engage with the discourse of their mathematics classroom in a manner that…

  1. Quantitative modeling of flavonoid glycosides isolated from Paliurus spina-christi Mill.

    OpenAIRE

    Medić-Šarić, Marica; Maleš, Željan; Šarić, Slavko; Brantner, Adelheid

    1996-01-01

    Several QSPR models for predicting the properties of flavonoid glycosides isolated from Paliurus spina-christi Mill, and of some related flavonoids were described and evaluated. Log P values for all of them were calculated according to the method of Rekker. All investigated flavonoids showed expressive hydrophobicity. Significant correlation between the partition coefficient, log P, and van der Waals volume, Vw (calculated according to the method described by Moriguchi et al.) was obtained. T...

  2. EMF 7 model comparisons: key relationships and parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, B.G.

    1983-12-01

    A simplified textbook model of aggregate demand and supply interprets the similarities and differences in the price and income responses of the various EMF 7 models to oil and policy shocks. The simplified model is a marriage of Hicks' classic IS-LM formulation of the Keynesian theory of effective demand with a rudimentary model of aggregate supply, combining a structural Phillips curve for wage determination and a markup theory of price determination. The reduced-form income equation from the fix-price IS-LM model is used to define an aggregate demand (AD) locus in P-Y space, showing alternative pairs of the implicit GNP deflator and real GNP which would simultaneously satisfy the saving-investment identity and the condition for money market equilibrium. An aggregate supply (AS) schedule is derived by a similar reduction of relations between output and labor demand, unemployment and wage inflation, and the wage-price-productivity nexus governing markup pricing. Given a particular econometric model it is possible to derive IS and LM curves algebraically. The resulting locuses would show alternative combinations of interest rate and real income which equilibrate real income identity on the IS side and the demand and supply of money on the LM side. By further substitution the reduced form fix-price income relation could be obtained for direct quantification of the AD locus. The AS schedule is obtainable by algebraic reduction of the structural supply side equations.

  3. On Use of the Variable Zagreb vM2 Index in QSPR: Boiling Points of Benzenoid Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Albin Jurić

    2004-12-01

    Full Text Available The variable Zagreb vM2 index is introduced and applied to the structure-boiling point modeling of benzenoid hydrocarbons. The linear model obtained (thestandard error of estimate for the fit model Sfit=6.8 oC is much better than thecorresponding model based on the original Zagreb M2 index (Sfit=16.4 oC. Surprisingly,the model based on the variable vertex-connectivity index (Sfit=6.8 oC is comparable tothe model based on vM2 index. A comparative study with models based on the vertex-connectivity index, edge-connectivity index and several distance indices favours modelsbased on the variable Zagreb vM2 index and variable vertex-connectivity index.However, the multivariate regression with two-, three- and four-descriptors givesimproved models, the best being the model with four-descriptors (but vM2 index is notamong them with Sfit=5 oC, though the four-descriptor model contaning vM2 index isonly slightly inferior (Sfit=5.3 oC.

  4. Data-Model Relationship in Text-Independent Speaker Recognition

    Directory of Open Access Journals (Sweden)

    Stapert Robert

    2005-01-01

    Full Text Available Text-independent speaker recognition systems such as those based on Gaussian mixture models (GMMs do not include time sequence information (TSI within the model itself. The level of importance of TSI in speaker recognition is an interesting question and one addressed in this paper. Recent works has shown that the utilisation of higher-level information such as idiolect, pronunciation, and prosodics can be useful in reducing speaker recognition error rates. In accordance with these developments, the aim of this paper is to show that as more data becomes available, the basic GMM can be enhanced by utilising TSI, even in a text-independent mode. This paper presents experimental work incorporating TSI into the conventional GMM. The resulting system, known as the segmental mixture model (SMM, embeds dynamic time warping (DTW into a GMM framework. Results are presented on the 2000-speaker SpeechDat Welsh database which show improved speaker recognition performance with the SMM.

  5. What do short-term and long-term relationships look like? Building the relationship coordination and strategic timing (ReCAST) model.

    Science.gov (United States)

    Eastwick, Paul W; Keneski, Elizabeth; Morgan, Taylor A; McDonald, Meagan A; Huang, Sabrina A

    2018-05-01

    Close relationships research has examined committed couples (e.g., dating relationships, marriages) using intensive methods that plot relationship development over time. But a substantial proportion of people's real-life sexual experiences take place (a) before committed relationships become "official" and (b) in short-term relationships; methods that document the time course of relationships have rarely been applied to these contexts. We adapted a classic relationship trajectory-plotting technique to generate the first empirical comparisons between the features of people's real-life short-term and long-term relationships across their entire timespan. Five studies compared long-term and short-term relationships in terms of the timing of relationship milestones (e.g., flirting, first sexual intercourse) and the occurrence/intensity of important relationship experiences (e.g., romantic interest, strong sexual desire, attachment). As romantic interest was rising and partners were becoming acquainted, long-term and short-term relationships were indistinguishable. Eventually, romantic interest in short-term relationships plateaued and declined while romantic interest in long-term relationships continued to rise, ultimately reaching a higher peak. As relationships progressed, participants evidenced more features characteristic of the attachment-behavioral system (e.g., attachment, caregiving) in long-term than short-term relationships but similar levels of other features (e.g., sexual desire, self-promotion, intrasexual competition). These data inform a new synthesis of close relationships and evolutionary psychological perspectives called the Relationship Coordination and Strategic Timing (ReCAST) model. ReCAST depicts short-term and long-term relationships as partially overlapping trajectories (rather than relationships initiated with distinct strategies) that differ in their progression along a normative relationship development sequence. (PsycINFO Database Record (c

  6. Formal and Informal Work Group Relationships With Performance: A Moderation Model Using Social

    National Research Council Canada - National Science Library

    Knost, Benjamin R

    2006-01-01

    .... This field study, conducted at a military training course, attempted to further refine this social network-performance relationship by modeling characteristics of both the formal and informal work...

  7. THE RELATIONSHIP BETWEEN MODELS OF QUALITY MANAGEMENT AND CSR

    Directory of Open Access Journals (Sweden)

    CĂTĂLINA SITNIKOV

    2015-03-01

    Full Text Available Lately, the quality management has integrated more and more among its components Corporate Social Responsibility (CSR. With strong roots in the foundation for sustainable development, protection of the environment, issues of social justness and economic growth, CSR raises numerous issues related to obtaining profits, business performance and firms and activities based on the quality of management. From the point of view of the last issues, the models of quality management built on the fundamental principles of quality become the foundation and catalyst for the effective implementation of CSR in organizations. This is the reason why it is necessary to investigate the extent to which quality management models provide frameworks and guidelines for integrating CSR in the management of quality and, moreover, in the management of the organization, with a clear focus on the extent to which the concept can be institutionalized and operated by the organization.

  8. Physiologically Based Pharmacokinetic Modeling in Lead Optimization. 1. Evaluation and Adaptation of GastroPlus To Predict Bioavailability of Medchem Series.

    Science.gov (United States)

    Daga, Pankaj R; Bolger, Michael B; Haworth, Ian S; Clark, Robert D; Martin, Eric J

    2018-03-05

    When medicinal chemists need to improve bioavailability (%F) within a chemical series during lead optimization, they synthesize new series members with systematically modified properties mainly by following experience and general rules of thumb. More quantitative models that predict %F of proposed compounds from chemical structure alone have proven elusive. Global empirical %F quantitative structure-property (QSPR) models perform poorly, and projects have too little data to train local %F QSPR models. Mechanistic oral absorption and physiologically based pharmacokinetic (PBPK) models simulate the dissolution, absorption, systemic distribution, and clearance of a drug in preclinical species and humans. Attempts to build global PBPK models based purely on calculated inputs have not achieved the optimization. In this work, local GastroPlus PBPK models are instead customized for individual medchem series. The key innovation was building a local QSPR for a numerically fitted effective intrinsic clearance (CL loc ). All inputs are subsequently computed from structure alone, so the models can be applied in advance of synthesis. Training CL loc on the first 15-18 rat %F measurements gave adequate predictions, with clear improvements up to about 30 measurements, and incremental improvements beyond that.

  9. A Socio-Cultural Model Based on Empirical Data of Cultural and Social Relationship

    DEFF Research Database (Denmark)

    Lipi, Afia Akhter; Nakano, Yukiko; Rehm, Matthias

    2010-01-01

    The goal of this paper is to integrate culture and social relationship as a computational term in an embodied conversational agent system by employing empirical and theoretical approach. We propose a parameter-based model that predicts nonverbal expressions appropriate for specific cultures...... in different social relationship. So, first, we introduce the theories of social and cultural characteristics. Then, we did corpus analysis of human interaction of two cultures in two different social situations and extracted empirical data and finally, by integrating socio-cultural characteristics...... with empirical data, we establish a parameterized network model that generates culture specific non-verbal expressions in different social relationships....

  10. NONPARAMETRIC FIXED EFFECT PANEL DATA MODELS: RELATIONSHIP BETWEEN AIR POLLUTION AND INCOME FOR TURKEY

    Directory of Open Access Journals (Sweden)

    Rabia Ece OMAY

    2013-06-01

    Full Text Available In this study, relationship between gross domestic product (GDP per capita and sulfur dioxide (SO2 and particulate matter (PM10 per capita is modeled for Turkey. Nonparametric fixed effect panel data analysis is used for the modeling. The panel data covers 12 territories, in first level of Nomenclature of Territorial Units for Statistics (NUTS, for period of 1990-2001. Modeling of the relationship between GDP and SO2 and PM10 for Turkey, the non-parametric models have given good results.

  11. Estimating species – area relationships by modeling abundance and frequency subject to incomplete sampling

    Science.gov (United States)

    Yamaura, Yuichi; Connor, Edward F.; Royle, Andy; Itoh, Katsuo; Sato, Kiyoshi; Taki, Hisatomo; Mishima, Yoshio

    2016-01-01

    Models and data used to describe species–area relationships confound sampling with ecological process as they fail to acknowledge that estimates of species richness arise due to sampling. This compromises our ability to make ecological inferences from and about species–area relationships. We develop and illustrate hierarchical community models of abundance and frequency to estimate species richness. The models we propose separate sampling from ecological processes by explicitly accounting for the fact that sampled patches are seldom completely covered by sampling plots and that individuals present in the sampling plots are imperfectly detected. We propose a multispecies abundance model in which community assembly is treated as the summation of an ensemble of species-level Poisson processes and estimate patch-level species richness as a derived parameter. We use sampling process models appropriate for specific survey methods. We propose a multispecies frequency model that treats the number of plots in which a species occurs as a binomial process. We illustrate these models using data collected in surveys of early-successional bird species and plants in young forest plantation patches. Results indicate that only mature forest plant species deviated from the constant density hypothesis, but the null model suggested that the deviations were too small to alter the form of species–area relationships. Nevertheless, results from simulations clearly show that the aggregate pattern of individual species density–area relationships and occurrence probability–area relationships can alter the form of species–area relationships. The plant community model estimated that only half of the species present in the regional species pool were encountered during the survey. The modeling framework we propose explicitly accounts for sampling processes so that ecological processes can be examined free of sampling artefacts. Our modeling approach is extensible and could be applied

  12. A Model of Female Sexual Desire: Internalized Working Models of Parent-Child Relationships and Sexual Body Self-Representations.

    Science.gov (United States)

    Cherkasskaya, Eugenia; Rosario, Margaret

    2017-11-01

    The etiology of low female sexual desire, the most prevalent sexual complaint in women, is multi-determined, implicating biological and psychological factors, including women's early parent-child relationships and bodily self-representations. The current study evaluated a model that hypothesized that sexual body self-representations (sexual subjectivity, self-objectification, genital self-image) explain (i.e., mediate) the relation between internalized working models of parent-child relationships (attachment, separation-individuation, parental identification) and sexual desire in heterosexual women. We recruited 614 young, heterosexual women (M = 25.5 years, SD = 4.63) through social media. The women completed an online survey. Structural equation modeling was used. The hypotheses were supported in that the relation between internalized working models of parent-child relationships (attachment and separation-individuation) and sexual desire was mediated by sexual body self-representations (sexual body esteem, self-objectification, genital self-image). However, parental identification was not related significantly to sexual body self-representations or sexual desire in the model. Current findings demonstrated that understanding female sexual desire necessitates considering women's internalized working models of early parent-child relationships and their experiences of their bodies in a sexual context. Treatment of low or absent desire in women would benefit from modalities that emphasize early parent-child relationships as well as interventions that foster mind-body integration.

  13. Predictor Relationships between Values Held by Married Individuals, Resilience and Conflict Resolution Styles: A Model Suggestion

    Science.gov (United States)

    Tosun, Fatma; Dilmac, Bulent

    2015-01-01

    The aim of the present research is to reveal the predictor relationships between the values held by married individuals, resilience and conflict resolution styles. The research adopts a relational screening model that is a sub-type of the general screening model. The sample of the research consists of 375 married individuals, of which 173 are…

  14. Relationships among Adolescents' Leisure Motivation, Leisure Involvement, and Leisure Satisfaction: A Structural Equation Model

    Science.gov (United States)

    Chen, Ying-Chieh; Li, Ren-Hau; Chen, Sheng-Hwang

    2013-01-01

    The purpose of this cross-sectional study was to test a cause-and-effect model of factors affecting leisure satisfaction among Taiwanese adolescents. A structural equation model was proposed in which the relationships among leisure motivation, leisure involvement, and leisure satisfaction were explored. The study collected data from 701 adolescent…

  15. The Development of Spelling-Sound Relationships in a Model of Phonological Reading.

    Science.gov (United States)

    Zorzi, Marco; Houghton, George; Butterworth, Brian

    1998-01-01

    Developmental aspects of spelling-to-sound mapping for English monosyllabic words are investigated with a simple two-layer network model using a simple, general learning rule. The model is trained on both regularly and irregularly spelled words but extracts regular spelling to sound relationships, which it can apply to new words. Training-related…

  16. The Sport Commitment Model: An Investigation of Structural Relationships with Thai Youth Athlete Populations

    Science.gov (United States)

    Choosakul, Chairat; Vongjaturapat, Naruepon; Li, Fuzhong; Harmer, Peter

    2009-01-01

    Grounded in the conceptual framework of the Sport Commitment Model and previous empirical studies conducted in Western countries, this study was designed to (a) test and validate a Thai version of the Athlete Opinion Survey to assess components of the Sport Commitment Model in Thai youth athletes and (b) examine structural relationships among…

  17. Exploring Third-Grade Student Model-Based Explanations about Plant Relationships within an Ecosystem

    Science.gov (United States)

    Zangori, Laura; Forbes, Cory T.

    2015-01-01

    Elementary students should have opportunities to develop scientific models to reason and build understanding about how and why plants depend on relationships within an ecosystem for growth and survival. However, scientific modeling practices are rarely included within elementary science learning environments and disciplinary content is often…

  18. Multi-wavelength spectrophotometric determination of acidity constant of some newly synthesized Schiff bases and their QSPR study

    Science.gov (United States)

    Hemmateenejad, Bahram; Emami, Leila; Sharghi, Hashem

    2010-01-01

    The acidity constants of some newly synthesized Schiff base derivatives were determined by hard-model based multivariate data analysis of the spectrophotometric data in the course of pH-metric titration in 50% (v/v) methanol-water binary solvent. The employed data analysis method was also able to extract the pure spectra and pH-dependent concentration profiles of the acid-base species. The molecules that possess different substituents (both electron donating and withdrawing) on the ortho-, meta- and para-positions of one of the phenyl ring showed variable acidity constants ranging from 8.77 to 11.07 whereas the parent molecule had an acidity constant of 10.25. To investigate the quantitative effects of changing of substitution pattern on the acidity constant, a quantitative structure-property relation analysis was conducted using substituent constants and molecular descriptor. Some models with high statistical quality (measured by cross-validation Q2) were obtained. It was found that the acidity constant of the studied molecules in the methanol-water mixed solvent not only is affected by electronic features of the solutes but also by the lipophilic interaction between methanol part of solvent and the deprotonated solutes.

  19. A continuum model for pressure-flow relationship in human pulmonary circulation.

    Science.gov (United States)

    Huang, Wei; Zhou, Qinlian; Gao, Jian; Yen, R T

    2011-06-01

    A continuum model was introduced to analyze the pressure-flow relationship for steady flow in human pulmonary circulation. The continuum approach was based on the principles of continuum mechanics in conjunction with detailed measurement of vascular geometry, vascular elasticity and blood rheology. The pulmonary arteries and veins were considered as elastic tubes and the "fifth-power law" was used to describe the pressure-flow relationship. For pulmonary capillaries, the "sheet-flow" theory was employed and the pressure-flow relationship was represented by the "fourth-power law". In this paper, the pressure-flow relationship for the whole pulmonary circulation and the longitudinal pressure distribution along the streamlines were studied. Our computed data showed general agreement with the experimental data for the normal subjects and the patients with mitral stenosis and chronic bronchitis in the literature. In conclusion, our continuum model can be used to predict the changes of steady flow in human pulmonary circulation.

  20. Relationship between soil erodibility and modeled infiltration rate in different soils

    Science.gov (United States)

    Wang, Guoqiang; Fang, Qingqing; Wu, Binbin; Yang, Huicai; Xu, Zongxue

    2015-09-01

    The relationship between soil erodibility, which is hard to measure, and modeled infiltration rate were rarely researched. Here, the soil erodibility factors (K and Ke in the USLE, Ki and K1 in the WEPP) were calculated and the infiltration rates were modeled based on the designed laboratory simulation experiments and proposed infiltration model, in order to build their relationship. The impacts of compost amendment on the soil erosion characteristics and relationship were also studied. Two contrasting agricultural soils (bare and cultivated fluvo-aquic soils) were used, and different poultry compost contents (control, low and high) were applied to both soils. The results indicated that the runoff rate, sediment yield rate and soil erodibility of the bare soil treatments were generally higher than those of the corresponding cultivated soil treatments. The application of composts generally decreased sediment yield and soil erodibility but did not always decrease runoff. The comparison of measured and modeled infiltration rates indicated that the model represented the infiltration processes well with an N-S coefficient of 0.84 for overall treatments. Significant negative logarithmic correlations have been found between final infiltration rate (FIR) and the four soil erodibility factors, and the relationship between USLE-K and FIR demonstrated the best correlation. The application of poultry composts would not influence the logarithmic relationship between FIR and soil erodibility. Our study provided a useful tool to estimate soil erodibility.

  1. Using Carl Rogers' person-centered model to explain interpersonal relationships at a school of nursing.

    Science.gov (United States)

    Bryan, Venise D; Lindo, Jascinth; Anderson-Johnson, Pauline; Weaver, Steve

    2015-01-01

    Faculty members are viewed as nurturers within the academic setting and may be able to influence students' behaviors through the formation of positive interpersonal relationships. Faculty members' attributes that best facilitated positive interpersonal relationships according to Carl Rogers' Person-Centered Model was studied. Students (n = 192) enrolled in a 3-year undergraduate nursing program in urban Jamaica were randomly selected to participate in this descriptive cross-sectional study. A 38-item questionnaire on interpersonal relationships with nursing faculty and students' perceptions of their teachers was utilized to collect data. Factor analysis was used to create factors of realness, prizing, and empathetic understanding. Multiple linear regression analysis on the interaction of the 3 factors and interpersonal relationship scores was performed while controlling for nursing students' study year and age. One hundred sixty-five students (mean age: 23.18 ± 4.51years; 99% female) responded. The regression model explained over 46% of the variance. Realness (β = 0.50, P < .001) was the only significant predictor of the interpersonal relationship scores assigned by the nursing students. Of the total number of respondents, 99 students (60%) reported satisfaction with the interpersonal relationships shared with faculty. Nursing students' perception of faculty members' realness appeared to be the most significant attribute in fostering positive interpersonal relationships. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Dog owner interaction style: the transmission of working models in human/non-human caregiving relationships

    OpenAIRE

    Taggart, Jill Monica

    2011-01-01

    A model of parental sensitivity in caregiving informs later romantic relationships and is transmitted in caregiving behaviours to children. Differences in parental caregiving contribute to individual differences in infant attachment style. The owner/dog bond mirrors this relationship as dog careseeking activates owner caregiving. The aim of this thesis was to investigate the role of individual differences in owner caregiving on dog attachment style.The first study defined dog attachment style...

  3. Statistical Methods for Detecting and Modeling General Patterns and Relationships in Lifetime Data

    Energy Technology Data Exchange (ETDEWEB)

    Kvaloey, Jan Terje

    1999-04-01

    In this thesis, the author tries to develop methods of detecting and modeling general patterns and relationships in lifetime data. Tests with power against nonmonotonic trends and nonmonotonic co variate effects are considered, and nonparametric regression methods which allow estimation of fairly general nonlinear relationships are studied. Practical uses of some of the methods are illustrated although in a medical rather than engineering or technological context.

  4. DESIGNING A MODEL OF CUSTOMER RELATIONSHIP MANAGEMENT FOR A MOBILE PHONE COMPANY

    OpenAIRE

    BRUTU MĂDĂLINA; MIHAI DANIELA MELANIA

    2015-01-01

    Customer relationship management refers to establishing, maintaining, developing and optimizing the relations between an organization and its customers and focuses on understanding and meeting its customers’ wishes and demands, the core items of the business strategy of any performant company. This paper aims at designing and testing a model of customer relationship management applicable within a mobile phone company. Starting from this purpose, the main objectives of the research were: prese...

  5. The model relationship of wastes for parameter design with green lean production of fresh water

    Directory of Open Access Journals (Sweden)

    Mastiadi Tamjidillah

    2017-12-01

    Full Text Available Lean manufacturing is about eliminating waste including the seven traditional, this writing suggested an observation on no value added of seven wastes influencing the process of fresh water production. The relationship value among waste was statistically verified to create an approach for continuous improvement action. Thus, the main goal of this research is to develop a methodology of relationship among wastes and eliminate them. In relationship among wastes, it could be known that the high value indicating how often it happened in the production process gave direct cause in the system of fresh water treatment. A recommendation to reduce the highest value of waste is by doing improvement on parameter setting to obtain an optimum mixing model between water supply, alum and stroke pump with Taguchi method. The interaction of relationship among these seven types of waste can be portrayed using fishbone diagram and a relationship model among wastes using PLS smart (partial least squares. The final relationship model with the highest value of waste was analyzed using off-line quality control to upgrade the quality of fresh water used as the basis to eliminate waste and find out the optimal parameter of mixing process in accordance with the health standard.

  6. QSAR as a random event: modeling of nanoparticles uptake in PaCa2 cancer cells.

    Science.gov (United States)

    Toropov, Andrey A; Toropova, Alla P; Puzyn, Tomasz; Benfenati, Emilio; Gini, Giuseppina; Leszczynska, Danuta; Leszczynski, Jerzy

    2013-06-01

    Quantitative structure-property/activity relationships (QSPRs/QSARs) are a tool to predict various endpoints for various substances. The "classic" QSPR/QSAR analysis is based on the representation of the molecular structure by the molecular graph. However, simplified molecular input-line entry system (SMILES) gradually becomes most popular representation of the molecular structure in the databases available on the Internet. Under such circumstances, the development of molecular descriptors calculated directly from SMILES becomes attractive alternative to "classic" descriptors. The CORAL software (http://www.insilico.eu/coral) is provider of SMILES-based optimal molecular descriptors which are aimed to correlate with various endpoints. We analyzed data set on nanoparticles uptake in PaCa2 pancreatic cancer cells. The data set includes 109 nanoparticles with the same core but different surface modifiers (small organic molecules). The concept of a QSAR as a random event is suggested in opposition to "classic" QSARs which are based on the only one distribution of available data into the training and the validation sets. In other words, five random splits into the "visible" training set and the "invisible" validation set were examined. The SMILES-based optimal descriptors (obtained by the Monte Carlo technique) for these splits are calculated with the CORAL software. The statistical quality of all these models is good. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. The relationship between relational models and individualism and collectivism: evidence from culturally diverse work groups.

    Science.gov (United States)

    Vodosek, Markus

    2009-04-01

    Relational models theory (Fiske, 1991 ) proposes that all thinking about social relationships is based on four elementary mental models: communal sharing, authority ranking, equality matching, and market pricing. Triandis and his colleagues (e.g., Triandis, Kurowski, & Gelfand, 1994 ) have suggested a relationship between the constructs of horizontal and vertical individualism and collectivism and Fiske's relational models. However, no previous research has examined this proposed relationship empirically. The objective of the current study was to test the association between the two frameworks in order to further our understanding of why members of culturally diverse groups may prefer different relational models in interactions with other group members. Findings from this study support a relationship between Triandis' constructs and Fiske's four relational models and uphold Fiske's ( 1991 ) claim that the use of the relational models is culturally dependent. As hypothesized, horizontal collectivism was associated with a preference for equality matching and communal sharing, vertical individualism was related to a preference for authority ranking, and vertical collectivism was related to a preference for authority ranking and communal sharing. However, contrary to expectations, horizontal individualism was not related to a preference for equality matching and market pricing, and vertical individualism was not associated with market pricing. By showing that there is a relationship between Triandis' and Fiske's frameworks, this study closes a gap in relational models theory, namely how culture relates to people's preferences for relational models. Thus, the findings from this study will enable future researchers to explain and predict what relational models are likely to be used in a certain cultural context.

  8. SST and OLR relationship during Indian summer monsoon: a coupled climate modelling perspective

    Science.gov (United States)

    Chaudhari, Hemantkumar S.; Hazra, Anupam; Pokhrel, Samir; Chakrabarty, Chandrima; Saha, Subodh Kumar; Sreenivas, P.

    2018-04-01

    The study mainly investigates sea surface temperature (SST) and outgoing longwave radiation (OLR) relationships in coupled climate model. To support the analysis, high-level cloud and OLR relationship is also investigated. High-level cloud and OLR relationship depicts significant negative correlation over the entire monsoon regime. Coupled climate model is able to produce the same. SST and OLR relationship in observation also depicts significant negative relationship, in particular, over the Equatorial Eastern Indian Ocean (EIO) region. Climate Forecast System version 2 (CFSv2) is able to portray the negative relationship over EIO region; however, it is underestimated as compared to observation. Significant negative correlations elucidate that local SSTs regulate the convection and further it initiates Bjerknes feedback in the central Indian Ocean. It connotes that SST anomalies during monsoon period tend to be determined by oceanic forcing. The heat content of the coastal Bay of Bengal shows highest response to EIO SST by a lag of 1 month. It suggests that the coastal region of the Bay of Bengal is marked by coastally trapped Kelvin waves, which might have come from EIO at a time lag of 1 month. Sea surface height anomalies, depth at 20 °C isotherms and depth at 26 isotherms also supports the above hypothesis. Composite analysis based on EIO index and coupled climate model sensitivity experiments also suggest that the coastal Bay of Bengal region is marked by coastally trapped Kelvin waves, which are propagated from EIO at a time lag of 1 month. Thus, SST and OLR relationship pinpoints that the Bay of Bengal OLR (convection) is governed by local ocean-atmospheric coupling, which is influenced by the delayed response from EIO brought forward through oceanic planetary waves at a lag of 1 month. These results have utmost predictive value for seasonal and extended range forecasting. Thus, OLR and SST relationship can constitute a pivotal role in investigating the

  9. Vp-Vs relationship and amplitude variation with offset modelling of glauconitic greensand

    DEFF Research Database (Denmark)

    Hossain, Zakir; Mukerji, Tapan; Fabricius, Ida Lykke

    2012-01-01

    The relationship between Vp and Vs may be used to predict Vs where only Vp is known. Vp/Vs is also used to identify pore fluids from seismic data and amplitude variation with offset analysis. Theoretical, physical, as well as statistical empirical Vp-Vs relationships have been proposed...... modelling works well for greensand shear-wave velocity prediction. We model the seismic response of glauconitic greensand by using laboratory data from the Nini field. Our studies here reveal that brine-saturated glauconitic greensand can have a similar seismic response to that from oil-saturated quartzitic...

  10. On the relationship between two popular lattice models for polymer melts

    Science.gov (United States)

    Subramanian, Gopinath; Shanbhag, Sachin

    2008-10-01

    A mapping between two well known lattice bond-fluctuation models for polymers [I. Carmesin and K. Kremer, Macromolecules 21, 2819 (1988); J. S. Shaffer, J. Chem. Phys. 101, 4205 (1994)] is investigated by performing primitive path analysis to identify the average number of monomers per entanglement. Simulations conducted using both models, and previously published data are compared in an attempt to establish relationships between molecular weight, lengthscale, and timescale. Using these relationships, an examination of the self-diffusion coefficient yields excellent agreement not only between the two models, but also with experimental data on polystyrene, polybutadiene, and polydimethylsiloxane. However, it is shown that even with the limited set of criteria examined in this paper, a true mapping between these two models is elusive. Nevertheless, a practical guide to convert between models is provided.

  11. Object and subject relations in adulthood--towards an integrative model of interpersonal relationships.

    Science.gov (United States)

    Zvelc, Gregor

    2010-12-01

    In the article the author presents a model of interpersonal relationships based on integration of object relations theory and theory of attachment. He proposes three main bipolar dimensions of interpersonal relationships: Independence - Dependence, Connectedness - Alienation and Reciprocity - Self-absorption. The author also proposes that it is important to distinguish between two main types of adult interpersonal relationships: object and subject relations. Object relations describe relationships in which the other person is perceived as an object that serves the satisfaction of the first person's needs. Object relations are a manifestation of the right pole of the three main dimensions of interpersonal relationships (Dependence, Alienation and Self-absorption). Subject relations are a counter-pole to the concept of object relations. They describe relationships with other people who are experienced as subjects with their own wishes, interests and needs. Subject relations are a manifestation of the left pole of the main dimensions (Independence, Connectedness and Reciprocity). In this article the author specifically focuses on definitions of object relations in adulthood through a description of six sub-dimensions of object relations: Symbiotic Merging, Separation Anxiety, Social Isolation, Fear of Engulfment, Egocentrism and Narcissism. Every sub-dimension is described in connection to adaptive and pathological functioning. Further research is needed to test the clinical and scientific validity of the model.

  12. Training mode's influences on the relationships between training-load models during basketball conditioning.

    Science.gov (United States)

    Scanlan, Aaron T; Wen, Neal; Tucker, Patrick S; Borges, Nattai R; Dalbo, Vincent J

    2014-09-01

    To compare perceptual and physiological training-load responses during various basketball training modes. Eight semiprofessional male basketball players (age 26.3 ± 6.7 y, height 188.1 ± 6.2 cm, body mass 92.0 ± 13.8 kg) were monitored across a 10-wk period in the preparatory phase of their training plan. Player session ratings of perceived exertion (sRPE) and heart-rate (HR) responses were gathered across base, specific, and tactical/game-play training modes. Pearson correlations were used to determine the relationships between the sRPE model and 2 HR-based models: the training impulse (TRIMP) and summated HR zones (SHRZ). One-way ANOVAs were used to compare training loads between training modes for each model. Stronger relationships between perceptual and physiological models were evident during base (sRPE-TRIMP r = .53, P training load than the TRIMP (15-65 AU) and SHRZ models (27-170 AU) transitioning between training modes. While the training-load models were significantly correlated during each training mode, weaker relationships were observed during specific conditioning. Comparisons suggest that the HR-based models were less effective in detecting periodized increases in training load, particularly during court-based, intermittent, multidirectional drills. The practical benefits and sensitivity of the sRPE model support its use across different basketball training modes.

  13. Parental Modeling and Deidentification in Romantic Relationships Among Mexican-origin Youth.

    Science.gov (United States)

    Kuo, Sally I-Chun; Wheeler, Lorey A; Updegraff, Kimberly A; McHale, Susan M; Umaña-Taylor, Adriana J; Perez-Brena, Norma J

    2017-10-01

    This study investigated youth's modeling of and de-identification from parents in romantic relationships, using two phases of data from adolescent siblings, mothers, and fathers in 246 Mexican-origin families. Each parent reported his/her marital satisfaction and conflict, and youth reported on parent-adolescent warmth and conflict at Time 1. Youth's reports of modeling of and de-identification from their mothers and fathers and three romantic relationship outcomes were assessed at Time 2. Findings revealed that higher parental marital satisfaction, lower marital conflict, and higher warmth and lower conflict in parent-adolescent relationships were associated with more modeling and less de-identification from parents. Moreover, higher de-identification was linked to a greater likelihood of youth being involved in a romantic relationship and cohabitation, whereas more modeling was linked to a lower likelihood of cohabitation and older age of first sex. Discussion underscores the importance of assessing parental modeling and de-identification and understanding correlates of these processes.

  14. A phenomenological model of muscle fatigue and the power-endurance relationship.

    Science.gov (United States)

    James, A; Green, S

    2012-11-01

    The relationship between power output and the time that it can be sustained during exercise (i.e., endurance) at high intensities is curvilinear. Although fatigue is implicit in this relationship, there is little evidence pertaining to it. To address this, we developed a phenomenological model that predicts the temporal response of muscle power during submaximal and maximal exercise and which was based on the type, contractile properties (e.g., fatiguability), and recruitment of motor units (MUs) during exercise. The model was first used to predict power outputs during all-out exercise when fatigue is clearly manifest and for several distributions of MU type. The model was then used to predict times that different submaximal power outputs could be sustained for several MU distributions, from which several power-endurance curves were obtained. The model was simultaneously fitted to two sets of human data pertaining to all-out exercise (power-time profile) and submaximal exercise (power-endurance relationship), yielding a high goodness of fit (R(2) = 0.96-0.97). This suggested that this simple model provides an accurate description of human power output during submaximal and maximal exercise and that fatigue-related processes inherent in it account for the curvilinearity of the power-endurance relationship.

  15. Coopetitive Supply Chain Relationship Model: Application to the Smartphone Manufacturing Network

    Science.gov (United States)

    Kwok, Jeremy Jie Ming; Lee, Dong-Yup

    2015-01-01

    Previous researches for understanding supply chain relationship have mostly focused on its vertical collaboration between buyers and suppliers. However, there have been some instances of volatile and stable collaborative relationships amongst competitors such as Apple-Samsung product manufacturer-component supplier relationship and airline alliances, respectively, which is recognized as coopetition. Even though there have been several qualitative studies and a number of game theory models on coopetition, it is rare to find any attempts on quantitative characterization of such coopetitive dynamic behavior in supply chain relationship. Hence, in this work, we formulated a MINLP model mathematically representing coopetitive relationships in a cost efficient supply chain network. In particular, the coopetition factor was newly introduced to measure the degree of coopetition among supply chain players and determine the optimal level of coopetition to engage in. The utility and practicality of the model were strongly demonstrated using a case study of a hypothetical smartphone supply chain network under different scenarios, thus proposing their strategically viable optimal interactions. Therefore, this exploratory study can herald a new era of global coopetitive business. PMID:26186227

  16. Coopetitive Supply Chain Relationship Model: Application to the Smartphone Manufacturing Network.

    Directory of Open Access Journals (Sweden)

    Jeremy Jie Ming Kwok

    Full Text Available Previous researches for understanding supply chain relationship have mostly focused on its vertical collaboration between buyers and suppliers. However, there have been some instances of volatile and stable collaborative relationships amongst competitors such as Apple-Samsung product manufacturer-component supplier relationship and airline alliances, respectively, which is recognized as coopetition. Even though there have been several qualitative studies and a number of game theory models on coopetition, it is rare to find any attempts on quantitative characterization of such coopetitive dynamic behavior in supply chain relationship. Hence, in this work, we formulated a MINLP model mathematically representing coopetitive relationships in a cost efficient supply chain network. In particular, the coopetition factor was newly introduced to measure the degree of coopetition among supply chain players and determine the optimal level of coopetition to engage in. The utility and practicality of the model were strongly demonstrated using a case study of a hypothetical smartphone supply chain network under different scenarios, thus proposing their strategically viable optimal interactions. Therefore, this exploratory study can herald a new era of global coopetitive business.

  17. Coopetitive Supply Chain Relationship Model: Application to the Smartphone Manufacturing Network.

    Science.gov (United States)

    Kwok, Jeremy Jie Ming; Lee, Dong-Yup

    2015-01-01

    Previous researches for understanding supply chain relationship have mostly focused on its vertical collaboration between buyers and suppliers. However, there have been some instances of volatile and stable collaborative relationships amongst competitors such as Apple-Samsung product manufacturer-component supplier relationship and airline alliances, respectively, which is recognized as coopetition. Even though there have been several qualitative studies and a number of game theory models on coopetition, it is rare to find any attempts on quantitative characterization of such coopetitive dynamic behavior in supply chain relationship. Hence, in this work, we formulated a MINLP model mathematically representing coopetitive relationships in a cost efficient supply chain network. In particular, the coopetition factor was newly introduced to measure the degree of coopetition among supply chain players and determine the optimal level of coopetition to engage in. The utility and practicality of the model were strongly demonstrated using a case study of a hypothetical smartphone supply chain network under different scenarios, thus proposing their strategically viable optimal interactions. Therefore, this exploratory study can herald a new era of global coopetitive business.

  18. Prediction of Surfactants’ Properties using Multiscale Molecular Modeling Tools: A Review Prédiction de propriétés des tensioactifs à l’aide d’outils de modélisation moléculaire : une revue

    Directory of Open Access Journals (Sweden)

    Creton B.

    2013-01-01

    Full Text Available During one of the existing Enhanced Oil Recovery (EOR procedures, a mixture of Alkaline/Surfactant/Polymer (ASP is injected into wells in order to move the trapped oil from the reservoir to the wellbores. The conception and/or the tuning of new ASP combinations, structures of surfactants and/or mixtures of surfactants is of primary interest to improve the efficiency of a such procedure. Molecular modeling tools can be used to understand microscopic effects, predict surfactants’ properties and finally to optimize structures and mixtures of surfactants. We propose in this article a review of the literature on the ability of molecular simulation techniques such as Molecular Dynamics (MD, Monte Carlo (MC simulations, Dissipative Particle Dynamics (DPD and upper scale modeling methods such as Quantitative Structure-Property Relationship (QSPR approaches to predict thermo-physical and structural properties of surfactants. Une des voies possibles de récupération assistée du pétrole, l’EOR (Enhanced Oil Recovery, consiste en l’injection d’un fluide ASP (Alkaline/Surfactant/Polymer dans le réservoir dans le but de déplacer le pétrole piégé vers le puits de production. La conception et/ou l’optimisation de mélanges ASP, de tensioactifs ou de mélanges de tensioactifs est donc d’un intérêt premier pour améliorer l’efficacité d’un tel procédé. Les codes de simulation moléculaire développés et largement validés durant ces dernières décennies apparaissent comme des outils incontournables pour la compréhension des effets microscopiques, la prédiction de propriétés de tensioactifs complexes ou encore l’optimisation des structures voire de la composition de mélanges de tensioactifs. Dans cet article, nous présentons une revue des travaux de la littérature sur le potentiel de diverses techniques de simulation moléculaire pour la prédiction de propriétés structurales ou thermophysiques des tensioactifs. Les

  19. An assessment Model for Customer Relationship Management Process in Iranian Private-Commercial Banks

    Directory of Open Access Journals (Sweden)

    Tahmoures Hasangholi Pour

    2012-03-01

    Full Text Available According to several reports, in spite of huge investment on customer relationship management (CRM, risk of implementing such projects is high. One of failure factors is having no method to assess CRM success comprehensively. Nowadays, classic financial methods are common ways for assessing marketing and CRM initiatives. But, the mentioned models are unsuitable to assess investments like CRM that we expect to have intangible, indirect and strategic benefits. So, we need a process-oriented approach to assess all tangible and intangible factors of CRM process and complete existing models. In this paper, using a qualitative approach and grounded theory, a comprehensive and process-oriented CRM assessment model will be provided that considers all factors of customer relationship management in private-commercial banks of Iran. Finally, based on analysis of developed model, some suggestions will be offered for banking managers and future researchers.

  20. Exploring the Relationship Between Business Model Innovation, Corporate Sustainability, and Organisational Values within the Fashion Industry

    DEFF Research Database (Denmark)

    Pedersen, Esben Rahbek Gjerdrum; Gwozdz, Wencke; Hvass, Kerli Kant

    2018-01-01

    their origin in the fundamental principles guiding the organisation. In addition, the study also finds a positive relationship between the core organisational values and financial performance. The analysis of the paper is based on survey responses from 492 managers within the Swedish fashion industry.......The objective of this paper is to examine the relationship between business model innovation, corporate sustainability, and the underlying organisational values. Moreover, the paper examines how the three dimensions correlate with corporate financial performance. It is concluded that companies...... with innovative business models are more likely to address corporate sustainability and that business model innovation and corporate sustainability alike are typically found in organisations rooted in values of flexibility and discretion. Business model innovation and corporate sustainability thus seem to have...

  1. Leadership models with an emphasis on relationships and the completion of the project in information science

    Science.gov (United States)

    Damaskinou, Aikaterini I.; Drivas, Ioannis C.; Sakas, Damianos P.

    2015-02-01

    While attempting decision-making in leadership, one of the criteria that should be considered is the actual behavior of the leader towards the work group. The object of this study is the prevalence of two key leadership models, the Task Behavior and the Relationship Behavior. Firstly, the leader's behavior is focused on completing the project combined with a leadership style which is more interventionist and less conciliatory. The second leadership model focuses on working relationships, developed between leaders and employees. In this case, the character of the model is associated with a leadership behavior more supportive, motivating and participative. This article refers to the characteristics of the two models and the mechanisms and strategies that can be adopted in both leadership behaviors. Furthermore, through the research which took place, we have come to conclusions regarding the public's views about the different leadership behaviors and, also, the possibility of combining the two styles of leadership.

  2. Competing probabilistic models for catch-effort relationships in wildlife censuses

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, J.R.; Robson, D.S.; Matsuzaki, C.L.

    1983-01-01

    Two probabilistic models are presented for describing the chance that an animal is captured during a wildlife census, as a function of trapping effort. The models in turn are used to propose relationships between sampling intensity and catch-per-unit-effort (C.P.U.E.) that were field tested on small mammal populations. Capture data suggests a model of diminshing C.P.U.E. with increasing levels of trapping intensity. The catch-effort model is used to illustrate optimization procedures in the design of mark-recapture experiments for censusing wild populations. 14 references, 2 tables.

  3. The Relationship between Economic Growth and Money Laundering – a Linear Regression Model

    Directory of Open Access Journals (Sweden)

    Daniel Rece

    2009-09-01

    Full Text Available This study provides an overview of the relationship between economic growth and money laundering modeled by a least squares function. The report analyzes statistically data collected from USA, Russia, Romania and other eleven European countries, rendering a linear regression model. The study illustrates that 23.7% of the total variance in the regressand (level of money laundering is “explained” by the linear regression model. In our opinion, this model will provide critical auxiliary judgment and decision support for anti-money laundering service systems.

  4. Applying the Nominal Response Model within a Longitudinal Framework to Construct the Positive Family Relationships Scale

    Science.gov (United States)

    Preston, Kathleen Suzanne Johnson; Parral, Skye N.; Gottfried, Allen W.; Oliver, Pamella H.; Gottfried, Adele Eskeles; Ibrahim, Sirena M.; Delany, Danielle

    2015-01-01

    A psychometric analysis was conducted using the nominal response model under the item response theory framework to construct the Positive Family Relationships scale. Using data from the Fullerton Longitudinal Study, this scale was constructed within a long-term longitudinal framework spanning middle childhood through adolescence. Items tapping…

  5. Through the Looking Glass: No Wonderland Yet! (The Reciprocal Relationship between Methodology and Models of Reality).

    Science.gov (United States)

    Unger, Rhoda Kesler

    1983-01-01

    Discusses the relationship between conceptual frameworks and methodology in psychology. Argues that models of reality influence research in terms of question selection, causal factors hypothesized, and interpretation of data. Considers the position and role of women as objects and agents of research using a sociology of knowledge perspective.…

  6. A High-Dimensional, Multivariate Copula Approach to Modeling Multivariate Agricultural Price Relationships and Tail Dependencies

    Science.gov (United States)

    Xuan Chi; Barry Goodwin

    2012-01-01

    Spatial and temporal relationships among agricultural prices have been an important topic of applied research for many years. Such research is used to investigate the performance of markets and to examine linkages up and down the marketing chain. This research has empirically evaluated price linkages by using correlation and regression models and, later, linear and...

  7. The relationship between the key elements of Donabedian's conceptual model within the field of assistive technology

    DEFF Research Database (Denmark)

    Sund, Terje; Iwarsson, Susanne; Brandt, Åse

    2015-01-01

    Previous research has suggested that there is a relationship between the three key components of Donabedian's conceptual model for quality assessments: structure of care, process, and outcome of care. That is, structure predicted both process and outcome of care, and better processes predict better...

  8. Expanding business-to-business customer relationships : modeling the customer's upgrade decision

    NARCIS (Netherlands)

    Bolton, R.; Lemon, K.N.; Verhoef, P.C.

