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Potential Models (potential + models)
Selected AbstractsSmoking, Mood Regulation, and Personality: An Event-Sampling Exploration of Potential Models and ModerationJOURNAL OF PERSONALITY, Issue 3 2007Nima G. Moghaddam ABSTRACT The aim of the present study was to test potential models of smoking-related changes in mood and how these are moderated by personality (behavioral activation and inhibition systems). Three models yielding distinct predictions regarding mood changes associated with cues to smoking and effects of ingestion were identified: the negative reinforcement model, the appetitive-incentive model, and the incentive-sensitization model. Seventy participants provided baseline data on personality and mood, and subsequently monitored their smoking behavior over 48 hours using an event-contingent diary,eliciting reports of mood state immediately prior to, and after, each cigarette smoked. MANOVA and multilevel modeling indicated that mood (hedonic tone and energetic arousal) improved significantly (p<.001) from baseline to pre-smoking, but did not change from pre- to post-smoking, thereby supporting the incentive-sensitization model. Further multilevel analyses indicated that significant variability in hedonic tone was moderated by the behavioral activation system. [source] Oxidatively Robust Monophenolate-Copper(II) Complexes as Potential Models of Galactose Oxidase.CHEMINFORM, Issue 23 2003Robertus J. M. Klein Gebbink No abstract is available for this article. [source] Pair distribution functions calculated from interatomic potential models using the General Utility Lattice ProgramJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3 2007Elizabeth R. Cope A new module has been developed for the widely used General Utility Lattice Program (GULP). The phonon-based theory developed by Chung & Thorpe [Phys. Rev. B (1999), 59, 4807,4812] to calculate pair distribution function (PDF) peak widths has been utilized to give a selection of commonly used correlation functions. A numerical library of neutron scattering information is now available within GULP, and is used to produce results that can be compared with neutron scattering experimental data. The influence of different phonon modes on the PDF can be assessed by excluding modes above or below a cut-off frequency. Results are presented for sample crystallographic systems, MgO, SrTiO3 and ,-cristobalite, as well as CaxSr1,xTiO3 at x = 0.5, which makes use of the capability to handle partial occupancies to compare different Ca/Sr ordering arrangements with a disordered model in which every Ca/Sr site has 50% occupancy of both species. [source] Impartial graphical comparison of multivariate calibration methods and the harmony/parsimony tradeoffJOURNAL OF CHEMOMETRICS, Issue 11-12 2006Forrest Stout Abstract For multivariate calibration with the relationship y,=,Xb, it is often necessary to determine the degrees of freedom for parsimony consideration and for the error measure root mean square error of calibration (RMSEC). This paper shows that degrees of freedom can be estimated by an effective rank (ER) measure to estimate the model fitting degrees of freedom and the more parsimonious model has the smallest ER. This paper also shows that when such a measure is used on the X-axis, simultaneous graphing of model errors and other regression diagnostics is possible for ridge regression (RR), partial least squares (PLS) and principal component regression (PCR) and thus, a fair comparison between all potential models can be accomplished. The ER approach is general and applicable to other multivariate calibration methods. It is often noted that by selecting variables, more parsimonious models are obtained; typically by multiple linear regression (MLR). By using the ER, the more parsimonious model is graphically shown to not always be the MLR model. Additionally, a harmony measure is proposed that expresses the bias/variance tradeoff for a particular model. By plotting this new measure against the ER, the proper harmony/parsimony tradeoff can be graphically assessed for RR, PCR and PLS. Essentially, pluralistic criteria for fairly valuating and characterizing models are better than a dualistic or a single criterion approach which is the usual tactic. Results are presented using spectral, industrial and quantitative structure activity relationship (QSAR) data. Copyright © 2007 John Wiley & Sons, Ltd. [source] A new approach to batch process optimization using experimental designAICHE JOURNAL, Issue 2 2009Paul J. Wissmann Abstract Empirical and mechanistic experimental design methods are combined to construct partial models, which are, thus, used to design a process. The grid algorithm restricts the next experimental point to potential process optima, according to the confidence intervals around the optimal points, and works with any experimental design algorithm such as D-optimal. Two case studies show the advantages of implementing the grid algorithm. On average the improvement due to the grid algorithm was 15,20% in the first case study. The second case study is based on thin film growth using four potential models, with the most probable model used for experimental design. The grid algorithm balances the trade-off between two extremes: D-optimal designs and sampling at the predicted optimal point. The methodology presented shows that the experimenter does not have to decide ahead of time on purely empirical or mechanistic experimental design methods, since both may be useful. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source] Smoking, Mood Regulation, and Personality: An Event-Sampling Exploration of Potential Models and ModerationJOURNAL OF PERSONALITY, Issue 3 2007Nima G. Moghaddam ABSTRACT The aim of the present study was to test potential models of smoking-related changes in mood and how these are moderated by personality (behavioral activation and inhibition systems). Three models yielding distinct predictions regarding mood changes associated with cues to smoking and effects of ingestion were identified: the negative reinforcement model, the appetitive-incentive model, and the incentive-sensitization model. Seventy participants provided baseline data on personality and mood, and subsequently monitored their smoking behavior over 48 hours using an event-contingent diary,eliciting reports of mood state immediately prior to, and after, each cigarette smoked. MANOVA and multilevel modeling indicated that mood (hedonic tone and energetic arousal) improved significantly (p<.001) from baseline to pre-smoking, but did not change from pre- to post-smoking, thereby supporting the incentive-sensitization model. Further multilevel analyses indicated that significant variability in hedonic tone was moderated by the behavioral activation system. [source] Is the sky falling?MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008RAVE surveys, Searching for stellar streams in the local Milky Way disc in the CORAVEL ABSTRACT We have searched for in-falling stellar streams on to the local Milky Way disc in the CORrelation RAdial VELocities (CORAVEL) and RAdial Velocity Experiment (RAVE) surveys. The CORAVEL survey consists of local dwarf stars (Nördstrom et al. Geneva,Copenhagen survey) and local Famaey et al. giant stars. We select RAVE stars with radial velocities that are sensitive to the Galactic vertical space velocity (Galactic latitude b < ,45°). Kuiper statistics have been employed to test the symmetry of the Galactic vertical velocity distribution functions in these samples for evidence of a net vertical flow that could be associated with a (tidal?) stream of stars with vertically coherent kinematics. In contrast to the ,Field of Streams' found in the outer halo, we find that the local volumes of the solar neighbourhood sampled by the CORAVEL dwarfs (complete within ,3 × 10,4 kpc3), CORAVEL giants (complete within ,5 × 10,2 kpc3) and RAVE (5,15 per cent complete within ,8 kpc3) are devoid of any vertically coherent streams containing hundreds of stars. This is sufficiently sensitive to allow our RAVE sample to rule out the passing of the tidal stream of the disrupting Sagittarius (Sgr) dwarf galaxy through the solar neighbourhood. This agrees with the most-recent determinations of its orbit and dissociates it from the Helmi et al. halo stream. Our constraints on the absence of the Sgr stream near the Sun could prove a useful tool for discriminating between Galactic potential models. The lack of a net vertical flow through the solar neighbourhood in the CORAVEL giants and RAVE samples argues against the Virgo overdensity crossing the disc near the Sun. There are no vertical streams in the CORAVEL giants and RAVE samples with stellar densities ,1.6 × 104 and 1.5 × 103 stars kpc,3, respectively, and therefore no evidence for locally enhanced dark matter. [source] Medical masters: A pilot study of adaptive ageing in physiciansAUSTRALASIAN JOURNAL ON AGEING, Issue 3 2009Carmelle Peisah Aim:, To describe models of career and lifestyle options for ageing doctors that suggest adaptability to ageing and retirement. Method:, Doctors aged 60 or older from Australia, Canada and the United States (n= 25) deemed to be ageing well by peers were administered a semistructured interview to obtain demographic and qualitative data regarding lifestyle, attitudes to ageing and retirement. Results:, Emergent themes included: (i) insights into the physical and psychological vicissitudes of ageing and the effects of such on practice; (ii) the need for adaptations in working hours and choice of work; (iii) the importance of long-term retirement planning; (iv) the usefulness of a transitional phase to ease into retirement; and (v) the need to cultivate a variety of medical and non-medical pursuits and relationships early in one's career. Conclusion:, These insights might encourage doctors to engage in long-term occupational, familial, social and financial planning and provide potential models of adaptive ageing in doctors for further study. [source] | ||||||||||