    This article develops a model of a business customer's decision to upgrade service contracts conditional on the decision to renew the contract. It proposes that the firm's upgrade decision is influenced by (1) decision-maker perceptions of the relationship with the supplier, (2) contract-level

  9. Predictive and Explanatory Relationship Model between Procrastination, Motivation, Anxiety and Academic Achievement

    Science.gov (United States)

    Akpur, Ugur

    2017-01-01

    Purpose: The purpose of this study is to determine the predictive and explanatory relationship model between procrastination, motivation, anxiety and academic achievement of university students. Research Methods: In this study, a causal research design was used. The study group consisted of 211 participants. In order to determine their motivation…

  10. Modeling the Relationship between Pre-Service Teachers' TPACK and Digital Nativity

    Science.gov (United States)

    Kabakci Yurdakul, Isil

    2018-01-01

    The purpose of this study is to build a structural equation model that predicts the relationship between Technological Pedagogical Content Knowledge (TPACK) competencies and digital nativity. The data was collected from 1493 Turkish pre-service teachers. Two instruments were used in the data collection; a TPACK-deep scale and a Turkish adaptation…

  11. The Relationship between the Big-Five Model of Personality and Self-Regulated Learning Strategies

    Science.gov (United States)

    Bidjerano, Temi; Dai, David Yun

    2007-01-01

    The study examined the relationship between the big-five model of personality and the use of self-regulated learning strategies. Measures of self-regulated learning strategies and big-five personality traits were administered to a sample of undergraduate students. Results from canonical correlation analysis indicated an overlap between the…

  12. The love equation: Computational modeling of romantic relationships in French classical drama

    NARCIS (Netherlands)

    Karsdorp, F.; Kestemont, M.; Schöch, C.; Bosch, A.P.J. van den; Finlayson, M.; Miller, B.; Lieto, A.; Ronfard, R.

    2015-01-01

    We report on building a computational model of romantic relationships in a corpus of historical literary texts. We frame this task as a ranking problem in which, for a given character, we try to assign the highest rank to the character with whom (s)he is most likely to be romantically involved. As

  13. The Love Equation : Computational Modeling of Romantic Relationships in French Classical Drama

    NARCIS (Netherlands)

    Karsdorp, F.B.; Kestemont, Mike; Schöch, Christof; van den Bosch, Antal; Finlayson, Mark; Miller, Ben; Lieto, Antonio; Ronfard, Remi

    We report on building a computational model of romantic relationships in a corpus of historical literary texts. We frame this task as a ranking problem in which, for a given character, we try to assign the highest rank to the character with whom (s)he is most likely to be romantically involved. As

  14. Computational modeling of the structure-function relationship in human placental terminal villi.

    OpenAIRE

    Plitman, Mayo R; Olsthoorn, Jason; Charnock-Jones, David Stephen; Burton, Graham James; Oyen, Michelle Lynn

    2016-01-01

    Placental oxygen transport takes place at the final branches of the villous tree and is dictated by the relative arrangement of the maternal and fetal circulations. Modeling techniques have failed to accurately assess the structure-function relationship in the terminal villi due to the geometrical complexity. Three-dimensional blood flow and oxygen transport was modeled in four terminal villi reconstructed from confocal image stacks. The blood flow was analyzed along the center lines of capil...

  15. Relationship between Family Adaptability, Cohesion and Adolescent Problem Behaviors: Curvilinearity of Circumplex Model

    OpenAIRE

    Joh, Ju Youn; Kim, Sun; Park, Jun Li; Kim, Yeon Pyo

    2013-01-01

    Background The Family Adaptability and Cohesion Evaluation Scale (FACES) III using the circumplex model has been widely used in investigating family function. However, the criticism of the curvilinear hypothesis of the circumplex model has always been from an empirical point of view. This study examined the relationship between adolescent adaptability, cohesion, and adolescent problem behaviors, and especially testing the consistency of the curvilinear hypotheses with FACES III. Methods We us...

  16. Some insights for a relationship marketing model integrating SERVQUAL and customer loyalty in dental clinics

    OpenAIRE

    Vargas Perez, Ana Maria; Grijalvo Martin, Maria Mercedes; Mercado Idoeta, Carmelo

    2012-01-01

    The demand of new services, the emergence of new business models, insufficient innovation, underestimation of customer loyalty and reluctance to adopt new management are evidence of the deficiencies and the lack of research about the relations between patients and dental clinics. In this article we propose the structure of a model of Relationship Marketing (RM) in the dental clinic that integrates information from SERVQUAL, Customer Loyalty (CL) and activities of RM and combines the vision of...

  17. Study of solar radiation prediction and modeling of relationships between solar radiation and meteorological variables

    International Nuclear Information System (INIS)

    Sun, Huaiwei; Zhao, Na; Zeng, Xiaofan; Yan, Dong

    2015-01-01

    Highlights: • We investigate relationships between solar radiation and meteorological variables. • A strong relationship exists between solar radiation and sunshine duration. • Daily global radiation can be estimated accurately with ARMAX–GARCH models. • MGARCH model was applied to investigate time-varying relationships. - Abstract: The traditional approaches that employ the correlations between solar radiation and other measured meteorological variables are commonly utilized in studies. It is important to investigate the time-varying relationships between meteorological variables and solar radiation to determine which variables have the strongest correlations with solar radiation. In this study, the nonlinear autoregressive moving average with exogenous variable–generalized autoregressive conditional heteroscedasticity (ARMAX–GARCH) and multivariate GARCH (MGARCH) time-series approaches were applied to investigate the associations between solar radiation and several meteorological variables. For these investigations, the long-term daily global solar radiation series measured at three stations from January 1, 2004 until December 31, 2007 were used in this study. Stronger relationships were observed to exist between global solar radiation and sunshine duration than between solar radiation and temperature difference. The results show that 82–88% of the temporal variations of the global solar radiation were captured by the sunshine-duration-based ARMAX–GARCH models and 55–68% of daily variations were captured by the temperature-difference-based ARMAX–GARCH models. The advantages of the ARMAX–GARCH models were also confirmed by comparison of Auto-Regressive and Moving Average (ARMA) and neutral network (ANN) models in the estimation of daily global solar radiation. The strong heteroscedastic persistency of the global solar radiation series was revealed by the AutoRegressive Conditional Heteroscedasticity (ARCH) and Generalized Auto

  18. Complementary models of tree species-soil relationships in old-growth temperate forests

    Science.gov (United States)

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

  19. Modeling the relationship between energy consumption and economy development in China

    International Nuclear Information System (INIS)

    Zhang, Jing; Deng, Shihuai; Shen, Fei; Yang, Xinyao; Liu, Guodong; Guo, Hang; Li, Yuanwei; Hong, Xiao; Zhang, Yanzong; Peng, Hong; Zhang, Xiaohong; Li, Li; Wang, Yingjun

    2011-01-01

    This paper investigated the empirical relationship between economy development and energy consumption by material production, nonmaterial production and household. Empirical models accounting for the key influential factors were constructed. Ordinary Least Square Regression (OLS) analysis of the official data of China for the year 1985-2007 permitted the relationship between individual energy consumption components and the corresponding coefficients to be investigated. The results showed that (1) the Unit Energy Consumption by Primary Industry (UECPI), Secondary Industry (UECSI), and Tertiary Industry (UECTI) demonstrated an inverse relationship with Gross Domestic Product (GDP); (2) a linear relationship exists between the Energy Consumption by Nonmaterial Production (ECNP) and GDP; (3) the hypotheses that there is an inverse S-shaped relationship between Unit Energy Consumption by Household (UECH) and Personal Income (PI) is valid. Based on the above findings and an analysis of China's energy policies, suggestions on China's energy policy were given in the end. -- Highlights: → Decomposed total energy consumption in three parts, branch of material produces, branch of the immaterial production, and households. → Energy consumed by branch of material produces considered the economic scale and construction. → Energy consumed by immaterial production was first referred in this article. → The relationship between energy consumed by household and GDP fits the invert-S curve, which is first referred too.

  20. Maintaining Sexual Desire in Long-Term Relationships: A Systematic Review and Conceptual Model.

    Science.gov (United States)

    Mark, Kristen P; Lasslo, Julie A

    The most universally experienced sexual response is sexual desire. Though research on this topic has increased in recent years, low and high desire are still problematized in clinical settings and the broader culture. However, despite knowledge that sexual desire ebbs and flows both within and between individuals, and that problems with sexual desire are strongly linked to problems with relationships, there is a critical gap in understanding the factors that contribute to maintaining sexual desire in the context of relationships. This article offers a systematic review of the literature to provide researchers, educators, clinicians, and the broader public with an overview and a conceptual model of nonclinical sexual desire in long-term relationships. First, we systematically identified peer-reviewed, English-language articles that focused on the maintenance of sexual desire in the context of nonclinical romantic relationships. Second, we reviewed a total of 64 articles that met inclusion criteria and synthesized them into factors using a socioecological framework categorized as individual, interpersonal, and societal in nature. These findings are used to build a conceptual model of maintaining sexual desire in long-term relationships. Finally, we discuss the limitations of the existing research and suggest clear directions for future research.

  1. Infertile Individuals’ Marital Relationship Status, Happiness, and Mental Health: A Causal Model

    Directory of Open Access Journals (Sweden)

    Seyed Habiballah Ahmadi Forooshany

    2014-11-01

    Full Text Available Background: This study examined the causal model of relation between marital relationship status, happiness, and mental health in infertile individuals. Materials and Methods: In this descriptive study, 155 subjects (men: 52 and women: 78, who had been visited in one of the infertility Centers, voluntarily participated in a self-evaluation. Golombok Rust Inventory of Marital Status, Oxford Happiness Questionnaire, and General Health Questionnaire were used as instruments of the study. Data was analyzed by SPSS17 and Amos 5 software using descriptive statistics, independent sample t test, and path analysis. Results: Disregarding the gender factor, marital relationship status was directly related to happiness (p<0.05 and happiness was directly related to mental health, (p<0.05. Also, indirect relation between marital relationship status and mental health was significant (p<0.05. These results were confirmed in women participants but in men participants only the direct relation between happiness and mental health was significant (p<0.05. Conclusion: Based on goodness of model fit in fitness indexes, happiness had a mediator role in relation between marital relationship status and mental health in infertile individuals disregarding the gender factor. Also, considering the gender factor, only in infertile women, marital relationship status can directly and indirectly affect happiness and mental health.

  2. Network modeling reveals prevalent negative regulatory relationships between signaling sectors in Arabidopsis immune signaling.

    Directory of Open Access Journals (Sweden)

    Masanao Sato

    Full Text Available Biological signaling processes may be mediated by complex networks in which network components and network sectors interact with each other in complex ways. Studies of complex networks benefit from approaches in which the roles of individual components are considered in the context of the network. The plant immune signaling network, which controls inducible responses to pathogen attack, is such a complex network. We studied the Arabidopsis immune signaling network upon challenge with a strain of the bacterial pathogen Pseudomonas syringae expressing the effector protein AvrRpt2 (Pto DC3000 AvrRpt2. This bacterial strain feeds multiple inputs into the signaling network, allowing many parts of the network to be activated at once. mRNA profiles for 571 immune response genes of 22 Arabidopsis immunity mutants and wild type were collected 6 hours after inoculation with Pto DC3000 AvrRpt2. The mRNA profiles were analyzed as detailed descriptions of changes in the network state resulting from the genetic perturbations. Regulatory relationships among the genes corresponding to the mutations were inferred by recursively applying a non-linear dimensionality reduction procedure to the mRNA profile data. The resulting static network model accurately predicted 23 of 25 regulatory relationships reported in the literature, suggesting that predictions of novel regulatory relationships are also accurate. The network model revealed two striking features: (i the components of the network are highly interconnected; and (ii negative regulatory relationships are common between signaling sectors. Complex regulatory relationships, including a novel negative regulatory relationship between the early microbe-associated molecular pattern-triggered signaling sectors and the salicylic acid sector, were further validated. We propose that prevalent negative regulatory relationships among the signaling sectors make the plant immune signaling network a "sector

  3. The Relationship between Race and Students' Identified Career Role Models and Perceived Role Model Influence

    Science.gov (United States)

    Karunanayake, Danesh; Nauta, Margaret M.

    2004-01-01

    The authors examined whether college students' race was related to the modal race of their identified career role models, the number of identified career role models, and their perceived influence from such models. Consistent with A. Bandura's (1977, 1986) social learning theory, students tended to have role models whose race was the same as…

  4. Refusal of Treatment by Mentally Competent Patient: The Choice of Doctor-Patient Relationship Models

    Directory of Open Access Journals (Sweden)

    Andrei M. Beliaev

    2010-01-01

    Full Text Available Introduction: In modern medicine professional relationship between the clinician and the patient is patient-centered. Patients become actively involved in the treatment decision making process and are encouraged to express their health-related preferences. Some patients may, however, refuse a favorable risk/benefit ratio treatment. This manuscript presents three cases of refusal of treatment by mentally competent surgical patients and discusses differences in their management. Conclusion: To achieve the best medical outcome for patients who possess the Actual Understanding test of mental competence clinicians use the deliberate model of medical professional relationship. For patients demonstrating the Understanding test of mental competence and wishing to utilize their health-related preferences physicians are obliged to deploy the interpretive model of doctor-patient relationship. In mentally competent patients with an illness-induced acute psychological regression the interpretive model of doctor-patient relationship as an initial strategy and cognitive behavior therapy can be useful in modifying treatment rejecting behavior and improving medical outcome.

  5. Cost model relationships between textile manufacturing processes and design details for transport fuselage elements

    Science.gov (United States)

    Metschan, Stephen L.; Wilden, Kurtis S.; Sharpless, Garrett C.; Andelman, Rich M.

    1993-01-01

    Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design.

  6. The Relationship between entrepreneurial orientation, entrepreneurial competencies, entrepreneurial leadership, and firm performance: A proposed model

    Directory of Open Access Journals (Sweden)

    Chijioke Nwachukwu

    2017-06-01

    Full Text Available This study develops a conceptual model and propositions for researchers to explore the direct and indirect relationship between entrepreneurial orientation, entrepreneurial competencies, entrepreneurial leadership and firm performance. Authors searched various databases including ProQuest, EBSCOhost databases, Scopus for peer reviewed Journals, books, and other relevant publications on the subject. A conceptual review provides direction for researchers to empirically examine the direct relationships between entrepreneurial orientation (EO, entrepreneurial competencies (EC, and firm performance and the mediating effect of entrepreneurial leadership (EL in the relationship between EO, EC, and firm performance. We suggest the use of entrepreneurial orientation scale (EOS, The entrecomp framework (2016, Renko et al., 2015 entrepreneurial leadership styles scale (ENTRELEAD, and Santos & Brito (2012 subjective measurement model for firm performance for measurement of the constructs of EO, EC, EL and performance. For researchers and academics, the model provides a basis for further research by testing empirically the validity of the model. Testing of this model could provide a better understanding of the EO, EC constructs that better predicts strategic and financial performance.

  7. Use of Occupancy Models to Evaluate Expert Knowledge-based Species-Habitat Relationships

    Directory of Open Access Journals (Sweden)

    Monica N. Iglecia

    2012-12-01

    Full Text Available Expert knowledge-based species-habitat relationships are used extensively to guide conservation planning, particularly when data are scarce. Purported relationships describe the initial state of knowledge, but are rarely tested. We assessed support in the data for suitability rankings of vegetation types based on expert knowledge for three terrestrial avian species in the South Atlantic Coastal Plain of the United States. Experts used published studies, natural history, survey data, and field experience to rank vegetation types as optimal, suitable, and marginal. We used single-season occupancy models, coupled with land cover and Breeding Bird Survey data, to examine the hypothesis that patterns of occupancy conformed to species-habitat suitability rankings purported by experts. Purported habitat suitability was validated for two of three species. As predicted for the Eastern Wood-Pewee (Contopus virens and Brown-headed Nuthatch (Sitta pusilla, occupancy was strongly influenced by vegetation types classified as "optimal habitat" by the species suitability rankings for nuthatches and wood-pewees. Contrary to predictions, Red-headed Woodpecker (Melanerpes erythrocephalus models that included vegetation types as covariates received similar support by the data as models without vegetation types. For all three species, occupancy was also related to sampling latitude. Our results suggest that covariates representing other habitat requirements might be necessary to model occurrence of generalist species like the woodpecker. The modeling approach described herein provides a means to test expert knowledge-based species-habitat relationships, and hence, help guide conservation planning.

  8. A revival of the autoregressive distributed lag model in estimating energy demand relationships

    Energy Technology Data Exchange (ETDEWEB)

    Bentzen, J.; Engsted, T.

    1999-07-01

    The findings in the recent energy economics literature that energy economic variables are non-stationary, have led to an implicit or explicit dismissal of the standard autoregressive distribution lag (ARDL) model in estimating energy demand relationships. However, Pesaran and Shin (1997) show that the ARDL model remains valid when the underlying variables are non-stationary, provided the variables are co-integrated. In this paper we use the ARDL approach to estimate a demand relationship for Danish residential energy consumption, and the ARDL estimates are compared to the estimates obtained using co-integration techniques and error-correction models (ECM's). It turns out that both quantitatively and qualitatively, the ARDL approach and the co-integration/ECM approach give very similar results. (au)

  9. The Colonization of Private Relationships by the Economic Discourse: A Critic to Descriptive Models of Company

    Directory of Open Access Journals (Sweden)

    Sergio Marcos Carvalho de Avila Negri

    2015-12-01

    Full Text Available Through the reconstructive method of approach and by adopting the communicative rationality habermasian as epistemological framework, this paper discusses the process of colonization of private relations by economic discourse in the corporate field. It examines, in particular, descriptive models of business relationships, as the nexus of contracts theory and dispute resolution forms as the "default rule" and the "hypothetical bargain." With a content analysis of these models, it investigates the hypothesis that there are non-problematized normative claims in the descriptions of business relationships and decision-making in the corporate field, such as specialization and efficiency while rationality parameters. It addresses procedural and substantive objections to the approached models.

  10. An explanatory model regarding the relationships between psychological traits and creativity

    Directory of Open Access Journals (Sweden)

    María Luisa Sanz de Acedo Lizarraga

    2014-01-01

    Full Text Available This research tested a theoretical model of the relationships between certain psychological variables and creativity. Specifically, the relationships among intelligence, personality, intrinsic motivation, creative self-efficacy, and ideational creativity were examined. This study was conducted with a sample of 180 college students (136 women and 44 men who were evaluated with regard to the variables above in two sessions outside the regular academic schedule. The results obtained via structural equation analysis supported the model and revealed that the independent variables (intelligence and personality and the intermediate variables (intrinsic motivation and creative self-efficacy that comprise the proposed model influenced creativity. Furthermore, creative self-efficacy was the most significant trait associated with ideational creativity.

  11. A revival of the autoregressive distributed lag model in estimating energy demand relationships

    Energy Technology Data Exchange (ETDEWEB)

    Bentzen, J; Engsted, T

    1999-07-01

    The findings in the recent energy economics literature that energy economic variables are non-stationary, have led to an implicit or explicit dismissal of the standard autoregressive distribution lag (ARDL) model in estimating energy demand relationships. However, Pesaran and Shin (1997) show that the ARDL model remains valid when the underlying variables are non-stationary, provided the variables are co-integrated. In this paper we use the ARDL approach to estimate a demand relationship for Danish residential energy consumption, and the ARDL estimates are compared to the estimates obtained using co-integration techniques and error-correction models (ECM's). It turns out that both quantitatively and qualitatively, the ARDL approach and the co-integration/ECM approach give very similar results. (au)

  12. Models of physician-patient relationships in pharmaceutical direct-to-consumer advertising and consumer interviews.

    Science.gov (United States)

    Arney, Jennifer; Lewin, Benjamin

    2013-07-01

    The rise of direct-to-consumer advertising (DTCA) has mirrored, if not facilitated, the shift toward more active health care consumers. We used content analysis to identify models of physician-patient interaction in DTCA from the 1997 to 2006 issues of a broad sample of women's, men's, and common readership magazines. We also conducted 36 in-depth interviews to examine the ways consumers receive and regard advertising messages, and to explore their preferences for clinical communication and decision making. We identified four models of physician-patient relationships that vary in their locus of control (physician, patient, or shared) and the form of support sought or obtained in the relationship (emotional or instrumental). Whereas consumer interviews reflected references to all four models of interaction, only two appeared in DTCA. The limited range of interactions seen in these advertisements creates a lack of congruity between interaction styles found in advertisements vs. styles reported by actual consumers.

  13. Development of knowledge models by linguistic analysis of lexical relationships in technical documents

    International Nuclear Information System (INIS)

    Seguela, Patrick

    2001-01-01

    This research thesis addresses the problem of knowledge acquisition and structuring from technical texts, and the use of this knowledge in the development of models. The author presents the Cameleon method which aims at extracting binary lexical relationships from technical texts by identifying linguistic markers. The relevance of this method is assessed in the case of four different corpuses: a written technical corpus, an oral technical corpus, a corpus of texts of instructions, and a corpus of academic texts. The author reports the development of a model of representation of knowledge of a specific field by using lexical relationships. The method is then applied to develop a model used in document search within a knowledge management system [fr

  14. Dose-stochastic radiobiological effect relationship in model of two reactions and estimation of radiation risk

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1997-01-01

    The model of dose-stochastic effect relationship for biological systems capable of self-defence under danger factor effect is developed. A defence system is realized in two forms of organism reaction, which determine innate μ n and adaptive μ a radiosensitivities. The significances of μ n are determined by host (inner) factors; and the significances of μ a , by external factors. The possibilities of adaptive reaction are determined by the coefficient of capabilities of the defence system. The formulas of the dose-effect relationship are the solutions of differential equations of assumed process in the defence system of organism. The model and formulas have been checked both at cell and at human levels. Based on the model and personal monitoring data, the estimation of radiation risk at the Joint Institute for Nuclear Research is done

  15. Exploring the relationship between volunteering and hospice sustainability in the UK: a theoretical model.

    Science.gov (United States)

    Scott, Ros; Jindal-Snape, Divya; Manwaring, Gaye

    2018-05-02

    To explore the relationship between volunteering and the sustainability of UK voluntary hospices. A narrative literature review was conducted to inform the development of a theoretical model. Eight databases were searched: CINAHL (EBSCO), British Nursing Index, Intute: Health and Life Sciences, ERIC, SCOPUS, ASSIA (CSA), Cochrane Library and Google Scholar. A total of 90 documents were analysed. Emerging themes included the importance of volunteering to the hospice economy and workforce, the quality of services, and public and community support. Findings suggest that hospice sustainability is dependent on volunteers; however, the supply and retention of volunteers is affected by internal and external factors. A theoretical model was developed to illustrate the relationship between volunteering and hospice sustainability. It demonstrates the factors necessary for hospice sustainability and the reciprocal impact that these factors and volunteering have on each other. The model has a practical application as an assessment framework and strategic planning tool.

  16. Pharmacokinetic/Pharmacodynamic Relationship of Gabapentin in a CFA-induced Inflammatory Hyperalgesia Rat Model

    DEFF Research Database (Denmark)

    Larsen, Malte Selch; Keizer, Ron; Munro, Gordon

    2016-01-01

    PURPOSE: Gabapentin displays non-linear drug disposition, which complicates dosing for optimal therapeutic effect. Thus, the current study was performed to elucidate the pharmacokinetic/pharmacodynamic (PKPD) relationship of gabapentin's effect on mechanical hypersensitivity in a rat model of CFA......-induced inflammatory hyperalgesia. METHODS: A semi-mechanistic population-based PKPD model was developed using nonlinear mixed-effects modelling, based on gabapentin plasma and brain extracellular fluid (ECF) time-concentration data and measurements of CFA-evoked mechanical hyperalgesia following administration...

  17. A model of the instantaneous pressure-velocity relationships of the neonatal cerebral circulation.

    Science.gov (United States)

    Panerai, R B; Coughtrey, H; Rennie, J M; Evans, D H

    1993-11-01

    The instantaneous relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), measured with Doppler ultrasound in the anterior cerebral artery, is represented by a vascular waterfall model comprising vascular resistance, compliance, and critical closing pressure. One min recordings obtained from 61 low birth weight newborns were fitted to the model using a least-squares procedures with correction for the time delay between the BP and CBFV signals. A sensitivity analysis was performed to study the effects of low-pass filtering (LPF), cutoff frequency, and noise on the estimated parameters of the model. Results indicate excellent fitting of the model (F-test, p model parameters have a mean correlation coefficient of 0.94 with the measured flow velocity tracing (N = 232 epochs). The model developed can be useful for interpreting clinical findings and as a framework for research into cerebral autoregulation.

  18. The evolution of facility management business models in supplier–client relationships

    DEFF Research Database (Denmark)

    Nardelli, Giulia; Rajala, Risto

    2018-01-01

    Purpose – The study improves the current understanding of business model innovation by outlining how business models unfold over time within supplier–client relationships in facilities management (FM) services. Design/methodology/approach – This study of FM services in Denmark consists...... of an explorative case study and three case studies of facilities management clients. Both phases, related and overlapping, involved collection and analysis of in-depth, semi-structured interviews and archive data. Findings – Findings shows that business model innovation entails interorganisational collaboration...... consequences of changes in the ecosystem. Originality/value – This paper introduces new thinking on the subject of business model innovation to the context of FM. It presents the external orientation of FM business models as a way to combine planned and emergent business model innovation through...

  19. Infertile individuals' marital relationship status, happiness, and mental health: a causal model.

    Science.gov (United States)

    Ahmadi Forooshany, Seyed Habiballah; Yazdkhasti, Fariba; Safari Hajataghaie, Saiede; Nasr Esfahani, Mohammad Hossein

    2014-10-01

    This study examined the causal model of relation between marital relation- ship status, happiness, and mental health in infertile individuals. In this descriptive study, 155 subjects (men: 52 and women: 78), who had been visited in one of the infertility Centers, voluntarily participated in a self-evaluation. Golombok Rust Inventory of Marital Status, Oxford Happiness Ques- tionnaire, and General Health Questionnaire were used as instruments of the study. Data was analyzed by SPSS17 and Amos 5 software using descriptive statistics, independent sample t test, and path analysis. Disregarding the gender factor, marital relationship status was directly related to happiness (phappiness was directly related to mental health, (phappiness and mental health was significant (phappiness had a mediator role in relation between marital relationship status and mental health in infertile individu- als disregarding the gender factor. Also, considering the gender factor, only in infertile women, marital relationship status can directly and indirectly affect happiness and mental health.

  20. In silico modeling on ADME properties of natural products: Classification models for blood-brain barrier permeability, its application to traditional Chinese medicine and in vitro experimental validation.

    Science.gov (United States)

    Zhang, Xiuqing; Liu, Ting; Fan, Xiaohui; Ai, Ni

    2017-08-01

    In silico modeling of blood-brain barrier (BBB) permeability plays an important role in early discovery of central nervous system (CNS) drugs due to its high-throughput and cost-effectiveness. Natural products (NP) have demonstrated considerable therapeutic efficacy against several CNS diseases. However, BBB permeation property of NP is scarcely evaluated both experimentally and computationally. It is well accepted that significant difference in chemical spaces exists between NP and synthetic drugs, which calls into doubt on suitability of available synthetic chemical based BBB permeability models for the evaluation of NP. Herein poor discriminative performance on BBB permeability of NP are first confirmed using internal constructed and previously published drug-derived computational models, which warrants the need for NP-oriented modeling. Then a quantitative structure-property relationship (QSPR) study on a NP dataset was carried out using four different machine learning methods including support vector machine, random forest, Naïve Bayes and probabilistic neural network with 67 selected features. The final consensus model was obtained with approximate 90% overall accuracy for the cross-validation study, which is further taken to predict passive BBB permeability of a large dataset consisting of over 10,000 compounds from traditional Chinese medicine (TCM). For 32 selected TCM molecules, their predicted BBB permeability were evaluated by in vitro parallel artificial membrane permeability assay and overall accuracy for in vitro experimental validation is around 81%. Interestingly, our in silico model successfully predicted different BBB permeation potentials of parent molecules and their known in vivo metabolites. Finally, we found that the lipophilicity, the number of hydrogen bonds and molecular polarity were important molecular determinants for BBB permeability of NP. Our results suggest that the consensus model proposed in current work is a reliable tool for

  1. Investigating the Influence Relationship Models for Stocks in Indian Equity Market: A Weighted Network Modelling Study.

    Science.gov (United States)

    Bhattacharjee, Biplab; Shafi, Muhammad; Acharjee, Animesh

    2016-01-01

    The socio-economic systems today possess high levels of both interconnectedness and interdependencies, and such system-level relationships behave very dynamically. In such situations, it is all around perceived that influence is a perplexing power that has an overseeing part in affecting the dynamics and behaviours of involved ones. As a result of the force & direction of influence, the transformative change of one entity has a cogent aftereffect on the other entities in the system. The current study employs directed weighted networks for investigating the influential relationship patterns existent in a typical equity market as an outcome of inter-stock interactions happening at the market level, the sectorial level and the industrial level. The study dataset is derived from 335 constituent stocks of 'Standard & Poor Bombay Stock Exchange 500 index' and study period is 1st June 2005 to 30th June 2015. The study identifies the set of most dynamically influential stocks & their respective temporal pattern at three hierarchical levels: the complete equity market, different sectors, and constituting industry segments of those sectors. A detailed influence relationship analysis is performed for the sectorial level network of the construction sector, and it was found that stocks belonging to the cement industry possessed high influence within this sector. Also, the detailed network analysis of construction sector revealed that it follows scale-free characteristics and power law distribution. In the industry specific influence relationship analysis for cement industry, methods based on threshold filtering and minimum spanning tree were employed to derive a set of sub-graphs having temporally stable high-correlation structure over this ten years period.

  2. Using a High-Dimensional Graph of Semantic Space to Model Relationships among Words

    Directory of Open Access Journals (Sweden)

    Alice F Jackson

    2014-05-01

    Full Text Available The GOLD model (Graph Of Language Distribution is a network model constructed based on co-occurrence in a large corpus of natural language that may be used to explore what information may be present in a graph-structured model of language, and what information may be extracted through theoretically-driven algorithms as well as standard graph analysis methods. The present study will employ GOLD to examine two types of relationship between words: semantic similarity and associative relatedness. Semantic similarity refers to the degree of overlap in meaning between words, while associative relatedness refers to the degree to which two words occur in the same schematic context. It is expected that a graph structured model of language constructed based on co-occurrence should easily capture associative relatedness, because this type of relationship is thought to be present directly in lexical co-occurrence. However, it is hypothesized that semantic similarity may be extracted from the intersection of the set of first-order connections, because two words that are semantically similar may occupy similar thematic or syntactic roles across contexts and thus would co-occur lexically with the same set of nodes. Two versions the GOLD model that differed in terms of the co-occurence window, bigGOLD at the paragraph level and smallGOLD at the adjacent word level, were directly compared to the performance of a well-established distributional model, Latent Semantic Analysis (LSA. The superior performance of the GOLD models (big and small suggest that a single acquisition and storage mechanism, namely co-occurrence, can account for associative and conceptual relationships between words and is more psychologically plausible than models using singular value decomposition.

  3. Using a high-dimensional graph of semantic space to model relationships among words.

    Science.gov (United States)

    Jackson, Alice F; Bolger, Donald J

    2014-01-01

    The GOLD model (Graph Of Language Distribution) is a network model constructed based on co-occurrence in a large corpus of natural language that may be used to explore what information may be present in a graph-structured model of language, and what information may be extracted through theoretically-driven algorithms as well as standard graph analysis methods. The present study will employ GOLD to examine two types of relationship between words: semantic similarity and associative relatedness. Semantic similarity refers to the degree of overlap in meaning between words, while associative relatedness refers to the degree to which two words occur in the same schematic context. It is expected that a graph structured model of language constructed based on co-occurrence should easily capture associative relatedness, because this type of relationship is thought to be present directly in lexical co-occurrence. However, it is hypothesized that semantic similarity may be extracted from the intersection of the set of first-order connections, because two words that are semantically similar may occupy similar thematic or syntactic roles across contexts and thus would co-occur lexically with the same set of nodes. Two versions the GOLD model that differed in terms of the co-occurence window, bigGOLD at the paragraph level and smallGOLD at the adjacent word level, were directly compared to the performance of a well-established distributional model, Latent Semantic Analysis (LSA). The superior performance of the GOLD models (big and small) suggest that a single acquisition and storage mechanism, namely co-occurrence, can account for associative and conceptual relationships between words and is more psychologically plausible than models using singular value decomposition (SVD).

  4. Chemically Aware Model Builder (camb): an R package for property and bioactivity modelling of small molecules.

    Science.gov (United States)

    Murrell, Daniel S; Cortes-Ciriano, Isidro; van Westen, Gerard J P; Stott, Ian P; Bender, Andreas; Malliavin, Thérèse E; Glen, Robert C

    2015-01-01

    In silico predictive models have proved to be valuable for the optimisation of compound potency, selectivity and safety profiles in the drug discovery process. camb is an R package that provides an environment for the rapid generation of quantitative Structure-Property and Structure-Activity models for small molecules (including QSAR, QSPR, QSAM, PCM) and is aimed at both advanced and beginner R users. camb's capabilities include the standardisation of chemical structure representation, computation of 905 one-dimensional and 14 fingerprint type descriptors for small molecules, 8 types of amino acid descriptors, 13 whole protein sequence descriptors, filtering methods for feature selection, generation of predictive models (using an interface to the R package caret), as well as techniques to create model ensembles using techniques from the R package caretEnsemble). Results can be visualised through high-quality, customisable plots (R package ggplot2). Overall, camb constitutes an open-source framework to perform the following steps: (1) compound standardisation, (2) molecular and protein descriptor calculation, (3) descriptor pre-processing and model training, visualisation and validation, and (4) bioactivity/property prediction for new molecules. camb aims to speed model generation, in order to provide reproducibility and tests of robustness. QSPR and proteochemometric case studies are included which demonstrate camb's application.Graphical abstractFrom compounds and data to models: a complete model building workflow in one package.

  5. Externally predictive single-descriptor based QSPRs for physico-chemical properties of polychlorinated-naphthalenes: Exploring relationships of log SW, log KOA, and log KOW with electron-correlation

    International Nuclear Information System (INIS)

    Chayawan; Vikas

    2015-01-01

    Highlights: • Aqueous solubility and partition coefficient are modelled using single-parameter. • Electron-correlation observed as a vital predictorof physico-chemical properties. • For octanol-air partition coefficient, energy and polarizability yield best models. • Dipole-moment is found to be worst single-descriptor for the properties analysed. - Abstract: Quantitative structure–property relationships (QSPRs), based only on a single-parameter, are proposed for the prediction of physico-chemical properties, namely, aqueous solubility (log S W ), octanol–water partition coefficient (log K OW ) and octanol–air partition coefficient (log K OA ) of polychloronaphthalenes (PCNs) including all the 75 chloronaphthalene congeners. The QSPR models are developed using molecular descriptors computed through quantum mechanical methods including ab-initio as well as advanced semi-empirical methods. The predictivity of the developed models is tested through state-of-the-art external validation procedures employing an external prediction set of compounds. To analyse the role of instantaneous interactions between electrons (the electron-correlation), the models are also compared with those developed using only the electron-correlation contribution of the quantum chemical descriptor. The electron-correlation contribution towards the chemical hardness and the LUMO energy are observed to be the best predictors for octanol–water partition coefficient, whereas for the octanol–air partition coefficient, the total electronic energy and electron-correlation energy are found to be reliable descriptors, in fact, even better than the polarisability. For aqueous solubility of PCNs, the absolute electronegativity is observed to be the best predictor. This work suggests that the electron-correlation contribution of a quantum-chemical descriptor can be used as a reliable indicator for physico-chemical properties, particularly the partition coefficients

  6. Externally predictive single-descriptor based QSPRs for physico-chemical properties of polychlorinated-naphthalenes: Exploring relationships of log S{sub W}, log K{sub OA}, and log K{sub OW} with electron-correlation

    Energy Technology Data Exchange (ETDEWEB)

    Chayawan; Vikas, E-mail: qlabspu@pu.ac.in

    2015-10-15

    Highlights: • Aqueous solubility and partition coefficient are modelled using single-parameter. • Electron-correlation observed as a vital predictorof physico-chemical properties. • For octanol-air partition coefficient, energy and polarizability yield best models. • Dipole-moment is found to be worst single-descriptor for the properties analysed. - Abstract: Quantitative structure–property relationships (QSPRs), based only on a single-parameter, are proposed for the prediction of physico-chemical properties, namely, aqueous solubility (log S{sub W}), octanol–water partition coefficient (log K{sub OW}) and octanol–air partition coefficient (log K{sub OA}) of polychloronaphthalenes (PCNs) including all the 75 chloronaphthalene congeners. The QSPR models are developed using molecular descriptors computed through quantum mechanical methods including ab-initio as well as advanced semi-empirical methods. The predictivity of the developed models is tested through state-of-the-art external validation procedures employing an external prediction set of compounds. To analyse the role of instantaneous interactions between electrons (the electron-correlation), the models are also compared with those developed using only the electron-correlation contribution of the quantum chemical descriptor. The electron-correlation contribution towards the chemical hardness and the LUMO energy are observed to be the best predictors for octanol–water partition coefficient, whereas for the octanol–air partition coefficient, the total electronic energy and electron-correlation energy are found to be reliable descriptors, in fact, even better than the polarisability. For aqueous solubility of PCNs, the absolute electronegativity is observed to be the best predictor. This work suggests that the electron-correlation contribution of a quantum-chemical descriptor can be used as a reliable indicator for physico-chemical properties, particularly the partition coefficients.

  7. Modelling world gold prices and USD foreign exchange relationship using multivariate GARCH model

    Science.gov (United States)

    Ping, Pung Yean; Ahmad, Maizah Hura Binti

    2014-12-01

    World gold price is a popular investment commodity. The series have often been modeled using univariate models. The objective of this paper is to show that there is a co-movement between gold price and USD foreign exchange rate. Using the effect of the USD foreign exchange rate on the gold price, a model that can be used to forecast future gold prices is developed. For this purpose, the current paper proposes a multivariate GARCH (Bivariate GARCH) model. Using daily prices of both series from 01.01.2000 to 05.05.2014, a causal relation between the two series understudied are found and a bivariate GARCH model is produced.

  8. Make or Buy in a Mature Industry? Models of Clientsupplier Relationships under TCT and RBV Perspectives

    Directory of Open Access Journals (Sweden)

    Manuel Portugal Ferreira

    2010-01-01

    Full Text Available In this paper, we use the transaction cost theory [TCT] and the resource-based view [RBV] to discuss three propositions on the models of client-supplier relationships in mature industries. The two theories seem to advance different organizational forms of the client-supplier relationships, and in some instances are contradictory. How should firms organize to prosper and grow, namely in the international markets? Through the case study of three Portuguese packaging firms, with primary (interviews and secondary data, we discuss how the three firms deploy three distinct strategic organization models in a mature industry. One firm utilizes marketbased governance mechanisms, and concentrates its production in a few selected locations. Another firm vertically integrates almost the entire value chain of the product to provide full service to its clients. The third firm operates in a model of integrated outsourcing, with the installation wall to wall with its clients. The clientsupplier models adopted by these firms are based on efficient, stable, and trustworthy relationships that permit them to focus on their core competences and reduce transaction costs. The superior performance of firms requires a proper alignment of hierarchical and relational governance, taking the dimensions of their transactions into consideration.

  9. Enacting Firm, Fair and Friendly Practice: A Model for Strengths-Based Child Protection Relationships?

    Science.gov (United States)

    Oliver, Carolyn; Charles, Grant

    2016-06-01

    Strengths-based solution-focused approaches are gaining ground in statutory child protection work, but few studies have asked front line practitioners how they navigate the complex worker-client relationships such approaches require. This paper describes one component of a mixed-methods study in a large Canadian statutory child protection agency in which 225 workers described how they applied the ideas of strengths-based practice in their daily work. Interviews with twenty-four practitioners were analysed using an interpretive description approach. Only four interviewees appeared to successfully enact a version of strengths-based practice that closely mirrored those described by key strengths-based child protection theorists and was fully congruent with their mandated role. They described navigating a shifting balance of collaboration and authority in worker-client relationships based on transparency, impartial judgement, attentiveness to the worker-client interaction and the value that clients were fellow human beings. Their accounts extend current conceptualisations of the worker-client relationship in strengths-based child protection work and are congruent with current understandings of effective mandated relationships. They provide what may be a useful model to help workers understand and navigate relationships in which they must reconcile their own authority and expertise with genuine support for the authority and expertise of their clients.

  10. Improvements of ENSO-monsoon relationship in CMIP5 models through statistical downscaling over India.

    Science.gov (United States)

    Akhter, J.; Das, L.; Deb, A.

    2017-12-01

    Present study has assessed the skills of global climate models (GCMS) from coupled model inter-comparison project phase five (CMIP5) in simulating ENSO-monsoon relationships over seven homogeneous zones of India. Observational sea surface temperature (SST) data has revealed that there has been a significant negative correlation between zonal precipitation and Nino 3.4 index over North Mountainous India, North West India, North Central India, West Peninsular India and South Peninsular India. First and third principal component (PC) of zonal precipitation explaining 44.4% and 14.2% variance respectively has also shown significant anti-correlation with Nino 3.4. Analysis with CMIP5 models revealed that majority of GCMs have failed to reproduce both magnitude and phase of such relationships mainly due to poor simulation of Nino 3.4 index. Therefore, an attempt has been made to improve the results through empirical orthogonal function (EOF) based statistical downscaling of CMIP5 GCMs. To downscale Nino 3.4 index, an optimal predictor combination of PCs extracted from EOF fields of large scale GCM predictors like Geo-potential height, u and v wind, Specific and relative humidity and air temperature at pressure levels 500, 850 and 1000 hpa, mean sea level pressure and atmospheric vapor content has been utilized. Results indicated improvements of downscaled CMIP5 models in simulating ENSO-monsoon relationship for zone wise precipitation. Multi-model ensemble (MME) of downscaled GCMs has better skill than individuals GCM. Therefore, downscaled MME may be used more reliably to investigate future ENSO-monsoon relationship under various warming scenarios

  11. Parent-adolescent relationship and adolescent internet addiction: A moderated mediation model.

    Science.gov (United States)

    Wang, Wei; Li, Dongping; Li, Xian; Wang, Yanhui; Sun, Wenqiang; Zhao, Liyan; Qiu, Lilan

    2018-09-01

    Substantial research has found that positive parent-adolescent relationship is associated with low levels of adolescent Internet addiction (IA). However, little is known about the mediating and moderating mechanisms underlying this relation. The present study examined a moderated mediation model that included the parent-adolescent relationship (predictor variable), emotion regulation ability (mediator), stressful life events (moderator), and IA (outcome variable) simultaneously. A total of 998 (M age  = 15.15 years, SD = 1.57) Chinese adolescents completed the Parent-Adolescent Relationship Scale, Emotion Regulation Ability Scale, Adolescent Stressful Life Events Scale, and Internet Addiction Diagnostic Questionnaire. After controlling for adolescent gender, age, and family socioeconomic status, results revealed that good parent-adolescent relationship was positively associated with adolescent emotion regulation ability, which in turn was negatively associated with their IA. Moreover, stressful life events moderated the second part of the mediation process. In accordance with the reverse stress-buffering model, the relation between emotion regulation ability and adolescent IA was stronger for adolescents who experienced lower levels of stressful life events. The findings and their implications are discussed and a resilient contextual perspective proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Relationships between hormones and aggressive behavior in green anole lizards: an analysis using structural equation modeling.

    Science.gov (United States)

    Yang, Eun-Jin; Wilczynski, Walter

    2002-09-01

    We investigated the relationship between aggressive behavior and circulating androgens in the context of agonistic social interaction and examined the effect of this interaction on the androgen-aggression relationship in response to a subsequent social challenge in male Anolis carolinensis lizards. Individuals comprising an aggressive encounter group were exposed to an aggressive conspecific male for 10 min per day during a 5-day encounter period, while controls were exposed to a neutral stimulus for the same period. On the sixth day, their responses to an intruder test were observed. At intervals, individuals were sacrificed to monitor plasma androgen levels. Structural equation modeling (SEM) was used to test three a priori interaction models of the relationship between social stimulus, aggressive behavior, and androgen. Model 1 posits that exposure to a social stimulus influences androgen and aggressive behavior independently. In Model 2, a social stimulus triggers aggressive behavior, which in turn increases circulating levels of androgen. In Model 3, exposure to a social stimulus influences circulating androgen levels, which in turn triggers aggressive behavior. During the 5 days of the encounter period, circulating testosterone (T) levels of the aggressive encounter group followed the same pattern as their aggressive behavioral responses, while the control group did not show significant changes in their aggressive behavior or T level. Our SEM results supported Model 2. A means analysis showed that during the intruder test, animals with 5 days of aggressive encounters showed more aggressive responses than did control animals, while their circulating androgen levels did not differ. This further supports Model 2, suggesting that an animal's own aggressive behavior may trigger increases in levels of plasma androgen. Copyright 2002 Elsevier Science (USA)

  13. Aligning drivers, contract, and management of IT-outsourcing relationships: a type-dependent model

    DEFF Research Database (Denmark)

    Arenfeldt, Katrine; Corty Dam, Amalie; Fenger, Kim Harder

    2017-01-01

    In today’s competitive business environment, information technology outsourcing has become a wide-spread reality across all industries and sectors. Researchers have investigated this complex phenomenon from various angles, and established a sound knowledge base regarding the drivers, management......, and success factors related to IT outsourcing. However, little is known about the relationship between outsourcing drivers and goals on the one hand, and contractual and managerial aspects on the other hand. To overcome this gap, this study presents a synthesized conceptual model of existing literature...... that relates aspects of contractual governance and relationship management to three generic types of IT outsourcing, based on their underlying drivers: task-based, process-based, and partnership-based outsourcing. Our model identifies the specific contractual and managerial factors relevant for each type...

  14. Relationship between Temperament, Depression, Anxiety, and Hopelessness in Adolescents: A Structural Equation Model

    Directory of Open Access Journals (Sweden)

    Paolo Iliceto

    2011-01-01

    Full Text Available The purpose of this study was to test the validity of affective temperaments for predicting psychiatric morbidity and suicide risk, using a two-factor model to explain the relationships between temperament, anxiety, depression, and hopelessness. We investigated 210 high school students, 103 males and 107 females, 18-19 years old, who were administered self-report questionnaires to assess temperament (TEMPS-A, depression (BDI-II, anxiety (STAI and hopelessness (BHS. The final structural model had a good fit with the data, with two factors significantly correlated, the first labeled unstable cyclothymic temperament including Dysthymic/Cyclothymic/Anxious temperament, Irritable temperament and Depression, and the second labeled Demoralization including Anxiety (State/Trait and Hopelessness. Depression, anxiety and hopelessness are in a complex relationship partly mediated by temperament.

  15. A comprehensive model of stress - The roles of experienced stress and neuroticism in explaining the stress-distress relationship

    NARCIS (Netherlands)

    De Jong, GM; van Sonderen, E; Emmelkamp, PMG

    1999-01-01

    Background: In this study, a complex theoretical model regarding the stress-distress relationship was evaluated. The various components in the model included experienced stress (daily hassles), psychological distress, neuroticism, problem-focused coping, avoidant coping, satisfaction with received

  16. Evaluating the Relationship between Team Performance and Joint Attention with Longitudinal Multivariate Mixed Models

    Science.gov (United States)

    2016-09-23

    Sweller, J. (2005). Cognitive load theory and complex learning: Recent developments and future directions. Educational Psychology Review, 17(2), 147–177...Relationship between Team Performance and Joint Attention with Longitudinal Multivariate Mixed Models 5a. CONTRACT NUMBER FA8650-14-D-6501-0009 5b...Annual Meeting, 19-23 September 2016. 14. Previous research indicates that measures of joint attention provide unique insight into team cognition

  17. Perceived Social Relationships and Science Learning Outcomes for Taiwanese Eighth Graders: Structural Equation Modeling with a Complex Sampling Consideration

    Science.gov (United States)

    Jen, Tsung-Hau; Lee, Che-Di; Chien, Chin-Lung; Hsu, Ying-Shao; Chen, Kuan-Ming

    2013-01-01

    Based on the Trends in International Mathematics and Science Study 2007 study and a follow-up national survey, data for 3,901 Taiwanese grade 8 students were analyzed using structural equation modeling to confirm a social-relation-based affection-driven model (SRAM). SRAM hypothesized relationships among students' perceived social relationships in…

  18. The relationship of family characteristics and bipolar disorder using causal-pie models.

    Science.gov (United States)

    Chen, Y-C; Kao, C-F; Lu, M-K; Yang, Y-K; Liao, S-C; Jang, F-L; Chen, W J; Lu, R-B; Kuo, P-H

    2014-01-01

    Many family characteristics were reported to increase the risk of bipolar disorder (BPD). The development of BPD may be mediated through different pathways, involving diverse risk factor profiles. We evaluated the associations of family characteristics to build influential causal-pie models to estimate their contributions on the risk of developing BPD at the population level. We recruited 329 clinically diagnosed BPD patients and 202 healthy controls to collect information in parental psychopathology, parent-child relationship, and conflict within family. Other than logistic regression models, we applied causal-pie models to identify pathways involved with different family factors for BPD. The risk of BPD was significantly increased with parental depression, neurosis, anxiety, paternal substance use problems, and poor relationship with parents. Having a depressed mother further predicted early onset of BPD. Additionally, a greater risk for BPD was observed with higher numbers of paternal/maternal psychopathologies. Three significant risk profiles were identified for BPD, including paternal substance use problems (73.0%), maternal depression (17.6%), and through poor relationship with parents and conflict within the family (6.3%). Our findings demonstrate that different aspects of family characteristics elicit negative impacts on bipolar illness, which can be utilized to target specific factors to design and employ efficient intervention programs. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  19. Minority stress and relationship functioning among young male same-sex couples: An examination of actor-partner interdependence models.

    Science.gov (United States)

    Feinstein, Brian A; McConnell, Elizabeth; Dyar, Christina; Mustanski, Brian; Newcomb, Michael E

    2018-05-01

    In different-sex couples, individual and partner stress can both have a negative impact on relationship functioning (actor and partner effects). Gay and bisexual men experience unique stress (sexual minority stress), but few studies have examined the effects of this stress on relationship functioning among young male couples. The current study examined (a) actor and partner effects of general and minority stress (internalized stigma, microaggressions, victimization, and outness) on relationship functioning (relationship quality and negative relationship interactions), (b) interactions between individual and partner stress as predictors of relationship functioning, and (c) dyadic coping and relationship length as moderators of actor and partner effects. Actor-partner interdependence models were tested using data from 153 young male couples. There was strong support for actor effects. Higher general stress and internalized stigma were associated with lower relationship quality, but only for those in longer relationships. Additionally, higher general stress, internalized stigma, and microaggressions, and lower outness, were associated with more negative relationship interactions. There was limited support for partner effects. Having a partner with higher internalized stigma was associated with more negative relationship interactions, but none of the other partner effects were significant. There was no support for individual and partner stress interacting to predict relationship functioning or for dyadic coping as a stress buffer. Findings highlight the influence of one's own experiences of general and minority stress on relationship functioning, but raise questions about how partner stress influences relationship functioning among young male couples. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  20. Phosphorus Export Model Development in a Terminal Lake Basin using Concentration-Streamflow Relationship

    Science.gov (United States)

    Jeannotte, T.; Mahmood, T. H.; Matheney, R.; Hou, X.

    2017-12-01

    Nutrient export to streams and lakes by anthropogenic activities can lead to eutrophication and degradation of surface water quality. In Devils Lake, ND, the only terminal lake in the Northern Great Plains, the algae boom is of great concern due to the recent increase in streamflow and consequent rise in phosphorus (P) export from prairie agricultural fields. However, to date, very few studies explored the concentration (c) -streamflow (q) relationship in the headwater catchments of the Devils Lake basin. A robust watershed-scale quantitative framework would aid understanding of the c-q relationship, simulating P concentration and load. In this study, we utilize c-q relationships to develop a simple model to estimate phosphorus concentration and export from two headwater catchments of different size (Mauvais Coulee: 1032 km2 and Trib 3: 160 km2) draining to Devils Lake. Our goal is to link the phosphorus export model with a physically based hydrologic model to identify major drivers of phosphorus export. USGS provided the streamflow measurements, and we collected water samples (filtered and unfiltered) three times daily during the spring snowmelt season (March 31, 2017- April 12, 2017) at the outlets of both headwater catchments. Our results indicate that most P is dissolved and very little is particulate, suggesting little export of fine-grained sediment from agricultural fields. Our preliminary analyses in the Mauvais Coulee catchment show a chemostatic c-q relationship in the rising limb of the hydrograph, while the recession limb shows a linear and positive c-q relationship. The poor correlation in the rising limb of the hydrograph suggests intense flushing of P by spring snowmelt runoff. Flushing then continues in the recession limb of the hydrograph, but at a more constant rate. The estimated total P load for the Mauvais Coulee basin is 193 kg/km2, consistent with other catchments of similar size across the Red River of the North basin to the east. We expect

  1. Garrison's model of self-directed learning: preliminary validation and relationship to academic achievement.

    Science.gov (United States)

    Abd-El-Fattah, Sabry M

    2010-11-01

    In this project, 119 undergraduates responded to a questionnaire tapping three psychological constructs implicated in Garrison's model of self-directed learning: self-management, self-monitoring, and motivation. Mediation analyses showed that these psychological constructs are interrelated and that motivation mediates the relationship between self-management and self-monitoring. Path modeling analyses revealed that self-management and self-monitoring significantly predicted academic achievement over two semesters with self-management being the strongest predictor. Motivation significantly predicted academic achievement over the second semester only. Implications of these findings for self-directed learning and academic achievement in a traditional classroom setting are discussed.

  2. Estimation in a multiplicative mixed model involving a genetic relationship matrix

    Directory of Open Access Journals (Sweden)

    Eccleston John A

    2009-04-01

    Full Text Available Abstract Genetic models partitioning additive and non-additive genetic effects for populations tested in replicated multi-environment trials (METs in a plant breeding program have recently been presented in the literature. For these data, the variance model involves the direct product of a large numerator relationship matrix A, and a complex structure for the genotype by environment interaction effects, generally of a factor analytic (FA form. With MET data, we expect a high correlation in genotype rankings between environments, leading to non-positive definite covariance matrices. Estimation methods for reduced rank models have been derived for the FA formulation with independent genotypes, and we employ these estimation methods for the more complex case involving the numerator relationship matrix. We examine the performance of differing genetic models for MET data with an embedded pedigree structure, and consider the magnitude of the non-additive variance. The capacity of existing software packages to fit these complex models is largely due to the use of the sparse matrix methodology and the average information algorithm. Here, we present an extension to the standard formulation necessary for estimation with a factor analytic structure across multiple environments.

  3. Information System Success Model for Customer Relationship Management System in Health Promotion Centers

    Science.gov (United States)

    Choi, Wona; Rho, Mi Jung; Park, Jiyun; Kim, Kwang-Jum; Kwon, Young Dae

    2013-01-01

    Objectives Intensified competitiveness in the healthcare industry has increased the number of healthcare centers and propelled the introduction of customer relationship management (CRM) systems to meet diverse customer demands. This study aimed to develop the information system success model of the CRM system by investigating previously proposed indicators within the model. Methods The evaluation areas of the CRM system includes three areas: the system characteristics area (system quality, information quality, and service quality), the user area (perceived usefulness and user satisfaction), and the performance area (personal performance and organizational performance). Detailed evaluation criteria of the three areas were developed, and its validity was verified by a survey administered to CRM system users in 13 nationwide health promotion centers. The survey data were analyzed by the structural equation modeling method, and the results confirmed that the model is feasible. Results Information quality and service quality showed a statistically significant relationship with perceived usefulness and user satisfaction. Consequently, the perceived usefulness and user satisfaction had significant influence on individual performance as well as an indirect influence on organizational performance. Conclusions This study extends the research area on information success from general information systems to CRM systems in health promotion centers applying a previous information success model. This lays a foundation for evaluating health promotion center systems and provides a useful guide for successful implementation of hospital CRM systems. PMID:23882416

  4. Information system success model for customer relationship management system in health promotion centers.

    Science.gov (United States)

    Choi, Wona; Rho, Mi Jung; Park, Jiyun; Kim, Kwang-Jum; Kwon, Young Dae; Choi, In Young

    2013-06-01

    Intensified competitiveness in the healthcare industry has increased the number of healthcare centers and propelled the introduction of customer relationship management (CRM) systems to meet diverse customer demands. This study aimed to develop the information system success model of the CRM system by investigating previously proposed indicators within the model. THE EVALUATION AREAS OF THE CRM SYSTEM INCLUDES THREE AREAS: the system characteristics area (system quality, information quality, and service quality), the user area (perceived usefulness and user satisfaction), and the performance area (personal performance and organizational performance). Detailed evaluation criteria of the three areas were developed, and its validity was verified by a survey administered to CRM system users in 13 nationwide health promotion centers. The survey data were analyzed by the structural equation modeling method, and the results confirmed that the model is feasible. Information quality and service quality showed a statistically significant relationship with perceived usefulness and user satisfaction. Consequently, the perceived usefulness and user satisfaction had significant influence on individual performance as well as an indirect influence on organizational performance. This study extends the research area on information success from general information systems to CRM systems in health promotion centers applying a previous information success model. This lays a foundation for evaluating health promotion center systems and provides a useful guide for successful implementation of hospital CRM systems.

  5. External validation of structure-biodegradation relationship (SBR) models for predicting the biodegradability of xenobiotics.

    Science.gov (United States)

    Devillers, J; Pandard, P; Richard, B

    2013-01-01

    Biodegradation is an important mechanism for eliminating xenobiotics by biotransforming them into simple organic and inorganic products. Faced with the ever growing number of chemicals available on the market, structure-biodegradation relationship (SBR) and quantitative structure-biodegradation relationship (QSBR) models are increasingly used as surrogates of the biodegradation tests. Such models have great potential for a quick and cheap estimation of the biodegradation potential of chemicals. The Estimation Programs Interface (EPI) Suite™ includes different models for predicting the potential aerobic biodegradability of organic substances. They are based on different endpoints, methodologies and/or statistical approaches. Among them, Biowin 5 and 6 appeared the most robust, being derived from the largest biodegradation database with results obtained only from the Ministry of International Trade and Industry (MITI) test. The aim of this study was to assess the predictive performances of these two models from a set of 356 chemicals extracted from notification dossiers including compatible biodegradation data. Another set of molecules with no more than four carbon atoms and substituted by various heteroatoms and/or functional groups was also embodied in the validation exercise. Comparisons were made with the predictions obtained with START (Structural Alerts for Reactivity in Toxtree). Biowin 5 and Biowin 6 gave satisfactorily prediction results except for the prediction of readily degradable chemicals. A consensus model built with Biowin 1 allowed the diminution of this tendency.

  6. Advances in applied homeostatic modelling of the relationship between thyrotropin and free thyroxine.

    Directory of Open Access Journals (Sweden)

    Rudolf Hoermann

    Full Text Available The relationship between pituitary TSH and thyroid hormones is central to our understanding of thyroid physiology and thyroid function testing. Here, we generated distribution patterns by using validated tools of thyroid modelling.We simulated patterns of individual set points under various conditions, based on a homeostatic model of thyroid feedback control. These were compared with observed data points derived from clinical trials.A random mix of individual set points was reconstructed by simulative modelling with defined structural parameters. The pattern displayed by the cluster of hypothetical points resembled that observed in a natural control group. Moderate variation of the TSH-FT4 gradient over the functional range introduced further flexibility, implementing a scenario of adaptive set points. Such a scenario may be a realistic possibility for instance in treatment where relationships and equilibria between thyroid parameters are altered by various influences such as LT4 dose and conversion efficiency.We validated a physiologically based homeostatic model that permits simulative reconstruction of individual set points. This produced a pattern resembling the observed data under various conditions. Applied modelling, although still experimental at this stage, shows a potential to aid our physiological understanding of the interplay between TSH and thyroid hormones. It should eventually benefit personalised clinical decision making.

  7. A linear solvation energy relationship model of organic chemical partitioning to dissolved organic carbon.

    Science.gov (United States)

    Kipka, Undine; Di Toro, Dominic M

    2011-09-01

    Predicting the association of contaminants with both particulate and dissolved organic matter is critical in determining the fate and bioavailability of chemicals in environmental risk assessment. To date, the association of a contaminant to particulate organic matter is considered in many multimedia transport models, but the effect of dissolved organic matter is typically ignored due to a lack of either reliable models or experimental data. The partition coefficient to dissolved organic carbon (K(DOC)) may be used to estimate the fraction of a contaminant that is associated with dissolved organic matter. Models relating K(DOC) to the octanol-water partition coefficient (K(OW)) have not been successful for many types of dissolved organic carbon in the environment. Instead, linear solvation energy relationships are proposed to model the association of chemicals with dissolved organic matter. However, more chemically diverse K(DOC) data are needed to produce a more robust model. For humic acid dissolved organic carbon, the linear solvation energy relationship predicts log K(DOC) with a root mean square error of 0.43. Copyright © 2011 SETAC.

  8. Quantitative structure-activity relationship (QSAR) for insecticides: development of predictive in vivo insecticide activity models.

    Science.gov (United States)

    Naik, P K; Singh, T; Singh, H

    2009-07-01

    Quantitative structure-activity relationship (QSAR) analyses were performed independently on data sets belonging to two groups of insecticides, namely the organophosphates and carbamates. Several types of descriptors including topological, spatial, thermodynamic, information content, lead likeness and E-state indices were used to derive quantitative relationships between insecticide activities and structural properties of chemicals. A systematic search approach based on missing value, zero value, simple correlation and multi-collinearity tests as well as the use of a genetic algorithm allowed the optimal selection of the descriptors used to generate the models. The QSAR models developed for both organophosphate and carbamate groups revealed good predictability with r(2) values of 0.949 and 0.838 as well as [image omitted] values of 0.890 and 0.765, respectively. In addition, a linear correlation was observed between the predicted and experimental LD(50) values for the test set data with r(2) of 0.871 and 0.788 for both the organophosphate and carbamate groups, indicating that the prediction accuracy of the QSAR models was acceptable. The models were also tested successfully from external validation criteria. QSAR models developed in this study should help further design of novel potent insecticides.

  9. Does Your Terrestrial Model Capture Key Arctic-Boreal Relationships?: Functional Benchmarks in the ABoVE Model Benchmarking System

    Science.gov (United States)

    Stofferahn, E.; Fisher, J. B.; Hayes, D. J.; Schwalm, C. R.; Huntzinger, D. N.; Hantson, W.

    2017-12-01

    The Arctic-Boreal Region (ABR) is a major source of uncertainties for terrestrial biosphere model (TBM) simulations. These uncertainties are precipitated by a lack of observational data from the region, affecting the parameterizations of cold environment processes in the models. Addressing these uncertainties requires a coordinated effort of data collection and integration of the following key indicators of the ABR ecosystem: disturbance, vegetation / ecosystem structure and function, carbon pools and biogeochemistry, permafrost, and hydrology. We are continuing to develop the model-data integration framework for NASA's Arctic Boreal Vulnerability Experiment (ABoVE), wherein data collection is driven by matching observations and model outputs to the ABoVE indicators via the ABoVE Grid and Projection. The data are used as reference datasets for a benchmarking system which evaluates TBM performance with respect to ABR processes. The benchmarking system utilizes two types of performance metrics to identify model strengths and weaknesses: standard metrics, based on the International Land Model Benchmarking (ILaMB) system, which relate a single observed variable to a single model output variable, and functional benchmarks, wherein the relationship of one variable to one or more variables (e.g. the dependence of vegetation structure on snow cover, the dependence of active layer thickness (ALT) on air temperature and snow cover) is ascertained in both observations and model outputs. This in turn provides guidance to model development teams for reducing uncertainties in TBM simulations of the ABR.

  10. Modelling concentration-analgesia relationships for morphine to evaluate experimental pain models

    DEFF Research Database (Denmark)

    Sverrisdóttir, Eva; Foster, David John Richard; Upton, Richard Neil

    2015-01-01

    The aim of this study was to develop population pharmacokinetic-pharmacodynamic models for morphine in experimental pain induced by skin heat and muscle pressure, and to evaluate the experimental pain models with regard to assessment of morphine pharmacodynamics. In a randomized, double......-blind, placebo-controlled, crossover study, 39 healthy volunteers received an oral dose of 30 mg morphine hydrochloride or placebo. Non-linear mixed effects modelling was used to describe the plasma concentrations of morphine and metabolites, and the analgesic effect of morphine on experimental pain in skin...... and muscle. Baseline pain metrics varied between individuals and occasions, and were described with interindividual and interoccasion variability. Placebo-response did not change with time. For both pain metrics, morphine effect was proportional to baseline pain and was described with a linear model...

  11. IntPath--an integrated pathway gene relationship database for model organisms and important pathogens.

    Science.gov (United States)

    Zhou, Hufeng; Jin, Jingjing; Zhang, Haojun; Yi, Bo; Wozniak, Michal; Wong, Limsoon

    2012-01-01

    Pathway data are important for understanding the relationship between genes, proteins and many other molecules in living organisms. Pathway gene relationships are crucial information for guidance, prediction, reference and assessment in biochemistry, computational biology, and medicine. Many well-established databases--e.g., KEGG, WikiPathways, and BioCyc--are dedicated to collecting pathway data for public access. However, the effectiveness of these databases is hindered by issues such as incompatible data formats, inconsistent molecular representations, inconsistent molecular relationship representations, inconsistent referrals to pathway names, and incomprehensive data from different databases. In this paper, we overcome these issues through extraction, normalization and integration of pathway data from several major public databases (KEGG, WikiPathways, BioCyc, etc). We build a database that not only hosts our integrated pathway gene relationship data for public access but also maintains the necessary updates in the long run. This public repository is named IntPath (Integrated Pathway gene relationship database for model organisms and important pathogens). Four organisms--S. cerevisiae, M. tuberculosis H37Rv, H. Sapiens and M. musculus--are included in this version (V2.0) of IntPath. IntPath uses the "full unification" approach to ensure no deletion and no introduced noise in this process. Therefore, IntPath contains much richer pathway-gene and pathway-gene pair relationships and much larger number of non-redundant genes and gene pairs than any of the single-source databases. The gene relationships of each gene (measured by average node degree) per pathway are significantly richer. The gene relationships in each pathway (measured by average number of gene pairs per pathway) are also considerably richer in the integrated pathways. Moderate manual curation are involved to get rid of errors and noises from source data (e.g., the gene ID errors in WikiPathways and

  12. Distensibility and pressure-flow relationship of the pulmonary circulation. II. Multibranched model.

    Science.gov (United States)

    Bshouty, Z; Younes, M

    1990-04-01

    The contribution of distensibility and recruitment to the distinctive behavior of the pulmonary circulation is not known. To examine this question we developed a multibranched model in which an arterial vascular bed bifurcates sequentially up to 8 parallel channels that converge and reunite at the venous side to end in the left atrium. Eight resistors representing the capillary bed separate the arterial and venous beds. The elastic behavior of capillaries and extra-alveolar vessels was modeled after Fung and Sobin (Circ. Res. 30: 451-490, 1972) and Smith and Mitzner (J. Appl. Physiol. 48: 450-467, 1980), respectively. Forces acting on each component are modified and calculated individually, thus enabling the user to explore the effects of parallel and longitudinal heterogeneities in applied forces (e.g., gravity, vasomotor tone). Model predictions indicate that the contribution of distensibility to nonlinearities in the pressure-flow (P-F) and atrial-pulmonary arterial pressure (Pla-Ppa) relationships is substantial, whereas gravity-related recruitment contributes very little to these relationships. In addition, Pla-Ppa relationships, obtained at a constant flow, have no discriminating ability in identifying the presence or absence of a waterfall along the circulation. The P-F relationship is routinely shifted in a parallel fashion, within the physiological flow range, whenever extra forces (e.g., lung volume, tone) are applied uniformly at one or more branching levels, regardless of whether a waterfall is created. For a given applied force, the magnitude of parallel shift varies with proportion of the circulation subjected to the added force and with Pla.

  13. A structural equation model of the relationship between insomnia, negative affect, and paranoid thinking.

    Directory of Open Access Journals (Sweden)

    Alexander J Scott

    Full Text Available A growing body of evidence points to relationships between insomnia, negative affect, and paranoid thinking. However, studies are needed to examine (i whether negative affect mediates the relation between insomnia and paranoid thinking, (ii whether different types of insomnia exert different effects on paranoia, and (iii to compare the impact of objective and self-reported sleeping difficulties.Structural equation modelling was therefore used to test competing models of the relationships between self-reported insomnia, negative affect, and paranoia. n = 348 participants completed measures of insomnia, negative affect and paranoia. A subset of these participants (n = 91 went on to monitor their sleep objectively (using a portable sleep monitor made by Zeo for seven consecutive nights. Associations between objectively recorded sleep, negative affect, and paranoia were explored using linear regression.The findings supported a fully mediated model where self-reported delayed sleep onset, but not self-reported problems with sleep maintenance or objective measures of sleep, was directly associated with negative affect that, in turn, was associated with paranoia. There was no evidence of a direct association between delayed sleep onset or sleep maintenance problems and paranoia.Taken together, the findings point to an association between perceived (but not objective difficulties initially falling asleep (but not maintaining sleep and paranoid thinking; a relationship that is fully mediated by negative affect. Future research should seek to disentangle the causal relationships between sleep, negative affect, and paranoia (e.g., by examining the effect of an intervention using prospective designs that incorporate experience sampling. Indeed, interventions might profitably target (i perceived sleep quality, (ii sleep onset, and / or (iii emotion regulation as a route to reducing negative affect and, thus, paranoid thinking.

  14. Investigating genotype-phenotype relationships in Saccharomyces cerevisiae metabolic network through stoichiometric modeling

    DEFF Research Database (Denmark)

    Brochado, Ana Rita

    processes. Metabolism is an extensively studied and characterised subcellular system, for which several modeling approaches have been proposed over the last 20 years. Nowadays, stoichiometric modeling of metabolism is done at the genome scale and it has diverse applications, many of them for helping....... This chapter aims at providing the reader with relevant state-of-the-art information concerning Systems Biology, Genome-Scale Metabolic Modeling and Metabolic Engineering. Particular attention is given to the yeast Saccharomyces cerevisiae, the eukaryotic model organism used thought the thesis.......A holistic view of the cell is fundamental for gaining insights into genotype to phenotype relationships. Systems Biology is a discipline within Biology, which uses such holistic approach by focusing on the development and application of tools for studying the structure and dynamics of cellular...

  15. Modeling the relationship between family home environment factors and parental health.

    Science.gov (United States)

    Didericksen, Katharine Wickel; Berge, Jerica M

    2015-06-01

    Understanding parental health is an important part of understanding family health. Previous research suggests that family meals, familial relationship satisfaction, and family physical activity may separately be related to physical health. The current study aims to combine these variables into a structural equation model to determine the collective relationship they have with adult health within a sample of parents (n = 1,435). Most parents were married, White, and highly educated. The relationship between family meals and parental health was significant (β = -.07, t = -2.29, p Familial relationship satisfaction and family physical activity were not found to be associated with parental health. Exploratory findings of the sample stratified by biological sex are described. Findings from the current study were consistent with a systemic perspective in that parents may have health benefits when they participate in family-level behavior (e.g., family meals). Additional areas for research and limitations to the current study are also discussed. (c) 2015 APA, all rights reserved).

  16. THE MODERATING EFFECT OF STRENGTH OF MANUFACTURER’S BRANDS ON THE RELATIONSHIP BETWEEN RETAILER’S RELATIONSHIP SATISFACTION AND COMMITMENT: A THEORETICAL MODEL

    Directory of Open Access Journals (Sweden)

    Majid Mapkhot Goaill

    2013-01-01

    Full Text Available Many recent studies emphasized the importance of retailer's satisfaction and commitment to manufacturer/supplier. These studies investigated the relationship between them as an overall relationship. However, there is a dearth of studies that investigated the dimensions of retailer's satisfaction on commitment, and analyzed the mysterious relationship via strength of manufacturer's brands as a moderating effect. Therefore, this study is an attempt to provide a value conceptual model that explains the theoretical linkages existing between dimensions of retailer's satisfaction and commitment, and tries to explain the in-depth meaning of this relationship through the moderating effect of manufacturer's brand strength in the context of social exchange theory. Additionally, hypotheses on the association between the constructs are presented as a basis for further study.

  17. The relationship between occupational culture dimensions and reward preferences: A structural equation modelling approach

    Directory of Open Access Journals (Sweden)

    Mark Bussin

    2016-06-01

    Full Text Available Orientation: Reward has links to employee attraction and retention and as such has a role to play in managing talent. However, despite a range of research, there is still lack of clarity on employee preferences relating to reward. Research purpose: The purpose of the research was to recommend and appraise a theoretical model of the relationship between occupational culture dimensions and reward preferences of specific occupational groups in the South African context. Motivation for the study: The motivation for this study was to address the gap that exists with reward preferences and occupational culture with a view to identifying and gaining insight into individual preferences. Research design, approach and method: A structural equation modelling approach was adopted in exploring the proposed relationships. A South African Information, Communication, and Technology (ICT organisation served as the population, and a web-based survey assisted in gathering study data (n = 1362. Main findings: The findings provided support for the relationship between occupational culture dimensions and certain reward preferences. In particular, statistically significant results were obtained with the inclusion of the Environment, Team, and Time occupational culture dimensions as independent variables. Practical implications and value-add: The study provides workable input to organisations and reward professionals in the design of their reward strategies and programmes. Keywords: compensation; employee preferences; occupational culture; remuneration; reward preferences

  18. Barriers to Effective Doctor-Patient Relationship Based on PRECEDE PROCEED Model

    Science.gov (United States)

    Ghaffarifar, Saeideh; Ghofranipour, Fazlollah; Ahmadi, Fazlollah; Khoshbaten, Manouchehr

    2015-01-01

    Objective: This study intends to investigate interns and faculty members’ insights into constructing relationship between physicians and patients at 3 more accredited Iranian universities of medical sciences. Method: Applying PRECEDE PROCEED model, semi-structured interviews were completed with 7 interns and 14 faculty members and two themes were emerged from directed content analysis. The meaning units of the first theme, barriers to effective doctor-patient relationship, are discussed in this paper. Results: According to the participants, building doctor-patient relationship is influenced by many contextual and regulatory factors as well as content, process and perceptual skills of physicians. Conclusions: Faculty and curriculum development, as well as foundation of the department of communication skills at medical schools are recommended to eliminate the impact of poor communication on patients’ satisfaction and physicians’ self-efficacy specific to their communication skills. Practice Implications: Applying theories and models of health education and health promotion, researchers and educators can use the most predictive constructs of theories to design and implement effective interventions. PMID:26153160

  19. Methods for Specifying Scientific Data Standards and Modeling Relationships with Applications to Neuroscience

    Science.gov (United States)

    Rübel, Oliver; Dougherty, Max; Prabhat; Denes, Peter; Conant, David; Chang, Edward F.; Bouchard, Kristofer

    2016-01-01

    Neuroscience continues to experience a tremendous growth in data; in terms of the volume and variety of data, the velocity at which data is acquired, and in turn the veracity of data. These challenges are a serious impediment to sharing of data, analyses, and tools within and across labs. Here, we introduce BRAINformat, a novel data standardization framework for the design and management of scientific data formats. The BRAINformat library defines application-independent design concepts and modules that together create a general framework for standardization of scientific data. We describe the formal specification of scientific data standards, which facilitates sharing and verification of data and formats. We introduce the concept of Managed Objects, enabling semantic components of data formats to be specified as self-contained units, supporting modular and reusable design of data format components and file storage. We also introduce the novel concept of Relationship Attributes for modeling and use of semantic relationships between data objects. Based on these concepts we demonstrate the application of our framework to design and implement a standard format for electrophysiology data and show how data standardization and relationship-modeling facilitate data analysis and sharing. The format uses HDF5, enabling portable, scalable, and self-describing data storage and integration with modern high-performance computing for data-driven discovery. The BRAINformat library is open source, easy-to-use, and provides detailed user and developer documentation and is freely available at: https://bitbucket.org/oruebel/brainformat. PMID:27867355

  20. Modelling Inter-relationships among water, governance, human development variables in developing countries with Bayesian networks.

    Science.gov (United States)

    Dondeynaz, C.; Lopez-Puga, J.; Carmona-Moreno, C.

    2012-04-01

    relationships between variable are set a priori according to literature and/or experience in the field (expert knowledge). The statistical validation is verified according to error rate of classification, and the significance of the variables. Sensibility analysis has also been performed to characterise the relative influence of every single variable in the model. Once validated, the models allow the estimation of impact of each variable on the behaviour of the water supply or sanitation providing an interesting mean to test scenarios and predict variables behaviours. The choices made, methods and description of the various models, for each cluster as well as the global model for water supply and sanitation will be presented. Key results and interpretation of the relationships depicted by the models will be detailed during the conference.

  1. The Relationship between Spiritual Health and other Dimensions of Health: Presentation of a Model

    Directory of Open Access Journals (Sweden)

    Akram Heidari

    2016-06-01

    Full Text Available Attitudes to humankind will have different effects on health service delivery. Health might used to be intended to provide physical health in the past; today, however, many researchers and clinicians consider the concept health to be beyond physical health. In support of this claim, it is enough to indicate that the bio-psycho-social model has for years been held by scientific communities to be a fully admitted model. However, the missing ring in this model, as suggested by many, is the spiritual health. In recent years, the relationship between spirituality and clinical interventions with a comprehensive focus on health has been under increasing scrutiny. Although different models have been presented for investigation of the relationship between spiritual health and other dimensions, the fundamental challenge in this regard is the actual place of spiritual health compared with other dimensions. In this article, attempts are made to address the position and weight of spiritual health from the Islam’s point of view.

  2. Sequence-structure relationships in RNA loops: establishing the basis for loop homology modeling.

    Science.gov (United States)

    Schudoma, Christian; May, Patrick; Nikiforova, Viktoria; Walther, Dirk

    2010-01-01

    The specific function of RNA molecules frequently resides in their seemingly unstructured loop regions. We performed a systematic analysis of RNA loops extracted from experimentally determined three-dimensional structures of RNA molecules. A comprehensive loop-structure data set was created and organized into distinct clusters based on structural and sequence similarity. We detected clear evidence of the hallmark of homology present in the sequence-structure relationships in loops. Loops differing by structures. Thus, our results support the application of homology modeling for RNA loop model building. We established a threshold that may guide the sequence divergence-based selection of template structures for RNA loop homology modeling. Of all possible sequences that are, under the assumption of isosteric relationships, theoretically compatible with actual sequences observed in RNA structures, only a small fraction is contained in the Rfam database of RNA sequences and classes implying that the actual RNA loop space may consist of a limited number of unique loop structures and conserved sequences. The loop-structure data sets are made available via an online database, RLooM. RLooM also offers functionalities for the modeling of RNA loop structures in support of RNA engineering and design efforts.

  3. The relationships between internal and external training load models during basketball training.

    Science.gov (United States)

    Scanlan, Aaron T; Wen, Neal; Tucker, Patrick S; Dalbo, Vincent J

    2014-09-01

    The present investigation described and compared the internal and external training loads during basketball training. Eight semiprofessional male basketball players (mean ± SD, age: 26.3 ± 6.7 years; stature: 188.1 ± 6.2 cm; body mass: 92.0 ± 13.8 kg) were monitored across a 7-week period during the preparatory phase of the annual training plan. A total of 44 total sessions were monitored. Player session ratings of perceived exertion (sRPE), heart rate, and accelerometer data were collected across each training session. Internal training load was determined using the sRPE, training impulse (TRIMP), and summated-heart-rate-zones (SHRZ) training load models. External training load was calculated using an established accelerometer algorithm. Pearson product-moment correlations with 95% confidence intervals (CIs) were used to determine the relationships between internal and external training load models. Significant moderate relationships were observed between external training load and the sRPE (r42 = 0.49, 95% CI = 0.23-0.69, p external training load and the SHRZ model (r42 = 0.61, 95% CI = 0.38-0.77, p internal and external training load models, the magnitude of the correlations and low commonality suggest that internal training load models measure different constructs of the training process than the accelerometer training load model in basketball settings. Basketball coaching and conditioning professionals should not assume a linear dose-response between accelerometer and internal training load models during training and are recommended to combine internal and external approaches when monitoring training load in players.

  4. Dose-response relationships for environmentally mediated infectious disease transmission models.

    Directory of Open Access Journals (Sweden)

    Andrew F Brouwer

    2017-04-01

    Full Text Available Environmentally mediated infectious disease transmission models provide a mechanistic approach to examining environmental interventions for outbreaks, such as water treatment or surface decontamination. The shift from the classical SIR framework to one incorporating the environment requires codifying the relationship between exposure to environmental pathogens and infection, i.e. the dose-response relationship. Much of the work characterizing the functional forms of dose-response relationships has used statistical fit to experimental data. However, there has been little research examining the consequences of the choice of functional form in the context of transmission dynamics. To this end, we identify four properties of dose-response functions that should be considered when selecting a functional form: low-dose linearity, scalability, concavity, and whether it is a single-hit model. We find that i middle- and high-dose data do not constrain the low-dose response, and different dose-response forms that are equally plausible given the data can lead to significant differences in simulated outbreak dynamics; ii the choice of how to aggregate continuous exposure into discrete doses can impact the modeled force of infection; iii low-dose linear, concave functions allow the basic reproduction number to control global dynamics; and iv identifiability analysis offers a way to manage multiple sources of uncertainty and leverage environmental monitoring to make inference about infectivity. By applying an environmentally mediated infectious disease model to the 1993 Milwaukee Cryptosporidium outbreak, we demonstrate that environmental monitoring allows for inference regarding the infectivity of the pathogen and thus improves our ability to identify outbreak characteristics such as pathogen strain.

  5. The relationship between quality management practices and organisational performance: A structural equation modelling approach

    Science.gov (United States)

    Jamaluddin, Z.; Razali, A. M.; Mustafa, Z.

    2015-02-01

    The purpose of this paper is to examine the relationship between the quality management practices (QMPs) and organisational performance for the manufacturing industry in Malaysia. In this study, a QMPs and organisational performance framework is developed according to a comprehensive literature review which cover aspects of hard and soft quality factors in manufacturing process environment. A total of 11 hypotheses have been put forward to test the relationship amongst the six constructs, which are management commitment, training, process management, quality tools, continuous improvement and organisational performance. The model is analysed using Structural Equation Modeling (SEM) with AMOS software version 18.0 using Maximum Likelihood (ML) estimation. A total of 480 questionnaires were distributed, and 210 questionnaires were valid for analysis. The results of the modeling analysis using ML estimation indicate that the fits statistics of QMPs and organisational performance model for manufacturing industry is admissible. From the results, it found that the management commitment have significant impact on the training and process management. Similarly, the training had significant effect to the quality tools, process management and continuous improvement. Furthermore, the quality tools have significant influence on the process management and continuous improvement. Likewise, the process management also has a significant impact to the continuous improvement. In addition the continuous improvement has significant influence the organisational performance. However, the results of the study also found that there is no significant relationship between management commitment and quality tools, and between the management commitment and continuous improvement. The results of the study can be used by managers to prioritize the implementation of QMPs. For instances, those practices that are found to have positive impact on organisational performance can be recommended to

  6. Relationship between the transverse-field Ising model and the X Y model via the rotating-wave approximation

    Science.gov (United States)

    Kiely, Thomas G.; Freericks, J. K.

    2018-02-01

    In a large transverse field, there is an energy cost associated with flipping spins along the axis of the field. This penalty can be employed to relate the transverse-field Ising model in a large field to the X Y model in no field (when measurements are performed at the proper stroboscopic times). We describe the details for how this relationship works and, in particular, we also show under what circumstances it fails. We examine wave-function overlap between the two models and observables, such as spin-spin Green's functions. In general, the mapping is quite robust at short times, but will ultimately fail if the run time becomes too long. There is also a tradeoff between the length of time one can run a simulation out to and the time jitter of the stroboscopic measurements that must be balanced when planning to employ this mapping.

  7. Conceptual Model of Relationships among Customer Perceptions of Components of Insurance Service

    Directory of Open Access Journals (Sweden)

    Sebjan Urban

    2015-04-01

    Full Text Available The objective of this study was to examine the conceptual model and to study the relationships between customer perceptions of the benefits of sales promotion, quality, adequacy of premium, and adequacy of information about the coverage of insurance services. The research model was tested with structural equation modeling (SEM with a sample of 200 Slovenian users of insurance services. The results indicated that higher perceived benefits of sales promotion were associated with higher perceived quality of insurance services. In addition, higher perceived quality was associated with higher perceived adequacy of information about the coverage and the premium for insurance services. The study also found that higher perceived adequacy of premium was associated with higher perceived adequacy of information about the coverage of insurance services.

  8. MARKETING RELATIONSHIP AND TRADING IN THE RELATIONSHIP BETWEEN SERVICE PROVIDERS, HEALTH OPERATORS AND FINAL CUSTOMER: THE SEARCH FOR AN INTEGRATING MODEL

    Directory of Open Access Journals (Sweden)

    Nilda Catalina, Tañski

    2012-01-01

    Full Text Available The marketing relationship finds similarities with the concept of cooperative bargaining, the purpose of this is to find solutions to mutual gains with long-term vision. Within this approach, we sought to build an integrative model of relationship marketing and negotiation in the relationship between service providers, health operators and final customers in the health plan market in Brazil, this relationship is complex, full of conflicts and stagnation. It was first used, first, as an exploratory research of direct observation of the phenomenon referred to relationship marketing, trading and health insurance to increase employment opportunities. Then, the method of data collection was in that environment through online questionnaires using the survey method, in the representative sector. The type of sample used, where n = 217 and the confidence level was 95%, not intentional probabilistic. In the final, it was concluded that the initially proposed model was fully accepted, taking into account the choice of methodology, then achieving the main objective of this study.

  9. Assessment of source-receptor relationships of aerosols: An integrated forward and backward modeling approach

    Science.gov (United States)

    Kulkarni, Sarika

    This dissertation presents a scientific framework that facilitates enhanced understanding of aerosol source -- receptor (S/R) relationships and their impact on the local, regional and global air quality by employing a complementary suite of modeling methods. The receptor -- oriented Positive Matrix Factorization (PMF) technique is combined with Potential Source Contribution Function (PSCF), a trajectory ensemble model, to characterize sources influencing the aerosols measured at Gosan, Korea during spring 2001. It is found that the episodic dust events originating from desert regions in East Asia (EA) that mix with pollution along the transit path, have a significant and pervasive impact on the air quality of Gosan. The intercontinental and hemispheric transport of aerosols is analyzed by a series of emission perturbation simulations with the Sulfur Transport and dEposition Model (STEM), a regional scale Chemical Transport Model (CTM), evaluated with observations from the 2008 NASA ARCTAS field campaign. This modeling study shows that pollution transport from regions outside North America (NA) contributed ˜ 30 and 20% to NA sulfate and BC surface concentration. This study also identifies aerosols transported from Europe, NA and EA regions as significant contributors to springtime Arctic sulfate and BC. Trajectory ensemble models are combined with source region tagged tracer model output to identify the source regions and possible instances of quasi-lagrangian sampled air masses during the 2006 NASA INTEX-B field campaign. The impact of specific emission sectors from Asia during the INTEX-B period is studied with the STEM model, identifying residential sector as potential target for emission reduction to combat global warming. The output from the STEM model constrained with satellite derived aerosol optical depth and ground based measurements of single scattering albedo via an optimal interpolation assimilation scheme is combined with the PMF technique to

  10. Incorporating shape constraints in generalized additive modelling of the height-diameter relationship for Norway spruce

    Directory of Open Access Journals (Sweden)

    Natalya Pya

    2016-02-01

    Full Text Available Background: Measurements of tree heights and diameters are essential in forest assessment and modelling. Tree heights are used for estimating timber volume, site index and other important variables related to forest growth and yield, succession and carbon budget models. However, the diameter at breast height (dbh can be more accurately obtained and at lower cost, than total tree height. Hence, generalized height-diameter (h-d models that predict tree height from dbh, age and other covariates are needed. For a more flexible but biologically plausible estimation of covariate effects we use shape constrained generalized additive models as an extension of existing h-d model approaches. We use causal site parameters such as index of aridity to enhance the generality and causality of the models and to enable predictions under projected changeable climatic conditions. Methods: We develop unconstrained generalized additive models (GAM and shape constrained generalized additive models (SCAM for investigating the possible effects of tree-specific parameters such as tree age, relative diameter at breast height, and site-specific parameters such as index of aridity and sum of daily mean temperature during vegetation period, on the h-d relationship of forests in Lower Saxony, Germany. Results: Some of the derived effects, e.g. effects of age, index of aridity and sum of daily mean temperature have significantly non-linear pattern. The need for using SCAM results from the fact that some of the model effects show partially implausible patterns especially at the boundaries of data ranges. The derived model predicts monotonically increasing levels of tree height with increasing age and temperature sum and decreasing aridity and social rank of a tree within a stand. The definition of constraints leads only to marginal or minor decline in the model statistics like AIC. An observed structured spatial trend in tree height is modelled via 2-dimensional surface

  11. The Relationship between Residential Electricity Consumption and Income: A Piecewise Linear Model with Panel Data

    Directory of Open Access Journals (Sweden)

    Yanan Liu

    2016-10-01

    Full Text Available There are many uncertainties and risks in residential electricity consumption associated with economic development. Knowledge of the relationship between residential electricity consumption and its key determinant—income—is important to the sustainable development of the electric power industry. Using panel data from 30 provinces for the 1995–2012 period, this study investigates how residential electricity consumption changes as incomes increase in China. Previous studies typically used linear or quadratic double-logarithmic models imposing ex ante restrictions on the indistinct relationship between residential electricity consumption and income. Contrary to those models, we employed a reduced piecewise linear model that is self-adaptive and highly flexible and circumvents the problem of “prior restrictions”. Robust tests of different segment specifications and regression methods are performed to ensure the validity of the research. The results provide strong evidence that the income elasticity was approximately one, and it remained stable throughout the estimation period. The income threshold at which residential electricity consumption automatically remains stable or slows has not been reached. To ensure the sustainable development of the electric power industry, introducing higher energy efficiency standards for electrical appliances and improving income levels are vital. Government should also emphasize electricity conservation in the industrial sector rather than in residential sector.

  12. Model of Communication Strategy for Public Relations in Private University in Building the Relationship with the Media

    OpenAIRE

    Darmastuti, Rini; Sinatra Wijaya, Lina

    2009-01-01

    The success of Public Relations work in Private University depends on the public relations strategy in building the relationship with the media. For knowing how effective PR strategy is in building the relationship with the media, A research has been done with 10 respondents ( 10 Private Universities in Central Java ) by using descriptive qualitative approach and direct observation. There are two relationship models that have been found from this research, they are “ Imbalanced Commensalisms ...

  13. The relationship between trading volumes, number of transactions, and stock volatility in GARCH models

    Science.gov (United States)

    Takaishi, Tetsuya; Chen, Ting Ting

    2016-08-01

    We examine the relationship between trading volumes, number of transactions, and volatility using daily stock data of the Tokyo Stock Exchange. Following the mixture of distributions hypothesis, we use trading volumes and the number of transactions as proxy for the rate of information arrivals affecting stock volatility. The impact of trading volumes or number of transactions on volatility is measured using the generalized autoregressive conditional heteroscedasticity (GARCH) model. We find that the GARCH effects, that is, persistence of volatility, is not always removed by adding trading volumes or number of transactions, indicating that trading volumes and number of transactions do not adequately represent the rate of information arrivals.

  14. Seismic attenuation relationship with homogeneous and heterogeneous prediction-error variance models

    Science.gov (United States)

    Mu, He-Qing; Xu, Rong-Rong; Yuen, Ka-Veng

    2014-03-01

    Peak ground acceleration (PGA) estimation is an important task in earthquake engineering practice. One of the most well-known models is the Boore-Joyner-Fumal formula, which estimates the PGA using the moment magnitude, the site-to-fault distance and the site foundation properties. In the present study, the complexity for this formula and the homogeneity assumption for the prediction-error variance are investigated and an efficiency-robustness balanced formula is proposed. For this purpose, a reduced-order Monte Carlo simulation algorithm for Bayesian model class selection is presented to obtain the most suitable predictive formula and prediction-error model for the seismic attenuation relationship. In this approach, each model class (a predictive formula with a prediction-error model) is evaluated according to its plausibility given the data. The one with the highest plausibility is robust since it possesses the optimal balance between the data fitting capability and the sensitivity to noise. A database of strong ground motion records in the Tangshan region of China is obtained from the China Earthquake Data Center for the analysis. The optimal predictive formula is proposed based on this database. It is shown that the proposed formula with heterogeneous prediction-error variance is much simpler than the attenuation model suggested by Boore, Joyner and Fumal (1993).

  15. The Models of Relationship between Training and Psyche development in Cultural-historical and Activity Approaches

    Directory of Open Access Journals (Sweden)

    Pogozhina I.N.,

    2016-12-01

    Full Text Available The possibility of referring of the psychological theories studying interrelation of training and mental development processes to this or that stage of scientific knowledge formation on the basis of studied objects types and corresponded determination systems as a basic criterion distinguishing the ideals of scientific rationality is justified. General characteristics of classical, non-classical and post-non-classical models, determination of the mechanisms of dissipative systems, requirements for learning and development model building in the context of post-non-classic science paradigm on the criterion of the system features of the object of cognition are described. Domestic psychological school models are compared with associanism, behaviorism, gestalt psychology and Piaget determination models on the number of options allocated to these determinants, types of causal chains and types of links between causal chains. It is shown that cultural-historical approach is situated intermediately between post-non-classical and non-classical models, while activity approach corresponds to post-non-classical understanding of the object of study as complicated self-developing "man-size" system. Determination relationships models developed by L.V.Vygotskii, S.L. Rubinstein, A.N. Leont’ev continue to play the heuristic role at the present stage of scientific development.

  16. Mapping using the Tsyganenko long magnetospheric model and its relationship to Viking auroral images

    International Nuclear Information System (INIS)

    Elphinstone, R.D.; Hearn, D.; Murphree, J.S.; Cogger, L.L.

    1991-01-01

    The Tsyganenko long magnetospheric model (1987) has been used in conjunction with ultra-violet images taken by the Viking spacecraft to investigate the relationship of the auroral distribution to different magnetospheric regions. The model describes the large-scale structure of the magnetosphere reasonably well for dipole tilt angles near zero, but it appears to break down at higher tilt angles. Even so, a wide variety of auroral configurations can be accurately described by the model. It appears that the open-closed field line boundary is a poor indicator of auroral arc systems with the possible exception of high-latitude polar arcs. The auroral distribution typically called the oval maps to a region in the equatorial plane quite close to the Earth and can be approximately located by mapping the model current density maximum from the equatorial plane into the ionosphere. Although the model may break down along the flanks of the magnetotail, the large-scale auroral distribution generally reflects variations in the near-Earth region and can be modeled quite effectively

  17. Highlighting the Structure-Function Relationship of the Brain with the Ising Model and Graph Theory

    Directory of Open Access Journals (Sweden)

    T. K. Das

    2014-01-01

    Full Text Available With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model or global dynamics (e.g., the Ising model have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions.

  18. Infertile Individuals’ Marital Relationship Status, Happiness, and Mental Health: A Causal Model

    Science.gov (United States)

    Ahmadi Forooshany, Seyed Habiballah; Yazdkhasti, Fariba; Safari Hajataghaie, Saiede; Nasr Esfahani, Mohammad Hossein

    2014-01-01

    Background This study examined the causal model of relation between marital relation- ship status, happiness, and mental health in infertile individuals. Materials and Methods In this descriptive study, 155 subjects (men: 52 and women: 78), who had been visited in one of the infertility Centers, voluntarily participated in a self-evaluation. Golombok Rust Inventory of Marital Status, Oxford Happiness Ques- tionnaire, and General Health Questionnaire were used as instruments of the study. Data was analyzed by SPSS17 and Amos 5 software using descriptive statistics, independent sample t test, and path analysis. Results Disregarding the gender factor, marital relationship status was directly related to happiness (phappiness was directly related to mental health, (phappiness and mental health was significant (phappiness had a mediator role in relation between marital relationship status and mental health in infertile individu- als disregarding the gender factor. Also, considering the gender factor, only in infertile women, marital relationship status can directly and indirectly affect happiness and mental health. PMID:25379161

  19. Different phylogenomic approaches to resolve the evolutionary relationships among model fish species.

    Science.gov (United States)

    Negrisolo, Enrico; Kuhl, Heiner; Forcato, Claudio; Vitulo, Nicola; Reinhardt, Richard; Patarnello, Tomaso; Bargelloni, Luca

    2010-12-01

    Comparative genomics holds the promise to magnify the information obtained from individual genome sequencing projects, revealing common features conserved across genomes and identifying lineage-specific characteristics. To implement such a comparative approach, a robust phylogenetic framework is required to accurately reconstruct evolution at the genome level. Among vertebrate taxa, teleosts represent the second best characterized group, with high-quality draft genome sequences for five model species (Danio rerio, Gasterosteus aculeatus, Oryzias latipes, Takifugu rubripes, and Tetraodon nigroviridis), and several others are in the finishing lane. However, the relationships among the acanthomorph teleost model fishes remain an unresolved taxonomic issue. Here, a genomic region spanning over 1.2 million base pairs was sequenced in the teleost fish Dicentrarchus labrax. Together with genomic data available for the above fish models, the new sequence was used to identify unique orthologous genomic regions shared across all target taxa. Different strategies were applied to produce robust multiple gene and genomic alignments spanning from 11,802 to 186,474 amino acid/nucleotide positions. Ten data sets were analyzed according to Bayesian inference, maximum likelihood, maximum parsimony, and neighbor joining methods. Extensive analyses were performed to explore the influence of several factors (e.g., alignment methodology, substitution model, data set partitions, and long-branch attraction) on the tree topology. Although a general consensus was observed for a closer relationship between G. aculeatus (Gasterosteidae) and Di. labrax (Moronidae) with the atherinomorph O. latipes (Beloniformes) sister taxon of this clade, with the tetraodontiform group Ta. rubripes and Te. nigroviridis (Tetraodontiformes) representing a more distantly related taxon among acanthomorph model fish species, conflicting results were obtained between data sets and methods, especially with respect

  20. Modeling bioaccumulation in humans using poly-parameter linear free energy relationships (PPLFERS)

    Energy Technology Data Exchange (ETDEWEB)

    Undeman, Emma, E-mail: emma.undeman@itm.su.se; Czub, Gertje; McLachlan, Michael S.

    2011-04-01

    Chemical partition coefficients between environmental media and biological tissues are a key component of bioaccumulation models. The single-parameter linear free energy relationships (spLFERs) commonly used for predicting partitioning are often derived using apolar chemicals and may not accurately capture polar chemicals. In this study, a poly-parameter LFER (ppLFER) based model of organic chemical bioaccumulation in humans is presented. Chemical partitioning was described by an air-body partition coefficient that was a volume weighted average of ppLFER based partition coefficients for the major organs and tissues constituting the human body. This model was compared to a spLFER model treating the body as a mixture of lipid ({approx} octanol) and water. Although model agreement was good for hydrophobic chemicals (average difference 15% for log K{sub OW} > 4 and log K{sub OA} > 8), the ppLFER model predicted {approx} 90% lower body burdens for hydrophilic chemicals (log K{sub OW} < 0). This was mainly due to lower predictions of muscle and adipose tissue sorption capacity for these chemicals. A comparison of the predicted muscle and adipose tissue sorption capacities of hydrophilic chemicals with measurements indicated that the ppLFER and spLFER models' uncertainties were similar. Consequently, little benefit from the implementation of ppLFERs in this model was identified. - Research Highlights: {yields}Implementation of ppLFERs resulted in on average 90% lower predicted body burdens. {yields}Uncertainties in spLFER and ppLFER predictions were similar. {yields}The benefit from implementation of ppLFERs in bioaccumulation models was limited.

  1. ON THE INFLUENTIAL POINTS IN THE FUNCTIONAL CIRCULAR RELATIONSHIP MODELS WITH AN APPLICATION ON WIND DATA

    Directory of Open Access Journals (Sweden)

    ALi Hassan Abuzaid

    2013-12-01

    Full Text Available If the interest is to calibrate two instruments then the functional relationship model is more appropriate than regression models. Fitting a straight line when both variables are circular and subject to errors has not received much attention. In this paper, we consider the problem of detecting influential points in two functional relationship models for circular variables. The first is based on the simple circular regression the (SC, while the last is derived from the complex linear regression the (CL.   The covariance matrices are derived and then the COVRATIO statistics are formulated for both models. The cut-off points are obtained and the power of performance is assessed via simulation studies.   The performance of COVRATIO statistics depends on the concentration of error, sample size and level of contamination. In the case of linear relationship between two circular variables COVRATIO statistics of the (SC model performs better than the (CL.  On the other hand, a novel diagram, the so-called spoke plot, is utilized to detect possible influential points For illustration purposes, the proposed procedures are applied on real data of wind directions measured by two different instruments. COVRATIO statistics and the spoke plot were able to identify two observations as influential points. Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"جدول عادي"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;}

  2. The Analysis And Design Of Customer Relationship Management Model At STMIK STIKOM BALI

    Directory of Open Access Journals (Sweden)

    Ni Wayan Deriani

    2016-06-01

    Full Text Available The advantages of an organization can be seen from the organization's ability to compete in the business world today is increasingly more competition. The competition should be used as well as possible in order to retain customers by providing the best service. one way to provide the best service is the provision of means in the form of comprehensive information systems and integrated. CRM is an integrated system that is useful for both of the organization and of course for the customer. In this research, design analysis model of CRM approach from the perspective Planner and owner of Zachman framework. Design analysis using DFD, ERD and conceptual database. The expected outcome of this research is a form of planning the Customer Relationship Management system model as a reference for the managers in the development of an integrated system in the future.

  3. Developing an Innovative Customer Relationship Management Model for Better Health Examination Service

    Directory of Open Access Journals (Sweden)

    Lyu JrJung

    2014-11-01

    Full Text Available People emphasize on their own health and wish to know more about their conditions. Chronic diseases now take up to 50 percent of top 10 causes of death. As a result, the health-care industry has emerged and kept thriving. This work adopts an innovative customer-oriented business model since most clients are proactive and spontaneous in taking the “distinguished” health examination programs. We adopt the soft system dynamics methodology (SSDM to develop and to evaluate the steps of introducing customer relationship management model into a case health examination organization. Quantitative results are also presented for a case physical examination center and to assess the improved efficiency. The case study shows that the procedures developed here could provide a better service.

  4. Developing a Customer Relationship Management Model for Better Health Examination Service

    Directory of Open Access Journals (Sweden)

    Lyu Jr-Jung

    2014-11-01

    Full Text Available People emphasize on their own health and wish to know more about their conditions. Chronic diseases now take up to 50 percent of top 10 causes of death. As a result, the health-care industry has emerged and kept thriving. This work adopts a customer-oriented business model since most clients are proactive and spontaneous in taking the “distinguished” health examination programs. We adopt the soft system dynamics methodology (SSDM to develop and to evaluate the steps of introducing customer relationship management model into a case health examination organization. Quantitative results are also presented for a case physical examination center and to assess the improved efficiency. The case study shows that the procedures developed here could provide a better service.

  5. The Relationship Between Life Satisfaction and ADHD Symptoms in Middle School Students: Using a Bifactor Model.

    Science.gov (United States)

    Ogg, Julia A; Bateman, Lisa; Dedrick, Robert F; Suldo, Shannon M

    2016-05-01

    ADHD is associated with increased academic and social difficulties and comorbid psychopathology which may lead to decreased life satisfaction (LS). The current study utilized a bifactor model of ADHD consisting of a general factor and two specific factors (inattention and hyperactivity-impulsivity) to determine if ADHD symptoms place middle school students (n= 183) at risk for diminished LS and if this relationship differed depending on whether teachers versus students reported ADHD symptoms. Confirmatory factor analyses indicated that the bifactor model provided very good fit to the ADHD symptoms reported by students (comparative fit index [CFI] = .995; root mean square error of approximation [RMSEA] = .028) and teachers (CFI = .997; RMSEA = .043). Results also demonstrated that when students rated ADHD symptoms, the general ADHD factor and inattention were negatively related to LS; however, when teachers rated ADHD symptoms, only inattention was negatively related to LS. Implications and future directions related to these results are discussed. © The Author(s) 2014.

  6. A Novel Numerical Approach for a Nonlinear Fractional Dynamical Model of Interpersonal and Romantic Relationships

    Directory of Open Access Journals (Sweden)

    Jagdev Singh

    2017-07-01

    Full Text Available In this paper, we propose a new numerical algorithm, namely q-homotopy analysis Sumudu transform method (q-HASTM, to obtain the approximate solution for the nonlinear fractional dynamical model of interpersonal and romantic relationships. The suggested algorithm examines the dynamics of love affairs between couples. The q-HASTM is a creative combination of Sumudu transform technique, q-homotopy analysis method and homotopy polynomials that makes the calculation very easy. To compare the results obtained by using q-HASTM, we solve the same nonlinear problem by Adomian’s decomposition method (ADM. The convergence of the q-HASTM series solution for the model is adapted and controlled by auxiliary parameter ℏ and asymptotic parameter n. The numerical results are demonstrated graphically and in tabular form. The result obtained by employing the proposed scheme reveals that the approach is very accurate, effective, flexible, simple to apply and computationally very nice.

  7. Modeling Relationships Between Flight Crew Demographics and Perceptions of Interval Management

    Science.gov (United States)

    Remy, Benjamin; Wilson, Sara R.

    2016-01-01

    The Interval Management Alternative Clearances (IMAC) human-in-the-loop simulation experiment was conducted to assess interval management system performance and participants' acceptability and workload while performing three interval management clearance types. Twenty-four subject pilots and eight subject controllers flew ten high-density arrival scenarios into Denver International Airport during two weeks of data collection. This analysis examined the possible relationships between subject pilot demographics on reported perceptions of interval management in IMAC. Multiple linear regression models were created with a new software tool to predict subject pilot questionnaire item responses from demographic information. General patterns were noted across models that may indicate flight crew demographics influence perceptions of interval management.

  8. Multivariate characterisation and quantitative structure-property relationship modelling of nitroaromatic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Joensson, S. [Man-Technology-Environment Research Centre, Department of Natural Sciences, Orebro University, 701 82 Orebro (Sweden)], E-mail: sofie.jonsson@nat.oru.se; Eriksson, L.A. [Department of Natural Sciences and Orebro Life Science Center, Orebro University, 701 82 Orebro (Sweden); Bavel, B. van [Man-Technology-Environment Research Centre, Department of Natural Sciences, Orebro University, 701 82 Orebro (Sweden)

    2008-07-28

    A multivariate model to characterise nitroaromatics and related compounds based on molecular descriptors was calculated. Descriptors were collected from literature and through empirical, semi-empirical and density functional theory-based calculations. Principal components were used to describe the distribution of the compounds in a multidimensional space. Four components described 76% of the variation in the dataset. PC1 separated the compounds due to molecular weight, PC2 separated the different isomers, PC3 arranged the compounds according to different functional groups such as nitrobenzoic acids, nitrobenzenes, nitrotoluenes and nitroesters and PC4 differentiated the compounds containing chlorine from other compounds. Quantitative structure-property relationship models were calculated using partial least squares (PLS) projection to latent structures to predict gas chromatographic (GC) retention times and the distribution between the water phase and air using solid-phase microextraction (SPME). GC retention time was found to be dependent on the presence of polar amine groups, electronic descriptors including highest occupied molecular orbital, dipole moments and the melting point. The model of GC retention time was good, but the precision was not precise enough for practical use. An important environmental parameter was measured using SPME, the distribution between headspace (air) and the water phase. This parameter was mainly dependent on Henry's law constant, vapour pressure, log P, content of hydroxyl groups and atmospheric OH rate constant. The predictive capacity of the model substantially improved when recalculating a model using these five descriptors only.

  9. Modelling price and volatility inter-relationships in the Australian wholesale spot electricity markets

    International Nuclear Information System (INIS)

    Higgs, Helen

    2009-01-01

    This paper examines the inter-relationships of wholesale spot electricity prices among the four regional electricity markets in the Australian National Electricity Market (NEM): namely, New South Wales, Queensland, South Australia and Victoria using the constant conditional correlation and Tse and Tsui's (Tse, Y.K., Tsui, A.K.C., 2002. A multivariate generalised autoregressive conditional heteroscedasticity model with time-varying correlations. Journal of Business and Economic Statistics 20 (3), 351-362.) and Engle's (Engle, R., 2002. Dynamic conditional correlation: a sample class of multivariate generalized autoregressive conditional heteroskedasticity models. Journal of Business and Economic Statistics 20 (3), 339-350.) dynamic conditional correlation multivariate GARCH models. Tse and Tsui's (Tse, Y.K., Tsui, A.K.C., 2002. A multivariate generalised autoregressive conditional heteroscedasticity model with time-varying correlations. Journal of Business and Economic Statistics 20 (3), 351-362.) dynamic conditional correlation multivariate GARCH model which takes account of the Student t specification produces the best results. At the univariate GARCH(1,1) level, the mean equations indicate the presence of positive own mean spillovers in all four markets and little evidence of mean spillovers from the other lagged markets. In the dynamic conditional correlation equation, the highest conditional correlations are evident between the well-connected markets indicating the presence of strong interdependence between these markets with weaker interdependence between the not so well-interconnected markets. (author)

  10. Models of Workplace Incivility: The Relationships to Instigated Incivility and Negative Outcomes

    Directory of Open Access Journals (Sweden)

    Kristoffer Holm

    2015-01-01

    Full Text Available The aim of the study was to investigate workplace incivility as a social process, examining its components and relationships to both instigated incivility and negative outcomes in the form of well-being, job satisfaction, turnover intentions, and sleeping problems. The different components of incivility that were examined were experienced and witnessed incivility from coworkers as well as supervisors. In addition, the organizational factors, social support, control, and job demands, were included in the models. A total of 2871 (2058 women and 813 men employees who were connected to the Swedish Hotel and Restaurant Workers Union completed an online questionnaire. Overall, the results from structural equation modelling indicate that whereas instigated incivility to a large extent was explained by witnessing coworker incivility, negative outcomes were to a high degree explained by experienced supervisor incivility via mediation through perceived low social support, low control, and high job demands. Unexpectedly, the relationships between incivility (experienced coworker and supervisor incivility, as well as witnessed supervisor incivility and instigated incivility were moderated by perceived high control and high social support. The results highlight the importance of including different components of workplace incivility and organizational factors in future studies of the area.

  11. A Model for Investigation of the Intensity of Trust Relationships' Strength among Users in Social Media

    Directory of Open Access Journals (Sweden)

    rojiar pir mohammadiani

    2017-06-01

    Full Text Available Although trust relations among users in social media are the evidence of social influence, but the level of this impact depends on strength of trust among users. Therefore, in this paper we study the effect of trust relationships’ strength among users through the development of matrix factorization method. Matrix factorization is a method to predict the rate that user assign to the products. For this purpose, based on similarity factors the strength of trust relationship is measured, then this feature as an effective parameter was added to matrix factorization. The proposed model is applied on Epinions data set. The weight of trust relationships’ strength parameter is determined through the proposed model. Based on the results, by adding the strength of trust relationship the error rate is reduced. Furthermore, if the strength of trust between users is larger than 0.8, the error reduction will be more significant. Improving the results through more accurate estimation shows that this effect is set correctly.

  12. Relationship between Family Adaptability, Cohesion and Adolescent Problem Behaviors: Curvilinearity of Circumplex Model

    Science.gov (United States)

    Joh, Ju Youn; Kim, Sun; Park, Jun Li

    2013-01-01

    Background The Family Adaptability and Cohesion Evaluation Scale (FACES) III using the circumplex model has been widely used in investigating family function. However, the criticism of the curvilinear hypothesis of the circumplex model has always been from an empirical point of view. This study examined the relationship between adolescent adaptability, cohesion, and adolescent problem behaviors, and especially testing the consistency of the curvilinear hypotheses with FACES III. Methods We used the data from 398 adolescent participants who were in middle school. A self-reported questionnaire was used to evaluate the FACES III and Youth Self Report. Results According to the level of family adaptability, significant differences were evident in internalizing problems (P = 0.014). But, in externalizing problems, the results were not significant (P = 0.305). Also, according to the level of family cohesion, significant differences were in internalizing problems (P = 0.002) and externalizing problems (P = 0.004). Conclusion The relationship between the dimensions of adaptability, cohesion and adolescent problem behaviors was not curvilinear. In other words, adolescents with high adaptability and high cohesion showed low problem behaviors. PMID:23730484

  13. Models of Workplace Incivility: The Relationships to Instigated Incivility and Negative Outcomes.

    Science.gov (United States)

    Holm, Kristoffer; Torkelson, Eva; Bäckström, Martin

    2015-01-01

    The aim of the study was to investigate workplace incivility as a social process, examining its components and relationships to both instigated incivility and negative outcomes in the form of well-being, job satisfaction, turnover intentions, and sleeping problems. The different components of incivility that were examined were experienced and witnessed incivility from coworkers as well as supervisors. In addition, the organizational factors, social support, control, and job demands, were included in the models. A total of 2871 (2058 women and 813 men) employees who were connected to the Swedish Hotel and Restaurant Workers Union completed an online questionnaire. Overall, the results from structural equation modelling indicate that whereas instigated incivility to a large extent was explained by witnessing coworker incivility, negative outcomes were to a high degree explained by experienced supervisor incivility via mediation through perceived low social support, low control, and high job demands. Unexpectedly, the relationships between incivility (experienced coworker and supervisor incivility, as well as witnessed supervisor incivility) and instigated incivility were moderated by perceived high control and high social support. The results highlight the importance of including different components of workplace incivility and organizational factors in future studies of the area.

  14. Team Investment and Longitudinal Relationships: An Innovative Global Health Education Model.

    Science.gov (United States)

    Myers, Kimberly R; Fredrick, N Benjamin

    2017-12-01

    Increasing student interest in global health has resulted in medical schools offering more global health opportunities. However, concerns have been raised, particularly about one-time, short-term experiences, including lack of follow-through for students and perpetuation of unintentional messages of global health heroism, neocolonialism, and disregard for existing systems and communities of care. Medical schools must develop global health programs that address these issues. The Global Health Scholars Program (GHSP) was created in 2008-2009 at Penn State College of Medicine. This four-year program is based on values of team investment and longitudinal relationships and uses the service-learning framework of preparation, service, and reflection. Teams of approximately five students, with faculty oversight, participate in two separate monthlong trips abroad to the same host community in years 1 and 4, and in campus- and Web-based activities in years 2 and 3. As of December 2016, 191 students have been accepted into the GHSP. Since inception, applications have grown by 475% and program sites have expanded from one to seven sites on four continents. The response from students has been positive, but logistical challenges persist in sustaining team investment and maintaining longitudinal relationships between student teams and host communities. Formal methods of assessment should be used to compare the GHSP model with more traditional approaches to global health education. Other medical schools with similar aims can adapt the GHSP model to expand their global health programming.

  15. Relationship between Family Adaptability, Cohesion and Adolescent Problem Behaviors: Curvilinearity of Circumplex Model.

    Science.gov (United States)

    Joh, Ju Youn; Kim, Sun; Park, Jun Li; Kim, Yeon Pyo

    2013-05-01

    The Family Adaptability and Cohesion Evaluation Scale (FACES) III using the circumplex model has been widely used in investigating family function. However, the criticism of the curvilinear hypothesis of the circumplex model has always been from an empirical point of view. This study examined the relationship between adolescent adaptability, cohesion, and adolescent problem behaviors, and especially testing the consistency of the curvilinear hypotheses with FACES III. We used the data from 398 adolescent participants who were in middle school. A self-reported questionnaire was used to evaluate the FACES III and Youth Self Report. According to the level of family adaptability, significant differences were evident in internalizing problems (P = 0.014). But, in externalizing problems, the results were not significant (P = 0.305). Also, according to the level of family cohesion, significant differences were in internalizing problems (P = 0.002) and externalizing problems (P = 0.004). The relationship between the dimensions of adaptability, cohesion and adolescent problem behaviors was not curvilinear. In other words, adolescents with high adaptability and high cohesion showed low problem behaviors.

  16. A Two-Factor Autoregressive Moving Average Model Based on Fuzzy Fluctuation Logical Relationships

    Directory of Open Access Journals (Sweden)

    Shuang Guan

    2017-10-01

    Full Text Available Many of the existing autoregressive moving average (ARMA forecast models are based on one main factor. In this paper, we proposed a new two-factor first-order ARMA forecast model based on fuzzy fluctuation logical relationships of both a main factor and a secondary factor of a historical training time series. Firstly, we generated a fluctuation time series (FTS for two factors by calculating the difference of each data point with its previous day, then finding the absolute means of the two FTSs. We then constructed a fuzzy fluctuation time series (FFTS according to the defined linguistic sets. The next step was establishing fuzzy fluctuation logical relation groups (FFLRGs for a two-factor first-order autoregressive (AR(1 model and forecasting the training data with the AR(1 model. Then we built FFLRGs for a two-factor first-order autoregressive moving average (ARMA(1,m model. Lastly, we forecasted test data with the ARMA(1,m model. To illustrate the performance of our model, we used real Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX and Dow Jones datasets as a secondary factor to forecast TAIEX. The experiment results indicate that the proposed two-factor fluctuation ARMA method outperformed the one-factor method based on real historic data. The secondary factor may have some effects on the main factor and thereby impact the forecasting results. Using fuzzified fluctuations rather than fuzzified real data could avoid the influence of extreme values in historic data, which performs negatively while forecasting. To verify the accuracy and effectiveness of the model, we also employed our method to forecast the Shanghai Stock Exchange Composite Index (SHSECI from 2001 to 2015 and the international gold price from 2000 to 2010.

  17. The Entropy Solutions for the Lighthill-Whitham-Richards Traffic Flow Model with a Discontinuous Flow-Density Relationship

    National Research Council Canada - National Science Library

    Lu, Yadong; Wong, S. C; Zhang, Mengping; Shu, Chi-Wang

    2007-01-01

    ...) traffic flow model with a flow-density relationship which is piecewise quadratic, concave, but not continuous at the junction points where two quadratic polynomials meet, and with piecewise linear...

  18. The Relationship between Ethical Culture and Unethical Behavior in Work Groups: Testing the Corporate Ethical Virtues Model

    NARCIS (Netherlands)

    S.P. Kaptein (Muel)

    2008-01-01

    textabstractThe Corporate Ethical Virtues Model, which is a model for measuring the ethical culture of organizations, has not been tested on its predictive validity. This study tests the relationship between this model and observed unethical behavior in work groups. The sample consists of 301 triads

  19. Dynamics of the Indian monsoon and ENSO relationships in the SINTEX global coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Terray, P. [LODYC, Paris (France); Universite Paris 7, Paris (France); Guilyardi, E. [LSCE, Gif-sur-Yvette (France); CGAM, Reading (United Kingdom); Fischer, A.S. [LODYC, Paris (France); Delecluse, P. [LODYC, Paris (France); LSCE, Gif-sur-Yvette (France)

    2005-02-01

    This paper uses recent gridded climatological data and a coupled general circulation model (GCM) simulation in order to assess the relationships between the interannual variability of the Indian summer monsoon (ISM) and the El Nino-Southern Oscillation (ENSO). The focus is on the dynamics of the ISM-ENSO relationships and the ability of the state-of-the-art coupled GCM to reproduce the complex lead-lag relationships between the ISM and the ENSO. The coupled GCM is successful in reproducing the ISM circulation and rainfall climatology in the Indian areas even though the entire ISM circulation is weaker relative to that observed. In both observations and in the simulation, the ISM rainfall anomalies are significantly associated with fluctuations of the Hadley circulation and the 200 hPa zonal wind anomalies over the Indian Ocean. A quasi-biennial time scale is found to structure the ISM dynamical and rainfall indices in both cases. Moreover, ISM indices have a similar interannual variability in the simulation and observations. The coupled model is less successful in simulating the annual cycle in the tropical Pacific. Despite some problems in simulation of the annual cycle and the Southern Oscillation, the coupled model captures some aspects of the interannual variability in the tropical Pacific. ENSO events are phase-locked with the annual cycle as observed, but are of reduced amplitude relative to the observations. Wavelet analysis of the model Nino34 time series shows enhanced power in the 2-4 year band, as compared to the 2-8 year range for observations during the 1950-2000 period. The ISM circulation is weakened during ENSO years in both the simulation and the observations. However, the model fails to reproduce the lead-lag relationship between the ISM and Nino34 sea surface temperatures (SSTs). Furthermore, lag correlations show that the delayed response of the wind stress over the central Pacific to ISM variability is insignificant in the simulation. These

  20. Investigating the relationship between tree heights derived from SIBBORK forest model and remote sensing measurements

    Science.gov (United States)

    Osmanoglu, B.; Feliciano, E. A.; Armstrong, A. H.; Sun, G.; Montesano, P.; Ranson, K.

    2017-12-01

    Tree heights are one of the most commonly used remote sensing parameters to measure biomass of a forest. In this project, we investigate the relationship between remotely sensed tree heights (e.g. G-LiHT lidar and commercially available high resolution satellite imagery, HRSI) and the SIBBORK modeled tree heights. G-LiHT is a portable, airborne imaging system that simultaneously maps the composition, structure, and function of terrestrial ecosystems using lidar, imaging spectroscopy and thermal mapping. Ground elevation and canopy height models were generated using the lidar data acquired in 2012. A digital surface model was also generated using the HRSI technique from the commercially available WorldView data in 2016. The HRSI derived height and biomass products are available at the plot (10x10m) level. For this study, we parameterized the SIBBORK individual-based gap model for Howland forest, Maine. The parameterization was calibrated using field data for the study site and results show that the simulated forest reproduces the structural complexity of Howland old growth forest, based on comparisons of key variables including, aboveground biomass, forest height and basal area. Furthermore carbon cycle and ecosystem observational capabilities will be enhanced over the next 6 years via the launch of two LiDAR (NASA's GEDI and ICESAT 2) and two SAR (NASA's ISRO NiSAR and ESA's Biomass) systems. Our aim is to present the comparison of canopy height models obtained with SIBBORK forest model and remote sensing techniques, highlighting the synergy between individual-based forest modeling and high-resolution remote sensing.

  1. Modelling cross-scale relationships between climate, hydrology, and individual animals: Generating scenarios for stream salamanders

    Directory of Open Access Journals (Sweden)

    Philippe eGirard

    2015-07-01

    Full Text Available Hybrid modelling provides a unique opportunity to study cross-scale relationships in environmental systems by linking together models of global, regional, landscape, and local-scale processes, yet the approach is rarely applied to address conservation and management questions. Here, we demonstrate how a hybrid modelling approach can be used to assess the effect of cross-scale interactions on the survival of the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus in response to changes in temperature and water availability induced by climate change at the northern limits of its distribution. To do so, we combine regional climate modelling with a landscape-scale integrated surface-groundwater flow model and an individual-based model of stream salamanders. On average, climate scenarios depict a warmer and wetter environment for the 2050 horizon. The increase in average annual temperature and extended hydrological activity time series in the future, combined with a better synchronization with the salamanders’ reproduction period, result in a significant increase in the long-term population viability of the salamanders. This indicates that climate change may not necessarily limit the survivability of small, stream-dwelling animals in headwater basins located in cold and humid regions. This new knowledge suggests that habitat conservation initiatives for amphibians with large latitudinal distributions in Eastern North America should be prioritized at the northern limits of their ranges to facilitate species migration and persistence in the face of climate change. This example demonstrates how hybrid models can serve as powerful tools for informing management and conservation decisions.

  2. Pharmacokinetic/Pharmacodynamic Relationship of Gabapentin in a CFA-induced Inflammatory Hyperalgesia Rat Model.

    Science.gov (United States)

    Larsen, Malte Selch; Keizer, Ron; Munro, Gordon; Mørk, Arne; Holm, René; Savic, Rada; Kreilgaard, Mads

    2016-05-01

    Gabapentin displays non-linear drug disposition, which complicates dosing for optimal therapeutic effect. Thus, the current study was performed to elucidate the pharmacokinetic/pharmacodynamic (PKPD) relationship of gabapentin's effect on mechanical hypersensitivity in a rat model of CFA-induced inflammatory hyperalgesia. A semi-mechanistic population-based PKPD model was developed using nonlinear mixed-effects modelling, based on gabapentin plasma and brain extracellular fluid (ECF) time-concentration data and measurements of CFA-evoked mechanical hyperalgesia following administration of a range of gabapentin doses (oral and intravenous). The plasma/brain ECF concentration-time profiles of gabapentin were adequately described with a two-compartment plasma model with saturable intestinal absorption rate (K m  = 44.1 mg/kg, V max  = 41.9 mg/h∙kg) and dose-dependent oral bioavailability linked to brain ECF concentration through a transit compartment. Brain ECF concentration was directly linked to a sigmoid E max function describing reversal of hyperalgesia (EC 50, plasma  = 16.7 μg/mL, EC 50, brain  = 3.3 μg/mL). The proposed semi-mechanistic population-based PKPD model provides further knowledge into the understanding of gabapentin's non-linear pharmacokinetics and the link between plasma/brain disposition and anti-hyperalgesic effects. The model suggests that intestinal absorption is the primary source of non-linearity and that the investigated rat model provides reasonable predictions of clinically effective plasma concentrations for gabapentin.

  3. EMD-regression for modelling multi-scale relationships, and application to weather-related cardiovascular mortality

    Science.gov (United States)

    Masselot, Pierre; Chebana, Fateh; Bélanger, Diane; St-Hilaire, André; Abdous, Belkacem; Gosselin, Pierre; Ouarda, Taha B. M. J.

    2018-01-01

    In a number of environmental studies, relationships between natural processes are often assessed through regression analyses, using time series data. Such data are often multi-scale and non-stationary, leading to a poor accuracy of the resulting regression models and therefore to results with moderate reliability. To deal with this issue, the present paper introduces the EMD-regression methodology consisting in applying the empirical mode decomposition (EMD) algorithm on data series and then using the resulting components in regression models. The proposed methodology presents a number of advantages. First, it accounts of the issues of non-stationarity associated to the data series. Second, this approach acts as a scan for the relationship between a response variable and the predictors at different time scales, providing new insights about this relationship. To illustrate the proposed methodology it is applied to study the relationship between weather and cardiovascular mortality in Montreal, Canada. The results shed new knowledge concerning the studied relationship. For instance, they show that the humidity can cause excess mortality at the monthly time scale, which is a scale not visible in classical models. A comparison is also conducted with state of the art methods which are the generalized additive models and distributed lag models, both widely used in weather-related health studies. The comparison shows that EMD-regression achieves better prediction performances and provides more details than classical models concerning the relationship.

  4. Deconstructing Constructivism: Modeling Causal Relationships Among Constructivist Learning Environment Factors and Student Outcomes in Introductory Chemistry

    Science.gov (United States)

    Komperda, Regis

    The purpose of this dissertation is to test a model of relationships among factors characterizing aspects of a student-centered constructivist learning environment and student outcomes of satisfaction and academic achievement in introductory undergraduate chemistry courses. Constructivism was chosen as the theoretical foundation for this research because of its widespread use in chemical education research and practice. In a constructivist learning environment the role of the teacher shifts from delivering content towards facilitating active student engagement in activities that encourage individual knowledge construction through discussion and application of content. Constructivist approaches to teaching introductory chemistry courses have been adopted by some instructors as a way to improve student outcomes, but little research has been done on the causal relationships among particular aspects of the learning environment and student outcomes. This makes it difficult for classroom teachers to know which aspects of a constructivist teaching approach are critical to adopt and which may be modified to better suit a particular learning environment while still improving student outcomes. To investigate a model of these relationships, a survey designed to measure student perceptions of three factors characterizing a constructivist learning environment in online courses was adapted for use in face-to-face chemistry courses. These three factors, teaching presence, social presence, and cognitive presence, were measured using a slightly modified version of the Community of Inquiry (CoI) instrument. The student outcomes investigated in this research were satisfaction and academic achievement, as measured by standardized American Chemical Society (ACS) exam scores and course grades. Structural equation modeling (SEM) was used to statistically model relationships among the three presence factors and student outcome variables for 391 students enrolled in six sections of a

  5. Using plant biomonitors and flux modelling to develop O3 dose-response relationships in Catalonia

    International Nuclear Information System (INIS)

    Filella, Iolanda; Pen-tilde uelas, Josep; Ribas, Angela

    2005-01-01

    We used tobacco Bel-W3 biomonitoring data and ozone flux modelling (WINDEP model) with the aim of developing the absorbed dose-response relationship, and comparing this approach with the most commonly used AOT40 (the sum of hourly ozone concentrations above a cut-off of 40 ppb during daylight hours, when global radiation exceeds 50 W m -2 ) in the estimation of exposure-damage curves. Leaf damage values were more related to OAD 15days,potential (potential ozone absorbed dose calculated over 15 consecutive days) than to AOT40 in all the studied stations. An OAD 15days,potential of 180 mg m -2 was found to be the threshold for damage to the most sensitive species in this region under well watered conditions. The results show the applicability of the flux approach for risk assessment at the local scale, the improvement of the ozone damage estimation when the potential absorbed dose is modelled and used instead of just the ozone exposure, and finally, the possibilities opened by the use of biomonitoring networks. - Modelling of biomonitors ozone absorbed dose improves damage estimation in comparison with exposure indices such as AOT40

  6. Relationship between long working hours and depression in two working populations: a structural equation model approach.

    Science.gov (United States)

    Amagasa, Takashi; Nakayama, Takeo

    2012-07-01

    To test the hypothesis that relationship reported between long working hours and depression was inconsistent in previous studies because job demand was treated as a confounder. Structural equation modeling was used to construct five models, using work-related factors and depressive mood scale obtained from 218 clerical workers, to test for goodness of fit and was externally validated with data obtained from 1160 sales workers. Multiple logistic regression analysis was also performed. The model that showed that long working hours increased depression risk when job demand was regarded as an intermediate variable was the best fitted model (goodness-of-fit index/root-mean-square error of approximation: 0.981 to 0.996/0.042 to 0.044). The odds ratio for depression risk with work that was high demand and 60 hours or more per week was estimated at 2 to 4 versus work that was low demand and less than 60 hours per week. Long working hours increased depression risk, with job demand being an intermediate variable.

  7. Towards a unified model for leaf trait and trait-environment relationships

    Science.gov (United States)

    Wang, H.; Harrison, S. P.; Prentice, I. C.; Peng, C.; Yang, Y.

    2016-12-01

    A widely accepted core set of leaf traits describes key aspects of plant function including the coupling among carbon, nitrogen and water cycles at the leaf, plant and ecosystem scales. Our current research focuses on two questions: (1) what dimensions of correlated variation among traits apply across all vascular plants irrespective of environment; (2) how, and to what extent, can variations in community mean values of leaf traits be predicted along environmental gradients? Based on a large quantitative trait data set covering the major environmental gradients across China, we are tackling these questions via two complementary approaches: multivariate analysis of trait-trait, trait-site, and trait-environment relationships, and the development of conceptual models and testable hypotheses for the dependencies of each trait on other traits and/or specific environmental predictors. Preliminary multivariate analyses suggest the existence of at least two independent axes of variation in leaf traits, and show robust relationships between trait syndromes and growing-season climate variables. A minimal conceptual model then considers nitrogen per unit leaf area (Narea) as a function of leaf mass per unit area (LMA) and carboxylation capacity (Vcmax); LMA as a function of irradiance, temperature and water and/or nutrient stress; Vcmax as a function of irradiance, temperature and the long-term ci:ca ratio (indexed by δ13C); and the ci:ca ratio as a function of vapour pressure deficit, temperature and atmospheric pressure. Each of these dependencies has support from observations, pointing the way towards a comprehensive set of equations to predict community-mean values of core traits in next-generation terrestrial ecosystem models.

  8. A model to incorporate organ deformation in the evaluation of dose/volume relationship

    International Nuclear Information System (INIS)

    Yan, D.; Jaffray, D.; Wong, J.; Brabbins, D.; Martinez, A. A.

    1997-01-01

    treatment have been collected prospectively during their course of treatment. The data was used retrospectively to examine the model, and to evaluate the cumulative dose/volume relationships of the prostate, rectum and bladder in comparison with those in the initial treatment plan. Results: Characteristics of daily organ deformation were specific to the individual patient and could not be easily represented by a global description. Daily deformation of the prostate secondary to local filling of rectum and bladder could not be simply modeled using the linear transformation of rigid body motion. The cumulative dose distribution in the prostate was either overestimated or underestimated using the linear model. Deformation of the rectum due to rectal filling occurred at different positions on different days. Consequently, daily hot spots occurred on different locations of the rectal wall. Therefore, the direct combination of the daily dose volume histograms would overestimate the actual dose/volume relation. Furthermore, the shapes and positions of the prostate, rectum, and bladder defined in the initial planning CT scan were not representative of the mean shape and position as assumed in the linear model for rigid organ motion. As such, the linear convolution method based upon rigid motion of the initial CT volumes led to misleading results in the planning evaluation and optimization for the individual patient. Conclusion: Our proposed model provides a more realistic description of the viscoelastic nature of daily organ deformation than the current rigid body models. It provides a systematic framework to incorporate the daily organ motion in the calculation of cumulative dose/volume relationships throughout the course of treatment. This information may play an important role in the treatment evaluation and reoptimization for the individual patient

  9. Relationship between US Societal Fatality Risk per Vehicle Miles of Travel and Mass, for Individual Vehicle Models over Time (Model Year)

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, Tom P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Technologies Area. Building Technology and Urban Systems Division

    2016-07-27

    This report presents a new approach to analyze the relationship between vehicle mass and risk: tracking fatality risk by vehicle model year and mass, for individual vehicle models. This approach is appealing as it greatly minimizes the influence of driver characteristics and behavior, and crash circumstances, on fatality risk. However, only the most popular vehicle models, with the largest number of fatalities, can be analyzed in this manner. While the analysis of all vehicle models of a given type suggests that there is a relationship between increased mass and fatality risk, analysis of the ten most popular four-door car models separately suggests that this relationship is weak: in many cases when the mass of a specific vehicle model is increased societal fatality risk is unchanged or even increases. These results suggest that increasing the mass of an individual vehicle model does not necessarily lead to decreased societal fatality risk.

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

    Directory of Open Access Journals (Sweden)

    Sharifuddin M. Zain

    2011-11-01

    Full Text Available 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.

  11. Relationship between inflammation, the gut microbiota, and metabolic osteoarthritis development: studies in a rat model.

    Science.gov (United States)

    Collins, K H; Paul, H A; Reimer, R A; Seerattan, R A; Hart, D A; Herzog, W

    2015-11-01

    Osteoarthritis (OA) may result from intrinsic inflammation related to metabolic disturbance. Obesity-associated inflammation is triggered by lipopolysaccharide (LPS) derived from the gut microbiota. However, the relationship between gut microbiota, LPS, inflammation, and OA remain unclear. To evaluate the associations between gut microbiota, systemic LPS levels, serum and local inflammatory profiles, and joint damage in a high fat/high sucrose diet induced obese rat model. 32 rats were randomized to a high fat/high sucrose diet (diet-induced obese (DIO), 40% fat, 45% sucrose, n = 21) or chow diet group (12% fat, 3.7% sucrose n = 11) for 28 weeks. After a 12-week obesity induction period, DIO animals were stratified into Obesity Prone (DIO-P, top 33% by change in body mass, n = 7), and Obesity Resistant groups (DIO-R, bottom 33%, n = 7). At sacrifice, joints were scored using a Modified Mankin Criteria. Blood and synovial fluid analytes, serum LPS, and fecal gut microbiota were analyzed. DIO animals had greater Modified Mankin scores than chow animals (P = 0.002). There was a significant relationship (r = 0.604, p = 0.001) between body fat, but not body mass, and Modified Mankin score. Eighteen synovial fluid and four serum analytes were increased in DIO animals. DIO serum LPS levels were increased compared to chow (P = 0.031). Together, Lactobacillus species (spp.) and Methanobrevibacter spp. abundance had a strong predictive relationship with Modified Mankin Score (r(2) = 0.5, P gut microbiota and adiposity-derived inflammation and metabolic OA warrants further investigation. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  12. Parent-Adolescent Relationship Qualities, Internal Working Models, and Styles as Predictors of Adolescents’ Observed Interactions with Friends

    Science.gov (United States)

    Shomaker, Lauren B.; Furman, Wyndol

    2010-01-01

    This study examined how current parent-adolescent relationship qualities and adolescents’ representations of relationships with parents were related to friendship interactions in 200 adolescent-close friend dyads. Adolescents and friends were observed discussing problems during a series of structured tasks. Negative interactions with mothers were significantly related to adolescents’ greater conflict with friends, poorer focus on tasks, and poorer communication skills. Security of working models (as assessed by interview) was significantly associated with qualities of friendship interactions, whereas security of attachment styles (as assessed by questionnaire) was not. More dismissing (vs. secure) working models were associated with poorer focus on problem discussions and weaker communication skills with friends, even after accounting for gender differences and current parent-adolescent relationship qualities. We discuss possible mechanisms for the observed links between dimensions of parent-adolescent relationships and friendships. We also consider methodological and conceptual differences between working model and style measures of attachment representations. PMID:20174459

  13. Development-based Trust: Proposing and Validating a New Trust Measurement Model for Buyer-Seller Relationships

    Directory of Open Access Journals (Sweden)

    José Mauro da Costa Hernandez

    2010-04-01

    Full Text Available This study proposes and validates a trust measurement model for buyer-seller relationships. Baptized as development-based trust, the model encompasses three dimensions of trust: calculus-based, knowledge-based and identification-based. In addition to recognizing that trust is a multidimensional construct, the model also assumes that trust can evolve to take on a different character depending on the stage of the relationship. In order to test the proposed model and compare it to the characteristic-based trust measurement model, the measure most frequently used in the buyer-seller relationship literature, data were collected from 238 clients of an IT product wholesaler. The results show that the scales are valid and reliable and the proposed development-based trust measurement model is superior to the characteristic-based trust measurement model in terms of its ability to explain certain variables of interest in buyer-seller relationships (long-term relationship orientation, information sharing, behavioral loyalty and future intentions. Implications for practice, limitations and suggestions for future studies are discussed.

  14. Engineering and validation of a novel lipid thin film for biomembrane modeling in lipophilicity determination of drugs and xenobiotics

    Directory of Open Access Journals (Sweden)

    Ogbonna Udochi

    2009-09-01

    Full Text Available Abstract Background Determination of lipophilicity as a tool for predicting pharmacokinetic molecular behavior is limited by the predictive power of available experimental models of the biomembrane. There is current interest, therefore, in models that accurately simulate the biomembrane structure and function. A novel bio-device; a lipid thin film, was engineered as an alternative approach to the previous use of hydrocarbon thin films in biomembrane modeling. Results Retention behavior of four structurally diverse model compounds; 4-amino-3,5-dinitrobenzoic acid (ADBA, naproxen (NPX, nabumetone (NBT and halofantrine (HF, representing 4 broad classes of varying molecular polarities and aqueous solubility behavior, was investigated on the lipid film, liquid paraffin, and octadecylsilane layers. Computational, thermodynamic and image analysis confirms the peculiar amphiphilic configuration of the lipid film. Effect of solute-type, layer-type and variables interactions on retention behavior was delineated by 2-way analysis of variance (ANOVA and quantitative structure property relationships (QSPR. Validation of the lipid film was implemented by statistical correlation of a unique chromatographic metric with Log P (octanol/water and several calculated molecular descriptors of bulk and solubility properties. Conclusion The lipid film signifies a biomimetic artificial biological interface capable of both hydrophobic and specific electrostatic interactions. It captures the hydrophilic-lipophilic balance (HLB in the determination of lipophilicity of molecules unlike the pure hydrocarbon film of the prior art. The potentials and performance of the bio-device gives the promise of its utility as a predictive analytic tool for early-stage drug discovery science.

  15. Emotion dysregulation mediates the relationship between child maltreatment and psychopathology: A structural equation model.

    Science.gov (United States)

    Jennissen, Simone; Holl, Julia; Mai, Hannah; Wolff, Sebastian; Barnow, Sven

    2016-12-01

    The present study investigated the mediating effects of emotion dysregulation on the relationship between child maltreatment and psychopathology. An adult sample (N=701) from diverse backgrounds of psychopathology completed the Childhood Trauma Questionnaire (CTQ), the Difficulties in Emotion Regulation Scale (DERS), the Brief Symptom Inventory (BSI), and the negative affect subscale of the Positive and Negative Affect Schedule (PANAS) in a cross-sectional online survey. Correlational analyses showed that all types of child maltreatment were uniformly associated with emotion dysregulation, and dimensions of emotion dysregulation were strongly related to psychopathology. Limited access to strategies for emotion regulation emerged as the most powerful predictor. Structural equation modeling analyses revealed that emotion dysregulation partially mediated the relationship between child maltreatment and psychopathology, even after controlling for shared variance with negative affect. These findings emphasize the importance of emotion dysregulation as a possible mediating mechanism in the association between child maltreatment and later psychopathology. Additionally, interventions targeting specific emotion regulation strategies may be effective to reduce psychopathology in victims of child maltreatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Foundation-industry relationships--a new business model joint-venture philanthropy in therapy development.

    Science.gov (United States)

    Bartek, Ronald J

    2014-01-01

    The business model for medical therapy development has changed drastically. Large companies that once conducted their own Research and Development (R&D) and funded all the preclinical studies, all phases of clinical development and marketing of the products are increasingly turning to others for more and more of the earlier work in hopes of being able to in-license a de-risked program well downstream, take it through the final phases of clinical development and into the marketplace. This new paradigm has required patient-advocacy foundations, especially in the rare-disease space, to become far more effective in building relationships with all the players along the therapy-development pathway -- academic scientists, government agencies, other foundations with overlapping interests, biotechs, small biopharmaceutical entities and even the larger industry companies. From the perspective of the patient-advocacy community, these increasingly essential public-private partnerships have taken on the nature of what could be called joint-venture philanthropy and involve a broad spectrum of collaborations and financial relationships between foundations and industry partners that are not without concerns about potential conflicts of interest.

  17. The Relationship between SES and Reading Comprehension in Chinese: A Mediation Model

    Directory of Open Access Journals (Sweden)

    Yahua Cheng

    2017-04-01

    Full Text Available An increasing body of research provides evidence that socioeconomic status (SES was significantly related to children’s reading development; however, the psychological mechanism underlying the association between them remained an open question. The present study is designed to test the hypothesized three-path effect of vocabulary knowledge and morphological awareness as mediators between SES and sentence reading comprehension in Chinese first-graders. Results of mediation model showed that SES exerted its effect on sentence reading comprehension through the indirect path via the simple mediating effect of morphological awareness and the three-path mediating effect of vocabulary knowledge and morphological awareness. The findings highlight a previously unidentified mechanism of the relationship between SES and reading comprehension in Chinese young children.

  18. Motivation and personality: relationships between putative motive dimensions and the five factor model of personality.

    Science.gov (United States)

    Bernard, Larry C

    2010-04-01

    There are few multidimensional measures of individual differences in motivation available. The Assessment of Individual Motives-Questionnaire assesses 15 putative dimensions of motivation. The dimensions are based on evolutionary theory and preliminary evidence suggests the motive scales have good psychometric properties. The scales are reliable and there is evidence of their consensual validity (convergence of self-other ratings) and behavioral validity (relationships with self-other reported behaviors of social importance). Additional validity research is necessary, however, especially with respect to current models of personality. The present study tested two general and 24 specific hypotheses based on proposed evolutionary advantages/disadvantages and fitness benefits/costs of the five-factor model of personality together with the new motive scales in a sample of 424 participants (M age=28.8 yr., SD=14.6). Results were largely supportive of the hypotheses. These results support the validity of new motive dimensions and increase understanding of the five-factor model of personality.

  19. Level of paranormal beliefs and its relationship with explanatory models, treatment adherence and satisfaction

    Directory of Open Access Journals (Sweden)

    Dushad Ram

    2016-06-01

    Full Text Available Abstract Background Paranormal beliefs are common among patients with mental illness. Such beliefs may mediate conceptualization of illness, treatment satisfaction and medication adherence. Objective To study the level of paranormal beliefs and its relationship with explanatory models, treatment adherence and satisfaction using standardized assessment tool. Methods Eighty nine patients with mental illness in remission were assessed with Sociodemographic proforma, Revised Paranormal Belief Scale (RPBS, Mental Distress Explanatory Model Questionnaire (MMAS, Morisky Medication Adherence Scale (MMAS and Short Assessment of Patient Satisfaction (SAPS. Results Results revealed a high level of paranormal beliefs on RPBS (Mean 83.96, SD ± 23.91. Variables that had a statistically significant group difference on the score of RPBS were domicile status (p < 05, diagnosis (p < 001, method of treatment sought before (p < 001. In a linear regression analysis four variables explained 35.4% of the variance (R2 = .38, R2Adjusted = .35, F = 13.04, p < .001 in RPBS Score. These variables were total score of MDEMQ (Beta = .308, t = 3.435, p < .001, total score of MMAS (beta = .357, t = 3. 716, p < .001 and magico-religious treatment received earlier (beta = .306, t = 3.52, p < .001 and SAPS. Discussion Based on the finding of this study, it may be concluded that the level of paranormal beliefs may vary with some demographic variables. Levels of paranormal beliefs is positively associated with explanatory models and adherence in patients with mental illness in remission.

  20. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, Stephen [Cleveland State Univ., Cleveland, OH (United States)

    2013-09-09

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  1. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    International Nuclear Information System (INIS)

    Duffy, Stephen

    2013-01-01

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  2. The Relationship between Trabecular Bone Structure Modeling Methods and the Elastic Modulus as Calculated by FEM

    Directory of Open Access Journals (Sweden)

    Tomasz Topoliński

    2012-01-01

    Full Text Available Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty. Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E=10 MPa and ν=0.3. The compressive deformation as calculated by finite elements (FE analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns. The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.

  3. Monitoring and modeling wetland chloride concentrations in relationship to oil and gas development

    Science.gov (United States)

    Post van der Burg, Max; Tangen, Brian A.

    2015-01-01

    Extraction of oil and gas via unconventional methods is becoming an important aspect of energy production worldwide. Studying the effects of this development in countries where these technologies are being widely used may provide other countries, where development may be proposed, with some insight in terms of concerns associated with development. A fairly recent expansion of unconventional oil and gas development in North America provides such an opportunity. Rapid increases in energy development in North America have caught the attention of managers and scientists as a potential stressor for wildlife and their habitats. Of particular concern in the Northern Great Plains of the U.S. is the potential for chloride-rich produced water associated with unconventional oil and gas development to alter the water chemistry of wetlands. We describe a landscape scale modeling approach designed to examine the relationship between potential chloride contamination in wetlands and patterns of oil and gas development. We used a spatial Bayesian hierarchical modeling approach to assess multiple models explaining chloride concentrations in wetlands. These models included effects related to oil and gas wells (e.g. age of wells, number of wells) and surficial geology (e.g. glacial till, outwash). We found that the model containing the number of wells and the surficial geology surrounding a wetland best explained variation in chloride concentrations. Our spatial predictions showed regions of localized high chloride concentrations. Given the spatiotemporal variability of regional wetland water chemistry, we do not regard our results as predictions of contamination, but rather as a way to identify locations that may require more intensive sampling or further investigation. We suggest that an approach like the one outlined here could easily be extended to more of an adaptive monitoring approach to answer questions about chloride contamination risk that are of interest to managers.

  4. Myotoxicity of Gemfibrozil in Cynomolgus Monkey Model and Its Relationship to Pharmacokinetic Properties

    Science.gov (United States)

    Liu, Aiming; Xie, Shuilin; Sun, He; Gonzalez, Frank J.; Wei, Xiaoxiong; Dai, Renke

    2008-01-01

    Fibrate drugs are PPARα agonists prescribed for the treatment of dyslipidemia. Severe myotoxicity has been reported associated with their use albeit at a low frequency, especially for gemfibrozil. Few studies have investigated the mechanism of fibrate-induced myotoxicity in vivo. Considering the apparent species-related differences in PPARα agonist-induced hepatotoxicity, we studied the myotoxicity of gemfibrozil in a Cynomolgus monkey model and explored the relationship between myotoxicity and pharmacokinetics. Six Cynomolgus monkeys were dosed with gemfibrozil twice daily at 600 mg/kg/day for the first two periods (P1 and P2, 8 days and 9 days respectively) and 300 mg/kg/day for the third period (P3, 14 days). Creatine kinase and myoglobin were measured, together with hepatotoxicity and nephrotoxicity markers. Behavioral responses were recorded for indication of toxicity. Pharmacokinetics was carried out following the 16th dosage of P1 and 17th dosage of P2 when myotoxicity was identified. Multivariable data analysis was employed to explore the relationship between pharmacokinetic parameters and myotoxicity markers. Consequently, myotoxicity occurred in monkey #2 (M2) and M6 in P1, M3 and M4 in P2, M3 and M6 in P3. Data analysis showed T80-150 (sustained time above the given concentration) contributed for myotoxicity discriminance and correlated with myotoxicity risk. This study revealed Cynomolgus monkey may be a good animal model for myotoxicity evaluation with sensitivity, reproducibility and similarities to humans. More interestingly they exhibited a much higher incidence of myotoxicity than that of human. Sustained high drug concentration plays an important role for the occurrence of myotoxicity. This may suggest an influence of drug transport and metabolism on myotoxicity. PMID:19150455

  5. Relationship of mechanical impact magnitude to neurologic dysfunction severity in a rat traumatic brain injury model.

    Directory of Open Access Journals (Sweden)

    Tsung-Hsun Hsieh

    Full Text Available Traumatic brain injury (TBI is a major brain injury type commonly caused by traffic accidents, falls, violence, or sports injuries. To obtain mechanistic insights about TBI, experimental animal models such as weight-drop-induced TBI in rats have been developed to mimic closed-head injury in humans. However, the relationship between the mechanical impact level and neurological severity following weight-drop-induced TBI remains uncertain. In this study, we comprehensively investigated the relationship between physical impact and graded severity at various weight-drop heights.The acceleration, impact force, and displacement during the impact were accurately measured using an accelerometer, a pressure sensor, and a high-speed camera, respectively. In addition, the longitudinal changes in neurological deficits and balance function were investigated at 1, 4, and 7 days post TBI lesion. The inflammatory expression markers tested by Western blot analysis, including glial fibrillary acidic protein, beta-amyloid precursor protein, and bone marrow tyrosine kinase gene in chromosome X, in the frontal cortex, hippocampus, and corpus callosum were investigated at 1 and 7 days post-lesion.Gradations in impact pressure produced progressive degrees of injury severity in the neurological score and balance function. Western blot analysis demonstrated that all inflammatory expression markers were increased at 1 and 7 days post-impact injury when compared to the sham control rats. The severity of neurologic dysfunction and induction in inflammatory markers strongly correlated with the graded mechanical impact levels.We conclude that the weight-drop-induced TBI model can produce graded brain injury and induction of neurobehavioral deficits and may have translational relevance to developing therapeutic strategies for TBI.

  6. Myotoxicity of gemfibrozil in Cynomolgus monkey model and its relationship to pharmacokinetic properties

    International Nuclear Information System (INIS)

    Liu Aiming; Xie Shuilin; Sun He; Gonzalez, Frank J.; Wei Xiaoxiong; Dai Renke

    2009-01-01

    Fibrate drugs are PPARα agonists prescribed for the treatment of dyslipidemia. Severe myotoxicity has been reportedly associated with their use albeit at a low frequency, especially for gemfibrozil. Few studies have investigated the mechanism of fibrate-induced myotoxicity in vivo. Considering the apparent species-related differences in PPARα agonist-induced hepatotoxicity, we studied the myotoxicity of gemfibrozil in a Cynomolgus monkey model and explored the relationship between myotoxicity and pharmacokinetics. Six Cynomolgus monkeys were dosed with gemfibrozil twice daily at 600 mg/kg/day for the first two periods (P1 and P2, 8 days and 9 days respectively) and 300 mg/kg/day for the third period (P3, 14 days). Creatine kinase and myoglobin were measured, together with hepatotoxicity and nephrotoxicity markers. Behavioral responses were recorded for indication of toxicity. Pharmacokinetics was carried out following the 16th dosage of P1 and 17th dosage of P2 when myotoxicity was identified. Multivariable data analysis was employed to explore the relationship between pharmacokinetic parameters and myotoxicity markers. Consequently, myotoxicity occurred in monkey no. 2 (M2) and M6 in P1, M3 and M4 in P2, M3 and M6 in P3. Data analysis showed T80-150 (sustained time above the given concentration) contributed for myotoxicity discriminance and correlated with myotoxicity risk. This study revealed Cynomolgus monkey may be a good animal model for myotoxicity evaluation with sensitivity, reproducibility and similarities to humans. More interestingly, they exhibited a much higher incidence of myotoxicity than that of humans. Sustained high drug concentration plays an important role for the occurrence of myotoxicity. This may suggest an influence of drug transport and metabolism on myotoxicity

  7. Myotoxicity of gemfibrozil in Cynomolgus monkey model and its relationship to pharmacokinetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Aiming, Liu; Shuilin, Xie [Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510663 (China); He, Sun [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China); Gonzalez, Frank J [National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Xiaoxiong, Wei [Medpace, Inc., Cincinnati, OH 45212 (United States); Dai Renke [Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510663 (China)], E-mail: dai_renke@gibh.ac.cn

    2009-03-15

    Fibrate drugs are PPAR{alpha} agonists prescribed for the treatment of dyslipidemia. Severe myotoxicity has been reportedly associated with their use albeit at a low frequency, especially for gemfibrozil. Few studies have investigated the mechanism of fibrate-induced myotoxicity in vivo. Considering the apparent species-related differences in PPAR{alpha} agonist-induced hepatotoxicity, we studied the myotoxicity of gemfibrozil in a Cynomolgus monkey model and explored the relationship between myotoxicity and pharmacokinetics. Six Cynomolgus monkeys were dosed with gemfibrozil twice daily at 600 mg/kg/day for the first two periods (P1 and P2, 8 days and 9 days respectively) and 300 mg/kg/day for the third period (P3, 14 days). Creatine kinase and myoglobin were measured, together with hepatotoxicity and nephrotoxicity markers. Behavioral responses were recorded for indication of toxicity. Pharmacokinetics was carried out following the 16th dosage of P1 and 17th dosage of P2 when myotoxicity was identified. Multivariable data analysis was employed to explore the relationship between pharmacokinetic parameters and myotoxicity markers. Consequently, myotoxicity occurred in monkey no. 2 (M2) and M6 in P1, M3 and M4 in P2, M3 and M6 in P3. Data analysis showed T80-150 (sustained time above the given concentration) contributed for myotoxicity discriminance and correlated with myotoxicity risk. This study revealed Cynomolgus monkey may be a good animal model for myotoxicity evaluation with sensitivity, reproducibility and similarities to humans. More interestingly, they exhibited a much higher incidence of myotoxicity than that of humans. Sustained high drug concentration plays an important role for the occurrence of myotoxicity. This may suggest an influence of drug transport and metabolism on myotoxicity.

  8. Modeling Chemical Interaction Profiles: I. Spectral Data-Activity Relationship and Structure-Activity Relationship Models for Inhibitors and Non-inhibitors of Cytochrome P450 CYP3A4 and CYP2D6 Isozymes

    OpenAIRE

    McPhail, Brooks; Tie, Yunfeng; Hong, Huixiao; Pearce, Bruce A.; Schnackenberg, Laura K.; Ge, Weigong; Valerio, Luis G.; Fuscoe, James C.; Tong, Weida; Buzatu, Dan A.; Wilkes, Jon G.; Fowler, Bruce A.; Demchuk, Eugene; Beger, Richard D.

    2012-01-01

    An interagency collaboration was established to model chemical interactions that may cause adverse health effects when an exposure to a mixture of chemicals occurs. Many of these chemicals—drugs, pesticides, and environmental pollutants—interact at the level of metabolic biotransformations mediated by cytochrome P450 (CYP) enzymes. In the present work, spectral data-activity relationship (SDAR) and structure-activity relationship (SAR) approaches were used to develop machine-learning classifi...

  9. Quantitative structure-activity relationship modeling of the toxicity of organothiophosphate pesticides to Daphnia magna and Cyprinus carpio

    NARCIS (Netherlands)

    Zvinavashe, E.; Du, T.; Griff, T.; Berg, van den J.H.J.; Soffers, A.E.M.F.; Vervoort, J.J.M.; Murk, A.J.; Rietjens, I.

    2009-01-01

    Within the REACH regulatory framework in the EU, quantitative structure-activity relationships (QSAR) models are expected to help reduce the number of animals used for experimental testing. The objective of this study was to develop QSAR models to describe the acute toxicity of organothiophosphate

  10. Using the Expectancy Value Model of Motivation to Understand the Relationship between Student Attitudes and Achievement in Statistics

    Science.gov (United States)

    Hood, Michelle; Creed, Peter A.; Neumann, David L.

    2012-01-01

    We tested a model of the relationship between attitudes toward statistics and achievement based on Eccles' Expectancy Value Model (1983). Participants (n = 149; 83% female) were second-year Australian university students in a psychology statistics course (mean age = 23.36 years, SD = 7.94 years). We obtained demographic details, past performance,…

  11. Expression model for multiple relationships in the ontology of traditional Chinese medicine knowledge

    Directory of Open Access Journals (Sweden)

    Mingyue Gao

    2016-01-01

    Conclusion: When applied in TCM, the semantic relationships constructed by Protégé are superior than those constructed by correlation and/or attribute relationships, but less ideal than those constructed by the human cognitive process.

  12. Exploring Coworker Relationships: Antecedents and Dimensions of Interpersonal Fit, Coworker Satisfaction, and Relational Models

    NARCIS (Netherlands)

    E.K. Byington (Eliza)

    2013-01-01

    textabstractManagement scholarship has revealed the myriad ways in which relationships between coworkers impact individual, team, and organizational phenomena. However, our scientific understanding of coworker relationships and what makes for satisfying connections with colleagues is still in its

  13. Relationships between southeastern Australian rainfall and sea surface temperatures examined using a climate model

    Science.gov (United States)

    Watterson, I. G.

    2010-05-01

    Rainfall in southeastern Australia has declined in recent years, particularly during austral autumn over the state of Victoria. A recent study suggests that sea surface temperature (SST) variations in both the Indonesian Throughflow (ITF) region and in a meridional dipole in the central Indian Ocean have influenced Victorian late autumn rainfall since 1950. However, it remains unclear to what extent SSTs in these and other regions force such a teleconnection. Analysis of a 1080 year simulation by the climate model CSIRO Mk3.5 shows that the model Victorian rainfall is correlated rather realistically with SSTs but that part of the above relationships is due to the model ENSO. Furthermore, the remote patterns of pressure, rainfall, and land temperature greatly diminish when the data are lagged by 1 month, suggesting that the true forcing by the persisting SSTs is weak. In a series of simulations of the atmospheric Mk3.5 with idealized SST anomalies, raised SSTs to the east of Indonesia lower the simulated Australian rainfall, while those to the west raise it. A positive ITF anomaly lowers pressure over Australia, but with little effect on Victorian rainfall. The meridional dipole and SSTs to the west and southeast of Australia have little direct effect on southeastern Australia in the model. The results suggest that tropical SSTs predominate as an influence on Victorian rainfall. However, the SST indices appear to explain only a fraction of the observed trend, which in the case of decadal means remains within the range of unforced variability simulated by Mk3.5.

  14. A Moderated Mediation Model of the Relationship between Organizational Citizenship Behaviors and Job Performance

    Science.gov (United States)

    Ozer, Muammer

    2011-01-01

    Addressing numerous calls for future research on understanding the theoretical mechanisms that explain the relationship between organizational citizenship behaviors (OCBs) and job performance, this study focused on how an employee's relationships with coworkers mediate the relationship between his or her OCBs and his or her job performance. It…

  15. Modeling relationships between physical fitness, executive functioning, and academic achievement in primary school children

    NARCIS (Netherlands)

    van der Niet, Anneke G.; Hartman, Esther; Smith, Joanne; Visscher, Chris

    Objectives: The relationship between physical fitness and academic achievement in children has received much attention, however, whether executive functioning plays a mediating role in this relationship is unclear. The aim of this study therefore was to investigate the relationships between physical

  16. The relationships between behavioral addictions and the five-factor model of personality.

    Science.gov (United States)

    Andreassen, Cecilie Schou; Griffiths, Mark D; Gjertsen, Siri Renate; Krossbakken, Elfrid; Kvam, Siri; Pallesen, Ståle

    2013-06-01

    Aims Although relationships between addiction and personality have previously been explored, no study has ever simultaneously investigated the interrelationships between several behavioral addictions, and related these to the main dimensions of the five-factor model of personality. Methods In this study, 218 university students completed questionnaires assessing seven different behavioral addictions (i.e., Facebook addiction, video game addiction, Internet addiction, exercise addiction, mobile phone addiction, compulsive buying, and study addiction) as well as an instrument assessing the main dimensions of the five-factor model of personality. Results Of the 21 bivariate intercorrelations between the seven behavioral addictions, all were positive (and nine significantly). The results also showed that (i) Neuroticism was positively associated with Internet addiction, exercise addiction, compulsive buying, and study addiction, (ii) Extroversion was positively associated with Facebook addiction, exercise addiction, mobile phone addiction, and compulsive buying, (iii) Openness to experience was negatively associated with Facebook addiction and mobile phone addiction, (iv) Agreeableness was negatively associated with Internet addiction, exercise addiction, mobile phone addiction, and compulsive buying, and (v) Conscientiousness was negatively associated with Facebook addiction, video game addiction, Internet addiction, and compulsive buying and positively associated with exercise addiction and study addiction. Conclusions The positive associations between the seven behavioral addictions suggest one or several underlying pathological factors. Hierarchical multiple regressions showed that personality traits explained between 6% and 17% of the variance in the seven behavioral addictions, suggesting that personality to a varying degree explains scores on measures of addictive behaviors.

  17. Accounting for Trust: A Conceptual Model for the Determinants of Trust in the Australian Public Accountant – SME Client Relationship

    Directory of Open Access Journals (Sweden)

    Michael Cherry

    2016-06-01

    Full Text Available This paper investigates trust as it relates to the relationship between Australia’s public accountants and their SME clients. It describes the contribution of the accountancy profession to the SME market, as well as the key challenges faced by accountants and their SME clients. Following the review of prior scholarly studies, a working definition of trust as it relates to this important relationship is also developed and presented. A further consequence of prior academic work is the development of a comprehensive conceptual model to describe the determinants of trust in the Australian public accountant – SME client relationship, which requires testing via empirical studies.

  18. On the Development and Use of Large Chemical Similarity Networks, Informatics Best Practices and Novel Chemical Descriptors Towards Materials Quantitative Structure Property Relationships

    Science.gov (United States)

    Krein, Michael

    After decades of development and use in a variety of application areas, Quantitative Structure Property Relationships (QSPRs) and related descriptor-based statistical learning methods have achieved a level of infamy due to their misuse. The field is rife with past examples of overtrained models, overoptimistic performance assessment, and outright cheating in the form of explicitly removing data to fit models. These actions do not serve the community well, nor are they beneficial to future predictions based on established models. In practice, in order to select combinations of descriptors and machine learning methods that might work best, one must consider the nature and size of the training and test datasets, be aware of existing hypotheses about the data, and resist the temptation to bias structure representation and modeling to explicitly fit the hypotheses. The definition and application of these best practices is important for obtaining actionable modeling outcomes, and for setting user expectations of modeling accuracy when predicting the endpoint values of unknowns. A wide variety of statistical learning approaches, descriptor types, and model validation strategies are explored herein, with the goals of helping end users understand the factors involved in creating and using QSPR models effectively, and to better understand relationships within the data, especially by looking at the problem space from multiple perspectives. Molecular relationships are commonly envisioned in a continuous high-dimensional space of numerical descriptors, referred to as chemistry space. Descriptor and similarity metric choice influence the partitioning of this space into regions corresponding to local structural similarity. These regions, known as domains of applicability, are most likely to be successfully modeled by a QSPR. In Chapter 2, the network topology and scaling relationships of several chemistry spaces are thoroughly investigated. Chemistry spaces studied include the

  19. Gut Microbiota and a Selectively Bred Taste Phenotype: A Novel Model of Microbiome-Behavior Relationships.

    Science.gov (United States)

    Lyte, Mark; Fodor, Anthony A; Chapman, Clinton D; Martin, Gary G; Perez-Chanona, Ernesto; Jobin, Christian; Dess, Nancy K

    2016-06-01

    The microbiota-gut-brain axis is increasingly implicated in obesity, anxiety, stress, and other health-related processes. Researchers have proposed that gut microbiota may influence dietary habits, and pathways through the microbiota-gut-brain axis make such a relationship feasible; however, few data bear on the hypothesis. As a first step in the development of a model system, the gut microbiome was examined in rat lines selectively outbred on a taste phenotype with biobehavioral profiles that have diverged with respect to energy regulation, anxiety, and stress. Occidental low and high-saccharin-consuming rats were assessed for body mass and chow, water, and saccharin intake; littermate controls had shared cages with rats in the experimental group but were not assessed. Cecum and colon microbial communities were profiled using Illumina 16S rRNA sequencing and multivariate analysis of microbial diversity and composition. The saccharin phenotype was confirmed (low-saccharin-consuming rats, 0.7Δ% [0.9Δ%]; high-saccharin-consuming rats, 28.1Δ% [3.6Δ%]). Regardless of saccharin exposure, gut microbiota differed between lines in terms of overall community similarity and taxa at lower phylogenetic levels. Specifically, 16 genera in three phyla distinguished the lines at a 10% false discovery rate. The study demonstrates for the first time that rodent lines created through selective pressure on taste and differing on functionally related correlates host different microbial communities. Whether the microbiota are causally related to the taste phenotype or its correlates remains to be determined. These findings encourage further inquiry on the relationship of the microbiome to taste, dietary habits, emotion, and health.

  20. Modelling relationships between match events and match outcome in elite football.

    Science.gov (United States)

    Liu, Hongyou; Hopkins, Will G; Gómez, Miguel-Angel

    2016-08-01

    Identifying match events that are related to match outcome is an important task in football match analysis. Here we have used generalised mixed linear modelling to determine relationships of 16 football match events and 1 contextual variable (game location: home/away) with the match outcome. Statistics of 320 close matches (goal difference ≤ 2) of season 2012-2013 in the Spanish First Division Professional Football League were analysed. Relationships were evaluated with magnitude-based inferences and were expressed as extra matches won or lost per 10 close matches for an increase of two within-team or between-team standard deviations (SD) of the match event (representing effects of changes in team values from match to match and of differences between average team values, respectively). There was a moderate positive within-team effect from shots on target (3.4 extra wins per 10 matches; 99% confidence limits ±1.0), and a small positive within-team effect from total shots (1.7 extra wins; ±1.0). Effects of most other match events were related to ball possession, which had a small negative within-team effect (1.2 extra losses; ±1.0) but a small positive between-team effect (1.7 extra wins; ±1.4). Game location showed a small positive within-team effect (1.9 extra wins; ±0.9). In analyses of nine combinations of team and opposition end-of-season rank (classified as high, medium, low), almost all between-team effects were unclear, while within-team effects varied depending on the strength of team and opposition. Some of these findings will be useful to coaches and performance analysts when planning training sessions and match tactics.

  1. Dynamic relationships between microbial biomass, respiration, inorganic nutrients and enzyme activities: informing enzyme based decomposition models

    Directory of Open Access Journals (Sweden)

    Daryl L Moorhead

    2013-08-01

    Full Text Available We re-examined data from a recent litter decay study to determine if additional insights could be gained to inform decomposition modeling. Rinkes et al. (2013 conducted 14-day laboratory incubations of sugar maple (Acer saccharum or white oak (Quercus alba leaves, mixed with sand (0.4% organic C content or loam (4.1% organic C. They measured microbial biomass C, carbon dioxide efflux, soil ammonium, nitrate, and phosphate concentrations, and β-glucosidase (BG, β-N-acetyl-glucosaminidase (NAG, and acid phosphatase (AP activities on days 1, 3, and 14. Analyses of relationships among variables yielded different insights than original analyses of individual variables. For example, although respiration rates per g soil were higher for loam than sand, rates per g soil C were actually higher for sand than loam, and rates per g microbial C showed little difference between treatments. Microbial biomass C peaked on day 3 when biomass-specific activities of enzymes were lowest, suggesting uptake of litter C without extracellular hydrolysis. This result refuted a common model assumption that all enzyme production is constitutive and thus proportional to biomass, and/or indicated that part of litter decay is independent of enzyme activity. The length and angle of vectors defined by ratios of enzyme activities (BG/NAG versus BG/AP represent relative microbial investments in C (length, and N and P (angle acquiring enzymes. Shorter lengths on day 3 suggested low C limitation, whereas greater lengths on day 14 suggested an increase in C limitation with decay. The soils and litter in this study generally had stronger P limitation (angles > 45˚. Reductions in vector angles to < 45˚ for sand by day 14 suggested a shift to N limitation. These relational variables inform enzyme-based models, and are usually much less ambiguous when obtained from a single study in which measurements were made on the same samples than when extrapolated from separate studies.

  2. The rat intervertebral disk degeneration pain model: relationships between biological and structural alterations and pain.

    Science.gov (United States)

    Kim, Jae-Sung; Kroin, Jeffrey S; Li, Xin; An, Howard S; Buvanendran, Asokumar; Yan, Dongyao; Tuman, Kenneth J; van Wijnen, Andre J; Chen, Di; Im, Hee-Jeong

    2011-01-01

    Degeneration of the interverterbral disk is as a cause of low-back pain is increasing. To gain insight into relationships between biological processes, structural alterations and behavioral pain, we created an animal model in rats. Disk degeneration was induced by removal of the nucleus pulposus (NP) from the lumbar disks (L4/L5 and L5/L6) of Sprague Dawley rats using a 0.5-mm-diameter microsurgical drill. The degree of primary hyperalgesia was assessed by using an algometer to measure pain upon external pressure on injured lumbar disks. Biochemical and histological assessments and radiographs of injured disks were used for evaluation. We investigated therapeutic modulation of chronic pain by administering pharmaceutical drugs in this animal model. After removal of the NP, pressure hyperalgesia developed over the lower back. Nine weeks after surgery we observed damaged or degenerated disks with proteoglycan loss and narrowing of disk height. These biological and structural changes in disks were closely related to the sustained pain hyperalgesia. A high dose of morphine (6.7 mg/kg) resulted in effective pain relief. However, high doses of pregabalin (20 mg/kg), a drug that has been used for treatment of chronic neuropathic pain, as well as the anti-inflammatory drugs celecoxib (50 mg/kg; a selective inhibitor of cyclooxygenase 2 (COX-2)) and ketorolac (20 mg/kg; an inhibitor of COX-1 and COX-2), did not have significant antihyperalgesic effects in our disk injury animal model. Although similarities in gene expression profiles suggest potential overlap in chronic pain pathways linked to disk injury or neuropathy, drug-testing results suggest that pain pathways linked to these two chronic pain conditions are mechanistically distinct. Our findings provide a foundation for future research on new therapeutic interventions that can lead to improvements in the treatment of patients with back pain due to disk degeneration.

  3. Understanding the relationship between Kano model's customer satisfaction scores and self-stated requirements importance.

    Science.gov (United States)

    Mkpojiogu, Emmanuel O C; Hashim, Nor Laily

    2016-01-01

    Customer satisfaction is the result of product quality and viability. The place of the perceived satisfaction of users/customers for a software product cannot be neglected especially in today competitive market environment as it drives the loyalty of customers and promotes high profitability and return on investment. Therefore understanding the importance of requirements as it is associated with the satisfaction of users/customers when their requirements are met is worth the pain considering. It is necessary to know the relationship between customer satisfactions when their requirements are met (or their dissatisfaction when their requirements are unmet) and the importance of such requirement. So many works have been carried out on customer satisfaction in connection with the importance of requirements but the relationship between customer satisfaction scores (coefficients) of the Kano model and users/customers self-stated requirements importance have not been sufficiently explored. In this study, an attempt is made to unravel the underlying relationship existing between Kano model's customer satisfaction indexes and users/customers self reported requirements importance. The results of the study indicate some interesting associations between these considered variables. These bivariate associations reveal that customer satisfaction index (SI), and average satisfaction coefficient (ASC) and customer dissatisfaction index (DI) and average satisfaction coefficient (ASC) are highly correlated (r = 96 %) and thus ASC can be used in place of either SI or DI in representing customer satisfaction scores. Also, these Kano model's customer satisfaction variables (SI, DI, and ASC) are each associated with self-stated requirements importance (IMP). Further analysis indicates that the value customers or users place on requirements that are met or on features that are incorporated into a product influences the level of satisfaction such customers derive from the product. The

  4. ETHICAL MODELS OF PHYSICIAN--PATIENT RELATIONSHIP REVISITED WITH REGARD TO PATIENT AUTONOMY, VALUES AND PATIENT EDUCATION.

    Science.gov (United States)

    Borza, Liana Rada; Gavrilovici, Cristina; Stockman, René

    2015-01-01

    The present paper revisits the ethical models of patient--physician relationship from the perspective of patient autonomy and values. It seems that the four traditional models of physician--patient relationship proposed by Emanuel & Emanuel in 1992 closely link patient values and patient autonomy. On the other hand, their reinterpretation provided by Agarwal & Murinson twenty years later emphasizes the independent expression of values and autonomy in individual patients. Additionally, patient education has been assumed to join patient values and patient autonomy. Moreover, several authors have noted that, over the past few decades, patient autonomy has gradually replaced the paternalistic approach based on the premise that the physician knows what is best for the patient. Neither the paternalistic model of physician-patient relationship, nor the informative model is considered to be satisfactory, as the paternalistic model excludes patient values from decision making, while the informative model excludes physician values from decision making. However, the deliberative model of patient-physician interaction represents an adequate alternative to the two unsatisfactory approaches by promoting shared decision making between the physician and the patient. It has also been suggested that the deliberative model would be ideal for exercising patient autonomy in chronic care and that the ethical role of patient education would be to make the deliberative model applicable to chronic care. In this regard, studies have indicated that the use of decision support interventions might increase the deliberative capacity of chronic patients.

  5. Leaving an Abusive Dating Relationship: A Prospective Analysis of the Investment Model and Theory of Planned Behavior.

    Science.gov (United States)

    Edwards, Katie M; Gidycz, Christine A; Murphy, Megan J

    2015-10-01

    The purpose of the current study was to build on the existing literature to better understand young women's leaving processes in abusive dating relationships using a prospective design. Two social psychological models-the investment model and theory of planned behavior-were tested. According to the investment model, relationship continuation is predicted by commitment, which is a function of investment, satisfaction, and low quality of alternatives. The theory of planned behavior asserts that a specific behavior is predicted by an individual's intention to use a behavior, which is a function of the individual's attitudes toward the behavior, the subjective norms toward the behavior, and the individual's perceived behavioral control over the behavior. College women (N = 169 young women in abusive relatinships) completed surveys at two time points, approximately 4 months apart, to assess initially for the presence of intimate partner violence (IPV) in a current relationship and investment model and theory of planned behavior variables; the purpose of the 4-month follow-up session was to determine if women had remained in or terminated their abusive relationship. Path analytic results demonstrated that both the theory of planned behavior and investment models were good fits to the data in prospectively predicting abused women's stay/leave decisions. However, the theory of planned behavior was a better fit to the data than the investment model. Implications for future research and intervention are discussed. © The Author(s) 2014.

  6. A Bowen Family Systems Model of Generalized Anxiety Disorder and Romantic Relationship Distress.

    Science.gov (United States)

    Priest, Jacob B

    2015-07-01

    Many individuals with generalized anxiety disorder (GAD) do not respond well to currently available treatments. Moreover, treatments are less effective when GAD is accompanied by romantic relationship distress. In order to develop effective treatments for GAD and relationship distress, it is necessary to conduct theory-based research to identify links common to both GAD and romantic relationship distress. Drawing on Bowen's family systems theory, the roles of family abuse/violence and differentiation in GAD and romantic relationship distress were examined using existing data from the National Comorbidity Survey Replication (n = 2,312; 2005). As predicted, family abuse/violence was directly linked to both GAD and romantic relationship distress. Differentiation mediated the relationship between family abuse/violence and GAD, and partially mediated the relationship between family abuse/violence and romantic relationship distress. Findings suggest that current and past relationship processes may help maintain chronic anxiety and that Bowen's theory may be a useful framework for developing couple therapy treatment of GAD and romantic relationship distress. © 2013 American Association for Marriage and Family Therapy.

  7. Coupling Longitudinal Data and Multilevel Modeling to Examine the Antecedents and Consequences of Jealousy Experiences in Romantic Relationships: A Test of the Relational Turbulence Model

    Science.gov (United States)

    Theiss, Jennifer A.; Solomon, Denise Haunani

    2006-01-01

    We used longitudinal data and multilevel modeling to examine how intimacy, relational uncertainty, and failed attempts at interdependence influence emotional, cognitive, and communicative responses to romantic jealousy, and how those experiences shape subsequent relationship characteristics. The relational turbulence model (Solomon & Knobloch,…

  8. Analisis & Perumusan Fitur Aplikasi Sms-marketing Berdasarkan Customer Relationship Management Model

    OpenAIRE

    Wijaya, Sidiq Wahyu Surya; Laksito, Arif Dwi

    2015-01-01

    The growth of Micro, Small and Medium Enterprises (UMKM) in Indonesia is very rapid. However, in terms of Customer Relationship Management, it is still few of UMKM which actually implement it. In fact, it can ensure that all customers have/use a mobile phone, either a normal mobile phone or smartphone, which should be used for the purposes of customer relationship management (Customer Relationship Management). One of these is the use of SMS (Short Message Services) technplogy. Therefore, in ...

  9. On the Relationship between Aquatic Plant Stem Characteristics and Drag Force: Is a Modeling Application Possible?

    Directory of Open Access Journals (Sweden)

    Anna Maria Łoboda

    2018-04-01

    Full Text Available This paper presents a basic model that shows the relationship between the diameter of a stem and its flexural rigidity. The model was developed from experimental measurements of biomechanical traits (i.e., tensile and bending traits like maximum forces, stresses, moduli of elasticity, flexural rigidity, strain of three freshwater macrophyte species (Elodea canadensis Michx., Potamogeton pectinatus L., and P. crispus L., reflecting the seasonal changes in plant biomechanics throughout the vegetative season. These were obtained with the use of a bench-top testing machine in 2016 and 2017. The presented calculations are based on the ratio of drag-to-bending forces, in which the flexural rigidity plays a key role. The proposed model has the form EI = adb, and two approaches based on a regression analysis were applied to determine the parameters of the model—a and b. In the first method, the parameters were identified separately for each day of measurement, while in the second method, the coefficient b was calculated for all data from all days as a unified number for individual plants. The results suggest that coefficient b may provide information about the proportion of changes in drag forces depending on plant stiffness. The values of this coefficient were associated with the shape of the stem cross-section. The more circular the cross-section, the closer the value of the parameter was to 1. The parameter values were 1.60 for E. canadensis, 1.98 for P. pectinatus, and 2.46 for P. crispus. Moreover, this value also depended on the density of the cross-section structure. Most of the results showed that with an increase in stem diameter, the ratio between the drag and bending forces decreased, which led to fewer differences between these two forces. The model application may be introduced in many laboratory measurements of flow–biota interactions as well as in aquatic plant management applications. The implementation of these results in control

  10. Assessing the toxic effects of ethylene glycol ethers using Quantitative Structure Toxicity Relationship models

    International Nuclear Information System (INIS)

    Ruiz, Patricia; Mumtaz, Moiz; Gombar, Vijay

    2011-01-01

    Experimental determination of toxicity profiles consumes a great deal of time, money, and other resources. Consequently, businesses, societies, and regulators strive for reliable alternatives such as Quantitative Structure Toxicity Relationship (QSTR) models to fill gaps in toxicity profiles of compounds of concern to human health. The use of glycol ethers and their health effects have recently attracted the attention of international organizations such as the World Health Organization (WHO). The board members of Concise International Chemical Assessment Documents (CICAD) recently identified inadequate testing as well as gaps in toxicity profiles of ethylene glycol mono-n-alkyl ethers (EGEs). The CICAD board requested the ATSDR Computational Toxicology and Methods Development Laboratory to conduct QSTR assessments of certain specific toxicity endpoints for these chemicals. In order to evaluate the potential health effects of EGEs, CICAD proposed a critical QSTR analysis of the mutagenicity, carcinogenicity, and developmental effects of EGEs and other selected chemicals. We report here results of the application of QSTRs to assess rodent carcinogenicity, mutagenicity, and developmental toxicity of four EGEs: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol and their metabolites. Neither mutagenicity nor carcinogenicity is indicated for the parent compounds, but these compounds are predicted to be developmental toxicants. The predicted toxicity effects were subjected to reverse QSTR (rQSTR) analysis to identify structural attributes that may be the main drivers of the developmental toxicity potential of these compounds.

  11. A molecular modeling approach to understand the structure and conformation relationship of (GlcpA)Xylan.

    Science.gov (United States)

    Guo, Qingbin; Kang, Ji; Wu, Yan; Cui, Steve W; Hu, Xinzhong; Yada, Rickey Y

    2015-12-10

    The structure and conformation relationships of a heteropolysaccharide (GlcpA)Xylan in terms of various molecular weights, Xylp/GlcpA ratio and the distribution of GlcpA along xylan chain were investigated using computer modeling. The adiabatic contour maps of xylobiose, XylpXylp(GlcpA) and (GlcpA)XylpXylp(GlcpA) indicated that the insertion of the side group (GlcpA) influenced the accessible conformational space of xylobiose molecule. RIS-Metropolis Monte Carlo method indicated that insertion of GlcpA side chain induced a lowering effect of the calculated chain extension at low GlcpA:Xylp ratio (GlcpA:Xylp = 1:3). The chain, however, became extended when the ratio of GlcpA:Xylp above 2/3. It was also shown that the spatial extension of the polymer chains was dependent on the distribution of side chain: the random distribution demonstrated the most flexible structure compared to block and alternative distribution. The present studies provide a unique insight into the dependence of both side chain ratio and distribution on the stiffness and flexibility of various (GlcpA)Xylan molecules. Copyright © 2015. Published by Elsevier Ltd.

  12. Compound toxicity screening and structure-activity relationship modeling in Escherichia coli.

    Science.gov (United States)

    Planson, Anne-Gaëlle; Carbonell, Pablo; Paillard, Elodie; Pollet, Nicolas; Faulon, Jean-Loup

    2012-03-01

    Synthetic biology and metabolic engineering are used to develop new strategies for producing valuable compounds ranging from therapeutics to biofuels in engineered microorganisms. When developing methods for high-titer production cells, toxicity is an important element to consider. Indeed the production rate can be limited due to toxic intermediates or accumulation of byproducts of the heterologous biosynthetic pathway of interest. Conversely, highly toxic molecules are desired when designing antimicrobials. Compound toxicity in bacteria plays a major role in metabolic engineering as well as in the development of new antibacterial agents. Here, we screened a diversified chemical library of 166 compounds for toxicity in Escherichia coli. The dataset was built using a clustering algorithm maximizing the chemical diversity in the library. The resulting assay data was used to develop a toxicity predictor that we used to assess the toxicity of metabolites throughout the metabolome. This new tool for predicting toxicity can thus be used for fine-tuning heterologous expression and can be integrated in a computational-framework for metabolic pathway design. Many structure-activity relationship tools have been developed for toxicology studies in eukaryotes [Valerio (2009), Toxicol Appl Pharmacol, 241(3): 356-370], however, to the best of our knowledge we present here the first E. coli toxicity prediction web server based on QSAR models (EcoliTox server: http://www.issb.genopole.fr/∼faulon/EcoliTox.php). Copyright © 2011 Wiley Periodicals, Inc.

  13. Combining region- and network-level brain-behavior relationships in a structural equation model.

    Science.gov (United States)

    Bolt, Taylor; Prince, Emily B; Nomi, Jason S; Messinger, Daniel; Llabre, Maria M; Uddin, Lucina Q

    2018-01-15

    Brain-behavior associations in fMRI studies are typically restricted to a single level of analysis: either a circumscribed brain region-of-interest (ROI) or a larger network of brain regions. However, this common practice may not always account for the interdependencies among ROIs of the same network or potentially unique information at the ROI-level, respectively. To account for both sources of information, we combined measurement and structural components of structural equation modeling (SEM) approaches to empirically derive networks from ROI activity, and to assess the association of both individual ROIs and their respective whole-brain activation networks with task performance using three large task-fMRI datasets and two separate brain parcellation schemes. The results for working memory and relational tasks revealed that well-known ROI-performance associations are either non-significant or reversed when accounting for the ROI's common association with its corresponding network, and that the network as a whole is instead robustly associated with task performance. The results for the arithmetic task revealed that in certain cases, an ROI can be robustly associated with task performance, even when accounting for its associated network. The SEM framework described in this study provides researchers additional flexibility in testing brain-behavior relationships, as well as a principled way to combine ROI- and network-levels of analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Exploring the relationship between socioeconomic status, control beliefs and exercise behavior: a multiple mediator model.

    Science.gov (United States)

    Murray, Terra C; Rodgers, Wendy M; Fraser, Shawn N

    2012-02-01

    The purpose of this study was to examine the relationship between control beliefs, socioeconomic status and exercise intentions and behavior. Specifically, we examined whether distal and proximal control beliefs mediated the association between socioeconomic status and exercise intentions and behavior. A one time, cross sectional mail out survey (N = 350) was conducted in a large urban Canadian city. Distal (i.e., personal constraints) and proximal (i.e., scheduling self-efficacy) control beliefs mediated the association between socioeconomic status and exercise, explaining approximately 30% of the variance. Proximal control beliefs (i.e., scheduling self-efficacy) partially mediated the association between socioeconomic status and intentions, with the models explaining approximately 50% of the variance. Compared to individuals with lower socioeconomic status, individuals with higher socioeconomic status reported more exercise and stronger intentions to exercise. This was at least partly because higher socioeconomic status respondents reported fewer barriers in their lives, and were more confident to cope with the scheduling demands of exercise.

  15. A novel complex model of hemodialysis adequacy: Predictive value and relationship with malnutrition inflammation score

    Directory of Open Access Journals (Sweden)

    Vlatković Vlastimir

    2017-01-01

    Full Text Available Target dialysis dose to ensure the best patient outcome is still a matter of debate. Traditional models have a number of limitations and do not comprehensively reflect all factors involved. In this study we present a new complex model of dialysis adequacy, the hemodialysis adequacy score (HAS, and evaluate its prognostic value, as well as its relationship with the malnutrition-inflammation score (MIS. The components of HAS included paradigms of the 6 major factors known to influence the outcome of hemodialysis (HD patients: the modified Karnofsky index (KI, the Charlson comorbidity index (CCI, Kt/V and URR measures of dialysis dose, body mass index (BMI and serum albumin level, serum levels of hemoglobin and ferritin, intact parathyroid hormone (iPTH and calciumphosphorus solubility product. The score was evaluated in a 24-month prospective study on 147 HD patients. Odds ratio analysis showed that hospitalized patients had twice the chance to have HAS >13 compared to those who were not hospitalized during the study period (OR=2.152, CI 95% (1.0024- 4.619. Mortality rate was significantly higher in patients with a HAS >13 at the 12-month follow-up (χ2=16.416, p 13 had significantly higher probability of death (log-rank Cox- Mantel=17.920, df=1, p <0.00023. The HAS directly and significantly correlated with the MIS at all measurements (p <0.0001. Results confirmed that the HAS is a useful tool to assess dialysis adequacy with a good prognostic value. The cutoff level for the HAS at 13 points was associated with an unfavorable outcome.

  16. Quantifying statistical relationships between commonly used in vitro models for estimating lead bioaccessibility.

    Science.gov (United States)

    Yan, Kaihong; Dong, Zhaomin; Liu, Yanju; Naidu, Ravi

    2016-04-01

    Bioaccessibility to assess potential risks resulting from exposure to Pb-contaminated soils is commonly estimated using various in vitro methods. However, existing in vitro methods yield different results depending on the composition of the extractant as well as the contaminated soils. For this reason, the relationships between the five commonly used in vitro methods, the Relative Bioavailability Leaching Procedure (RBALP), the unified BioAccessibility Research Group Europe (BARGE) method (UBM), the Solubility Bioaccessibility Research Consortium assay (SBRC), a Physiologically Based Extraction Test (PBET), and the in vitro Digestion Model (RIVM) were quantified statistically using 10 soils from long-term Pb-contaminated mining and smelter sites located in Western Australia and South Australia. For all 10 soils, the measured Pb bioaccessibility regarding all in vitro methods varied from 1.9 to 106% for gastric phase, which is higher than that for intestinal phase: 0.2 ∼ 78.6%. The variations in Pb bioaccessibility depend on the in vitro models being used, suggesting that the method chosen for bioaccessibility assessment must be validated against in vivo studies prior to use for predicting risk. Regression studies between RBALP and SRBC, RBALP and RIVM (0.06) (0.06 g of soil in each tube, S:L ratios for gastric phase and intestinal phase are 1:375 and 1:958, respectively) showed that Pb bioaccessibility based on the three methods were comparable. Meanwhile, the slopes between RBALP and UBM, RBALP and RIVM (0.6) (0.6 g soil in each tube, S:L ratios for gastric phase and intestinal phase are 1:37.5 and 1:96, respectively) were 1.21 and 1.02, respectively. The findings presented in this study could help standardize in vitro bioaccessibility measurements and provide a scientific basis for further relating Pb bioavailability and soil properties.

  17. Analysis of the Attachment-Aversion Model of Consumer-brand Relationships in a Different Cultural Background

    Directory of Open Access Journals (Sweden)

    Veranika Novik

    2017-09-01

    Full Text Available Originally the Attachment-Aversion model of consumer-brand relationships, elaborated by Park, Eisingerich & Park in 2013, was analyzed with the help of the sample of English speaking respondents, living in Great Britain and the USA, and focused on two brands: Manchester United Football Club and Apple iPhone. The present study tries to validate the model regarding other type of brand and in conditions of another cultural background. The focal brand for the study was chosen from a high-end beauty category (Chanel. For the purposes of this research, a questionnaire was designed and spread online within the target population: the current students and alumni of Belarusian universities that are Russian/speaking, fluent in English and had a class in branding. A total of 273 responses was analysed using structural equation modelling. The outcomes of the research have shown that the Attachment-Aversion model of consumer-brand relationships has not proven to be totally versatile, while applied in the conditions of the other cultural background as some of the relationships of the model have shown to be insignificant. The enticing determinant has no effect on brand attachment relationship and the enabling determinant has no effect on the brand prominence. The implications of the findings are discussed.

  18. Analysis of albedo versus cloud fraction relationships in liquid water clouds using heuristic models and large eddy simulation

    Science.gov (United States)

    Feingold, Graham; Balsells, Joseph; Glassmeier, Franziska; Yamaguchi, Takanobu; Kazil, Jan; McComiskey, Allison

    2017-07-01

    The relationship between the albedo of a cloudy scene A and cloud fraction fc is studied with the aid of heuristic models of stratocumulus and cumulus clouds. Existing work has shown that scene albedo increases monotonically with increasing cloud fraction but that the relationship varies from linear to superlinear. The reasons for these differences in functional dependence are traced to the relationship between cloud deepening and cloud widening. When clouds deepen with no significant increase in fc (e.g., in solid stratocumulus), the relationship between A and fc is linear. When clouds widen as they deepen, as in cumulus cloud fields, the relationship is superlinear. A simple heuristic model of a cumulus cloud field with a power law size distribution shows that the superlinear A-fc behavior is traced out either through random variation in cloud size distribution parameters or as the cloud field oscillates between a relative abundance of small clouds (steep slopes on a log-log plot) and a relative abundance of large clouds (flat slopes). Oscillations of this kind manifest in large eddy simulation of trade wind cumulus where the slope and intercept of the power law fit to the cloud size distribution are highly correlated. Further analysis of the large eddy model-generated cloud fields suggests that cumulus clouds grow larger and deeper as their underlying plumes aggregate; this is followed by breakup of large plumes and a tendency to smaller clouds. The cloud and thermal size distributions oscillate back and forth approximately in unison.

  19. A Structural Model of Depression Based on Interpersonal Relationships: The Mediating Role of Coping Strategies and Loneliness.

    Science.gov (United States)

    Majd Ara, Elahe; Talepasand, Siavash; Rezaei, Ali Mohammad

    2017-06-01

    The present study was conducted with the aim of examining the structural model of interpersonal relationships and depression using coping strategies and loneliness as mediators. Using multistage random sampling, 301 high-school students were selected from Minudasht city, Iran. The participants were aksed to complete the Network of Relationships Inventory (NRI); the Ways of Coping Questionnaire (Lazarus and Folkman); the Children's Loneliness Scale (CLS); and the Depression, Anxiety, and Stress Scale (DASS-21). Structural equation modeling was used to examine the pattern of direct and indirect effects. Findings of the present study show that the data are well fitted to the model. The indirect effect of the positive quality of relationships was significant on depression through loneliness. Moreover, the indirect effects of the negative quality of relationships on depression through loneliness and through emotion-focused coping strategies were statistically significant. Although the effect of loneliness and emotion-focused coping strategies on depression was significant, problem-focused coping strategies did not have a significant effect on depression. Additionally, the findings suggested that the indirect effect through loneliness on depression was stronger compared with the indirect effect through emotion-focused coping strategies. The positive or negative quality of interpersonal relationships, loneliness, and emotion-focused coping strategy can significantly predict depression.

  20. Modelling long term rockslide displacements with non-linear time-dependent relationships

    Science.gov (United States)

    De Caro, Mattia; Volpi, Giorgio; Castellanza, Riccardo; Crosta, Giovanni; Agliardi, Federico

    2015-04-01

    Rockslides undergoing rapid changes in behaviour pose major risks in alpine areas, and require careful characterization and monitoring both for civil protection and mitigation activities. In particular, these instabilities can undergo very slow movement with occasional and intermittent acceleration/deceleration stages of motion potentially leading to collapse. Therefore, the analysis of such instabilities remains a challenging issue. Rockslide displacements are strongly conditioned by hydrologic factors as suggested by correlations with groundwater fluctuations, snowmelt, with a frequently observed delay between perturbation and system reaction. The aim of this work is the simulation of the complex time-dependent behaviour of two case studies for which also a 2D transient hydrogeological simulation has been performed: Vajont rockslide (1960 to 1963) and the recent Mt. de La Saxe rockslide (2009 to 2012). Non-linear time-dependent constitutive relationships have been used to describe long-term creep deformation. Analyses have been performed using a "rheological-mechanical" approach that fits idealized models (e.g. viscoelastic, viscoplastic, elasto-viscoplastic, Burgers, nonlinear visco-plastic) to the experimental behaviour of specific materials by means of numerical constants. Bidimensional simulations were carried out using the finite difference code FLAC. Displacements time-series, available for the two landslides, show two superimposed deformation mechanisms: a creep process, leading to movements under "steady state" conditions (e.g. constant groundwater level), and a "dynamic" process, leading to an increase in displacement rate due to changes of external loads (e.g. groundwater level). For both cases sliding mass is considered as an elasto-plastic body subject to its self-weight, inertial and seepage forces varying with time according to water table fluctuation (due to snowmelt or changing in reservoir level) and derived from the previous hydrogeological

  1. Mediating effects of emotional exhaustion on the relationship between job demand–control model and mental health.

    Science.gov (United States)

    Huang, Yu-Hwa; Du, Pey-Ian; Chen, Chin-Hui; Yang, Chin-Ann; Huang, Ing-Chung

    2011-04-01

    This study attempted to investigate the role of emotional exhaustion as a mediator on the relationship between job demands-control (JDC) model and mental health. Three-wave data from 297 employees were collected. The results showed that job demands were positively related to emotional exhaustion, and increasing job demands will increase the level of emotional exhaustion. Job control was negatively associated with emotional exhaustion; therefore, increasing job control will decrease the level of emotional exhaustion. Emotional exhaustion was negatively related to mental health. Emotional exhaustion fully mediated the relationship between job demands and mental health, and partially mediated the positive relationship between job control and mental health. In addition, job control was positively associated with mental health directly. The remarkable finding of the present study was that emotional exhaustion served as the key mediator between the JDC model and mental health. Theoretical and managerial implications and limitations were discussed.

  2. For the Construction of a Historico-anthropological Model of Musical Relationships between Brazil, Portugal, and Africa

    Directory of Open Access Journals (Sweden)

    Rafael José de Menezes Bastos

    2016-02-01

    Full Text Available The text postulates a model of a historico-anthropological nature for understanding the musical relationships from Brazil, Portugal, and Atlantic lusophone Africa during the XVII and XIX centuries. The model stars from the constitution of the Atlantic lusophone space as one of continual sociocultural relationships in general and musical in particular up to the first decades of the XIX century and even before. Those musical relationships are based on the existence of vast transatlantic system of musical and dance genres connected through historic and structural transformations. Because it belongs to that system, the lundu-modinha-fado transformation system will be studied, with emphasis on Bazilian dance and Portuguese song. The article elaborates the concept of "musical genre" from the notions of Mikhail Bakhtin´s "discursive genre" and Claude Lévi-Strauss and Marshall Sahlins’s "transformation".

  3. A Marketing-Finance Approach towards Industrial Channel Contract Relationships: A Model and Application

    NARCIS (Netherlands)

    Pennings, J.M.E.

    2004-01-01

    Channel contract relations are dynamic. In this paper, it is argued that one of the drivers for this dynamism is a firm's strive for shareholder value. Using channel contract relationships as market-based assets, firms are managing a portfolio of spot and forward contract relationships. By

  4. A Risk-Amelioration Model of Sibling Relationships: Conceptual Underpinnings and Preliminary Findings.

    Science.gov (United States)

    Brody, Gene H.; Stoneman, Zolinda

    1996-01-01

    This study represents further work into the area of what specific processes determine whether a sibling relationship will be positive or negative. Specifically addressed was the influence of each child's personality or temperament in shaping the quality and type of sibling relationship. Significant attention was paid to analyzing sibling…

  5. Dynamic modelling of inter-organisational information management systems and relationships in food chains

    NARCIS (Netherlands)

    Storer, C.E.; Soutar, G.N.; Trienekens, J.H.; Beulens, A.J.M.; Quaddus, M.A.

    2004-01-01

    It is agreed that good communication systems between organisations increase customer satisfaction and relationship behaviour. However, less is known about the details of how information is used to manage relationships. Theories that have been found have either been tested on non-perishable goods or

  6. Item response theory and structural equation modelling for ordinal data: Describing the relationship between KIDSCREEN and Life-H.

    Science.gov (United States)

    Titman, Andrew C; Lancaster, Gillian A; Colver, Allan F

    2016-10-01

    Both item response theory and structural equation models are useful in the analysis of ordered categorical responses from health assessment questionnaires. We highlight the advantages and disadvantages of the item response theory and structural equation modelling approaches to modelling ordinal data, from within a community health setting. Using data from the SPARCLE project focussing on children with cerebral palsy, this paper investigates the relationship between two ordinal rating scales, the KIDSCREEN, which measures quality-of-life, and Life-H, which measures participation. Practical issues relating to fitting models, such as non-positive definite observed or fitted correlation matrices, and approaches to assessing model fit are discussed. item response theory models allow properties such as the conditional independence of particular domains of a measurement instrument to be assessed. When, as with the SPARCLE data, the latent traits are multidimensional, structural equation models generally provide a much more convenient modelling framework. © The Author(s) 2013.

  7. Precision comparison of the erosion rates derived from 137Cs measurements models with predictions based on empirical relationship

    International Nuclear Information System (INIS)

    Yang Mingyi; Liu Puling; Li Liqing

    2004-01-01

    The soil samples were collected in 6 cultivated runoff plots with grid sampling method, and the soil erosion rates derived from 137 Cs measurements were calculated. The models precision of Zhang Xinbao, Zhou Weizhi, Yang Hao and Walling were compared with predictions based on empirical relationship, data showed that the precision of 4 models is high within 50m slope length except for the slope with low slope angle and short length. Relatively, the precision of Walling's model is better than that of Zhang Xinbao, Zhou Weizhi and Yang Hao. In addition, the relationship between parameter Γ in Walling's improved model and slope angle was analyzed, the ralation is: Y=0.0109 X 1.0072 . (authors)

  8. Giving Work a Rain Check: Relationship Between Soldiering and Positive Work Outcomes Within the Job Demands-Resources Model

    Directory of Open Access Journals (Sweden)

    Ümit Baran Metin

    2015-07-01

    Full Text Available Soldiering is defined as engaging behaviourally or cognitively into non-work-related activities during working hours with no intention of harming the employer, co-workers, and/or clients. The present study will investigate this phenomenon using the Job-Demands Resources Model. The proposed model will consider the influence of job demands and resources on soldiering, as well as the relationship of soldiering with employee wellbeing and performance. The data, collected via online questionnaires across seven European countries, will be analysed using structural equation modelling in order to explore the goodness-of-fit of the proposed model as well as its potential cross cultural variations.

  9. Modeling the Relationship between Transportation-Related Carbon Dioxide Emissions and Hybrid-Online Courses at a Large Urban University

    Science.gov (United States)

    Little, Matthew; Cordero, Eugene

    2014-01-01

    Purpose: This paper aims to investigate the relationship between hybrid classes (where a per cent of the class meetings are online) and transportation-related CO[subscript 2] emissions at a commuter campus similar to San José State University (SJSU). Design/methodology/approach: A computer model was developed to calculate the number of trips to…

  10. A nonalcoholic fatty liver disease cirrhosis model in gerbil : the dynamic relationship between hepatic lipid metabolism and cirrhosis

    NARCIS (Netherlands)

    Li, Wei; Guan, Zheng; Brisset, Jean C.; Shi, Qiaojuan; Lou, Qi; Ma, Yue; Suriguga, Su; Ying, Huazhong; Sa, Xiaoying; Chen, Zhenwen; Quax, Wim J.; Chu, Xiaofeng

    2018-01-01

    Nonalcoholic fatty liver disease (NAFLD) usually takes decades to develop into cirrhosis, which limits the longitudinal study of NAFLD. This work aims at developing a NAFLD-caused cirrhosis model in gerbil and examining the dynamic relationship between hepatic lipid metabolism and cirrhosis. We fed

  11. The Relational-Behavior Model: The Relationship between Intrinsic Motivational Instruction and Extrinsic Motivation in Psychologically Based Instruction

    Science.gov (United States)

    Chandler, Donald S., Jr.

    2008-01-01

    This pilot study examined the relational-behavior model (RBM) as a method of intrinsic motivational instruction in psychology courses. Among a sample of 33 college students enrolled in two undergraduate psychology courses, a Spearman rho analysis revealed a significant relationship between the intrinsic motivational factors (e.g. student/class…

  12. The Relationship of Core Self-Evaluations and Life Satisfaction in College Students with Disabilities: Evaluation of a Mediator Model

    Science.gov (United States)

    Smedema, Susan Miller; Chan, Fong; Yaghmaian, Rana A.; Cardoso, Elizabeth DaSilva; Muller, Veronica; Keegan, John; Dutta, Alo; Ebener, Deborah J.

    2015-01-01

    This study examined the factorial structure of the construct core self-evaluations (CSE) and tested a mediational model of the relationship between CSE and life satisfaction in college students with disabilities. We conducted a quantitative descriptive design using exploratory and confirmatory factor analysis and multiple regression analysis.…

  13. Examining the Relationship between Technological Pedagogical Content Knowledge (TPACK) and Student Achievement Utilizing the Florida Value-Added Model

    Science.gov (United States)

    Farrell, Ivan K.; Hamed, Kastro M.

    2017-01-01

    Utilizing a correlational research design, we sought to examine the relationship between the technological pedagogical content knowledge (TPACK) of in-service teachers and student achievement measured with each individual teacher's Value-Added Model (VAM) score. The TPACK survey results and a teacher's VAM score were also examined, separately,…

  14. Comparative Analysis of Predictive Models for Liver Toxicity Using ToxCast Assays and Quantitative Structure-Activity Relationships (MCBIOS)

    Science.gov (United States)

    Comparative Analysis of Predictive Models for Liver Toxicity Using ToxCast Assays and Quantitative Structure-Activity Relationships Jie Liu1,2, Richard Judson1, Matthew T. Martin1, Huixiao Hong3, Imran Shah1 1National Center for Computational Toxicology (NCCT), US EPA, RTP, NC...

  15. Bivariate functional data clustering: grouping streams based on a varying coefficient model of the stream water and air temperature relationship

    Science.gov (United States)

    H. Li; X. Deng; Andy Dolloff; E. P. Smith

    2015-01-01

    A novel clustering method for bivariate functional data is proposed to group streams based on their water–air temperature relationship. A distance measure is developed for bivariate curves by using a time-varying coefficient model and a weighting scheme. This distance is also adjusted by spatial correlation of streams via the variogram. Therefore, the proposed...

  16. Hop-distance relationship analysis with quasi-UDG model for node localization in wireless sensor networks

    Directory of Open Access Journals (Sweden)

    Chen Ping

    2011-01-01

    Full Text Available Abstract In wireless sensor networks (WSNs, location information plays an important role in many fundamental services which includes geographic routing, target tracking, location-based coverage, topology control, and others. One promising approach in sensor network localization is the determination of location based on hop counts. A critical priori of this approach that directly influences the accuracy of location estimation is the hop-distance relationship. However, most of the related works on the hop-distance relationship assume the unit-disk graph (UDG model that is unrealistic in a practical scenario. In this paper, we formulate the hop-distance relationship for quasi-UDG model in WSNs where sensor nodes are randomly and independently deployed in a circular region based on a Poisson point process. Different from the UDG model, quasi-UDG model has the non-uniformity property for connectivity. We derive an approximated recursive expression for the probability of the hop count with a given geographic distance. The border effect and dependence problem are also taken into consideration. Furthermore, we give the expressions describing the distribution of distance with known hop counts for inner nodes and those suffered from the border effect where we discover the insignificance of the border effect. The analytical results are validated by simulations showing the accuracy of the employed approximation. Besides, we demonstrate the localization application of the formulated relationship and show the accuracy improvement in the WSN localization.

  17. Rapid and Accurate Machine Learning Recognition of High Performing Metal Organic Frameworks for CO2 Capture.

    Science.gov (United States)

    Fernandez, Michael; Boyd, Peter G; Daff, Thomas D; Aghaji, Mohammad Zein; Woo, Tom K

    2014-09-04

    In this work, we have developed quantitative structure-property relationship (QSPR) models using advanced machine learning algorithms that can rapidly and accurately recognize high-performing metal organic framework (MOF) materials for CO2 capture. More specifically, QSPR classifiers have been developed that can, in a fraction of a section, identify candidate MOFs with enhanced CO2 adsorption capacity (>1 mmol/g at 0.15 bar and >4 mmol/g at 1 bar). The models were tested on a large set of 292 050 MOFs that were not part of the training set. The QSPR classifier could recover 945 of the top 1000 MOFs in the test set while flagging only 10% of the whole library for compute intensive screening. Thus, using the machine learning classifiers as part of a high-throughput screening protocol would result in an order of magnitude reduction in compute time and allow intractably large structure libraries and search spaces to be screened.

  18. Evaluation of air-soil temperature relationships simulated by land surface models during winter across the permafrost region

    Science.gov (United States)

    Wang, Wenli; Rinke, Annette; Moore, John C.; Ji, Duoying; Cui, Xuefeng; Peng, Shushi; Lawrence, David M.; McGuire, A. David; Burke, Eleanor J.; Chen, Xiaodong; Delire, Christine; Koven, Charles; MacDougall, Andrew; Saito, Kazuyuki; Zhang, Wenxin; Alkama, Ramdane; Bohn, Theodore J.; Ciais, Philippe; Decharme, Bertrand; Gouttevin, Isabelle; Hajima, Tomohiro; Krinner, Gerhard; Lettenmaier, Dennis P.; Miller, Paul A.; Smith, Benjamin; Sueyoshi, Tetsuo

    2016-01-01

     A realistic simulation of snow cover and its thermal properties are important for accurate modelling of permafrost. We analyze simulated relationships between air and near-surface (20 cm) soil temperatures in the Northern Hemisphere permafrost region during winter, with a particular focus on snow insulation effects in nine land surface models and compare them with observations from 268 Russian stations. There are large across-model differences as expressed by simulated differences between near-surface soil and air temperatures, (ΔT), of 3 to 14 K, in the gradients between soil and air temperatures (0.13 to 0.96°C/°C), and in the relationship between ΔT and snow depth. The observed relationship between ΔT and snow depth can be used as a metric to evaluate the effects of each model's representation of snow insulation, and hence guide improvements to the model’s conceptual structure and process parameterizations. Models with better performance apply multi-layer snow schemes and consider complex snow processes. Some models show poor performance in representing snow insulation due to underestimation of snow depth and/or overestimation of snow conductivity. Generally, models identified as most acceptable with respect to snow insulation simulate reasonable areas of near-surface permafrost (12–16 million km2). However, there is not a simple relationship between the quality of the snow insulation in the acceptable models and the simulated area of Northern Hemisphere near-surface permafrost, likely because several other factors such as differences in the treatment of soil organic matter, soil hydrology, surface energy calculations, and vegetation also provide important controls on simulated permafrost distribution.

  19. Teacher-student interpersonal relationships do change and affect academic motivation: a multilevel growth curve modelling.

    Science.gov (United States)

    Maulana, Ridwan; Opdenakker, Marie-Christine; Bosker, Roel

    2014-09-01

    Research has shown that the teacher-student interpersonal relationship (TSIR) is important for student motivation. Although TSIR has received a growing interest, there are only few studies that focus on changes and links between TSIR and student academic motivation in a longitudinal fashion in non-Western contexts. This study investigated changes in TSIR and links with academic motivation as perceived by first-grade secondary school students in Indonesia. TSIR was studied from the perspective of interpersonal behaviour in terms of Influence and Proximity. Students' academic motivation was studied from the perspective of self-determination theory. A total of 504 first-grade secondary school students of 16 mathematics and English classes participated in the study. Surveys were administered in five waves throughout the school year. Multilevel growth curve modelling was applied. Contrary to the (limited) general research findings from Western contexts, we found that the quality of TSIR (student perceptions) increased over time. The increase was slightly more pronounced for Proximity than for Influence. In accordance with the findings for the Western countries, the level of students' controlled motivation increased, while that of autonomous motivation decreased over time. However, the negative change in autonomous motivation was less pronounced. As in Western countries, TSIR was longitudinally linked with academic motivation, in particular, with autonomous motivation. Evidence is found that TSIR can change in a favourable way, and this positively affects student motivation. Future research could benefit from unravelling the influences of cultures on changes in TSIR in broader contexts. © 2013 The British Psychological Society.

  20. Working alliance, real relationship, session quality, and client improvement in psychodynamic psychotherapy: A longitudinal actor partner interdependence model.

    Science.gov (United States)

    Kivlighan, Dennis M; Hill, Clara E; Gelso, Charles J; Baumann, Ellen

    2016-03-01

    We used the Actor Partner Interdependence Model (APIM; Kashy & Kenny, 2000) to examine the dyadic associations of 74 clients and 23 therapists in their evaluations of working alliance, real relationship, session quality, and client improvement over time in ongoing psychodynamic or interpersonal psychotherapy. There were significant actor effects for both therapists and clients, with the participant's own ratings of working alliance and real relationship independently predicting their own evaluations of session quality. There were significant client partner effects, with clients' working alliance and real relationship independently predicting their therapists' evaluations of session quality. The client partner real relationship effect was stronger in later sessions than in earlier sessions. Therapists' real relationship ratings (partner effect) were a stronger predictor of clients' session quality ratings in later sessions than in earlier sessions. Therapists' working alliance ratings (partner effect) were a stronger predictor of clients' session quality ratings when clients made greater improvement than when clients made lesser improvement. For clients' session outcome ratings, there were complex three-way interactions, such that both Client real relationship and working alliance interacted with client improvement and time in treatment to predict clients' session quality. These findings strongly suggest both individual and partner effects when clients and therapists evaluate psychotherapy process and outcome. Implications for research and practice are discussed. (c) 2016 APA, all rights reserved).

  1. Uniaxial Extensional Behavior of A--B--A Thermoplastic Elastomers: Structure-Properties Relationship and Modeling

    Science.gov (United States)

    Martinetti, Luca

    relation between the observed power-law exponent and molecular structure was established. The measured low-frequency response, originating from the incipient glass transition of the A domains, was exploited and extrapolated to lower frequencies via a sequential application of the fractional Maxwell model and the fractional Zener model. With only a few, physically meaningful material parameters a realistic description of the A--B--A self-similar relaxation was obtained over a frequency range much broader than the experimental window and not accessible via time-temperature superposition. The relationship between large-strain response and network structure of A--B--A triblocks was investigated, by examining (1) the effect of linear relaxation mechanisms on the tensile behavior, (2) the sources of elastic and viscoelastic nonlinearities, and (3) the strain rate dependence of the ultimate properties. For the first time in the literature, the complex high-dimensional rheological signature of chewing gum was analyzed, especially in response to nonlinear and unsteady deformations in both shear and extension. A unique rheological fingerprint was obtained that is sufficient to provide a new robust definition of chewing gum that is independent of specific molecular composition. (Abstract shortened by ProQuest.).

  2. DEVELOPMENT OF AQUATIC MODELS FOR TESTING THE RELATIONSHIP BETWEEN GENETIC DIVERSITY AND POPULATION EXTINCTION RISK

    Science.gov (United States)

    The relationship between population adaptive potential and extinction risk in a changing environment is not well understood. Although the expectation is that genetic diversity is directly related to the capacity of populations to adapt, the statistical and predictive aspects of ...

  3. Task Group on a Strategic Relationship Model Between the Department of Defense and the Industrial Base

    National Research Council Canada - National Science Library

    2008-01-01

    ...) to evaluate and make recommendations to the Department of Defense (DoD) regarding actions that could improve the strategic relationship between the Department and its manufacturer and service suppliers...

  4. Measuring Relationships: A Model for Evaluating U.S. Air Force Public Affairs Programs

    National Research Council Canada - National Science Library

    Della Vedova, Joseph P

    2005-01-01

    The thesis advanced here is that Air Force Public Affairs should be responsible for managing the organization-public relationship and that the effectiveness of that management can be measured in terms...

  5. Women report being more likely than men to model their relationships after what they have seen on TV.

    Science.gov (United States)

    Morrison, C; Westman, A S

    2001-10-01

    Students (21 men and 50 women) anonymously answered questions about imitating relationships seen on TV. The women were more likely than men to report trying to model family life after what they saw on TV situational comedies and to expect their significant other to act as those seen on TV. They also more frequently reported experiencing a significant other acting as those on TV. There was no difference by sex in current age, parents' marital status during the students' formative years, or age of separation, divorce, or widowing if any occurred. For neither women nor men did a broken home during the formative years correlate with looking to TV for information on relationships.

  6. Modeling dynamics in career construction : reciprocal relationship between future work self and career exploration.

    OpenAIRE

    Guan, Y.; Zhuang, M.; Cai, Z.; Ding, Y.; Wang, Y.; Huang, Z.; Lai, X.

    2017-01-01

    In extant research, scholars have treated proactive career behavior (e.g., career exploration) primarily as a consequence of future work self. Yet, emerging evidence provides support for a relationship in the opposite direction, suggesting that career exploration may also be an antecedent. Using a cross-lagged panel design, we empirically tested the reciprocal relationship between future work self and career exploration. In Study 1, we measured both future work self and career exploration at ...

  7. Exploring Coworker Relationships: Antecedents and Dimensions of Interpersonal Fit, Coworker Satisfaction, and Relational Models

    OpenAIRE

    Byington, Eliza

    2013-01-01

    textabstractManagement scholarship has revealed the myriad ways in which relationships between coworkers impact individual, team, and organizational phenomena. However, our scientific understanding of coworker relationships and what makes for satisfying connections with colleagues is still in its early days. This dissertation helps advance our understanding by proposing new drivers of coworker satisfaction, unpacking the nature of coworker satisfaction itself, and examining the sources and an...

  8. A method for extending stage-discharge relationships using a hydrodynamic model and quantifying the associated uncertainty

    Science.gov (United States)

    Shao, Quanxi; Dutta, Dushmanta; Karim, Fazlul; Petheram, Cuan

    2018-01-01

    Streamflow discharge is a fundamental dataset required to effectively manage water and land resources. However, developing robust stage - discharge relationships called rating curves, from which streamflow discharge is derived, is time consuming and costly, particularly in remote areas and especially at high stage levels. As a result stage - discharge relationships are often heavily extrapolated. Hydrodynamic (HD) models are physically based models used to simulate the flow of water along river channels and over adjacent floodplains. In this paper we demonstrate a method by which a HD model can be used to generate a 'synthetic' stage - discharge relationship at high stages. The method uses a both-side Box-Cox transformation to calibrate the synthetic rating curve such that the regression residuals are as close to the normal distribution as possible. By doing this both-side transformation, the statistical uncertainty in the synthetically derived stage - discharge relationship can be calculated. This enables people trying to make decisions to determine whether the uncertainty in the synthetically generated rating curve at high stage levels is acceptable for their decision. The proposed method is demonstrated in two streamflow gauging stations in north Queensland, Australia.

  9. High-risk diagnosis, social stress, and parent-child relationships: A moderation model.

    Science.gov (United States)

    Bentley, Eryn; Millman, Zachary B; Thompson, Elizabeth; Demro, Caroline; Kline, Emily; Pitts, Steven C; DeVylder, Jordan E; Smith, Melissa Edmondson; Reeves, Gloria; Schiffman, Jason

    2016-07-01

    Stress is related to symptom severity among youth at clinical high-risk (CHR) for psychosis, although this relation may be influenced by protective factors. We explored whether the association of CHR diagnosis with social stress is moderated by the quality of parent-child relationships in a sample of 96 (36 CHR; 60 help-seeking controls) adolescents and young adults receiving mental health services. We examined self-reported social stress and parent-child relationships as measured by the Behavior Assessment System for Children, Second Edition (BASC-2), and determined CHR status from the clinician-administered Structured Interview for Psychosis-Risk Syndrome (SIPS). The social stress subscale, part of the clinical domain of the BASC-2, assesses feelings of stress and tension in personal relationships and the relations with parents subscale, part of the adaptive domain of the BASC-2, assesses perceptions of importance in family and quality of parent-child relationship. There was a modest direct relation between risk diagnosis and social stress. Among those at CHR, however, there was a significant relation between parent-child relationships and social stress (b=-0.73, t[92]=-3.77, psocial stress for those at risk for psychosis. Findings provide additional evidence to suggest that interventions that simultaneously target both social stress and parent-child relationships might be relevant for adolescents and young adults at clinical high-risk for psychosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. EVOLUTION OF THEORIES AND EMPIRICAL MODELS OF A RELATIONSHIP BETWEEN ECONOMIC GROWTH, SCIENCE AND INNOVATIONS (PART I

    Directory of Open Access Journals (Sweden)

    Kaneva M. A.

    2017-12-01

    Full Text Available This article is a first chapter of an analytical review of existing theoretical models of a relationship between economic growth / GRP and indicators of scientific development and innovation activities, as well as empirical approaches to testing this relationship. Aim of the paper is a systematization of existing approaches to modeling of economic growth geared by science and innovations. The novelty of the current review lies in the authors’ criteria of interconnectedness of theoretical and empirical studies in the systematization of a wide range of publications presented in a final table-scheme. In the first part of the article the authors discuss evolution of theoretical approaches, while the second chapter presents a time gap between theories and their empirical verification caused by the level of development of quantitative instruments such as econometric models. The results of this study can be used by researchers and graduate students for familiarization with current scientific approaches that manifest progress from theory to empirical verification of a relationship «economic growth-innovations» for improvement of different types of models in spatial econometrics. To apply these models to management practices the presented review could be supplemented with new criteria for classification of knowledge production functions and other theories about effect of science on economic growth.

  11. Model test on the relationship feed energy and protein ratio to the production and quality of milk protein

    Science.gov (United States)

    Hartanto, R.; Jantra, M. A. C.; Santosa, S. A. B.; Purnomoadi, A.

    2018-01-01

    The purpose of this research was to find an appropriate relationship model between the feed energy and protein ratio with the amount of production and quality of milk proteins. This research was conducted at Getasan Sub-district, Semarang Regency, Central Java Province, Indonesia using 40 samples (Holstein Friesian cattle, lactation period II-III and lactation month 3-4). Data were analyzed using linear and quadratic regressions, to predict the production and quality of milk protein from feed energy and protein ratio that describe the diet. The significance of model was tested using analysis of variance. Coefficient of determination (R2), residual variance (RV) and root mean square prediction error (RMSPE) were reported for the developed equations as an indicator of the goodness of model fit. The results showed no relationship in milk protein (kg), milk casein (%), milk casein (kg) and milk urea N (mg/dl) as function of CP/TDN. The significant relationship was observed in milk production (L or kg) and milk protein (%) as function of CP/TDN, both in linear and quadratic models. In addition, a quadratic change in milk production (L) (P = 0.003), milk production (kg) (P = 0.003) and milk protein concentration (%) (P = 0.026) were observed with increase of CP/TDN. It can be concluded that quadratic equation was the good fitting model for this research, because quadratic equation has larger R2, smaller RV and smaller RMSPE than those of linear equation.

  12. Structural equation modeling assessing relationship between mathematics beliefs, teachers' attitudes and teaching practices among novice teachers in Malaysia

    Science.gov (United States)

    Borhan, Noziati; Zakaria, Effandi

    2017-05-01

    This quantitative study was conducted to investigate the perception level of novice teachers about mathematics belief, teachers' attitude towards mathematics and teaching practices of mathematics in the classroom. In addition, it also aims to identify whether there is a correspondence model with the data obtained and to identify the relationship between the variables of beliefs, attitudes and practices among novice teachers in Malaysia. A total of 263 primary novice teachers throughout the country were involved in this study were selected randomly. Respondents are required to provide a response to the questionnaire of 66 items related to mathematics beliefs, attitudes and practices of the teaching mathematics. There are ten sub-factors which have been established in this instrument for three major constructs using a Likert scale rating of five points. The items of the constructs undergo the exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) procedure involve of unidimensionality test, convergent validity, construct validity and discriminant validity. Descriptive statistics were used to describe the frequency, percentage, the mean and standard deviation for completing some research questions that have been expressed. As for inferential statistical analysis, the researchers used structural equation modeling (SEM) to answer the question of correspondents model and the relationship between these three variables. The results of the study were found that there exist a correspondence measurement and structural model with the data obtained. While the relationship between variable found that mathematics beliefs have a significant influence on teachers' attitudes towards mathematics as well as the relationship between the attitudes with teaching practices. Meanwhile, mathematics belief had no significant relationship with mathematics teaching practices among novice teachers in Malaysia.

  13. Novel Uses of In Vitro Data to Develop Quantitative Biological Activity Relationship Models for in Vivo Carcinogenicity Prediction.

    Science.gov (United States)

    Pradeep, Prachi; Povinelli, Richard J; Merrill, Stephen J; Bozdag, Serdar; Sem, Daniel S

    2015-04-01

    The availability of large in vitro datasets enables better insight into the mode of action of chemicals and better identification of potential mechanism(s) of toxicity. Several studies have shown that not all in vitro assays can contribute as equal predictors of in vivo carcinogenicity for development of hybrid Quantitative Structure Activity Relationship (QSAR) models. We propose two novel approaches for the use of mechanistically relevant in vitro assay data in the identification of relevant biological descriptors and development of Quantitative Biological Activity Relationship (QBAR) models for carcinogenicity prediction. We demonstrate that in vitro assay data can be used to develop QBAR models for in vivo carcinogenicity prediction via two case studies corroborated with firm scientific rationale. The case studies demonstrate the similarities between QBAR and QSAR modeling in: (i) the selection of relevant descriptors to be used in the machine learning algorithm, and (ii) the development of a computational model that maps chemical or biological descriptors to a toxic endpoint. The results of both the case studies show: (i) improved accuracy and sensitivity which is especially desirable under regulatory requirements, and (ii) overall adherence with the OECD/REACH guidelines. Such mechanism based models can be used along with QSAR models for prediction of mechanistically complex toxic endpoints. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Neurological soft signs and their relationships to neurocognitive functions: a re-visit with the structural equation modeling design.

    Directory of Open Access Journals (Sweden)

    Raymond C K Chan

    Full Text Available BACKGROUND: Neurological soft signs and neurocognitive impairments have long been considered important features of schizophrenia. Previous correlational studies have suggested that there is a significant relationship between neurological soft signs and neurocognitive functions. The purpose of the current study was to examine the underlying relationships between these two distinct constructs with structural equation modeling (SEM. METHODS: 118 patients with schizophrenia and 160 healthy controls were recruited for the current study. The abridged version of the Cambridge Neurological Inventory (CNI and a set of neurocognitive function tests were administered to all participants. SEM was then conducted independently in these two samples to examine the relationships between neurological soft signs and neurocognitive functions. RESULTS: Both the measurement and structural models showed that the models fit well to the data in both patients and healthy controls. The structural equations also showed that there were modest to moderate associations among neurological soft signs, executive attention, verbal memory, and visual memory, while the healthy controls showed more limited associations. CONCLUSIONS: The current findings indicate that motor coordination, sensory integration, and disinhibition contribute to the latent construct of neurological soft signs, whereas the subset of neurocognitive function tests contribute to the latent constructs of executive attention, verbal memory, and visual memory in the present sample. Greater evidence of neurological soft signs is associated with more severe impairment of executive attention and memory functions. Clinical and theoretical implications of the model findings are discussed.

  15. Modelling relationships between lichen bioindicators, air quality and climate on a national scale: Results from the UK OPAL air survey

    International Nuclear Information System (INIS)

    Seed, Lindsay; Wolseley, Pat; Gosling, Laura; Davies, Linda; Power, Sally A.

    2013-01-01

    Air pollution has many negative effects on the natural environment, from changes in plant growth patterns to loss of ecosystem function. This study uses citizen science to investigate national-scale patterns in the distribution and abundance of selected lichen species on tree trunks and branches, and to relate these to air pollution and climate. Volunteers collected data for nine lichen indicators on 19,334 deciduous trees. Submitted data provided information on species-level patterns, and were used to derive composite lichen indices. Multiple linear regression and ANCOVA were used to model the relationships between lichen response variables on Quercus spp. and pollution, climate and location. The study demonstrated significant relationships between patterns in indicator lichens and levels of N- and S-containing pollutants on trunks and twigs. The derived lichen indices show great potential as a tool to provide information on local, site-specific levels of air quality. -- Highlights: •Data on presence and abundance of selected lichens were collected by members of the public. •Indicator species and indices were modelled against air pollution and climate data. •Lichens and indices show significant relationships with nitrogenous air pollution. •Lichen indices are useful tools for providing information on local air quality. -- Data on selected lichen taxa collected by members of the public in England is used to show the relationship of indicator taxa and pollution indices to air pollution and climate data

  16. Model analysis of the relationship between intracellular Po2 and energy demand in skeletal muscle

    OpenAIRE

    Spires, Jessica; Gladden, L. Bruce; Grassi, Bruno; Saidel, Gerald M.; Lai, Nicola

    2012-01-01

    On the basis of experimental studies, the intracellular O2 (iPo2)-work rate (WR) relationship in skeletal muscle is not unique. One study found that iPo2 reached a plateau at 60% of maximal WR, while another found that iPo2 decreased linearly at higher WR, inferring capillary permeability-surface area (PS) and blood-tissue O2 gradient, respectively, as alternative dominant factors for determining O2 diffusion changes during exercise. This relationship is affected by several factors, including...

  17. Different relationships between temporal phylogenetic turnover and phylogenetic similarity and in two forests were detected by a new null model.

    Science.gov (United States)

    Huang, Jian-Xiong; Zhang, Jian; Shen, Yong; Lian, Ju-yu; Cao, Hong-lin; Ye, Wan-hui; Wu, Lin-fang; Bin, Yue

    2014-01-01

    Ecologists have been monitoring community dynamics with the purpose of understanding the rates and causes of community change. However, there is a lack of monitoring of community dynamics from the perspective of phylogeny. We attempted to understand temporal phylogenetic turnover in a 50 ha tropical forest (Barro Colorado Island, BCI) and a 20 ha subtropical forest (Dinghushan in southern China, DHS). To obtain temporal phylogenetic turnover under random conditions, two null models were used. The first shuffled names of species that are widely used in community phylogenetic analyses. The second simulated demographic processes with careful consideration on the variation in dispersal ability among species and the variations in mortality both among species and among size classes. With the two models, we tested the relationships between temporal phylogenetic turnover and phylogenetic similarity at different spatial scales in the two forests. Results were more consistent with previous findings using the second null model suggesting that the second null model is more appropriate for our purposes. With the second null model, a significantly positive relationship was detected between phylogenetic turnover and phylogenetic similarity in BCI at a 10 m×10 m scale, potentially indicating phylogenetic density dependence. This relationship in DHS was significantly negative at three of five spatial scales. This could indicate abiotic filtering processes for community assembly. Using variation partitioning, we found phylogenetic similarity contributed to variation in temporal phylogenetic turnover in the DHS plot but not in BCI plot. The mechanisms for community assembly in BCI and DHS vary from phylogenetic perspective. Only the second null model detected this difference indicating the importance of choosing a proper null model.

  18. Defining the relationship between Plasmodium falciparum parasite rate and clinical disease: statistical models for disease burden estimation

    Directory of Open Access Journals (Sweden)

    Snow Robert W

    2009-08-01

    Full Text Available Abstract Background Clinical malaria has proven an elusive burden to enumerate. Many cases go undetected by routine disease recording systems. Epidemiologists have, therefore, frequently defaulted to actively measuring malaria in population cohorts through time. Measuring the clinical incidence of malaria longitudinally is labour-intensive and impossible to undertake universally. There is a need, therefore, to define a relationship between clinical incidence and the easier and more commonly measured index of infection prevalence: the "parasite rate". This relationship can help provide an informed basis to define malaria burdens in areas where health statistics are inadequate. Methods Formal literature searches were conducted for Plasmodium falciparum malaria incidence surveys undertaken prospectively through active case detection at least every 14 days. The data were abstracted, standardized and geo-referenced. Incidence surveys were time-space matched with modelled estimates of infection prevalence derived from a larger database of parasite prevalence surveys and modelling procedures developed for a global malaria endemicity map. Several potential relationships between clinical incidence and infection prevalence were then specified in a non-parametric Gaussian process model with minimal, biologically informed, prior constraints. Bayesian inference was then used to choose between the candidate models. Results The suggested relationships with credible intervals are shown for the Africa and a combined America and Central and South East Asia regions. In both regions clinical incidence increased slowly and smoothly as a function of infection prevalence. In Africa, when infection prevalence exceeded 40%, clinical incidence reached a plateau of 500 cases per thousand of the population per annum. In the combined America and Central and South East Asia regions, this plateau was reached at 250 cases per thousand of the population per annum. A temporal

  19. Bond-based linear indices of the non-stochastic and stochastic edge-adjacency matrix. 1. Theory and modeling of ChemPhys properties of organic molecules.

    Science.gov (United States)

    Marrero-Ponce, Yovani; Martínez-Albelo, Eugenio R; Casañola-Martín, Gerardo M; Castillo-Garit, Juan A; Echevería-Díaz, Yunaimy; Zaldivar, Vicente Romero; Tygat, Jan; Borges, José E Rodriguez; García-Domenech, Ramón; Torrens, Francisco; Pérez-Giménez, Facundo

    2010-11-01

    Novel bond-level molecular descriptors are proposed, based on linear maps similar to the ones defined in algebra theory. The kth edge-adjacency matrix (E(k)) denotes the matrix of bond linear indices (non-stochastic) with regard to canonical basis set. The kth stochastic edge-adjacency matrix, ES(k), is here proposed as a new molecular representation easily calculated from E(k). Then, the kth stochastic bond linear indices are calculated using ES(k) as operators of linear transformations. In both cases, the bond-type formalism is developed. The kth non-stochastic and stochastic total linear indices are calculated by adding the kth non-stochastic and stochastic bond linear indices, respectively, of all bonds in molecule. First, the new bond-based molecular descriptors (MDs) are tested for suitability, for the QSPRs, by analyzing regressions of novel indices for selected physicochemical properties of octane isomers (first round). General performance of the new descriptors in this QSPR studies is evaluated with regard to the well-known sets of 2D/3D MDs. From the analysis, we can conclude that the non-stochastic and stochastic bond-based linear indices have an overall good modeling capability proving their usefulness in QSPR studies. Later, the novel bond-level MDs are also used for the description and prediction of the boiling point of 28 alkyl-alcohols (second round), and to the modeling of the specific rate constant (log k), partition coefficient (log P), as well as the antibacterial activity of 34 derivatives of 2-furylethylenes (third round). The comparison with other approaches (edge- and vertices-based connectivity indices, total and local spectral moments, and quantum chemical descriptors as well as E-state/biomolecular encounter parameters) exposes a good behavior of our method in this QSPR studies. Finally, the approach described in this study appears to be a very promising structural invariant, useful not only for QSPR studies but also for similarity

  20. The use of social networking services and their relationship with the big five personality model and job satisfaction in Korea.

    Science.gov (United States)

    Kim, Hyondong; Chung, Yang Woon

    2014-10-01

    Social networking services (SNSs) have been garnering attention from society due to their recent rapid growth. This study examines whether SNS use can affect the relationship between the Big Five personality model and individual job satisfaction. Based on a sample of 1,452 workers in Korea, the results of this study indicate that the Big Five personality model (extroversion, agreeableness, and neuroticism) was significantly related to individual job satisfaction. Further, SNS use moderated the relationship between extroversion and neuroticism with individual job satisfaction. Also, SNS use was found to increase job satisfaction of Korean workers who are more extroverted, while it also affected job satisfaction of Korean workers with low agreeableness. As SNS use plays an important role in the workplace, it is necessary to realize and appreciate the importance of SNSs in shaping and promoting job satisfaction of working individuals.

  1. Jackson System Development, Entity-relationship Analysis and Data Flow Models: a comparative study

    NARCIS (Netherlands)

    Wieringa, Roelf J.

    1994-01-01

    This report compares JSD with ER modeling and data flow modeling. It is shown that JSD can be combined with ER modeling and that the result is a richer method than either of the two. The resulting method can serve as a basis for a pratical object-oriented modeling method and has some resemblance to

  2. An explanation for the multiplicative and the additive dose-effect relationship with the single-hit model

    International Nuclear Information System (INIS)

    Kottbauer, M.M.; Fleck, C.M.; Schoellnberger, H.

    1997-01-01

    For solid tumors and for leukemia the excess cancer rate after a single radiation dose D is different. The multiplicative model describes the excess solid tumor probability rate which is proportional to the background rate of cancer and dependent on dose D. The additive model describes the excess probability rate for leukaemia which is proportional to the dose D but unrelated to the spontaneous rate of cancer. A second great difference between the two models is the duration of the increased cancer probability rate. The multiplicative mode predicts that the additional cancer risk persist the whole lifetime after exposure and the additive model predicts excess risk over a period of time. With the Single-hit model (SHM) which is a multistage cancer model both dose-response relationships can be described. It will be shown that only small differences in the derivation will lead to the different relationships. We then analyze the incidence data of leukemia (1950-1987) and of all solid tumors (1958-1987) of the atomic bomb survivors. (author)

  3. Emotional Demands, Emotional Labour and Occupational Outcomes in School Principals: Modelling the Relationships

    Science.gov (United States)

    Maxwell, Aimee; Riley, Philip

    2017-01-01

    Most research into emotional labour is focussed on front-line service staff and health professionals, in short-term interactions. Little exists exploring the emotional labour involved in repeated on-going interactions by educational leaders with key stakeholders. This study explored the relationships between emotional demands, three emotional…

  4. Relationship between Physical Disability and Depression by Gender : A Panel Regression Model

    NARCIS (Netherlands)

    Noh, Jin-Won; Kwon, Young Dae; Park, Jumin; Oh, In-Hwan; Kim, Jinseok

    2016-01-01

    Background Depression in persons with physical disabilities may be more common than in the general population. The purpose of this study was to examine the relationship between physical disability and depression by gender among adults, using a large, nationally representative sample. Methods This

  5. Evaluating avian-habitat relationships models in mixed-conifer forests of the Sierra Nevada

    Science.gov (United States)

    Kathryn L. Purcell; Sallie J. Hejl; Terry A. Larson

    1992-01-01

    Using data from two studies in the southern and central Sierra Nevada, we compared the presence and abundance of bird species breeding in mixedconifer forests during 1978-79 and 1983-85 to predictions &om the California Wildlife Habitat Relationships (WHR) System. Twelve percent of the species observed in either study were not predicted by the WHR database to occur...

  6. Structural Modeling on the Relationship between Basic Psychological Needs, Academic Engagement, and Test Anxiety

    Science.gov (United States)

    Maralani, Farnaz Mehdipour; Lavasani, Masoud Gholamali; Hejazi, Elahe

    2016-01-01

    Some of the key issues in educational psychology are the way of students' engagement at school, controlling anxiety, and academic achievement. In line with that, the purpose of the present study is to determine the relationship between variables that are basic psychological needs, academic engagement, and test anxiety with regard to structural…

  7. Teacher-student interpersonal relationships do change and affect academic motivation : A multilevel growth curve modelling

    NARCIS (Netherlands)

    Maulana, Ridwan; Opdenakker, Marie; Bosker, Roel

    Background Research has shown that the teacher–student interpersonal relationship (TSIR) is important for student motivation. Although TSIR has received a growing interest, there are only few studies that focus on changes and links between TSIR and student academic motivation in a longitudinal

  8. Improving Sibling Relationships among Young Children: A Social Skills Training Model.

    Science.gov (United States)

    Kramer, Laurie; Radey, Chad

    1997-01-01

    Evaluates a new approach to improving sibling relationships in which social skills training was used to coach small groups of children (n=21) in prosocial sibling behaviors. Results show that children in the training group exhibited increased warmth, decreased rivalry, fewer problematic sibling behaviors, and a reduced status/power differential…

  9. Using "Relationship Marketing" Theory To Develop a Training Model for Admissions Recruiters.

    Science.gov (United States)

    Gyure, James F.; Arnold, Susan G.

    2001-01-01

    Addresses a critical aspect of enrollment management by providing a "conceptual training outline" based on relationship marketing and management principles for admissions recruiters and other appropriate enrollment staff. Provides a set of "Attitude Tools" to suggest how various training methods might benefit from a consistent…

  10. The Relationship of Coping, Self-Worth, and Subjective Well-Being: A Structural Equation Model

    Science.gov (United States)

    Smedema, Susan Miller; Catalano, Denise; Ebener, Deborah J.

    2010-01-01

    The purpose of this study was to determine the relationship between various coping-related variables and the evaluation of self-worth and subjective well-being among persons with spinal cord injury. Positive coping variables included hope, proactive coping style, and sense of humor, whereas negative coping variables included perceptions of stress,…

  11. The Measurement of the Relationship between Taiwan’s Bond Funds’ Net Flow and the Investment Risk -Threshold Autoregressive Model

    OpenAIRE

    Wo-Chiang Lee; Joe-Ming Lee

    2014-01-01

    This article applies the threshold autoregressive model to investigate the relationship between bond funds’ net flow and investment risk in Taiwan. Our empirical findings show that bond funds’ investors are concerned about the investment return and neglect the investment risk. In particular, when expanding the size of the bond funds, fund investors believe that the fund cannot lose any money on investment products. In order to satisfy investors, bond fund managers only target short-term retur...

  12. The Relationships Among Leadership, Entrepreneurial Mindset, Innovation and Competitive Advantage (a Conceptual Model of Logistics Service Industry)

    OpenAIRE

    Sudrajat, Darjat

    2015-01-01

    Nowadays, improvement of competitive advantage is an important and urgent issue facing logistics service companies in Indonesia. Some previous researches showed that to improve the competitive advantage could be conducted through improvement of leadership, entrepreneurial mindset and innovation variables. This research intended to recognize relationships among the variables. The research used causal-explanatory method. The results of research encompass a conceptual model, status of each varia...

  13. On the relationship of steady states of continuous and discrete models arising from biology.

    Science.gov (United States)

    Veliz-Cuba, Alan; Arthur, Joseph; Hochstetler, Laura; Klomps, Victoria; Korpi, Erikka

    2012-12-01

    For many biological systems that have been modeled using continuous and discrete models, it has been shown that such models have similar dynamical properties. In this paper, we prove that this happens in more general cases. We show that under some conditions there is a bijection between the steady states of continuous and discrete models arising from biological systems. Our results also provide a novel method to analyze certain classes of nonlinear models using discrete mathematics.

  14. On the relationship between justice judgments, outcomes and identity orientations among Iranian EFL learners: A structural equation model

    Directory of Open Access Journals (Sweden)

    Seyyed Ayatollah Razmjoo

    2015-06-01

    Full Text Available One problem which can be observed in the field of EFL/ESL learning is that a number of English major BA and MA students are not highly committed to their major and decide not to continue their graduate studies. Sometimes even graduate students from English majors prefer to extend their education or work in an unrelated field. This might be attributed to the extent to which they perceive evaluation procedures and outcomes as fair. Considering this, the present study investigates first the relationships between justice judgments, outcomes and identity orientations. The study, then, uses structural equation modeling in order to examine whether identity orientation has any mediating effect on the relationship between justice judgment and outcomes. Participants were74 students in Department of Foreign Languages and Linguistics, Shiraz University selected based on convenience sampling. They filled out three questionnaires on distributive and procedural justice judgments, rule compliance and outcome satisfaction, and personal and social identity orientations. The collected data was then analyzed using descriptive statistics, correlation, and structural equation modeling. Based on the obtained findings, procedural justice had significant positive correlation with rule compliance and distributive justice was significantly correlated with outcome satisfaction. The generated structural equation model also indicated that justice judgments only directly affected outcomes and identity had no mediating effect on the causal relationship between the two.

  15. A Relational Model of Sexual Minority Mental and Physical Health: The Negative Effects of Shame on Relationships, Loneliness, and Health

    Science.gov (United States)

    Mereish, Ethan H.; Poteat, V. Paul

    2015-01-01

    Sexual minorities (e.g., lesbians, gay men, bisexual individuals) are at higher risk for mental and physical health disparities than heterosexuals, and some of these disparities relate to minority stressors such as discrimination. Yet, there is little research elucidating pathways that predict health or that promote resiliency among sexual minorities. Building on the minority stress model, the present study utilized relational cultural theory to situate sexual minority health within a relational framework. Specifically, the study tested mediators of the relationships between distal (i.e., discrimination, rejection, victimization) and proximal stressors (i.e., internalized homophobia, sexual orientation concealment) and psychological and physical distress for sexual minorities. Among 719 sexual minority adults, structural equation modeling analyses were used to test four models reflecting the mediating effects of shame, poorer relationships with a close peer and the LGBT community, and loneliness on the associations between minority stressors and psychological distress (i.e., depression and anxiety) and physical distress (i.e., distressing physical symptoms). As hypothesized, the associations between distal and proximal minority stressors and distress were mediated by shame, poorer relationships with a close peer and the LGBT community, and loneliness. Findings underscore the possible relational and interpersonal mechanisms by which sexual minority stressors lead to psychological and physical distress. PMID:26010289

  16. Modeled dosage-response relationship on the net photosynthetic rate for the sensitivity to acid rain of 21 plant species.

    Science.gov (United States)

    Deng, Shihuai; Gou, Shuzhen; Sun, Baiye; Lv, Wenlin; Li, Yuanwei; Peng, Hong; Xiao, Hong; Yang, Gang; Wang, Yingjun

    2012-08-01

    This study investigated the sensitivity of plant species to acid rain based on the modeled dosage-response relationship on the net photosynthetic rate (P (N)) of 21 types of plant species, subjected to the exposure of simulated acid rain (SAR) for 5 times during a period of 50 days. Variable responses of P (N) to SAR occurred depending on the type of plant. A majority (13 species) of the dosage-response relationship could be described by an S-shaped curve and be fitted with the Boltzmann model. Model fitting allowed quantitative evaluation of the dosage-response relationship and an accurate estimation of the EC(10), termed as the pH of the acid rain resulting in a P (N) 10 % lower than the reference value. The top 9 species (Camellia sasanqua, Cinnamomum camphora, etc. EC(10) ≤ 3.0) are highly endurable to very acid rain. The rare, relict plant Metasequoia glyptostroboides was the most sensitive species (EC(10) = 5.1) recommended for protection.

  17. The Relationship Among School Safety, School Liking, and Students' Self-Esteem: Based on a Multilevel Mediation Model.

    Science.gov (United States)

    Zhang, Xinghui; Xuan, Xin; Chen, Fumei; Zhang, Cai; Luo, Yuhan; Wang, Yun

    2016-03-01

    Perceptions of school safety have an important effect on students' development. Based on the model of "context-process-outcomes," we examined school safety as a context variable to explore how school safety at the school level affected students' self-esteem. We used hierarchical linear modeling to examine the link between school safety at the school level and students' self-esteem, including school liking as a mediator. The data were from the National Children's Study of China (NCSC), in which 6618 fourth- to fifth-grade students in 79 schools were recruited from 100 counties in 31 provinces in China. Multilevel mediation analyses showed that the positive relationship between school safety at the school level and self-esteem was partially mediated by school liking, controlling for demographics at both student and school levels. Furthermore, a sex difference existed in the multilevel mediation model. For boys, school liking fully mediated the relationship between school safety at the school level and self-esteem. However, school liking partially mediated the relationship between school safety at the school level and self-esteem among girls. School safety should receive increasing attention from policymakers because of its impact on students' self-esteem. © 2016, American School Health Association.

  18. A relational model of sexual minority mental and physical health: The negative effects of shame on relationships, loneliness, and health.

    Science.gov (United States)

    Mereish, Ethan H; Poteat, V Paul

    2015-07-01

    Sexual minorities (e.g., lesbians, gay men, bisexual individuals) are at an increased risk for poorer mental and physical health outcomes than heterosexuals, and some of these health disparities relate to minority stressors such as discrimination. Yet, there is little research elucidating pathways that predict health or that promote resiliency among sexual minorities. Building on the minority stress model, the present study utilized relational cultural theory to situate sexual minority health within a relational framework. Specifically, the study tested mediators of the relationships between distal (i.e., discrimination, rejection, victimization) and proximal stressors (i.e., internalized homophobia, sexual orientation concealment) and psychological and physical distress for sexual minorities. Among 719 sexual minority adults, structural equation modeling analyses were used to test 4 models reflecting the mediating effects of shame, poorer relationships with a close peer and the lesbian/gay/bisexual/transgender (LGBT) community, and loneliness on the associations between minority stressors and psychological distress (i.e., depression and anxiety) and physical distress (i.e., distressing physical symptoms). As hypothesized, the associations between distal and proximal minority stressors and distress were mediated by shame, poorer relationships with a close peer and the LGBT community, and loneliness. Findings underscore the possible relational and interpersonal mechanisms by which sexual minority stressors lead to psychological and physical distress. (c) 2015 APA, all rights reserved).

  19. Intraocular pressure, blood pressure, and retinal blood flow autoregulation: a mathematical model to clarify their relationship and clinical relevance.

    Science.gov (United States)

    Guidoboni, Giovanna; Harris, Alon; Cassani, Simone; Arciero, Julia; Siesky, Brent; Amireskandari, Annahita; Tobe, Leslie; Egan, Patrick; Januleviciene, Ingrida; Park, Joshua

    2014-05-29

    This study investigates the relationship between intraocular pressure (IOP) and retinal hemodynamics and predicts how arterial blood pressure (BP) and blood flow autoregulation (AR) influence this relationship. A mathematical model is developed to simulate blood flow in the central retinal vessels and retinal microvasculature as current flowing through a network of resistances and capacitances. Variable resistances describe active and passive diameter changes due to AR and IOP. The model is validated by using clinically measured values of retinal blood flow and velocity. The model simulations for six theoretical patients with high, normal, and low BP (HBP-, NBP-, LBP-) and functional or absent AR (-wAR, -woAR) are compared with clinical data. The model predicts that NBPwAR and HBPwAR patients can regulate retinal blood flow (RBF) as IOP varies between 15 and 23 mm Hg and between 23 and 29 mm Hg, respectively, whereas LBPwAR patients do not adequately regulate blood flow if IOP is 15 mm Hg or higher. Hemodynamic alterations would be noticeable only if IOP changes occur outside of the regulating range, which, most importantly, depend on BP. The model predictions are consistent with clinical data for IOP reduction via surgery and medications and for cases of induced IOP elevation. The theoretical model results suggest that the ability of IOP to induce noticeable changes in retinal hemodynamics depends on the levels of BP and AR of the individual. These predictions might help to explain the inconsistencies found in the clinical literature concerning the relationship between IOP and retinal hemodynamics. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  20. On the relationship between aerosol model uncertainty and radiative forcing uncertainty.

    Science.gov (United States)

    Lee, Lindsay A; Reddington, Carly L; Carslaw, Kenneth S

    2016-05-24

    The largest uncertainty in the historical radiative forcing of climate is caused by the interaction of aerosols with clouds. Historical forcing is not a directly measurable quantity, so reliable assessments depend on the development of global models of aerosols and clouds that are well constrained by observations. However, there has been no systematic assessment of how reduction in the uncertainty of global aerosol models will feed through to the uncertainty in the predicted forcing. We use a global model perturbed parameter ensemble to show that tight observational constraint of aerosol concentrations in the model has a relatively small effect on the aerosol-related uncertainty in the calculated forcing between preindustrial and present-day periods. One factor is the low sensitivity of present-day aerosol to natural emissions that determine the preindustrial aerosol state. However, the major cause of the weak constraint is that the full uncertainty space of the model generates a large number of model variants that are equally acceptable compared to present-day aerosol observations. The narrow range of aerosol concentrations in the observationally constrained model gives the impression of low aerosol model uncertainty. However, these multiple "equifinal" models predict a wide range of forcings. To make progress, we need to develop a much deeper understanding of model uncertainty and ways to use observations to constrain it. Equifinality in the aerosol model means that tuning of a small number of model processes to achieve model-observation agreement could give a misleading impression of model robustness.

  1. The multidecadal variations of the interannual relationship between the East Asian summer monsoon and ENSO in a coupled model

    Science.gov (United States)

    Liu, Bo; Huang, Gang; Hu, Kaiming; Wu, Renguang; Gong, Hainan; Wang, Pengfei; Zhao, Guijie

    2017-10-01

    This study investigates the multidecadal variations of the interannual relationship between the East Asian summer monsoon (EASM) and El Niño-Southern Oscillation (ENSO) in 1000-year simulation of a coupled climate model. The interannual relationship between ENSO and EASM has experienced pronounced changes throughout the 1000-year simulation. During the periods with significant ENSO-EASM relationship, the ENSO-related circulation anomalies show a Pacific-Japan (PJ)-like pattern with significant wave-activity flux propagating from the tropics to the north in lower troposphere and from the mid-latitudes to the south in upper troposphere. The resultant ENSO-related precipitation anomalies are more (less) than normal over the East Asia (western North Pacific) in the decaying summers of El Niño events. In contrast, the circulation and precipitation anomalies are weak over East Asia-western North Pacific during the periods with weak ENSO-EASM relationship. Based on the energy conversion analysis, the related anomalies achieve barotropic and baroclinic energy from the mean flow during the periods with strong ENSO-EASM relationship. On the contrary, during the low-correlation periods, the energy conversion is too weak to form the link between the tropics and mid-latitudes. The main reason for the multidecadal variations of ENSO-EASM relationship is the amplitude discrepancy of SST anomalies over the Indo-western Pacific Ocean which, in turn, leads to the intensity difference of the western North Pacific anomalous anticyclone (WPAC) and related climate anomalies.

  2. Caring about caring: developing a model to implement compassionate relationship centred care in an older people care setting.

    Science.gov (United States)

    Dewar, Belinda; Nolan, Mike

    2013-09-01

    This study actively involved older people, staff and relatives in agreeing a definition of compassionate relationship-centred care and identifying strategies to promote such care in acute hospital settings for older people. It was a major component of a three year programme (the Leadership in Compassionate Care Programme, LCCP) seeking to integrate compassionate care across practice and educational environments. Compassionate caring and promoting dignity are key priorities for policy, practice and research worldwide, being central to the quality of care for patients and families, and job satisfaction for staff. Therapeutic relationships are essential to achieving excellence in care but little is known about how to develop and sustain such relationships in a culture that increasingly focuses on throughput and rapid turnover. The study used appreciative inquiry and a range of methods including participant observation, interviews, story telling and group discussions to actively engage older people, relatives and staff. A process of immersion crystallization was used to analyze data with staff as co-analysts. The study adds considerably to the conceptualization of compassionate, relationship-centred care and provides a model to aid staff deliver such care in practice, based on 'appreciative caring conversations' that enable all parties to gain two forms of 'person and relational knowledge' about 'who people are and what matters to them' and 'how people feel about their experience'. Such knowledge enables staff, patients and carers to 'work together to shape the way things are done'. The study generated a model called the 7 'C's that captures in detail the factors necessary to promote 'appreciative caring conversations'. The study demonstrates that engaging in 'appreciative caring conversations' promotes compassionate, relationship-centred care but that these conversations involve practitioners taking risks. Such 'relational practices' must therefore be valued and

  3. A structural equation model of patient-healthcare provider relationships and HIV-infected patient outcomes in Chinese populations.

    Science.gov (United States)

    Chen, Wei-Ti; Shiu, Chengshi; Yang, Joyce P; Chuang, Peing; Zhang, Lin; Bao, Meijuan; Lu, Hongzhou

    2018-03-01

    Obtaining maximum antiretroviral therapy (ART) adherence is critical for maintaining a high CD4 count and strong immune function in PLWHA. Key factors for achieving optimum adherence include good medication self-efficacy, decreased medication-taking difficulties, and positive patient-healthcare provider (HCP) relationships. Limited studies have analyzed the correlation of these factors and ART adherence in Chinese population. In this paper, structural equation modeling was performed to assess the proposed model of relations between patient-HCP relationships and adherence. Audio Computer-Assisted Self-Interview (ACASI) software was used to collect data on ART adherence and patient variables among 227 PLWHA in Shanghai and Taipei. Participants completed a one-time 60-minute ACASI survey that consisted of standardized measures to assess demographics, recent CD4 counts, self-efficacy, patient-HCP relationship, adherence, and medication-taking difficulties. The data shown the relationship between patient-HCP relationships and adherence was significantly consistent with mediation by medication self-efficacy. However, patient-HCP interaction did not directly influence medication-taking difficulties, and medication-taking difficulties did not significantly affect CD4 counts. Furthermore, patient-HCP interactions did not directly impact CD4 counts; rather, the relation was consistent with mediation (by either better medication self-efficacy or better adherence) or by improved adherence alone. Future interventions should be designed to enhance self-management and provide better patient-HCP communication. This improved communication will enhance medication self-efficacy and decrease medication-taking difficulties. This in turn will improve medication adherence and immune function among PLWHA.

  4. A model of buyer-supplier relationships in a transnational company: the role of the business network context

    Directory of Open Access Journals (Sweden)

    Matevž Rasković

    2012-04-01

    Full Text Available The paradigmatic shift in marketing from the beginning of the 1990’s has transformed marketing in its view of business exchange to increasingly start addressing the relational aspects of market exchanges. This is particularly true in transnational supply exchanges, where specialization and outsourcing have increased the importance of effective and efficient management of buyer-supplier relationships, and their corresponding networks in which they are embedded in. In this regard particularly, TNCs are seen “as a [key] method of organizing international exchange”. The purpose of this paper is to analyze selected elements of buyer-supplier relationships within a specific TNC business-to-business (B2B setting, vis-à-vis their impact on business performance and TNC competitiveness. This is done through the perspective of the TNC’s suppliers. The paper analyzes the impact of the functional aspect of the business network context on selected elements of buyer-supplier relationships, and their impact on business performance and the overall competitiveness. This is analyzed within a confirmatory testing of a reflective structural equation model. A unique feature of the model is its focus on the business network context - namely information obtained from the network and network spillover effects – as key network-embedded determinants of the “traditional” elements of buyer-supplier relationships (i.e. transaction-specific investments, trust, flexibility, and collaboration, where these elements have been so far mostly studied at the dyadic level in buyer-supplier relationships. The dataset includes a sample of 157 suppliers of the focal TNC world-wide (47.9 response rate on a web-based survey.

  5. The Relationships among Leadership, Entrepreneurial Mindset, Innovation and Competitive Advantage (A Conceptual Model of Logistics Service Industry

    Directory of Open Access Journals (Sweden)

    Darjat Sudrajat

    2015-11-01

    Full Text Available Nowadays, improvement of competitive advantage is an important and urgent issue facing logistics service companies in Indonesia. Some previous researches showed that to improve the competitive advantage could be conducted through improvement of leadership, entrepreneurial mindset and innovation variables. This research intended to recognize relationships among the variables. The research used causal-explanatory method. The results of research encompass a conceptual model, status of each variable and hypotheses. The conceptual model could be further verified through verification research. 

  6. Modeling Chemical Interaction Profiles: I. Spectral Data-Activity Relationship and Structure-Activity Relationship Models for Inhibitors and Non-inhibitors of Cytochrome P450 CYP3A4 and CYP2D6 Isozymes

    Directory of Open Access Journals (Sweden)

    Richard D. Beger

    2012-03-01

    Full Text Available An interagency collaboration was established to model chemical interactions that may cause adverse health effects when an exposure to a mixture of chemicals occurs. Many of these chemicals—drugs, pesticides, and environmental pollutants—interact at the level of metabolic biotransformations mediated by cytochrome P450 (CYP enzymes. In the present work, spectral data-activity relationship (SDAR and structure-activity relationship (SAR approaches were used to develop machine-learning classifiers of inhibitors and non-inhibitors of the CYP3A4 and CYP2D6 isozymes. The models were built upon 602 reference pharmaceutical compounds whose interactions have been deduced from clinical data, and 100 additional chemicals that were used to evaluate model performance in an external validation (EV test. SDAR is an innovative modeling approach that relies on discriminant analysis applied to binned nuclear magnetic resonance (NMR spectral descriptors. In the present work, both 1D 13C and 1D 15N-NMR spectra were used together in a novel implementation of the SDAR technique. It was found that increasing the binning size of 1D 13C-NMR and 15N-NMR spectra caused an increase in the tenfold cross-validation (CV performance in terms of both the rate of correct classification and sensitivity. The results of SDAR modeling were verified using SAR. For SAR modeling, a decision forest approach involving from 6 to 17 Mold2 descriptors in a tree was used. Average rates of correct classification of SDAR and SAR models in a hundred CV tests were 60% and 61% for CYP3A4, and 62% and 70% for CYP2D6, respectively. The rates of correct classification of SDAR and SAR models in the EV test were 73% and 86% for CYP3A4, and 76% and 90% for CYP2D6, respectively. Thus, both SDAR and SAR methods demonstrated a comparable performance in modeling a large set of structurally diverse data. Based on unique NMR structural descriptors, the new SDAR modeling method complements the existing SAR

  7. The method of modelling of relationships between hardenability and chemical composition of the constructional alloy steels

    International Nuclear Information System (INIS)

    Dobrzanski, L.A.; Sitek, W.

    1998-01-01

    Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The model of neural networks, making it possible to design the steel chemical composition, basing on the known Jominy hardenability curve shape, was developed also and fully verified numerically. The practical usability of the models developed is presented. (author)

  8. Multilevel models in the explanation of the relationship between safety climate and safe behavior.

    Science.gov (United States)

    Cheyne, Alistair; Tomás, José M; Oliver, Amparo

    2013-01-01

    This study examines the relationships between components of organizational safety climate, including employee attitudes to organizational safety issues; perceptions of the physical working environment, and evaluations of worker engagement with safety issues; and relates these to self-reported levels of safety behavior. It attempts to explore the relationships between these variables in 1189 workers across 78 work groups in a large transportation organization. Evaluations of safety climate, the working environment and worker engagement, as well as safe behaviors, were collected using a self report questionnaire. The multilevel analysis showed that both levels of evaluation (the work group and the individual), and some cross-level interactions, were significant in explaining safe behaviors. Analyses revealed that a number of variables, at both levels, were associated with worker engagement and safe behaviors. The results suggest that, while individual evaluations of safety issues are important, there is also a role for the fostering of collective safety climates in encouraging safe behaviors and therefore reducing accidents.

  9. Towards a Better Understanding of the Relationship Between Probabilistic Models in IR

    NARCIS (Netherlands)

    Aly, Robin; Demeester, Thomas

    Probability of relevance (PR) models are generally assumed to implement the Probability Ranking Principle (PRP) of IR, and recent publications claim that PR models and language models are similar. However, a careful analysis reveals two gaps in the chain of reasoning behind this statement. First,

  10. Improving customer churn models as one of customer relationship management business solutions for the telecommunication industry

    OpenAIRE

    Slavescu, Ecaterina; Panait, Iulian

    2012-01-01

    Nowadays, when companies are dealing with severe global competition, they are making serious investments in Customer Relationship Management (CRM) strategies. One of the cornerstones in CRM is customer churn prediction, the practice of determining a mathematical relation between customer characteristics and the likelihood to end the business contract with the company. This paper focuses on how to better support marketing decision makers in identifying risky customers in telecom industry by us...

  11. Application of Structural Equations Modeling to assess relationship among Emotional Intelligence, General Health and Occupational Accidents

    OpenAIRE

    MOAMMAD KHANDAN; AMIR KAVOUSI; ALIREZA KOOHPAEI

    2015-01-01

    ORIGINAL ARTICLEEmotional intelligence (EI) has been subject of significant amounts of literature over the past two decades. However, little has been contributed to how emotional intelligence may be practically applied to enhance both accident prevention program and general health in workplaces. Purpose of this paper is to survey relationship among these variables in working society of Iran in 2014. As well as identify practical approaches to application of emotional intelligence skills to ma...

  12. Early-branching euteleost relationships: areas of congruence between concatenation and coalescent model inferences

    Directory of Open Access Journals (Sweden)

    Matthew A. Campbell

    2017-09-01

    Full Text Available Phylogenetic inference based on evidence from DNA sequences has led to significant strides in the development of a stable and robustly supported framework for the vertebrate tree of life. To date, the bulk of those advances have relied on sequence data from a small number of genome regions that have proven unable to produce satisfactory answers to consistently recalcitrant phylogenetic questions. Here, we re-examine phylogenetic relationships among early-branching euteleostean fish lineages classically grouped in the Protacanthopterygii using DNA sequence data surrounding ultraconserved elements. We report and examine a dataset of thirty-four OTUs with 17,957 aligned characters from fifty-three nuclear loci. Phylogenetic analysis is conducted in concatenated, joint gene trees and species tree estimation and summary coalescent frameworks. All analytical frameworks yield supporting evidence for existing hypotheses of relationship for the placement of Lepidogalaxias salamandroides, monophyly of the Stomiatii and the presence of an esociform + salmonid clade. Lepidogalaxias salamandroides and the Esociformes + Salmoniformes are successive sister lineages to all other euteleosts in the majority of analyses. The concatenated and joint gene trees and species tree analysis types produce high support values for this arrangement. However, inter-relationships of Argentiniformes, Stomiatii and Neoteleostei remain uncertain as they varied by analysis type while receiving strong and contradictory indices of support. Topological differences between analysis types are also apparent within the otomorph and the percomorph taxa in the data set. Our results identify concordant areas with strong support for relationships within and between early-branching euteleost lineages but they also reveal limitations in the ability of larger datasets to conclusively resolve other aspects of that phylogeny.

  13. Early-branching euteleost relationships: areas of congruence between concatenation and coalescent model inferences.

    Science.gov (United States)

    Campbell, Matthew A; Alfaro, Michael E; Belasco, Max; López, J Andrés

    2017-01-01

    Phylogenetic inference based on evidence from DNA sequences has led to significant strides in the development of a stable and robustly supported framework for the vertebrate tree of life. To date, the bulk of those advances have relied on sequence data from a small number of genome regions that have proven unable to produce satisfactory answers to consistently recalcitrant phylogenetic questions. Here, we re-examine phylogenetic relationships among early-branching euteleostean fish lineages classically grouped in the Protacanthopterygii using DNA sequence data surrounding ultraconserved elements. We report and examine a dataset of thirty-four OTUs with 17,957 aligned characters from fifty-three nuclear loci. Phylogenetic analysis is conducted in concatenated, joint gene trees and species tree estimation and summary coalescent frameworks. All analytical frameworks yield supporting evidence for existing hypotheses of relationship for the placement of Lepidogalaxias salamandroides , monophyly of the Stomiatii and the presence of an esociform + salmonid clade. Lepidogalaxias salamandroides and the Esociformes + Salmoniformes are successive sister lineages to all other euteleosts in the majority of analyses. The concatenated and joint gene trees and species tree analysis types produce high support values for this arrangement. However, inter-relationships of Argentiniformes, Stomiatii and Neoteleostei remain uncertain as they varied by analysis type while receiving strong and contradictory indices of support. Topological differences between analysis types are also apparent within the otomorph and the percomorph taxa in the data set. Our results identify concordant areas with strong support for relationships within and between early-branching euteleost lineages but they also reveal limitations in the ability of larger datasets to conclusively resolve other aspects of that phylogeny.

  14. Constitutive relationships of hot stamping boron steel B1500HS based on the modified Arrhenius and Johnson–Cook model

    International Nuclear Information System (INIS)

    Li, Huiping; He, Lianfang; Zhao, Guoqun; Zhang, Lei

    2013-01-01

    Constitutive relationship of boron steel is one of the most necessary mathematical models in the numerical simulation of hot stamping; it describes the relationship of the flow stress with strain, strain rate and temperature. In order to attain the constitutive relationship of boron steel B1500HS, four types of samples with microstructure of austenite, ferrite+pearlite, bainite or martensite are prepared by the Gleeble 1500D thermo-mechanical simulator. Isothermal uniaxial tension testings for these specimens are performed at 20–900 °C at the strain rates of 0.01 s –1 , 0.1 s –1 , 1.0 s –1 and 10 s –1 by Gleeble 1500D, and the true stress–strain curves at the relative conditions are gained. The experimental results show that, the flow stress of samples with relative microstructure rises with the decrease of the deformation temperature, and with the increase of the strain rate. The modified Arrhenius model is used to describe the hot deformation of samples with austenite microstructure, and the modified Johnson–Cook model is used to describe the deformation process of samples with ferrite+pearlite, bainite or martensite microstructure. The constitutive equations depending on the strain, strain rate and temperature are attained by the regression analysis for the experimental data of flow stress, strain, strain rate, temperature, etc. The comparison of the computational data and the experimental results shows that, the computational data using the constitutive relationships are well consistent with the experimental data

  15. Long-term relationships of major macro-variables in a resource-related economic model of Australia

    International Nuclear Information System (INIS)

    Harvie, Charles; Hoa, T. van

    1993-01-01

    The paper reports the results of a simple cointegration analysis applied to bivariate causality models using data on resource output, oil prices, terms of trade, current account and output growth to investigate the long-term relationships among these major macroeconomic aggregates in a resource-related economic model of Australia. For the period 1960-1990, the empirical evidence indicates that these five macro-variables, as formulated in our model, are not random walks. In addition, resource production and oil prices are significantly cointegrated, and they are also significantly cointegrated with the current account, terms of trade and economic growth. These findings provide support to the long-term adjustments foundation of our resource-related model. (author)

  16. The relationship between wave and geometrical optics models of coded aperture type x-ray phase contrast imaging systems.

    Science.gov (United States)

    Munro, Peter R T; Ignatyev, Konstantin; Speller, Robert D; Olivo, Alessandro

    2010-03-01

    X-ray phase contrast imaging is a very promising technique which may lead to significant advancements in medical imaging. One of the impediments to the clinical implementation of the technique is the general requirement to have an x-ray source of high coherence. The radiation physics group at UCL is currently developing an x-ray phase contrast imaging technique which works with laboratory x-ray sources. Validation of the system requires extensive modelling of relatively large samples of tissue. To aid this, we have undertaken a study of when geometrical optics may be employed to model the system in order to avoid the need to perform a computationally expensive wave optics calculation. In this paper, we derive the relationship between the geometrical and wave optics model for our system imaging an infinite cylinder. From this model we are able to draw conclusions regarding the general applicability of the geometrical optics approximation.

  17. A model for the training effects in swimming demonstrates a strong relationship between parasympathetic activity, performance and index of fatigue.

    Directory of Open Access Journals (Sweden)

    Sébastien Chalencon

    Full Text Available Competitive swimming as a physical activity results in changes to the activity level of the autonomic nervous system (ANS. However, the precise relationship between ANS activity, fatigue and sports performance remains contentious. To address this problem and build a model to support a consistent relationship, data were gathered from national and regional swimmers during two 30 consecutive-week training periods. Nocturnal ANS activity was measured weekly and quantified through wavelet transform analysis of the recorded heart rate variability. Performance was then measured through a subsequent morning 400 meters freestyle time-trial. A model was proposed where indices of fatigue were computed using Banister's two antagonistic component model of fatigue and adaptation applied to both the ANS activity and the performance. This demonstrated that a logarithmic relationship existed between performance and ANS activity for each subject. There was a high degree of model fit between the measured and calculated performance (R(2=0.84±0.14,p<0.01 and the measured and calculated High Frequency (HF power of the ANS activity (R(2=0.79±0.07, p<0.01. During the taper periods, improvements in measured performance and measured HF were strongly related. In the model, variations in performance were related to significant reductions in the level of 'Negative Influences' rather than increases in 'Positive Influences'. Furthermore, the delay needed to return to the initial performance level was highly correlated to the delay required to return to the initial HF power level (p<0.01. The delay required to reach peak performance was highly correlated to the delay required to reach the maximal level of HF power (p=0.02. Building the ANS/performance identity of a subject, including the time to peak HF, may help predict the maximal performance that could be obtained at a given time.

  18. Relationships: empirical contribution. Understanding personality pathology in adolescents: the five factor model of personality and social information processing.

    Science.gov (United States)

    Hessels, Christel; van den Hanenberg, Danique; de Castro, Bram Orobio; van Aken, Marcel A G

    2014-02-01

    This study seeks to integrate two research traditions that lie at the base of the understanding of personality pathology in adolescents. The first research tradition refers to normal personality according to the Five Factor Model (FFM). The second tradition specifies the key feature of personality disorder as the capacity to mentalize, which can be reflected in Social Information Processing (SIP). In a clinical sample of 96 adolescents, the authors investigated response generation, coping strategy, and memories of past frustrating experiences as part of SIP, as mediator in the relationship between personality and personality pathology, and a possible moderating role of personality on the relationship between SIP and personality pathology. The hypothesized mediation, by which the effects of personality dimensions on personality pathology was expected to be mediated by SIP variables, was found only for the effect of Neuroticism, most specifically on BPD, which appeared to be mediated by memories the patients had about past frustrating conflict situations with peers. Some moderating effects of personality on the relationship between SIP variables and personality pathology were found, suggesting that high Agreeableness and sometimes low Neuroticism can buffer this relationship. These results suggest that personality dimensions and social cognitions both independently and together play a role in adolescents' personality pathology.

  19. Relationships among mental health status, social context, and demographic characteristics in Taiwanese aboriginal adolescents: a structural equation model.

    Science.gov (United States)

    Yen, Cheng-Fang; Hsu, Chia-Chuang; Liu, Shu-Chun; Huang, Chi-Fen; Ko, Chih-Hung; Yen, Ju-Yu; Cheng, Chung-Ping

    2006-10-01

    The purposes of this study were to examine the relationships among mental health status, demographic characteristics, and social contexts, including family conflict and support, connectedness to school, and affiliation with peers who exhibit delinquent behavior and who use substances, among Taiwanese aboriginal adolescents. A total of 251 aboriginal junior high school students in an isolated mountainous area of southern Taiwan were recruited, and the relationships among mental health status, demographic characteristics, and social contexts among them were examined using a structural equation model (SEM). The SEM revealed that family conflict and support had direct influences on mental health status and connectedness to school. Family conflict had a direct relationship with affiliation with peers who use substances, and family conflict and support were both indirectly linked with affiliation with peers who exhibit delinquent behavior and who used substances; these were mediated by a poor mental health status. Female and older age were directly linked with a poor mental health status and were indirectly linked with a greater number of peers who exhibit delinquent behavior and who use substances via the poor mental health status. Disruptive parenting was directly linked with affiliation with peers who use substances. The authors suggest that those who devise strategies to improve aboriginal adolescents' mental health and discourage substance use should take these relationships among mental health, demographic characteristics, and social contexts into account.

  20. Animal models of polycystic ovary syndrome: a focused review of rodent models in relationship to clinical phenotypes and cardiometabolic risk.

    Science.gov (United States)

    Shi, Danni; Vine, Donna F

    2012-07-01

    To review rodent animal models of polycystic ovary syndrome (PCOS), with a focus on those associated with the metabolic syndrome and cardiovascular disease risk factors. Review. Rodent models of PCOS. Description and comparison of animal models. Comparison of animal models to clinical phenotypes of PCOS. Animals used to study PCOS include rodents, mice, rhesus monkeys, and ewes. Major methods to induce PCOS in these models include subcutaneous injection or implantation of androgens, estrogens, antiprogesterone, letrozole, prenatal exposure to excess androgens, and exposure to constant light. In addition, transgenic mice models and spontaneous PCOS-like rodent models have also been developed. Rodents are the most economical and widely used animals to study PCOS and ovarian dysfunction. The model chosen to study the development of PCOS and other metabolic parameters remains dependent on the specific etiologic hypotheses being investigated. Rodent models have been shown to demonstrate changes in insulin metabolism, with or without induction of hyperandrogenemia, and limited studies have investigated cardiometabolic risk factors for type 2 diabetes and cardiovascular disease. Given the clinical heterogeneity of PCOS, the utilization of different animal models may be the best approach to further our understanding of the pathophysiologic mechanisms associated with the early etiology of PCOS and cardiometabolic risk. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  1. An update on modeling dose-response relationships: Accounting for correlated data structure and heterogeneous error variance in linear and nonlinear mixed models.

    Science.gov (United States)

    Gonçalves, M A D; Bello, N M; Dritz, S S; Tokach, M D; DeRouchey, J M; Woodworth, J C; Goodband, R D

    2016-05-01

    Advanced methods for dose-response assessments are used to estimate the minimum concentrations of a nutrient that maximizes a given outcome of interest, thereby determining nutritional requirements for optimal performance. Contrary to standard modeling assumptions, experimental data often present a design structure that includes correlations between observations (i.e., blocking, nesting, etc.) as well as heterogeneity of error variances; either can mislead inference if disregarded. Our objective is to demonstrate practical implementation of linear and nonlinear mixed models for dose-response relationships accounting for correlated data structure and heterogeneous error variances. To illustrate, we modeled data from a randomized complete block design study to evaluate the standardized ileal digestible (SID) Trp:Lys ratio dose-response on G:F of nursery pigs. A base linear mixed model was fitted to explore the functional form of G:F relative to Trp:Lys ratios and assess model assumptions. Next, we fitted 3 competing dose-response mixed models to G:F, namely a quadratic polynomial (QP) model, a broken-line linear (BLL) ascending model, and a broken-line quadratic (BLQ) ascending model, all of which included heteroskedastic specifications, as dictated by the base model. The GLIMMIX procedure of SAS (version 9.4) was used to fit the base and QP models and the NLMIXED procedure was used to fit the BLL and BLQ models. We further illustrated the use of a grid search of initial parameter values to facilitate convergence and parameter estimation in nonlinear mixed models. Fit between competing dose-response models was compared using a maximum likelihood-based Bayesian information criterion (BIC). The QP, BLL, and BLQ models fitted on G:F of nursery pigs yielded BIC values of 353.7, 343.4, and 345.2, respectively, thus indicating a better fit of the BLL model. The BLL breakpoint estimate of the SID Trp:Lys ratio was 16.5% (95% confidence interval [16.1, 17.0]). Problems with

  2. Managers as role models for health: Moderators of the relationship of transformational leadership with employee exhaustion and cynicism.

    Science.gov (United States)

    Kranabetter, Caroline; Niessen, Cornelia

    2017-10-01

    Drawing on social learning literature, this study examined managers' health awareness and health behavior (health-related self-regulation) as a moderator of the relationships between transformational leadership and employee exhaustion and cynicism. In 2 organizations, employees (n = 247; n = 206) rated their own exhaustion and cynicism, and their managers' transformational leadership. Managers (n = 57; n = 30) assessed their own health-related self-regulation. Multilevel modeling showed that, as expected, managers' health awareness moderated the relationship between transformational leadership and employee exhaustion and cynicism. Employees experienced less exhaustion and cynicism when transformational leaders were aware of their own health. Managers' health behavior moderated the relationship between transformational leadership and employee exhaustion in 1 organization, but not in the other. With respect to health behavior, we found no significant results for employee cynicism. In sum, the results indicate that when managers are role models for health, employees will benefit more from the transformational leadership style. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Development of polyparameter linear free energy relationship models for octanol-air partition coefficients of diverse chemicals.

    Science.gov (United States)

    Jin, Xiaochen; Fu, Zhiqiang; Li, Xuehua; Chen, Jingwen

    2017-03-22

    The octanol-air partition coefficient (K OA ) is a key parameter describing the partition behavior of organic chemicals between air and environmental organic phases. As the experimental determination of K OA is costly, time-consuming and sometimes limited by the availability of authentic chemical standards for the compounds to be determined, it becomes necessary to develop credible predictive models for K OA . In this study, a polyparameter linear free energy relationship (pp-LFER) model for predicting K OA at 298.15 K and a novel model incorporating pp-LFERs with temperature (pp-LFER-T model) were developed from 795 log K OA values for 367 chemicals at different temperatures (263.15-323.15 K), and were evaluated with the OECD guidelines on QSAR model validation and applicability domain description. Statistical results show that both models are well-fitted, robust and have good predictive capabilities. Particularly, the pp-LFER model shows a strong predictive ability for polyfluoroalkyl substances and organosilicon compounds, and the pp-LFER-T model maintains a high predictive accuracy within a wide temperature range (263.15-323.15 K).

  4. Development of quantitative structure activity relationship (QSAR) model for disinfection byproduct (DBP) research: A review of methods and resources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baiyang, E-mail: poplar_chen@hotmail.com [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Zhang, Tian [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Bond, Tom [Department of Civil and Environmental Engineering, Imperial College, London SW7 2AZ (United Kingdom); Gan, Yiqun [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China)

    2015-12-15

    Quantitative structure–activity relationship (QSAR) models are tools for linking chemical activities with molecular structures and compositions. Due to the concern about the proliferating number of disinfection byproducts (DBPs) in water and the associated financial and technical burden, researchers have recently begun to develop QSAR models to investigate the toxicity, formation, property, and removal of DBPs. However, there are no standard procedures or best practices regarding how to develop QSAR models, which potentially limit their wide acceptance. In order to facilitate more frequent use of QSAR models in future DBP research, this article reviews the processes required for QSAR model development, summarizes recent trends in QSAR-DBP studies, and shares some important resources for QSAR development (e.g., free databases and QSAR programs). The paper follows the four steps of QSAR model development, i.e., data collection, descriptor filtration, algorithm selection, and model validation; and finishes by highlighting several research needs. Because QSAR models may have an important role in progressing our understanding of DBP issues, it is hoped that this paper will encourage their future use for this application.

  5. Development of quantitative structure activity relationship (QSAR) model for disinfection byproduct (DBP) research: A review of methods and resources

    International Nuclear Information System (INIS)

    Chen, Baiyang; Zhang, Tian; Bond, Tom; Gan, Yiqun

    2015-01-01

    Quantitative structure–activity relationship (QSAR) models are tools for linking chemical activities with molecular structures and compositions. Due to the concern about the proliferating number of disinfection byproducts (DBPs) in water and the associated financial and technical burden, researchers have recently begun to develop QSAR models to investigate the toxicity, formation, property, and removal of DBPs. However, there are no standard procedures or best practices regarding how to develop QSAR models, which potentially limit their wide acceptance. In order to facilitate more frequent use of QSAR models in future DBP research, this article reviews the processes required for QSAR model development, summarizes recent trends in QSAR-DBP studies, and shares some important resources for QSAR development (e.g., free databases and QSAR programs). The paper follows the four steps of QSAR model development, i.e., data collection, descriptor filtration, algorithm selection, and model validation; and finishes by highlighting several research needs. Because QSAR models may have an important role in progressing our understanding of DBP issues, it is hoped that this paper will encourage their future use for this application.

  6. Spiritual AIM and the work of the chaplain: a model for assessing spiritual needs and outcomes in relationship.

    Science.gov (United States)

    Shields, Michele; Kestenbaum, Allison; Dunn, Laura B

    2015-02-01

    Distinguishing the unique contributions and roles of chaplains as members of healthcare teams requires the fundamental step of articulating and critically evaluating conceptual models that guide practice. However, there is a paucity of well-described spiritual assessment models. Even fewer of the extant models prescribe interventions and describe desired outcomes corresponding to spiritual assessments. This article describes the development, theoretical underpinnings, and key components of one model, called the Spiritual Assessment and Intervention Model (Spiritual AIM). Three cases are presented that illustrate Spiritual AIM in practice. Spiritual AIM was developed over the past 20 years to address the limitations of existing models. The model evolved based in part on observing how different people respond to a health crisis and what kinds of spiritual needs appear to emerge most prominently during a health crisis. Spiritual AIM provides a conceptual framework for the chaplain to diagnose an individual's primary unmet spiritual need, devise and implement a plan for addressing this need through embodiment/relationship, and articulate and evaluate the desired and actual outcome of the intervention. Spiritual AIM's multidisciplinary theory is consistent with the goals of professional chaplaincy training and practice, which emphasize the integration of theology, recognition of interpersonal dynamics, cultural humility and competence, ethics, and theories of human development. Further conceptual and empirical work is needed to systematically refine, evaluate, and disseminate well-articulated spiritual assessment models such as Spiritual AIM. This foundational work is vital to advancing chaplaincy as a theoretically grounded and empirically rigorous healthcare profession.

  7. Full Random Coefficients Multilevel Modeling of the Relationship between Land Use and Trip Time on Weekdays and Weekends

    Directory of Open Access Journals (Sweden)

    Tae-Hyoung Tommy Gim

    2017-10-01

    Full Text Available Interests in weekend trips are increasing, but few have studied how they are affected by land use. In this study, we analyze the relationship between compact land use characteristics and trip time in Seoul, Korea by comparing two research models, each of which uses the weekday and weekend data of the same travelers. To secure sufficient numbers of subjects and groups, full random coefficients multilevel models define the trip as level one and the neighborhood as level two, and find that level-two land use characteristics account for less variation in trip time than level-one individual characteristics. At level one, weekday trip time is found to be reduced by the choice of the automobile as a travel mode, but not by its ownership per se. In addition, it becomes reduced if made by high income travelers and extended to travel to quality jobs. Among four land use characteristics at level two, population density, road connectivity, and subway availability are shown to be significant in the weekday model. Only subway availability has a positive relationship with trip time and this finding is consistent with the level-one result that the choice of automobile alternatives increases trip time. The other land use characteristic, land use balance, turns out to be a single significant land use variable in the weekend model, implying that it is concerned mainly with non-work, non-mandatory travel.

  8. Relationship between root water uptake and soil respiration: A modeling perspective

    Science.gov (United States)

    Teodosio, Bertrand; Pauwels, Valentijn R. N.; Loheide, Steven P.; Daly, Edoardo

    2017-08-01

    Soil moisture affects and is affected by root water uptake and at the same time drives soil CO2 dynamics. Selecting root water uptake formulations in models is important since this affects the estimation of actual transpiration and soil CO2 efflux. This study aims to compare different models combining the Richards equation for soil water flow to equations describing heat transfer and air-phase CO2 production and flow. A root water uptake model (RWC), accounting only for root water compensation by rescaling water uptake rates across the vertical profile, was compared to a model (XWP) estimating water uptake as a function of the difference between soil and root xylem water potential; the latter model can account for both compensation (XWPRWC) and hydraulic redistribution (XWPHR). Models were compared in a scenario with a shallow water table, where the formulation of root water uptake plays an important role in modeling daily patterns and magnitudes of transpiration rates and CO2 efflux. Model simulations for this scenario indicated up to 20% difference in the estimated water that transpired over 50 days and up to 14% difference in carbon emitted from the soil. The models showed reduction of transpiration rates associated with water stress affecting soil CO2 efflux, with magnitudes of soil CO2 efflux being larger for the XWPHR model in wet conditions and for the RWC model as the soil dried down. The study shows the importance of choosing root water uptake models not only for estimating transpiration but also for other processes controlled by soil water content.

  9. A Model for Behavioral Management and Relationship Training for Parents in Groups,

    Science.gov (United States)

    Behavior, Human relations, *Training, *Families(Human), Symposia, Models, Children, Psychotherapy, Problem solving, Management, Control, Learning, Skills, Decision making , Group dynamics, Military psychology, Military medicine

  10. EVALUATION OF THE TRADE RELATIONSHIP BETWEEN VIETNAM AND CHINA; VIETNAM AND UNITED STATES: A COMPARISON USING GRAVITY MODEL

    Directory of Open Access Journals (Sweden)

    Lien Thi Dinh

    2017-06-01

    Full Text Available This study aims to evaluate the determinants of trade relationship between two largest trading partners of Vietnam, United States and China. Using gravity model for time series data from 1986 to 2015, the study found that economic growth rate plays a crucial role in stimulating the trade flow. Both trade relationships fit with the practical approach of Heckscher-Ohlin theory, stating that trade flow increases between countries with different income levels. The most important finding of this study lines on the results regarding the impact of trade agreements. While United States-Vietnam bilateral agreement creates trade, the trade agreement between ASEAN and China produced trade diversion. As China expands its markets among ASEAN countries, Vietnam should diversify its export markets to improve its export flow.

  11. A model for establishing a win-win relationship between a wood pellets manufacturer and its customers

    International Nuclear Information System (INIS)

    Uran, Vedran

    2010-01-01

    This paper investigates the possibility of establishing a win-win relationship between a wood pellets manufacturer and its customers when the manufacturer possesses a power plant fueled by biomass and buys wood material from forest companies. Two prerequisites must be fulfilled for this relationship. First, the price of wood pellets should be lower than the fuel currently used by potential wood pellets customers and, second, the price of wood material as a raw material for producing the wood pellets should not jeopardize the profitability of the operations of the wood pellets manufacturer, who also produces electricity from biomass and sells it to the state at the feed-in tariff price. A mathematical model has been developed for each prerequisite and applied to several examples. The results demonstrate that a win-win relation can be established in Croatia and most of the Member States of the EU. (author)

  12. Differentiation of Self and Dyadic Adjustment in Couple Relationships: A Dyadic Analysis Using the Actor-Partner Interdependence Model.

    Science.gov (United States)

    Lampis, Jessica; Cataudella, Stefania; Agus, Mirian; Busonera, Alessandra; Skowron, Elizabeth A

    2018-06-10

    Bowen's multigenerational theory provides an account of how the internalization of experiences within the family of origin promotes development of the ability to maintain a distinct self whilst also making intimate connections with others. Differentiated people can maintain their I-position in intimate relationships. They can remain calm in conflictual relationships, resolve relational problems effectively, and reach compromises. Fusion with others, emotional cut-off, and emotional reactivity instead are common reactions to relational stress in undifferentiated people. Emotional reactivity is the tendency to react to stressors with irrational and intense emotional arousal. Fusion with others is an excessive emotional involvement in significant relationships, whilst emotional cut-off is the tendency to manage relationship anxiety through physical and emotional distance. This study is based on Bowen's theory, starting from the assumption that dyadic adjustment can be affected both by a member's differentiation of self (actor effect) and by his or her partner's differentiation of self (partner effect). We used the Actor-Partner Interdependence Model to study the relationship between differentiation of self and dyadic adjustment in a convenience sample of 137 heterosexual Italian couples (nonindependent, dyadic data). The couples completed the Differentiation of Self Inventory and the Dyadic Adjustment Scale. Men's dyadic adjustment depended only on their personal I-position, whereas women's dyadic adjustment was affected by their personal I-position and emotional cut-off as well as by their partner's I-position and emotional cut-off. The empirical and clinical implications of the results are discussed. © 2018 Family Process Institute.

  13. Model integrating the processes of consumer perceived value creation and consumer relationship development

    OpenAIRE

    Vaitkienė, Rimgailė; Pilibaitytė, Vestina

    2008-01-01

    Straipsnyje analizuojamos vertės vartotojui kūrimo bei santykių vystymo procesų sąsajos. Jame apžvelgiama santykių nauda, kaip vertės vartotojui dedamoji, santykių su vartotojais vystymo procesas bei jo etapai, vertės vartotojui kūrimo procesas santykių marketingo kontekste bei pateikiamas vertės vartotojui kūrimo ir santykių su vartotojais vystymo procesus integruojantis modelis. The article analyses the links between the consumer perceived value creation and relationship development proc...

  14. The relationship between multilevel models and non-parametric multilevel mixture models: Discrete approximation of intraclass correlation, random coefficient distributions, and residual heteroscedasticity.

    Science.gov (United States)

    Rights, Jason D; Sterba, Sonya K

    2016-11-01

    Multilevel data structures are common in the social sciences. Often, such nested data are analysed with multilevel models (MLMs) in which heterogeneity between clusters is modelled by continuously distributed random intercepts and/or slopes. Alternatively, the non-parametric multilevel regression mixture model (NPMM) can accommodate the same nested data structures through discrete latent class variation. The purpose of this article is to delineate analytic relationships between NPMM and MLM parameters that are useful for understanding the indirect interpretation of the NPMM as a non-parametric approximation of the MLM, with relaxed distributional assumptions. We define how seven standard and non-standard MLM specifications can be indirectly approximated by particular NPMM specifications. We provide formulas showing how the NPMM can serve as an approximation of the MLM in terms of intraclass correlation, random coefficient means and (co)variances, heteroscedasticity of residuals at level 1, and heteroscedasticity of residuals at level 2. Further, we discuss how these relationships can be useful in practice. The specific relationships are illustrated with simulated graphical demonstrations, and direct and indirect interpretations of NPMM classes are contrasted. We provide an R function to aid in implementing and visualizing an indirect interpretation of NPMM classes. An empirical example is presented and future directions are discussed. © 2016 The British Psychological Society.

  15. Spekkens’ toy model in all dimensions and its relationship with stabiliser quantum mechanics

    Science.gov (United States)

    Catani, Lorenzo; E Browne, Dan

    2017-07-01

    Spekkens’ toy model is a non-contextual hidden variable model with an epistemic restriction, a constraint on what an observer can know about reality. The aim of the model, developed for continuous and discrete prime degrees of freedom, is to advocate the epistemic view of quantum theory, where quantum states are states of incomplete knowledge about a deeper underlying reality. Many aspects of quantum mechanics and protocols from quantum information can be reproduced in the model. In spite of its significance, a number of aspects of Spekkens’ model remained incomplete. Formal rules for the update of states after measurement had not been written down, and the theory had only been constructed for prime-dimensional and infinite dimensional systems. In this work, we remedy this, by deriving measurement update rules and extending the framework to derive models in all dimensions, both prime and non-prime. Stabiliser quantum mechanics (SQM) is a sub-theory of quantum mechanics with restricted states, transformations and measurements. First derived for the purpose of constructing error correcting codes, it now plays a role in many areas of quantum information theory. Previously, it had been shown that Spekkens’ model was operationally equivalent to SQM in the case of odd prime dimensions. Here, exploiting known results on Wigner functions, we extend this to show that Spekkens’ model is equivalent to SQM in all odd dimensions, prime and non-prime. This equivalence provides new technical tools for the study of technically difficult compound-dimensional SQM.

  16. The Relationship between Students' Performance on Conventional Standardized Mathematics Assessments and Complex Mathematical Modeling Problems

    Science.gov (United States)

    Kartal, Ozgul; Dunya, Beyza Aksu; Diefes-Dux, Heidi A.; Zawojewski, Judith S.

    2016-01-01

    Critical to many science, technology, engineering, and mathematics (STEM) career paths is mathematical modeling--specifically, the creation and adaptation of mathematical models to solve problems in complex settings. Conventional standardized measures of mathematics achievement are not structured to directly assess this type of mathematical…

  17. Student Identification with Business Education Models: Measurement and Relationship to Educational Outcomes

    Science.gov (United States)

    Halbesleben, Jonathon R. B.; Wheeler, Anthony R.

    2009-01-01

    Although management scholars have provided a variety of metaphors to describe the role of students in management courses, researchers have yet to explore students' identification with the models and how they are linked to educational outcomes. This article develops a measurement tool for students' identification with business education models and…

  18. The complementary relationship in estimation of regional evapotranspiration: An enhanced Advection-Aridity model

    Science.gov (United States)

    Michael T. Hobbins; Jorge A. Ramirez; Thomas C. Brown

    2001-01-01

    Long-term monthly evapotranspiration estimates from Brutsaert and Stricker’s Advection-Aridity model were compared with independent estimates of evapotranspiration derived from long-term water balances for 139 undisturbed basins across the conterminous United States. On an average annual basis for the period 1962-1988 the original model, which uses a Penman wind...

  19. The Relationship between Shared Mental Models and Task Performance in an Online Team- Based Learning Environment

    Science.gov (United States)

    Johnson, Tristan E.; Lee, Youngmin

    2008-01-01

    In an effort to better understand learning teams, this study examines the effects of shared mental models on team and individual performance. The results indicate that each team's shared mental model changed significantly over the time that subjects participated in team-based learning activities. The results also showed that the shared mental…

  20. Relationship between risk assessment and payment models in Swedish Public Dental Service

    DEFF Research Database (Denmark)

    Petersson, Gunnel Hänsel; Twetman, Svante

    2017-01-01

    risk preferred the prepaid model while those in the higher risk categories selected fee-for-service. As more additional preventive care was delivered to patients in the subscribed care, oral health planners and decision makers should be aware of the fact that capitation payment models may enhance...

  1. Modeling precipitation-runoff relationships to determine water yield from a ponderosa pine forest watershed

    Science.gov (United States)

    Assefa S. Desta

    2006-01-01

    A stochastic precipitation-runoff modeling is used to estimate a cold and warm-seasons water yield from a ponderosa pine forested watershed in the north-central Arizona. The model consists of two parts namely, simulation of the temporal and spatial distribution of precipitation using a stochastic, event-based approach and estimation of water yield from the watershed...

  2. Spekkens’ toy model in all dimensions and its relationship with stabiliser quantum mechanics

    International Nuclear Information System (INIS)

    Catani, Lorenzo; Browne, Dan E

    2017-01-01

    Spekkens’ toy model is a non-contextual hidden variable model with an epistemic restriction, a constraint on what an observer can know about reality. The aim of the model, developed for continuous and discrete prime degrees of freedom, is to advocate the epistemic view of quantum theory, where quantum states are states of incomplete knowledge about a deeper underlying reality. Many aspects of quantum mechanics and protocols from quantum information can be reproduced in the model. In spite of its significance, a number of aspects of Spekkens’ model remained incomplete. Formal rules for the update of states after measurement had not been written down, and the theory had only been constructed for prime-dimensional and infinite dimensional systems. In this work, we remedy this, by deriving measurement update rules and extending the framework to derive models in all dimensions, both prime and non-prime. Stabiliser quantum mechanics (SQM) is a sub-theory of quantum mechanics with restricted states, transformations and measurements. First derived for the purpose of constructing error correcting codes, it now plays a role in many areas of quantum information theory. Previously, it had been shown that Spekkens’ model was operationally equivalent to SQM in the case of odd prime dimensions. Here, exploiting known results on Wigner functions, we extend this to show that Spekkens’ model is equivalent to SQM in all odd dimensions, prime and non-prime. This equivalence provides new technical tools for the study of technically difficult compound-dimensional SQM. (paper)

  3. The Relationship between Big Data and Mathematical Modeling: A Discussion in a Mathematical Education Scenario

    Science.gov (United States)

    Dalla Vecchia, Rodrigo

    2015-01-01

    This study discusses aspects of the association between Mathematical Modeling (MM) and Big Data in the scope of mathematical education. We present an example of an activity to discuss two ontological factors that involve MM. The first is linked to the modeling stages. The second involves the idea of pedagogical objectives. The main findings…

  4. Modeling the relationship between photosynthetically active radiation and global horizontal irradiance using singular spectrum analysis

    International Nuclear Information System (INIS)

    Zempila, Melina-Maria; Taylor, Michael; Bais, Alkiviadis; Kazadzis, Stelios

    2016-01-01

    We report on the construction of generic models to calculate photosynthetically active radiation (PAR) from global horizontal irradiance (GHI), and vice versa. Our study took place at stations of the Greek UV network (UVNET) and the Hellenic solar energy network (HNSE) with measurements from NILU-UV multi-filter radiometers and CM pyranometers, chosen due to their long (≈1 M record/site) high temporal resolution (≈1 min) record that captures a broad range of atmospheric environments and cloudiness conditions. The uncertainty of the PAR measurements is quantified to be ±6.5% while the uncertainty involved in GHI measurements is up to ≈±7% according to the manufacturer. We show how multi-linear regression and nonlinear neural network (NN) models, trained at a calibration site (Thessaloniki) can be made generic provided that the input–output time series are processed with multi-channel singular spectrum analysis (M-SSA). Without M-SSA, both linear and nonlinear models perform well only locally. M-SSA with 50 time-lags is found to be sufficient for identification of trend, periodic and noise components in aerosol, cloud parameters and irradiance, and to construct regularized noise models of PAR from GHI irradiances. Reconstructed PAR and GHI time series capture ≈95% of the variance of the cross-validated target measurements and have median absolute percentage errors <2%. The intra-site median absolute error of M-SSA processed models were ≈8.2±1.7 W/m"2 for PAR and ≈9.2±4.2 W/m"2 for GHI. When applying the models trained at Thessaloniki to other stations, the average absolute mean bias between the model estimates and measured values was found to be ≈1.2 W/m"2 for PAR and ≈0.8 W/m"2 for GHI. For the models, percentage errors are well within the uncertainty of the measurements at all sites. Generic NN models were found to perform marginally better than their linear counterparts. - Highlights: • Generic linear regression and nonlinear neural network

  5. Mycobacterium-Host Cell Relationships in Granulomatous Lesions in a Mouse Model of Latent Tuberculous Infection

    Directory of Open Access Journals (Sweden)

    Elena Ufimtseva

    2015-01-01

    Full Text Available Tuberculosis (TB is a dangerous infectious disease characterized by a tight interplay between mycobacteria and host cells in granulomatous lesions (granulomas during the latent, asymptomatic stage of infection. Mycobacterium-host cell relationships were analyzed in granulomas obtained from various organs of BALB/c mice with chronic TB infection caused by in vivo exposure to the Bacillus Calmette-Guérin (BCG vaccine. Acid-fast BCG-mycobacteria were found to be morphologically and functionally heterogeneous (in size, shape, and replication rates in colonies in granuloma macrophages, dendritic cells, and multinucleate Langhans giant cells. Cord formation by BCG-mycobacteria in granuloma cells has been observed. Granuloma macrophages retained their ability to ingest damaged lymphocytes and thrombocytes in the phagosomes; however, their ability to destroy BCG-mycobacteria contained in these cells was compromised. No colocalization of BCG-mycobacteria and the LysoTracker dye was observed in the mouse cells. Various relationships between granuloma cells and BCG-mycobacteria were observed in different mice belonging to the same line. Several mice totally eliminated mycobacterial infection. Granulomas in the other mice had mycobacteria actively replicating in cells of different types and forming cords, which is an indicator of mycobacterial virulence and, probably, a marker of the activation of tuberculous infection in animals.

  6. Mycobacterium-Host Cell Relationships in Granulomatous Lesions in a Mouse Model of Latent Tuberculous Infection

    Science.gov (United States)

    2015-01-01

    Tuberculosis (TB) is a dangerous infectious disease characterized by a tight interplay between mycobacteria and host cells in granulomatous lesions (granulomas) during the latent, asymptomatic stage of infection. Mycobacterium-host cell relationships were analyzed in granulomas obtained from various organs of BALB/c mice with chronic TB infection caused by in vivo exposure to the Bacillus Calmette-Guérin (BCG) vaccine. Acid-fast BCG-mycobacteria were found to be morphologically and functionally heterogeneous (in size, shape, and replication rates in colonies) in granuloma macrophages, dendritic cells, and multinucleate Langhans giant cells. Cord formation by BCG-mycobacteria in granuloma cells has been observed. Granuloma macrophages retained their ability to ingest damaged lymphocytes and thrombocytes in the phagosomes; however, their ability to destroy BCG-mycobacteria contained in these cells was compromised. No colocalization of BCG-mycobacteria and the LysoTracker dye was observed in the mouse cells. Various relationships between granuloma cells and BCG-mycobacteria were observed in different mice belonging to the same line. Several mice totally eliminated mycobacterial infection. Granulomas in the other mice had mycobacteria actively replicating in cells of different types and forming cords, which is an indicator of mycobacterial virulence and, probably, a marker of the activation of tuberculous infection in animals. PMID:26064970

  7. Molecular descriptor subset selection in theoretical peptide quantitative structure-retention relationship model development using nature-inspired optimization algorithms.

    Science.gov (United States)

    Žuvela, Petar; Liu, J Jay; Macur, Katarzyna; Bączek, Tomasz

    2015-10-06

    In this work, performance of five nature-inspired optimization algorithms, genetic algorithm (GA), particle swarm optimization (PSO), artificial bee colony (ABC), firefly algorithm (FA), and flower pollination algorithm (FPA), was compared in molecular descriptor selection for development of quantitative structure-retention relationship (QSRR) models for 83 peptides that originate from eight model proteins. The matrix with 423 descriptors was used as input, and QSRR models based on selected descriptors were built using partial least squares (PLS), whereas root mean square error of prediction (RMSEP) was used as a fitness function for their selection. Three performance criteria, prediction accuracy, computational cost, and the number of selected descriptors, were used to evaluate the developed QSRR models. The results show that all five variable selection methods outperform interval PLS (iPLS), sparse PLS (sPLS), and the full PLS model, whereas GA is superior because of its lowest computational cost and higher accuracy (RMSEP of 5.534%) with a smaller number of variables (nine descriptors). The GA-QSRR model was validated initially through Y-randomization. In addition, it was successfully validated with an external testing set out of 102 peptides originating from Bacillus subtilis proteomes (RMSEP of 22.030%). Its applicability domain was defined, from which it was evident that the developed GA-QSRR exhibited strong robustness. All the sources of the model's error were identified, thus allowing for further application of the developed methodology in proteomics.

  8. Structure-Activity Relationship Models for Rat Carcinogenesis and Assessing the Role Mutagens Play in Model Predictivity

    Science.gov (United States)

    Carrasquer, C. Alex; Batey, Kaylind; Qamar, Shahid; Cunningham, Albert R.; Cunningham, Suzanne L.

    2016-01-01

    We previously demonstrated that fragment based cat-SAR carcinogenesis models consisting solely of mutagenic or non-mutagenic carcinogens varied greatly in terms of their predictive accuracy. This led us to investigate how well the rat cancer cat-SAR model predicted mutagens and non-mutagens in their learning set. Four rat cancer cat-SAR models were developed: Complete Rat, Transgender Rat, Male Rat, and Female Rat, with leave-one-out (LOO) validation concordance values of 69%, 74%, 67%, and 73%, respectively. The mutagenic carcinogens produced concordance values in the range of 69–76% as compared to only 47–53% for non-mutagenic carcinogens. As a surrogate for mutagenicity comparisons between single site and multiple site carcinogen SAR models was analyzed. The LOO concordance values for models consisting of 1-site, 2-site, and 4+-site carcinogens were 66%, 71%, and 79%, respectively. As expected, the proportion of mutagens to non-mutagens also increased, rising from 54% for 1-site to 80% for 4+-site carcinogens. This study demonstrates that mutagenic chemicals, in both SAR learning sets and test sets, are influential in assessing model accuracy. This suggests that SAR models for carcinogens may require a two-step process in which mutagenicity is first determined before carcinogenicity can be accurately predicted. PMID:24697549

  9. The relationship between a deformation-based eddy parameterization and the LANS-α turbulence model

    Science.gov (United States)

    Bachman, Scott D.; Anstey, James A.; Zanna, Laure

    2018-06-01

    A recent class of ocean eddy parameterizations proposed by Porta Mana and Zanna (2014) and Anstey and Zanna (2017) modeled the large-scale flow as a non-Newtonian fluid whose subgridscale eddy stress is a nonlinear function of the deformation. This idea, while largely new to ocean modeling, has a history in turbulence modeling dating at least back to Rivlin (1957). The new class of parameterizations results in equations that resemble the Lagrangian-averaged Navier-Stokes-α model (LANS-α, e.g., Holm et al., 1998a). In this note we employ basic tensor mathematics to highlight the similarities between these turbulence models using component-free notation. We extend the Anstey and Zanna (2017) parameterization, which was originally presented in 2D, to 3D, and derive variants of this closure that arise when the full non-Newtonian stress tensor is used. Despite the mathematical similarities between the non-Newtonian and LANS-α models which might provide insight into numerical implementation, the input and dissipation of kinetic energy between these two turbulent models differ.

  10. MODELING OF RELATIONSHIP BETWEEN GROUNDWATER FLOW AND OTHER METEOROLOGICAL VARIABLES USING FUZZY LOGIC

    Directory of Open Access Journals (Sweden)

    Şaban YURTÇU

    2006-02-01

    Full Text Available In this study, modeling of the effect of rainfall, flow and evaporation as independent variables on the change of underground water levels as dependent variables were investigated by fuzzy logic (FL. In the study, total 396 values taken from six observation stations belong to Afyon inferior basin in Akarçay from 1977 to 1989 years were used. Using the monthly average values of stations, the change of underground water level was modeled by FL. It is observed that the results obtained from FL and the observations are compatible with each other. This shows FL modeling can be used to estimate groundwater levels from the appropriate meteorological value.

  11. Relationship of the Williams-Poulios and Manning-Rosen Potential Energy Models for Diatomic Molecules

    Science.gov (United States)

    Jia, Chun-Sheng; Liang, Guang-Chuan; Peng, Xiao-Long; Tang, Hong-Ming; Zhang, Lie-Hui

    2014-06-01

    By employing the dissociation energy and the equilibrium bond length for a diatomic molecule as explicit parameters, we generate an improved form of the Williams-Poulios potential energy model. It is found that the negative Williams-Poulios potential model is equivalent to the Manning-Rosen potential model for diatomic molecules. We observe that the Manning-Rosen potential is superior to the Morse potential in reproducing the interaction potential energy curves for the {{a}3 Σu+} state of the 6Li2 molecule and the {{X}1 sum+} state of the SiF+ molecule.

  12. Simulation of Relationship between ENSO and winter precipitation over Western Himalayas: Application of Regional climate model (RegT-Band)

    Science.gov (United States)

    Tiwari, P. R.; Mohanty, U. C.; Dey, S.; Acharaya, N.; Sinha, P.

    2012-12-01

    Precipitation over the Western Himalayas region during winter is mainly associated with the passage of midlatitude synoptic systems known as western disturbances (WDs). Recently, many observational and modeling studies reported that the relationship of the Indian southwest monsoon rainfall with El Niño- Southern Oscillation (ENSO) has weakened since around 1980. But, in contrast, only very few observational studies are reported so far to examine the relationship between ENSO and the winter precipitation over the Western Himalayas region from December to February (DJF). But there is a huge gap of modeling this phenomenon. So keeping in view of the absence of modeling studies, an attempt is made to simulate the relationship between wintertime precipitations associated with large scale global forcing of ENSO over the Western Himalayas. In the present study, RegT-Band, a tropical band version of the regional climate model RegCM4 is integrated for a set of 5 El Niño (1986-87, 1991-92, 1997-98, 2002-03, 2009-10) and 4 La Niña (1984-85, 1988-89, 1999-2000, 2007-08) years with the observed sea-surface temperature and lateral boundary condition. The domain extends from 50° S to 50° N and covers the entire tropics at a grid spacing of about 45 km, i.e. it includes lateral boundary forcing only at the southern and northern boundaries. The performance evaluation of the model in capturing the large scale fields followed by ENSO response with wintertime precipitation over the Western Himalayas region has been carried out by using National Center for Environmental Prediction (NCEP)-Department of Energy (DOE) reanalysis 2 (NNRP2) data (2.5° x 2.5°) and Aphrodite precipitation data (0.25° x 0.25°). The model is able to delineate the mean circulation associated with ENSO over the region during DJF reasonably well and shows strong southwesterly to northwesterly wind flow, which is there in verification analysis also. The vertical structure of the low as well as upper level

  13. 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...

  14. A Simple Model to Describe the Relationship among Rainfall, Groundwater and Land Subsidence under a Heterogeneous Aquifer

    Science.gov (United States)

    Zheng, Y. Y.; Chen, Y. L.; Lin, H. R.; Huang, S. Y.; Yeh, T. C. J.; Wen, J. C.

    2017-12-01

    Land subsidence is a very serious problem of Zhuoshui River alluvial fan, Taiwan. The main reason of land subsidence is a compression of soil, but the compression measured in the wide area is very extensive (Maryam et al., 2013; Linlin et al., 2014). Chen et al. [2010] studied the linear relationship between groundwater level and subsurface altitude variations from Global Positioning System (GPS) station in Zhuoshui River alluvial fan. But the subsurface altitude data were only from two GPS stations. Their distributions are spared and small, not enough to express the altitude variations of Zhuoshui River alluvial fan. Hung et al. [2011] used Interferometry Synthetic Aperture Radar (InSAR) to measure the surface subsidence in Zhuoshui River alluvial fan, but haven't compared with groundwater level. The study compares the correlation between rainfall events and groundwater level and compares the correlation between groundwater level and subsurface altitude, these two correlation affected by heterogeneous soil. From these relationships, a numerical model is built to simulate the land subsidence variations and estimate the coefficient of aquifer soil compressibility. Finally, the model can estimate the long-term land subsidence. Keywords: Land Subsidence, InSAR, Groundwater Level, Numerical Model, Correlation Analyses

  15. Relationship between work-family balance and job satisfaction among employees in China: A moderated mediation model.

    Science.gov (United States)

    Yu, Yue; Wang, Yuchen; Zhang, Jianxin

    2017-09-01

    Previous studies have revealed the association between work-family balance and job satisfaction. The present research further explored the underlying mechanism of this association and aimed to provide a moderated mediation model to explain if personality traits moderate the relationship between work-family balance and job satisfaction through work engagement. A cross-sectional study was conducted in which 263 employees from a petrochemical enterprise in China completed self-report questionnaires including the Work-Family Balance Scale, the Utrecht Work Engagement Scale, the Big Five Inventory-10, and the Job Satisfaction Scale. Hierarchical regression analysis and structural equation modeling showed that work engagement partially mediated the relationship between work-family balance and job satisfaction, and the indirect effect was further moderated only by extraversion. Therefore, an integrative moderated mediation model was proposed wherein work-family balance boosts job satisfaction by first enhancing employees' work engagement, while the indirect effect was in turn moderated by extraversion. The results suggest that interventions for improving job satisfaction may be enhanced by targeting work engagement, especially for employees with higher extraversion. © 2017 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  16. Stability of attachment-related anxiety and avoidance and their relationships with the five-factor model and the psychobiological model of personality.

    Science.gov (United States)

    Picardi, Angelo; Caroppo, Emanuele; Toni, Alessandro; Bitetti, Daniela; Di Maria, Giuseppe

    2005-09-01

    The stability of attachment-related anxiety and avoidance and their relationship with influential personality models are issues worth further investigation. Studying discriminant validity with respect to aspects of personality deemed as prevalently heritable, such as temperament, is particularly important. Our aims were to examine the stability of attachment dimensions and to study their relationship with psychological distress, the Big Five factors, and temperament and character dimensions. The Experiences in Close Relationships (ECR) questionnaire, the State-Trait Anxiety Inventory (STAI), the Zung depression scale (ZDS), the Temperament and Character Inventory (TCI-125), and the Big Five Questionnaire (BFQ) were administered to 222 undergraduate and graduate students. After 1 month, 115 participants completed again the ECR, the STAI, and the ZDS. Attachment-related anxiety was modestly correlated with depression and anxiety, while attachment-related avoidance was modestly correlated with depression. The test-retest reliability of ECR scores was high. Changes in attachment-related anxiety were not related to changes in depression or anxiety, and changes in attachment-related avoidance were modestly correlated with changes in depression. In separate multiple regression models also including gender and age, attachment-related anxiety was correlated with harm avoidance, reward dependence, low novelty seeking, low self-directedness and low cooperativeness; low energy/extraversion and low emotional stability; attachment-related avoidance was correlated with low reward dependence and tended to be correlated with low self-directedness. These findings corroborate the reliability and the convergent and discriminant validity of the ECR, and support the notion that the attachment dimensions are only modestly related to psychological distress and are not redundant with constructs developed within influential personality models such as the five-factor model and the

  17. Modeling the marketing strategy-performance relationship : towards an hierarchical marketing performance framework

    NARCIS (Netherlands)

    Huizingh, Eelko K.R.E.; Zengerink, Evelien

    2001-01-01

    Accurate measurement of marketing performance is an important topic for both marketing academics and marketing managers. Many researchers have recognized that marketing performance measurement should go beyond financial measurement. In this paper we propose a conceptual framework that models

  18. Wearout Effects of Different Advertising Themes: A Dynamic Bayesian Model of the Advertising-Sales Relationship

    OpenAIRE

    Frank M. Bass; Norris Bruce; Sumit Majumdar; B. P. S. Murthi

    2007-01-01

    Models of advertising response implicitly assume that the entire advertising budget is spent on disseminating one message. In practice, managers use different themes of advertising (for example, price advertisements versus product advertisements) and within each theme they employ different versions of an advertisement. In this study, we evaluate the dynamic effects of different themes of advertising that have been employed in a campaign. We develop a model that jointly considers the effects o...

  19. Modeling relationship between runoff and soil properties in dry-farming lands, NW Iran

    OpenAIRE

    Vaezi, A. R.; Bahrami, H. A.; Sadeghi, S. H. R.; Mahdian, M. H.

    2010-01-01

    The process of transformation of rainfall into runoff over a catchment is very complex and exhibits both temporal and spatial variability. However, in a semi-arid area this variability is mainly controlled by the physical and chemical properties of the soil surface. Developing an accurate and easily-used model that can appropriately determine the runoff generation value is of strong demand. In this study a simple, an empirically based model developed to explore effect of soil properties on ru...

  20. Survey Relationship between IT-business Alignment and Business Performance: Using Structural Equation Model

    Directory of Open Access Journals (Sweden)

    amir manian

    2009-09-01

    Full Text Available In spite of importance of IT deployment, nowadays in many organizations we are witness of appearing problems related to dissatisfaction of business needs due to high investment in the field of IT. The fervent debate concerning IT productivity–or lack of such productivity- named productivity paradox persuade us to survey relationship between IT–business alignment and business performance. The purpose of this research is to investigate whether IT-business alignment could have a decisive influence on their performance in IT-base firms by adopting a contingency theory perspective and operationalizing the fit systemically. Also to measure organizational performance, we adopt BSC framework which is not applied in this matter yet. Finally, this paper will explore the notion that alignment between business and IT is the key to achieving improved business performance through IT.